Formulation for 3D printing and a 3D printed article
A flowable liquid formulation for 3D printing is described. The formulation comprises from 0.1 to 25 wt. % radiopaque particles, wherein at least 50% by weight of the particles have a diameter of at most 100 nm. The formulation further comprises monomeric, oligomeric and/or polymeric precursors adapted for polymerization to form a solidified article. Also described is an article ( 100 ) formed by 3D printing, the article ( 100 ) comprising a first 3D printed region ( 110 ) having a first radiopacity and a second 3D printed region ( 120 ) having a second radiopacity, wherein the first radiopacity is greater than the second radiopacity. Also described is a method of forming the article ( 100 ).
1. A flowable liquid formulation for 3D printing a solidified article having a radiopacity of at least 200 HU up to 1200 HU, the flowable liquid formulation comprising:
from 0.1 to 25 wt. % radiopaque particles, wherein at least 50% of the particles have a diameter of at most 100 nm; and
monomeric, oligomeric and/or polymeric precursors adapted for polymerization to form the solidified article;
wherein the flowable liquid formulation comprises from 5 to 80 wt. % oligomeric precursors; and
wherein the dynamic viscosity, measured at 20° C., of the flowable liquid formulation is in a range from 100 to 1000 centipoise.
2. The flowable liquid formulation according to claim 1 comprising from 5 to 10 wt. % radiopaque particle.
3. The flowable liquid formulation according to claim 1 wherein the radiopaque particles comprise ZrO 2 particles, Nb 2 O 5 particles, Ta 2 O 5 particles and/or silver acetate (CH 3 CO 2 Ag) particles.
4. The flowable liquid formulation according to claim 1 comprising from 40 to 80 wt. % monomeric, oligomeric and/or polymeric precursors.
5. The flowable liquid formulation according to claim 1 comprising from 20 to 60 wt. % monomeric precursors.
6. The flowable liquid formulation according to claim 1 comprising at least one of a photoinitiator, a retarder solvent, a filler and a colouring agent.
7. An article formed by 3D printing, the article having a radiopacity of at least 200 HU up to 1200 HU, the article comprising a first 3D printed region having a first radiopacity and a second 3D printed region having a second radiopacity, wherein the first radiopacity is greater than the second radiopacity, wherein the first 3D printed region is obtained by polymerisation of the formulation according to claim 1 .
8. The article according to claim 7 , wherein the artic a calibration standard for a medical radiography apparatus.
9. The article according to claim 7 , wherein the article is a medical device.