Polymer powder with polyamide, use in a shaping process, and moldings produced from this 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 be achieved, 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 production of moldings via a layer-by-layer process comprising:
(1) selectively applying at least one component selected from the group consisting of a susceptor, an inhibitor, an absorber, and at least one mask to a respective pulverulent layer which comprises a powder comprising at least one polyamide prepared by a method comprising:
polycondensation of at least one lactam selected from the group consisting of enantholactam and caprylolactam without conducting an extraction of a residual monomer during the preparation, wherein a content of the residual monomer in the at least one polyamide is less than 1%; and
(2) melting regions of the selective application from (1) by electromagnetic energy.
2. The process according to claim 1 , which comprises polyamide powder which has been obtained via precipitative crystallization.
3. The process according to claim 1 , which comprises polyamide powder which has been obtained via grinding.
4. The process according to claim 1 , which comprises a polyamide with a solution viscosity of from 1.4 to 2.1.
5. The process according to claim 4 , which comprises a polyamide with a solution viscosity of from 1.5 to 1.9.
6. The process according to claim 5 , which comprises a polyamide with a solution viscosity of from 1.6 to 1.7.
7. The process according to claim 1 , which further comprises auxiliaries and/or filler.
8. The process according to claim 7 , which comprises powder-flow aids as the auxiliaries.
9. The process according to claim 7 , which comprises glass particles as the filler.
10. The process according to claim 7 , which comprises metal soaps as the auxiliaries.
11. The process according to claim 1 , which comprises organic and/or inorganic pigments.
12. The process according to claim 11 , which comprises carbon black.
13. The process according to claim 11 , which comprises titanium dioxide.
14. The process according to claim 1 , wherein said lactam is enantholactam.
15. The process according to claim 1 , wherein said lactam is caprylolactam.
16. The process according to claim 1 , wherein said powder further comprises at least one additional polyamide prepared by polycondensation of a lactam selected from the group consisting of pelargolactam and caprinolactam.
17. A process for production of moldings via a layer-by-layer process comprising:
(1) polycondensing at least one lactam selected from the group consisting of enantholactam and caprylolactam without conducting an extraction of a residual monomer during the preparation, thereby obtaining at least one polyamide, wherein a content of the residual monomer in the at least one polyamide is less than 1%;
(2) selectively applying at least one component selected from the group consisting of a susceptor, an inhibitor, an absorber, and at least one mask to a respective pulverulent layer which comprises a powder comprising the at least one polyamide prepared of (1); and
(3) melting regions of the selective application from (1) by electromagnetic energy.