Composition and method for 3D printing for molding application

Abstract

To provide compositions or build materials for use with an additive manufacturing system, in one aspect.SOLUTION: In some embodiments, compositions described herein comprise: a compound having a structure of Formula (I) and / or a compound having a structure of Formula (II), wherein the compound having the structure of Formula (I) and / or Formula (II) is present in an amount of 10 to 35 wt.%, based on a total weight of the composition; and a monomeric curable material having the structure of Formula (III). In some implementations, the monomeric curable material of Formula (III) is present in an amount of 30 to 50 wt.%, based on the total weight of the composition. In some cases, the composition further comprises an acrylate or acrylamide component. In some examples, the acrylate or acrylamide component is present in an amount of 25 to 50 wt.%, based on the total weight of the composition.SELECTED DRAWING: Figure 1A

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority pursuant to 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 63 / 641,450, filed May 2, 2024, which is incorporated herein by reference in its entirety. [Technical Field]

[0002] The present disclosure relates to compositions and methods for additive manufacturing, including molding applications. [Background technology]

[0003] Three-dimensional (3D) printers and other additive manufacturing systems use compositions, sometimes known as build materials, inks, or polymerizable liquids, to form various 3D objects, articles, or parts according to computer-generated files or other digital representations of the object, article, or part. In some examples, the compositions are solid at ambient temperatures and change to a liquid at elevated jetting temperatures. In other examples, the compositions are liquid at ambient temperatures. The build material can be formed into the 3D object in various ways, for example, by jetting or otherwise depositing the build material onto a substrate. The build material can also be selectively cured, solidified, or otherwise transformed during building. For example, some 3D printers form 3D articles from reservoirs, vats, or containers of fluid or powder build material. In some cases, a binder material or a laser or other energy source is used to selectively solidify or consolidate layers of the build material in a stepwise manner to provide the 3D article.

[0004] Additive manufacturing or 3D printing systems can be used to form articles with a variety of end uses. However, the end uses of some articles formed by additive manufacturing may be limited by the build materials used to form the articles. For example, some articles formed by additive manufacturing may not be able to withstand high temperatures, may not be able to dissolve or disperse or remove in a desired manner, and / or may not provide sufficient mechanical properties for certain end uses. Molding applications may be particularly difficult to achieve. Summary of the Invention [Problem to be solved by the invention]

[0005] Thus, there is a need for improved compositions or build materials for 3D printing that have improved properties, particularly related to certain end uses that may require high stiffness, such as forming thin molds for injection molding or other molding processes, or molds configured to produce fine features. [Means for solving the problem]

[0006] In one aspect, compositions or build materials for additive manufacturing are described herein, which, in some embodiments, may offer one or more advantages over some conventional compositions or build materials. For reference purposes herein in the context of additive manufacturing, the term "build material" can be used interchangeably with the terms "ink" or "polymerizable liquid." In some embodiments, the compositions described herein can be used as build materials for printing articles, objects, or parts. Furthermore, the compositions or build materials described herein can, in some cases, be used in a variety of different 3D printers or additive manufacturing systems, such as systems based on stereolithography (SLA), digital light processing (DLP), or multi-jet printing (MJP). Furthermore, the compositions or build materials described herein can, in some cases, be particularly useful for forming molds via additive manufacturing. The compositions described herein can also be used in other methods and for other end uses, and the uses of the compositions described herein are not necessarily limited.

[0007] In some embodiments, the compositions described herein comprise a compound having the structure of Formula (I) and / or a compound having the structure of Formula (II): [ka] [ka] Including, wherein n is an integer from 4 to 40. In some cases, the composition further comprises a monomeric curable material having a structure of formula (III): [ka] Including, In the formula, the sum of p and q is an integer of 2 to 30, R1 and R2 are each independently H or CH3, and R3 and R4 are each independently C1 to C4 alkyl; In the formula, X is a straight or branched chain C1-C4 alkyl or the following structure: [ka] is a group having the formula During the ceremony [ka] represents the point of attachment to the remainder of the structure of formula (III).

[0008] In some examples, the compositions described herein further comprise an acrylate or acrylamide component. In some such embodiments, the acrylate or acrylamide component comprises one or more (meth)acrylates. In some such examples, the one or more (meth)acrylates comprise carboxyethyl acrylate, hydroxypropyl acrylate, acrylic acid, or a mixture thereof. Furthermore, in some cases, the acrylate or acrylamide component comprises one or more acrylamides. In some such examples, the one or more acrylamides comprise dimethylacrylamide, diethylacrylamide, acryloylmorpholine, isopropylacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide, hydroxyethylacrylamide, or a mixture thereof.

[0009] In another aspect, methods for forming 3D articles by additive manufacturing are described herein. In some embodiments, such methods include providing a composition or build material described herein and selectively curing one or more portions of the composition. Any of the compositions described herein can be used. For example, in some cases, the composition includes a compound having the structure of formula (I) and / or a compound having the structure of formula (II), as described herein, and a monomeric curable material having the structure of formula (III). Furthermore, in some examples, providing the composition includes selectively depositing a layer of the composition in a fluid state onto a substrate to form the 3D article. This deposition process can be repeated any desired number of times to complete the article.

[0010] In yet another aspect, the present invention provides a printed 3D article.This printed 3D article can be formed from any composition described herein using any method.In some cases, this printed 3D article has specific properties compared with some other 3D articles.In some embodiments, for example, the Young's modulus of the article is greater than 100,000 kPa when measured according to ASTM D638.

[0011] In yet another aspect, methods of forming a 3D article by molding are described herein. In some embodiments, such methods include providing a mold defining an interior volume and injecting a fluid material into the interior volume of the mold. Furthermore, in some cases, the method further includes solidifying the fluid material within the interior volume of the mold to form an article, and then removing the mold from the formed article. It should be understood that the mold can comprise or be formed from any of the compositions or build materials described herein. Furthermore, as described herein, in some cases, providing the mold includes forming the mold using additive manufacturing, including using a 3D printing method described herein. Furthermore, using the compositions or build materials described herein may also allow for easy removal of the mold after solidification of the fluid material within the mold. In some embodiments, removing the mold from the article includes dissolving or dispersing the mold in water or an aqueous solution. In some such embodiments, the aqueous solution includes glycol.

[0012] These and other embodiments are described in greater detail in the detailed description that follows. [Brief explanation of the drawings]

[0013] [Figure 1A] FIG. 1 is a perspective view of a 3D printed article that is also a mold according to one embodiment described herein. [Figure 1B] FIG. 1B is a perspective view of the 3D printed mold of FIG. 1A filled with a fluid material and solidified to form a first article, according to one embodiment described herein. [Figure 1C] FIG. 1C is a perspective view of the first article of FIG. 1B with the mold removed according to one embodiment described herein. [Figure 1D] 1D is a perspective view of the first article of FIG. 1C surrounded by a hydrogel material according to one embodiment described herein. [Figure 1E] FIG. 1E is a perspective view of a second mold formed from the hydrogel material of FIG. 1D according to one embodiment described herein. DETAILED DESCRIPTION OF THE INVENTION

[0014] The embodiments described herein can be more readily understood by reference to the following detailed description, examples, and drawings. However, the elements, devices, and methods described herein are not limited to the specific embodiments presented in the detailed description, examples, and drawings. It should be recognized that these embodiments are merely illustrative of the principles of the present disclosure. Numerous modifications and adaptations will be readily apparent to those skilled in the art without departing from the spirit and scope of the present disclosure.

[0015] Furthermore, all ranges disclosed herein should be understood to encompass all subranges subsumed therein. For example, the stated range "1.0 to 10.0" should be interpreted to include any and all subranges beginning with a minimum value greater than or equal to 1.0 and ending with a maximum value less than or equal to 10.0, such as 1.0 to 5.3, 1 to 4, 3 to 7, 4.7 to 10.0, 3.6 to 7.9, or 5 to 8.

[0016] Additionally, all ranges disclosed herein should be considered to include the endpoints of the range unless otherwise specified. For example, a range "between 5 and 10," "from 5 to 10," or "5-10" should generally be considered to include the endpoints of 5 and 10.

[0017] Furthermore, when the term "up to" is used in connection with an amount or quantity, it should be understood that the amount is at least a detectable amount or quantity (i.e., the amount is a non-zero amount). For example, a substance present in an amount "up to" a particular amount can be present in an amount from a detectable (or non-zero) amount up to and including the particular amount.

[0018] The article "a" or "an" should also be understood to refer to "at least one" unless the context of a particular use requires otherwise.

[0019] Terms such as "3D printing system," "3D printer," and "printing" generally describe various solid freeform manufacturing techniques for creating three-dimensional articles or objects by stereolithography (SLA), digital light processing (DLP), selective deposition, jetting, fused deposition modeling (FDM), multi-jet modeling (MJM) or multi-jet printing (MJP), and other additive manufacturing techniques now or in the future known in the art that use build materials to produce three-dimensional objects.

[0020] I. Compositions for Additive Manufacturing In one aspect, described herein are compositions or build materials for use in additive manufacturing systems. In some embodiments, the compositions described herein comprise a compound having the structure of Formula (I) and / or a compound having the structure of Formula (II): [ka] [ka] Including, wherein n is an integer between 4 and 40. In some cases, n is an integer between 4 and 14, between 4 and 20, between 6 and 30, between 10 and 40, or between 10 and 20. Other values ​​of n are possible. Additionally, species of formula (I) may be referred to as "MA-PEG#-MA," where "#" is understood to be the approximate weight average molecular weight of the poly(ethylene glycol) or "PEG" portion of the compound. For example, "MA-PEG200-MA" refers to a compound of formula (I) where n has a value corresponding to a PEG portion having a molecular weight of about 200. Similarly, species of formula (II) may be referred to as "MA-PEG#," where "#" is understood to be the approximate weight average molecular weight of the PEG portion of the compound.

[0021] In some implementations, the compound having the structure of Formula (I) and / or the compound having the structure of Formula (II) is present in an amount of 10 to 35% by weight, based on the total weight of the composition. In some cases, the compound having the structure of Formula (I) and / or the compound having the structure of Formula (II) is present in an amount of 10 to 35%, 10 to 30%, 10 to 25%, 10 to 20%, 10 to 15%, 15 to 35%, 15 to 30%, 15 to 25%, 15 to 20%, 20 to 35%, 20 to 30%, 20 to 25%, 25 to 35%, 25 to 30%, or 30 to 35% by weight.

[0022] Additionally, in some cases, the compositions described herein may comprise a monomeric curable material having a structure of formula (III): [ka] further comprising In the formula, the sum of p and q is an integer of 2 to 30, R1 and R2 are each independently H or CH3, and R3 and R4 are each independently C1 to C4 alkyl; In the formula, X is a straight or branched chain C1-C4 alkyl or the following structure: [ka] is a group having the formula During the ceremony [ka] represents the point of attachment to the remainder of the structure of Formula (III). In some examples, in Formula (III), X is C(CH). In other cases, in Formula (III), X is CH. Non-limiting examples of monomeric curable materials for use in some embodiments described herein include ethoxylated (10) bisphenol A diacrylate and ethoxylated (30) bisphenol A diacrylate.

[0023] For reference purposes herein, "C n ~Cm It is understood that a "C alkyl moiety" (e.g., a "C1-C4 alkyl moiety") is a divalent saturated aliphatic radical having "n" to "m" carbon atoms (e.g., 1 to 4 carbon atoms, but not more than 4 carbon atoms). n " moiety has exactly "n" carbon atoms (no more, no less). Furthermore, it is understood that "n" and "m" may or may not be subscripts and the meaning remains the same (e.g., "C n ~C m " may alternatively be written as "Cn-Cm." Similarly, in the present disclosure, a Cn-Cm "alkyl" moiety may be referred to as an "alkylene" moiety. It will be understood by those skilled in the art that these terms may be used interchangeably in this context, in view of the relevant principles of chemistry.

[0024] Generally, the monomeric curable material can be present in the compositions described herein in any amount consistent with the technical objectives of the present disclosure. In some embodiments, the monomeric curable material is present in an amount of 30-50 wt%, 30-45 wt%, 30-40 wt%, 30-35 wt%, 35-50 wt%, 35-45 wt%, 35-40 wt%, 40-50 wt%, 40-45 wt%, or 45-50 wt%, based on the total weight of the composition.

[0025] Turning to other components that may be present in the compositions described herein, in some examples, the compositions described herein can further include an acrylate or acrylamide component. Generally, the acrylate or acrylamide component of the compositions described herein can be present in any amount consistent with the technical objectives of the present disclosure. In some examples, the acrylate or acrylamide component is present in an amount of 25-50 wt%, 25-45 wt%, 25-40 wt%, 25-35 wt%, 25-30 wt%, 30-50 wt%, 30-45 wt%, 30-40 wt%, 30-35 wt%, 35-50 wt%, 35-45 wt%, 35-40 wt%, 40-50 wt%, 40-45 wt%, or 45-50 wt%, based on the total weight of the composition.

[0026] Furthermore, in some implementations, the acrylate or acrylamide component comprises one or more (meth)acrylates. It should be understood that the term "(meth)acrylate" includes acrylates or methacrylates, or mixtures or combinations thereof. Furthermore, in some cases, the (meth)acrylate comprises a (meth)acrylate monomer, a (meth)acrylate oligomer, or a mixture thereof.

[0027] Additionally, the (meth)acrylate monomers and / or (meth)acrylate oligomers described herein can include monofunctional, difunctional, trifunctional, tetrafunctional, pentafunctional, or higher functional (meth)acrylate species. For reference purposes herein, a "monofunctional" (meth)acrylate species includes a species containing one (meth)acrylate moiety. Similarly, a "difunctional" (meth)acrylate species includes a species containing two (meth)acrylate moieties; a "trifunctional" (meth)acrylate species includes a species containing three (meth)acrylate moieties; a "tetrafunctional" (meth)acrylate species includes a species containing four (meth)acrylate moieties; and a "pentafunctional" (meth)acrylate species includes a species containing five (meth)acrylate moieties. Thus, in some embodiments, the monofunctional (meth)acrylate component of the compositions described herein comprises a mono(meth)acrylate, the difunctional (meth)acrylate component of the compositions described herein comprises a di(meth)acrylate, the trifunctional (meth)acrylate component of the compositions described herein comprises a tri(meth)acrylate, the tetrafunctional (meth)acrylate component of the compositions described herein comprises a tetra(meth)acrylate, and the pentafunctional (meth)acrylate component of the compositions described herein comprises a penta(meth)acrylate. Other (meth)acrylate species can also be used.

[0028] Furthermore, it is understood that the (meth)acrylate species (such as mono-, di-, tri-, tetra-, or penta-functional (meth)acrylate species) may optionally comprise or be relatively low molecular weight species, i.e., (meth)acrylate monomers (e.g., species having a molecular weight less than 300, less than 200, or less than 100), or relatively high molecular weight species, i.e., (meth)acrylate oligomers (e.g., species having a molecular weight greater than 300, greater than 400, greater than 500, or greater than 600, and optionally less than 10,000), and that the molecular weight may be a weight average molecular weight in the case of oligomeric species having a molecular weight distribution. Furthermore, in some embodiments, the (meth)acrylate "monomer" has a viscosity of 500 centipoise (cP) or less at 25°C as measured according to ASTM D2983 (2022 edition), while the (meth)acrylate "oligomer" has a viscosity of 1000 cP or more at 25°C as measured according to ASTM D2983.

[0029] As mentioned above, the build materials described herein can include (meth)acrylate monomers. The (meth)acrylate monomers can include any (meth)acrylate monomers not inconsistent with the objectives of the present disclosure. In some cases, for example, the (meth)acrylate monomers include one or more hydrophilic or water-soluble (meth)acrylates. For reference purposes herein, a "water-soluble" species or material has a solubility in water (or an acidic or basic aqueous solution as further described herein) of at least 1 gram per liter of water (or aqueous solution) at 25°C. In some cases, a water-soluble species or material has a solubility of at least 5 g / L, at least 10 g / L, or at least 100 g / L at 25°C.

[0030] In some embodiments described herein, the (meth)acrylate monomer comprises a hydrophilic or water-soluble mono-, di-, and / or tri(meth)acrylate species. The (meth)acrylate monomer can comprise, for example, one or more of a hydroxylalkyl (meth)acrylate (e.g., hydroxypropyl acrylate), ethoxylated trimethylolpropane triacrylate ("TAC" or trimethylolpropane ethoxylate triacrylate), and various combinations or mixtures thereof. In some embodiments, the hydroxyalkyl (meth)acrylate comprises hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and / or mixtures thereof. In some implementations, the (meth)acrylate comprises carboxyethyl acrylate, hydroxypropyl acrylate, acrylic acid, or mixtures thereof.

[0031] Further, in some cases, the (meth)acrylate monomer of the compositions described herein comprises a cyclocarbonate (meth)acrylate monomer. In some such cases, the cyclocarbonate (meth)acrylate monomer has the structure of Formula (IV): [ka] and wherein Y is a linear or branched C1-C6 alkylene moiety; wherein Z is H or CH3.

[0032] For reference purposes herein, a "Cn-Cm alkylene moiety" (e.g., a "C1-C4 alkylene moiety") is understood to be a divalent saturated aliphatic radical having from "n" to "m" carbon atoms (e.g., 1 to 4 carbon atoms, but no more than 4 carbon atoms). In some preferred embodiments, Y is a linear or branched C1-C4 alkylene moiety, particularly preferably, for example, CH2. Further, in some embodiments, Z is H. Furthermore, in some instances, Y is CH2 and Z is H. Thus, in some instances, the cyclocarbonate (meth)acrylate monomer of the compositions described herein has the structure of formula (V): [ka]

[0033] It should be understood that the (meth)acrylate monomers of the compositions described herein can include a combination of monomer species, for example, a combination of two or more of the above (meth)acrylate species. For example, in some cases, the (meth)acrylate monomer includes one or more hydroxyalkyl (meth)acrylates, one or more poly(ethylene glycol) acrylates, one or more poly(ethylene glycol) diacrylates, one or more cyclocarbonate (meth)acrylates, or a combination of two or more of the foregoing. Thus, the present disclosure contemplates many combinations and compositions of (meth)acrylate monomers that can be included in exemplary implementations, but which are not explicitly listed herein.

[0034] The compositions described herein also include, in some embodiments, a (meth)acrylate oligomer. Any (meth)acrylate oligomer species consistent with the technical objectives of the present disclosure may be used. In some preferred embodiments, the (meth)acrylate oligomer includes one or more hydrolyzable oligomer species. For reference purposes herein, a "hydrolyzable" oligomer species includes at least one hydrolyzable bond. In some cases, the hydrolyzable bond is part of a repeating unit of the oligomer. For example, in some instances, the hydrolyzable oligomer species includes one or more urethane bonds, one or more ester bonds, or one or more carbonate bonds in the backbone of the oligomer species. As will be understood by those skilled in the art, such bonds can be hydrolyzed by water, including relatively easily when exposed to water or the aqueous solutions described herein for the times and temperatures described herein.

[0035] Furthermore, in some embodiments, the (meth)acrylate oligomer may be difunctional or higher and may be hydrolyzable. Furthermore, in some embodiments, a majority of the total amount of (meth)acrylate oligomers is difunctional or higher. For example, in some cases, at least 60% by weight, at least 70% by weight, at least 80% by weight, or at least 90% by weight of the (meth)acrylate oligomer component is difunctional or higher, the weight percentages being based on the total amount of the (meth)acrylate oligomer component.

[0036] In some implementations, the (meth)acrylate oligomer of the compositions described herein comprises a poly(ethylene glycol) diacrylate (PEGDA) component. As used herein, the poly(ethylene glycol) diacrylate component can comprise a single poly(ethylene glycol) diacrylate species or multiple poly(ethylene glycol) diacrylate species of different molecular weights. In some embodiments, the PEGDA species has a weight-average molecular weight of 0.1 kilodaltons (kDa) to 20 kDa or 0.2 to 20 kDa.

[0037] The molecular weight of an individual species of PEGDA can be, for example, within one or more ranges shown in Table 1. [Table 1]

[0038] Any combination or mixture of poly(ethylene glycol) diacrylates of different molecular weights is contemplated. In some cases, the PEGDA component comprises a mixture of two or more PEGDA species, each having a weight average molecular weight of 0.5 to 5 kDa.

[0039] In some embodiments of the compositions described herein, the (meth)acrylate oligomer comprises a urethane acrylate oligomer, a urethane methacrylate oligomer, a polyether urethane oligomer, an aliphatic polyester urethane acrylate oligomer, or a combination of two or more of the foregoing. Further, in some cases, the (meth)acrylate oligomer can comprise an aliphatic urethane diacrylate oligomer.

[0040] Non-limiting examples of commercially available (meth)acrylate oligomers useful in some embodiments described herein include: a monofunctional urethane acrylate available from RAHN USA under the trade name GENOMER 1122; an aliphatic urethane diacrylate available from ALLNEX under the trade name EBECRYL 8402; an aliphatic urethane diacrylate oligomer available from IGM Resins under the trade name PHOTOMER 6210; an aliphatic urethane diacrylate oligomer available from IGM Resins under the trade name PHOTOMER 6710; a multifunctional acrylate oligomer available from DYMAX Corporation under the trade name BR-952; an aliphatic polyether urethane acrylate available from DYMAX Corporation under the trade name BR-371S; and a polyether urethane methacrylate available from DYMAX Corporation under the trade name BR-541MD. Other commercially available oligomeric (meth)acrylates may also be used.

[0041] Urethane (meth)acrylates suitable for use in the compositions described herein can be prepared by known methods, typically by reacting a hydroxyl-terminated urethane with acrylic or methacrylic acid to obtain the corresponding urethane (meth)acrylate, or by reacting an isocyanate-terminated prepolymer with a hydroxyalkyl acrylate or methacrylate to obtain the urethane (meth)acrylate. Suitable processes are disclosed, inter alia, in EP-A 114 982 and EP-A 133 908. The weight-average molecular weight of such (meth)acrylate oligomers can range from about 500 to 6,000. Urethane (meth)acrylates are commercially available from SARTOMER under the product names CN980, CN981, CN975, and CN2901. In some embodiments, urethane acrylate oligomers are used in the compositions described herein. Suitable urethane acrylates include difunctional aliphatic urethane acrylates from DYMAX Corporation under the trade names BR-741 and BR-970. In some embodiments, the (meth)acrylate oligomer comprises an aliphatic polyester urethane acrylate or an aliphatic polyether urethane acrylate. Commercially available products of these oligomer species are available from DYMAX Corporation under the trade names BR-7432 and BR-543, respectively.

[0042] In some examples, the acrylate or acrylamide component of the compositions described herein comprises one or more acrylamides. For reference purposes herein, it should be understood that "acrylamide" can include chemical species that contain at least one acrylamide moiety or functional group. In some embodiments, the one or more acrylamides comprise dimethylacrylamide, diethylacrylamide, acryloylmorpholine, isopropylacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide, hydroxyethylacrylamide, or a mixture thereof.

[0043] Generally, one or more acrylamides can be present in the compositions described herein in any amount consistent with the technical objectives of the present disclosure. In some embodiments, one or more acrylamides are present in an amount of 10-40% by weight, based on the total weight of the composition. In some cases, one or more acrylamides are present in an amount of 10-35%, 10-30%, 10-25%, 10-20%, 10-15%, 15-40%, 15-35%, 15-30%, 15-25%, 15-20%, 20-40%, 20-35%, 20-30%, 20-25%, 25-40%, 25-35%, 25-30%, 30-40%, 30-35%, or 35-40% by weight, based on the total weight of the composition.

[0044] Turning to another possible component of the compositions described herein, the compositions described herein can also include a photoinitiator component. Any photoinitiator not inconsistent with the objectives of the present disclosure can be used in the compositions described herein. In some embodiments, for example, the photoinitiator component comprises an α-cleavage (unimolecular decomposition process) photoinitiator or a hydrogen abstraction photosensitizer-tertiary amine synergist operable to absorb light at about 250 nm to about 400 nm, about 250 nm to about 405 nm, or about 300 nm to about 385 nm to generate free radicals. Examples of α-cleavage photoinitiators are Irgacure 184 (CAS 947-19-3), Irgacure 369 (CAS 119313-12-1), and Irgacure 819 (CAS 162881-26-7). An example of a photosensitizer-amine combination is Darocur BP (CAS 119-61-9) in combination with diethylaminoethyl methacrylate.

[0045] Further, in some examples, the photoinitiator may be selected from the group consisting of benzoins, such as benzoin, benzoin ethers (e.g., benzoin methyl ether, benzoyl ethyl ether, and benzoyl isopropyl ether), benzoin phenyl ether, and benzoin acetate; acetophenones, such as acetophenone, 2,2-dimethoxyacetophenone, and 1,1-dichloroacetophenone; benzil, benzil ketals (e.g., benzil dimethyl ketal and benzil diethyl ketal); anthraquinones, such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone; triphenylphosphine; benzoylphosphine oxides (e.g., 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin benzophenone and benzophenones such as 4,4'-bis(N,N'-dimethylamino)benzophenone; thioxanthone and xanthone; acridine derivatives; phenazine derivatives; quinoxaline derivatives or 1-phenyl-1,2-propanedione; 2-O-benzoyloxime; 1-aminophenyl ketone; or 1-hydroxyphenyl ketones such as 1-hydroxycyclohexyl phenyl ketone, phenyl 1-hydroxyisopropyl ketone, and 4-isopropylphenyl 1-hydroxyisopropyl ketone.

[0046] Suitable photoinitiators may also include those operable for use with a HeCd laser radiation source, such as acetophenone, 2,2-dialkoxybenzophenone, and 1-hydroxyphenyl ketone (e.g., 1-hydroxycyclohexyl phenyl ketone or 2-hydroxyisopropyl phenyl ketone (=2-hydroxy-2,2-dimethylacetophenone)). Furthermore, in some examples, suitable photoinitiators include those operable for use with an Ar laser radiation source, such as benzil ketals, such as benzil dimethyl ketal. In some embodiments, the photoinitiator includes α-hydroxyphenyl ketone, benzil dimethyl ketal, or 2,4,6-trimethylbenzoyldiphenylphosphine oxide, or a mixture thereof.

[0047] Another class of photoinitiators that can be included in the compositions described herein includes ionic dye-counterion compounds that can absorb actinic radiation and generate free radicals for polymerization initiation. In some embodiments, compositions containing ionic dye-counterion compounds can polymerize upon exposure to visible light within a tunable wavelength range of about 400 nm to about 700 nm. Ionic dye-counterion compounds and their mode of operation are disclosed in EP 0223587 A1, U.S. Pat. Nos. 4,751,102, 4,772,530, and 4,772,541.

[0048] In some cases, the photoinitiator that can be included in the compositions described herein includes a water-soluble pyrrolidone or a phosphine oxide, such as a monoacylphosphine oxide (MAPO) salt or a bisacylphosphine oxide (BAPO) salt, which in some cases can be a sodium or lithium MAPO or BAPO salt. In some embodiments, the photoinitiator included in the compositions described herein has the structure of Formula (VI) or Formula (VII): [ka] [ka] and where Y is Na or Li, and R-R 14 are each independently H, CH, or CHCH. For example, in some preferred embodiments, each of R, R, and R in formula (VI) is CH, and R, R, R 10 , R 11 , R 12 , R 13 , and R 14 is H. Such species may be referred to herein as "NaP," "Na-TPO," "sodium TPO," or "sodium TPO-L" when Y is Na, and as "LiP," "Li-TPO," "lithium TPO," or "lithium TPO-L" when Y is Li. In other preferred embodiments, R5, R7, R9, and R in formula (VII) 10 , R 12 , and R 14 Each of R, R, R, and R 13 is H. Such species may be referred to herein as BAPO-ONa when Y is Na and as BAPO-OLi when Y is Li. Furthermore, with reference to formulas (VI) and (VII) above, it should be understood that these structures also represent resonance structures, or (for convenience of illustration) structures in which the PO single bond and PO double bond "switch places" in the depiction of the structure (e.g., the PO double bond points "up" like the two adjacent CO double bonds, rather than pointing "down" as above).

[0049] The photoinitiator component may be present in the compositions described herein in any amount consistent with the objectives of the present disclosure. In some embodiments, the photoinitiator component is present in the composition in an amount of up to about 7 wt.%, up to about 5 wt.%, up to about 3 wt.%, or up to about 2 wt.%, based on the total weight of the composition. In some cases, the photoinitiator is present in an amount of about 0.1-7 wt.%, 0.1-5 wt.%, 0.1-3 wt.%, 0.1-2 wt.%, 0.5-5 wt.%, 0.5-3 wt.%, 0.5-2 wt.%, 1-7 wt.%, 1-5 wt.%, 1-3 wt.%, or 2-3 wt.%, based on the total weight of the composition.

[0050] Furthermore, it should be understood that the amounts (weight percent) set forth in the immediately preceding paragraph refer to photoinitiators that are non-oligomeric and non-polymeric. That is, the amounts above refer to "monomeric" or "molecular" photoinitiators, e.g., having a molecular weight of less than 400. However, it should also be understood that oligomeric or polymeric photoinitiators can also be used in the compositions and methods described herein. However, in such cases (when oligomeric or polymeric photoinitiators are used), the amounts (weight percent) above should be calculated without taking into account the weight of the oligomeric or polymeric portion of the oligomeric or polymeric photoinitiator. That is, to determine the total amount (weight percent) of oligomeric or polymeric photoinitiator present in a composition, the calculation (specifically, the numerator of the fraction) should be based only on the molecular weight of the photoactive portion of the photoinitiator (for purposes of this disclosure), and not on the molecular weight of the remainder or repeating units of the oligomeric or polymeric photoinitiator.

[0051] Additionally, in some examples, the compositions described herein may also include at least one colorant. Such colorants of the compositions described herein may be particulate colorants, such as particulate pigments, or molecular colorants, such as molecular dyes. Any such particulate or molecular colorant not inconsistent with the technical objectives of the present disclosure may be used. In some examples, for example, the colorant of the composition includes an inorganic pigment, such as TiO2 and / or ZnO. In some embodiments, the colorant of the composition may be any of RGB, sRGB, CMY, CMYK, L, and / or IL.* a * b * or colorants for use in a Pantone® color scheme. Furthermore, in some examples, the granular colorants described herein have an average particle size of less than about 5 μm or less than about 1 μm. In some examples, the granular colorants described herein have an average particle size of less than about 500 nm, e.g., less than about 400 nm, less than about 300 nm, less than about 250 nm, less than about 200 nm, or less than about 150 nm. In some examples, the granular colorants have an average particle size of about 50-5000 nm, about 50-1000 nm, or about 50-500 nm.

[0052] The colorant can be present in the compositions described herein in any amount consistent with the technical objectives of the present disclosure. In some examples, the colorant is present in the composition in an amount of up to about 2% by weight, or in an amount of about 0.005-2%, 0.01-2%, 0.01-1.5%, 0.01-1%, 0.01-0.5%, 0.1-2%, 0.1-1%, 0.1-0.5%, or 0.5-1.5% by weight, based on the total weight of the composition. In some embodiments, the compositions described herein exclude colorants as described above.

[0053] The compositions described herein can be prepared by any method consistent with the technical objectives of the present disclosure. In some embodiments, for example, methods for preparing the compositions described herein include mixing the components of the composition, optionally melting the mixture, and filtering the (optionally melted) mixture. In some cases, the components are mixed and optionally melted at a temperature of about 25°C to about 35°C, or at a temperature in the range of 25 to 55°C, 35 to 65°C, or 45 to 75°C. In some instances where melting one or more solid components of the composition is desirable or necessary, mixing and / or melting can be performed at a temperature in the range of about 75°C to about 85°C. In some embodiments, the compositions described herein are prepared by placing all of the components of the composition in a reaction vessel, optionally heating the resulting mixture, and stirring the resulting mixture at a temperature in the range of about 25°C to about 75°C or about 75°C to about 85°C. Stirring (and optionally heating) is continued until the mixture reaches a substantially homogenized liquid (or molten) state. Generally, the liquid (or molten) mixture can be filtered while in a flowable state to remove any large, undesirable particles that may interfere with the jetting or extrusion or other printing process. The filtered mixture can then be cooled to ambient temperature (if cooling is required) and stored until ready for use in the 3D printing system.

[0054] II. Methods for Forming 3D Articles by Additive Manufacturing In another aspect, described herein are methods of forming or "printing" a 3D article or object by additive manufacturing. The methods of forming a 3D article or object described herein may include forming the 3D article from multiple layers of a composition described herein in a layer-by-layer manner. In such cases, the composition can be used as a build material. In some embodiments, the compositions described herein can also be used as a support material. The methods of forming a 3D article by additive manufacturing may include forming the object in a manner other than a layer-by-layer manner. Any of the compositions described above in Section I can be used in the methods described herein. For example, in some embodiments, the methods described herein include providing a composition comprising a compound having a structure of Formula (I) or Formula (II) described in Section I and a monomeric curable material having a structure of Formula (III) described in Section I.

[0055] In some cases, methods described herein include providing a build material comprising the composition described above and selectively curing portions of the build material with incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength at wavelength λ. Furthermore, in some embodiments described herein, the build material is selectively cured according to a digital file or image of the desired article, such as according to preselected computer-aided design (CAD) parameters. Furthermore, in some cases, one or more layers of the build material described herein have a thickness of about 10 μm to about 100 μm, about 10 μm to about 80 μm, about 10 μm to about 50 μm, about 10 μm to about 40 μm, about 20 μm to about 100 μm, about 20 μm to about 80 μm, or about 20 μm to about 40 μm. Other thicknesses are possible.

[0056] By implementing the printing processes described herein, 3D articles printed from the build materials described herein can be provided that have high feature resolution. For purposes of reference herein, the "feature resolution" of an article may be the smallest controllable physical feature size of the article, or the pixel or voxel size of the printing process, with "pixel" and "voxel" understood to refer to the CAD parameters or other digital model of the article. In some embodiments, the printed articles described herein have an average voxel size that is greater than 50 μm per side on average (e.g., where the average voxel size corresponds to a volume having an average length in all three dimensions of 50-100 μm, 50-75 μm, 60-100 μm, 60-80 μm, or 60-70 μm). In other cases, the printed articles described herein have an average voxel size that is, on average, less than 50 μm, less than 40 μm, less than 30 μm, or less than 20 μm per side (e.g., where the average voxel size corresponds to a volume having an average length in all three dimensions of 10-45 μm, 10-40 μm, 10-30 μm, 10-25 μm, 10-20 μm, 15-45 μm, or 15-40 μm).

[0057] It should further be understood that the methods of printing 3D articles described herein can include, for example, MJP, DLP, or SLA 3D printing methods. For example, in some examples, an MJP method of printing a 3D article includes selectively depositing layers of a build material described herein in a fluid state onto a substrate, such as a build pad of a 3D printing system. Furthermore, in some embodiments, the methods described herein further include supporting at least one of the layers of build material with a support material. Any support material not inconsistent with the objectives of the present disclosure can be used.

[0058] The methods described herein can also include curing the layer of build material, including using curing radiation as described above (e.g., curing radiation having a peak wavelength λ). Additionally, curing can include polymerizing one or more polymerizable moieties or functional groups of one or more components of the build material. In some examples, a deposited layer of build material is cured prior to deposition of another or adjacent layer of build material. Additionally, in some embodiments, curing of one or more layers of deposited build material is achieved by exposing the one or more layers to electromagnetic radiation, such as ultraviolet (UV) light, visible light, or infrared light, as described above.

[0059] It is further noted that the wavelength λ used to cure materials according to the methods described herein can be any wavelength consistent with the objectives of the present disclosure. For example, in some cases, λ is a wavelength in the ultraviolet (UV) or visible region of the electromagnetic spectrum. In some cases, the peak wavelength λ is in the infrared (IR) region of the electromagnetic spectrum. In some embodiments, the wavelength λ is 250 nm to 400 nm, 300 nm to 385 nm, or 385 nm to 405 nm. In other cases, the wavelength λ is 600 nm to 800 nm or 900 nm to 1.3 μm. However, the exact wavelength λ is not particularly limited.

[0060] Further details regarding various methods, including "material deposition" methods (such as MJP) or "vat polymerization" methods (such as SLA or DLP), are provided below.

[0061] A. Material deposition method In material deposition methods, one or more layers of the build material described herein are selectively deposited onto a substrate and then cured, which may occur after the selective deposition of one, each, some, or all layers of the build material.

[0062] In some examples, a build material described herein (e.g., a composition described above in Section I) is selectively deposited in a fluid state onto a substrate, such as a build pad of a 3D printing system. Selective deposition may include, for example, depositing the build material according to preselected CAD parameters or other preselected parameters based on a digital file, image, or model of the desired article. For example, in some embodiments, a CAD file drawing corresponding to the desired 3D article to be printed is created and sliced ​​into a sufficient number of horizontal slices. The build material is then selectively deposited layer-by-layer according to the horizontal slices of the CAD file drawing to print the desired 3D article. A "sufficient" number of horizontal slices is the number necessary to successfully print the desired 3D article, for example, to manufacture it accurately and precisely.

[0063] Furthermore, in some embodiments, a preselected amount of the build material described herein is heated to an appropriate temperature and jetted through one or more print heads of a suitable inkjet printer to form a layer on a print pad in a print chamber. In some examples, each layer of build material is deposited according to preselected CAD or other preselected parameters based on a digital file, image, or model of the desired article. In some embodiments, a print head suitable for depositing the build material is a piezoelectric print head. Additional print heads suitable for depositing the build materials and support materials described herein are commercially available from various inkjet printing equipment manufacturers. For example, in some examples, print heads from Xerox, Hewlett Packard, or Ricoh can be used.

[0064] Additionally, in some embodiments, the build materials described herein remain substantially fluid upon deposition. Alternatively, in other examples, the build material exhibits a phase change and / or solidifies upon deposition. Furthermore, in some examples, the temperature of the printing environment can be controlled so that jetted droplets of the build material solidify upon contact with the receiving surface. In other embodiments, the jetted droplets of the build material do not solidify upon contact with the receiving surface but remain substantially fluid. Furthermore, in some examples, after each layer is deposited, the deposited material is planarized and cured using electromagnetic radiation (e.g., UV, visible, or infrared) before depositing the next layer. Optionally, several layers may be deposited before planarization and curing, or multiple layers may be deposited and cured, followed by deposition of one or more layers and subsequent planarization without curing. Planarization compensates for the thickness of one or more layers before curing by leveling the dispensed material and removing excess material to create a uniformly smooth exposed or flat, upward-facing surface on the printer's support platform. In some embodiments, planarization is achieved using a wiper device, such as a roller that may counter-rotate in one or more print directions but not in one or more other print directions. In some examples, the wiper device comprises a roller and a wiper that removes excess material from the roller. Additionally, in some examples, the wiper device is heated. Note that the viscosity of the jetted build material described herein before curing is, in some embodiments, desirably sufficient to retain its shape and not experience excessive viscous drag from the planarization device.

[0065] Furthermore, the support material, if used, can be deposited in a manner consistent with that described above for the build material. The support material can be deposited according to preselected CAD parameters (or other parameters described herein), for example, such that the support material is adjacent to or contiguous with one or more layers of the build material. The jetted droplets of support material, in some embodiments, solidify or solidify upon contact with the receiving surface. In some examples, the deposited support material also undergoes planarization, hardening, or planarization and hardening. Any support material not inconsistent with the objectives of this disclosure can be used.

[0066] The layer-by-layer deposition of the build material and the support material can be repeated until the 3D article is formed. In some embodiments, the method of printing a 3D article further includes removing the support material from the build material. The support material can be removed by any method not inconsistent with the technical objectives of the present disclosure. In some cases, for example, removing the support material includes melting the support material. In some such embodiments, the support material has a melting point, softening point, heat distortion temperature (HDT), or glass transition temperature (T g ), which has a melting point at least 20°C, at least 30°C, at least 40°C, at least 50°C, at least 70°C, or at least 100°C lower. In some such cases, the support material comprises or is formed from a wax. Furthermore, in some preferred embodiments described herein, the support material is not removed by dissolving or dispersing the support material in water or by using an aqueous solution as described herein.

[0067] Curing of the build material can occur after the selective deposition of one layer of build material, each layer of build material, several layers of build material, or all layers of build material necessary to print the desired 3D article. In some embodiments, partial curing of the deposited build material occurs after the selective deposition of one layer of build material, each layer of build material, several layers of build material, or all layers of build material necessary to print the desired 3D article. For reference purposes herein, a "partially cured" build material is one that can undergo further curing. For example, a partially cured build material is up to about 30% polymerized or crosslinked, or up to about 50% polymerized or crosslinked. In some embodiments, a partially cured ink is up to about 60%, up to about 70%, up to about 80%, up to about 90%, or up to about 95% polymerized or crosslinked.

[0068] Partially curing the deposited build material may include irradiating the build material with an electromagnetic radiation source or photocuring the build material (including using the curing radiation described above). Any electromagnetic radiation source consistent with the objectives of the present disclosure may be used, such as an electromagnetic radiation source that emits UV, visible, or infrared radiation. For example, in some embodiments, the electromagnetic radiation source may emit light having a wavelength of about 300 nm to about 900 nm, such as a xenon (Xe) arc lamp.

[0069] Further, in some embodiments, a post-cure is performed after the partial cure. For example, in some cases, the post-cure is performed after selectively depositing all layers of build material necessary to form the desired 3D article, after partially curing all layers of build material, or after performing both of the foregoing steps. Furthermore, in some embodiments, the post-cure includes photo-curing, including using the curing radiation described above having a peak wavelength λ. Again, any electromagnetic radiation source consistent with the objectives of the present disclosure may be used for the post-cure step described herein. For example, in some embodiments, the electromagnetic radiation source may be a light source having higher energy, lower energy, or the same energy as the electromagnetic radiation source used for the partial cure. In some cases where the electromagnetic radiation source used for the post-cure has higher energy (i.e., shorter wavelength) than that used for the partial cure, a xenon (Xe) arc lamp may be used for the partial cure, and a mercury (Hg) lamp may be used for the post-cure.

[0070] Furthermore, after post-curing, in some cases, the deposited layer of build material is at least about 80% polymerized or crosslinked, or at least about 85% polymerized or crosslinked. In some embodiments, the deposited layer of build material is at least about 90%, at least about 95%, at least about 98%, or at least about 99% polymerized or crosslinked. In some cases, the deposited layer of build material is about 80-100%, about 80-99%, about 80-95%, about 85-100%, about 85-99%, about 85-95%, about 90-100%, or about 90-99% polymerized or crosslinked.

[0071] The degree of polymerization or crosslinking can be determined using any protocol or method consistent with the technical objectives of the present disclosure, for example, by determining the percentage of monomer incorporated into the polymer network (e.g., based on the molecular weight of the polymer compared to the molecular weight of the monomer, or based on the total polymer mass compared to the theoretical maximum total polymer mass), or by determining the amount of unincorporated monomer. When multiple methods are used to determine the degree of polymerization or crosslinking, the results of these methods can be averaged to arrive at the percentages described herein. It should be further understood that the degree of polymerization or crosslinking described herein is different from the "degree of polymerization," which is defined as the number of repeat units in a polymer molecule.

[0072] B. Vat Polymerization Method It is also possible to form 3D articles from the build materials described herein using vat polymerization methods, such as SLA or DLP methods. Thus, in some examples, a method of printing a 3D article described herein includes holding the build material described herein in a fluid state in a container and selectively applying energy (e.g., curing radiation having a peak wavelength λ) to the build material in the container to solidify at least a portion of the fluid layer of build material, thereby forming a solidified layer that defines a cross-section of the 3D article. Furthermore, the method described herein may further include raising or lowering the solidified layer of build material to provide a new or second fluid layer of unsolidified build material on the surface of the fluid build material in the container, and then selectively applying energy again to the build material in the container to solidify at least a portion of the new or second fluid layer of build material to form a second solidified layer that defines a second cross-section of the 3D article. Furthermore, applying energy to solidify the build material can bond or adhere the first and second cross sections of the 3D article to one another in the z-direction (or a build direction corresponding to the above-described lifting or lowering direction). Furthermore, in some examples, the electromagnetic radiation has an average wavelength of 300-900 nm, and in other embodiments, the electromagnetic radiation has an average wavelength of less than 300 nm. In some examples, the curing radiation is provided by a computer-controlled laser beam or other light source, such as a DLP light source. Furthermore, in some examples, raising or lowering the solidified layer of build material is performed using a lifting platform positioned within the container of fluid build material. The methods described herein can also include a step of planarizing the new layer of fluid build material provided by raising or lowering the lifting platform. Such planarization can, in some examples, be performed by a wiper or roller.

[0073] It should further be appreciated that the foregoing process may be repeated as many times as desired to provide a 3D article. For example, in some instances, the process may be repeated "n" times, where n may be up to about 100,000, up to about 50,000, up to about 10,000, up to about 5000, up to about 1000, or up to about 500. Thus, in some embodiments, a method of printing a 3D article described herein may include selectively applying energy (e.g., curing radiation at a peak wavelength λ) to the build material in the container to solidify at least a portion of the nth fluid layer of the build material, thereby forming an nth solidified layer that defines the nth cross-section of the 3D article; raising or lowering the nth solidified layer of the build material to provide an (n+1)th layer of unsolidified ink on the surface of the fluid build material in the container; selectively applying energy to the (n+1)th layer of ink in the container to solidify at least a portion of the (n+1)th layer of the build material to form the (n+1)th solidified layer that defines the (n+1)th cross-section of the 3D article; raising or lowering the (n+1)th solidified layer of the build material to provide an (n+2)th layer of unsolidified build material on the surface of the fluid build material in the container; and continuing to repeat the foregoing steps to form the 3D article. It should further be understood that one or more steps of the methods described herein, such as selectively applying energy (e.g., curing radiation as described herein) to layers of build material, can be performed in accordance with an image of the 3D article in a computer-readable or digital format. General methods of 3D printing using stereolithography are further described in, among other places, U.S. Patent Nos. 5,904,889 and 6,558,606.

[0074] In such vat polymerization processes, the build material can be partially cured, as described above in Section IIA. For example, in some embodiments, selectively applying energy to the build material in the container to solidify at least a portion of the fluid layer of build material can include partially curing at least a portion of the fluid layer of build material. In other embodiments, the partial curing of at least a portion of the fluid layer of build material can occur after providing and solidifying a first layer of build material, before or after providing or solidifying a second layer of build material, or before or after providing or solidifying one, some, or all subsequent layers of build material.

[0075] Additionally, some embodiments of the vat polymerization processes described herein may undergo a post-cure, as described above in Section IIA, after partial curing or after the desired 3D article has been formed. The desired 3D article may be, for example, an article that corresponds to a design in a CAD file or other digital file, image, or model that corresponds to the desired 3D article.

[0076] III. Printed 3D Articles In another aspect, printed 3D articles are described herein. In some embodiments, the printed 3D articles are formed from compositions described herein and / or using additive manufacturing methods described herein. Any of the compositions described above in Section I can be used. For example, in some cases, the composition includes a compound having a structure of Formula (I) or Formula (II) and a monomeric curable material having a structure of Formula (III), as described in Section I. Similarly, any of the methods described above in Section II can be used to form articles according to the present disclosure.

[0077] In some examples, printed 3D articles are described herein that can have particular properties. In such cases, for example, a printed three-dimensional article formed from a composition or method described herein has a Young's modulus of greater than 100,000 kPa, as measured according to ASTM D638 (2022 edition).

[0078] The compositions and / or methods according to the present disclosure can be used to form a variety of articles via additive manufacturing, including, but not limited to, additive manufacturing. Similarly, articles printed according to the methods described herein can find application in a variety of fields. However, in some preferred embodiments, the article is a mold, e.g., an eggshell mold or other mold for use in molding applications such as injection molding or eggshell molding. In some such embodiments, the eggshell mold has an average wall thickness of 10 mm or less, or 5 mm or less. In some cases, the eggshell mold has an average wall thickness of 1 to 10 mm or 1 to 5 mm. Other articles can also be formed according to the additive manufacturing methods described herein. The average wall thickness of the mold can be measured by any method consistent with the technical objectives of the present disclosure. In some examples, the average wall thickness is measured based on all sides of the mold, or based on all sides except one side of the mold.

[0079] IV. Methods of Forming 3D Articles by Molding In another aspect, methods of forming a 3D article by molding are described herein. In some embodiments, such methods include providing a mold defining an interior volume and injecting a fluid material into the interior volume of the mold. In some cases, the method further includes solidifying the fluid material within the interior volume of the mold to form an article, and then removing the mold from the formed article. It should be understood that the mold can include or be formed from a composition described herein. Any of the compositions described above in Section I can be used. Furthermore, in some cases, providing the mold includes forming the mold using additive manufacturing, including using a 3D printing method described above in Section II.

[0080] Furthermore, forming a mold using the compositions described herein can, in some cases, allow for the injection of fluid materials at relatively high temperatures. For example, in some embodiments, the fluid materials are injected at temperatures of at least 40°C, at least 50°C, at least 75°C, at least 100°C, at least 150°C, at least 200°C, at least 220°C, at least 250°C, at least 270°C, or at least 300°C. Furthermore, using the compositions described herein can also allow for easy removal of the mold after solidification of the fluid material in the mold. For example, in some embodiments of the methods described herein, removing the mold from the article includes dissolving or dispersing the mold in water or an aqueous solution.

[0081] Referring now in more detail to particular steps of the methods described herein, the methods described herein include providing a mold defining an interior volume. The mold can have any interior volume not inconsistent with the objectives of the present disclosure. For example, in some cases, the mold may be configured to accommodate a range of sizes from 0.01 to 100L, 0.01 to 50L, 0.01 to 25L, 0.01 to 10L, 0.01 to 1L, 0.01 to 0.5L, 0.01 to 0.25L, 0.01 to 0.1L, 0.01 to 0.05L, 0.05 to 100L, 0.05 to 50L, 0.05 to 25L, 0.05 to 10L, 0.05 to 1L, 0.05 to 0.5L, 0.05 to 0.25L, 0.05 to 0.1L, 0.1 to 100L, 0.1 to 50L, 0.1 to 25L, 0.1 to 10L, 0.1 to 1L, 0.1 to 0.5L, 0. The mold may have an internal volume of 1 to 0.25 L, 0.25 to 100 L, 0.25 to 50 L, 0.25 to 25 L, 0.25 to 10 L, 0.25 to 1 L, 0.25 to 0.5 L, 0.25 to 0.1 L, 0.5 to 100 L, 0.5 to 50 L, 0.5 to 25 L, 0.5 to 10 L, 0.5 to 5 L, 0.5 to 1 L, 1 to 100 L, 1 to 50 L, 1 to 25 L, 1 to 10 L, 1 to 5 L, 5 to 100 L, 5 to 50 L, 5 to 25 L, 5 to 10 L, 10 to 100 L, 10 to 50 L, 10 to 25 L, 25 to 100 L, 25 to 50 L, or 50 to 100 L. Further, the mold and its internal volume may have any shape not inconsistent with the objectives of the present disclosure. In some examples, the interior volume has a shape that corresponds to the exterior surface of the final molded article formed by the methods described herein.

[0082] The methods described herein also include a step of injecting a fluid material into the interior volume. The fluid material can be injected by any method not inconsistent with the objectives of the present disclosure. For example, in some cases, the fluid material is injected at high pressure, e.g., 50-150 MPa or 70-115 MPa. Lower pressures can also be used. Any equipment known to one of skill in the art can be used to inject the fluid material into the interior volume described herein.

[0083] Additionally, in some examples, the fluid material is injected at an elevated temperature, e.g., at least 40°C, at least 50°C, at least 75°C, 100°C, 150°C, at least 200°C, at least 220°C, at least 250°C, at least 270°C, or at least 300°C. In some cases, the fluid material is injected at a temperature of 40-350°C, 40-300°C, 40-250°C, 40-220°C, 40-200°C, 40-150°C, 40-100°C, 40-75°C, 50-350°C, 50-300°C, 50-250°C, 50-220°C, 50-200°C, 50-150°C, 50-100°C, 50-75°C, 75-350°C, 75-300°C, 75-250°C, 75-220°C, 75-200°C, Injected at temperatures of 75-150°C, 75-100°C, 100-350°C, 100-300°C, 100-250°C, 100-220°C, 100-200°C, 100-150°C, 150-350°C, 150-300°C, 150-250°C, 150-220°C, 150-200°C, 200-350°C, 200-300°C, 200-250°C, 220-300°C, 250-350°C, or 250-300°C. Other temperatures may also be used. It should further be understood that in some embodiments, the injection temperature is within 30°C, 20°C, or 10°C of the melting point of the material being injected into the interior volume of the mold, and the melting point of the material is generally lower than the injection temperature (e.g., 1-30°C lower, 1-20°C lower, or 1-10°C lower).

[0084] Furthermore, any fluid material consistent with the technical objectives of the present disclosure may be used in the methods described herein. In some embodiments, for example, the fluid material includes a polymeric material such as polyurethane, polyamide (such as nylon), polyalkylene (such as polypropylene or polyethylene), or polyethylene terephthalate (PET). In some cases, the fluid material includes polystyrene (such as high impact polystyrene (HIPS)), polybutadiene, poly-acrylonitrile, polyacrylate, or a copolymer of two or more of the above, such as acrylonitrile butadiene styrene (ABS) or acrylonitrile styrene acrylate (ASA). In some embodiments, the fluid material includes polydimethylsiloxane (PDMS). Furthermore, in some cases, the fluid material includes polyetheretherketone (PEEK). In other examples, the fluid material includes a metallic material, such as an elemental metal or a combination, mixture, or alloy of metals. In other cases, the fluid material includes a wax, such as paraffin wax, soy wax, or palm wax.

[0085] The methods described herein may, in some cases, further include solidifying the fluid material within the mold after injecting the fluid material into the mold. Such solidification may be accomplished by any method consistent with the technical objectives of the present disclosure. In some embodiments, for example, solidifying the fluid material may include cooling the fluid material below its melting point (e.g., a melting point as described above). Such cooling may be passive (e.g., simply allowing time for the fluid material to reach thermal equilibrium with its surroundings) or active (e.g., directing relatively cool air or other fluid above or over the fluid material or its surroundings to promote a temperature decrease rather than simply allowing time to pass).

[0086] Furthermore, in some preferred embodiments, the method for forming a 3D article by molding further includes removing the mold from the article after solidification of the fluid material to form the article. The mold can be removed by any method consistent with the technical objectives of the present disclosure. In some cases, for example, removing the mold includes dissolving or dispersing the mold in water or an aqueous solution. The mold may be washed multiple times with water or an aqueous solution. Furthermore, it should be understood that an "aqueous solution" is a solution in which at least 50% of the solvent is water. In some embodiments, the aqueous solution includes a glycol. In some cases, the glycol may include glycerol or polyethylene glycol. Other glycols may also be used. In some implementations, the glycol may be used in the aqueous solution in an amount of 10 to 40% by weight, for example, 10%, 20%, 30%, or 40% by weight, based on the total weight of the aqueous solution.

[0087] It should be further understood that the water (or aqueous solution) may have a basic or acidic pH in some cases. For example, in some cases, the water or aqueous solution used to remove the mold has a pH of about 5 to about 7. In some embodiments, the water or aqueous solution used to remove the mold has a pH of about 7-14, 7-13, 7-12, 7-10, 8-10, 8-14, 8-13, 8-12, or 8-10. As will be appreciated by those skilled in the art, such a pH can be achieved, for example, by the inclusion of a Bronsted-Lowry acid or base. For example, in some cases, as will be appreciated by those skilled in the art, a strong acid or base, such as hydrochloric acid or sodium hydroxide, respectively, can be included in the water (or aqueous solution) at a desired concentration to provide the desired pH. For example, in some implementations, an aqueous solution of 3M NaOH or 6M NaOH can be used. Additionally, other proton or hydroxide sources can also be used.

[0088] Additionally, in some embodiments, removing the mold according to the methods described herein includes immersing the mold (and the molded article contained therein) in water or an aqueous solution (e.g., in a container). Additionally, in some cases, the mold (and the article contained therein) is immersed for a specific time and at a specific temperature. For example, in some embodiments, the mold is immersed at a temperature of 25-50°C, 25-45°C, 25-40°C, 30-50°C, 30-45°C, or 35-40°C for 6-12 hours, 0.5-1 day, 1-5 days, or 1-3 days.

[0089] Additionally, agitation is optionally used in addition to exposing the mold to water or an aqueous solution. Such agitation may optionally be provided by mechanical shaking or stirring, or by sonication.

[0090] Furthermore, in some embodiments, the method of forming a 3D article by molding can result in a 3D article mold having various end uses, including facilitating additional molding processes. In some implementations, the 3D article mold can be used to produce additional molds. For example, in some cases, the method can include providing a first mold defining a first interior volume, injecting a first fluid material into the interior volume of the first mold, and solidifying the first fluid material within the first interior volume of the first mold to form a first article. The first mold can include or be formed from any of the compositions described above in Section I or can be formed using any of the methods from Section II. In some implementations, the method can further include removing the first mold from the formed first article and applying a second fluid material to the exterior surface of the first article. In some cases, applying the second fluid material to the exterior surface of the first article includes placing or immersing the first article in the second fluid material. In other embodiments, applying the second fluid material to the exterior surface of the first article comprises spraying or coating the second fluid material onto the exterior surface of the first article.

[0091] Additionally, in some embodiments, the method further includes solidifying the second fluid material (or a portion thereof) on the exterior surface of the first article to form a mold for the first article. Such solidifying may be performed in some implementations by simply solidifying the second fluid material while it is in contact with or adhered or bonded to the exterior surface of the first article, which may occur in some cases due to hydrogen bonding, van der Waals forces, or other forces or bonds.

[0092] In some cases, the methods described herein may further include removing the first article from the second fluid material (e.g., after the second fluid material has solidified as described above) to provide a second mold defining a second interior volume. That is, in some embodiments, the method may provide a second mold formed from the solidified second fluid material. In such cases, removal of the first article can be considered to leave a void corresponding to the shape of the outer surface of the first article. In some such implementations, the methods described herein may further include injecting a third fluid material into the interior volume of the second mold. In some cases, the method further includes solidifying the third fluid material within the interior volume of the second mold to form the second article. The third fluid material may be any material consistent with the technical objectives of the present disclosure. In some embodiments, the third fluid material includes a material described above with respect to the first fluid material (e.g., a polymer, a metal, or a wax). Other fluid materials may also be used.

[0093] Similarly, it should be understood that in some cases, the second fluid material may be a material that can be applied as a liquid to the first article and solidify around the first article without altering the first article, particularly without altering the size or shape of the outer surface of the first article. The fluid material used to form the second mold may be any material consistent with the technical objectives of the present disclosure. In some embodiments, the liquid material may be a biocompatible material. In some cases, the biocompatible material includes a hydrogel material. As will be understood by those skilled in the art, a "hydrogel" can be considered a gel in which the liquid component is water or a water-based material. In some cases, the hydrogel may further include hyaluronic acid, chitosan, heparin, alginate, gelatin, fibrin, polyvinyl alcohol, polyethylene glycol, sodium polyacrylate, or a mixture thereof. Many suitable hydrogel materials will be readily apparent to those skilled in the art.

[0094] Non-limiting examples of the methods described herein are shown in Figures 1A-E. In Figure 1A, a 3D printed article (120) formed from the composition described in Section I is shown within a container (100). The printed article (120) can function as a mold (e.g., a first mold). In Figure 1B, the printed article or mold (120) is filled with a fluid material (e.g., a first fluid material) that solidifies to form a first article (140). In Figure 1C, the printed mold (120) is removed, resulting in a first article of the solidified first fluid material (140). In Figure 1D, this article (140) is molded into a hydrogel (160) within the container (100). The hydrogel (160) conforms to the exterior surface of the first article (140). Thus, as the hydrogel (160) solidifies, it forms or defines a second mold around the first article (140). In FIG. 1E, the first article (140) is removed, revealing the hydrogel material mold (160) having an interior volume (180). Additionally, it is noted in FIGS. 1A-1E that a conduit (shown as a vertically oriented conduit near the bottom of the container (100)) can be used to insert or remove material from the interior volume at certain steps in the method (e.g., by injecting a fluid material into the interior volume or by melting and extracting a previously solidified material from the interior volume).

[0095] V. Molded 3D articles In another aspect, molded 3D articles are described herein. In some embodiments, the molded 3D articles are formed by the method described above in Section IV using a mold formed from the composition described above in Section I. Furthermore, in some cases, the mold is formed using the method described above in Section II. The articles formed by the molding processes described herein can have any size, shape, and composition consistent with the objectives of the present disclosure, and these characteristics are not particularly limited. In some embodiments, for example, the molded articles are formed from the injected material described above in Section IV, such as a polymer or metal. [Example]

[0096] Some embodiments of compositions for 3D printing are illustrated in the following non-limiting examples.

[0097] Table 2 provides formulations of build materials according to some embodiments described herein. In Table 2, "Comp." means "composition," and the amounts listed for a given composition are weight percent based on the total weight of the composition. It is understood that all components of a given composition add up to 100 weight percent. Table 3 provides the components of Compositions 1-5. Additionally, Tables 2 and 3 include various abbreviations: "MCM" refers to monomer-curable material; "QY" refers to quinoline yellow; "E(10)-BPA-DA" refers to ethoxylated (10) bisphenol A diacrylate; "E(30)-BPA-DA" refers to ethoxylated (30) bisphenol A diacrylate; "HPA" refers to hydroxypropyl acrylate; "BEA" refers to 2-carboxyethyl acrylate; "AA" refers to acrylic acid; and "HEAA" refers to hydroxyethyl acrylamide. [Table 2] [Table 3]

[0098] Printed articles from compositions 1, 3, and 5 were tested using ASTM D638 to determine the Young's modulus of each composition, and the results are shown in Table 4. [Table 4]

[0099] A disk of a printed article of Compositions 1-5, weighing 0.2 g, was immersed in 20 g of an aqueous solution of 6 M NaOH in 30% glycerol. Every 8 hours, the disk was removed from the solution, gently tapped dry, and the diameter and height of the disk were measured to determine the total volume of the disk. The change in disk volume at each time point was averaged over time to determine the average degradation rate for each composition. The average degradation rates are shown in Table 5. [Table 5]

[0100] Some additional non-limiting exemplary embodiments are as follows:

[0101] Embodiment 1. A composition for additive manufacturing comprising: a compound having a structure of formula (I) or formula (II), wherein n is an integer from 4 to 40, and the compound having the structure of formula (I) and / or formula (II) is present in an amount of 10 to 35% by weight, based on the total weight of the composition; and a monomeric curable material having a structure of formula (III): Including, In the formula, the sum of p and q is an integer of 2 to 30. wherein R1 and R2 are each independently H or CH3; In the formula, R3 and R4 are each independently a C1-C4 alkyl group; In the formula, X is a straight or branched chain C1-C4 alkyl or the following structure: [ka] is a group having the formula During the ceremony [ka] represents the point of attachment to the remainder of the structure of formula (III).

[0102] Embodiment 2. The composition of embodiment 1, wherein X is C(CH3)2.

[0103] Embodiment 3. The composition of embodiment 1, wherein X is CH2.

[0104] Embodiment 4. X has the following structure: [ka] is a group having the formula During the ceremony [ka] represents the point of attachment to the remainder of the structure of formula (III).

[0105] Embodiment 5. The composition of any one of embodiments 1-4, wherein the monomeric curable material is present in an amount of 30-50% by weight, based on the total weight of the composition.

[0106] Embodiment 6. The composition of any one of embodiments 1-5, wherein the composition further comprises an acrylate or acrylamide component.

[0107] Embodiment 7. The composition of embodiment 6, wherein the acrylate or acrylamide component is present in an amount of 25 to 50% by weight, based on the total weight of the composition.

[0108] Embodiment 8. The composition of embodiment 6 or embodiment 7, wherein the acrylate or acrylamide component comprises one or more (meth)acrylates.

[0109] Embodiment 9. The composition of embodiment 8, wherein the one or more (meth)acrylates comprise carboxyethyl acrylate, hydroxypropyl acrylate, acrylic acid, or a mixture thereof.

[0110] Embodiment 10. The composition of embodiment 6 or embodiment 7, wherein the acrylate or acrylamide component comprises one or more acrylamides.

[0111] Embodiment 11. The composition of embodiment 10, wherein the one or more acrylamides comprise dimethylacrylamide, diethylacrylamide, acryloylmorpholine, isopropylacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide, hydroxyethylacrylamide, or a mixture thereof.

[0112] Embodiment 12. The composition of embodiment 10 or embodiment 11, wherein the one or more acrylamides are present in an amount of 10 to 40% by weight, based on the total weight of the composition.

[0113] Embodiment 13. The composition of any one of embodiments 1-12, wherein the composition further comprises a photoinitiator component.

[0114] Embodiment 14. The composition of embodiment 13, wherein the photoinitiator component is present in an amount of 0.1 to 3 weight percent, based on the total weight of the composition.

[0115] Embodiment 15. A method of forming a three-dimensional article by additive manufacturing, comprising: providing a composition according to any one of embodiments 1 to 14; and selectively curing a portion of the composition A method comprising:

[0116] Embodiment 16. The method of embodiment 15, wherein providing the composition comprises selectively depositing a layer of the composition in a fluid state onto a substrate.

[0117] Embodiment 17. A printed three-dimensional article formed from the composition of any one of embodiments 1-14.

[0118] Embodiment 18. The article of embodiment 17, wherein the article has a Young's modulus, as measured according to ASTM D638, of greater than 100,000 kPa.

[0119] Embodiment 19. A method of forming a three-dimensional article by molding, comprising: providing a mold defining an interior volume; injecting a fluid material into the interior volume of the mold; solidifying the fluid material within the interior volume of the mold to form an article; and removing the mold from the formed article. Including, The method wherein the mold comprises or is formed from the composition of any one of embodiments 1-14.

[0120] Embodiment 20. The method of embodiment 19, wherein the step of providing the mold comprises forming the mold using additive manufacturing.

[0121] Embodiment 21. The method of embodiment 19 or embodiment 20, wherein the fluid material comprises a polymeric material.

[0122] Embodiment 22. The method of embodiment 19 or embodiment 20, wherein the fluid material comprises a wax.

[0123] Embodiment 23. The method of any one of embodiments 19-22, wherein removing the mold from the article comprises dissolving or dispersing the mold in water or an aqueous solution.

[0124] Embodiment 24. The method of embodiment 23, wherein the aqueous solution comprises a glycol.

[0125] Embodiment 25. A method of forming a three-dimensional article by molding, comprising: providing a first mold defining a first interior volume; injecting a first fluid material into an interior volume of the first mold; solidifying the first fluid material within the interior volume of the first mold to form a first article; removing the first mold from the formed first article; applying a second fluid material to the exterior surface of the first article; and solidifying the second fluid material on the exterior surface of the first article to form a mold for the first article. Including, The method wherein the first mold comprises or is formed from the composition of any one of embodiments 1-14.

[0126] Embodiment 26. The method of embodiment 25, further comprising removing the first article from the second fluid material and providing a second mold defining a second interior volume.

[0127] Embodiment 27. The method of embodiment 26, further comprising injecting a third fluid material into the second interior volume of the second mold.

[0128] Embodiment 28. The method of embodiment 27, further comprising solidifying the third fluid material within the second interior volume of a second mold to form a second article.

[0129] Embodiment 29. The method of any one of embodiments 25 to 28, wherein the second fluid material is a biocompatible material.

[0130] Embodiment 30. The method of embodiment 29, wherein the biocompatible material is a hydrogel.

[0131] All patent documents mentioned herein are incorporated by reference in their entirety. In accomplishing various objectives of the present invention, various embodiments of the present invention have been described. It is to be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. 1. A composition for additive manufacturing comprising: Compounds having the structure of formula (I) and / or formula (II): 【Chemistry 1】 【Chemistry 2】 And, In the formula, n is an integer from 4 to 40; the compound having the structure of formula (I) and / or formula (II) is present in an amount of 10 to 35% by weight, based on the total weight of the composition; and A monomeric curable material having the structure of formula (III): 【Transformation 3】 And, In the formula, the sum of p and q is an integer from 2 to 30, In the formula, R １ and R ２ are each independently H or CH ３ and In the formula, R ３ and R ４ are each independently C １ ~C ４ is alkyl, In the formula, X is a straight or branched chain C １ ~C ４ Alkyl or the following structure: 【Chemistry 4】 is a group having the formula During the ceremony 【Transformation 5】 represents the point of attachment to the remainder of the structure of formula (III), A composition comprising:

2. X is C(CH ３ ) ２ The composition according to claim 1, characterized in that

3. X is CH ２ The composition according to claim 1, characterized in that

4. X is the following structure: 【Transformation 6】 is a group having the formula During the ceremony 【Transformation 7】 2. The composition of claim 1, wherein represents the point of attachment to the remainder of the structure of formula (III).

5. 10. The composition of claim 1, wherein the monomeric hardenable material is present in an amount of 30 to 50 weight percent, based on the total weight of the composition.

6. The composition of claim 1 , wherein the composition further comprises an acrylate or acrylamide component.

7. The composition of claim 6, wherein the acrylate or acrylamide component is present in an amount of 25 to 50% by weight, based on the total weight of the composition.

8. The composition of claim 6, wherein the acrylate or acrylamide component comprises one or more (meth)acrylates.

9. The composition of claim 8, wherein the one or more (meth)acrylates comprise carboxyethyl acrylate, hydroxypropyl acrylate, acrylic acid, or a mixture thereof.

10. The composition of claim 6, wherein the acrylate or acrylamide component comprises one or more acrylamides.

11. 11. The composition of claim 10, wherein the one or more acrylamides comprise dimethylacrylamide, diethylacrylamide, acryloylmorpholine, isopropylacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide, hydroxyethylacrylamide, or mixtures thereof.

12. 11. The composition of claim 10, wherein the one or more acrylamides are present in an amount of 10 to 40% by weight, based on the total weight of the composition.

13. The composition of claim 1 , wherein the composition further comprises a photoinitiator component.

14. 14. The composition of claim 13, wherein the photoinitiator component is present in an amount of 0.1 to 3 weight percent, based on the total weight of the composition.

15. 1. A method of forming a three-dimensional article by additive manufacturing, comprising: Providing the composition of claim 1; and selectively curing a portion of the composition A method comprising:

16. 1. A method of forming a three-dimensional article by molding, comprising: providing a mold defining an interior volume; injecting a fluid material into the interior volume of the mold; solidifying the fluid material within the interior volume of the mold to form an article; and removing the mold from the formed article. Including, 10. The method of claim 1, wherein the mold comprises or is formed from the composition of claim 1.

17. 17. The method of claim 16, wherein the step of providing a mold comprises forming the mold using additive manufacturing.

18. 17. The method of claim 16, wherein removing the mold from the article comprises dissolving or dispersing the mold in water or an aqueous solution.

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