Dual cure resins for mixed modulus materials

Abstract

Provided are dual cure resin compositions useful for additive manufacturing that include an elastomer-producing light polymerizable monomer and / or prepolymer; a monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture; a photoinitiator; optionally, one or more additional light polymerizable monomers and / or prepolymers; and optionally, a thiol crosslinker. Methods of forming a polymer and / or three-dimensional object with the resin, and polymers and / or three-dimensional objects produced are also described.

Description

[0001] DUAL CURE RESINS FOR MIXED MODULUS MATERIALS

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 589,675, filed October 12, 2023, the disclosure of which is hereby incorporated by reference in its entirety.

[0004] FIELD

[0005] The present invention relates to compositions and methods for use in additive manufacturing. In particular, the present invention relates to resin compositions and methods of using the same in additive manufacturing.

[0006] BACKGROUND

[0007] Tougheners such as polybutadiene are commonly used in rigid thermoset materials to improve the notched impact toughness of otherwise relatively brittle materials. When such tougheners are used in additive manufacturing, they are generally unreactive during printing and frequently introduced as particulates, for example, as core-shell rubber particles. As such, reactive diluents, often with relatively high glass transition temperatures, may be needed to dissolve the particulates, to lower the viscosity, and to increase the green printed stiffness. However, the inclusion of such reactive diluents may limit the final performance of the material and may inhibit thermal network formation in dual cure materials, particularly in highly vitrified and / or crosslinked green UV-networks.

[0008] Accordingly, it would be desirable to have the benefits provided by the tougheners in resin compositions without their limitations.

[0009] SUMMARY

[0010] Monomers and / or prepolymers that provide rubbery or “elastomeric” materials (e.g., such as polybutadiene) may be included in dual cure materials to improve the performance of rigid networks with desirable thermomechanical properties. The present invention uses elastomeric-producing light polymerizable monomers and / or prepolymers to react with light or radiati on -initiated radicals to produce printed “green” parts that include or contain monomers and / or prepolymers that are solidified by exposure to heat, microwave irradiation and / or moisture. The low glass transition temperature (Tg) of the elastomer-producing monomers and / or prepolymers may produce a rubbery polymer scaffold that may allow for improved thermal network conversion of heat solidified monomers, particularly in highly crosslinked systems, and which may allow for the formation of three-dimensional objects having high heat deflection temperatures. The rubbery or elastomeric UV-network is capable of surviving baking temperatures required to anneal commonly used rigid, heat cured, thermoset materials. Furthermore, the low-Tgpolymer scaffold may allow for the use of solvent to lower the viscosity of the liquid resin without introducing irreversible defects in the final baked part and can allow for the use of volatile blocking groups. When paired with high-Tgchemistries in a dual-cure system, three-dimensional objects having high impact values, while maintaining high heat deflection temperatures, may be formed.

[0011] Accordingly, provided according to embodiments of the invention are dual cure resin compositions for additive manufacturing that include an elastomer-producing light polymerizable monomer and / or prepolymer; a monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture; a photoinitiator; optionally, one or more additional light polymerizable monomers and / or prepolymers; and optionally, a thiol crosslinker.

[0012] Also provided according to embodiments of the invention are methods of forming a three- dimensional object using a resin composition of the invention. In some embodiments, such methods include (a) providing a carrier and an optically transparent member having a build surface, the carrier and the build surface defining a build region therebetween; (b) filling the build region with a dual cure resin composition of the invention; (c) irradiating the build region with actinic radiation or light through the optically transparent member to solidify at least a portion of the dual cure resin composition in contact with the carrier; (d) advancing said carrier away from the build surface; (e) repeating steps (b) through (d) to form a solid polymer scaffold; wherein the solid polymer scaffold is a three-dimensional intermediate having the same shape as, or a shape to be imparted to, the three-dimensional object, and wherein the three-dimensional intermediate is further reacted to form the three-dimensional object. Also provided herein are polymers and / or three-dimensional objects formed using a resin composition and / or method of the invention. In some embodiments, such three- dimensional objects comprise a polymer matrix that includes (a) a primary phase having a glass transition temperature greater than 100 °C, which optionally includes a thermoset polymer (e.g., a polymer formed by a monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture cyanate, e.g., a cyanate ester polymer, a polyepoxide, polyurea, and / or a polyurethane) and / or a thermoplastic polymer; and (b) a secondary elastomeric phase (Tgless than 25 °C) dispersed within the primary phase. In some embodiments, such three-dimensional objects have a heat deflection temperature greater than 150 °C or 175 °C and / or a notched impact strength greater than 50 J / m; and / or the three- dimensional object has a notched impact strength greater than 50 J / m after 500, 700, or 1000 hours at 125 °C.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a graph showing a heat deflection temperature of 206 °C for the polymer formed from the composition in Table 1 A. This sample also showed a desirable IZOD impact strength of 70 J / m. After remaining at 125°C for 1000 hours, samples had notched IZOD impact values that were 80-90% of the original value.

[0015] FIG. 2 is a graph showing a heat deflection temperature of 231 °C for the polymer formed from the composition in Table 1C. This sample also showed a desirable IZOD impact strength of 49 J / m.

[0016] DETAILED DESCRIPTION

[0017] The present invention is now described more fully hereinafter with reference to particular embodiments. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.

[0018] The terminology used herein is for the purpose of describing the particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include plural forms as well, unless the context clearly indicates otherwise.

[0019] It will be further understood that the terms “comprises” or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements components and / or groups or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups or combinations thereof. The sequence of operations (or steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise. Any element that comprises certain features, integers, steps, operations, elements, components and / or groups may also “consist of’ or “consist essentially of’ such features, integers, steps, operations, elements, components and / or groups, respectively.

[0020] As used herein, the term “and / or” includes any and all possible combinations of one or more of the associated listed items, as well as the lack of combinations when interpreted in the alternative (“or”).

[0021] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and claims and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0022] It will be understood that, although the terms first, second, etc. (or the use of “additional”) may be used herein to describe various elements or components, these elements and components should not be limited by these terms. Rather, these terms are only used to distinguish one element or component from another element or component. Thus, a first element or component could be termed a second element or component without departing from the teachings of the present invention.

[0023] All publications and patents cited herein are specifically incorporated by reference to disclose the methods and / or materials with which the documents are cited.

[0024] As used herein, the term “about” with reference to a numerical number or range refers to the exact numbers and to values that are + / - 1%, 2%, 5%, or 10% thereof. It is also to be understood that where a range of values is provided, each intervening integer within the upper and lower limit of the range is also explicitly disclosed.

[0025] "Shape to be imparted to" refers to the case where the shape of the intermediate object slightly changes between formation thereof and forming the subsequent three-dimensional product, typically by shrinkage (e.g., up to 1, 2 or 4 percent by volume), expansion (e.g., up to 1, 2 or 4 percent by volume), removal of support structures, or by intervening forming steps (e.g., intentional bending, stretching, drilling, grinding, cutting, polishing, or other intentional forming after formation of the intermediate product, but before formation of the subsequent three-dimensional product).

[0026] As used herein, the term “UV polymerization” or “light polymerization” may be used for simplicity, but such terms may be used interchangeably, and each includes any polymerization by actinic radiation or light.

[0027] As used herein, the term “amino” includes primary, secondary and tertiary amine functional groups.

[0028] As used herein, the term “aryl” refers to an aromatic functional group including but not limited to phenyl or benzyl, and includes unsubstituted and substituted aryl groups (e.g., substituted with a hydroxyl, nitrile, silyl, epoxy, glycidyl, vinyl, and / or carboxyl).

[0029] As used herein, the term “silyl” refers to -SiHs and longer saturated silyl chains (e.g., those having 2-10 Si atoms) and includes both straight chain, branched, and / or cyclic silyl groups. The silyl group may be unsubstituted or substituted (e.g., substituted with a hydroxyl, nitrile, silyl, epoxy, glycidyl, vinyl, and / or carboxyl).

[0030] As used herein, the term “acryloyl” refers to any functional group that includes a CH2=CH-C(=O)- moiety including, but not limited to, CH2=CH-C(=O)-O-R- and CH2=CH- C(=O)-N-R- wherein R is absent (only a bond), alkylene (e.g., methylene, ethylene, propylene, butylene), substituted alkylene, and the like.

[0031] As used herein, the term “methacryloyl” refers to any functional group that includes a CH2=C(CH3)-C(=O)- moiety including, but not limited to, CH2=C(CH3)-C(=O)-O-R-, and CH2=C(CH3)-C(=O)-N-R- wherein R is absent (only a bond), alkylene (e.g., methylene, ethylene, propylene, butylene), substituted alkylene, and the like. Resin Compositions

[0032] Provided according to embodiments of the invention are dual cure resins for additive manufacturing. Such resins include an elastomer-producing light polymerizable monomer and / or prepolymer (which solidify in a “first cure” via UV polymerization); a monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture (and which predominantly solidify in a “second cure” by exposure to heat, microwave irradiation, and / or moisture); and a photoinitiator. The elastomer-producing light polymerizable monomers and / or prepolymers from the first cure may combine with more rigid materials from the second cure to form elastomeric phases within a rigid material. Such elastomeric phases may provide the toughening properties traditionally provided by particulate tougheners (e.g., by core-shell rubbers). Thus, the elastomeric phases within the polymer matrix may increase the impact strength of the more rigid materials and the dual cure materials may require a greater amount of energy for crack propagation relative to the rigid materials alone.

[0033] In addition, the incorporation of the elastomeric component may increase the ductility of more rigid systems through a variety of mechanisms such as crazing, cavitation, shear yielding, and others. The mechanism of toughening will be dependent on the composition resin and morphology of the network. However, the incorporation of the elastomer-producing light polymerizable monomers and / or prepolymer may obviate the need for toughening particulates in the resin. Thus, in some embodiments, provided are dual cure resins having a reduced concentration of particulate filler and / or toughener or dual cure resins that are free or substantially free of particulate filler and / or toughener. Further, as the viscosity of the elastomer-producing light polymerizable monomers and / or prepolymers in the resin may be suitably low and the particulate filler and / or toughener may be reduced or eliminated, in some embodiments, the concentration of reactive diluent may be reduced, or the composition may be free or substantially free of reactive diluent.

[0034] (1) Elastomer-producing light polymerizable monomer and / or prepolymers

[0035] As used herein, “elastomer-producing light polymerizable monomers and / or prepolymers” refers to monomers and / or prepolymers that:

[0036] (a) solidify via exposure to actinic light or radiation (e.g., in combination with a photoinitiator); (b) do not form a polymer scaffold by UV polymerization that degrades during subsequent heating (e.g., to a temperature less than 250 or 300 °C), microwave irradiation, and / or contacting with moisture; and

[0037] (c) form a polymer having a glass transition temperature below room temperature (e.g., below 20 °C or below 25 °C at 1 atm) when homopolymerized.

[0038] The term “elastomer-producing light polymerizable monomers and / or prepolymers” specifically excludes reactive (e.g., acrylate and methacrylate) blocked polyurethane, polyurea, and / or polyisocyanate prepolymers. The term “prepolymer” refers to a compound that is formed of two or more monomeric units but undergoes polymerization upon exposure to actinic light or radiation. In some embodiments, the elastomer-producing light polymerizable monomers and / or prepolymers have at least one alkene bond, and in some embodiments, a plurality of alkene bonds (e.g., 2, 3, 4, 5 or more alkene bonds).

[0039] In some embodiments, the elastomer-producing light polymerizable monomers and / or prepolymers include at least one polybutadiene unit. As used herein, the term “polybutadiene unit” refers to a repeating unit in a monomer and / or prepolymer that is formed (or could be formed) from butadiene, and includes both 1,4-polybutadiene units, -(CH2-CH=CH-CH2)-, and 1,2-polybutadiene units, -(CH2-CH-(CH=CH2))-, wherein one or more of the hydrogen atoms may optionally be substituted (e.g., substituted with a hydroxyl, amino, nitrile, silyl, epoxy, glycidyl, vinyl, and / or carboxyl). Each 1,4-polybutadiene unit may be present in the cis or trans configuration. In particular embodiments, the ratio of 1,4-polybutadiene units to 1,2 polybutadiene units in the monomers and / or prepolymers is in a range of 15: 1 to 1 :5 (e.g., 10: 1 to 1 :3). In some embodiments, the elastomer-producing monomers and / or prepolymers may include units that, by themselves, may not produce an elastomer, but combined with the other components in the monomer or prepolymer will still form a polymer having a glass transition temperature that is less room temperature (e.g., below 20 °C or below 25 °C at 1 atm). For example, in some embodiments, the elastomer-producing monomers and / or prepolymer(s) include subunits formed from a styrene (including a substituted styrene), acrylonitrile, methacrylonitrile, and / or maleic anhydride.

[0040] In some embodiments, one or more additional light polymerizable monomers (that are not elastomer-producing when homopolymerized) may be combined with the elastomerproducing monomers and / or prepolymers in the resin composition provided that the glass transition temperature of the intermediate / polymer scaffold formed during the UV polymerization process has a glass transition temperature that is less room temperature (e.g., below 20 °C or below 25 °C at 1 atm).

[0041] In some embodiments of the invention, the elastomer-producing light polymerizable monomers and / or prepolymers may be unsubstituted or substituted with one or more pendant or terminal functional groups including, but not limited to: a functional group that is or includes a hydroxyl, amino, nitrile, nitro, azido, silyl, epoxy, glycidyl, vinyl, carboxyl, aryl (e.g., phenyl, benzyl), acryloyl (e.g., acrylamido or acryloxy), methacrylol (e.g., methacrylamido or methacryloxy), maleimide, succinimide, maleic anhydride, succinic anhydride, a boryl group, and / or a cationic, anionic, or zwitterionic functional group, with the proviso that even with any of such substitutions, the polymer scaffold / intermediate formed by UV polymerization has a glass transition temperature below room temperature (e.g., below 20 °C or below 25 °C at 1 atm).

[0042] In some embodiments, the elastomer-producing light polymerizable monomers and / or prepolymers includes two or more (e.g., 2, 3, 4, 5, or more) acrylate and / or methacrylate functional groups.

[0043] In some embodiments, the elastomer-producing light polymerizable monomer and / or prepolymer has a structure of Formula I:

[0044] R1-(CR2R3-CR4=CR5-CR6R7)a-(CR8R9-CR10R11)b-(CR12R13-CR14R15)c-R16(Formula I) wherein a, b, and c are each independently an integer (e.g., wherein a + b + c = 10-200 and / or wherein a + b = 30 to 75); wherein a + b + c > 1 (e.g., wherein a = 1-100 and (b + c) = 0-100); wherein each of RkR16independently is a hydrogen, hydroxyl, amino, nitrile, nitro, azido, silyl, epoxy, glycidyl, vinyl, carboxyl, aryl (e.g., phenyl, benzyl), acryloyl (e.g., acrylamido or acryloxy), methacrylol (e.g., methacrylamido or methacryloxy), maleimide, succinimide, maleic anhydride, succinic anhydride, a boryl group, a cationic, anionic, or zwitterionic functional group, or a functional group comprising one or more of the foregoing.

[0045] In some embodiments of the invention, the polymer having the structure of Formula I includes at least two alkene bonds (i.e., double bonds). In some embodiments, the compound of Formula I includes both 1,4-polybutadiene and 1,2-polybutadiene units, while in other embodiments, only 1,4-polybutadiene units or only 1,2- polybutadiene units are present, alone or in combination within other non-butadiene units. In some embodiments, the ratio of 1,4 polybutadiene units to 1,2 polybutadiene units is in a range of 15: 1 to 1 :5 (e.g., 10: 1 to 1 :3), and includes 15: 1, 14: 1, 13: 1, 12: 1, 11 : 1, 10: 1, 9: 1, 8: 1, 7: 1, 6: 1, 5: 1, 4: 1, 3: 1, 2: 1, 1 : 1, 1 :2, 1 :3, 1 :4, 1 :5, and any range defined therebetween. In particular embodiments, the ratio of 1,4 polybutadiene units to 1,2 polybutadiene units is in a range 15: 1 to 8:1, 7: 1, or 6: 1. The cis to trans ratio of the 1,4-polybutadiene unit may be varied but in some embodiments, the cis to trans ratio is in a range of 20:80 to 80:20, including 20:80, 40:60, 45:55, 50:50, 55:45, 60:40, 80:20, and any range defined therebetween. In some embodiments, the number of repeating units for all polybutadiene units (1,4 polybutadiene + 1,2 polybutadiene units) in the compound of Formula I is in a range of 10 to 200 (e.g., in a range of 30 to 75).

[0046] In particular embodiments, at least one of R8-R15includes a nitrile. In particular embodiments, at least one of R8-R15includes a phenyl. In particular embodiments, at least one of R8-R15includes a vinyl group and / or an alkene (double) bond. In particular embodiments, at least one of R1and R16includes a vinyl, acrylate, methacrylate, maleic anhydride, succinic anhydride, and / or an alkene bond.

[0047] Monomers and / or Prepolymers Solidified by Exposure to Heat, Microwave Irradiation, and / or Moisture

[0048] Further included in the dual cure compositions according to embodiments of the invention are monomers and / or prepolymers that are solidified by exposure to heat, microwave irradiation and / or moisture. A number of possible monomers and / or prepolymers may be used. However, in some embodiments, the monomer(s) and / or prepolymer(s) solidified by exposure to heat, microwave irradiation, and / or moisture have one or more of the following reactive end groups pairs: epoxy / amine, epoxy / hydroxyl, oxetane / amine, oxetane / alcohol, isocyanate / hydroxyl, isocyanate / amine, isocyanate / carboxylic acid, isocyanate / cyanate ester, isocyanate / epoxy, anhydride / amine, amine / carboxylic acid, amine / ester, hydroxyl / carboxylic acid, hydroxyl / acid chloride, amine / acid chloride, vinyl / Si — H, Si — Cl / hydroxyl, Si — Cl / amine, hydroxyl / aldehyde, amine / aldehyde, hydroxymethyl or alkoxymethyl amide / alcohol, aminoplast, alkyne / azide, click chemistry reactive groups, hydroxyl / halide, isocyanate / water, Si — OH / hydroxyl, Si — OH / water, Si — OH / Si — H, Si — OH / Si — OH, perfluorovinyl, diene / dienophiles, olefin metathesis polymerization groups, olefin polymerization groups for Ziegler-Natta catalysis, and ring-opening polymerization groups. The monomer(s) and / or prepolymer(s) solidified by exposure to heat, microwave irradiation, and / or moisture may include a combination of the foregoing groups as well.

[0049] In some embodiments, the monomer(s) and / or prepolymer(s) solidified by exposure to heat, microwave irradiation, and / or moisture include a cyanate ester (e.g., bisphenol-E cyanate ester), an epoxy group (e.g., bisphenol-A-diglycidyl ether), a blocked isocyanate (e.g., IPDI trimer blocked, for example, with TBAEMA or MEKO), and / or a reactive isocyanate. Other monomers that may be used include, but are not limited to, those found in U.S. Patent Nos. 9,676,963, 10,155,882, 11,299,579, 10,647,879, 10,471,655, 10,975,193, 10,350,823, 10,501,572, 11,034,084, and 11,208,517.

[0050] Photoinitiators

[0051] A number of different types of photoinitiators may be included in resin compositions according to embodiments of the invention. Typically, the photoinitiator is a free radical photoinitiator. A “free radical photoinitiator,” as used herein, includes type I free radical photoinitiators, such as phosphineoxide (TPO) or hydroxyacetophenone (HAP), and / or type II free radical photoinitiators, such as a benzophenone photoinitiator (optionally but preferably in combination with a co-initiator (e.g., an alcohol or amine)). Particular examples include, but are not limited to, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), TPO-L, diphenylphosphinyl(2,4,6-trimethylphenyl)methanone; benzophenone; substituted benzophenones; acetophenone; substituted acetophenones; benzoin; benzoin alkyl esters; xanthone; substituted xanthones; diethoxy-acetophenone; benzoin methyl ether; benzoin ethyl ether; benzoin isopropyl ether; diethoxyxanthone; chloro-thio-xanthone; N-methyl diethanol- amine-benzophenone; 2-hydroxy-2-methyl- 1 -phenyl -prop an- 1 -one; 2-benzyl-2-

[0052] (dimethylamino)-l-[4-(4-morpholinyl)phenyl]-l-butanone; and mixtures thereof. For additional examples, see, e.g., U.S. Pat. No. 9,090,765.

[0053] Poly thiol Crosslinkers

[0054] In some embodiments, the dual cure resin composition of the invention further includes a polythiol crosslinker. Such polythiol crosslinkers may react with radicals formed by the photoinitiator, thus creating a reactive species that reacts with unsaturation in the monomers and / or prepolymers (e.g., in the elastomer-producing light polymerizable monomers / prepolymers, and / or the additional light polymerizable monomers / prepolymers) to form thiolene crosslinks.

[0055] Examples of suitable polythiol crosslinkers for use in the present invention include, but are not limited to: thiogly colic acid (CAS #68-11-1); glyceryl mercaptoacetate (CAS #30618-84-9);

[0056] 3 -mercaptopropionic acid (CAS #107-96-0); butyl-3 -mercaptopropionate (CAS #16215-21-7);

[0057] 2-ethylhexyl 3 -mercaptopropionate (CAS #50448-95-8);

[0058] 2-ethylhexyl mercaptoacetate (CAS #7659-86-1); iso-octylmercaptoacetate (CAS #25103-09-7); iso-octyl 3 -mercaptopropionate (CAS #30374-01-7); iso-tridecyl 3 -mercaptopropionate (CAS #1040871-35-9); iso-tridecyl mercaptoacetate (CAS #57417-85-3); octadecyl 3 -mercaptopropionate (CAS #31778-15-1); glycol dimercaptoacetate (GDMA) (CAS #123-81-9); glycol di(3 -mercaptopropionate) (GDMP) (CAS #22504-50-3); trimethylolpropane tri (3 -mercaptopropionate) (TMPMP) (CAS #33007-83-9); ethoxylated-trimethylolpropane tri(3 -mercaptopropionate) (CAS #345352-19-4); tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate (TEMPIC) (CAS #36196-44-8); pentaerythritol tetramercaptoacetate (PETMA) (CAS #10193-99-4); pentaerythritol tetra(3 -mercaptopropionate) (PETMP) (CAS #7575-23-7); dipentaerythritol hexa(3 -mercaptopropionate) (DiPETMP) (CAS #25359-71-1); polycaprolactone tetra(3-mercaptopropionate)(PCL4MP 1350)(CAS #1622079-69-9); l,4-bis(3-mercaptobutylyloxy) butane (CAS #594836-83-6); l,3,5-tris(3-mercaptobutyloxethyl)-l,3,5-triazine-2,4,6(lH,3H,5H)-trione; pentaerythritol tetrakis(3 -mercaptopropionate) (CAS #31775-89-0); methyl thioglycolate (CAS #2365-48-2);

[0059] (3 -mercaptopropyl)trimethoxy silane (CAS #4420-74-0);

[0060] 2,2'-(ethylenedioxy)diethanethiol (CAS #14970-87-7); hexa(ethylene glycol) dithiol (CAS #89141-22-0);

[0061] (mercaptopropyl)methylsiloxane homopolymer (CAS #102783-03-9);

[0062] (mercaptopropyl)methylsiloxane-dimethylsiloxane copolymer (CAS #102783-03-9); thiol-terminated polydimethylsiloxane; thiolated polyhedral oligomeric silsesquioxane (POSS); and combinations thereof.

[0063] Other polythiol crosslinkers and their methods of use are described in U.S. Patent No. 11,535,714.

[0064] Additional Optional Resin Components

[0065] In some embodiments, the dual cure resin may further include other components, such as, for example, a light absorber(s) (e.g., a pigment, dye, UV absorber) and / or an odor scavenger. Suitable examples of light absorbers include, but are not limited to: (1) titanium dioxide (e.g., included in an amount of from 0.05 or 0.1 to 1 or 5 percent by weight), (ii) carbon black (e.g., included in an amount of from 0.05 or 0.1 to 1 or 5 percent by weight), and / or (iii) an organic ultraviolet light absorber such as a hydroxybenzophenone, hydroxyphenylbenzotriazole, oxanilide, benzophenone, thioxanthone, hydroxypenyltriazine, and / or benzotriazole ultraviolet light absorber (e.g., Mayzo BLS1326) (e.g., included in an amount of 0.001 or 0.005 to 1, 2 or 4 percent by weight). Examples of suitable organic ultraviolet light absorbers include, but are not limited to, those described in U.S. Pat. Nos. 3,213,058; 6,916,867; 7,157,586; and 7,695,643.

[0066] A number of possible odor scavengers (odor absorbents / adsorbents) may be included in the composition. Examples of odor scavengers include carbon black, zeolite, a- / - / y- cyclodextrin, chitosan, and the like.

[0067] In some embodiments, a resin composition of the invention may further include a stabilizer. A “stabilizer” as used herein includes, but is not limited to, hydroquinones (e.g., hydroquinone and hydroquinone monomethyl ether) and catechols (e.g., 4-tert-butylcatechol) for stabilizing reactive monomers or oligomers such as acrylates or methacrylates. Stabilizers can also include antioxidants and additives used for increasing the long-term stability of printed polymer-based materials. Examples include hindered amine light stabilizers, primary and secondary antioxidants, including hindered or semi-hindered phenols, thiosynergists, phosphites, hydroxylamines, and hindered amines.

[0068] While the resins described herein may obviate the need for fillers such as tougheners, in some embodiments, the resin compositions may include solid particles suspended or dispersed therein. Any suitable solid particles can be used and the type and amount of such particles may depend on the end product being fabricated. The particles can be metallic, organic / polymeric, inorganic, or composites or mixtures thereof. The particles can be nonconductive, semi -conductive, or conductive (including metallic and non-metallic or polymer conductors); and the particles can be magnetic, ferromagnetic, paramagnetic, or nonmagnetic. The particles can be of any suitable shape, including spherical, elliptical, cylindrical, etc. The particles can be of any suitable size (for example, ranging from 1 nm to 20 pm average diameter).

[0069] Fillers, when included, may be solid or liquid, organic or inorganic, and may include reactive and non-reactive rubbers, siloxanes, acrylonitrile-butadiene rubbers, reactive and non- reactive thermoplastics (including but not limited to: poly(ether imides), maleimide-styrene terpolymers, polyarylates, polysulfones and polyethersulfones, etc.), inorganic fillers such as silicates (such as talc, clays, silica, mica), glass, carbon nanotubes, graphene, cellulose nanocrystals, including combinations of all of the foregoing.

[0070] One or more polymeric and / or inorganic tougheners can be used as a filler in the present invention. The toughener may be uniformly distributed in the form of particles in the cured product. The particles could be less than 5 microns (pm) in diameter. Such tougheners include, but are not limited to, those formed from elastomers, branched polymers, hyperbranched polymers, dendrimers, rubbery polymers, rubbery copolymers, block copolymers, core-shell particles, oxides or inorganic materials such as clay, polyhedral oligomeric silsesquioxanes (POSS), carbonaceous materials (e.g., carbon black, carbon nanotubes, carbon nanofibers, fullerenes), ceramics and silicon carbides, with or without surface modification or functionalization.

[0071] Core-shell rubbers are particulate materials (particles) having a rubbery core and may be used in some resin compositions of the invention. Such materials are known and described in, for example, U.S. Patent Application Publication No. 2015 / 0184039, as well as US Patent Application Publication No. 2015 / 0240113, and U.S. Pat. Nos. 6,861,475, 7,625,977, 7,642,316, 8,088,245, and elsewhere. In some embodiments, the core-shell rubber particles are nanoparticles (i.e., having an average particle size of less than 1000 nanometers (nm)). Generally, the average particle size of the core-shell rubber nanoparticles is less than 500 nm, e.g., less than 300 nm, less than 200 nm, less than 100 nm, or even less than 50 nm. Typically, such particles are spherical, so the particle size is the diameter; however, if the particles are not spherical, the particle size is defined as the longest dimension of the particle. Suitable coreshell rubbers include, but are not limited to, those sold by Kaneka Corporation under the designation Kaneka Kane Ace, including the Kaneka Kane Ace 15 and 120 series of products, including Kaneka Kane Ace MX 120, Kaneka Kane Ace MX 153, Kaneka Kane Ace MX 154, Kaneka Kane Ace MX 156, Kaneka Kane Ace MX 170, Kaneka Kane Ace MX257, and Kaneka Kane Ace MX 120 core-shell rubber dispersions, and mixtures thereof.

[0072] In particular embodiments of the invention, the filler is a reactive filler, meaning that the filler may participate in a chemical reaction after the object is formed. For example, in some embodiments, the reactive filler includes an explosive and / or a propellant. Explosives and propellants are combustible materials that contain energetic groups or oxidizers, have high energy densities, and are inherently unstable. They can undergo independent oxidation / reduction reactions and release energy upon stimulation by external energy sources. Examples include but are not limited to oxidizers such as ammonium perchlorate, ammonium sulfate, iron oxide, aluminum, copper oxide, and aluminum-thermite; and explosives such as trinitrotoluene (TNT), hexahydro-1, 3, 5-trinitro-l, 3, 5-triazine (RDX), 2-

[0073] (butylnitroamino)ethyl nitrate, hexanitrohexaazaisowurtzitane (CL-20), cyclotetramethylenetetranitramine (HMX), and 2,4,6-triamino-l,3,5-trinitrobenzene (TATB).

[0074] In some embodiments, a composition and / or polymer of the invention is blended with an energetic or non-energetic binder. An energetic binder is a polymer that can release energy through a chemical reaction or decomposition. Examples of energetic binders include but are not limited to glycidyl azide polymers (GAP), poly(3-azidemethyl-3-methyl oxetane) (PAMMO), 3,3'-bisazidomethyloxetane (BAMMO), 3-azidomethyl-3'-methyloxetane (AMMO), and copolymers including any one or more of the foregoing.

[0075] In some embodiments, the compositions and / or polymers of the invention may include fillers, additives, and / or copolymers that may be used in energy storage applications. For example, the compositions and / or polymers of the invention may include blends with conductive polymers including but not limited to polypyrrole, polyaniline, and conductive butadiene, conductive styrene-butadiene copolymers. Additionally, the compositions may include a solid polymer electrolyte including but not limited to poly ethers (polyethylene oxide), polycarbonates, polyesters, polynitriles, polyalcohols, polyamines, polysiloxanes, and fluoropolymers, and combinations thereof. In some embodiments, such solid polymer electrolytes have a conductivity of at least 10'9S / cm. In some embodiments, the composition and / or polymer of the invention includes one or more dopants (e.g. cations and / or anions) that alter the ionic conductivity of at least one polymer therein. Examples of cationic dopants include but are not limited to Li+, Na+, K+, Ag+, Mg2+, Ca2+, Ba2+, and Zn2+. Examples of anionic dopants include but are not limited to O2, bis(trifluoromethane)sulfonimide (TFSE), bis(fluorosulfonyl)imide (FSE), imidazolium bis(oxalato)borate (BOB ), difluoro(oxalato)borate (DFOB ), hexafluorophosphate (PFe"), hexafluoroarsenate (AsFe"), tetrafluoroborate (BF4), Br , CE, I , triflate (TFO ), trifluoroacetate (TFA ), tricyanomethanide (TCM ), and 4,5-dicyano-2-(trifluoromethyl)imidazolium (TDE). In some embodiments, a combination of dopants is included. In some embodiments, the dopant is provided via one or more salt solution(s).

[0076] Resin compositions of the invention may also reduce or eliminate the need for including reactive diluents. However, in some embodiments, reactive diluents may be included in a resin composition of the invention. Such reactive diluents may degrade, isomerize, cross-react, or polymerize, with themselves or a light polymerizable component, during the additive manufacturing step. In general, the reactive diluent(s) are included in an amount sufficient to reduce the viscosity of the polymerizable liquid or resin (e.g., to not more than 15,000, 10,000, 6,000, 5,000, 4,000, or 3,000 centipoise at 25 degrees Centigrade). Suitable examples of diluents include, but are not limited to, N,N-dimethylacrylamide, N-vinyl-2-pyrrolidone, and N-vinyl formamide, or a mixture of two or more thereof. The diluent may be included in the polymerizable liquid in any suitable amount, typically from 1, 5 or 10 percent by weight, up to about 30 or 40 percent by weight, or more.

[0077] In some embodiments, non-reactive diluents may be included in resin compositions of the invention, including those described in U.S. Patent No. 11,518,089.

[0078] Particular resin compositions include:

[0079] 20 weight % to 50 weight % elastomer-producing light polymerizable monomers and / or prepolymers; 50 weight % to 80 weight % monomers and / or prepolymers that are solidified by exposure to heat, microwave irradiation and / or moisture;

[0080] 0.01 weight % to 2 weight % photoinitiator; optionally, 1 weight % to 10 weight % (or 2 weight % to 5 weight %) thiol crosslinker; and optionally, 1 weight % to 50 weight % (or 1, 5, or 10 weight % to 20, 30, 40 or 50 weight %) filler.

[0081] Additive Manufacturins Methods

[0082] Resin compositions or resins as described herein may be used to make three- dimensional objects in a “UV” or “light” cure or photopolymerization step (typically by additive manufacturing), which in some embodiments generates a final product, and in other embodiments generates a “green” intermediate object, followed in those latter embodiments by a second (typically heat, microwave irradiation, or moisture) cure of that intermediate object to produce the final object.

[0083] Techniques for additive manufacturing are known. Suitable techniques include bottom- up or top-down additive manufacturing, generally known as stereolithography. Such methods are known and described in, for example, U.S. Pat. No. 5,236,637 to Hull, U.S. Pat. Nos. 5,391,072 and 5,529,473 to Lawton, U.S. Pat. No. 7,438,846 to John, U.S. Pat. No. 7,892,474 to Shkolnik, U.S. Pat. No. 8,110,135 to El-Siblani, U.S. Patent Application Publication No. 2013 / 0292862 to Joyce, and US Patent Application Publication No. 2013 / 0295212 to Chen et al. The disclosures of these patents and applications are incorporated by reference herein in their entirety.

[0084] In some embodiments, the intermediate object is formed by continuous liquid interface production (CLIP). CLIP is known and described in, for example, U.S. Pat. Nos. 9,211,678, 9,205,601, and 9,216,546, and in J. Tumbleston, D. Shirvanyants, N. Ermoshkin et al., Continuous liquid interface production of 3D Objects, Science, 347, 1349-1352 (2015). See also R. Janusziewcz et al., Layerless fabrication with continuous liquid interface production, Proc. Natl. Acad. Sci. USA, 113, 11703-11708 (2016). In some embodiments, CLIP employs features of a bottom-up three-dimensional fabrication as described above, but the irradiating and / or advancing steps are carried out while also concurrently maintaining a stable or persistent liquid interface between the growing object and the build surface or window, such as by: (i) continuously maintaining a dead zone of polymerizable liquid in contact with said build surface, and (ii) continuously maintaining a gradient of polymerization zone (such as an active surface) between the dead zone and the solid polymer scaffold and in contact with each thereof, the gradient of polymerization zone in some embodiments comprising the light polymerizable component in partially-cured form. In some embodiments of CLIP, the optically transparent member comprises a semipermeable member (e.g., a fluoropolymer), and the continuously maintaining a dead zone is carried out by feeding an inhibitor of polymerization through the optically transparent member, thereby creating a gradient of inhibitor in the dead zone and optionally in at least a portion of the gradient of polymerization zone. Other approaches for carrying out CLIP that can be used in the present invention and potentially obviate the need for a semipermeable “window” or window structure include utilizing a liquid interface comprising an immiscible liquid (see L. Robeson et al., WO 2015 / 164234), generating oxygen as an inhibitor by electrolysis (see I. Craven et al., WO 2016 / 133759), and incorporating magnetically positionable particles to which the photoactivator is coupled into the polymerizable liquid (see J. Rolland, WO 2016 / 145182).

[0085] After the intermediate three-dimensional object is formed, it is optionally washed, optionally dried (e.g., air dried) and / or rinsed (in any sequence). Examples of washing liquids and methods are described in U.S. Patent No. 11,535,714 to Kao et al. It is then further cured by heating, microwave irradiation, and / or by contact with moisture (although further curing may in some embodiments be concurrent with the first cure, or may be by different mechanisms, as described in U.S. Pat. No. 9,453,142 to Rolland et al.).

[0086] Heating may be active heating (e.g., in an oven, such as an electric, gas, solar oven or microwave oven, heated bath, or combination thereof), or passive heating (e.g., at ambient (room) temperature). Active heating will generally be more rapid than passive heating and in some embodiments is preferred, but passive heating — such as simply maintaining the intermediate at ambient temperature for a sufficient time to effect further cure — is in some embodiments preferred.

[0087] In some embodiments, the heating step is carried out at at least a first (oven) temperature and a second (oven) temperature, with the first temperature greater than ambient temperature, the second temperature greater than the first temperature, and the second temperature less than 300° C (e.g., with ramped or step-wise increases between ambient temperature and the first temperature, and / or between the first temperature and the second temperature).

[0088] For example, the intermediate may be heated in a stepwise manner at a first temperature of about 70° C to about 150° C, and then at a second temperature of about 150° C to 200 or 250° C, with the duration of each heating depending on the size, shape, and / or thickness of the intermediate. In another embodiment, the intermediate may be cured by a ramped heating schedule, with the temperature ramped from ambient temperature through a temperature of 70 to 150° C, and up to a final (oven) temperature of 250 or 300° C, at a change in heating rate of 0.5° C per minute, to 5° C per minute. See, e.g., U.S. Pat. No. 4,785,075.

[0089] In some embodiments, the heating step is carried out in an inert gas atmosphere. Inert atmosphere ovens are known, and generally employ an atmosphere enriched in nitrogen, argon, or carbon dioxide in the oven chamber. Suitable examples include but are not limited to those available from Grieve Corporation, 500 Hart Road Round Lake, Ill. 60073-2898 USA, Davron Technologies, 4563 Pinnacle Lane, Chattanooga, Tenn. 37415 USA, Despatch Thermal Processing Technology, 8860 207th Street, Minneapolis, Minn. 55044 USA, and others.

[0090] In other embodiments, the heating step is carried out in an inert liquid bath. Suitable inert liquids may be aqueous liquids (i.e., pure water, salt solutions, etc.), organic liquids (e.g., mineral oil, fluorinated, perfluorinated, and polysiloxane organic compounds such as perfluorohexane, perfluoro(2-butyl-tetrahydrofurane), perfluorotripentylamine, etc. (commercially available as PERFLUORINERT® inert liquids from 3M Company), and mixtures thereof. These inert liquids can be deoxygenated if necessary, such as by bubbling an inert gas such as nitrogen through the liquid, by boiling the inert liquid, by mixing oxygenscavenging agents with the inert liquid medium (or contacting them to one another), etc., including combinations thereof. See, e.g., U.S. Pat. No. 5,506,007.

[0091] In some embodiments, the further curing or heating step (whether carried out in a liquid or gas fluid) is carried out at an elevated pressure (e.g., elevated sufficiently to reduce volatilization or out-gassing of residual monomers, prepolymers, chain extenders, and / or reactive diluents, etc.). Suitable pressure ranges are from 10 or 15 psi to 70 or 100 psi, or more. Three-Dimensional Objects

[0092] Also provided according to embodiments of the invention are polymers and / or three- dimensional objects formed from a resin composition of the invention. In some embodiments, the three-dimensional obj ect includes a polymer matrix that includes (a) a primary phase having a glass transition temperature greater than 100 °C; and (b) a secondary elastomeric phase (Tgless than 25 °C) dispersed within the primary phase. In some embodiments, the primary phase includes a thermoset polymer (e.g., a polymer formed by a monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture cyanate, e.g., a cyanate ester polymer, a polyepoxide, polyurea, and / or a polyurethane). In some embodiments, the primary phase includes a thermoplastic polymer. The weight ratio of the primary phase to the secondary phase may vary. However, in some embodiments, the weight ratio is in a range of 85: 15 to 35:65, including 85: 15, 80:20, 60:40, 50:50, 40:60, 35:65, and any range defined therebetween. In some embodiments, the primary phase is covalently bound to the secondary elastomeric phase and in some embodiments, the primary phase and secondary phase form a polymer blend, interpenetrating polymer network, semi -interpenetrating polymer network, or sequential interpenetrating polymer network. In some embodiments, the three-dimensional object is free of particulate tougheners.

[0093] In some embodiments, the objects produced by the compositions and methods described herein have a heat deflection temperature greater than 150 °C, or greater than 175 °C, for example, in a range of 150 °C, 160 °C, 175 °C to 250 °C, 260 °C, or 275 °C, and / or a notched impact strength greater than 50 J / m, for example in a range of 50 J / m to 300 J / m, 350 J / m, 400 J / m, or more. In some embodiments, provided are three-dimensional objects that maintain a notched impact strength greater than 50 J / m (or within a range described herein), or at least 80%, 85%, 90% or more of the original value, after 500, 600, 700, 800, 900, or 1000 hours at 125 °C. The notched impact strength may be measured by ASTM D256.

[0094] In some embodiments, a polymer and / or three-dimensional object of the invention is included in an explosive and / or propellant device. Accordingly, also provided according to embodiments of the invention is an explosive device and / or vehicle that includes a polymer and / or three-dimensional object of the invention.

[0095] In some embodiments, the three-dimensional object is a part or all of an energetic storage device such as a battery and the three-dimensional object may be conductive. Accordingly, also provided are energy storage devices such as batteries that include a three- dimensional object or a polymer of the invention.

[0096] The present invention is explained in greater detail in the following non-limiting Examples.

[0097] EXAMPLES

[0098] Example 1 : Methacrylate-functionalized polybutadiene-co-acrylonitrile as UV scaffold

[0099] The components listed in the tables below were added to a container and thoroughly mixed (either by an overhead stirrer or a centrifugation mixer such as TE1INKY mixer) to obtain a homogeneous resin. The mixture was then used to produce a test specimen either by flood curing in a predefined mold or with additive manufacturing processes. The formed test specimen was then heated on a progressively ramped schedule from room temperature to 220 °C for 12 hours or 140 °C for 12 hours. To test thermal stability, samples were also placed in an oven and held at 125 °C for 1000 hours.

[0100] Table 1A: Cyanate Ester (not filled) Resin Composition

[0101] Table IB: Properties of Polymer formed from composition in Table 1A As reflected in FIG. 1, the polymer formed from the composition in Table 1 A shows a heat deflection temperature of 206 °C. This sample also showed a desirable IZOD impact strength of 70 J / m. After remaining at 125°C for 1000 hours, samples had notched IZOD impact values that were 80-90% of the original value.

[0102] Table 1C: Cyanate Ester (filled) Resin Composition

[0103] Table ID: Properties of Polymer formed from composition in Table 1C

[0104] As reflected in FIG. 2, the polymer formed from the composition in Table 1C shows a heat deflection temperature of 231 °C for. This sample also showed a desirable IZOD impact strength of 49 J / m. Table IE: Epoxy Resin Composition

[0105] Table IF: Properties of Polymer formed from composition in Table IE

[0106] Table 1G: Blocked polyurethane Resin Composition

[0107] Prepolymers were prepared by adding a blocking agent to a solution of IPDI-trimer, Desomodur Z 4470A, and mixing in a centrifugal mixer until the isocyanate is fully reacted. Two blocking agents were screened: tert-butylamino methacrylate (TB) and methylethyl ketone oxime (MEKO), but others can be used to inhibit chain extension of the isocyanate. These blocking groups can also be used individually. The stoichiometry of the isocyanate to blocking group was 1 : 1 and the reaction was complete without the need for additional heating. Antioxidants can be added to these materials to improve their thermal stability.

[0108] Table 1H: Properties of Polymer formed from composition in Table 1G

[0109] As shown in Tables 1A-1H, resin compositions of the invention may produce objects having desirable notched impact strengths and / or heat deflection temperatures.

[0110] Example 2: Thiolene UV curing

[0111] The components listed in the tables below were added to a container and thoroughly mixed (either by an overhead stirrer or a centrifugation mixer such as TE1INKY mixer) to obtain a homogeneous resin. The mixture was then used to produce a test specimen either by flood curing in a predefined mold or with additive manufacturing processes. The formed test specimen was then heated on a progressively ramped schedule from room temperature to 220 °C for 12 hours or 140 °C for 12 hours. To understand the thermal stability, samples were also placed in an oven and held at 125 °C for 1000 hours.

[0112] Table 2A: Epoxy Resin Composition Table 2B: Properties of Polymer formed from composition in Table 2A

[0113] Table 2C: Cyanate Ester Resin Composition

[0114] Table 2D: Properties of Polymer formed from composition in Table 2C

[0115] As shown in Tables 2A-2D, resin compositions of the invention may produce objects having desirable impact strength.

[0116] The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.

Claims

What is claimed is:

1. A dual cure resin composition for additive manufacturing comprising an elastomer-producing light polymerizable monomer and / or prepolymer; a monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture; a photoinitiator; optionally, one or more additional light polymerizable monomers and / or prepolymers; and optionally, a thiol crosslinker.

2. The dual cure resin composition of claim 1, wherein the elastomer-producing light polymerizable monomer and / or prepolymer comprises a plurality of alkene bonds, and optionally comprises one or more pendant and / or terminal groups selected from the group consisting of hydroxyl, amino, nitrile, nitro, boryl, azido, silyl, epoxy, glycidyl, vinyl, carboxyl, aryl (e.g., phenyl, benzyl), acryloyl (e.g., acrylamide or acryloxy), methacrylol (e.g., methacrylamide or methacryloxy), maleimide, succinimide, maleic anhydride, succinic anhydride, a cationic, anionic or zwitterionic functional group, and a group including one or more of the foregoing.

3. The dual cure resin composition of claim 1 or claim 2, wherein the elastomerproducing polymerizable monomer and / or prepolymer comprises at least one (e.g., a plurality of) polybutadiene unit(s); optionally wherein the at least one (e.g., the plurality of) polybutadiene unit(s) includes 1,4 polybutadiene units and 1,2 polybutadiene units (e.g., at a 15: 1 to 1 :5 ratio), and optionally wherein the elastomer-producing polymerizable monomer and / or prepolymer comprises an acrylonitrile unit and / or a styrenic unit.

4. The dual cure resin composition of any one of claim 1-3, wherein the elastomerproducing light polymerizable monomer and / or prepolymer comprises two or more pendant and / or terminal acrylate and / or methacrylate functional groups.

5. The dual cure resin composition of any one of claims 1-4, wherein the monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture comprises reactive end groups selected from the group consisting of epoxy / amine, epoxy / hydroxyl, oxetane / amine, oxetane / alcohol, isocyanate / hydroxyl, isocyanate / amine, isocyanate / carboxylic acid, isocyanate / cyanate ester, isocyanate / epoxy, anhydride / amine, amine / carboxylic acid, amine / ester, hydroxyl / carboxylic acid, hydroxyl / acid chloride, amine / acid chloride, vinyl / Si — H, Si — Cl / hydroxyl, Si — Cl / amine, hydroxyl / aldehyde, amine / aldehyde, hydroxymethyl or alkoxymethyl amide / alcohol, aminoplast, alkyne / azide, click chemistry reactive groups, hydroxyl / halide, isocyanate / water, Si — OH / hydroxyl, Si — OH / water, Si — OH / Si — H, Si — OH / Si — OH, perfluorovinyl, diene / dienophiles, olefin metathesis polymerization groups, olefin polymerization groups for Ziegler-Natta catalysis, ring-opening polymerization groups, and any combination thereof.

6. The dual cure resin composition of any one of claims 1 -5, wherein the monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture comprises a cyanate ester, an epoxy group, a blocked isocyanate, and / or a reactive (free or not blocked) isocyanate.

7. The dual cure resin composition of any one of claims 1-6, wherein the elastomer-producing light polymerizable monomer and / or prepolymer has a structure of Formula I:R1-(CR2R3-CR4=CR5-CR6R7)a-(CR8R9-CR10R11)b-(CR12R13-CR14R15)c-R16(Formula I) wherein a, b, and c are each independently an integer; wherein a + b + c > 1 (e.g., wherein a = 1-100 and (b + c) = 0-100); and wherein each of RkR16is independently selected from the group consisting of hydrogen, hydroxyl, amino, nitrile, nitro, azido, boryl, silyl, epoxy, glycidyl, vinyl, carboxyl, aryl (e.g., phenyl, benzyl), acryloyl (e.g., acrylamide or acryloxy), methacrylol (e.g., methacrylamide or methacryloxy), maleimide, succinimide, maleic anhydride, succinic anhydride, a cationic, anionic and / or zwitterionic functional group, and a functional group including one or more of the foregoing.

8. The dual cure resin composition of claim 7, wherein the structure of Formula I comprises at least two alkene bonds.

9. The dual cure resin composition of claim 7 or claim 8, wherein the compound of Formula I comprises 1,4-polybutadiene and 1,2-polybutadiene units and the ratio of 1,4 polybutadiene units to 1,2 polybutadiene units is in a range of 15: 1 to 1 :5 (e.g., 10: 1 to 1 :3).

10. The dual cure resin composition of any one of claims 7-9, wherein at least one of R8-R15comprises a nitrile, optionally wherein at least one of R8-R15comprises a phenyl.

11. The dual cure resin composition of any one of claims 1-10, wherein the dual cure resin composition further comprises a polythiol crosslinker (e.g., a polythiol crosslinker described herein).

12. The dual cure resin composition of any one of claims 1-11, wherein the dual cure resin composition further comprises a pigment, dye, UV absorber, stabilizer, and / or odor scavenger.

13. The dual cure resin composition of any one of claims 1-12, wherein the dual cure resin composition is free or substantially free (e.g., less than 1, 0.5, or 0.1 % by weight) of reactive diluent, and / or the dual cure resin composition is free or substantially free (e.g., less than 1, 0.5, or 0.1 % by weight) of particulate filler.

14. A method of forming a three-dimensional object, comprising:(a) providing a carrier and an optically transparent member having a build surface, the carrier and the build surface defining a build region therebetween;(b) filling the build region with a dual cure resin composition of any one of claims 1- 13;(c) irradiating the build region with actinic radiation or light through the optically transparent member to solidify at least a portion of the dual cure resin composition in contact with the carrier;(d) advancing said carrier away from the build surface;(e) repeating steps (b) through (d) to form a solid polymer scaffold; wherein the solid polymer scaffold is a three-dimensional intermediate having the same shape as, or a shape to be imparted to, the three-dimensional object, and(f) further reacting the three-dimensional intermediate to form the three-dimensional object.

15. The method of claim 14, wherein the further reacting comprises heating, microwave irradiation, and / or exposure to moisture.

16. The method of claim 14 or claim 15, wherein the three-dimensional intermediate carries unsolidified and / or uncured resin (e.g., the monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture) within the solid polymer scaffold and the further reacting solidifies the unsolidified and / or uncured resin.

17. The method of any one of claims 14-16, wherein step (b) and / or step (c) is carried out while also concurrently (i) continuously maintaining a dead zone of the dual cure resin composition in contact with the build surface; and (ii) continuously maintaining a gradient of polymerization zone between the dead zone and the solid polymer scaffold in contact with the carrier, the gradient of polymerization zone comprising the dual cure resin composition in partially cured form.

18. The method of claim 17, wherein the optically transparent member comprises a semipermeable member (optionally wherein the semipermeable member comprises a fluoropolymer), and continuously maintaining a dead zone is carried out by feeding an inhibitor (e.g., oxygen) through said optionally transparent member (optionally creating a gradient of inhibitor in the dead zone and optionally in at least a portion of the gradient of polymerization zone).

19. The method of any one of claims 14-18, wherein the three-dimensional object has a heat deflection temperature greater than 175 °C and / or a notched impact strength greater than 50 J / m.

20. The method of any one of claims 14-19, wherein the three-dimensional object has a notched impact strength greater than 50 J / m after 1000 hours at 125 °C.

21. A three-dimensional object formed by a method of any one of claims 14-20.

22. A three-dimensional object comprising a polymer matrix that includes (a) a primary phase having a glass transition temperature greater than 100 °C, which optionally includes a thermoset polymer (e.g., a polymer formed by a monomer and / or prepolymer that is solidified by exposure to heat, microwave irradiation, and / or moisture cyanate, e.g., a cyanate ester polymer, a polyepoxide, polyurea, and / or a polyurethane) and / or a thermoplastic polymer; and (b) a secondary elastomeric phase (Tgless than 25 °C) dispersed within the primary phase.

23. The three-dimensional object of claim 21 or claim 22, wherein the three- dimensional object has a heat deflection temperature greater than 175 °C and / or a notched impact strength greater than 50 J / m; and / or the three-dimensional object has a notched impact strength greater than 50 J / m after 1000 hours at 125 °C.

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