Liquid, hybrid UV/vis radiation curable resin compositions for additive fabrication

Patent metadata

Field	Value
Publication number	US-9708442-B1
Application number	US-201615281978-A
Country	US
Kind code	B1
Filing date	Sep 30, 2016
Priority date	Oct 1, 2015
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

Described herein are thermoset compositions suitable for hybrid polymerization when processed via additive fabrication equipment utilizing sources of actinic radiation with peak spectral intensities in the UV and/or visible region containing a photoinitiating package, a cationically curable constituent, a free-radically curable component, and optionally, one or more additives. Such thermoset compositions preferably contain a Norrish Type I photoinitiator that is an alkyl-, aryl-, or acyl-substituted compound centered around a Group 14 atom, and further possesses specified ranges of ionization potential values with respect to its known triplet state. Also disclosed are methods of creating three-dimensional parts via additive fabrication processes utilizing sources of actinic radiation with peak spectral intensities in the UV and/or visible regions employing the claimed thermosetting compositions, along with the parts cured therefrom.

First claim

What is claimed is:

1. A UV/vis radiation curable composition for additive fabrication comprising:
a photoinitiating package comprising:
from about 0.1 wt. % to about 15 wt. % of an iodonium salt cationic photoinitiator;
from about 0.1 wt. % to about 8 wt. % of a Norrish Type I photoinitiator;
from about 0.1 wt. % to about 15 wt. % of an accelerator; and
optionally, a photosensitizer;

a cationically curable constituent comprising
from about 1 wt. % to about 20 wt. % of an oxetane component;
from about 3 wt. % to about 40 wt. % of a cycloaliphatic epoxide component; and
from about 2 wt. % to about 40 wt. % of a glycidyl ether component;

from about 5 wt. % to about 40 wt. % of a free-radically curable component; and
optionally, up to about 50 wt. % of one or more additives;
wherein the Norrish Type I photoinitiator is an alkyl-, aryl-, or acyl-substituted compound which possesses an atom selected from the group consisting of silicon, germanium, tin, and lead;
wherein the accelerator comprises an electron-donating substituent attached to a vinyl group;
and wherein all weight percentages are listed relative to the weight of the entire composition.

2. The UV/vis radiation curable composition for additive fabrication according to claim 1 , wherein the molar ratio of the iodonium salt cationic photoinitiator to the accelerator is from 1:2 to 1:20,
the molar ratio of the Norrish Type I photoinitiator to the accelerator is from 1:2 to 1:20, and
the molar ratio of the iodonium salt cationic photoinitiator to the Norrish Type I photoinitiator is from 1:2 to 2:1.

3. The UV/vis radiation curable composition for additive fabrication according to claim 2 , wherein the electron-donating substituent attached to a vinyl group is selected from one or more of the group consisting of vinyl, ethers, vinyl esters, vinyl thioethers, n-vinyl carbazoles, n-vinyl pyrollidones, n-vinyl caprolactams, allyl ethers, and vinyl carbonates.

4. The UV/vis radiation curable composition for additive fabrication according to claim 2 , wherein the accelerator is a multifunctional vinyl ether compound.

5. The UV/vis radiation curable composition for additive fabrication according to claim 4 , wherein the iodonium salt is selected from the group consisting of (4-methylphenyl)[4-(2-methylpropyl)phenyl]-, hexafluorophosphate, [4-(1-methylethyl)phenyl](4-methylphenyl)-, tetrakis(pentafluorophenyl)borate(1-), (Bis(4-dodecylphenyl)iodonium hexaflurorantimonate), and (Bis(4-tert-butylphenyl)iodonium hexafluorophosphate).

6. The UV/vis radiation curable composition for additive fabrication according to claim 3 , wherein the Norrish Type I photoinitiator comprises a compound meeting the following formula (I):

in which Ar 1 is an aromatic group, either unsubstituted or further substituted in any position by one or more alkyl radicals, ethers, sulfides, silyl groups, halogens, carboxyl groups, vinyl groups, additional aromatic or heterocyclic groups, alkyl radicals, or aromatic or heterocyclic groups interrupted by one or more ether, sulfide, silyl, carboxyl, or vinyl groups, and in which R 1 , R 2 , and R 3 independently may be an acyl, aryl, alkyl, or carbonyl group, either unsubstituted or further substituted one or more alkyl radicals, ethers, sulfides, silyl groups, halogens, carboxyl groups, vinyl groups, additional aromatic or heterocyclic groups, alkyl radicals, or aromatic or heterocyclic groups interrupted by one or more ether, sulfide, silyl, carboxyl, or vinyl groups.

7. The UV/vis radiation curable composition for additive fabrication according to claim 6 , wherein one of the following conditions is satisfied:
(a) each of R 1 -R 3 is an aryl-substituted or aromatic acyl group; or
b) if exactly two of R 1 -R 3 are an aryl-substituted or aromatic acyl group, the remaining substituted groups are a C 1 -C 10 alkyl; or
(c) if exactly one of R 1 -R 3 is an aryl-substituted or aromatic acyl group, the remaining two substituted groups are a C 1 -C 10 alkyl; or
(d) each of R 1 -R 3 is a C 1 -C 10 alkyl.

8. The UV/vis radiation curable composition for additive fabrication according to claim 3 , wherein the Norrish Type I photoinitiator comprises at least 80% by weight, relative to the entire weight of all Norrish Type I photoinitiators present in the composition, of one or both of the following compounds:

9. The UV/vis radiation curable composition for additive fabrication according to claim 1 , wherein the accelerator is capable of forming a vinyl-based or ether radical, wherein said vinyl-based or ether radical possesses a calculated ionization potential from about 3.3 eV to about 4.89 eV when the ionization potential is calculated in accordance with molecular modeling under B3LYP/6-31G(d) in combination with Koopman's Theorem (IP=−ε HOMO ).

10. The UV/vis radiation curable composition for additive fabrication according to claim 9 , wherein the calculated ionization potential of the vinyl-based or ether radical is from about 3.80 eV to about 4.20 eV when the ionization potential is calculated in accordance with molecular modeling under B3LYP/6-31G(d) in combination with Koopman's Theorem (IP=−ε HOMO ).

11. The UV/vis radiation curable composition for additive fabrication according to claim 3 , wherein the Norrish Type I photoinitiator is capable of forming a radical that possesses a rate of addition to the vinyl ether greater than or equal to 3×10 6 M −1 s −1 .

12. The UV/vis radiation curable composition for additive fabrication according to claim 10 , wherein the composition comprises at least 80 wt. %, relative to the weight of all of the Norrish Type I photoinitiators present in the entire composition, of a Norrish Type I photoinitiator possessing a potential excited triplet state with an ionization potential of from about 3.0 eV to about 3.98 eV, wherein the ionization potential is calculated in accordance with molecular modeling B3LYP/6-31G(d) in combination with Koopman's Theorem (IP=−ε HOMO ).

13. The UV/vis radiation curable composition for additive fabrication according to claim 4 , wherein the multifunctional vinyl ether compound is present in an amount by weight, relative to the entire composition, of from about 1.5 wt. % to about 8 wt. %.

14. A liquid UV/vis radiation curable composition for additive fabrication comprising:
a photoinitiating package comprising
an onium salt cationic photoinitiator;
a reductant comprising
an effective amount of a Norrish Type I photoinitiator dissolved in a vinyl ether compound that is a liquid at 25 degrees C.; and

optionally, a photosensitizer;

a cationically polymerizable constituent;
a free-radically polymerizable component; and
optionally, one or more additives;
wherein the Norrish Type I photoinitiator is capable of entering a triplet state upon excitation by exposure to actinic radiation, wherein said excited triplet state possesses an ionization potential of from about 2.5 eV to about 4.15 eV, wherein the ionization potential is calculated in accordance with molecular modeling under B3LYP/6-31G(d) in combination with Koopman's Theorem (IP=−ε HOMO ).

15. The liquid UV/vis radiation curable composition for additive fabrication according to claim 14 , wherein the excited triplet state of the Norrish Type I photoinitiator possesses an ionization potential of from about 3.0 eV to about 3.55 eV, wherein the ionization potential is calculated in accordance

Assignees

• Dsm Ip Assets Bv
• Dsm Ip Assets Bv

Inventors

• Kwisnek Luke
• Lee Tai Yeon
• Jansen Johan Franz Gradus Antonius
• Coussens Betty
• Ren Kangtai

Classifications

• G03F7/029

  Inorganic compounds; Onium compounds; Organic compounds having hetero atoms other than oxygen, nitrogen or sulfur · CPC title

• G03F7/038

  Macromolecular compounds which are rendered insoluble or differentially wettable (G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021) · CPC title

• G03F7/0045 Primary

  with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• C08G59/68

  characterised by the catalysts used · CPC title