Dual-cure method and system for manufacturing 3D polymeric structures

Abstract

This invention provides a dual-curing method for forming a solid polymeric structure. A one-terminated terminal imide prepolymer is combined with at least one photopolymerizable olefinic monomer, at least one photoinitiator, and a diamine to form a curable resin composition. In a first step, this resin composition is irradiated under conditions that effectively polymerize the at least one olefinic monomer, thereby forming a scaffold composed of the prepolymer and a polyolefin, wherein the diamine is trapped within the scaffold. Then, the irradiated composition is heat-treated at a temperature that effectively induces transimidization of the prepolymer and the diamine, thereby releasing the end groups of the prepolymer and providing the solid polymeric structure. A curable resin composition comprising a one-terminated terminal imide prepolymer, at least one photopolymerizable olefinic monomer, at least one photoinitiator, and a diamine, and a related method of use are also provided.

Description

[0001] This invention patent is a divisional application of patent application number "201980093395.5", application date "December 31, 2019", and invention title "Dual curing method and system for manufacturing 3D polymer structures". Technical Field

[0002] The present invention relates generally to the manufacture of three-dimensional (3D) objects, and more specifically to the manufacture of 3D structures using a “dual-curing” system. Background Technology

[0003] 3D printing typically involves producing 3D objects using additive manufacturing (AM) processes. Additive manufacturing was initially developed in the early 1980s, utilizing UV-curable liquid resins to form thermosetting polymers. Solid structures are built layer by layer, each layer corresponding to a cross-sectional slice of the structure, and formed through the deposition and photocuring of the liquid resin. A few years later, stereolithography additive manufacturing (SLA) was developed, in which a cross-sectional pattern of the object to be formed is created as digital data, and the object is then formed based on that pattern. Since then, many technologies have been developed in the field of 3D printing, resulting in numerous improvements and refinements to the basic additive manufacturing process:

[0004] Speed ​​and precision have been greatly improved, enabling the manufacture of extremely small or complex structures with exceptional accuracy.

[0005] Additive manufacturing has now achieved large-scale commercialization in many application areas (from "bioprinting" of blood vessels and organs to integrated circuit manufacturing);

[0006] Prototyping can be implemented quickly and at low cost through SLA (Rapid Prototyping) technology, which is a time-saving and cost-effective business advantage; and the cost of 3D printing materials and equipment has been reduced to a level that individuals, small businesses and large organizations can use the technology.

[0007] However, improvements are still needed, particularly in the mechanical properties and surface finish of the manufactured objects. Summary of the Invention

[0008] Therefore, the present invention relates to methods and compositions for addressing the above-mentioned needs in the art.

[0009] In one embodiment, the present invention provides a dual-curing method for forming a solid polymer structure, the method comprising:

[0010] (a) Combining a one-terminated and imide-terminated prepolymer with at least one photopolymerizable olefinic monomer, at least one photoinitiator, and a diamine to form a curable resin composition;

[0011] (b) Irradiating the resin composition under conditions that enable efficient polymerization of the at least one olefinic monomer and provision of a polyolefin within a scaffold, the scaffold comprising the prepolymer and the polyolefin, wherein the diamine is physically trapped within the scaffold; and

[0012] (c) The irradiated composition is heat-treated at a temperature that allows a transimide reaction to occur between the prepolymer and the diamine, while releasing the end groups of the prepolymer to provide the solid polymer structure.

[0013] It should be understood that when implementing the aforementioned method in the field of 3D printing, the solid polymer structure corresponds to a 3D object of a predetermined shape and size contained in a 3D printable model, which can be generated, for example, using computer-aided design (CAD) software, a 3D scanner, or photogrammetry software that works based on two-dimensional digital images.

[0014] In one aspect of the foregoing embodiments, prior to irradiating the resin in step (b), the curable resin composition produced in step (a) is added to a building region that corresponds in size to a predetermined shape and size of the object.

[0015] In another embodiment, a method for forming layers of a 3D object is provided, which is carried out, for example, in the context of an additive manufacturing process. The method includes:

[0016] (a) Combining an imide-terminated prepolymer with at least one photopolymerizable olefinic monomer, at least one photoinitiator and a diamine to form a curable resin composition;

[0017] (b) Providing the curable resin composition as a layer on a substrate by coating, deposition, or other means; and

[0018] (c) Irradiating the layer under conditions that enable the olefinic monomer to polymerize effectively and provide a polyolefin within a scaffold layer, the scaffold layer comprising the prepolymer and the polyolefin, wherein the diamine is physically trapped within the scaffold layer.

[0019] In another embodiment, the present invention provides an improved method for forming 3D objects using an additive manufacturing process comprising continuously forming layers on a substrate in a computer-controlled manner at dimensions corresponding to a 3D digital image, the improvement comprising forming the layers by means of the following steps:

[0020] (a) An initial curable layer is provided on a substrate, wherein the layer comprises a curable resin composition prepared by combining a capped and imide-terminated prepolymer, a photopolymerizable olefinic monomer, at least one photoinitiator and a diamine.

[0021] (b) Irradiating the initial layer under conditions that enable the olefinic monomer to polymerize effectively and provide polyolefin within the first scaffold layer, wherein the first scaffold layer comprises the prepolymer and the polyolefin, and the diamine is physically trapped within the scaffold layer;

[0022] (c) Repeat step (a) to provide an additional layer on the first support layer;

[0023] (d) Irradiate the additional layer under conditions that enable the polymerization of the olefinic monomer and provide an additional support layer;

[0024] (e) Repeat steps (c) and (d) until the 3D object is fully formed; and

[0025] (f) The 3D object is heat-treated at a temperature that allows a transimide reaction to occur between the prepolymer and the diamine.

[0026] In any of the foregoing embodiments, the prepolymer has a structure of formula (I):

[0027] (I)

[0028] in,

[0029] L includes unsubstituted, substituted, heteroatom-containing, or substituted and heteroatom-containing oligomeric hydrocarbon moieties;

[0030] Ar is an aryl group;

[0031] R 1 and R 3 They can be the same or different, and they are non-oligomeric linking groups;

[0032] q and r can be the same or different, and can be 0 or 1; and

[0033] R 2 and R 4 It is an imide-terminated group that can be removed during transimide reaction.

[0034] In one relevant aspect, Ar is phenyl, such that the prepolymer has the structure of formula (II):

[0035] (II)

[0036] In another related aspect, the weight-average molecular weight of the prepolymer is about 500 to about 5000.

[0037] In another aspect of any of the foregoing embodiments, the photopolymerizable olefinic monomer is used as an active diluent.

[0038] In one related aspect, the photopolymerizable olefin monomer is an acrylate or a methacrylate monomer.

[0039] In another related aspect, the photopolymerizable olefinic monomer has the structure of the following formula (XIV):

[0040] (XKIIV)

[0041] in,

[0042] R 5 For H or CH3, R 6 For C1-C 36 Hydrocarbon group, substituted C1-C 36 Hydrocarbon groups, C1-C containing heteroatoms 36 Hydrocarbon group, or substituted C1-C containing heteroatoms 36 Hydrocarbon group.

[0043] In another aspect of any of the foregoing embodiments, the diamine is used as a chain extender and has the structure of the following formula (XV):

[0044] (XV)H2N-L 1 -NH2

[0045] Among them, L 1 For C2-C 14 Hydroxyl group, substituted C2-C 14 Hydroxyl groups, C2-C containing heteroatoms 14 Hydroxyl groups, or substituted C2-C groups containing heteroatoms 14 Hydroxyl group.

[0046] In another embodiment, the present invention provides a curable resin composition as a novel material composition, comprising a capped terminal imide prepolymer, at least one photopolymerizable olefinic monomer, at least one photoinitiator, and a diamine.

[0047] In another embodiment, the present invention provides a method for synthesizing the capped and imide-terminated prepolymer, the synthesis method comprising:

[0048] (a) Combining diphthalic anhydride with a single-amino-terminated oligomer at a molar ratio of at least about 2:1 under conditions that effectively produce the reaction product phthalimide oligomer; and

[0049] (b) The terminal phthalimide oligomer is capped by mixing an amino-substituted cyclic reactant with the terminal phthalimide oligomer at a molar ratio of at least about 2:1 and reacting at high temperature for at least about 12 h.

[0050] In another embodiment, the present invention provides a dual-curing method for forming a solid polymer structure, the method comprising:

[0051] (a) A capped terminal imide prepolymer is synthesized by the following steps: (i) combining diphthalic anhydride with an amino-terminated oligomer in a molar ratio of at least about 2:1 under conditions that can effectively produce the reaction product, the terminal phthalimide oligomer; and (ii) capping the terminal phthalimide oligomer by mixing an amino-substituted cyclic reactant with the terminal phthalimide oligomer in a molar ratio of at least about 2:1 and reacting at high temperature for at least about 12 h.

[0052] (b) Combining the prepolymer with at least one photopolymerizable olefinic monomer, at least one photoinitiator, and a diamine to form a curable resin composition;

[0053] (c) Irradiating the resin composition under conditions that enable efficient polymerization of the at least one olefinic monomer and provision of a polyolefin within a scaffold, the scaffold comprising the prepolymer and the polyolefin, wherein the diamine is physically trapped within the scaffold; and

[0054] (d) The irradiated composition is heat-treated at a temperature that allows a transimide reaction to occur between the prepolymer and the diamine, thereby releasing the end groups of the prepolymer and providing the solid polymer structure.

[0055] In another embodiment, a method is provided for forming a layer of a 3D object in an additive manufacturing process, comprising:

[0056] (a) A capped imide-terminated prepolymer is synthesized by the following steps: (i) combining diphthalic anhydride with an amino-terminated oligomer in a molar ratio of at least about 2:1 under conditions that can effectively produce the reaction product, the phthalimide-terminated oligomer; and (ii) capping the phthalimide-terminated oligomer by mixing an amino-substituted cyclic reactant with the phthalimide-terminated oligomer in a molar ratio of at least about 2:1 and reacting at high temperature for at least about 12 h.

[0057] (b) Combining the prepolymer with at least one photopolymerizable olefinic monomer, at least one photoinitiator, and a diamine to form a curable resin composition;

[0058] (c) Providing the curable resin composition as a layer on a substrate; and

[0059] (d) Irradiating the layer under conditions that enable the polymerization of the olefinic monomer and provide a polyolefin within a scaffold layer, the scaffold layer comprising the prepolymer and the polyolefin, wherein the diamine is physically trapped within the scaffold layer.

[0060] In another embodiment, the present invention provides a photocurable composition prepared by irradiating a photocurable resin composition with photochemical radiation that can effectively cure a photopolymerizable olefinic monomer, wherein the photocurable resin composition comprises a capped and imide-terminated prepolymer, at least one of the photopolymerizable olefinic monomers, at least one photoinitiator, and a diamine.

[0061] In another embodiment, the present invention provides a solid material composition prepared by the following steps: (a) irradiating a curable resin composition with photochemical radiation of a wavelength capable of effectively curing a photopolymerizable olefinic monomer, thereby providing a photocurable composition comprising a capped end-imide prepolymer, at least one photopolymerizable olefinic monomer, at least one photoinitiator, and a diamine; and

[0062] (b) The photocurable composition is heat-treated by heating under conditions that promote the transimidization reaction between the capped terminal imide prepolymer and the diamine. Detailed Implementation

[0063] 1. Naming and Overview

[0064] Unless otherwise defined, all technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains. Specific terms that are particularly important in describing this invention will be defined below.

[0065] In this specification and claims, the singular forms “a” and “the” include plural references unless the context clearly indicates otherwise. Thus, for example, “a prepolymer” refers not only to a single prepolymer but also to a combination of two or more different prepolymers, “a diamine” refers to a single diamine or a combination of diamines, and so on.

[0066] The phrases “having a form” or “having a structure” as used in this document are not used for limitation, but rather in the same way that the term “including” is typically used.

[0067] As used herein, the term "alkyl" refers to a branched or unbranched saturated hydrocarbon group containing 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, octyl, decyl, etc., and also refers to cycloalkyl, such as cyclopentyl, cyclohexyl, etc. Typically (but not always), alkyl groups as used herein contain 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms. The term "lower alkyl" refers to an alkyl group containing 1 to 6 carbon atoms. Preferred lower alkyl substituents contain 1 to 3 carbon atoms, and particularly preferred such substituents contain 1 or 2 carbon atoms (i.e., methyl and ethyl). "Substituted alkyl" refers to an alkyl group substituted with one or more substituents, and "heteroatom-containing alkyl" and "heteroalkyl" refer to an alkyl group in which at least one carbon atom is substituted with a heteroatom (e.g., O, S, or N). Unless otherwise specified, the terms "alkyl" and "lower alkyl" respectively include straight-chain, branched, cyclic, unsubstituted, substituted, and / or heteroatom-containing alkyl or lower alkyl groups.

[0068] As used herein, the term "alkylene" refers to a bifunctional, straight-chain, branched, or cyclic saturated hydrocarbon group containing 1 to 24 carbon atoms, such as methylene, ethylene, n-propylene, n-butylene, n-hexylene, decylene, tetradecylene, hexadecylene, etc. Preferred alkylene groups contain 1 to 12 carbon atoms, and the term "lower alkylene" refers to an alkylene group containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms. The term "substituted alkylene" refers to an alkylene group substituted with one or more substituents, i.e., a hydrogen atom is substituted by a non-hydrogen substituent; the terms "heteroatom-containing alkylene" and "heteroalkylene" refer to alkylene groups in which at least one carbon atom is substituted with a heteroatom. Unless otherwise specified, the terms "alkylene" and "lower alkylene" include linear, branched, cyclic, unsubstituted, substituted, and / or heteroatom-containing alkylene and lower alkylene, respectively. Oligomeric and polymeric "alkylene" are also contemplated herein, for example, substituted or unsubstituted optional heteroatom-containing poly(ethylene) (polyethylene).

[0069] As used herein, the term "alkenyl" refers to a straight-chain, branched, or cyclic hydrocarbon group containing at least one double bond and having 2 to 24 carbon atoms, such as vinyl, n-propenyl, isopropenyl, n-butenyl, isobutenyl, octenyl, decenyl, tetradecenyl, hexadecenyl, octadecenyl, tetratetradecenyl, etc. Typically (but not always), alkenyl groups as used herein contain 2 to 18 carbon atoms, preferably 2 to 12 carbon atoms. The term "lower alkenyl" refers to an alkenyl group containing 2 to 6 carbon atoms, and "cycloalkenyl" refers to a cyclic alkenyl group, preferably having 5 to 8 carbon atoms. The term "substituted alkenyl" refers to an alkenyl group substituted by one or more substituents, and the terms "heteroatom-containing alkenyl" and "heteroalkenyl" refer to an alkenyl group in which at least one carbon atom is substituted by a heteroatom. Unless otherwise specified, the terms "alkenyl" and "lower alkenyl" include straight-chain, branched, cyclic, unsubstituted, substituted, and / or heteroatom-containing alkenyl and lower alkenyl, respectively.

[0070] As used herein, the term "alkenyl" refers to a bifunctional linear, branched, or cyclic hydrocarbon bond containing 2 to 24 carbon atoms, such as vinylene, n-propenylene, isopropenylene, n-butenylene, isobutenylene, octeneylene, deceneylene, tetradeceneylene, hexadeceneylene, octadeceneylene, tetratetradeceneylene, etc. Preferred alkenyl bonds contain 2 to 12 carbon atoms. The term "lower alkenyl" refers to an alkenyl bond containing 2-6 carbon atoms, preferably 2-4 carbon atoms. The term "substituted alkenyl" refers to an alkenyl bond substituted by one or more substituents, i.e., a hydrogen atom is substituted by a non-hydrogen substituent. The terms "heteroatom-containing alkenyl" and "heteroalkenyl" refer to alkenyl bonds in which at least one carbon atom is substituted by a heteroatom. Unless otherwise specified, the terms “alkenyl” and “lower alkenyl” include linear, branched, cyclic, unsubstituted, substituted, and / or heteroatom-containing alkenyl and lower alkenyl groups, respectively. Oligomeric and polymeric “alkenyl bonds” are also contemplated herein, for example, substituted or unsubstituted optional heteroatom-containing poly(vinylene) linking groups that can form the backbone of an oligomer or polymer bridging two end groups.

[0071] Unless otherwise stated, the term "aryl" as used herein refers to an aromatic substituent containing a single aromatic ring, or multiple aromatic rings fused together, directly or indirectly linked (such that different aromatic rings are bonded to a common group, e.g., a methylene or ethylene moiety). Preferably, the aryl group contains 5 to 24 carbon atoms, and particularly preferably, 5 to 14 carbon atoms. Exemplary aryl groups contain one aromatic ring or two fused or linked aromatic rings, such as phenyl, naphthyl, biphenyl, diphenyl ether, diphenylamine, benzophenone, etc. "Substituted aryl" refers to an aryl moiety substituted with one or more substituents, and the terms "heteroatom-containing aryl" and "heteroaryl" refer to aryl substituents in which at least one carbon atom is substituted with a heteroatom, as will be further detailed below. Unless otherwise stated, the term "aryl" includes unsubstituted, substituted, and / or heteroatom-containing aromatic substituents.

[0072] The term "arylene" refers to a divalent aromatic group containing one to three fused or linked aromatic rings that are either unsubstituted or substituted by one or more substituents. Unless otherwise stated, the term "arylene" includes substituted arylene groups and / or heteroatom-containing arylene groups.

[0073] The term "alkylaryl" refers to an aryl group having an alkyl substituent, and the term "aralkyl group" refers to an alkyl group having an aryl substituent, wherein "aryl" and "alkyl" are as defined above. Preferably, aralkyl groups contain 6 to 24 carbon atoms, and particularly preferably, aralkyl groups contain 6 to 16 carbon atoms. Examples of aralkyl groups include, but are not limited to, benzyl, 2-phenyl-ethyl, 3-phenyl-propyl, 4-phenyl-butyl, 5-phenyl-pentyl, 4-phenylcyclohexyl, 4-benzylcyclohexyl, 4-phenylcyclohexylmethyl, 4-benzylcyclohexylmethyl, etc. Alkylaryl groups include, for example, p-tolyl, 2,4-xylyl, p-cyclohexylphenyl, 2,7-dimethylnaphthyl, 7-cyclooctylnaphthyl, 3-ethyl-cyclopent-1,4-diene, etc. The terms "alkylaryloxy" and "aralkyloxy" refer to a substituent of the formula -OR, wherein R is an alkylaryl or aralkyl group as defined above.

[0074] The term "acyl" refers to a substituent having the formula -(CO)-alkyl, -(CO)-aryl, or -(CO)-aralkyl, and the term "acyloxy" refers to a substituent having the formula -O(CO)-alkyl, -O(CO)-aryl, or -O(CO)-aralkyl, wherein "alkyl", "aryl", and "aralkyl" are as defined above.

[0075] The term "cyclic" refers to an alicyclic or aromatic substituent that may or may not be substituted and / or contains heteroatoms; it may be monocyclic, bicyclic, or polycyclic.

[0076] The term "alicyclic" is used in its conventional sense to refer to the aliphatic ring portion, which is different from the aromatic ring portion; it can be monocyclic, bicyclic, or polycyclic. Alicyclic compounds or substituents may contain heteroatoms and / or be substituted, but are usually unsubstituted and do not contain heteroatoms, i.e., they are carbocyclic.

[0077] The term "heteroatom-containing" in "heteroatom-containing alkyl" (also known as "heteroalkyl") or "heteroatom-containing aryl" (also known as "heteroaryl") refers to a molecule, linking group, or substituent in which one or more carbon atoms are replaced by atoms other than carbon. The atoms other than carbon are, for example, nitrogen, oxygen, sulfur, phosphorus, or silicon, typically nitrogen, oxygen, or sulfur, preferably nitrogen or oxygen. Similarly, the term "heteroalkyl" refers to an alkyl substituent containing heteroatoms, the term "heterocyclic" refers to a cyclic substituent containing heteroatoms, and the terms "heteroaryl" and "aromatic heterocyclic" refer to "aryl" and "aromatic" substituents containing heteroatoms, respectively, and so on. Examples of heteroalkyl groups include alkoxyaryl, alkylsulfanyl-substituted alkyl groups, N-alkylated aminoalkyl groups, etc. Examples of heteroaryl substituents include pyrrolidinyl, pyrrolidinyl, pyridinyl, quinolinyl, indolyl, pyrimidinyl, imidazoleyl, 1,2,4-triazolyl, tetrazolyl, etc., and examples of alicyclic groups containing heteroatoms include pyrrolidinyl, morpholinyl, piperazineyl, piperidinyl, etc.

[0078] "Hydrocarbon group" refers to a monovalent hydrocarbon group containing 1 to 30 carbon atoms, preferably 1 to 24 carbon atoms, more preferably 1 to 18 carbon atoms, and most preferably about 1 to 12 carbon atoms, including straight-chain, branched, cyclic, saturated and unsaturated groups, such as alkyl, alkenyl, aryl, etc. "Substituted hydrocarbon group" refers to a hydrocarbon group substituted by one or more substituents, and the term "heteroatom-containing hydrocarbon group" refers to a hydrocarbon group in which at least one carbon atom is substituted by a heteroatom. Unless otherwise stated, the term "hydrocarbon group" should be interpreted as including substituted and / or heteroatom-containing hydrocarbon groups.

[0079] The term "hydroalkyl group" refers to a divalent hydrocarbon moiety containing 1 to 24 carbon atoms, most preferably 1 to 12 carbon atoms, including straight-chain, branched, cyclic, saturated, and unsaturated groups. The term "lower hydrocarbon group" refers to a hydrocarbon group containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms. The term "substituted hydrocarbon group" refers to a hydrocarbon group substituted by one or more substituents. The terms "heteroatom-containing hydrocarbon group" and "heteroatom-containing hydrocarbon group" refer to hydrocarbon groups in which at least one carbon atom is substituted by a heteroatom. Similarly, "substituted hydrocarbon group" refers to a hydrocarbon group substituted by one or more substituents, and the terms "heteroatom-containing hydrocarbon group" and "heteroatom-containing hydrocarbon group" refer to hydrocarbon groups in which at least one carbon atom is substituted by a heteroatom. Unless otherwise stated, the terms "hydrocarbon group" and "hydroalkyl group" should be interpreted as including substituted and / or heteroatom-containing hydrocarbon and hydrocarbon group moiety, respectively. It is also envisioned that oligomeric and polymeric alkylene groups, including heteroatom-containing alkylene groups, such as poly(ethylene oxide), and their substituted analogues.

[0080] When a functional group is referred to as “protected” or “terminated,” such as in a “terminated” group, it means that the group is in a modified form to exclude undesirable reactions and / or promote desired reactions. Suitable protecting groups for the compounds of this invention will be determined from this application, taking into account the level of skill in the art and with reference to standard textbooks (e.g., Greene et al., Protective Groups in Organic Synthesis (New York: Wiley, 1991)).

[0081] In the aforementioned definitions, the term "substituted" in simple terms such as "substituted alkyl" and "substituted aryl" refers to a group in which at least one hydrogen atom bonded to a carbon (or other) atom in the alkyl, aryl, or other moiety is replaced by one or more non-hydrogen substituents. Examples of such substituents include, but are not limited to, functional groups such as halogens, hydroxyl groups, mercapto groups, and C1-C6 groups. 24 Alkoxy, C2-C 24 Alkenyl groups, C2-C 24 Acryloxy group, C5-C 24 Aryloxy groups, acyl groups (including C2-C) 24 Alkyl carbonyl (-CO-alkyl) and C 6- C 24 aryl carbonyl (-CO-aryl)), acyloxy (-O-acyl), C2-C 24 Alkoxycarbonyl (-(CO)-O-alkyl), C6-C 24 Aryloxycarbonyl (-(CO)-O-aryl), halocarbonyl (-(CO)-X, where X is a halogen), C2-C 24 Alkyl carbonate (-O-(CO)-O-alkyl), C6-C 24aryl carbonate (-O-(CO)-O-aryl), carboxyl (-COOH), carboxylato (-COO-), carbamoyl (-(CO)-NH2), mono-(C1-C 24 alkyl)-substituted carbamoyl (-(CO)-NH(C1-C) 24 Alkyl), bis-(C1-C) 24 alkyl)-substituted carbamoyl (-(CO)-N(C1-C) 24 Alkyl)2), mono-(C6-C) 24 aryl)-substituted carbamoyl (-(CO)-NH-aryl), bis-(C6-C) 24 aryl-substituted carbamoyl (-(CO)-N(aryl)2), bis-N-(C1-C 24 alkyl), N-(C6-C) 24 Aryl-substituted carbamoyl, thiocarbamoyl (-(CS)-NH2), urea (-NH-(CO)-NH2), cyano (-C≡N), isocyano (-N) + ≡C - -), cyanooxy (-OC≡N), isocyanooxy (-ON) + ≡C - -), isothiocyano (-SC≡N), azide (-N=N) + ≡N - ), formyl (-(CO)-H), thioaldehyde (-(CS)-H), amino (-NH2), mono-(C1-C) 24 alkyl)-substituted amino, bis-(C1-C) 24 Alkyl)-substituted amino, mono-(C5-C) 24 aryl)-substituted amino groups, bis-(C5-C) 24 aryl-substituted amino groups, C2-C 24 Alkylamide group (-NH-(CO)-alkyl), C6-C 24 Aryl amide group (-NH-(CO)-aryl), imino group (-CR=NH, where R is hydrogen, C1-C) 24 Alkyl, C5-C 24 Aryl, C6-C 24 Alkyl, C6-C 24 Aryl alkyl, etc.), alkyl imino (-CR=N(alkyl), where R is hydrogen, C1-C 24 Alkyl, C5-C 24 Aryl, C6-C 24 Alkyl, C6-C 24 Arylalkyl, etc.), arylimino (-CR=N(aryl), where R is hydrogen, C1-C 24Alkyl, C5-C 24 Aryl, C6-C 24 Alkyl, C6-C 24 Aryl groups, nitro groups (-NO2), nitroso groups (-NO), sulfonyl groups (-SO2-OH), sulfonic acid groups (-SO2-O-), C1-C 24 Alkylthioalkyl (-S-alkyl; also known as "alkathio"), arylthioalkyl (-S-aryl; also known as "arylthio"), C1-C 24 alkylsulfinyl (-(SO)-alkyl), C5-C 24 arylsulfinyl (-(SO)-aryl), C1-C 24 alkylsulfonyl (-SO2-alkyl), C5-C 24 Arylsulfonyl (-SO2-aryl), phosphonyl (-P(O)(OH)2), phosphonic acid (-P(O)(O-)2), phosphonite (-P(O)(O-)), dioxophosphoric (-PO2), and phosphonic (-PH2); and hydrocarbon moiety C1-C 24 Alkyl (preferably C1-C) 18 Alkyl, more preferably C1-C 12 Alkyl groups, most preferably C1-C6 alkyl groups, C2-C 24 Alkenyl (preferably C2-C) 18 Alkenyl, more preferably C2-C 12 Alkenyl, preferably C2-C6 alkenyl), C2-C 24 Alkyne group (preferably C2-C) 18 Alkyne group, more preferably C2-C 12 Alkyne group, preferably C2-C6 alkyne group), C5-C 24 Aryl (preferably C5-C) 14 Aryl), C6-C 24 Alkyl (preferably C6-C) 18 alkylaryl), and C6-C 24 Aryl alkyl group (preferably C6-C) 18 Aryl groups).

[0082] Furthermore, the aforementioned functional group may (if a particular group allows) be further replaced by one or more additional functional groups or one or more hydrocarbon moieties, such as those specifically listed above. Similarly, the aforementioned hydrocarbon moieties may be further replaced by one or more functional groups or additional hydrocarbon moieties, such as those specifically listed above.

[0083] The term "polymer" is used to refer to a compound comprising linked monomers, which can be linear, branched, or cross-linked. The term also includes homopolymers, copolymers, terpolymers, tetrpolymers, etc. Any polymer identified as containing more than one type of repeating unit (i.e., copolymer, terpolymer, tetrpolymer, etc.) is not intended to limit its configuration. That is, for example, copolymers in this document can be block copolymers, alternating copolymers, random copolymers, and terpolymers can be block copolymers, random copolymers, etc. The term "oligomer" refers to a low molecular weight linear polymer that can participate in one or more reactions with itself or other compounds (e.g., monomers and / or other oligomers) to form higher molecular weight polymer structures.

[0084] When the term "substituted" appears before a series of possible substituted groups, it means that the term applies to each group in that series. For example, "substituted alkyl, alkenyl, and aryl" should be interpreted as "substituted alkyl, substituted alkenyl, and substituted aryl". Similarly, when the term "heteroatomic" appears before a series of possible heteroatomic groups, it means that the term applies to each group in that series. For example, "heteroatomic alkyl, alkenyl, and aryl" should be interpreted as "heteroatomic alkyl, heteroatomic alkenyl, and heteroatomic aryl".

[0085] The terms "optional" or "optionally" mean that the situation described below may or may not occur, and therefore the description includes both the case where the situation occurs and the case where the situation does not occur. For example, "optionally substituted" means that a non-hydrogen substituent may or may not be present on a given atom, and therefore the description includes structures with and without a non-hydrogen substituent. Similarly, a bond "optionally present" as indicated by dashed lines in the chemical formulas herein means that a bond may or may not be present.

[0086] In one embodiment, the present invention provides a curable resin composition by combining (i) a capped, imide-terminated prepolymer with (ii) a photopolymerizable olefinic monomer, (iii) at least one photoinitiator, and (iv) a diamine; in another embodiment, the present invention provides a method for synthesizing the capped, imide-terminated prepolymer. The curable resin composition can be used in a dual-curing method for forming a solid polymeric structure, for example, in the context of additive manufacturing processes or other 3D printing methods. A first step of the dual-curing method includes irradiating the curable resin composition under conditions that effectively polymerize the olefinic monomer and provide a polyolefin within a scaffold, the scaffold comprising the prepolymer and the polyolefin, wherein the diamine is physically trapped within the scaffold. In a second step, the photocurable composition, i.e., the scaffold formed by photopolymerization, is heat-treated under conditions that effectively promote the transimidization reaction between the prepolymer and the diamine, thereby releasing the end groups of the prepolymer and providing a final polymeric structure with excellent mechanical properties and optimal surface characteristics.

[0087] 2. Photocurable resin composition

[0088] A. Prepolymer:

[0089] The capped terminal imide prepolymer has the structure of formula (I):

[0090] (I)

[0091] in,

[0092] L comprises an oligoalkylene moiety and may be unsubstituted, substituted with one or more non-carbon, non-hydrogen substituents and / or functional groups as described in Section 1 of this Specific Embodiments, contain heteroatoms, or be both substituted and contain heteroatoms. Thus, L may be alkylene, substituted alkylene, heteroalkylene, or substituted alkylene, wherein any heteroatoms present are typically selected from nitrogen, oxygen, and sulfur, but most typically oxygen atoms. An example of alkylene L is polyethylene in an oligomeric form, and an example of heteroalkylene L is poly(ethylene oxide) in an oligomeric form, such that L are respectively:

[0093]

[0094] Wherein, n represents the number of monomer units contained in L. The number of monomer units is typically chosen such that the prepolymer has a weight-average molecular weight of about 500 to about 5000, typically about 1000 to about 3000.

[0095] Ar is an aryl group, as described in the previous section, including unsubstituted aryl, substituted aryl, heteroaryl, and substituted heteroaryl groups. Ar can be monocyclic, bicyclic, or polycyclic, and if it is bicyclic or polycyclic, the rings are fused or linked together. The two Ar moieties shown in formula (I) can be the same or different, but are usually the same. When Ar is phenyl, the prepolymer has the structure of formula (II):

[0096] (II)

[0097] In equation (II), it can be seen that the two end bases are controlled by R. 2 Or R 4 N-substituted phthalimide moiety, wherein R 2 and R 4 This refers to the imide-capped group removed during the transimide reaction. In other words, R... 2 and R 4 The following transimide reaction is chosen such that it can be carried out under heating (this reaction is shown in a simplified form for illustrative purposes, where only one end of the prepolymer and the monofunctional R-NH2 reactant are shown instead of the diamine):

[0098]

[0099] imide-terminated group R 2 and R 4 Generally the same, to promote prepolymer synthesis, as described below. However, it should be understood that the present invention does not require R... 2 With R 4 same.

[0100] R 1 and R 3 The linker is an optional non-oligomeric linker, provided that r and q are independently selected from 0 and 1. With the end-capping group R 2 and R 4 Similarly, preferred (but not necessarily): r and q are the same, and when r and q are 1, R 1 and R 3 The same.

[0101] In some embodiments, R 1 and R 3 The presence of phthalimide groups gives the prepolymer the structure of formula (III):

[0102] (III)

[0103] Wherein, s and t are independently selected from 0 and 1, but in a preferred embodiment, s and t are the same. X and Y are independently selected from O, S, and lower alkylene groups (e.g., substituted or unsubstituted methylene, ethylene, n-propylene, or n-butylene), but preferably X and Y are the same. When s and t are 0, the prepolymer of formula (III) has the structure of formula (IV):

[0104] (IV)

[0105] When L is poly(ethylene oxide), the prepolymer of formula (IV) has the structure shown in formula (V):

[0106] (v)

[0107] When L is polyethylene, it should be understood that the prepolymer of formula (IV) has the structure of formula (VI):

[0108]

[0109] When s and t are 1 and X and Y are both 0, the prepolymer of formula (III) has the structure of formula (VII):

[0110]

[0111] When L is poly(ethylene oxide) or polyethylene, the prepolymer of formula (VII) has the structure of formula (VIII) or formula (IX), respectively:

[0112]

[0113] The imide-terminated group R as described above 2 and R 4 The selection is made to enable transimide hydration with the diamine. Any such end-capping groups may be used advantageously herein, provided they promote transimide hydration and do not adversely interact with any component of the curable resin composition and have an adverse effect on the final product.

[0114] In some embodiments, R 2 and R 4The end-capping portion is identical, being a five- to six-membered cyclic group containing 1-4, preferably 1-3, most preferably 1 or 2 heteroatoms, wherein at least one heteroatom is a nitrogen atom, and the cyclic nitrogen of the phthalimide group is directly bonded to the carbon atom of the end-capping portion. Examples of such end-capping portions include, but are not limited to: nitrogen-containing heterocyclic substituents, such as pyridinyl, dipyridinyl, pyridazinyl, pyrazinyl, bipyridaminyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, pyrroleyl, 2H-pyrroleyl, 3H-pyrroleyl, pyrazolyl, 2H-imidazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, indoleyl, 3H-indoleyl, 1H-isoindoleyl, cyclopentadienyl(b)pyridinyl (cyclopen) The preferred nitrogen-containing heterocycles suitable as imide end groups are aryl groups, including pyrrole, imidazolyl, quinolinyl, isoquinolinyl, diisoquinolinyl, cyclopentinyl, quinazolinyl, naphthidyl, piperidinyl, piperazinyl, pyrrolyl, pyrazolyl, quinuclidinyl, imidazolyl, picolyliminyl, purine, benzimidazolyl, bisimidazolyl, phenazinyl, acridineyl, and carbazoleyl.

[0115] R 2 and R 4 Representative prepolymers of the present invention that are pyrimidine-based are shown in the following formulas (X)-(XIII):

[0116]

[0117] Ideally, the weight-average molecular weight of the prepolymer is about 500 to about 5000, typically about 1000 to about 3000.

[0118] B. Photopolymerizable olefinic monomers

[0119] The photopolymerizable olefinic monomer is used as a reactive diluent and polymerized under irradiation, thereby promoting the formation of a stable and uniform network or scaffold, which can then be heat-treated to form the final polymerized product. In some embodiments, the polymerizable olefinic monomer used as a reactive diluent is an acrylate or methacrylate monomer. In other embodiments, the olefinic monomer includes vinyl esters, such as vinyl acetate; vinyl chloride; vinyl alcohol; vinyltoluene; styrene; acrylonitrile; propylene; butadiene; cyclohexene; or divinylbenzene. It should be understood that the foregoing monomers are illustrative and not limiting; in fact, any photopolymerizable olefinic monomer can be advantageously combined with the present invention.

[0120] In some embodiments, the polymerizable olefinic monomer described above is an acrylate or methacrylate monomer, which may be monofunctional, difunctional, or polyfunctional.

[0121] "Monofunctional" means that the acrylate or methacrylate monomer has an alkenyl functional group, which is a double bond contained in the acrylate moiety (i.e., =CH2 on the carbonyl α-carbon atom), but the monomer may include one or more aryl moieties. The term "acrylate monomer" as used herein includes acrylates and methacrylates, i.e., esters of acrylic acid and methacrylic acid, respectively, and also includes higher acrylates, such as ethyl acrylate, butyl acrylate, etc. However, in some embodiments, methacrylates are preferred over acrylates, provided that the photopolymerization reaction (1) is carried out in a more controlled manner than with methacrylate monomers, and (2) ultimately produces a product with more desirable mechanical properties and surface finish.

[0122] In one embodiment, the photopolymerizable monofunctional acrylate monomer has the structure of the following formula (XIV):

[0123] (XIV)

[0124] Among them, R 5 The presence of H or methyl groups allows the monomer to be either an acrylate or a methacrylate, respectively; R 6 For C1-C 36 Hydrocarbon group, substituted C1-C 36 Hydrocarbon groups, C1-C containing heteroatoms 36 Hydrocarbon group or substituted C1-C containing heteroatoms 36 Hydrocarbon group, and usually C1-C 24 Hydrocarbon group, substituted C1-C 24 Hydrocarbon groups, C1-C containing heteroatoms 24 Hydrocarbon group or substituted C1-C containing heteroatoms 24 Hydrocarbon groups, for example, C2-C16 Hydrocarbon group, substituted C2-C 16 Hydrocarbon group, C2-C containing heteroatoms 16 Hydrocarbon group or substituted C2-C containing heteroatoms 16 Hydrocarbon group; or, C4-C 12 Hydrocarbon group, substituted C4-C 12 Hydrocarbon group, C4-C containing heteroatoms 12 Hydrocarbon group or substituted C4-C containing heteroatoms 12 Hydrocarbon group. As an example, among the categories mentioned above, R... 5 It can be C1-C 36 Alkyl, substituted C1-C 36 Alkyl groups, C1-C groups containing heteroatoms 36 Alkyl groups or substituted C1-C groups containing heteroatoms 36 Alkyl groups, and typically C1-C. 24 Alkyl, substituted C1-C 24 Alkyl groups, C1-C groups containing heteroatoms 24 Alkyl or substituted C1-C containing heteroatoms 24 Alkyl groups, for example, C2-C 16 Alkyl, substituted C2-C 16 Alkyl groups, C2-C groups containing heteroatoms 16 Alkyl or substituted C2-C containing heteroatoms 16 Alkyl, or C4-C 12 Alkyl, substituted C4-C 12 Alkyl groups, C4-C groups containing heteroatoms 12 Alkyl or substituted and containing heteroatoms C4-C 12 Alkyl group. As described above, R 5 The portion can also be aryl, including unsubstituted aryl, substituted aryl, heteroaryl, substituted heteroaryl, unsubstituted aralkyl, substituted aralkyl, heteroaryl, substituted heteroaryl, for example, C5-C 36 Unsubstituted aryl, substituted C5-C 36 Aryl, C2-C 36 heteroaryl, substituted C2-C 36 heteroaryl, unsubstituted C6-C 36 Aryl groups, substituted C6-C 36 Aryl alkyl, C3-C 36 Heteroaryl, substituted C3-C 36 Heteroalkyl groups, typically C5-C 24 Unsubstituted aryl, substituted C5-C 24 Aryl, C2-C 24 heteroaryl, substituted C2-C24 heteroaryl, unsubstituted C6-C 24 Aryl groups, substituted C6-C 24 Aryl alkyl, C3-C 24 Heteroaryl, substituted C3-C 24 Heteroalkyl groups, for example, C5-C 16 Unsubstituted aryl, substituted C5-C 16 Aryl, C2-C 16 heteroaryl, substituted C2-C 16 heteroaryl, unsubstituted C6-C 16 Aryl groups, substituted C6-C 16 Aryl alkyl, C3-C 16 Heteroaryl, substituted C3-C 16 Heteroaryl, or C5-C 12 Unsubstituted aryl, substituted C5-C 12 Aryl, C2-C 12 heteroaryl, substituted C2-C 12 heteroaryl, unsubstituted C6-C 12 Aryl groups, substituted C6-C 12 Aryl alkyl, C3-C 12 Heteroaryl, substituted C3-C 12 Heteroalkyl groups. The heteroatom is usually N or O, and the aryl group is usually (but not necessarily) monocyclic, but fused and linked bicyclic or tricyclic groups can also be imagined.

[0125] In some embodiments, R 6 Includes the C6-C36 alicyclic portion, typically a bridging (two or more rings) C6-C 36 The alicyclic moiety can be substituted and / or contain heteroatoms. Therefore, R 6 This includes optionally substituted and / or heteroatom-containing C6-C24 and C6-C16 alicyclic groups. Suitable as R 5 Non-limiting examples of such groups include adamantyl, 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl, 5-hydroxy-2-methyl-2-adamantyl, 5-hydroxy-2-ethyl-2-adamantyl, 1-methyl-1-adamantylethyl, 2-methyl-2-norbornyl, 2-ethyl-2-norbornyl, 1,2,7,7-tetramethyl-2-norbornyl, isobornyl, etc.

[0126] Therefore, specific examples of photocurable monofunctional acrylate and methacrylate monomers include, but are not limited to: isobornyl acrylate, isobornyl methacrylate, adamantane acrylate, adamantane methacrylate, isodecanyl acrylate, isodecanyl methacrylate, lauryl acrylate, lauryl methacrylate, 3,3,5-trimethylcyclohexane acrylate, 3,3,5-trimethylcyclohexane methacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, 2-(2-ethoxyethoxy)ethyl methacrylate, cyclic trimethylolpropane formal acrylate, cyclic trimethylolpropane formal methacrylate, tetrahydrofuran acrylate, tetrahydrofuran methacrylate, tridecane acrylate, tridecane methacrylate, 2-phenoxyethyl acrylate, and 2-phenoxyethyl methacrylate. Other examples will be apparent to those skilled in the art or can be found in relevant texts and literature. For example, see U.S. Patent No. 7,041,846 to Watanabe et al., the disclosure of which regarding monofunctional acrylates and methacrylate monomers is incorporated herein.

[0127] The difunctional acrylate and methacrylate portions that can be used in conjunction with the methods and compositions of the present invention include tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, tricyclodecanediethanol diacrylate, diethylene glycol dimethacrylate, dipropylene glycol diacrylate, difunctional glycol acrylate, ethoxylated bisphenol A diacrylates, propyoxylated neopentyl glycol diacrylates, neopentyl glycol diacrylate, and ethylene glycol dimethacrylate, while examples suitable for use with the polyfunctional acrylates and methacrylates described herein include trimethylpropane triacrylate and trimethylpropane trimethacrylate. Trimethacrylate, ethoxylated trimethylpropane triacrylate, propoxylated glycerol triacrylate, tris-(2-hydroxyethyl)isocyanurate triacrylate, pentaerythritol triacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane triacrylate (TMPTA), di(trimethylolpropane)tetraacrylate, dipentaerythritol hexaacrylate, and dipentaerythritol hexaacrylate.

[0128] C. Polymerization initiator

[0129] Another component of the curable resin composition is a photopolymerization initiator or "photoinitiator". Since the initiation step in the dual-curing process requires the photopolymerization of the olefinic monomer, the curable resin composition includes at least one photoinitiator, i.e., a free radical photoinitiator. As an example, this free radical photoinitiator may be, but is not limited to, acylphosphine oxides, such as 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide. (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (TEPO), (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (TPO), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, etc.; α-hydroxy ketones, such as 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxy-cyclohexylbenzophenone, 2-hydroxy-2-methyl-lp-hydroxyethyl ether phenylpropanone, etc.; diaryl ketones, such as benzophenone, 2,2-dimethoxy-2-diphenylethyl ketone (DMPA), or benzoyl peroxide; azobisisobutyronitrile (AIBN); or oxime esters, such as those from BASF under the trademark name Irgacure.

[0130] D. diamine

[0131] The diamine reactant or "chain extender" is selected to undergo transimidization with the imide-terminated prepolymer during heat treatment of the UV-curable resin composition. The diamine has the structure of the following formula (XV):

[0132] (XV)H2N-L 1 -NH2

[0133] Among them, L 1 For C2-C 14 Hydroxyl groups, including unsubstituted, substituted, heteroatom-containing, and substituted C2-C containing heteroatoms. 14 Hydroxyl group. Typically, L... 1 For unreplaced C2-C 14 Alkylene, such that the diamine is 1,3-propanediamine, 1,2-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine, or 4,4'-diaminodicyclohexylmethane.

[0134] E. Additives:

[0135] The curable resin composition may include any additives to facilitate the curing process and impart one or more advantageous properties to the final product. Examples of such additives include: toughening agents; fillers; stabilizers; non-reactive light absorbers; polymerization inhibitors; colorants, including dyes and pigments; thickeners; detectable compounds (e.g., radioactive or luminescent compounds); metal powders or fibers or other conductive materials; semiconductor microparticles or fibers; magnetic materials; flame retardants; and so on. Preferred additives are those described in U.S. Patent No. 9,598,608 to Rolland et al., the contents of which are incorporated herein by reference.

[0136] 3. New material compositions

[0137] In one embodiment, the present invention provides a curable resin composition as a novel material composition, wherein the composition comprises: (i) a capped and imide-terminated prepolymer; (ii) at least one photopolymerizable olefinic monomer; (iii) at least one photoinitiator; and (iv) a diamine, wherein each component is as defined in A to E above.

[0138] In another embodiment, the present invention provides a photocurable composition prepared by irradiating the curable resin composition with photochemical radiation of a wavelength capable of effectively curing the photopolymerizable olefinic monomer.

[0139] In another embodiment, the present invention provides a solid material composition prepared by the following steps: (a) irradiating the curable resin composition with photochemical radiation of a wavelength capable of effectively curing the photopolymerizable olefinic monomer; and (b) heat-treating the photocurable composition provided in step (a) by heating under conditions that promote the transimidization reaction between the capped terminal imide prepolymer and the diamine.

[0140] 4. Other embodiments

[0141] The present invention also includes other embodiments in which prepolymers other than end-capped imide prepolymers are used. The method for forming a 3D sample from such other prepolymers is similar to the method described above for the end-capped imide prepolymers. That is, the selected prepolymer is combined with at least one photopolymerizable olefinic monomer, at least one photoinitiator, and a diamine to form a curable resin composition. The composition is irradiated under conditions that effectively allow the at least one photopolymerizable olefinic monomer to form a scaffold comprising the prepolymer and a polyolefin, wherein the diamine is physically trapped within the scaffold. The irradiated scaffold is then heat-treated at a temperature that effectively allows the prepolymer and the diamine to crosslink, providing a solid polymeric structure.

[0142] One such example is illustrated in Example 3 of the Experimental Section of this paper. This example describes the preparation of a photocurable ester amide prepolymer, which is then mixed with cyclic trimethylolpropane-formaldehyde acrylate as a photopolymerizable monomer and a photoinitiator TPO. After complete mixing, a selected diamine and 4,4'-diaminocyclohexylmethane are added. The resulting stirred resin mixture is then irradiated to polymerize the acrylate monomer, followed by heating to crosslink the prepolymer with the diamine.

[0143] The photocurable esteramide prepolymer can be represented by the structure of the following formula (XVI):

[0144] (XV / I)

[0145] The substituents are as follows:

[0146] R 8 and R 11 The substituent is a relatively large substituent, typically comprising an optionally substituted, optionally heteroatom-containing hydrocarbon group, which may be alkyl, aryl, etc. In some embodiments, R 8 and R 11 Hydrocarbon groups including 3-12 carbon atoms, such as isopropyl, tert-butyl, cyclohexyl, etc. 8 and R 11 They can be the same or different, but they are usually the same because this allows for a simpler synthesis method.

[0147] R 9 and R 10 It is a bifunctional hydrocarbon group comprising 1 to 24 carbon atoms, typically 2 to 12, and may be substituted and / or contain heteroatoms. For example, R 9 and R 10 It can be a substituted or unsubstituted lower alkylene or phenylene; if it is phenylene, the linker is usually in the form of a p-phenylene linkage.

[0148] L 2 It is a oligomeric hydrocarbon linking group, which can be substituted or unsubstituted. L 2 For the definition of L, see Section 2(A) of this Detailed Description section. Therefore, it is suitable to use L. 2 The part is the same as those suitable for use as L.

[0149] As another example, the prepolymer may be anhydride-terminated, having the structure of formula (XVII):

[0150] (XVII)

[0151] Among them, L 3As defined by L.

[0152] The present invention also includes a dual-curing method for forming a solid polymer structure, wherein the method comprises:

[0153] (a) Combining (i) a prepolymer having end groups that covalently react with a monoamine upon heating with (ii) at least one photopolymerizable olefinic monomer, (iii) at least one photoinitiator and (iv) a diamine to form a curable resin composition.

[0154] (b) Irradiating the resin composition under conditions that enable efficient polymerization of the at least one olefinic monomer and provision of a polyolefin within a scaffold, the scaffold comprising the prepolymer and the polyolefin, wherein the diamine is physically trapped within the scaffold; and

[0155] (c) The irradiated composition is heat-treated at a temperature that allows the prepolymer end groups to react effectively with the diamine.

[0156] It should be understood that the reaction between the prepolymer end groups and the diamine will produce a cross-linked structure. Heat treatment and irradiation are performed as described above regarding the end-capped imide prepolymer.

[0157] Therefore, the prepolymer can generally be represented by the structure of the following formula (XVIII):

[0158] (XVIII)

[0159] Among them, L 4 As defined by L, R 12 and R 13 The functional group is a covalently reacted with a monoamine, which is usually a primary or secondary amine, preferably a primary amine, such as a diamine containing two primary amine groups.

[0160] In some embodiments, the curable resin composition is added to a build region prior to irradiation, the build region being sized to correspond to a predetermined shape and size of the 3D structure to be manufactured.

[0161] In other embodiments, the method is implemented within the context of an improved additive manufacturing process that includes the computer-controlled continuous formation of layers with dimensions corresponding to a 3D data image, the improvement comprising forming the layers by the following steps:

[0162] (a) An initial curable layer is provided on a substrate, wherein the layer comprises a curable resin composition prepared by the prepolymer with at least one photopolymerizable olefinic monomer, at least one photoinitiator and a diamine;

[0163] (b) Irradiating the initial layer under conditions that enable the polymerization of the olefinic monomer and provide polyolefin within the first scaffold layer, wherein the first scaffold layer comprises the prepolymer and the polyolefin, and the diamine is physically trapped within the scaffold layer;

[0164] (c) Repeat step (a) to provide an additional layer on the first support layer;

[0165] (d) Irradiate the additional layer under conditions that enable the polymerization of the olefinic monomer and provide an additional support layer;

[0166] (e) Repeat steps (c) and (d) until the 3D object is fully formed; and

[0167] (f) The 3D object is heat-treated at a temperature that allows a covalent reaction to occur between the prepolymer and the diamine.

[0168] It should be understood that although the present invention has been described above with reference to many specific embodiments, the foregoing description and the examples below are merely illustrative and are not intended to limit the scope of the present invention.

[0169] Example 1

[0170] Synthetic N-(2-pyrimidinyl)phthalimide imide prepolymer:

[0171] 100.00 g (0.05 mol) of molten anhydrous end-imide polyethylene glycol (molecular weight 2000 g / mol) was added to a 500 mL four-necked flask equipped with a top stirrer, nitrogen inlet, thermometer, and a reverse Dean-Stark trap with a condenser. Then, 31.02 g (0.10 mol) of 4,4'-oxydiphthalic anhydride was added to the flask, followed by 39 mL of cyclohexylpyrrolidone. The solution was stirred for 4 hours, and an increase in viscosity was observed. The temperature was then raised to 175 °C, and stirring was continued for 12 hours. Afterward, 9.51 g (0.10 mol) of 2-aminopyrimidine was added to the solution, and stirring was continued at 175 °C for another 12 hours. The viscous liquid was cooled and poured off to obtain the final product.

[0172] These two steps of the reaction are shown in Scheme 1 below:

[0173] Scheme 1:

[0174]

[0175] Example 2

[0176] Samples were formed and tested using phthalimide-terminated imide prepolymers.

[0177] (a) General Procedures

[0178] The prepolymer synthesized in Example 1 was polymerized and cured to form the 3D structure described below. The tensile properties were evaluated according to the following ISO standards: ISO 37 (2017) Rubber, Vulcanized or Thermoplastic - Determination of tensile stress-strain properties for non-rigid materials; and ISO 527 (2017) Plastics - Determination of tensile properties for rigid materials (International Organization for Standardization, BIBC IIChemin de Blandonnet 8, CP 401,1214 Vernier, Geneva, Switzerland).

[0179] The tensile specimen was loaded onto the GNT5 universal testing machine of NCS (NCS Testing Technology Co., Ltd., No. 13 Gaoliangqiao Xiejie, Haidian District, Beijing, 100081, China), with the specimen vertically oriented and parallel to the test direction. An LED UV chamber (UV wavelength = 405±5nm, intensity = 130-150×10⁻⁶) was used. 2 μm / cm 2 The cast samples were fully cured for 60 seconds. Then, these samples were heat-treated in a convection oven under the conditions described below. Table 1 shows the types of tensile specimens tested, their general material properties, and the associated strain rates.

[0180] Dog bone samples that do not break in the central rectangular section are excluded. Samples that break in the fixture or before testing do not represent the expected failure mode and are also excluded from the data.

[0181] To ensure that the strain rate of the sample is sufficient to capture the deformation, tensile fracture tests are performed on the sample for a duration of 30 seconds to 5 minutes.

[0182] Depending on the material type and in accordance with ISO 37 and ISO 527, the Young's modulus (the slope of the stress-strain diagram at 0.05%–0.25% strain), tensile strength at break, yield tensile strength, elongation at break, elongation at yield, and ultimate tensile strength are measured.

[0183] For elastic materials with high elongation at break, high strain rates are required to induce fracture within the typical range of the specified test. For rigid materials, the ISO standard recommends using a modulus of elasticity test rate of 1 mm / min to ensure that the lowest possible fracture strain occurs within 5 minutes.

[0184] Table 1

[0185]

[0186] (b) Sample formation and evaluation

[0187] The UV-curable N-(2-pyrimidinyl)phthalimide imide prepolymer prepared in Example 1 was thoroughly mixed with isobornyl methacrylate, trimethylolpropane trimethacrylate (TMPTMA), and TPO using a top-mounted stirrer to obtain a homogeneous resin. This resin was poured into a 150 mm × 100 mm × 4 mm mold and UV-cured for 1 min. The sample was then thermocured at 100 °C for 1 h, followed by heating at 220 °C for 4 h. The cured elastic sheet thus formed was cut into rectangular strips with dimensions of 150 mm × 10 mm × 4 mm. The mechanical properties of each sample were tested on an NCS universal testing machine according to ISO 527 (specifically as described above).

[0188] The average tensile strength (MPa) and elongation at break (%) are shown in Table 2, which also shows the weight percentage of each component in the transimide reaction mixture.

[0189] Table 2

[0190]

[0191]

[0192] Example 3

[0193] Synthetic UV-curable polyamide prepolymers:

[0194] 100.0 g (0.05 mol) of molten anhydrous polytetramethylene oxide (molecular weight 2000 g / mol) was added to a 500 mL three-necked flask equipped with a top stirrer, a nitrogen inlet, and a thermometer. Then, 20.3 g (0.1 mol) of terephthaloyl chloride was added to the flask, and the mixture was stirred to form a homogeneous solution containing polytetramethylene oxide. The temperature was raised to 80 °C, and the solution was stirred for 4 hours. After 4 hours, a vacuum was applied. The vacuum was removed 30 minutes after the bubbles disappeared from the solution. The reaction temperature was gradually lowered to 40 °C. Then, 37.0 g (0.2 mol) of 2-(t-butylamino)ethyl methacrylate was added, and the temperature was raised to 50 °C and maintained at this temperature for 2 hours. The resulting viscous liquid was then poured off as the reaction product.

[0195] This two-step reaction is illustrated in Scheme 3 below (where “Ph” represents phenyl and “t-Bu” represents tert-butyl).

[0196]

[0197] Example 4

[0198] Samples were formed and tested using polyamide prepolymers.

[0199] The UV-curable polyamide prepolymer prepared in Example 3 was used to form specimens and evaluate them, following the general procedures of Example 2.

[0200] The prepolymer prepared in Example 3 was thoroughly mixed with cyclic trimethylolpropane acetal acrylate and (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (TPO) photoinitiator using a top-mounted stirrer to obtain a homogeneous resin. Then, 4,4'-diaminocyclohexylmethane was added, and mixing continued for 10 min. The resin was poured into a 150 mm × 100 mm × 4 mm mold and UV cured for 1 min. The sample was then thermocured at 100 °C for 1 h, followed by heating at 220 °C for 4 h. The cured elastic sheet thus formed was cut into rectangular strips with dimensions of 150 mm × 10 mm × 4 mm. The mechanical properties of each sample were tested on an NCS universal testing machine according to ISO 527 (specifically as described above).

[0201] The average tensile strength (MPa) and elongation at break (%) are shown in Table 3, which also shows the weight percentage of each component in the transimide reaction mixture.

[0202] Table 3

[0203] Components weight% UV-curable polyamide prepolymer 70.0 Cyclic Trimethylolpropane Formaldehyde Acrylate 24.2 TPO 1.0 4,4'-Diaminodicyclohexylmethane 4.8 Tensile strength (MPa) 4.6 Elongation at break (%) 236

Claims

1. A dual-curing method for forming a solid polymer structure, characterized in that, The dual-curing method includes: (a) Combining (i) a closed-end imide-terminated prepolymer, (ii) at least one photopolymerizable olefinic monomer, (iii) at least one photoinitiator, and (iv) a diamine to form a curable resin composition; (b) Irradiating the resin composition under conditions that enable efficient polymerization of the at least one olefinic monomer and provision of a polyolefin within a scaffold, the scaffold comprising the prepolymer and the polyolefin, wherein the diamine is physically trapped within the scaffold; and (c) The irradiated composition is heat-treated at a temperature that allows for effective transimide reaction between the prepolymer and the diamine, thereby releasing the end groups of the prepolymer and providing the solid polymer structure; The capped and imide-terminated prepolymer has the structure of formula (I): in, L includes unsubstituted, substituted, heteroatom-containing, or substituted and heteroatom-containing oligomeric hydrocarbon moieties; Ar is an aryl group; R 1 and R 3 They can be the same or different, and they are non-oligomeric linking groups; q and r can be the same or different, and can be 0 or 1; and R 2 and R 4 All are 2-pyrimidinyl.

2. The dual-curing method according to claim 1, characterized in that, The solid polymer structure corresponds to a 3D object of a predetermined shape and size.

3. The dual-curing method according to claim 1 or 2, characterized in that, Between steps (a) and (b), the curable resin composition is added to a construction area that corresponds in size to the predetermined shape and size of the 3D object.

4. The dual-curing method according to claim 1 or 2, characterized in that, The L is selected from any one or more of the following: poly(ethylene oxide) chain, unsubstituted poly(ethylene oxide) chain, polyethylene chain, and unsubstituted polyethylene chain.

5. The dual-curing method according to claim 1 or 2, characterized in that, The Ar is a single ring.

6. The dual-curing method according to claim 5, characterized in that, The Ar does not contain heteroatoms.

7. The dual-curing method according to claim 6, characterized in that, Ar is phenyl, such that the prepolymer has the structure of formula (II): Where r and q are both 1.

8. The dual-curing method according to claim 7, characterized in that, R 1 and R 3 same.

9. The dual-curing method according to claim 8, characterized in that, When L is a polyethylene chain, r and q are both 1, R 1 and R 3 When phthalimide groups are included, the prepolymer has the structure of formula (III): Wherein, s and t are independently 0 or 1, and X and Y are selected from O, S and lower alkylene groups.

10. The dual-curing method according to claim 9, characterized in that, When both s and t are 0, the prepolymer has the structure of the following formula (IV): 。 11. The dual-curing method according to claim 10, characterized in that, When L is poly(ethylene oxide), the prepolymer has the structure of the following formula (V): Where n is the number of oxyvinyl monomer units in L.

12. The dual-curing method according to claim 10, characterized in that, When L is polyethylene, the prepolymer has the structure of formula (VI): Where n is the number of ethylene monomer units in L.

13. The dual-curing method according to claim 9, characterized in that, Both s and t are 1, and both X and Y are 0, such that the prepolymer has the structure of the following formula (VII): 。 14. The dual-curing method according to claim 13, characterized in that, When L is poly(ethylene oxide), the prepolymer has the structure of the following formula (VIII): Where n is the number of oxyvinyl monomer units in L.

15. The dual-curing method according to claim 13, characterized in that, When L is poly(ethylene), the prepolymer has the structure of the following formula (IX): Where n is the number of ethylene monomer units in L.

16. The dual-curing method according to claim 1 or 2, characterized in that, The prepolymer has a weight-average molecular weight of 500 to 5000; and / or the prepolymer accounts for 30 wt.% to 70 wt.% of the composition.

17. The dual-curing method according to claim 16, characterized in that, The weight-average molecular weight of the prepolymer is between 1,000 and 3,000.

18. The dual-curing method according to claim 16, characterized in that, The prepolymer accounts for 40 wt.% to 60 wt.% of the composition.

19. The dual-curing method according to claim 1 or 2, characterized in that, The at least one photopolymerizable olefin monomer accounts for 25 wt.% to 65 wt.% of the composition.

20. The dual-curing method according to claim 19, characterized in that, The at least one photopolymerizable olefin monomer accounts for 35 wt.% to 55 wt.% of the composition.

21. The dual-curing method according to claim 1 or 2, characterized in that, The diamine accounts for 1 wt.% to 15 wt.% of the composition.

22. The dual-curing method according to claim 21, characterized in that, The diamine accounts for 1 wt.% to 10 wt.% of the composition.

23. The dual-curing method according to claim 22, characterized in that, The diamine accounts for 1 wt.% to 5 wt.% of the composition.

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