Additives used to build materials and related printed 3D products

Abstract

Described herein are additives for three-dimensional build materials or inks, which in some embodiments can impart one or more structural enhancements to an article printed from the build material. In one aspect, a polymerizable liquid comprises at least one additive comprising a plurality of ring-polymerizable functional groups separated by an aliphatic linker or an alkanol ether linker.

Description

[0001] Cross-referencing related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 185,763, filed May 7, 2021, pursuant to 35 USC §119, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to additives for use in three-dimensional building materials, and more particularly, to additives that can impart structural reinforcement to articles printed from building materials. Background Technology

[0004] 3D printers use build-up materials, also known as inks, to form various 3D objects, articles, or parts based on computer-generated files. In some cases, the build-up material is solid at ambient temperature and transforms into a liquid upon increasing the spray temperature. In other cases, the build-up material is liquid at ambient temperature.

[0005] Build materials can contain a variety of chemicals. The types of chemicals to be included in the build materials can be selected based on 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 apparatus. For example, UV-curable acrylate formulations can often be printed on DLP systems at high resolution. However, in many cases, the resulting parts lack the desired mechanical properties and may be prone to breakage or other degradation pathways. Such degradation pathways impair article performance, leading to premature failure. Summary of the Invention

[0006] In view of the foregoing, this document describes additives for three-dimensional building materials or inks, wherein in some embodiments, the additives may impart one or more structural reinforcements to articles printed from the building material. In one aspect, the polymerizable liquid comprises at least one additive, said additive including a plurality of cyclopolymerizable functional groups separated by aliphatic linkers or alkanoyl ether linkers, the cyclopolymerizable functional groups having the following formula:

[0007]

[0008] In some embodiments, when present, the alkanol ether linker is an oligomer or a polymer.

[0009] In some embodiments, the polymerizable liquid further includes oligomeric curable materials, monomeric curable materials, or mixtures thereof. In some embodiments, the polymerizable liquid may contain a photoinitiator component that initiates polymerization via one or more free radical mechanisms.

[0010] In another aspect, this document describes a method for printing three-dimensional articles. 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, said additive comprising a plurality of cyclopolymerizable functional groups separated by aliphatic linkers or alkanoyl ether linkers, the cyclopolymerizable functional groups having the following formula:

[0011]

[0012] A polymerizable liquid is printed and cured to form an article. In some embodiments, the article is formed via a layer-by-layer method, wherein layer formation is performed via layer deposition and curing of the polymerizable liquid. As further described herein, the polymerizable liquid may further comprise a photoinitiator component, and curing of the polymerizable liquid can be performed by irradiating the liquid with light of an appropriate wavelength to initiate free radical polymerization.

[0013] These and other implementation schemes are further described in detail below. Detailed Implementation

[0014] The embodiments described herein can be more readily understood by referring to the following detailed description and examples. However, the elements, apparatus, and methods described herein are not limited to the specific embodiments provided in the detailed description and examples. It should be recognized that these embodiments are merely illustrative of the principles of the invention. Many improvements and modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

[0015] Furthermore, it should be understood that all ranges disclosed herein include any and all subranges contained herein. For example, it should be considered that the stated range “1.0 to 10.0” includes any and all subranges that begin with a minimum of 1.0 or greater and end with a maximum of 10.0 or less, such as 1.0 to 5.3, or 4.7 to 10.0, or 3.6 to 7.9.

[0016] Unless otherwise explicitly stated, all scopes disclosed herein should be considered to include the endpoints of the scopes. For example, the scope “between 5 and 10” should generally be considered to include the endpoints 5 and 10.

[0017] Additionally, when the phrase “at most” is used in relation to quantity or amount, it should be understood that the quantity is at least a detectable quantity or amount. For example, material present in a quantity specified as “at most” can exist from a detectable quantity and at most include the specified quantity.

[0018] The terms “3D printing system,” “3D printer,” “printing,” etc., generally describe various solid freeform fabrication techniques used to manufacture 3D articles or objects, such as selective deposition, jetting, fused deposition modeling, multi-jet modeling, and other additive manufacturing techniques known in the art or that may be known in the future, that use building materials or inks to manufacture 3D objects.

[0019] In one aspect, the polymerizable liquid comprises at least one additive, said additive including a plurality of cyclizable functional groups separated by aliphatic linkers or alkanoyl ether linkers, the cyclizable functional groups having the following formula:

[0020]

[0021] in This represents the connection point between the cyclic functional group and the linker. In some embodiments, the additive has the following formula:

[0022]

[0023] Where L is an aliphatic or alkanoyl ether linker. In some embodiments, the alkanoyl ether linker may be an oligomer or a polymer. In such embodiments, the additive may have the following formula:

[0024]

[0025] Where R 1 It is hydrogen or alkyl (e.g., C1-C10 alkyl, where "Cn" alkyl should be understood to include exactly "n" carbon atoms), and m is an integer from 1 to 20. In some embodiments, the additive contains three or more cyclopolymerizable functional groups.

[0026] Additives may be present in the polymerizable liquid in any amount that is not consistent with the technical purpose of improving or enhancing the mechanical properties of the three-dimensional articles printed from the polymerizable liquid. In some embodiments, the amount of additive is selected based on a variety of considerations, including but not limited to the desired set of mechanical properties of the articles printed from the polymerizable liquid, printing conditions, and / or other kinds of chemical properties in the polymerizable liquid. In some embodiments, one or more additives having the formula described herein are present in the polymerizable liquid in a total amount of 5 to 40 wt%, 5 to 30 wt%, 7 to 30 wt%, or 10 to 30 wt% based on the total weight of the polymerizable liquid. Of course, it should also be understood that the total weight of the polymerizable liquid is 100 wt%.

[0027] Polymerizable liquids may also include oligomeric curable materials, monomeric curable materials, or mixtures thereof. For the purposes of this reference, "curable material" includes a chemical class comprising one or more curable or polymerizable portions. For the purposes of this reference, "polymerizable portion" includes a portion that is polymerizable or curable to provide a printed 3D article or object. Such polymerization or curing can be carried out in any manner not inconsistent with the purposes of this disclosure. For example, in some embodiments, 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 may be used. Thus, in some cases, the polymerizable portion includes a photopolymerizable or photocurable portion, such as a UV-polymerizable portion. In some embodiments, the curable material described herein is photopolymerizable or photocurable at wavelengths in the range of about 300 nm to about 400 nm or about 320 nm to about 380 nm. Alternatively, in other cases, the curable material is photopolymerizable at visible wavelengths of the electromagnetic spectrum.

[0028] Additionally, in some cases, the polymerization reaction includes free radical polymerization, for example, reactions between unsaturation points, including olefinic unsaturation points. Other polymerization reactions may also be used. As will be understood by those skilled in the art, the polymerization reaction used to polymerize the curable material described herein may include reactions of multiple “monomers” or chemical species having one or more functional groups or portions capable of reacting with each other to form one or more covalent bonds.

[0029] A non-limiting example of the polymerizable portion of the curable material described herein is an olefinically unsaturated portion, such as a vinyl portion, an allyl portion, or a (meth)acrylate portion, wherein throughout this disclosure the term "(meth)acrylate" includes acrylates or methacrylates or mixtures or combinations thereof.

[0030] Furthermore, the oligomeric curable materials and / or monomeric curable materials described herein may include curable types that are monofunctional, difunctional, trifunctional, tetrafunctional, pentafunctional, or higher functional. For the purposes of this document, a "monofunctional" curable type includes a chemical type containing one curable or polymerizable moiety. Similarly, a "difunctional" curable type includes a chemical type containing two curable or polymerizable moieties, a "trifunctional" curable type includes a chemical type containing three curable or polymerizable moieties, a "tetrafunctional" curable type includes a chemical type containing four curable or polymerizable moieties, and a "pentafunctional" curable type includes a chemical type containing five curable or polymerizable moieties. Therefore, in some embodiments, the monofunctional curable material of the polymerizable liquid described herein includes mono(meth)acrylate, the difunctional curable material of the polymerizable liquid described herein includes di(meth)acrylate, the trifunctional curable material of the polymerizable liquid described herein includes tri(meth)acrylate, the tetrafunctional curable material of the polymerizable liquid described herein includes tetra(meth)acrylate, and the pentafunctional curable material of the polymerizable liquid described herein includes penta(meth)acrylate. Other monofunctional, difunctional, trifunctional, tetrafunctional, and pentafunctional curable materials may also be used.

[0031] In addition, in some cases, monofunctional, difunctional, trifunctional, tetrafunctional, and pentafunctional curable materials may contain relatively low molecular weight species, i.e., monomer species (e.g., species with molecular weights below 300, below 200, or below 100), or relatively high molecular weight species, i.e., oligomer species (e.g., species with molecular weights above 300, above 400, above 500, or above 600 and optionally below 10,000 (e.g., weight-average molecular weight, in the case of species with molecular weight distribution)).

[0032] Generally, any oligomeric curable material or combination of oligomeric curable materials that is not inconsistent with the purpose of this disclosure may be used in the polymerizable liquids described herein. In some cases, oligomeric curable materials include polyester acrylate oligomers, polyester (meth)acrylate oligomers, urethane acrylate oligomers, urethane (meth)acrylate oligomers, polyether urethane oligomers, or epoxy (meth)acrylate oligomers. Additionally, in some embodiments, the oligomeric curable materials described herein include aliphatic polyester urethane acrylate oligomers and / or acrylate amine oligomer resins, such as EBECRYL 7100.

[0033] Some non-limiting examples of commercially available oligomeric curable materials that can be used in some of the embodiments described herein include the following: alkoxylated tetrahydrofurfuryl acrylate, available under the trade name SR 611 from SARTOMER; monofunctional urethane acrylate, available under the trade name GENOMER 1122 from RAHN USA; aliphatic urethane diacrylate, available under the trade name EBECRYL 8402 from ALLNEX; polyfunctional acrylate oligomer, available under the trade name BR-952 from DYMAX Corporation; aliphatic polyether urethane acrylate, available under the trade name BR-371S from DYMAX Corporation; and polyether urethane methacrylate, available under the trade name BR-541MD from DYMAX Corporation. Other commercially available oligomeric curable materials may also be used.

[0034] In some cases, urethane (meth)acrylates suitable for the polymerizable liquids described herein can be prepared in known ways, generally by reacting a hydroxyl-terminated urethane with acrylic acid or methacrylic acid to obtain the corresponding urethane (meth)acrylate, or by reacting an isocyanate-terminated prepolymer with hydroxyalkyl acrylate or hydroxyalkyl methacrylate to obtain the urethane (meth)acrylate. Suitable methods are disclosed in particular in EP-A 114982 and EP-A133 908. In some cases, the weight-average molecular weight of such (meth)acrylate oligomers can be from about 500 to 6,000. Urethane (meth)acrylates are also available from SARTOMER under the product names CN980, CN981, CN975, and CN2901. In some embodiments, the urethane acrylate oligomers are used in the polymerizable liquids described herein. Suitable urethane acrylates may include difunctional aliphatic urethane acrylates from DYMAX Corporation under the trade names BR-741 and BR-970. In some implementations, the oligomeric curable material includes aliphatic polyester urethane acrylate or aliphatic polyether urethane acrylate. Commercially available examples of these oligomer types are available from DYMAX Corporation under the trade names BR-7432 and BR-543, respectively.

[0035] Oligomeric curable materials may be present in any desired amount in the polymerizable liquid described herein. In some embodiments, the total amount of oligomeric curable material present is 5-50% by weight or 10-50% by weight based on the total weight of the polymerizable liquid.

[0036] In some embodiments, the polymerizable liquid described herein may include a monomer-curable material. In some cases, the monomer-curable material of the polymerizable liquid described herein comprises one or more (meth)acrylate species, such as one or more monofunctional, difunctional, trifunctional, tetrafunctional (meth)acrylates and / or pentafunctional (meth)acrylates. For example, in some embodiments, the monomer-curable material includes methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-decyl methacrylate, n-dodecyl methacrylate, 2-hydroxyethyl methacrylate, 2- or 3-hydroxypropyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2- or 3-ethoxypropyl methacrylate, tetrahydrofurfuryl methacrylate, isobornyl methacrylate, dicyclopentyl methacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, cyclohexyl methacrylate, 2-phenoxyethyl acrylate, glycidyl acrylate, isodecyl acrylate, 2-phenoxyethyl methacrylate, lauryl methacrylate, or combinations thereof. In some embodiments, the monomer-curable material includes one or more of allyl acrylate, allyl methacrylate, triethylene glycol di(meth)acrylate, tricyclodecanedimethyl diacrylate, and cyclohexanedimethyl diacrylate. Additionally, in some cases, the monomer-curable material includes diacrylates and / or dimethacrylates of aliphatic, alicyclic, or aromatic diols, 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 materials described herein may also include 1,1-trimethylolpropane tri(meth)acrylate, pentaerythritol monohydroxytri(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, bis(trimethylolpropane)tetra(meth)acrylate and / or acryloylmorpholine.

[0037] Non-limiting examples of commercially available monomer-curable materials that can be used in some of the embodiments described herein include the following: isobornyl acrylate (IBOA), available from SARTOMER under the trade name SR 506; isobornyl methacrylate, available from SARTOMER under the trade name SR423A; monofunctional acrylate monomer, available from SARTOMER under the trade name SR 420; cyclic trimethylolpropane acrylate monomer, available from SARTOMER under the trade name SR 531; triethylene glycol diacrylate, available from SARTOMER under the trade name SR 272; triethylene glycol dimethacrylate, available from SARTOMER under the trade name SR 205; tricyclodecanedimethyl alcohol diacrylate, available from SARTOMER under the trade name SR 833S; tri(2-hydroxyethyl)isocyanurate triacrylate, available from SARTOMER under the trade name SR 368; 2-phenoxyethyl acrylate, available from SARTOMER under the trade name SR 339 was purchased from SARTOMER; ethoxylated (3 mol) bisphenol A diacrylate, purchased from SARTOMER under the trade name SR 349; cyclic monofunctional acrylate, purchased from RAHN USA Corp. under the trade name GENOMER 1120; dipentaerythritol pentaacrylate, purchased from SARTOMER under the trade name SR 399LV; and dicyclopentamethacrylate, purchased from ShowaDenko Materials under the trade name FA-513M. Other commercially available monomer-curable materials may also be used.

[0038] In some embodiments, isocyanurate polyacrylates have the following formula:

[0039]

[0040] Where R 1 -R 3 Each is independently selected from hydrogen and alkyl (e.g., C1-C10 alkyl), and m, n, and p are independently integers ranging from 1 to 10.

[0041] In some embodiments, the monomer-curable material comprises a heterocycle containing two or more unsaturated substituents. For example, the substituted heterocycle may contain three unsaturated substituents. In some embodiments, the heterocycle may be polyallylated. Upon polyallylation, the heterocycle contains two or more allyl substituents. For example, the polyallylated heterocycle may comprise a polyallyl isocyanurate. Alternatively, the heterocycle containing two or more unsaturated substituents may have the following formula:

[0042]

[0043] Where R 4 -R 6Each is independently selected from hydrogen and alkyl (e.g., C1-C10 alkyl), and m, n, and p are independently integers ranging from 1 to 10.

[0044] In some embodiments, the monomer-curable material comprises a cyclic carbonate (meth)acrylate monomer. For example, the monomer-curable material may comprise a cyclic carbonate (meth)acrylate monomer of the following formula:

[0045]

[0046] Wherein R1 is a straight-chain or branched C1-C6 alkylene moiety; and wherein R2 is H or CH3.

[0047] Monomer-curable materials may be present in any desired amount in the polymerizable liquid described herein. In some embodiments, the monomer-curable material is present in an amount of 5-70% by weight or 10-60% by weight based on the total weight of the polymerizable liquid. The monomer-curable material may comprise one type of monomer or a mixture of any of the aforementioned monomer types.

[0048] In some embodiments, the polymerizable liquid comprises polymer particles dispersed in a curable carrier. The polymer particles may have any composition and / or structure that is not inconsistent with achieving the technical objectives described herein. The polymer particles may comprise elastomers, thermoplastics, thermosolids, or any combination thereof. The specific compositional characteristics of the polymer particles may be selected based on the desired mechanical properties of the printed article. In some embodiments, the polymer particles exhibit a core-shell structure. For example, the polymer particles may comprise an elastomer core and a thermoplastic or thermosolid shell. In some embodiments, a composite resin comprising core-shell particles in a curable resin is used in Kane... The trade name MX is purchased from Kaneka Texas Corporation. The polymer particles can have any desired size. In some embodiments, the polymer particles have a size less than 1 μm. For example, the polymer particles can have an average size of 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.

[0049] Polymer particles may be present in the curable carrier in any desired amount. In some embodiments, the polymer particles are present in an amount of 20-70% by weight or 30-60% by weight based on the total weight of the composite resin. Furthermore, the composite resin may be present in the polymerizable liquid in any amount not inconsistent with the technical objectives described herein. For example, the composite resin may 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 5-30% by weight based on the total weight of the polymerizable liquid.

[0050] The polymerizable liquids described herein may further comprise a photoinitiator component for initiating the polymerization of one or more components of the liquid upon exposure to light of a suitable wavelength. In some embodiments, the photoinitiator component may initiate the polymerization of the additives described herein, the additives comprising one or more sites unsaturated and polymerizable via a free radical mechanism. Similarly, a (meth)acrylate component may be polymerized using a photoinitiator. In some embodiments, the additives described herein may copolymerize with the (meth)acrylate component. In other embodiments, the additives and the (meth)acrylate component polymerize independently.

[0051] Any photoinitiator that is not inconsistent with the purpose of this disclosure may be used. In some embodiments, the photoinitiator includes an α-cleavage type (unimolecular decomposition process) photoinitiator or a hydrogen-extractable photosensitizer-tertiary amine synergist, operable to absorb light preferably between about 250 nm and about 420 nm or between about 300 nm and about 385 nm to generate free radicals.

[0052] Examples of α-cleavage photoinitiators include Irgacure 184 (CAS 947-19-3), Irgacure 369 (CAS119313-12-1), and Irgacure 819 (CAS162881-26-7). Examples of photosensitizer-amine combinations include DarocurBP (CAS119-61-9) with diethylaminoethyl methacrylate.

[0053] Additionally, in some cases, suitable photoinitiators include benzoin derivatives (including benzoin, benzoin ethers (e.g., benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether, benzoin phenyl ether) and benzoin acetate), acetophenone derivatives (including acetophenone, 2,2-dimethoxyacetophenone, and 1,1-dichloroacetophenone), benzoinyl, benzoinyl ketals (e.g., benzoinyl dimethyl ketal and benzoinyl diethyl ketal), anthraquinones (including 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and 2-pentylanthraquinone), triphenylphosphine, benzoylphosphine oxide (e.g., 2,4,6-trimethylbenzoyl diphenylphosphine oxide (Lucirin)). TPO), benzophenones (e.g., benzophenone and 4,4'-bis(N,N'-dimethylamino)benzophenone), thioxanone and xanthonone, acridine derivatives, phenazine derivatives, quinoxaline derivatives or 1-phenyl-1,2-propanedione, 2-O-benzoyl oxime, 1-aminophenyl ketone or 1-hydroxyphenyl ketone (e.g., 1-hydroxycyclohexylphenyl ketone, phenyl-1-hydroxyisopropyl ketone and 4-isopropylphenyl-1-hydroxyisopropyl ketone).

[0054] Suitable photoinitiators may also include those operable for use with HeCd laser sources, including acetophenone, 2,2-dialkoxybenzophenone, and 1-hydroxyphenyl ketone (e.g., 1-hydroxycyclohexylphenyl ketone) or 2-hydroxyisopropylphenyl ketone (=2-hydroxy-2,2-dimethylacetophenone). Additionally, in some cases, suitable photoinitiators include those operable for use with Ar laser sources, including benzoylayl ketals, such as benzoylayldimethyl ketal. In some embodiments, the photoinitiator includes α-hydroxyphenyl ketone, benzoylayldimethyl ketal, or 2,4,6-trimethylbenzoyldiphenylphosphine oxide, or mixtures thereof.

[0055] In some cases, another suitable class of photoinitiators includes ionic dye-counterionic compounds capable of absorbing photochemical radiation and generating free radicals for polymerization initiation. In some embodiments, the polymerizable liquid containing the ionic dye-counterionic compound can be polymerized upon exposure to visible light in a tunable wavelength range of about 400 nm to about 700 nm. Ionic dye-counterionic compounds and their operating modes are disclosed in EP-A-0 223 587 and U.S. Patent Nos. 4,751,102, 4,772,530, and 4,772,541.

[0056] Photoinitiators may be present in the polymerizable liquid described herein in any amount not inconsistent with the purposes of this disclosure. In some embodiments, the photoinitiator is present in an amount of up to about 5% by weight based on the total weight of the polymerizable liquid. In some cases, the photoinitiator is present in an amount ranging from about 0.1% by weight to about 5% by weight.

[0057] Additionally, in some embodiments, the polymerizable liquid described herein may also contain one or more sensitizers. Sensitizers may be added to increase the potency of one or more photoinitiators that may also be present. Any sensitizer not inconsistent with the purposes of this disclosure may be used. In some cases, the sensitizer includes isopropylthioxanthone (ITX) or 2-chlorothioxanthone (CTX).

[0058] The sensitizer may be present in the polymerizable liquid in any amount that is not inconsistent with the purpose of this disclosure. In some embodiments, the sensitizer is present in an amount ranging from about 0.1% by weight to about 2% by weight or from about 0.5% by weight to about 1% by weight of the total weight of the polymerizable liquid.

[0059] In some embodiments, one or more UV absorbers and / or light stabilizers may be present in the polymerizable liquid. For example, in some embodiments, one or more UV absorbers and / or light stabilizers may be present in an amount of 0.1-2% by weight based on the total weight of the polymerizable liquid. In some embodiments, UV absorbers and / or light stabilizers may... The trademark name was acquired from BASF in Florham Park, New Jersey.

[0060] Additionally, this document describes a method for printing three-dimensional articles. 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, said additive comprising a plurality of cyclopolymerizable functional groups separated by aliphatic linkers or alkanolate linkers, the cyclopolymerizable functional groups having the following formula:

[0061]

[0062] A polymerizable liquid is printed and cured to form an article. In some embodiments, the article is formed via a layer-by-layer method, wherein layer formation is performed via layer deposition and curing of the polymerizable liquid. As further described herein, the polymerizable liquid may further comprise a photoinitiator component, and curing of the polymerizable liquid can be performed by irradiating the liquid with light of an appropriate wavelength to initiate free radical polymerization.

[0063] In some embodiments, the polymerizable liquid layer can be deposited in a computer-readable format during the formation of the 3D article based on an image of the 3D article. The polymerizable liquid can be deposited according to pre-selected computer-aided design (CAD) parameters. Additionally, in some cases, one or more polymerizable liquid layers 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.

[0064] Additionally, it should be understood that the methods for printing 3D articles described herein may include so-called “multi-jet” or “stereolithography” 3D printing methods. For example, in some cases, multi-jet methods for printing 3D articles include selectively depositing the polymerizable liquid layer 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 polymerizable liquid layer with a support material. Any support material that is not inconsistent with the purposes of this disclosure may be used.

[0065] 3D articles can also be formed from the polymerizable liquids described herein using stereolithography. For example, in some cases, the method of printing 3D articles includes holding the 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 cured layer defining a cross-section of the 3D article. Additionally, the method described herein may further include raising or lowering the cured layer to provide a new or second polymerizable liquid layer, and then again selectively applying energy to the polymerizable liquid in the container to solidify at least a portion of the new or second polymerizable liquid, which defines a second cross-section of the 3D article. Furthermore, by applying energy to solidify the polymerizable liquid, the first and second cross-sections of the 3D article can be bonded or adhered to each other in the z-direction (or the construction direction equivalent to the raised or lowered direction mentioned above). Furthermore, selectively applying energy to the polymerizable liquid in the container may include applying electromagnetic radiation, such as UV and / or visible radiation, with sufficient energy to initiate polymerization of the polymerizable material as described herein. Additionally, in some cases, raising or lowering the cured layer of the polymerizable liquid is performed using a lifting platform arranged in a fluid construction material container. The method described herein may also include planarizing the new polymerizable liquid layer provided by raising or lowering the lifting platform. In some cases, such leveling can be done using a scraper or rollers.

[0066] Articles printed according to the methods described herein can exhibit one or more desired mechanical properties. 3D articles printed from the polymerizable liquids described herein can also exhibit tensile modulus of 1900–2700 MPa. In some embodiments, 3D printed articles can exhibit tensile strength of 40–70 MPa or 50–65 MPa. The tensile strength and tensile modulus values ​​provided herein can be determined according to ASTM D638.

[0067] Additionally, 3D articles printed from the polymerizable liquid described herein may exhibit an elongation at break of at least 3%, at least 5%, or at least 10% (e.g., when determined according to ASTM D638). In some embodiments, the printed 3D articles have an elongation at break of 10-20%. 3D articles printed from the polymerizable liquid described herein may also exhibit a thermal flexural temperature (HDT) of at least 90°C, for example, 100-260°C. In some embodiments, the 3D articles printed from the polymerizable liquid described herein may have an HDT greater than 300°C. HDT is measured using DMA at 0.455 MPa according to ASTM D648.

[0068] Furthermore, 3D articles printed from the polymerizable liquids described herein (and the polymerizable liquids themselves, during polymerization) are resistant to hydrolysis or degradation due to water exposure. For example, in some cases, the polymerizable liquids described herein (or 3D articles printed from them) may exhibit hydrolysis resistance with respect to maintaining certain mechanical properties, such as flexural strength, flexural modulus, and / or elongation at break, after exposure to water. Therefore, the 3D articles or polymerizable liquids described herein may (due to their composition / microstructure) exhibit one, two, or all three of the following hydrolysis resistance measures:

[0069] At least 80%, at least 85%, at least 90%, or at least 95% of the flexural strength (FS) hydrolysis resistance;

[0070] At least 80%, at least 85%, at least 90%, or at least 95% of the flexural modulus (FM) hydrolysis resistance; and

[0071] Hydrolysis resistance of at least 80%, at least 85%, at least 90%, or at least 95% elongation at break (EOB).

[0072] The above measurements are based on the following "water exposure" of 3D articles (or polymerizable liquids). Relevant properties (i.e., flexural strength, flexural modulus, or elongation at break) of the test sample (e.g., a 3D article formed from a polymerizable liquid) are measured after the 3D article is printed (e.g., within 12 hours). The test sample is then immersed in water at 37°C for 24 hours. After this immersion stage, the test sample is dried, and the relevant properties (i.e., flexural strength, flexural modulus, or elongation at break) are measured again in the same manner as before (e.g., using ASTM D638 and providing MPa output). The post-immersion measurements are then compared to the pre-immersion measurements. For example, if a given test sample has a flexural strength of 100 MPa before water immersion and 95 MPa after 24 hours of water immersion, the flexural strength hydrolysis resistance is 95% of the value obtained from 100 MPa compared to 95 MPa.

[0073] Furthermore, in some embodiments, water impregnation may even improve specific properties, such as elongation at break. For example, in some cases, the 3D articles described herein have EOB hydrolysis resistance of 80-130%, 80-125%, 90-125%, or 90-120%. In some cases, flexural strength hydrolysis resistance and / or flexural modulus hydrolysis resistance can also be as high as 110% or 105%, although it should be understood that 100% is a typical maximum value.

[0074] These and other implementations are further illustrated in the following non-limiting embodiments.

[0075] Example

[0076] Table 1 provides formulations of polymerizable liquids according to some of the embodiments described herein.

[0077] Table 1

[0078]

[0079] Table 2 provides the physical properties of 3D products printed using formulations 1-5.

[0080] Table 2 - Properties of 3D Printed Products

[0081] Preparation 1 Preparation 2 Preparation 3 Preparation 4 Preparation 5 Tensile strength (MPa) 62 61 69 59 54 Tensile modulus (MPa) 2486 2404 2561 2383 2082 Elongation at break (%) 8.6 16.5 12.1 11.6 7.4 Impact strength (J / m) 30.9 29.4 29.4 30.2 21.7 HDT 0.455MPa, via DMA(C) 99.7 96.2 104.8 96.7 109.4

[0082] Table 3 provides formulations of polymerizable liquids according to some of the embodiments described herein.

[0083] Table 3

[0084]

[0085] Table 4 provides the physical properties of 3D artifacts printed using formulations 6-10.

[0086] Table 4 - Properties of 3D Printed Products

[0087]

[0088] Table 5 provides formulations of polymerizable liquids according to some of the embodiments described herein.

[0089] Table 5

[0090] Components Preparation 11 Preparation 12 Polyether carbamate methacrylate 30 30 Cyclopolymerizable additives 10 10 Dicyclopentyl methacrylate - 10 Vinylmethyloxazolidinone - - Isocyanurate acrylate 10 10 Polyallyl isocyanurate 46 36 Cyclic carbonate methacrylate monomers - - Core / shell granular resin - - Colorant 0.1 0.1 UV absorbers / light stabilizers 1 1 Photoinitiator 2 2 dispersant 0.9 0.9 antioxidants - -

[0091] Table 6 provides the physical properties of 3D articles printed with formulations 11 and 12, including hydrolytic resistance as tested as described above.

[0092] Table 6 - Properties of 3D Printed Products

[0093]

[0094]

[0095] The following describes some additional, unrestricted example implementations.

[0096] Implementation Scheme 1. A polymerizable liquid, said polymerizable liquid comprising:

[0097] At least one additive, said additive comprising a plurality of cyclizable functional groups separated by aliphatic linkers or alkanoyl ether linkers, the cyclizable functional groups having the following formula:

[0098]

[0099] Implementation Scheme 2. The polymerizable liquid of Implementation Scheme 1, wherein the additive is present in an amount of 5-40% by weight based on the total weight of the polymerizable liquid.

[0100] Implementation Scheme 3. The polymerizable liquid of Implementation Scheme 1, wherein the additive is present in an amount of 5-30% by weight, 7-30% by weight, or 10-30% by weight based on the total weight of the polymerizable liquid.

[0101] Implementation Scheme 4. A polymerizable liquid of any of the foregoing implementation schemes, wherein the alkanol ether linker is an oligomer or a polymer.

[0102] Implementation Scheme 5. The polymerizable liquid of any of the foregoing implementation schemes, wherein the additive has the following formula:

[0103]

[0104] Where L is an aliphatic or alkanoyl ether linker.

[0105] Implementation Scheme 6. The polymerizable liquid of any of the foregoing implementation schemes, wherein the additive has the following formula:

[0106]

[0107] Where R 1 It is hydrogen or alkyl, and m is an integer from 1 to 20.

[0108] Implementation Scheme 7. The polymerizable liquid of any of the foregoing implementation schemes, wherein the polymerizable liquid further comprises an oligomer curable material, a monomer curable material, or a mixture thereof.

[0109] Implementation Scheme 8. The polymerizable liquid of Implementation Scheme 7, wherein the polymerizable liquid comprises an amount of oligomeric curable material of 5-50% by weight based on the total weight of the polymerizable liquid.

[0110] Implementation Scheme 9. The polymerizable liquid of Implementation Scheme 7, wherein the polymerizable liquid comprises a monomeric curable material in an amount of 10-70% by weight based on the total weight of the polymerizable liquid.

[0111] Implementation Scheme 10. The polymerizable liquid of Implementation Scheme 7, wherein the polymerizable liquid comprises an amount of oligomeric curable material in a quantity of 5-50% by weight based on the total weight of the polymerizable liquid and an amount of monomeric curable material in a quantity of 10-70% by weight based on the total weight of the polymerizable liquid.

[0112] Implementation Scheme 11. A polymerizable liquid of any one of Implementation Schemes 7 to 10, wherein the oligomer curable material comprises acrylate oligomers, methacrylate oligomers, or mixtures thereof.

[0113] Implementation Scheme 12. A polymerizable liquid of any one of Implementation Schemes 7 to 11, wherein the monomer curable material comprises acrylate monomers, methacrylate monomers, or mixtures thereof.

[0114] Implementation Scheme 13. The polymerizable liquid of Implementation Scheme 12, wherein the acrylate monomer includes cyclic carbonate (meth)acrylate monomer.

[0115] Implementation Scheme 14. The polymerizable liquid of Implementation Scheme 13, wherein the cyclic carbonate (meth)acrylate monomer has the following formula:

[0116]

[0117] Wherein R1 is a straight-chain or branched C1-C6 alkylene moiety; and

[0118] R2 is either H or CH3.

[0119] Implementation Scheme 15. A method for printing three-dimensional articles, the method comprising:

[0120] Provide a polymerizable liquid according to any one of embodiments 1 to 14; and print and light-cur the polymerizable liquid to form an article.

[0121] All patent documents mentioned herein are incorporated herein by reference in their entirety. Various embodiments of the invention have been described to satisfy various objectives of the invention. It should be understood that these embodiments are merely illustrative of the principles of the invention. Many improvements and modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A method of printing a three-dimensional article, the method comprising: providing a polymerizable liquid, the polymerizable liquid comprising: an oligomeric curable material, a monomeric curable material, or a mixture thereof; and at least one additive comprising a plurality of ring-cyclizable functional groups separated by an aliphatic or alkylene oxide linker, wherein the ring-cyclizable functional groups have the formula: wherein is the point of attachment of the cyclo-merizable functional group to the linker; and printing and photocuring the polymerizable liquid to form an article.

2. The method of claim 1, wherein the additive is present in an amount of 5 to 40 weight percent based on the total weight of the polymerizable liquid.

3. The method of claim 1, wherein the additive is present in an amount of 7 to 30 weight percent based on the total weight of the polymerizable liquid.

4. The method of claim 1, wherein the alkylene oxide linker is an oligomer or a polymer.

5. The method of claim 1, wherein the additive has the formula: ###0001### wherein L is an aliphatic or alkylene oxide linker.

6. The method of claim 5, wherein the additive has the formula: ###0002### 7. The method of claim 1, wherein the oligomeric curable material is present in an amount of 5 to 50 weight percent based on the total weight of the polymerizable liquid. wherein R 1 is hydrogen or alkyl, and m is an integer from 1 to 20.

8. The method of claim 1, wherein the monomeric curable material is present in an amount of 10 to 70 weight percent based on the total weight of the polymerizable liquid.

9. The method of claim 1, wherein the oligomeric curable material comprises an acrylate oligomer, a methacrylate oligomer, or a mixture thereof.

10. The method of claim 1, wherein the monomeric curable material comprises an acrylate monomer, a methacrylate monomer, or a mixture thereof.

11. The method of claim 10, wherein the acrylate monomer comprises a cyclic carbonate (meth)acrylate monomer.

12. The method of claim 11, wherein the cyclic carbonate (meth)acrylate monomer has the formula: ###0003### wherein R1 is a linear or branched C1-C6 alkylene moiety; and wherein R2 is H or CH3.

13. A polymerizable liquid, the polymerizable liquid comprising: ， at least one additive comprising a plurality of ring-cyclizable functional groups separated by an aliphatic or alkylene oxide linker, wherein the ring-cyclizable functional groups have the formula: ###0004### 14. The polymerizable liquid of claim 13, wherein the additive is present in an amount of 5 to 40 weight percent based on the total weight of the polymerizable liquid.

15. The polymerizable liquid of claim 13, wherein the additive is present in an amount of 7 to 30 weight percent based on the total weight of the polymerizable liquid. ， wherein is the point of attachment of the cycloaddition functionality to the linker.

16. The polymerizable liquid of claim 13, wherein the alkylene oxide linker is an oligomer or a polymer.

17. The polymerizable liquid of claim 13, wherein the additive has the formula: ###0005### wherein L is an aliphatic or alkylene oxide linker.

18. The polymerizable liquid of claim 16, wherein the additive has the formula: ###0006### 19. The polymerizable liquid of claim 13, further comprising an oligomeric curable material, a monomeric curable material, or a mixture thereof.

20. The polymerizable liquid of claim 19, comprising the oligomeric curable material in an amount of 5 to 50 weight percent based on the total weight of the polymerizable liquid. ​ wherein R 1 is hydrogen or alkyl, and m is an integer from 1 to 20. ​ ​ 21. The polymerizable liquid of claim 19, comprising a monomeric curable material in an amount of 10 to 70 weight percent based on the total weight of the polymerizable liquid.

22. The polymerizable liquid of claim 19, 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.

23. The polymerizable liquid of claim 19, wherein the oligomeric curable material comprises an acrylate oligomer, a methacrylate oligomer, or a mixture thereof.

24. The polymerizable liquid of claim 19, wherein the monomeric curable material comprises an acrylate monomer, a methacrylate monomer, or a mixture thereof.

25. The polymerizable liquid of claim 24, wherein the acrylate monomer comprises a cyclic carbonate (meth)acrylate monomer.

26. The polymerizable liquid of claim 25, wherein the cyclic carbonate (meth)acrylate monomer has the formula: ###0001### wherein R1 is a linear or branched C1-C6 alkylene moiety; and ###0002### ， wherein R2 is H or CH3. ​

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