High-performance thermosetting resin for 3D printing

Abstract

This technology relates to additive manufacturing ink formulations that include a combination of imide-extended-bismaleimide (IE-BMI) and cyanate esters.

Description

[Technical field]

[0001] The present invention relates generally to ink compositions for use in additive manufacturing (AM), and more specifically to the development of high performance thermoset-based inks for three-dimensional (3D) printing by digital light processing (DLP) and stereolithography (SLA) techniques. [Background technology]

[0002] In the Digital Light Processing / Stereolithography (DLP / SLA) 3D printing technology, the construction of three-dimensional objects is done stepwise or layer by layer. In particular, the layer formation is done by the solidification of a photocurable resin mediated by visible or UV light radiation. Two printing techniques are known, one that forms new layers on the top surface of the growing object, and the other that forms new layers on the bottom surface of the growing object [1]. Other techniques are disclosed in US Pat. No. 7,438,846 [2], US Pat. No. 7,892,474 [3], US Patent Application Publication No. 2013 / 0292862 [4], US Patent Application Publication No. 2013 / 0295212 [5], etc. Materials for use in such methods are generally limited, and novel resins with high-performance properties for various product groups are needed for three-dimensional manufacturing to fully realize its potential.

[0003] High performance thermoset polymers have excellent thermal stability and mechanical properties that make them valuable materials in the manufacture of structural products. Examples of high performance thermoset polymers include polyimides, cyanate esters, epoxies, bismaleimides, phenolics, and polybenzoxazines. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] [1] U.S. Patent No. 5,236,637 [Patent Document 2] [2] U.S. Patent No. 7,438,846 [Patent Document 3] [3] U.S. Patent No. 7,892,474 [Patent Document 4] [4] U.S. Patent Application Publication No. 2013 / 0292862 [Patent Document 5] [5] U.S. Patent Application Publication No. 2013 / 0295212 Summary of the Invention

[0005] The present invention relates to a bismaleimide-triazine (BT) ink-based formulation for 3D printing by photopolymerization of high performance thermoset materials. Most generally, the ink formulation of the present invention comprises at least one imide-extended-bismaleimides (IE-BMI) based material acting as a chemical precursor and at least one cyanate ester as a reactive diluent. [Means for solving the problem]

[0006] In a first aspect of the present invention, there is provided an ink formulation for additive manufacturing, the formulation comprising at least one imide-extended-bismaleimide (IE-BMI), at least one cyanate ester, and optionally at least one additive.

[0007] The present invention further provides the use of IE-BMI in a formulation for additive manufacturing, optionally further comprising a cyanate ester, a liquid carrier, and at least one additive.

[0008] Further provided is a method of 3D printing comprising using an ink formulation comprising IE-BMI and / or E-BMI, optionally further comprising a cyanate ester, a liquid carrier, and at least one additive, wherein 3D printing comprises additive manufacturing, as further defined herein.

[0009] In some embodiments of this aspect of the invention, a formulation according to the invention or used according to the methods of the invention comprises at least one IE-BMI and / or at least one E-BMI, at least one cyanate ester, and optionally at least one additive.

[0010] In some further embodiments, the formulation further comprises a carrier, in some embodiments, no carrier is used and the cyanate ester present is used to dissolve the IE-BMI.

[0011] Additives that may be present may be selected from reactive and non-reactive materials. Non-limiting examples of reactive materials include photoreactive diluents such as acrylates, methacrylates, thiols, vinyl ethers, and epoxy-containing curable materials; aromatic bismaleimides; short chain aliphatic bismaleimides; radical polymerization initiators; and / or photoinitiators such as benzophenones, aromatic α-hydroxyketones, benzil ketals, aromatic α-aminoketones, phenylglyoxalic acid esters, monoacylphosphine oxides, bisacylphosphine oxides, trisacylphosphine oxides, and / or oxime esters derived from aromatic ketones. Non-limiting examples of non-reactive materials (i.e., non-curable materials) include surface active agents, i.e., surfactants; inhibitors; antioxidants; pigments; dyes; dispersants; and / or reinforcing fillers, including microparticles and nanoparticles composed of silica, alumina, carbon black, carbon nanotubes, boron nitride, or chopped fibers.

[0012] The formulations of the present invention may further include carbonaceous materials and other functional materials such as graphite, short carbon fibers, carbon nanotubes (CNTs), fused silica particles, graphene oxide, and 2D materials such as boron nitride (BN), MoS2, and WS2.

[0013] The formulation of the present invention may further include an inorganic precursor or sol-gel precursor that is soluble in the formulation. This material is not an inorganic particulate matter. In some embodiments, the inorganic precursor or sol-gel precursor is added to form metal oxide particles that act as fillers or to directly bond to the resin and act as a crosslinker. The in situ sol-gel process can be carried out in two ways: One-step sol-gel - where liquid precursors and additives are mixed with the epoxide component in one pot. b. In two steps, a homogeneous sol solution is prepared from the liquid precursors and then added to the epoxide component.

[0014] In either case, intermediate reactive M-OH moieties may be formed, where M is a metal atom. Sol-gel precursors may include di-, tri-, and tetra-alkoxysilanes (e.g., tetraethoxysilane (TEOS), (3-isocyanatopropyl)trimethoxysilane); bisaminosilanes; acryloxymethyltrimethoxysilane; methyltriethoxysilane; dimethyldimethoxysilane; phenyltrimethoxysilane; acryloxypropyltrimethoxysilane (APTMS); (3-glycidoxypropyl)trimethylsilane; silanols such as silanediol, silanetriol, and trisilanolphenyl (POSS); aluminum lactate; aluminum alkoxides such as aluminum isopropoxide; aluminum chloride; aluminum tris(ethyl acetoacetate); zirconium alkoxides such as zirconium propoxide; zirconium nitrate; titanium alkoxides such as titanium isopropoxide, titanium n-butoxide, and titanium ethoxide; niobium ethoxide. The sol-gel precursor may be present in an amount of less than 40% by weight.

[0015] In some embodiments, the formulations of the present invention may include at least one additive, typically a reactive additive, such as a polyamine, e.g., an oligomeric polyamine capable of undergoing a Michael addition reaction with a maleimide functionality; a photoreactive diluent; an aromatic bismaleimide; a radical polymerization initiator; a photoinitiator; a surfactant; a stabilizer; a carrier or solvent; and a reinforcing material, such as nanoparticles or chopped fibers.

[0016] In some embodiments, the formulations of the present invention may further comprise at least one metal catalyst, such as zinc(II) acetylacetonate hydrate.

[0017] In some embodiments, the formulation may further include melamine, melamine derivatives, cyanate esters, phenols, and aromatic amines. In some embodiments, the melamine derivatives are alkylated melamines having an alkyl moiety with 1 to 10 carbon atoms (C1-C10 alkyl), such as methylated or butylated melamine.

[0018] Extended bismaleimides are a type of bismaleimide (BMI) used in the preparation of thermosetting materials. They consist of imide moieties in low molecular weight prepolymers with reactive end or pendant groups that can undergo homopolymerization and / or copolymerization by UV, thermal, or catalytic means, resulting in the formation of crosslinked solid products. These materials are characterized by their relative ease of processing and the ability to tailor specific rheological properties by controlling their molecular weight. In addition, crosslinked thermosetting BMIs retain exceptional physical properties at elevated temperatures, in humid environments, and in the presence of solvents and lubricating fluids.

[0019] Imide-extended-bismaleimide (IE-BMI) is a material having a bismaleimide structure where two maleimides are separated by a variable moiety R, which is an extended structural portion having a terminal maleimide functional group. A typical extended bismaleimide can be represented by the structure: TIFF2025504595000001.tif26170, where R can be any carbon chain or carbon-based functional group separating the two maleimide groups. The R functional group can be any moiety with a terminal imide (e.g., cyclic imide) functional group; TIFF2025504595000002.tif30170, where variable moiety G is any carbon-based moiety, and where each dashed line indicates a link to a nitrogen atom of the extended bismaleimide shown above. Thus, the imide extended bismaleimide may be of the general structure (I): wherein each of R1, R2, and G, independently of one another, is as defined herein, and wherein any of the imide moieties attached to the variable moiety G may be selected from among substituted cyclic imides, fused cyclic imides, aryl-substituted or aryl-fused cyclic imides, and the like, as further disclosed herein.

[0020] The IE-BMIs used in accordance with the present invention are amorphous, low molecular weight bismaleimide oligomers that exhibit good adhesion to a variety of substrates. These materials can be homo-cured under UV or free radical conditions to form tough, hydrophobic crosslinked polyimides, as shown in Figure 1A, or specifically, Figure 1B.

[0021] The amorphous nature of these imide-extended BMIs allows them to form room temperature stable solutions in a variety of reactive diluents. IE-BMIs are used in industries such as aerospace, microelectronics, and automotive. These materials have excellent thermal stability, very good low pH hydrolysis resistance, low dielectric constant, radiation resistance, inertness to solvents, dielectric loss, and moisture absorption, high ductility, high hydrophobicity, and relatively low modulus and strength. IE-BMIs are photo- and thermo-curable with or without the addition of photo- or thermal initiators, making them suitable for light-induced 3D printing processes. However, IE-BMIs have a relatively high viscosity, making them less suitable as an ink component in 3D printing processes.

[0022] The IE-BMI used according to the invention is of general structure (I): TIFF2025504595000004.tif34170 wherein each of R1 and R2 is independently selected from a carbon-based group having 1 to 50 carbon atoms and which may be selected from an aliphatic group, an aromatic group, a heteroaromatic group, a carbocyclic group, a saturated group, and an unsaturated group; G is a carbon-based group having 1 to 50 carbon atoms and which may be selected from aliphatic, aromatic, heteroaromatic, carbocyclic, saturated, and unsaturated groups; and Each of the cyclic imides is optionally a fused or substituted ring system.

[0023] In some embodiments, each of R1, R2, and G is, independently of the others, an alkylene group having 1 to 50 carbon atoms, an alkenylene or alkynylene group having 2 to 50 carbon atoms, a carbocyclyl group having 4 to 10 carbon atoms, an aromatic or heteroaromatic group having 6 to 10 carbon atoms and, optionally, one or more heteroatoms, and each of R1, R2, and G is optionally substituted.

[0024] In some embodiments, R1, R2, and G are each independently an alkylene group having 1 to 50 carbon atoms. In some embodiments, an alkylene group having any number of methylene groups between 1 to 45, 1 to 40, 1 to 45, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, 1 to 9, 1 to 8, 1 to 7, 1 to 6, 1 to 5, 1 to 4, 10 to 50, 10 to 45, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 5 to 45, 5 to 35, 5 to 25, 5 to 15, or 1 to 50.

[0025] In some embodiments, R1, R2, and G are each independently an alkenylene group (having one or more double bonds) or an alkynylene group (having one or more triple bonds) having 2 to 50 carbon atoms. In some embodiments, an alkenylene or alkynylene having any number of methylene groups between 2 to 45, 2 to 40, 2 to 45, 2 to 35, 2 to 30, 2 to 25, 2 to 20, 2 to 15, 2 to 10, 2 to 9, 2 to 8, 2 to 7, 2 to 6, 2 to 5, 2 to 4, 10 to 50, 10 to 45, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 5 to 45, 5 to 35, 5 to 25, 5 to 15, or between 2 and 50.

[0026] In some embodiments, R1, R2, and G are each, independently of one another, a carbocyclyl group having from 4 to 10 carbon atoms. In some embodiments, the carbocyclic group is a 4-membered ring, or a 5-, 6-, 7-, or 8-membered ring, or a bicyclic ring system, which may be fused or unfused, and may be optionally substituted as described in more detail below.

[0027] In some embodiments, each of R1, R2, and G is, independently of the others, an aromatic or heteroaromatic group having 6 to 10 carbon atoms, which, if a heteroaromatic group, may contain one or more heteroatoms selected from N, O, and S.

[0028] As used herein, the term "aliphatic" refers to alkyl, alkenyl, alkynyl, and carbocyclic groups. Similarly, the term "heteroaliphatic" refers to heteroalkyl, heteroalkenyl, heteroalkynyl, and heterocyclic groups.

[0029] "Alkyl" or "alkylene" refers to the radical of a linear or branched saturated hydrocarbon group having 1 to 100 carbon atoms. In some embodiments, the alkyl / alkylene group has 1 to 20 carbon atoms. In some embodiments, the alkyl / alkylene group has 1 to 50 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl (e.g., n-propyl, isopropyl), butyl (e.g., n-butyl, tert-butyl, sec-butyl, isobutyl), pentyl (e.g., n-pentyl, 3-pentanyl, amyl, neopentyl, 3-methyl-2-butanyl, tert-amyl), hexyl (e.g., n-hexyl), and the like. Any of the alkyl / alkylene groups may be substituted as disclosed herein.

[0030] "Heteroalkyl / heteroalkylene" is an alkyl or alkylene group that further includes at least one heteroatom (e.g., 1, 2, 3, or 4 heteroatoms) selected from oxygen, nitrogen, or sulfur, which may be substituted on the carbon chain, may be part of a substituent, or may be an intervening atom provided along the carbon chain.

[0031] "Alkenyl / alkenylene" means the radical of a straight or branched chain hydrocarbon group having 2 to 100 carbon atoms and one or more carbon-carbon double bonds (e.g., 1, 2, 3, or 4 double bonds), which may be in the (E)- or (Z)-configuration.

[0032] "Alkynyl / alkynylene" means a radical of a straight or branched chain hydrocarbon group having 2 to 100 carbon atoms and one or more carbon-carbon triple bonds (e.g., 1, 2, 3, or 4 triple bonds).

[0033] "Carbocyclyl" or "carbocyclic" refers to the radical of a non-aromatic cyclic hydrocarbon group having 3 to 100 ring carbon atoms and no heteroatoms in the ring structure. Exemplary carbocyclyl groups include cyclopropyl, cyclopropenyl, cyclobutyl, cyclobutenyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cyclohexadienyl, cycloheptyl, cyclooctyl, cyclooctenyl, bicyclo[2.2.1]heptanyl, bicyclo[2.2.2]octanyl, cyclodecenyl, octahydro-1H-indenyl, and the like. Carbocyclic systems may be monocyclic or polycyclic, including fused polycyclic structures. Similarly, carbocyclic systems may be monocyclic or polycyclic, including fused, bridged, or spiro ring systems.

[0034] "Heterocyclyl" or "heterocyclic" refers to a non-aromatic ring system containing one or more heteroatoms independently selected from nitrogen, oxygen, and sulfur, having from 3 to 100 carbon atoms. Examples of heterocyclic systems include azirdinyl, oxiranyl, thiiranyl, azetidinyl, oxetanyl, thietanyl, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothiophenyl, dihydrothiophenyl, pyrrolidinyl, dihydropyrrolyl, oxadiazolinyl, thiadiazolinyl, and the like.

[0035] As opposed to heterocyclic systems, an "aryl" system refers to a radical of a mono- or polycyclic (e.g., bicyclic or tricyclic) aromatic ring system having 6 to 14 ring carbon atoms and no heteroatoms.

[0036] "Heteroaryl" means a radical of 5 to 100 carbon atoms forming a mono- or polycyclic (e.g., bicyclic, tricyclic) aromatic ring system having ring carbon atoms and from one to four ring heteroatoms selected from nitrogen, oxygen, and sulfur.

[0037] As used herein, an "unsaturated" group contains a double or triple bond, and a "saturated" group does not contain double or triple bonds, e.g., the moiety contains only single bonds.

[0038] Each of the groups defining the variable R, i.e., each of the carbon-based groups having from one to several hundred or more carbon atoms and which may be selected from aliphatic, aromatic, heteroaromatic, carbocyclic, saturated, unsaturated groups, etc., may be independently selected from halogen, -CN, -NO2, -N3, -SO2H, -SO3H, -OH, -OX, -ON(X)2, -N(X)2, -N(OX)X', -SH, -SX, -SSX, -C(=O)X, -CO2H, -CHO, -CO2X, -OC(=O)X, -OCOX, -C(=O)N(X)2, -SO2X, -SO2OX, -OSO2X, -S(=O)X, -OS(=O)X, -Si(X)3, -O and optionally substituted with one or more groups selected from Si(X)3-C(=O)SX, -C(=S)SX, -SC(=S)SX, -SC(=O)SX, C1-C20 alkyl, C1-C20 perhaloalkyl, C1-C20 alkenyl, C1-C20 alkynyl, heteroC1-C20 alkyl, heteroC1-C20 alkenyl, heteroC1-C20 alkynyl, C3-C10 carbocyclyl, heterocyclyl, aryl, and heteroaryl, where each instance of X or X' is an independent group independently selected from hydrogen, alkyl, alkenyl, alkynyl, or aryl, as defined.

[0039] In some embodiments, each of the cyclic imide groups can be selected from among fused cyclic imides, aryl substituted cyclic imides, and aryl fused cyclic imides.

[0040] In some embodiments, the IE-BMI is a compound of formula (II): TIFF2025504595000005.tif47170, wherein R1 and R2 are each as defined herein, R3 is selected from an aliphatic group, an aromatic group, a heteroaromatic group, a carbocyclic group, a saturated group, and an unsaturated group, each as defined, and n is an integer from 0 (forming E-BMI) to 10 (forming IE-BMI).

[0041] In some embodiments, n is different from zero. In some embodiments, n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0042] In the compound of formula (II), R1, R2, and R3 each independently represent a saturated, unsaturated, aromatic, or mixed aliphatic and aromatic group; and n is an integer from 0 to 10.

[0043] In some embodiments, each of R1, R2, and R3 is different.

[0044] In some embodiments, each of R1, R2, and R3 are the same.

[0045] In some embodiments, each of R1, R2, and R3, independently of one another, is selected from saturated, unsaturated, aromatic, or mixed aliphatic and aromatic groups.

[0046] In some embodiments, each of R1, R2, and R3 is selected from alkyl or alkylene, alkenyl or alkenylene, alkynyl or alkynylene, aryl or arylene, heteroaryl or heteroarylene, and aralkyl or aralkylene.

[0047] In some embodiments, R1 is selected from -CH2-, -O-, -SiR2-, C=O, bisphenol, and the like.

[0048] In some embodiments, R2 is selected from -CH2-, -O-, -SiR2-, C=O, bisphenol, and the like.

[0049] In some embodiments, R3 is selected from -CH2-, -O-, -SiR2-, C=O, bisphenol, and the like.

[0050] In some embodiments, each of R1, R2, and R3, independently of each other, is a long chain linker moiety containing 20-50 carbon atoms, 25-45 carbon atoms, or 30-40 carbon atoms.

[0051] In some embodiments, each of R1, R2, and R3, independently of the others, contains 30 to 40 carbon atoms, or 35 to 40 carbon atoms, or 36 carbon atoms.

[0052] In some embodiments, R1, R2, and R3 are each independently a C 1 -C 2 -O 3 group that is a methylene group. 36 H 70 It is an alkylene group.

[0053] In some embodiments, R1, R2, and R3 each independently include one or more double bonds. In some embodiments, R1, R2, and R3 each independently include one or more carbocyclyl groups.

[0054] The reactively extended BMI can be a liquid or solid or semi-solid resin having an average molecular weight up to 10,000 Daltons, for example, from 500 to 3,000 Daltons.

[0055] The reactive IE-BMI can similarly be liquid or solid or semi-solid with an average molecular weight of 500-5,000 Daltons.

[0056] In some embodiments, the IE-BMI according to the present invention is selected from structures (III), (IV), and (V): In each of the foregoing materials of structures (III)-(V), R1 and R2 are each independently as defined herein. Each n is 1 to 10.

[0057] In some embodiments, the compound used in the formulations of the present invention is an E-BMI, such as: TIFF2025504595000007.tif94170

[0058] In some embodiments, in each of structures (III), (IV), and (V), each of R and R is C36 H 70 It is an alkylene group.

[0059] Non-limiting examples of E-BMIs and IE-BMIs according to the present invention include: TIFF2025504595000008.tif43170This is an example of IE-BMI, TIFF2025504595000009.tif49170This is an example of IE-BMI, TIFF2025504595000010.tif53170This is an example of IE-BMI, and TIFF2025504595000011.tif73170This is an example of E-BMI.

[0060] In a first aspect of the present invention, there is provided an ink formulation for additive manufacturing, the formulation comprising at least one imide-extended-bismaleimide (IE-BMI) and / or at least one extended-bismaleimide (E-BMI), at least one cyanate ester, and optionally at least one additive.

[0061] In some embodiments, the IE-BMI is of structure (I), as defined herein. TIFF2025504595000012.tif35170

[0062] The double bond of the maleimide end group is highly electron deficient due to the adjacent electron-withdrawing carbonyl group. Thus, low molecular weight bismaleimide precursors can undergo homopolymerization and / or copolymerization at their carbon-carbon double bonds to provide crosslinked networks. Thus, such crosslinked networks can be achieved using reactive additives such as oligomeric polyamines that undergo Michael addition reactions with the maleimide functional groups. The extended-BMI component cures quickly (0.1-20 seconds per layer) under actinic radiation to form a three-dimensional network of thermoset polymeric materials.

[0063] Cyanate esters are an important class of high temperature thermosets that have extremely high glass transition temperatures (up to 400°C), high tensile strength, high modulus, and low dielectric constant, dielectric loss, and moisture absorption. These materials are thermally cured at elevated temperatures. The curing mechanism involves the trimerization of three cyano groups of the cyanate ester to produce a triazine ring, as shown in Figure 2.

[0064] The general structure of a cyanate ester is shown in Figure 3 A. In the structure shown, n is an integer from 1 to 6, and R is selected from alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, and hydrocarbon (saturated or unsaturated), each as defined herein, which may be optionally interrupted and / or substituted by one or more heteroatoms selected from Si, P, S, O, and N.

[0065] In some embodiments, in the cyanate ester, R is an aryl selected from a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, or a pyrenyl group, each of which is substituted or unsubstituted.

[0066] In some embodiments, in the cyanate ester, R is aryl selected from phenyl, biphenyl, naphthyl, bis(phenyl)methane, bis(phenyl)ethane, bis(phenyl)propane, bis(phenyl)butane, bis(phenyl)ether, bis(phenyl)thioether, bis(phenyl)sulfone, bis(phenyl)phosphine oxide, bis(phenyl)silane, bis(phenyl)hexafluoropropane, bis(phenyl)trifluoroethane, bis(phenyl)dicyclopentadiene, phenol formaldehyde resins, each unsubstituted or substituted, for example, with 1 to 6 substituents.

[0067] In some embodiments, in the cyanate ester, n is 1, 2, 3, 4, 5, or 6. In some embodiments, n is 2, 3, 4, or 5. In some embodiments, n is 2 or 3.

[0068] Exemplary cyanate ester compounds include, but are not limited to, 1,3- or 1,4-dicyanatobenzene; 1,3,5-tricyanatobenzene; 1,3-, 1,4-, 1,6-, 1,8-, 2,6-, or 2,7-dicyanatonaphthalene; 1,3,6-tricyanatonaphthalene; 2,2' or 4,4'-dicyanatobiphenyl; bis(4-cyanatophenyl)methane; 2,2-bis(4-cyanatophenyl)methane; phenyl)propane;2,2-bis(3,5-dichloro-4-cyanatophenyl)propane;2,2-bis(3-dibromo-4-dicyanatophenyl)propane;Bis(4-cyanatophenyl)ether;Bis(4-cyanatophenyl)thioether;Bis(4-cyanatophenyl)sulfone;Tris(4-cyanatophenyl)phosphite;Tris(4-cyanatophenyl)phosphate;Bis(3-chloro-4 -Cyanatophenyl)methane;4-Cyanatobiphenyl;4-Cumylcyanatobenzene;2-tert-Butyl-1,4-dicyanatobenzene;2,4-Dimethyl-1,3-dicyanatobenzene;2,5-Di-tert-butyl-1,4-dicyanatobenzene;Tetramethyl-1,4-dicyanatobenzene;4-Chloro-1,3-dicyanatobenzene;3,3',5,5'-Tetramethyl-4,4'dicyanatodi phenyl; bis(3-chloro-4-cyanatophenyl)methane; 1,1,1-tris(4-cyanatophenyl)ethane; 1,1-bis(4-cyanatophenyl)ethane; 2,2-bis(3,5-dichloro-4-cyanatophenyl)propane; 2,2-bis(3,5-dibromo-4-cyanatophenyl)propane; bis(p-cyanophenoxyphenoxy)benzene; and mixtures of any of these.

[0069] Curing of the cyanate ester results in the trimerization of three CN groups to form a triazine ring, as shown in Figure 2. If the monomer contains two cyanate groups, the resulting structure is a 3D polymer network. The properties of the thermosetting polymer matrix can be fine-tuned by the selection of the substituents of the bisphenol compound. Cyanate esters based on bisphenol A and novolac are the main products, with bisphenol F and bisphenol E also being used. The aromatic rings of the bisphenols may be substituted with allylic groups to improve the toughness of the material.

[0070] A specific example of thermal curing of a cyanate ester is shown in FIG. 3B for bis(4-cyanatophenyl)methane.

[0071] Cationic photopolymerization of epoxies is one of the fastest growing segments in the UV curing industry. It offers advantages over conventional UV curing because it is solvent-free, energy-efficient, and occurs at ambient temperature. Compared to free radical photopolymerization, ring-opening polymerization of epoxies does not suffer from oxygen inhibition, resulting in very low shrinkage, excellent adhesion and chemical resistance, and allows dark curing and thermal post-curing after photoinitiation due to the very long active center lifetime. Cationic systems also benefit from the recent availability of triarylsulfonium and diaryliodonium salt photoinitiators that are thermally stable at room temperature and can be efficiently photoactivated or photosensitized by thioxanthone derivatives.

[0072] Furthermore, the wide variety of cationic systems has attracted much interest in combination with hyperbranched polymers and polyols to tailor material properties, or in organic-inorganic hybrid nanocomposites based on fillers or dual-cure sol-gel photopolymerization processes to improve mechanical properties, thermal stability, scratch resistance, and reduce cure shrinkage.

[0073] Bismaleimide triazine (BT) resin is a high-temperature thermosetting resin that contains a mixture of bismaleimide and cyanate ester. BT resin is one of the most commonly used resins in the manufacture of printed circuit boards (PCBs). It is used in the manufacture of substrates used to connect chips used in PCB handsets. The three cyano groups of the cyanate ester can homo-cure and trimerize to a triazine ring structure. In addition to the homo-cure of IE-BMI and cyanate ester, as previously mentioned, the double bond of the maleimide group can copolymerize with the cyano group to produce a heterocyclic six-membered ring structure (Figure 4A and Figure 4B), thus producing a triple cure system.

[0074] Bismaleimide triazine resins are co-reacted with epoxy resins to enhance flexibility. BT-epoxy belongs to a group of thermosetting resins that are also used for printed circuit boards (PCBs). It is a mixture of epoxy resin and BT resin, which are common raw materials for PCBs. The triazine resin and epoxy resin blend cures by a combination of the intercalation of the epoxy into the polycyanurate network and the formation of a five-membered oxazolidinone ring (Figure 5), thus producing a quadruple cure system. The properties of the cured state show higher T values ​​than aromatic diamine cured epoxies. g It is characterized by low thermal expansion coefficient, low moisture absorption, and low dielectric loss properties.

[0075] Bismaleimide triazine (BT) resins can also be mixed with epoxy resins to optimize end-use properties. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers that contain epoxide groups. Epoxy resins can react (crosslink) with themselves by catalytic homopolymerization or with a wide range of co-reactants, including multifunctional amines, acids, anhydrides, phenols, alcohols, and thiols. The reaction of polyepoxides with themselves or with multifunctional curing agents results in the formation of thermoset polymers that often have favorable mechanical properties as well as high heat and chemical resistance. Cycloaliphatic epoxides contain one or more aliphatic rings in the molecule, which in turn contain oxirane rings. Cycloaliphatic epoxides are characterized by their aliphatic structure, high oxirane content, and absence of chlorine, resulting in low viscosity and (after curing) good weatherability, low dielectric constant, and high T g Cycloaliphatic epoxides are usually homopolymerized by electrophilic or cationic reactions, either thermally or UV initiated.

[0076] Thus, in order to tailor specific mechanical and chemical attributes to the printed pattern or object, as well as to modify the 3D printing technique to achieve such an object, the formulations of the present invention may include, in addition to at least one IE-BMI and cyanate ester, at least one additional reactive monomer or oligomer selected from polyepoxides or epoxide-rich resins, bismaleimide triazine (BT) resins, extended BMIs, and the like.

[0077] The formulation of the present invention is configured or constructed for use in a method of additive manufacturing. As known in the art, "additive manufacturing" generally refers to any process that combines materials, usually layer by layer, to create an object from 3D model data. The method used may vary depending on whether the curing of the formulation of the present invention can be achieved by thermal curing or photocuring. In some embodiments, the additive manufacturing is a liquid bath polymerization, in which the formulation is cured layer by layer under light irradiation conditions of a certain wavelength. The two main liquid bath polymerization techniques are digital light processing (DLP) and stereolithography (SLA).

[0078] Digital Light Processing, or DLP, is a 3D printing technology that uses light and liquid resin to create solid parts and products using designs created in 3D modeling software. In this process, a 3D design is sent to the printer, and a bath of liquid polymer is exposed to light from a DLP projector that projects an image of the 3D model onto the liquid polymer. The exposed liquid polymer hardens, and the process is repeated again, layer by layer. This process is repeated until the 3D model is complete and the liquid is drained from the bath, revealing the solidified model.

[0079] Stereolithography (SLA) and DLP are very similar 3D printing technologies. Both technologies work by selectively exposing liquid resin to a light source, but SLA uses a laser and DLP uses a projector. Although very similar in principle, the two technologies can produce very different outputs.

[0080] The invention further provides a method for producing an object, the method comprising printing a formulation according to the invention, wherein the printing is carried out under DLP or SLA conditions.

[0081] Thus, the formulations of the present invention can be utilized as ink materials in various additive manufacturing processes, hi some embodiments, the formulations are used as resin baths in vat-based 3D printing processes.

[0082] A method of producing or manufacturing a 3D object may comprise depositing an ink formulation according to the present invention onto a substrate and curing said deposited formulation under thermal or photocuring conditions to obtain a 3D object.

[0083] In some embodiments, the deposition of the ink formulation is layer-by-layer, with each layer being cured before the next layer is deposited.

[0084] In some embodiments, the ink formulation is provided in a bath bath.

[0085] Once formed, the body may be further treated under post-treatment conditions including one or more of the following: - cleaning the object with hydrophobic solvents such as hexyl acetate, pentyl acetate, butyl acetate, propyl acetate, methyl ethyl ketone, tert-butyl methyl ether, cyclohexane, hexane, petroleum ether pentane; - evaporating any solvent that may be contained in or associated with the object; - Light-curing the object (UV irradiation), for example for 5-180 minutes or 10-60 minutes; - heat treating and post-hardening the object, for example under a nitrogen atmosphere, at temperatures above room temperature, for example at temperatures between 150°C and 300°C for 1 to 12 hours, or by stepwise heating to 180°C for 3 hours, to 220°C for 1 hour, and to 275°C for 1 hour.

[0086] The method of manufacturing 3D objects is an additive manufacturing process that may involve layer-by-layer deposition of ink formulations from a 3D computer-aided design (CAD) model. Materials and processes for special-purpose products, such as those used in aerospace and automotive applications, pose several challenges, including low mass requirement, small production series, difficult material sourcing, very high performance, and very high reliability. Additive manufacturing is well suited for such applications, i.e., it is adaptable to very small series, applicable to a size range from a few micrometers to several meters, applicable to a wide variety of materials (polymers, metals, ceramics, composites, tissues and living cells, astronaut food, etc.), allows complex shapes that could not be manufactured before, allows reduction of connections (e.g. flanges, connectors, cables), allows significant mass reduction, resulting in improved performance, short lead times, minimal material waste, and may be used in spacecraft construction and even in-orbit manufacturing.

[0087] There are numerous advantages to using objects or generally polymeric materials formed according to the present invention or from the formulations of the present invention in space applications. The polymers and objects of the present invention exhibit properties that allow them to function in the space environment for extended periods of time with minimal degradation, despite the harsh conditions of space, including exposure to ultra-high vacuum (UHV), ultraviolet light (UV), ionizing radiation (i.e., high-energy electrons, protons, and heavy ions), high temperatures, and even micrometeorites and debris. Without being bound by theory, the advantages of polymers arise from their valued thermal and mechanical properties, such as strength, modulus, elongation, and thermal stability.

[0088] The products of the methods of the present invention or products formed from the formulations of the present invention can be characterized as polymeric objects, structures, or patterns, which can be of any shape and size and can be implemented in a variety of applications. In general, the products of the present invention can be implemented in aerospace, automotive, electronics packaging, microelectronic insulation, corrosion protection, films, medical devices, medical implants, and many other fields.

[0089] Thus, in another aspect, there is provided a polymeric object, element, or device formed from the ink formulation of the present invention.

[0090] The present invention further provides an ink formulation for the printing method disclosed herein, the ink formulation comprising at least one IE-BMI, (1,1'-bis(4-cyanatophenyl)ethane) as the cyanate ester, zinc(II) acetylacetonate hydrate in isobornyl acrylate, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. In some embodiments, the formulation further comprises at least one E-BMI.

[0091] In some embodiments, the IE-BMI and E-BMI are selected from the following: TIFF2025504595000013.tif197158

[0092] The invention further relates to the formulation, its uses, methods and processes, and articles in general.

[0093] An ink formulation for additive manufacturing, the formulation comprising at least one imide-extended-bismaleimide (IE-BMI), at least one cyanate ester, and optionally at least one additive.

[0094] Any of the formulations of the present invention may further include at least one extended bismaleimide (E-BMI).

[0095] Any of the formulations of the present invention may be carrier-free.

[0096] Any of the formulations of the present invention may further include at least one additive.

[0097] For any of the formulations of the present invention, the at least one additive may be selected from reactive and non-reactive materials.

[0098] For any of the formulations of the present invention, the reactive material may be selected from photoreactive diluents, aromatic bismaleimides, short chain aliphatic bismaleimides, radical polymerization initiators, and photoinitiators.

[0099] For any of the formulations of the present invention, the non-reactive materials may be selected from surfactants, inhibitors, antioxidants, pigments, dyes, dispersants, and reinforcing fillers.

[0100] Any of the formulations of the present invention may further comprise at least one carbonaceous material and / or at least one functional material.

[0101] For any of the formulations of the present invention, the at least one carbonaceous material and / or the at least one functional material may be selected from graphite, short carbon fibers, carbon nanotubes (CNTs), fused silica particles, graphene oxide, and 2D materials.

[0102] For any of the formulations of the present invention, the 2D material may be selected from boron nitride (BN), MoS2, and WS2.

[0103] Any of the formulations of the present invention may further comprise inorganic or sol-gel precursors that are soluble in the formulation.

[0104] For any of the formulations of the present invention, the sol-gel precursor may be a di-, tri-, or tetra-alkoxysilane.

[0105] For any of the formulations of the present invention, the sol-gel precursor may be selected from tetraethoxysilane (TEOS), 3-isocyanatopropyltrimethoxysilane, bisaminosilane, acryloxymethyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, acryloxypropyltrimethoxysilane (APTMS), (3-glycidoxypropyl)trimethylsilane, silanediol, silanetriol, trisilanolphenyl (POSS), aluminum lactate, aluminum alkoxide, aluminum isopropoxide, aluminum chloride, aluminum tris(ethyl acetoacetate), zirconium alkoxide, zirconium propoxide, zirconium nitrate, titanium alkoxide, titanium isopropoxide, titanium n-butoxide, titanium ethoxide, and niobium ethoxide.

[0106] For any of the formulations of the present invention, the IE-BMI may be of general structure (I): TIFF2025504595000014.tif34170 wherein R1 and R2 are each independently selected from a carbon-based group having 1 to 50 carbon atoms; G is a carbon-based group having 1 to 50 carbon atoms, and Each of the cyclic imides is optionally a fused or substituted ring system.

[0107] For any of the formulations of the present invention, each of R1 and R2 may be independently selected from an aliphatic group, an aromatic group, a heteroaromatic group, a carbocyclic group, a saturated group, and an unsaturated group.

[0108] For any of the formulations of the present invention, G may be selected from an aliphatic group, an aromatic group, a heteroaromatic group, a carbocyclic group, a saturated group, and an unsaturated group.

[0109] For any of the formulations of the present invention, each of R1, R2, and G may be, independently of the others, an alkylene group having 1 to 50 carbon atoms, an alkenylene or alkynylene group having 2 to 50 carbon atoms, a carbocyclyl group having 4 to 10 carbon atoms, an aromatic group having 6 to 10 carbon atoms, and a heteroaromatic group having 6 to 10 carbon atoms and one or more heteroatoms, and each of R1, R2, and G may be optionally substituted.

[0110] For any of the formulations of the present invention, each of R1, R2, and G may be, independently of the others, an alkylene group having 1 to 45, 1 to 40, 1 to 45, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, 1 to 9, 1 to 8, 1 to 7, 1 to 6, 1 to 5, 1 to 4, 10 to 50, 10 to 45, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 5 to 45, 5 to 35, 5 to 25, or 5 to 15 carbon atoms, or having 1 to 50 methylene groups.

[0111] For any of the formulations of the present invention, each of R1, R2, and G may be, independently of the others, an alkenylene or alkynylene group having 2 to 45, 2 to 40, 2 to 45, 2 to 35, 2 to 30, 2 to 25, 2 to 20, 2 to 15, 2 to 10, 2 to 9, 2 to 8, 2 to 7, 2 to 6, 2 to 5, 2 to 4, 10 to 50, 10 to 45, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 5 to 45, 5 to 35, 5 to 25, or 5 to 15 carbon atoms.

[0112] For any of the formulations of the present invention, each of R1, R2, and G may be, independently of each other, a carbocyclyl group that is a 4-membered ring, or a 5-, 6-, 7-, or 8-membered ring, or a bicyclic ring system.

[0113] For any of the formulations of the present invention, each of R1, R2, and G, independently of the others, may be an aromatic or heteroaromatic group having 6 to 10 carbon atoms and, in the case of a heteroaromatic group, one or more heteroatoms selected from N, O, and S.

[0114] For any of the formulations of the present invention, each of the cyclic imide group moieties of the IE-BMI may be selected from among fused cyclic imides, aryl substituted cyclic imides, and aryl fused cyclic imides.

[0115] For any of the formulations of the present invention, the IE-BMI may be a compound of formula (II): TIFF2025504595000015.tif46170 wherein R1 and R2 are as defined in claim 12, R3 is selected from an aliphatic group, an aromatic group, a heteroaromatic group, a carbocyclic group, a saturated group, and an unsaturated group, and n is an integer from 0 to 10.

[0116] For any of the formulations of the present invention, n may not be zero.

[0117] For any of the formulations of the present invention, n can be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0118] For any of the formulations of the present invention, each of R1, R2, and R3, independently of the others, may represent a saturated, unsaturated, aromatic, or mixed aliphatic-aromatic group, and n is an integer from 0 to 10.

[0119] For any of the formulations of the present invention, each of R1, R2, and R3 may be different.

[0120] For any of the formulations of the present invention, each of R1, R2, and R3 may be the same.

[0121] For any of the formulations of the present invention, R1 may be selected from -CH2-, -O-, -SiR2-, C=O, and bisphenols.

[0122] For any of the formulations of the present invention, R2 may be selected from -CH2-, -O-, -SiR2-, C=O, and bisphenols.

[0123] For any of the formulations of the present invention, R3 may be selected from -CH2-, -O-, -SiR2-, C=O, and bisphenols.

[0124] For any of the formulations of the present invention, each of R1, R2, and R3, independently of each other, may be a long chain linker moiety containing from 20 to 50 carbon atoms, from 25 to 45 carbon atoms, or from 30 to 40 carbon atoms.

[0125] For any of the formulations of the present invention, each of R1, R2, and R3, independently of each other, may contain 30 to 40 carbon atoms, or 35 to 40 carbon atoms, or 36 carbon atoms.

[0126] For any of the formulations of the present invention, each of R1, R2, and R3, independently of each other, may be a C36H70 alkylene group, all of which are methylene groups.

[0127] For any of the formulations of the present invention, the extended BMI may be a liquid or solid or semi-solid resin with an average molecular weight of up to 10,000 Daltons.

[0128] For any of the formulations of the present invention, the IE-BMI may be liquid or solid or semi-solid with an average molecular weight of 500-5,000 Daltons.

[0129] For any of the formulations of the present invention, the IE-BMI may be selected from structures (III), (IV), and (V): TIFF2025504595000016.tif177170 In each of structures (III)-(V), each of R1 and R2 is independently as defined in claim 21, and each n is 1 to 10.

[0130] For any of the formulations of the present invention, the E-BMI is of the following structure: TIFF2025504595000017.tif87170

[0131] For any of the formulations of the present invention, each of R1 and R2 may be a C36H70 alkylene group.

[0132] For any of the formulations of the present invention, the IE-BMI may be selected from the following: TIFF2025504595000018.tif182170

[0133] 1. An ink formulation for additive manufacturing, the formulation comprising at least one imide-extended-bismaleimide (IE-BMI) and / or at least one extended-bismaleimide (E-BMI), at least one cyanate ester, and at least one additive, wherein the IE-BMI is of structure (I): TIFF2025504595000019.tif34170 wherein R1 and R2 are each independently selected from a carbon-based group having 1 to 50 carbon atoms; G is a carbon-based group having 1 to 50 carbon atoms, and Each of the cyclic imides is optionally a fused or substituted ring system.

[0134] For any of the formulations of the present invention, the cyanate ester is of the structure: TIFF2025504595000020.tif29170, wherein R is selected from alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, and saturated or unsaturated hydrocarbon, optionally interrupted and / or substituted by one or more heteroatoms selected from Si, P, S, O, and N, and n is an integer from 1 to 6.

[0135] For any of the formulations of the present invention, R may be an aryl selected from a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, or a pyrenyl group, each of which may be substituted or unsubstituted.

[0136] For any of the formulations of the present invention, R may be an aryl selected from phenyl, biphenyl, naphthyl, bis(phenyl)methane, bis(phenyl)ethane, bis(phenyl)propane, bis(phenyl)butane, bis(phenyl)ether, bis(phenyl)thioether, bis(phenyl)sulfone, bis(phenyl)phosphine oxide, bis(phenyl)silane, bis(phenyl)hexafluoropropane, bis(phenyl)trifluoroethane, bis(phenyl)dicyclopentadiene, phenol formaldehyde resins, each of which is unsubstituted or substituted.

[0137] For any of the formulations of the present invention, n may not be zero, or may be 1, 2, 3, 4, 5, or 6, or n is 2 or 3.

[0138] For any of the formulations of the present invention, the cyanate ester may be 1,3- or 1,4-dicyanatobenzene; 1,3,5-tricyanatobenzene; 1,3-, 1,4-, 1,6-, 1,8-, 2,6-, or 2,7-dicyanatonaphthalene; 1,3,6-tricyanatonaphthalene; 2,2' or 4,4'-dicyanatobiphenyl; bis(4-cyanatophenyl)methane; 2,2-bis(4-cyanatophenyl)propane; Pan;2,2-Bis(3,5-dichloro-4-cyanatophenyl)propane;2,2-Bis(3-dibromo-4-dicyanatophenyl)propane;Bis(4-cyanatophenyl)ether;Bis(4-cyanatophenyl)thioether;Bis(4-cyanatophenyl)sulfone;Tris(4-cyanatophenyl)phosphite;Tris(4-cyanatophenyl)phosphate;Bis(3-chloro-4-cyanato Phenyl)methane;4-Cyanatobiphenyl;4-Cumylcyanatobenzene;2-tert-Butyl-1,4-dicyanatobenzene;2,4-Dimethyl-1,3-dicyanatobenzene;2,5-Di-tert-butyl-1,4-dicyanatobenzene;Tetramethyl-1,4-dicyanatobenzene;4-Chloro-1,3-dicyanatobenzene;3,3',5,5'-Tetramethyl-4,4'dicyanatodiphenyl bis(3-chloro-4-cyanatophenyl)methane; 1,1,1-tris(4-cyanatophenyl)ethane; 1,1-bis(4-cyanatophenyl)ethane; 2,2-bis(3,5-dichloro-4-cyanatophenyl)propane; 2,2-bis(3,5-dibromo-4-cyanatophenyl)propane; bis(p-cyanophenoxyphenoxy)benzene; and mixtures of any of these.

[0139] Any of the formulations of the present invention may further include a bismaleimide triazine (BT) resin.

[0140] Any of the formulations of the present invention may further include an epoxy resin.

[0141] Any of the formulations of the present invention may be for use in processes of additive manufacturing.

[0142] For any of the formulations of the present invention, the additive manufacturing may be liquid bath polymerization.

[0143] For any of the formulations of the present invention, the method may involve layer-by-layer deposition of the formulation, with each layer being cured under conditions of light irradiation.

[0144] Any of the formulations of the present invention may be for use in digital light processing (DLP) or stereolithography (SLA).

[0145] A method for producing an object, the method comprising printing a formulation according to any one of claims 1 to 53, wherein the printing is carried out under digital light processing (DLP) or stereolithography (SLA) conditions.

[0146] For any of the methods of the present invention, the method includes depositing a formulation onto a substrate and curing the deposited formulation under thermal or photocuring conditions to obtain a 3D object.

[0147] For any of the methods of the present invention, deposition of the formulation may be layer by layer, with each layer being cured before the next layer is deposited.

[0148] For any of the methods of the present invention, the ink formulation may be provided in a bath bath.

[0149] The objects formed from the formulations according to the present invention are polymer objects, structures or patterns implemented for use in aerospace, automotive, electronics packaging, microelectronic insulation, corrosion protection, films, medical devices and medical implants.

[0150] The objects formed from the methods according to the present invention are polymer objects, structures or patterns implemented for use in aerospace, automotive, electronics packaging, microelectronics insulation, corrosion protection, films, medical devices and medical implants.

[0151] A formulation for use in additive manufacturing, the formulation comprising at least one cyanate ester, optionally at least one additive, and at least one bismaleimide selected from the following: TIFF2025504595000021.tif199127

[0152] For any of the formulations of the present invention, the formulation may be in the form of a resin, which optionally further comprises a photoinitiator and at least one metal catalyst, such as zinc(II) acetylacetonate hydrate.

[0153] In order to better understand the subject matter disclosed herein, and to illustrate how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0154] [Figure 1A] 1A shows a general mechanistic diagram of the homopolymerization of maleimides. Each R group is independently an N-substituted moiety as disclosed herein. [Figure 1B] FIG. 1B is a diagram of the homopolymerization of IE-BMI of structure (IV), as defined herein. [Diagram 2] FIG. 2 is a mechanistic diagram of the homopolymerization of cyanate esters, where each R group is independently a substituted moiety as disclosed herein. [Figure 3A] FIG. 3A shows the general structure of a cyanate ester. [Figure 3B] FIG. 3B shows a general mechanistic diagram of cyanate ester homopolymerization. [Figure 4A]FIG. 4A shows a diagram of the curing mechanism of maleimides and cyanate esters, where each R group is independently an N- or O-substituted moiety, as disclosed herein. [Figure 4B] FIG. 4B shows the copolymerization of IE-BMI of structure (IV) with a cyanate ester. [Diagram 5] FIG. 5 shows the curing mechanism of an epoxy with a cyanate ester, where each R group is independently a substituted moiety as disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0155] Working Example Example 1: Triple cure resin and product of BT-based formulation The BT formulation was prepared by mixing 20 g of IE-BMI (BMI-1700), 20 g of bismaleimide based on a non-hydrogenated dimer diamine backbone (E-BMI, BMI-689), 60 g of cyanate ester (1,1'-bis(4-cyanatophenyl)ethane), 2 g of a metal catalyst solution (3000 ppm zinc(II) acetylacetonate hydrate in isobornyl acrylate) to promote the polymerization of the cyanate ester, and 0.8 g of a photoinitiator (phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide) and mixing at 60 °C using a magnetic stirrer until completely dissolved to obtain a homogeneous resin.

[0156] From this resin, an ASIGA DLP printer was used, with a light intensity of 31 mW / cm 2 A three-dimensional intermediate was formed using a 385 nm LED projector by a 385 nm LED projector. The formed material was washed and cured under UV irradiation for 30 minutes. Further post-curing was performed at 180°C for 180 minutes, 250°C for 60 minutes, and 275°C for 1 hour to obtain the desired product. The thermo-mechanical properties of the product were evaluated and are shown in Table 1 below.

[0157] Example 2: Quadruple cure resin and products of BT-epoxy based formulations The BT-epoxy formulation was prepared by mixing 16 g of IE-BMI (BMI-1700), 16 g of E-BMI (BMI-689), 60 g of cyanate ester (1,1'-bis(4-cyanatophenyl)ethane), 2 g of metal catalyst solution (3000 ppm zinc(II) acetylacetonate hydrate in isobornyl acrylate) to promote polymerization of the cyanate ester, 0.8 g of radical photoinitiator (phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide), 8 g of reactive diluent for epoxy methacrylate hybrid crosslinker (3,4-epoxycyclohexylmethyl methacrylate), and 0.16 g of cationic photoinitiator (triarylsulfonium hexafluoroantimonate salt mixture in propylene carbonate) at 60 °C using a magnetic stirrer until completely dissolved to obtain a homogenous resin.

[0158] From this resin, an ASIGA DLP printer was used, with a light intensity of 31 mW / cm 2 A three-dimensional intermediate was formed using a 385 nm LED projector by a 385 nm LED projector. The formed material was washed and cured under UV irradiation for 30 minutes. Further post-curing was performed at 180°C for 180 minutes, 250°C for 60 minutes, and 275°C for 1 hour to obtain the desired product. The thermo-mechanical properties of the product were evaluated and are shown in Table 1 below.

[0159] Example 3: Quadruple cure resin and products of BT-epoxy based formulations The BT-epoxy formulation was prepared by mixing 13.5 g of IE-BMI (BMI-1700), 13.5 g of E-BMI (BMI-689), 60 g of cyanate ester (1,1'-bis(4-cyanatophenyl)ethane), 2 g of metal catalyst solution (3000 ppm zinc(II) acetylacetonate hydrate in isobornyl acrylate) to promote polymerization of the cyanate ester, 0.8 g of radical photoinitiator (phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide), 13.1 g of reactive diluent for epoxy methacrylate hybrid crosslinker (3,4-epoxycyclohexylmethyl methacrylate), and 0.26 g of cationic photoinitiator (triarylsulfonium hexafluoroantimonate salt mixture in propylene carbonate) and mixed at 60 °C using a magnetic stirrer until completely dissolved to obtain a homogenous resin.

[0160] From this resin, an ASIGA DLP printer was used, with a light intensity of 31 mW / cm 2 A three-dimensional intermediate was formed using a 385 nm LED projector by a 385 nm LED projector. The formed material was washed and cured under UV irradiation for 30 minutes. Further post-curing was performed at 180°C for 180 minutes, 250°C for 60 minutes, and 275°C for 1 hour to obtain the desired product. The thermo-mechanical properties of the product were evaluated and are shown in Table 1 below.

[0161] Example 4: Quadruple cure resins and products of BT-acrylate based formulations The BT-epoxy formulation was prepared by mixing 16 g of IE-BMI (BMI-1700), 16 g of E-BMI (BMI-689), 60 g of cyanate ester (1,1'-bis(4-cyanatophenyl)ethane), 2 g of a metal catalyst solution (3000 ppm zinc(II) acetylacetonate hydrate in isobornyl acrylate) to promote the polymerization of the cyanate ester, 0.8 g of a radical photoinitiator (phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide), and 8 g of an acrylic crosslinker (tricyclodecane dimethanol diacrylate) at 60 °C using a magnetic stirrer until completely dissolved to obtain a homogenous resin.

[0162] From this resin, an ASIGA DLP printer was used, with a light intensity of 31 mW / cm 2 A three-dimensional intermediate was formed using a 385 nm LED projector by a 385 nm LED projector. The formed material was washed and cured under UV irradiation for 30 minutes. Further post-curing was performed at 180°C for 180 minutes, 250°C for 60 minutes, and 275°C for 1 hour to obtain the desired product. The thermo-mechanical properties of the product were evaluated and are shown in Table 1 below.

[0163] Example 5: Quadruple cure resins and products of BT-acrylate based formulations The BT-epoxy formulation was prepared by mixing 13.5 g of IE-BMI (BMI-1700), 13.5 g of E-BMI (BMI-689), 60 g of cyanate ester (1,1'-bis(4-cyanatophenyl)ethane), 2 g of a metal catalyst solution (3000 ppm zinc(II) acetylacetonate hydrate in isobornyl acrylate) to promote the polymerization of the cyanate ester, 0.8 g of a radical photoinitiator (phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide), and 13.1 g of an acrylic crosslinker (tricyclodecane dimethanol diacrylate) at 60 °C using a magnetic stirrer until completely dissolved to obtain a homogenous resin.

[0164] From this resin, an ASIGA DLP printer was used, with a light intensity of 31 mW / cm 2 A three-dimensional intermediate was formed using a 385 nm LED projector by a 385 nm LED projector. The formed material was washed and cured under UV irradiation for 30 minutes. Further post-curing was performed at 180°C for 180 minutes, 250°C for 60 minutes, and 275°C for 1 hour to obtain the desired product. The thermo-mechanical properties of the product were evaluated and are shown in Table 1 below. TIFF2025504595000022.tif77170

Claims

1. An ink formulation for additive manufacturing, the formulation comprising at least one imide-extended-bismaleimide (IE-BMI), at least one cyanate ester, and optionally at least one additive.

2. 10. The formulation of claim 1, further comprising at least one extended bismaleimide (E-BMI).

3. The formulation of claim 1 which does not contain a carrier.

4. The formulation according to any one of claims 1 to 3, further comprising at least one additive.

5. 5. The formulation of claim 4, wherein the at least one additive is selected from reactive and non-reactive materials.

6. 6. The formulation of claim 5, wherein the reactive material is selected from photoreactive diluents, aromatic bismaleimides, short chain aliphatic bismaleimides, radical polymerization initiators, and photopolymerization initiators.

7. 6. The formulation of claim 5, wherein the non-reactive materials are selected from surfactants, inhibitors, antioxidants, pigments, dyes, dispersants, and reinforcing fillers.

8. The formulation of any one of claims 1 to 7, further comprising at least one carbonaceous material and / or at least one functional material.

9. 9. The formulation of claim 8, wherein the at least one carbonaceous material and / or the at least one functional material is selected from graphite, short carbon fibers, carbon nanotubes (CNTs), fused silica particles, graphene oxide, and 2D materials.

10. The 2D material is boron nitride (BN), MoS ２ , and W.S. ２ The formulation of claim 9, wherein the formulation is selected from the group consisting of

11. The formulation according to any one of claims 1 to 10, further comprising an inorganic precursor or a sol-gel precursor that is soluble in the formulation.

12. The formulation of claim 11, wherein the sol-gel precursor is a di-, tri-, or tetra-alkoxysilane.

13. 13. The formulation of claim 12, wherein the sol-gel precursor is selected from tetraethoxysilane (TEOS), 3-isocyanatopropyltrimethoxysilane, bisaminosilane, acryloxymethyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, acryloxypropyltrimethoxysilane (APTMS), (3-glycidoxypropyl)trimethylsilane, silanediol, silanetriol, trisilanolphenyl (POSS), aluminum lactate, aluminum alkoxide, aluminum isopropoxide, aluminum chloride, aluminum tris(ethyl acetoacetate), zirconium alkoxide, zirconium propoxide, zirconium nitrate, titanium alkoxide, titanium isopropoxide, titanium n-butoxide, titanium ethoxide, and niobium ethoxide.

14. The IE-BMI is of general structure (I): wherein each of R1 and R2 is independently selected from a carbon-based group having 1 to 50 carbon atoms; G is a carbon-based group having 1 to 50 carbon atoms, and The formulation of any one of claims 1 to 13, wherein each of the cyclic imides is optionally a fused or substituted ring system.

15. 15. The formulation of claim 14, wherein each of R1 and R2 is independently selected from an aliphatic group, an aromatic group, a heteroaromatic group, a carbocyclic group, a saturated group, and an unsaturated group.

16. 15. The formulation of claim 14, wherein G is selected from an aliphatic group, an aromatic group, a heteroaromatic group, a carbocyclic group, a saturated group, and an unsaturated group.

17. 15. The formulation of claim 14, wherein each of R1, R2, and G is, independently of one another, an alkylene group having 1 to 50 carbon atoms, an alkenylene or alkynylene group having 2 to 50 carbon atoms, a carbocyclyl group having 4 to 10 carbon atoms, an aromatic group having 6 to 10 carbon atoms, and a heteroaromatic group having 6 to 10 carbon atoms and one or more heteroatoms, and each of R1, R2, and G is optionally substituted.

18. 18. The formulation of claim 17, wherein each of R1, R2, and G, independently of one another, is an alkylene group having 1-45, 1-40, 1-45, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10, 1-9, 1-8, 1-7, 1-6, 1-5, 1-4, 10-50, 10-45, 10-40, 10-35, 10-30, 10-25, 10-20, 5-45, 5-35, 5-25, or 5-15 carbon atoms, or having 1-50 methylene groups.

19. 18. The formulation of claim 17, wherein each of R1, R2, and G, independently of one another, is an alkenylene or alkynylene group having 2-45, 2-40, 2-45, 2-35, 2-30, 2-25, 2-20, 2-15, 2-10, 2-9, 2-8, 2-7, 2-6, 2-5, 2-4, 10-50, 10-45, 10-40, 10-35, 10-30, 10-25, 10-20, 5-45, 5-35, 5-25, or 5-15 carbon atoms.

20. 18. The formulation of claim 17, wherein each of R1, R2, and G is independently a 4-membered ring, or a 5-, 6-, 7-, or 8-membered carbocyclyl group, or a bicyclic ring system.

21. 18. The formulation of claim 17, wherein each of R1, R2, and G, independently of one another, is an aromatic or heteroaromatic group having 6 to 10 carbon atoms and, in the case of a heteroaromatic group, one or more heteroatoms selected from N, O, and S.

22. 22. The formulation of any one of claims 1 to 21, wherein each of the cyclic imide group moieties of the IE-BMI is selected from among a fused cyclic imide, an aryl substituted cyclic imide, and an aryl fused cyclic imide.

23. The IE-BMI is a compound of formula (II), 23. The formulation of any one of claims 1 to 22, wherein each of R1 and R2 is as defined in claim 12, R3 is selected from an aliphatic group, an aromatic group, a heteroaromatic group, a carbocyclic group, a saturated group, and an unsaturated group, and n is an integer from 0 to 10.

24. 24. The formulation of claim 23, wherein n is not zero.

25. 25. The formulation of claim 23 or 24, wherein n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

26. 24. The formulation of claim 23, wherein each of R1, R2, and R3, independently of one another, represents a saturated, unsaturated, aromatic, or mixed aliphatic-aromatic group, and n is an integer from 0 to 10.

27. The formulation of claim 23, wherein each of R1, R2, and R3 is different.

28. The formulation of claim 23, wherein each of R1, R2, and R3 is the same.

29. R1 is -CH ２ -, -O-, -SiR ２ 24. The formulation of claim 23, wherein the alkyl group is selected from -, C=O, and bisphenol.

30. R2 is -CH ２ -, -O-, -SiR ２ 24. The formulation of claim 23, wherein the alkyl group is selected from -, C=O, and bisphenol.

31. R3 is -CH ２ -, -O-, -SiR ２ 24. The formulation of claim 23, wherein the alkyl group is selected from -, C=O, and bisphenol.

32. 24. The formulation of claim 23, wherein each of R1, R2, and R3, independently of each other, is a long chain linker moiety comprising 20 to 50 carbon atoms, 25 to 45 carbon atoms, or 30 to 40 carbon atoms.

33. 24. The formulation of claim 23, wherein each of R1, R2, and R3, independently of each other, comprises 30 to 40 carbon atoms, or 35 to 40 carbon atoms, or 36 carbon atoms.

34. 24. The formulation of claim 23, wherein each of R1, R2, and R3, independently of one another, is a C36H70 alkylene group which are all methylene groups.

35. 35. The formulation of any one of claims 1 to 34, wherein the extended BMI is a liquid or solid or semi-solid resin having an average molecular weight of up to 10,000 Daltons.

36. 36. The formulation of any one of claims 1 to 35, wherein the IE-BMI is a liquid or solid or semi-solid with an average molecular weight of 500 to 5,000 Daltons.

37. said IE-BMI is selected from structures (III), (IV), and (V); 37. The formulation of any one of claims 1 to 36, wherein in each of structures (III)-(V), each of R1 and R2 is independently as defined in claim 21 and each n is 1 to 10.

38. 23. The formulation of any one of claims 1-22, wherein the E-BMI is of the following structure:

39. The formulation of claim 37, wherein each of R1 and R2 is a C36H70 alkylene group.

40. The formulation of any one of claims 1 to 39, wherein the IE-BMI is selected from the following:

41. 1. An ink formulation for additive manufacturing, the formulation comprising at least one imide-extended-bismaleimide (IE-BMI) and / or at least one extended-bismaleimide (E-BMI), at least one cyanate ester, and at least one additive, the IE-BMI being of structure (I): wherein each of R1 and R2 is independently selected from a carbon-based group having 1 to 50 carbon atoms; G is a carbon-based group having 1 to 50 carbon atoms, and Each of said cyclic imides is optionally a fused or substituted ring system.

42. The cyanate ester has the structure:

42. The formulation of any one of claims 1 to 41, wherein R is selected from alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, and saturated or unsaturated hydrocarbon, optionally interrupted and / or substituted by one or more heteroatoms selected from Si, P, S, O, and N, and n is an integer from 1 to 6.

43. 43. The formulation of claim 42, wherein R is an aryl selected from a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, or a pyrenyl group, each of which is substituted or unsubstituted.

44. 43. The formulation of claim 42, wherein R is an aryl selected from phenyl, biphenyl, naphthyl, bis(phenyl)methane, bis(phenyl)ethane, bis(phenyl)propane, bis(phenyl)butane, bis(phenyl)ether, bis(phenyl)thioether, bis(phenyl)sulfone, bis(phenyl)phosphine oxide, bis(phenyl)silane, bis(phenyl)hexafluoropropane, bis(phenyl)trifluoroethane, bis(phenyl)dicyclopentadiene, phenol formaldehyde resin, each unsubstituted or substituted.

45. 43. The formulation of claim 42, wherein n is 1, 2, 3, 4, 5, or 6.

46. 43. The formulation of claim 42, wherein n is 2 or 3.

47. The cyanate ester may be 1,3- or 1,4-dicyanatobenzene; 1,3,5-tricyanatobenzene; 1,3-, 1,4-, 1,6-, 1,8-, 2,6-, or 2,7-dicyanatonaphthalene; 1,3,6-tricyanatonaphthalene; 2,2' or 4,4'-dicyanatobiphenyl; bis(4-cyanatophenyl)methane; 2,2-bis(4-cyanatophenyl)propane; 2,2-bis(3 ,5-dichloro-4-cyanatophenyl)propane; 2,2-bis(3-dibromo-4-dicyanatophenyl)propane; bis(4-cyanatophenyl)ether; bis(4-cyanatophenyl)thioether; bis(4-cyanatophenyl)sulfone; tris(4-cyanatophenyl)phosphite; tris(4-cyanatophenyl)phosphate; bis(3-chloro-4-cyanatophenyl)methane; 4-cyanatobiphenyl; 4-cumylcyanatobenzene; 2-tert-butyl-1,4-dicyanatobenzene; 2,4-dimethyl-1,3-dicyanatobenzene; 2,5-di-tert-butyl-1,4-dicyanatobenzene; tetramethyl-1,4-dicyanatobenzene; 4-chloro-1,3-dicyanatobenzene; 3,3',5,5'-tetramethyl-4,4'dicyanatodiphenyl; bis(3-chloro-4-cyanatophenyl)methane; 47. The formulation of any one of claims 1 to 46, wherein the aryl ether is selected from 1,1,1-tris(4-cyanatophenyl)ethane; 1,1-bis(4-cyanatophenyl)ethane; 2,2-bis(3,5-dichloro-4-cyanatophenyl)propane; 2,2-bis(3,5-dibromo-4-cyanatophenyl)propane; bis(p-cyanophenoxyphenoxy)benzene; and mixtures of any of these.

48. 48. The formulation of any one of claims 1 to 47, further comprising a bismaleimide triazine (BT) resin.

49. 49. The formulation of any one of claims 1 to 48, further comprising an epoxy resin.

50. A formulation according to any one of claims 1 to 49 for use in a process for additive manufacturing.

51. 51. The formulation of claim 50, wherein the additive manufacturing is liquid bath polymerization.

52. 51. The formulation of claim 50, wherein the process comprises layer-by-layer deposition of the formulation, each layer being cured under conditions of light irradiation.

53. A formulation according to any one of claims 1 to 52 for use in digital light processing (DLP) or stereolithography (SLA).

54. 54. A method for manufacturing an object, said method comprising printing a formulation according to any one of claims 1 to 53, said printing being carried out under Digital Light Processing (DLP) or Stereo Lithography (SLA) conditions.

55. 56. The method of claim 55, comprising depositing the formulation onto a substrate and curing the deposited formulation under thermal or photocuring conditions to obtain the 3D object.

56. 54. The method of claim 53, wherein the deposition of the formulation is layer by layer, each layer being cured before the next layer is deposited.

57. 54. The method of claim 53, wherein the ink formulation is provided in a bath bath.

58. 54. An object formed from the formulation of any one of claims 1 to 53, said object being a polymer object, structure or pattern implemented for use in aerospace, automotive, electronics packaging, microelectronics insulation, corrosion protection, films, medical devices and medical implants.

59. 58. An object formed from the method of any one of claims 54 to 57, wherein the object is a polymer object, structure or pattern implemented for use in aerospace, automotive, electronics packaging, microelectronics insulation, corrosion protection, films, medical devices and medical implants.

60. 1. A formulation for use in additive manufacturing, said formulation comprising at least one cyanate ester, optionally at least one additive, and at least one bismaleimide selected from the following:

61. The formulation according to any one of claims 1 to 53 and claim 60, which is in the form of a resin.

62. 62. The formulation of claim 61, wherein the resin further comprises a photoinitiator and at least one metal catalyst.

63. 63. The formulation of claim 62, wherein the metal catalyst is zinc(II) acetylacetonate hydrate.

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