Photocurable Resins For Volumetric Additive Manufacturing

Patent metadata

Field	Value
Publication number	US-2020361152-A1
Application number	US-202015930822-A
Country	US
Kind code	A1
Filing date	May 13, 2020
Priority date	May 13, 2019
Publication date	Nov 19, 2020
Grant date	—

Abstract

Methods and materials for volumetric additive manufacturing, including computed axial lithography (“CAL”), using photosensitive resins comprising a photocurable resin prepolymer; a photoinitiator; and (optionally) a curing inhibitor. In various embodiments, such photosensitive polymers comprise (a) one or more monomer (or prepolymer) molecules, which form the backbone of the polymer network of the polymeric material and define its architecture; and (b) a photoinitiator that captures illumination energy and initiates polymerization.

First claim

What is claimed is:

1 . A method of forming a three dimensional (3D) object, comprising:
simultaneously directing optical projections of light from optical subsystems at a plurality of angles θ through a volume of photocurable composition contained within an optically transparent resin container, the optical projections further being directed about a z axis extending through the volume of photocurable composition; and providing each of the optical projections with a calculated three-dimensional intensity distribution acting over a fixed temporal exposure period, which is sufficient to cure selected portions of the volume of photocurable composition, and leave other portions unmodified, to form the 3D object;
wherein the photocurable composition comprises a monomer, a photoinitiator, and a curing inhibitor, and exhibits transparency to the light and a non-linear response to the light.

2 . The photocurable resin of claim 1 , wherein the curing inhibitor is selected from the group consisting of oxygen; (2,2,6,6-Tetramethyl-1-piperidinyloxy); phenothiazine; 4-methoxyphenol; N-Nitroso-N-phenylhydroxylamine aluminum salt; tetraethylthiuram disulfide; nitroxide spin trap agents such as Di-tert-butyl nitroxide, and 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide; and combinations thereof.

3 . The method of claim 2 , wherein the curing inhibitor comprises oxygen and the monomer is an acrylate

4 . The method of claim 1 , wherein the photocurable composition further has a viscosity which inhibits diffusive transport, preferably having a viscosity of at least 1000 cP.

5 . The method of claim 1 , wherein the change in refractive index of the photocurable composition upon curing is not greater than 0.01.

6 . A photocurable resin for use in a volumetric additive manufacturing process wherein curing of the resin in a volume of the resin is initiated upon projection of illumination energy into the volume to form images of cured material, the resin comprising:
a photocurable resin prepolymer; and a photoinitiator; wherein the resin has one or more of the following characteristics: (a) non-linearity of curing response to the illumination energy; (b) transparency to the illumination energy; (c) viscosity suitable to control diffusive transport and settling of cured material in the volume; and (d) a refractive index suitable to minimize distortions of the images as they are projected into the volume of the resin.

7 . The photocurable resin of claim 6 , wherein the photocurable resin prepolymer comprises acrylate, methacrylate, olefin, epoxide, or silane monomers, or mixtures thereof.

8 . The photocurable resin of claim 6 , wherein the photoinitiator is a Norish Type I or Type II photoinitiator.

9 . The photocurable resin of claim 8 , wherein the photoinitiator is selected from the group consisting of: camphorquinone; ethyl 4-dimethylaminobenzoate (EDAB); phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; bis(η5-2,4-cylcopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl) titanium; 2-Methyl-4′-(methylthio)-2-morpholinopropiophenone; tris(2,2-bipyridyl)dichlororuthenium(II) hexahydrate; sodium persulfate; and mixtures thereof.

10 . The photocurable resin of claim 6 , further comprising a curing inhibitor.

11 . The photocurable resin of claim 7 , wherein the curing inhibitor is selected from the group consisting of oxygen; (2,2,6,6-Tetramethyl-1-piperidinyloxy); phenothiazine; 4-methoxyphenol; N-Nitroso-N-phenylhydroxylamine aluminum salt; tetraethylthiuram disulfide; nitroxide spin trap agents such as Di-tert-butyl nitroxide, and 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide; and combinations thereof.

12 . The photocurable resin of claim 11 , wherein the resin prepolymer comprises an acrylate, and the curing inhibitor comprises oxygen.

13 . The photocurable resin of claim 6 , wherein the photocurable resin has a viscosity of at least 1000 cP.

14 . A photocurable resin for use in a volumetric additive manufacturing process comprising:
a photocurable resin prepolymer; a photoinitiator; and a curing inhibitor.

15 . The photocurable resin of claim 14 , wherein the photocurable resin prepolymer comprises acrylate, methacrylate, olefin, epoxide, or silane monomers, or mixtures thereof.

16 . The photocurable resin of claim 14 , wherein the photoinitiator is a Norish Type I or Type II photoinitiator.

17 . The photocurable resin of claim 16 , wherein the photoinitiator is selected from the group consisting of: camphorquinone; ethyl 4-dimethylaminobenzoate (EDAB); phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; bis(η5-2,4-cylcopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl) titanium; 2-Methyl-4′-(methylthio)-2-morpholinopropiophenone; tris(2,2-bipyridyl)dichlororuthenium(II) hexahydrate; sodium persulfate; and mixtures thereof.

18 . The photocurable resin of claim 14 , wherein the resin exhibits a non-linear curing response to illumination energy used in the volumetric additive manufacturing process.

19 . The photocurable resin of claim 14 , wherein the resin prepolymer comprises an acrylate, and the curing inhibitor comprises oxygen.

20 . The photocurable resin of claim 14 , wherein the photocurable resin has a viscosity of at least 1000 cP.

Assignees

• L Livermore Nat Security Llc
• Univ California

Inventors

• Shusteff Maxim
• Oakdale James
• Panas Robert Matthew
• Spadaccini Christopher M
• Taylor Hayden K
• Kelly Brett
• Bhattacharya Indrasen
• Heidari Hossein

Classifications

• B29C64/386

  Data acquisition or data processing for additive manufacturing · CPC title

• B29C64/282

  of the same type, e.g. using different energy levels · CPC title

• B29C64/277

  using multiple radiation means, e.g. micromirrors or multiple light-emitting diodes [LED] · CPC title

• B29C64/268

  using laser beams; using electron beams [EB] · CPC title

• B29C64/264

  Arrangements for irradiation · CPC title