WO2019048986A1 - Method for producing a polycarbonate article - Google Patents

Abstract

A method for producing a polycarbonate article comprises printing a droplet onto a target location in a build area to obtain a printed droplet, wherein the droplet comprises a precursor solution comprising a precursor composition, a catalyst, and a solvent; removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate, wherein the precursor precipitate comprises the precursor composition and the catalyst; repeating the printing step and the removing step adjacent to or on the bead to obtain a plurality of adjacent beads comprising precursor precipitates; and polymerizing the precursor precipitates to obtain the polycarbonate article.

Description

METHOD FOR PRODUCING A POLYCARBONATE ARTICLE

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is an International Application claiming priority to U.S. Provisional Application No. 62/555,946, filed September 8, 2017, which is incorporated herein in its entirety, including the color version of the figures.

BACKGROUND

[0002] Polycarbonates, particularly polycarbonates derived from bisphenol A, are valuable commercial engineering thermoplastics that offer mechanical strength, high

temperature tolerance, and excellent optical transparency. A wide range of applications for polycarbonates include the automobile industry, civil construction, and optical devices.

[0003] However, polycarbonates and other high molecular weight polymers can have low solubility in organic solvents and high viscosities, which can make it impractical to print the high molecular weight polymers in additive manufacturing processes such as inkjet printing processes. Thus, polycarbonate articles are primarily manufactured using extrusion and molding processes. In both additive manufacturing and molding processes, there can be limitations to the quality of surface finish and resolution achieved in the article when manufacturing micro-scale structures.

[0004] Thus, it would be desirable to provide methods for producing articles, such as polycarbonate articles, which avoid the aforementioned disadvantages.

BRIEF DESCRIPTION

[0005] A method for producing a polycarbonate article includes printing a droplet onto a target location in a build area to obtain a printed droplet, wherein the droplet comprises a precursor solution comprising a precursor composition, a catalyst, and a solvent, removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate, wherein the precursor precipitate comprises the precursor composition and the catalyst, repeating the printing step and the removing step adjacent to or on the bead to obtain a plurality of adjacent beads comprising precursor precipitates, and polymerizing the precursor precipitates to obtain the polycarbonate article.

[0006] A polycarbonate article can be produced by the above-described method. [0007] A method for producing a polycarbonate article can include printing a droplet onto a target location in a build area to obtain a printed droplet, wherein the droplet comprises a precursor solution comprising a precursor composition, a catalyst, and a solvent, removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate, wherein the precursor precipitate comprises the precursor composition and the catalyst, repeating the printing step and the removing step adjacent to or on the bead to obtain a plurality of adjacent beads comprising precursor precipitates, and polymerizing the precursor precipitates to obtain the polycarbonate article. The precursor composition can be bisphenol A and bis(methyl salicyl) carbonate. The catalyst can be tetramethyl ammonium hydroxide pentahydrate. The solvent can be 1,4-dioxane. The target location can be positioned on a substrate heated to a temperature of 50°C to 95°C, or 55°C to 90°C, preferably 60°C to 85°C. The step of polymerizing can be at a polymerizing temperature equal to or greater than 100°C, or 150°C to 300°C, or 180°C to 290°C, preferably 180°C to 280°C. At least one dimension of the polycarbonate article is equal to or less than 200 micrometers, or equal to or less than 100 micrometers.

[0008] The above described and other features are exemplified by the following figures, detailed description, claims, and examples.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following figures are exemplary embodiments wherein the like elements are numbered alike.

[0010] FIG. 1 is an illustration of a method for producing an article.

[0011] FIG. 2 is graphical illustration of viscosity versus shear rate at 25°C, 35°C, and 45°C for the precursor solution used in Example 2.

[0012] FIG. 3 is a microscopic image of a portion of the array of beads produced in Example 2.

[0013] FIG. 4 is an image of the layer comprising a plurality of beads produced in Example 3.

[0014] FIG. 5 is a surface profile image of the 5 layer structure comprising a plurality of beads that was produced in Example 4.

[0015] FIGs. 6A-B are images of the polycarbonate articles produced in Example 5.

[0016] The above described and other features are exemplified by the following detailed description, examples, and claims. DETAILED DESCRIPTION

[0017] Described herein are methods for producing a polycarbonate article using multiple steps including printing droplets comprising a precursor solution, removing at least a portion of the solvent from the printed droplets to obtain a bead comprising a precursor precipitate, repeating the printing step and the removing step to obtain a plurality of beads, and polymerizing the precursor precipitates to form the article. By utilizing the multiple steps, the methods can produce articles with a micro- scale dimension on the order of several micrometers comprising polycarbonate with molecular weights comparable to polycarbonate produced by bulk methods (e.g., melt or interfacial polymerization). For example, the polycarbonate articles can include at least one dimension equal to or less than 200 micrometers (μιτι), or equal to or less than 100 micrometers, and include polycarbonate with an average molecular weight (Mw) of 10,000 Daltons to 200,000 Daltons).

[0018] Previous processes suffered from an inability to fabricate microscale

polycarbonate articles with tunable mechanical or optical properties via additive manufacturing. For example, Fused Deposition Modeling (FDM), which melts polycarbonate directly and extrudes the hot melted polymer to form polycarbonate articles, can encounter issues such as low resolution, poor surface textures, and low optical clarity. Due to the high viscosity of molten polycarbonate, FDM processes deposited beads of polycarbonate with larger volumes as compared to beads produced by inkjet printing of lower viscosity materials. In addition, the mechanical properties, including the intralayer bonding strength was poor between adjacent layers of polycarbonate articles formed by such methods.

[0019] Desirably, the present methods use reactive inkjet printing (RIP) to address these issues by depositing precursor compositions (e.g., monomers or oligomers) in precursor solutions onto target locations to form the polycarbonate article. The low viscosity precursor solutions can be deposited through inkjet printing systems and the removal of at least a portion of the solvent to form precursor precipitates enables smaller features (e.g., patterns and structures) to be printed with enhanced resolution, surface texture, and clarity in comparison to polycarbonate articles produced by FDM processes. Via polymerization of the precursor precipitates, polycarbonate articles can be formed in-situ for a broad range of polycarbonate applications such as in the automobile industry, civil construction, and optical device industry.

[0020] A method for producing a polycarbonate article can include printing a droplet onto a target location in a build area to obtain a printed droplet. The droplet can comprise a precursor solution including a precursor composition, a catalyst, and a solvent. The method for producing a polycarbonate article can further include removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate, repeating the printing step and the removing step adjacent to or on the bead to obtain a plurality of adjacent beads comprising the precursor precipitate, and polymerizing the precursor precipitate to obtain the polycarbonate article. The precursor precipitate includes the precursor composition and the catalyst.

[0021] As used herein, "target location" refers to a predetermined or precise space, shape, or pattern in three-dimensional space according to a virtual article design.

[0022] As used herein, "bead" refers to a droplet or a line of material. A plurality of beads can form a plurality of layers of a polycarbonate article or a portion of a layer of a polycarbonate article. For example, a bead can be a continuous line of material forming all the layers of a polycarbonate article. Alternatively, a bead can be a discontinuously formed droplet or a line of material, which forms a portion of the polycarbonate article.

[0023] As used herein, "build area" refers to the three dimensional space where a polycarbonate article is printed. The build area can include a substrate on which droplets are printed. The build area can be open to a larger space (e.g., a room or an outdoor environment) or enclosed (e.g., in a chamber).

[0024] Additive manufacturing processes, or three dimensional (3-D) printing, are generally defined as processes that build an object from a series of layers with each layer formed on top of the previous layer. For example, 3-D printing refers to a variety of processes including Fused Deposition Modeling (FDM) or Fused Filament Fabrication (FFF), Selective Laser Sintering (SLS), Stereolithography (SLA), Digital Light Processing (DLP), and 3D inkjet printing.

[0025] Inkjet printing (e.g., 3D inkjet printing) is a method for fabricating structures by selectively printing droplets of a build material onto a substrate in a build area. Materials used in inkjet printing can be dissolved in a solvent to adjust the solution viscosity for the inkjet process. By printing a material onto a target location, formation of an article can be in a directed or patterned manner according to a virtual (i.e., computer) article design, in contrast to forming or extruding a material according to an article design physically dictated by forming equipment or extruding equipment in macroscopic or bulk proportions (e.g., slit extrusion die of a bulk extruded film article or laminated pattern). The inkjet printing processes can be used to make two dimensional or three dimensional articles. Examples of inkjet printing include reactive inkjet printing (RIP), PolyJet printing, and MultiJet printing. The printing can be performed on an inkjet printer.

[0026] In the present method for producing a polycarbonate article, during the step of printing, a build pressure in the build area can be equal to or greater than 80 kilopascals, or equal to or greater than 90 kilopascals, preferably equal to or greater than 100 kilopascals. As used herein, "pressure" refers to gauge pressure unless otherwise indicated.

[0027] The printed droplet comprises a precursor solution including a precursor compound, a catalyst, and a solvent. Desirably, the precursor compound includes two or more precursor compounds (e.g., monomers or oligomers). For instance, the precursor composition can include a dihydroxy compound and a carbonate compound. In one example, each of the droplets comprises the same composition (e.g., the droplets include the same precursor composition, the same catalyst, and the same solvent in the same relative amounts). For example, in that embodiment, the droplets comprise the catalyst, solvent, and precursor composition. The droplets do not need to be mixed with another material after being printed (e.g., by a nozzle).

[0028] Some illustrative examples of dihydroxy compounds that can be used are described, for example, in WO 2013/175448 Al, US 2014/0295363, and WO 2014/072923.

[0029] Specific dihydroxy compounds include resorcinol, 2,2-bis(4-hydroxyphenyl) propane ("bisphenol A" or "BPA"), 3,3-bis(4-hydroxyphenyl) phthalimidine, 2-phenyl-3,3'- bis(4-hydroxyphenyl) phthalimidine (also known as N-phenyl phenolphthalein bisphenol, "PPPBP", or 3,3-bis(4-hydroxyphenyl)-2-phenylisoindolin-l-one), l,l-bis(4-hydroxy-3- methylphenyl)cyclohexane, l,l-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (isophorone bisphenol), or a combination comprising at least one of the foregoing.

[0030] The carbonate compound (e.g., an activated carbonate) can be a carbonyl halide, a bishaloformate of a dihydroxy compound, a diaryl carbonate, or a combination comprising at least one of the foregoing. The carbonyl halide can be carbonyl bromide or carbonyl chloride (e.g., phosgene). The bischloroformate can be the bischloroformate of bisphenol A,

hydroquinone, ethylene glycol, neopentyl glycol, or a combination comprising at least one of the foregoing. The diaryl carbonate can have the formula I

(I) wherein n is an integer 1 to 3 and each R¹ is independently a linear or branched, optionally substituted Ci-₃₄ alkyl (specifically C_1-6 alkyl, more specifically Ci-₄ alkyl), Ci-₃₄ alkoxy

(specifically C_1-6 alkoxy, more specifically Ci-₄ alkoxy), C5-34 cycloalkyl, C7-34 alkylaryl C₆-34 aryl, a halogen radical (specifically a chlorine radical), or -C(=0)OR' wherein R' is H, linear or branched Ci-₃₄ alkyl (specifically C_1-6 alkyl, more specifically C1-4 alkyl), Ci-₃₄ alkoxy

(specifically C_1-16 alkoxy, specifically C1-4 alkoxy), C5-34 cycloalkyl, C7-34 alkylaryl, or C₆-34 aryl.

[0031] The diaryl carbonate (I) can be diphenyl carbonate, methylphenyl-phenyl carbonates or di-(methylphenyl) carbonates (wherein the methyl group can be in any desired position on the phenyl rings), dimethylphenyl-phenyl carbonates or di-(dimethylphenyl) carbonates (wherein the methyl groups can be in any desired position on the phenyl rings), chlorophenyl-phenyl carbonates and di-(chlorophenyl) carbonates (wherein the chloro group can be in any desired position on the phenyl rings), 4-ethylphenyl-phenyl carbonate, di-(4- ethylphenyl) carbonate, 4-n-propylphenyl-phenyl carbonate, di-(4-n-propylphenyl) carbonate, 4- isopropylphenyl-phenyl carbonate, di-(4-isopropylphenyl) carbonate, 4-n-butylphenyl-phenyl carbonate, di-(4-n-butylphenyl) carbonate, 4-isobutylphenyl-phenyl carbonate, di-(4- isobutylphenyl) carbonate, 4-tert-butylphenyl-phenyl carbonate, di-(4-tert-butylphenyl) carbonate, 4-n-pentylphenyl-phenyl carbonate, di-(4-npentylphenyl) carbonate, 4-n- hexylphenyl-phenyl carbonate, di-(4-n-hexylphenyl) carbonate, 4-isooctylphenyl-phenyl carbonate, di-(4-isooctylphenyl) carbonate, 4-n-nonylphenyl-phenyl carbonate, di-(4-n-nonyl- phenyl) carbonate, 4-cyclohexylphenyl-phenyl carbonate, di-(4-cyclohexylphenyl) carbonate, 4- (1 -methyl- l-phenylethyl)-phenyl-phenyl carbonate, di- [4-(l -methyl- 1-phenylethyl)- phenyl] carbonate, biphenyl-4-yl-phenyl carbonate, di-(biphenyl-4-yl) carbonate, (1-naphthyl)- phenyl carbonate, (2-naphthyl)-phenyl carbonate, di-(l-naphthyl) carbonate, di-(2-naphthyl) carbonate, 4-(l-naphthyl)-phenyl-phenyl carbonate, 4-(2-naphthyl)-phenyl-phenyl carbonate, di- [4-(l-naphthyl)-phenyl] carbonate, di-[4-(2 -naphthyl)phenyl] carbonate, 4-phenoxyphenyl- phenyl carbonate, di-(4-phenoxyphenyl) carbonate, 3-pentadecylphenyl-phenyl carbonate, di-(3- pentadecylphenyl) carbonate, 4-tritylphenyl-phenyl carbonate, di-(4-tritylphenyl) carbonate, methyl salicylate -phenyl carbonate, di-(methyl salicylate) carbonate, ethyl salicylate-phenyl carbonate, di-(ethyl salicylate) carbonate, n-propyl salicylate-phenyl carbonate, di-(n-propyl salicylate) carbonate, isopropyl salicylate-phenyl carbonate, di-(isopropyl salicylate) carbonate, n-butyl salicylate-phenyl carbonate, di-(n-butyl salicylate) carbonate, isobutyl salicylate -phenyl carbonate, di-(isobutyl salicylate) carbonate, tert-butyl salicylate -phenyl carbonate, di-(tert-butyl salicylate) carbonate, di-(phenyl salicylate)-carbonate, di-(benzyl salicylate) carbonate, and a combination comprising at least one of the foregoing.

[0032] The diaryl carbonate can be diphenyl carbonate, or a diaryl carbonate wherein one or both aryl groups have an electron-withdrawing substituents, for example, bis(4- nitrophenyl)carbonate, bis(2-chlorophenyl)carbonate, bis(4-chlorophenyl)carbonate, substituted or unsubstituted bis(alkyl salicyl)carbonate (e.g., bis(ethyl salicyl) carbonate, bis(propyl salicyl) carbonate, bis(phenyl salicyl) carbonate, bis(benzyl salicyl) carbonate, and bis(methyl salicyl)carbonate ("BMSC")), bis(4-methylcarboxylphenyl) carbonate, bis(2-acetylphenyl) carboxylate, bis(4-acetylphenyl) carboxylate, or a combination comprising at least one of the foregoing. The diaryl carbonate can comprise bis(alkyl salicyl)carbonate ("BASC"), for example, BMSC.

[0033] The carbonate compound and dihydroxy compound can be present in the precursor compound in a molar ratio of 2: 1 to 1 :2, or in a molar ratio of 1.5: 1 to 1 : 1.5, preferably in a molar ratio of 1.05: 1 to 1: 1.05, more preferably in a molar ratio of 1 : 1. The molar ratio of the carbonate compound to the dihydroxy compound when expressed to three decimal places can be 0.996 or less, or 0.962 to 0.996, preferably 0.968 to 0.996, more preferably 0.971 to 0.994.

[0034] Desirably, BPA and bis(alkyl salicyl)carbonate (e.g., BMSC) can be used to produce the polycarbonate article to reduce the time required for polymerization, eliminate unfavorable degradation products, avoid color issues, and provide thermal stability at relatively high temperatures (i.e., at temperatures greater than 200°C). The polycarbonate article can be produced from BPA and bis(alkyl salicyl)carbonate in a period of time of less than 120 minutes, for example, less than or equal to 90 minutes, or less than or equal to 60 minutes, and even less than or equal to 50 minutes. The polymerization can be at a temperature of under 300°C, for example, at less than or equal to 295°C, or at 275°C to 285°C. For instance, polymerization of BPA and BMSC can be at a temperature of 280°C to obtain the polycarbonate article in 40 minutes. In comparison, in order to produce an article having a similar weight average molecular weight (Mw) polycarbonate and using of BPA and diphenyl carbonate ("DPC") the polymerization would be at a temperature of 300°C for 135 minutes.

[0035] "Polycarbonate" as used herein means a polymer or copolymer having repeating structural carbonate units of formula (1)

O wherein at least 60 percent of the total number of R¹ groups are aromatic, or each R¹ contains at least one C₆-30 aromatic group. Specifically, each R¹ can be derived from a dihydroxy compound such as an aromatic dihydroxy compound of formula (2) or a bisphenol of formula (3).

In formula (2), each R^h is independently a halogen atom, for example bromine, a Ci-io hydrocarbyl group such as a Ci-io alkyl, a halogen-substituted Ci-io alkyl, a C₆-io aryl, or a halogen-substituted C6-10 aryl, and n is 0 to 4.

[0036] In formula (3), R^a and R^b are each independently a halogen, Ci-12 alkoxy, or Ci-12 alkyl, and p and q are each independently integers of 0 to 4, such that when p or q is less than 4, the valence of each carbon of the ring is filled by hydrogen. For instance, p and q can each be 0, or p and q is each 1, and R^a and R^b are each a C1-3 alkyl group, specifically methyl, disposed meta to the hydroxy group on each arylene group. X^a is a bridging group connecting the two hydroxy-substituted aromatic groups, where the bridging group and the hydroxy substituent of each Ce arylene group are disposed ortho, meta, or para (specifically para) to each other on the Ce arylene group, for example, a single bond, -0-, -S-, -S(O)-, -S(0)₂-, -C(O)-, or a Ci-is organic group, which can be cyclic or acyclic, aromatic or non-aromatic, and can further comprise heteroatoms such as halogens, oxygen, nitrogen, sulfur, silicon, or phosphorous. For instance, X^a can be a substituted or unsubstituted C3-18 cycloalkylidene; a Ci-25 alkylidene of the formula - C(R^c)(R^d) - wherein R^c and R^d are each independently hydrogen, Ci-12 alkyl, Ci-12 cycloalkyl, C7-12 arylalkyl, Ci-12 heteroalkyl, or cyclic C7-12 heteroarylalkyl; or a group of the formula - C(=R^e)- wherein R^e is a divalent Ci-12 hydrocarbon group.

[0037] The polycarbonate can include carbonate units (1) and non-carbonate units, for example ester units, polysiloxane units such as polydimethylsiloxane units, or a combination comprising at least one of the foregoing. In some embodiments the ester units can be aromatic ester units (e.g., resorcinol terephthalate or isophthalate), or aromatic-aliphatic esters, based on C6-20 aliphatic diacids.

[0038] Desirably, the polycarbonate can be a linear homopolymer containing bisphenol A carbonate units (BPA-PC), commercially available under the trade name LEXAN from SABIC; or a branched, cyanophenol end-capped bisphenol A homopolycarbonate, containing 3 mol% l,l, l-tris(4-hydroxyphenyl)ethane (THPE) branching agent, commercially available under the trade name LEXAN CFR from SABIC . A combination of a linear polycarbonate and a branched polycarbonate can be used. It is also possible to use a polycarbontate copolymer or interpolymer rather than a homopolymer. Polycarbonate copolymers can include

copolycarbonates comprising two or more different types of carbonate units, for example units derived from BPA and PPPBP (commercially available under the trade name XHT from

SABIC™); BPA and DMBPC (commercially available under the trade name DMX from SABIC™); or BPA and isophorone bisphenol (commercially available under the trade name APEC from Bayer). The polycarbonate copolymers can further comprise non-carbonate repeating units, for example repeating ester units (polyester-carbonates), such as those comprising resorcinol isophthalate and terephthalate units and bisphenol A carbonate units, such as those commercially available under the trade name LEXAN™ SLX from SABIC; bisphenol A carbonate units and isophthalate-terephthalate -bisphenol A ester units, also commonly referred to as poly(carbonate-ester)s (PCE) or poly(phthalate-carbonate)s (PPC), depending on the relative ratio of carbonate units and ester units; or bisphenol A carbonate units and C₆-i2 dicarboxy ester units such as sebacic ester units (commercially available under the trade name HFD from SABIC™) Other polycarbonate copolymers can comprise repeating siloxane units (polycarbonate- siloxanes), for example those comprising bisphenol A carbonate units and siloxane units (e.g., blocks containing 5 to 200 dimethylsiloxane units), such as those commercially available under the trade name EXL from SABIC™; or both ester units and siloxane units (polycarbonate-ester- siloxanes), for example those comprising bisphenol A carbonate units, isophthalate-terephthalate-bisphenol A ester units, and siloxane units (e.g., blocks containing 5 to 200 dimethylsiloxane units), such as those commercially available under the trade name FST from SABIC™. For instance, an ester in the precursor solution can react with the diol producing a random copolymer of poly(ester-carbonate). Combinations of any of the above materials can be used.

[0039] Combinations of polycarbonates with other polymers can be used, for example an alloy of bisphenol A polycarbonate with an ester such as poly(butylene terephalate) or poly(ethylene terephthalate), each of which can be semicrystalline or amorphous. Such combinations are commercially available under the trade name XENOY™ and XYLEX™ from SABIC™.

[0040] Catalysts used in the precursor solution can include transesterification catalysts such as an alpha catalyst and/or a beta catalyst. For example, catalyst can be only a beta catalyst. Alpha catalysts can be more thermally stable and less volatile than beta catalysts. Beta catalysts can be volatile and degrade at elevated temperatures. Beta catalysts therefore can be preferred for use in low-temperature polymerization.

[0041] The alpha catalyst can comprise a source of alkali or alkaline earth ions. The sources of these ions include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, as well as alkaline earth hydroxides such as magnesium hydroxide and calcium hydroxide. Other possible sources of alkali and alkaline earth metal ions include the corresponding salts of carboxylic acids (such as sodium acetate) and derivatives of ethylene diamine tetraacetic acid (EDTA) (such as EDTA tetrasodium salt, and EDTA magnesium disodium salt). Other alpha transesterification catalysts include alkali or alkaline earth metal salts of carbonate, such as CS2CO3, NaHC0₃, and Na₂C0₃, and the like, non-volatile inorganic acid such as NaH₂P0₃, NaH₂P0₄, Na₂HP0₃, KH₂P0₄, CsH₂P0₄, Cs₂HP0₄, and the like, or mixed salts of phosphoric acid, such as NaKHP0₄, CsNaHP0₄, CsKHP0₄, and the like. Combinations comprising at least one of any of the foregoing catalysts can be used.

[0042] Possible beta catalysts can comprise a quaternary ammonium compound, a quaternary phosphonium compound, or a combination comprising at least one of the foregoing. The quaternary ammonium compound can be a compound of the structure (R⁴)₄N⁺X^~, wherein each R⁴ is the same or different, and is a Ci-20 alkyl, a C₄-₂o cycloalkyl, or a C₄-₂o aryl; and X^" is an organic or inorganic anion, for example, a hydroxide, halide, carboxylate, sulfonate, sulfate, formate, carbonate, or bicarbonate. Examples of organic quaternary ammonium compounds include tetramethyl ammonium hydroxide, tetrabutyl ammonium hydroxide, tetramethyl ammonium acetate, tetramethyl ammonium formate, tetrabutyl ammonium acetate, or a combination comprising at least one of the foregoing, preferably tetramethyl ammonium hydroxide such tetramethyl ammonium hydroxide pentahydrate. The quaternary phosphonium compound can be a compound of the structure (R⁵)₄P⁺X^~, wherein each R⁵ is the same or different, and is a Ci-20 alkyl, a C₄-₂o cycloalkyl, or a C₄-₂o aryl; and X^" is an organic or inorganic anion, for example a hydroxide, phenoxide, halide, carboxylate such as acetate or formate, sulfonate, sulfate, formate, carbonate, or bicarbonate. Where X^" is a polyvalent anion such as carbonate or sulfate it is understood that the positive and negative charges in the quaternary ammonium and phosphonium structures are properly balanced. For example, where R⁴ or R⁵ are each methyl and X^" is carbonate, it is understood that X^" represents ½(C0₃ ^"2). Examples of organic quaternary phosphonium compounds include tetramethyl phosphonium hydroxide, tetramethyl phosphonium acetate, tetramethyl phosphonium formate, tetrabutyl phosphonium hydroxide, tetrabutyl phosphonium acetate (TBPA), tetraphenyl phosphonium acetate, tetraphenyl phosphonium phenoxide, and combinations comprising at least one of the foregoing.

[0043] The amount of alpha and beta catalyst used can be based upon the total number of moles of dihydroxy compound. When referring to the ratio of beta catalyst, for example, a phosphonium salt, to all dihydroxy compounds used in the polymerization reaction, it is convenient to refer to moles of phosphonium salt per mole of the dihydroxy compound, meaning the number of moles of phosphonium salt divided by the sum of the moles of each individual dihydroxy compound present in the reaction mixture. The alpha catalyst can be used in an amount sufficient to provide 1 x 10^"2 to 1 x 10 ^s moles, specifically, 1 x 10^"4 to 1 x 10^"7 moles of metal per mole of the dihydroxy compounds used. The amount of beta catalyst (e.g., organic ammonium or phosphonium salts) can be 1 x 10^"2 to 1 x 10^"5, specifically 1 x 10^"3 to 1 x 10^"4 moles per total mole of the dihydroxy compounds in the reaction mixture. Desirably, a mole ratio of the catalyst to the precursor composition can be equal to or greater than 0.000001: 1, or equal to or greater than 0.00001: 1, preferably equal to or greater than 0.0001: 1.

[0044] Desirably the solvent has a moderate evaporation rate (e.g., 0.1 to 3) measured using ft-butyl acetate as a reference material in accordance with ASTM D3539-87) and can dissolve the precursor composition and the catalyst. Desirably, the solvent allows for a greater amount of the precursor composition to be dissolved in comparison to previous reactive inkjet printing inks comprising different compositions while retaining the printability of the precursor solution.

[0045] The surface tension of the precursor solution should be selected so as to avoid movement of the printed droplet (e.g., creep or formation of satellite-beads, which are smaller drops that fall behind the droplet when it is printed), which can affect the resolution and accuracy of a pattern of printed droplets. Desirably, a surface tension of the precursor solution is 10 millinewtons/meter (mN/m) to 50 millinewtons/meter, or 20 millinewtons/meter to 40 millinewtons/meter, preferably 25 millinewtons/meter to 38 millinewtons/meter. Surface tension is measured using a Kruss DSA 100S drop shape analyzer in accordance with the pendant drop method described in Stauffer, Clyde E. "The Measurement of Surface Tension By the Pendant Drop Technique." The Journal of Physical Chemistry 69.6 (1965): 1933-1938.

[0046] The solvent can be stable before and during the step of printing, but allow for subsequent removal after printing of the precursor solution. Moreover, selection of the solvent can be selected to reduce evaporation of the solvent at the meniscus layer of the precursor solution on a printing nozzle, where the precursor solution can be exposed to a build area, causing evaporation of the solvent and formation of precipitate that can potentially block the printing nozzle. This phenomenon can be significant when the printing is on stand-by. The physical properties of the solvent related to this evaporation are the boiling point and vapor pressure of the solvent at the build area temperature. Although a solvent with a low boiling point and high vapor pressure will evaporate quickly on contact with a target location, such a solvent can increase the evaporation of the solvent at the meniscus layer. Desirably, at least one of a vapor pressure of the solvent can be equal to or greater than 500 pascals, or equal to or greater than 525 pascals, preferably equal to or greater than 550 pascals and a boiling point of the solvent can be equal to or less than 150°C, or equal to or less than 125°C, preferably equal to or less than 100°C. As referred to herein, "vapor pressure" is determined according to ASTM D323-06. As referred to herein, "boiling point" is determined according to ASTM D5399-06.

[0047] The solvent can include at least one of an amide, ether, and dichlorobenzene. The amide can include dimethylformamide, dimethyelacetamide, formamide, n-methyl-2- pyrrolidone, n-methylformamide, 2-pyrrolidone, tetramethylurea, n-vinylacetamide, n- vinylpyrronlidone, or a combination of at least one of the foregoing. The ether can include 1,4- dioxane, diethyl ether, isopropyl ether, t-butyl. ether, methyl tert-butyl ether, oxane,

tetrahydrofuran (THF), or a combination comprising at least one of the foregoing.

[0048] The solvent can include multiple solvents to reduce movement of the printed droplets, e.g., to avoid the "coffee ring" effect. The multiple solvents can be miscible with each other and result in a solvent with a viscosity that allows the precursor solution to be printable (e.g., 1 centipoise to 30 centipoise). A multiple solvent system can include a mixture of a higher boiling point solvent and a lower boiling point solvent.

[0049] The concentration of the precursor composition in the precursor solution can be selected to be as high as possible. High concentrations of the precursor composition reduces the movement (e.g., creep, formation of satellite-beads, and "coffee ring" effect) of the printed droplet and reduces the amount of solvent to be removed, which can affect the resolution, surface finish, and clarity of the printed polycarbonate article. In addition, greater thicknesses (e.g., equal to or greater than 1 micrometer) of the printed layers can be achieved due to less volume loss associated with removal of the solvent in comparison to use of precursor solutions with lower concentrations of the precursor composition (e.g., less than 10 weight percent (wt%) of the precursor composition, based on the total weight of the precursor solution). These greater thickness of the printed layers result in faster process speeds and greater mechanical strength (e.g., due to fewer layers). Therefore, the concentration of precursor composition in the precursor solution is a balance of processing speeds, control, and product quality, versus printability. Desirably, the precursor composition can be present in the precursor solution in an amount equal to or greater than 10 wt%, or equal to or greater than 20 wt%, preferably equal to or greater than 30 wt%, based on the total weight of the precursor solution (wherein the total weight of the precursor composition, solvent, and the catalyst can be 100 wt%). The precursor composition can be present in the precursor solution in an amount equal to or less than 50 wt%, or 10 wt% to 50 wt%, preferably 20 wt% to 50 wt%, based on the total weight of the precursor solution,

[0050] It should be understood, however, that high concentrations of the precursor composition in the precursor solution can result in a precursor solution viscosity higher than printable range (i.e., greater than 30 centipoise) and non-Newtonian behavior of the precursor solution, which cause instability in printing. To allow the precursor solution to be printed, the viscosity of the precursor solution can be 1 centipoise to 30 centipoise, or 1 centipoise to 10 centipoise, preferably 1 centipoise to 5 centipoise. Viscosity was measured using a Malvern Kinexus Pro rotational rheometer with a Peltier plate and an active hood cartridge.

[0051] In the method for producing a polycarbonate article, the step of removing at least a portion of the solvent can be via evaporation of the solvent. For instance, at least 70 wt%, or 80 wt%, preferably 90 wt%, more preferably 100 wt% of the solvent, based on the total weight of the solvent, can be removed.

[0052] Evaporation of the solvent can be by heating the solvent. For instance, the solvent can be heated by a substrate on which the target location is positioned and that is heated. The substrate can be heated directly or indirectly with a heating element (e.g., an infrared heater positioned over the target location). The solvent can be heated by heating the plurality of adjacent beads including precursor precipitates in an oven (e.g., vacuum oven). Desirably, at least one of the target location and the build area is heated. The target location can be positioned on a substrate heated to a temperature of 50°C to 95°C, or 55°C to 90°C, preferably 60°C to 85°C. The build area can be at a temperature of 50°C to 95°C, or 55°C to 90°C, preferably 60°C to 85°C. For instance, the build area can comprise an enclosed chamber and the enclosed chamber can heated with a heating element.

[0053] Upon removal of at least a portion of the solvent, the precursor precipitate can have a low degree of polymerization due to the effect of the solvent on at least one of: the mobility of the precursor compositions for reaction with one another and acceleration of the polymerization by the presence of protons in the precursor solution. A weight average molecular weight of the precursor precipitate can be 500 Daltons to 5,000 Daltons, or 1,000 Daltons to 4,000 Daltons, preferably 1,500 Daltons to 3,000 Daltons. As used herein, "weight average molecular weight" refers to the molecular weight as measured by gel permeation chromatography (GPC), using a PLgel Mixed-D column and calibrated to poly(methyl methacrylate) references GPC samples are prepared at a concentration of 1 mg per ml, and are eluted at a flow rate of 1.5 ml per minute.

[0054] During the step of polymerization, the precursor precipitate is polymerized to form polycarbonate. Concurrently, the remainder of the solvent can be removed.

[0055] Desirably, the step of polymerizing the precursor precipitate is performed outside the build area. For instance, the step of polymerizing can be in a vacuum oven.

[0056] The step of polymerizing can be at a polymerizing temperature equal to or greater than 100°C, or 150°C to 300°C, or 180°C to 290°C, preferably 180°C to 280°C.

[0057] The step of polymerizing can be at polymerizing pressure equal to or less than 100 kilopascals, or equal to or less than 25 kilopascals, or equal to or less than 10 kilopascals. The step of polymerization can be at a polymerizing pressure greater than or equal to 0.5 kilopascals, or 0.5 kilopascals to 100 kilopascals, preferably 0.5 to 25 kilopascals.

[0058] A weight average molecular weight of the resultant polycarbonate that forms the article (i.e., the polymerized precursor precipitate) can be 10,000 Daltons to 200,000 Daltons, or 15,000 Daltons to 150,000 Daltons, preferably 20,000 Daltons to 100,000 Daltons.

[0059] A dimension (e.g., a thickness, a width, a length, a diameter, or a combination of at least one of the foregoing) of the polycarbonate article can be equal to or less than 10,000 micrometers, or equal to or less than 1,000 micrometers, preferably equal to or less than 100 micrometers.

[0060] Desirably, a method for producing a polycarbonate article can include printing a droplet onto a target location in a build area to obtain a printed droplet, wherein the droplet comprises the precursor solution, removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate, wherein the precursor precipitate comprises the precursor composition and the catalyst; repeating the printing step and the removing step adjacent to or on the bead to obtain a plurality of adjacent beads comprising precursor precipitates; and polymerizing the precursor precipitates to obtain the polycarbonate article. The precursor composition can include bisphenol A and bis(alkyl salicyl)carbonate (e.g., bis(methyl salicyl)carbonate). The catalyst can include tetramethyl ammonium hydroxide (e.g., tetramethyl ammonium hydroxide pentahydrate). The solvent can include 1,4 dioxane. [0061] By using the methods of the present disclosure, the formulation of precursor solutions for reactive inkjet printing can be achieved and the resolution, surface texture, and optical properties of polycarbonate articles (e.g., micro-scale polycarbonate articles) can be improved as compared to polycarbonate articles produced by the previous processes described herein.

[0062] A more complete understanding of the components, processes, and apparatuses disclosed herein can be obtained by reference to the accompanying drawings. These figures (also referred to herein as "FIG.") are merely schematic representations based on convenience and the ease of demonstrating the present disclosure, and are, therefore, not intended to indicate relative size and dimensions of the devices or components thereof and/or to define or limit the scope of the exemplary embodiments. Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function.

[0063] As illustrated in FIG. 1, a method 100 for producing an article can include, at step 102, printing a droplet onto a target location to obtain a printed droplet comprising a precursor solution. At step 104, the method includes removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate. At step 106, the method includes repeating the steps of printing 102 and removing 104 to obtain a plurality of beads comprising precursor precipitates. At step 108, the method includes polymerizing the precursor precipitates to form the polycarbonate article.

[0064] This disclosure is further illustrated by the following examples, which are non- limiting.

EXAMPLES

[0065] The following components in Table 1 are used in the examples.

Unless specifically indicated otherwise, the amount of each component is in weight percent in the following examples, based on the total weight of the composition. [0066] Physical measurements were made using the tests and test methods described herein. Example 1

[0067] In Example 1, the maximum solubility in 1, 4-dioxane of a precursor composition including BPA and BMSC was determined.

[0068] BMSC flakes and BPA flakes were ground to powder with a mortar and pestle for ease of measuring and dissolving in the solvent. The BMSC and BPA powders were stored separately in two capped glass vials. A stoichiometric ratio of 1.02 of BMSC powder and BPA powder were weighed and mixed in another capped vial. The stoichiometric ratio was chosen to compensate for the potential evaporative loss of BMSC when heated.

[0069] Next, 4.5 grams, 4.0 grams, 3.5 grams, 3.0 grams, and 2.5 grams of 1, 4-dioxane solvent were each added to an empty vial and 0.5 grams, 1.0 grams, 1.5 grams, 2.0 grams, and 2.5 grams of the BMSC and BPA mixture were added to each vial, respectively, to produce 10 wt%, 20 wt%, 30 wt%, 40 wt%, and 50 wt% of BMSC and BPA in the five solutions, based on the total weight of the precursor and the solvent.

[0070] Tetramethyl ammonium hydroxide pentahydrate (TMAH) (ΤΜΑΗ· 5Η₂0, 181.23 grams/mole, Sigma- Aldrich) was used as a catalyst. TMAH was added to each solution in an amount of 0.0001 moles per mole of BPA and care was taken to minimize the exposure of TMAH to moisture in the air by immediate transfer of the catalyst from the scale to the precursor solution. The precursor solutions were then left at 25°C and magnetically stirred with a IKA RCT Basic IKAMAG™ Magnetic Stirrer for 5 hours.

[0071] The 30 wt%, 40 wt% and 50 wt% precursor solutions were turbid. A small amount of powder was observed in the 10 wt%, 20 wt%, and 30 wt% precursor solutions. The five precursor solutions were heated and stirred at 40°C for 1 hour and then cooled down to a temperature of 20°C. The powders in the 10 wt% and 20 wt% wt% precursor solutions were fully dissolved. There was no significant change observed in the 30 wt%, 40 wt%, and 50 wt% precursor solutions; they remained turbid.

[0072] The reactive solutions with a total amount of BMSC and BPA of 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, based on the total weight of the precursor solution, were produced using the procedure described above. The precursor solutions were stirred and heated at 40°C for 1 hour. The BMSC and BPA were fully dissolved in the precursor solutions with equal to or less than 25 wt% of BMSC and BPA, based on the total weight of the precursor solution.

Example 2

[0073] Based on the results in Example 1, the 25 wt% (wt.%) precursor solution was selected for use in inkjet printing. The precursor solution was allowed to settle for 24 hours at room temperature to release any bubbles.

[0074] The composition of the precursor solution is summarized in Table 2.

[0075] The viscosity of the precursor solution was measured at different temperatures. Viscosity was measured at 25°C to 45°C between the shear rate of 10 seconds^"1 to 1,000 seconds^"1.

[0076] As shown in FIG. 2, the viscosity had a temperature dependent profile where it decreased with an increase in temperature. The viscosities were 3.5 centipoise, 3.3 centipoise, and 3.2 centipoise at 25°C, 35°C, and 45°C, respectively.

[0077] The surface tension of the precursor solution was also measured. The surface tension of the precursor solution was 25.2 mN/m at 25°C, 23.7 mN/m at 35°C, and 21.1 mN/m at 45°C.

[0078] The precursor solution was printed with a Dimatix DMP-2830 materials printer (commercially available from Fujifilm) assembled with a disposable piezoelectric printhead and cartridge. The precursor solution was filtered through a 0.4 micrometer nylon syringe filter (Minisart, commercially available from Sartorius Stedim) by a fill needle (supplied with the cartridge) to remove any solid which might block the print nozzles. Bubbles formation in the precursor solution was reduced by tapping the cartridge. The jetting module was attached onto the plastic cartridge and installed onto the Dimatix printer. There were 16 square 20 micrometer print nozzles. The volume of each droplet from each nozzle was 10 picoliters.

[0079] A specific single pulse waveform tuned for low viscosity precursor solutions in the Dimatix was used. The waveform had a jetting voltage of 20 V to 40 V, a level of 80%, a raising slew rate of 0.4 V/microseconds, a falling slew rate of 0.4 microseconds, a duration of maximum level of 7 microseconds, and an overall duration of 20 microseconds.

[0080] The droplets were printed onto a microscope glass slide. In preparation for printing, the microscope glass slide was rinsed with acetone and dried with a blower. The microscope glass slide was then heated to 60°C with a thin film heater (KHLV- 103/5

KAPTON™ insulated flexible heater, Omega).

[0081] A single droplet array was printed with a 100 micrometer droplet spacing and the printed droplet side dimension (i.e., diameter) was calculated from FIG. 3. The average droplet diameter was calculated to be 46.6 + 8 micrometers using ImageJ software. The "coffee ring" effect was not observed in the droplets.

Example 3

[0082] Using the equipment setup of Example 2 and the 25 wt% precursor solution, a 5 millimeter x 5 millimeter layer was printed with a 30 micrometer droplet spacing. After printing, the layer was held on the 60°C microscope glass slide for 2 minutes to allow the solvent to evaporate.

[0083] The layer morphology was observed by the camera view on the Dimatix printer as can be seen from FIG. 4. No uneven surface profile (e.g., no waviness) was observed and the surface displayed continuity.

Example 4

[0084] Using the equipment setup of Example 2 and the 25 wt% precursor solution, multilayer (5-layer) printing was conducted by printing with a 30 micrometer droplet spacing. The average thickness of the multilayer structure was 5.43 micrometers and the surface roughness (Ra) was 0.73 micrometers, both as measured with a white light interferometer (Bruker Contour GT-I) in accordance with ASTM D7127.

Example 5

[0085] The precursor solution of Example 2 was used to print an array of 40-layer squares (5 mm x 5 mm) with a droplet spacing of 30 micrometers using the method described in Example 3. The printed array was polymerized in a vacuum oven starting at initial a temperature of 180°C, which was increased to a final temperature of 280°C under full vacuum. [0086] Thus, the methods described herein provide methods for producing a polycarbonate article with enhanced the resolution, surface finish, and clarity as compared to previous processes (e.g., FDM).

[0087] This disclosure further encompasses the following aspects.

[0088] Aspect 1. A method for producing a polycarbonate article, comprising: printing a droplet onto a target location in a build area to obtain a printed droplet, wherein the droplet comprises a precursor solution comprising a precursor composition, a catalyst, and a solvent; removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate, wherein the precursor precipitate comprises the precursor composition and the catalyst; repeating the printing step and the removing step adjacent to or on the bead to obtain a plurality of adjacent beads comprising precursor precipitates; and polymerizing the precursor precipitates to obtain the polycarbonate article.

[0089] Aspect 2. The method of Aspect 1, wherein the precursor composition comprises a dihydroxy compound and a carbonate compound, preferably a diaryl carbonate, more preferably bis(alkyl salicyl)carbonate, and still more preferably bis(methyl salicyl)carbonate.

[0090] Aspect 3. The method of any one or more of the preceding aspects, wherein the precursor composition is present in the precursor solution in an amount equal to or greater than 10 wt%, or equal to or greater than 20 wt%, preferably equal to or greater than 30 wt%, based on the total weight of the precursor solution.

[0091] Aspect 4. The method of any one or more of the preceding aspects, wherein a mole ratio of the catalyst to the precursor composition is equal to or greater than 0.000001: 1, or equal to or greater than 0.00001: 1, preferably equal to or greater than 0.0001: 1.

[0092] Aspect 5. The method of any one or more of the preceding aspects, wherein at least one of: a viscosity of the precursor solution is 1 centipoise to 30 centipoise, or 1 centipoise to 10 centipoise, preferably 1 centipoise to 5 centipoise; and a surface tension of the precursor solution is 10 millinewtons/meter to 50 millinewtons/meter, or 20 millinewtons/meter to 40 millinewtons/meter, preferably 25 millinewtons/meter to 38 millinewtons/meter.

[0093] Aspect 6. The method of any one or more of the preceding aspects, wherein at least one of: a vapor pressure of the solvent is equal to or greater than 500 pascals, or equal to or greater than 525 pascals, preferably equal to or greater than 550 pascals; and a boiling point of the solvent is equal to or less than 150°C, or equal to or less than 125°C, preferably equal to or less than 100°C. [0094] Aspect 7. The method of any one or more of the preceding aspects, wherein the solvent comprises an amide, ether, dichlorobenzene, or a combination comprising at least one of the foregoing, preferably an ether comprising 1, 4-dioxane.

[0095] Aspect 8. The method of any one or more of the preceding aspects, wherein each of the droplets comprises the same composition.

[0096] Aspect 9. The method of any one or more of the preceding aspects, wherein during the step of removing at least a portion of the solvent, the build area is at a temperature of 50°C to 95°C, or 55°C to 90°C, preferably 60°C to 85°C.

[0097] Aspect 10. The method of any one or more of the preceding aspects, wherein the target location is positioned on a substrate heated to a temperature of 50°C to 95°C, or 55°C to 90°C, preferably 60°C to 85°C.

[0098] Aspect 11. The method of any one or more of the preceding aspects, wherein during the step of printing, a build pressure in the build area is equal to or greater than 80 kilopascals, or equal to or greater than 90 kilopascals, preferably equal to or greater than 100 kilopascals.

[0099] Aspect 12. The method of any one or more of the preceding aspects, wherein the step of polymerizing the precursor precipitates is performed outside the build area.

[0100] Aspect 13. The method of any one or more of the preceding aspects, wherein the step of polymerizing is at a polymerizing temperature equal to or greater than 100°C, or 150°C to 300°C, or 180°C to 290°C, preferably 180°C to 280°C.

[0101] Aspect 14. The method of any one or more of the preceding aspects, wherein the step of polymerizing is at a polymerizing pressure equal to or less than 100 kilopascals, or equal to or less than 25 kilopascals, or equal to or less than 10 kilopascals.

[0102] Aspect 15. The method of any one or more of the preceding aspects, wherein a weight average molecular weight of the precursor precipitate is 500 Daltons to 5,000 Daltons, or 1,000 Daltons to 4,000 Daltons, preferably 1,500 Daltons to 3,000 Daltons.

[0103] Aspect 16. The method of any one or more of the preceding aspects, wherein a weight average molecular weight of the polycarbonate is 10,000 Daltons to 200,000 Daltons, or 15,000 Daltons to 150,000 Daltons, preferably 20,000 Daltons to 100,000 Daltons.

[0104] Aspect 17. The method of any one or more of the preceding aspects, wherein a dimension of the polycarbonate article is equal to or less than 10,000 micrometers, or equal to or less than 1,000 micrometers, preferably equal to or less than 100 micrometers. [0105] Aspect 18. The method of any one or more of the preceding aspects, wherein the printing is performed by an inkjet printer.

[0106] Aspect 19. The method of any one or more of the preceding aspects, wherein the precursor composition is present in the precursor solution in an amount of 10 wt% to 50 wt%, preferably 20 wt% to 50 wt%, based on the total weight of the precursor solution.

[0107] Aspect 20. A polycarbonate article produced by the method of any one or more of the preceding aspects.

[0108] Aspect 21. A method for producing a polycarbonate article, comprising: printing a droplet onto a target location in a build area to obtain a printed droplet, wherein the droplet comprises a precursor solution comprising a precursor composition, a catalyst, and a solvent; removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate, wherein the precursor precipitate comprises the precursor composition and the catalyst; repeating the printing step and the removing step adjacent to or on the bead to obtain a plurality of adjacent beads comprising precursor precipitates; and polymerizing the precursor precipitates to obtain the polycarbonate article, wherein the precursor composition comprises bisphenol A and bis(methyl salicyl)carbonate, and wherein the catalyst comprises tetramethyl ammonium hydroxide pentahydrate, and wherein the solvent comprises 1,4 dioxane, and wherein the target location is positioned on a substrate heated to a temperature of 50°C to 95°C, or 55°C to 90°C, preferably 60°C to 85°C, and wherein the step of polymerizing is at a polymerizing temperature equal to or greater than 100°C, or 150°C to 300°C, or 180°C to 290°C, preferably 180°C to 280°C, and wherein at least one dimension of the polycarbonate article is equal to or less than 200 micrometers, or equal to or less than 100 micrometers.

[0109] The compositions, methods, and articles can alternatively comprise, consist of, or consist essentially of, any appropriate materials, steps, or components herein disclosed. The compositions, methods, and articles can additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any materials (or species), steps, or components, that are otherwise not necessary to the achievement of the function or objectives of the compositions, methods, and articles.

[0110] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of "up to 25 wt.%, or, more specifically, 5 wt.% to 20 wt.%", is inclusive of the endpoints and all intermediate values of the ranges of "5 wt.% to 25 wt.%," etc.). "Combinations" is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms "first," "second," and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms "a" and "an" and "the" do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. "Or" means "and/or" unless clearly stated otherwise. Reference throughout the specification to "some embodiments", "an embodiment", and so forth, means that a particular element described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

[0111] Unless specified to the contrary herein, all test standards are the most recent standard in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0112] Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this application belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0113] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.

[0114] What is claimed is:

Claims

1. A method for producing a polycarbonate article, comprising:

printing a droplet onto a target location in a build area to obtain a printed droplet, wherein the droplet comprises a precursor solution comprising a precursor composition, a catalyst, and a solvent;

removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate, wherein the precursor precipitate comprises the precursor composition and the catalyst;

repeating the printing step and the removing step adjacent to or on the bead to obtain a plurality of adjacent beads comprising precursor precipitates; and

polymerizing the precursor precipitates to obtain the polycarbonate article.

2. The method of Claim 1, wherein the precursor composition comprises a dihydroxy compound and a carbonate compound, preferably comprises a diaryl carbonate, more preferably comprises bis(alkyl salicyl)carbonate, and still more preferably comprises bis(methyl salicyl)carbonate,

3. The method of any one or more of the preceding claims, wherein the precursor composition is present in the precursor solution in an amount equal to or greater than 10 wt%, or equal to or greater than 20 wt%, preferably equal to or greater than 30 wt%, based on the total weight of the precursor solution.

4. The method of any one or more of the preceding claims, wherein a mole ratio of the catalyst to the precursor composition is equal to or greater than 0.000001: 1, or equal to or greater than 0.00001: 1, preferably equal to or greater than 0.0001: 1.

5. The method of any one or more of the preceding claims, wherein at least one of: a viscosity of the precursor solution is 1 centipoise to 30 centipoise, or 1 centipoise to 10 centipoise, preferably 1 centipoise to 5 centipoise; and

a surface tension of the precursor solution is 10 millinewtons/meter to 50

millinewtons/meter, or 20 millinewtons/meter to 40 millinewtons/meter, preferably 25 millinewtons/meter to 38 millinewtons/meter.

6. The method of any one or more of the preceding claims, wherein at least one of: a vapor pressure of the solvent is equal to or greater than 500 pascals, or equal to or greater than 525 pascals, preferably equal to or greater than 550 pascals; and

a boiling point of the solvent is equal to or less than 150°C, or equal to or less than 125°C, preferably equal to or less than 100°C.

7. The method of any one or more of the preceding claims, wherein the solvent comprises an amide, ether, dichlorobenzene, or a combination comprising at least one of the foregoing, preferably an ether comprising 1, 4-dioxane.

8. The method of any one or more of the preceding claims, wherein each of the droplets comprises the same composition.

9. The method of any one or more of the preceding claims, wherein during the step of removing at least a portion of the solvent, the build area is at a temperature of 50°C to 95 °C, or 55°C to 90°C, preferably 60°C to 85°C.

10. The method of any one or more of the preceding claims, wherein the target location is positioned on a substrate heated to a temperature of 50°C to 95°C, or 55°C to 90°C, preferably 60°C to 85°C.

11. The method of any one or more of the preceding claims, wherein during the step of printing, a build pressure in the build area is equal to or greater than 80 kilopascals, or equal to or greater than 90 kilopascals, preferably equal to or greater than 100 kilopascals.

12. The method of any one or more of the preceding claims, wherein the step of polymerizing the precursor precipitates is performed outside the build area.

13. The method of any one or more of the preceding claims, wherein the step of polymerizing is at a polymerizing temperature equal to or greater than 100°C, or 150°C to 300°C, or 180°C to 290°C, preferably 180°C to 280°C.

14. The method of any one or more of the preceding claims, wherein the step of polymerizing is at a polymerizing pressure equal to or less than 100 kilopascals, or equal to or less than 25 kilopascals, or equal to or less than 10 kilopascals.

15. The method of any one or more of the preceding claims, wherein a weight average molecular weight of the precursor precipitate is 500 Daltons to 5,000 Daltons, or 1,000 Daltons to 4,000 Daltons, preferably 1,500 Daltons to 3,000 Daltons.

16. The method of any one or more of the preceding claims, wherein a weight average molecular weight of the polycarbonate is 10,000 Daltons to 200,000 Daltons, or 15,000 Daltons to 150,000 Daltons, preferably 20,000 Daltons to 100,000 Daltons.

17. The method of any one or more of the preceding claims, wherein a dimension of the polycarbonate article is equal to or less than 10,000 micrometers, or equal to or less than 1,000 micrometers, preferably equal to or less than 100 micrometers.

18. The method of any one or more of the preceding claims, wherein the printing is performed by an inkjet printer.

19. A polycarbonate article produced by the method of any one or more of the preceding claims.

20. A method for producing a polycarbonate article, comprising:

printing a droplet onto a target location in a build area to obtain a printed droplet, wherein the droplet comprises a precursor solution comprising a precursor composition, a catalyst, and a solvent;

removing at least a portion of the solvent from the printed droplet to obtain a bead comprising a precursor precipitate, wherein the precursor precipitate comprises the precursor composition and the catalyst;

repeating the printing step and the removing step adjacent to or on the bead to obtain a plurality of adjacent beads comprising precursor precipitates; and

polymerizing the precursor precipitates to obtain the polycarbonate article;

wherein the precursor composition comprises bisphenol A and bis(methyl

salicyl)carbonate;

wherein the catalyst comprises tetramethyl ammonium hydroxide pentahydrate, and wherein the solvent comprises 1,4 dioxane;

wherein the target location is positioned on a substrate heated to a temperature of 50°C to 95°C, or 55°C to 90°C, preferably 60°C to 85°C;

wherein the step of polymerizing is at a polymerizing temperature equal to or greater than 100°C, or 150°C to 300°C, or 180°C to 290°C, preferably 180°C to 280°C; and

wherein at least one dimension of the polycarbonate article is equal to or less than 200 micrometers, or equal to or less than 100 micrometers.