Curable resin compositions for additive manufacturing

Abstract

Liquid radiation curable resin compositions are disclosed which are suitable for hybrid polymerization involving free radical and cationic photoinitiators when processed via additive fabrication equipment. According to one aspect, the compositions contain a monofunctional component, such as a monofunctional epoxy and / or a monofunctional (meth)acrylate. Also disclosed are methods of creating three-dimensional parts from the liquid radiation curable resin compositions via additive fabrication processes, which utilize sources of actinic radiation, and the parts cured therefrom.

Description

2024P20002WQCURABLE RESIN COMPOSITIONS FOR ADDITIVE MANUFACTURINGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 735,367, filed December 18, 2025, the entire disclosure of which is hereby expressly incorporated by reference in their entirety.FIELD

[0002] The present disclosure relates to additive manufacturing compositions, methods and systems for building three-dimensional (3D) parts with layer-based additive manufacturing techniques. In particular, the present disclosure relates to a liquid radiation curable resin composition, and methods for printing and using the same.BACKGROUND

[0003] Additive manufacturing systems are used to print or otherwise build 3D parts from digital representations of the 3D parts (e.g., 3MF and STL format files) using one or more additive manufacturing techniques. Examples of commercially available additive manufacturing techniques include extrusion-based techniques, jetting, selective laser sintering, powder / binder jetting, electron-beam melting, and stereolithographic processes. For each of these techniques, the digital representation of the 3D part is initially sliced into multiple horizontal layers. For each sliced layer, one or more tool paths are then generated, which provides instructions for the particular additive manufacturing system to print the given layer.SUMMARY

[0004] 3D-printable resins, including hybrid resins (e.g., mixtures of epoxy(ies) and (meth)acrylate(s)), may be used for a wide variety of applications including prototyping and end-use product. Resin compositions having improved printability and water absorption properties are needed.

[0005] Compositions having reduced viscosity and moisture absorption, without compromising mechanical performance, would expand the utility of compositions produced2024P20002WQ by additive manufacturing. The compositions and methods described herein address these and other needs.

[0006] The present disclosure provides a liquid radiation curable resin composition containing monofunctional reactants and methods for printing and using the composition. Advantageously, the liquid radiation curable resin composition has reduced viscosity and a lower propensity for water adsorption compared to a typical resin composition.

[0007] Embodiment 1 is a liquid radiation curable resin composition for additive manufacturing comprising:(a) a multifunctional cationically polymerizable component;(b) a multifunctional (meth)acrylate component;(c) a monofunctional component comprising a cationically polymerizable epoxy component, a monofunctional (meth)acrylate component, or any combination thereof;(d) a cationic photoinitiator; and(e) a free-radical photoinitiator.

[0008] Embodiment 2 is the composition of embodiment 1 , wherein the monofunctional cationically polymerizable epoxy and acrylate do not contain another polymerizable unit.

[0009] Embodiment 3 is the composition of embodiment 1 or 2, wherein the composition has a viscosity (mPa*s), when measured at 25°C, of less than 20000 mPa*s.

[0010] Embodiment 4 is the composition of any one of embodiments 1 -3, comprising both the monofunctional cationically polymerizable epoxy and the monofunctional (meth)acrylate component.

[0011] Embodiment 5 is the composition of any one of embodiments 1 -4, wherein the cationic photoinitiator is selected from the group consisting of aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, triarylsulfonium salts, diaryliodonium salts, and metallocene based compounds metallocene based compounds, aromatic phosphonium salts, acylsulfonium salts, naphthyl-sulfonium salt and any combination thereof.

[0012] Embodiment 6 is the composition of any one of embodiments 1 -5, wherein the cationic photoinitiator has an anion selected from the group consisting of BF4", AsFe", SbFe", PF6-, [B(CF3)4]-, B(C6F5)4-, B[C6H3-3,5(CF3)2]4-, B(C6H4CF3)4-, B(C6H3F2)4-, B[C6F4-4(CF3)]4-, Ga(C6F5)4-, [(C6F5)3B-C3H3N2-B(C6F5)3]-, [(C6F5)3B-NH2-B(C6F5)3]-; tetrakis(3,5-difluoro-4-alkyloxyphenyl)borate, tetrakis(2,3,5,6-tetrafluoro-4-alkyloxyphenyl)borate, perfluoroalkylsulfonates, tris[(perfluoroalkyl)sulfonyl]methides, bis[(perfluoroalkyl)sulfonyl]imides, perfluoroalkylphosphates, tris(perfluoroalkyl)trifluorophosphates, bis(perfluoroalkyl)tetrafluorophosphates, tris(pentafluoroethy)trifluorophosphates, and (CHeBnBre)-, (CHeBnCle)- and other halogenated carborane anions.

[0013] Embodiment 7 is the composition of any one of embodiments 1-6, wherein the free-radical photoinitiator is selected from the group consisting of benzoylphosphine oxides, aryl ketones, beuzophenones, hydroxylated ketones, 1 -hydroxyphenyl ketones, ketals, metallocenes, and any combination thereof.

[0014] Embodiment 8 is the composition of any one of embodiments 1 -7, wherein an epoxy component comprises the multifunctional cationically polymerizable component and the monofunctional cationically polymerizable epoxy, wherein the monofunctional cationically polymerizable epoxy is 10-90 wt.%, 20- 80 wt.%, 30-70 wt.%, or 40-60 wt.% of the epoxy component; or wherein an acrylate component comprises the multifunctional (meth)acrylate component and the monofunctional (meth)acrylate component, wherein the monofunctional (meth)acrylate component is 1 -65 wt.%, 5-60 wt.%, 10-55 wt.%, or 15-50 wt.% of the acrylate component.

[0015] Embodiment 9 is the composition of any one of embodiments 1 -8, wherein an epoxy component comprises the multifunctional cationically polymerizable component and the monofunctional cationically polymerizable epoxy, and wherein the multifunctional cationically polymerizable component is present in a total amount of 15-95 wt.%, 20-90 wt.%, 25-85 wt.%, or 30-80 wt.% of the epoxy component.

[0016] Embodiment 10 is the composition of any one of embodiments 1 -9, wherein an acrylate component comprises the multifunctional (meth)acrylate component and the monofunctional (meth)acrylate component, and wherein the multifunctional (meth)acrylate component is present in a total amount of 1 -70 wt.%, 5-65 wt.%, 10-60 wt.%, or 15-55 wt.% of the acrylate component.

[0017] Embodiment 11 is the composition of any one of embodiments 1 -10, wherein the monofunctional cationically polymerizable epoxy comprises a compound of formula (16) or (17):wherein Ri , R2, R3, and R4 are the same or different and are selected from H, straight-chain alkyl or alkoxy groups, branched or cyclic alkyl or alkoxy groups, aromatic ring systems, and heteroaromatic ring systems, where an R1 and R2 radical may optionally be joined to one another and may form a ring; and where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems optionally substituted by one or more radicals selected from Cl, I, Br, F, or a functional group comprising carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide.

[0018] Embodiment 12 is the composition of any one of embodiments 1 -11 , wherein the monofunctional cationically polymerizable epoxy comprises a compound of formula (18),wherein R1, R2, R3, and R4 are the same or different and are selected from H, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 40 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; and where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems optionally substituted by one or more radicals selected from2024P20002WQCl, I, Br, F, or a functional group comprising carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide.

[0019] Embodiment 13 is the composition of any one of embodiments 1 -12, wherein Ri , R2, R3, and / or R4 comprise an alkyl having 12 to 14 carbon atoms.

[0020] Embodiment 14 is the composition of any one of embodiments 1 -13, wherein the monofunctional cationically polymerizable epoxy comprises at least one of

[0021] Embodiment 15 is the composition of any one of embodiments 1 -14, wherein the monofunctional meth(acrylate) component comprises at least one of:

[0022] Embodiment 16 is the composition of any one of embodiments 1 -15, wherein the multifunctional cationically polymerizable component comprises a difunctional epoxy, a bicyclic bis-epoxide monomer, or a poly(glycidyl ether).

[0023] Embodiment 17 is the composition of any one of embodiments 1 -16, wherein the multifunctional cationically polymerizable component comprises hydrogenated Bisphenol A digycydylether epoxy, polymeric aryl glycidylethers, 3,4-Epoxycyclohexylmethyl 3', 4'- epoxycyclohexanecarboxylate, bisphenol A diglycidyl ether, poly(1 ,4-butanediol diglycidyl ether, neopentylglycol diglycidylether, or 1 ,4-Butanediol diglycidyl ether.2024P20002WQ

[0024] Embodiment 18 is the composition of any one of embodiments 1 -17, wherein the multifunctional cationically polymerizable component comprises a structure of formula (1 ):wherein R1 and R2 are the same or different and are selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, for example R1 and R2 may be selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethylene, propene, butene, pentene, hexene, acetylene, propargyl, butynyl, pentynyl, hexynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, morpholinyl, piperidyl, pyrrolidinyl, tetrahydrofuranyl, phenyl, benzyl, napthyl, toluyl, anisyl, aromatic ring systems such as diphenylmethane, cycloalkyl ring systems such as dicyclohexylmethane, wherein the R1 and / or R2 group can be optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, cycloalkyl, aromatic, aryl, heteroaryl, heteroalkyl, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide, and wherein n and m, independently, are 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0025] Embodiment 19 is the composition of any one of embodiments 1 -18, wherein the multifunctional cationically polymerizable component comprises a compound selected from the group consisting of:2024P20002WQwherein n is 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0026] Embodiment 20 is the composition of any one of embodiments 1 -19, wherein the multifunctional (meth)acrylate component comprises a compound of formula (6) or (7):wherein R, R3, and R4 are the same or different and are selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, for example R, R3, and R4 may be selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethylene, propene, butene, pentene, hexene, acetylene, propargyl, butynyl, pentynyl, hexynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, morpholinyl, piperidyl, pyrrolidinyl, tetrahydrofuranyl, phenyl, benzyl, napthyl, toluyl, anisyl, aromatic ring systems such as diphenylmethane, cycloalkyl ring systems such as dicyclohexylmethane, wherein the R, R3, and / or R4 group can be optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, cycloalkyl, aromatic, aryl, heteroaryl, heteroalkyl, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide.R1 and R2 are the same or different and are selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, for example R1 and R2 may be selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethylene, propene, butene,2024P20002WQ pentene, hexene, acetylene, propargyl, butynyl, pentynyl, hexynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, morpholinyl, piperidyl, pyrrolidinyl, tetrahydrofuranyl, phenyl, benzyl, napthyl, toluyl, anisyl, aromatic ring systems such as diphenylmethane, cycloalkyl ring systems such as dicyclohexylmethane, wherein the R1 and / or R2 group can be optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, cycloalkyl, aromatic, aryl, heteroaryl, heteroalkyl, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide, a= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and b= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0027] Embodiment 21 is the composition of any one of embodiments 1 -20, wherein the multifunctional (meth)acrylate component comprises a compound of formula (8) or (9):wherein a= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and b= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.(9), wherein n= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and m= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0028] Embodiment 22 is the composition of any one of embodiments 1 -21 , wherein the multifunctional (meth)acrylate component comprises at least one ofm= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0029] Embodiment 23 is the composition of any one of embodiments 1 -22, wherein the composition further comprises a chain transfer agent.

[0030] Embodiment 24 is the composition of any one of embodiments 1 -23, wherein the chain transfer agent (CTA) comprises a reactive hydroxyl group, a reactive sulfonyl group, a reactive sulfonamide group, a reactive sulfhydryl group, a reactive amine group, or a combination thereof.

[0031] Embodiment 25 is the composition of any one of embodiments 1 -24, wherein the chain transfer agent (CTA) comprises less than 40 wt.% of the total weight of the composition.

[0032] Embodiment 26 is the composition of any one of embodiments 1 -25, further comprising an additive.

[0033] Embodiment 27 is the composition of any one of embodiments 1 -26, wherein the additive comprises flame retardants, anti-dripping agents, antioxidants, thermal stabilizers, impact modifiers, fillers, antistats, colorants, pigments, lubricants, defoamers, flow control agents, demolding agents, hydrolysis stabilizers, compatibilizers, UV and / or IR absorbers, or any combination thereof.

[0034] Embodiment 28 is the composition of any one of embodiments 1 -27, wherein the composition further comprises an oxetane.

[0035] Embodiment 29 is the composition of any one of embodiments 1 -28, wherein the oxetane comprises a monofunctional and / or multifunctional oxetane.

[0036] Embodiment 30 is the composition of any one of embodiments 1 -29, wherein the oxetane is from about 0 to about 50 wt.% of the composition.

[0037] Embodiment 31 is the composition of any one of embodiments 1 -30, wherein the multifunctional cationically polymerizable component is a multifunctional cationically polymerizable aliphatic epoxide, and wherein the monofunctional cationically polymerizable epoxy is a monofunctional cationically polymerizable aliphatic epoxide.

[0038] Embodiment 32 is an article comprising the composition of any one of embodiments 1 -31 .

[0039] Embodiment 33 is the article of embodiment 32, wherein the article has a percent water adsorption of less than 1 .5%.

[0040] Embodiment 34 is the article of embodiment 32 or 33, wherein the article has a modulus of elasticity from about 10 to about 5000 MPa.

[0041] Embodiment 35 is the article of any one of embodiments 32-34, wherein the article has a maximum tensile stress from about 5 to about 100 MPa.

[0042] Embodiment 36 is the article of any one of embodiments 32-35, wherein the article has an elongation at break from about 1 to about 100%.

[0043] Embodiment 37 is the article of any one of embodiments 32-36, wherein the article has a load value of about 100 to about 5000 N.

[0044] Embodiment 38 is a method of manufacturing a 3D printed article, comprising: curing the composition of any one of embodiments 1-31 , the curing comprising irradiating the composition to form a crosslinked material.

[0045] Embodiment 39 is the method of embodiment 38, wherein irradiating the composition generates radicals from radical starters present in the composition, wherein the radicals initiate a reaction between radically polymerizable multifunctional and monofunctional (meth)acrylate components in the composition.

[0046] Embodiment 40 is the method of embodiment 39, wherein irradiating the composition generates cations from cation starters present in the composition, wherein the cations initiate a reaction between the multifunctional cationically polymerizable component and the monofunctional epoxy component in the composition.

[0047] Embodiment 41 is the method of embodiment 38 or 39, comprising: selectively irradiating the composition according to a pre-determined crosssection of a target article to be manufactured; and repeating the selective irradiation until a predetermined intermediate article comprising the composition is obtained.

[0048] Embodiment 42 is the method of any one of embodiments 38-41 , wherein prior to step irradiating, the composition is selectively applied onto a surface according to the predetermined cross-section of a target article to be manufactured.BRIEF DESCRIPTION OF THE DRAWINGS2024P20002WG

[0049] The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments, and together with the description serve to explain the principles of the disclosure.

[0050] FIG. 1 shows a couple of 3D printed objects, the first object being printed with a liquid radiation curable resin composition according to an embodiment of the present invention (M1 ), and the second object being printed with a reference composition (C1); and

[0051] FIGs. 2A-2C shows three different views of another couple of 3D printed objects, the first object being printed with a liquid radiation curable resin composition according to an embodiment of the present invention (M1 ), and the second object being printed with a reference composition (C1 ).DETAILED DESCRIPTIONI. Definitions

[0052] As used herein, the singular forms “a”, “an” and “the” include plural unless the context clearly dictates otherwise. Moreover, when an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the disclosure be limited to the specific values recited when defining a range.

[0053] As used herein, the term “room temperature” refers to a temperature of 25°C.

[0054] As used herein throughout, the term “about” refers to ± 10 % or ± 5 %.

[0055] The terms "comprises", "comprising", "includes", "including", “having” and their conjugates mean "including but not limited to".

[0056] The term “consisting of” means “including and limited to”.

[0057] The term "consisting essentially of" means that the liquid radiation curable resin composition, method or structure may include additional ingredients, steps and / or parts, butonly if the additional ingredients, steps and / or parts do not materially alter the basic and novel characteristics of the claimed liquid radiation curable resin composition, method or structure.

[0058] Throughout this application, various embodiments of the present disclosure may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the present disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1 , 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0059] As used herein, the phrase “within any range encompassing any two of these values as endpoints” literally means that any range may be selected from any two of the values listed prior to such phrase regardless of whether the values are in the lower part of the listing or in the higher part of the listing. For example, a pair of values may be selected from two lower values, two higher values, or a lower value and a higher value.

[0060] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging / ranges between” a first indicate number and a second indicate number and “ranging / ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[0061] Herein the terms "method" and “process” are used interchangeably and refer to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts.

[0062] Herein throughout, whenever the phrase “weight percent”, or “% by weight” or “wt.%”, is indicated in the context of embodiments of a formulation (e.g., a modeling2024P20002WQ formulation), it is meant weight percent of the total weight of the respective uncured formulation.

[0063] Herein throughout, an acrylic material is used to collectively describe material featuring one or more acrylate, e.g., methacrylate, acrylamide and / or methacrylamide group(s).

[0064] Similarly, an acrylic group is used to collectively describe curable groups which can include acrylate, methacrylate, acrylamide and / or methacrylamide group(s), e.g., acrylate or methacrylate groups (referred to herein also as (meth)acrylate groups).

[0065] Herein throughout, the term “(meth)acrylic” encompasses acrylic and methacrylic materials, including urethane acrylates.

[0066] Herein throughout, the phrase “linking moiety” or “linking group” describes a group that connects two or more moieties or groups in a compound. A linking moiety can be derived from a bi- or tri-functional compound, and can be regarded as a bi- or tri-radical moiety, which is connected to two or three other moieties, via two or three atoms thereof, respectively.

[0067] Exemplary linking moieties include a hydrocarbon moiety or chain, optionally interrupted by one or more heteroatoms, as defined herein, and / or any of the chemical groups listed below, when defined as linking groups.

[0068] When a chemical group is referred to herein as an “end group,” the chemical group is to be interpreted as a substituent, which is connected to another group via one atom thereof.

[0069] Herein throughout, the term “hydrocarbon” collectively describes a chemical group composed mainly of carbon and hydrogen atoms. A hydrocarbon can be comprised of alkyl, alkene, alkyne, aryl, and / or cycloalkyl, each can be substituted or unsubstituted, and can be interrupted by one or more heteroatoms. The number of carbon atoms can range from 2 to 30, e.g., from 1 to 10, from 1 to 6, from 3 to 7, or from 1 to 4. A hydrocarbon can be a linking group or an end group.

[0070] Bisphenol A is an example of a hydrocarbon comprised of two aryl groups and one alkyl group. Dimethylenecyclohexane is an example of a hydrocarbon comprised of two alkyl groups and one cycloalkyl group.

[0071] As used herein, the term “amine” describes both a -NR’R” group and a -NR'- group, wherein R’ and R" are each independently hydrogen, alkyl, cycloalkyl, aryl, as these terms are defined herein.

[0072] The amine group can therefore be a primary amine, where both R’ and R” are hydrogen, a secondary amine, where R’ is hydrogen and R” is alkyl, cycloalkyl or aryl, or a tertiary amine, where each of R’ and R” is independently alkyl, cycloalkyl or aryl.

[0073] R' and R" can each independently be hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, carbonyl, C-carboxylate, O-carboxylate, N thiocarbamate, O thiocarbamate, urea, thiourea, N carbamate, O carbamate, C-amide, N amide, guanyl, guanidine and hydrazine.

[0074] The term “amine” is used herein to describe a -NR'R" group in cases where the amine is an end group, as defined herein, and is also used herein to describe a -NR'- group in cases where the amine is a linking group or is or part of a linking moiety.

[0075] The term "alkyl" describes a saturated aliphatic hydrocarbon including straight chain and branched chain groups. In some examples, the alkyl group has 1 to 30, or 1 to 20 carbon atoms. Whenever a numerical range; e.g., "1-20", is stated herein, it implies that the group has anywhere from 1 to 20 ca. In this case the alkyl group, may contain 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms. The alkyl group may be substituted or unsubstituted. Substituted alkyl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N thiocarbamate, O thiocarbamate, urea, thiourea, N carbamate, O carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine.

[0076] The alkyl group can be an end group, as this phrase is defined herein, wherein it is attached to a single adjacent atom, or a linking group, as this phrase is defined herein, which connects two or more moieties via at least two carbons in its chain. When the alkyl is a linking group, it is also referred to herein as “alkylene” or “alkylene chain”.

[0077] Alkene and alkyne, as used herein, are an alkyl, as defined herein, which contains one or more double bond or triple bond, respectively.

[0078] The term "cycloalkyl" describes an all-carbon monocyclic ring or fused rings (i. e. , rings which share an adjacent pair of carbon atoms) group where one or more of the rings does not have a completely conjugated pi-electron system. Examples include, without limitation, cyclohexane, adamantine, norbornyl, isobornyl, and the like. The cycloalkyl group may be substituted or unsubstituted. Substituted cycloalkyl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N thiocarbamate, 0 thiocarbamate, urea, thiourea, N carbamate, 0 carbamate, C amide, N amide, guanyl, guanidine and hydrazine. The cycloalkyl group can be an end group, as this phrase is defined herein, wherein it is attached to a single adjacent atom, or a linking group, as this phrase is defined herein, connecting two or more moieties at two or more positions thereof.

[0079] The term "heteroalicyclic" describes a monocyclic or fused ring group having in the ring(s) one or more atoms such as nitrogen, oxygen and sulfur. The rings may also have one or more double bonds. However, the rings do not have a completely conjugated pi- electron system. Representative examples are piperidine, piperazine, tetrahydrofurane, tetrahydropyrane, morpholino, oxalidine, and the like.

[0080] The heteroalicyclic may be substituted or unsubstituted. Substituted heteroalicyclic have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N thiocarbamate, O thiocarbamate, urea, thiourea, O-carbamate, N- carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine. The heteroalicyclic group can be an end group, as this phrase is defined herein, where it is attached to a single adjacent atom, or a linking group, as this phrase is defined herein, connecting two or more moieties at two or more positions thereof.2024P20002WC

[0081] The term "aryl" describes an all-carbon monocyclic or fused-ring polycyclic (i.e., rings which share adjacent pairs of carbon atoms) groups having a completely conjugated pi- electron system. The aryl group may be substituted or unsubstituted. Substituted aryl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, 0- carboxylate, N thiocarbamate, 0 thiocarbamate, urea, thiourea, N carbamate, 0 carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine. The aryl group can be an end group, as this term is defined herein, wherein it is attached to a single adjacent atom, or a linking group, as this term is defined herein, connecting two or more moieties at two or more positions thereof.

[0082] The term "heteroaryl" describes a monocyclic or fused ring (i.e., rings which share an adjacent pair of atoms) group having in the ring(s) one or more atoms, such as, for example, nitrogen, oxygen and sulfur and, in addition, having a completely conjugated pi- electron system. Examples, without limitation, of heteroaryl groups include pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, pyrimidine, quinoline, isoquinoline and purine. The heteroaryl group may be substituted or unsubstituted. Substituted heteroaryl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O- carboxylate, N thiocarbamate, 0 thiocarbamate, urea, thiourea, O-carbamate, N-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine. The heteroaryl group can be an end group, as this phrase is defined herein, where it is attached to a single adjacent atom, or a linking group, as this phrase is defined herein, connecting two or more moieties at two or more positions thereof. Representative examples are pyridine, pyrrole, oxazole, indole, purine and the like.

[0083] The term "halide" and “halo” describes fluorine, chlorine, bromine or iodine.

[0084] The term “haloalkyl” describes an alkyl group as defined above, further substituted by one or more halide.

[0085] The term “sulfate” describes a -O-S(=O)2-OR’ end group, as this term is defined herein, or an -O-S(=O)2-O- linking group, as these phrases are defined herein, where R’ is as defined herein.

[0086] The term “thiosulfate” describes a -O-S(=S)(=O)-OR’ end group or a -0- S(=S)(=O)-O- linking group, as these phrases are defined herein, where R’ is as defined herein.

[0087] The term “sulfite” describes an -O-S(=O)-O-R’ end group or a O S(=O) O- group linking group, as these phrases are defined herein, where R’ is as defined herein.

[0088] The term “thiosulfite” describes a -O-S(=S)-O-R’ end group or an -O-S(=S)- O- group linking group, as these phrases are defined herein, where R’ is as defined herein.

[0089] The term “sulfinate” describes a -S(=O)-OR’ end group or an -S(=O)-O- group linking group, as these phrases are defined herein, where R’ is as defined herein.

[0090] The term “sulfoxide” or “sulfinyl” describes a -S(=O)R’ end group or an -S(=O)- linking group, as these phrases are defined herein, where R’ is as defined herein.

[0091] The term "sulfonate” describes a -S(=O)2-R’ end group or an -S(=O)2- linking group, as these phrases are defined herein, where R’ is as defined herein.

[0092] The term “S-sulfonamide” describes a -S(=O)2-NR’R” end group or a -S(=O)2- NR’- linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0093] The term "N-sulfonamide" describes an R’S(=O)2-NR”- end group or a S(=O)2 NR’- linking group, as these phrases are defined herein, where R’ and R” are as defined herein.

[0094] The term “disulfide” refers to a -S-SR’ end group or a -S-S- linking group, as these phrases are defined herein, where R’ is as defined herein.

[0095] The term “phosphonate” describes a -P(=O)(OR’)(OR”) end group or a P(=O)(OR’)(O)- linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0096] The term “thiophosphonate” describes a -P(=S)(OR’)(OR”) end group or a P(=S)(OR’)(O)- linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0097] The term “phosphinyl” describes a -PR'R" end group or a -PR’- linking group, as these phrases are defined herein, with R’ and R" as defined herein.

[0098] The term “phosphine oxide” describes a -P(=O)(R’)(R”) end group or a P(=O)(R’) linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0099] The term “phosphine sulfide” describes a -P(=S)(R’)(R”) end group or a P(=S)(R’) linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0100] The term “phosphite” describes an -O-PR'(=O)(OR") end group or an -O- PH(=O)(O)- linking group, as these phrases are defined herein, with R’ and R" as defined herein.

[0101] The term "carbonyl" or "carbonate" as used herein, describes a -C(=O)-R’ end group or a -C(=O)- linking group, as these phrases are defined herein, with R’ as defined herein.

[0102] The term "thiocarbonyl" as used herein, describes a -C(=S)-R’ end group or a - C(=S)- linking group, as these phrases are defined herein, with R’ as defined herein.

[0103] The term “oxo” as used herein, describes a (=0) group, wherein an oxygen atom is linked by a double bond to the atom (e.g., carbon atom) at the indicated position.

[0104] The term “thiooxo” as used herein, describes a (=S) group, wherein a sulfur atom is linked by a double bond to the atom (e.g., carbon atom) at the indicated position.

[0105] The term “oxime” describes a =N-OH end group or a =N-O- linking group, as these phrases are defined herein.

[0106] The term “hydroxyl” describes a -OH group.

[0107] The term "alkoxy" describes both an -O-alkyl and an -O-cycloalkyl group, as defined herein. The term alkoxide describes -R’O- group, with R’ as defined herein.

[0108] The term "aryloxy" describes both an -O-aryl and an -O-heteroaryl group, as defined herein.

[0109] The term "thiohydroxy" or “thiol” describes a -SH group. The term “thiolate” describes a -S- group.

[0110] The term "thioalkoxy" describes both a -S-alkyl group, and a -S-cycloalkyl group, as defined herein.

[0111] The term "thioaryloxy" describes both a -S-aryl and a -S-heteroaryl group, as defined herein.

[0112] The “hydroxyalkyl” is also referred to herein as “alcohol”, and describes an alkyl, as defined herein, substituted by a hydroxy group.

[0113] The term "cyano" describes a -C=N group.

[0114] The term “isocyanate” describes an -N=C=O group.

[0115] The term “isothiocyanate” describes an -N=C=S group.

[0116] The term "nitro" describes an -NO2 group.

[0117] The term “acyl halide” describes a -(C=O)R"" group wherein R"" is halide, as defined herein.

[0118] The term "azo" or “diazo” describes an -N=NR’ end group or an -N=N linking group, as these phrases are defined herein, with R’ as defined herein.

[0119] The term "peroxo" describes an -O-OR’ end group or an -0-0 linking group, as these phrases are defined herein, with R’ as defined herein.

[0120] The term “carboxylate” as used herein encompasses C-carboxylate and O- carboxylate.

[0121] The term “C carboxylate” describes a -C(=O)-OR’ end group or a -C(=0)-0 linking group, as these phrases are defined herein, where R’ is as defined herein.

[0122] The term “O carboxylate” describes a -OC(=O)R’ end group or a -OC(=O) linking group, as these phrases are defined herein, where R’ is as defined herein.

[0123] A carboxylate can be linear or cyclic. When cyclic, R’ and the carbon atom are linked together to form a ring, in C-carboxylate, and this group is also referred to as lactone. Alternatively, R’ and O are linked together to form a ring in O -carboxy I ate. Cyclic carboxylates can function as a linking group, for example, when an atom in the formed ring is linked to another group.

[0124] The term “thiocarboxylate” as used herein encompasses C-th iocarboxylate and O-thiocarboxylate.

[0125] The term “C thiocarboxylate” describes a -C(=S)-OR’ end group or a -C(=S)-0 linking group, as these phrases are defined herein, where R’ is as defined herein.

[0126] The term “O thiocarboxylate” describes a -OC(=S)R’ end group or a -OC(=S) linking group, as these phrases are defined herein, where R’ is as defined herein.

[0127] A thiocarboxylate can be linear or cyclic. When cyclic, R’ and the carbon atom are linked together to form a ring, in C-th iocarboxylate, and this group is also referred to as i n9thiolactone. Alternatively, R’ and 0 are linked together to form a ring in O-th iocarboxylate. Cyclic thiocarboxylates can function as a linking group, for example, when an atom in the formed ring is linked to another group.

[0128] The term “carbamate” as used herein encompasses N-carbamate and 0- carbamate.

[0129] The term “N-carbamate” describes an R”0C(=0)-NR’- end group or a OC(=O)- NR’- linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0130] The term “O-carbamate” describes an -OC(=O)-NR’R” end group or an - OC(=O)-NR’ linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0131] A carbamate can be linear or cyclic. When cyclic, R’ and the carbon atom are linked together to form a ring, in O-carbamate. Alternatively, R’ and O are linked together to form a ring in N-carbamate. Cyclic carbamates can function as a linking group, for example, when an atom in the formed ring is linked to another group.

[0132] The term “carbamate” as used herein encompasses N-carbamate and O- carbamate.

[0133] The term “thiocarbamate” as used herein encompasses N-thiocarbamate and O-thiocarbamate.

[0134] The term “O-thiocarbamate” describes a OC(=S) NR’R” end group or a OC(=S) NR’ linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0135] The term “N-thiocarbamate” describes an R”OC(=S)NR’- end group or a OC(=S)NR’- linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0136] Thiocarbamates can be linear or cyclic, as described herein for carbamates.

[0137] The term “dithiocarbamate” as used herein encompasses S-dithiocarbamate and N-dithiocarbamate.

[0138] The term “S-dithiocarbamate” describes a SC(=S) NR’R” end group or a SC(=S)NR’ linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0139] The term “N-dithiocarbamate” describes an R”SC(=S)NR’- end group or a SC(=S)NR’- linking group, as these phrases are defined herein, with R’ and R” as defined herein.

[0140] The term "urea", which is also referred to herein as “ureido”, describes a NR’C(=O)-NR”R”’ end group or a NR’C(=O)-NR” linking group, as these phrases are defined herein, where R’ and R” are as defined herein and R'" is as defined herein for R' and R".

[0141] The term “thiourea”, which is also referred to herein as “thioureido”, describes a -NR’-C(=S)-NR”R”’ end group or a -NR’-C(=S)-NR” linking group, with R’, R” and R’” as defined herein.

[0142] The term “amide” as used herein encompasses C-amide and N-amide.

[0143] The term “C-amide” describes a -C(=O)-NR’R” end group or a -C(=O)-NR’ linking group, as these phrases are defined herein, where R’ and R” are as defined herein.

[0144] The term “N-amide” describes a R’C(=O)-NR”- end group or a R’C(=O)-N- linking group, as these phrases are defined herein, where R’ and R” are as defined herein.

[0145] An amide can be linear or cyclic. When cyclic, R’ and the carbon atom are linked together to form a ring, in C-amide, and this group is also referred to as lactam. Cyclic amides can function as a linking group, for example, when an atom in the formed ring is linked to another group.

[0146] The term “guanyl” describes a R’R”NC(=N)- end group or a -R’NC(=N)- linking group, as these phrases are defined herein, where R’ and R” are as defined herein.

[0147] The term “guanidine” describes a -R’NC(=N)-NR”R”’ end group or a -R’NC(=N) NR” linking group, as these phrases are defined herein, where R’, R" and R'" are as defined herein.

[0148] The term “hydrazine” describes a -NR’-NR”R”’ end group or a -NR’-NR” linking group, as these phrases are defined herein, with R’, R”, and R'" as defined herein.

[0149] As used herein, the term “hydrazide” describes a -C(=O)-NR’ NR”R”’ end group or a -C(=O)-NR’-NR” linking group, as these phrases are defined herein, where R’, R” and R’” are as defined herein.

[0150] As used herein, the term “thiohydrazide” describes a -C(=S)-NR’ NR”R”’ end group or a -C(=S)-NR’-NR” linking group, as these phrases are defined herein, where R’, R” and R’” are as defined herein.

[0151] As used herein, the term “alkylene glycol” describes a -O-[(CR’R”)z-O]y-R”’ end group or a -O-[(CR’R”)z-O]y- linking group, with R’, R” and R’” being as defined herein, and with z being an integer of from 1 to 10, preferably, from 2 to 6, more preferably 2 or 3, and y being an integer of 1 or more. Preferably R’ and R” are both hydrogen. When z is 2 and y is 1 , this group is ethylene glycol. When z is 3 and y is 1 , this group is propylene glycol. When y is 2-4, the alkylene glycol is referred to herein as oligo(alkylene glycol).

[0152] The term “silanol” describes a -Si(OH)R’R” group, or -Si(OH)2R’ group or - Si(OH)3 group, with R’ and R” as described herein.

[0153] The term “silyl” describes a -SiR’R”R”’ group, with R’, R” and R’” as described herein.

[0154] As used herein, the term “urethane” or “urethane moiety” or “urethane group” describes a Rx-O-C(=O)-NR’R” end group or a -Rx-O-C(=O)-NR’- linking group, with R’ and R” being as defined herein, and Rx being an alkyl, cycloalkyl, aryl, alkylene glycol or any combination thereof. Preferably R’ and R” are both hydrogen.

[0155] The term “polyurethane” or “oligourethane” describes a moiety that comprises at least one urethane group as described herein in the repeating backbone units thereof, or at least one urethane bond, -O-C(=O)-NR’-, in the repeating backbone units thereof.

[0156] Herein throughout, whenever the phrase “weight percents”, or “% by weight” or “wt.%”, is indicated in the context of embodiments of a formulation (e.g., a modeling formulation), it is meant weight percents of the total weight of the respective uncured formulation.

[0157] Herein, an “ethoxylated” material describes an acrylic or methacrylic compound which comprises one or more alkylene glycol groups, or, preferably, one or more alkylene glycol chains, as defined herein. Ethoxylated (meth)acrylate materials can be monofunctional, or, preferably, multi-functional, namely, di-functional, tri-functional, tetrafunctional, etc.

[0158] In multi-functional materials, each of the (meth)acrylate groups can be linked to an alkylene glycol group or chain, and the alkylene glycol groups or chains are linked to one another through a branching unit, such as, for example, a branched alkyl, cycloalkyl, aryl (e.g., Bisphenol A), etc.2024P20002WQ

[0159] In some embodiments, the ethoxylated material comprises at least one, or at least two ethoxylated group(s), that is, at least one or at least two alkylene glycol moieties or groups. Some or all of the alkylene glycol groups can be linked to one another to form an alkylene glycol chain. For example, an ethoxylated material that comprises 30 ethoxylated groups can comprise a chain of 30 alkylene glycol groups linked to one another, two chains, each, for example, of 15 alkylene glycol moieties linked to one another, the two chains linked to one another via a branching moiety, or three chains, each, for example, of 10 alkylene glycol groups linked to one another, the three chains linked to one another via a branching moiety. Shorter and longer chains are also part of the present disclosure.

[0160] The ethoxylated material can comprise one, two or more alkylene glycol chains, of any length.

[0161] The term “branching unit” as used herein describes a multi-radical, e.g., aliphatic or alicyclic group. By “multi-radical” it is meant that the unit has two or more attachment points such that it links between two or more atoms and / or groups or moieties.

[0162] In some embodiments, the branching unit is derived from a chemical moiety that has two, three or more functional groups. In some embodiments, the branching unit is a branched alkyl or a cycloalkyl (alicyclic) or an aryl (e.g., phenyl) as defined herein.

[0163] Herein throughout, "Tg" of a material refers to glass transition temperature defined as the location of the local maximum of the E" curve, where E" is the loss modulus of the material as a function of the temperature.

[0164] Broadly speaking, as the temperature is raised within a range of temperatures containing the Tg temperature, the state of a material, e.g., a polymeric material, gradually changes from a glassy state into a rubbery state.

[0165] Herein, "Tg range" is a temperature range at which the E" value is at least half its value (e.g., can be up to its value) at the Tg temperature as defined above.

[0166] Without wishing to be bound to any particular theory, it is assumed that the state of a polymeric material gradually changes from the glassy state into the rubbery within the Tg range as defined above. The lowest temperature of the Tg range is referred to herein as Tg(low) and the highest temperature of the Tg range is referred to herein as Tg (high).II. Liquid Radiation Curable Resin Compositions

[0167] The present disclosure provides liquid radiation curable resin compositions including a series of monomer, oligomer, and polymer components, a cationic photoinitiator and a free-radical photoinitiator. The liquid radiation curable resin compositions of the present disclosure can be used in 3D-printing processes where a UV cure is performed first to form a specific part, followed by an optional thermal cure to fully set the part.

[0168] Generally, the liquid radiation curable resin compositions of the present disclosure include the following components:(a) a multifunctional cationically polymerizable component;(b) a multifunctional (meth)acrylate component;(c) a monofunctional component comprising a cationically polymerizable epoxy component, a monofunctional (meth)acrylate component, or any combination thereof;(d) a cationic photoinitiator; and(e) a free-radical photoinitiator

[0169] While current knowledge in the art teaches several disadvantages to including a monofunctional reactant in a curable composition, the present disclosure of liquid radiation curable resin compositions containing monofunctional reactants had unexpectedly advantageous properties, including low viscosity and low water adsorption. Whereas slow reaction speed of monofunctional reactants and poor mechanical properties discourage the use of monofunctional reactants in 3D printing applications, the present disclosure describes the discovery of several advantageous properties of the liquid radiation curable resin compositions, methods, and articles.

[0170] Multifunctional Cationically Polymerizable Component

[0171] In some embodiments, the liquid radiation curable resin compositions for additive fabrication of the present disclosure comprise at least one cationically polymerizable component; that is a component which undergoes polymerization initiated by cations or in the presence of acid generators. The cationically polymerizable components may be monomers, oligomers, and / or polymers, and may contain aliphatic, aromatic, cycloaliphatic, arylaliphatic, heterocyclic moiety(ies), and any combination thereof. In some embodiments, the cationically polymerizable component includes at least one cycloaliphatic compound. Suitable cyclic2024P20002WQ ether compounds can comprise cyclic ether groups as side groups or groups that form part of an alicyclic or heterocyclic ring system.

[0172] The cationically polymerizable component can be selected from the group consisting of cyclic ether compounds, cyclic acetal compounds, cyclic thioethers compounds, spiro-orthoester compounds, cyclic lactone compounds, and any combination thereof.

[0173] Suitable cationically polymerizable components include cyclic ether compounds such as epoxy compounds and oxetanes, cyclic lactone compounds, cyclic acetal compounds, cyclic thioether compounds, and spiro-orthoester compounds. Specific examples of cationically polymerizable components include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, epoxy novolac resins, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 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 doxide, 4- vinylepoxycyclohexane, vinylcyclohexene dioxide, limonene oxide, limonene dioxide, bis(3,4- epoxy-6-methylcyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexyl-3',4'-epoxy-6 - methylcyclohexanecarboxylate, E-caprolactone-modified 3,4-epoxycyclohexylmethyl-3',4'- epoxycyclohexane carboxylates, trimethylcaprolactone-modified 3,4-epoxycyclohexylmethyl- 3',4'-epoxycyclohexane carboxylates, [3-methyl-b-valerolactone-modified 3,4- epoxycyclohexcylmethyl-3',4'-epoxycyclohexane carboxylates, methylenebis(3,4- epoxycyclohexane), bicyclohexyl-3,3'-epoxide, bis(3,4-epoxyeyclohexyl) with a linkage of — 0— , — S— , —SO—, — C(CH3)2— , — CBr2— , — C(CBr3)2— , — C(CCI3)2— , or — CH(C6H5)— , dicyclopentadiene diepoxide, di(3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis(3,4-epoxycyclohexanecarboxylate), epoxyhexahydrodioctylphthalate, epoxyhexahydro-di-2 -ethylhexyl phthalate, 1 ,4-butanediol diglycidyl ether, 1 ,6-hexanediol diglycidyl ether, neopentylglycol diglycidyl ether (available as DE 203 from Kukdo Chemical), glycerol triglycidy I ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, diglycidyl esters of aliphatic long-chain dibasic acids, monoglycidyl ethers of aliphatic higher alcohols, monoglycidyl ethers of phenol, cresol, butyl phenol, or polyether alcohols obtained by the addition of alkylene oxide to thesecompounds, glycidyl esters of higher fatty acids, epoxidated soybean oil, epoxybutylstearic acid, epoxyoctylstearic acid, epoxidated linseed oil, epoxidated polybutadiene, 1 ,4-bis[(3- ethyl-3-oxetanylmethoxy)methyl]benzene, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(3- hydroxypropyl)oxymethyloxetane, 3-ethyl-3-(4-hydroxybutyl)oxymethyloxetane, 3-ethyl-3-(5- hydroxypentyl)oxymethyloxetane, 3-ethyl-3-phenoxymethyloxetane, bis(( 1 -ethyl(3- oxetanyl))methyl)ether, 3-ethyl-3((2-ethylhexyloxy)methyl)oxetane, 3-ethyl- ((triethoxysilylpropoxymethyl)oxetane, 3-(meth)-allyloxymethyl-3-ethyloxetane, 3- hydroxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy)methylbenzene, 4-fluoro-[1 -(3- ethyl-3-oxetanylmethoxy)methyl]benzene, 4-methoxy-[1 (3-ethyl-3-oxetanylmethoxy)methyl]- benzene, [1-(3-ethyl-3-oxetanylmethoxy)ethyl]phenyl ether, isobutoxymethyl(3-ethyl-3- oxetanylmethyl)ether, 2-ethylhexyl(3-ethyl-3-oxetanylmethyl)ether, ethyldiethylene glycol(3- ethyl-3-oxetanylmethyl)ether, dicyclopentadiene (3-ethyl-3-oxetanylmethyl)ether, dicyclopentenyloxyethyl(3-ethyl-3-oxetanylmethyl)ether, dicyclopentenyl(3-ethyl-3- oxetanylmethyl)ether, tetrahydrofurfuyl(3-ethyl-3-oxetanylmethyl)ether, 2-hydroxyethyl(3- ethyl-3-oxetanylmethyl)ether, 2-hydroxypropyl(3-ethyl-3-oxetanylmethyl)ether, and any combination thereof.

[0174] The multifunctional cationically polymerizable component may contain polyfunctional materials including dendritic polymers such as dendrimers, linear dendritic polymers, dendrigraft polymers, hyperbranched polymers, star branched polymers, and hypergraft polymers with epoxy or oxetane functional groups. The dendritic polymers may contain one type of polymerizable functional group or different types of polymerizable functional groups, for example, epoxy and oxetane functions.

[0175] In some embodiments, the liquid radiation curable resin composition of the present disclosure also includes one or more mono or poly glycidylethers of aliphatic alcohols, aliphatic polyols, aliphatic epoxides, polyesterpolyols or polyetherpolyols. Examples of components include 1 ,4-butanedioldiglycidylether, glycidylethers of polyoxyethylene and polyoxypropylene glycols and triols of molecular weights from about 200 to about 10,000; glycidylethers of polytetramethylene glycol or poly(oxyethylene-oxybutylene) random or block copolymers. In some embodiments, the cationically polymerizable component comprises a polyfunctional glycidylether that lacks a cyclohexane ring in the molecule. In some embodiments, the cationically polymerizable component includes a neopentyl glycol diglycidyl2024P20002WG ether. In some embodiments, the cationically polymerizable component includes a 1 ,4cyclohexanedimethanol diglycidyl ether.

[0176] Examples of commercially available polyfunctional glycidylethers include Erisys™ GE 22 (Erisys™ products are available from Emerald Performance Materials™). Heloxy™ 48, Heloxy™ 67, Heloxy™ 68, Heloxy™ 107 (Heloxy™ modifiers are available from Momentive Specialty Chemicals), and Grilonit® F713. Examples of commercially available monofunctional glycidylethers include Heloxy™ 71 , Helsoxy™ 505, Heloxy™ 7, Heloxy™ 8, and Heloxy™ 61.

[0177] In some embodiments, the epoxide is 3,4-epoxycyclohexylmethyl-3',4- epoxycyclohexanecarboxylate (available as CELLOXIDE™ 2021 P from Daicel Chemical, or as CYRACURE™ UVR-6105 from Dow Chemical), hydrogenated bisphenol A- epichlorohydrin based epoxy resin (available as EPON™ 1510 from Momentive), 1 ,4- cyclohexanedimethanol diglycidyl ether (available as HELOXY™ 107 from Momentive), a hydrogenated bisphenol A diglycidyl ether (available as EPON™ 825 from Momentive) a bisphenol A / epichlorohydrin derived epoxy resin (available as EPON™ 828 from Brenntag North America), a mixture of dicyclohexyl diepoxide and nanosilica (available as NANOPOX™), and any combination thereof.

[0178] The multifunctional cationically polymerizable component can include a difunctional epoxy, a bicyclic bis-epoxide monomer, or a poly(g lycidy I ether). In some embodiments, the multifunctional cationically polymerizable component includes bisphenol A diglycidyl ether monoacrylate, hydrogenated Bisphenol A digycydylether epoxy, polymeric aryl glycidylethers, 3,4-Epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate, bisphenol A diglycidyl ether, poly(1 ,4-butanediol diglycidyl ether, neopentylglycol diglycidylether, 1 ,4- Butanediol diglycidyl ether, 3-Hydroxymethyl-3-ethyloxetane (available as OXT-101 from Toagosei), or derivatives thereof.

[0179] In some embodiments, the multifunctional cationically polymerizable component comprises a structure of formula (1 ):2024P20002WQwherein R1 and R2 are the same or different and are selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, for example R1 and R2 may be selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethylene, propene, butene, pentene, hexene, acetylene, propargyl, butynyl, pentynyl, hexynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, morpholinyl, piperidyl, pyrrolidinyl, tetrahydrofuranyl, phenyl, benzyl, napthyl, toluyl, anisyl, aromatic ring systems such as diphenylmethane, cycloalkyl ring systems such as dicyclohexylmethane, wherein the R1 and / or R2 group can be optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, cycloalkyl, aromatic, aryl, heteroaryl, heteroalkyl, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide, and wherein n and m, independently, are 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0180] In some embodiments, the multifunctional cationically polymerizable component can be selected from the group consisting of:wherein n is 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0181] An epoxy component can include any of the described multifunctional cationically polymerizable components. The epoxy component can contain the multifunctional cationically polymerizable component in a total amount of at least 1 wt.% and about or less than 97 wt.%, 95 wt.%, 90 wt.%, 85 wt.%, 80 wt.%. For example, the multifunctional cationically polymerizable component may be present in a total amount of 15-95 wt.%, 20-90 wt.%, 25-85 wt.%, or 30-80 wt.% relative to the epoxy component.

[0182] The cationically polymerizable components can be used singly or in combination of two or more thereof. In some embodiments, the cationically polymerizable component further comprises at least two different epoxy components.

[0183] In some embodiments, the cationically polymerizable component also comprises an oxetane component. In some embodiments, the cationically polymerizable component includes an oxetane, for example, an oxetane containing 1 , 2 or more than 2 oxetane groups. In some embodiments, the oxetane employed is monofunctional, and additionally possesses a hydroxyl group.

[0184] If utilized in the liquid radiation curable resin composition, the oxetane component is present in a suitable amount, e.g., up to about 50 wt.% of the liquid radiation curable resin composition. In some embodiments, the oxetane component is present in an amount from about 0 to about 30 wt.% of the liquid radiation curable resin composition. In some embodiments, the oxetane component is present in an amount from 5 to about 15 wt.%, 5 to about 10 wt.%, or 10 to about 15 wt.% of the liquid radiation curable resin composition.

[0185] The liquid radiation curable resin composition for additive fabrication can include suitable amounts of the cationically polymerizable component, for example, in some embodiments, in an amount from about 10 to about 80% by weight of the liquid radiation curable resin composition, in an amount from about 15 to about 95% by weight of the liquid radiation curable resin composition, in an amount from about 25 to about 85% by weight of2024P20002WQ the liquid radiation curable resin composition, in an amount from about 20 to about 90% by weight of the liquid radiation curable resin composition, in some embodiments from about 20 to about 70 wt.% of the liquid radiation curable resin composition, in some embodiments from about 25 to about 65 wt.% of the liquid radiation curable resin composition, in some embodiments from about 30 to about 80 wt.% of the liquid radiation curable resin composition, and in some embodiments from about 50 to about 85 wt.% of the liquid radiation curable resin composition.

[0186] Free-Radical Curable Component

[0187] In some embodiments, the liquid radiation curable resin composition for additive fabrication of the present disclosure comprises at least one free-radical curable component, that is, a component which undergoes polymerization initiated by free radicals. The free- radical curable component can include a multifunctional (meth)acrylate component and / or a monofunctional meth(acrylate) component. The free-radical curable components are monomers, oligomers, and / or polymers; the free-radical curable components are monofunctional polyfunctional materials, i.e., have 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, . . . 20 . . . 30 . . . 40 . . . 50 . . . 100, or more functional groups that can polymerize by free radical initiation, may contain aliphatic, aromatic, cycloaliphatic, arylaliphatic, heterocyclic moiety(ies), or any combination thereof. Examples of polyfunctional materials include dendritic polymers such as dendrimers, linear dendritic polymers, dendrigraft polymers, hyperbranched polymers, star branched polymers, and hypergraft polymers. The dendritic polymers may contain one type of polymerizable functional group or different types of polymerizable functional groups, for example, acrylates and methacrylate functions.

[0188] Multifunctional (meth)acrylate Component

[0189] In some embodiments, the multifunctional (meth)acrylate component comprises a compound of formula (6) or (7):2024P20002WQwherein R, R3, and R4 are the same or different and are selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, for example R, R3, and R4 may be selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethylene, propene, butene, pentene, hexene, acetylene, propargyl, butynyl, pentynyl, hexynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, morpholinyl, piperidyl, pyrrolidinyl, tetrahydrofuranyl, phenyl, benzyl, napthyl, toluyl, anisyl, aromatic ring systems such as diphenylmethane, cycloalkyl ring systems such as dicyclohexylmethane, wherein the R, R3, and / or R4 groups can be optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, cycloalkyl, aromatic, aryl, heteroaryl, heteroalkyl, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide,R1 and R2 are the same or different and are selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, for example R1 and R2 may be selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethylene, propene, butene, pentene, hexene, acetylene, propargyl, butynyl, pentynyl, hexynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, morpholinyl, piperidyl, pyrrolidinyl, tetrahydrofuranyl, phenyl, benzyl, napthyl, toluyl, anisyl, aromatic ring systems such as diphenylmethane, cycloalkyl ring systems such as dicyclohexylmethane, wherein the R1 and / or R2 group can be optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, cycloalkyl, aromatic, aryl, heteroaryl, heteroalkyl, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide, a= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and b= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0190] In some embodiments, the multifunctional (meth)acrylate component includes a compound of formula (8) or (9):wherein a= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and b= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0191] In some embodiments, the multifunctional (meth)acrylate component includes a compound of formula (9):(9), wherein n= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and m= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0192] In some embodiments, the multifunctional (meth)acrylate component comprises at least one of:wherein n= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and m= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0193] Examples of multifunctional (meth)acrylate component include those with (meth)acryloyl groups such as trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, ethylene glycol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, dicyclopentadiene dimethanol di(meth)acrylate, [2-[1 , 1 -dimethyl-2-[(1 - oxoallyl)oxy]ethyl]-5-ethyl-1 ,3-dioxan-5-yl]methyl acrylate; 3 ,9-bis(1 , 1 -dimethyl-2- hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane di(meth)acrylate; dipentaerythritol monohydroxypenta(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1 ,4-butanediol di(meth)acrylate, 1 ,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polybutanediol di(meth)acrylate, tripropyleneglycol di(meth)acrylate, glycerol tri(meth)acrylate, phosphoric acid mono- anddi(meth)acrylates, C7-C20 alkyl di(meth)acrylates, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tricyclodecane diyl dimethyl di(meth)acrylate and alkoxylated versions (e.g., ethoxylated and / or propoxylated) of any of the preceding monomers, and also di(meth)acrylate of a diol which is an ethylene oxide or propylene oxide adduct to bisphenol A, di(meth)acrylate of a diol which is an ethylene oxide or propylene oxide adduct to hydrogenated bisphenol A, epoxy (meth)acrylate which is a (meth)acrylate adduct to bisphenol A of diglycidyl ether, diacrylate of polyoxyalkylated bisphenol A, and triethylene glycol divinyl ether, and adducts of hydroxyethyl acrylate.

[0194] The multifunctional (meth)acrylate component of the present disclosure may include all methacryloyl groups, all acryloyl groups, or any combination of methacryloyl and acryloyl groups. In some embodiments, the multifunctional (meth)acrylate component can be selected from the group consisting of bisphenol A diglycidyl ether di(meth)acrylate, ethoxylated or propoxylated bisphenol A or bisphenol F di(meth)acrylate, dicyclopentadiene dimethanol di(meth)acrylate, [2-[1 ,1-dimethyl-2-[(1-oxoallyl)oxy]ethyl-]5-ethyl-1 ,3-dioxan-5- yl]methyl acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)crylate, propoxylated trimethylolpropane tri(meth)acrylate, and propoxylated neopentyl glycol di(meth)acrylate, and any combination thereof.

[0195] In some embodiments, the multifunctional (meth)acrylate component has more than 2 functional groups. In some embodiments, the multifunctional (meth)acrylate component has more than 3 functional groups. In some embodiments, the multifunctional (meth)acrylate component has more than 4 functional groups. In some embodiments, the multifunctional (meth) aery I ate component consists exclusively of a single multifunctional (meth)acrylate component. In some embodiments, the multifunctional (meth)acrylate component is tetra-functional. In some embodiments, the multifunctional (meth)acrylate component is penta-functional. In some embodiments, the multifunctional (meth)acrylate component is hexa-functional.

[0196] In some embodiments, the multifunctional (meth)acrylate component includes an aromatic (meth)acrylate. Aromatic acrylates may be derived from, as non-limitingexamples, bisphenol-A, bisphenol-S, or bisphenol-F. In some embodiments, the aromatic can be selected from the group consisting of bisphenol A diglycidyl ether diacrylate, fatty acid modified bisphenol-A epoxy diacrylate (available as EB 3702 from Rahn), dicyclopentadiene dimethanol diacrylate, [2-[1 , 1 -dimethyl-2-[(1 -oxoallyl)oxy]ethyl]-5-ethyl-1 ,3-dioxan-5-yl]methyl acrylate, dipentaerythritol monohydroxypentaacrylate, propoxylated trimethylolpropane triacrylate, and propoxylated neopentyl glycol diacrylate, and any combination thereof. In some embodiments, the aromatic (meth)acrylate is difunctional.

[0197] In some embodiments, the liquid radiation curable resin compositions for additive fabrication of the present disclosure include one or more of bisphenol A diglycidyl ether di(meth)acrylate, dicyclopentadiene dimethanol di(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, and / or propoxylated neopentyl glycol di(meth)acrylate, and more specifically one or more of bisphenol A diglycidyl ether diacrylate, dicyclopentadiene dimethanol diacrylate, dipentaerythritol pentaacrylate, propoxylated, trimethylolpropane triacrylate, and / or propoxylated neopentyl glycol diacrylate.

[0198] The above-mentioned multifunctional (meth)acrylate components can be used singly or in combination of two or more thereof. The liquid radiation curable resin composition for additive fabrication can include any suitable amount of the multifunctional (meth)acrylate components and / or monofunctional (meth)acrylate components, for example, in some embodiments, in an amount up to about 50 wt.% of the liquid radiation curable resin composition, from about 2 to about 40 wt.% of the liquid radiation curable resin composition, from about 5 to about 30 wt.% of the liquid radiation curable resin composition, from about 10 to about 20 wt.% of the liquid radiation curable resin composition, from about 8 to about 50 wt.% of the liquid radiation curable resin composition, or from about 15 to about 25 wt.% of the liquid radiation curable resin composition.

[0199] An acrylate component may include any of the described multifunctional (meth)acrylate components. Relative to the total amount of the acrylate component, the multifunctional (meth)acrylate component may be present in an amount of at least 1 % and about or less than 80 wt.%, 75 wt.%, 70 wt.%, 65 wt.%, 60 wt.%, 55 wt.%, or 50 wt.%. For example, the acrylate component may include a multifunctional (meth)acrylate component ina total amount of 1 -70 wt.%, 5-65 wt.%, 10-60 wt.%, or 15-55 wt.% relative to the acrylate component.

[0200] Monofunctional Component

[0201] Disclosed liquid radiation curable resin compositions contain a monofunctional component. The monofunctional component can be a monofunctional cationically polymerizable epoxy component, a monofunctional (meth)acrylate component, or a combination thereof. In some embodiments, disclosed liquid radiation curable resin compositions include both a monofunctional cationically polymerizable epoxy component and a monofunctional radically polymerizable (meth)acrylate component.

[0202] Monofunctional Cationically Polymerizable Epoxy Component

[0203] In some embodiments, the monofunctional cationically polymerizable epoxy component is a monofunctional cationically polymerizable aliphatic epoxide.

[0204] The monofunctional cationically polymerizable epoxy component can be characterized by having a single epoxy group per molecule, which can exist in either solid or liquid form. The monofunctional cationically polymerizable epoxy component can contain a long-chain hydrocarbon skeleton with 7 to 20 carbon atoms, referred to as long-chain monofunctional epoxy compounds. The use of such long-chain monofunctional epoxy compounds allows for the creation of liquid ultraviolet curable resin compositions with low viscosity and cured articles having water adsorption. Monofunctional epoxy compounds generally have low viscosity, especially compared to multifunctional epoxy compounds. The reactivity of monofunctional epoxy compounds is reduced compared to di- or multi-functional epoxy compounds due to the presence of a single epoxy group. Such physical properties may impart greater flexibility to cured systems than multifunctional epoxy compounds. Monofunctional epoxy compounds are often used as reactive diluents to reduce viscosity in epoxy formulations, resin stabilizers, adhesion modifiers, components in coatings and electronic materials. Many monofunctional epoxy compounds are hydrophobic, especially those with longer hydrocarbon chains. Examples of monofunctional epoxy compounds include: 1 ,2-epoxydodecane 1 ,2-epoxyeicosane 1 ,2-epoxydecane 2-ethylhexyl glycidyl ether 1 ,2-epoxytetradecane 1 ,2-epoxyhexadecane, and glycidyl lauryl ether.

[0205] The monofunctional epoxy compound having a long-chain hydrocarbon skeleton includes compounds with a hydrocarbon skeleton having 7 to 20 carbon atoms and2024P20002WQ having one epoxy group in the chain or at the chain end. Examples include 1 ,2- epoxydodecane, 1 ,2-epoxyeicosane, 1 ,2-epoxydecane, 2-ethylhexyl glycidyl ether, 1 ,2- epoxytetradecane, 1 ,2-epoxyhexadecane, glycidyl lauryl ether, and the like. Specifically, for example, “YED111AN”, “YED111 N”, “YED188” from Mitsubishi Chemical Corporation, “Lika Resin L-200” from Shin Nippon Chemical Co., Ltd., “EX-121”, “EX-192” from Nagase ChemteX Corporation Etc. can be used.

[0206] In some embodiments, the monofunctional cationically polymerizable epoxy component is a compound of formula (16):wherein Ri , R2, R3, and R4 are the same or different and are selected from H, straight-chain alkyl or alkoxy groups, branched or cyclic alkyl or alkoxy groups, aromatic ring systems, and heteroaromatic ring systems, where an R1 and R2 radical may optionally be joined to one another and may form a ring; and where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide.

[0208] In other embodiments, the monofunctional cationically polymerizable epoxy component is a compound of formula (18):

[0209] wherein R1 , R2, R3, and R4 are the same or different and are selected from H, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups2024P20002WQ having 3 to 40 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; and where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide. In embodiments, Ri , R2, R3, and / or R4 is an alkyl having 12 to 14 carbon atoms.

[0210] In some embodiments, the monofunctional cationically polymerizable epoxy component comprises at least one of:cationically polymerizable epoxy components. The monofunctional cationically polymerizable epoxy component can be present in an amount of at least 1% and about or less than 95 wt.%, 90 wt.%, 85 wt.%, 80 wt.%, 75 wt.%, or 70 wt.% relative to the total epoxy component. For example, the amount of the monofunctional cationically polymerizable epoxy present in the epoxy component may range from 10-90 wt.%, 20-80 wt.%, 30-70 wt.%, or 40-60 wt.%.

[0212] Monofunctional (meth)acrylate Component

[0213] The monofunctional meth(acrylate) component can be characterized by (meth)acrylate compounds having a single reactive (meth)acrylate group per molecule. Monofunctional meth(acrylate) compounds generally have low viscosity, especially compared to multifunctional (meth)acrylate compounds. The reactivity of monofunctional meth(acrylate) compounds is reduced compared to multifunctional (meth)acrylate compounds due to the presence of a single meth(acrylate) group. Such physical properties may impart greater flexibility to cured systems than multifunctional meth(acrylate) compounds. Monofunctional meth(acrylate) compounds are often used as reactive diluents to reduce viscosity in epoxy formulations, resin stabilizers, adhesion modifiers, components in coatings and electronic materials.

[0214] Examples of monofunctional meth(acrylate) components include: acrylates and methacrylates such as isobornyl (meth)acrylate, bonyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, acryloyl morpholine, (meth)acrylic acid, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2- hydroxybutyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, caprolactone acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, tridecyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, diacetone (meth)acrylamide, beta-carhoxyethyl (meth)acrylate, phthalic acid (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, butylcarbamylethyl (meth)acrylate, n-isopropyl (meth)acrylamide fluorinated (meth)acrylate, 7-amino-3,7- dimethyloctyl (meth)acrylate.

[0215] In some embodiments, the monofunctional meth(acrylate) components include at least one of:

[0216] An acrylate component may include any of the described monofunctional (meth)acrylate components. Relative to the total acrylate component, the monofunctional(meth)acrylate component may be present in an amount of 1 -65 wt.%, 5-60 wt.%, 10-55 wt.%, or 15-50 wt.% of the acrylate component.

[0217] Photoinitiators

[0218] In some embodiments, the liquid radiation curable resin composition includes at least one photoinitiator. A photoinitiator is a compound that chemically changes due to the action of light (or the synergy between the action of light and the electronic excitation of a sensitizing dye) to produce at least one of a radical, an acid, and a base, whereupon the radical, acid, and / or base effectuates a polymerization reaction in one or more of the polymerizable substances present in the corresponding liquid radiation curable resin composition. To successfully formulate a liquid radiation curable resin composition for additive fabrication, the wavelength sensitivity of the photoinitiator(s) present in the liquid radiation curable resin composition can be reviewed to determine if the photoinitiator(s) will be activated by the radiation source chosen to provide the curing light. In some embodiments, the liquid radiation curable resin composition includes a photoinitiator useful to effectuate polymerization in the free-radical ly curable constituent, the cationically curable constituent, or both such constituents.

[0219] A photoinitiator which is capable (when subjected to light of an appropriate wavelength and / or intensity) of effectuating polymerization of the free-radically curable constituent is a free-radical photoinitiator. A photoinitiator which is capable (when subjected to light of an appropriate wavelength and / or intensity) of effectuating polymerization of the cationically curable constituent is a cationic photoinitiator. A particular photoinitiator may serve as both a free-radical photoinitiator and a cationic photoinitiator, although at least two different photoinitiators can be employed for this purpose. In some embodiments, the liquid radiation curable resin composition includes a photoinitiating system contains at least one photoinitiator having a cationic initiating function, and at least one photoinitiator having a free radical initiating function. In some embodiments, the photoinitiating system can include a photoinitiator that contains both free-radical initiating function and cationic initiating function on the same molecule.

[0220] Cationic Photoinitiators

[0221] In some embodiments, the liquid radiation curable resin composition includes a cationic photoinitiator. The cationic photoinitiator initiates cationic ring-opening polymerization2024P20002WQ upon irradiation of light. In some embodiments, the cationic photoinitiator comprises, consists of, or consists essentially of an iodonium salt-based cationic photoinitiator.

[0222] In some embodiments, any suitable iodonium-based cationic photoinitiator can be used, for example, those with cations selected from the group consisting of diaryl iodonium salts, triaryl iodonium salts, aromatic iodonium salts, and any combination thereof.

[0223] In some embodiments, the cation of the cationic photoinitiator can be selected from the group consisting of aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, metallocene based compounds, aromatic phosphonium salts, acylsulfonium salts, and any combination thereof. In another embodiment, the cation is a polymeric sulfonium salt, such as in U.S. Pat. Nos. 5,380,923 or 5,047,568, or other aromatic heteroatom-containing cations and naphthyl-sulfonium salts such as in U.S. Pat. Nos. 7,611 ,817, 7,230,122, US2011 / 0039205, US2009 / 0182172, U.S. Pat. No. 7,678,528, EP7308865, WO2010046240, or EP2218715.

[0224] In some embodiments, the cationic photoinitiator can be selected from the group consisting of triarylsulfonium salts, diaryliodonium salts, and metallocene based compounds, and any combination thereof. Onium salts, e.g., iodonium salts and sulfonium salts, and ferrocenium salts, have the advantage of generally being more thermally stable.

[0225] In some embodiments, the cationic photoinitiator has an anion selected from the group consisting of BF4", AsFe", SbFe’, PFe", [B(CF3)4]“, B(C6F5)4", B[C6H3’3,5(CF3)2]4“, B(C6H4CF3)4-, B(C6H3F2)4-, B[C6F4-4(CF3)]4-, Ga(C6F5)4-, [(CeFs^B-CsHs^-B CeFs^]- [(C6F5)3B-NH2-B(C6F5)3]-; tetrakis(3,5-difluoro-4-alkyloxyphenyl)borate, tetrakis(2, 3,5,6- tetrafluoro-4-alkyloxyphenyl)borate, perfluoroalkylsulfonates, tris[(perfluoroalkyl)sulfonyl]methides, bis[(perfluoroalkyl)sulfonyl]imides, perfluoroalkylphosphates, tris(perfluoroalkyl)trifluorophosphates, bis(perfluoroalkyl)tetrafluorophosphates, tris(pentafluoroethy)trifluorophosphates, and (CHeBnBre)-, (CHeBuCle)- and other halogenated carborane anions.

[0226] A survey of other onium salt initiators and / or metallocene salts can be found in “UV Curing, Science and Technology”, (Editor s. P. Pappas, Technology Marketing Corp., 642 Westover Road, Stamford, Conn., U.S.A.) “Chemistry & Technology of UV & EB Formulation for Coatings, Inks & Paints”, Vol. 3 (edited by P. K. T Oldring), or J. P. Fouassier, J. Lavelee, “Photoinitiators for polymer synthesis” Wiley 2012 ISBN978-3-527-33210-6.2024P20002WG

[0227] In some embodiments, the cationic photoinitiator has a cation selected from the group consisting of aromatic sulfonium salts, aromatic iodonium salts, and metallocene based compounds with at least an anion selected from the group consisting of SbFe", PFe", B(C6F5) , [B(CF3)4]“, tetrakis(3,5-difluoro-4-methoxyphenyl)borate, perfluoroalkylsulfonates, perfluoroalkylphosphates, tris[(perfluoroalkyl)sulfonyl]methides, and [(C2Fs)3PF3]".

[0228] Examples of known cationic photoinitiators include 4-[4-(3- chlorobenzoyl)phenylthio]phenylbis(4-fluorophenyl)sulfonium hexafluoroantimonate, 4-[4-(3- chlorobenzoyl)phenylthio]phenylbis(4-fluorophenyl)sulfonium tetrakis(pentafluorophenyl)borate, 4-[4-(3-chlorobenzoyl)phenylthio]phenylbis(4- fluorophenyl)sulfonium tetrakis(3,5-difluoro-4-methyloxyphenyl)borate, 4-[4-(3- chlorobenzoyl)phenylthio]phenylbis(4-fluorophenyl)sulfonium tetrakis(2,3,5,6-tetrafluaro-4- methyloxyphenyl)borate, tris(4-(4-acetylphenyl)thiophenyl)sulfonium tetrakis(pentafluorophenyl)borate (Irgacure® PAG 290 from BASF), tris(4-(4- acetylphenyl)thiophenyl)sulfonium tris[(trifluoromethyl)sulfonyl]methide (Irgacure® GSID 26-1 from BASF), tris(4-(4-acetylphenyl)thiophenyl)sulfonitun hexafluorophosphate (Irgacure® 270 from BASF), and HS-1 available from San-Apro Ltd.

[0229] Known cationic photoinitiators include, either alone or in a mixture: Bis (4-tert- butyl phenyl) iodonium tetraphenylborate (available as FP 5041 from Hampford Research), bis[4-diphenylsulfoniumphenyl]sulfide bishexafluoroantimonate; thiophenoxyphenylsulfonium hexafluoroantimonate (available as Chivacure 1176 from Chitec), tris(4-(4- acetylphenyl)thiophenyl)sulfonium tetrakis(pentafluorophenyl)borate (Irgacure® PAG 290 from BASF), tris(4-(4-acetylphenyl)thiophenyl)sulfonium tris[(trifluoromethyl)sulfonyl]methide (Irgacure® GSID 26-1 from BASF), and tris(4-(4-acetylphenyl)thiophenyl)sulfonium hexafluorophosphate (Irgacure® 270 from BASF), [4-(1 -methylethyl)phenyl](4-methylphenyl) iodonium tetrakis(pentafluorophenyl)borate (available as Rhodorsil 2074 from Rhodia), (4- octyloxyphenyl) phenyliodonium hexafluoroantimonate (available as OPPI FP 5386 from Hampford), 4-[4-(2-chlorobenzoyl)phenylthio]phenylbis(4-fluorophenyl)sulfonium hexafluoroantimonate (as SP-172 from Adeka), SP-300 from Adeka, and aromatic sulfonium salts with anions of (PF6-m(CnF2n+1 )m)- where in is an integer from 1 to 5, and n is an integer from 1 to 4 (available as CPI-200K or CPI-200S, which are monovalent sulfoniumsalts from San-Apro Ltd., TK-1 available from San-Apro Ltd., or HS-1 available from San- Apro Ltd.).

[0230] In some embodiments, the liquid radiation curable resin composition for additive fabrication comprises an aromatic triaryl sulfonium salt cationic photoinitiator. Aromatic triaryl sulfonium salts can be used in additive fabrication applications, e.g., US 20120251841 to DSM IP Assets, B.V., U.S. Pat. No. 6,368,769, to Asahi Denki Kogyo, which discusses aromatic triaryl sulfonium salts with tetraryl borate anions, including tetrakis(pentafluorophenyl)borate, and use of the compounds in stereolithography applications. Triarylsulfoniun salts are disclosed in, for example, J Photopolymer Science Tech (2000), 13(1 ), 117-118 and J Poly Science, Part A (2008), 46(11 ), 3820-29.Triarylsulfonium salts Ar3S+MXn- with complex metal halide anions such as BF4", AsFe", PFe", and SbFe", are disclosed in J Polymr Sci, Part A (1996), 34(16), 3231 -3253.

[0231] An example of a triaryl sulfonium tetrakis(pentafluorophenyl)borate cationic photoinitiator is tris(4-(4-acetylphenyl)thiophenyl)sulfonium tetrakis(pentafluorophenyl)borate. Tris(4-(4-acetylphenyl)thiophenyl)sulfonium tetrakis(pentafluorophenyl)borate is known commercially as IRGACURE® PAG-290, and is available from Ciba / BASF.

[0232] In some embodiments, the cationic photoinitiator is an aromatic triaryl sulfonium salt that possesses an anion represented by SbFe", PFe", (CF3CF2)3PF3", (CeFs^B- ((CF3)2CeH3)4B", (CeF5)4Ga- ((CF3)2CeH3)4Ga-, trifluoromethanesulfonate, nonafluorobutanesulfonate, methanesulfonate, butanesulfonate, benzenesulfonate, or p- toluenesulfonate. Such photoinitiators are described in, for example, U.S. Pat. No. 8,617,787.

[0233] Another cationic photoinitiator is an aromatic triaryl sulfonium cationic photoinitiator that has an anion that is a fluoroalkyl-substituted fluorophosphate. Commercial examples of an aromatic triaryl sulfonium cationic photoinitiator having a fluoroalkyl- substituted fluorophosphate anion is the CPI-200 series (for example CPI-200K® or CPI- 21 OS®) or 300 series, available from San-Apro Limited.

[0234] The liquid radiation curable resin composition can include any suitable amount of the cationic photoinitiator, for example, in some embodiments, in an amount up to about 15% by weight of the liquid radiation curable resin composition, up to about 5% by weight of the liquid radiation curable resin composition, from about 2% to about 10% by weight of the liquid radiation curable resin composition, from about 0.1 % to about 5% by weight of theliquid radiation curable resin composition. In some embodiments, the amount of cationic photoinitiator is from about 0.2 wt.% to about 4 wt.% of the liquid radiation curable resin composition, or from about 0.5 wt.% to about 3 wt.% of the liquid radiation curable resin composition.

[0235] Free-radical Photoinitiators

[0236] In some embodiments, the liquid radiation curable resin composition for additive fabrication of the present disclosure includes a free-radical photoinitiator. Free radical photoinitiators include those which form radicals by either a Norrish Type I or II mechanism. Such mechanisms are well-known in the art to which this present disclosure applies, and are described in, for example, Parikh, A., Parikh, H., & Parikh, K. (2006). Norrish Type I and II Reaction (Cleavage). In Name Reactions in Organic Synthesis (pp. 325-329). Foundation Books. Such photoinitiators include those which form radicals by cleavage, known as “Norrish Type I”, and those that form radicals by hydrogen abstraction, known as “Norrish type II”. The Norrish type II photoinitiators require a hydrogen donor, which serves as the free radical source. As the initiation is based on a bimolecular reaction, the Norrish type II photoinitiators are generally slower than Norrish type I photoinitiators which are based on the unimolecular formation of radicals. On the other hand, Norrish type II photoinitiators possess better optical absorption properties in the near-UV spectroscopic region. Photolysis of aromatic ketones, such as benzophenone, thioxanthones, benzil, and quinones, in the presence of hydrogen donors, such as alcohols, amines, or thiols leads to the formation of a radical produced from the carbonyl compound (ketyl-type radical) and another radical derived from the hydrogen donor. The photopolymerization of vinyl monomers is usually initiated by the radicals produced from the hydrogen donor. The ketyl radicals are usually not reactive toward vinyl monomers because of the steric hindrance and the delocalization of an unpaired electron.

[0237] In some embodiments, the liquid radiation curable resin composition for additive fabrication includes at least one free radical photoinitiator, e.g., those selected from the group consisting of phosphine oxides, aryl ketones, benzophenones, hydroxylated ketones, 1 - hydroxyphenyl ketones, ketals, metallocenes, and any combination thereof.

[0238] In some embodiments, the liquid radiation curable resin composition for additive fabrication includes at least one free-radical photoinitiator selected from the group consisting of 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl phenyl, ethoxy2024P20002WC phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide, 2-methyl-1 -[4- (methylthio)phenyl]-2-morpholinopropanone-1 ,2-benzyl-2-(dimethylamino)-1-[4-(4- morpholinyl) phenyl]-1 -butanone, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl- phenyl)-butan-1-one, 4-benzoyl-4'-methyl diphenyl sulphide, 4,4'-bis(diethylamino) benzophenone, and 4,4'-bis(N,N’-dimethylamino) benzophenone (Michler's ketone), benzophenone, 4-methyl benzophenone, 2,4,6-trimethyl benzophenone, dimethoxybenzophenone, 1 -hydroxycyclohexyl phenyl ketone, phenyl (1- hydroxyisopropyl)ketone, 2-hydroxy-1-[4-(2-hydroxyethoxy) phenyl]-2-methyl-1 -propanone, 4- isopropylphenyl(1 -hydroxyisopropyl)ketone, oligo-[2-hydroxy-2-methyl-1 -[4-(1 - methylvinyl)phenyl] propanone], camphorquinone, 4,4'-bis(diethylamino) benzophenone, benzil dimethyl ketal, bis(eta 5-2-4-cyclopentadien-1-yl) bis[2,6-difluoro-3-(1 H-pyrrol-1-yl) phenyl] titanium, and any combination thereof. In some embodiments, the at least one free- radical photoinitiator is bis(2,4,6-trimethylbenxoyl)phenylphosphine oxide.

[0239] For light sources emitting in the about 300-475 nm wavelength range, e.g., light sources emitting at about 365 nm, 390 nm, or 395 nm, examples of suitable free-radical photoinitiators absorbing in this area include: benzoylphosphine oxides, such as, for example, 2,4,6-trimethylbenzoyl diphenylphosphine oxide (Lucirin TPO from BASF) and 2,4,6- trimethylbenzoyl phenyl, ethoxy phosphine oxide (Lucirin TPO-L from BASF), bis(2,4,6- trimethylbenzoyl)-phenylphosphineoxide (Irgacure 819 or BAPO from Ciba), 2-methyl-1 -[4- (methylthio)phenyl]-2-morpholinopropanone-1 (Irgacure 907 from Ciba), 2-benzyl-2- (dimethylamino)-1-[4-(4-morpholinyl) phenyl]-1 -butanone (Irgacure 369 from Ciba), 2- dimethylamino-2-(4-methyl-benzyl)-1 -(4-morpholin-4-yl-phenyl)-butan-1 -one (Irgacure 379 from Ciba), 4-benzoyl-4'-methyl diphenyl sulphide (Chivacure BMS from Chitec), 4,4'- bis(diethylamino) benzophenone (Chivacure EMK from Chitec), and 4,4'-bis(N,N'- dimethylamino) benzophenone (Michler's ketone). Also suitable are mixtures thereof.

[0240] Photosensitizers can be useful in conjunction with photoinitiators in effecting cure with LED light sources emitting in this wavelength range. Examples of suitable photosensitizers include: anthraquinones, such as 2-methylanthraquinone, 2- ethylanthraquinone, 2-tertbutylanthraquinone, 1 -chloroanthraquinone, and 2- amylanthraquinone, thioxanthones and xanthones, such as isopropyl thioxanthone, 2- chlorothioxanthone, 2,4-diethylthioxanthone, and 1 -ch loro-4-propoxyth ioxanthone (availableas SpeedCure CPTX from Labmson Arkema), methyl benzoyl formate (Darocur MBF from Ciba), methyl-2-benzoyl benzoate (Chivacure OMB from Chitec), 4-benzoyl-4'-methyl diphenyl sulphide (Chivacure BMS from Chitec), 4,4'-bis(diethylamino) benzophenone (Chivacure EMK from Chitec).

[0241] According to some embodiments of the present disclosure, the free-radical photoinitiator may additionally include are acylphosphine oxide photoinitiator. Acylphosphine oxide photoinitiator are disclosed for example in U.S. Pat. Nos. 4,324744, 4,737593, 5,942,290, 5534,559, 6,020,528, 6,486,228, and 6,486,226. The acylphosphine oxide photoinitiators include bisacylphosphine oxides (BAPO) and monoacylphosphine oxides (MAPO). Although generally, acyl phosphine oxide photoinitiators are preferred for use with UV / vis optics since acyl phosphine oxide photoinitiators have a good delocalization of the phosphinoyl radical upon photo irradiation, when iodonium salt photoinitiators of a nonfluorinated borate anion are used, such phosphorous-containing photoinitiators are not necessarily needed, and may not facilitate curing much or even at all. Therefore, in an embodiment, the liquid radiation curable resin composition is substantially devoid of a free- radical phosphorous-containing photoinitiator, or contains an amount by weight of a free- radical phosphorous-containing photoinitiator of less than about 0.1 wt.%, preferably less than about 0.05 wt.%, or preferably less than about 0.01 wt.%, or about 0.00 wt.%.

[0242] The liquid radiation curable resin composition for additive fabrication can include any suitable amount of the free-radical photoinitiator as prescribed herein, for example, in certain embodiments, in an amount up to about 10 wt.% of the liquid radiation curable resin composition, from about 0.1 to about 10 wt.% of the liquid radiation curable resin composition, or from about 1 to about 6 wt.% of the liquid radiation curable resin composition.

[0243] It is possible for UV radiation sources to be designed to emit light at shorter wavelengths. For light sources emitting at wavelengths from between about 100 and about 300 nm, other photoinitiators absorbing at shorter wavelengths can be used. Examples of such photoinitiators include: benzophenones, such as benzophenone, 4-methyl benzophenone, 2,4,6-trimethyl benzophenone, dimethoxybenzophenone, and 1 - hydroxyphenyl ketones, such as 1 -hydroxycyclohexyl phenyl ketone, phenyl (1 - hydroxyisopropyl)ketone, 2-hydroxy-1-[4-(2-hroxyethoxy) phenyl]-2-methyl-1 -propanone, and2024P20002WG4-isopropylphenyl(1-hydroxyisopropyl)ketone, benzil dimethyl ketal, and oligo-[2-hydroxy-2- methyl-1 -[4-(1-methylvinyl)phenyl] propanone] (Esacure KIP 150 from Lamberti).

[0244] Radiation sources can also be designed to emit at higher wavelengths. For radiation sources emitting light at wavelengths from about 475 nm to about 900 nm, examples of suitable free radical photoinitiators include: camphorquinone, 4,4'- bis(diethylamino) benzophenone (Chivacure EMK from Chitec), 4,4'-bis(N,N'-dimethylamino) benzophenone (Michler's ketone), bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (“BAPO,” or Irgacure 819 from Ciba), metallocenes such as bis (eta 5-2-4-cyclopentadien-1 - yl) bis [2,6-difluoro-3-(1 H-pyrrol-1 -yl) phenyl] titanium (Irgacure 784 from Ciba), and the visible light photoinitiators from Spectra Group Limited, Inc. such as H-Nu 470, H-Nu-535, H- Nu-635, H-Nu-Blue-640, and H-Nu-Blue-660.

[0245] In some embodiments of the present disclosure, the light emitted by the radiation source is UVA radiation, which is radiation with a wavelength between about 320 and about 400 nm. In some embodiments, the light emitted by the radiation source is UVB radiation, which is radiation with a wavelength between about 280 and about 320 nm. In some embodiments, the light emitted by the radiation source is UVC radiation, which is radiation with a wavelength between about 100 and about 280 nm.

[0246] In some embodiments, the photoinitiator may be included in an amount of about 0.1 wt.%, 0.5 wt.%, 1 wt.%, 2 wt.%, or as high as about 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.%, or within any range encompassed by any two of the foregoing values as endpoints. For example, the photoinitiator may be present in an amount of about 0.5 wt.% to about 5 wt.%, based on the total weight of the liquid radiation curable resin composition.

[0247] Additives

[0248] In some embodiments, the liquid radiation curable resin composition includes a chain transfer agent (CTA). The chain transfer agent may have a reactive hydroxyl group, a reactive sulfonyl group, a reactive sulfonamide group, a reactive sulfhydryl group, a reactive amine group, or a combination thereof. Exemplary CTA PTMO 1000 is a polyether diol, specifically a poly(oxytetramethylene) diol with a Mn = 1000 g / mol, having terminal hydroxyl groups. Additional exemplary CTAs include thiols (mercaptans), such as dodecyl mercaptan (DDM), n-Butyl mercaptan, nonyl thiol, halocarbons, such as carbon tetrachloride (CCk),hydrocarbons, such as benzene, toluene, ethyl benzene, and other organic compounds, including acetone, methyl styrene linear dimer, sulfur-free CTAs, and divalent bis-metalated chain transfer agents. In solution polymerization, solvents can act as chain transfer agents, and in some cases, the monomer itself can act as a chain transfer agent. Existing polymer chains can participate in chain transfer reactions as can some initiators.

[0249] The chain transfer agent (CTA) can be present in an amount of about less than 50 wt.%, 40 wt.%, 30 wt.%, 20 wt.%, or 10 wt.% of the total weight of the liquid radiation curable resin composition. In some embodiments, the chain CTA may be included in an amount of about 1 wt.%, 5 wt.%, 10 wt.%, 20 wt.%, or as high as about 30 wt.%, 40 wt.%, 50 wt.%, or within any range encompassed by any two of the foregoing values as endpoints.

[0250] In some embodiments, the liquid radiation curable resin composition includes further additives such as flame retardants, anti-dripping agents, antioxidants, thermal stabilizers, impact modifiers, fillers, antistats, colorants, dyes, pigments, lubricants, defoamers, flow control agents, wetting / dispersing agents, surface agents, rheology modifiers, processing agents, demolding agents, hydrolysis stabilizers, compatibilizers, and UV and / or IR absorbers. In some embodiments, these further additives may be included in the liquid radiation curable resin composition, alone or combination, in an amount of about 0.01 wt.%, 0.05 wt.%, 0.1 wt.%, 0.2 wt.%, 0.3 wt.%. 0.4 wt.%, 0.5 wt.%, 0.6 wt.%, 0.7 wt.%, 0.8 wt.%, 0.9 wt.%, 1 wt.%, 1 .5 wt.%, 2 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 10 wt.%, or within any range encompassed by any two of the foregoing values as endpoints, based on the total weight of the liquid radiation curable resin composition. For example, these further additives may constitute, alone or in combination, about 0.01 wt.% to about 3 wt.%, about 0.1 wt.% to about 2 wt.%, or about 0.5 wt.% to about 1 wt.%, of the total weight of the liquid radiation curable resin composition. For example, in some embodiments, the additives may be dyes in an amount of about 0.3 wt.% of the total weight of the liquid radiation curable resin composition; in some embodiments, the additives may be dyes and pigments in an amount of about 0.3 wt.% of the total weight of the liquid radiation curable resin composition.

[0251] In some embodiments, suitable demolding agents for the liquid radiation curable resin compositions of the present disclosure include pentaerythritol tetrastearate (PETS) or glycerol monostearate (GMS), carbonates thereof and / or mixtures of these demolding agents.2024P20002WG

[0252] In some embodiments, suitable colorants and pigments include, for example, sulfur containing pigments such as cadmium red and cadmium yellow, iron cyanide-based pigments such 25 as Prussian blue, oxide pigments such as titanium dioxide, zinc oxide, red iron oxide, black iron oxide, chromium oxide, titanium yellow, zinc / iron-based brown, titanium / cobalt-based green, cobalt blue, copper / chromium-based black and copper / iron- based black or chromium-based pigments such as chromium yellow, phthalocyanine-derived dyes such as copper phthalocyanine blue and copper phthalocyanine green, fused polycyclic dyes and pigments such as azo-based (e.g. nickel azo yellow), 30 sulfur indigo dyes, perinone-based, perylene-based, quinacridone-derived, dioxazine-based, isoindolinone- based and quinophthalone-derived derivatives, and anthraquinone-based heterocyclic systems.

[0253] Specific examples of commercial products are, for instance, MACROLEX® Blue RR, MACROLEX® Violet 3R, MACROLEX® EG, MACROLEX® Violet B (Lanxess AG, Germany), Sumiplast® Violet RR, Sumiplast® Violet B, Sumiplast® Blue OR, (Sumitomo Chemical Co., Ltd.), Diaresin® Violet D, Diaresin® Blue G, Diaresin® Blue N (Mitsubishi Chemical Corporation), Heliogen® Blue or Heliogen® Green (5 BASF AG, Germany). In certain embodiments, the suitable colorants and pigments are cyanine derivatives, quinoline derivatives, anthraquinone derivatives, phthalocyanine derivatives, or combinations thereof.

[0254] In some embodiments, the employed carbon blacks are nanoscale carbon blacks, or nanoscale pigment blacks. The employed carbon blacks can have an average primary particle size, determined by scanning electron microscopy, of less than about 100 nm, about 10 to about 99 nm, about 10 to about 50 nm, about 10 to about 30 nm, or about 10 to about 20 nm. In some embodiments, the employed carbon blacks are finely divided pigment blacks.

[0255] Suitable antioxidants can be sterically hindered phenols which may be selected from the group consisting of 2,6-di-tert-butyl-4-methylphenol (ionol), pentaerythritol tetrakis(3- (3,5-di-tert-butyl-4-hydroxyphenyl)propionate), octadecyl 3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate, triethylene glycol bis(3-tert-butyl-4-hydroxy-5- methylphenyl)propionate, 2,2'-thiobis(4-methyl-6-tert-butylphenol), thiodiethylene bis(3-(3,5- di-tert-butyl-4-hydroxyphenyl)propionate), and 2,2'-thiodiethyl bis[3-(3,5-di-tert-butyl-4-2024P20002WQ hydroxyphenyl)propionate]. These may be used either individually or in any desired combinations with one another as required.III. Liquid Radiation Curable Resin Composition Properties

[0256] The liquid radiation curable resin composition described in Section II above may have certain properties that are advantageous for additive manufacturing processes.

[0257] In some embodiments, the liquid radiation curable resin composition may have a viscosity, when measured at 25°C of about 25 mPa*s, 50 mPa*s, 75 mPa*s, 100 mPa*s, 125 mPa*s, 150 mPa*s, 175 mPa*s, 200 mPa«s, 225 mPa*s, 250 mPa«s, 275 mPa*s, 300 mPa*s, 325 mPa»s, 350 mPa*s, 375 mPa*s, 400 mPa»s, 425 mPa»s, 450 mPa»s, 475 mPa*s, 500 mPa»s, or within any range encompassed by any two of the foregoing values as endpoints, as measured using a Paar Physica Rheometer at a constant frequency of 50 1 / s and 25°C. For example, the liquid radiation curable resin composition may have a viscosity at 25°C of about 25 mPa»s, 50 mPa»s, 75 mPa»s, 100 mPa»s, 125 mPa*s, 150 mPa»s, 175 mPa«s, 200 mPa*s, 225 mPa«s, 250 mPa*s, 275 mPa*s, 300 mPa*s, 325 mPa*s, 350 mPa«s, 375 mPa*s, 400 mPa*s, 425 mPa*s, 450 mPa*s, 475 mPa*s, or 500 mPa*s.

[0258] After being cured with actinic radiation and an optional post curing treatment, 3D printed articles may have a different set of properties from the liquid uncured resin compositions. Suitable optional post curing treatments include UV treatment and / or a thermal treatment. 3D printing and curing methods are discussed in further detail in Section V below.

[0259] In some embodiments, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resin composition may have a heat distortion temperature (HDT) at 0.46 MPa of more than or equal to about 35°C such as about 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, or within any range encompassed by any two of the foregoing values as endpoints, according to ASTM D648. For example, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resin composition may have a heat distortion temperature (HDT) at 0.46 MPa of about 65°C to about 100°C, about 70°C to about 95°C, or about 80°C to about 90°C.

[0260] In some embodiments, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resin composition may have an elongation at break of more than or equal to about 5% such as about 5%, 6%, 7%, 8%, 9%, 10%, 11 %, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21 %, 22%, 23%, 24%, 25%, 26%, 27%,28%, 29%, 30%, 31 %, 32%, 33%, 34%, 35%, or within any range encompassed by any two of the foregoing values as endpoints, according to ASTM D638. For example, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resin composition may have an elongation at break of about 12% to about 25%, about 1 % to about 22%, or about 15% to about 20%.

[0261] In some embodiments, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resin composition may have a tensile stress of more than or equal to about 5 MPa such as about 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa, 50 MPa, 55 MPa, 60 MPa, 65 MPa, 70 MPa, 75 MPa, 80 MPa, or within any range encompassed by any two of the foregoing values as endpoints, according to ASTM D638. For example, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resin composition may have a tensile strength of about 5 MPa, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa, 50 MPa, 55 MPa, 60 MPa, 65 MPa, 70 MPa, 75 MPa, or 80 MPa.

[0262] In some embodiments, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resin composition may have a tensile modulus of more than or equal to about 500 MPa such as about 500 MPa, 550 MPa, 600 MPa, 650 MPa, 700 MPa, 750 MPa, 800 MPa, 850 MPa, 900 MPa, 950 MPa, 1000 MPa, 1050 MPa, 1100 MPa, 1150 MPa, 1200 MPa, 1250 MPa, 1300 MPa, 1350 MPa, 1400 MPa, 1450 MPa, 1500 MPa, or within any range encompassed by any two of the foregoing values as endpoints, according to ASTM D638. For example, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resin composition may have a tensile modulus of about 500 MPa to about 1000 MPa, about 1500 MPa to about 2,000 MPa, or about 500 MPa to about 800 MPa.

[0263] In some embodiments, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resin composition may have a water absorption of less than or equal to about 0.5% after 1 day immersion at room temperature such as about 0.4%, 0.3%, 0.2%, 0.1 %, 0.05%, 0.01 %, 0.001 %, or within any range encompassed by any two of the foregoing values as endpoints, according to ASTM D570. For example, after curing with actinic radiation and an optional post curing treatment, the liquid radiation curable resincomposition may have a water absorption of about 0.01 % to about 0.4%, about 0.05% to about 0.3%, or about 0.1 % to about 0.2%.

[0264] In some embodiments, the liquid radiation curable resin compositions of the present disclosure may have increased resistance to wet weather conditions, such as rain, sleet, snow, and other forms of precipitation, after curing, according to SAE J2527.IV. Cured Articles

[0265] The present disclosure also provides cured articles which are formed using the liquid radiation curable resin compositions described in Sections II and III above.

[0266] In some embodiments, the present disclosure includes a three-dimensional article including the liquid radiation curable resin composition of the present disclosure. The present disclosure also includes an object which is or includes a three-dimensional article including the liquid radiation curable resin composition of the present disclosure. Examples of three-dimensional articles and objects which may be formed using the liquid radiation curable resin compositions of the present disclosure include 3D printed medical devices, such as prosthetics, orthotics, and dental implants, resins for 3D printing electronic components and enclosures, among other articles. Monofunctional epoxy compounds may also be used in the creation of prototypes and functional parts that require specific mechanical properties and durability. The low viscosity and controlled reactivity of monofunctional epoxy compounds allows for the production of high-quality, detailed prints with enhanced flexibility and strength.

[0267] The objects and / or cured articles of the present disclosure may have a tensile modulus of about or less than 2,000 MPa, such as about or less than 100 MPa, about or less than 200 MPa, about or less than 300 MPa, about or less than 400 MPa, about or less than 500 MPa, about or less than 600 MPa, about or less than 700 MPa, about or less than 800 MPa, about or less than 900 MPa, about or less than 1000 MPa, about or less than 1100 MPa, about or less than 1200 MPa, about or less than 1300 MPa, about or less than 1400MPa, about or less than 1500 MPa, about or less than 1600 MPa, about or less than 1700MPa, about or less than 1800 MPa, about or less than 1900 MPa, about or less than 2000MPa, or within any range encompassed by any two of the foregoing values as endpoints, in the X, Y, and Z directions according to ASTM D638. For example, the objects and / or cured articles of the present disclosure may have a tensile modulus of about 500 MPa to about2024P20002WQ1000 MPa, about 250 MPa to about 750 MPa, or about 150 MPa to about 2,000 MPa, in the X, Y, and Z directions according to ASTM D638.

[0268] The objects and / or cured articles of the present disclosure may have a tensile stress of at least about 5 MPa, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa, 50 MPa, 55 MPa, 60 MPa, 65 MPa, 70 MPa, 75 MPa, 80 MPa, 85 MPa, 90 MPa, 95 MPa, 100 MPa, or within any range encompassed by any two of the foregoing values as endpoints, in the X, Y, and Z directions according to ASTM D638. For example, the objects and / or cured articles of the present disclosure may have a tensile stress of about 5 MPa to about 100 MPa, about 45 MPa to about 75 MPa, or about 50 MPa to about 70 MPa, in the X, Y, and Z directions according to ASTM D638.

[0269] The objects and / or cured articles of the present disclosure may have an elongation at break of at least about 5%, at least 10%, at least 11 %, at least 12%, at least 13%, at least 14%, at least 15%, at least 16 %, at least 17%, at least 18%, at least 19%, at least 20%, or within any range encompassed by any two of the foregoing values as endpoints, in the X, Y, and Z directions according to ASTM D638. For example, the objects and / or cured articles of the present disclosure may have an elongation at break of about 5% to about 15%, about 10% to about 20%, about 12% to about 18%, or about 14% to about 16%, in the X, Y, and Z directions according to ASTM D638.

[0270] The objects and / or cured articles of the present disclosure may have an HDT at 0.46 MPa of at least about 30°C, at least 35°C, at least 40°C, at least 45°C, at least 50°C, at least 55°C, at least 60°C, at least 65°C, at least 70°C, at least 75°C, at least 80°C, at least 85°C, at least 90°C, at least 95°C, at least 100°C, or within any range encompassed by any two of the foregoing values as endpoints, according to ASTM D648. For example, the objects and / or cured articles of the present disclosure may have an HDT at 0.46 MPa of about 30°C to about 50°C, about 40°C to about 96°C, or about 40°C to about 70°C, according to ASTM D648.

[0271] The objects and / or cured articles of the present disclosure may have a load value (N) of at least about 500 N, at least 750 N, at least 1000 N, at least 1250 N, at least 1500 N, at least 1750 N, at least 2000 N, or within any range encompassed by any two of the foregoing values as endpoints, according to ASTM D256. For example, the objects and / or cured articles of the present disclosure may have a load value of about 500 N, 550 N, 600 N,2024P20002WQ650 N, 700 N, 750 N, 800 N, 850 N, 900 N, 950 N, 1000 N, 1050 N, 1100 N, 1150 N, 1200 N, 1250 N, 1300 N, 1350 N, 1400 N, 1450 N, 1500 N, 1550 N, 1600 N, 1650 N, 1700 N, 1750 N, 1800 N, 1850 N, 1900 N, 1950 N, or 2000 N, according to ASTM D256.

[0272] The objects and / or cured articles of the present disclosure may have a water absorption percentage of less than about 0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1 %, less than 0.05%, less than 0.01 %, less than 0.001 %, or within any range encompassed by any two of the foregoing values as endpoints, after 25 hours at room temperature according to ASTM D570. For example, the objects and / or cured articles of the present disclosure may have a water absorption percentage of about 0.01 % to about 0.5%, about 0.1 % to about 0.4%, or about 0.2% to about 0.3%, according to ASTM D570.V. Printing Methods

[0273] The liquid radiation curable resin compositions of the present disclosure may be used with a variety of 3D printing methods to form three dimensional articles such as those described in Section IV above. Such methods involve irradiating disclosed liquid radiation curable resin compositions to form a crosslinked material. Irradiating the liquid radiation curable resin composition leads to the generation of free radicals from radical starters present in the liquid radiation curable resin composition. The radicals are capable of initiating a reaction between the multifunctional cationically polymerizable component or the monofunctional (meth)acrylate component in the composition. Accordingly, the liquid radiation curable resin composition can be selectively irradiated according to a predetermined cross-section of a target article to be manufactured. Selective irradiation may be repeated until a predetermined intermediate article comprising the liquid radiation curable resin composition is obtained.

[0274] In some embodiments, the liquid radiation curable resin compositions of the present disclosure may be used in a process to produce a three-dimensional object. The process may involve the steps of: (i) retaining the liquid radiation curable resin composition of the present disclosure in a container; (ii) selectively irradiating the liquid radiation curable resin composition in the container with activating radiation to solidify at least a portion of a first liquid layer of the liquid radiation curable resin composition, thereby forming a first photocured layer that defines a first cross-section of the article; (iii) raising or lowering the first2024P20002WQ photocured layer to provide a second fluid layer of the liquid radiation curable resin composition at a surface of the fluid composition in the container; (iv) selectively irradiating the liquid radiation curable resin composition in the container with activating radiation to solidify at least a portion of the second liquid layer of the composition, thereby forming a second photocured layer that defines a second cross-section of the article; the first crosssection and the second cross-section being bonded one to another in a z-direction; and (v) repeating the raising or lowering step and the selectively irradiating step to form the three- dimensional article

[0275] In some embodiments of the 3D printing process according to the disclosure, the three-dimensional article is obtained by additively curing multiple layers atop one another until the article is formed. This curing process may be realized by means of ray-optic additive manufacturing processes such as stereolithography or the digital light processing (DLP) process or by inkjet printing processes combined with radiative crosslinking.

[0276] The initial steps (i) and (ii) of the process, discussed above, may further involve irradiating the liquid radiation curable resin composition onto the surface of a carrier, tray, build head or platform. This is usually the first step in stereolithography and DLP processes. In this way, the first layer of the liquid radiation curable resin composition is cured onto the surface of a carrier, tray, build head or platform, which may correspond to a first selected cross section of the three-dimensional article.

[0277] Steps (iii), (iv), and (v), discussed above, can involve repeatedly depositing and curing additional liquid radiation curable resin composition atop a previously cured layer of the three-dimensional article to obtain a further layer. Each further layer can be a cross section of the article being printed and can be bonded to the previously printed layer. Also, in accordance with the present disclosure, the curing of the liquid radiation curable resin composition involves exposure and / or irradiation of a selected region of the liquid radiation curable resin composition corresponding to the respectively selected cross section of the three-dimensional article. The liquid radiation curable resin composition is converted to the solid three-dimensional material by exposure and / or irradiation which triggers free-radical crosslinking reactions. “Exposure” as used herein means introduction of light in the range between near-IR and near-UV light (wavelengths of 1400 nm to 315 nm). The remaining2024P20002WQ shorter wavelength ranges are covered by the term “irradiation”, for example, far UV light, x- ray radiation, gamma radiation and electron radiation.

[0278] In some embodiments, the activating radiation may have a wavelength in the range of about 350 nm to about 450 nm, 355 nm to about 430 nm, or 375 nm to about 420 nm.

[0279] In some embodiments, the thickness of each photocured layer may be between about 50 pm and about 250 pm, greater than about 50 pm, or less than about 250 pm.

[0280] The selection of respective cross-sections may be accomplished by use of a CAD program, with which a model of the object to be produced has been generated. This operation is also known as “slicing” and serves as a basis for controlling the exposure and / or irradiation of the liquid radiation curable resin composition.

[0281] After step (v) is completed, and the three-dimensional article is formed, the three-dimensional article may be subjected to further post-processing treatments such as further irradiation, thermal curing, solvent cleaning, surface smoothing, painting and surface finishing, or support removal.

[0282] In some embodiments, the post-processing treatment may involve exposure to irradiation with a wavelength in the range of about 300 nm to about 400 nm, 350 nm to 450 nm, or 375nm to 425 nm, for about 30 minutes, 1 hour, 1 .5 hours, or 2 hours.

[0283] In some embodiments, the post-processing treatment may involve heating the object at a temperature of at least about 80°C, 90°C, 100°C, 110°C, or 120°C, for at least about 30 minutes, 1 hour, 1.5 hours, or 2 hours.

[0284] In some embodiments, the post-processing treatment may involve cleaning the surface of the three-dimensional article with a solvent. The solvent may include isopropyl alcohol, methyl ethyl ketone, acetone, ethanol, or water.

[0285] A variety of different 3D printing processes for forming 3D objects are known to those skilled in art, such as those described in U.S. Pat. Nos. 9,453,142; and 10,793,745; and in U.S. Pat. Pub. 2021 / 0054125. These and other processes not mentioned here may use the liquid radiation curable resin composition of the present disclosure to produce objects.EXAMPLES

[0286] The non-limiting and non-exhaustive examples that follow are intended to further describe various non-limiting and non-exhaustive embodiments without restricting the scope of the embodiments described in this specification. All quantities given in “parts” and “percents” are understood to be by weight, unless otherwise indicated.Experimental methods

[0287] Tensile Modulus (TM) was determined in accordance with ASTM D 638 and is expressed in megapascal (MPa). Tensile Stress (TS) was determined in accordance with ASTM D 638 and is expressed in megapascal (MPa). Elongation at Break (EaB) was determined in accordance with ASTM D 638 and is expressed in percent (%). Flexural Modulus (FM) was determined in accordance with ASTM D 790 and is expressed in megapascal (MPa). Flexural Stress (FS) was determined in accordance with ASTM D 790 and is expressed in megapascal (MPa). Tan Delta Tg(Tg) was determined in accordance with ASTM E 1545 and is expressed in Celsius degree (°C). Heat Deflection Temperature (HDT) was determined at 0.46 MPa in accordance with ASTM D 648 and is expressed in Celsius degree (°C). Water absorption (H2O abs.) was determined in accordance with ASTM D 570, the testing being made 24 h at room temperature (e.g. about 25 °C), and is expressed in percent (%). Viscosity was measured at 25 °C using a Paar Physica Rheometer at a constant frequency of 50 1 Is and 25°C, and is presented either in centipoise (cP), or in mPa / second (mPa*s), 1 cP corresponding to 1 mPa*s.Example 1

[0288] Disclosed herein are liquid radiation curable resin compositions containing monofunctional reactants that can be efficiently used in additive manufacturing and which present reduced viscosity and water absorption among other advantageous mechanical properties.

[0289] More specifically, the present disclosure includes formulations that can be used as curable additive formulations in photopolymerization technologies, such as vat photopolymerization technologies, for instance, but without being limited, to Digital Light Processing (DLP) or StereoLithography (SLA) technologies. In some embodiments, the liquid radiation curable resin composition of the present disclosure is particularly suitable for2024P20002WC additive manufacturing systems having a photopolymerization wavelength in a range of 350 nm to 450 nm, for instance 385 nm or 405 nm. One example of such additive manufacturing system is the Origin® One printer (Stratasys, Israel).

[0290] In some embodiments, the liquid radiation curable resin composition of the present disclosure, once cured and optionally post-cured, demonstrates advantageous mechanical properties whereas use of chain transfer agents (CTAs) in known compositions is associated with high water absorption, cloudiness, and high viscosity, liquid radiation curable resin composition of the present disclosure, which contain a monofunctional epoxy diluent instead of the CTA, afford easy control of network structure, low water absorption, low viscosity, a high concentration of oligomers, high viscosity resin design, high filler content, and ease of dissolving specific additives.Sample Preparation

[0291] In order to evaluate the feasibility of utilizing a monofunctional epoxy in a liquid radiation curable resin composition, the properties of the following sample compositions were evaluated.

[0292] Samples:• C1 and C2 containing chain transfer agent (CTA)• D1 and D2 containing a difunctional epoxy diluent instead of CTA• M1 and M2 containing a monofunctional epoxy diluent instead of CTA

[0293] Samples C1 , D1 , and M1 contained (3'-4'-Epoxycyclohexane)methyl 3'-4'- epoxycyclohexyl-carboxylate (Celloxide 2021 ), and C2, D2, and M2 contained difunctional bisphenol A / epichlorohydrin derived epoxy resin (Epon 828). Celloxide 2021 P and Epon 828 are both difunctional epoxy compounds but have distinct oligomers.

[0294] Based upon current knowledge, there are several drawbacks to including monofunctional reactants in a liquid radiation curable resin composition for additive manufacturing. In some examples, monofunctional reactants are understood to react slowly, leading to incompatibility with the fast reaction rates required for 3D printing. In some examples, monofunctional reactants are understood to contribute to brittle materials prone to chipping and shattering, not materials having resistance to high temperature, desirable hardness, and high elastic modulus.

[0295] Contrary to knowledge in the art, liquid radiation curable resin compositions containing a monofunctional epoxy diluent yielded 3D-printed articles with desirable properties. Relative to formulations containing CTA and a difunctional epoxy diluent, it was unexpectedly found that the samples containing monofunctional epoxy diluent, C1 and C2, had both reduced water adsorption and viscosity. For example, relative to C1 , which contained CTA, and D1 , which contained difunctional epoxy, M1 had about 82% and 57% lower viscosity, respectively. With respect to water adsorption (%), M1 had about 52% less water adsorption compared to C1 , and about 4% less water adsorption compared to D1 .

[0296] M2 showed a similar trend. The monofunctional epoxy containing sample, M2, had a viscosity that was about 77% less than that of C2 and about 44% less than that of D2. Regarding water adsorption, M2 adsorbed about 23% less water compared to C1 , but adsorbed 38% more water compared to difunctional epoxy sample D2.

[0297] Despite having lower viscosity and reduced water adsorption relative to formulations containing chain transfer agents, M1 and M2 had comparable, if not improved mechanical properties. For example, and as shown in Table 2, despite demonstrating lower water adsorption and lower viscosity relative to the respective CTA formulation, M1 and M2 had comparable load (N) and heat deflection temperature (°C) (HDT) to C1 and C2, respectively. A reduced propensity for water adsorption and low viscosity are advantageous for several reasons. For example, lower water adsorption may improve dimensional stability and resistance to environmental factors, like humidity. Additionally, reduced viscosity expands the liquid radiation curable resin composition’s potential for use in a wider range of application methods, such as spraying or injection molding, which may not be feasible with higher viscosity resins.

[0298] Table 1 below presents the chemical composition of exemplary tested formulations (values refers to wt.%). Component A is a difunctional epoxy compound (Celloxide 2021 P, Daicel ChemTech Inc.). Component B is a difunctional epoxy containing a different oligomer than Component A (Epon 828, Brenntag North America). Component C is a type of oxetane monomer used in UV-curable resin formulations, particularly for improving cure speed (OXT 101 , Toagosei). Component D is a CTA (PTMO 1000, BASF). Component E is a difunctional epoxy compound (DE203, Kukdo Chemical). Components F (ME 102, Kukdo Chemical) and G (ME 101 , Kukdo Chemical) are monofunctional epoxy compounds.Component H is an acrylate (EB3702, Rahn Chemical). Component I is a photoinitiator compound (OPPI, Hampford Research Institute). Component J is a cationic photoinitiator (FP5041 , Hampford Research Institute). Component K is a photoinitiator compound used in cationic UV-curable resin systems (CPTX, Arkema). Component L is trivinyl ether (TVE (Triethyleneglycol Divinylether), BASF).Table 1

[0299] The above compositions were used to print three-dimensional objects on a Stratasys Origin® One 3D printer (Stratasys, Israel) to test mechanical properties according to the ASTM standards mentioned herein.

[0300] The compositions were slightly agitated and then poured into the resin tray of the 3D printer. The printer was set at a constant temperature of 25 °C and light intensity of about 5 mW / cm2(385 nm). To start building a part, a computer-generated file containing a specific geometry was sent to the printer software. Thereafter, parameters such as layer thickness, part orientation, and exposure time were determined by the user and the printing of the object started.

[0301] When the printing was completed, the parts were washed in a suitable solvent such as isopropanol (IPA) for 3 minutes with continuous sonication. Thereafter, the parts were dried for 1 hour. Finally, the 3D printed parts were UV and thermally post-cured to achieve the desirable performance. The basic mechanical properties were determined using tensile bars and following procedures described in the ASTM standard methods.Physical appearance

[0302] FIG. 1 shows a comparison of 3D printed articles made in accordance with the exemplary methods described. The M1 article (110), prepared from the M1 components detailed in Table 1 , included the monofunctional epoxy ME 102 instead of a CTA. The image shows a smooth and consistent texture, even around the sharp edges of the M1 article. In comparison, the CTA-containing 3D printed article C1 (120), which was formulated in accordance with C1 in Table 1 , had an irregular surface texture with large chips (130).

[0303] FIGs. 2A-C show additional comparisons of 3D printed articles made in accordance with an embodiment of the present disclosure (M1 ) and a comparator composition including a CTA (C1 ). The article according to the present disclosure containing monofunctional epoxy M1 (210a) shows an intact article with consistent surface texture, even given the complex shape of the 3D printed article. In contrast, C1 (240a) was prone to chipping (220a and 230a) and did not form a complete, intact article. FIG. 2B shows an alternative view of M1 (210b) and C1 (240b) shown in FIG. 2A. FIG. 2C shows an inversion of M1 (210c) and C1 (240c).Mechanical properties

[0304] Table 2 below presents the properties of the exemplary tested compositions of Table 1 after printing and post-curing.Table 2

[0305] Table 2 shows that the formulations of the present invention (e.g. M1 and M2) have comparable or improved mechanical properties at a lower viscosity and with no printing speed reduction if compared to formulations comprising a CTA and / or a multifunctional (e.g. difunctional) epoxy as a diluent.

Claims

2024P20002WQCLAIMSWhat is claimed is:1 . A liquid radiation curable resin composition for additive manufacturing comprising:(a) a multifunctional cationically polymerizable component;(b) a multifunctional (meth)acrylate component;(c) a monofunctional component comprising a cationically polymerizable epoxy component, a monofunctional (meth)acrylate component, or any combination thereof;(d) a cationic photoinitiator; and(e) a free-radical photoinitiator.

2. The composition of claim 1 , wherein the monofunctional cationically polymerizable epoxy and acrylate do not contain another polymerizable unit.

3. The composition of claim 1 , wherein the composition has a viscosity (mPa*s), when measured at 25°C, of less than 20000 mPa*s.

4. The composition of claim 1 , comprising both the monofunctional cationically polymerizable epoxy and the monofunctional (meth)acrylate component.

5. The composition of claim 1 , wherein the cationic photoinitiator is selected from the group consisting of aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, triarylsulfonium salts, diaryliodonium salts, and metallocene based compounds metallocene based compounds, aromatic phosphonium salts, acylsulfonium salts, naphthyl-sulfonium salt and any combination thereof.

6. The composition of claim 1 , wherein the cationic photoinitiator has an anion selected from the group consisting of BFT, AsFe”, SbFe”, PFe", [B(CF3)4]", B(C6F5) , B[CeH3- 3,5(CF3)2]4-, B(C6H4CF3)4-, B(C6H3F2)4-, B[C6F4-4(CF3)]4-, Ga CeFs , [(C6F5)3B- C3H3N2-B(C6F5)3]-, [(C6F5)3B-NH2-B(C6F5)3]-; tetrakis(3,5-difluoro-4- alkyloxyphenyl)borate, tetrakis(2,3,5,6-tetrafluoro-4-alkyloxyphenyl)borate,perfluoroalkylsulfonates, tris[(perfluoroalkyl)sulfonyl]methides, bis[(perfluoroalkyl)sulfonyl]imides, perfluoroalkylphosphates, tris(perfluoroalkyl)trifluorophosphates, bis(perfluoroalkyl)tetrafluorophosphates, tris(pentafluoroethy)trifluorophosphates, and (CHeBnBre)-, (CHeBnCle)- and other halogenated carborane anions7. The composition of claim 1 , wherein the free-radical photoinitiator is selected from the group consisting of benzoylphosphine oxides, aryl ketones, benzophenones, hydroxylated ketones, 1 -hydroxyphenyl ketones, ketals, metallocenes, and any combination thereof.

8. The composition of claim 1 , wherein an epoxy component comprises the multifunctional cationically polymerizable component and the monofunctional cationically polymerizable epoxy, wherein the monofunctional cationically polymerizable epoxy is 10-90 wt.%, 20-80 wt.%, 30-70 wt.%, or 40-60 wt.% of the epoxy component; or wherein an acrylate component comprises the multifunctional (meth)acrylate component and the monofunctional (meth)acrylate component, wherein the monofunctional (meth)acrylate component is 1 -65 wt.%, 5-60 wt.%, 10-55 wt.%, or 15-50 wt.% of the acrylate component.

9. The composition of claim 1 , wherein an epoxy component comprises the multifunctional cationically polymerizable component and the monofunctional cationically polymerizable epoxy, and wherein the multifunctional cationically polymerizable component is present in a total amount of 15-95 wt.%, 20-90 wt.%, 25-85 wt.%, or 30-80 wt.% of the epoxy component.

10. The composition of claim 1 , wherein an acrylate component comprises the multifunctional (meth)acrylate component and the monofunctional (meth)acrylate component, andwherein the multifunctional (meth)acrylate component is present in a total amount of 1- 70 wt.%, 5-65 wt.%, 10-60 wt.%, or 15-55 wt.% of the acrylate component.11 . The composition of claim 1 , wherein the monofunctional cationically polymerizable epoxy comprises a compound of formula (16) or (17):wherein Ri, R2, R3, and R4 are the same or different and are selected from H, straight-chain alkyl or alkoxy groups, branched or cyclic alkyl or alkoxy groups, aromatic ring systems, and heteroaromatic ring systems, where an R1 and R2 radical may optionally be joined to one another and may form a ring; and where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems optionally substituted by one or more radicals selected from Cl, I Br, F, or a functional group comprising carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide.

12. The composition of claim 1 , wherein the monofunctional cationically polymerizable epoxy comprises a compound of formula (18),wherein R1 , R2, R3, and R4 are the same or different and are selected from H, straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 40 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;2024P20002WQ and where the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems optionally substituted by one or more radicals selected from Cl, I, Br, F, or a functional group comprising carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide.

13. The composition of claim 12, wherein Ri , R2, R3, and / or R4 comprise an alkyl having 12 to 14 carbon atoms.

14. The composition of claim 1 , wherein the monofunctional cationically polymerizable epoxy comprises at least one of15. The composition of claim 1 , wherein the monofunctional meth(acrylate) component comprises at least one of:

16. The composition of claim 1 , wherein the multifunctional cationically polymerizable component comprises a difunctional epoxy, a bicyclic bis-epoxide monomer, or a poly(glycidyl ether).

17. The composition of claim 1 , wherein the multifunctional cationically polymerizable component comprises hydrogenated Bisphenol A digycydylether epoxy, polymeric aryl glycidylethers, 3,4-Epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate, bisphenol A2024P20002WQ diglycidyl ether, poly( 1 ,4-butanediol diglycidyl ether, neopentylglycol d iglycidylether, or 1 ,4- Butanediol diglycidyl ether.

18. The composition of claim 1 , wherein the multifunctional cationically polymerizable component comprises a structure of formula (1 ):wherein R1 and R2 are the same or different and are selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, for example R1 and R2 may be selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethylene, propene, butene, pentene, hexene, acetylene, propargyl, butynyl, pentynyl, hexynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, morpholinyl, piperidyl, pyrrolidinyl, tetrahydrofuranyl, phenyl, benzyl, napthyl, toluyl, anisyl, aromatic ring systems such as diphenylmethane, cycloalkyl ring systems such as dicyclohexylmethane, wherein the R1 and / or R2 group can be optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, cycloalkyl, aromatic, aryl, heteroaryl, heteroalkyl, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide, and wherein n and m are, independently, 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

19. The composition of claim 1 , wherein the multifunctional cationically polymerizable component comprises a compound selected from the group consisting of:wherein n is 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

20. The composition of claim 1 , wherein the multifunctional (meth)acrylate component comprises a compound of formula (6) or (7):wherein R, R3, and R4 are the same or different and are selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, for example R, R3, and R4 may be selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethylene, propene, butene, pentene, hexene, acetylene, propargyl, butynyl, pentynyl, hexynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, morpholinyl, piperidyl,2024P20002WQ pyrrolidinyl, tetrahydrofuranyl, phenyl, benzyl, napthyl, toluyl, anisyl, aromatic ring systems such as diphenylmethane, cycloalkyl ring systems such as dicyclohexylmethane, wherein the R, R3, and / or R4 group can be optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, cycloalkyl, aromatic, aryl, heteroaryl, heteroalkyl, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide,R1 and R2 are the same of different and are selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, for example R1 and R2 may be selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethylene, propene, butene, pentene, hexene, acetylene, propargyl, butynyl, pentynyl, hexynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, morpholinyl, piperidyl, pyrrolidinyl, tetrahydrofuranyl, phenyl, benzyl, napthyl, toluyl, anisyl, aromatic ring systems such as diphenylmethane, cycloalkyl ring systems such as dicyclohexylmethane, wherein the R1 and / or R2 group can be optionally substituted by one or more radicals selected from Cl, I, Br, F, or functional groups including carboxyl, hydroxyl, carbonyl, amine, ether, ester, amide, alkene, alkyne, cycloalkyl, aromatic, aryl, heteroaryl, heteroalkyl, thiol, nitro, sulfonic acid, phosphate alkyl halide, or acyl halide, a= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and b= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.21 . The composition of claim 1 , wherein the multifunctional (meth)acrylate component comprises a compound of formula (8) or (9):wherein a= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and b= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.wherein n= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and m= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

22. The composition of claim 1 , wherein the multifunctional (meth)acrylate component comprises at least one of2024P20002WQwherein n= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10, and m= 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10.

23. The composition of any one of claims 1-22, wherein the composition further comprises a chain transfer agent.

24. The composition of claim 23, wherein the chain transfer agent (CTA) comprises a reactive hydroxyl group, a reactive sulfonyl group, a reactive sulfonamide group, a reactive sulfhydryl group, a reactive amine group, or a combination thereof.

25. The composition of claim 23 or 24, wherein the chain transfer agent (CTA) comprises less than 40 wt.% of the total weight of the composition.

26. The composition of any one of claims 1-25, further comprising an additive.

27. The composition of claim 26, wherein the additive comprises flame retardants, antidripping agents, antioxidants, thermal stabilizers, impact modifiers, fillers, antistats, colorants,pigments, lubricants, defoamers, flow control agents, demolding agents, hydrolysis stabilizers, compatibilizers, UV and / or IR absorbers, or any combination thereof.

28. The composition of any one of claims 1-27, wherein the composition further comprises an oxetane.

29. The composition of claim 28, wherein the oxetane comprises a monofunctional and / or multifunctional oxetanes.

30. The composition of claim 28 or 29, wherein the oxetane is from about 0 to about 50 wt.% of the composition.31 . The composition of claim 1 , wherein the multifunctional cationically polymerizable component is a multifunctional cationically polymerizable aliphatic epoxide, and wherein the monofunctional cationically polymerizable epoxy is a monofunctional cationically polymerizable aliphatic epoxide.

32. An article comprising the composition of any one of claims 1-31 .

33. The article of claim 32, wherein the article has a percent water adsorption of less than 1.5%.

34. The article of claim 32, wherein the article has a modulus of elasticity from about 10 to about 5000 MPa.

35. The article of claim 32, wherein the article has a maximum tensile stress from about 5 to about 100 MPa.

36. The article of claim 32, wherein the article has an elongation at break from about 1 to about 100%.2024P20002WQ37. The article of claim 32, wherein the article has a load value of about 100 to about 5000 N.

38. A method of manufacturing a 3D printed article, comprising: curing the composition of any one of claims 1 -31 , the curing comprising irradiating the composition to form a crosslinked material.

39. The method of claim 38, wherein irradiating the composition generates radicals from radical starters present in the composition, wherein the radicals initiate a reaction between radically polymerizable multifunctional and monofunctional (meth)acrylate components in the composition.

40. The method of claim 38, wherein irradiating the composition generates cations from cation starters present in the composition, wherein the cations initiate a reaction between the multifunctional cationically polymerizable component and the monofunctional epoxy component in the composition.41 . The method of claim 38, comprising: selectively irradiating the composition according to a pre-determined cross-section of a target article to be manufactured; and repeating the selective irradiation until a predetermined intermediate article comprising the composition is obtained.

42. The method of claim 38, wherein prior to step irradiating, the composition is selectively applied onto a surface according to the pre-determined cross-section of a target article to be manufactured.

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