Polymer powder comprising polyamide use thereof in a moulding method and moulded body made from said polymer powder
View Patent ↗The present invention relates to a polymer powder which comprises polyamide, and to the use of this powder for shaping processes, and also to moldings produced from this polymer powder. The shaping processes are layer-by-layer processes which use powders, where regions of the respective layer are selectively melted via introduction of electromagnetic energy. The selectivity may—with no intention of restricting the invention thereto—be achieved via masks, application of inhibitors, of absorbers, or of susceptors, or via focusing of the energy introduced. After cooling, the regions then solidified can be removed in the form of moldings from the powder bed.
1. A process for the production of moldings via a layer-by-layer process in which regions of respective polymer pulverulent layers are selectively melted via introduction of electromagnetic energy,
which comprises
using a powder which comprises at least one homopolyamide prepared via polycondensation of diamines and dicarboxylic acids, wherein the homopolyamide has an enthalpy of fusion of at least 125 J/g and a recrystallization temperature of at least 148° C.
2. The process as claimed in claim 1 ,
wherein the homopolyamide, prepared via polycondensation of diamines and dicarboxylic acids, has an enthalpy of fusion of at least 130 J/g and a recrystallization temperature of at least 150° C.
3. The process as claimed in claim 1 ,
wherein the homopolyamide, prepared via polycondensation of diamines and dicarboxylic acids, has an enthalpy of fusion of at least 130 J/g and with a recrystallization temperature of at least 155° C.
4. The process as claimed in claim 1 ,
wherein,
during the process, regions of the pulverulent layer are selectively melted via introduction of electromagnetic energy, this selectivity being achieved via the application of susceptors, of inhibitors, or of absorbers, or via masks.
5. The process as claimed in claim 1 ,
wherein,
during the process, regions of the pulverulent layer are selectively melted via introduction of electromagnetic energy, this selectivity being achieved via the focusing of a laser beam.
6. The process as claimed in claim 1 ,
wherein at least one homopolyamide is prepared via polycondensation of a diamine selected from the group consisting of butanediamine, hexamethylenediamine, decane-diamine, and 1,12-diaminododecane, and of a dicarboxylic acid selected from the group consisting of adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, pentadecanedioic acid, and octadecanedioic acid.
7. The process as claimed in claim 1 ,
which
comprises at least one homopolyamide prepared via polycondensation of decanediamine and sebacic acid (PA1010).
8. The process as claimed in claim 1 ,
wherein at least one homopolyamide is prepared via polycondensation of decanediamine and dodecanedioic acid.
9. The process as claimed in claim 1 ,
which
comprises at least one homopolyamide prepared via polycondensation of hexamethylenediamine and dodecanedioic acid (PA612).
10. The process as claimed in claim 1 ,
which
comprises at least one homopolyamide prepared via polycondensation of hexamethylenediamine and sebacic acid (PA610).
11. The process as claimed in claim 1 ,
which
comprises at least one homopolyamide prepared via polycondensation of 1,12-diaminododecane and dodecanedioic acid (PA1212).
12. The process as claimed in claim 1 ,
which
comprises at least one homopolyamide prepared via polycondensation of hexamethylenediamine and brassylic acid (PA613).
13. The process as claimed in claim 1 ,
wherein
the polyamide powder has been obtained via precipitative crystallization.
14. The process as claimed in claim 1 ,
wherein
the polyamide powder has an enthalpy of fusion of at least 130 J/g.
15. The process as claimed in claim 1 ,
wherein
the polyamide powder has an enthalpy of fusion of at least 135 J/g.
16. The process as claimed in claim 1 ,
wherein
the polyamide powder has an enthalpy of fusion of at least 140 J/g.
17. The process as claimed in claim 1 ,
wherein
the polyamide powder has a recrystallization temperature of at least 150° C.
18. The process as claimed in claim 1 ,
wherein
the polyamide powder has a recrystallization temperature of at least 155° C.
19. The process as claimed in claim 1 ,
wherein
the polyamide powder has a solution viscosity of from 1.4 to 2.1.
20. The process as claimed in claim 1 ,
wherein
the polyamide powder has a solution viscosity of from 1.5 to 1.9.
21. The process as claimed in claim 1 ,
wherein
the polyamide powder has a solution viscosity of from 1.6 to 1.7.
22. The process as claimed in claim 1 ,
wherein
the polyamide powder has a median particle size of from 10 to 250 μm.
23. The process as claimed in claim 1 ,
wherein
the polyamide powder has a median particle size of from 45 to 150 μm.
24. The process as claimed in claim 1 ,
wherein
the polyamide powder has a median particle size of from 50 to 125 μm.
25. The process as claimed in claim 1 , wherein one or more auxiliaries and/or one or more fillers are used.
26. The process as claimed in claim 1 , further comprising precipitated and/or fumed silica.
27. The process as claimed in claim 1 , further comprising
glass particles.
28. The process as claimed in claim 1 , wherein further comprising
metal soaps.
29. The process as claimed in claim 1 , wherein
organic and/or inorganic pigments are used.
30. The process as claimed in claim 1 , wherein
carbon black is used.
31. The process as claimed in claim 1 , wherein
titanium dioxide is used.