Stabilized matrix-filled liquid radiation curable resin compositions for additive fabrication

1. A liquid radiation curable composition for additive fabrication comprising:

(a) a cationically polymerizable aliphatic epoxide;

(b) a multifunctional (meth)acrylate component;

(c) a cationic photoinitiator;

(d) a free-radical photoinitiator; and

(e) a filled matrix comprising a nanoparticle constituent comprising

a plurality of inorganic nanoparticles, and a microparticle constituent comprising a plurality of inorganic microparticles;

wherein the ratio by weight of the microparticle constituent to the nanoparticle constituent is from about 1:1 to about 12:1; and

wherein the ratio of the average particle size of the inorganic microparticles in the microparticle constituent to the average particle size of the inorganic nanoparticles in the nanoparticle constituent is from about 2.41:1 to about 200:1 less than 200:1.

2. The liquid radiation curable composition for additive fabrication of claim 1 , wherein

the inorganic nanoparticles of the nanoparticle constituent have an average particle size of from about 50 nanometers to about 100 nanometers; and

the inorganic microparticles of the microparticle constituent have an average particle size of from about 2 microns to about 8 microns.

3. The liquid radiation curable composition for additive fabrication of claim 2 , wherein at least one of the microparticle constituent or the nanoparticle constituent comprises spherical particles selected from the group consisting of ceramics, glass, and metal.

4. The liquid radiation curable composition for additive fabrication of claim 3 , wherein

the ratio by weight of the microparticle constituent to the nanoparticle constituent is from about 4:1 to about 8:1; and

the ratio of the average particle size of the inorganic microparticles in the microparticle constituent to the average particle size of the inorganic nanoparticles in the nanoparticle constituent is from about 6.46:1 to about 100:1.

5. The liquid radiation curable composition for additive fabrication claim 4 , wherein the aliphatic epoxide component is a cycloaliphatic epoxy selected from the group consisting of: 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)-cyclohexane-1,4-dioxane, bis(3,4-epoxycyclohexylmethyl)adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, vinylcyclohexene dioxide, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexyl-3′,4′-epoxy-6′-methylcyclohexanecarboxylate, ε-caprolactone-modified 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylates, trimethylcaprolactone-modified 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylates, β-methyl-δ-valerolactone-modified 3,4-epoxycyclohexcylmethyl-3′,4′-epoxycyclohexane carboxylates, methylenebis(3,4-epoxycyclohexane), bicyclohexyl-3,3′-epoxide, bis(3,4-epoxycyclohexyl) with a linkage of —O—, —S—, —SO—, —SO 2 —, —C(CH 3 ) 2 —, —CBr 2 —, —C(CBr 3 ) 2 —, —C(CF 3 ) 2 —, —C(CCl 3 ) 2 —, or —CH(C 6 H 5 )—, dicyclopentadiene diepoxide, di(3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis(3,4-epoxycyclohexanecarboxylate), and epoxyhexahydrodioctylphthalate.

6. The liquid radiation curable composition for additive fabrication of claim 5 , wherein the ratio by volume of the microparticle constituent to the nanoparticle constituent is from about 1:1 to about 12:1.

7. The liquid radiation curable composition for additive fabrication of claim 6 , wherein the ratio by number of the inorganic nanoparticles in the nanoparticle constituent to the inorganic microparticles in the microparticle constituent is from about 50:1 to about 1,000,000:1.

8. The liquid radiation curable composition for additive fabrication of claim 7 , wherein the ratio by number of the inorganic nanoparticles in the nanoparticle constituent to the inorganic microparticles in the microparticle constituent is from about 5,000:1 to about 50,000:1.

9. The liquid radiation curable composition for additive fabrication of claim 7 , wherein, relative to the total weight of the entire composition:

component (a) is present in an amount of from about 10 wt % to about 30 wt %;

component (b) is present in an amount of from about 2 wt % to about 10 wt %;

component (c) is present in an amount of from about 1 wt % to about 10 wt %;

component (d) is present in an amount of from about 0.1 wt % to about 5 wt %; and

component (e) is present in an amount of from about 30 wt % to about 80 wt %.

10. The liquid radiation curable composition for additive fabrication of claim 9 , further comprising a multifunctional glycidyl ether that is devoid of cyclohexane groups.

11. The liquid radiation curable composition for additive fabrication of claim 10 , wherein the multifunctional glycidyl ether that is devoid of cyclohexane groups is a neopentyl glycol diglycidyl ether.

12. The liquid radiation curable composition for additive fabrication of claim 11 further comprising an oxetane, and wherein component (c) is an R-substituted aromatic thioether triaryl sulfonium or iodonium tetrakis(pentafluorophenyl) borate cationic photoinitiator with a tetrakis(pentafluorophenyl)borate anion and a cation of the following formula (I):

wherein Y1, Y2, and Y3 are the same or different and wherein Y1, Y2, or Y3 are R-substituted aromatic thioether with R being an acetyl or halogen group.

13. The liquid radiation curable composition of claim 11 further comprising an oxetane, wherein component (c) possesses an anion represented by SbF 6 − , PF 6 − , BF 4 − , (CF 3 CF 2 ) 3 PF 3 − , (C 6 F 5 ) 4 B − , ((CF 3 ) 2 C 6 H 3 ) 4 B − , (C 6 F 5 ) 4 Ga − , ((CF 3 ) 2 C 6 H 3 ) 4 Ga − , trifluoromethanesulfonate, nonafluorobutanesulfonate, methanesulfonate, butanesulfonate, benzenesulfonate, or p-toluenesulfonate, and a cation of the following formula (II):

wherein in formula (II), R 1 , R 2 , R 3 , R 5 and R 6 each independently represent an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxy(poly)alkyleneoxy group, an optionally substituted amino group, a cyano group, a nitro group, or a halogen atom, R 4 represents an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, a heterocyclic hydrocarbon group, an alkylsulfinyl group, an alkylsulfonyl group, a hydroxy(poly)alkyleneoxy group, an optionally substituted amino group, a cyano group, a nitro group, or a halogen atom, m 1 to m 6 each represent the number of occurrences of each of R 1 to R 6 , m 1 , m 4 , and m 6 each represent an integer of 0 to 5, and m 2 , m 3 , and m 5 each represent an integer of 0 to 4.

14. The liquid radiation curable composition for additive fabrication of claim 11 , wherein the composition has a viscosity of between about 600 cPs and about 1200 cPs, and after full cure with actinic radiation and 60 min UV and thermal postcure, has the following properties:

(a) a heat distortion temperature at 1.82 MPa of between about 80 degrees C. and about 120 degrees C., and

(b) a flexural modulus of between about 8,000 MPa and about 12,000 MPa.

15. The liquid radiation curable composition of claim 11 , further comprising a second aliphatic epoxide component, and wherein

the microparticle constituent consists of colloidal silica microparticles,

and the nanoparticle constituent consists of colloidal silica nanoparticles.

16. A process of forming a three-dimensional object comprising the steps of forming and selectively curing a layer of the liquid radiation curable resin composition for additive fabrication of claim 1 with actinic radiation and repeating the steps of forming and selectively curing a layer of the liquid radiation curable resin composition for additive fabrication of claim 1 a plurality of times to obtain a three-dimensional object.

17. The process of claim 16 wherein the source of actinic radiation is one or more LEDs emitting a wavelength of from 340 nm-415 nm, preferably having a peak at about 365 nm.

18. A three-dimensional object formed by the process of claim 16 .

19. A liquid radiation curable composition for additive fabrication comprising:

(a) a cationically polymerizable component;

(b) a (meth)acrylate component;

(c) a cationic photoinitiator;

(d) a free-radical photoinitiator;

(e) a filled matrix, further comprising

a filled particle dispersion containing a nanoparticle constituent made up of a plurality of silica nanoparticles having an average particle size of at least about 50 nanometers, and a solvent, and a microparticle constituent made up of a plurality of inorganic microparticles; wherein the ratio by weight of the microparticle constituent to the nanoparticle constituent is from about 1:1 to about 12:1, wherein the ratio of an average particle size of the inorganic microparticles in the microparticle constituent to an average particle size of the silica nanoparticles in the nanoparticle constituent is from about 2.41:1 to less than 200:1, and wherein the filled particle dispersion has a particle dispersion pH of greater than about 5.5.

20. The liquid radiation curable composition for additive fabrication of claim 19 , wherein

said plurality of silica nanoparticles have an average particle size of from about 50 nanometers to about 100 nanometers;

said plurality of inorganic microparticles have an average particle size of from about 0.2 microns to 20 microns; and

wherein the particle dispersion pH of the filled particle dispersion is from 6.0 to about 7.5.

21. The liquid radiation curable composition for additive fabrication of claim 20 , wherein the filled matrix is present in an amount by weight, relative to the entire composition, of from about 50 wt % to about 70 wt %.

22. The liquid radiation curable composition for additive fabrication of claim 21 , wherein

the ratio of the average particle size of the inorganic microparticles in the microparticle constituent to the average particle size of the silica nanoparticles in the nanoparticle constituent is from about 6.46:1 to about 100:1; and

the ratio by weight of the microparticle constituent to the nanoparticle constituent is from about 4:1 to about 8:1.

23. The liquid radiation curable composition for additive fabrication of claim 22 , wherein the solvent is selected from one or more of the group consisting of methyl ethyl ketone, isopropanol, an epoxide, an oxetane, and an acrylate.

24. The liquid radiation curable composition for additive fabrication of claim 23 , wherein the solvent is a 3,4-epoxycyclohexylmethyl 3′,4′-epoxycyclohexanecarboxylate.

25. The liquid radiation curable composition for additive fabrication of claim 24 , wherein component (c) is an R-substituted aromatic thioether triaryl sulfonium or iodonium tetrakis(pentafluorophenyl) borate cationic photoinitiator with a tetrakis(pentafluorophenyl)borate anion and a cation of the following formula (I):

wherein Y1, Y2, and Y3 are the same or different and wherein Y1, Y2, or Y3 are R-substituted aromatic thioether with R being an acetyl or halogen group.

26. The liquid radiation curable composition for additive fabrication of claim 24 , wherein component (c) is a fluoroalkyl-substituted fluorophosphate with a cation of the following general formula (II):

wherein R 1 , R 2 , R 3 , R 5 and R 6 each independently represent an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxy(poly)alkyleneoxy group, an optionally substituted amino group, a cyano group, a nitro group, or a halogen atom, R 4 represents an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, a heterocyclic hydrocarbon group, an alkylsulfinyl group, an alkylsulfonyl group, a hydroxy(poly)alkyleneoxy group, an optionally substituted amino group, a cyano group, a nitro group, or a halogen atom, m 1 to m 6 each represent the number of occurrences of each of R 1 to R 6 , m 1 , m 4 , and m 6 each represent an integer of 0 to 5, and m 2 , m 3 , and m 5 each represent an integer of 0 to 4.