Epoxy dual cure resins for additive manufacturing

1. A method of forming a three-dimensional object, comprising:

(a) providing an epoxy dual cure resin;

(b) forming a three-dimensional intermediate from said epoxy dual cure resin, wherein said three-dimensional intermediate is formed in a layerless or layer-by-layer manner through multiple exposures of the epoxy dual cure resin to patterned actinic radiation or light, and

where said three-dimensional intermediate has the shape of, or a shape to be imparted to, said three-dimensional object; then

(c) optionally washing the three-dimensional intermediate, and

(d) heating and/or microwave irradiating said three-dimensional intermediate sufficiently to further cure said epoxy dual cure resin and form said three-dimensional object;

wherein said epoxy dual cure resin comprises:

(i) a photoinitiator;

(ii) monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light;

(iii) optionally, a light absorbing pigment or dye;

(iv) an epoxy resin;

(v) an organic hardener co-polymerizable with said epoxy resin;

(vi) optionally a dual reactive compound having substituted thereon a first reactive group reactive with said monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light, and a second reactive group reactive with said epoxy resin;

(vii) optionally a diluent;

(viii) optionally a filler; and

(ix) optionally, a co-monomer and/or a co-prepolymer.

2. The method of claim 1 , wherein said epoxy resin comprises a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolac epoxy resin, an aliphatic epoxy resin, a glycidylamine epoxy resin, an epoxidized vegetable oil, or a combination thereof.

3. The method of claim 1 , wherein

said organic hardener comprises an amine, an acid, a phenol, and/or an alcohol.

4. The method of claim 1 , wherein said organic hardener comprises an anhydride.

5. The method of claim 1 , wherein said organic hardener comprises a latent hardener, optionally included in said epoxy dual cure resin in solid particulate form.

6. The method of claim 1 , wherein said monomers and/or prepolymers polymerizable by exposure to actinic radiation or light comprise reactive end groups selected from the group consisting of acrylates, methacrylates, α-olefins, N-vinyls, acrylamides, methacrylamides, styrenics, epoxides, thiols, 1,3-dienes, vinyl halides, acrylonitriles, vinyl esters, maleimides, and vinyl ethers.

7. The method of claim 1 , wherein said light absorbing pigment or dye is present and is:

(i) titanium dioxide,

(ii) carbon black, and/or

(iii) an organic ultraviolet light absorber.

8. The method of claim 1 , wherein said diluent is present and comprises an acrylate, a methacrylate, a styrene, an acrylic acid, 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.

9. The method of claim 1 , wherein said filler is present and comprises a core-shell rubber.

10. The method of claim 1 , wherein said epoxy dual cure resin comprises:

(i) from 0.1 to 4 percent by weight of said photoinitiator,

(ii) from 10 to 90 percent by weight of said monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light,

(iii) from 0.1 to 2 percent by weight of said light absorbing pigment or dye when present,

(iv) from 2 to 60 percent by weight of said epoxy resin;

(v) from 1 to 30 percent by weight of said organic hardener;

(vi) from 1 to 40 percent by weight of said dual reactive compound when present;

(vii) from 1 to 40 percent by weight of said diluent when present; and

(viii) from 1 to 50 percent by weight of said filler when present.

11. The method of claim 1 , wherein said forming step is carried out by additive manufacturing.

12. The method of claim 1 , wherein said forming step is carried out by either bottom-up three-dimensional fabrication between a carrier and a build surface, or top-down three-dimensional fabrication between a carrier and a fill level.

13. The method of claim 1 , wherein said forming step is carried out by continuous liquid interface production (CLIP).

14. The method of claim 13 , wherein said forming step is carried out between a carrier and a build surface, and said method further comprises vertically reciprocating said carrier with respect to the build surface to enhance or speed the refilling of a build region with the epoxy dual cure resin.

15. The method of claim 1 , wherein said three-dimensional object comprises a polymer blend, interpenetrating polymer network, semi-interpenetrating polymer network, or sequential interpenetrating polymer network.

16. The method of claim 1 , wherein said heating and/or microwave irradiating step is carried out at at least a first temperature and a second temperature,

with said first temperature greater than ambient temperature, said second temperature greater than said first temperature, and said second temperature less than 300° C.

17. An epoxy dual cure resin useful for additive manufacturing of three-dimensional objects, comprising:

(i) a photoinitiator;

(ii) monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light, wherein said monomers and/or prepolymers are present in the epoxy dual cure resin in an amount of from 10 to 90 percent by weight;

(iii) optionally, a light absorbing pigment or dye;

(iv) an epoxy resin present in the epoxy dual cure resin an amount of from 10 to 60 percent by weight;

(v) an organic hardener co-polymerizable with said epoxy resin, wherein said organic hardener comprises an anhydride and is present in the epoxy dual cure resin in an amount of from 1 to 30 percent by weight;

(vi) optionally a dual reactive compound having substituted thereon a first reactive group reactive with said monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light, and a second reactive group reactive with said epoxy resin;

(vii) optionally a diluent;

(viii) optionally a filler; and

(ix) optionally, a co-monomer and/or a co-prepolymer.

18. The epoxy dual cure resin of claim 17 , wherein said epoxy resin comprises a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolac epoxy resin, an aliphatic epoxy resin, a glycidylamine epoxy resin, an epoxidized vegetable oil, or a combination thereof.

19. The epoxy dual cure resin of claim 17 , wherein said organic hardener further comprises an amine, an acid, a phenol, an alcohol, and/or a thiol.

20. The epoxy dual cure resin of claim 17 , wherein said organic hardener further comprises a latent hardener.

21. The epoxy dual cure resin of claim 17 , wherein said monomers and/or prepolymers polymerizable by exposure to actinic radiation or light comprise reactive end groups selected from the group consisting of acrylates, methacrylates, α-olefins, N-vinyls, acrylamides, methacrylamides, styrenics, epoxides, thiols, 1,3-dienes, vinyl halides, acrylonitriles, vinyl esters, maleimides, and vinyl ethers.

22. The epoxy dual cure resin of claim 17 , wherein said light absorbing pigment or dye is present and is:

(i) titanium dioxide,

(ii) carbon black, and/or

(iii) an organic ultraviolet light absorber.

23. The epoxy dual cure resin of claim 17 , wherein said diluent is present and comprises an acrylate, a methacrylate, a styrene, an acrylic acid, 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.

24. The epoxy dual cure resin of claim 17 , wherein said filler is present and comprises a core-shell rubber.

25. The epoxy dual cure resin of claim 17 , wherein said epoxy dual cure resin comprises:

(i) from 0.1 to 4 percent by weight of said photoinitiator,

(ii) from 0.1 to 2 percent by weight of said light absorbing pigment or dye when present,

(iii) from 1 to 40 percent by weight of said dual reactive compound when present;

(iv) from 1 to 40 percent by weight of said diluent when present; and

(v) from 1 to 50 percent by weight of said filler when present.

26. A product produced by a method of claim 1 .

27. An intermediate product produced by a method comprising

(a) providing an epoxy dual cure resin; and

(b) forming a three-dimensional intermediate from said epoxy dual cure resin, wherein said three-dimensional intermediate is formed in a layerless or layer-by-layer manner through multiple exposures of the epoxy dual cure resin to patterned actinic radiation or light, and where said three-dimensional intermediate has the shape of, or a shape to be imparted to, a three-dimensional object;

wherein said epoxy dual cure resin comprises:

(i) a photoinitiator;

(ii) monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light;

(iii) optionally, a light absorbing pigment or dye;

(iv) an epoxy resin;

(v) an organic hardener co-polymerizable with said epoxy resin;

(vi) optionally a dual reactive compound having substituted thereon a first reactive group reactive with said monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light, and a second reactive group reactive with said epoxy resin;

(vii) optionally a diluent;

(viii) optionally a filler; and

(ix) optionally, a co-monomer and/or a co-prepolymer.

28. The method of claim 1 , wherein said dual reactive compound is present and comprises a compound of the formula: (X) n R(X′) m , wherein:

X is the first reactive group and is selected from the group consisting of acrylate, methacrylate, α-olefin, N-vinyl, acrylamide, methacrylamide, styrenic, thiol, 1,3-diene, vinyl halide, acrylonitrile, vinyl ester, maleimide, and vinyl ether reactive groups, and combinations thereof;

X′ is the second reactive group and is selected from the group consisting of epoxy, amine, isocyanate, alcohol, and anhydride reactive groups, and combinations thereof;

n and m are each independently an integer of from 1 to 20, and

R is a hydrocarbyl group.

29. The method of claim 1 , wherein said organic hardener comprises one or more linear and/or cyclic anhydride(s) selected from the group consisting of polysebacic anhydride; polyazelaic anhydride; methyltetrahydrophthalic anhydride; tetrahydro phthalic anhydride; methyl nadic anhydride; hexahydro phthalicanhydride; methylhexahydro phthalic anhydride; succinic anhydride; substituted succinic anhydride; citric acid anhydride; maleic anhydride; adducts of maleic anhydride; dodecyl succinic anhydride; vinyl and styrene copolymers of maleic anhydride; a multi-ring alicyclic anhydride; phthalic anhydride; and trimellitic anhydride.

30. The epoxy dual cure resin of claim 17 , wherein said organic hardener comprises one or more linear and/or cyclic anhydride(s) selected from the group consisting of polysebacic anhydride; polyazelaic anhydride; methyltetrahydrophthalic anhydride; tetrahydro phthalic anhydride; methyl nadic anhydride; hexahydro phthalicanhydride; methylhexahydro phthalic anhydride; succinic anhydride; substituted succinic anhydride; citric acid anhydride; maleic anhydride; adducts of maleic anhydride; dodecyl succinic anhydride; vinyl and styrene copolymers of maleic anhydride; a multi-ring alicyclic anhydride; phthalic anhydride; and trimellitic anhydride.

31. The epoxy dual cure resin of claim 17 , wherein, when cured, the epoxy dual cure resin produces a polymer product having a glass transition temperature in a range of 60 to 80° C.