Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
  • B29C64/10—Processes of additive manufacturing
  • B29C64/141—Processes of additive manufacturing using only solid materials
  • B29C64/153—Processes of additive manufacturing using only solid materials using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y10/00—Processes of additive manufacturing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y70/00—Materials specially adapted for additive manufacturing
  • B33Y70/10—Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/12—Chemical modification
  • C08J7/14—Chemical modification with acids, their salts or anhydrides
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
  • C08K7/02—Fibres or whiskers
  • C08K7/04—Fibres or whiskers inorganic
  • C08K7/06—Elements
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
  • C08K7/02—Fibres or whiskers
  • C08K7/04—Fibres or whiskers inorganic
  • C08K7/08—Oxygen-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
  • C08K7/02—Fibres or whiskers
  • C08K7/04—Fibres or whiskers inorganic
  • C08K7/10—Silicon-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
  • C08K7/02—Fibres or whiskers
  • C08K7/04—Fibres or whiskers inorganic
  • C08K7/14—Glass
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
  • C08L77/02—Polyamides derived from omega-amino carboxylic acids or from lactams thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
  • C08L77/06—Polyamides derived from polyamines and polycarboxylic acids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2077/00—Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2077/00—Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
  • B29K2077/10—Aromatic polyamides [polyaramides] or derivatives thereof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
  • B29K2105/08—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns
  • B29K2105/0809—Fabrics
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y80/00—Products made by additive manufacturing

Definitions

• the present invention relates to a method for producing a shaped article by selective laser sintering of a sintered powder (SP).
• the sintering powder (SP) contains at least one partially crystalline polyamide, at least one polyamide 6I / 6T and at least one reinforcing agent.
• the present invention relates to a molded article obtainable by the process according to the invention and to the use of polyamide 6I / 6T in a sintering powder (SP) containing at least one partially crystalline polyamide, at least one polyamide 6I / 6T and at least one reinforcing agent to broaden the sintering window (W S p) of the sintering powder (SP). Rapid deployment of prototypes is a common task in recent times.
• SLS selective laser sintering
• WO 2009/1 14715 describes a sintering powder for selective laser sintering which contains at least 20% by weight of polyamide polymer.
• This polyamide polymer contains a branched polyamide, wherein the branched polyamide is prepared starting from a polycarboxylic acid having three or more carboxylic acid groups.
• WO 201 1/124278 describes sintering powders which contain coprecipitates of PA 1 1 with PA 1010, PA 1 1 with PA 1012, PA 12 with PA 1012, PA 12 with PA 1212 or PA 12 with PA 1013.
• EP 1 443 073 describes sintering powder for a selective laser sintering process. These sintering powders contain a polyamide 12, polyamide 1 1, polyamide 6.10, polyamide 6.12, polyamide 10.12, polyamide 6 or polyamide 6.6 and a flow aid.
• US 2015/0259530 describes a partially crystalline polymer and a secondary material which can be used in a sintering powder for selective laser sintering.
• Polyetheretherketone or polyetherketone ketone are preferably used as partially crystalline polymer and polyetherimide as secondary material.
• RD Goodridge et al., Polymer Testing 201 1, 30, 94-100 describes the preparation of polyamide 12 / carbon nanofiber composites by melt blending followed by cryogenic milling. The resulting composite materials are then used as sintering powder in a selective laser sintering process.
• the polyamide blend contains a partially crystalline polyamide such as polyamide 6, polyamide 66, polyamide 69, polyamide 7, polyamide 1 1, polyamide 12 and mixtures thereof and as amorphous polyamide 30 to 70 wt .-% of, for example, nylon 6 / 3T.
• a partially crystalline polyamide such as polyamide 6, polyamide 66, polyamide 69, polyamide 7, polyamide 1 1, polyamide 12 and mixtures thereof and as amorphous polyamide 30 to 70 wt .-% of, for example, nylon 6 / 3T.
• WO 2008/057844 describes sintering powders comprising a partially crystalline polyamide, such as, for example, polyamide 6, polyamide 1 1 or polyamide 12, and a reinforcing agent contain.
• a partially crystalline polyamide such as, for example, polyamide 6, polyamide 1 1 or polyamide 12
• a reinforcing agent such as, for example, polyamide 6, polyamide 1 1 or polyamide 12
• molded articles produced from these sintered powders have only low strength.
• a disadvantage of the sintering powders described in the prior art for the production of moldings by selective laser sintering is also that the sintering window of the sintering powder is often reduced in size compared to the sintered window of the pure polyamide or the pure semi-crystalline polymer.
• a reduction of the sintering window is disadvantageous, as this often warp the moldings during production by selective laser sintering.
• the object underlying the present invention is therefore to provide a process for the production of moldings by selective laser sintering, which does not or only to a small extent has the aforementioned disadvantages of the processes described in the prior art.
• the method should be as simple and inexpensive to carry out.
• This object is achieved by a method for producing a shaped body by selective laser sintering of a sintered powder (SP), wherein the sintered powder (SP) the components (A) at least one partially crystalline polyamide containing at least one unit selected from the group consisting of -NH- (CH 2 ) m -NH- units, where m is 4, 5, 6, 7 or 8, -CO- (CH 2 ) n -NH- units, where n is 3, 4, 5, 6 or 7, and -CO - (CH 2 ) 0 -CO- units, where o is 2, 3, 4, 5 or 6, (B) at least one polyamide 6I / 6T,
• component (C) containing at least one reinforcing agent, wherein component (C) is a fibrous reinforcing agent in which the ratio of the length of the fibrous reinforcing agent to the diameter of the fibrous reinforcing agent is in the range of 2: 1 to 40: 1.
• Another object of the present invention is a method for producing a shaped article by selective laser sintering of a sintering powder (SP), wherein the sintered powder (SP), the components (A) at least one partially crystalline polyamide containing at least one unit selected from the group consisting of -NH- (CH 2 ) m -NH- units, where m is 4, 5, 6, 7 or 8, -CO- (CH 2 ) n is -NH units, where n is 3, 4, 5, 6 or 7, and -CO- (CH 2 ) 0 -CO- units, where o is 2, 3, 4, 5 or 6,
• (C) contains at least one reinforcing agent.
• the sintering powder (SP) used in the process according to the invention has such a widened sintering window (W SP ) that the shaped body produced by selective laser sintering of the sintering powder (SP) has no or significantly reduced distortion.
• the molding has an increased elongation at break.
• an improvement in the thermo-oxidative stability of the sintering powder (SP), ie in particular a better recyclability of the sintering powder (SP) used in the process according to the invention was achieved in comparison to sintered powders containing only a partially crystalline polyamide and polyamide 6I / 6T.
• the sintered powder (SP) therefore has similar advantageous sintering properties after several laser sintering cycles as in the first sintering cycle.
• polyamide 6I / 6T achieves a widened sintering window (W S p) in the sintering powder (SP) compared to the sintered window (W AC ), a mixture of at least one semicrystalline polyamide and at least one reinforcing agent.
• a first layer of a sinterable powder is arranged in a powder bed and exposed locally and briefly with a laser beam.
• a laser beam In this case, only the part of the sinterable powder which has been exposed by the laser beam, selectively melted (selective laser sintering).
• the molten sinterable powder flows into one another and thus forms a homogeneous melt in the exposed area. Subsequently, the area cools down again and the homogeneous melt solidifies again. Then the powder bed becomes the layer thickness of the first layer lowered, applied a second layer of sinterable powder, selectively exposed to the laser and melted.
• the upper second layer of the sinterable powder connects to the lower first layer, and in addition the particles of the sinterable powder within the second layer combine with one another by melting.
• the application of the sinterable powder and the melting of the sinterable powder three-dimensional molded bodies can be produced.
• By the selective exposure of certain points with the laser beam it is possible to produce molded bodies which, for example, also have cavities.
• An additional support material is not necessary because the unfused sinterable powder itself acts as a support material.
• Suitable sinterable powders in selective laser sintering are all powders known to those skilled in the art which can be melted by exposure to a laser.
• the sintering powder (SP) is used as the sinterable powder in selective laser sintering.
• Suitable lasers for selective laser sintering are known to the person skilled in the art and, for example, fiber lasers, Nd: YAG lasers (neodymium-doped yttrium aluminum garnet lasers) and carbon dioxide lasers.
• the sintering window (W) is referred to as "sintered window” (US Pat. W S p) "of the sintering powder (SP).
• the sintering window (W) is described as "sintered window (W AC )" of the mixture of the components (A).
• the sintering window (W) of a sinterable powder can be determined, for example, by differential scanning calorimetry (DSC).
• the temperature of a sample in this case a sample of the sinterable powder, and the temperature of a reference are changed linearly with time.
• the sample and the reference heat is supplied or removed from it. It determines the amount of heat Q, the necessary to keep the sample at the same temperature as the reference.
• the reference value used is the quantity of heat Q R supplied or discharged to the reference.
• the measurement provides a DSC diagram in which the amount of heat Q, which is supplied to the sample and discharged from it, is plotted as a function of the temperature T.
• a heating run is first carried out during the measurement, that is, the sample and the reference are heated linearly.
• an additional amount of heat Q must be supplied to keep the sample at the same temperature as the reference.
• a peak is then observed, the so-called melting peak.
• a cooling run (K) is usually measured.
• the sample and the reference are cooled linearly, so heat is dissipated from the sample and the reference.
• a larger amount of heat Q has to be dissipated in order to keep the sample at the same temperature as the reference, since heat is released during crystallization or solidification.
• a peak, the so-called crystallization peak is then observed in the opposite direction to the melting peak.
• the heating during the heating run usually takes place at a heating rate of 20 K / min.
• the cooling during the cooling is usually carried out in the context of the present invention with a cooling rate of 20 K / min.
• a DSC diagram with a heating run (H) and a cooling run (K) is shown by way of example in FIG.
• the onset temperature of the melting (T M onset ) and the onset temperature of the crystallization (T c onset ) can be determined.
• T M onset To determine the onset temperature of the reflow (T M onset ), a tangent is applied to the baseline of the heating run (H), which runs at the temperatures below the melting peak. A second tangent is applied to the first inflection point of the reflow peak, which at temperatures below the temperature is at the maximum of the reflow peak. The two tangents become extrapolated so far that they intersect. The vertical extrapolation of the point of intersection to the temperature axis indicates the onset temperature of the melting (T M onset ). To determine the onset temperature of the crystallization (T c onset ), a tangent is applied to the baseline of the cooling run (K), which runs at the temperatures above the crystallization peak.
• a second tangent is applied to the inflection point of the crystallization peak, which at temperatures above the temperature is at the minimum of the crystallization peak.
• the two tangents are extrapolated to intersect.
• the vertical extrapolation of the point of intersection to the temperature axis indicates the onset temperature of the crystallization (T c onset ).
• the sintering window (W) results from the difference between the onset temperature of the melting (T M onset ) and the onset temperature of the crystallization (T c onset ). The following applies: onset onset
• the terms "sintering window (W)", “size of the sintering window (W)” and “difference between the onset temperature of the melting (T M onset ) and the onset temperature of the crystallization (T c onset ) "the same meaning and are used synonymously.
• the determination of the sintering window (W S p) of the sintering powder (SP) and the determination of the sintering window (W A c) of the mixture of the components (A) and (C) is carried out as described above.
• the sintering powder (SP) is then used as the sample for determining the sintering window (W S p) of the sintering powder (SP).
• a mixture (blend) of the components (A) and (C) contained in the sintering powder (SP) is used as a sample.
• the sintered powder (SP) contains at least one partially crystalline polyamide as component (A), at least one polyamide 6I / 6T as component (B) and at least one reinforcing agent as component (C).
• component (A) and “at least one partially crystalline polyamide” are used synonymously and therefore have the same meaning.
• component (B) and “at least one polyamide 6I / 6T” and to the terms “component (C)” and “at least one reinforcing agent”.
• component (C) and “at least one reinforcing agent”.
• the sintered powder (SP) may contain the components (A), (B) and (C) in any amounts.
• the sintered powder (SP) contains in the range of 30 to 70 wt .-% of component (A), in the range of 5 to 30 wt .-% of component (B) and in the range of 10 to 60 wt .-% of Component (C), in each case based on the sum of the percentages by weight of components (A), (B) and (C), preferably based on the total weight of the sintering powder (SP).
• the sintering powder (SP) contains in the range of 35 to 65 wt .-% of component (A), in the range of 5 to 25 wt .-% of component (B) and in the range of 15 to 50 wt .-% of Component (C), in each case based on the sum of the percentages by weight of components (A), (B) and (C), preferably based on the total weight of the sintering powder (SP).
• the sintering powder contains in the range of 40 to 60 wt .-% of component (A), in the range of 5 to 20 wt .-% of component (B) and in the range of 15 to 45 wt .-% of the component ( C), in each case based on the sum of the percentages by weight of components (A), (B) and (C), preferably based on the total weight of the sintering powder (SP).
• the present invention therefore also provides a process in which the sintering powder (SP) is in the range of 30 to 70 wt .-% of component (A), in the range of 5 to 25 wt .-% of component (B) and im Range of 15 to 50 wt .-% of component (C), in each case based on the sum of the weight percent of components (A), (B) and (C).
• SP sintering powder
• the sintering powder (SP) may additionally contain at least one additive selected from the group consisting of antinucleating agents, stabilizers, end group functionalizers and dyes.
• the present invention therefore also provides a process in which the sintering powder (SP) additionally contains at least one additive selected from the group consisting of antinucleating agents, stabilizers, end group functionalizers and dyes.
• a suitable antinucleating agent is, for example, lithium chloride.
• Suitable stabilizers are, for example, phenols, phosphites and copper stabilizers.
• Suitable end group functionalizers are, for example, terephthalic acid, adipic acid and propionic acid.
• Preferred dyes are, for example, selected from the group consisting of carbon black, neutral red, inorganic black dyes and organic black dyes.
• the at least one additive is selected from the group consisting of stabilizers and dyes.
• phenols are particularly preferred.
• the at least one additive is particularly preferably selected from the group consisting of phenols, carbon black, inorganic black dyes and organic black dyes.
• Carbon black is known to the person skilled in the art and is available, for example, under the trade name Special Black 4 from Evonik, under the trade name Printex U from Evonik, under the trade name Printex 140 from Evonik, under the trade name Special Black 350 from Evonik or under the trade name Special Black 100 from Evonik.
• a preferred inorganic black dye is obtainable, for example, under the trade name Sicopal Black K0090 from BASF SE or under the trade name Sicopal Black K0095 from BASF SE.
• a preferred organic black dye is, for example, nigrosine.
• the sintering powder (SP) may, for example, in the range of 0.1 to 10 wt .-% of the at least one additive, preferably in the range of 0.2 to 5 wt .-% and particularly preferably in the range of 0.3 to 2, 5 wt .-%, each based on the total weight of the sintering powder (SP).
• the sum of the percentages by weight of components (A), (B) and (C) and optionally of the at least one additive usually add up to 100 percent by weight.
• the sintering powder (SP) has particles. These particles have, for example, a size in the range of 10 to 250 ⁇ m, preferably in the range of 15 to 200 ⁇ m, particularly preferably in the range of 20 to 120 ⁇ m, and particularly preferably in the range of 20 to 110 ⁇ m.
• the sintered powder (SP) according to the invention has, for example, a D10 value in the range from 10 to 30 ⁇ m,
• the sintering powder (SP) according to the invention preferably has a D10 value in the range from 20 to 30 ⁇ m,
• the present invention therefore also relates to a process in which the sintering powder (SP) has a D10 value in the range from 10 to 30 ⁇ m,
• the "D10 value” is understood as meaning the particle size at which 10% by volume of the particles, based on the total volume of the particles, is less than or equal to the D10 value and 90% by volume of the particles, based on The total volume of the particles is greater than the D10 value.
• the "D50 value” is understood to mean the particle size at which 50% by volume of the particles, based on the total volume of the particles, is less than or equal to the D50 value and 50% by volume of the particles, based on the total volume of the particles, are greater than the D50 value.
• the "D90 value” is understood to mean the particle size at which 90% by volume of the particles, based on the total volume of the particles, is less than or equal to the D90 value and 10% by volume of the particles, based on the total volume of the particles greater than the D90 value.
• the sintered powder (SP) is suspended by means of compressed air or in a solvent, such as water or ethanol, and measured this suspension.
• the D10, D50 and D90 values are determined by means of laser diffraction using a Master Sizers 3000 from Malvern. The evaluation is carried out by means of Fraunhofer diffraction.
• the sintered powder (SP) usually has a melting temperature (T M ) in the range of 180 to 270 ° C.
• T M melting temperature of the Sintering powder (SP) in the range of 185 to 260 ° C, and more preferably in the range of 190 to 245 ° C.
• the present invention therefore also relates to a process in which the sintering powder (SP) has a melting temperature (T M ) in the range from 180 to 270 ° C.
• the melting temperature (T M ) is determined within the scope of the present invention by means of Differential Scanning Calorimetry (DSC). As described above, a heating run (H) and a cooling run (K) are usually measured. In this case, a DSC diagram as shown by way of example in FIG. 1 is obtained. The melting temperature (T M ) is then understood to be the temperature at which the melting peak of the heating run (H) of the DSC diagram has a maximum. The melting temperature (T M ) is therefore different from the onset temperature of the melting (T M onset ). The melting temperature (T M ) is usually above the onset temperature of the melting (T M onset ).
• DSC Differential Scanning Calorimetry
• the sintered powder (SP) also usually has a crystallization temperature (T c ) in the range of 120 to 190 ° C.
• the crystallization temperature (T c ) of the sintering powder (SP) is preferably in the range from 130 to 180 ° C. and particularly preferably in the range from 140 to 180 ° C.
• the present invention therefore also provides a process in which the sintering powder (SP) has a crystallization temperature (T c ) in the range from 120 to 190 ° C.
• the crystallization temperature (T c ) is determined in the context of the present invention by means of differential scanning calorimetry (DSC). As described above, a heating run (H) and a cooling run (K) are usually measured. In this case, a DSC diagram as shown by way of example in FIG. 1 is obtained. The crystallization temperature (T c ) is then the temperature at the minimum of the crystallization peak of the DSC curve. The crystallization temperature (T c ) is therefore different from the onset temperature of the crystallization (T c onset ). The crystallization temperature (T c ) is usually below the onset temperature of the crystallization (T c onset ).
• the sintered powder (SP) usually also has a glass transition temperature (T G ).
• the glass transition temperature (T G ) of the sintering powder (SP) is, for example, in the range of 30 to 80 ° C, preferably in the range of 40 to 70 ° C and particularly preferably in the range of 45 to 60 ° C.
• the glass transition temperature (T G ) of the sintering powder (SP) is determined by differential scanning calorimetry. For the determination according to the invention, first a first heating run (H1), then a cooling run (K) and then a second heating run (H2) of a sample of the sintering powder (SP) (weighing approx. 8.5 g) are measured.
• the heating rate for the first heating (H1) and the second heating (H2) is 20 K / min
• the cooling rate for the cooling (K) is also 20 K / min.
• a step is obtained in the second heating run (H2) of the DSC diagram.
• the glass transition temperature (T G ) of the sintering powder (SP) corresponds to the temperature at half the step height in the DSC diagram. This method for determining the glass transition temperature is known to the person skilled in the art.
• the sintered powder (SP) also usually has a sintering window (W SP ).
• the sintering window (W S p) is, as described above, the difference between the onset temperature of the reflow (T M onset ) and the onset temperature of the crystallization (T c onset ).
• the onset temperature of the reflow (T M onset ) and the onset temperature of the crystallization (T c onset ) are determined as described above.
• the sintering window (W S p) of the sintering powder (SP) is preferably in the range of 15 to 40 K (Kelvin), particularly preferably in the range of 20 to 35 K and particularly preferably in the range of 20 to 33 K.
• the subject matter of the present invention is therefore also a method in which the sintering powder (SP) has a sintering window (W SP ), the sintering window (W SP ) representing the difference between the onset temperature of the melting (T M onset ) and the onset temperature crystallization (T c onset ) and wherein the sintering window (W SP ) is in the range of 15 to 40K.
• the sintering powder (SP) has a sintering window (W SP ), the sintering window (W SP ) representing the difference between the onset temperature of the melting (T M onset ) and the onset temperature crystallization (T c onset ) and wherein the sintering window (W SP ) is in the range of 15 to 40K.
• the sintering powder (SP) can be prepared by all methods known to those skilled in the art.
• the sintering powder (SP) is prepared by grinding the components (A), (B) and (C) and optionally the at least one additive.
• the preparation of the sintering powder (SP) by grinding can be carried out by all methods known to those skilled in the art.
• the components (A), (B) and (C) and optionally the at least one additive are added to a mill and ground.
• Suitable mills are all mills known to the person skilled in the art, for example classifier mills, counter-jet mills, hammer mills, ball mills, vibrating mills or rotor mills. Milling in the mill can also be carried out by all methods known to those skilled in the art. For example, the grinding may take place under inert gas and / or under cooling with liquid nitrogen. Cooling with liquid nitrogen is preferred.
• the temperature during grinding is arbitrary.
• the grinding is preferably carried out at temperatures of liquid nitrogen, for example at a temperature in the range from -210 to -195 ° C.
• the present invention therefore also relates to a process in which the sintering powder (SP) is prepared by grinding the components (A), (B) and (C) at a temperature in the range from -210 to -195 ° C.
• the component (A), the component (B), the component (C) and optionally the at least one additive can be introduced into the mill by all methods known to those skilled in the art.
• the component (A), the component (B) and the component (C) and optionally the at least one additive may be added separately to the mill and ground therein and mixed together.
• the component (A), the component (B) and the component (C) and optionally the at least one additive are compounded together and then added to the mill.
• the component (A), the component (B) and the component (C) and optionally the at least one additive can be compounded in an extruder, then extruded from this and added to the mill.
• Component (A) is at least one partially crystalline polyamide.
• At least one partially crystalline polyamide means both exactly one partially crystalline polyamide and one mixture of two or more partially crystalline polyamides.
• Partially crystalline in the context of the present invention means that the polyamide has a melting enthalpy ⁇ H2 (A) of greater than 45 J / g, preferably greater than 50 J / g and particularly preferably greater than 55 J / g, in each case measured using differential scanning calorimetry (DSC) according to ISO 1 1357-4: 2014.
• the component (A) according to the invention also preferably has a melting enthalpy ⁇ H2 (A) of less than 200 J / g, more preferably less than 150 J / g and particularly preferably less than 100 J / g, measured by differential scanning calorimetry (differential scanning calorimetry, DSC) according to ISO 1 1357-4: 2014.
• component (A) contains at least one unit selected from the group consisting of -NH- (CH 2 ) m -NH- units, where m is 4, 5, 6, 7 or 8, -CO- (CH 2 ) n is -NH units, where n is 3, 4, 5, 6 or 7 and -CO- (CH 2 ) 0 -CO- units, where o is 2, 3, 4, 5 or 6.
• Component (A) preferably contains at least one unit selected from the group consisting of -NH- (CH 2 ) m -NH- units, where m is 5, 6 or 7, - CO- (CH 2 ) n - NH units, where n is 4, 5 or 6 and -CO- (CH 2 ) 0 -CO- units, where o is 3, 4 or 5.
• component (A) contains at least one unit selected from the group consisting of -NH- (CH 2 ) 6 -NH- units, -CO- (CH 2 ) 5 -NH- units and -CO- (CH 2 ) 4 -CO units.
• component (A) contains at least one unit selected from the group consisting of -CO- (CH 2 ) n -NH units, then these units derive from lactams having 5 to 9 ring members, preferably from lactams having 6 to 8 ring members, more preferably from lactams with 7 ring members.
• Lactams are known to the person skilled in the art. According to the invention, lactams are generally understood to mean cyclic amides. These have in the ring according to the invention 4 to 8 carbon atoms, preferably 5 to 7 carbon atoms and more preferably 6 carbon atoms.
• the lactams are selected from the group consisting of butyro-4-lactam ( ⁇ -lactam, ⁇ -butyrolactam), 2-piperidinone ( ⁇ -lactam, ⁇ -valerolactam), hexano-6-lactam ( ⁇ -lactam, ⁇ - Caprolactam), heptano-7-lactam ( ⁇ -lactam, ⁇ -heptanolactam) and octano-8-lactam ( ⁇ -lactam; ⁇ -octanolactam).
• the lactams are preferably selected from the group consisting of 2-piperidinone ( ⁇ -lactam; ⁇ -valerolactam), hexano-6-lactam ( ⁇ -lactam, ⁇ -caprolactam) and heptano-7-lactam ( ⁇ -lactam; ⁇ - Heptanolactam). Especially preferred is ⁇ -caprolactam.
• component (A) contains at least one unit selected from the group consisting of -NH- (CH 2 ) m -NH- units, these units are derived from diamines from.
• the component (A) is then obtained by reaction of diamines, preferably by reaction of diamines with dicarboxylic acids.
• Suitable diamines contain from 4 to 8 carbon atoms, preferably from 5 to 7 carbon atoms and most preferably 6 carbon atoms.
• Such diamines are for example selected from the group consisting of
• 1, 5-diaminopentane pentane-1, 5-diamine, cadaverine
• 1,6-diaminohexane hexamethylenediamine, hexane-1,6-diamine
• 1,7-diaminoheptane 1,7-diaminoheptane
• the diamines are selected from the group consisting of 1, 5-diaminopentane, 1, 6-diaminohexane and 1, 7-diaminoheptane. Particular preference is given to 1,6-diaminohexane.
• component (A) contains at least one unit selected from the group consisting of -CO- (CH 2 ) 0 -CO- units, these units are usually derived from dicarboxylic acids. The component (A) was then thus obtained by reacting dicarboxylic acids, preferably by reacting dicarboxylic acids with diamines.
• the dicarboxylic acids then contain 4 to 8 carbon atoms, preferably 5 to 7 carbon atoms and most preferably 6 carbon atoms.
• dicarboxylic acids are, for example, selected from the group consisting of butanedioic acid (succinic acid), pentanedioic acid (glutaric acid), hexanedioic acid (adipic acid), heptanedioic acid (pimelic acid) and octanedioic acid (suberic acid, suberic acid).
• the dicarboxylic acids are selected from the group consisting of pentanedioic acid, hexanedioic acid and heptanedioic acid, particularly preferred is hexanedioic acid.
• Component (A) may also contain other units.
• the component (A) may contain units derived from dicarboxylic acid alkanes (aliphatic dicarboxylic acids) having 9 to 36 carbon atoms, preferably 9 to 12 carbon atoms, and more preferably 9 to 10 carbon atoms.
• dicarboxylic acid alkanes aliphatic dicarboxylic acids having 9 to 36 carbon atoms, preferably 9 to 12 carbon atoms, and more preferably 9 to 10 carbon atoms.
• aromatic dicarboxylic acids are suitable.
• component (A) may contain, for example, units derived from m-xylylenediamine, di- (4-aminophenyl) methane, di (4-aminocyclohexyl) methane, 2,2-di- (4-aminophenyl) - Propane and 2,2-di- (4-aminocyclohexyl) propane and / or 1, 5-diamino-2-methyl-pentane.
• PA 6 / 6I (see PA 6), hexamethylenediamine, isophthalic acid
• PA 6 / 6T (see PA 6 and PA 6T)
• PA 6/66 (see PA 6 and PA 66)
• PA 66/6/610 see PA 66, PA 6 and PA 610)
• PA 6I / 6T / PACM such as PA 6I / 6T and diaminodicyclohexylmethane
• PA 6 / 6I6T (see PA 6 and PA 6T), hexamethylenediamine, isophthalic acid
• Component (A) is therefore preferably selected from the group consisting of PA 6, PA 6.6, PA 6.10, PA 6.12, PA 6.36, PA 6 / 6.6, PA 6 / 6I6T, PA 6 / 6T and PA 6 / 6I
• component (A) is preferably selected from the group consisting of PA 6, PA 6.10, PA 6.6 / 6, PA 6 / 6T and PA 6.6. More preferred is the Component (A) selected from the group consisting of PA 6 and PA 6 / 6.6. Most preferably, component (A) is PA 6.
• the present invention therefore also provides a process in which component (A) is selected from the group consisting of PA 6, PA 6.6, PA 6.10, PA 6.12, PA 6.36, PA 6 / 6.6, PA 6 / 6I6T, PA 6 / 6T and PA 6 / 6I.
• Component (A) generally has a viscosity number of from 70 to 350 ml / g, preferably from 70 to 240 ml / g.
• the determination of the viscosity number is carried out according to the invention from a 0.5 wt .-% solution of the component (A) and in 96 wt .-% sulfuric acid at 25 ° C according to ISO 307th
• the component (A) preferably has a weight-average molecular weight (M w ) in the range of 500 to 2,000,000 g / mol, more preferably in the range of 5,000 to 500,000 g / mol, and particularly preferably in the range of 10,000 to 100,000 g / mol, up.
• M w weight-average molecular weight
• the component (A) usually has a melting temperature (T M ).
• the melting temperature (T M ) of the component (A) is, for example, in the range of 70 to 300 ° C, and preferably in the range of 220 to 295 ° C.
• the melting temperature (T M ) of component (A) is determined as described above for the melting temperature (T M ) of the sintering powder (SP) by means of differential scanning calorimetry.
• the component (A) also usually has one
• Component (A) is, for example, in the range of 0 to 10 ° C, and preferably in the range of 40 to 105 ° C.
• the glass transition temperature (T G ) of component (A) is determined by differential scanning calorimetry. For the determination according to the invention, first a first heating run (H1), then a cooling run (K) and then a second heating run (H2) of a sample of the component (A) (weighing approx. 8.5 g) are measured.
• the heating rate for the first heating (H1) and the second heating (H2) is 20 K / min
• the cooling rate for the cooling (K) is also 20 K / min.
• a step is obtained in the second heating run (H2) of the DSC diagram.
• the glass transition temperature (T G ) of component (A) corresponds to the temperature at half the step height in the DSC diagram. This method for determining the glass transition temperature is known to the person skilled in the art.
• component (B) is at least one polyamide 6I / 6T.
• At least one polyamide 6I / 6T in the context of the present invention means both exactly one polyamide 6I / 6T and a mixture of two or more polyamides 6I / 6T.
• Polyamide 6I / 6T is a copolymer of polyamide 61 and polyamide 6T.
• component (B) consists of units derived from hexamethylenediamine, terephthalic acid and isophthalic acid.
• component (B) is thus preferably a copolymer prepared from hexamethylenediamine, terephthalic acid and isophthalic acid.
• the component (B) is preferably a random copolymer.
• the at least one polyamide 6I / 6T used as component (B) may contain any proportions of 6I and 6T units.
• the molar ratio of 6I units to 6T units in the range of 1 to 1 to 3 to 1, more preferably in the range of 1, 5 to 1 to 2.5 to 1 and particularly preferably in the range of 1, 8 to 1 to 2.3 to 1.
• Component (B) is an amorphous copolyamide.
• amorphous means that the pure component (B) has no melting point in differential scanning calorimetry (DSC) measured according to ISO 1 1357.
• Component (B) has a glass transition temperature (T G ).
• the glass transition temperature (T G ) of the component (B) is usually in the range of 100 to 150 ° C, preferably in the range of 1 15 to 135 ° C and particularly preferably in the range of 120 to 130 ° C.
• the determination of the glass transition temperature (T G ) of component (B) is carried out by means of differential scanning calorimetry as described above for the determination of the glass transition temperature (T G ) of component (A).
• the MVR (275 ° C / 5 kg) (melt volume-flow rate, MVR) is preferably in the range of 50 ml / 10 min to 150 ml / 10 min, more preferably in the range of 95 ml / 10 min to 105 ml / 10 min.
• the zero viscosity rate ⁇ 0 (zero shear rate viscosity) of component (B) is, for example, in the range from 770 to 3250 Pas.
• Zero shear rate viscosity ( ⁇ 0 ) is determined using a TA Instruments "DHR-1" rotational viscometer and a 25 mm diameter plate-and-plate geometry with a gap distance of 1 mm to form unannealed samples of the component (B) dried for 7 days at 80 ° C under vacuum and then measured with time-dependent frequency sweep (sequence test) with an angular frequency range of 500 to 0.5 rad / s
• deformation 1, 0%
• Measuring temperature 240 ° C
• measuring time 20 min
• preheating time after sample preparation 1, 5 min.
• the component (B) has an amino end group concentration (AEG) which is preferably in the range of 30 to 45 mmol / kg, and more preferably in the range of 35 to 42 mmol / kg.
• AEG amino end group concentration
• component (B) is dissolved in 30 ml of a phenol / methanol mixture (phenol: methanol 75:25 by volume) and then titrated potentiometrically with 0.2 N hydrochloric acid in water.
• the component (B) has a carboxyl end group concentration (CEG) which is preferably in the range of 60 to 155 mmol / kg, and more preferably in the range of 80 to 135 mmol / kg.
• CEG carboxyl end group concentration
• component (C) is at least one reinforcing agent.
• At least one reinforcing agent in the context of the present invention means both exactly one reinforcing agent and a mixture of two or more reinforcing agents.
• a reinforcing agent is understood as meaning a material which improves the mechanical properties of shaped bodies produced by the process according to the invention compared to shaped bodies which do not contain the reinforcing agent. Reinforcing agents as such are known to the person skilled in the art.
• the component (C) may, for example, be spherical, platelet-shaped or fibrous. Preferably, component (C) is fibrous.
• the present invention therefore also provides a process in which component (C) is a fibrous reinforcing agent.
• a “fibrous reinforcing agent” is understood to mean a reinforcing agent in which the ratio of the length of the fibrous reinforcing agent to the diameter of the fibrous reinforcing agent is in the range from 2: 1 to 40: 1, preferably in the range from 3: 1 to 30: 1, and in particular preferably in the range from 5: 1 to 20: 1, the length of the fibrous reinforcing agent and the diameter of the fibrous reinforcing agent being determined by microscopy by means of image evaluation on samples after incineration, wherein at least 70,000 parts of the fibrous reinforcing agent are evaluated after ashing.
• component (C) is a fibrous reinforcing agent in which the ratio of the length of the fibrous reinforcing agent to the diameter of the fibrous reinforcing agent is in the range of 2: 1 to 40: 1.
• the length of the component (C) is usually in the range of 5 to 1000 ⁇ , preferably in the range of 10 to 600 ⁇ and particularly preferably in the range of 20 to 500 ⁇ , determined by microscopy with image analysis after incineration.
• the diameter of component (C) is for example in the range of 1 to 30 ⁇ , preferably in the range of 2 to 20 ⁇ and particularly preferably in the range of 5 to 15 ⁇ , determined by microscopy with image analysis after incineration.
• component (C) it is possible for component (C) to have a greater length and / or larger diameter than described above at the beginning of the production of the sintering powder (SP) and that the length and / or diameter of the component (C) in the manufacture of the sintering powder (SP), for example by compounding and / or grinding, reduced, so that in the sintering powder (SP) the above-described lengths and / or diameters for the component (C) are obtained.
• the component (C) is, for example, selected from the group consisting of inorganic reinforcing agents and organic reinforcing agents.
• Inorganic reinforcing agents are known to the person skilled in the art and are selected, for example, from the group consisting of carbon nanotubes, carbon fibers, boron fibers, glass fibers, silica fibers, ceramic fibers and basalt fibers.
• Suitable silica fibers are, for example, wollastonite. Wollastonite is preferred as a silica fiber.
• Organic reinforcing agents are also known to the person skilled in the art and are selected, for example, from the group consisting of aramid fibers, polyester fibers and polyethylene fibers.
• the component (C) is therefore preferably selected from the group consisting of carbon nanotubes, carbon fibers, boron fibers, glass fibers, silica fibers, ceramic fibers, basalt fibers, aramid fibers, polyester fibers and polyethylene fibers.
• component (C) is particularly preferably selected from the group consisting of carbon nanotubes, carbon fibers, boron fibers, glass fibers, silica fibers, ceramic fibers and basalt fibers. Most preferably, component (C) is selected from the group consisting of wollastonite, carbon fibers and glass fibers.
• component (C) is selected from the group consisting of carbon nanotubes, carbon fibers, boron fibers, glass fibers, silica fibers, ceramic fibers, basalt fibers, aramid fibers, polyester fibers and polyethylene fibers.
• component (C) is not wollastonite.
• the sintering powder (SP) then does not contain wollastonite.
• the component (C) is selected from the group consisting of carbon fibers and glass fibers.
• Another object of the present invention is therefore also a process in which the sintering powder (SP) contains no wollastonite and the component (C) is selected from the group consisting of carbon fibers and glass fibers.
• the component (C) may further be surface-treated. Suitable surface treatments are known to the person skilled in the art. moldings
• a shaped body is obtained by the method described above for selective laser sintering.
• the sintered powder (SP) melted in the selective exposure with the laser solidifies again after the exposure and thus forms the shaped body according to the invention.
• the shaped body can be removed from the powder bed immediately after the solidification of the melted sintering powder (SP), and it is also possible to cool the shaped body first and then remove it from the powder bed.
• adhering particles of the sintering powder (SP) which has not been melted, can be mechanically removed from the surface by known methods.
• the method for surface treatment of the molded article includes, for example, the slide grinding or Gleitspanen and sandblasting, glass, shot peening or micro-jets. It is also possible to further process the resulting shaped articles or, for example, to treat the surface.
• the shaped article according to the invention contains in the range from 30 to 70% by weight of component (A), in the range from 5 to 50% by weight of component (B) and in the range from 10 to 60% by weight of component (C ), in each case based on the total weight of the molding.
• the shaped body contains in the range of 35 to 65 wt .-% of component (A), in the range of 5 to 25 wt .-% of component (B) and in the range of 15 to 50 wt .-% of component (C ), in each case based on the total weight of the molding.
• the shaped body contains in the range of 40 to 60 wt .-% of component (A), in the range of 5 to 20 wt .-% of component (B) and in the range of 15 to 45 wt .-% of the component ( C), in each case based on the total weight of the molding.
• the component (A) is the component (A) contained in the sintered powder (SP). Also, the component (B) is the component (B) contained in the sintering powder (SP) and the component (C) is the component (C) contained in the sintering powder (SP).
• the shaped body obtained according to the invention also contains the at least one additive.
• the at least one additive can undergo chemical reactions and can thereby change. Such reactions are known in the art.
• the component (A), the component (B), the component (C) and optionally the at least one additive preferably undergoes no chemical reaction by the exposure of the sintering powder (SP) to the laser, but the sintering powder (SP) merely melts ,
• the present invention therefore also provides a molded article obtainable by the process according to the invention.
• the sintering window (W SP ) of the sintering powder (SP) is widened with respect to the sintering window (W A c) of a mixture of components (A) and (C).
• the present invention therefore also provides the use of polyamide 6I / 6T in a sintering powder (SP) comprising the components (A) at least one partially crystalline polyamide containing at least one unit selected from the group consisting of -NH- (CH 2 ) m - NH units, where m is 4, 5, 6, 7 or 8, -CO- (CH 2 ) n -NH- units, where n is 3, 4, 5, 6 or 7, and -CO- (CH 2 ) 0 -CO- units, where o is 2, 3, 4, 5 or 6, (B) at least one polyamide 6I / 6T,
• (C) comprises at least one reinforcing agent for widening the sintering window (W S p) of the sintering powder (SP) relative to the sintering window (W AC ) of a mixture of components (A) and (C), the sintering window (W S p; W A c) is in each case the difference between the onset temperature of the melting (T M onset ) and the onset temperature of the crystallization (T c onset ).
• the sintering window (W AC ) of a mixture of components (A) and (C) is in the range from 10 to 21 K (Kelvin), more preferably in the range from 13 to 20 K and particularly preferably in the range from 15 to 19 K.
• the sintering window (W SP ) of the sintering powder (SP) widens in relation to the sintering window (W AC ) of the mixture of components (A) and (C), for example by 5 to 15 K, preferably by 6 to 12 K and particularly preferably by 7 to 10 K. It goes without saying that the sintering window (W SP ) of the sintering powder (SP) is wider than the sintering window (W A c) of the mixture of components (A) and (C) contained in the sintering powder.
• the invention will be explained in more detail below by means of examples, without limiting it thereto.
• Partially crystalline polyamide (component (A)): (P1) Polyamide 6 (Ultramid® B27, BASF SE) Amorphous polyamide (component (B)):
• Reinforcing agent (component (C)): (VS1) carbon fiber Tenax E HT C604, Toho Tenax (chopped fiber, 6 mm,
• AEG indicates the amino end group concentration. This is determined by means of titration. To determine the amino end group concentration (AEG), 1 g of the component (semicrystalline polyamide or amorphous polyamide) was dissolved in 30 ml of a phenol / methanol mixture (phenol: methanol 75:25 by volume) and then titrated potentiometrically with 0.2 N hydrochloric acid in water ,
• the CEG indicates the carboxyl end group concentration. This is determined by means of titration. To determine the carboxyl end group concentration (CEG), 1 g of the component (semicrystalline polyamide or amorphous polyamide) was dissolved in 30 ml of benzyl alcohol. It was then titrated visually at 120 ° C with 0.05 N potassium hydroxide in water.
• the melting temperature (T M ) of the partially crystalline polyamides and all glass transition temperatures (T G ) were determined in each case by means of differential scanning calorimetry. To determine the melting temperature (T M ), as described above, a first heating run (H1) was measured at a heating rate of 20 K / min. The melting temperature (T M ) then corresponded to the temperature at the maximum of the melting peak of the heating run (H1).
• T G glass transition temperature
• Zero shear rate viscosity ⁇ 0 was determined using a TA Instruments "DHR-1" rotational viscometer and a 25 mm diameter plate-and-plate geometry with a gap spacing of 1 mm Days were dried under vacuum at 80 ° C. and then measured with a time-dependent frequency sweep (sequence test) with an angular frequency range of 500 to 0.5 rad / s The following further measuring parameters were used: deformation: 1.0%, measuring temperature: 240 ° C. , Measuring time: 20 min, preheating time after sample preparation: 1, 5 min.
• Blends prepared in a mini extruder For the preparation of blends, the components shown in Table 3 were in the proportions shown in Table 3 in a DSM 15 cm 3 mini extruder (DSM Micro15 microcompounder) with a speed of 80 rev / min (revolutions per minute) compounded at 260 ° C for 3 min (minutes) mixing time and then extruded. The resulting extrudates were then ground in a mill and screened to a particle size of ⁇ 200 ⁇ .
• DSM 15 cm 3 mini extruder DSM Micro15 microcompounder
• T M The melting temperature
• the crystallization temperature (T c ) was determined by differential scanning calorimetry. For this purpose, first a heating run (H) with a heating rate of 20 K / min and then a cooling run (K) with a cooling rate of 20 K / min were measured.
• the crystallization temperature (T c ) is the temperature at the extremum of the crystallization peak.
• the amount of complex shear viscosity was determined by a plate-plate rotary rheometer at an angular frequency of 0.5 rad / s and a temperature of 240 ° C.
• a rotary viscometer "DHR-1" from TA Instruments was used, the diameter being 25 mm and the gap spacing being 1 mm, and unannealed samples were dried for 7 days at 80 ° C. under vacuum and then subjected to a time-dependent frequency sweep (sequence test). measured with a circular frequency range of 500 to 0.5 rad / s The following further measuring parameters were used: deformation: 1, 0%, measuring time: 20 min, preheating time after sample preparation: 1, 5 min.
• the sintering window (W) was determined as described above as the difference between the onset temperature of the melting (T M onset ) and the onset temperature of the crystallization (T c onset ).
• the complex shear viscosity of freshly prepared blends and of blends after furnace storage at 0.5% oxygen was determined for 16 hours and 195 ° C.
• the ratio of the viscosity after storage (after aging) to the viscosity before storage (before aging) was determined.
• the viscosity is measured by means of rotational rheology at a measuring frequency of 0.5 rad / s at a temperature of 240 ° C.
• the comparative examples V2, V3, V9 and V1 1 clearly show that a mixture of the components (A) and (C) has a reduced sintering window (W AC ) compared to the sintering window of the pure component (A) (comparative example V1). This is a consequence of the nucleating effect of the components (C) used in these comparative examples.
• the sintered powders (SP) of Examples B5, B6, B10 and B12 according to the invention exhibit a widened sintering window (W S p) both compared with the mixture of components (A) and (C) and with respect to the pure component (A).
• Blends made in a twin-screw extruder For the production of sintered powders, the components shown in Table 5 were in the ratio shown in Table 5 in a twin-screw extruder (MC26) at a speed of 300 rpm (revolutions per minute) and throughput of 10 kg / h at a temperature of 270 ° C compounded with a subsequent strand granulation. The granules thus obtained were ground to a particle size of 20 to 100 ⁇ . The resulting sintered powders were characterized as described above. In addition, the bulk density was determined according to DIN EN ISO 60 and the tamped density according to DIN EN ISO 787-1 1 and the Hausner factor as the ratio of tamped density to bulk density. The particle size distribution, reported as d10, d50 and d90, was determined as described above with a Malvern Mastersizer.
• the reinforcing agent content of the sintering powder (SP) was determined gravimetrically after incineration.
• the sintering powders (SP) according to the invention have a larger sintering window even after aging than sintered powder in which instead of polyamide 6I6T as component (B) polyamide 6.3T is contained. Therefore, the sintering powder according to the invention also have a significantly lower tendency to warp during the production of moldings in the selective laser sintering process. As can be seen from Table 7 below, the sintering powders according to the invention also require a lower installation space temperature in the production of moldings in the selective laser sintering method. This makes the process more cost efficient. Laser sintering tests
• the sintered powder was introduced with a layer thickness of 0.1 mm into the installation space at the temperature indicated in Table 7. Subsequently, the sintering powder was exposed with a laser at the laser power indicated in Table 7 and the specified dot pitch, with the speed of the laser over the sample during exposure at 5 m / s.
• the dot pitch is also referred to as laser spacing or track pitch. In selective laser sintering, scanning is usually done in stripes. The dot pitch indicates the distance between the centers of the stripes, ie between the two centers of the laser beam of two stripes.
• the heat deflection temperature (HDT) was determined according to ISO 75-2 2013 using both method A with a marginal fiber stress of 1.8 N / mm 2 and method B with a marginal fiber tension of 0.45 N / mm 2 , The processability of the sintering powder and the distortion of the sintered bars were evaluated qualitatively according to the scale given in Table 8.
• Table 10 shows the properties of the molded bodies in the conditioned state.
• the moldings were stored after the drying described above for 336 hours at 70 ° C and 62% relative humidity. The water content was determined by weighing the samples after drying and after conditioning. Table 10
• the shaped bodies produced from the sintering powders according to the invention have a low distortion and therefore the sintering powder according to the invention can be used well in the selective laser sintering process.

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