KR20070017406A - Polymer powder containing polyamide, use of said powder in a moulding method and moulded body produced from the same - Google Patents

Abstract

The present invention relates to polymer powders containing polyamide (nylon-11), the use of said powders in molding processes and moldings made from said polymer powders. The molding method includes a lamination process of selectively melting regions of each layer through the injection of electromagnetic waves and using powder. The selectivity can be achieved by masking, by the application of an inhibitor, absorbent or susceptor, or by the concentrated input of energy. After cooling, the solidified area can be removed from the powder bed as a shaped body. Molded bodies made from the polymer powders of the present invention according to one of the methods of the present invention show significant advantages in component properties, in particular finish, over molded bodies composed of conventional powders. Processing properties and recycling are likewise improved compared to conventional polyamide powders.

Polyamide, Polymer Powder, Lamination Process

Description

POLYMER POWDER CONTAINING POLYAMIDE, USE OF SAID POWDER IN A MOULDING METHOD AND MOULDED BODY PRODUCED FROM THE SAME}

High speed manufacturing of prototypes is a frequently required task in recent years. Particularly suitable processes are those in which the process is based on the fine powder material and, through selective melting and curing, produces the desired layer-by-layer structure. Since the powder bed around the molten area provides a suitable support, the support structure for overhang and undercut can be omitted. There is also no need for subsequent work to remove the support. The process is also suitable for short term production.

The present invention relates to a polymer powder based on nylon-11, preferably produced via polycondensation of ω-aminoundecanoic acid, the use of said powder in the molding process, and also fine powders using the powder. A molding produced through a lamination process that selectively melts regions of a layer. After cooling and curing the laminated melt treated region in the previous step, the molding can be removed from the powder bed.

For example, the selectivity of the lamination process can be achieved by susceptors, absorbers, inhibitors, or masks, by intensive injection of energy, for example by laser beams, or by glass fibers. The input of energy can be accomplished by electromagnetic waves.

While some of the processes by which the inventive moldings can be made from the powders of the invention are described below, there is no intention to limit the invention to these.

One process that has particularly good suitability for high speed molding purposes is selective laser sintering. This process selectively and shortly irradiates a laser beam to the plastic powder in the chamber to melt the powder particles irradiated with the laser beam. The molten particles aggregate and quickly solidify again to produce a solid material. This process makes it possible to produce three-dimensional objects simply and quickly through repeated irradiation of successive newly applied layers.

The patent specifications US 6,136,948 and WO 96/06881 (both DTM Corporation) detail a laser-sintering (fast molding) process for producing moldings from micropowder polymers. Various polymers and copolymers, such as polyacetate, polypropylene, polyethylene, ionomers, and polyamides, are claimed in this application.

Another process with good suitability is the SIB process described in WO 01/38061, or the process described in EP 1 015 214. All of the above processes heat the entire surface in infrared to melt the powder. The selectivity of the melting is achieved through the application of an inhibitor in the first process and through a mask in the second process. DE 103 11 438 describes another process. Here, the energy required for the melting process is introduced through the microwave generator, and selectivity is achieved through the application of susceptors.

Fine powder substrates, in particular polymers, preferably polyesters, polyvinyl chlorides, polyacetals, polypropylenes, polyethylenes, polystyrenes, polycarbonates, polys for the mentioned high speed molding or high speed manufacturing processes (RP processes or RM processes) Polymers selected from (N-methylmethacrylimide) (PMMI), polymethyl methacrylate (PMMA), ionomers, polyamides or mixtures thereof can be used.

WO 95/11006 is suitable for laser sintering and shows no overlap of melting and recrystallization peaks during measurement of melting behavior via differential scanning calorimetry at a scan rate of 10-20 ° C./min, and crystallinity of 10 as measured via DSC as well. Polymer powders having a -90% and number-average molecular weights Mn 30 000 to 500 000 and Mw / Mn ratios 1 to 5 are described.

DE 197 47 309 describes the use of nylon-12 powders with elevated melting points and increased melt enthalpy obtained through the ring opening of laurolactam and the reprecipitation of polyamides prepared previously via subsequent polycondensation. This is nylon-12. The disadvantages of this powder are mostly relatively high BET surface areas of more than 6 m ² / g, which firstly leads to stringent requirements for powder-flow aids and reduces the processing range, ie the temperature range, so that only curl stops at the lower limit. And at the upper end the pre-surface melting of the fine powder layer is only prevented. Secondly, the high BET surface area impairs the recyclability of the unmelted powder in the first run. Low BET surface areas are obtained by making more granulated-grain materials, but this adversely affects the resolution that can be achieved for the components in powder-based processes.

The problem with processing by the molding process described above is that the temperature in the production chamber must be kept at a level just below the melting point of the polymeric material in order to avoid what is known as curl. The curl implies distortion of the molten region previously, causing at least some protrusion from the face of the article. In this regard, there is a risk that the protruding areas may shift or even break completely when the next fine powder layer is applied. The consequence of this with respect to the process is that all manufacturing space temperatures must be maintained at relatively high levels. In order to accurately separate the region into which electromagnetic energy is injected from the region not intended for melting, the resulting maximum melting enthalpy with sharp DSC (differential scanning calorimetry according to DIN 53765) peaks is preferred. Thermal conductivity and heat dissipation from the molten region, which, of course, cannot be prevented, also cause relatively severe errors in the molding from the intended contours. The maximum melting enthalpy of the powder inhibits the sintering of the powder bed on the melting zone.

It is therefore an object of the present invention to provide polymer powders that allow the production of moldings with maximum surface quality and maximum dimensional precision. The processing ranges herein are large enough to eliminate the need to carry out the process at the upper or lower limits while at the same time maintaining the grain size of the standard powder currently on the market. The method herein is a layer-by-layer method in which the regions of each micropowder layer are selectively melted by electromagnetic energy, and after cooling, are combined to produce the desired molding.

Surprisingly, as claimed in the claims, polymer powders are prepared via precipitous crystallization using nylon-11, from which surface quality and dimensional precision are obtained through a lamination process in which regions of each micropowder layer are selectively melted. It has been found that it is possible to produce moldings which have advantages and better processing properties than those obtained from polymer powders in the art, for example in DE 197 47 309.

The present invention therefore comprises a polymer powder for processing in a lamination process comprising nylon-11 prepared by polycondensation of at least one nylon-11, preferably ω-aminoundecanoic acid, and selectively melting the regions of each layer To provide. The polymer powder of the invention has a melt enthalpy of at least 125 J / g and a recrystallization temperature of at least 148 ° C, preferably at least 130 J / g of melting enthalpy and at least 150 ° C of recrystallization temperature, particularly preferably melt enthalpy measured by DSC. 130 J / g or more and a recrystallization temperature of 151 ° C. or more. The BET surface area of the nylon-11 powder of the present invention is less than 6 m ² / g, preferably less than 5 m ² / g, and particularly preferably less than 4 m ² / g, and the medium grain diameter is preferably 40 to 120 μm, more preferably 45 to 100 μm, and particularly preferably 50 to 70 μm.

The BET surface area was determined by gas adsorption using the Brunauer, Emmet and Teller principle and the standard utilized was DIN / ISO 9277 66333.

The invention also relates to nylon-11 prepared via polycondensation of at least one nylon-11, preferably ω-aminoundecanoic acid and, where appropriate, additional auxiliaries such as stabilizers, fillers, pigments, flow promoters and powders. Providing a molding comprising a flow aid and produced through a lamination process that selectively melts the regions of each layer.

An advantage of the polymer powders of the present invention is that, through a lamination process that selectively melts regions of each layer, moldings made from these powders have better dimensional accuracy and better surface quality than those made of conventional polyamide powders. will be. The powder of the invention has a larger processing range and better recyclability than conventional polyamide powders.

The mechanical properties of moldings made from the powders of the invention are more than the mechanical properties of moldings made from conventional powders. The polymer powders of the invention are described below, but are not intended to limit the invention to the following description.

The polymer powder of the present invention for processing in a lamination process that selectively melts regions of each layer comprises at least one nylon-11.

For example, the powder of the present invention is obtained through the process described in DE 29 06 647 B1 or DE 197 08 146, but uses nylon-11 pellets as starting material. The polyamide is dissolved in ethanol and crystallized under certain conditions. This gives a powder which is different from the ground powder and has a relatively round grain. If appropriate, the material is carefully sifted and further sorted or cold milled. Those skilled in the art can easily establish conditions through preliminary experiments.

Surprisingly, it has been found that with nylon-11 the advantageous properties described in DE 197 47 309, ie high melt enthalpy, can be achieved even more advantageously for polyamide powders. Low BET specific surface areas can also be obtained along with low intermediate particle diameters.

Unlike DE 197 47 309 A1, a high remelting temperature is also advantageous because the high melting point of the first precipitated nylon-11 powder is maintained and secondly the recyclability of the material is significantly improved; At high recrystallization temperatures, powders that do not melt during the manufacturing process can be reused in a more favorable ratio with the initial material without adversely affecting the surface properties.

The polymer powders of the invention therefore have a melt enthalpy of at least 125 J / g and a recrystallization temperature of at least 148 ° C, preferably at least 130 J / g of melting enthalpy and a recrystallization temperature of at least 150 ° C, and particularly preferably measured by DSC. Melt enthalpy of 130 J / g or more and a recrystallization temperature of 151 ° C or more. The BET surface area of the nylon-11 of the present invention is less than 6 m ² / g, preferably less than 5 m ² / g, particularly preferably less than 4 m ² / g, the median grain diameter is preferably 40 μm to 120 Μm, more preferably 45 μm to 100 μm, particularly preferably 50 μm to 70 μm.

Various parameters can be determined by DSC (differential scanning calorimetry) according to DIN 53765, or AN-SAA 0663. Measurements were made using Perkin Elmer DSC 7 with nitrogen and a heating rate and cooling rate of 20 K / min as flushing gas. The measurement range was -90 to + 250 ° C.

The solution viscosity according to DIN 53727 of the polyamide powder solution of the invention in m-cresol at 0.5% concentration is preferably from 1.4 to 2.1, particularly preferably from 1.5 to 1.9, very particularly preferably from 1.6 to 1.7.

Polyamides can be unregulated, partially regulated, or regulated. Modulation may be applied to amino or acid end groups and may be mono-, di- or polyfunctional. Examples of suitable regulators are alcohols, amines, esters, or carboxylic acids. Mono-, di-, or polyamines or -carboxylic acids can be used as modifiers. It is preferred to use uncontrolled or amine-controlled materials, which during the manufacturing process provide a good flow of molten particles and also provide good mechanical properties to the finished component.

Pellets used as starting materials for processing to obtain the powders of the invention are commercially available, for example, from Elf Atochem (Rilsan, Nylon-11), France. An example of a material suitable for use is lrylic acid BMNO TL with a relative solution viscosity of 1.61.

The polymer powders of the invention may also comprise auxiliaries and / or fillers and / or other organic or inorganic pigments. Examples of such adjuvants may be powder-flow aids, for example precipitated and / or fumed silica. Examples of precipitated silica are available from Degussa AG under the trade name Aerosil having various specifications. The polymer powder of the present invention preferably comprises less than 3% by weight, more preferably 0.001% to 2% by weight, and very preferably 0.05 to 1% by weight, based on the total amount of polymer present. . For example, the filler may be glass particles, metal particles, or ceramic particles, such as glass beads, steel shots, or granulated metals, or pigments of other materials, such as transition metal oxides. For example, the pigment may be rutile (preferably) or anata based titanium dioxide, or carbon black particles.

The median particle size of the filler particles is preferably about the same or smaller than the median particle size of the polyamide particles. Preferably the median particle size d ₅₀ of this amount in excess of the median particle size d ₅₀ of the polyamide up to 20%, preferably not more than 15%, very preferably more than 5% of the filler. Particular limiting factors of particle size are the total height and the respective layer thicknesses that are acceptable in a rapid build / high speed manufacturing system.

The polymer powders of the invention are preferably less than 75% by weight, preferably 0.001 to 70% by weight, particularly preferably 0.05 to 50% by weight, very particularly preferably 0.5 to%, based on the total amount of polyamides present. 25 wt% filler.

If the maximum limits mentioned for the auxiliaries and / or fillers are exceeded, depending on the fillers or auxiliaries used, the mechanical properties of the moldings produced using the polymer powders may be markedly damaged. It is also possible to mix conventional polymer powders with the polymer powders of the present invention. In this way, polymer powders having various combinations of surface properties can be prepared. The process for preparing the mixture can be found for example in DE 34 41 708.

In order to improve the melt flow during the production of the moldings, flow promoters, for example metal soaps, preferably alkali metal or alkaline earth metal salts of base alkanonocarboxylic acids or dimer acids are added to the precipitated polyamide powder. Can be. Metal soap particles may be incorporated into the polymer particles or a mixture of fine metal soap particles and polymer particles may be used.

The amount of the metal soap used is 0.01 to 30% by weight, preferably 0.5 to 15% by weight, based on the total amount of polyamide present in the powder. Preferred metal soaps used are the sodium or calcium salts of the base alkanonocarboxylic acids or dimer acids. Examples of commercially available products are Clariant's Licomont NaV 101 or Licomont CaV 102.

In order to improve processability or to further modify the polymer powder, inorganic pigments, stabilizers, for example phenols, in particular sterically hindered phenols, flow promoters and powder-flow aids, eg composed of other materials, for example transition metal oxides For example fumed silica, or other filler particles may be added. Based on the total weight of the polymer in the polymer powder, the amount of said substance added to the polymer preferably depends on the concentrations mentioned for the fillers and / or auxiliaries of the polymer powders of the invention.

  The present invention is also prepared through the polycondensation of at least one nylon-11, preferably ω-amino-undecanoic acid, in which the regions of each layer are selectively melted and the melt enthalpy is at least 125 J / g and the recrystallization temperature is at least 148 ° C. Provided are methods for producing moldings through a lamination process in which the polymer powders of the present invention comprising nylon-11 are used.

Energy is injected through electromagnetic waves and selectivity can be achieved, for example, by means of a mask, by the application of an inhibitor, absorbent, or susceptor, or by means of intensive irradiation, for example by means of a laser. The electromagnetic wave comprises a range of 100 nm to 10 cm, preferably 400 nm to 10600 nm, or 800 nm to 1060 nm. The source of radiation can be, for example, a microwave generator, a suitable laser, a radiant heater, or a lamp, or a combination thereof. When all the layers are cooled, the moldings of the present invention can be removed.

The following examples of the process are provided for illustration and are not intended to limit the invention.

The laser sintering process is well-known and based on the selective sintering of the polymer particles, and the layer of polymer particles is briefly exposed to the laser light, causing bonding between the polymer particles exposed to the laser light. Three-dimensional objects are produced by sequential sintering of layers of polymer particles. Details regarding the selective laser sintering process are found, for example, in US Pat. No. 6,136,948 and WO 96/06881.

Another process with good suitability is the SIB process described in WO 01/38061, or the process described in EP 1 015 214. All of the above processes melt the powder by infrared heating the entire surface. The selectivity of the melting is achieved through the application of an inhibitor in the first process and through a mask in the second process. DE 103 11 438 describes another process. Here, the energy required for the melting process is introduced through the microwave generator, and selectivity is achieved through the application of susceptors.

The moldings of the present invention made through a lamination process in which the zones are selectively melted can be subjected to polycondensation of at least one nylon-11, preferably ω-aminoundecanoic acid with a melt enthalpy of at least 125 J / g and a recrystallization temperature of at least 148 ° C. Nylon-11 prepared through.

The moldings may also comprise fillers and / or auxiliaries (data for polymer powders are similarly applied), for example heat stabilizers such as sterically hindered phenol derivatives. Examples of fillers may be glass particles, ceramic particles, or other metal particles, such as iron shots, or suitable hollow beads. The moldings of the invention preferably comprise glass particles, very preferably glass beads. The moldings of the present invention preferably comprise less than 3% by weight, preferably 0.001% to 2% by weight, and particularly preferably 0.05% to 1% by weight, based on the total amount of polymer present. . The moldings of the invention are likewise preferably less than 75% by weight, preferably 0.001% to 70% by weight, particularly preferably 0.05% to 50% by weight, very particularly preferably based on the total amount of polymer present Comprises 0.5% to 25% by weight of filler.

The following examples are intended to describe the polymer powders of the present invention and their use without limiting the invention to the examples.

The measured laser scattering values were obtained using the Malvern Mastersizer S, version 2.18.

Comparative Example 1: Reprecipitation of Nylon-12 (PA 12) (Not Inventive)

3 m ³ stirred tank was prepared by hydrolytic polymerization and prepared with 400 kg of unregulated PA 12 having a relative solution viscosity of 1.62 and a COOH end group content of 75 mmol / kg and NH ₂ end group content of 69 mmol / kg. d = 160 cm) and heated to 145 ° C. with 2500 l of ethanol denatured to 2-butanone and 1% water content in 5 hours and maintained this temperature for 1 hour with stirring (blade stirrer, d = 80 cm , Rotational speed = 49 rpm). The ethanol was subsequently distilled off while the jacket temperature was lowered to 124 ° C. and at the same stirrer rotation rate, the internal temperature was brought to 125 ° C. using a cooling rate of 25 K / h. Thereafter, using the same cooling rate, the jacket temperature was kept 2 K to 3 K lower than the internal temperature. The internal temperature was brought to 117 ° C. at the same cooling rate and then held constant for 60 minutes. Subsequently, while further distilling off the material, the internal temperature was brought to 111 ° C. at a cooling rate of 40 K / h. Precipitation started at this temperature and was detectable through heat generation. The distillation rate was increased to maintain the internal temperature no higher than 111.3 ° C. After 25 minutes, the internal temperature had dropped, indicating the end of the precipitation process. After further removal of material by distillation and cooling by jacket, the temperature of the suspension was brought to 45 ° C., and then the suspension was transferred to a paddle dryer. Ethanol was distilled from the mixture at 70 ° C./400 mbar until the internal temperature reached the jacket temperature, and then the residue was further dried at 20 mbar / 86 ° C. for 3 hours.

This gave precipitated PA 12 with a median grain diameter of 55 μm. Bulk density was 435 g / l.

Powders composed of PA 11 were prepared according to methods analogous to those set forth in Example 1, or according to DE 197 08 146.

Comparative Example 2: Cold Milled Powder Based on PA 11 (Not Inventive)

The PA 11 pellets of Example 1 having a relative solution viscosity of 1.61 and a COOH end group content of 125 mmol / kg and an NH ₂ end group content of 9 mmol / kg were milled in a pinned disk mill at −35 ° C. to have the following characteristics: A powder was obtained:

D (10%) = 34 μm D (50%) = 88 μm D (90%) = 136 μm

BET = 0.34 m ² / g Bulk Density 476 g / l

Example 3 Reprecipitation of Carboxy-terminated Nylon-11 (PA 11) (Invention)

Carboxy-terminated, prepared via polycondensation of 50 kg of ω-aminoundecanoic acid in the presence of 450 g of dodecanediic acid and having a relative solution viscosity of 1.61 and a COOH end group content of 125 mmol / kg and an NH ₂ end group content of 9 mmol / kg 4.0 kg of PA 11 were heated to 152 ° C. with 20 l of ethanol denatured to 2-butanone and 1% water content within 5 hours in a 40 l stirred tank (D = 40 cm) and stirred for 1 hour while stirring. (Blade stirrer, d = 30 cm, rotation speed = 89 rpm). The jacket temperature was then lowered to 120 ° C. and at the same stirrer rotation rate, the internal temperature was brought to 125 ° C. using a cooling rate of 25 K / h. Thereafter, using the same cooling rate, the jacket temperature was kept 2 K to 3 K lower than the internal temperature. The internal temperature was brought to 112 ° C. at the same cooling rate and then held constant for 60 minutes. Precipitation started at this temperature and was detectable through heat generation. After 25 minutes, the internal temperature had dropped, indicating the end of the precipitation process. After stirring was continued for an additional 35 minutes at this temperature, the mixture was cooled to 75 ° C. and then the suspension was transferred to a paddle dryer. Ethanol was distilled from the mixture at 70 ° C./400 mbar until the internal temperature reached the jacket temperature, and then the residue was further dried at 20 bar / 86 ° C. for 3 hours.

Bulk Density 481 g / l BET: 1.63 m ² / g

D (10%) = 75 μm D (50%) = 127 μm D (90%) = 200 μm

Example 4 Reprecipitation of Amine-terminated Nylon-11 (PA 11) (Invention)

Prepared via the polymerization of 50 kg of ω-aminoundecanoic acid in the presence of 250 g of 4,4'-diaminocyclohexylmethane (PACM, isomer mixture) and having a relative solution viscosity of 1.82 and a COOH end group content of 15 mmol / kg and NH ₂ 4.0 kg of diamine-terminated PA 11 having an end group content of 87 mmol / kg were 152 ° C. with 20 l of ethanol modified to 2-butanone and 1% water content in a 40 l stirred tank (D = 40 cm) within 5 hours. Heated to and maintained at that temperature for 1 hour with stirring (blade stirrer, d = 30 cm, rotation speed = 89 rpm). The jacket temperature was then lowered to 120 ° C. and at the same stirrer rotation rate, the internal temperature was brought to 125 ° C. using a cooling rate of 25 K / h. Thereafter, using the same cooling rate, the jacket temperature was kept 2 K to 3 K lower than the internal temperature. The internal temperature was brought to 112 ° C. at the same cooling rate and then kept constant within ± 0.5 ° C. for 60 minutes. Precipitation started at this temperature and was detectable through heat generation. After 30 minutes, the internal temperature had dropped, indicating the end of the precipitation process. After continuing stirring for an additional 30 minutes at this temperature, the mixture was cooled to 75 ° C. and then the suspension was transferred to a paddle dryer. After ethanol was distilled from the mixture at 70 ° C./400 mbar, the residue was further dried at 20 bar / 84 ° C. for 3 hours.

Bulk Density 486 g / l BET: 0.31 m ² / g

D (10%) = 66 μm D (50%) = 110 μm D (90%) = 162 μm

Examples 5 and 6: Reprecipitation of Amine-terminated Nylon-11 (PA 11) (Invention)

Example 3 was repeated at a stirring rotation speed of 120 rpm (Example 5 of the present invention) or 150 rpm (Example 6 of the present invention) to obtain precipitated powder as follows.

Example 5 of the invention

Bulk Density 391 g / l BET: 4.80 m ² / g

D (10%) = 44 μm D (50%) = 59 μm D (90%) = 84 μm

Example 6 of the invention

Bulk Density 366 g / l BET: 4.70 m ² / g

D (10%) = 28 μm D (50%) = 37 μm D (90%) = 51 μm

Example 7 of the Invention Two-Step Reprecipitation of Amine-terminated Nylon-11 (Invention)

4.0 kg of the diamine-terminated PA 11 of Example 3 of the present invention were heated to 152 ° C. in 20 l stirred tank (D = 40 cm) with 20 l of ethanol modified to 2-butanone and 1% water content in 5 hours. And maintained at this temperature for 1 hour with stirring (blade stirrer, d = 30 cm, rotation speed = 120 rpm). The jacket temperature was then lowered to 120 ° C. and at the same stirrer rotation rate, the internal temperature was brought to 125 ° C. using a cooling rate of 25 K / h. The internal temperature was then kept constant for 30 minutes. The internal temperature was brought to 112 ° C. at the same cooling rate and then held constant for 60 minutes. Precipitation started at this temperature and was detectable through heat generation. After 35 minutes, the internal temperature had dropped, indicating the end of the precipitation process. After stirring was continued for an additional 25 minutes at this temperature, the mixture was cooled to 75 ° C. and then the suspension was transferred to a paddle dryer. After ethanol was distilled from the mixture at 70 ° C./400 mbar, the residue was further dried at 20 bar / 85 ° C. for 3 hours.

Bulk Density 483 g / l BET: 0.28 m ² / g

D (10%) = 42 μm D (50%) = 82 μm D (90%) = 127 μm

Example 8 Reprecipitation of Unregulated Nylon-11 (PA 11) (Invention)

Unregulated PA 11, prepared via polycondensation of 50 kg ω-aminoundecanoic acid in the absence of end group regulator and having a relative solution viscosity of 1.59 and a COOH end group content of 69 mmol / kg and an NH ₂ end group content of 66 mmol / kg 4.0 kg were dissolved at 152 ° C. with 20 l of ethanol modified to 2-butanone and 1% water content under the conditions of Example 2 of the present invention and precipitated at 112.5 ° C. After ethanol was distilled off at 70 ° C./400 mbar, the residue was dried for 3 hours in the manner described at 20 bar / 85 ° C.

Bulk Density 487 g / l BET: 1.51 m ² / g

D (10%) = 71 μm D (50%) = 122 μm D (90%) = 191 μm

BET surface area [m ² / g] Medium grain diameter [μm] Melting point [℃] Melt enthalpy y [J / g] Recrystallization temperature [℃] Comparative Example 1 (Not Inventive) 6.3 55 186 112 141 Comparative Example 2 (Not Invention) 0.34 88 191 87 157 Embodiment 3 of the present invention 1.63 127 191 132 150 Embodiment 4 of the present invention 0.31 110 191 139 154 Embodiment 5 of the present invention 4.8 59 193 129 151 Embodiment 6 of the present invention 4.7 37 192 126 151 Example 7 of the present invention 0.28 82 192 133 152 Embodiment 8 of the present invention 1.51 122 191 136 152

The examples clearly showed that the polyamide powders of the present invention had significantly higher melt enthalpy and also higher recrystallization temperatures than conventional polymer powders. Therefore, because less powder adheres to the molten area, components with higher surface quality can be produced. Along with the fine medium grain diameter, the BET surface area is also low. Therefore, the reproducibility of the powders of the present invention is similarly improved compared to conventional polyamide powders.

Claims (40)

A layer-by-layer that selectively melts the regions of each micropowder layer through the input of electromagnetic energy, comprising at least one nylon-11 having a melt enthalpy of at least 125 J / g and a recrystallization temperature of at least 148 ° C. ) Polymer powder for use in the process. Polymers for use in lamination processes that selectively melt regions of each micropowder layer through the input of electromagnetic energy, comprising at least one nylon-11 having a melt enthalpy of 130 J / g or more and a recrystallization temperature of 150 ° C. or more. powder. Input of electromagnetic energy, comprising at least one nylon-11 having a melt enthalpy of at least 125 J / g and a recrystallization temperature of at least 148 ° C., and having a BET surface area of less than 6 m ² / g and a median grain diameter of 40 μm to 120 μm. A polymer powder for use in a lamination process that selectively melts the region of each micropowder layer through. Input of electromagnetic energy, comprising at least one nylon-11 having a melt enthalpy of at least 125 J / g and a recrystallization temperature of at least 148 ° C., and having a BET surface area of less than 5 m ² / g and a medium grain diameter of 45 μm to 100 μm. A polymer powder for use in a lamination process that selectively melts the region of each micropowder layer through. Input of electromagnetic energy, comprising at least one nylon-11 having a melt enthalpy of at least 125 J / g and a recrystallization temperature of at least 148 ° C. and having a BET surface area of less than 5 m ² / g and a median grain diameter of 50 μm to 70 μm. A polymer powder for use in a lamination process that selectively melts the region of each micropowder layer through. At least one nylon-11 for use in a lamination process that selectively melts the regions of each micropowder layer through the application of electromagnetic energy and achieves selectivity through the application of susceptors or inhibitors or absorbers, or masks Polymer powder comprising a. A polymer powder comprising at least one nylon-11 for use in a lamination process that selectively melts regions of each micropowder layer through the injection of electromagnetic energy and achieves selectivity through the concentrated injection of a laser beam. The polymer powder according to any one of claims 1 to 3, comprising at least one nylon-11 prepared via polycondensation of ω-aminoundecanoic acid. The polymer powder according to claim 1, wherein the polyamide powder is obtained through precipitated grain clarification. 10. The polymer powder of claim 1, wherein the polymer powder comprises unregulated nylon-11. 11. 10. The polymer powder of claim 1, comprising controlled nylon-11. 11. 10. The polymer powder of claim 1, comprising partially controlled nylon-11. 11. The polymer powder of claim 1, wherein the modulator used comprises a mono-, di-, or polyamine. The polymer powder according to any one of claims 1 to 12, wherein the regulator used comprises a mono-, di-, or polycarboxylic acid. The polymer powder according to any one of claims 1 to 11, wherein the polyamide powder has a solution viscosity of 1.4 to 2.1. 12. The polymer powder of claim 1, wherein the polyamide powder has a solution viscosity of 1.5 to 1.9. The polymer powder according to any one of claims 1 to 11, wherein the polyamide powder has a solution viscosity of 1.6 to 1.7. 18. The polymer powder of claim 1, comprising an adjuvant and / or a filler. 19. The polymer powder of claim 18 comprising a powder-flow aid as an adjuvant. The polymer powder of claim 18 comprising glass particles as filler. The polymer powder of claim 18 comprising metal soap as an adjuvant. 22. Polymer powder according to any one of the preceding claims, comprising an organic and / or inorganic pigment. The polymer powder of claim 22 comprising carbon black. The polymer powder of claim 22 comprising titanium dioxide. Selectively melting the regions of each micropowder layer through the input of electromagnetic energy, comprising using at least one nylon-11 having a melting enthalpy of at least 125 J / g and a recrystallization temperature of at least 148 ° C .; Or application of an absorbent or a lamination process to achieve selectivity through a mask. Selective melting of the area of each micropowder layer through the injection of electromagnetic energy, including the use of at least one nylon-11 having a melting enthalpy of 125 J / g or more and a recrystallization temperature of 148 ° C. or more, and a concentrated injection of the laser beam. Method of producing a molding through a lamination process to achieve selectivity through. 25. Process for the production of moldings via selective laser sintering of the polymer powder according to any one of claims 1 to 24. 28. A molding made through the process according to any one of claims 25 to 27, comprising at least one nylon-11 having a melt enthalpy of at least 125 J / g and a recrystallization temperature of at least 148 ° C. 29. The molding according to any one of claims 1 to 28, comprising at least one nylon-11 prepared via polycondensation of ω-aminoundecanoic acid. 30. The molding according to any one of claims 1 to 29, comprising a polyamide powder obtained through precipitated crystallization. 31. The molding according to any one of claims 1 to 30, comprising nylon-11 having a solution viscosity of 1.4 to 2.1. 32. The molding according to any one of claims 1 to 31 comprising nylon-11 having a solution viscosity of 1.5 to 1.9. 33. The molding according to any one of the preceding claims comprising nylon-11 having a solution viscosity of 1.6 to 1.7. 34. The molding according to any one of claims 1 to 33, comprising an adjuvant and / or a filler. 35. The molding according to any one of claims 1 to 34, comprising a powder-flow aid as an adjuvant. 36. The molding according to any one of claims 1 to 35, comprising glass particles as filler. 37. The molding according to any one of claims 1 to 36, comprising metal soap as an adjuvant. 38. The molding according to any one of claims 1 to 37, comprising an organic and / or inorganic pigment. 39. The molding according to any one of claims 1 to 38 comprising carbon black. 40. The molding according to any one of claims 1 to 39 comprising titanium dioxide.