Fabrication of solid materials or films from polymerizable liquid

Abstract

To provide an energy-polymerizable liquid which can be cured by a single reaction mechanism to form a photoplastic material, and to provide a method for manufacturing the photoplastic material and an article made of the photoplastic material.SOLUTION: Provided is a free radical polymerizable liquid for forming a three-dimensional object. The free radical polymerizable liquid comprises: a reactive oligomer, the reactive oligomer being at least one of (i) a multi-functional methacrylate oligomer, and (ii) a multi-functional acrylate oligomer; and a reactive monofunctional monomer, the reactive monofunctional monomer being at least one of (i) a monofunctional N-vinyl monomer, (ii) a monofunctional vinyl ether monomer, (iii) a monofunctional vinyl ester monomer, (iv) a monofunctional vinylamide monomer, (v) a styrene monomer, (vi) a monofunctional acrylamide monomer, (vii) a multi-functional (meth)acrylate monomer, (viii) a cyanoacrylate monomer, (ix) a monofunctional vinyl carbonate monomer, and (x) a monofunctional acryloyl monomer.SELECTED DRAWING: None

Description

Technical Field

[0001] This application claims priority to U.S. Patent Application No. 15 / 698,059, filed on September 7, 2017, which claims the benefit of U.S. Provisional Patent Application No. 62 / 484,103, filed on April 11, 2017, and U.S. Provisional Patent Application 62 / 484,644, filed on April 12, 2017.

[0002] The entire contents of the above applications are incorporated herein by reference.

[0003] The present disclosure relates to materials and methods for manufacturing solid materials or films from liquid materials, and to articles manufactured by such methods. More specifically, the present disclosure relates to energy polymerizable materials of a single reaction mechanism designed as photoplastics.

Background Art

[0004] Energy polymerizable resins of a single reaction mechanism, when cured, generally have inferior mechanical properties compared to conventional thermoplastic resins. This is the main reason why thermoplastic materials are dominant in many materials found in manufacturing environments and are trusted. Specifically, the toughness of thermoplastic materials, including all of impact strength, elongation, and tensile strength, is many times greater than or equal to that of energy polymerizable materials of a single reaction mechanism. The energy-initiated reaction mechanism is generally free radical polymerization, but cationic polymerization may also be the case. In most cases, polymerization occurs under ambient conditions (25°C, 1 atm). There are four aspects known to limit mechanical properties in the polymerization of a single reaction mechanism.

[0005] 1) Linear polymers, such as polyethylene, polypropylene, PET, polycarbonate, and nylon, are very tough and are important for the production of high-strength, high-elongation thermoplastic resins. The main-chain structures of these widely used thermoplastic resins often contain many repeating units with high-strength structures that have the ability to stack, align, and weakly bond polymer chains to each other and / or small side chains or branched chains off the main chain, but these generally do not significantly interfere with the entanglement of polymer chains and chain mobility. In the most common reaction mechanism for producing linear polymers by energy-initiated free-radical polymerization, monofunctional monomers are used. However, these reactions are usually carried out in ambient air, and due to chain termination reactions caused by inhibition such as dissolved oxygen, the chain length is much shorter than that of the thermoplastic resin used as a control. In addition, these linear polymers have a completely carbon backbone chain, with little entanglement and large side chains. These characteristics result in the loss of many beneficial interactions with small forces seen in the above-mentioned thermoplastic resins, and the toughness of the material is reduced.

[0006] 2) Due to the rate of free-radical polymerization, polymers with a very small molecular weight are produced compared to the conventional polymers described above. In the energy polymerization of a single reaction mechanism, the use of difunctional or larger-functional monomers results in non-linear polymers with a high cross-link density. Although the molecular weight is very high or extremely large, these highly cross-linked systems generally have very high strength. On the other hand, due to cross-linking and high-density covalent bonds, polymer chains cannot move within the network, so the elongation is very low. For this reason, linear polymers have been produced using monofunctional monomers as before. The polymerization of these monomers is carried out in three steps: initiation, growth, and termination. The growth in the above steps is generally significantly shortened by the energy received by the system during polymerization, the amount of initiator used, or all or any of the inhibitors. One of the reasons for the short growth is the occurrence of chain termination by O 2It is unstable in generating free radicals that can react with other chemical inhibitors. Another reason lies in the vitrification that occurs during curing, which restricts the molecular mobility and then the conversion rate. For this reason, the number of repeating units in the energy polymerization monofunctional system with a single reaction mechanism is significantly less than that of thermoplastic materials. In such cases of low molecular weight, it is known that the resulting material has extremely low strength due to very few entanglements between linear chains.

[0007] 3) One of the methods considered to avoid many of the above problems is the use of energy-polymerizable oligomers that are of high molecular weight and generally polyfunctional. These oligomers serve as higher molecular weight initiators, and the resulting final material has a lower crosslink density and a higher molecular weight throughout the polymer chains. However, these high molecular weight oligomers have very high viscosities, severely limiting their use in applications with limited viscosities such as inkjet printing and additive manufacturing.

[0008] 4) Finally, it has been shown that in energy-initiated free radical polymerization, it is very difficult to control the polymerization mechanism and polymerization rate of chemical species having reactive functional groups that induce various free radicals. To achieve the desired rapid polymerization rate, there is a trade-off between high energy curing and a high ratio of photoinitiators. Any of these can essentially lead to chain termination or low molecular weight. For this reason, controlling the system at the molecular level is very challenging, and the molecular weight construction, crosslink density distribution, construction of the polymer network, conversion rate, chain termination, reaction rates of individual molecular species, etc. become non-uniform, and in the final product, a wide glass transition temperature (Tg) distribution and unstable mechanical strength are confirmed.

[0009] Inkjet inks used for printing onto films on a substrate or for material jetting in additive manufacturing require a very low viscosity, typically less than about 20 cPs, at the ejection temperature. Hot melt inks have been used, but liquid inks are generally more suitable for high volume industrial printing. For energy curable inks with a single reaction mechanism, low viscosity reactive materials are used to obtain the desired viscosity. The reactive materials have reactive groups that polymerize upon irradiation such as UV irradiation or electron beam after printing. The low viscosity reactive materials in energy curable inks with a single reaction mechanism generally include low viscosity monomers and optionally low ratio low viscosity oligomers. Energy curable inks with a single reaction mechanism may include low ratio high viscosity reactive or non-reactive oligomers and polymers. Monofunctional monomers are particularly low in viscosity, and thus inkjet inks have heretofore included large amounts of monofunctional monomers. As described above, these monofunctional monomers result in low performance mechanical properties in the final product upon polymerization.

[0010] In conventional additive or three-dimensional manufacturing techniques, the construction of a three-dimensional object is performed in a multi-step or layer-by-layer process. In particular, layer formation is generally performed by curing a photocurable resin under the implementation of visible or UV light irradiation. Two techniques are known. In one, a new layer is formed on the upper surface of the growing body, and in the other, a new layer is formed on the lower surface of the growing body.

[0011] When a new layer is formed on the upper surface of the growing body, after each irradiation step, the object under construction is dropped into a "tank" of resin, a new layer of resin is coated on top, and a new irradiation step is performed. The disadvantage of such a "top-down" technique is that the growing body has to be submerged in a (possibly deep) tank of liquid resin and a precise upper layer of liquid resin has to be reconstituted.

[0012] When a new layer is formed under the growing body, after each irradiation step, the object under construction is sufficiently separated from the bottom plate during manufacturing. Such "bottom-up" techniques can eliminate the need for deep tanks in which the object is submerged by instead lifting the object from relatively shallow holes or tanks. The limitation of both of these lamination techniques is also viscosity, and generally a fluid with a viscosity of less than 2000 cPs is required to form a homogeneous layer at the upper or lower interface. In addition, in the bottom-up technique, a more rigid material is preferred to obtain a homogeneous layer arrangement and surface finish of the final part. Finally, polymerization that can occur without energy initiation can partially result in defects or, worse, solidify the entire tank, so pot life stability is important in any technique. Such reactions include, for example, many dual reaction mechanism materials provided by Carbon 3D, such as CE220, CE221, EPU40, EPX81, FPU50, RPU60, RPU61, RPU70, etc.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0013] Therefore, there is a need for new materials and methods for inkjet printing or manufacturing three-dimensional objects with good mechanical properties by additive manufacturing, with a single polymerization mechanism that improves storage stability in pot life, reduces the toxicity of unpolymerized materials, and / or reduces the time for post-curing by heat.

MEANS FOR SOLVING THE PROBLEMS

[0014] According to some aspects, (i) a reactive oligomer that is at least one of a polyfunctional methacrylate oligomer and (ii) a polyfunctional acrylate oligomer; A reactive monofunctional monomer which is at least one of (i) a monofunctional N-vinyl monomer, (ii) a monofunctional vinyl ether monomer, (iii) a monofunctional vinyl ester monomer, (iv) a monofunctional vinyl amide monomer, (v) a styrene monomer, (vi) a monofunctional acrylamide monomer, (vii) a monofunctional (meth)acrylate monomer, (viii) a cyanoacrylate monomer, (ix) a monofunctional vinyl carbonate monomer, (x) a monofunctional acryloyl monomer, and (xi) a monofunctional vinyl carbamate monomer A free-radical polymerizable liquid for forming a three-dimensional object, which contains The molar bonding ratio of the reactive ethylenically unsaturated groups of the reactive monofunctional species to those of the reactive polyfunctional species is at least 10:1. The free-radical polymerizable liquid is an energy-polymerizable liquid that cures by a single reaction mechanism to form a photoplastic material.

[0015] In an additional embodiment of the present disclosure, the polymerizable liquid contains from about 0.01 wt% to about 15 wt% of a photoinitiator.

[0016] In other embodiments of the present disclosure, the polymerizable liquid has toughness above the utilization curve defined by the formulas: 1) Tensile strength (MPa) = -0.75 × elongation + 130 (when the elongation is from about 15% to about 95%), 2) Tensile strength (MPa) = 4500 / (elongation - 25) - 5 (when the elongation is from about 95% to about 500%).

[0017] In other embodiments of the present disclosure, the polymerizable liquid has toughness above the utilization curve defined by the formulas: 1) Tensile strength (MPa) = -1 × elongation + 120 (when the elongation is less than 105%), 2) Tensile strength (MPa) = 2000 / (elongation + 10) - 3 (when the elongation is from about 105% to about 550%), 3) Tensile strength (MPa) = 0.5 (when the elongation is more than about 550%).

[0018] In other embodiments of the present disclosure, the polymerized material attains predetermined mechanical properties without heat supply.

[0019] In other embodiments of the present disclosure, the polymerizable liquid comprises at least one of a non-reactive light-absorbing pigment, a filler, a polymerization inhibitor, and a polymerization catalyst in an amount of from about 0.001 wt% to about 10 wt%.

[0020] In other embodiments of the present disclosure, the polymerizable liquid comprises a non-reactive light-absorbing pigment and a filler in an amount of from about 0.001 wt% to about 10 wt%.

[0021] In other embodiments of the present disclosure, the oligomers and monomers react by the same reaction mechanism and have different reaction rates.

[0022] In other embodiments of the present disclosure, the solubility of the monomers and oligomers changes during polymerization, thereby promoting the homopolymerization of either the monomer species or the oligomer species.

[0023] In other embodiments of the present disclosure, a material having multiple glass transition temperatures is produced in the polymerization.

[0024] In other embodiments of the present disclosure, a material having two different glass transition temperatures with a difference in Tg of at least 60 °C is produced in the polymerization.

[0025] In other embodiments of the present disclosure, the molar bonding ratio of the reactive ethylenically unsaturated groups of the reactive monofunctional species to the reactive ethylenically unsaturated groups of the reactive polyfunctional species is at least 25:1.

[0026] In other embodiments of the present disclosure, the molar bonding ratio of the reactive ethylenically unsaturated groups of the reactive monofunctional species to the reactive ethylenically unsaturated groups of the reactive polyfunctional species is at least 30:1.

[0027] In other embodiments of the present disclosure, the polymerizable liquid forms a print on the substrate.

[0028] In other embodiments of the present disclosure, the polymerizable liquid is cured by stereolithography (SLA), digital light projection (DLP), material jetting, or inkjet printing to form a film or a three-dimensional object.

[0029] In other embodiments of the present disclosure, the thickness of the inkjet film or the 3D printed layer is greater than about 30 μm.

[0030] In other embodiments of the present disclosure, by varying the energy polymerization conditions, the polymerizable liquid has adjustable mechanical properties upon curing.

[0031] In other embodiments of the present disclosure, the polymerizable liquid is non-toxic.

[0032] In other embodiments of the present disclosure, the oligomer has a molecular weight greater than about 1500 g / mol.

[0033] In other embodiments of the present disclosure, the oligomer has a molecular weight greater than about 4000 g / mol.

[0034] In other embodiments of the present disclosure, the monomer is a monofunctional N-vinyl, vinyl ester, or acryloyl selected from the group consisting of N-vinyl pyrrolidone, N-vinyl caprolactam, N-vinyl formamide, acryloyl morpholine, or vinyl cinnamate.

[0035] According to some aspects, (i) A functional N-vinyl oligomer with a functionality of 1 or more, (ii) A functional vinyl ether oligomer with a functionality of 1 or more, (iii) A functional vinyl ester oligomer with a functionality of 1 or more, (iv) A functional vinyl amide oligomer with a functionality of 1 or more, (v) A styrene oligomer, (vi) A functional acrylamide oligomer with a functionality of 1 or more, (vii) A functional (meth)acrylate oligomer with a functionality of 1 or more having a reaction rate different from that of a (meth)acrylate monomer, (viii) A cyanoacrylate oligomer, (ix) A functional vinyl carbonate oligomer with a functionality of 1 or more, and (x) A functional acryloyl oligomer with a functionality of 1 or more, (xi) A reactive oligomer which is at least one of a functional vinyl carbamate oligomer with a functionality of 1 or more, (i) A functional N-vinyl monomer with a functionality of 1 or more, (ii) A functional vinyl ether monomer with a functionality of 1 or more, (iii) A functional vinyl ester monomer with a functionality of 1 or more, (iv) A functional vinyl amide monomer with a functionality of 1 or more, (v) A styrene monomer, (vi) A functional acrylamide monomer with a functionality of 1 or more, (vii) A functional (meth)acrylate monomer with a functionality of 1 or more having a reaction rate different from that of a (meth)acrylate oligomer, (viii) A cyanoacrylate monomer, (ix) A functional vinyl carbonate monomer with a functionality of 1 or more, (x) A functional acryloyl monomer with a functionality of 1 or more, and (xi) A reactive monomer which is at least one of a functional vinyl carbamate monomer with a functionality of 1 or more, A method for forming a polymerizable liquid, comprising the step of mixing the above two together. The polymerizable liquid is an energy polymerizable liquid that cures by a single reaction mechanism to form a photoplastic material.

[0036] In an additional embodiment of the present disclosure, the polymerizable liquid cures by stereolithography (SLA), digital light projection (DLP), material jetting (3D inkjet printing), or inkjet printing to form a film or a three-dimensional object.

[0037] In other embodiments of the present disclosure, the film or three-dimensional object is part of a medical device, or part of footwear, or part of soft robotics.

[0038] In other embodiments of the present disclosure, the film or three-dimensional object is a hydrogel.

[0039] In other embodiments of the present disclosure, various physical properties are obtained by using pixel or voxel polymerization and changing the energy polymerization conditions.

[0040] In other embodiments of the present disclosure, the method further includes irradiating the polymerizable liquid with pattern irradiation.

[0041] In other embodiments of the present disclosure, the method further includes mixing a photoinitiator in an amount of from about 0.01 wt% to about 15 wt%.

[0042] According to some aspects, the article contains an energy-polymerizable liquid that cures by a single reaction mechanism to form a photoplastic material. The energy-polymerizable liquid comprises (i) one or more functional N-vinyl oligomers, (ii) one or more functional vinyl ether oligomers, (iii) one or more functional vinyl ester oligomers, (iv) one or more functional vinyl amide oligomers, (v) styrene oligomers, (vi) one or more functional acrylamide oligomers, (vii) one or more functional (meth)acrylate oligomers having a reaction rate different from that of one or more functional (meth)acrylate monomers, (viii) cyanoacrylate oligomers, (ix) one or more functional vinyl carbonate oligomers, and (x) one or more functional acryloyl oligomers, (xi) at least one reactive oligomer that is at least one of one or more functional vinyl carbamate oligomers, and (i) one or more functional N-vinyl monomers, (ii) one or more functional vinyl ether monomers, (iii) one or more functional vinyl ester monomers, (iv) one or more functional vinyl amide monomers, (v) styrene monomers, (vi) one or more functional acrylamide monomers, (vii) one or more functional (meth)acrylate monomers having a reaction rate different from that of one or more functional (meth)acrylate oligomers, (viii) cyanoacrylate monomers, (ix) one or more functional vinyl carbonate monomers. (x) one or more functional acryloyl monomers, and (xi) at least one reactive monomer that is at least one of one or more functional vinyl carbamate monomers.

[0043] In additional embodiments of the present disclosure, by varying the energy polymerization conditions, the polymerizable liquid has adjustable mechanical properties upon curing.

[0044] Furthermore, the present disclosure provides a method of forming a solid photoplastic material comprising (i) an energy-polymerizable liquid of a first component and (ii) an energy-polymerizable liquid of a second component different from the first component by a single reaction mechanism, in which these components are mixed, irradiated with energy to polymerize, and a solid photoplastic material is formed.

[0045] In some embodiments, the reactive diluent includes acrylate, methacrylate, styrene, acrylic acid, vinyl amide, vinyl ether, vinyl ester (including derivatives), polymers containing any one or more of these, combinations of two or more of these (e.g., acrylonitrile, styrene, divinylbenzene, vinyltoluene, methyl acrylate, ethyl acrylate, butyl acrylate, methyl (meth)acrylate, amine (meth)acrylate, and mixtures of two or more of these as described above).

[0046] In some embodiments, the non-reactive polymer includes a polymer or polymer blend having no functional groups involved in the polymerization of the bulk material. Without limitation, many polymers can be used, including polyethylene, polypropylene, polycarbonate, polyvinyl chloride, PET, and mixtures of two or more of these.

[0047] In some embodiments, the first component includes a reactive monomer or oligomer having acrylate functionality. In this embodiment, the first components preferably or necessarily react with each other to form a single polymer network.

[0048] In some embodiments, the second component includes a reactive monomer or oligomer having (meth)acrylate functionality. In this embodiment, the first components preferably or necessarily react with each other to form a single polymer network.

[0049] In some embodiments, the second component includes a reactive monomer or oligomer having N-vinyl, vinyl ether, acryloyl, vinyl carbonate, vinyl carbamate, vinyl ester, and / or vinyl amide functionality. In this embodiment, the second components preferably or necessarily react with each other to form a single polymer network.

[0050] In some embodiments, the first component includes a reactive monomer or oligomer having acrylate and / or methacrylate functionality, and the second component includes a reactive monomer or oligomer having N-vinyl, vinyl ether, vinyl carbonate, vinyl carbamate, acryloyl, vinyl ester, and / or vinyl amide functionality. In this embodiment, the components react with each other to form a random copolymer.

[0051] In some embodiments, the first component includes a reactive monomer or oligomer having acrylate and / or methacrylate functionality, and the second component includes a reactive monomer or oligomer having N-vinyl, vinyl ether, vinyl carbonate, vinyl carbamate, acryloyl, vinyl ester, and / or vinyl amide functionality. In this embodiment, the components react with each other to form a full IPN, semi-IPN, pseudo-IPN, or dual network. In some embodiments, the three-dimensional object includes a polymer blend (e.g., IPN, semi-IPN, pseudo-IPN, sequential IPN, simultaneous IPN, dual network) formed from the first component and the second component.

[0052] In some embodiments, the energy-polymerizable liquid of a single reaction mechanism includes 1, 2, or 5 wt% to 20, 30, 40, 90, or 99 wt% of the first component; and 1, 10, 60, 70, or 80 wt% to 95, 98, or 99 wt% of the second component (optionally including one or more additional components). In other embodiments, the energy-polymerizable liquid of a single reaction mechanism includes 1, 2, or 5 wt% to 20, 30, 40, 90, or 99 wt% of the second component; and 1, 10, 60, 70, or 80 wt% to 95, 98, or 99 wt% of the first component (optionally including one or more additional components).

[0053] In some embodiments, the second component cures simultaneously with the same light as the first component in the same irradiation step.

[0054] In some embodiments, the second component is cured later with light having a wavelength different from that of the light in the irradiation step.

[0055] In some embodiments, the second component is cured later with light having the same wavelength as that of the light in the irradiation step.

[0056] In some embodiments, the second component is cured later with an electron beam.

[0057] One particular embodiment of the invention disclosed herein is a method of forming a three-dimensional object comprising an energy-polymerizable liquid of a single reaction mechanism. This method includes the steps of providing a light-transmissive member having a carrier and a build surface (the carrier and the build surface define a build region therebetween); filling the build region with a polymerizable liquid comprising at least two of a (meth)acrylate oligomer, a cyanoacrylate monomer, an acrylamide monomer, a vinyl ether monomer, a vinyl ester monomer, an N-vinyl monomer, a vinyl carbonate monomer, a vinyl carbamate monomer, an acryloyl monomer, and a vinylamide monomer; irradiating the build region with light through the light-transmissive member to form a solid polymer skeleton; separating the carrier from the build surface to form a three-dimensional intermediate having the same shape as the three-dimensional object or a shape incorporated into the three-dimensional object; and then sufficiently energy-irradiating the three-dimensional intermediate to form the three-dimensional object from the three-dimensional intermediate.

[0058] In some embodiments, during this method, the curable or energy-polymerizable liquid of a single reaction mechanism is changed at least once to a next curable or energy-polymerizable liquid of a single reaction mechanism. Optionally, the next curable or energy-polymerizable liquid of a single reaction mechanism is cross-reactive with the previous curable or energy-polymerizable liquid in the next polymerization to form an object having structural segments with different mechanical properties (such as tension) bonded to each other by covalent bonds.

[0059] A further aspect of the disclosure described herein is an energy-polymerizable liquid of a single reaction mechanism useful for the production of films or three-dimensional objects containing (meth)acrylates and their vinyl-functional resins by additive manufacturing or inkjet printing. The energy-polymerizable liquid of a single reaction mechanism comprises a) at least one component selected from the group of oligomers consisting of (i) one or more functional acrylate oligomers, (ii) one or more functional (meth)acrylate oligomers, (iii) one or more functional vinyl oligomers, b) at least one component having a reaction rate different from that of (a), selected from the group of vinyls consisting of (i) one or more functional N-vinyl monomers, (ii) one or more functional vinyl ether monomers, (iii) one or more functional vinyl ester monomers, (iv) one or more functional vinyl amide monomers, (v) styrene monomers, (vi) acrylamide monomers, (vii) (meth)acrylate monomers, (viii) cyanoacrylate monomers, (ix) one or more functional vinyl carbonate monomers, (x) one or more functional acryloyl monomers, (xi) one or more functional vinyl carbamate monomers, c) one or more photoinitiators d) a reactive diluent as an optional component, e) a non-reactive polymer as an optional component, f) one or more polymerization inhibitors as an optional component, g) one or more non-reactive light-absorbing pigments or dyes (if present, included in an amount of 0.001 to 10% by weight), and h) a filler as an optional component (e.g., silica, carbon fiber, aluminum, core-shell rubber and other reinforcing agents, combinations thereof, etc.) and comprises a mixture thereof.

[0060] A further aspect of the disclosure described herein is an energy-polymerizable liquid of a single reaction mechanism useful for the production of films or three-dimensional objects containing acrylates and their methacrylate-functional resins by additive manufacturing or inkjet printing. The energy-polymerizable liquid of a single reaction mechanism comprises a) At least one constituent component selected from an oligomer group composed of a functional acrylate oligomer having a functionality of 1 or more, b) At least one constituent component selected from a methacrylate group composed of a functional methacrylate monomer having a functionality of 1 or more, c) One or more photoinitiators, d) A reactive diluent as an optional component, e) A non-reactive polymer as an optional component, f) One or more polymerization inhibitors as an optional component, g) One or more non-reactive light-absorbing pigments or dyes (when present, contained in an amount of 0.001 to 10% by weight) as an optional component, and h) A filler as an optional component (for example, reinforcing agents such as silica, carbon fiber, aluminum, core-shell rubber, combinations thereof, etc.) contains a mixture of.

[0061] In some embodiments, the single-reaction mechanism energy-polymerizable liquid used in the present invention contains a non-reactive pigment or dye. Although not limited, for example, (i) titanium dioxide (for example, in an amount of 0.05 or 0.1 to 1 or 5% by weight), (ii) carbon black (for example, in an amount of 0.05 or 0.1 to 1 or 5% by weight), and / or (iii) organic ultraviolet absorbers such as hydroxybenzophenone, hydroxyphenylbenzotriazole, oxanilide, benzophenone, thioxanthone, hydroxyphenyltriazine, and / or benzotriazole ultraviolet absorbers (for example, in an amount of 0.001 or 0.005 to 1, 2 or 4% by weight) can be mentioned.

[0062] In some embodiments, a hindered amine light stabilizer, or a Lewis acid, or an oxidizable tin salt is contained in the single-reaction mechanism energy-polymerizable liquid in an amount effective to promote the formation of three-dimensional intermediates during production (for example, 0.01 or 0.1 to 1 or 2% by weight or more).

[0063] In some embodiments, a hindered amine light stabilizer, or a Lewis acid, or an oxidizable tin salt, is included in the energy-polymerizable liquid of a single reaction mechanism in an amount effective to selectively promote the polymerization of the first component and / or the second component of the polymerizable resin (e.g., 0.01 or 0.1 to 1 or 2 wt% or more).

[0064] A further aspect of the disclosure described herein is a three-dimensional object comprising an energy-polymerizable first component and an energy-polymerizable component that polymerizes by the same reaction mechanism as the first component but at a different reaction rate than the first component, and / or the three-dimensional object is manufactured by an additive manufacturing process.

[0065] A further aspect of the disclosure described herein is a three-dimensional object comprising an energy-polymerizable first component and an energy-polymerizable component that polymerizes by the same reaction mechanism as the first component but has different solubility before polymerization than the first component, and / or the three-dimensional object is manufactured by an additive manufacturing process.

[0066] A further aspect of the invention described herein is a three-dimensional object comprising an energy-polymerizable first component and an energy-polymerizable component that is different from the first component in terms of solubility after polymerization of the first component. Both components polymerize by the same reaction mechanism, and / or the three-dimensional object is manufactured by an additive manufacturing process. If the solubility of the components relative to each other changes during polymerization, phase separation may induce homopolymerization of any of the components and change the refractive index of the material.

[0067] A further aspect of the disclosure described herein is a three-dimensional object comprising an energy-polymerizable first component and an energy-polymerizable component that polymerizes by the same reaction mechanism as the first component but is different at a molar bond ratio of 500% (a molar bond ratio of the second component to the first component of 5:1 or more), and / or the three-dimensional object is manufactured by an additive manufacturing process.

[0068] A further aspect of the disclosure herein is a three-dimensional object comprising an energy-polymerizable first component and an energy-polymerizable component that is different from the first component in a molar bond ratio of 700% (a molar bond ratio of the second component: the first component being 7:1 or more) and that polymerizes by the same reaction mechanism as the first component, and / or the three-dimensional object is manufactured by a layered manufacturing process.

[0069] In some embodiments, the object comprises a third component that is curable (or further reacts, polymerizes, or chain extends) and is different from the first and second components, in which case the object has at least a first structural segment and a second structural segment bonded to each other by a covalent bond, the first structural segment comprises the curable second component, the second structural segment comprises the curable third component, and both the first structural segment and the second structural segment comprise the same or different photo-polymerized first component.

[0070] In some embodiments, the object comprises a polymer blend formed from the first and second components.

[0071] The object may have a shape that cannot be formed by injection molding or casting.

[0072] Applicability to further areas is apparent from the description provided herein. It should be understood that the description and examples are for illustrative purposes only and do not limit the scope of the present disclosure.

[0073] The drawings are for illustrative purposes only and do not limit the scope of the present disclosure in any way.

Brief Description of the Drawings

[0074]

Figure 1A

Figure 1B

Figure 1C

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9A

Figure 9B

Figure 9C

Figure 9D

Figure 10A

Figure 10B

Figure 10C

Figure 10D

Figure 10E

Figure 10F

Figure 11

[0075] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses.

[0076] Here, the present invention will be described more fully with reference to the accompanying drawings. The same numbers refer to the same elements throughout. In the figures, certain lines, layers, components, elements, or features may be thickened for clarity. When used, unless otherwise specified, broken lines indicate any function or operation.

[0077] When an element is described as "on", "attached to", "connected to", "coupled to", "in contact with", etc., it may be understood to be directly on, attached to, connected to, coupled to, and / or in contact with another element, or intervening elements may be present. On the other hand, when an element is described as, for example, "directly on another element", "directly attached to another element", "directly connected to another element", "directly coupled to another element", "directly in contact with another element", there are no intervening elements. Those skilled in the art will understand that a description of a structure or feature placed adjacent to another feature may overlap with the adjacent feature or have a portion underlying the adjacent feature.

[0078] For the sake of simplicity in describing the relationship between elements and features and other elements and features when shown in the figures, spatially related terms such as "below", "above", etc. may be used in this specification. It is understood that spatially related terms include different directions of the device or operation in use in addition to the directions shown in the figures. For example, when the device in the figure is turned upside down, an element described as "below" other elements or features will be placed "above" the other elements or features. Thus, for example, the term "below" can include both upward and downward directions. The device may be oriented in different directions (rotated 90° or other directions), and for this reason, the spatially related terms used in this specification are to be interpreted as appropriate. Similarly, terms such as "upward", "downward", "vertically", "horizontally", etc. are used in this specification for illustrative purposes only unless otherwise specified.

[0079] "The shape imparted" typically refers to a situation where the shape of the intermediate object changes slightly between its formation and the subsequent formation of the three-dimensional product, for example, by shrinkage (e.g., ~1, 2, or 4 volume %), expansion (e.g., ~1, 2, or 4 volume %), removal of the support structure, or introduction of a forming process (e.g., intentional bending, stretching, drilling, grinding, cutting, polishing, or other intentional shaping after the formation of the intermediate product and before the subsequent formation of the three-dimensional product). As described above, the three-dimensional intermediate may be washed as desired, before further polymerization and / or before, during, or after intervening shaping steps.

[0080] The polymerization material may achieve predetermined mechanical properties without heat supply. Also, the polymerization material may be heated. The heating may be active heating (e.g., in an oven such as an electric oven, a gas oven, a solar oven, etc.) or passive heating (such as ambient temperature). Active heating is generally faster than passive heating and is preferred in some embodiments, but passive heating, such as simply maintaining the intermediate at ambient temperature for a time sufficient to effect further polymerization, is preferred in some embodiments.

[0081] A voxel represents a value for a regular grid of three-dimensional space. Similar to the pixels of a bitmap, the voxel itself is usually not explicitly coded with its position (coordinates) along with the value. Instead, the position of the voxel is inferred based on its relative position to other voxels (i.e., its position within the data structure that makes up a single volumetric image). In contrast to pixels and voxels, points and polygons are often explicitly represented by the coordinates of their vertices. A direct result of this difference is that polygons can efficiently represent simple 3D structures with significant empty or uniformly filled spaces, while voxels are excellent at representing non-uniformly filled and regularly sampled spaces.

[0082] In contrast to polymers, which generally have no restriction on the number of monomers, oligomers are molecular complexes consisting of a small number of monomer units. Dimers, trimers, and tetramers are oligomers composed of two, three, and four monomers, respectively, for example.

[0083] Energy polymerization by a single reaction mechanism, energy polymerizability by a single reaction mechanism, energy-polymerized by a single reaction mechanism, performing energy polymerization by a single reaction mechanism, energy irradiation by a single reaction mechanism, and being subjected to energy irradiation by a single reaction mechanism mean inducing polymerization by any of actinic rays, UV light, visible light, or electrons. Examples of such include UV light (100 nm to 405 nm), visible light (405 nm to 700 nm), or an electron beam. A non-exhaustive but exemplary list of light sources for practicing the present invention includes LEDs, laser diodes, laser beams, lamps (such as halogen lamps, Xe, Xe-Hg lamps, etc.), LED lasers, or LED projectors used in stereolithography, LCDs that irradiate visible light, LEDs, or plasma screens, mobile or tablet devices. This polymerization is carried out by a single reaction mechanism such as free radical, cationic, Michael addition, sequential, click chemistry, etc.

[0084] Photoplastics are materials formed by an energy polymerization method of a liquid material with a single reaction mechanism. Compared with existing photopolymers, photoplastics have mechanical properties comparable to those of materials known as thermoplastic resins, as shown in, for example, FIGS. 1A, 1B, 1C, and 2. Photoplastics can exhibit physical and mechanical properties superior to or equivalent to those of high-performance thermoplastic resins such as nylon 6, polycarbonate, PET, polypropylene, polyethylene, and a wide range of thermoplastic copolymers. Furthermore, photoplastics can exhibit physical and mechanical properties superior to or equivalent to those of other high-performance rubbers such as silicone and vulcanized natural rubber. Photoplastics can take various forms of polymer networks, including, but not limited to, interpenetrating networks and random copolymer networks.

[0085] Interpenetrating network. An interpenetrating network, or interpenetrating polymer network, or IPN, refers to a polymer that contains two or more networks that are at least partially intertwined on a polymer scale (but not necessarily covalently bonded to each other). These IPNs can take various forms in these embodiments: full, semi, or pseudo. In some embodiments, these networks are also referred to as dual networks (DN). Finally, in some embodiments, either or both of continuous or simultaneous processes may be used to construct these networks. Examples of various classifications of IPNs are shown in FIG. 3.

[0086] An interpenetrating polymer network (IPN) is a method utilized in polymer science when preparing composite materials from two immiscible or miscible raw materials. The final product is composed of two networks that are independently cross-linked by chemical or physical bonds. In such a system, the two phases are each continuous in space and each is in contact with the entire portion of the sample's space.

[0087] As shown in FIG. 4, full and semi IPNs differ depending on whether cross-linking is present in one or both of the respective components. Here, less than 1% cross-linking is defined as a full IPN network, and 1% - 99% partial cross-linking is defined as a semi IPN network. Semi IPNs include separable linear and / or branched networks. Pseudo IPNs have polymer chains that fill or grow within the internal voids of an existing structure or network.

[0088] The pseudo IPN seen in FIG. 5 becomes a special category of rotaxane and usually partially or completely phase-separates because the linear chains are not thermodynamically compatible with the cross-linking components and have sufficient molecular mobility to usually spontaneously phase-separate.

[0089] The dual network (DN) shown in Fig. 6 is known as having a concept different from that of full, semi, or pseudo IPN. IPN has no significant improvement in mechanical strength compared to the original single network structure, but it can combine various physical and chemical properties such as cell adhesion, water absorption, biocompatibility, biodegradability, etc. A fiber-reinforced hydrogel composed of a mechanically strong "dry" component (hydrophobic plastic) and a mechanically weak "wet" component (hydrophilic gel) is different from the DN gel in that the mechanical properties of the composite are basically determined by the strong dry component, and the hydrophilic component functions as a water absorbent but does not practically function to improve mechanical strength. The high strength of the DN gel is due to the non-linear effect of the binary structure, rather than the linear combination of the two-component network such as general IPN or fiber-reinforced hydrogel. Each of the two networks is mechanically weak, i.e., the first network is hard and brittle, and the second network is soft and ductile, but the DN gel formed by their combination is hard but not brittle and ductile but not soft.

[0090] These interpenetrating polymer networks can be obtained by the simultaneous method shown in Fig. 8, in which all the chemicals are mixed together and reacted simultaneously, or by the sequential method shown in Fig. 7. The sequential polymerization may be carried out stepwise. In this case, the pre-mixed resin has a skeleton network swollen by the unpolymerized material to be polymerized in the next step, together with the component polymerized in the first step. Also, the sequential network polymerization may rely on the swelling of a pre-synthesized network in a solution containing the second polymer to be cross-linked. In the latter case, the high porosity of the first network can be useful for obtaining a sufficient content ratio of the second polymer in the composite to be produced. For this reason, in an aqueous system such as a hydrogel, freeze-drying can be a suitable method for effectively removing the retained moisture and forming a macroporous sponge.

[0091] As shown in FIG. 9, the molecular weight of each network in the IPN can be adjusted. Various factors, such as the relative ratio of each component in the system, the relative ratio of the component to the initiator, and the relative ratio of the component to the inhibitor, can be used to adjust the molecular weight of each network. In addition, when UV energy is used for polymerization, the power consumption and light energy can be used to adjust the molecular weight.

[0092] IPN, semi-IPN, pseudo-IPN, and dual network can be detected by two different glass transition temperatures measured by DMA or DSC.

[0093] In some embodiments, the material has low toxicity. Toxic materials are often used to obtain properties such as thermoplasticity in dual polymerization materials and are also shown in FIG. 2. Toxic substances are substances that are either toxic or may affect health. When a toxic substance is ingested or inhaled by a human, it usually has the potential to cause physiological damage. There are various concerns about chemical substances such as low molecular weight amines, for example, trimethylolpropane poly(oxypropylene) triamine or 4,4'-methylenebis(2-methylcyclohexylamine). There are also various concerns about chemical substances with isocyanate functionality.

[0094] Although not limited thereto, hindered amine light stabilizers useful in the practice of the present invention include 2,2,6,6-tetramethylpiperidine derivatives, 1,6-hexanediamine, polymers having N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-, 2,4,6-trichloro-1,3,5-triazine, reaction products of N-butyl-1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidineamine, polymers having 1,4-dimethyl butanedioate, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate + methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 2,2,6,6-tetramethyl-4-piperidinyl stearate (fatty acid mixture), polymers having 1,6-hexanediamine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-, 2,4,6-trichloro-1,3,5-triazine, and reaction products with 2,4,4-trimethyl-2-pentanamine.

[0095] Although not limited thereto, oxidizable tin salts useful in the practice of the present invention include stannous butyrate, stannous octoate, stannous hexanoate, stannous heptanoate, stannous linoleate, stannous phenylbutyrate, stannous phenylstearate, stannous phenyloleate, stannous nonanoate, stannous decanoate, stannous undecenoate, stannous dodecanoate, stannous stearate, stannous oleate, stannous octoate, dibutyltin dilaurate, dibutyltin dioleate, dibutyltin distearate, dipropyltin dilaurate, dipropyltin dioleate, dipropyltin distearate, dibutyltin dihexanoate, and combinations thereof. See U.S. Pat. Nos. 5,298,532, 4,421,822, and 4,389,514, the disclosures of which are incorporated herein by reference. In addition to the above-described oxidizable tin salts, Lewis acids such as those described in Chu et al., Macromolecular Symposia, Vol. 95, No. 1, pp. 233-242 (June 1995) are known to increase the polymerization rate of free radical polymerization, which is incorporated herein by reference.

[0096] Depending on the properties desired for the part or object being manufactured, any suitable filler can be utilized in the various embodiments described herein. Thus, the filler can be solid or liquid, organic or inorganic, and can include reactive and non-reactive rubbers: siloxanes, acrylonitrile-butadiene rubber; reactive and non-reactive thermoplastic resins (including, but not limited to, poly(etherimide), maleimide-styrene terpolymer, polyarylate, polysulfone, polyethersulfone, etc.); inorganic fillers such as silicates (talc, clay, silica, mica, etc.), glass, carbon nanotubes, graphene, carbon fibers, metals, cellulose nanocrystals, etc., and all combinations of the above. Suitable fillers include reinforcing agents such as core-shell rubber, as described below.

[0097] Reinforcing agents. For example, one or more polymers and / or inorganic reinforcing agents as described in US Patent Application Publication No. 20150215430, the entire content of which is incorporated herein by reference, can be used as fillers in the present invention. The reinforcing agents may be uniformly dispersed in particulate form in the polymerization product. The particles may have a diameter of less than 5 micrometers (μm). Although not limited, such reinforcing agents include elastomers, branched polymers, hyperbranched polymers, dendrimers, rubbery polymers, rubbery copolymers, block copolymers, core-shell particles, oxides or inorganic materials such as clay, polyhedral oligomeric silsesquioxane (POSS), carbonaceous materials (e.g., carbon black, carbon nanotubes, carbon nanofibers, fullerenes), ceramics, and silicon carbide, etc., and the surface may or may not be modified or functionalized. Examples of block copolymers include, for example, the copolymers described in US Patent No. 6,894,113, the entire content of which is incorporated herein by reference, and also "NANOSTRENGTH (registered trademark)" SBM (polystyrene-polybutadiene-polymethacrylate) and AMA (polymethacrylate-polybutyl acrylate-polymethacrylate), both of which are manufactured by Arkema. Other suitable block copolymers include FORTEGRA (registered trademark) and the amphiphilic block copolymers described in US Patent No. 7,820,760, the entire content of which is incorporated herein by reference.Examples of known core-shell particles include, for example, core-shell (dendrimer) particles having a composition described in U.S. Patent Application Publication No. 20100280151 (Nguyen et al., Toray Industries, Inc., 2010) of an amine-branched polymer in which a shell is grafted onto a core polymer obtained by polymerizing a polymerizable monomer containing an unsaturated carbon-carbon bond; core-shell rubber particles described in European Patent Application Publication No. 1632533 and European Patent Application Publication No. 2123711, the entire contents of which are incorporated herein by reference; polymer cores obtained by polymerizing polymerizable monomers such as butadiene, styrene, other unsaturated carbon-carbon bond monomers, or combinations thereof, and polymer shells that are miscible with epoxy, typically polymethyl methacrylate, polyglycidyl methacrylate, polyacrylonitrile, or similar polymers further described below, such as the "KaneAce MX" product series of particle / epoxy blends having particles. Also, examples of block copolymers suitable in the present invention include the "JSR SX" series of carboxylated polystyrene / polyvinylbenzene manufactured by JSR Corporation; "Kureha Paraloid" EXL-2655, a butadiene alkyl methacrylate styrene copolymer manufactured by Kureha Corporation; "Stafiloid" AC-3355 and TR-2122, each an acrylate methacrylate copolymer manufactured by Takeda Pharmaceutical Company Limited; and "PARALOID" EXL-2611 and EXL-3387, each a butyl acrylate methyl methacrylate copolymer manufactured by Rohm & Haas. Examples of suitable oxide particles include, for example, NANOPDX® manufactured by nanoresins AG. This is a masterbatch of functionalized nanosilica particles and epoxy.

[0098] Core-shell rubber. The core-shell rubber is a particulate material (particle) having a rubbery core. Such materials are known and are described in U.S. Patent Application Publication No. 20150184039, U.S. Patent Application Publication No. 20150240113, and U.S. Patents 6,861,475, 7,625,977, 7,642,316, 8,088,245, etc., the entire contents of which are incorporated herein by reference.

[0099] In some embodiments, the core-shell rubber particles are nanoparticles (i.e., those having an average particle size of less than 1000 nanometers (nm)). Generally, the average particle size of the core-shell rubber nanoparticles is less than 500 nm, such as less than 300 nm, less than 200 nm, less than 100 nm, or even less than 50 nm. Typically, since such particles are spherical, the particle size is the diameter. However, when the particles are not spherical, the particle size is defined as the longest dimension of the particle.

[0100] In some embodiments, the rubbery core may have a Tg of less than -25 °C, more preferably less than -50 °C, and even more preferably less than -70 °C. The Tg of the rubbery core may also be significantly lower than -100 °C. Further, the core-shell rubber also has at least one shell portion having a Tg of 50 °C or higher. The "core" means the interior of the core-shell rubber. The core may be the center of the core-shell particle or may form an inner shell or region of the core-shell rubber. The shell is a part of the core-shell rubber that is outside the rubbery core. The shell portion(s) typically form the outermost part of the core-shell rubber particle. The shell material may be grafted or crosslinked to the core. The rubber core may constitute 50 to 95% by weight or 60 to 90% by weight of the core-shell rubber particles.

[0101] The core of the core-shell rubber may be a polymer or copolymer of a conjugated diene such as butadiene, or a lower alkyl acrylate such as n-butyl-, ethyl-, isobutyl- or 2-ethylhexyl acrylate. The core polymer may further contain up to 20% by weight of other copolymerized mono-unsaturated monomers such as styrene, vinyl acetate, vinyl chloride, methyl methacrylate. The core polymer may be crosslinked. The core polymer may contain up to 5% of a copolymerized graft-bond monomer having two or more heterogeneous reactive unsaturated sites (wherein at least one reactive site is non-conjugated), such as diallyl maleate, monoallyl fumarate, allyl methacrylate.

[0102] The core polymer may be a silicone rubber. This material often has a glass transition point below -100°C. Examples of core-shell rubbers having a silicone rubber core include those commercially available under the trade name Genioperl from Wacker Chemie, Munich, Germany.

[0103] The shell polymer that can be chemically grafted or crosslinked to the rubbery core can be polymerized from at least one lower alkyl methacrylate such as methyl methacrylate, ethyl methacrylate or t-butyl methacrylate. A homopolymer of such a methacrylate monomer may be used. Further, up to 40% by weight of the shell polymer may be formed from other monovinylidene monomers such as styrene, vinyl acetate, vinyl chloride, methyl acrylate, ethyl acrylate, butyl acrylate. The molecular weight of the grafted shell polymer may be between 20,000 and 500,000.

[0104] One suitable type of core-shell rubber is one having a reactive group in the shell polymer that can react with an epoxy resin or an epoxy resin curing agent. Glycidyl groups are suitable. Glycidyl groups are provided by monomers such as glycidyl methacrylate.

[0105] As an example of a suitable core-shell rubber, there is one of the type described in Imperial Patent Application Publication No. 2007 / 0027233 (European Patent Application Publication No. 1632533), the entire contents of which are incorporated herein by reference. As described herein, core-shell rubber particles are in most cases a crosslinked rubber core that is a copolymer of crosslinked butadiene, and a shell that is preferably a copolymer of styrene, methyl methacrylate, glycidyl methacrylate, and optionally acrylonitrile. The core-shell rubber is preferably dispersed in a polymer or an epoxy resin, as described in the literature. Without limitation, suitable core-shell rubbers include those sold under the name Kaneka Kane Ace by Kaneka Corporation, for example products of the Kaneka Kane Ace 15 and 120 series, such as Kaneka Kane Ace MX120, Kaneka Kane Ace MX153, Kaneka Kane Ace MX154, Kaneka Kane Ace MX156, Kaneka Kane Ace MX170, and Kaneka Kane Ace MX257, and the Kaneka Kane Ace MX120 core-shell rubber dispersion, and mixtures thereof.

[0106] I. Since the parts of 2 or more can be premixed or combined in a liquid state, the energy-polymerizable liquid of a single reaction mechanism is more beneficial than conventional IPN systems. However, here, each component is referred to as part A and part B.: Part A

[0107] As described herein, the polymerization system includes a first polymerization system (which may be referred to herein as "Part A") that polymerizes by energy rays, generally light, and optionally ultraviolet (UV) light. Any suitable polymerizable liquid may be used as the first component. The liquid (which may be referred to herein as "liquid resin", "ink" or simply "resin") may include monomers or preferably oligomers, particularly photopolymerizable and / or free radical polymerizable monomers or oligomers, suitable initiators such as free radical initiators, and combinations thereof. By way of non-limiting example, these may include acrylic, methacrylic, vinyl, acrylamide, styrene, olefin, halogenated olefin, cyclic alkene, maleic anhydride, alkene, alkyne, carbon monoxide, functionalized oligomers, multifunctional curtosite monomers, functionalized PEG, and combinations thereof. By way of non-limiting example, liquid resins, monomers and initiators include those described in U.S. Patent Nos. 8,232,043, 8,119,214, 7,935,476, 7,767,728, 7,649,029, International Publication No. 2012129968, Chinese Patent No. 102715751, and Japanese Patent Application Publication No. 2012210408, the entire contents of which are incorporated herein by reference.

[0108] Hydrogel. In some embodiments, suitable resins include photopolymerizable hydrogels such as poly(ethylene glycol) (PEG) and gelatin. PEG hydrogels are used for the delivery of various biopharmaceuticals such as growth factors. However, a major problem faced by PEG hydrogels crosslinked by chain-growth polymerization is the potential for irreversible protein damage. Conditions for maximizing the release of biopharmaceuticals from photopolymerized PEG diacrylate hydrogels are improved by including affinity-binding peptide sequences in the monomer resin solution prior to photopolymerization, which enables sustained delivery. Gelatin is a biopolymer frequently used in the food, cosmetic, pharmaceutical, and photographic industries. Gelatin is obtained by the thermal denaturation or chemical and physical degradation of collagen. There are three types of gelatin, such as those identified in animals, fish, and humans. Gelatin obtained from the skin of cold-water fish is considered safe for pharmaceutical use. Appropriately modified gelatin can be crosslinked using UV or visible light. Crosslinking methods for gelatin include polymer derivatives obtained from dyes such as rose bengal.

[0109] Acid-catalyzed polymerizable liquid. In some embodiments, as described above, the energy-polymerizable liquid of a single reaction mechanism includes a free-radical polymerizable liquid (in this case, the inhibitor may be oxygen as described below), while in other embodiments, the polymerizable liquid of a single reaction mechanism includes a polymerizable liquid polymerized by an acid catalyst or a cation. In such embodiments, the polymerizable liquid includes monomers containing groups suitable for an acid catalyst, such as an epoxide group and a vinyl ether group. Therefore, suitable monomers include olefins such as methoxyethene, 4-methoxystyrene, styrene, 2-methylprop-1-ene, 1,3-butadiene; heterocyclic monomers (including lactones, lactams, and cyclic amines) such as oxirane, thietane, tetrahydrofuran, oxazoline, 1,3-dioxepane, oxetan-2-one, and combinations thereof. A suitable (generally ionic or non-ionic) photoacid generator (PAG) is included in the acid-catalyzed polymerizable liquid, and examples thereof include, but are not limited to, onium salts, sulfonium and iodonium salts, such as diphenyliodide hexafluorophosphate, diphenyliodide hexafluoroarsenate, diphenyliodide hexafluoroantimonate, diphenyl p-methoxyphenyl triflate, diphenyl p-toluenyl triflate, diphenyl p-isobutylphenyl triflate, diphenyl p-tert-butylphenyl triflate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium triflate, dibutylnaphthylsulfonium triflate, and mixtures thereof.For example, reference is made to U.S. Patent Nos. 7,824,839, 7,550,246, 7,534,844, 6,692,891, 5,374,500, and 5,017,461, the entire contents of which are incorporated herein by reference, and also to Photoacid Generator Selection Guide for the electronics industry and energy curable coatings (BASF 2010), the entire contents of which are incorporated herein by reference.

[0110] Photopolymerizable silicone. Suitable resins include photopolymerizable silicone. UV curable silicone rubbers such as Siliopren® UV curable silicone rubber can be used in the same way as LOCTITE® curable silicone adhesive sealants. Applications include optical instruments, medical and surgical instruments, external lighting and enclosures, electrical connectors / sensors, optical fibers, gaskets, and molds.

[0111] Biodegradable resin. Biodegradable resins are particularly important for implantable devices for drug delivery or temporary function applications such as biodegradable screws and stents (U.S. Patent Nos. 7,919,162 and 6,932,930, the entire contents of which are incorporated herein by reference). A biodegradable copolymer of lactic acid and glycolic acid (PLGA) is dissolved in PEG di(meth)acrylate to obtain a transparent resin suitable for use. Polycaprolactone and PLGA oligomers can be functionalized with acrylic or methacrylic groups to make effective resins in use.

[0112] Photopolymerizable polyurethanes. Particularly useful materials are photopolymerizable polyurethanes (such as polyureas, and copolymers of polyurethanes and polyureas (e.g., poly(urethane-urea))). (1) A polyurethane based on an aliphatic diisocyanate, poly(hexamethylene isophthalate glycol), and optionally 1,4-butanediol, (2) a polyfunctional acrylate ester, (3) a photoinitiator, and (4) an antioxidant can be prepared to be a hard, abrasion-resistant, and stain-resistant material (U.S. Patent No. 4,337,130, the entire content of which is incorporated herein by reference). A photopolymerizable thermoplastic polyurethane elastomer incorporates a photoreactive diacetylene diol as a chain extender.

[0113] High-performance resins. In some embodiments, high-performance resins are used. Such high-performance resins may require heating to melt and / or reduce viscosity, as described above and further below. Without limitation, such resins include, for example, resins for materials sometimes called liquid crystal polymers of esters, ester imides, and ester amides, as described in U.S. Patent Nos. 7,507,784 and 6,939,940, the entire content of which is incorporated herein by reference. Since such resins are sometimes used as high-temperature thermosetting resins, the present invention further includes suitable photoinitiators such as benzophenone, anthraquinone, and fluorenone initiators (including their derivatives) to initiate crosslinking upon irradiation, as further described below.

[0114] Examples of additional resins. Resins particularly useful for dental applications include EnvisionTEC's Clear Guide and EnvisionTEC's E-Denstone Material. Resins particularly useful for hearing aid applications include EnvisionTEC's e-Shell 300 series of resins. Particularly useful resins include EnvisionTEC's HTM140IV high-temperature molding material for direct use with vulcanized rubber in molding / casting applications. Materials particularly useful for making strong and hard parts include EnvisionTEC's RC31 resin. Resins particularly useful for investment casting applications include EnvisionTEC's Easy Cast EC500 resin and MadeSolid FireCast resin.

[0115] Photoplastic materials can exhibit qualities particularly useful for dental industry use. The improved toughness of photoplastics compared to conventional (meth)acrylate and vinyl ether-based materials suggests good functionality in some dental applications. Photoplastics can be formulated and processed to have improved biocompatibility compared to conventional SLA materials.

[0116] Additional resin components. The liquid resin or polymerizable material may have solid particles suspended or dispersed therein. Depending on the final product to be manufactured, any suitable solid particles can be used. The particles can be metals, organics / polymers, inorganics, or composites or mixtures thereof. The particles can be non-conductive, semi-conductive, or conductive (such as metal and non-metal or polymer conductors), and the particles can be magnetic, ferromagnetic, paramagnetic, or non-magnetic. The particles can be of any suitable shape such as spherical, elliptical, cylindrical, etc. The particles can be of any suitable size (e.g., in the range of an average diameter of 1 nm to 20 μm).

[0117] The particles may contain activators or contrast compounds as described below, but these can also be provided in a dissolved and solubilized form in the liquid resin as described below. For example, magnetic or paramagnetic particles or nanoparticles can be used.

[0118] The liquid resin may have additional components to be solubilized, such as pigments, dyes, active compounds or pharmaceutical compounds, contrast compounds (e.g., fluorescent, phosphorescent, radioactive), etc., depending on the specific purpose of the product to be manufactured. Without being particularly limited, such additional components include, for example, nucleic acids (DNA, RNA) such as proteins, peptides, siRNA, sugars, small organic compounds (drugs and drug-like compounds), combinations thereof, and the like.

[0119] Light absorbers. In some embodiments, the energy polymerizable liquid of a single reaction mechanism for practicing the present invention includes a pigment or dye that absorbs light, particularly UV light. Without being particularly limited, suitable examples of such light absorbers include (i) titanium dioxide (e.g., included in an amount of 0.05 or 0.1 to 1 or 5 wt%), (ii) carbon black (e.g., included in an amount of 0.05 or 0.1 to 1 or 5 wt%), and / or (iii) organic UV absorbers such as hydroxybenzophenone, hydroxyphenylbenzotriazole, oxanilide, benzophenone, thioxanthone, hydroxyphenyltriazine, and / or benzotriazole UV absorbers (e.g., Mayzo BLS1326) (e.g., included in an amount of 0.001 or 0.005 to 1, 2, or 4 wt%). Without being particularly limited, suitable organic UV absorbers include, for example, those described in U.S. Patent Nos. 3,213,058, 6,916,867, 7,157,586, and 7,695,643, which are incorporated herein by reference.

[0120] Coincidence inhibitor. The inhibitor or polymerization inhibitor for use in the present invention may be in a liquid or gaseous state. In some embodiments, a gaseous inhibitor is preferred. In some embodiments, a liquid inhibitor such as an oil or lubricating oil (e.g., a fluorinated oil such as perfluoropolyether) may be used as the inhibitor (or as a release layer maintaining a liquid interface). Specific inhibitors vary depending on the monomer to be polymerized and the polymerization reaction. In the case of free radical polymerization monomers, oxygen is convenient as an inhibitor, and it is provided in a gaseous state such as air, an oxygen-rich gas (in some embodiments, preferably containing an additional inert gas to reduce flammability in some cases) or in some embodiments pure oxygen gas. Also, free radical scavengers and inhibitors such as MEHQ (monomethyl ether hydroquinone) and PTZ (phenothiazine) may be used to inhibit polymerization. In addition, a stable radical compound capable of capturing free radicals may be used to inhibit radical polymerization. In an alternative embodiment where the monomer is polymerized by a photoacid generator initiator, the inhibitor may be a base such as ammonia, trace amines (e.g., methylamine, ethylamine, di- and trialkylamines such as dimethylamine, diethylamine, trimethylamine, triethylamine), carbon dioxide, or a mixture or combination thereof.

[0121] Polymerizable liquid for transporting living cells. In some embodiments, the energy polymerizable liquid of a single reaction mechanism transports living cells as particles. Such polymerizable liquids are generally aqueous and may be hydrogen peroxide, and may be considered an "emulsion" in which living cells are the dispersed phase. Suitable living cells may be plant cells (e.g., monocotyledonous plants, dicotyledonous plants), animal cells (e.g., mammalian, avian, amphibian, reptilian cells), microbial cells (e.g., prokaryotes, eukaryotes, protozoa, etc.). The cells may be cells differentiated from any type of tissue (e.g., blood, cartilage, bone, muscle, endocrine gland, exocrine gland, epithelium, endothelium, etc.) or corresponding thereto, or undifferentiated cells such as stem cells and progenitor cells. In such embodiments, the polymerizable liquid may be one that forms a hydrogel, including but not limited to those described in U.S. Patent Nos. 7,651,683, 7,651,682, 7,556,490, 6,602,975, 5,836,313, the entire contents of which are incorporated herein by reference.

[0122] II. Energy Polymerizable Liquid of a Single Reaction Mechanism: Part B

[0123] As described above, in some embodiments of the present invention, the energy-polymerizable liquid of a single reaction mechanism includes a first energy-polymerizable component (which may also be referred to herein as "Part A"), and typically a second component (which may also be referred to herein as "Part B") that cures by energy polymerization with the same reaction mechanism as the first component through further reaction, polymerization, or chain extension. A number of these embodiments can be implemented. It should be noted that in the following, when specific acrylates such as methacrylates are described, other acrylates can also be used. It should be noted that in the following, when specific vinyls such as N-vinyl are described, other vinyls can also be used. FIG. 10 shows the formation of various IPNs that can occur between acrylate-functional materials and vinyl-functional materials. These include semi-IPNs (FIGS. 10A, 10D) when monofunctional monomers are used with multifunctional monomers or oligomers, full IPNs (FIGS. 10B, 10C, 10E) when multifunctional monomers or oligomers are used with oligomeric multifunctional monomers, and pseudo-IPNs (FIG. 10F) when monofunctional monomers are used with monofunctional monomers.

[0124] Chemistry of Part A. As described above, in some embodiments of the present invention, the resin has a first component referred to as "Part A". Part A includes a mixture of monomers and / or oligomers and / or prepolymers that are polymerizable by exposure to actinic radiation or light. This resin may have one or more functionalities. The purpose of Part A is to "lock" the shape of the material or object being formed or to form the backbone of one or more additional components (e.g., Part B). It is important that there is more than the minimum amount necessary to maintain the shape of the material or object formed after the initial cure. In some embodiments, this amount corresponds to less than 10, 20, or 30 weight percent of the total resin (polymerizable liquid) composition.

[0125] In some embodiments, Part A can form a crosslinked polymer network or a solid homopolymer by reaction.

[0126] Although not limited thereto, examples of reactive end groups suitable for the components, oligomers, or prepolymers of part A include acrylates, methacrylates, α-olefins, N-vinyls, vinylamides, cyanoacrylates, acrylamides, methacrylamides, acryloyls, styrenes, epoxides, thiols, 1,3-dienes, vinyl halides, acrylonitriles, vinyl esters, maleimides, and vinyl ethers, vinyl carbonates, vinyl carbamates.

[0127] The mode of curing of part A is to provide a backbone in which a second reactive resin component, called "part B", can cure during a second step (which can occur simultaneously with or after the curing of part A). This second reaction preferably occurs without significantly distorting the initially defined shape during the curing of part A. Otherwise, the desired initial shape will be distorted.

[0128] In certain embodiments, the curing of part A is continuously inhibited during printing within a specific region by oxygen or amine or other reactive species, forming a liquid interface between the cured portion and the inhibitor-permeable film or window (e.g., implemented by continuous liquid interphase / interface printing).

[0129] Chemistry of part B. Part B may comprise a mixture of monomers and / or prepolymers having reactive end groups that participate in a second curing reaction during or after the curing reaction of part A. In some embodiments, part A and part B may be premixed, part B may be added to part A simultaneously such that it is present during exposure to energy irradiation, or part B may be injected into the material or object in a subsequent step after the polymerization of part A. Although not limited thereto, methods used for curing part B include, for example, exposing the material or object to light of a wavelength different from that used to polymerize part A, or light of the same wavelength as that used to polymerize part A, or in the case of electron beam polymerization, contacting the material or object with electrons (or combinations thereof).

[0130] Although not limited thereto, examples of reactive end groups suitable for the components, monomers, or prepolymers of part B include acrylates, methacrylates, α-olefins, N-vinyls, vinylamides, cyanoacrylates, vinyl carbonates, vinyl carbamates, acrylamides, methacrylamides, styrenes, epoxides, thiols, 1,3-dienes, vinyl halides, acryloyls, acrylonitriles, vinyl esters, maleimides, and vinyl ethers.

[0131] Other reactive species suitable for part B are recognized by those skilled in the art. Components of part B that are useful for forming polymers are described in "Concise Polymeric Materials Encyclopedia" and "Encyclopedia of Polymer Science and Technology", the entire contents of which are incorporated herein by reference.

[0132] Organic peroxides. In some embodiments, for example, organic peroxides can be included in the energy-polymerizable liquid or resin of a single reaction mechanism to promote the reaction of double bonds that may remain unreacted during thermal and / or microwave irradiation polymerization. Such organic peroxides can be included in the resin or polymerizable liquid in any suitable amount, such as 0.001 or 0.01 or 0.1 wt% to 1, 2, or 3 wt%. Although not limited thereto, examples of suitable organic peroxides include 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (e.g., LUPEROX 101 (registered trademark)), dilauroyl peroxide (e.g., LUPEROX LP (registered trademark)), benzoyl peroxide (e.g., LUPEROX A98 (registered trademark)), bis(tert-butyldioxyisopropyl)benzene (e.g., VulCUP R (registered trademark)), and combinations thereof. Such organic peroxides are available from various suppliers, such as Arkema (420 rued’Estienned’Orves, 92705 Colombes Cedex, France).

[0133] Catalyst. Other catalysts known to those skilled in the art that can affect the polymerization rate of other parts A or B may be used to adjust the energy polymerization rate of the single reaction mechanism of either or both of parts A and B (for example, metal catalysts such as peroxides, tin catalysts, and / or amine catalysts; platinum or tin catalysts for silicone resins; ruthenium catalysts for ring-opening metathesis polymerization resins; copper catalysts for click chemistry resins (these catalysts contact the article as a liquid aerosol by dipping, etc.), or aminoplast-containing resins such as those containing N-(alkoxymethyl)acrylamide, hydroxyl groups, blocked acid catalysts).

[0134] Inhibitor. In some embodiments, other inhibitors known to those skilled in the art that can affect the rate or initiation of polymerization of part A or part B may be used to adjust the initiation or the energy polymerization rate of the single reaction mechanism of either or both of parts A and B.

[0135] In some embodiments, the reaction rate of one component is significantly slower compared to the other component. This can be achieved by selecting raw materials with significantly different reactivities or using inhibitors that preferentially inhibit one component. By slowing down the reaction rate, the other component can be more completely polymerized before one component is fully polymerized. In some embodiments, this can form a sequential IPN.

[0136] In some embodiments, the solubility of the second component in the first component changes during the polymerization of the first component. Generally, all components are dissolved in the liquid state. In some embodiments, during the polymerization of the first component to form a solid, the solubility of the other liquid components changes, resulting in solid-liquid phase separation at the nano, micro, and macro levels. This phase separation can be confirmed by a change in the refractive index of the material. This phase separation changes the reaction selectivity of the components and can promote homopolymerization. This phase separation may change the mechanical properties of the material, such as the elasticity and resilience of the elastomer.

[0137] In some embodiments, the solubility of the second component in other components changes during the polymerization of the second component. Generally, all components are soluble in the liquid state. In some embodiments, while one component polymerizes to form a solid, the solubility of the other liquid components does not change significantly. When the second component polymerizes into a solid, the solubility in the second component changes, resulting in solid phase separation at the nano, micro, and macro levels. This phase separation can be confirmed by a change in the refractive index of the material. This phase separation may change the mechanical properties of the material, such as the elasticity and resilience of the elastomer.

[0138] In some embodiments of the present invention, it may be useful to use photoplastics for soundproofing or noise cancellation applications. IPN materials are known for exhibiting interesting and unique sound absorption, sound, and vibration characteristics over a wide temperature range.

[0139] In some embodiments of the present invention, part A consists of a high elongation urethane-based (meth)acrylate oligomer. The UV-polymerizable part A is mainly blended with part B consisting of a monofunctional n-vinyl monomer and is used to solidify an object into a desired shape using 3D printing with a high reaction rate and a selective reaction pathway as described herein, and serves as the backbone of part B in an energy-polymerizable liquid with a single reaction mechanism. This backbone is generally very elastic but weak. After printing, the object is further polymerized by energy polymerization of a single reaction mechanism, whereby the second component is polymerized to form a strong linear, semi-crosslinked, or fully crosslinked IPN through the backbone, and an object containing an elastomer is obtained.

[0140] Adhesion of the formed objects. In some embodiments, it may be useful to define the shapes of a number of objects by curing part A, arrange these objects in a specific configuration, make sure there is a hermetic seal between the objects, and then polymerize the secondary curing of part B. In this way, strong adhesion between the parts can be provided during manufacturing. A particularly useful example is in the formation and adhesion of sneaker components.

[0141] Fusion of particles as part B. In some embodiments, "part B" may simply comprise small particles of a pre-formed polymer. After curing of part A, the object may be heated above the glass transition temperature of part B to polymerize the encapsulated polymer particles.

[0142] Photocleavable end groups. In some embodiments, the reactive species of part A are cleaved upon energy irradiation to generate new reactive species after curing of part A. The newly formed reactive species can further react with part B in secondary curing.

[0143] Method of mixing components. In some embodiments, the components may be continuously mixed before being introduced onto the build plate of a printer. This can be implemented using a multi-barrel syringe and a mixing nozzle. For example, part A may comprise a UV curable di(meth)acrylate resin, and part B may comprise or consist of a vinyl monomer. Since both part A and part B have high storage stability even when all components are mixed, it is usually possible to premix both part A and part B sufficiently before application. Storage stability can be defined as having a viscosity within 10% of the initial viscosity in a bottle premixed under ambient conditions for 1, 2, 3, or 4 years. This can be simulated by high temperature stability at 60 °C for 1, 2, 3, 4 weeks. However, if necessary, a second syringe barrel will contain the material of part B. Further, when the resin is introduced into the printer in this way, a certain time is defined from the mixing of all components to the curing of part A or part B.

[0144] Other additive manufacturing techniques. It will be apparent to those skilled in the art that the materials described in the present invention are useful in other additive manufacturing techniques such as fused deposition modeling (FDM), selective laser sintering (SLS), and inkjet methods.

[0145] In some embodiments, part A includes acrylates, methacrylates, styrene, acrylic acid, N-vinyl, acryloyl, vinylamide, vinyl ether, vinyl carbonate, vinyl carbamate, vinyl esters (including their derivatives), polymers including any one or more of the foregoing, and combinations of two or more of the foregoing (e.g., acrylonitrile, styrene, divinylbenzene, vinyltoluene, methyl acrylate, ethyl acrylate, butyl acrylate, methyl (meth)acrylate, amine (meth)acrylate, and mixtures of any two or more thereof as described above) (see, e.g., U.S. Patent Application Publication No. 20140072806, which is incorporated herein by reference in its entirety).

[0146] In some embodiments, part B includes acrylates, methacrylates, styrene, acrylic acid, N-vinyl, vinylamide, acryloyl, vinyl ether, vinyl carbonate, vinyl carbamate, vinyl esters (including their derivatives), polymers including any one or more of the foregoing, and combinations of two or more of the foregoing (e.g., acrylonitrile, styrene, divinylbenzene, vinyltoluene, methyl acrylate, ethyl acrylate, butyl acrylate, methyl (meth)acrylate, amine (meth)acrylate, and mixtures of any two or more thereof as described above) (see, e.g., U.S. Patent Application Publication No. 20140072806, which is incorporated herein by reference in its entirety).

[0147] Elastomers. Embodiments particularly useful in the practice of the present invention are directed to the formation of elastomers. It is difficult to achieve tough, high-elongation, and high-strength elastomers using conventional liquid UV-polymerizable precursors. However, through the formation of an IPN network, elastomers having properties equivalent to or better than known polyurethanes, silicones, natural rubbers, etc. can be formed under energy polymerization of a single reaction mechanism. These elastomers energy-polymerized by a single reaction mechanism can have an elongation of >750% and / or a tensile strength of >20 MPa.

[0148] In some embodiments, as described in more detail above, the energy-polymerizable liquid of a single reaction mechanism comprises: a) a portion A of 5 or 20 or 40 wt% to 60 or 80 or 90 wt%; b) a portion B of 10 or 20 wt% to 30 or 40 or 50 or 60 or 70 wt%; c) a photoinitiator of 0.1 or 0.2 wt% to 1, 2 or 4 or 8 wt%; and d) optional additional materials such as dyes, fillers (e.g., silica), surfactants, etc. Since these energy-polymerizable liquids of a single reaction mechanism do not polymerize upon mixing, an advantage of some embodiments of the present invention is that they can be pre-formulated and the filling process can be carried out by pouring or supplying the polymerizable liquid from a single source (e.g., a single reservoir containing the polymerizable liquid in a pre-mixed form) into the build region, eliminating the need to modify the apparatus to provide separate reservoirs or mixing capabilities.

[0149] In some embodiments, the three-dimensional object produced by this process is foldable or compressible (i.e., having elasticity (e.g., a Young's modulus at room temperature of about 0.001, 0.01, or 0.1 GPa to about 1, 2, or 4 GPa, and / or a tensile strength at maximum load at room temperature of about 0.01, 0.1, or 1 to about 50, 100, or 500 MPa, and / or an elongation at break at room temperature of about 10, 20, 50, or 100% to 1000, 2000, or 5000% or more)).

[0150] In some embodiments, after forming an intermediate molded article having a polyurethane oligomer as a backbone by energy polymerization of a single reaction mechanism, when the IPN of the second component polymerizes, the entire material is subjected to another energy polymerization. The time required for this energy polymerization varies depending on the energy source, temperature, size, shape, and density of the product, but is typically from 1 second to several hours, and varies depending on the energy of the specific single reaction mechanism used and the size of the product.

[0151] Generally, a film or three-dimensional article produced by the single reaction mechanism of the above method may include, for example, as an IPN, semi-IPN, simultaneous IPN, sequential IPN, dual network, or combinations thereof, (i) a linear or semi-crosslinked or fully crosslinked energy polymerized network, (ii) a fully or semi-crosslinked energy polymerized polymer constructed from monomers or oligomers having energy polymerizable functional groups, or (iii) combinations thereof. In some embodiments, the film or three-dimensional article may include unreacted photoinitiator remaining in the film or three-dimensional formed article. For example, in some embodiments, 0.1 or 0.2 wt% to 1, 2, or 4 wt% of photoinitiator may remain in the film or three-dimensional formed article, and the photoinitiator may be present in even lesser amounts or trace amounts only. In some embodiments, the film or three-dimensional article may include fragments of the reacted photoinitiator. For example, in some embodiments, the fragments of the reacted photoinitiator may be the remainder of the first polymerization forming an intermediate product. For example, 0.1 or 0.2 wt% to 1, 2, or 4 wt% of the fragments of the reacted photoinitiator may remain in the film or three-dimensional formed article, and the fragments of the reacted photoinitiator may be present in even lesser amounts or trace amounts only. In an exemplary embodiment, a film or three-dimensional article produced by the single reaction mechanism may include a crosslinked or linear energy polymerized network, different crosslinked energy polymerized networks, unreacted photoinitiator, and reacted photoinitiator species, in whole or any combination.

[0152] These materials can be used in bottom-up additive manufacturing techniques such as the continuous liquid interface printing techniques described herein and other additive manufacturing techniques described above and below.

[0153] These materials can be used in inkjet printing manufacturing techniques such as the piezoelectric printing techniques described herein and other inkjet printing techniques described above and below.

[0154] An article composed of an interpenetrating polymer network (IPN) formed from an energy-polymerizable liquid of a single reaction mechanism.

[0155] In some embodiments, the energy-polymerizable liquid of a single reaction mechanism, including those of the above, is also useful for forming films and three-dimensional articles containing IPNs.

[0156] By way of non-limiting example, the energy-polymerizable liquid and method steps of a single reaction mechanism are selected such that the film or three-dimensional object includes the following.

[0157] A sol-gel composition. This can be carried out using an amine (ammonia) permeable window or a semi-permeable member. In the system described here, tetraethyl orthosilicate (TEOS), epoxy (diglycidyl ether of bisphenol A), and 4-aminopropyltriethoxysilane are added to a free radical crosslinking agent. During the process, the free radical crosslinking agent polymerizes and includes the above reactants that react in another step or stage later. The reaction requires the presence of water and an acid. A photoacid generator (PAG) may be added to the above mixture to promote the reaction of the silica-based network. Note that if only TEOS is included, it will ultimately result in a silica (glass) network. Next, the temperature is raised to remove the organic layer, leaving behind a silica structure that is difficult to prepare by conventional methods. This process allows for the preparation of many variants (different polymer structures) in addition to epoxies such as urethane, functionalized polyols, and silicone rubber.

[0158] Hydrophobic-hydrophilic IPN. For example, a hydrophobic-hydrophilic network for improving the tissue compatibility and blood compatibility of biomedical parts can be mentioned. Poly(N-vinylpyrrolidone) is an example of a hydrophilic component. Polybutadiene is an example of a hydrophobic component.

[0159] Conductive polymer. To produce the conductive part, aniline and ammonium persulfate are incorporated into a polymerizable liquid with a single reaction mechanism energy. After the reaction system polymerizes and is post-treated with an acid (such as HCl vapor), the polymerization to polyaniline can be initiated.

[0160] Natural product-based IPN. Many natural product-based IPNs based on triglyceride oils such as castor oil, or gelatin, or polyvinyl alcohol are known. These can be incorporated into a polymerizable liquid with a single reaction mechanism energy. Upon completion of the part, these can form additional IPNs. Glycerol can also be used, of course.

[0161] Continuous IPN. In some embodiments, the skeletal crosslinked network swells with a monomer and a free radical photoinitiator and an optional crosslinking agent, and then polymerizes.

[0162] Simultaneous IPN. In some embodiments, both networks are formed in a first polymerization step.

[0163] III. Manufactured Products

[0164] A. Three-dimensional (3D) objects

[0165] The three-dimensional objects manufactured by the methods and processes of the present invention may be end products, finished products or substantially finished products, or intermediate products that are subjected to further manufacturing processes such as surface treatment, laser cutting, electrical discharge machining, etc. Intermediate products include products that can be further stereolithographically formed using the same apparatus or different apparatuses. For example, in order to halt one region of the end product, or simply because a particular region or "build" of the end product is more fragile than others, intentional fault lines or score lines can be introduced into the ongoing "build" by disturbing and then restoring the slope of the polymerization region.

[0166] A number of different products such as large-scale models or prototypes, small custom-made products, miniature or microminiature products or devices can be manufactured by the method and apparatus of the present invention. By way of example, and not limitation, medical devices and implantable medical devices such as hearing aids, stents, drug delivery depots, functional structures, micro-needle arrays, fibers and rods such as waveguides, micro-mechanical devices, and micro-fluidic devices can be mentioned.

[0167] Accordingly, in some embodiments, the product may have a height of 0.1 or 1 mm to 10 or 100 mm or more, and / or a maximum width of 0.1 or 1 mm to 10 or 100 mm or more. In other embodiments, the product may have a height of 10 or 100 nm to 10 or 100 μm or more, and / or a maximum width of 10 or 100 nm to 10 or 100 μm or more. These are merely examples. The maximum diameter and maximum width vary depending on the configuration of the particular device and the resolution of the light source, and may be adjusted according to the particular purpose of the embodiment or the article being manufactured.

[0168] In some embodiments, the ratio of the height to the width of the product is at least 2:1, 10:1, 50:1, or 100:1, or more, and the ratio of the width to the height is 1:1, 10:1, 50:1, or 100:1, or more.

[0169] As further described below, in some embodiments, the product has at least one, or a plurality of holes or grooves formed therein.

[0170] The processes described herein can produce articles having a variety of different properties. In some embodiments, the article is rigid, and in some other embodiments, the article is flexible and elastic. In some embodiments, the article is solid. In other embodiments, the article is a gel such as a hydrogel. In some embodiments, the article has shape memory (i.e., it generally returns to its previous shape after deformation unless deformed beyond the structural break point). In some embodiments, the article is a single entity (i.e., formed from one single reactive mechanism energy polymerizable liquid). In some embodiments, the article is a composite (i.e., formed from two or more different single reactive mechanism energy polymerizable liquids). Specific properties are determined by factors such as the selection of the single reactive mechanism energy polymerizable liquid used.

[0171] In some embodiments, the article or article produced has at least one protrusion (or "projection"), such as a crosslinking element between two supports or a cantilever element projecting from one substantially vertical support. The problem of formation of a fault line or cleavage line between layers when a substantial time interval occurs before each layer has polymerized substantially to completion and the next pattern is exposed is significantly reduced by the unidirectional and continuous nature of some embodiments of this process. Thus, in some embodiments, this method is particularly advantageous for reducing or eliminating the number of support structures for such protrusions produced simultaneously with the article.

[0172] B. Structural and Shape Examples of 3D Objects

[0173] In an exemplary embodiment, thousands or millions of shape changes can be imparted to a three-dimensional object during formation to form a three-dimensional (3D) object. In an exemplary embodiment, a pattern generator generates different light pattern irradiations, activates photoinitiators in the polymerization gradient region, and imparts different shapes when obtaining an object from the polymerization gradient. In an exemplary embodiment, the pattern generator may have a high resolution with millions of pixel elements that can be changed to change the shape to be imparted. For example, the pattern generator may be a DLP having 1,000, 2,000, or more than 3,000 rows and / or 1,000, 2,000, or more than 3,000 columns of micromirrors or pixels of an LCD panel that can be used to change the shape. As a result, very fine changes or gradations can be imparted to the object along the length of the object. In an exemplary embodiment, this enables the formation of complex three-dimensional objects with a substantially continuous surface without cleavage lines or seams at high speed. In some examples, there are no cleavage lines or seams over the length of the object to be formed, such as 1 mm, 1 cm, more than 10 cm, or more, or over the entire length of the formed object, and more than 100, 1000, 10000, 100000, or more than 1000000 shape changes may be imparted to the three-dimensional object to be formed. In an exemplary embodiment, the object can be continuously formed from the polymerization gradient at a speed of 1, 10, 100, 1000, more than 10000 microns per second or more.

[0174] In an exemplary embodiment, this enables the formation of complex three-dimensional (3D) objects. In some exemplary embodiments, the 3D formed objects have complex non-injection-moldable shapes. This shape may not be easily formed by injection molding or casting. For example, this shape may not be formed by a mold that is adapted to form a cavity for injecting and polymerizing a filling material, such as in conventional two-part molding. For example, in some embodiments, the 3D formed objects can include sealed cavities or partially open cavities, repeating unit cells, or open-cell or closed-cell foam structures not suitable for injection molding, and can include hundreds, thousands, or millions of these structures or interconnected networks of these structures. However, in exemplary embodiments, these shapes can be 3D formed using the method described in this application, utilizing a wide range of elastomeric properties, tensile strength, and elongation at break, etc., by using dual-polymerization materials and / or IPNs that form these structures. In an exemplary embodiment, the 3D object can be formed without cleavage lines, parting lines, seams, sprues, gate marks, or ejector pin marks that may exist in injection molding or other prior arts. In some embodiments, the 3D formed object can have a continuous surface texture (smoothness, pattern, or roughness) without molded objects or other printed objects (such as cleavage lines, parting lines, seams, sprues, gate marks, or ejector pin marks) over 1 mm, 1 cm, 10 cm or more, or over the entire length of the formed object. In an exemplary embodiment, the complex 3D object can be formed such that there are no discontinuous layers visible in the completed 3D object or easily detectable from the printing process over a length of 1 mm, 1 cm, 10 cm or more, or over the entire length of the formed object. For example, since printing is generated by the inclination of the polymerization region (where the 3D object is generated when exposed to various patterns projected from the pattern generator), when the 3D object is completed, the various shapes imparted by the pattern generator during printing may not be visible or detectable as different layers.The 3D object resulting from this process can also be referred to as a 3D printed object, although this 3D object can be formed by continuous liquid interphase printing without the discontinuous layers or cleavage lines associated with some 3D printing processes.

[0175] In some embodiments, the 3D formed object may include one or more repeating structural elements for forming a 3D object, such as, for example, a sealed cavity, a partially closed cavity, a repeating unit cell or a network of unit cells, a foam cell, a Kelvin foam cell or other open cell or closed cell foam structure, a cross structure, an overhang structure, a cantilever, a micro needle, a fiber, a paddle, a protrusion, a pin, a dimple, a ring, a tunnel, a tube, a shell, a panel, a beam (including I-beam, U-beam, W-beam, cylindrical beam), a strut, a tie, a channel (open, closed, or partially closed), a waveguide, a triangular structure, a tetrahedron or other pyramidal shape, a cube, an octahedron, an octagonal prism, an icosahedron, a rhombic triacontahedron or other polyhedral shape or module (including tetrahedron, prism or other polyhedral shape of the Kelvin minimal surface), a pentagon, a hexagon, an octagon and other polygonal structures or prisms, a polygonal mesh or other three-dimensional structure. In some embodiments, the 3D formed object may include any combination of these structures, or an interconnected network of these structures. In an exemplary embodiment, all or some of the structures of the 3D formed object correspond (or substantially correspond) to one or more Bravais lattice or unit cell structures such as a cube (including simple, body-centered or face-centered), a tetragonal system (including simple or body-centered), a monoclinic system (including simple or base-centered), an orthorhombic system (including simple, body-centered, face-centered or base-centered), a rhombohedron, a hexagon, a triclinic structure, etc. In an exemplary embodiment, the 3D formed object corresponds (or substantially corresponds) to one or more Bravais lattice or unit cell structures such as a catenoid, a helicoid, a gyroid or a lissajoid, other triply periodic minimal surfaces (TPMS), or other shapes from related families (or Bonnet families), or Schwarz P (“Primitive”), Schwarz D (“Diamond”), Schwarz H (“Hexagonal”) or Schwarz CLP (“Crossed layers of parallels”) surfaces, an argyle or diamond pattern, a lattice or other pattern or structure.

[0176] In an exemplary embodiment, the pattern generator can be programmed to rapidly change during printing to impart different shapes with high resolution to the polymerization gradient. As a result, any of the above structural elements can be formed with a wide range of dimensions and properties, and the above structural elements can be repeated or combined with other structural elements to form a 3D object. In an exemplary embodiment, the 3D formed object may include a single three-dimensional structure, or may include one, ten, one hundred, one thousand, ten thousand, one hundred thousand, more than one million, or more of these structural elements. The structural elements may be repeating structural elements of similar shape, may be a combination of different structural elements, and may be any of the above or other regular or irregular shapes. In an exemplary embodiment, each of these structural elements may have a structural dimension of at least 10 nm, 100 nm, 10 μm, 100 μm, 1 mm, 1 cm, 10 cm, 50 cm, or more, and may have a structural dimension of less than 50 cm, 10 cm, 1 cm, 1 mm, 100 μm, 10 μm, 100 nm, 10 nm, or less. In an exemplary embodiment, the height, width, or other dimension of the structure may be in the range of about 10 nm to about 50 cm or more, or any range subsumed therein. As used herein, "any range subsumed therein" means any range within the recited range. For example, the following ranges: 10 nm to 1 μm, 1 μm to 1 mm, 1 mm to 1 cm, 1 cm to 50 cm, or any other range and group of ranges within the above ranges are all subsumed within the range of about 10 nm to about 50 cm and will be described herein. In an exemplary embodiment, each structural element is about 10 nm 3 ~ about 50 cm 3 or more, or may form a 3D object having a volume within any range subsumed therein. In an exemplary embodiment, each structural element may form a cavity, or a void region or gap having dimensions in the range of about 10 nm to about 50 cm or more, or any range subsumed therein, between the faces of the structural element, or about 10 nm 3 ~ about 50 cm 3The volume within the region of a 3D formed object of or more than or any range subsumed therein may be defined.

[0177] The structural elements may be of the same size and the size may vary across the entire volume of the 3D formed object. The size may increase or decrease (gradually or stepwise) from one side of the 3D formed object to the other, and elements of various shapes may be intermixed in a regular or irregular pattern (e.g., a 3D elastomeric foam having open cells and / or closed cell cavities of various sizes intermixed in the foam).

[0178] In some embodiments, the 3D formed object may have an irregular shape with protrusions, cross-linking elements, or asymmetry, or may have an offset center of gravity in the direction of formation. For example, the 3D formed object may be asymmetric. In an exemplary embodiment, the 3D formed object may not have rotational symmetry about any axis, or may have rotational symmetry about only a single axis. In an exemplary embodiment, the 3D formed object may not have plane symmetry about any plane passing through the 3D formed object, or may have plane symmetry about only a single plane. In an exemplary embodiment, the 3D object may have an offset center of gravity. For example, the center of gravity of the 3D formed object may not be at the center of the position of the object. In some examples, the center of gravity may not be located along the central axis of the object. For example, the 3D formed object may generally be a sole or insole of a shoe conforming to the contour of a foot. The sole or insole of the shoe may be tilted to the right or left and may have different widths at the heel and toe. As a result, the 3D formed object in this example is not plane-symmetric in the left-right and front-back directions. However, in the case of a uniformly flat shoe sole or insole, it may be plane-symmetric in the up-down direction. In other examples, the shoe sole or insole is flat on one side and contoured to receive the arch of the foot on the opposite side, resulting in it not being plane-symmetric in the up-down direction either. 3D formed objects for shapes or devices for wearables, prosthetics, or body structures may have similar asymmetries and / or offset centers of gravity. For example, a 3D formed object for a dental mold or dental implant may substantially match the shape of a tooth and may not be plane-symmetric about any surface. In another example, it is a 3D molding component for soft robotics such as a grip, handle, or internal pressurizing material that may come into contact with an object for picking up, lifting, or moving. The elastomeric materials described in this example can be particularly useful for soft robotics applications. In other examples, 3D molding components for wearable devices such as athletic wear, such as left and right curved thigh pads, hard thigh pads, or foam pads or inserts used between a helmet or other wearable component and the body, may substantially match the shape of the body and may have corresponding asymmetries. These are merely examples, and many 3D formed objects may be asymmetric or may have an offset center of gravity.In exemplary embodiments, where there are significant asymmetries or protruding elements (such as arms, bridge elements, cantilevers, brush fibers, etc.) or where the desired structural elements are elastomers, they may deform during 3D printing or subsequent polymerization. For example, when a large amount of non-UV polymerizable elastomer resin material is included, deformation may occur due to gravity before final polymerization. While the skeleton formed from the UV polymerizable material during 3D printing (from the first polymerization in the dual polymerization process) aids in shape fixation, some elastomer compositions of highly asymmetric or protruding shapes may be prone to deformation. In some embodiments, the UV polymerizable material in the composition may be adjusted to form a stronger skeleton to avoid deformation. In other exemplary embodiments, especially when the 3D formed object or protruding element is relatively long, connectors that will be removed later may be used to form objects in pairs (or other combinations) having an asymmetric shape and / or an offset center of gravity. In one example, an elastomer 3D object may be formed along its length, having asymmetry, an offset center of gravity, and / or being transverse to the length, and having protruding elements that are 10%, 20%, 30%, 40%, more than 50%, or more of the length. For example, the 3D formed object may have a length of about 1 cm to 50 cm, or more, or any range subsumed therein, and may have lateral or side asymmetric elements or protruding elements in the range of about 1 cm to 50 cm, or more, or any range subsumed therein. In exemplary embodiments, two or more of these objects may be formed together to provide support for the lateral or protruding elements until the elastomer material is polymerized and the objects are separated. For example, two shoe soles (e.g., rotationally and reversely formed shoe soles formed together using a small removable connector therebetween) may be formed in pairs such that they support each other during formation (when formed in the longitudinal direction). In other embodiments, other supports may be formed and removed after polymerization of the elastomer material.

[0179] C. Examples of Materials and Compositions of 3D Objects

[0180] In an exemplary embodiment, a 3D formed object manufactured by a single reaction mechanism may have any of the above shapes and structures, for example, as an IPN, semi-IPN, simultaneous IPN, or sequential IPN, or a combination thereof, (i) a linear, semi-, or fully cross-linked energy polymerization network, (ii) a fully or semi-cross-linked energy polymerization polymer constructed from monomers or oligomers containing energy polymerizable functional groups, or (iii) a combination thereof, and / or (iv) may include, may be composed of, or may be essentially composed of a photoinitiator such as an unreacted photoinitiator and / or a reaction photoinitiator fragment.

[0181] In some exemplary embodiments, the 3D formed object may include a sol-gel composition, a hydrophobic or hydrophilic composition, a phenol resole, a cyanate ester, a polyimide, a conductive polymer, a natural product-based IPN, a sequential IPN, a simultaneous IPN, and a polyolefin, as described above.

[0182] In an exemplary embodiment, the 3D formed object may have any of the above shapes or structures, may include, or may be composed of, or may consist essentially of, a plurality of different materials having different tensile strengths or other different properties in different regions of the 3D formed object. In an exemplary embodiment, the different materials may be selected from any of the above. In some exemplary embodiments, the manufacturing process of the product may be stopped or interrupted one or more times to change the energy-polymerizable liquid of a single reaction mechanism. In an exemplary embodiment, the 3D formed object may further include, as described below, a number of materials having different tensile strengths (e.g., thermoplastic or thermosetting polyurethanes, polyureas, or copolymers thereof, or silicone rubbers, or epoxies, or combinations thereof). Although a fault line or fault plane may be formed in the intermediate due to the interruption, if the subsequent energy-polymerizable liquid of the single reaction mechanism is reactive with the first one in the second polymerizable material, two different segments of the intermediate cross-react (e.g., by heating or microwave irradiation) during the second polymerization and covalently bond to each other. Thus, for example, any of the materials described herein can be continuously changed to form a product having a number of different segments with different tensile strength characteristics, but this product is a single product having different segments covalently bonded to each other.

[0183] In an exemplary embodiment, the above-described photoplastic material or a combination thereof may occupy a majority of the weight of the 3D formed object and may constitute more than 50 wt%, 60 wt%, 70 wt%, 80 wt% or 90 wt% of the 3D formed object.

[0184] In an exemplary embodiment, a 3D formed object manufactured by a single reaction mechanism may have any of the above shapes and structures, for example, as an IPN, semi-IPN, simultaneous IPN, or sequential IPN, or a combination thereof, (i) a linear, semi-crosslinked, or fully crosslinked energy polymerization network, (ii) a fully or semi-crosslinked energy polymerization polymer constructed from monomers or oligomers containing energy polymerizable functional groups, or (iii) a combination thereof, or may be composed of, or may be essentially composed of, and may constitute a majority of the 3D formed object, and may constitute more than 50 wt%, 60 wt%, 70 wt%, 80 wt%, or 90 wt% of the 3D formed object.

[0185] In some embodiments, the 3D formed object may include a sol-gel composition, a hydrophobic or hydrophilic composition, a phenol resol, a cyanate ester, a polyimide, a conductive polymer, a natural product-based IPN, a sequential IPN, and a polyolefin as described above.

[0186] D. Examples of Film Materials

[0187] Any material applied to a substrate by flexography, lithography, gravure, offset, spray coating, roll coating, curtain coating, inkjet deposition, stamping, or brushing.

[0188] These films may be of various sizes. The American Society for Testing and Materials (ASTM) defines a film as a plastic sheet having a thickness of 0.25 mm or less. Sheet materials having a thickness greater than 0.25 mm are considered sheets. Sheet extrusion produces materials for use in most thermoforming operations. However, as long as it is permanently attached to a substrate, it may be considered a film even if it is more than 0.25 mm thick.

[0189] Examples of photoinitiators and photoinitiator fragments. In some embodiments, the film or 3D formed object may contain unreacted photoinitiators remaining in the film or 3D formed object. For example, in some embodiments, 0.1 or 0.2 wt% to 1, 2, or 4 wt% of a photoinitiator may remain in the film or 3D formed object, or the photoinitiator may be present in a lesser amount or only a trace amount. In some embodiments, the film or 3D formed object may contain reacted photoinitiator fragments. For example, in some embodiments, the reacted photoinitiator fragments may be residues of a first polymerization that forms an intermediate product. For example, 0.1 or 0.2 wt% to 1, 2, or 4 wt% of the reacted photoinitiator fragments may remain in the film or 3D formed object, or the reacted photoinitiator fragments may be present in a lesser amount or only a trace amount.

[0190] In an exemplary embodiment, since the system consists in part of monomers and oligomers that are polymerizable by exposure to UV light, the final product may contain residual photoinitiator molecules and photoinitiator fragments.

[0191] In some embodiments, in photopolymerization, there are chemical changes as described below. In the first step, initiation, UV light cleaves the initiator into reactive radical fragments. These reactive radical fragments then react with the monomer group "M". In the growth stage, the reactive monomer reacts with additional monomers that add to the growing polymer chain. Finally, termination occurs either by recombination or disproportionation.

[0192] Initiation

[0193] Initiator + h v → R’

[0194] R’ + M → RM’

[0195] Growth

[0196] RM’ + M n→RM’ n+1

[0197] Stop

[0198] Combine

[0199] RM’ n +’M m R→RM n M m R

[0200] Disproportionation

[0201] RM’ n +’M m R→RM n +M m R

[0202] In an exemplary embodiment, the 3D formed object generated by the process described herein may contain the following chemicals after the object is formed.

[0203] Potential unreacted photoinitiator. The photoinitiator is seldom consumed 100% in photopolymerization. For this reason, the product typically contains unreacted photoinitiator incorporated throughout the solid object.

[0204] Photoinitiator that is a byproduct covalently attached to the polymer network. In an exemplary embodiment, examples of photoinitiators can include the following.

[0205] Benzoyl chromophore-based: These systems take the following forms.

[0206]

Chem.

[0207] Wherein, "R" is any number of elements such as H, O, C, N, S. These initiators cleave to form the following.

[0208]

Chem.

[0209] In the formula, "·" represents a free radical. Any of these components initiates the polymerization and, for this purpose, is covalently bonded to the polymer network.

[0210]

Chemical formula

[0211] Examples of such initiators are shown below.

[0212]

Chemical formula

[0213] Morpholino and aminoketone. These systems take the following forms.

[0214]

Chemical formula

[0215] In the formula, "R" is any number of elements such as H, O, C, N, S. These initiators cleave to form the following.

[0216]

Chemical formula

[0217] In the formula, "·" represents a free radical. Any of these components initiates the polymerization and, for this purpose, is covalently bonded to the polymer network.

[0218]

Chemical formula

[0219] Examples of such initiators are shown below. [Chemical formula]

[0220] Benzoylphosphine oxide. These systems take the following forms.

[0221] [Chemical formula]

[0222] In the formula, "R" is any number of elements such as H, O, C, N, S. These initiators cleave to form the following.

[0223] [Chemical formula]

[0224] In the formula, "." represents a free radical. Any of these components initiates polymerization and is covalently bonded to the polymer network for this purpose.

[0225] [Chemical formula]

[0226] Examples of such initiators are shown below.

[0227] [Chemical formula]

[0228] Amine. Many photoinitiators can be used in combination with amines. Here, the photoinitiator in the excited state is used to abstract a hydrogen atom from the amine, thereby generating active radicals. These radicals can then initiate polymerization and are incorporated into the polymer network formed for this purpose. This process is shown below.

[0229] [Chemical formula]

[0230] Any of these active species can then form an active polymer chain, resulting in the following structure.

[0231]

Chemical formula

[0232] Other systems. Other types of photoinitiators that can be used for the generation of such materials and that generate fragments that are covalently attached to the polymer network being formed include triazines, ketones, peroxides, diketones, azides, azo derivatives, disulfide derivatives, disilane derivatives, thiol derivatives, diselenide derivatives, diphenylditelluride derivatives, digermanium derivatives, distannane derivatives, carbon-germanium compounds, carbon-silicon derivatives, sulfur-carbon derivatives, sulfur-silicon derivatives, peresters, Barton ester derivatives, hydroxamic acids and thiohydroxamic acids and esters, organic borates, organometallic compounds, titanocenes, chromium complexes, aluminate complexes, carbon-sulfur or sulfur-sulfur initiator compounds, oximes, aldehydes, acetals, silanes, phosphorus-containing compounds, borane complexes, thioxanthone derivatives, coumarins, anthraquinones, fluorenones, ferrocenium salts. These photoinitiators can also be oligomers or polymers when attached to larger molecules so as to reduce the mobility and risk of the initiator species, etc.

[0233] Detection. Detection of the chemical characteristics specific to the photoinitiator fragments in the polymerized polymer object can be achieved by many spectroscopic techniques. Specific techniques that are useful alone or in combination include UV-Vis spectroscopy, fluorescence spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry, atomic absorption spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy.

[0234] E. Characteristics Examples of 3D Objects

[0235] A 3D object can be formed, and the structural properties of the 3D formed object can be selected along with the properties of the material that provides a wide range of properties of the 3D object. Using the materials and methods described above in this application, a complex shape with desired material properties can be formed, and a wide range of 3D objects can be formed.

[0236] In some embodiments, the 3D formed object may be rigid, for example, having a Young's modulus (MPa) in the range of about 800 to 4500 or any range subsumed therein, a tensile strength (MPa) in the range of about 30 to 150 or any range subsumed therein, an elongation at break (%) in the range of about 1 to 100 or any range subsumed therein, and / or an Izod impact strength with a notched shape in the range of 10 to 200 J / m or any range subsumed therein. Non-limiting examples of such rigid 3D formed objects include fasteners; electronic device housings; gears, propellers, and impellers; wheels, machinery housings; tools, and other rigid 3D objects.

[0237] In some embodiments, the 3D formed object may be semi-rigid, for example, having a Young's modulus (MPa) in the range of about 300 to 3500 or any range subsumed therein, a tensile strength (MPa) in the range of about 20 to 90 or any range subsumed therein, an elongation at break (%) in the range of about 20 to 300 or 600 or any range subsumed therein, and / or an Izod impact strength with a notched shape in the range of about 30 to 400 J / m or any range subsumed therein. Non-limiting examples of such semi-rigid 3D formed objects include structural elements; hinges such as living hinges; boat and ship hulls and decks; wheels; bottles, flasks, and other containers; pipes, liquid tubes, and connectors, and other semi-rigid 3D objects.

[0238] In some embodiments, the 3D formed object may be an elastomer, for example, having a Young's modulus (MPa) in the range of about 0.25 to 300 or any range subsumed therein, a tensile strength (MPa) in the range of about 0.5 to 30 or any range subsumed therein, an elongation at break (%) in the range of about 50 to 1500 or any range subsumed therein, and / or a tear strength in the range of about 10 to 200 kN / m or any range subsumed therein. Non-limiting examples of such 3D formed elastomeric objects include shoe soles, heels, insoles, midsoles; bushings and gaskets; components of soft robotics; cushions; electronic device housings, and other 3D objects of elastomers.

Example

[0239] In Examples 1 - 3 shown below, exemplary comparative materials for the formation of products having various different tensile properties ranging from semi-rigid to flexible from such elastomers as described above are given, and all tensile data are measured according to ASTM D638, Type 4 specimens. These examples are shown in FIGS. 1A and 1B together with all known commercially available single-reaction mechanism energy polymerizable materials.

[0240]

Table 1

[0241]

Table 2

[0242]

Table 3

[0243] A further example of generating a photoplastic using a single-reaction mechanism energy polymerizable liquid.

[0244]

Table 4

[0245]

Table 5

[0246]

Table 6

[0247]

Table 7

[0248]

Table 8

[0249] 1-Vinyl-2-pyrrolidone and N-vinylcaprolactam are shown above by way of example, but many other monomers can be used to obtain desirable results. Without limitation, these include N-vinylformamide, acryloylmorpholine or vinyl cinnamate.

[0250] <Example #5 Calculation of molar binding ratio>

[0251]

Number

[0252] First, determine the number of moles of each raw material in a given mass or volume of the material.

[0253]

Number

[0254] By multiplying the number of moles of each component by its functionality, the number of moles of each bond type in the composition is given.

[0255]

Mathematics

[0256] The molar bond ratio is given by dividing the total number of moles of bonds contributed by monofunctional molecular species by the total number of moles of bonds contributed by polyfunctional molecular species.

[0257]

Mathematics

[0258] Calculation of the number of molar bonds. Exemplary calculations of the molar bond ratios in Examples #4 to #8 are shown below.

[0259]

Table 9

[0260]

Table 10

[0261]

Table 11

[0262]

Table 12

[0263]

Table 13

[0264] In Example #8, the molar bond ratio between the monofunctional species and the polyfunctional species is at least 1000% (molar bond ratio: monofunctional species: polyfunctional species = 10:1 or more).

[0265] In Example #7, the molar binding ratio of the monofunctional species to the polyfunctional species is at least 3000% (molar binding ratio: monofunctional species:polyfunctional species = 30:1 or more).

[0266] Molar binding ratio. The molar binding ratio is the ratio of the number of functional groups (sites where reaction / polymerization is possible) contributed by a single different molecular species to the number of functional groups contributed by different molecular species in a closed system. This is the relative ratio between different molecules, taking into account the relative weight %, molecular weight, and functionality (number of functional groups per molecule) in the composition.

[0267] Molar binding ratio. According to one particularly useful definition of the molar binding ratio used to characterize a photoplastic material, the number of functional groups contributing to the composition is compared: the total of the monofunctional reaction species and the total of the polyfunctional reaction species. The molar binding ratio is the ratio of the number of functional groups (sites where reaction / polymerization is possible) contributed by the monofunctional species to the number of functional groups contributed by the polyfunctional species in a closed system. This is the relative ratio between different monofunctional and polyfunctional species, taking into account the relative weight %, molecular weight, and functionality (number of functional groups per molecule) in the composition. A monofunctional species is defined as a molecule containing one functional group that forms a covalent bond in a fully polymerized material. A polyfunctional species is defined as a molecule containing more than one functional group that forms a covalent bond in a fully polymerized material. For a given system, the molar binding ratio is calculated only for the functional groups that will become covalent bonds when the material polymerizes. For example, in a 100% free radical polymerization reaction, if a monomer contains one acrylate group and one epoxide group and only the acrylate group reacts, then that monomer is considered monofunctional. Considering the same molecule, if the material is polymerized using both free radical and cationic polymerization methods, then both the acrylate group and the epoxide group form covalent bonds in the final polymer structure, so that monomer is considered to have two functional groups and is therefore considered polyfunctional in that system. The molar binding ratio is also one way to examine the crosslink density of a polymer material.

[0268] The crosslink density of the polymer material greatly affects the final physical and mechanical properties of the polymer material. Generally, a highly crosslinked polymer exhibits a more brittle mechanical behavior than a polymer with a lower crosslink density. The crosslink density is a useful physical property that can be used as an alternative method for characterizing materials as photoplastics.

[0269] Manufacturing of the product may be stopped or interrupted one or more times to change the energy polymerizable liquid of a single reaction mechanism. In an exemplary embodiment, the 3D formed object includes a number of materials having different tensile strengths. When a fault line or fault plane is formed in the intermediate due to the interruption, if the energy polymerizable liquid of the next single reaction mechanism is reactive with the first one in its second polymerizable material, then two different segments of the intermediate cross-react (e.g., by heat or microwave irradiation) and covalently bond to each other during the second polymerization. Thus, for example, by sequentially changing any of the materials described herein, a single product having different segments covalently bonded to each other can be formed, but a product having a number of different segments with different tensile strengths can be formed. In some embodiments, the 3D object can be formed from a plurality of regions having different materials and properties. For example, the 3D formed object includes one or more regions formed from a first material or a first group of one or more materials having a tensile strength (MPa) in the range of about 30 to 100 or any range subsumed herein, and / or a second material or a second group of one or more materials having a tensile strength (MPa) in the range of about 20 to 70 or any range subsumed herein, and / or a third material or a third group of one or more materials having a tensile strength (MPa) in the range of about 0.5 to 30 or any range subsumed herein, or any combination thereof. For example, the 3D object may have 1 to 10 or more (or any range subsumed herein) different regions having various tensile strengths selected from any of the above materials and tensile strengths. For example, a hinge may be formed. By sequentially changing the energy polymerizable liquid of a single reaction mechanism during the formation of the 3D intermediate, the hinge may include a rigid segment, a second elastic segment coupled thereto, and a third rigid segment coupled thereto. A shock absorber or vibration damper may be formed in a similar manner, and the second segment may be either elastic or semi-rigid. A single rigid funnel and a flexible hose assembly can be formed in a similar manner.

[0270] In some embodiments, the use of an energy polymerizable resin of a single reaction mechanism can enable the adjustment of mechanical properties even within the same photoplastic material / object (see Fig. 11). This can be achieved by changing the energy polymerization of the photoplastic material and changing the reaction activity or reaction mechanism of the system. For example, by changing light irradiation, light energy, light wavelength, or using an electron beam, the polymerization reaction mechanism and polymerization reaction rate can be changed. This is to some extent due to the different polymerizable functional groups contained in the resin and the reactivity or non-reactivity of these same or different functional groups with each other, which can change the molecular weight and network of the final polymer. Also, this is to some extent due to the same kind of initiation that can polymerize all the functional groups in the photoplastic material. By controlling these process parameters, different mechanical properties can be achieved by constructing different chemical structures: full IPN, semi-IPN, pseudo-IPN, dual network, and random copolymer, each having different mechanical properties in turn, using one resin. In addition, by selecting specific stoichiometric ratios of the components, the ability to achieve different mechanical properties can be optimized. 4 mJ / cm per layer 2 , specimens 1, 2, 4, and 5 are 3D printed to a layer thickness of 100 μm using a 395 nm LED. 25 mJ / cm per layer 2 , specimens 6 and 7 are 3D printed to a layer thickness of 100 μm using a 395 nm LED. All specimens are post-cured with a broad-spectrum mercury lamp at 5 J / cm 2 . Differences in mechanical properties are seen, and the Young's modulus is 10 MPa to 70 MPa under different printing conditions. This represents a seven-fold difference in Young's modulus. Furthermore, the elongation seems to differ by about 10 - 20%. Finally, the Shore D of the first group of samples is ~15, while the Shore D of the second group of samples is ~40. All specimens have the same composition as in Example 8 above.

[0271] Furthermore, various polymer networks, molecular weights, liquid-solid, solid-solid solubility, or phase separation of the above structure can be adjusted and controlled by the above process parameters. Therefore, it is possible to greatly change the mechanical properties of one resin in either pixel units in a film or voxel units in an object. Specifically, in additive manufacturing, VAT polymerization generally occurs by a laser of a projector or a screen light source. These and each light source of the next generation can be controlled to emit lower wattage or lower energy in pixel units. Therefore, three-dimensional control of voxel polymerization is possible, and an object having various mechanical properties in three-dimensional space can be produced. As a result, the performance of 3D objects of all additive manufacturing machines is greatly extended.

[0272] The main parts of SLA and DLP 3D printing methods use bottom-up printing technology. A similarly useful method for 3D printing is top-down vat printing. Bottom-up and top-down printing each have characteristic advantages and disadvantages. The quality and success rate of building parts by bottom-up 3D printing are greatly affected by and limited by the green strength of the parts being printed. Green strength includes the strength, rigidity, and dimensional stability of the green-state 3D printed parts in the 3D printer before any additional post-curing method that brings the reaction components to a high conversion rate. When the green strength or mechanical integrity of the 3D printed object overcomes the potential deformation effects due to gravity, unwanted adhesion to the resin tank bottom, and other accumulations in the bottom-up 3D printing system, the 3D printed object tends to be printed with high quality and stability. The effect of green strength on print quality in a bottom-up system can be greatly affected by the shape of the part being 3D printed and the printing conditions. Top-down vat printing technology reduces the influence of some properties such as green strength on the success of the printing process. Top-down vat printing technology keeps the part being printed in the vat of the constituent liquid material during printing, which acts as a buffer against gravity on the printed part. For this reason, the part being printed can exhibit a "floating" behavior due to the equivalent density of the part being printed and the surrounding fluid. The floating performance of the part being printed in the resin layer reduces the resultant force applied from gravity to the part during printing, especially when the green strength is low and / or the adhesion of the intermediate layer is low in the green state. Also, the viscosity of the top-down vat resin may apply an unwanted force to the green part during printing, resulting in deformation or the introduction of defects. To reduce the risk of deformation due to solid-liquid interaction, a resin with a low viscosity of 750 cP or less is desirable. One potential advantage of photoplastics in top-down printing technology is that they can be formulated to have a low viscosity. Photoplastic materials can have a low green strength, suggesting that top-down vat printing is a more appropriate method than bottom-up printing.

[0273] F. Additional Examples of 3D Objects

[0274] Using the above methods, structures, materials, compositions, and properties, an essentially infinite number of products can be 3D printed. Without limitation, for example, medical devices and implantable medical devices such as stents, drug delivery sustained release formulations, catheters, bladders, breast implants, testicular implants, chest implants, eye implants, contact lenses, dental aligners, microfluidics, seals, shrouds, and other applications, functional structures, microneedle arrays, fibers, rods, waveguides, micro-mechanical devices, microfluidic devices, fasteners, electronic device housings, gears, propellers, impellers, wheels, mechanical device housings, tools, structural members, hinges including living hinges, boats, ship hulls and decks, wheels, bottles, jars, and other containers, pipes, liquid tubes and connectors, shoe soles, heels, insoles, and midsoles, bushings, O-rings and gaskets, shock absorbers, funnel / hose assemblies, cushions, electronic device housings, shin guards, athletic cups, knee pads, elbow pads, foam liners, padding or inserts, helmets, helmet straps, headgear, shoe grips, gloves, other wearable or sports equipment, brushes, combs, rings, jewelry, buttons, snaps, fasteners, watch bands or watch housings, mobile phone or tablet casings or housings, computer keyboards or keyboard buttons or components, remote control buttons or components, automotive dashboard components, buttons, dials, body parts, panels, other automotive, aircraft or hull parts, cooking utensils, heat-resistant dishes, kitchenware, steamers, and many other 3D objects. The use of energy polymerization with a single reaction mechanism that can fix the shape while being able to impart elasticity or desired properties by printing with additional energy polymerization enables the world of useful 3D products that can be formed to be greatly expanded in order to have the performance of imparting various shapes and properties (such as elasticity). Any of the above structures, materials, and properties can be combined to form 3D objects such as the above 3D formed objects.These are merely examples, and many other 3D objects can be formed by the methods and materials described herein.

[0275] IV. Another Method and Apparatus

[0276] The present invention is preferably implemented by stereolithography, material jetting, or inkjet printing, as described in detail above and in more detail below. However, in some embodiments, other methods and apparatuses for bottom-up or top-down 3D manufacturing, such as layer-by-layer manufacturing, may be used. Such methods and apparatuses include, but are not limited to, those described in U.S. Patent No. 5,236,637, U.S. Patent No. 5,391,072, 5,529,473, U.S. Patent No. 7,438,846, U.S. Patent No. 7,892,474, U.S. Patent No. 8,110,135, U.S. Patent Application Publication Nos. 2013 / 0292862 and 2013 / 029521, and International Publication No. WO2015 / 164234, the entire contents of which are incorporated herein by reference.

[0277] The advantages of photoplastic materials are numerous and can be summarized as follows. The ability to achieve the design of thermoplastic resin properties and performance with energy-polymerizable materials. Manufacturing techniques in cases where the use of thermoplastic resins is severely restricted due to the need to dissolve and deposit / mold thermoplastic resins into the desired shape. Manufacturing techniques using energy-polymerizable materials have few restrictions as long as there is an energy source available for polymerization. These techniques include inkjet printing, 3D printing, molding, laminating, and the like.

[0278] The description of the present disclosure is illustrative in nature, and modifications that do not depart from the spirit of the present disclosure are intended to be within the scope of the present disclosure. Such modifications should not be regarded as a departure from the spirit and scope of the present disclosure.

Claims

1. A reactive oligomer, which is at least one of (i) a multifunctional methacrylate oligomer and (ii) a multifunctional acrylate oligomer; and a reactive monofunctional monomer which is at least one of (i) a monofunctional N-vinyl monomer, (ii) a monofunctional vinyl ether monomer, (iii) a monofunctional vinyl ester monomer, (iv) a monofunctional vinyl amide monomer, (v) a styrene monomer, (vi) a monofunctional acrylamide monomer, (vii) a monofunctional (meth)acrylate monomer, (viii) a cyanoacrylate monomer, (ix) a monofunctional vinyl carbonate monomer, (x) a monofunctional acryloyl monomer, and (xi) a monofunctional vinyl carbamate monomer; A free radical polymerizable liquid for forming three-dimensional objects, comprising: a molar bond ratio of reactive ethylenically unsaturated groups of the reactive monofunctional species to reactive ethylenically unsaturated groups of the reactive multifunctional species of at least 10:1; The free radical polymerizable liquid for forming three-dimensional objects is an energy polymerizable liquid that cures by a single reaction mechanism to form a photoplastic material.

2. 10. The polymerizable liquid of claim 1, further comprising about 0.01% to about 15% by weight of a photoinitiator.

3. 2) tensile strength (MPa) = 4500 / (elongation - 25) - 5 (when elongation is about 95% to about 500%).

4. 2) tensile strength (MPa) = 2000 / (elongation + 10) - 3 (when elongation is about 105% to about 550%); 3) tensile strength (MPa) = 0.5 (when elongation is more than about 550%).

5. 10. The polymerizable liquid of claim 1, wherein the polymerized material assumes predetermined mechanical properties without the input of heat.

6. 10. The polymerizable liquid of claim 1, further comprising at least one of a non-reactive light absorbing pigment, a filler, a polymerization inhibitor, and a polymerization catalyst in an amount of about 0.001% to about 10% by weight.

7. 10. The polymerizable liquid of claim 1, further comprising a non-reactive light absorbing pigment in an amount of about 0.001% to about 10% by weight, and a filler.

8. 10. The polymerizable liquid of claim 1, wherein said oligomer and said monomer react by the same polymerization mechanism but have different reaction rates.

9. 10. The polymerizable liquid of claim 1, wherein the solubility of the monomer and oligomer changes during polymerization, thereby favoring homopolymerization of either the monomer or oligomeric species.

10. 10. The polymerizable liquid of claim 1, wherein upon polymerization a material having multiple glass transition temperatures is produced.

11. 10. The polymerizable liquid of claim 1, wherein the polymerization produces a material having two different glass transition temperatures that differ by at least 60 degrees Celsius.

12. 10. The polymerizable liquid of claim 1, wherein the molar combination ratio of reactive ethylenically unsaturated groups of the reactive monofunctional species to reactive ethylenically unsaturated groups of the reactive multifunctional species is at least 25:

1.

13. 13. The polymerizable liquid of claim 12, wherein the molar combination ratio of reactive ethylenically unsaturated groups of the reactive monofunctional species to reactive ethylenically unsaturated groups of the reactive multifunctional species is at least 30:

1.

14. The polymerizable liquid of claim 1 which forms a print on a substrate.

15. 10. The polymerizable liquid of claim 1 that is cured to form a film or three-dimensional object by stereolithography (SLA), digital light projection (DLP), material jetting, or inkjet printing.

16. 16. The polymerizable liquid of claim 15, wherein the inkjet film or 3D printed layer has a thickness greater than about 30 μm.

17. 10. The polymerizable liquid of claim 1, having mechanical properties upon curing that are tunable by varying the energy polymerization conditions.

18. 10. The polymerizable liquid of claim 1 which is non-toxic.

19. 10. The polymerizable liquid of claim 1 , wherein the oligomer has a molecular weight greater than about 1500 g / mole.

20. 20. The polymerizable liquid of claim 19, wherein the oligomer has a molecular weight greater than about 4000 g / mole.

21. 2. The polymerizable liquid of claim 1, wherein the monomer is a monofunctional N-vinyl, vinyl ester, or acryloyl selected from the group consisting of N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylformamide, acryloylmorpholine, or vinylcinnamate.

22. a reactive oligomer which is at least one of: (i) an N-vinyl oligomer having one or more functionalities, (ii) a vinyl ether oligomer having one or more functionalities, (iii) a vinyl ester oligomer having one or more functionalities, (iv) a vinyl amide oligomer having one or more functionalities, (v) a styrene oligomer, (vi) an acrylamide oligomer having one or more functionalities, (vii) a (meth)acrylate oligomer having one or more functionalities that has a different reaction rate than the (meth)acrylate monomer having one or more functionalities, (viii) a cyanoacrylate oligomer, (ix) a vinyl carbonate oligomer having one or more functionalities, and (x) an acryloyl oligomer having one or more functionalities, (xi) a vinyl carbamate oligomer having one or more functionalities; (i) one or more functional N-vinyl monomers, (ii) one or more functional vinyl ether monomers, (iii) one or more functional vinyl ester monomers, (iv) one or more functional vinyl amide monomers, (v) styrene monomers, (vi) one or more functional acrylamide monomers, (vii) one or more functional (meth)acrylate monomers having a different reaction rate than the one or more functional (meth)acrylate oligomers, (viii) cyanoacrylate monomers, (ix) one or more functional vinyl carbonate monomers, (x) one or more functional acryloyl monomers, and (xi) one or more functional vinyl carbamate monomers; 1. A method of forming a polymerizable liquid comprising mixing together A method for forming a polymerizable liquid, wherein the polymerizable liquid is an energy polymerizable liquid capable of being cured by a single reaction mechanism to form a photoplastic material.

23. 23. The method of claim 22, wherein the polymerizable liquid is cured to produce a film or three dimensional object by stereolithography (SLA), digital light / projection (DLP), material jetting (inkjet printing in 3D), or inkjet printing.

24. 24. The method of claim 23, wherein the film or three-dimensional object is a medical device, or a part of footwear, or a part of soft robotics.

25. 24. The method of claim 23, wherein the film or three-dimensional object is a hydrogel.

26. 22. The method of claim 21, wherein pixel or voxel polymerization is used to obtain different physical properties by varying the energy polymerization conditions.

27. 23. The method of claim 22, further comprising irradiating the polymerizable liquid with patterned radiation.

28. The method of claim 22 further comprising the step of mixing a photoinitiator in an amount of about 0.01% to about 15% by weight.

29. 1. An article comprising an energy-polymerizable liquid that hardens by a single reaction mechanism to form a photoplastic material, comprising: The energetically polymerizable liquid is a reactive oligomer which is at least one of: (i) an N-vinyl oligomer having one or more functionalities, (ii) a vinyl ether oligomer having one or more functionalities, (iii) a vinyl ester oligomer having one or more functionalities, (iv) a vinyl amide oligomer having one or more functionalities, (v) a styrene oligomer, (vi) an acrylamide oligomer having one or more functionalities, (vii) a (meth)acrylate oligomer having one or more functionalities that has a different reaction rate than the (meth)acrylate monomer having one or more functionalities, (viii) a cyanoacrylate oligomer, (ix) a vinyl carbonate oligomer having one or more functionalities, and (x) an acryloyl oligomer having one or more functionalities, (xi) a vinyl carbamate oligomer having one or more functionalities; (i) one or more functional N-vinyl monomers, (ii) one or more functional vinyl ether monomers, (iii) one or more functional vinyl ester monomers, (iv) one or more functional vinyl amide monomers, (v) styrene monomers, (vi) one or more functional acrylamide monomers, (vii) one or more functional (meth)acrylate monomers having a different reaction rate than the one or more functional (meth)acrylate oligomers, (viii) cyanoacrylate monomers, (ix) one or more functional vinyl carbonate monomers, (x) one or more functional acryloyl monomers, and (xi) one or more functional vinyl carbamate monomers; An article made from

30. 30. The article of claim 29, wherein the polymerizable liquid upon curing has mechanical properties that are tunable by varying the energy polymerization conditions.

Images