Methods and compositions for forming three-dimensional objects by additive fabrication
A method of forming a three-dimensional object comprises the steps of forming a layer of a particulate composition, selectively depositing a liquid composition onto the layer of the particulate composition in accordance with computer data corresponding to the shape of at least a portion of a three-dimensional object, initiating polymerization, and repeating the steps a plurality of times to form a three-dimensional object. The particulate composition comprises a plurality of first particles that comprise a resin component comprising a first resin, the first resin comprising a first resin polymerizable group, the first resin polymerizable group comprising a carbon-carbon double bond directly attached to an electron withdrawing group, a thermal radical initiator dispersed or dissolved in the resin component, and a retardant dispersed or dissolved in the resin component.
1. A kit of materials for forming an object by an additive fabrication process comprising:
a. a particulate composition comprising a plurality of first particles that comprise:
i. a resin component comprising a first resin, the first resin comprising a first resin polymerizable group, the first resin polymerizable group comprising a carbon-carbon double bond directly attached to an electron withdrawing group,
ii. a thermal radical initiator having an activation temperature of greater than 40° C. dispersed or dissolved in the resin component, and
iii. a retardant dispersed or dissolved in the resin component; and
b. a liquid composition comprising:
i. a first liquid polymerizable component, the first liquid polymerizable component comprising a first liquid polymerizable group, the first liquid polymerizable group comprising a carbon-carbon double bond that is able to (co)polymerize with the first resin polymerizable group.
2. The kit of materials of claim 1 , wherein the activation temperature of the thermal radical initiator is greater than 50° C.
3. The kit of materials of claim 2 , wherein the kit further comprises an accelerator for the thermal radical initiator.
4. The kit of materials of claim 3 , wherein the accelerator comprises a transition metal catalyst.
5. The kit of materials of claim 4 , wherein the transition metal catalyst comprises a transition metal salt or transition metal complex.
6. The kit of materials of claim 5 , wherein the transition metal catalyst comprises Co, Mn, Cu, Fe, V, or Ti.
7. The kit of materials of claim 3 , wherein the liquid composition further comprises a plasticizer.
8. The kit of materials of claim 7 , wherein the plasticizer comprises a polyalkylene ether.
9. The kit of materials of claim 3 , wherein the plurality of first particles further comprise a non-reactive polymer having a number average molecular weight of 1000 to 20,000 g/mol.
10. The kit of materials of claim 3 , wherein the accelerator comprises an aromatic tertiary amine.
11. The kit of materials of claim 10 , wherein the aromatic tertiary amine comprises diisopropanol-p-toluidine.
12. The kit of materials of claim 3 , wherein the retardant comprises a phenolic compound.
13. The kit of materials of claim 12 , wherein the retardant comprises 2-methyl hydroquinone or 2-t-butyl hydroquinone.
14. The kit of materials of claim 2 , wherein the resin component further comprises a second resin.
15. The kit of materials of claim 14 , wherein the first resin comprises a polyester (meth)acrylate, the first resin polymerizable group comprises a (meth)acrylate, and the first liquid polymerizable group comprises a (meth)acrylate.
16. The kit of materials of claim 14 , wherein the first resin comprises an unsaturated polyester, and the first liquid polymerizable group is a vinyl ether.
17. The kit of materials of claim 14 , wherein the first resin polymerizable group comprises an acrylate, the first liquid polymerizable group comprises a vinyl ether, and the second resin comprises a second resin polymerizable group.
18. The kit of materials of claim 17 , wherein the first resin is not able to copolymerize with the second resin, and wherein the second resin polymerizable group comprises an epoxy.
19. The kit of materials of claim 18 , wherein the first resin polymerizable group is a (meth)acrylate and the second resin polymerizable group comprises an epoxy or a fumarate.
20. The kit of materials of claim 18 , wherein the second liquid polymerizable group comprises an acrylate, methacrylate, maleate, or itaconate.