Use of latent metathesis polymerization systems for additive manufacturing

Patent metadata

Field	Value
Publication number	US-11840586-B2
Application number	US-202217677558-A
Country	US
Kind code	B2
Filing date	Feb 22, 2022
Priority date	Mar 8, 2021
Publication date	Dec 12, 2023
Grant date	Dec 12, 2023

Abstract

The invention is directed to latent metathesis-active resin compositions and additive manufacturing approaches. The latent metathesis-active compositions comprise at least one latent metathesis catalyst, at least one curable metathesis-active monomer, and optional fillers, photosensitizers, and/or a secondary monomer resin system for dual-cure. A method comprises extruding a latent metathesis-active resin from a dispensing apparatus and spatially triggering a ring-opening metathesis polymerization by directed irradiation with light or directed application of a thermal stimuli for direct-ink write printing of objects. Another method uses a latent metathesis-active resin for vat photopolymerization and stereolithographic printing of objects.

First claim

We claim:

1. A resin for direct ink write additive manufacturing, comprising:
a metathesis-active monomer;
a latent metathesis catalyst that can be activated by an external stimulus to initiate a ring-opening metathesis polymerization (ROMP) of the metathesis-active monomer; and
at least one filler that provides the resin with a shear-thinning property.

2. The resin of claim 1 , wherein the metathesis-active monomer comprises a cyclic olefin.

3. The resin of claim 2 , wherein the cyclic olefin comprises a norbornadiene, norbornene, oxonorbornene, azanorbornene, cyclobutene, cyclooctene, cyclooctadiene, cyclooctatetraene, dicyclopentadiene, or derivatives thereof.

4. The resin of claim 1 , wherein the latent metathesis catalyst comprises a thermally latent, photolatent, or a redox-latent ROMP catalyst.

5. The resin of claim 4 , wherein the latent metathesis catalyst comprises a ruthenium, tungsten, molybdenum, rhenium, or titanium catalyst.

6. The resin of claim 4 , wherein the latent metathesis catalyst comprises a ruthenium-based Grubbs catalyst.

7. The resin of claim 1 , wherein the resin comprises 0.01 to 1 mol % latent metathesis catalyst.

8. The resin of claim 1 , wherein the resin comprises 0.01 to 0.08 mol % latent metathesis catalyst.

9. The resin of claim 1 , further comprising at least one photosensitizer.

10. The resin of claim 9 , wherein the at least one photosensitizer comprises isopropylthioxanthone, camphorquinone, benzophenone, phenothiazine, benzil, Rose Bengal, rhodamine, or coumarin.

11. The resin of claim 9 , wherein the resin comprises less than 3 wt % photosensitizer.

12. The resin of claim 9 , wherein the resin comprises 1:1 to 16:1 wt/wt latent metathesis catalyst to photosensitizer.

13. The resin of claim 9 , further comprising a co-initiator that accelerates the rate of initiation of the photosensitizer.

14. The resin of claim 13 , wherein the co-initiator comprises ethyl 4-(dimethylamino)benzoate.

15. The resin of claim 1 , further comprising ethylidene norbornene.

16. The resin of claim 1 , wherein the at least one filler comprises silica, clay, fumed silica, zirconate, aluminate, or precipitated calcium carbonate.

17. The resin of claim 1 , wherein the at least one filler comprises a carbon or glass fiber, carbon nanotube, inorganic fiber or filler, or organic or natural fiber or filler.

18. The resin of claim 1 , further comprising a non-metathesis-active monomer to provide a dual-cure resin, wherein the non-metathesis-active monomer can be polymerized post-print by a non-ROMP process.

19. The resin of claim 18 , wherein the non-metathesis-active monomer comprises a thermally initiated monomer.

20. The resin of claim 19 , wherein the thermally initiated monomer comprises an epoxy monomer.

21. The resin of claim 18 , wherein the non-metathesis-active monomer comprises a photoinitiated monomer.

22. The resin of claim 21 , wherein the photoinitiated monomer comprises a free-radical acrylate monomer or a cationic/anionic polymerizable monomer.

23. A method for direct-ink write additive manufacturing, comprising:
providing the resin of claim 1 comprising a metathesis-active monomer and a latent metathesis catalyst;
extruding the resin through a nozzle;
depositing the extruded resin on a surface along a defined path;
activating the latent metathesis catalyst using an external stimulus to initiate a ring-opening metathesis polymerization (ROMP) of the metathesis-active monomer of the deposited resin to provide a layer of polymerized resin; and
printing a shape of polymerized resin layer-by-layer, thereby forming a printed object.

24. The method of claim 23 , wherein the external stimulus comprises a thermal or photo stimulus.

25. The method of claim 23 , further comprising post-print curing of the printed object.

26. A method for stereolithographic additive manufacturing, comprising
irradiating a bath of the resin of claim 1 with a targeted light exposure, thereby activating the latent metathesis catalyst to initiate a ring-opening metathesis polymerization (ROMP) of the metathesis-active monomer and forming a layer of polymerized resin, and
repeating the irradiating step to build a printed object layer-by-layer.

27. A method for additive manufacturing of dual-cure thermoset resins, comprising:
providing a resin of claim 1 , wherein the resin further comprises one or more non-metathesis-active monomers to provide a dual-cure resin;
extruding the dual-cure resin from direct-ink write apparatus along a defined path; and
photo or thermally activating the dual-cure resin, thereby initiating a latent ring-opening metathesis polymerization (ROMP) of the metathesis-active monomer, whereby a structure is printed layer-by-layer; and
polymerizing the one or more non-metathesis-active monomers in the printed structure by a non-ROMP process to provide a printed object.

28. The method of claim 27 , wherein the one or more non-metathesis-active monomers comprises a homopolymerized epoxy resin, an epoxy/amine resin, or an epoxy/anhydride resin.

29. The method of claim 27 , wherein the one or more non-metathesis-active monomers comprises a free-radical acrylate monomer or a cationic/anionic polymerizable monomer.

Assignees

• Nat Tech & Eng Solutions Sandia Llc

Inventors

• Appelhans Leah
• Leguizamon Samuel
• Jones Brad Howard
• Cook Adam Wade

Classifications

• C08F236/20 Primary

  unconjugated · CPC title

• B29C64/124

  using layers of liquid which are selectively solidified · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y40/20

  Post-treatment, e.g. curing, coating or polishing · CPC title

• B33Y70/00 Primary

  Materials specially adapted for additive manufacturing · CPC title