Hydrogel for 3D printing with high resolution

Abstract

In one aspect, a modeling material intended for use with a three-dimensional (3D) printing system is described herein. In some embodiments, the modeling material described in the present invention comprises an acrylate component, a photoinitiator component, a non-curable absorbent component, and water. The photoinitiator component of the modeling material is operable to initiate the curing of the acrylate component and / or any other curable material that may optionally be present when the photoinitiator component is exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ. The modeling material has a penetration depth (D p ) and a critical energy (E c ) at the wavelength λ. In some embodiments, D p is greater than 200 μm and less than 300 μm, and E c is 3 - 12 mj / cm 2 . In other embodiments, D p is greater than 10 μm and less than 50 μm, and E c is 5 - 40 mj / cm 2 .

Description

Cross - reference to related applications

[0001] This application claims priority under 35 U.S.C.§119 to U.S. Provisional Patent Application No. 63 / 389,459, filed on July 15, 2022, and U.S. Provisional Patent Application No. 63 / 408,554, filed on September 21, 2022, which are hereby incorporated by reference in their entireties respectively into this specification.

Technical Field

[0002] The present invention relates to a method of three - dimensional (3D) printing and a shaping material for use in a 3D printing system, and more particularly, to a shaping material for 3D printing a hydrogel object at a desired resolution.

Background Art

[0003] A layered manufacturing system or 3D printer uses a shaping material, which may also be referred to as an ink or a polymerizable liquid in some cases, to form various objects, articles, or parts according to a computer - generated file. In some examples, the shaping material is solid at ambient temperature and changes to a liquid at a high ejection temperature. In other examples, the shaping material is liquid at ambient temperature. The shaping material can be formed into a 3D object in various ways, for example, by ejecting the shaping material onto a substrate or depositing it in other ways. The shaping material can also be selectively cured, solidified, or otherwise changed during the shaping process. For example, some 3D printers form 3D articles from reservoirs, vats, or containers of fluid shaping material or powder shaping material. In some cases, a binder material, or a laser or other energy source is used to selectively solidify or consolidate layers of the shaping material in a step - by - step manner to provide a 3D article.

[0004] In a 3D printing system that uses curing radiation, the curing radiation can penetrate the shaping material deeper than intended or desired. More specifically, the radiation can penetrate deeper than the portion of the shaping material that is intended to be cured or solidified as part of the printed article structure. Such an undesirable excessive curing depth can be referred to as "print through" or "print through depth". The occurrence of print through can be problematic for several reasons. First, print through can cause an undesirable "gummy" layer of partially cured shaping material to form on certain surfaces (such as one or more "down surfaces") of the additive manufacturing system. Second, print through wastes the shaping material. Third, even if it is the least problematic, considering that print through generally causes a certain layer or other layers of the printed article to be different from what is intended (e.g., different from the instructions of the corresponding computer-aided design or "CAD" file), corrections are required in the shaping process. For example, such a deviation can be considered or corrected when creating or selecting the specific CAD file used to form the printed article. However, such corrections may not be accurate and can lead to part distortion and a general loss of print accuracy. Finally, when print through occurs, generally more unknown or inaccurate values are introduced into the shaping process. Moreover, the greater the print through, the greater the introduction of errors and / or uncertainties. Such uncertainties are of course undesirable in the additive manufacturing process. Summary of the Invention Problems to be Solved by the Invention

[0005] There is a need for improved methods, and more particularly for improved shaping materials for 3D printing having improved printing characteristics, including but not limited to those related to the penetration depth of light or printed-through characteristics. There is a particular need for improved shaping materials that can be used to form biomaterials such as hydrogel implants that serve as scaffolds for tissue regeneration and / or various cell therapies, including the desired printing resolution.

Means for Solving the Problems

[0006] In one aspect, a shaping material for use in a 3D printer is described herein, which in some embodiments can provide one or more advantages over conventional shaping materials, particularly radiation-curable shaping materials for use in stereolithography. For the purposes of reference herein in the context of stereolithography, the term "shaping material" can be used interchangeably with the term "ink" or "polymerizable liquid". In some embodiments, the shaping materials described herein can be used to print hydrogel articles with improved accuracy and / or precision. The shaping materials described herein can also, in some examples, provide improved resolution without sacrificing the speed of the stereolithography process, without sacrificing the energy efficiency of the stereolithography process, and / or without sacrificing the desired mechanical properties of the printed article. Further, the shaping materials described herein can be used in a variety of different 3D printers or stereolithography systems, such as systems based on stereolithography (SLA), digital light processing (DLP), and multi-jet printing (MJP).

[0007] In some embodiments, the shaping material for use in the 3D printing system described herein includes an acrylate component, a photoinitiator component, a non-curable absorbent component, and water. Further, optionally, in addition to the acrylate component, one or more additional curable materials may be optionally present in the shaping material. In some embodiments, additional non-curable components may be present. Of course, it should be understood that the total amount or sum of the acrylate component, photoinitiator component, non-curable absorbent component, additional curable material component (if present), additional non-curable material component (if present), and water is equal to 100 mass percent (mass %). Further, the additional non-curable component may include a colorant, an inhibitor, and / or a stabilizer.

[0008] Further, the photoinitiator component of the shaping material is operable to initiate the curing of the acrylate component (and / or, optionally, the curing of any other curable material that may be present) when the photoinitiator component is exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ. Further, the shaping material has a penetration depth (D p ) and a critical energy (E c ) at the wavelength λ. The terms D p and E c are described in more detail below. In some preferred embodiments, the D p of the shaping material is greater than 200 μm and less than 300 μm. Further, in some such cases, E c is 3 - 12 mJ / cm 2 . Alternatively, in other preferred embodiments, D p is greater than 10 μm and less than 50 μm (e.g., 15 - 25 μm). Further, in some such cases, E c is 5 - 40 mJ / cm 2 or 10 - 40 mJ / cm 2 . In still other preferred embodiments, D p is greater than 25 μm and less than 50 μm. Further, in some such cases, E c is 5 - 30 mJ / cm 2It is. In some examples, a shaping material having such properties can provide various advantages, including improved resolution and / or printing speed.

[0009] As will be further described below, the amount of photoinitiator and / or non-curable absorber material included in the shaping material, in combination with the other components of the shaping material, can be selected to obtain the desired D p E c and / or D PT values (the terms D p E c and D PT are further described below). In some embodiments, for example, the shaping materials described herein include a photoinitiator component of up to 5 wt%, up to 3 wt%, or up to 2 wt% and a non-curable absorber component of up to 2 wt%, up to 1.5 wt%, or up to 1 wt% based on the total weight of the shaping material. Further, in some examples, the total absorbance of the non-curable absorber component at wavelength λ is about 0.1 to 10 times the total absorbance of the photoinitiator component at wavelength λ. Further, in some examples, both the non-curable absorber component and the photoinitiator component of the shaping materials described herein have an absorption peak within 30 nm of wavelength λ.

[0010] In another aspect, a method of forming a 3D article by additive manufacturing is described herein. In some embodiments, such a method includes providing a shaping material as described herein and selectively curing a portion of the shaping material using incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength at wavelength λ. For example, in some examples, the shaping material has a D p greater than 200 μm and less than 300 μm and an E 2 of 3 to 12 mJ / cm c . In other embodiments, D p is greater than 10 μm and less than 50 μm (e.g., 15 - 25 μm) and E c is 5 to 40 mJ / cm 2 or 10 to 40 mJ / cm 2 . In yet other embodiments, D pis greater than 25 μm and less than 50 μm, and E c is 5 - 30 mJ / cm 2 is. Further, in some embodiments of the methods described herein, the shaping material is selectively cured according to preselected computer-aided design (CAD) parameters, and D p corresponds to the voxel depth of the CAD parameters.

[0011] Further, in some examples, the step of providing the shaping material includes selectively depositing a layer of the shaping material in a fluid state on a substrate to form a three-dimensional article. Alternatively, in other embodiments, the step of providing the shaping material includes holding the shaping material in a fluid state within a container, and the step of selectively curing a portion of the shaping material includes selectively applying curing radiation to the shaping material within the container to solidify or consolidate at least a portion of a first fluid layer of the shaping material, thereby forming a first solidified or consolidated layer that defines a first cross-section of the article. Such a method may further include raising or lowering the first solidified layer to provide a second fluid layer of the shaping material on the surface of the fluid shaping material within the container, and selectively applying curing radiation to the shaping material within the container to solidify at least a portion of the second fluid layer of the shaping material, thereby forming a second solidified layer that defines a second cross-section of the article, wherein the first cross-section and the second cross-section are joined to each other in the z-direction. As will be further described below, the foregoing steps may be repeated any desired number of times necessary to complete the 3D article.

[0012] In yet another aspect, a printed 3D article is described herein. Such a printed 3D article can be formed from any shaping material and using any of the methods described herein. Such a printed 3D article may, in some cases, have superior accuracy compared to some other 3D articles.

[0013] These and other embodiments are described in more detail in the following detailed description.

DETAILED DESCRIPTION OF THE INVENTION

[0014] The embodiments described in this specification can be more easily understood by referring to the following detailed description and examples. However, the elements, devices, and methods described in this specification are not limited to the specific embodiments presented in the detailed description and examples. It should be recognized that these embodiments are merely illustrative of the principles of the present disclosure. Without departing from the spirit and scope of the present disclosure, numerous modifications and adaptations will be readily apparent to those skilled in the art.

[0015] Furthermore, it should be understood that all ranges disclosed in this specification encompass all sub-ranges contained therein. For example, the described range "1.0 to 10.0" should be interpreted to include any and all sub-ranges that start at a minimum value of 1.0 or greater and end at a maximum value of 10.0 or less, such as 1.0 to 5.3, 1 to 4, 3 to 7, 4.7 to 10.0, 3.6 to 7.9, or 5 to 8.

[0016] Also, all ranges disclosed in this specification should be considered to include their endpoints, unless specifically stated otherwise. For example, ranges such as "between 5 and 10", "from 5 to 10", or "5 - 10" should generally be considered to include the endpoints 5 and 10.

[0017] Furthermore, when the term "maximum" is used in relation to an amount or quantity, that amount should be understood to be at least a detectable amount or quantity (i.e., this amount is a non-zero amount). For example, a substance present in an amount "up to a maximum" of a particular amount can be present in an amount from a detectable (or non-zero) amount up to that particular amount.

[0018] It should also be understood that the articles "a" or "an" refer to "at least one", unless the context of a particular use requires otherwise.

[0019] Terms such as "3D printing system", "3D printer", "printing", etc. generally describe various solid freeform manufacturing techniques for creating 3D articles or objects by stereolithography, selective deposition, jetting, fused deposition modeling, multi-jet modeling, and other additive manufacturing techniques now known or that may become known in the art for manufacturing 3D objects using a shaping material.

[0020] I. Shaping Materials for 3D Printing In one aspect, shaping materials for use in a 3D printer are described herein. In some embodiments, the shaping materials described herein include an acrylate component, a photoinitiator component, a non-curable absorbent component, and water. Other components such as one or more additional curable materials or one or more additional non-curable materials may also be included in the shaping materials described herein. Further, the photoinitiator component is operable to initiate the curing of the acrylate component (and, optionally, any other curable materials present) when the photoinitiator component is exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ. That is, the photoinitiator component is a photoinitiator that cures the acrylate component and / or other curable materials present in the shaping material. Further, the shaping material has a penetration depth (D p ) and a critical energy (E c ) at wavelength λ.

[0021] The shaping materials described herein may also have a print-through depth (D p ) and / or E c corresponding to D PT ). As will be understood by those skilled in the art, D PTrefers to subtracting the layer thickness from the total hardening depth, where "total hardening depth" refers to the depth at which any hardening or polymerization of the shaping material occurs in response to the incident hardening radiation. "Layer thickness" refers to the thickness of the region where "complete" hardening or polymerization of the shaping material occurs in response to the incident hardening radiation. Such "complete" hardening refers to the maximum hardening brought about by the incident radiation. For example, "complete" hardening corresponds to 80 - 100% hardening, 80 - 95% hardening, 80 - 90% hardening, 85 - 100% hardening, 85 - 99% hardening, 85 - 95% hardening, 90 - 100% hardening, 90 - 99% hardening, or 90 - 95% hardening, where the percentage (%) is based on the total number of available curable portions.

[0022] The degree or percentage of hardening (or polymerization) can be determined using any protocol or method that does not conflict with the technical objectives of the present disclosure, for example, by specifying the percentage of monomers (or curable portions) incorporated into the polymer network (e.g., based on the molecular weight of the polymer compared to the molecular weight of the monomer, or based on the total polymer mass compared to the theoretical maximum value of the total polymer mass), or by specifying the amount of unincorporated monomers or unreacted curable portions. When multiple methods are used to determine the degree of hardening or polymerization, the results of these methods can be averaged to obtain the percentages described herein. It should be further understood that the degree of hardening or polymerization described herein is different from the "degree of polymerization" defined as the number of repeating units in a polymer molecule.

[0023] Parameter or property D p , E c , and D PTIt is to be understood that these are the structural parameters or properties of the shaping material described herein. Discussions of the "structural" or "compositional" nature of these values can be found, for example, in Chapter 4 of Paul F. Jacobs, Rapid Prototyping & Manufacturing: Fundamentals of Stereolithography (Society of Manufacturing Engineers, McGraw-Hill, 1992) (1st Edition) (hereinafter referred to as "Jacobs" in this specification). As will be understood by those skilled in the art, the value D p is the penetration depth of the shaping material defined as the depth of the shaping material that results in a reduction in irradiance to a level equal to 1 / e of the surface irradiance, where e is the base of the natural logarithm (equal to 2.7182818...). As described on page 86 of Jacobs, E c is the critical energy that is the energy required to obtain the gelation point of the shaping material. Further, as further explained in Jacobs (pages 86-89), the metric E c is equal to the intercept of the working curve corresponding to a semi-logarithmic plot of the cured depth on the vertical axis and the logarithm of the maximum radiation exposure on the horizontal axis. E c is specified at the intercept where the cured depth is zero. See also "Fundamentals of Stereolithography" by Dr. Paul F. Jacobs in the Proceedings of the 1992 International Solid Freeform Fabrication Symposium held in Austin, Texas, USA (pages 196-211).

[0024] The amount of the photoinitiator component and / or non-curable absorber component contained in the shaping material described herein, in combination with the other components of the shaping material, provides the desired D p , E c , and / or D PTIt is further desired to be understood that it can be selected to obtain a value. However, in some examples, the desired D obtained by a specific combination of a photoinitiator component and / or a non-curable absorbent component p , E c , and / or D PT values can be understood to be able to change the type and / or amount of other components of the shaping material, such as acrylate components, without substantially changing the value. For example, in some examples, changing the type and / or amount of the acrylate component (within the ranges of the types and amounts currently disclosed) changes the D of the shaping material p , E c , and / or D PT value by 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less. More specifically, D p , E c , and / or D PT such minimal changes in value can be obtained when components of the shaping material other than the photoinitiator component and the non-curable absorbent component (such as acrylate components) do not absorb (or refract or reflect) light of wavelength λ, or absorb (or refract or reflect) only minimally. Alternatively, D p , E c , and / or D PT such minimal changes in value can also be obtained when components of the shaping material other than the photoinitiator component and the non-curable absorbent component (such as acrylate components) absorb (or refract or reflect) light of wavelength λ to approximately the same extent, regardless of which exact component species or amounts (within the range of the species and amount options currently disclosed) are selected. That is, in the context of the compositions and methods described herein, the components of the shaping material described herein other than the photoinitiator component and the non-curable absorbent component can be essentially (and generally) optically "spectator" species at wavelength λ, and thus these "spectator" species are the D of the entire shaping material p , E c , and / or D PTIt does not substantially affect the value. Thus, as will be described in more detail below, the acrylate component or other curable components can be varied as desired for each shaping material (with respect to the exact species and / or amounts) so that in some examples the exact species and / or amounts used for each shaping material have similar light absorption profiles and / or refractive indices.

[0025] Furthermore, in some cases, the shaping materials described herein have a D at wavelength λ corresponding to the desired optical and chemical properties or performance metrics of the shaping material. p value and an E c value. It is also possible to define a particular "regime" of shaping materials that is particularly desirable for a particular end use of the shaping material, having a particular D p and E c value or range of values. For example, in some embodiments, the D of the shaping material or "family" of shaping materials is selected based on the output and / or wavelength of the curing radiation source desired to be used with the shaping material, based on the desired voxel size or voxel depth of the CAD profile desired to be used with the shaping material, based on the desired functional resolution of the printed article formed from the shaping material, and / or based on the desired printing speed to be used with the shaping material. p and E c value.

[0026] For example, in one "regime", the D of the shaping material is greater than 200 μm and less than 300 μm, and the E of the shaping material is 3 - 12 mJ / cm p . Furthermore, in some such cases, the shaping materials described herein have a D / E ratio in units of (μm cm c greater than 10 or greater than 15. In some embodiments, the shaping material has a D / E ratio in units of (μm cm 2 ) / mJ of 15 - 100, 15 - 50, 15 - 25, or 20 - 50. 2 ) / mJ. p / E c ratio. 2 In some embodiments, the shaping material has a D / E ratio in units of (μm cm p / E chas a ratio. Such D p , E c , and D p / E c The values of, for example, when the desired voxel size is on average over 50 μm per side (e.g., when the desired voxel size corresponds to a volume having an average length in all three dimensions of 50 - 100 μm, 50 - 75 μm, 60 - 100 μm, 60 - 80 μm, or 60 - 70 μm), can provide the desired performance as described above.

[0027] In other exemplary embodiments, D p of the shaping material is greater than 10 μm and less than 50 μm (e.g., in some such cases, D p is 15 - 25 μm), E c is 5 - 40 mJ / cm 2 , 10 - 40 mJ / cm 2 , or 5 - 35 mJ / cm 2 . Further, in some such examples, the shaping material described herein has a D 2 / E p ratio of less than 5, less than 3, less than 2, less than 1.5, or less than 1 in units of (μm cm c . For example, in some embodiments, the shaping material described herein has a D 2 / E p ratio of 0.2 - 2, 0.3 - 1.5, 0.5 - 1.5, or 1 - 2 in units of (μm cm c . Such D p , E c , and D p / E c The values of can provide the desired performance as described above, for example, when the desired voxel size is on average less than 100 μm, less than 70 μm, less than 50 μm, less than 40 μm, or less than 30 μm per side (e.g., when the desired voxel size corresponds to a volume having an average length in all three dimensions of 10 - 100 μm, 10 - 45 μm, 10 - 40 μm, 10 - 30 μm, 15 - 45 μm, 15 - 40 μm, or 15 - 25 μm).

[0028] In yet another exemplary embodiment, D of the build material p is greater than 25 μm and less than 50 μm, and E c is 5~30mJ / cm 2 or 5-10mJ / cm 2 Further, in some such examples, the build materials described herein have a surface area of ​​less than (μm cm 2 ) / mJ, less than 10, e.g., 2-6, or 3-5 D p / E c Such a ratio is p , E c , and D. p / E c Values ​​of can provide desirable performance, as discussed above, for example, when the desired voxel size is less than 50 μm, less than 40 μm, or less than 30 μm on average (e.g., when the desired voxel size corresponds to a volume having average lengths in all three dimensions of 10-45 μm, 10-40 μm, 10-30 μm, 15-45 μm, or 15-40 μm).

[0029] D as described above in one form or another p , E c , and D. p / E c In addition to the value, the build materials described herein may also exhibit a desired or beneficial D PT For example, in some cases, the build materials described herein may have a 1.5xD p Below, 1.3xD p Below, 1.2xD p Less than or equal to 1.1xD p D at wavelength λ PT In some cases, D at wavelength λ PT 0.8x~2xD p , 0.8x~1.5xD p , 0.9x~2xD p , 0.9x~1.8xD p , 0.9x~1.5xD p , 0.9x~1.3xD p , 1x~2xD p , 1x~1.7xD p , 0.1x~1.5xDp 、1.1x to 2xD p 、1.1x to 1.5xD p 、1.2x to 2xD p 、1.2x to 1.8xD p 、1.3x to 2xD p 、1.3x to 1.7xD p 、or 1.5x to 2xD p is.

[0030] Although not intended to be bound by theory, D p 、E c 、and D p / E c 、and optionally D PT A shaping material having such a combination, when used as a shaping material in a stereolithography process including the stereolithography process described herein for a particular end use, is believed to provide improved consistency, accuracy, and resolution.

[0031] For the purposes of reference herein, a "non-curable absorbent" component or material is a material or species that cannot be cured or is not substantially curable by the curing radiation described herein and that absorbs at least a portion of the curing radiation without causing substantial curing of the other components of the shaping material. Thus, a "non-curable" absorbent component or material can also be referred to as a "non-curing" or "non-reactive" absorbent component or material. Further, a non-curable or non-curing absorbent component described herein that is "not substantially" curable or that does not cause "substantial" curing is understood to convert less than 5%, less than 1%, less than 0.5%, or less than 0.1% of the absorbed curing radiation photons into a curing event (or use in a curing event). For example, in some embodiments, a non-curable (or non-curing) absorbent component or material described herein can convert less than 2%, less than 1%, less than 0.5%, or less than 0.1% of the absorbed photons into free radical species, which can initiate or participate in a (meth)acrylate polymerization or other curing process.

[0032] It should be further understood that the non-curing or non-curing absorbent components or materials described herein can still be polymerization "spectators" (i.e., non-polymerizable or non-polymerization initiating) species that "compete" with the photoinitiator component of the shaping material with respect to the absorption of photons of incident curing radiation. Thus, in some examples, the non-curing absorbent component and the photoinitiator component of the shaping material described herein have substantially overlapping photon absorption profiles, particularly in the region of the electromagnetic spectrum corresponding to or including the above-mentioned peak wavelength λ. In some examples, for example, both the non-curing absorbent component and the photoinitiator component have absorption peaks within 30 nm, 20 nm, 15 nm, 10 nm, or 5 nm of wavelength λ.

[0033] However, it should be understood that the non-curing absorbent component and the photoinitiator component of the shaping material described herein do not necessarily have the same absorbance, optical density, attenuation coefficient, and / or molar absorptivity at wavelength λ or any other arbitrary specific wavelength. Rather, the non-curing absorbent component and the photoinitiator component can have different absorbances, optical densities, attenuation coefficients, and / or molar absorptivities at wavelength λ, as well as at other wavelengths.

[0034] Furthermore, in some examples, the amounts of the photoinitiator component and the non-curing absorbent component included in the shaping material described herein are selected based on the similarity or difference in the absorbance, optical density, attenuation coefficient, and / or molar absorptivity of those species, including at wavelength λ. For example, in some examples, the amounts of the photoinitiator component and the non-curing absorbent component provide a desired ratio of the total absorbances of the various species at wavelength λ and / or the desired D PT 、D p 、E c 、or D p / E cIt is selected to provide a value. In some such embodiments, the total absorbance of the non-curable absorbent component at wavelength λ is about 0.1 to 10 times, about 0.2 to 5 times, or about 0.5 to 2 times the total absorbance of the photoinitiator component at wavelength λ. The "total absorbance" of a species or component at wavelength λ is understood to be the amount (moles) of the species or component multiplied by the molar extinction coefficient of that species or component at wavelength λ.

[0035] Further, it should be noted that the wavelength λ can be any wavelength that does not conflict with the objectives of the present disclosure. For example, in some examples, λ is a wavelength in the ultraviolet (UV) or visible region of the electromagnetic spectrum. In some examples, the peak wavelength λ is in the infrared (IR) region of the electromagnetic spectrum. In some embodiments, the wavelength λ is 250 nm to 400 nm, 300 nm to 385 nm, or 385 nm to 405 nm. In other examples, the wavelength λ is 600 nm to 800 nm or 900 nm to 1.3 μm. However, the exact wavelength λ is not particularly limited. Further, in some cases, the photoinitiator component and / or non-curable absorbent component of the shaping material described herein have an absorption peak within the above wavelength ranges such as 300 nm to 385 nm or 385 nm to 405 nm.

[0036] Any non-curable absorbent material or component that does not conflict with the technical objectives of the present disclosure may be used in the shaping material described herein. For example, in some embodiments, the non-curable absorbent component includes a "dye" having an absorption profile consistent with the above description. Such a "dye" may more particularly be a hydrophilic or water-soluble dye. For example, in some implementations, the non-curable absorbent component includes a water-soluble yellow dye. Also, a water-soluble blue dye or green dye may be used.

[0037] In some embodiments, the non-curable absorbent component of the shaping material described herein includes quinoline yellow or sulfonated quinoline yellow. In some examples, the sulfonated quinoline yellow includes at least one of a monosulfonate species, a disulfonate species, and a trisulfonate species. Further, in some cases, the sulfonated quinoline yellow can be of formula I: [Chemical Formula] wherein M is sodium or hydrogen, and the subscript n is an integer from 1 to 3. It should be further understood that the above formula I can have resonance structures or other structures in an equilibrium state. The above formula I can be understood to represent such structures as well.

[0038] Furthermore, in some cases, the non-curable absorbent component of the shaping material described herein includes tartrazine. In some embodiments, the non-curable absorbent component includes UV386A (commercially available from QCR Solutions). Other non-curable absorbent materials can also be used.

[0039] The non-curing absorbent component can be present in the shaping material described herein in any amount that does not conflict with the technical objectives of the present invention. In some embodiments, for example, the non-curing absorbent component is present in the shaping material in an amount of up to 10% by mass or up to 5% by mass based on the total weight of the shaping material. For example, in some instances, the shaping material includes up to 3% by mass, up to 2% by mass, up to 1.5% by mass, or up to 1% by mass of the non-curing absorbent material. In some embodiments, the shaping material includes from 0.01 to 10% by mass, from 0.01 to 5% by mass, from 0.01 to 3% by mass, from 0.01 to 2% by mass, from 0.01 to 1% by mass, from 0.05 to 10% by mass, from 0.05 to 5% by mass, from 0.05 to 3% by mass, from 0.05 to 1% by mass, from 0.1 to 10% by mass, from 0.1 to 7% by mass, from 0.1 to 5% by mass, from 0.1 to 3% by mass, from 0.1 to 2% by mass, from 0.1 to 1% by mass, from 0.1 to 0.5% by mass, from 0.2 to 1% by mass, from 0.2 to 0.5% by mass, from 0.5 to 10% by mass, from 0.5 to 7% by mass, from 0.5 to 5% by mass, from 0.5 to 2% by mass, from 0.5 to 1% by mass, from 1 to 10% by mass, from 1 to 7% by mass, from 1 to 5% by mass, or from 1 to 3% by mass of the non-curing absorbent component based on the total weight of the shaping material. In some preferred embodiments, the amount of the non-curing absorbent component is about 1% by mass or less. For example, in some preferred embodiments, the shaping material described herein includes from 0.0001 to 1% by mass, from 0.0001 to 0.5% by mass, from 0.0001 to 0.1% by mass, from 0.001 to 1% by mass, from 0.001 to 0.5% by mass, from 0.001 to 0.1% by mass, from 0.001 to 0.05% by mass, from 0.01 to 1% by mass, from 0.01 to 0.5% by mass, from 0.01 to 0.1% by mass, from 0.01 to 0.05% by mass, from 0.1 to 1% by mass, or from 0.1 to 0.5% by mass of the non-curing absorbent component. The "inert" non-curing absorbent component can not only serve as a material optically related during curing but also act as a non-reactive "filler". Thus, the use of a relatively small amount of the non-curing absorbent component, such as the amounts described above, can be particularly advantageous in some instances for maintaining or achieving the desired mechanical properties of an article formed from a given shaping material.Furthermore, in some embodiments, a non-curable absorbent component (such as sulfonated quinoline yellow) is present in the shaping material in an amount sufficient to limit the penetration of light into the shaping material to a depth of 30 μm or less, and the light has a peak wavelength of 385 nm to 405 nm.

[0040] The shaping materials described herein also include a photoinitiator component for initiating the polymerization of one or more components of the shaping material upon exposure to light of an appropriate wavelength. In some embodiments, the photoinitiator component can initiate the polymerization of the acrylate component of the shaping material and / or one or more additional polymerizable or curable material components.

[0041] Any photoinitiator that is not inconsistent with the objectives of the present disclosure can be used in the shaping materials described herein. In some embodiments, for example, the photoinitiator component is an α-cleavage type (unimolecular decomposition process) photoinitiator or a hydrogen abstraction type photosensitizer - tertiary amine synergist that is operable to absorb light in the range of about 250 nm to about 400 nm, about 250 nm to about 405 nm, or about 300 nm to about 385 nm to generate free radicals. Examples of α-cleavage type photoinitiators are Irgacure 184 (CAS 947-19-3), Irgacure 369 (CAS 119313-12-1), and Irgacure 819 (CAS 162881-26-7). An example of a photosensitizer - amine combination is the combination of Darocur BP (CAS 119-61-9) and diethylaminoethyl methacrylate.

[0042] Furthermore, in some examples, the photoinitiator includes benzoins such as benzoin, benzoin ethers (e.g., benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether, etc.), benzoin phenyl ether, and benzoin acetate; acetophenones such as acetophenone, 2,2-dimethoxyacetophenone, and 1,1-dichloroacetophenone; benzyl, benzyl ketals (e.g., benzyldimethyl ketal and benzyldiethyl ketal, etc.); anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone; triphenylphosphine; benzoylphosphine oxides (e.g., 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin TPO), etc.); benzophenones such as benzophenone and 4,4'-bis(N,N'-dimethylamino)benzophenone; thioxanthone and xanthone; acridine derivatives; phenazine derivatives; quinoxaline derivatives or 1-phenyl-1,2-propanedione; 2-O-benzoyloxime; 1-aminophenyl ketone; or 1-hydroxy phenyl ketones such as 1-hydroxycyclohexyl phenyl ketone, phenyl 1-hydroxyisopropyl ketone, and 4-isopropylphenyl 1-hydroxyisopropyl ketone.

[0043] Suitable photoinitiators may also include photoinitiators operable for use with HeCd laser radiation sources, such photoinitiators including acetophenone, 2,2-dialkoxybenzophenone, and 1-hydroxy phenyl ketones (such as 1-hydroxy cyclohexyl phenyl ketone or 2-hydroxy isopropyl phenyl ketone (=2-hydroxy-2,2-dimethyl acetophenone), etc.). Further, in some examples, suitable photoinitiators include photoinitiators operable for use with Ar laser radiation sources, such photoinitiators including benzyl ketals such as benzyl dimethyl ketal. In some embodiments, the photoinitiator includes α-hydroxy phenyl ketone, benzyl dimethyl ketal or 2,4,6-trimethyl benzoyl diphenyl phosphine oxide, or mixtures thereof.

[0044] Another class of photoinitiators that can be included in the shaping materials described herein includes ionic dye-counterion compounds that can absorb actinic radiation and generate free radicals for polymerization initiation. In some embodiments, a shaping material containing an ionic dye-counterion compound can polymerize when exposed to visible light within an adjustable wavelength range of about 400 nm to about 700 nm. The ionic dye-counterion compounds, and their mode of operation, are disclosed in European Patent Application Publication No. 0223587, U.S. Patent Nos. 4,751,102, 4,772,530, and 4,772,541.

[0045] In some cases, the photoinitiators that can be included in the shaping materials described herein include water-soluble pyrrolidone or phosphine oxide, such as monoacyl phosphine oxide (MAPO) salts or bisacyl phosphine oxide (BAPO) salts, which can in some cases be sodium or lithium MAPO or BAPO salts. In some embodiments, the photoinitiator included in the shaping materials described herein has the structure of Formula II or Formula III:

Chemical formula

[0046] The photoinitiator component may be present in the shaping material described herein in any amount that is not inconsistent with the purposes of the present disclosure. In some embodiments, the photoinitiator component is present in the shaping material in an amount of up to about 7 wt%, up to about 5 wt%, up to about 3 wt%, or up to about 2 wt% based on the total weight of the shaping material. In some cases, the photoinitiator is present in an amount of about 0.1 to 7 wt%, 0.1 to 5 wt%, 0.1 to 3 wt%, 0.1 to 2 wt%, 0.5 to 5 wt%, 0.5 to 3 wt%, 0.5 to 2 wt%, 1 to 7 wt%, 1 to 5 wt%, or 1 to 3 wt% based on the total weight of the shaping material. In some particularly preferred embodiments, the shaping material described herein contains the photoinitiator component in an amount of up to about 5 wt%. For example, in some instances, the photoinitiator component is present in the shaping material in an amount of 0.1 to 5 wt% or 0.5 to 5 wt%, or even more preferably, 1 to 5 wt%, 1 to 3 wt%, or 2 to 4 wt% based on the total weight of the shaping material.

[0047] Furthermore, it should be understood that the amounts (weight percentages) described in the immediately preceding paragraph refer to photoinitiators that are non-oligomeric and non-polymeric. That is, the above amounts refer to "monomer" or "molecular" photoinitiators having, for example, a molecular weight of less than 400. However, it should also be understood that oligomeric or polymeric photoinitiators can also be used in the shaping materials and methods described herein. However, in such cases (when oligomeric or polymeric photoinitiators are used), the above amounts (weight percentages) should be calculated without considering the weight of the oligomeric or polymeric portion of the oligomeric or polymeric photoinitiator. That is, to determine the total amount (weight percentage) of oligomeric or polymeric photoinitiator present in the shaping material, the calculation (specifically, the numerator of the fraction) should be based only on the molecular weight of the photoactive portion of the photoinitiator (for the purposes of the present disclosure) and not on the molecular weight of the remaining portion or repeating units of the oligomeric or polymeric photoinitiator.

[0048] Furthermore, as described above, the amounts of the photoinitiator component and the non-curable absorbent component can be selected with reference to each other. For example, in some examples, the shaping material described herein includes a photoinitiator component of up to 5% by mass and a non-curable absorbent component of up to 1% by mass. In other examples, the shaping material described herein includes a photoinitiator component of up to 4% by weight and a non-curable absorbent component of up to 0.5% by mass, or a photoinitiator component of up to 5% by mass and a non-curable absorbent component of up to 0.05% by mass. In some particularly preferred embodiments, the shaping material described herein includes at least 1% by mass of the photoinitiator component in combination with an amount of the non-curable absorbent component described herein, such as, for example, a non-curable absorbent component in an amount of up to 0.5% by mass. As further described herein, a composition in which the photoinitiator component is too low (especially compared to the amount of the non-curable absorbent component) cannot sufficiently react to the curing radiation within distance D p and as a result, sufficient polymerization does not occur within the spatial region defined by D p . In some examples, the preferred (weight) ratio of the photoinitiator component to the non-curable absorbent component is 1 or more, 5 or more, or 10 or more. In some embodiments, the preferred (weight) ratio of the photoinitiator component to the non-curable absorbent component is 1 to 200, 1 to 100, 5 to 100, 1 to 200, 10 to 150, 10 to 100, 25 to 200, 25 to 100, 50 to 200, 50 to 150, or 50 to 100 (where the weight of the photoinitiator component is the numerator and the weight of the non-curable absorbent component is the denominator). Such ratios can, in some examples, achieve the desired curing effect (e.g., achieving the desired D p , E c , or D p / E c ratio) while minimizing the amount of other non-functional or non-curing "filler" materials with respect to the formation of the cured polymer network.

[0049] Furthermore, as noted above, the relative amounts of the photoinitiator component and the non-curable absorber component can be based, at least in part (as opposed to being based only on mass percent or weight), on the respective total (optical) absorbances of the photoinitiator component and the non-curable absorber component at wavelength λ. For example, if the non-curable absorber component absorbs relatively weakly at wavelength λ, a relatively large amount (moles or mass percent) of the non-curable absorber component may be required to achieve the desired “photon competition” with the photoinitiator component as compared to a situation where the non-curable absorber component absorbs relatively strongly at wavelength λ (in which case a relatively small amount (moles or mass percent) of the non-curable absorber component may be required to achieve the same desired “photon competition”). Thus, in some embodiments, the ratio of the photoinitiator component described herein to the non-curable absorber component (such as the weight-based ratio described above) is used when the photoinitiator component and the non-curable absorber component have absorption (or optical density) values within a factor of two of each other at wavelength λ. Further still, in some examples, the ratio described in the previous paragraph (such as the ratio of the photoinitiator component to the non-curable absorber component in the range of 10 to 100) is a ratio of the total absorbances at wavelength λ rather than a weight-based ratio.

[0050] Turning now to other specific components of the shaping material described herein, the shaping material described herein includes an acrylate component. Any acrylate component that does not conflict with the technical objectives of the present disclosure can be used. In particular, for reference purposes herein, it is observed that the “acrylate” component can include one or more chemical species that include at least one acrylate, methacrylate, acrylamide, or methacrylamide moiety or functional group. Further, it is to be understood that the term “(meth)acrylate” includes acrylate or methacrylate or mixtures or combinations thereof. Similarly, it is to be understood that the term “(meth)acrylamide” includes acrylamide or methacrylamide or mixtures or combinations thereof. Thus, the term “acrylate component” refers to the totality of the aforementioned species in the shaping material.

[0051] In some embodiments described herein, the acrylate component includes hydrophilic (or water-soluble) mono-, di-, and / or tri(meth)acrylate species. The acrylate component can include, for example, a hydroxylalkyl (meth)acrylate (e.g., hydroxypropyl acrylate), a hydroxyalkyl (meth)acrylamide (e.g., N-hydroxyethyl acrylamide), ethoxylated trimethylolpropane triacrylate (“TAC” or trimethylolpropane ethoxylate triacrylate), acryloylmorpholine, and one or more of their various combinations or mixtures. In some embodiments, the hydroxylalkyl (meth)acrylate includes hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and / or mixtures thereof.

[0052] The acrylate component of the shaping material described herein may also include a poly(ethylene glycol) diacrylate (PEGDA) component. With respect to the poly(ethylene glycol) diacrylate component used herein, the PEGDA component can include a single poly(ethylene glycol) diacrylate species or multiple poly(ethylene glycol) diacrylate species of different molecular weights. In some embodiments, the species of the PEGDA component have a weight average molecular weight of 0.1 kilodalton (kDa) to 20 kDa or 0.2 to 20 kDa. The molecular weight of an individual species of PEGDA can be, for example, within one or more of the ranges shown in Table 1.

Table 1

[0053] It should be understood that the acrylate component of the shaping materials described herein can include combinations of acrylate species. For example, in some cases, the acrylate component can be selected from one or more hydroxyalkyl (meth)acrylates, one or more poly(ethylene glycol) acrylates, one or more poly(ethylene glycol) diacrylates, one or more hydroxyalkyl (meth)acrylamides, or combinations of two or more of the foregoing. In a particular shaping material, the acrylate component can comprise only one hydroxyalkyl (meth)acrylate. In other shaping materials, the acrylate component can comprise multiple (two or more) hydroxyalkyl (meth)acrylates. In still other shaping materials, the acrylate component can comprise at least one hydroxyalkyl (meth)acrylate and at least one hydroxyalkyl (meth)acrylamide. In still other shaping materials, the acrylate component can comprise at least one hydroxyalkyl (meth)acrylate and at least one poly(ethylene glycol) diacrylate. Accordingly, the present disclosure contemplates many combinations and compositions of acrylate components that can be included in exemplary implementations, but they are not explicitly enumerated herein.

[0054] Generally, the acrylate component of the shaping material described in this specification can be present in the shaping material in any amount that does not conflict with the technical objectives of the present disclosure. In some embodiments, for example, the acrylate component is present in an amount or concentration of 1 to 90% by mass based on the total weight of the shaping material. In some examples, the acrylate component is 1 to 60% by mass, 1 to 40% by mass, 10 to 90% by mass, 10 to 80% by mass, 10 to 70% by mass, 10 to 60% by mass, 10 to 50% by mass, 15 to 90% by mass, 15 to 80% by mass, 15 to 75% by mass, 15 to 60% by mass, 15 to 50% by mass, 15 to 40% by mass, 20 to 90% by mass, 20 to 85% by mass, 20 to 70% by mass, 20 to 60% by mass, 20 to 50% by mass, 30 to 90% by mass, 30 to 80% by mass, 30 to 75% by mass, 30 to 60% by mass, 30 to 50% by mass, 40 to 90% by mass, 40 to 80% by mass, 40 to 70% by mass, 40 to 60% by mass, 50 to 90% by mass, 50 to 85% by mass, 50 to 75% by mass, 50 to 70% by mass, 50 to 60% by mass, 60 to 90% by mass, 60 to 80% by mass, 60 to 75% by mass, 60 to 70% by mass, 70 to 90% by mass, 70 to 85% by mass, 70 to 80% by mass, or 75 to 90% by mass based on the total weight of the shaping material.

[0055] Furthermore, in some cases, the shaping material described herein includes an acrylate component that conforms to the embodiments provided in Table 2 below, and the amounts listed in Table 2 are the mass percentages of the specified components based on the total weight of the shaping material.

Table 2

[0056] The shaping materials described herein may also optionally include additional curable material components, which are added to the acrylate component. Any such additional curable material components that do not conflict with the technical objectives of the present disclosure can be used. For reference purposes herein, a curable material includes chemical species that contain one or more curable or polymerizable moieties. For reference purposes herein, a "polymerizable moiety" includes moieties that can polymerize or cure to provide a printed 3D article or object. Such polymerization or curing can be carried out in any manner that does not conflict with the objectives of the present disclosure. In some embodiments, for example, the polymerization or curing involves irradiating the polymerizable or curable material with electromagnetic radiation having sufficient energy to initiate a polymerization or crosslinking reaction, or exposing the polymerizable or curable material to reactive species (e.g., photoinitiators, or other species that are already "activated" to provide reactive moieties such as free radical moieties) that can initiate a polymerization reaction. One non-limiting example of a polymerizable moiety of the curable materials described herein is an ethylenically unsaturated moiety such as a vinyl moiety or an allyl moiety. Further, in some examples, the polymerization reaction includes a free radical polymerization reaction such as a reaction between unsaturation points that includes ethylenically unsaturated points. Other polymerization reactions may be used. As will be understood by those skilled in the art, the polymerization reactions used to polymerize or cure the curable materials described herein may include the reaction of a plurality of "monomers" or chemical species having one or more functional groups or moieties that can react with each other to form one or more covalent bonds.

[0057] Generally, any additional curable materials or combinations of additional curable materials that do not conflict with the objectives of the present disclosure can be used in the shaping materials described herein. For example, in some examples, additional curable materials suitable for use in the shaping materials described herein have similar wavelength absorption profiles and / or refractive indices, including the absorption profiles and / or refractive indices described above in relation to a wavelength λ or a wavelength close to wavelength λ (within 30 nm). In some examples, the additional curable material component has a photon absorption profile that is outside or does not include the curing radiation having a peak wavelength λ.

[0058] In some cases, the additional curable material component comprises a compound having the structure of Formula IV or the structure of Formula V: [Chemical Formula] [Chemical Formula] Wherein n is an integer from 4 to 40 or 4 to 20. In some embodiments, such compounds have the structure of Formula IV or Formula V, wherein n is an integer from 4 to 14, 4 to 20, 6 to 30, 10 to 40, or 10 to 20. Other values of n are possible. The compounds of Formula IV or Formula V can be prepared by any method that does not conflict with the technical objectives of the present disclosure. For example, in some cases, the compounds described herein are formed from the reaction of poly(ethylene glycol) (PEG) and maleic anhydride (MA). Thus, the species of Formula IV can be referred to as "MA-PEG#-MA", where "#" is the approximate weight average molecular weight of the PEG portion of the compound. For example, "MA-PEG200-MA" refers to a compound of Formula IV having a value corresponding to a PEG portion with a molecular weight of about 200.

[0059] The additional curable material component, when present, can be used in any amount that does not conflict with the technical objectives of the present disclosure. In some embodiments, for example, the additional curable material component can be present in an amount of 1 to 30 wt%, 1 to 20 wt%, 5 to 20 wt%, 5 to 15 wt%, 10 to 30 wt%, or 10 to 20 wt% based on the total weight of the shaping material.

[0060] The shaping material described in this specification can also contain water. Water can be present in any amount that does not conflict with the technical objectives of the present disclosure. For example, in some cases, water can be present in the shaping material in an amount of 5 to 90% by mass, 10 to 85% by mass, 20 to 85% by mass, or 20 to 80% by mass based on the total weight of the shaping material. In some implementations, water is present in an amount or concentration of 10 to 60% by mass, 20 to 70% by mass, 20 to 50% by mass, 30 to 80% by mass, 30 to 60% by mass, 40 to 80% by mass, 40 to 60% by mass, 50 to 80% by mass, or 50 to 70% by mass based on the total weight of the shaping material.

[0061] It should be further understood that water (or the entire shaping material) can have a pH of about 1 to about 7, about 3 to about 7, or about 4 to about 6 in some cases. As understood by those skilled in the art, such a pH can be obtained, for example, by including a Bronsted-Lowry acid or base. For example, in some cases, a strong acid or strong base such as hydrochloric acid or sodium hydroxide, respectively, can be included in water (or the entire shaping material) at a desired concentration to provide the desired pH, as understood by those skilled in the art. Other sources of protons or hydroxides can also be used.

[0062] The shaping material described in this specification can optionally further include one or more photosensitizers. Generally, such sensitizers can be added to the shaping material to enhance the effectiveness of one or more photoinitiators that may be present. In some examples, the sensitizer includes isopropylthioxanthone (ITX) or 2-chlorothioxanthone (CTX).

[0063] The sensitizer can be present in the shaping material in any amount that does not conflict with the objectives of the present disclosure. In some embodiments, the sensitizer is present in an amount in the range of about 0.1% by mass to about 2% by mass or about 0.5% by mass to about 1% by mass based on the total weight of the shaping material. However, in other examples, the shaping material described herein excludes sensitizers as described above.

[0064] Regarding another possible component of the shaping material described herein, the shaping material can also include at least one colorant that may be different from the non-curable absorbent component of the shaping material. That is, in some examples, the colorant does not have the same photon absorption characteristics as described above for the non-curable absorbent component, and in particular, does not have photon absorption characteristics that cause "competition" of the colorant for photons with the photoinitiator and / or non-curable absorbent component of the shaping material. Such a colorant of the shaping material described herein can be a particulate colorant such as a particulate pigment or a molecular colorant such as a molecular dye. Any such particulate or molecular colorant that does not conflict with the objectives of the present disclosure can be used. In some examples, for example, the colorant of the shaping material includes inorganic pigments such as TiO2 and / or ZnO. In some embodiments, the colorant of the shaping material is for RGB, sRGB, CMY, CMYK, L * a * b * , or a colorant for use in a Pantone® color scheme. Furthermore, in some examples, the particulate colorant described herein has an average particle size of less than about 5 μm or less than about 1 μm. In some examples, the particulate colorant described herein has an average particle size of less than about 500 nm, for example, less than about 400 nm, less than about 300 nm, less than about 250 nm, less than about 200 nm, or less than about 150 nm. In some examples, the particulate colorant has an average particle size of about 50 - 5000 nm, about 50 - 1000 nm, or about 50 - 500 nm.

[0065] The colorant can be present in the shaping material described herein in any amount that does not conflict with the technical objectives of the present disclosure. In some examples, the colorant is present in the shaping material in an amount of up to about 2% by weight, or about 0.005 - 2% by weight, 0.01 - 2% by weight, 0.01 - 1.5% by weight, 0.01 - 1% by weight, 0.01 - 0.5% by weight, 0.1 - 2% by weight, 0.1 - 1% by weight, 0.1 - 0.5% by weight, or 0.5 - 1.5% by weight, based on the total weight of the shaping material. In some embodiments, the shaping material described herein excludes colorants as described above.

[0066] Furthermore, in some embodiments, the shaping material described herein further includes one or more polymerization inhibitors and / or stabilizers. The polymerization inhibitor can be added to the shaping material to provide additional thermal stability to the composition. Any polymerization inhibitor that does not conflict with the objectives of the present disclosure can be used. Furthermore, the polymerization inhibitor can delay or reduce the polymerization rate and / or prevent polymerization from occurring during a certain period or "induction time" until the polymerization inhibitor is consumed. Additionally, in some examples, the polymerization inhibitors described herein are "additive" inhibitors. The inhibitors described herein can also be "chain transfer type" inhibitors. In some examples, suitable polymerization inhibitors include methoxyhydroquinone (MEHQ).

[0067] In some embodiments, the stabilizer includes one or more antioxidants. The stabilizer can include any antioxidant that does not conflict with the objectives of the present invention. In some examples, suitable antioxidants include various aryl compounds such as butylated hydroxytoluene (BHT), which can also be used as polymerization inhibitors in some of the embodiments described herein. More generally, a single species may serve both as a stabilizer and a polymerization inhibitor. In some examples, it is also possible to use multiple inhibitors and / or stabilizers, in which case different inhibitors and / or stabilizers have different effects and / or function synergistically.

[0068] The polymerization inhibitor and / or stabilizer can be present in the shaping material in any amount that does not conflict with the objectives of the present disclosure. In some embodiments, the polymerization inhibitor is present in an amount in the range of about 0.01 wt% to about 2 wt% or about 0.05 wt% to about 1 wt%. Similarly, in some examples, the stabilizer is present in the shaping material in an amount in the range of about 0.1 wt% to about 5 wt%, about 0.1 wt% to about 2 wt%, about 0.5 wt% to about 4 wt%, or about 1 wt% to about 3 wt% based on the total weight of the shaping material. In some embodiments, the shaping material described herein excludes polymerization inhibitors and / or stabilizers.

[0069] The shaping materials described herein can have various properties in a cured or uncured state, including properties related to the microstructure of shaping materials that can be composite mixtures or other composite material systems. In some embodiments, such structural features or other properties relate to the shaping material in a cured or polymerized state. The "cured" or "polymerized" state of the shaping material used throughout this disclosure includes shaping materials that include curable materials or polymerizable components that are at least partially cured, i.e., at least partially polymerized and / or crosslinked. For example, in some cases, the cured shaping material is at least about 70% polymerized or crosslinked, or at least about 80% polymerized or crosslinked. In some embodiments, the cured shaping material is at least about 85%, at least about 90%, at least about 95%, at least about 98%, or at least 99% polymerized or crosslinked. In some examples, the cured shaping material is about 80% to about 99% polymerized or crosslinked. The degree of polymerization or crosslinking can be determined using any protocol or method that does not conflict with the technical objectives of this disclosure, for example, by specifying the proportion of monomers incorporated into the polymer network (e.g., based on the molecular weight of the polymer compared to the molecular weight of the monomers, or based on the total polymer mass compared to the theoretical maximum value of the total polymer mass), or by specifying the amount of unincorporated monomers. When multiple methods are used to determine the degree of polymerization or crosslinking, the results of these methods can be averaged to obtain the percentages described herein. It should be further understood that the degree of polymerization or crosslinking described herein is different from the "degree of polymerization" defined as the number of repeating units in a polymer molecule.

[0070] In some embodiments, the shaping materials described herein, when cured or polymerized, have an elongation at break of greater than 150% when measured according to the method of Example 18. For example, a particular article formed from the polymerization of a shaping material according to this disclosure can have an elongation at break of 150 to 300%, 150 to 275%, 150 to 250%, 200 to 275%, or 200 to 250% when measured according to the method of Example 18.

[0071] Further, in some embodiments, the shaping material described herein has a viscosity profile that, when uncured, is compatible with the requirements and parameters of one or more 3D printing systems, such as MJP, SLA, or DLP systems. For example, in some instances, the shaping material described herein has a dynamic viscosity of 1600 centipoise (cP) or less, 1200 cP or less, or 800 cP or less at 23 or 30 °C. In preferred embodiments, the shaping material described herein has a dynamic viscosity of 500 cP or less at 23 or 30 °C when measured in accordance with ASTM standard D2983 (e.g., using a Brookfield model DV-II+ viscometer). In some instances, the shaping material described herein exhibits a dynamic viscosity of about 200 to 1600 cP, about 200 to 1200 cP, about 200 to 800 cP, about 200 to 500 cP, or about 200 to 400 cP at 23 or 30 °C when measured in accordance with ASTM standard D2983.

[0072] The shaping materials described herein can individually include, have, or exhibit any combination of the above components and / or properties, provided that the combination of components and / or properties does not conflict with the principles and technical objectives of the present invention. Further, in some embodiments, the shaping materials described herein improve the accuracy and / or precision of additive manufacturing while maintaining the normal (or faster) speed of the additive manufacturing process, while maintaining (or improving) the normal energy efficiency of additive manufacturing (with respect to the energy required for curing), and / or while maintaining (or improving) the desired mechanical properties of the printed article, and can have a combination of compositional features that are particularly preferred for this purpose. It should be understood that the above "normal" or "maintained" properties are comparable to the shaping materials of the present invention according to the present disclosure / preferred embodiments, but are compared to shaping materials that are not included within the measurement criteria of the present invention identified above. Similarly, it should be further understood that the "desired mechanical properties" can vary based on a given selection of shaping material components. Again, however, shaping materials such as the preferred shaping materials described herein can provide the advantages contemplated in the present disclosure without substantially impairing the mechanical properties provided by the shaping material when they are outside the scope of the parameters of the present invention described herein. For example, a shaping material formulated to have high elongation (e.g., through the selection of specific acrylate components and / or other components) can maintain such elongation despite including a photoinitiator component and a non-curable absorber component in the formulation in a manner consistent with the above preferred embodiments (e.g., the elongation can be achieved using the preferred shaping materials described herein, where the elongation does not deviate by more than 5% from the desired elongation, using the desired value as the denominator for calculating the percentage deviation).

[0073] The shaping materials described in this specification can be manufactured by any method that does not conflict with the objectives of the present disclosure. In some embodiments, for example, the method for preparing the shaping materials described herein includes a step of mixing the components of the shaping materials, an optional step of melting the mixture, and an optional step of filtering the (optionally melted) mixture. In some cases, the components are mixed at a temperature of about 25°C to about 35°C, or in the temperature range of 25 - 55°C, 35 - 65°C, or 45 - 75°C, and optionally melted. In some examples where it is desirable or necessary to melt one or more solid components of the shaping material, mixing and / or melting can be carried out at a temperature in the range of about 75°C to about 85°C. In some embodiments, the shaping materials described herein are manufactured by placing all the components of the shaping material into a reaction vessel, optionally heating the resulting mixture, and stirring the resulting mixture at a temperature of about 25°C to about 75°C or in the temperature range of about 75°C to about 85°C. Stirring (and optionally heating) is continued until the mixture reaches a substantially homogeneous liquid (or molten) state. Generally, the liquid (or molten) mixture can be filtered while in a fluid state to remove any large and undesired particles that may interfere with the injection or extrusion or other printing processes. The filtered mixture is then cooled to ambient temperature (if cooling is required) and can be stored until it is ready to be used in a 3D printing system.

[0074] II. Method of forming 3D articles In another aspect, a method of forming or "printing" a 3D article or object by additive manufacturing is described herein. The method of forming a 3D article or object described herein may include forming the 3D article from a plurality of layers of the shaping materials described herein in a layer-by-layer manner. The method of forming an object by additive manufacturing may also include forming the object in a manner other than the layer-by-layer manner. Any of the shaping materials described above in Section I can be used in the methods described herein.

[0075] For example, in some examples, the method described herein has a penetration depth (D) at a wavelength λ p) and the critical energy (E c ), and selectively curing portions of the build material using incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength of λ, wherein the build material has a D greater than 200 μm and less than 300 μm. p , and 3–12 mJ / cm 2 E c Further, in some such cases, the build material has a 2 ) / mJ for D > 10 or > 15 p / E c In some embodiments, the build material used in the methods described herein has a ratio of (μm cm 2 ) / mJ, 15-100, 15-50, 15-25, or 20-50 D p / E c In other examples, the D of the build material used in the methods described herein p is greater than 10 μm and less than 50 μm, and the E of the building material c is 5~40mJ / cm 2 or 10-40mJ / cm 2 Furthermore, in some such cases, the build material has a surface area of ​​(μm cm 2 ) / mJ, with D less than 3, less than 2, or less than 1 p / E c In yet another example, the D of the build material used in the methods described herein has a ratio of 0.2 to 2, or 0.5 to 1.5. p is greater than 25 μm and less than 50 μm, and the E of the building material c is 5~30mJ / cm 2 or 5-10mJ / cm 2 Furthermore, in some such cases, the build material has a surface area of ​​(μm cm 2 ) / mJ, less than 10 D p / E c In some embodiments described herein, the build material is selectively cured according to preselected computer-aided design (CAD) parameters to provide a Dp corresponds to the voxel depth of the CAD parameter. Further, in some examples, one or more layers of the shaping material described herein have a thickness of from about 10 μm to about 100 μm, from about 10 μm to about 80 μm, from about 10 μm to about 50 μm, from about 10 μm to about 40 μm, from about 20 μm to about 100 μm, from about 20 to about 80 μm, or from about 20 to about 40 μm. Other thicknesses are possible.

[0076] Furthermore, in some embodiments, the methods described herein can provide high-resolution prints that include hydrogel articles. In some cases, for example, a hydrogel article printed by the methods described herein includes one or more features having a growth overshoot of less than 20 percent or less than 10 percent relative to the computer dimensions of the feature. The growth overshoot can be measured in any desired direction and / or plane, including the x-y plane, the x-z plane, and / or the y-z plane. The direction of measurement of the growth overshoot can be determined by the nature of the structural features of the printed hydrogel article.

[0077] By performing the printing process described herein, 3D articles printed from the shaping materials described herein having a high feature resolution can be provided. For the purposes of reference herein, the "feature resolution" of an article may be the smallest controllable physical feature size of the article, or the pixel or voxel size of the printing process, and it is understood that "pixel" and "voxel" refer to the CAD parameters or models of the article. In some embodiments, the printed articles described herein have an average voxel size of greater than 50 μm per side on average (e.g., when the average voxel size corresponds to a volume having an average length in all three dimensions of 50-100 μm, 50-75 μm, 60-100 μm, 60-80 μm, or 60-70 μm). In other cases, the printed articles described herein have an average voxel size of less than 50 μm, less than 40 μm, less than 30 μm, or less than 20 μm per side on average (e.g., when the average voxel size corresponds to a volume having an average length in all three dimensions of 10-45 μm, 10-40 μm, 10-30 μm, 10-25 μm, 10-20 μm, 15-45 μm, or 15-40 μm).

[0078] Furthermore, it should be understood that the method of printing the 3D articles described herein can include, for example, MJP, DLP, or SLA 3D printing methods. For example, in some examples, the MJP method of printing a 3D article includes the step of selectively depositing a layer of the shaping material described herein in a fluid state onto a substrate such as a shaping pad of a 3D printing system. Furthermore, in some embodiments, the method described herein further includes the step of supporting at least one of the layers of the shaping material with a support material. Any support material that does not conflict with the objectives of the present disclosure can be used.

[0079] The method described in this specification can also include a step of curing a layer of the shaping material, which includes using the above-mentioned curing radiation (such as curing radiation having a peak wavelength λ). Further, the curing can include polymerizing one or more polymerizable moieties or functional groups of one or more components of the shaping material. In some examples, the deposited layer of the shaping material is cured prior to the deposition of another or adjacent layer of the shaping material. Further, in some embodiments, the curing of one or more layers of the deposited shaping material is performed by exposing the one or more layers to electromagnetic radiation such as UV light, visible light, or infrared light as described above.

[0080] Further details regarding various methods, including the "material deposition" method (such as MJP) or the "vat polymerization" method (such as SLA), are described below.

[0081] A. Material Deposition Method In the material deposition method, one or more layers of the shaping material described in this specification are selectively deposited on a substrate and further cured. The curing of the shaping material can occur after the selective deposition of one layer, each layer, some layers, or all layers of the shaping material.

[0082] In some examples, the shaping material described in this specification is selectively deposited in a fluid state on a substrate such as a shaping pad of a 3D printing system. Selective deposition can include, for example, depositing the shaping material according to preselected CAD parameters. For example, in some embodiments, a drawing of a CAD file corresponding to the desired 3D article to be printed is created and sliced into a sufficient number of horizontal slices. Thereafter, the shaping material is selectively deposited layer by layer according to the horizontal slices of the drawing of the CAD file to print the desired 3D article. A "sufficient" number of horizontal slices is, for example, the number required to successfully print the desired 3D article in order to manufacture it accurately and precisely.

[0083] Further, in some embodiments, a preselected amount of the shaping material described herein is heated to an appropriate temperature and injected through one or more printheads of a suitable inkjet printer to form a layer on a print pad within a print chamber. In some examples, each layer of the shaping material is deposited according to preselected CAD parameters. Suitable printheads for depositing the shaping material are, in some embodiments, piezoelectric printheads. Additional printheads suitable for depositing the shaping materials and support materials described herein are commercially available from various inkjet printer manufacturing vendors. For example, in some instances, printheads from Xerox, Hewlett Packard, or Ricoh can be used.

[0084] Furthermore, in some embodiments, the shaping materials described herein remain substantially fluid when deposited. Alternatively, in other examples, the shaping materials exhibit a phase change immediately upon deposition and / or solidify immediately upon deposition. Further, in some examples, the temperature of the printing environment can be controlled such that the ejected droplets of the shaping material solidify upon contact with the receiving surface. In other embodiments, the droplets of the ejected shaping material do not solidify upon contact with the receiving surface and remain substantially in a fluid state. Further, in some examples, after each layer is deposited, the deposited material is flattened and cured using electromagnetic radiation (e.g., UV light, visible light, or infrared light) prior to the deposition of the next layer. Optionally, several layers may be deposited before flattening and curing, or after depositing and curing a number of layers, one or more additional layers may be deposited and then flattened without curing. Flattening corrects the thickness of one or more layers before curing the material by flattening the dispensed material to remove excess material and creating a uniform, smooth, exposed surface or flat upward-facing surface on the support platform of the printer. In some embodiments, flattening is achieved using a wiper device, such as a roller that can rotate in reverse in one or more printing directions but not in one or more other printing directions. In some examples, the wiper device includes a roller and a wiper that removes excess material from the roller. Further, in some examples, the wiper device is heated. It should be noted that in some embodiments, the viscosity of the ejected shaping materials described herein prior to curing is desirably sufficient to maintain its shape and not receive excessive viscous resistance from the flattening device.

[0085] Furthermore, the support material, when used, can be deposited in a manner compliant with what was described above for the shaping material. The support material can be deposited, for example, according to preselected CAD parameters such that the support material is adjacent to or continuous with one or more layers of the shaping material. In some embodiments, the droplets of the ejected support material solidify or coagulate upon contact with the receiving surface. In some examples, the deposited support material also undergoes flattening, curing, or both flattening and curing. Any support material that does not conflict with the purposes of the present disclosure can be used.

[0086] The layer-by-layer deposition of the shaping material and the support material can be repeated until a 3D article is formed. In some embodiments, the method of printing a 3D article further includes the step of removing the support material from the shaping material.

[0087] The curing of the shaping material can occur after the selective deposition of one layer of the shaping material, each layer of the shaping material, some layers of the shaping material, or all layers of the shaping material necessary to print the desired 3D article. In some embodiments, the partial curing of the deposited shaping material is performed after the selective deposition of one layer of the shaping material, each layer of the shaping material, some layers of the shaping material, or all layers of the shaping material necessary to print the desired 3D article. For reference purposes herein, a "partially cured" shaping material is one that can undergo further curing. For example, a partially cured shaping material is up to about 30% polymerized or crosslinked, or up to about 50% polymerized or crosslinked. In some embodiments, a partially cured ink is up to about 60%, up to about 70%, up to about 80%, up to about 90%, or up to about 95% polymerized or crosslinked.

[0088] Partial curing of the deposited shaping material may include irradiating the shaping material with an electromagnetic radiation source or photocuring the shaping material (including using the above-mentioned curing radiation). For example, any electromagnetic radiation source that does not conflict with the purpose of the present disclosure can be used, such as an electromagnetic radiation source that emits ultraviolet rays, visible light, or infrared rays. For example, in some embodiments, the electromagnetic radiation source may emit light having a wavelength of about 300 nm to about 900 nm, such as a xenon (Xe) arc lamp.

[0089] Furthermore, in some embodiments, post-curing is performed after partial curing. For example, in some cases, post-curing is performed after selectively depositing all the layers of the shaping material required to form the desired 3D article, after partially curing all the layers of the shaping material, or after performing both of the above steps. Further, in some embodiments, post-curing includes photocuring, including using the above-mentioned curing radiation having a peak wavelength λ. Again, any electromagnetic radiation source that does not conflict with the purpose of the present disclosure may be used in the post-curing step described herein. For example, in some embodiments, the electromagnetic radiation source may be a light source having higher energy, lower energy, or the same energy as the electromagnetic radiation source used for partial curing. In some examples where the electromagnetic radiation source used for post-curing has higher energy (i.e., a shorter wavelength) than that used for partial curing, a xenon (Xe) arc lamp can be used for partial curing, and a mercury (Hg) lamp can be used for post-curing.

[0090] Furthermore, after post-curing, in some cases, at least about 80% or at least about 85% of the deposited layer of the shaping material is polymerized or crosslinked. In some embodiments, at least about 90%, at least about 95%, at least about 98%, or at least about 99% of the deposited layer of the shaping material is polymerized or crosslinked. In some examples, at least about 80 - 100%, about 80 - 99%, about 80 - 95%, about 85 - 100%, about 85 - 99%, about 85 - 95%, about 90 - 100%, or about 90 - 99% of the deposited layer of the shaping material is polymerized or crosslinked.

[0091] B. Bat Coincidence Method It is also possible to form a 3D article from the shaping material described herein using a bat coincidence method such as the SLA method. Thus, in some examples, the method of printing the 3D article described herein comprises holding the shaping material described herein in a fluid state within a container and selectively applying energy (in particular, for example, curing radiation having a peak wavelength λ) to the shaping material within the container to solidify at least a portion of the fluid layer of the shaping material, thereby forming a solidified layer that defines a cross-section of the 3D article. Further, the method described herein comprises raising or lowering the solidified layer of the shaping material to provide a new or second fluid layer of the unsolidified shaping material on the surface of the fluid shaping material within the container, and then selectively applying energy again to the shaping material within the container to solidify at least a portion of the new or second fluid layer of the shaping material to form a second solidified layer that defines a second cross-section of the 3D article. Further, by applying energy to solidify the shaping material, the first cross-section and the second cross-section of the 3D article can be joined or adhered to each other in the z-direction (or the shaping direction corresponding to the above-mentioned raising or lowering direction). Further, in some examples, the electromagnetic radiation has an average wavelength of 300 to 900 nm, and in other embodiments, the electromagnetic radiation has an average wavelength of less than 300 nm. In some examples, the curing radiation is provided by a computer-controlled laser beam or other light source. Further, in some examples, raising or lowering the solidified layer of the shaping material is performed using a lifting platform disposed within the container of the fluid shaping material. The method described herein may also include a step of flattening the new layer of the fluid shaping material brought about by raising or lowering the lifting platform. Such flattening can be performed, in some examples, by a wiper or a roller.

[0092] Furthermore, it is to be further understood that the aforementioned process may be repeated a desired number of times to provide a 3D article. For example, in some instances, this process can be repeated "n" times, where n can be up to about 100,000, up to about 50,000, up to about 10,000, up to about 5000, up to about 1000, or up to about 500. Thus, in some embodiments, a method of printing a 3D article described herein includes selectively applying energy (e.g., curing radiation of peak wavelength λ) to a shaping material within a container to solidify at least a portion of an nth fluid layer of the shaping material, thereby forming an nth solidified layer that defines an nth cross-section of the 3D article; raising or lowering the nth solidified layer of the shaping material to provide, on a surface of the fluid shaping material within the container, an (n + 1)th layer of uncured ink; selectively applying energy to the (n + 1)th layer of ink within the container to solidify at least a portion of the (n + 1)th layer of the shaping material to form an (n + 1)th solidified layer that defines an (n + 1)th cross-section of the 3D article; raising or lowering the (n + 1)th solidified layer of the shaping material to provide, on a surface of the fluid shaping material within the container, an (n + 2)th layer of uncured shaping material; and continuing to repeat the aforementioned steps to form a 3D article. Further, it is to be understood that one or more steps of the methods described herein, such as selectively applying energy (e.g., the curing radiation described herein) to a layer of the shaping material, can be performed in accordance with an image of the 3D article in a computer-readable format. General methods of 3D printing using stereolithography are further described, in particular, in U.S. Patent Nos. 5,904,889 and 6,558,606.

[0093] In the vat polymerization method as described above, as explained in Section IIA above, the shaping material can be partially cured. For example, in some embodiments, selectively applying energy to the shaping material in the container to solidify at least a portion of the fluid layer of the shaping material may include partially curing at least a portion of the fluid layer of the shaping material. In other embodiments, partial curing of at least a portion of the fluid layer of the shaping material can occur before or after providing and solidifying the second layer of the shaping material, or before or after providing or solidifying one, some, or all of the subsequent layers of the shaping material, after providing and solidifying the first layer of the shaping material.

[0094] Furthermore, in some embodiments of the vat polymerization method described herein, post-curing as described in Section IIA above may be performed after partial curing or after the desired 3D article has been formed. The desired 3D article can be, for example, an article corresponding to the design of a CAD file.

[0095] C. Further Features of the Method In some embodiments of the methods described herein in Section IIA or Section IIB, the method further comprises, after completion of the printing job, leaching a non-curable absorbent component (e.g., sulfonated quinoline yellow) from the printed three-dimensional hydrogel article produced by the method. The hydrogel article can be placed in a water bath or other water or aqueous environment, for example, before use as an implant or other biomedical device or scaffold. In particular, the leaching of the non-curable absorbent component (e.g., sulfonated quinoline yellow) from the printed article does not acidify the surrounding aqueous environment. The water bath or other surrounding aqueous environment containing the leached non-curable absorbent component (e.g., sulfonated quinoline yellow) can exhibit a pH of 6.5 - 8 in the absence of a buffer or other pH-regulating species added to the water. In some embodiments, the pH of the aqueous environment containing the leached non-curable absorbent component (e.g., sulfonated quinoline yellow) can have a pH of 7 - 7.5. This represents a fundamental departure from other hydrogel inks and can produce a strongly acidic aqueous environment upon leaching of the components after article completion.

[0096] III. Printed 3D Articles In another aspect, printed 3D articles are described herein. In some embodiments, the printed 3D article is formed from a shaping material described herein. Any of the shaping materials described in Section I above of this specification may be used. For example, in some examples, the shaping material comprises, based on the total weight of the shaping material (the total amount of the components equals 100% by weight), 1 - 90% by mass of an acrylate component, 0.5 - 3% by mass of a photoinitiator component, 0.1 - 1% by mass of a non-curable absorbent component, and 10 - 85% by mass of water, and the photoinitiator component is operable to initiate the curing of the acrylate component when the photoinitiator component is exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ, and the shaping material has a penetration depth (D p ) and a critical energy (E c ) at wavelength λ, where D p is greater than 200 μm and less than 300 μm, and E c is 3 - 12 mJ / cm 2is, or the molding material has a D of 10 to 50 μm p and an E of 5 to 40 mJ / cm 2 c and has.

[0097] Hydrogel articles printed according to the methods described herein can find uses in a variety of fields including the medical field. The hydrogel article can be, for example, a medical implant. The hydrogel medical implant can be used for tissue regeneration and / or can function as a scaffold for cell seeding and / or growth.

[0098] Examples Some embodiments of the molding material for 3D printing are further illustrated in the following non-limiting examples.

[0099] Examples 1-4 Some specific embodiments of the molding material are shown in Table 3 below. The amounts in Table 3 refer to the mass % of each component of the identified composition based on the total weight of the composition. Also, "SQY" represents "sulfonated quinoline yellow" and "PI" represents "photoinitiator". Further, in all cases of Table 3 below, water balances the components to reach 100 mass %. In Examples 1-4, the "PEGDA component" has a weight average molecular weight of 3000-7000; also, the "other acrylate component" includes monofunctional and polyfunctional alkoxylated acrylates and hydroxyalkyl acrylates. As noted above, it should be further noted that the following "PEGDA component" and "other acrylate component" can also be described together as a single "acrylate component".

Table 3

[0100] Examples 5-10 ​Table 4 provides formulations of the shaping materials according to some embodiments described herein. In Table 4, "Ex." means "Example", and the amounts listed for a given example are mass percentages based on the total weight of the composition of that example. It should be understood that all components of a given example composition total 100 mass percent. Table 5 provides the components of Examples 5-10. Table 6 provides the D p and E c values. Further, in Table 5, "SQY" refers to sulfonated quinoline yellow. All components of Examples 5-10 below other than the photoinitiator component and the non-curing absorbent component are substantially non-absorbing at wavelength λ, and thus these species were essentially optical spectators as described above herein.

Table 4

Table 5

Table 6

[0101] Examples 11-17 Table 7 provides formulations of the shaping materials according to some embodiments described herein. In Table 7, "Ex." means "Example", and the amounts listed for a given example are mass percentages based on the total weight of the composition of that example. A dash (--) indicates that the component is absent (zero mass percent). It should be understood that all components of a given example composition total 100 mass percent. Table 8 provides the components of Examples 11-17. In Table 8, "PEGDA X" refers to PEGDA having an average weight average molecular weight "X" (e.g., PEGDA 3400 has a weight average molecular weight of 3400). Further, in Table 8, "SQY" refers to sulfonated quinoline yellow, and "tart." refers to tartrazine. NaP refers to sodium TPO-L, and LiP refers to lithium TPO-L. Table 9 provides the D p and Ec It provides a value. All components of Examples 11-17 below other than the photoinitiator component and the non-curable absorbent component are substantially non-absorbent at wavelength λ, and thus these species were essentially optical spectrometers as described above herein.

Table 7

Table 8

Table 9

[0102] Example 18 The tensile test of the printed article for measuring the elongation at break was conducted as follows. The test formulation (ink, shaping material, or polymerizable liquid) was printed in a 20-μm-thick layer on a horizontal alignment ring at room temperature (about 23-25 °C) using a digital light processing (DLP) printer. The ring had a neck region with a defined 1-mm × 1-mm square cross-section. The ring was removed from the printer platform and the uncured material was rinsed away (e.g., by placing the ring in phosphate-buffered saline (PBS) or water for up to 10 minutes at room temperature). The ring was then loaded into a dynamic mechanical analysis (DMA) system and stretched vertically at 100% strain per minute (at room temperature) until the instrument reached maximum strain or the sample broke, thereby obtaining the elongation at break (EOB). The modulus of elasticity was determined by obtaining the slope of the first 10% strain.

[0103] Some additional non-limiting exemplary embodiments are provided below.

[0104] Embodiment 1. A shaping material for forming a hydrogel article, an acrylate component; a photoinitiator component; a non-curable absorbent component; and water comprising, The photoinitiator component is operable to initiate curing of the acrylate component when the photoinitiator component is exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ; The shaping material has a penetration depth (D p ) and a critical energy (E c ) at wavelength λ; D p is greater than 200 μm and less than 300 μm; E c is 3 to 12 mJ / cm 2 .

[0105] Embodiment 2. The shaping material according to Embodiment 1, having a D 2 / E p ratio greater than 10 or greater than 15 in units of (μm cm c ) / mJ.

[0106] Embodiment 3. The shaping material according to Embodiment 1, having a D 2 / E p ratio of 15 to 100, 15 to 50, 15 to 25, or 20 to 50 in units of (μm cm c ) / mJ.

[0107] Embodiment 4. A shaping material for forming a hydrogel article, comprising an acrylate component; a photoinitiator component; a non-curable absorbent component; and water , wherein the photoinitiator component is operable to initiate curing of the acrylate component when the photoinitiator component is exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ; the shaping material has a penetration depth (D p ) and a critical energy (E c ) at wavelength λ; D p is greater than 10 μm and less than 50 μm; E c is 5 to 40 mJ / cm 2 or 10 to 40 mJ / cm 2It is.

[0108] Embodiment 5. The shaping material is in the unit of (μm cm 2 ) / mJ and has a D p / E c ratio of 0.2 to 2, the shaping material according to Embodiment 4.

[0109] Embodiment 6. A shaping material for forming a hydrogel article, an acrylate component; a photoinitiator component; a non-curable absorbent component; and water containing, the photoinitiator component is operable to initiate the curing of the acrylate component when the photoinitiator component is exposed to incident curing radiation having a Gaussian distribution of wavelength and a peak wavelength λ; the shaping material has a penetration depth (D p ) and a critical energy (E c ) at wavelength λ; D p is greater than 25 μm and less than 50 μm; E c is 5 to 30 mJ / cm 2 or 5 to 10 mJ / cm 2 is.

[0110] Embodiment 7. The shaping material is in the unit of (μm cm 2 ) / mJ and has a D p / E c ratio of less than 10, the shaping material according to Embodiment 6.

[0111] Embodiment 8. The shaping material is in the unit of (μm cm 2 ) / mJ and has a D p / E c ratio of 2 to 6 or 3 to 5, the shaping material according to Embodiment 6.

[0112] Embodiment 9. The acrylate component is present in an amount of 1 to 90% by mass, 1 to 60% by mass, 1 to 40% by mass, 10 to 90% by mass, 10 to 80% by mass, 10 to 70% by mass, 10 to 60% by mass, 10 to 50% by mass, 15 to 90% by mass, based on the total weight of the shaping material. 15 to 80% by mass, 15 to 75% by mass, 15 to 60% by mass, 15 to 50% by mass, 15 to 40% by mass, 20 to 90% by mass, 20 to 85% by mass, 20 to 70% by mass, 20 to 60% by mass, 20 to 50% by mass, 30 to 90% by mass. 30 to 80% by mass, 30 to 75% by mass, 30 to 60% by mass, 30 to 50% by mass, 40 to 90% by mass, 40 to 80% by mass, 40 to 70% by mass, 40 to 60% by mass, 50 to 90% by mass, 50 to 85% by mass, 50 to 75% by mass. 50 to 70% by mass, 50 to 60% by mass, 60 to 90% by mass, 60 to 80% by mass, 60 to 75% by mass, 60 to 70% by mass, 70 to 90% by mass, 70 to 85% by mass, 70 to 80% by mass, or 75 to 90% by mass in the shaping material; The photoinitiator component is present in the shaping material in an amount of 0.1 to 5% by mass, 0.1 to 3% by mass, 0.1 to 2% by mass, or 0.5 to 2% by mass, based on the total weight of the shaping material; The non-curable absorbent component is present in the shaping material in an amount of 0.1 to 5% by mass, 0.1 to 3% by mass, 0.1 to 2% by mass, 0.1 to 1% by mass, or 0.1 to 0.5% by mass, based on the total weight of the shaping material; Water is present in the shaping material in an amount of 10 to 85% by mass or 20 to 80% by mass, based on the total weight of the shaping material, The shaping material according to any one of the foregoing embodiments:

[0113] Embodiment 10. The shaping material according to any one of the foregoing embodiments, wherein the acrylate component comprises one or more poly(ethylene glycol) diacrylate (PEGDA) species.

[0114] Embodiment 11. The shaping material according to Embodiment 9, wherein the acrylate component comprises a plurality of different PEGDA species having different molecular weights.

[0115] Embodiment 12. The shaping material according to Embodiment 10 or Embodiment 11, wherein one or more PEGDA species have a weight average molecular weight of 0.1 kDa to 20 kDa.

[0116] Embodiment 13. The shaping material according to any of the foregoing embodiments, wherein the acrylate component includes one or more hydroxyalkyl acrylates.

[0117] Embodiment 14. The shaping material includes a photoinitiator component of 0.5 to 2% by mass and a non-curable absorbent component of 0.1 to 1% by mass, and the weight ratio of the photoinitiator component to the non-curable absorbent component is 2 to 10 or 5 to 100, The shaping material according to any of the foregoing embodiments.

[0118] Embodiment 15. The shaping material according to any of the foregoing embodiments, wherein both the non-curable absorbent component and the photoinitiator component have an absorption peak within 30 nm of the wavelength λ.

[0119] Embodiment 16. The shaping material according to any of the foregoing embodiments, wherein the total absorbance of the non-curable absorbent component at the wavelength λ is about 0.1 to 10 times the total absorbance of the photoinitiator component at the wavelength λ.

[0120] Embodiment 17. The shaping material according to any of the foregoing embodiments, wherein the non-curable absorbent component includes a water-soluble yellow dye.

[0121] Embodiment 18. The shaping material according to any of the foregoing embodiments, wherein the non-curable absorbent component includes quinoline yellow.

[0122] Embodiment 19. The shaping material according to any of the foregoing embodiments, wherein the non-curable absorbent component includes sulfonated quinoline yellow.

[0123] Embodiment 20. The shaping material according to Embodiment 19, wherein the sulfonated quinoline yellow includes at least one of a monosulfonate species, a disulfonate species, and a trisulfonate species.

[0124] Embodiment 21. The acrylate component contains 0 to 50% by mass of PEGDA species; The PEGDA species has a weight average molecular weight of 200 to 20,000 Da; The acrylate component contains 0 to 60% by mass of hydrophilic or water-soluble acrylate; The photoinitiator component is present in an amount of 0.1 to 3% by mass; The non-curable absorbent component is present in an amount of 0.1 to 3% by mass; Water is present in an amount of 5 to 90% by mass. The shaping material according to Embodiment 4.

[0125] Embodiment 22. The shaping material according to Embodiment 21, wherein the acrylate component contains 5 to 30% by mass of PEGDA species.

[0126] Embodiment 23. The shaping material according to Embodiment 21 or Embodiment 22, wherein the acrylate component contains 5 to 50% by mass of water-soluble acrylate.

[0127] Embodiment 24. The shaping material according to Embodiment 21, Embodiment 22, or Embodiment 23, wherein the photoinitiator component is present in an amount of 0.5 to 2% by mass.

[0128] Embodiment 25. The shaping material according to Embodiment 21, Embodiment 22, Embodiment 23, or Embodiment 24, wherein the non-curable absorbent component is present in an amount of 0.1 to 1% by mass.

[0129] Embodiment 26. The shaping material according to Embodiment 21, Embodiment 22, Embodiment 23, Embodiment 24, or Embodiment 25, wherein water is present in an amount of 20 to 80% by mass.

[0130] Embodiment 27. The hydrophilic or water-soluble acrylate contains one or more hydroxylalkyl (meth) acrylates; The non-curable absorbent component contains UV386A, SQY, or tartrazine. The shaping material according to Embodiment 21, Embodiment 22, Embodiment 23, Embodiment 24, Embodiment 25, or Embodiment 26:

[0131] Embodiment 28. A method of forming a three-dimensional article by additive manufacturing, comprising: providing a modeling material according to any one of Embodiments 1 to 27; and selectively curing a portion of the modeling material using incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength at wavelength λ A method comprising.

[0132] Embodiment 29. The modeling material is selectively cured according to preselected computer-aided design (CAD) parameters; D p corresponds to the voxel depth of the CAD parameters, The method according to Embodiment 28.

[0133] Embodiment 30. The method according to Embodiment 29, wherein the voxel depth is 50 μm or less, 30 μm or less, or 25 μm or less.

[0134] Embodiment 31. The method according to Embodiment 29, wherein the voxel depth is 50 μm or more.

[0135] Embodiment 32. The method according to any one of Embodiments 28 to 31, wherein the step of providing the modeling material includes selectively depositing a layer of the modeling material in a fluid state on a substrate to form a three-dimensional article.

[0136] Embodiment 33. The step of providing the modeling material includes holding the modeling material in a fluid state in a container; The step of selectively curing a portion of the modeling material includes selectively applying curing radiation to the modeling material in the container to solidify at least a portion of a first fluid layer of the modeling material, thereby forming a first solidified layer that defines a first cross-section of the article; raising or lowering the first solidified layer to provide a second fluid layer of the modeling material on the surface of the fluid modeling material in the container; Selectively applying hardening radiation to the shaping material within the container to solidify at least a portion of the second fluid layer of the shaping material, thereby forming a second solidified layer that defines a second cross-section of the article, wherein the first cross-section and the second cross-section are joined to each other in the z-direction, the process The method according to any one of embodiments 28 to 31, including

[0137] Embodiment 34. The non-curable absorbent component is present in the shaping material in an amount that limits the penetration of the incident hardening radiation into one or more layers of the shaping material to a depth of 30 μm or less; λ is 385 nm to 405 nm The method according to any one of embodiments 28 to 33.

[0138] Embodiment 35. A printed three-dimensional article formed from the shaping material according to any one of embodiments 1 to 27 and / or using the method according to any one of embodiments 28 to 34.

[0139] Embodiment 36. The article according to embodiment 35, wherein the article is a medical implant.

[0140] Embodiment 37. The article according to embodiment 35, wherein the article is a tissue graft scaffold, a hydrogel capsule for delivery of therapeutic species to a biological environment, a microfluidic organ on a chip, a nerve graft, or a regenerated organ or tissue scaffold.

[0141] Embodiment 38. A shaping material for forming a hydrogel article, A poly(ethylene glycol) diacrylate component; Sulfonated quinoline yellow; A photoinitiator component; and Water The shaping material comprising

[0142] Embodiment 39. The shaping material according to embodiment 38, wherein the poly(ethylene glycol) diacrylate component comprises poly(ethylene glycol) diacrylate species of different molecular weights.

[0143] Embodiment 40. The shaping material according to Embodiment 39, wherein the poly(ethylene glycol) diacrylate species may have a molecular weight in the range of 0.1 kDa to 20 kDa.

[0144] Embodiment 41. The shaping material according to Embodiment 38, wherein the poly(ethylene glycol) diacrylate component is present in an amount of 1 to 60% by mass based on the total weight of the shaping material.

[0145] Embodiment 42. The shaping material according to Embodiment 38, wherein sulfonated quinoline yellow is present in an amount of 0.1 to 5% by mass based on the total weight of the shaping material.

[0146] Embodiment 43. The shaping material according to Embodiment 38, wherein sulfonated quinoline yellow is present in an amount of 0.1 to 1% by mass based on the total weight of the shaping material.

[0147] Embodiment 44. The shaping material according to Embodiment 38, wherein the sulfonated quinoline yellow contains at least one of a monosulfonate species, a disulfonate species, and a trisulfonate species.

[0148] Embodiment 45. The shaping material according to Embodiment 38, further comprising an acrylate component.

[0149] Embodiment 46. The shaping material according to Embodiment 45, wherein the acrylate component contains one or more hydroxyalkyl acrylates.

[0150] Embodiment 47. The shaping material according to Embodiment 46, wherein the acrylate component is present in an amount of 1 to 40% by mass based on the total weight of the shaping material.

[0151] Embodiment 48. The shaping material according to Embodiment 38, wherein the photoinitiator component is present in an amount of 0.1 to 5 mass percent based on the total weight of the shaping material.

[0152] Embodiment 49. A method for printing a three-dimensional hydrogel article, comprising: A step of providing a shaping material according to any one of Embodiments 38 to 48; and A step of printing and curing the shaping material with light to form a hydrogel article including, the method.

[0153] Embodiment 50. The method according to Embodiment 49, wherein the shaping material is provided in a layer-by-layer process.

[0154] Embodiment 51. The method according to Embodiment 49, wherein the polyethylene glycol diacrylate component includes poly(ethylene glycol) diacrylate species having different molecular weights.

[0155] Embodiment 52. The method according to Embodiment 49, wherein the hydrogel article includes one or more features having a growth overshoot of less than 20 percent relative to the computer dimensions of the features.

[0156] Embodiment 53. The method according to Embodiment 49, further including a step of leaching sulfonated quinoline yellow from the hydrogel article into a water bath.

[0157] Embodiment 54. The method according to Embodiment 53, wherein the pH of the water bath containing the leached sulfonated quinoline yellow is in the range of 6.5 to 8.

[0158] Embodiment 55. The method according to Embodiment 49, wherein the hydrogel article is a medical implant.

[0159] All patent documents referred to herein are incorporated by reference in their entirety. Various embodiments of the present invention have been described in achieving various objects of the present invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Many modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. A shaping material for forming a hydrogel article, comprising: an acrylate component; a photoinitiator component; a non-curable absorbent component; and water wherein the photoinitiator component is operable to initiate curing of the acrylate component when the photoinitiator component is exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ; The shaping material has a penetration depth (D ｐ ), and a critical energy (E ｃ ) at a wavelength λ; D ｐ is greater than 200 μm and less than 300 μm; E ｃ is 3 to 12 mJ / cm ２ is A shaping material, characterized in that.

2. The shaping material is in the unit of (μm / cm ２ ) / mJ and has a D ｐ / E ｃ ratio of less than 3, and is the shaping material according to claim 1.

3. The shaping material is (μm cm ２ ), in the unit of) / mJ, with a D ｐ / E ｃ ratio of 0.2 to 2, and the shaping material according to claim 1 is characterized by this.

4. The acrylate component is present in the shaping material in an amount of 5 to 80% by mass based on the total weight of the shaping material; The photoinitiator component is present in the shaping material in an amount of 0.1 to 3% by mass based on the total weight of the shaping material; The non-curable absorbent component is present in the shaping material in an amount of 0.1 to 1% by mass based on the total weight of the shaping material; The water is present in the shaping material in an amount of 10 to 85% by mass based on the total weight of the shaping material The shaping material according to claim 1, characterized in that.

5. The shaping material according to claim 1, characterized in that the acrylate component comprises one or more poly(ethylene glycol) diacrylate (PEGDA) species.

6. The shaping material according to claim 5, characterized in that the acrylate comprises a plurality of different PEGDA species having different molecular weights.

7. The shaping material according to claim 5, characterized in that the one or more PEGDA species have a weight average molecular weight of 0.1 kDa to 20 kDa.

8. The shaping material according to claim 1, characterized in that the acrylate component comprises one or more hydroxyalkyl acrylates.

9. The shaping material comprises 0.5 to 2% by mass of a photoinitiator component and 0.1 to 1% by mass of a non-curable absorbent component; The weight ratio of the photoinitiator component to the non-curable absorbent component is 2 to 10 The shaping material according to claim 1, characterized in that.

10. The shaping material according to claim 1, characterized in that both the non-curable absorbent component and the photoinitiator component have an absorption peak within 30 nm of the wavelength λ.

11. The total absorbance of the non-curable absorbent component at the wavelength λ is about 0.1 to 10 times the total absorbance of the photoinitiator component at the wavelength λ. The shaping material according to claim 1, characterized in that.

12. The shaping material according to claim 1, characterized in that the non-curable absorbent component comprises a water-soluble yellow dye.

13. The shaping material according to claim 1, wherein the non-curable absorbent component contains quinoline yellow or sulfonated quinoline yellow.

14. A method for forming a three-dimensional article by additive manufacturing, comprising: providing the shaping material according to claim 1; and selectively curing a part of the shaping material using incident curing radiation having a Gaussian distribution of wavelength and a peak wavelength at wavelength λ. The method is characterized by including the above steps.

15. The shaping material is selectively cured according to preselected computer-aided design (CAD) parameters; D ｐ corresponds to the voxel depth of the CAD parameter; the voxel depth is 50 μm or less. The method according to claim 14, characterized by the above.

16. The method according to claim 14, wherein the step of providing the shaping material includes selectively depositing a layer of the shaping material in a fluid state on a substrate to form the three-dimensional article.

17. The step of providing the shaping material includes holding the shaping material in a fluid state in a container; the step of selectively curing a part of the shaping material includes selectively applying curing radiation to the shaping material in the container to solidify at least a part of a first fluid layer of the shaping material, thereby forming a first solidified layer defining a first cross-section of the article; raising or lowering the first solidified layer to provide a second fluid layer of the shaping material on the surface of the fluid shaping material in the container; selectively applying curing radiation to the shaping material in the container to solidify at least a part of the second fluid layer of the shaping material, thereby forming a second solidified layer defining a second cross-section of the article, and the first cross-section and the second cross-section are joined to each other in the z direction. The method according to claim 14, characterized by including the above steps.

18. The non-curable absorbent component is present in the shaping material in an amount that limits the penetration of the incident curing radiation into one or more layers of the shaping material to a depth of 30 μm or less; λ is 385 nm to 405 nm. The method according to claim 14, characterized by the above.

19. A printed three-dimensional article formed from the shaping material according to claim 1.

20. The article according to claim 19, wherein the article is a medical implant.

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