Soluble materials produced by co-reactive extrusion

Abstract

A coreactive additive manufacturing composition comprising a first coreactive composition, the first coreactive composition comprising a first reactive compound and a second reactive compound. The first and second reactive compound are reactable and curable with one another under ambient conditions to form a first reaction product comprising a solid composition soluble in a solvent.

Description

SOLUBLE MATERIALS PRODUCED BY CO-REACTIVE EXTRUSIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63 / 511,517 entitled “SOLUBLE MATERIALS PRODUCED BY CO-REACTIVE EXTRUSION”, filed on June 30, 2023 which is incorporated by reference in its entirety.GOVERNMENT LICENSE RIGHTS

[0002] This invention was made with government support under Government Contract No. W91 INF-17-2-0227 awarded by the U.S. Army Contracting Command on behalf of the U.S. Army Research Laboratory (ARL). The government may have certain rights in the invention.FIELD

[0003] The present disclosure relates to a solvent soluble solid composition for three- dimensional printing.BACKGROUND

[0004] Three-dimensional (3D) printing is a process that is used to create objects out of cured compositions, such as plastics. The cured composition can be made of a thermoset composition. During the printing of the object using a thermoset composition, at least two coreactive components are mixed together to create a coreactive composition. The thermoset composition may be used in ambient reaction extrusion (ARE) printing, in which the coreactive composition is deposited onto a printing platform using an additive manufacturing device and cured at ambient conditions.

[0005] When printing a 3D object onto a print bed, portions of the object may need to be supported during the curing process. Additive manufacturing devices may print support structures made of a thermoset composition to support portions of the 3D object to ensure that printed material used to build the object does not sag or droop while the printed material dries. Once the 3D object with support structures is printed in completion, the support structures may be removed, leaving just the intended object.SUMMARY

[0006] The present disclosure provides a coreactive additive manufacturing composition comprising: a first coreactive composition comprising a Michael donorcontaining compound and a Michael acceptor-containing compound. The Michael donorcontaining compound and the Michael acceptor-containing compound are reactable and curable with one another under ambient conditions to form a first reaction product comprising a solid composition soluble in a solvent.

[0007] The present disclosure further provides an additively manufactured article comprising: a first coreactive composition comprising a first reactive component and a second reactive component and a second coreactive composition comprising a third reactive component and a fourth reactive component. The first reactive component and the second reactive component are reactable and curable with one another under ambient conditions to form a first reaction product comprising a solid composition soluble in a solvent. The third reactive component and the fourth reactive component are reactable and curable with one another under ambient conditions to form a second reaction product comprising a thermoset insoluble in a solvent. The first reaction product comprises a soluble support material, and the second reaction product comprises an insoluble build material.

[0008] The present disclosure further provides a method of additively manufacturing an article comprising: depositing a support material comprising a first coreactive composition soluble in an aqueous solution, depositing a build material comprising a second coreactive composition insoluble in an aqueous solution, and curing each of the support material and the build material at room temperature to create a cured support material and a cured build material. The first coreactive composition comprises a first coreactive component and a second coreactive component. The first coreactive component and the second coreactive component react with each other to form the support material. The second coreactive composition comprises a third coreactive component and a fourth coreactive component. The third coreactive component and the fourth coreactive component react with each other to form the build material. The support material and the build material are deposited such that the support material and the build material are in contact with each other.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the disclosure itself will bebetter understood by reference to the following description taken in conjunction with the accompanying drawings. These above-mentioned and other features of the disclosure may be used in any combination or permutation.

[0010] FIG. 1A is an illustration of a 3D printed object with a structure comprising a build material composition of the present disclosure and support structures comprising a dissolvable support structure composition of the present disclosure;

[0011] FIG. IB is an illustration of the 3D printed object of FIG. 1 A after dissolving the dissolvable support structure in a solvent, leaving only the build material composition;

[0012] FIG. 2A is an illustration of an enclosed object with shelves within a hollow inner portion of the object;

[0013] FIG. 2B is an illustration of a cross-section of the object in FIG. 2A after dissolving the dissolvable support structures in a solvent, leaving only the build material composition;

[0014] FIG. 3A is an image showing a linear sealing component comprising the build material that may be printed using support structures comprising the dissolvable support composition; and

[0015] FIG. 3B is an image showing the linear sealing component of FIG. 3 A fit in a panel gap between two panels.

[0016] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate the disclosure, and such exemplifications are not to be construed as limiting the scope of the disclosure in any manner.DETAILED DESCRIPTION

[0017] The present disclosure provides a water-soluble solid composition composition. The water-soluble solid composition may be a support structure composition for a 3D printed object comprising a water-insoluble build material.

[0018] I. Definitions

[0019] For purposes of the following detailed description, it is to be understood that the disclosure may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about." For example, numerical ranges provided for weight percentages of components oramounts of components added should be construed as being modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0020] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements.

[0021] Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of "1 to 10" is intended to include all sub-ranges from (and including) the recited minimum value of 1 to the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.

[0022] The use of the singular includes the plural and plural encompasses singular, unless specifically stated otherwise. In addition, the use of "or" means "and / or" unless specifically stated otherwise, even though "and / or" may be explicitly used in certain instances.

[0023] “Michael donor” refers to compounds capable of reacting with activated alkenyl groups in a 1,4-addition reaction. Examples of Michael donors include activated methylenes such as malonates and nitroalkanes.

[0024] ‘Michael acceptor” refers to an activated alkene, such as an alkenyl group proximate to an electron-withdrawing group such as a ketone, nitro, halo, nitrile, carbonyl, or nitro group. Michael acceptors are well known in the art. A “Michael acceptor group” refers to an activated alkenyl group and an electron-withdrawing group. A Michael acceptor group can be selected from a vinyl ketone, a vinyl sulfone, a quinone, an enamine, a ketimine, oxazolidine, and an acrylate. Other examples of Michael acceptors include acrylate esters, acrylonitrile, acrylamides, maleimides, alkyl methacrylates, cyanoacrylates. Other Michael acceptors include vinyl ketones, a,P-unsaturated aldehydes, vinyl phosphonates, acrylonitrile, vinyl pyridines, certain azo compounds, P-keto acetylenes and acetylene esters.

[0025] “Ambient conditions” refers to conditions including temperatures between 20 °C and 25 °C (or “room temperature”) and a pressure at 1 atm.

[0026] “Soluble in solvent” refers to a chemical compound having a solubility in a solvent of at least 0.05 g / L at 25 °C.

[0027] “Insoluble in solvent” refers to a chemical compound having a solubility in a solvent of less than 0.05 g / L at 25 °C.

[0028] II. Coreactive Chemistries

[0029] Additive manufacturing using coreactive compositions, also referred to as ambient reactive extrusion, or ARE type three-dimensional printing, typically utilizes at least two components that react with each other (e.g., are coreactive). A first coreactive component (sometimes referred to herein as a first reactant group, a first reactive functional group, part A) and at least one second coreactive component (sometimes referred to herein as a second reactant group, second reactive functional group, part B), when extruded in combination and / or succession, chemically react with one another to form a coreactive composition. The coreactive composition may thereafter cure under ambient conditions or, depending on the chemistry of the reaction, with the assistance of, for example, heat, actinic radiation, catalysts, addition of curing agents-post extrusion, etc. to form an object, or a portion of an object, comprising a thermosetting polymer (sometimes referred to as a thermoset), a thermoplastic polymer, or combinations thereof. At least the first coreactive component and the second coreactive component are chosen by one skilled in the art to result in the desired final product (e.g., thermoset, thermoplastic, etc.).

[0030] Three dimensional objects formed from coreactive compositions are additively manufactured by extruding the coreactive composition, which may be in an at least partially reacted state, onto a surface, such as a build platform. The coreactive composition may be in an at least partially reacted state at the time of extrusion and thereafter fully react and cure to form a layer of the coreactive composition. Successive layers of either the same, or different coreactive compositions can be deposited, forming additional layers of material. The coreactive composition may be at least partially reacted when the coreactive components come together, such as in a mixing volume, just prior to extrusion. Alternatively, the two coreactive components could be premixed before extrusion and treated in a way to arrest the reaction (e.g., arrest curing of the coreactive composition), such as freezing the upon mixing.

[0031] It may be desirable to select the chemistry of each layer of the deposited coreactive composition such that covalent bonds between each successive layer of materialare formed. Furthermore, different portions of the article can be printed from different coreactive compositions (e.g., a first coreactive composition printed to form a first portion of the object such as a base portion, an internal structure, etc., and a second coreactive composition printed to form a second portion of the object), and, depending on the chemical reactivity between the different coreactive compositions, covalent bonds might also form between different materials.

[0032] Specifically, an article may be printed so as to have a rigid portion and a flexible portion, a rigid portion and a foam-like portion, a tactile portion and a rigid and / or flexible portion, two portions comprising different densities, one or more conductive portions, one or more thermally / electrically conductive portions, two or more different colors, two or more different rheological profiles, two or more different materials comprising different affinities for water and / or solvent(s), and the like. The article may also be printed such that the coreactive compositions are deposited onto existing articles (e.g., other thermosets and / or thermoplastics, metals, woods, composite materials, ceramics, etc.) resulting in an article comprising both coreactive and non-coreactive compositions.

[0033] Additive manufacturing as described herein may result in an object having greater strength, particularly along the Z (e.g., vertical) axis, as compared to other extruded or printed parts due to the covalent bonding between the printed layers. Strong intralayer and interlayer covalent bonding results in not only stronger parts, but also in more uniform part geometries; that is, less print lines and / or portion differentials. The ability to form, in one process, objects having multiple substrates and / or portions comprising different coreactive or non-coreactive compositions is a further advantage.

[0034] Table 1 describes suitable coreactive compositions and the coreactive components from which they can be formed. These coreactive compositions can be printed by any of the methods described herein, either alone or in combination, to form three dimensional objects.

[0035] Another advantage of additive manufacturing using coreactive compositions may be that the coreactive compositions can be three dimensionally printed at relatively low viscosity. Therefore, relatively large amounts (e.g., high relative weight percents) of additives and / or fillers can be included with the coreactive components while maintaining a printable viscosity. Both the type and / or the amount of additives can be selected or “tuned” to result in desirable chemical and / or physical properties of the printed article. Coreactive compositions can be tuned with the addition of additives and / or fillers for desired mechanical performance (e.g., strength, elasticity, rigidity, sag resistance, etc.), surface features (e.g., hardness, texturing, smoothness, etc.), chemical resistance (e.g., solvent resistance, etc.), thermal resistance (including fire retardancy, etc.) or conductivity, and / or electrical insulation or conductivity. Coreactive compositions can also be tuned with the addition of one or morecatalytic / activator / accelerant additives in any of the coreactive components to result in desirable reaction kinetics, such as rate of reaction.

[0036] Table 2 describes additives that can be included with any coreactive compositions, such as those described in Table 1. The additives can be included in, either, or both of, the first and second coreactive components (e.g., either, or both of the Part A / Part B), depending on the desired chemical and / or physical properties of the resulting object. In this case, Table 2 describes specific additives and fillers that may be suitable for ambient reactive extrusion-based three-dimensional printing, however, Table 2 is non-limiting. Therefore, other additives may be included with the coreactive composition(s), such as additives known to those skilled in the coatings, extrusion, and thermoplastic areas.

[0037] Any suitable combination of coreactive composition(s) and optionally additive(s) / filler(s), can be printed by a three-dimensional printing system adapted for mixing and extruding feedstocks. Two or more volumetric metering pumps (e.g., positive displacement pumps, progressive cavity pumps, etc.) may each respectively discharge, in combination or succession, the two coreactive components associated with a coreactive composition (e.g., the first reactive component discharged by the first metering pump and the second coreactive component discharged by the second metering pump into a mixing volume). In some cases, the mixing volume can include mechanical (e.g., driven) mixing features. Upon entering the mixing volume, the first and second coreactive components begin to mix and react, and thereafter, are extruded through an extrusion print nozzle in an at least partially reacted state. Once extruded, the two coreactive components further react and cure, which, as described above, may be under ambient conditions, to form either a thermoset, a thermoplastic material, or combinations thereof.

[0038] III. Hydrophilic Support Structure Composition

[0039] A coreactive composition of the present disclosure may be a hydrophilic support structure dissolvable in a solvent. The hydrophilic support structure composition may be made of any of the coreactive compositions listed in section II, above, provided that the reaction product has a hydrophilicity of less than 0.5 g / L at 25oC and a water contact angle of less than 90°C.The hydrophilic support structure composition may employ Aza-Michael addition reactive components. Co-reactive compositions employing an Aza-Michael addition curing chemistry may comprise an amine composition including a Michael donor compound and an acrylate composition including a Michael acceptor compound. In instances where Michael addition comprises 1,4 addition of nitrogen nucleophiles, the addition may be referred to as an Aza-Michael rection or addition.

[0040] A. Amine Composition

[0041] The amine composition may have hydrophilic characteristics. To increase the hydrophilicity of the composition, monofunctional amines may be included in the amine composition to reduce crosslinking of the hydrophilic support structure composition.

[0042] i. Michael Donor Compound

[0043] The Michael donor compound may comprise a Michael donor monomer, a Michael donor prepolymer, or a combination thereof. Michael donors may include amines, hydroxy group containing oligomers or polymers, acetoacetates, malonates, thiols, and combinations of any of the foregoing.

[0044] The Michael donor of the first coreactive composition may comprise at least one amine resin. The amine resin may be hydrophilic. Suitable amine resins may include mono-, di-, and tri- functional amine resins, such as, Jeffamine ED900, Jeffamine T403, ethanolamines, polyetheramines. The amine composition may comprise an amount of Michael donor compound from 10 wt.%, 20 wt.%, 30 wt.% to 40 wt.%, 50 wt.%, 60 wt. %, or any range including any of the foregoing values as endpoints, such as 10 wt.% to 60 wt.%, 20 wt.% to 50 wt.%, or 30 wt.% to 40 wt.%, wherein the weight percent is based on the total weight of the amine composition.

[0045] The hydrophilic support structure composition may comprise an amount of amine composition from 10 wt.%, 20 wt.%, 30 wt.% to 40 wt.%, 50 wt.%, 60 wt. %, or any range including any of the foregoing values as endpoints, such as 10 wt.% to 60 wt.%, 20 wt.% to 50 wt.%, or 30 wt.% to 40 wt.%, wherein the weight percent is based on the total weight of the hydrophilic support structure composition.

[0046] B. Acrylate Composition

[0047] The acrylate composition may have hydrophilic characteristics. To increase the hydrophilicity of the composition, the acrylate composition may include hydrophilic polymers, such as a glycol-containing acrylate resin.

[0048] i. Michael Acceptor Compound

[0049] The Michael acceptor compound can comprise a Michael acceptor monomer, a Michael acceptor prepolymer, or a combination thereof. A Michael acceptor group refers to an activated alkenyl group such as an alkenyl group proximate to an electron-withdrawing group such as a ketone, nitro, halo, nitrile, carbonyl, or nitro group. Suitable Michael acceptor groups may include vinyl ketone, vinyl sulfone, quinone, enamine, ketimine, aldimine, oxazolidine, acrylate, acrylate esters, acrylonitrile, acrylamide, maleimide, alkylmethacrylates, vinyl phosphonates, and vinyl pyridines.

[0050] A Michael acceptor may be a poly(meth)acrylate. Suitable difunctional methacrylates may include 1,6-hexanediol diacrylate, 6-hexanediol diacrylate, hydroxypivalic acid neopentyl glycol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, dipropylene diglycol diacrylate, tricyclodecane dimethanol diacrylate, tetrapentylene glycol diacrylate, polyethylene glycol diacrylate such as polyethylene glycol 300 diacrylate, polyethylene glycol 600 diacrylate, and polyethylene glycol 400 diacrylate. Suitable trifunctional acrylates may include trimethylolpropane triacrylate, glycerin triacrylate, pentaerythritol triacrylate, tris(2- hydroxyethyl)isocyanurate triacrylate. Suitable multifunctional acrylates may include pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentacrylate, and dipentaerythritol hexaacrylate.

[0051] The hydrophilic support structure composition may comprise an amount of acrylate composition from 10 wt.%, 20 wt.%, 30 wt.% to 40 wt.%, 50 wt.%, 60 wt. % or any range including any of the foregoing values as endpoints, such as 10 wt.% to 60 wt.%, 20 wt.% to 50 wt.%, or 30 wt.% to 40 wt.%, wherein the weight percent is based on the total weight of the hydrophilic support structure composition.

[0052] C. Solvents

[0053] A solvent or mixture of solvents may be used to dissolve the support structure. The solvents may comprise an inorganic solvent, an organic solvent, or mixtures thereof. Suitable solvents may include water, aqueous solutions, hydrocarbons, alcohols, ketones, glycols, and combinations thereof. Specifically, he support structure material may dissolve in solvents that are substantially non-caustic and non-basic. For instance, he solvent may have a pH of less than, or equal to, 5, 6, 6.5 to 7, 8, 9, or any range including any of the foregoing values as endpoints, such as a pH of 5 to 9, 6 to 8, or 6.5 to 7.

[0054] D. Additives

[0055] The hydrophilic support structure composition may comprise an amount of additives, such as fillers, pigments, flow agents, wetting agents, defoamers, catalysts, and solvents. The amine composition may comprise an amount of the additives from 10 wt.%, 20 wt.%, 30 wt.% to 40 wt.%, 50 wt.%, 60 wt. %, or any range including any of the foregoing values as endpoints, such as 10 wt.% to 60 wt.%, 20 wt.% to 50 wt.%, or 30 wt.% to 40 wt.%, wherein the weight percent is based on the total weight of the amine composition.

[0056] E. Curing

[0057] The hydrophilic support structure composition of the present disclosure may be cured at ambient temperatures to form a solid composition. The solid composition may be a thermoset. Ambient temperatures include temperatures from 20 °C, 21 °C, 22 °C to 23 °C, 24 °C, 25 °C, or any range including any of the foregoing values as endpoints, such as 20°C to 25 °C, 21 °C to 24°C, or 22 °C to 23 °C.

[0058] For accelerated curing, the build material may be cured for 48 hours at a temperature of at least 65 °C, at least 70 °C, at least 75 °C, or at least 80 °C.

[0059] F. Properties of Support Structure Solid Composition

[0060] The cured support structure composition may be dissolvable in a solvent, such as water. The cured support structure composition may comprise long chains in between crosslinks and hydrophilic polymers. The increased space in the polymer chain may increase the solvability of the cured support structure composition.

[0061] i. Dissolvability

[0062] After being fully submerged in a solvent, the cured support structure composition may substantially dissolve, essentially dissolve, or completely dissolve with sonication. By “substantially dissolved” it is meant that less than 2 % of the starting weight of a composition remains after being submerged in a solvent at room temperature and subjected to sonication. By “essentially dissolved” it is meant that less than 1 % of the starting weight of a composition remains being submerged in a solvent at room temperature and subjected to after sonication. By “completely dissolved” it is meant that less than 0.5 grams of the composition remains after sonication. To perform sonication, an object is placed in a medium and sound energy, such as high-frequency sound waves, are sent through the medium to agitate the particle of the object. The medium may be a liquid, such as water. The frequency of sound waves applied to the object in the medium may be at least 30 kHz, at least 35 kHz, at least 40 kHz, at least 45 kHz, or at least 50 kHz according to the operation of a Fisher scientific FS30H sonicator.

[0063] The cured support structure composition may completely dissolve with sonication in 1 hour, 2 hours, 4 hours, to 6 hours, 8 hours, 10 hours, or any range including any of the foregoing values as endpoints, such as 1 to 10 hours, 2 to 8 hours, or 4 to 6 hours.

[0064] The hydrophilic support structure solid composition may have a dissolution rate in a solvent measured by the number of grams of solid composition dissolved in 1 hour. To test the dissolution rate of the hydrophilic support structure in a solvent, a cured support structure may be added to a volume of solvent at a certain temperature and subjected tosonication. The rate at which the cured support structure dissolves may be observed and recorded. The cured support structure composition may have a dissolution rate of 0.90 g / hr, 1.00 g / hr, 1.15 g / hr to 1.25 g / hr, 1.35 g / hr, 1.45 g / hr, or any range including any of the foregoing values as endpoints, such as 0.90 to 1.45 g / hr, 1.00 to 1.35 g / hr, or 1.15 to 1.25 g / hr, based on a 5 g sample of the cured support structure in 1 liter of water at room temperature subjected to sonication in a solvent at 40 kHz, according to the method described above.

[0065] The hydrophilic support structure solid composition may be “water-soluble.” The term “water-soluble” refers to a chemical compound having a water solubility of at least 0.05 g / L at 25 °C. The term “water-insoluble” refers to a chemical compound having a water solubility less than 0.05 g / L at 25 °C. The water dissolvability of a composition may be measured by determining the mass of a composition that will completely dissolve in 1 liter of water at room temperature. The weight of the composition may be determined by a scale. The cured support structure composition may have a dissolvability in water of 0.05 g / L, 1 g / L, 5 g / L, 10 g / L to 20 g / L, 40 g / L, 60 g / L, 80 g / L or any range including any of the foregoing values as endpoints, such as 0.05 g / L to 80 g / L, 1 g / L to 60 g / L, 5 g / L to 40 g / L, or 10 g / L to 20 g / L, according to the method described above using water as the solvent.

[0066] ii. Hydrophilicity

[0067] A water contact angle test may be used to measure the wettability or hydrophilicity of the cured support structure composition. The contact angle of water gives a measure of surface adhesion between water and a surface. The water contact angle is measured by placing a droplet of water onto a surface. The angle between the face of the solid surface and the tangent line to the contacting edge of the droplet is recorded using a camera to capture an image. Over a period of time, the change in angle of the tangent line to the contacting edge of the droplet indicates if the surface is hydrophobic or hydrophilic. If the angle is greater than 90°, indicating that the droplet has not spread, the affinity between the surface and water is low and the material of the surface is considered hydrophobic. If the angle is less than 90°, indicating that the droplet has spread, the hydrophilicity of the surface material increases.

[0068] The cured support structure composition may have a contact angle with water of 75°, 70°, 65°, to 60°, 55°, 50°, or any range including any of the foregoing values as endpoints, such as 75° to 50°, 70° to 55°, or 65° to 60°, as measured at 22 °C and 22%humidity with a Kruss Tension K100 Water Contact Angle Goniometer and SFE model according to ASTM D5946.

[0069] IV. Build Material Composition

[0070] The coreactive composition used to build a 3D object may be made of any of the coreactive compositions listed in section II., above. The build material composition may be a polyurea composition comprising a polyisocyanate-containing component and an amine component.

[0071] The polyisocyanate component may comprise a polyisocyanate prepolymer and / or polyisocyanate monomer and the polyamine component may comprise a polyamine prepolymer and / or polyamine monomer. The polyisocyanate prepolymer and / or polyamine prepolymer can have a number average molecular weight as low as about 500 Daltons, about 1000 Daltons, about 2000 Daltons, about 5000 Daltons, about 7000 Daltons, about 10,000 Daltons, as high as about 11,000 Daltons, about 13,000 Daltons, about 15,000 Daltons, about 20,000 Daltons, or within any range including these endpoints, as determined using gel permeation chromatography (GPC) using polystyrene standards.

[0072] A. Polyisocyanate Component

[0073] The isocyanate functional component that may include polyisocyanate monomers and / or prepolymers, or a blend of polyisocyanates. A polyisocyanate prepolymer can be prepared by reacting a polyol prepolymer and / or a polyamine prepolymer with a polyisocyanate such as a diisocyanate. Suitable polyisocyanate prepolymers are commercially available.

[0074] Suitable monomeric polyisocyanates may include isophorone diisocyanate (1PDI), which is 3,3,5-trimethyl-5-isocyanato-methyl-cyclohexyl isocyanate; hydrogenated diisocyanates such as cyclohexylene diisocyanate, 4,4'-methylenedicyclohexyl diisocyanate (HnMDI); mixed aralkyl diisocyanates, such as tetramethylxylyl diisocyanates, OCN-C(- CHih-Ce^CtCJ-hh-NCO; and polymethylene isocyanates such as 1,4-tetramethylene diisocyanate, 1,5 -pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate (HMDI), 1,7-heptamethylene diisocyanate, 2,2,4- and 2,4,4-trimethylhexamethylene diisocyanate, 1,10-decamethylene diisocyanate, and 2-methyl- 1,5 -pentamethylene diisocyanate.

[0075] Suitable monomeric aromatic polyisocyanates may include phenylene diisocyanate, toluene diisocyanate (TDI), xylene diisocyanate, 1,5 -naphthalene diisocyanate, chlorophenylene 2,4-diisocyanate, bitoluene diisocyanate, dianisidine diisocyanate, toluidine diisocyanate and alkylated benzene diisocyanates generally; methylene-interrupted aromaticdiisocyanates such as methylenediphenyl diisocyanate, especially the 4,4’-isomer (MDI), including alkylated analogs such as 3,3'-dimethyl-4,4’-diphenylmethane diisocyanate and polymeric methylenediphenyl diisocyanate.

[0076] Suitable polyisocyanates also include polyisocyanates prepared from dimers and trimers of diisocyanate monomers. Dimers and trimers of diisocyanate monomers may contain linkages selected from isocyanurate, uretdione, biuret, allophanate and combinations thereof: such as Desmodur® N3600, Desmodur® CP2410, and Desmodur® N3400, available from Bayer Material Science.

[0077] A polyisocyanate may also comprise a polyisocyanate prepolymer. A polyisocyanate may include an isocyanate-terminated polyether diol, an isocyanate- terminated extended polyether diol, or a combination thereof. An extended polyether diol refers to a polyether diol that has been reacted with an excess of a diisocyanate resulting in an isocyanate-terminated polyether prepolymer with increased molecular weight and urethane linkages in the backbone. Suitable polyether diol may include Terathane® polyether diols such as Terathane® 200 and Terathane® 650 available from Invista, or the PolyTHF® polyether diols available from BASF. Isocyanate-terminated polyether prepolymers can be prepared by reacting a diisocyanate and a polyether diol as described in U.S. Application Publication No. 2013 / 0244340, which is incorporated by reference in its entirety.

[0078] A polyisocyanate prepolymer may include an isocyanate-terminated polytetramethylene ether glycol such as polytetramethylene ether glycols produced through the polymerization of tetrahydrofuran. Suitable polytetramethylene ether glycols may include Polymeg® polyols (LyondellBasell), PolyTHF® polyether diols (BASF), or Terathane® polyols (In vista).

[0079] Polyisocyanate prepolymers may also include isocyanate-terminated polyetheramines. Suitable polyether amines may include polyetheramines, such as Jeffamine® (Huntsman Corp.), and polyetheramines available from BASF. Suitable polyetheramines may include polyoxypropylenediamine.

[0080] B. Amine Component

[0081] The amine-functional co-reactive component may include primary, secondary, or tertiary amines, or combinations thereof. Suitable aliphatic polyamines may include ethylamine, the isomeric propylamines, butylamines, pentylamines, hexylamines, cyclohexylamine, ethylene diamine, l,3-bis(aminomethyl)diamine, 1,2-diaminopropane, 1,3- diaminopropane, 1,4-diaminobutane, 1,5 -diaminobutane, 1,3-diaminopentane, 1,6-diaminohexane, 2-methyl-l,5-pentane diamine, 2,5-diamino-2,5-dimethylhexane, 2,2,4- and / or 2,4,4- trimethyl- 1,6-diamino-hexane, 1,11-diaminoundecane, 1,12-diaminododecane,1.3- and / or 1 ,4-cyclohexane diamine, l-amino-3,3,5-trimethyl-5-aminomethyl-cyclohexane,2.4- and / or 2,6-hexahydrotoluylene diamine, 2,4'- and / or 4,4'-diamino-dicyclohexyl methane and 3,3'-dialkyl-4,4'-diamino-dicyclohexyl methanes (such as 3,3’-dimethyl-4,4'-diamino- dicyclohexyl methane and 3,3’-diethyl-4,4'-diamino-dicyclohexyl methane), 2,4- and / or 2,6- diaminotoluene and 2,4'- and / or 4,4'-diaminodiphenyl methane, or mixtures thereof.

[0082] Suitable secondary amines may include aliphatic amines, such as a cycloaliphatic diamine. Such amines are available commercially from Huntsman Corporation (Houston, TX) under the designation of Jetfflink® such as Jefflink® 754. Other suitable amines may include Clearlink® 1000 (Dorf-Ketal Chemicals, LLC), and aspartic ester functional amines, such as those available under the name Desmophen® such as NH1220, Desmophen® NH 1420, and Desmophen® NH 1520 (Bayer Materials Science LLC). A secondary amine can be the reaction product of isophorone diamine and acrylonitrile, such as Polyclear® 136 (available from BASF / Hansen Group LLC). A polyamine can also be provided as an amine-functional resin. An amine-functional resin may comprise an ester of an organic acid, such as an aspartic ester-based amine-functional reactive resin that is compatible with isocyanates; e.g., one that is solvent-free, and / or has a mole ratio of amine - functionality to the ester of no more than 1:1 so there remains no excess primary amine upon reaction. Such polyaspartic esters may be the derivative of diethyl maleate and l,5-diamino-2- methylpentane, available commercially from Bayer Corporation under the trade name Desmophen® NH1220. Other suitable compounds containing aspartate groups may be employed as well. Additionally, the secondary polyamines can include polyaspartic esters which can include derivatives of compounds such as maleic acid, fumaric acid esters, aliphatic polyamines and the like.

[0083] Suitable secondary amines may include acrylates and methacrylate-modified amines, including both mono- and poly-acrylate modified amines as well as acrylate or methacrylate modified mono- or poly-amines. Acrylate or methacrylate modified amines may include aliphatic amines. Secondary amines may further include aliphatic amines, such as a cycloaliphatic diamine. The amine may be provided as an amine-functional resin. Such amine-functional resins may be a relatively low viscosity, amine-functional resin suitable for use in the formulation of high solids polyurea three-dimensional objects. An amine-functional resin may comprise an ester of an organic acid, an aspartic ester-based amine-functionalreactive resin that is compatible with isocyanates; e.g., one that is solvent-free. Such poly aspartic esters may be the derivative of diethyl maleate and l,5-diamino-2- methylpentane, available commercially from Bayer Corporation, PA under the trade name DesmophenTM NH1220. Other suitable compounds containing aspartate groups may be employed as well.

[0084] The polyamine may include polyoxy alkyleneamines. Poly oxy alkyleneamines contain two or more primary amino groups attached to a backbone derived from propylene oxide, ethylene oxide, or a mixture thereof. Such amines may include polyoxypropylenediamine and glycerol tris [polypropylene glycol), amine-terminated] ether such as those available under the designation Jeffamine™ from Huntsman Corporation.

[0085] The amine-functional co-reactive component may also include an aliphatic secondary amine such as Clearlink® 1000, available from Dor-Ketal Chemicals, LLC. The amine-functional co-reactive component may comprise an amine-functional aspartic acid ester, a polyoxyalkylene primary amine, an aliphatic secondary amine, or a combination of any of the foregoing.

[0086] C. Additives

[0087] The build material composition may comprise an amount of additives, such as fillers, pigments, flow agents, wetting agents, defoamers, catalysts, and solvents. The build material composition may comprise an amount of the additives from 1 wt.%, 2 wt.%, 4 wt.% to 6 wt.%, 8 wt.%, 10 wt. %, or any range including any of the foregoing values as endpoints, such as 1 wt.% to 10 wt.%, 2 wt.% to 8 wt.%, or 4 wt.% to 6 wt.%, wherein the weight percent is based on the total weight of the amine composition.

[0088] D. Curing

[0089] The build material composition of the present disclosure may be cured at ambient temperatures to form a solid composition. Ambient temperatures include temperatures from 20 °C, 21 °C, 22 °C to 23 °C, 24 °C, 25 °C, or any range including any of the foregoing values as endpoints, such as 20 °C to 25 °C, 21 °C to 24 °C, or 22 °C to 23 °C.

[0090] For accelerated curing, the build material may be cured for 48 hours at a temperature of at least 65 °C, at least 70 °C, at least 75 °C, or at least 80 °C, or any range including any of the foregoing values as endpoints.

[0091] E. Properties of Build Material Thermoset

[0092] The cured build material composition may be generally insoluble in water.

[0093] i. Dissolvability

[0094] After being fully submerged in a solvent, the cured build material composition may have little to no dissolution.

[0095] The hydrophobic build material composition may have a dissolution rate in a solvent measured by the number of grams of composition dissolved in 1 hour. The cured build material composition may have a dissolution rate of 0 g / hr, 0.01 g / hr, 0.02 g / hr to 0.03 g / hr, 0.04 g / hr, 0.05 g / hr, or any range including any of the foregoing values as endpoints, such as 0 to 0.05 g / hr, 0.01 to 0.04 g / hr, or 0.02 to 0.03 g / hr, based on a 5 g sample of the cured build material in 125 mL of water at room temperature, according to the method described in section III. E. i.

[0096] The hydrophobic build material thermoset may be “water-insoluble,” as defined above. The cured support structure composition may have a dissolvability in water of 0.04 g / L, 0.03 g / L to 0.02 g / L 0.01 g / L, or any range including any of the foregoing values as endpoints, such as 0.04 g / L to 0.01 g / L, or 0.03 g / L to 0.02 g / L, according to the method described in section III. E. i. using water as the solvent.

[0097] ii. Hydrophilicity

[0098] A water contact angle test may be used to measure the wettability or hydrophilicity of the cured support structure composition, as described above. The cured build material composition may have a contact angle with water of at least 90°, at least 95°, at least 100°, at least 105°, at least 110°, or any range including any of the foregoing values as endpoints, as measured at 22 °C and 22% humidity with a Kruss Tension K100 Water Contact Angle Goniometer and SFE model according to ASTM D5946.

[0099] V. Printing

[0100] The present disclosure may also provide a method of printing a three- dimensional object comprising the hydrophilic support structure composition and build material composition disclosed above.

[0101] The structure of the three-dimensional object may be printed by depositing the build material composition of the present disclosure onto a print bed or surface. The build material composition may be deposited in multiple successive layers to create a three- dimensional object.

[0102] Due to geometries of the three-dimensional object, support structures may be used to create supports of portions of the printed object that create an unstable vertical wall and / or an overhang of the build material. 1

[0103] An overhanging portion of the three-dimensional object may be created when a portion of subsequently printed layers of build material do not have previously printed layers directly under the subsequently printed layers that connect the subsequently printed layers to the print bed. Overhanging portions may droop, slide or otherwise move before the build material is cured. To avoid movement of the build material, a support material composition of the present disclosure is deposited onto a print bed or print surface.

[0104] The method of the present disclosure may comprise depositing a build material onto a print bed. A support material may be deposited onto the print bed or on top of already printed build material to provide support for portions of the three-dimensional object comprising the build material. The support structure may comprise multiple successive layers of the hydrophilic support structure composition of the present disclosure.

[0105] Before printing an overhanging portion of a three-dimensional object, the hydrophilic support structure composition may be deposited onto the print bed or on top of already printed build material such that the support structure is directly underneath any overhanging portions or otherwise unstable portions of the three-dimensional object comprising the build material. The build material may be above the support structure such that the build material is gravitationally supported by the support structure. Specifically, the build material may be deposited upward of the support material along a y-axis so that the support material keeps the build material in the correct and intended shape and place under downward forces along the y-axis (i.e., gravity). With the support structure composition underneath the overhanging portions, the overhanging portions of the object may not droop, slide, or otherwise deform.

[0106] To support a vertical wall comprising the build material, the hydrophilic support structure composition may be deposited on the bottom of a vertical wall, the lower surface of an inclined wall, or a horizontal surface. The support structure material may brace the vertical wall such that an otherwise unstable angle of vertical wall may be produced. With the support structure composition underneath the vertical wall comprising build material, the vertical wall of the object may not droop, slide, or otherwise deform.

[0107] Once the three-dimensional object is deposited and cured, the support structures may be removed to leave just the intended three-dimensional object comprising the build material. The three-dimensional object with hydrophilic support structure material may be submerged or exposed to a solvent, such as water, to dissolve the hydrophilic supportstructure composition. Once the hydrophilic support structure composition is dissolved, the three-dimensional object made of the build material will be left free of support structures.

[0108] As seen in FIG. 1A, an object 10 with overhanging portions I la, 11b is printed comprising cured build material 14 and dissolvable support structures 12. Object 10 may be an article such as a door seal, bulb seal, vehicle part, weather stripping, or any other 3-dimensional printed object. Support structures 12 may be printed to avoid overhanging portions 1 la, 1 lb from drooping, sagging, or otherwise deforming during the printing and curing process by supporting build material 14 that comprises overhanging portions Ila, 1 lb. However, the desired shape of object 10 comprises only build material 14. To achieve the desired shape, object 10 may be submerged in a solvent, such as water. FIG. IB shows object 10 after being submerged in a solvent. The dissolvable support structure may completely dissolved, leaving empty spaces 13a, 13b under the overhanging portions 1 la, 11b of object 10, achieving the desired shape of object 10.

[0109] The build material and dissolvable support composition may be used to 3D print objects that comprise enclosed spaces and / or encapsulated structures. FIGS. 2A and 2B illustrate an enclosed object 20, such as a cap, comprising the build material 24. Cap 20 may comprise of an outer surface 21, inner shelves 25 and at least one drain opening 26. To 3D print cap 20, outer surface 21 and shelves 25 may be supported during the cure time of build material 24 so that outer surface 21 and shelves 25 do not sag or otherwise deform before build material 24 cures. As described in the method above, cap 20 may be 3D printed using the dissolvable support material. The dissolvable support material may be printed within any hollow portion 23 of cap 20 such that outer surface 21 and shelves 25 may be supported by the dissolvable support material. Once cap 20 with the support material has been printed, cap 20 may be cured such that the dissolvable support material and build material 24 are cured. Cured cap 20 may be submerged in a solvent. The solvent may dissolve the dissolvable support material such that only outer surface 21 and shelves 25 made of the cured build material remain, as seen in FIG. 2B. The dissolvable support material may be able to dissolve and drain out of at least one drain opening 26. At least one drain opening 26 may be on the top of cap 20, the bottom of cap 20, or any other surface of outer surface 21 of cap 20.

[0110] VI. Application of 3D Printed Objects

[0111] A 3D printed object may be formed from the dissolvable water-soluble support structure and insoluble build material, as described above. The 3D printed object may be any suitable vehicle part, such as seals and gaskets. A vehicle part can be a part of anytype of aircraft, spacecraft, watercraft, and ground vehicles. A vehicle part can include a part of an aircraft such as airplanes including private aircraft, and small, medium, or large commercial passenger, freight, and military aircraft; helicopters, including private, commercial, and military helicopters; aerospace vehicles including, rockets and other spacecraft. A vehicle can include a ground vehicle such as, trailers, cars, trucks, buses, vans, construction vehicles, golf carts, motorcycles, bicycles, scooters, trains, and railroad cars. A vehicle can also include watercraft such as ships, boats, and hovercraft. A vehicle part can be part for a motor vehicle, including automobile, truck, bus, van, motorcycles, scooters, and recreational motor vehicles; railed vehicles including trains and trams; bicycles; aerospace vehicles including airplanes, rockets, spacecraft, jets, and helicopters; military vehicles including jeeps, transports, combat support vehicles, personnel carriers, infantry fighting vehicles, mine-protected vehicles, light armored vehicles, light utility vehicles, and military trucks; and watercraft including ships, boats, and recreational watercraft.

[0112] Suitable aviation vehicles may include F / A-18 jet or related aircraft such as the F / A-18E Super Hornet and F / A-18F; the Boeing 787 Dreamliner, 737, 747, 717 passenger jet aircraft, a related aircraft (produced by Boeing Commercial Airplanes); the V-22 Osprey; VH-92, S-92, and related aircraft (produced by NAVAIR and Sikorsky); the G650, G600, G550, G500, G450, and related aircraft (produced by Gulfstream); and the A35O, A320, A330, and related aircraft (produced by Airbus). Methods provided by the present disclosure can be used in any suitable commercial, military, or general aviation aircraft such as those produced by Bombardier Inc. and / or Bombardier Aerospace such as the Canadair Regional Jet (CRJ) and related aircraft; produced by Lockheed Martin such as the F- 22 Raptor, the F- 35 Lightning, and related aircraft; produced by Northrop Grumman such as the B-2 Spirit and related aircraft; produced by Pilatus Aircraft Ltd; produced by Eclipse Aviation Corporation; or produced by Eclipse Aerospace (Kestrel Aircraft).

[0113] A vehicle part can be an interior vehicle part or an exterior vehicle part.

[0114] A vehicle can comprise a motor vehicle and the motor vehicle part can comprise a hood, door, side panel, bumper, roof, wheel well, dashboard, seat, trunk, handle, floor, chassis, cabin, cargo bed, steering wheel, fuel tank, engine block, trim, bumper, console, instrument panel, armrest, headliner, airbag cover, mirror housing, grille, cladding, and / or a battery casing.

[0115] A vehicle can comprise a railed vehicle and the railed vehicle part can comprise an engine and / or a rail car.

[0116] A vehicle can comprise an aerospace vehicle and the aerospace part can comprise a cockpit, fuselage, wing, aileron, tail, door, seat, interior panel, fuel tank, interior panel, flooring, and / or frame.

[0117] A vehicle can comprise a military vehicle and the military vehicle part can comprise a hood, door, side panel, bumper, roof, wheel well, dashboard, seat, trunk, handle, floor, chassis, cabin, chassis, cargo bed, steering wheel, fuel tank, engine block, trim, bumper, a mount, a turret, an undercarriage, and / or a battery casing.

[0118] A vehicle can comprise a watercraft and the watercraft part can comprise a hull, an engine mount, a seat, a handle, a chassis, a battery, a battery mount, a fuel tank, an interior accessory, flooring, and / or paneling.

[0119] A vehicle part coated using a primer-surfacer composition provided by the present disclosure can have properties for the intended purpose. An automotive part can be designed have a light weight. An external part for military vehicle can be designed to have a high impact strength.

[0120] A part for a commercial aerospace vehicle can be designed to have a light weight and / or to be static dissipative. An external part for a military aircraft can be designed to exhibit RFI / EMI shielding properties.

[0121] A primer-surfacer composition provided by the present disclosure can be adapted to coat custom designed vehicle parts, replacement parts, upgraded parts, specialty parts, and / or high-performance parts rapidly and cost-effectively in low volume production.

[0122] Suitable architectural and construction parts may include pipes, such as plumbing pipes, potable water pipes, and drain pipes; conduit, such as electrical conduit; electrical wiring; lumber and composites, such as composite decking, wood decking, plastic decking, fencing, wall paneling, plastic sheeting, rubber sheeting, and pressure treated wood; roofing materials, such as metal roofing, asphalt shingles, roof flashing, gutters, and vents; cabinetry; flooring, such as composite flooring, laminate flooring, vinyl flooring, nylon flooring, carpet, gym flooring, garage flooring, and sealed stone or ceramic flooring; siding, such as vinyl siding, aluminum siding, composite siding, veneer siding, and cementitious siding; insulation, such as fiberglass insulation and foam insulation; ceiling tiles; trim, such as window trim, door trim, molding; fixtures, such as lighting fixtures, tubs, sinks, and showers; underlayments; leak barriers; and waterproofing membranes.

[0123] A part can comprise an elastomeric article such as seals, sealants, grommets, gaskets, washers, bushings, flanges, insulation, apparel, shoe soles, boots, footwear, handles,bumpers, shock absorbers, matting, tires, supports, automotive parts, vehicle parts, aerospace parts, marine parts, athletic equipment, toys, novelty items, and casings.

[0124] The build material and dissolvable support material may be used to 3D print sealing components, such as sealing gaskets or linear sealing components.

[0125] FIGS. 3A and 3B show a 3D printed linear sealing component 300 having a first volume 302, a second volume 304, a third volume 306, a first crescent recess 308, and a second crescent recess 310. A reference center line may be defined by first crescent recess 308 and second crescent recess 310 such that it runs through third volume 306. As shown, the third volume 306 is centrally positioned and defined by a first inner wall 312, a second inner wall 314, a third inner wall 316, and a fourth inner wall 318.

[0126] First volume 302 may be positioned on a first side of the reference center line and defined by a first exterior wall 324, the second inner wall 314, a first tip section 320, and a second tip section 322. The second volume 304 is positioned on a second side of the reference center line and defined by a second exterior wall 330, the fourth inner wall 318, a third tip section 326, and a fourth tip section 328. The first crescent recess 308 is defined by first inner wall 312, first tip section 320, and third tip section 326. The second crescent recess 310 is defined by third inner wall 316, second tip section 322, and fourth tip section 328.

[0127] FIG. 3B shows linear sealing component 300 of FIG. 3 A being fitted into a panel gap between a first panel 338 and a second panel 330, which may be panels in an aerospace vehicle such as an aircraft, for example, interior structural panels or interior spacedividing panels. Specifically, first panel 338 is received by first crescent recess 308 and secured (e.g., via friction and / or pressure) by first inner wall 312, first tip section 320, and third tip section 326. Second panel 330 is received by second crescent recess 310 and secured (e.g., via friction and / or pressure) by third inner wall 316, second tip section 322, and fourth tip section 328. In certain instances, a panel received in a crescent recess need not be in contact (e.g., continuous contact) with all three points of contact to maintain a seal. Panel 338 may not be in direct contact with the inner call 312 yet is secured by tip sections 320, 326 to form an effective seal. Each of first crescent recess 308 and second crescent recess 310 may be triangular with an opening that is narrower than a base near an inner wall. First crescent recess 308 ’s opening may be between linear sealing components of the present disclosure and may be configured to receive panels that are not in-plane. Linear sealing component 300 may couple (e.g., via elastic deformation) first panel 338 and second panel 1330 when the panels are out-of-plane. Linear sealing component 300 may receive in-plane panels as well. Additionally, linear sealing components of the present disclosure may be configured to receive panels spaced apart at various gap sizes. As depicted, linear sealing component 300 may couple (e.g., via elastic deformation) first panel 338 and second panel 330 when the panel gap is smaller than the natural first crescent recess-to-second crescent recess distance of the linear sealing component 300.

[0128] First, second, third, and fourth inner wall 312, 314, 316, 318, first and second exterior wall 324, and first, second, third, and fourth tip section 320, 322, 326, 328 may comprise the build material, such that construction and intended shape of linear sealing component 300 comprises the build material.

[0129] Each of the first, second, and third volume 302, 304, 306 and first and second crescent recess 308, 310 comprise a hollow portion 333 in the linear sealing component 300. Depending on the orientation of linear sealing component 300 on a print bed during printing, before the build material cures, the inner walls, exterior walls, and / or tip sections may shift, sag or otherwise deform due to gravity, the speed of printing, shifting of the print bed, under the weight of the build material, or other occurrences that may change the shape of the linear sealing component while the build material is uncured. To prevent deformation of the shape of the interior walls, exterior walls, and tip portions, a support structure comprising the dissolvable support composition may be printed within hollow portions 333. The dissolvable support composition may partially or entirely fill hollow portions 333.

[0130] Linear sealing component 300 may be cured such that both the build material and the dissolvable support structure composition cures. The cured linear sealing component may then be exposed or submerged in solvent. The dissolvable support structure may dissolve in the solvent, leaving only the intended shape of linear sealing component 300 comprising the cured build material. A sealing component comprising the build material and dissolvable support composition may comprise a variety of configurations of hollow portions 333, volumes, and recesses that are printed with support structures comprising the dissolvable support composition.EXAMPLES

[0131] Aspects of the present disclosure are further illustrated by reference to the following examples. It will be apparent to those skilled in the art that many modifications,both to materials, and methods, may be practiced without departing from the scope of the disclosure.Example 1-White Polvurea with Hydrophilic Support Material

[0132] For this example, a 2K polyurea formulation incorporating additives and rheology modifiers was printed with a 2K hydrophilic Aza-Michael support material, and the support material was tested for dissolving capability in water within the printed part.

[0133] Build Material Composition

[0134] The amine and the isocyanate components of the white polyurea formulation were formulated using the compositions below. The amine-side composition of the polyurea formulation was prepared according to the formulation in Table 3.Table 3: Amine-side composition

[0135] From Table 3, the amine resin, trifunctional polyether amine, chain extender, wetting and dispersing additive, pigment, UV stabilizer, liquid hindered amine light stabilizer, and filler were weighed in a Max 300 L Flacktek DAC cup and mixed via standard Speedmixer procedure.

[0136] The isocyanate-side composition of the polyurea formulation was prepared according to the formulation of Table 4.Table 4: Isocyanate-side composition

[0137] From Table 4, the polyisocyanate resin, isocyanate resin, and filler were weighed in a Max 300L Flacktek DAC cup and dispersed via standard Speedmixer procedure.

[0138] The amine and isocyanate formulations for the white polyurea were transferred from the DAC cup to a 32oz cartridge via Flacktek SpeedDisc for optimal 3D printing by reactive extrusion via ViscoTec 2k extruders mounted to a gantry such as the Cosine 3D printer. The amine and isocyanate formulations were printed at print parameters listed in Table 5.Table 5: Print Parameters For White Polyurea

[0139] Support Structure Composition

[0140] The amine and acrylate components of the hydrophilic Aza-Michael support formulation were formulated using the compositions below. The amine-side composition of the Aza-Michael formulation was prepared according to the formulation of Table 6.Table 6; Amine-side composition

[0141] From 6, the ethanolamine resin, glycol -containing acrylate resin, multifunctional amine resin, and filler were weighed in a Max 300L Flacktek DAC cup and dispersed via standard Speedmixer procedure.

[0142] The acrylate-side composition of the hydrophilic Aza-Michael formulation was prepared according to the formulation of Table 7.Table 7: Acrylate-side composition

[0143] From Table 7, the glycol-containing acrylate resin, multifunctional acrylate resin, and filler were weighed in a Max 300L Flacktek DAC cup and dispersed via standard Speedmixer procedure.

[0144] The amine and acrylate formulations for the hydrophilic Aza-Michael support material were transferred from the DAC cup to a 12oz cartridge via Flacktek SpeedDisc for optimal 3D printing by reactive extrusion via ViscoTec2k extruders mounted to a gantry such as the Cosine 3D printer. The amine and acrylate formulations were printed at print parameters listed in Table 8.Table 8; Print Parameters For Hydrophilic Aza-Michael Formulation with White Polyurea

[0145] Printing

[0146] The polyurea formulation was printed with a rectilinear 85% infill pattern at 450to form a hollow rectangular prism with the dimensions 3.35”x2.99”x2.99”. The hydrophilic aza-michael formulation was printed with a rectilinear 100% infill pattern at 00to form the support structure automatically generated in the slicer software. The support material was printed in sync layer height of the white polyurea part. The completed white polyurea 3D printed part with support structure was cured for 2 days at 160°F, and then the support material contained within the 3D printed part was placed in a plastic 32oz container with 200g of distilled water. The part was sonicated and soaked in distilled water until the support material was completely dissolved. A summary of the relevant data is shown in Table 9.Table 9: Analysis of Support Material’s Capability to Dissolve Completely in WaterExample 2-PPG Commercial Elastomer 2k with Hydrophilic Support Material

[0147] In this example, an elastomeric polythioether build material composition was printed with the hydrophilic Aza-Michael support material composition described in Tables 6 and 7 above. The support material was tested for capability of dissolving in water within the printed part. The polythioether components used are described in Table 10.Table 10; Polythioether Elastomer Components

[0148] From Table 10 the poly thiol prepolymer and the polyepoxy prepolymer were separately filled into a 300L Flacktek DAC cup each and mixed via standard Speedmixer procedure for ideal uniformity in mixture. The polythiol prepolymer and the polyepoxy were loaded into 32oz cartridges via Flacktek SpeedDisc which is optimal for 3D printing by reactive extrusion via ViscoTec 2k extruders mounted to a gantry such as the Cosine printer or the Lulzbot Taz 6. The polythioether elastomer formulation was printed at print parameters described in Table 11.Table 11: Print Parameters for Polythioether Elastomer Composition

[0149] The amine and acrylate components of the hydrophilic Aza-Michael support formulation were formulated and loaded into cartridges as described in Example 1. The AzaMichael formulation was printed at print parameters described in Tablet 2.Table 12; Print Parameters for Hydrophilic Aza-Michael Composition with Polythioether Elastomer Composition

[0150] The polythioether elastomer formulation was printed with a rectilinear 80% infill pattern at 450to form a hollow half sphere with the diameter 1.18”. The hydrophilic Aza-Michael formulation was printed with a rectilinear 100% infill pattern at 00to form the support structure automatically generated in the slicer software. The support material was printed in sync layer height of the PPG Commercial Elastomer part. The completed PPG Commercial Elastomer 3D printed part with support structure was cured for 2 days at 160°F, and then the support material contained within the 3D printed part was placed in a plastic 32oz container with 200g of distilled water. The part was sonicated and soaked in distilledwater until the support material was completely dissolved, and a summary of the relevant data is shown in Table 13.Table 13 Analysis of Support Material’s Capability to Dissolve Completely

Claims

CLAIMSWhat is claimed is:

1. A core active additive manufacturing composition comprising: a first coreactive composition comprising a Michael donor-containing compound and a Michael acceptor-containing compound, the Michael donorcontaining compound and the Michael acceptor-containing compound reactable and curable with one another under ambient conditions to form a first reaction product comprising a solid composition soluble in a solvent.

2. The composition of claim 1, further comprising a second coreactive composition, the second coreactive composition comprising a first reactive compound and a second reactive compound, the first and second reactive compound reactable and curable with one another under ambient conditions to form a second reaction product comprising a thermoset insoluble in a solvent.

3. The composition of claim 2, wherein the second reaction product has a water solubility of 0.04 g / L to 0 g / L at 25 °C.

4. The composition of any one of claims 2-3 wherein the first reactive compound comprises an epoxy-containing compound and the second reactive compound comprises a thiol-containing compound.

5. The composition of any one of claims 1-4, wherein a surface of an article formed of the second reaction product has a water contact angle equal to or greater than 90°, as measured at 22 °C and 22% humidity with a Kruss Tension K100 Water Contact Angle Goniometer and SFE model according to ASTM D5946.

6. The composition of any one of claims 1-5, wherein the first reaction product has a water solubility of 0.05 g / L to 80 g / L at 25 °C.

7. The composition of any one of claims 1-6, wherein a surface of an article formed of the first reaction product has a water contact angle between 75° and 50°, as measured at 22 °Cand 22% humidity with a Kruss Tension K100 Water Contact Angle Goniometer and SFE model according to ASTM D5946.

8. The composition of any one of claims 1-7, wherein the solvent comprises an aqueous solution.

9. The composition of any one of claims 1-8, wherein the Michael donor-containing compound comprises an amine-containing compound and the Michael acceptor-containing compound comprises an acrylate-containing compound.

10. The composition of claim 9, wherein the amine-containing compound comprises an ethanolamine resin.

11. The composition of either claim 9 or claim 10, wherein the acrylate-containing compound comprises a glycol-containing acrylate resin.

12. The composition of claim 11, wherein the glycol-containing acrylate resin comprises from 10 wt. % to 50 wt. % of the total weight of the first coreactive composition.

13. The composition of either claim 11 or claim 12, wherein the glycol-containing acrylate resin comprises from 20 wt. % to 30 wt. % of the total weight of the first coreactive composition.

14. The composition of any one of claims 11-13, wherein the glycol-containing acrylate resin comprises from 20 wt. % to 75 wt. % of the total weight of the Michael acceptorcontaining compound.

15. The composition any one of claims 11-14, wherein the glycol-containing acrylate resin comprises from 40 wt. % to 50 wt. % of the total weight of the Michael acceptorcontaining compound.

16. The composition of any one of claims 1-15, wherein the first coreactive composition comprises at least one of a multifunctional acrylate resin, a multifunctional amine resin, and combinations of thereof.

17. An additively manufactured article comprising: a first coreactive composition comprising a first reactive component and a second reactive component, the first reactive component and the second reactive component reactable and curable with one another under ambient conditions to form a first reaction product comprising a solid composition soluble in a solvent; and a second coreactive composition comprising a third reactive component and a fourth reactive component, the third reactive component and the fourth reactive component reactable and curable with one another under ambient conditions to form a second reaction product comprising a thermoset insoluble in a solvent, wherein the first reaction product comprises a soluble support material, and the second reaction product comprises an insoluble build material.

18. The article of claim 17, wherein the first reactive component comprises an amine - containing compound, the second reactive component comprises an acrylate-containing compound; and wherein the first reaction product of the first and second reactive components comprises an Aza-Michael addition-based support material.

19. The article of either claim 17 or claim 18, wherein the third reactive component comprises a polyisocyanate-containing compound and the fourth reactive component comprises an amine-containing compound; and wherein the second product of the third and fourth reactive components comprises a polyurea-based build material.

20. The article of any one of claims 17-19, wherein the first reactive component comprises a multifunctional amine and a glycol-containing amine.

21. The article of any one of claims 17-20, wherein the second reactive component comprises a multifunctional acrylate and a glycol-containing acrylate.

22. The article of any one of claims 17-21, wherein the second reaction product has a water solubility of 0.04 g / L to 0 g / L at 25 °C.

23. The article of any one of claims 17-22, wherein a surface of an article formed of the second reaction product has a water contact angle equal to or greater than 90°, as measured at 22 °C and 22% humidity with a Kruss Tension K100 Water Contact Angle Goniometer and SFE model according to ASTM D5946.

24. The article of any one of claims 17-23, wherein the first reaction product has a water solubility of 0.05 g / L to 0.50 g / L at 25 °C.

25. The article of any one of claims 17-24, wherein a surface of an article formed of the first reaction product has a water contact angle between 75° and 50°, as measured at 22 °C and 22% humidity with a Kruss Tension K100 Water Contact Angle Goniometer and SFE model according to ASTM D5946.

26. The article of any one of claims 17-25, wherein the article is an aerospace fuel cap.

27. A method of additively manufacturing an article comprising: depositing a support material comprising a first coreactive composition soluble in an aqueous solution, the first coreactive composition comprising a first coreactive component and a second coreactive component; wherein the first coreactive component and the second coreactive component react with each other to form the support material; depositing a build material comprising a second coreactive composition insoluble in an aqueous solution, the second coreactive composition comprising a third coreactive component and a fourth coreactive component; wherein the third coreactive component and the fourth coreactive component react with each other to form the build material; wherein the support material and the build material are deposited such that the support material and the build material are in contact with each other; andcuring each of the support material and the build material at room temperature to create a cured support material and a cured build material.

28. The method of claim 27, wherein the cured support material has a water solubility greater than or equal to 0.05 g / L and the cured build material has a water solubility less than 0.05 g / L.

29. The method of either claim 27 or 28, wherein a surface of an article formed of the cured support material has a water contact angle between 75° and 50° and the cured build material has a water contact angle equal to or greater than 90°, as measured at 22 °C and 22% humidity with a Kruss Tension K100 Water Contact Angle Goniometer and SFE model according to ASTM D594630. The method of any one of claims 27-29, further comprising after the curing step dissolving the support material in an aqueous solution.

31. The method of claim 30, further comprising after the dissolving step filling a space once occupied by the support material with aerospace sealant.

32. The method of any one of claims 27-31, wherein the first coreactive composition comprises a Michael addition-based composition, the Michael addition-based composition of the first coreactive composition comprises one or more hydrophilic amine-containing compounds dissolvable in an aqueous solution.

33. The method of any one of claims 27-32, wherein the second coreactive composition comprises a polyurea-based thermoset.

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