Improved Powders for Additive Manufacturing

Abstract

The present invention relates to a composition comprising at least one polymer, the polymer being in the form of a powder, the polymer comprising at least one thermoplastic polymer, the thermoplastic polymer being selected from at least one polyaryletherketone and / or their copolymers and / or block copolymers and / or polymer blends, the composition being at least 5 cm 3 The present invention also relates to a process for the manufacture and use of the composition. The present invention also deals with a fabricated element and a process for the manufacture of the fabricated element.

Description

[Technical Field]

[0001] The present invention relates to a composition comprising at least one thermoplastic polymer, the composition exhibiting a specific melt volume rate to enable an optimized additive manufacturing process. Furthermore, the present invention relates to a process for the production of the composition of the present invention, as well as an apparatus comprising the composition of the present invention and the use of the composition of the present invention. [Background technology]

[0002] Additive manufacturing processes for the industrial production of prototypes and devices based on powdered fabrication materials enable the production of plastic products and are continuously gaining importance. Using these processes, layers are selectively melted and solidified to produce desired structures by applying binders and / or adhesives, respectively. These processes are also known as "additive manufacturing," "digital fabrication," or "three-dimensional (3D) printing."

[0003] The industrial development process for the production of prototypes (rapid prototyping) has been used for decades, but technological advances in systems have led to the production of parts that meet the qualitative requirements of the final product instead of or in addition to prototypes (rapid manufacturing).

[0004] In practice, the term "additive manufacturing" is often replaced by the terms "generative manufacturing" or "rapid technology." Additive manufacturing includes processes that use powdered materials, such as sintering, melting, or bonding with binders.

[0005] Polymer systems are often used as powder materials for the manufacture of articles, and industrial users of such polymer systems require good processability, precision of shaping, and good mechanical properties of the articles produced by such systems.

[0006] For the purpose of manufacturing such articles, it is advantageous to obtain bonding between the molten mass and the underlying layers of the 3D structure, since interdiffusion can only occur within the molten mass. However, if the layer(s) are poorly bonded due to poor melting properties of the polymer, the 3D article tends to delaminate and lose stability. Therefore, the building temperature during manufacturing must be induced to optimize the melting properties of the polymer being manufactured.

[0007] Therefore, during the production of 3D articles, a build temperature higher than the crystallization temperature of the polymer is required. On the other hand, the build temperature must be essentially below the melting temperature to prevent the powder cake from melting in the build area. Generally, the temperature range applicable for building objects by additive manufacturing is called the process window or sintering window of the polymer, respectively. Summary of the Invention

[0008] It is therefore an object of the present invention to foresee compositions suitable for use as materials in additive manufacturing processes for the production of articles, in order to exhibit process-safe mechanical stability and high geometric accuracy. In particular, it is an object of the present invention to provide compositions that exhibit optimal process windows and melting properties.

[0009] According to the present invention, such an object is solved by a composition according to claim 1, which comprises at least one polymer having a defined melt volume rate. Furthermore, the object is solved by a process for the production of a composition according to claim 19, a process for the production of an object according to claim 21, and a use of the composition according to claim 25.

[0010] The present invention therefore relates to a composition, in particular a building material for the additive manufacturing processes described above, comprising: comprising at least one polymer, the polymer is in the form of a powder, and the polymer comprises at least one thermoplastic polymer; The thermoplastic polymer is selected from at least one polyaryletherketone, and copolymers and / or block copolymers and / or polymer blends thereof, and the composition has a thickness of at least 5 cm 3 / 10 min, more preferably at least 10 cm 3 / 10 minutes, and / or 55cm 3 / 10 minutes or less, preferably 40cm 3 / 10 minutes or less, preferably 30cm 3 / 10 minutes or less, especially 26cm 3 / 10 minutes or less, most preferably 24cm 3 / Has a melt volume rate (MVR) of 10 minutes or less.

[0011] In its simplest embodiment, the composition of the present invention comprises a polymer or polymer system, each selected from thermoplastic polymers. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 shows the location of the cross test element and pyrometer measurement spot (“P”, top right) on an EOS P800 with reduced mounting space (left). [Figure 2] Figure 1 shows a matrix (5x2 in xy) of smaller building platforms of the P800 in the center of each sector. [Figure 3] Figure 1 shows the location of the tensile specimen in the x-direction, z-direction, and powder box, as well as the density cube of the EOS P800. [Figure 4] Figure 1 shows the location of the tensile specimen in the x-direction, z-direction, and powder box, as well as the density cube of the EOS P800. [Figure 5] A printout of the original configuration of the software. [Figure 6] A printout of the original configuration of the software. [Figure 7] A printout of the original configuration of the software. DETAILED DESCRIPTION OF THE INVENTION

[0013] According to the present invention, the "composition" as used herein may contain one or more additives. The term "additive" as used herein refers in particular to substances which may be amorphous and / or semi-crystalline and / or crystalline polymers, polyols, surfactants and / or protective colloids.

[0014] As used herein, the term "powder" refers to a bulk solid composed of fine particles that are free to flow when shaken or tilted. According to the present invention, such fine particles have a particle size d50 of less than 500 μm.

[0015] In accordance with the present invention, the composition is at least about 5 cm 3 / 10 min, more preferably at least about 10 cm 3 / 10 min, particularly preferably at least about 15 cm 3 / 10 min, most preferably at least about 20 cm 3 / 10 minutes, and / or approximately 55 cm 3 / 10 minutes or less, preferably about 40cm 3 / 10 minutes or less, especially about 30 cm 3 / 10 minutes or less, especially about 26 cm 3 / 10 minutes or less, and most preferably about 24 cm 3 The melt volume rate (MVR) is 10 minutes or less. As used herein, the term "about" or "approximately" means that the specified number or range can vary by up to 10-15%.

[0016] As used herein, the term "melt volume rate (MVR)" (synonym: melt volume index, MVI) is a measure of the ease of flow of a thermoplastic polymer melt. It is the volume (cm) of polymer that will flow in 10 minutes through a capillary of a particular diameter and length under pressure exerted by a given gravimetric weight at a given temperature. 3 ) MVR is defined as cm 3 The method is reported in minutes per 10 minutes. The method is described, for example, in ASTM D1238-10.

[0017] MVR measurements of such polymers of the polyaryletherketone (PAEK) class, especially PEKK, are carried out on a Ceast instrument using the software Ceast-View 6.3.1. Prior to the measurement, the powder (4.8 g) is pre-dried at 120°C for 11 minutes using a Sartorius MA100 thermobalance. The powder is then loaded into the MVR unit within 30 seconds. A 5 kg weight is applied and the measurement is carried out according to ASTM D1238-10 at 380°C.

[0018] Surprisingly, according to the present invention, advantageous compositions exhibit excellent flow and melting properties of, for example, powder bulk materials, as well as a homogeneous structure, resulting in improved rheological properties such as viscosity, and therefore allowing for improved material deposition and mechanical properties. Good flow of a bulk material is assumed when the bulk material flows freely and easily.

[0019] As used herein, the term "flowability" is used synonymously with the term "pourability." The pourability of a powder is measured according to DIN EN ISO 6186 using a mm funnel (as described in the Methods section) and / or by a shear cell according to ASTM D 7891-15 and / or by the Hausner factor. According to the present application, the term "Hausner factor" is used synonymously with the term "Hausner ratio."

[0020] As used herein, the term "polymer" or "polymer system" refers to at least one homopolymer and / or heteropolymer constructed from multiple monomers. Homopolymers contain covalent bonds of the same monomers, while heteropolymers (also called copolymers) contain different monomers with covalent bonds. According to the present invention, a polymer or polymer system may comprise a mixture of the above-mentioned homopolymers and / or heteropolymers, or may comprise more than one polymer system, respectively. In this application, such mixtures are referred to as polymer blends.

[0021] In the context of the present invention, heteropolymers may be selected from statistical copolymers, which contain randomly assigned monomers; gradient copolymers, which are primarily similar to statistical copolymers but with increasing or decreasing content of monomers within the chain; alternating copolymers, which contain alternating monomers; block or segmented copolymers, which contain longer sequences or blocks of each monomer; and graft copolymers, in which blocks of each monomer are grafted onto a frame of a different monomer.

[0022] Advantageously, the compositions of the present invention can be used in additive manufacturing processes. In the context of this application, additive manufacturing processes include processes suitable for the production of prototypes (rapid prototyping) and the production of articles (rapid manufacturing), preferably from the group of powder bed processes including laser sintering, high-speed sintering, multi-jet fusion, binder jetting, selective mask sintering or selective laser melting. In particular, the compositions of the present invention can be used in laser sintering. As used herein, the term "laser sintering" is used interchangeably with the term "selective laser sintering", the latter representing an older name.

[0023] Furthermore, the present invention relates to a process for the preparation of the composition of the present invention, said process comprising: (i) providing at least one polymer, wherein the thermoplastic polymer is selected from at least one polyaryletherketone and / or copolymers and / or block copolymers and / or polymer blends thereof; (ii) optionally, grinding the polymer; (iii) optionally, rounding the polymer particles in a mixer, preferably by thermo-mechanical processing, at a temperature of at least 30° C. and below the melting point Tm of the polymer.

[0024] As used herein, the term "providing" refers to the production of a polymer or polymer system that occurs in situ and / or alternatively or additionally, the production of a polymer or polymer system that is sourced from an external site.

[0025] Preferably, to obtain polymer particles, grinding of polymer pellets or polymer flakes from the polymerization process is carried out. Such polymer flakes are coarse, porous shavings obtained from the polymerization process. Preferably, such powders are milled to a size of 1 m. 2 / g。 When using polymer pellets, such a grinding step is preferably carried out below room temperature, even more preferably by adding liquid nitrogen. Advantageously, the use of liquid nitrogen results in a higher yield of powder (of a particular particle size).

[0026] To obtain rounded particles, the polymer particles are preferably subjected to a thermo-mechanical treatment, which is carried out in a mixer, preferably a high-speed mixer, at a temperature preferably of at least 30° C. and below the melting point Tm of the polymer.

[0027] In the following, the terms mixing, mixing, blending and compounding are used synonymously. The processes of mixing, mixing, blending and compounding can be carried out by extrusion in an extruder, in a kneader, disperser and / or agitator and include, where appropriate, one or more operations such as melting, dispersing, etc.

[0028] When packaging the compositions of the present invention, such packaging process is preferably carried out with the exclusion of humidity or under defined humidity conditions, respectively.

[0029] The composition produced by the process of the invention is advantageously used as a powdered substance to be solidified in a process for the layer-by-layer production of three-dimensional objects, whereby successive layers of the object are produced successively from a powder that is selectively solidified at predetermined sites by energy, preferably by electromagnetic radiation, particularly preferably by laser light.

[0030] Furthermore, the present invention relates to a composition, in particular for laser sintering, obtained or obtainable by the process described above.

[0031] Finally, the compositions of the present invention are used to manufacture objects, particularly three-dimensional objects, by layer-by-layer application and by selectively solidifying the building material, preferably powder. As used herein, the term "solidifying" refers to at least partial melting and subsequent solidification or resolidification of the building material, which may also be referred to as sintering.

[0032] An advantageous process for the production of a production element, preferably a 3D object, comprises at least (i) a composition according to the invention, preferably in powder form Things and / or compositions produced by the process of the present invention. Layer to the manufacturing panel Applicable and (ii) preferably by using an illumination unit, at a section representing a cross section of the object to be produced; Applied composition Layer and selectively solidifying the (iii) lowering the carrier and repeating the steps of applying and solidifying until the fabrication element, preferably a 3D object, is completed.

[0033] The term "fabrication material" as used herein preferably refers to a powder or powder-like substance that is suitably solidified by an additive manufacturing process, preferably by applying a powder bed process, in particular by laser sintering or laser melting, to form a fabrication element or a 3D object, respectively. The compositions of the present invention described above are particularly suitable as fabrication materials.

[0034] Preferably, the process or part of the process for the production of the fabricated element is carried out under a nitrogen atmosphere.

[0035] A manufacturing panel according to the present invention refers to a plate that is placed on a carrier in a machine for additive manufacturing and positioned at a predefined distance to a radiation unit suitable for solidification of the carrier material. The manufacturing material is applied to the panel so that it corresponds to the level at which its upper layer will be solidified. The carrier can be adjusted during manufacturing, in particular during laser sintering, so that the last applied layer of manufacturing material has the same distance to the radiation unit, preferably a laser, and is thereby solidified by exposure to the radiation unit.

[0036] The articles, particularly 3D objects, produced from the compositions of the present invention exhibit advantageous tensile strength and elongation at break.The term "tensile strength" as used herein refers to the measurement of the maximum force required to pull a material to the breaking point.The determination of tensile strength is known to those skilled in the art and can be measured in accordance with DIN EN ISO 527.The term "elongation at break" as used herein refers to the ratio between the changed length and the initial length of a test specimen after breaking.This represents the ability of a material to withstand a change in shape without crack formation.The determination of elongation at break can be carried out, for example, according to DIN EN ISO 527-2.

[0037] Additionally, fabricated elements made 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 maintains its original dimensions when exposed to changes in temperature, pressure, force, strain, or humidity. In the laser sintering process, dimensional stability can be determined by the shape distortion of the fabricated element.

[0038] The invention also relates to a fabricated element obtained or obtainable by the manufacturing process described above.

[0039] The use of the composition of the present invention can be realized by rapid prototyping and rapid manufacturing. For example, an additive manufacturing process from the group of powder bed processes, preferably including laser sintering, rapid sintering, binder jetting, selective mask sintering, selective laser melting, especially laser sintering, is carried out to preferably produce three-dimensional objects, in which a laser beam with a predetermined energy is selectively projected onto a layer of powdered material. By applying this process, prototypes and production elements can be produced in a time- and cost-effective manner.

[0040] The term "rapid manufacturing" as used herein refers in particular to the production of fabricated elements, i.e., the production of more than one identical article, for which production, for example by mold assembly, is uneconomical or more complex or not possible due to the geometric characteristics of the fabricated elements. This is the case when the article as a whole exhibits a complex shape. Examples are luxury cars, racing cars, rally cars, which are produced in small numbers, or spare parts for motorsports, which are produced in small numbers and whose availability is also time-critical. Industries in which the article of the present invention can be implemented are, for example, the aerospace industry, medical engineering, mechanical engineering, the automotive industry, the sports industry, the household goods industry, the electrical industry, or lifestyle, respectively. Even more important is the production of large numbers of similar fabricated elements, for example, personalized elements such as prostheses, (cochlear) hearing aids, etc., whose geometry can be individually adjusted to the user.

[0041] Finally, the present invention comprises a composition in the form of a powdered material, which is suitable to be solidified in a process of layer-by-layer production of a three-dimensional object from such powdered material, from which successive layers of the object are subsequently built up at specific sites by applying energy, preferably by applying electromagnetic radiation, in particular by applying laser light.

[0042] Further preferred embodiments of the present invention are derived from the dependent claims together with the following description, whereby claims of a particular category may be formed by dependent claims of different categories, and features of different examples may be combined into new examples. It is to be understood that the definitions and explanations of terms above and below apply, as appropriate, to all embodiments described in this specification and the accompanying claims. In the following, particular embodiments of the method of the present invention are further specified.

[0043] Preferably, the at least one polyaryletherketone is selected from the group of polyetherketoneketone (PEKK), polyetheretherketone (PEEK) and / or from the group of copolymers of PEKK or of PEEK, such as, for example, polyetheretherketone-polyetherdiphenyletherketone (PEEK-PEDEK) and / or from the group of polyetheretherketone-polyethermetaetherketone (PEEK-PEmEK).

[0044] More preferably, the at least one polyaryletherketone is selected from the group: polyetherketoneketone (PEKK) and / or polyetheretherketone-polyetherdiphenyletherketone (PEEK-PEDEK) and / or polyetheretherketone-polyethermetaetherketone (PEEK-PEmEK), as follows.

[0045] [ka]

[0046] More preferably, the at least one polymer is selected from at least one homopolymer and / or heteropolymer and / or polymer blend, wherein the at least one homopolymer and / or heteropolymer and / or polymer blend preferably comprises a semi-crystalline homopolymer and / or heteropolymer and / or an amorphous homopolymer and / or heteropolymer. Particularly preferably, the at least one homopolymer and / or heteropolymer and / or polymer blend is selected from at least one semi-crystalline polymer, a semi-crystalline polymer blend of at least one semi-crystalline polymer with at least one further semi-crystalline polymer, or a semi-crystalline polymer blend of at least one semi-crystalline polymer with an amorphous polymer.

[0047] The term "semi-crystalline" as used herein refers to a material containing crystalline and amorphous regions. A polymer is considered to be essentially amorphous when the crystallinity in the solid phase of the polymer is about 5% by weight or less, particularly about 2% by weight or less. In particular, a polymer is considered to be essentially amorphous when the melting point cannot be determined by dynamic differential scanning calorimetry (DSC) and / or the melting enthalpy is less than 1 J / g on the first heating. A semi-crystalline material can contain up to 70% by weight, preferably up to 90% by weight, particularly up to 95% by weight of crystalline regions.

[0048] Preferably, the heteropolymer or copolymer comprises at least two different repeat units and / or at least a polymer blend based on the aforementioned polymers and copolymers, respectively. Advantageously, such heteropolymers or copolymers and / or polymer blends are semi-crystalline.

[0049] By using one or more of the above-mentioned polymers (homopolymers, copolymers, or polymer blends), it is possible to produce a material that is at least partially semi-crystalline, preferably a powder-like substance.

[0050] Advantageous compositions preferably comprise polymers and / or copolymers and / or polymer blends having a melting temperature of at least about 120° C., preferably at least about 150° C., and particularly preferably at least about 180° C. However, preferred polymers and / or copolymers and / or polymer blends have melting temperatures of about 320° C. or less, preferably about 300° C. or less, and particularly preferably about 280° C. or less.

[0051] As used herein, the term "melting temperature" refers to the temperature or temperature range at which a substance, preferably a polymer, copolymer, or polymer blend, transitions from a solid state to a liquid state.

[0052] Alternatively or additionally, advantageous compositions comprise polymers and / or copolymers and / or polymer blends having a glass transition temperature Tg 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 more than about 250°C, preferably not more than about 225°C, more preferably not more than about 200°C, particularly preferably not more than about 175°C.

[0053] The term "glass transition temperature" as used herein refers to the temperature at which a polymer changes into a gummy, viscous state. Determination of the glass transition temperature is known to those skilled in the art and can be carried out, for example, by DSC (according to DIN EN ISO 11357).

[0054] According to a preferred embodiment, the advantageous composition has an extrapolated onset temperature T of the melting peak that is at least 1° C., preferably at least 5° C. higher than that of a thermoplastic polymer that has not been treated by annealing. eim , and / or a difference ΔT between the crystallization temperature (Tc) and the melting temperature (Tm) that is at least 1°C higher, preferably at least 5°C higher eim / Tc.

[0055] Surprisingly, the inventors have found that annealing the composition results in T eim Increase and / or difference ΔT eim It has been found that this results in an increase in / Tc, i.e., causes an expansion of the process window. As used in the present invention, the term "process window" refers to the gap between the lowest possible build temperature (non-curl temperature: NCT) and the highest possible build temperature (upper build temperature: UBT). As used herein, the terms "crystallization temperature" and "extrapolated onset temperature of the melting peak" refer to the peak temperature as defined in DIN EN ISO 11357.

[0056] Methods for determining the crystallization temperature, melting temperature, and extrapolated onset temperature of the melting peak are known to those skilled in the art and can be carried out by the dynamic differential calorimetry (DSC) method in accordance with DIN EN ISO 11357. To allow for comparison of measurements of polymers with and without annealing treatment, the methods used take into account the application of the same hold times, heating rates, onset temperatures, and end temperatures.

[0057] The degree of crystallinity can be measured by various analytical methods, such as DSC or X-ray diffraction, whereby the degree of crystallinity is calculated by the enthalpy of fusion [J / g] (compared to a polymer with a theoretical crystallinity of 100%).

[0058] As used herein, 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 (isobar).

[0059] Furthermore, the inventors have surprisingly discovered that the process window can be increased not only by annealing within a specific temperature range below the melting point Tm, but also, alternatively or additionally, by varying the melt volume rate (MVR) of the polymer. Advantageously, within the MVR range specified above, 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 at least about 9°C, and / or about 200°C or less, preferably about 100°C or less, more preferably about 50°C or less, relative to the primary powder, i.e., virgin powder.

[0060] According to a preferred embodiment, the polyetherketoneketone described above comprises the following repeating units: [ka] wherein the ratio of repeating units A to repeating units B is preferably between approximately 80:20 and 10:90, preferably between 70:30 and 40:60, particularly preferably 60:40. Includes.

[0061] According to a particularly preferred embodiment, the polyaryletherketone has a melting temperature Tm of at least 250°C, preferably at least 260°C, particularly preferably at least 270°C, and / or up to 320°C, preferably up to 310°C, in particular up to 300°C, and / or the polyaryletherketone has a glass transition temperature Tg of at least 120°C, preferably at least 140°C, particularly preferably at least 150°C.

[0062] According to the following preferred embodiment, the polyetherimide is preferably [ka] and / or [ka] and / or [ka] Contains repeating units of

[0063] According to a next preferred embodiment, the polymer blend comprises polyaryletherketone-polyetherimide.

[0064] Even more preferably, the polyaryletherketone has a 60:40 ratio of repeat units A to repeat units B [ka] and / or the polyetherimide comprises a polyetherketone ketone having a ratio of [ka] Contains repeating units of

[0065] Further preferred compositions include the following repeating units: [ka] The polyether ketone ketone has the formula:

[0066] Preferably, the ratio of 1,4-phenylene units in repeat unit A to 1,3-phenylene units in repeat unit B is from 90:10 to 10:90, more preferably from 70:30 to 10:90, in particular from 60:40 to 10:90, most preferably about 60:40. The number n1 or n2 of repeat units A or repeat units B, respectively, may preferably be at least 10 and / or up to 2000.

[0067] More preferably, the viscosity number of the polymer is from 0.7 dl / g to 1.2 dl / g, preferably from 0.78 dl / g to 1.1 dl / g, as measured in 96 wt % sulfuric acid solution at 25°C according to ISO 307 applied to PAEK.

[0068] For example, preferred polyetherketoneketone polymers can be obtained under the trade name Kepstan 6000 series (Arkema, France).

[0069] According to a further preferred embodiment, the polyaryletherketone has a melting temperature Tm of at least 250°C, preferably at least 260°C, particularly preferably at least 270°C, and / or at most 320°C, preferably at most 310°C, in particular at most 300°C.

[0070] Furthermore, preferred polyaryletherketones have 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 not more than about 200°C, preferably not more than about 180°C, particularly preferably not more than about 170°C.

[0071] According to the following preferred embodiment, the polyetherketoneketone has an extrapolated onset of melting (T eim )

[0072] The melting temperature Tm and the extrapolated onset temperature of the melting peak (T eim The determination of Tm and T can be carried out, for example, by DSC (differential scanning calorimetry). eim The corresponding DSC method for the determination of is preferably carried out in accordance with DIN EN ISO 11357 (determined by the first heating curve of the DSC) on an apparatus such as a Mettler Toledo DSC 823 (initial temperature 0°C, maximum temperature 360°C, minimum temperature 0°C for PAEK, in particular PEKK; heating or cooling rate: 20 K / min, weight: 4.5 mg to 5.5 mg).

[0073] Such a melting temperature and / or glass transition temperature of the at least one polyaryletherketone advantageously allows for improved melting and bonding properties, in particular laser sintering, and therefore results in improved mechanical properties of fabricated elements made from such polymers.

[0074] In the next preferred compositions, the thermoplastic polymer is selected from at least one polyetherimide. Particularly preferred, such polyetherimide is [ka] and / or [ka] and / or [ka] Contains repeating units of

[0075] The number n of repeat units of formulae I, II and III is preferably at least 10 and / or up to 1000.

[0076] Preferably, the number average molecular weight (Mn) of such polyetherimides is at least 10,000 D, preferably at least 15,000 D and / or up to 200,000 D, particularly preferably at least 15,000 D and / or up to 100,000 D. The weight average molecular weight (Mw) of such preferred polymers is preferably at least 20,000 D, more preferably at least 30,000 D and / or up to 500,000 D, particularly preferably at least 30,000 D and / or up to 200,000 D.

[0077] Preferred polyetherimides according to Formula I can be obtained under the trade names Ultem® 1000, Ultem® 1010 and Ultem® 1040 (Sabic, Germany), and preferred polyetherimides of Formula II are available under the trade names Ultem® 5001 and Ultem® 5011 (Sabic, Germany).

[0078] Further preferred compositions include a polymer blend comprising a polyaryletherketone-polyetherimide, preferably a polyetherketoneketone having a 60:40 ratio of repeat units A to repeat units B. Preferred compositions may further comprise a polyetherimide, preferably comprising repeat units of formula I:

[0079] As mentioned above, the advantageous composition may contain one or more additives. According to a preferred embodiment, the additive may be a semi-crystalline polymer and / or a semi-crystalline polyol and / or a semi-crystalline surfactant and / or a semi-crystalline protective colloid. Preferably, the additive is water-soluble and / or immiscible with at least one thermoplastic polymer at room temperature.

[0080] As an advantage, the additive successfully prevents solidification of the polymer particles and the formation of cavities during the infusion of the composition during the additive manufacturing process, thereby positively increasing the bulk density of the composition.

[0081] As used herein, the term "bulk density" refers to the mass of many particles of a material divided by the total volume they occupy. The total volume includes particle volume, interparticle void volume, and internal pore volume. Determining bulk density is known to those skilled in the art and can be performed in accordance with DIN EN ISO 60:2000-01.

[0082] According to a preferred embodiment, the composition has a coating density of at least about 30 kg / m 3 and / or approximately 65 kg / m 3 or less, preferably at least 35 kg / m 3 and / or 55 kg / m 3 Less than or equal to 40 kg / m 3 and / or 50 kg / m 3 It has the following bulk density:

[0083] When the composition comprises a polyaryletherketone prepared by grinding from polymerized flakes, such compositions preferably have a density of at least about 30 kg / m 3 and / or approximately 50 kg / m 3 or less, preferably at least 32 kg / m 3 and / or 45 kg / m 3 Less than or equal to 34 kg / m 3 and / or 40 kg / m 3 The following bulk densities are given: This is particularly preferred when the composition is made from polymeric flakes.

[0084] Generally, for compositions used in laser sintering, a suitable bulk density and sufficient injectability are important for a particular particle size or particle size distribution, respectively.

[0085] As used herein, the term "particle size" refers to the size of a single particle in a composition, whereby the particle size distribution affects the properties of the bulk material present in an injectable form, such as a composition present in powder form.

[0086] According to a further preferred embodiment, the polymer particles of the composition have the following particle size distribution: - d10 = at least 10 μm, preferably at least 20 μm and / or not more than 50 μm, preferably not more than 40 μm d50 = at least 25 μm and / or ≦100 μm, preferably at least 30 μm and / or ≦80 μm, in particular at least 40 μm and / or ≦60 μm - d90 = at least 50 μm and / or not more than 150 μm, preferably not more than 120 μm

[0087] Methods for determining particle size or particle size distribution, respectively, are known to the person skilled in the art and can be determined in accordance with DIN ISO 13322-2.

[0088] A particularly preferred composition comprises polymer particles selected from polyaryletherketones, the polymer particles of which have the following particle size distribution: d10=at least 15 μm, preferably at least 20 μm, in particular at least 25 μm and / or not more than 50 μm, preferably not more than 40 μm, in particular not more than 30 μm d50 = at least 40 μm and / or ≦100 μm, preferably at least 45 μm and / or ≦80 μm, in particular at least 50 μm and / or ≦65 μm d90 = at least 70 μm and / or ≤ 150 μm, preferably at least 80 μm and / or ≤ 130 μm, more preferably ≤ 120 μm, particularly preferably ≤ 110 μm

[0089] Even more preferably, such preferred polyaryletherketone powders are obtained by grinding polymerized flakes.

[0090] According to a further preferred embodiment, the advantageous composition exhibits a distribution width (d90-d10) / d50 of less than or equal to 3, preferably less than or equal to 2, in particular less than or equal to 1.5, particularly preferably less than or equal to 1.

[0091] More preferred compositions contain less than about 5% by weight of fines, preferably less than about 3% by weight, particularly preferably less than about 2% by weight, and most preferably less than 1% by weight. As used herein, the term "fines" refers to particles having a particle size of less than 10 μm.

[0092] The polymer particles of the composition of the present invention preferably exhibit an essentially spherical to lenticular shape. 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 carried out, for example, by microscopic examination (on a Camsizer XT device (Retsch Technology, Germany)) in accordance with DIN ISO 13322-1 and / or DIN ISO 13322-2.

[0093] According to particularly preferred embodiments, the advantageous composition has a pourability (measured using a 25 mm funnel according to DIN EN ISO 6186) of at least 1 second, preferably at least 2 seconds, most preferably at least 3 seconds and / or not more than 12 seconds, preferably not more than 9 seconds, most preferably not more than 8 seconds.

[0094] Even more particularly preferred compositions exhibit 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.

[0095] It has further been found to be advantageous that the polymer particles of the composition of the present invention exhibit a small surface area. The surface of such polymer particles can be determined, for example, by gas adsorption according to Brunauer, Emmett and Teller (BET) (based on DIN EN ISO 9277). The particle surface measured according to this method is also called the BET surface.

[0096] According to a preferred embodiment, the BET surface of the advantageous composition is at least about 0.1 m 2 / g and / or approximately 10m 2 / g or less, preferably 5m 2 / g or less, more preferably 2m 2 / g or less, particularly preferably 1.5m 2 / g or less, most preferably 1m 2 In particular, such compositions comprise polymer particles selected from polyaryletherketones.

[0097] This is particularly preferred when the polyaryletherketone particles are made from polymerized flakes, but such polyaryletherketone particles preferably have a particle size of at least 0.5 m 2 / g BET surface. Particularly preferably, such polyaryletherketone particles are obtained by grinding.

[0098] The process of the present invention for producing the composition has been exemplified at the beginning. According to a further preferred embodiment for producing the composition, the polymer is preferably selected from polyaryletherketone or its copolymers or blends with other polymers, more preferably in powder form. Particularly preferably, the polymer is provided in the form of polymerized flakes from the polymerization process.

[0099] The preparation of advantageous compositions may include a step of melt-dispersing a polymer such as that provided in step i) above in an additive, such as a dispersant. Preferably, such a dispersant is selected from polyols, more preferably from semi-crystalline polyols. In particular, such polyols are 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, particularly preferably from at least one semi-crystalline polyethylene glycol. Preferably, the removal of such additives or dispersants is carried out by centrifugation and / or filtration, respectively.

[0100] The dispersion step, preferably the melt dispersion step, is carried out in a dispersion device, more preferably an extruder. Alternatively, the dispersion step may be carried out in a kneader. Preferably, the dispersion device comprises several successive zones, particularly in the forward direction.

[0101] In further processes, separation of the polymer or polymer particles from the mixture or dispersion, respectively, may be followed by a washing and / or drying step of the separated polymer or polymer particles.

[0102] Separation of the components of the mixture or dispersion from each other is preferably carried out by centrifugation and / or filtration. Drying of the solid composition to obtain a dried composition can be achieved, for example, in an oven, such as a vacuum dryer.

[0103] Alternatively or additionally, the advantageous composition can be obtained by melt compounding the polymer as provided in step i), further processing the polymer, fiberizing and chopping the fibers into micropellets.

[0104] Alternatively or additionally, the advantageous composition can be obtained by melt blending the polymers as provided in step i) and spraying the melt in a melt spraying process, preferably by applying high pressure through a nozzle.

[0105] Alternatively or additionally, advantageous compositions can be obtained by dissolving the polymer in a solvent, preferably at elevated temperature, and precipitating the polymer from the solvent, preferably by cooling and stirring, to form a powder.

[0106] According to a particularly preferred embodiment, the advantageous process for the preparation of the composition further comprises a subsequent step of annealing the polymer particles at a temperature above Tg and below Tm. Preferably, the annealing of the polymer particles is carried out in an oven.

[0107] The annealing step can be carried out in the same step as the rolling step described above. Alternatively, the annealing can be carried out before or even after rolling the polymer particles.

[0108] According to a particularly preferred embodiment, the annealing of the polymer, in particular the PAEK, is carried out in the same step as the step of rolling the polymer. Such a particularly preferred process 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 below about the melting temperature of the polymer.

[0109] The present invention also relates to compositions, in particular compositions comprising PAEK polymers, obtained or obtainable by the above process to include such an annealing step.

[0110] According to the most preferred embodiment, the process for the production of the advantageous composition comprises annealing polymer particles, preferably PEKK particles, at a preferred temperature of at least about 250°C, more preferably at least about 260°C, especially preferably at least about 265°C, and / or preferably at most 285°C, more preferably at most 280°C, especially preferably at most 275°C.

[0111] In a next step, the advantageous process comprises the addition of additives. In particular, such additives are selected from flow agents. Preferably, the addition of the additives, in particular the flow agents, is carried out in a mixer.

[0112] The inventive manufacture of fabricated elements has been described for the first time. Now, surprisingly, the inventors have discovered that an even more advantageous process for the manufacture of fabricated elements employs refreshing of the composition. Advantageously, the use of a refreshed composition enhances the mechanical stability of the fabricated elements. Furthermore, the use of a refreshed composition advantageously results in a cost-effective manufacturing process.

[0113] The term "refreshing of a composition" as used herein refers to a portion of the overall composition, i.e., a portion of the composition that has not been previously used in a laser sintering process, as opposed to a portion of the composition that has been used in at least one laser sintering process. In the context of the present invention, the portion of the composition that has not previously been used in a laser sintering process is referred to as the "primary powder" or "primary composition." The content of such a primary composition is preferably more than 10% by weight and less than 60% by weight, more preferably less than 50% by weight, even more preferably less than 40% by weight, and particularly preferably less than 30% by weight of the overall composition.

[0114] Depending on the job-volume size, distortion, especially in the xy direction, can be observed at high refresh rates above 60 wt. Therefore, according to a particularly preferred embodiment, it is preferred that the refresh rate is within the above range. This is particularly advantageous for PEKK, and most preferably for PEKK 60:40 (repeating unit A:repeating unit B) copolymers.

[0115] Thus, according to an advantageous embodiment, the preferred refresh is less than 50% by weight, preferably less than 40% by weight, particularly preferably less than 30% by weight. However, due to the possibility of a reduction in the surface of the article (the "orange skin" effect), the refresh should be greater than 10% by weight. This is particularly relevant when using machines with large build volumes, such as EOS P800 or P810 machines, and is even more relevant when carrying out builds with a z-height of more than about 100 mm, or most relevant when carrying out builds with a z-height of more than about 200 mm. Advantageously, such refresh is used for PEKK, most preferably a PEKK 60:40 (repeating unit A:repeating unit B) copolymer.

[0116] Still further, it has surprisingly been discovered that as an advantageous process for the production of production elements, preferably 3D objects, the above-mentioned step i) of applying a layer is applied by at least double coating, wherein applying the layer is subdivided into applying a first layer having a first height H1 and applying a second layer having a second height H2; A second layer of height H2 is applied over the first layer of height H1, preferably the height H1 of the first layer being equal to the height H2 of the second layer.

[0117] According to the following preferred embodiment, such layers preferably have a thickness of at least about 60 μm and / or not more than 120 μm, more preferably about 100 μm. Surprisingly, applying layers of such thickness improves layer bonding.

[0118] Particularly preferably, a layer of the advantageous process for the production of the production element uses a roof blade with a preferred angle of 1.9°.

[0119] The invention also encompasses a fabrication element, preferably a 3D object, which is obtained or can be obtained by the manufacturing process described above.

[0120] Finally, the advantageous process can include packaging the composition.The packaging of the composition, especially the powder, produced according to the method of the present invention is preferably carried out in an atmosphere that is free from humidity.Such packaged materials can be stored under reduced humidity to prevent caking, thereby improving the storage stability of the composition of the present invention.In addition, the advantageous packaging material can prevent moisture from accessing the composition of the present invention, especially humidity.

[0121] As mentioned above, the compositions of the present invention are suitable for additive manufacturing processes, especially laser sintering processes. Typically, the irradiation device, especially the target area of ​​the laser beam, e.g., the powder bed of the additive manufacturing device, is heated before use so that the temperature of the primary powdered material approaches its melting temperature, and only a small energy input is sufficient to increase the total energy input for the particles to coalesce and solidify. Thereby, energy-absorbing and / or energy-reflecting materials can be applied onto the target area of ​​the irradiation unit, as known from the processes of high-speed sintering or multi-jet fusion, respectively.

[0122] The term "melting" as used herein refers to a process in which, during an additive manufacturing process, powder, e.g., in a powder bed, is at least partially melted by the input of energy, preferably by electromagnetic radiation, in particular by laser radiation, whereby the compositions of the present invention allow for the at least partial melting and production of process-safe production elements with high mechanical stability and forming precision.

[0123] Additionally, it has been discovered that determination of tensile strength and elongation at break are useful as measures of the processability of the inventive compositions or fabricated elements, respectively, produced therefrom.

[0124] Accordingly, further preferred embodiments include fabricated elements produced by using the compositions of the present invention. Advantageously, such fabricated elements preferably exhibit an xy-direction tensile strength of at least about 50 MPa, more preferably at least about 70 MPa, particularly at least about 80 MPa, and most preferably at least about 90 MPa. Advantageous fabricated elements preferably have a tensile strength of not more than about 150 MPa, more preferably not more than about 120 MPa, and particularly not more than about 110 MPa.

[0125] Alternatively or additionally, such fabricated elements preferably exhibit an elongation at break of at least about 1%, more preferably at least about 2%, in particular at least about 2.5%, most preferably at least about 3%, and / or no more than about 50%, more preferably no more than about 20%, and particularly preferably no more than about 15%.

[0126] The determination of the tensile strength and elongation at break is known to the person skilled in the art and can be carried out in accordance with DIN EN ISO 527.

[0127] According to a further preferred embodiment, the advantageous composition comprises at least one additive, preferably selected from one or more of flow agents, heat stabilizers, oxidation stabilizers, UV stabilizers, colorants, and infrared absorbers. The preferred content of such additives 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, and most preferably at least about 0.2% by weight; and / or the preferred composition may contain one or more additives in an amount of preferably not more than about 3% by weight, more preferably not more than about 2% by weight, particularly preferably not more than about 1% by weight, and most preferably not more than about 0.5% by weight. The content of such additives refers to the content of each single additive in the composition.

[0128] Other functional additives, which can be used in higher amounts, preferably greater than 3% by weight, are selected from the group consisting of softeners, fillers, and reinforcing materials, as well as flame retardants, such as reinforcing fibers, SiO particles, carbon particles, carbon fibers, glass fibers, carbon nanotubes, mineral fibers (e.g., wollastonite), aramid fibers (especially Kevlar fibers), glass spheres, mineral fibers, inorganic and / or organic pigments, and / or flame retardants (especially including phosphates such as ammonium and / or bromine polyphosphates and / or other halogens and / or organics such as magnesium hydroxide or aluminum hydroxide). Particularly preferably, the additive comprises reinforcing fibers, especially carbon fibers.

[0129] Further particularly preferred additives include polysiloxanes, which can be used, for example, as flow agents to reduce the viscosity of polymer melts and / or as softening agents, especially for polymer blends.

[0130] According to a further preferred embodiment, the advantageous composition comprises at least one flow agent, which is usually present in particulate form and adheres to the polymer particles, thereby preventing agglomeration of the composition.

[0131] Such flow agents are preferably selected from the group of metal soaps, preferably silicon dioxide, stearates, tricalcium phosphate, calcium silicate, aluminum oxide, magnesium oxide, magnesium carbonate, zinc oxide or mixtures thereof. More preferably, at least one flow agent is selected from silicon dioxide (synonym: silica). Advantageous compositions contain at least about 0.01% by weight and / or not more than about 1% by weight of flow agent(s).

[0132] Further preferred embodiments of the invention are derived from the dependent claims together with the description, whereby claims of a particular category may be formed by dependent claims of different categories, and features of different examples may be combined into new examples. It is to be understood that the definitions and explanations of terms above and below apply, as appropriate, to all embodiments described in this specification and the accompanying claims. Specific embodiments of the invention are further specified below. [Example]

[0133] Example 1: PEKK having a 60:40 ratio of terephthalic acid units to isophthalic acid units was prepared as follows: Orthodichlorobenzene (1600 g) and 1,4-(phenoxybenzoyl)benzene (EKKE) (65 g) were placed in a 2-L reactor with stirring under a dry nitrogen stream. The following acid 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, and AlCl (115 g) was added while maintaining the temperature in the reactor below 5°C. After a homogenization period (approximately 10 minutes), the reactor temperature was increased to 90°C at 5°C per minute (polymerization was initiated during this temperature increase). The reactor was maintained at 90°C for 30 minutes and then cooled to 30°C. 400 g of acidified water (3% HCl) was slowly added so that the temperature in the reactor did not exceed 90°C. The reactor was stirred for 2 hours and then cooled to 30°C.

[0134] The reaction medium is removed from the reactor and a filtration / purification step is carried out according to the art. The purified wet PEKK is then dried overnight under vacuum (30 mbar) at 190°C. Flakes are obtained.

[0135] Example 2: The PEKK polymerized flakes from Example 1 were suitably ground and air classified to a fine powder. The powder data are shown in Table A.

[0136] [Table 1]

[0137] Example 3 Polyetherketoneketone (PEKK) was prepared according to Examples 1 and 2.

[0138] The powders were then mixed in a Henschel-type FML mixer according to Table 1. The mass of the powder is hereinafter referred to as m. Phase 1 refers to the heating phase, i.e., the phase until the mixture (powder) in the mixer reaches a maximum temperature Tmax. Tmax is the processing temperature T B The mixer speed for phase 1 is called D1. The duration of phase 1 is called t1. Phase 2 is the holding phase, i.e. the phase in which the reached temperature is maintained. The mixer speed for phase 2 is called D2. The duration of phase 2 is called t2.

[0139] The names m, Tmax, D1, D2, t1, t2 are also used in the following examples.

[0140] The obtained values ​​for the bulk density S, the BET surface, the volume percentage of powder particles having a particle size of 10 μm (“%<10 μm”), and the quantiles d10, d50 and d90 of the particle size distribution are given in Table 2.

[0141] [Table 2]

[0142] [Table 3]

[0143] Example 4 The powder of Example 3 was annealed for 3 hours under nitrogen atmosphere in a ventilated oven (Nabertherm type N250 / A) at different temperatures (according to Table 3a). After annealing, the powder was sieved through a 160 μm sieve on a Perflux 501 type vibrating sieve (Siebtechnik GmbH, Mülheim, Germany). The powder values ​​obtained are shown in Table 3a.

[0144] Test specimens were produced from the resulting three powders (primary powders) on a P800-type laser sintering system (EOS P800 with start-up kit PAEK 3302 CF) using the processing parameters shown in Table 3b. The layer thickness was 120 μm, which was applied using a double coating process (layer thickness 60 μm). The powders were analyzed with regard to processability (process window) and the mechanical properties of the laser sintered parts. The values ​​obtained are shown in Tables 3b and 3c.

[0145] [Table 4]

[0146] [Table 5]

[0147] As can be seen, the non-curl temperature (NCT) is increased with higher annealing temperatures, and therefore the powder needs to be built at a higher process chamber temperature (PK), which leads to a higher aging of the used powder (greater decrease in MVR value (see Table 3a)) and consequently a decrease in refresh rate with increasing heat treatment temperature.

[0148] [Table 6]

[0149] The effect of heat treatment on the mechanical properties is shown: the tensile strength at z is increased at an annealing temperature of 275°C.

[0150] Example 5 In Example 5, three PEKK types with different melt viscosities were produced, similar to Example 4. The exception was that the polymerization time (compared to Example 1) was adjusted to obtain powders with different melt viscosities (MVR). Furthermore, the processing temperature of the mixer in Example 5, Tmax, was between 110 and 120°C. t2 was adapted for each powder so that t1 + t2 was always maintained at 25 minutes. The annealing temperature in Example 5 for all three powders was 265°C. The analytical data for the powders are shown in Table 4a.

[0151] Test specimens were produced on a P800-type laser sintering system (EOS P800 with start-up kit PAEK 3302 CF) from the three resulting powders (primary powders) using the processing parameters shown in Table 4b. The layer thickness was 120 μm, which was applied by using a double coating process (layer thickness 60 μm). The powders were analyzed with regard to their processability (process window) and the mechanical properties of the laser sintered parts. The obtained values ​​can be seen in Tables 4b and 4c.

[0152] [Table 7]

[0153] [Table 8]

[0154] As can be seen in Tables 4a and 4b, the NCT increases with increasing powder MVR. This means that the build temperature (Tpk) is higher, which negatively impacts powder aging and refreshing. Also, the process window (the difference between UBT and NCT) decreases from 13°C to just 5°C with increasing powder MVR.

[0155] [Table 9]

[0156] The effect of melt viscosity on the mechanical properties can be clearly seen in Table 4c: the tensile strength and elongation at break in the xy direction increase significantly from 73 to 96 MPa and from 2.1 to 3.8% at low MVR, while in the z direction the elongation at break only decreases slightly from 1.3 to 1.2%.

[0157] Example 6 In Example 6, two PEKK types with different particle size distributions were produced, similar to Example 4, except that the polymerization time was adjusted (compared to Example 1) to produce a 24 cm 3 Powders with an MVR of 10 min were obtained. Furthermore, the processing temperature Tmax of the mixer in Example 6 was between 110 and 120 °C. t2 was adapted to each powder so that t1 + t2 was always maintained at 25 min. The annealing temperature in Example 6 was 265 °C for both powders. The analytical data of the primary powders are shown in Table 5a.

[0158] [Table 10]

[0159] The influence of particle size distribution on the flowability of the powder can be clearly seen: the coarse powder shows better flowability (pour time is reduced from 15 seconds to 8 seconds).

[0160] Test specimens were produced from the resulting powder (50% refreshed) on a P800-type laser sintering system (EOS P800 with start-up kit PAEK 3302 CF) using the processing parameters shown in Table 5b. The layer thickness was 120 μm, which was applied by using a double coating process (layer thickness 60 μm). The powder was analyzed with regard to the mechanical properties of the laser sintered parts. The values ​​obtained are shown in Table 6.

[0161] [Table 11]

[0162] [Table 12]

[0163] From Table 6 it can be seen that the powders with improved 8 second injectability show improved tensile strength and elongation at break in the xy direction.

[0164] Example 7 In Example 7, PEKK was produced as similarly described in Example 5, except that the polymerization time was adjusted (compared to Example 1) and the PEKK was 22 cm after heat treatment. 3 A powder with an MVR of 1 / 10 min was obtained. Furthermore, the processing temperature Tmax of the mixer from Example 7 was 116°C. t2 was adapted to the powder so that t1 + t2 was maintained for 25 min. The annealing temperature for Example 5 was 265°C.

[0165] [Table 13]

[0166] Test specimens were produced from the resulting powder (primary powder) at three different layer thicknesses of 120 μm, 100 μm, and 60 μm by applying a double coating process (layer thicknesses of 60 μm, 50 μm, and 30 μm, respectively) using the processing parameters shown in Table 7b on a P800-type laser sintering system (EOS P800 with start-up kit PAEK 3302 CF). The different layer thicknesses were analyzed with regard to the mechanical properties of the laser sintered parts. The values ​​obtained are shown in Table 7c.

[0167] [Table 14]

[0168] [Table 15]

[0169] The influence on the mechanical properties and density of the part in the z direction can be clearly seen: applying reduced layer thicknesses of 100 μm and 60 μm increases the tensile strength and elongation at break in the zx direction.

[0170] Example 8 In Example 8, the polymerization time was adjusted (compared to Example 1) to 23 cm before heat treatment. 3 PEKK was produced as described in Example 4, except that a powder with an MVR of 10 min was obtained. Furthermore, the processing temperature Tmax of the mixer in Example 8 was between 110 and 120°C. t2 was adapted so that t1 + t2 was always maintained at 25 min. The annealing temperature was also adjusted. The powder was annealed for 3 h under nitrogen atmosphere in a ventilated oven (Nabertherm type N250 / A) at different temperatures (according to Table 8a). After annealing, the powder was sieved through a 160 μm sieve using a Perflux 501 type vibrating sieve (Siebtehnik GmbH, Mülheim, Germany). The powder values ​​obtained are shown in Table 8a.

[0171] Test specimens were produced from the three resulting powders (primary powders) on a P810 type laser sintering system using the processing parameters shown in Table 8b. The layer thickness was 120 μm and was applied by using a double coating process (layer thickness 60 μm). The powders were analyzed with regard to processability (process window), powder bed hardness after build, and mechanical properties of the laser sintered parts. The values ​​obtained are shown in Tables 8b and 8c.

[0172] [Table 16]

[0173] [Table 17]

[0174] As can be seen, the non-curl temperature (NCT) is increased with higher annealing temperatures. Therefore, the powder must be built at a higher process chamber temperature (PK), which leads to a greater aging of the used powder (greater decrease in MVR value (see Table 8a)) and consequently a decrease in refresh rate with increasing heat treatment temperature. The lowest annealing temperature results in the greatest decrease in the bulk density of the used powder and the lowest powder flowability.

[0175] [Table 18]

[0176] The effect of heat treatment on the mechanical properties is shown, with maximum values ​​reached at an annealing temperature of 265°C.

[0177] Example 9 In Example 9, PEKK (Sample No. 1) was produced similarly to Example 2, but the polymerization time was adjusted to obtain a viscosity similar to that of Example 6. The PEKK was then mixed as described in Example 3, except that the mixer processing temperature, Tmax, was between 110 and 120°C. t2 was adjusted to maintain t1 + t2 for 25 minutes (Sample No. 2). Annealing was then performed similarly to Example 4 (Sample No. 3). The annealing temperature for Sample 3 was 265°C. A different PEKK was also produced (Sample No. 4) according to Example 9, Sample No. 3. The annealing temperature for Sample 4 was also 265°C. Powder data are shown in Table 9 below. These powders were analyzed for Hausner ratio.

[0178] [Table 19]

[0179] The values ​​obtained are shown in Table 9. The influence of the heat treatment on the Hausner ratio can be seen. The heat treatment shows a beneficial effect, especially on the flowability as measured by the Hausner ratio. As can be seen, the sphericity is influenced by mixing and heat treatment.

[0180] Example 10 In Example 10, PEKK was produced in the same manner as in Example 2, but the polymerization time was adjusted to 29 cm before heat treatment. 3 A powder with an MVR of 1 / 10 min was obtained (Sample No. 1). PEKK was then mixed as described in Example 3, except that the processing temperature of the mixer, Tmax, was between 110 and 120°C. t2 was adapted so that t1 + t2 was maintained for 25 min (Sample No. 2). Sample No. 2 was then annealed as in Example 4, except that the annealing time was adjusted (Sample No. 3). The annealing temperature for Sample 3 was 265°C. BET analysis was performed on these samples. The data obtained are shown in Table 10.

[0181] [Table 20]

[0182] The values ​​obtained are shown in Table 10. The effect of mixing and heat treatment on the BET surface of the particles can be seen.

[0183] Methods section: Thermal-mechanical rounding The thermo-mechanical treatment of the polymer particles can be preferably carried out in a mixer at a temperature of at least 30° C. and below the melting point Tm of the polymer. A mixer that can be used is, for example, a Henschel mixer of type FML, machine size 40 (Zeppelin Systems GmbH, Germany).

[0184] Hausner ratio The Hausner ratio, H, provides information about the compressibility of a bulk material. ρb0 (according to EN ISO-60) and tap density ρ t (in accordance with DIN EN ISO 787-11) is used for the assessment.

[0185]

number

[0186] Tap Density The tapped density is determined in accordance with DIN EN ISO 787-11.

[0187] [Table 21]

[0188] The mechanical properties of the three-dimensional object according to the invention can be determined based on test samples as explained below.

[0189] The test method and part dimensions of the test specimens are those of the standard DIN EN ISO 527-1:2012-06 for tensile tests. For this purpose, a materials testing machine TC-FR005TN.A50 from Zwick, document number: 605922, equipped with the software TestExpert II V3.6 was used.

[0190] In a standardized tensile test, test results such as modulus of elasticity [GPa], tensile strength [MPa], and elongation at break were determined using tensile specimens with the dimensions in Table 11. The test speed is 5 mm / min for PEKK components. The modulus of elasticity (E-modulus) is determined at a test speed of 1 mm / min.

[0191] Determination of extrapolated onset temperature of melting peak Materials require specific properties, which can be determined by dynamic differential calorimetry, usually called DSC (differential scanning calorimetry), to determine the extrapolated onset temperature T eim It can be judged based on T ei、mThe corresponding DSC measurements for the determination of T are preferably carried out in accordance with the standard ISO 11357. The apparatus is, for example, a Mettler Toledo DSC 823. The melting temperature Tm and the crystallization temperature Tc are also determined in this way. eim and Tm are determined from the first heating curve.

[0192] If the thermoplastic material contains or is a polymer of the PEKK class, the temperature gradient of 0°C-360°C-0°C-360°C deviates from the standard. The initial temperature (0°C), the maximum temperature (360°C), and the minimum temperature (0°C) are maintained for 3 minutes, but the final temperature (360°C) is not maintained. Furthermore, the heating or cooling rate is 20 K / min, and the weight of the test piece is 4.5 mg to 5.5 mg.

[0193] Optical methods for determining particle size and shape Measurements are performed on a Camsizer XT instrument and an X-Jet module (Retch Technology) using the associated software CamsizerXT64 (version 6.6.11.1069). The optical method for determining particle size and shape conforms to standard ISO 13322-2. After determining the speed adjustment, approximately 2 g of sample is dispersed with 80 kPa compressed air and passed through a 4 mm-wide passage on a calibrated optical unit equipped with two cameras with different magnifications ("basic" and "zoom"). At least 10,000 individual images are recorded for evaluation. To ensure good optical separation of the particles under study, images are used only if the areal density of the imaged particles is less than 3% ("basic" camera) or less than 5% ("zoom" camera). Particle size and shape are determined by the defined measurement parameters. The determined size is the equivalent diameter of a circle with the same extent of the particle projection x_area = √(4A / Π). The meridians or means of this evaluation method are comparable to laser diffraction (reported as d10, d50, and d90, i.e., the 10th, 50th, and 90th percentiles of the volume particle size distribution). Measurements are repeated several times to form a statistical measurement.

[0194] >2g / cm 3 For powders with high specific gravity or difficult to disperse powders, it may be necessary to adjust the method in terms of sample volume, dispersion pressure, or addition of 1% of the flow aid Alu C. The method is adapted to vary the sample amount (maximum 8 g) and dispersion pressure (maximum 150 kPa) to achieve the smallest possible d90.

[0195] Calibration and setup of camera parameters should be performed specific to the device, and adjustments and maintenance should be performed according to the manufacturer's specifications. (This can also be seen in printouts of the original software configuration in Figures 5, 6, and 7.) The following configuration of the Camsizer XT software was used:

[0196] CAMSIZER XT Software Configuration CAMSIZER XT:0301 Overlapping area: x area: 0.080mm~0.160mm xc min: 0.080mm~0.160mm xFe min:0.080mm~0.160mm xFe max: 0.080mm~0.160mm x area: 0.100mm~0.160mm xc min: 0.100mm~0.160mm xFE min:0.100mm~0.160mm xFE max: 0.100mm~0.160mm x area: 0.100mm~0.160mm xc min: 0.100mm~0.160mm xFe min:0.100mm~0.160mm xFe max: 0.100mm~0.160mm Fixed ratio between cameras for calculation: No Switching off light sources: Yes TIFF0007741069000034.tif29147 TIFF0007741069000035.tif219164 TIFF0007741069000036.tif246164 Camera (measurement parameters) CCD Basic: Yes Threshold Regarding particle size [mm] Less than: 0.0023 [mm] greater than: 20 Regarding mold parameters [mm] Less than: 0.0023 [mm] greater than: 20 CCD zoom: Yes Threshold Regarding particle size [mm] Less than: 0.0023 [mm] greater than: 2 Regarding mold parameters [mm] Less than: 0.0023 [mm] greater than: 2 Image rate: 100% (1:1) Warning if image rate < 0.95: Yes Display interval: 80 Transparent particle filling: Yes

[0197] Determining lower building temperature (NCT) The lower build temperature (also known as non-curl temperature, or NCT) is determined by cross testing, for example, on a matrix of test components in a cross (4x2 on the smaller build platform of the P800, Figure 1). For this purpose, the laser sintering machine is heated to a temperature approximately 10°C (estimated) lower than the normal build temperature, or alternatively, approximately 5°C lower than the expected non-curl temperature. After automatic powder application, layers of the cross are exposed from a height of z = 3 mm. If these show significant process-critical curl, e.g., the exposed edges of the test cross are significantly turned up and the cross peels away from the installation space, the temperature is increased by 2°C. After applying 1.2 mm powder layers (P800, 10 layers with a layer thickness of 0.12 mm, or 12 layers with a layer thickness of 0.10 mm, or 20 layers with a layer thickness of 0.06 mm), the test is repeated. If only slight curl is observed in the cross test, the temperature is increased by 1°C until no process-critical curl is observed. That is, the cross can be built to its full height (1.2 mm height) without being torn off the powder bed by the coater during the coating process. The temperature at which process-critical curl is not observed is called the no-curl temperature and defines the lowest possible build temperature. Figure 1 shows the location of the cross test components and the pyrometer measurement spot ("P", top right) on an EOS P800 with reduced mounting space (left).

[0198] The term "no process-critical curl" means that no curl can be observed, or minimal curl occurs, but only to a low degree that prevents the coater from peeling the exposed cross from the powder bed during powder application.

[0199] Determining the upper building temperature (UBT) The maximum build temperature is the build temperature of the powder material at which the powder material does not just stick together, thereby not forming agglomerates of powder particles, and the powder material is still sufficiently flowable for the coating process and without coating defects (e.g., banding due to agglomerates). The maximum processing temperature depends, inter alia, on the type of powder material used.

[0200] However, the maximum build temperature can also be reached without the formation of a (local) molten film of the powder, which can be seen in a glossy film (e.g. Polyamide 12, PA2200) or a local dark color of the powder (e.g. EOS PEEK-HP3 as described in the application manual).

[0201] To determine the build temperature, the process chamber temperature is gradually increased (1-2°C) after the lower build temperature has been determined, and the powder bed is observed to accurately observe when one of the above effects occurs. Additionally or alternatively, a higher build temperature can be determined by determining the powder bed's hardness via Shore measurements. This is useful if one of the above effects has not yet occurred. If the green powder bed is too hard after the build process is completed, it is no longer possible to separate the exposed components from the unsintered powder. This limits the accuracy of the build temperature. To this end, once the observed or assumed higher build temperature is reached, the process chamber temperature is reduced by 1°C, and another 3 mm layer of powder is applied as the top layer in an automated build operation. After the build process, the powder cake is cooled to room temperature. The surface of the top cooled powder cake is measured in the machine's interchangeable frame by a suitable Shore hardness measuring device (here, a Bareiss HPII) located on the P800's smaller build platform matrix (5x2 in xy, Figure 2) at the center of each sector. The Shore hardness value is obtained as the average value from the highest measured values ​​of 50% of the matrix. If there is a crack in the powder bed in the area of ​​the measured point (due to loss of powder cake during the cooling process to room temperature), the measurement in each sector must be detected at a sufficient distance of approximately 15 mm from the crack. The Shore hardness at higher build temperatures depends in particular on the type of powder used. How high it is depends on the respective material, the quality of the ingredients, and the requirements for waste powder recycling. Where appropriate, the same Shore hardness for the higher build temperature is used as a comparison. For all equally proportional refreshments, this is always essentially the same. Furthermore, it is important to ensure that there are no changes in the heating distribution of the laser sintering machine between the powders being compared, as this can have an effect on the determined Shore hardness value.

[0202] It can be determined which Shore hardness measurement is appropriate for which powder. Shore hardnesses of Shore 00, Shore 000, and Shore 000 S, as specified in ASTM D 2240, have proven to be preferable.

[0203] These and other hardness tests by Shore are described in the Bareiss HPII Operating Instructions (HPE II Shore [D], Version 26.05.2017), which lists the corresponding standards. As an example, for some polymer powders, the Shore hardness for higher build temperatures is determined using a Bareiss HPII Shore hardness tester: 1) Polyaryletherketone Shore-00=85

[0204] Operating temperature (T PK ) Process chamber temperature T PK The processing temperature, expressed as , is preferably selected to be at least 1°C, more preferably at least 2°C, even more preferably at least 4°C higher than the lower build temperature of the powder and / or at most 1°C, even more preferably at most 2°C, even more preferably at most 4°C lower than the higher build temperature. Preferably, the processing temperature is higher than the lower build temperature of the powder and lower than the higher build temperature. Sufficient process security (non-curling, maximum possible distance from NCT) must be guaranteed. Furthermore, the temperature must be as high as possible without causing adhesion of the powdered material.

[0205] Alternatively or additionally, the processing temperature for each powder can be determined by determining the Shore hardness of the cooled powder cake according to the method described in Upper Building Temperature Determination (UBT). The Shore hardness value is preferably 5% to up to 50% lower than the Shore hardness value of the UBT, preferably up to 15% lower, and more preferably up to 10% lower.

[0206] Component production on a laser sintering machine When the thermoplastic material was a polymer of the polyaryletherketone (PAEK) class, specifically PEKK, the experiment was performed on a modified P800 (EOSP800 with PAEK 3302 CF startup kit) equipped with PSW 3.8. After the warm-up phase, 50 layers (120 μm layer thickness), 60 layers (100 μm layer thickness), or 120 layers (60 μm layer thickness) were laid without any exposed bottom layer (= 6 mm) while the laser sintering machine's process chamber was warmed from room temperature to the specified build temperature or the start temperature of the temperature search within 120 minutes. After the bottom layer was laid, six tensile specimens (dimensions see Table 1) were positioned adjacent to each other in the center of the build site, with their parallel lengths aligned parallel to the x-direction. Four rectangular test components (dimensions: 20 mm x 4 mm x 13.56 mm) were positioned to the left and right of the tensile specimens. Layers are laid without exposure between components in the z direction. At z = 9,960 mm, 25 tensile specimens (positioned adjacent to each other in the center of the build site, aligned with their lengths parallel to the z direction) are constructed. Following the last exposed layer, another 3 mm of powder is automatically applied, and the machine is cooled to 180 °C within approximately 8 hours by a controlled cooling phase defined in the default job before the heaters are completely switched off. After reaching room temperature, the components are manually removed, blasted with glass beads, and measured / tested. Figures 3 and 4 show the position of the tensile specimens in the x- and z-directions, the powder box, and the density cube on the EOS P800.

[0207] The size of the build area is approximately 350 mm x 120 mm (approximately 1 / 8 of the size of the entire platform, modified build space reduction variant 1 for P800 in xy direction according to the EOS PEEK-HP3 application manual).

[0208] The job height is 72.96 mm.

[0209] The following settings were selected: The process chamber temperatures during part build are detailed in the Examples section; Removable frame / build platform temperature: 255°C (for PEKK); Default job settings:PAEK3302CF; Exposure parameters: Volume energy input as explained in the Example section.

[0210] When experiments were performed on a P810 (with PSW 3.8), the build was performed using the following parameters: After the warm-up phase, 50 layers (120 μm layer thickness), 60 layers (100 μm layer thickness), or 120 layers (60 μm layer thickness) were laid without an exposed bottom layer (= 6 mm) while the laser sintering machine's process chamber was warmed from room temperature to the specified build temperature or the start temperature of the temperature search within 120 minutes. After the bottom layer was laid, six tensile specimens (dimensions see Table 1) were positioned adjacent to each other in the center of the build site, with parallel lengths aligned parallel to the x-direction. Following the last exposed layer, another 3 mm of powder was automatically applied, and the machine was cooled to 180 °C within approximately 8 hours by a controlled cooling phase defined in the default job before the heater was completely switched off. After reaching room temperature, the components were manually removed, glass bead blasted, and measured / tested. Figure 3 shows the position of the tensile specimen in the x-direction on the EOS P810.

[0211] The size of the build area is approximately 350 mm x 120 mm (approximately 1 / 8 of the size of the entire platform, modified build space reduction variant 1 for P800 in xy direction according to the EOS PEEK-HP3 application manual).

[0212] The job height is 35.16 mm.

[0213] The following settings were selected: The process chamber temperatures during part build are detailed in the Examples section; The temperature of the removable frame is 265°C, and the temperature of the building platform is 255°C; Default job settings:EOS_PAEK3304_120_000; Exposure parameters: Volume energy input as explained in the Example section.

Claims

1. 1. A composition comprising: comprising at least one polymer, the polymer is in the form of a powder, and the polymer comprises at least one thermoplastic polymer; the thermoplastic polymer is selected from the group consisting of at least one polyaryletherketone, a copolymer comprising polyaryletherketone, a block copolymer comprising polyaryletherketone, a polymer blend comprising polyaryletherketone, and combinations thereof; the composition is in the form of a powder; The composition is at least 5 cm 3 / 10 minutes or 55cm 3 / Has a melt volume rate (MVR) of 10 minutes or less, The composition has a Hausner factor of at least 1.01 and not more than 1.7, wherein the Hausner factor is a function of the tap density ρ t (according to DIN EN ISO 787-11) is the bulk density ρ of the uncompressed bulk material b0 (according to EN ISO-60)

2. 2. The composition of claim 1, wherein the polyaryletherketone is selected from the group consisting of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), copolymers comprising PEKK, and copolymers comprising PEEK.

3. The polymer comprises at least one semi-crystalline polymer; and / or 3. The composition of claim 1 or 2, comprising at least one amorphous polymer.

4. The polyetherketoneketone comprises the following repeating units: 【Chemical 1】 4. The composition of claim 2 or 3, comprising: wherein the ratio of repeat units A to repeat units B is between 80:20 and 10:

90.

5. 5. The composition of claim 1, wherein the polyaryletherketone has a melting temperature Tm of at least 250°C and up to 320°C, and / or the polyaryletherketone has a glass transition temperature Tg of at least 120°C and up to 200°C.

6. The polyetherketoneketone (PEKK) has an extrapolated onset of melting temperature T of at least 250°C and up to 285°C according to DIN EN ISO 11357, as determined by a first heating curve of dynamic differential scanning calorimetry. eim The composition according to any one of claims 2 to 5, wherein

7. 7. The composition of claim 2, having a process window, which refers to the spread between the lowest possible build temperature and the highest possible build temperature, of at least 1° C. and not more than 200° C.

8. The composition of any one of claims 1 to 7, wherein the polymer blend comprises a polyaryletherketone and a polyetherimide.

9. The composition contains a polymer in powder form having the following particle size distribution: - d10 = at least 10 μm - d50 = at least 25 μm and not more than 100 μm A composition according to any one of claims 1 to 8, characterized in that the polymer particles have a d90 = at least 50 μm and not more than 150 μm.

10. The composition contains a polymer in powder form having the following particle size distribution: - d10 = at least 15 μm - d50 = at least 40 μm and not more than 100 μm polymer particles having a d90=at least 70 μm and not more than 150 μm, The composition according to any one of claims 1 to 9, wherein the polymer particles are obtained by grinding polymeric flakes.

11. The composition of any one of claims 1 to 10, wherein the composition has a distribution width (d90-d10) / d50 of 3 or less.

12. The composition according to any one of claims 1 to 11, wherein the powder-form polymer contained in the composition is polymer particles having a sphericity of at least 0.

8.

13. 13. The composition of any one of claims 1 to 12, wherein the composition comprises a primary composition, and the content of the primary composition is greater than 10% and less than 60% by weight of the total composition.

14. 14. The composition of any one of claims 1 to 13, having a pourability, measured using a 25 mm funnel according to DIN EN ISO 6186, of at least 1 second and not more than 12 seconds.

15. The composition of any one of claims 1 to 14, wherein the composition comprises at least one flow agent.

16. 16. The composition of claim 15, wherein the content of said at least one flow agent in said composition is 1% by weight or less.

17. The composition has a thickness of at least 0.1 m 2 / g and 10m 2 The composition according to any one of claims 1 to 16, having a BET surface of 0.1g or less.

18. A process for producing a composition according to any one of claims 1 to 17, said process comprising: (i) providing at least one thermoplastic polymer, wherein the thermoplastic polymer is selected from the group consisting of at least one polyaryletherketone, a copolymer comprising a polyaryletherketone, a block copolymer comprising a polyaryletherketone, a polymer blend comprising a polyaryletherketone, and combinations thereof; (ii) optionally, grinding the polymer; (iii) optionally, rounding the ground polymer by thermo-mechanical treatment in a mixer at a temperature of at least 30° C. and below the melting point Tm of the polymer.

19. 20. The process of claim 18, wherein the process further comprises the subsequent step of annealing the composition at a temperature above Tg and below Tm.

20. 1. A process for manufacturing a production element, said process comprising: (i) applying a layer of a composition according to any one of claims 1 to 17 and / or a composition produced by the process according to claims 18 or 19 to a manufacturing panel; (ii) selectively solidifying said applied layer of composition in areas representing a cross-section of the object to be produced; (iii) lowering the carrier and repeating the applying and solidifying steps until the fabricated element is complete.

21. 21. The process according to claim 20, wherein step i) of applying a layer is carried out by at least double coating, the application of the layer being 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, the second layer of said height H2 being applied on top of the first layer of said height H1.

22. A fabrication element comprising the composition of any one of claims 1 to 17.

23. Use of a composition according to any one of claims 1 to 17 for additive manufacturing.

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