Dual cure resins for additive manufacturing
Provided herein is a resin product useful for the production of three-dimensional objects by additive manufacturing, and methods using the same. The resin may include a reactive blocked prepolymer comprising a prepolymer blocked with reactive blocking groups; a polyol; a photoinitiator; and at least one organometallic catalyst. A packaged product useful for the production of three-dimensional objects by additive manufacturing, the product comprising a single container having a single chamber and a resin in the chamber with all components mixed together, is also provided.
1. A resin useful for the production of three-dimensional objects by additive manufacturing, comprising:
(a) a reactive blocked prepolymer comprising a prepolymer blocked with reactive blocking groups;
(b) a polyol;
(c) a photoinitiator;
(d) at least one organometallic catalyst comprising: a metal amidine complex and/or a second compound, wherein the second compound is a metal carboxylate or a carboxylic acid, and/or a third compound wherein the third compound is a metal chelate complex of an acetylacetonate;
(e) optionally, a reactive diluent;
(f) optionally, and
(g) optionally, a pigment or dye.
2. The resin of claim 1 , wherein said prepolymer comprises a polyurethane prepolymer, a polyurea prepolymer, a polyurethane-polyurea copolymer, or a combination thereof.
3. The resin of claim 1 , wherein said reactive blocked prepolymer comprises reactive end groups selected from the group consisting of acrylates, methacrylates, alpha-olefins, N-vinyls, acrylamides, methacrylamides, styrenics, epoxides, thiols, 1,3-dienes, vinyl halides, acrylonitriles, vinyl esters, maleimides, and vinyl ethers.
4. The resin of claim 1 , wherein said reactive blocking groups comprise an amine (meth)acrylate monomer blocking agent.
5. The resin of claim 1 , wherein said reactive blocked prepolymer comprises a (meth)acrylate-blocked prepolymer.
6. The resin of claim 1 , wherein said reactive blocked prepolymer is blocked with a vinyl amide blocking agent.
7. The resin of claim 1 , wherein said reactive blocked prepolymer comprises a vinyl amide blocked polyisocyanate.
8. The resin of claim 7 , wherein said vinyl amide blocked polyisocyanate comprises an N-vinyl formamide blocked polyisocyanate.
9. The resin of claim 1 , wherein said reactive diluent comprises an acrylate, a methacrylate, a styrene, a vinylamide, a vinyl ether, a vinyl ester, polymers containing any one or more of the foregoing, or a combination of two or more of the foregoing.
10. The resin of claim 1 , wherein said polyol is a diol or a triol.
11. The resin of claim 1 , wherein the metal of the metal amidine complex and the metal of the metal carboxylate and/or the metal of the metal acetylacetonate (when present) are not identical.
12. The resin of claim 1 , wherein the metal amidine complex is of the chemical formula metal(amidine) w (carboxylate) 2 , wherein w is an integer from 1 to 4.
13. The resin of claim 1 , wherein the metal of the metal amidine complex, the metal of the metal carboxylate, and the metal of the chelate complex are independently copper, zinc, lithium, sodium, magnesium, barium, potassium, calcium, bismuth, cadmium, aluminum, zirconium, tin, hafnium, titanium, lanthanum, vanadium, niobium, tantalum, tellurium, molybdenum, tungsten, or cesium.
14. The resin of claim 1 , wherein the metal of the metal amidine complex and the metal of the metal carboxylate are independently zinc or bismuth.
15. The resin of claim 1 , wherein the amidine is 1,1,3,3-tetramethyl guanidine or 1-methylimidazole.
16. The resin of claim 1 , wherein the chelate is pentanedione, hexafluoropentanedione or tetramethyloctanedione.
17. The resin of claim 1 , wherein the carboxylate is octoate, neodecanoate, naphthenate, stearate, or oxalate.
18. The resin of claim 1 , wherein the second compound comprises a zinc carboxylate and/or a bismuth carboxylate.
19. A packaged product useful for the production of three-dimensional objects by additive manufacturing, said product comprising a single container having a single chamber and a resin in the chamber, the resin comprising a resin of claim 1 , with all components mixed together.
20. A method of making a three-dimensional object, comprising:
(a) dispensing the resin of claim 1 into an additive manufacturing apparatus;
(b) producing an intermediate object from said resin by photopolymerization; and then
(c) heating and/or microwave irradiating said intermediate object to further polymerize said resin and form said three-dimensional object.
21. The method of claim 20 , wherein:
said producing step (b) is carried out by photopolymerizing said reactive blocked prepolymer to form a polymer scaffold carrying said polyol; and
said heating and/or microwave irradiating step (c) is carried out under conditions in which said polymer scaffold at least partially degrades and regenerates said prepolymer, said prepolymer in turn polymerizing with said polyol to form said three-dimensional object.