Optically active build materials for 3D printing
Build materials for 3D printing applications are described herein which, in some embodiments, comprise a dye component operable to alter spectral characteristics of the printed part over the course of the build cycle. In some embodiments, for example, the dye component can provide desirable light penetration depth during article printing and sufficient optical clarity during final light curing processes.
1. A polymerizable liquid comprising:
a monomeric photocurable material, an oligomeric photocurable material, or mixtures thereof;
a photoinitiator component; and
a dye component,
wherein the monomeric photocurable material comprises isocyanurate polyacrylate;
wherein the monomeric photocurable material is present in an amount of 10-90 wt. %, based on total weight of the polymerizable liquid;
wherein the oligomeric photocurable material is present in an amount of 10-70 wt. %, based on total weight of the polymerizable liquid;
wherein the photoinitiator component is present in an amount of up to 5 wt. %, based on the total weight of the polymerizable liquid;
wherein the dye component is present in an amount of 0.0005-0.02 wt. %, based on the total weight of the polymerizable liquid;
wherein the dye component fades during post photocuring of the polymerizable liquid to provide an article that when cured satisfies the relation
T
a
T
c
≥
0.75
where T a and T c are maximum transmittance values from 400-500 nm for the article and a dyeless control article, respectively.
2. The polymerizable liquid of claim 1 , wherein
T
a
T
c
≥
0
.
8
.
3. The polymerizable liquid of claim 1 , wherein
T
a
T
c
≥
0
.
9
.
4. The polymerizable liquid of claim 1 , wherein the dye component comprises a dye of formula I:
wherein R 1 -R 8 are independently selected from the group consisting or hydrogen, alkyl, and —OR 9 wherein R 9 is selected from the group consisting of hydrogen, alkyl, aryl, alkyl-aryl and aryl-alkyl.
5. The polymerizable liquid of claim 1 , wherein the isocyanurate polyacrylate is present in an amount of 20-90 wt. %, based on total weight of the polymerizable liquid.
6. The polymerizable liquid of claim 1 , wherein the monomeric photocurable component further comprises a polyallylated heterocycle.
7. The polymerizable liquid of claim 6 , wherein the polyallylated heterocycle is a polyallyl isocyanurate.
8. The polymerizable liquid of claim 7 , wherein a ratio of the isocyanurate polyacrylate to the polyallyl isocyanurate is 1:4 to 4:1.
9. The polymerizable liquid of claim 1 , wherein peak absorption of the dye component is less than 450 nm.
10. A polymerizable liquid comprising:
a monomeric photocurable material, an oligomeric photocurable material, or mixtures thereof;
a photoinitiator component; and
a dye component comprising a dye of formula I:
wherein R 1 -R 8 are independently selected from the group consisting or hydrogen, alkyl, and —OR 9 wherein R 9 is selected from the group consisting of hydrogen, alkyl, aryl, alkyl-aryl and aryl-alkyl,
wherein the monomeric photocurable material comprises isocyanurate polyacrylate:
wherein the monomeric photocurable material is present in an amount of 10-90 wt. %, based on total weight of the polymerizable liquid:
wherein the oligomeric photocurable material is present in an amount of 10-70 wt. %, based on total weight of the polymerizable liquid:
wherein the photoinitiator component is present in an amount of up to 5 wt. %, based on the total weight of the polymerizable liquid; and
wherein the dye component is present in an amount of 0.0005-0.02 wt. %, based on the total weight of the polymerizable liquid.
11. The polymerizable liquid of claim 10 , wherein the isocyanurate polyacrylate is present in an amount of 20-90 wt. %, based on total weight of the polymerizable liquid.
12. The polymerizable liquid of claim 1 having a post light curing heat deflection temperature of at least 200° C.
13. The polymerizable liquid of claim 1 having a post light curing storage modulus of at least 1500 MPa at 200° C.
14. The polymerizable liquid of claim 1 , wherein the monomeric photocurable material comprises a heterocycle comprising two or more unsaturated substituents.
15. The polymerizable liquid of claim 14 , wherein the heterocycle comprising two or more unsaturated substituents is present in an amount of 5-30 weight percent, based on total weight of the polymerizable liquid.
16. The polymerizable liquid of claim 1 , wherein the dye component fades when a green cured article is subjected to additional light curing.
17. The polymerizable liquid of claim 1 , wherein the dye component is a di-keto dye structure.