Additives for build materials and related printed 3D articles

Abstract

Described herein are additives for three-dimensional build materials or inks that, in some embodiments, can impart one or more structural improvements to articles printed from the build materials. In one aspect, a polymerizable liquid includes at least one additive that includes multiple cyclopolymerizable functional groups separated by aliphatic or alkylene oxide linkers.

Description

[Technical Field]

[0001] The present invention relates to additives for three-dimensional build materials, and in particular to additives that can impart structural reinforcement to articles printed from the build materials. [Background technology]

[0002] 3D printers use build materials, also known as inks, to form various 3D objects, articles, or parts according to computer-generated files. In some examples, the build materials are solid at ambient temperatures and turn into liquids at elevated jetting temperatures. In other examples, the build materials are liquids at ambient temperatures. Summary of the Invention [Problem to be solved by the invention]

[0003] The build material can include a variety of chemical species. The chemical species included in the build material can be selected according to various considerations, including, but not limited to, the desired chemical and / or mechanical properties of the printed article and the operating parameters of the 3D printing device. For example, ultraviolet (UV) curable acrylate formulations are generally capable of printing parts at high resolution in DLP systems. However, the resulting parts often lack desirable mechanical properties and are prone to fracture or other degradation pathways. Such degradation pathways impair the performance of the article and lead to premature failure. [Means for solving the problem]

[0004] In view of the above, in some embodiments, described herein are additives for three-dimensional build materials or inks that can impart structural reinforcement to articles printed from the build material. In one aspect, the polymerizable liquid includes at least one additive comprising a plurality of cyclopolymerizable functional groups separated by aliphatic or alkylene oxide linkers, the cyclopolymerizable functional groups being of the formula: [ka] When present, the alkylene oxide linker is, in some embodiments, oligomeric or polymeric.

[0005] In some embodiments, the polymerizable liquid further comprises an oligomeric curable material, a monomeric curable material, or a mixture thereof. In some embodiments, the polymerizable liquid can include a photoinitiator component for initiating polymerization via one or more free radical mechanisms.

[0006] In another aspect, described herein is a method for printing a three-dimensional article. In some embodiments, the method includes providing a polymerizable liquid comprising an oligomeric curable material, a monomeric curable material, or a mixture thereof, and at least one additive comprising a plurality of cyclopolymerizable functional groups separated by an aliphatic linker or an alkylene oxide linker, wherein the cyclopolymerizable functional groups are of the formula: [ka]

[0007] The polymerizable liquid is printed and cured to form an article. In some embodiments, the article is formed via a layer-by-layer process, where layer formation occurs via deposition and curing of layers of polymerizable liquid. As further described herein, the polymerizable liquid may further include a photoinitiator component, and curing of the polymerizable liquid may occur by irradiation of the liquid with light of an appropriate wavelength to initiate free radical polymerization.

[0008] These and other embodiments are further described in the detailed description that follows. DETAILED DESCRIPTION OF THE INVENTION

[0009] The embodiments described herein can be more readily understood by reference to the following detailed description and examples. However, the elements, devices, and methods described herein are not limited to the specific embodiments presented in the detailed description and examples. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Many modifications and adaptations will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention.

[0010] Furthermore, all ranges disclosed herein should be understood to encompass any and all subranges subsumed therein. For example, a stated range of "1.0 to 10.0" should be deemed 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, or 4.7 to 10.0, or 3.6 to 7.9.

[0011] All ranges disclosed herein should also be considered to include the endpoints of the range, unless otherwise specified. For example, the range "between 5 and 10" should generally be considered to include the endpoints 5 and 10.

[0012] Furthermore, when the term "up to" is used in reference to an amount or quantity, it is understood that the amount is at least a detectable amount or quantity. For example, a substance present in an amount "up to" a particular amount can be present in an amount from a detectable amount up to and including the particular amount.

[0013] 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 selective deposition, jetting, fused deposition modeling, multi-jet modeling, and other additive manufacturing techniques now known or that may become known in the art that use build materials or inks to fabricate three-dimensional objects.

[0014] In one embodiment, the polymerizable liquid comprises at least one additive comprising a plurality of cyclopolymerizable functional groups separated by aliphatic linkers or alkylene oxide linkers, the cyclopolymerizable functional groups being of the formula: [ka] During the ceremony, [ka] is the point of attachment of the cyclopolymerizable functional group to the linker. In some embodiments, the additive is of the formula: [ka] wherein L is an aliphatic or alkylene oxide linker. When present, in some embodiments, the alkylene oxide linker may be oligomeric or polymeric. In such embodiments, the additive may be of the following formula: [ka] In the formula, R 1 is hydrogen or alkyl (e.g., C1-C10 alkyl, where "Cn" alkyl is understood to contain exactly "n" carbon atoms), and m is an integer from 1 to 20. In some embodiments, the additive comprises three or more cyclopolymerizable functional groups.

[0015] Additives can be present in the polymerizable liquid in any amount consistent with the technical objective of improving or enhancing the mechanical properties of three-dimensional articles printed from the polymerizable liquid. In some embodiments, the amount of additive is selected according to various considerations, including, but not limited to, the desired set of mechanical properties of the article printed from the polymerizable liquid, the printing conditions, and / or the chemical identity of other species in the polymerizable liquid. In some embodiments, one or more additives having a formula described herein are present in the polymerizable liquid in a total amount of 5 to 40 weight percent (wt%), 5 to 30 wt%, 7 to 30 wt%, 10 to 30 wt%, or 10 to 20 wt%, based on the total weight of the polymerizable liquid. Of course, it should further be understood that the total weight of the polymerizable liquid is 100 wt%.

[0016] The polymerizable liquid can further comprise an oligomeric curable material, a monomeric curable material, or a mixture thereof. For purposes of reference herein, a curable material includes a chemical species containing one or more curable or polymerizable moieties. For purposes of reference herein, a "polymerizable moiety" includes a moiety that can be polymerized or cured to provide a printed 3D article or object. Such polymerization or curing can be carried out in any manner consistent with the purposes of this disclosure. In some embodiments, for example, polymerization or curing includes irradiating the polymerizable or curable material with electromagnetic radiation having sufficient energy to initiate a polymerization or crosslinking reaction. For example, in some cases, ultraviolet (UV) radiation can be used. Thus, in some cases, the polymerizable moiety includes a photopolymerizable or photocurable moiety, such as a UV-polymerizable moiety. In some embodiments, the curable materials described herein are photopolymerizable or photocurable at wavelengths ranging from about 300 nm to about 400 nm or from about 320 nm to about 380 nm. Alternatively, in other examples, the curable material is photopolymerizable at visible wavelengths in the electromagnetic spectrum.

[0017] Additionally, the polymerization reaction may optionally include a free radical polymerization reaction, such as between unsaturated points, including ethylenically unsaturated points. Other polymerization reactions may also be used. As will be appreciated by those skilled in the art, the polymerization reaction used to polymerize the curable materials described herein may include the reaction of multiple "monomers" or chemical species having one or more functional groups or moieties that can react with each other to form one or more covalent bonds.

[0018] One non-limiting example of a polymerizable moiety of the curable materials described herein is an ethylenically unsaturated moiety such as a vinyl moiety, an allyl moiety, or a (meth)acrylate moiety, and throughout this disclosure the term "(meth)acrylate" includes acrylate or methacrylate or mixtures or combinations thereof.

[0019] Additionally, the oligomeric and / or monomeric curable materials described herein can include monofunctional, difunctional, trifunctional, tetrafunctional, pentafunctional, or higher functional curable species. For purposes of reference herein, a "monofunctional" curable species includes a species that includes one curable or polymerizable moiety. Similarly, a "difunctional" curable species includes a species that includes two curable or polymerizable moieties; a "trifunctional" curable species includes a species that includes three curable or polymerizable moieties; a "tetrafunctional" curable species includes a species that includes four curable or polymerizable moieties; and a "pentafunctional" curable species includes a species that includes five curable or polymerizable moieties. Thus, in some embodiments, the polymerizable liquid monofunctional curable materials described herein comprise mono(meth)acrylates, the polymerizable liquid difunctional curable materials described herein comprise di(meth)acrylates, the polymerizable liquid trifunctional curable materials described herein comprise tri(meth)acrylates, and the polymerizable liquid tetrafunctional curable materials described herein comprise tetra(meth)acrylates. The polymerizable liquid pentafunctional curable materials described herein comprise penta(meth)acrylates. Other monofunctional, difunctional, trifunctional, tetrafunctional, and pentafunctional curable materials can also be used.

[0020] Additionally, the mono-, di-, tri-, tetra-, and penta-functional curable materials can, in some cases, include relatively low molecular weight species, i.e., monomeric species (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., oligomeric species (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 (e.g., weight average molecular weight, in the case of species having a molecular weight distribution)).

[0021] Generally, any oligomeric curable material or combination of oligomeric curable materials consistent with the objectives of the present disclosure can be used in the polymerizable liquids described herein. In some cases, the oligomeric curable material comprises a polyester acrylate oligomer, a polyester (meth)acrylate oligomer, a urethane acrylate oligomer, a urethane (meth)acrylate oligomer, a polyether urethane oligomer, or an epoxy (meth)acrylate oligomer. Furthermore, in some embodiments, the oligomeric curable material described herein comprises an aliphatic polyester urethane acrylate oligomer and / or an acrylate amine oligomer resin, such as EBECRYL 7100.

[0022] Some non-limiting examples of commercially available oligomeric curable materials useful in some embodiments described herein include: alkoxylated tetrahydrofurfuryl acrylate available from SARTOMER under the tradename SR 611; a monofunctional urethane acrylate available from RAHN USA under the tradename GENOMER 1122; an aliphatic urethane diacrylate available from ALLNEX under the tradename EBECRYL 8402; a multifunctional acrylate oligomer available from DYMAX under the tradename BR-952; an aliphatic polyether urethane acrylate available from DYMAX under the tradename BR-371S; and a polyether urethane methacrylate available from DYMAX under the tradename BR-541MD. Other commercially available oligomeric curable materials may also be used.

[0023] Urethane (meth)acrylates suitable for use in the polymerizable liquids described herein can be prepared by known methods, typically by reacting a hydroxyl-terminated urethane with acrylic or methacrylic acid to yield the corresponding urethane (meth)acrylate, or by reacting an isocyanate-terminated prepolymer with a hydroxyalkyl acrylate or methacrylate to yield the urethane (meth)acrylate, as the case may be. 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, in some cases, be about 500 to 6,000. Urethane (meth)acrylates are also commercially available from SARTOMER under the product names CN980, CN981, CN975, and CN2901. In some embodiments, urethane acrylate oligomers are used in the polymerizable liquids 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 oligomeric curable material comprises an aliphatic polyester urethane acrylate or an aliphatic polyethylene urethane acrylate. Commercially available examples of these oligomeric species are available from DYMAX Corporation under the trade names BR-7432 and BR-543, respectively.

[0024] Oligomeric hardenable materials can be present in any desired amount in the polymerizable liquids described herein. In some embodiments, the total amount of oligomeric hardenable materials present is 5-50%, 5-40%, 5-35%, 5-30%, 10-50%, 10-40%, 10-35%, 10-30%, 15-50%, 15-40%, 15-35%, 15-30%, 20-50%, 20-40%, 20-35%, or 20-30% by weight based on the total weight of the polymerizable liquid.

[0025] The polymerizable liquids described herein can, in some embodiments, comprise a monomer-curable material. In some cases, the monomer-curable material of the polymerizable liquids described herein comprises one or more species of (meth)acrylate, such as one or more monofunctional, difunctional, trifunctional, tetrafunctional (meth)acrylates, and / or pentafunctional (meth)acrylates. In some embodiments, for example, the monomer-curable material comprises methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl (meth)acrylate, 2-methyl ... In some embodiments, the monomeric curable material may comprise one or more of: allyl acrylate, allyl methacrylate, triethylene glycol di(meth)acrylate, tricyclodecane dimethanol diacrylate, and cyclohexane dimethanol diacrylate.Further, in some cases, the monomer-curable material comprises a diacrylate and / or dimethacrylate ester of an aliphatic, alicyclic, or aromatic diol, including 1,3- or 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, tripropylene glycol, 1,4-dihydroxymethylcyclohexane, 2,2-bis(4-hydroxycyclohexyl)propane or bis(4-hydroxycyclohexyl)methane, hydroquinone, 4,4′-dihydroxybiphenyl, bisphenol A, bisphenol F, or bisphenol S. The monomer-curable material described herein may also comprise 1,1-trimethylolpropane tri(meth)acrylate, pentaerythritol monohydroxytri(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, bis(trimethylolpropane), tetra(meth)acrylate, and / or acryloylmorpholine.

[0026] Non-limiting examples of commercially available monomer-curable materials useful in some embodiments described herein include: isobornyl acrylate (IBOA), available commercially under the tradename SR 506 from SARTOMER; isobornyl methacrylate, available commercially under the tradename SR 423A from SARTOMER; monofunctional acrylate monomer, available commercially under the tradename SR 420 from SARTOMER; cyclic trimethylolpropane formal acrylate monomer, available commercially under the tradename SR 531 from SARTOMER; triethylene glycol diacrylate, available commercially under the tradename SR 272 from SARTOMER; triethylene glycol dimethacrylate, available commercially under the tradename SR 205 from SARTOMER; tricyclodecane dimethanol diacrylate, available commercially under the tradename SR 833S from SARTOMER; tris(2-hydroxyethyl) isocyanurate triacrylate, available commercially under the tradename SR 368 from SARTOMER; 2-phenoxyethyl acrylate available under the trade name SR 339; ethoxylated (3 mole) bisphenol A diacrylate available under the trade name SR 349 ​​from SARTOMER; cyclic monofunctional acrylate available under the trade name GENOMER 1120 from RAHN USA; dipentaerythritol pentaacrylate available under the trade name SR 399 LV from SARTOMER; and dicyclopentanyl acrylate and / or dicyclopentanyl methacrylate available under the trade name FA-513M from Showa Denko Materials. Other commercially available monomer-curable materials can also be used.

[0027] In some embodiments, the isocyanurate polyacrylate is of the following formula: [ka] In the formula, R 1 ~R 3are independently selected from the group consisting of hydrogen and alkyl (eg, C1-C10 alkyl), and m, n, and p are independently integers ranging from 1 to 10.

[0028] In some embodiments, the monomer-curable material comprises a heterocycle containing two or more unsaturated substituents. The substituted heterocycle can contain, for example, three unsaturated substituents. In some embodiments, the heterocycle can be polyallylated. When polyallylated, the heterocycle contains two or more allyl substituents. For example, the polyallylated heterocycle can comprise polyallyl isocyanurate. Alternatively, the heterocycle containing two or more unsaturated substituents can be of the following formula: [ka] In the formula, R 4 ~R 6 are independently selected from the group consisting of hydrogen and alkyl (eg, C1-C10 alkyl), and m, n, and p are independently integers ranging from 1 to 10.

[0029] In some embodiments, the monomer-curable material comprises a cyclocarbonate(meth)acrylate monomer. For example, the monomer-curable material can comprise a cyclocarbonate(meth)acrylate monomer of the following formula: [ka] wherein R1 is a linear or branched C1-C6 alkylene moiety; and wherein R2 is H or CH3.

[0030] The monomeric hardenable material can be present in any desired amount in the polymerizable liquids described herein. In some embodiments, the monomeric curable material is present in an amount of 5-80%, 5-75%, 5-70%, 5-60%, 10-80%, 10-75%, 10-70%, 10-60%, 15-80%, 15-75%, 15-70%, 15-60%, 20-80%, 20-75%, 20-70%, 20-60%, 25-80%, 25-75%, 25-70%, 25-60%, 30-80%, 30-75%, 30-70%, 30-60%, 35-80%, 35-75%, 35-70%, or 35-60% by weight based on the total weight of the polymerizable liquid. The monomer-curable material can include one type of monomer or a mixture of any of the types of monomers described above.

[0031] In some embodiments, the polymerizable liquid comprises polymer particles dispersed in a curable carrier. The polymer particles can be of any composition and / or structure consistent with achieving the technical objectives described herein. The polymer particles can comprise an elastomer, a thermoplastic, a thermoset, or any combination thereof. The specific compositional identity of the polymer particles can be selected according to the desired mechanical properties of the printed article. In some embodiments, the polymer particles exhibit a core-shell structure. The polymer particles can comprise, for example, an elastomeric core and a thermoplastic or thermoset shell. In some embodiments, a composite resin comprising core-shell particles in a curable resin is commercially available from Kaneka Texas Corporation under the trade name Kane Ace® MX. The polymer particles can have any desired size. In some embodiments, the polymer particles have a size less than 1 μm. The polymer particles can have an average size of, for example, 50 nm to 500 nm. In other embodiments, the polymer particles can have an average size greater than 1 μm, for example, 5 μm to 50 μm.

[0032] The polymer particles can be present in the curable carrier in any desired amount. In some embodiments, the polymer particles are present in an amount of 20 to 70% by weight or 30 to 60% by weight, based on the total weight of the composite resin. Furthermore, the composite resin can be present in the polymerizable liquid in any amount consistent with the technical objectives described herein. For example, the composite resin can be present in an amount of at least 20% by weight or at least 30% by weight, based on the total weight of the polymerizable liquid. In some embodiments, the composite resin is present in an amount of 5 to 30% by weight, based on the total weight of the polymerizable liquid.

[0033] The polymerizable liquids described herein can further include a photoinitiator component to initiate polymerization of one or more components of the liquid upon exposure to light of an appropriate wavelength. In some embodiments, the photoinitiator component can initiate polymerization of additives described herein that contain one or more unsaturated points polymerizable via a free radical mechanism. Similarly, a photoinitiator can be used to polymerize a (meth)acrylate component. In some embodiments, the additives described herein can be copolymerized with a (meth)acrylate component. In other embodiments, the additive and the (meth)acrylate component are polymerized independently.

[0034] Any photoinitiator not inconsistent with the objectives of the present disclosure can be used. In some embodiments, the photoinitiator preferably comprises an alpha-cleavage (unimolecular decomposition process) photoinitiator or a hydrogen abstraction photosensitizer-tertiary amine synergist operable to absorb light at about 250 nm to about 420 nm or about 300 nm to about 385 nm to generate free radicals.

[0035] Examples of alpha-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) with diethylaminoethyl methacrylate.

[0036] Further, in some examples, suitable photoinitiators include: benzoins, including benzoin ethers, such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether, benzoin phenyl ether, and benzoin acetate; acetophenones, including 2,2-dimethoxyacetophenone and 1,1-dichloroacetophenone; benzil ketals, such as benzil, benzil dimethyl ketal, and benzil diethyl ketal; anthraquinones, including 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone; trianthraquinones, including benzoin ethers, such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; Phenylphosphine, benzoylphosphine oxides, for example 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin TPO), 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 ketones or 1-hydroxyphenyl ketones, for example 1-hydroxycyclohexyl phenyl ketone, phenyl 1-hydroxyisopropyl ketone and 4-isopropylphenyl 1-hydroxyisopropyl ketone.

[0037] Suitable photoinitiators may also include those operable for use with HeCd laser radiation sources, including acetophenones, 2,2-dialkoxybenzophenones, and 1-hydroxyphenyl ketones, such as 1-hydroxycyclohexyl phenyl ketone or 2-hydroxyisopropyl phenyl ketone (=2-hydroxy-2,2-dimethylacetophenone). Additionally, in some cases, suitable photoinitiators include those operable for use with Ar laser radiation sources, including benzil ketals, such as benzil dimethyl ketal. In some embodiments, the photoinitiator comprises an α-hydroxyphenyl ketone, benzil dimethyl ketal, or 2,4,6-trimethylbenzoyldiphenylphosphine oxide, or a mixture thereof.

[0038] Another class of suitable photoinitiators includes ionic dye-counterion compounds, which, in some instances, can absorb actinic radiation and generate free radicals for polymerization initiation. In some embodiments, polymerizable liquids 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 and U.S. Pat. Nos. 4,751,102; 4,772,530; and 4,772,541.

[0039] The photoinitiator can be present in the polymerizable liquids described herein in any amount consistent with the objectives of the present disclosure. In some embodiments, the photoinitiator is present in an amount up to about 5 wt. %, based on the total weight of the polymerizable liquid. In some cases, the photoinitiator is present in an amount ranging from about 0.1 wt. % to about 5 wt. %.

[0040] Additionally, in some embodiments, the polymerizable liquids described herein can further include one or more sensitizers. The sensitizers can be added to increase the effectiveness of one or more photoinitiators that may also be present. Any sensitizer not inconsistent with the objectives of the present disclosure can be used. In some cases, the sensitizer includes isopropylthioxanthone (ITX) or 2-chlorothioxanthone (CTX).

[0041] The sensitizer can be present in the polymerizable liquid in any amount consistent with the objectives of the present disclosure, hi some embodiments, the sensitizer is present in an amount ranging from about 0.1% to about 2% by weight, or from about 0.5% to about 1% by weight, based on the total weight of the polymerizable liquid.

[0042] In some embodiments, one or more UV absorbers and / or light stabilizers may be present in the polymerizable liquid. In some embodiments, for example, the one or more UV absorbers and / or light stabilizers may be present in an amount of 0.1 to 2 wt %, based on the total weight of the polymerizable liquid. In some embodiments, the UV absorbers and / or light stabilizers are commercially available from BASF, Florham Park, New Jersey, under the trade designation TINUVIN®.

[0043] Further described herein are methods for printing three-dimensional articles. In some embodiments, the methods include providing a polymerizable liquid comprising an oligomeric curable material, a monomeric curable material, or a mixture thereof, and at least one additive comprising a plurality of cyclopolymerizable functional groups separated by an aliphatic linker or an alkylene oxide linker, wherein the cyclopolymerizable functional groups are of the formula: [ka]

[0044] The polymerizable liquid is printed and cured to form an article. In some embodiments, the article is formed via a layer-by-layer process, where layer formation occurs via deposition and curing of layers of polymerizable liquid. As further described herein, the polymerizable liquid may further include a photoinitiator component, and curing of the polymerizable liquid may occur by irradiation of the liquid with light of an appropriate wavelength to initiate free radical polymerization.

[0045] In some embodiments, a layer of polymerizable liquid can be deposited according to an image of the 3D article in a computer-readable format during the formation of the three-dimensional article. The polymerizable liquid can be deposited according to preselected computer-aided design (CAD) parameters. Furthermore, in some cases, one or more layers of polymerizable liquid 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 20 μm to about 100 μm, about 20 μm to about 80 μm, or about 20 μm to about 40 μm. Other thicknesses are also possible.

[0046] It should further be understood that the methods of printing 3D articles described herein may include so-called "multi-jet" or "stereolithography" 3D printing methods. For example, in some examples, a multi-jet method of printing a 3D article includes selectively depositing layers of a polymerizable liquid described herein 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 polymerizable liquid with a support material. Any support material not inconsistent with the objectives of the present disclosure may be used.

[0047] Stereolithography can also be used to form 3D articles from the polymerizable liquids described herein. For example, in some cases, a method for printing a 3D article includes holding a polymerizable liquid in a container and selectively applying energy to the polymerizable liquid in the container to solidify at least a portion of the polymerizable liquid, thereby forming a solidified layer that defines a cross-section of the 3D article. Furthermore, the methods described herein further include raising or lowering the solidified layer to provide a new or second layer of polymerizable liquid, and then selectively applying energy to the polymerizable liquid in the container again to solidify at least a portion of the new or second polymerizable liquid that defines a second cross-section of the 3D article. Furthermore, the first and second cross-sections of the 3D article can be bonded or adhered to each other in the z-direction (or a build direction corresponding to the above-mentioned rising or lowering direction) by applying energy to solidify the polymerizable liquid. Additionally, selectively applying energy to the polymerizable liquid within the container can include applying electromagnetic radiation, e.g., UV and / or visible radiation, having sufficient energy to initiate polymerization of the polymerizable material described herein. Additionally, in some cases, raising or lowering the solidified layer of polymerizable liquid is performed using an elevator platform disposed within the container of fluid modeling material. The methods described herein can also include planarizing the new layer of polymerizable liquid provided by raising or lowering the elevator platform. Such planarization can, in some cases, be performed with a wiper or roller.

[0048] Articles printed according to the methods described herein can exhibit one or more desirable mechanical properties due to the composition and microstructure of the printed article. 3D articles printed from the polymerizable liquids described herein can exhibit a tensile modulus of 1900 to 2700 MPa. In some embodiments, the 3D printed articles can exhibit a tensile strength of greater than 40 MPa, e.g., 40 to 70 MPa or 50 to 65 MPa. The tensile strength and tensile modulus values ​​provided herein can be determined according to ASTM D638.

[0049] Additionally, 3D articles printed from the polymerizable liquids described herein can exhibit an elongation to break of at least 3%, at least 5%, or at least 10% (e.g., as determined according to ASTM D638). In some embodiments, the printed 3D articles have an elongation to break of greater than 10%, e.g., 10-20%, as determined by ASTM D638. 3D articles printed from the polymerizable liquids described herein can also exhibit a heat distortion temperature (HDT) of at least 90°C, e.g., 100-260°C. In some embodiments, 3D articles printed from the polymerizable liquids described herein can have an HDT of greater than 300°C. HDT is measured using DMA at 0.455 MPa according to ASTM D648.

[0050] Additionally, in some cases, 3D articles printed from the polymerizable liquids described herein (and the polymerizable liquid itself upon polymerization) may have other desirable compositional parameters or characteristics. For example, in some implementations, the 3D articles or polymerizable liquids described herein have relatively high stress relaxation values ​​or residual stress (e.g., as measured according to ASTM E837 or ASTM D638 Type IV). Furthermore, in some embodiments, the 3D articles or polymerizable liquids described herein have relatively high stress relaxation / residual stress values ​​in water at 37°C. For example, in some preferred embodiments, the 3D articles or polymerizable liquids described herein have stress relaxation / residual stress values ​​or stress relaxation residual loads (5% strain) in water at 37°C, as measured according to ASTM D638 Type IV, of greater than 1 Newton (N), e.g., values ​​between 1 and 5 N, between 1 and 3 N, between 1 and 2 N, or between 1 and 1.5 N.

[0051] Additionally, 3D articles printed from the polymerizable liquids described herein (and the polymerizable liquids themselves upon polymerization) can be resistant to hydrolysis or degradation due to exposure to water. For example, in some cases, the polymerizable liquids described herein (or 3D articles printed therefrom) can be hydrolysis resistant with respect to maintaining certain mechanical properties, such as flexural strength, flexural modulus, and / or elongation at break, after exposure to water. Thus, the 3D articles or polymerizable liquids described herein (depending on their composition / microstructure) can exhibit one, two, or all three of the following hydrolysis resistance metrics: Flexural strength (FS) hydrolysis resistance of at least 80%, at least 85%, at least 90%, or at least 95%; a flexural modulus (FM) hydrolysis resistance of at least 80%, at least 85%, at least 90%, or at least 95%; and At least 80%, at least 85%, at least 90%, or at least 95% elongation at break (EOB) hydrolysis resistance.

[0052] The above metrics are based on the "water exposure" of a 3D article (or polymerized liquid) as follows: The relevant property (i.e., flexural strength, flexural modulus, or elongation at break) of a test sample (e.g., a 3D article formed from a polymerizable liquid) is measured within 12 hours of printing the 3D article. The test sample is then immersed in water at 37°C for 24 hours. After this immersion period, the test sample is dried, and the relevant property (i.e., flexural strength, flexural modulus, or elongation at break) is measured again in the same manner as before (e.g., using ASTM D638, with the output provided in MPa). The post-immersion measurement is then compared to the pre-immersion measurement. For example, if a given test sample has a flexural strength of 100 MPa before water immersion and a flexural strength of 95 MPa after 24 hours of water immersion, the flexural strength hydrolysis resistance derived from comparing 95 MPa to 100 MPa is 95%.

[0053] Furthermore, in some embodiments, water immersion can even improve certain properties, such as elongation at break. In some cases, for example, the 3D articles described herein have EOB hydrolysis resistances of 80-130%, 80-125%, 90-125%, or 90-120%. While it should be understood that 100% is a typical maximum, flexural strength hydrolysis resistance and / or flexural modulus hydrolysis resistance can also, in some cases, be up to 110% or 105%.

[0054] Additionally, in some preferred embodiments, 3D articles printed from the polymerizable liquids described herein (and the polymerizable liquids themselves upon polymerization) have one, two, three, four, five, six, or all seven of the following compositional parameters: (1) A stress relaxation / residual stress value (or stress relaxation residual load, 5% strain) of greater than 1 N (e.g., 1-5 N, 1-3 N, 1-2 N, or 1-1.5 N) in water at 37°C when measured according to ASTM D638 Type IV; (2) a stress relaxation onset load (5% strain) of less than 35 N or less than 30 N (e.g., 15–35 N or 20–35 N) in water at 37°C when measured according to ASTM D638 Type IV; (3) a tensile strength of more than 40 MPa (e.g., 40-70 MPa or 50-65 MPa) when measured according to ASTM D638 Type IV; (4) A flexural strength of more than 35 MPa or more than 40 MPa (e.g., 35-50 MPa or 40-50 MPa), when measured in accordance with ISO 20795-2; (5) a flexural modulus of greater than 1000 MPa (e.g., 1000-2000 MPa or 1000-1500 MPa), as measured in accordance with ISO 20795-2; (6) 5 kJ / m when measured according to ISO 179 3 Super, 8kj / m 3 Over or 10kj / m 3 Ultra (e.g., 5 to 25 kj / m 3 , 5~20kj / m 3 , 8~25kj / m 3 , 8~20kj / m3 , 10~25kj / m 3 , 10~20kj / m 3 , or 15 to 25 kj / m 3 ) Charpy impact 1J value; and (7) Elongation at break of greater than 8% or greater than 10% (e.g., 10-20%) when measured according to ISO 527 or ASTM D638 Type IV.

[0055] These and other embodiments are further illustrated in the following non-limiting examples. [Example]

[0056] Table 1 provides formulations of polymerizable liquids according to some embodiments described herein. The amounts listed in Table 1 (and other composition / formula tables below) are weight percents based on the total weight of the polymerizable liquid. A dash (-) indicates the absence of a component in the case of a composition / formula table, or the absence of a measurement in the case of a measured property table. [Table 1]

[0057] Table 2 shows the physical properties of 3D articles printed using Formulations 1-5. [Table 2]

[0058] Table 3 provides formulations of polymerizable liquids according to some embodiments described herein. [Table 3]

[0059] Table 4 provides the physical properties of 3D articles printed using Formulations 6-10. [Table 4]

[0060] Table 5 provides formulations of polymerizable liquids according to some embodiments described herein. [Table 5]

[0061] Table 6 provides the physical properties of 3D articles printed using Formulations 11 and 12, including their resistance to hydrolysis when tested as described above. [Table 6]

[0062] Table 7 provides formulations of polymerizable liquids according to some embodiments described herein. In Table 7, the cyclic polymerizable additive had the formula of Example 6 below. Examples 14-16 are particularly preferred embodiments and can be compared to Example 13, which is a less preferred embodiment. [Table 7]

[0063] Table 8 provides the physical properties of 3D articles printed using Equations 13-16. In Table 8, stress relaxation values ​​were measured according to ASTM D638 Type IV using dog-bone shaped samples (L x W x H = 50 mm x 21 mm x 0.76 mm) with a support span of 16 mm and a strain rate of 32 mm / min. Values ​​were measured after immersing the samples at 37°C for at least 12 hours. Flexural strain was calculated as 6*D*H / L 2 where L is the support span, H is the height or depth of the test beam / sample, and D is the maximum deflection at the center of the test beam / sample. [Table 8]

[0064] Table 9 provides formulations of polymerizable liquids according to some preferred embodiments described herein. In Table 9, the cyclic polymerizable additive had the formula of Example 6 below. Examples 17 and 18 are particularly preferred embodiments and can be compared to Example 19, which is a non-preferred embodiment. [Table 9]

[0065] Table 10 provides the physical properties of 3D articles printed using Equations 17-19. In Table 10, stress relaxation values ​​were measured as described above for Table 8. [Table 10]

[0066] Table 11 provides formulations of polymerizable liquids according to some additional preferred embodiments described herein. [Table 11]

[0067] Table 12 provides the physical properties of 3D articles printed using Equations 20-22. In Table 12, stress relaxation values ​​were measured as described above for Table 8. [Table 12]

[0068] Some additional non-limiting exemplary embodiments are further described below.

[0069] Embodiment 1. A polymerizable liquid comprising at least one additive comprising a plurality of cyclopolymerizable functional groups separated by aliphatic linkers or alkylene oxide linkers, the cyclopolymerizable functional groups being of the formula: [ka]

[0070] Embodiment 2. The polymerizable liquid of embodiment 1, wherein the additive is present in an amount of 5 to 40 weight percent, based on the total weight of the polymerizable liquid.

[0071] Embodiment 3. The polymerizable liquid of embodiment 1, wherein the additive is present in an amount of 5 to 30 weight percent, 7 to 30 weight percent, or 10 to 30 weight percent, or 10 to 20 weight percent, based on the total weight of the polymerizable liquid.

[0072] Embodiment 4. The polymerizable liquid of any of the preceding embodiments, wherein the alkylene oxide linker is an oligomer or polymer.

[0073] Embodiment 5. The polymerizable liquid of any of the previous embodiments, wherein the additive is of the following formula: [ka] wherein L is an aliphatic or alkylene oxide linker.

[0074] Embodiment 6. The polymerizable liquid of any of the previous embodiments, wherein the additive is of the following formula: [ka] In the formula, R 1 is hydrogen or alkyl, and m is an integer of 1 to 20.

[0075] Embodiment 7. The polymerizable liquid of any of the previous embodiments, further comprising an oligomeric curable material, a monomeric curable material, or a mixture thereof.

[0076] Embodiment 8. The polymerizable liquid of embodiment 7, comprising an oligomeric hardenable material in an amount of 5 to 50 weight percent, based on the total weight of the polymerizable liquid.

[0077] Embodiment 9. The polymerizable liquid of embodiment 7, comprising a monomeric curable material in an amount of 10 to 70 weight percent, based on the total weight of the polymerizable liquid.

[0078] Embodiment 10. The polymerizable liquid of embodiment 7, comprising an oligomeric curable material in an amount of 5 to 50 weight percent, based on the total weight of the polymerizable liquid, and a monomeric curable material in an amount of 10 to 70 weight percent, based on the total weight of the polymerizable liquid.

[0079] Embodiment 11. The polymerizable liquid of any of embodiments 7-10, wherein the oligomeric hardenable material comprises an acrylate oligomer, a methacrylate oligomer, or a mixture thereof.

[0080] Embodiment 12. The polymerizable liquid of any of embodiments 7-11, wherein the monomer-curable material comprises an acrylate monomer, a methacrylate monomer, or a mixture thereof.

[0081] Embodiment 13. The polymerizable liquid of embodiment 12, wherein the acrylate monomer comprises a cyclocarbonate (meth)acrylate monomer.

[0082] Embodiment 14. The polymerizable liquid of embodiment 13, wherein the cyclocarbonate (meth)acrylate monomer is of the formula: [ka] wherein R1 is a linear or branched C1-C6 alkylene moiety; and wherein R2 is H or CH3.

[0083] Embodiment 15. A method of printing a three-dimensional article, comprising the steps of providing a polymerizable liquid according to any of embodiments 1-14; and printing and curing the polymerizable liquid with light to form an article.

[0084] Embodiment 16. A polymerizable liquid comprising: 15 to 35% by weight of an oligomeric curable material; 35 to 75% by weight of a monomer-curable material; and 10 to 20% by weight of an additive containing multiple cyclopolymerizable functional groups separated by aliphatic or alkylene oxide linkers Including, The cyclopolymerizable functional group is of the formula: [ka] During the ceremony, [ka] is the point of attachment of the cyclopolymerizable functional group to the linker; The polymerizable liquid, upon curing, has a stress relaxation / residual stress value of greater than 1 N in water at 37°C as measured according to ASTM D638 Type IV, and optionally, the polymerizable liquid, upon curing, exhibits one, two, three, four, five, or six of the additional structural features in the numbered list (1) through (7) set forth above immediately before the Examples section.

[0085] Embodiment 17. The polymerizable liquid of embodiment 16, wherein the oligomeric curable material comprises one or more urethane (meth)acrylate oligomers.

[0086] Embodiment 18. The polymerizable liquid of embodiment 16 or embodiment 17, wherein the monomer-curable material comprises one or more (meth)acrylate species.

[0087] Embodiment 19. The polymerizable liquid of embodiment 16 or embodiment 17, wherein the monomer-curable material comprises at least one monofunctional (meth)acrylate and at least one multifunctional (meth)acrylate.

[0088] Embodiment 20. The polymerizable liquid of embodiment 19, wherein the monomer-curable material comprises a monofunctional acrylate and a monofunctional methacrylate.

[0089] Embodiment 21. The polymerizable liquid of embodiment 20, wherein the monofunctional acrylate is present in the polymerizable liquid in an amount from 10 to 20 weight percent or from 20 to 30 weight percent, and the monofunctional methacrylate is present in the polymerizable liquid in an amount from 10 to 20 weight percent, based on the total weight of the polymerizable liquid.

[0090] Embodiment 22. The polymerizable liquid of embodiment 19, wherein the multifunctional (meth)acrylate comprises a di(meth)acrylate, and the di(meth)acrylate is present in the polymerizable liquid in an amount of 5 to 25 weight percent, based on the total weight of the polymerizable liquid.

[0091] Embodiment 23. The oligomeric curable material comprises one or more urethane (meth)acrylate oligomers; the monomeric curable material comprises a monofunctional acrylate, a monofunctional methacrylate, and a di(meth)acrylate, and optionally a urethane acrylate; the monofunctional acrylate is present in the polymerizable liquid in an amount of 10 to 20% by weight or 20 to 30% by weight; the monofunctional methacrylate is present in the polymerizable liquid in an amount of 10 to 20 weight percent, based on the total weight of the polymerizable liquid; The di(meth)acrylate is present in the polymerizable liquid in an amount of 5 to 25 weight percent, based on the total weight of the polymerizable liquid; 23. The polymerizable liquid according to any one of embodiments 16 to 22.

[0092] Embodiment 24. The additive has the following formula: [ka] It is of wherein L is an aliphatic or alkylene oxide linker; 24. The polymerizable liquid of embodiment 23.

[0093] Embodiment 25. The additive has the following formula: [ka] It is of In the formula, R 1 is hydrogen or alkyl, and m is an integer of 1 to 20; 25. The polymerizable liquid of embodiment 24.

[0094] Embodiment 26. A method for printing a three-dimensional object, comprising: Providing a polymerizable liquid according to any one of embodiments 16 to 25; and Printing and curing a polymerizable liquid with light to form an article Including, The polymerizable liquid, upon cure, has a stress relaxation / residual stress value of greater than 1 N in water at 37°C when measured according to ASTM D638 Type IV method.

[0095] 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 method of printing a three-dimensional object, comprising: providing a polymerizable liquid; and printing and curing said polymerizable liquid with light to form said article; Including, The polymerizable liquid is 15 to 35 wt. % of an oligomeric curative material; 35 to 75% by weight of a monomer-curable material; and 10 to 20% by weight of an additive containing multiple cyclopolymerizable functional groups separated by aliphatic or alkylene oxide linkers Including, The cyclopolymerizable functional group has the following formula: 【Chemistry 1】 It is of The polymerizable liquid, upon curing, has a stress relaxation / residual stress value of greater than 1 N in water at 37° C. as measured according to ASTM D638 Type IV. A method characterized by:

2. The method of claim 1 , wherein the oligomeric curable material comprises one or more urethane (meth)acrylate oligomers.

3. The method of claim 1 , wherein the monomer-curable material comprises one or more (meth)acrylate species.

4. 10. The method of claim 1, wherein the monomer-curable material comprises at least one monofunctional (meth)acrylate and at least one multifunctional (meth)acrylate.

5. The method of claim 4, wherein the monomer-curable material comprises a monofunctional acrylate and a monofunctional methacrylate.

6. the monofunctional acrylate is present in the polymerizable liquid in an amount of 20 to 30% by weight; The monofunctional methacrylate is present in the polymerizable liquid in an amount of 10 to 20% by weight, based on the total weight of the polymerizable liquid.

6. The method according to claim 5.

7. the multifunctional (meth)acrylate comprises a di(meth)acrylate; The di(meth)acrylate is present in the polymerizable liquid in an amount of 5 to 25% by weight, based on the total weight of the polymerizable liquid.

5. The method according to claim 4.

8. the oligomeric curable material comprises one or more urethane (meth)acrylate oligomers; the monomeric curable material comprises a monofunctional acrylate, a monofunctional methacrylate, and a di(meth)acrylate; the monofunctional acrylate is present in the polymerizable liquid in an amount of 20 to 30 weight percent; the monofunctional methacrylate is present in the polymerizable liquid in an amount of 10 to 20 weight percent, based on the total weight of the polymerizable liquid; The di(meth)acrylate is present in the polymerizable liquid in an amount of 5 to 25 weight percent, based on the total weight of the polymerizable liquid.

2. The method of claim 1.

9. The additive has the following formula: 【Chemistry 2】 It is of where L is an aliphatic or alkylene oxide linker 9. The method according to claim 8.

10. The additive has the following formula: 【Transformation 3】 It is of In the formula, R １ is hydrogen or alkyl, and m is an integer from 1 to 20.

10. The method according to claim 9.

11. A polymerizable liquid, 15 to 35 wt. % of an oligomeric curative material; 35 to 75% by weight of a monomer-curable material; and 10 to 20% by weight of an additive containing multiple cyclopolymerizable functional groups separated by aliphatic or alkylene oxide linkers Including, The cyclopolymerizable functional group has the following formula: 【Chemistry 4】 It is of During the ceremony, 【Transformation 5】 is the point of attachment of the cyclopolymerizable functional group to the linker; The polymerizable liquid, upon curing, has a stress relaxation / residual stress value of greater than 1 N in water at 37° C. as measured according to ASTM D638 Type IV. A polymerizable liquid characterized by:

12. 12. The polymerizable liquid of claim 11, wherein the oligomeric hardenable material comprises one or more urethane (meth)acrylate oligomers.

13. 12. The polymerizable liquid of claim 11, wherein the monomer-curable material comprises one or more (meth)acrylate species.

14. 12. The polymerizable liquid of claim 11, wherein the monomer-curable material comprises at least one monofunctional (meth)acrylate and at least one multifunctional (meth)acrylate.

15. 15. The polymerizable liquid of claim 14, wherein the monomeric curable material comprises a monofunctional acrylate and a monofunctional methacrylate.

16. the monofunctional acrylate is present in the polymerizable liquid in an amount of 20 to 30% by weight; the monofunctional methacrylate is present in the polymerizable liquid in an amount of 10 to 20 weight percent, based on the total weight of the polymerizable liquid; 16. The polymerizable liquid of claim 15.

17. the multifunctional (meth)acrylate comprises a di(meth)acrylate; the di(meth)acrylate is present in the polymerizable liquid in an amount of 5 to 25 weight percent, based on the total weight of the polymerizable liquid; 15. The polymerizable liquid of claim 14.

18. the oligomeric curable material comprises one or more urethane (meth)acrylate oligomers; the monomeric curable material comprises a monofunctional acrylate, a monofunctional methacrylate, and a di(meth)acrylate; the monofunctional acrylate is present in the polymerizable liquid in an amount of 20 to 30 weight percent; the monofunctional methacrylate is present in the polymerizable liquid in an amount of 10 to 20 weight percent, based on the total weight of the polymerizable liquid; the di(meth)acrylate is present in the polymerizable liquid in an amount of 5 to 25 weight percent, based on the total weight of the polymerizable liquid; The polymerizable liquid of claim 11 .

19. The additive has the following formula: 【Transformation 6】 It is of wherein L is an aliphatic or alkylene oxide linker; 20. The polymerizable liquid of claim 18.

20. The additive has the following formula: 【Transformation 7】 It is of In the formula, R １ is hydrogen or alkyl, and m is an integer from 1 to 20; 20. The polymerizable liquid of claim 19.

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