Polymer powder for 3D printing
The invention is targeted mainly at a polymer powder suitable for 3D printing by sintering, comprising: (a) a polymer composition comprising at least one thermoplastic elastomer; (b) a pigment composition comprising at least one pigment exhibiting an absorbance of the light with a wavelength of 1000 nm, as measured according to the standard ASTM E1790, of less than 50%; and also, if appropriate, (c) one or more fillers or reinforcements; and (d) one or more additional additives. The invention is also targeted at a process for the preparation of said powder and also at the use of said powder for 3D printing by sintering. Finally, it is targeted at the use of a pigment exhibiting an absorbance of the light with a wavelength of 1000 nm, as measured according to the standard ASTM E1790, of less than 50% to improve the definition and/or the mechanical properties of the articles printed by a process of 3D printing by sintering of a thermoplastic elastomer powder.
1 . A polymer powder suitable for three-dimensional (3D) printing by sintering, comprising:
(a) a polymer composition comprising at least one thermoplastic elastomer;
(b) a pigment composition comprising at least one pigment exhibiting an absorbance of the light with wavelengths of the spectrum from 750 to 1250 nm, as measured according to the standard ASTM E1790, of less than 35%;
(c) optionally, one or more fillers or reinforcements; and
(d) optionally, one or more additional additives,
wherein the pigment has a volume-median diameter Dv50 less than that of the polymer powder,
wherein the polymer powder comprises from 0.3% by weight to 2% by weight of the pigment composition.
2 . The powder as claimed in claim 1 , wherein the polymer powder exhibits a Dv50 diameter, as measured according to the standard ISO 9276-Parts 1 to 6, of 40 to 150 μm.
3 . The powder as claimed in claim 1 , wherein the thermoplastic elastomer is selected from the group consisting of a copolymer having polystyrene and polybutadiene blocks (SBS), a copolymer having polystyrene and polyisoprene blocks (SIS), a copolymer having polystyrene and poly(ethylene/butylene) blocks (SEBS), a copolymer having isocyanate and ether or ester blocks (TPU), a copolymer having polyester and polyester or polyether blocks (COPE), a copolymer having polyamide and polyether blocks (PEBA), and mixtures and alloys thereof.
4 . The powder as claimed in claim 3 , wherein the thermoplastic elastomer is selected from PEBA.
5 . The powder as claimed in claim 1 , wherein the thermoplastic elastomer is selected from the group consisting of thermoplastic polyolefin (TPO), a copolymer of butadiene and acrylonitrile, vulcanized or not, dispersed in a polypropylene (PP/NBR), a chlorinated polyethylene dispersed in a polyolefin (PO/CPE-VD), an ethylene vinylidene acetate dispersed in vinylidene chloride (EVA/VC), a copolymer of butadiene and acrylonitrile, vulcanized or not, dispersed in a polyvinyl chloride (PVC/NBR), and mixtures thereof.
6 . The powder as claimed in claim 1 , wherein the pigment is at least one compound selected form the group consisting of metal oxides, transition metal oxides, and mixtures thereof, mixed oxides, and doped oxides.
7 . The powder as claimed in claim 6 , wherein the pigment is at least one oxide selected from the group consisting of tin, magnesium, copper, zinc, iron, manganese, cobalt, nickel, aluminum, antimony, chromium, titanium, or silicon oxides, and mixtures thereof, mixed oxides, and doped oxides.
8 . A three-dimensional (3D) printing process comprising sintering the polymer powder as claimed in claim 1 .
9 . An article obtained by three-dimensional (3D) printing by sintering of the polymer powder as defined in claim 1 .