Inks for 3d printing having low print through depth

Patent metadata

Field	Value
Publication number	US-2019136079-A1
Application number	US-201816182926-A
Country	US
Kind code	A1
Filing date	Nov 7, 2018
Priority date	Nov 7, 2017
Publication date	May 9, 2019
Grant date	—

Abstract

In one aspect, inks for use with a three-dimensional (3D) printing system are described herein. In some embodiments, an ink described herein comprises up to 80 wt. % oligomeric curable material; up to 80 wt. % monomeric curable material; up to 10 wt. % photoinitiator; up to 1 wt. % non-curable absorber material; and up to 10 wt. % one or more additional components, based on the total weight of the ink, and wherein the total amount of the foregoing components is equal to 100 wt. %. Additionally, the photoinitiator is operable to initiate curing of the oligomeric curable material and/or the monomeric curable material when the photoinitiator is exposed to incident curing radiation having a peak wavelength λ. Moreover, the ink has a penetration depth (D p ), a critical energy (E c ), and a print through depth (D PT ) at the wavelength λ of less than or equal to 2×D p .

First claim

That which is claimed:

1 . An ink for use in a three-dimensional printing system, the ink comprising:
up to 80 wt. % oligomeric curable material; up to 80 wt. % monomeric curable material; up to 10 wt. % photoinitiator; up to 1 wt. % non-curable absorber material; and up to 10 wt. % one or more additional components, based on the total weight of the ink, wherein the total amount of the oligomeric curable material, monomeric curable material, photoinitiator, non-curable absorber material, and one or more additional components is equal to 100 wt. %; wherein the photoinitiator is operable to initiate curing of the oligomeric curable material and/or the monomeric curable material when the photoinitiator is exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ; wherein the ink has a penetration depth (D p ) and a critical energy (E c ) at the wavelength λ; and wherein the ink has a print through depth (D PT ) at the wavelength λ of less than or equal to 2×D p .

2 . The ink of claim 1 , wherein the ink has a print through depth (D PT ) at the wavelength λ of less than or equal to 1.5×D p .

3 . The ink of claim 1 , wherein:
the D p of the ink is 60-100 μm; and the E c of the ink is 2-4 mJ/cm 2 .

4 . The ink of claim 1 , wherein:
the D p of the ink is 101-150 μm; and the E c of the ink is 4-20 mJ/cm 2 .

5 . The ink of claim 1 , wherein:
the D p of the ink is 151-200 μm; and the E c of the ink is 8-15 mJ/cm 2 .

6 . The ink of claim 1 , wherein the ink has a ratio of D p to E c , in units of (μm cm 2 )/mJ, of between 10 and 50.

7 . The ink of claim 1 , wherein the ink comprises up to 5 wt. % photo initiator.

8 . The ink of claim 1 , wherein:
the ink comprises up to 5 wt. % photoinitiator and up to 0.5 wt. % non-curable absorber material; and the ratio of photoinitiator to non-curable absorber material, by weight, is between 5 and 100.

9 . The ink of claim 1 , wherein both the non-curable absorber material and the photoinitiator have an absorption peak within 30 nm of the wavelength λ.

10 . The ink of claim 1 , wherein the total absorbance of the non-curable absorber material at the wavelength λ is about 0.1 to 10 times the total absorbance of the photoinitiator at the wavelength λ.

11 . The ink of claim 1 , wherein the non-curable absorber material comprises pyrene.

12 . The ink of claim 1 , wherein the non-curable absorber material comprises an oil-soluble yellow dye.

13 . A method of forming a three-dimensional article by additive manufacturing, the method comprising:
providing the ink of claim 1 ; and selectively curing a portion of the ink using incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength at the wavelength λ.

14 . The method of claim 13 , wherein:
the ink is selectively cured according to preselected computer aided design (CAD) parameters; and the D p corresponds to a voxel depth of the CAD parameters.

15 . The method of claim 13 , wherein providing the ink comprises selectively depositing layers of the ink in a fluid state onto a substrate to form the three-dimensional article.

16 . The method of claim 13 , wherein:
providing the ink comprises retaining the ink in a fluid state in a container; selectively curing a portion of the ink comprises selectively applying the curing radiation to the ink in the container to solidify at least a portion of a first fluid layer of the ink, thereby forming a first solidified layer that defines a first cross-section of the article; raising or lowering the first solidified layer to provide a second fluid layer of the ink at a surface of the fluid ink in the container; and selectively applying the curing radiation to the ink in the container to solidify at least a portion of the second fluid layer of the ink, thereby forming a second solidified layer that defines a second cross-section of the article, the first cross-section and the second cross-section being bonded to one another in a z-direction.

17 . A printed three-dimensional article formed from the ink of claim 1 .

Assignees

• 3D Systems Inc

Inventors

• Moussa Khalil

Classifications

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• B29C64/124

  using layers of liquid which are selectively solidified · CPC title

• C09D11/037

  characterised by the pigment · CPC title

• C09D11/107

  from unsaturated acids or derivatives thereof · CPC title

• B29K2033/12

  Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate · CPC title