High-resolution hydrogel for 3D printing

Abstract

There is a need for improved shaping materials for 3D printing having improved printing characteristics, including but not limited to those related to light penetration depth or through-print characteristics. 【Solution】In one aspect, a shaping material intended to be used with a three-dimensional (3D) printing system is described herein. In some embodiments, the shaping material described in the present invention includes an acrylate component, a photoinitiator component, a non-curable absorption component, and water. The photoinitiator component of the shaping material is operable to initiate 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 shaping material has a penetration depth (D p ) and a critical energy (E c ). 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 of related applications

[0001] This application claims priority under 35 U.S. SC § 119 to U.S. Provisional Patent Application No. 63 / 389,459 filed July 15, 2022, and U.S. Provisional Patent Application No. 63 / 408,554 filed September 21, 2022, which are incorporated herein by reference in their entirety. [Technical Field]

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

[0003] Additive manufacturing systems, or 3D printers, use a build material, sometimes called ink or polymerizable liquid, to form various objects, articles, or parts according to computer-generated files. In some cases, the build material is solid at ambient temperature and changes to a liquid at high injection temperatures. In other cases, the build material is liquid at ambient temperature. The build material can be formed into 3D objects in various ways, for example, by spraying or otherwise depositing the build material onto a substrate. The build material can also be selectively cured, solidified, or otherwise altered during the build process. For example, some 3D printers form 3D articles from a reservoir, vat, or container of fluid or powder-based build material. In some cases, a binder material, or a laser or other energy source, is used to selectively solidify or consolidate layers of the build material in a stepwise manner to produce a 3D article.

[0004] In 3D printing systems that use curing radiation, the curing radiation may penetrate deeper into the build material than intended or desired. More specifically, the radiation may penetrate deeper than the portion of the build material that is intended to be cured or solidified as part of the structure of the printed article. Such undesirable excess curing depth can be referred to as "print through" or "print through depth." The occurrence of print through can be problematic for several reasons. Firstly, print through can cause an undesirable "gummy" layer of partially cured build material to form on certain surfaces of the additive manufacturing system (such as one or more "down surfaces"). Secondly, print through wastes build material. Thirdly, even in the least problematic cases, print through generally requires correction in the build process to account for the fact that some layers or other layers of the printed article will be different from what was intended (e.g., different from the instructions in the corresponding computer-aided design or "CAD" file). For example, such deviations can be considered or corrected when creating or selecting the specific CAD file used to form the build article. However, such corrections can be inaccurate, leading to part distortion and an overall loss of print accuracy. Finally, when print-through occurs, more unknown or inaccurate values ​​are generally introduced into the manufacturing 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. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Improved methods, more specifically, improved 3D printing materials with improved print properties, including but not limited to those relating to light penetration depth or print-through characteristics, are needed. In particular, improved 3D printing materials are needed that can be used to form biomaterials such as hydrogel implants that serve as scaffolds for tissue regeneration and / or various cell therapies, including desired print resolution. [Means for solving the problem]

[0006] In one embodiment, a 3D printing material for use in a 3D printer is described herein, which in some embodiments may offer one or more advantages over conventional 3D printing materials, particularly radiation-curable 3D printing materials for use in additive manufacturing. For reference purposes herein in the context of additive manufacturing, the term “printing material” may be used interchangeably with the terms “ink” or “polymerizable liquid.” In some embodiments, the 3D printing materials described herein may be used to print hydrogel articles with improved accuracy and / or precision. The 3D printing materials described herein also, in some examples, provide improved resolution without sacrificing the speed of the additive manufacturing process, without sacrificing the energy efficiency of the additive manufacturing process, and / or without sacrificing the desired mechanical properties of the printed article. Furthermore, the 3D printing materials described herein can be used in a variety of different 3D printers or additive manufacturing systems, including 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, the photoinitiator component, the non-curable absorbent component, the additional curable material component (if present), the additional non-curable material component (if present), and water is equal to 100 mass percent (mass%). Further, the additional non-curable components 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 the curing of any other curable materials 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. 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, 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 to 12 mJ / cm 2 . Alternatively, in other preferred embodiments, D p is greater than 10 μm and less than 50 μm (e.g., 15 to 25 μm). Further, in some such cases, E c is 5 to 40 mJ / cm 2 or 10 to 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 to 30 mJ / cm 2Therefore, in some cases, molding materials possessing such characteristics can offer various advantages, including improved resolution and / or print speed.

[0009] As will be further explained below, the amount of photoinitiator and / or non-curing absorber material contained in the printing material, in combination with other components of the printing material, determines the desired D p , E c , and / or D PT You can choose to obtain a value (Term D refers to the print-through depth of the build material). p , E c , and D PT (This is further explained below). In some embodiments, for example, the printing material described herein comprises, based on the total weight of the printing material, up to 5% by mass, up to 3% by mass, or up to 2% by mass of a photoinitiator component and up to 2% by mass, up to 1.5% by mass, or up to 1% by mass of a noncurable absorber component. Furthermore, in some examples, the total absorbance of the noncurable absorber component at wavelength λ is about 0.1 to 10 times the total absorbance of the photoinitiator component at wavelength λ. Furthermore, in some examples, both the noncurable absorber component and the photoinitiator component of the printing material described herein have absorption peaks within 30 nm of wavelength λ.

[0010] In another embodiment, a method for forming a 3D article by additive manufacturing is described herein. In some embodiments, such a method includes the steps of providing a 3D material as described herein, and selectively curing a portion of the 3D material using incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength at wavelength λ. For example, in some examples, the 3D material has a diameter greater than 200 μm and less than 300 μm. p , and 3-12 mJ / cm² 2 E c It has D p It is greater than 10 μm and less than 50 μm (for example, 15-25 μm), and E c The humidity is 5-40 mJ / cm². 2 Or 10-40 mJ / cm 2 In another embodiment, D pIt is greater than 25 μm and less than 50 μm, E c The humidity is 5-30 mJ / cm². 2 Furthermore, in some embodiments of the methods described herein, the molding material is selectively cured according to pre-selected computer-aided design (CAD) parameters, D p This corresponds to the voxel depth parameter in CAD.

[0011] Furthermore, in some examples, the step of providing the molding material includes the step of selectively depositing layers of the molding material in a fluid state onto a substrate to form a three-dimensional article. Alternatively, in other embodiments, the step of providing the molding material includes the step of holding the molding material in a fluid state within a container, and the step of selectively curing a portion of the molding material includes the step of selectively applying curing radiation to the molding material within the container to solidify or consolidate at least a portion of the first fluid layer of the molding material, thereby forming a first solidified or consolidated layer defining 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 molding material on the surface of the fluid molding material within the container, and selectively applying curing radiation to the molding material within the container to solidify at least a portion of the second fluid layer of the molding material, thereby forming a second solidified layer defining a second cross-section of the article, wherein the first and second cross-sections are coupled to each other in the z-direction. As will be further explained below, the above process may be repeated any desired number of times necessary to complete the 3D object.

[0012] In yet another embodiment, printed 3D articles are described herein. Such printed 3D articles can be formed from any molding material and using any method described herein. Such printed 3D articles may, in some cases, have superior accuracy compared to some other 3D articles.

[0013] These and other embodiments will be described in more detail in the following detailed description. [Modes for carrying out the invention]

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

[0015] Furthermore, all scopes disclosed herein should be understood to encompass all subscopes contained therein. For example, the scope “1.0–10.0” should be interpreted to include all any subscopes beginning with a minimum value greater than or equal to 1.0 and ending with a maximum value less than or equal to 10.0, such as 1.0–5.3, 1–4, 3–7, 4.7–10.0, 3.6–7.9, or 5–8.

[0016] Furthermore, all scopes disclosed herein should be considered to include the endpoints of that scope unless otherwise specified. For example, the scopes “between 5 and 10,” “5 to 10,” or “5 to 10” should generally be considered to include the endpoints 5 and 10.

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

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

[0019] Terms such as “3D printing systems,” “3D printers,” and “print” generally describe a variety of solid freeform manufacturing techniques for producing three-dimensional articles or objects by stereolithography, selective deposition, jetting, fusion deposition modeling, multi-jet modeling, and other additive manufacturing techniques currently known or to be known in the art that use fabrication materials to produce three-dimensional objects.

[0020] I. Materials for 3D printing In one embodiment, a printing material for use in a 3D printer is described herein. In some embodiments, the printing material described herein comprises an acrylate component, a photoinitiator component, a non-curable absorber 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 printing material described herein. Furthermore, the photoinitiator component is operable to initiate the curing of the acrylate component (and optionally, 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 printing material. Furthermore, the printing material has a penetration depth (D) at wavelength λ. p ) and critical energy (E c ) has.

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

[0022] The degree or percentage of curing (or polymerization) can be determined using any protocol or method not inconsistent with the technical objectives of this disclosure, for example, by identifying 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 monomers, or based on the total polymer mass compared to the theoretical maximum value of the total polymer mass), or by identifying the amount of unincorporated monomers or unreacted curable portions. When multiple methods are used to determine the degree of curing 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 curing or polymerization described herein is different from the “degree of polymerization” as defined as the number of repeating units in the polymer molecule.

[0023] Parameter or characteristic D p , E c , and D PTIt should be understood that these are structural parameters or properties of the molding materials 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) (first edition) (hereinafter referred to herein as "Jacobs"). As will be understood by those skilled in the art, the value D p E is defined as the penetration depth of the build material, which is the depth of the build material that causes a decrease 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 stated on page 86 of Jacobs, E c This is the critical energy, which is the energy required to obtain the gelation point of the molding material. Furthermore, as explained further in Jacobs (pages 86-89), metric E c E is equal to the intercept of the working curve corresponding to a semi-logarithmic plot of the hardening depth (vertical coordinate) and the logarithm of the maximum radiation exposure (horizontal coordinate). c This is specified for sections with a hardening depth of 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 amounts of photoinitiator components and / or non-curing absorber components contained in the molding material described herein, in combination with other components of the molding material, result in the desired D p , E c , and / or D PTIt is important to understand that you can choose to obtain a value. However, in some examples, the desired D can be obtained by a specific combination of photoinitiator and / or non-curing absorber components. p , E c , and / or D PT It should be understood that the type and / or amount of other components of the printing material, such as acrylate components, can be changed without substantially altering the value. For example, in some cases, changing the type and / or amount of acrylate components (within the range of currently disclosed types and amounts) will change the D of the printing material. p , E c , and / or D PT It affects the 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 a minimal change in value can be obtained if the components of the molding material other than the photoinitiator and noncuring absorber components (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 be obtained even if components of the printing material other than the photoinitiator and noncurable absorber components (such as acrylate components) absorb (or refract or reflect) light of wavelength λ to approximately the same degree, regardless of which exact type or amount of component is selected (within the range of currently disclosed options for types and amounts). That is, in the context of the compositions and methods described herein, components of the printing material other than the photoinitiator and noncurable absorber components can be essentially (and generally) optical "spectator" species at wavelength λ, and therefore these "spectator" species contribute to the overall D of the printing material. p , E c , and / or D PTIt does not substantially affect the value. Therefore, as will be explained in more detail below, the acrylate component or other curing component can be modified as desired for each material (with respect to the exact species and / or amount) so that, in some examples, the exact species and / or amount used for each material has a similar light absorption profile and / or refractive index.

[0025] Furthermore, in some cases, the molding materials described herein have a wavelength λ corresponding to the desired optical and chemical properties or performance indicators of the molding material. p Value and E c It has a value. A specific D p and E c A modeling material having a value or range of values ​​can also define a "regime" that is particularly desirable for a specific end use of the modeling material. For example, in some embodiments, the D of the modeling material or "family" of modeling materials p and E c The values ​​are selected based on the output and / or wavelength of the curing radiation source to be used with the build material, the desired voxel size or voxel depth of the CAD profile to be used with the build material, the desired functional resolution of the printed article formed from the build material, and / or the desired print speed to be used with the build material.

[0026] For example, in one "form," the D of the molding material p It is greater than 200 μm and less than 300 μm, and the E of the molding material c The humidity is 3-12 mJ / cm². 2 Furthermore, in some such cases, the molding material described herein has a particle size greater than 10 or greater than 15 (μm cm). 2 D in units of ) / mJ p / E c It has a ratio. In some embodiments, the molding material is (μm cm 2 ) / mJ units, 15-100, 15-50, 15-25, or 20-50 D p / E chas a ratio. Such D p , E c , and D p / E c The values of can, for example, provide desirable performance as described above when the desired voxel size is on average greater than 50 μm per side (for example, 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).

[0027] In other exemplary embodiments, D of the shaping material p is greater than 10 μm and less than 50 μm (for example, 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 ratio of less than 5, less than 3, less than 2, less than 1.5, or less than 1 in units of (μm cm p ). For example, in some embodiments, the shaping material described herein has a D c / E ratio of 0.2 - 2, 0.3 - 1.5, 0.5 - 1.5, or 1 - 2 in units of (μm cm<00--0091>). Such D p , E c , and D p , E c , and D p / E c The values of can, for example, provide desirable performance as described above when the desired voxel size is on average less than 100 μm per side, less than 70 μm per side, less than 50 μm per side, less than 40 μm per side, or less than 30 μm per side (for example, 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, the molding material D p It is greater than 25 μm and less than 50 μm, E c The humidity is 5-30 mJ / cm². 2 or 5-10 mJ / cm 2 Furthermore, in some such examples, the molding material described herein is (μm cm 2 ) / mJ units, less than 10, for example 2-6 or 3-5 D p / E c It has a ratio. Such D p , E c , and D p / E c The value of can provide the desired performance as described above, for example, when the desired voxel size has an average side length of less than 50 μm, less than 40 μm, or less than 30 μm (for example, when the desired voxel size corresponds to a volume with an average length in all three dimensions of 10-45 μm, 10-40 μm, 10-30 μm, 15-45 μm, or 15-40 μm).

[0029] D described above for one form or another form p , E c , and D p / E c In addition to the value, the molding materials described herein are desired or beneficial D PT It may also have a value. For example, in some cases the molding material described herein is 1.5xD p Below, 1.3xD p Below, 1.2xD p The following, or 1.1xD p D at the following wavelength λ PT It has D at wavelength λ. In some cases, D PT is 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~2xD p , 1.1x~1.5xD p , 1.2x~2xD p , 1.2x~1.8xD p , 1.3x~2xD p , 1.3x~1.7xD p , or 1.5x~2xD p That is the case.

[0030] Although not intended to be constrained by theory, D p , E c , and D p / E c , and optionally D PT A printing material having such a combination is expected to result in improved consistency, precision, and resolution when used as a printing material in an additive manufacturing process, including the additive manufacturing process described herein for a specific end application.

[0031] For the purposes of reference herein, a “non-curable absorbent” component or material is a material or chemical species that is not curable or substantially not curable by the curing radiation described herein and absorbs at least a portion of the curing radiation without causing substantial curing of other components of the molding material. Thus, a “non-curable” absorbent component or material may also be called a “non-curable” or “non-reactive” absorbent component or material. Furthermore, a non-curable or non-curable absorbent component described herein that is “substantially” not curable or 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-curable) absorbent component or material described herein may convert less than 2%, less than 1%, less than 0.5%, or less than 0.1% of the absorbed photons into a free radical species that can initiate or participate in (meth)acrylate polymerization or other curing processes.

[0032] It should be further understood that the non-curable or non-curable absorbing component or material described herein may still be a polymerization "spectator" (i.e., non-polymerizable or non-polymerizing) species that "competes" with the photoinitiator component of the fabrication material in terms of photon absorption of incident curing radiation. Therefore, in some examples, the non-curable absorbing component and the photoinitiator component of the fabrication material described herein have substantially overlapping photon absorption profiles, particularly in the region of the electromagnetic spectrum corresponding to or containing the peak wavelength λ. In some examples, for instance, both the non-curable absorbing 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-curable absorbing agent components and photoinitiator components of the molding materials described herein do not need to have the same absorbance, optical density, extenuation coefficient, and / or molar extinction coefficient at wavelength λ or any other specific wavelength. Rather, the non-curable absorbing agent components and photoinitiator components may have different absorbances, optical densities, extenuation coefficients, and / or molar extinction coefficients at wavelength λ, as well as other wavelengths.

[0034] Furthermore, in some examples, the amounts of photoinitiator components and noncurable absorbent components contained in the molding materials described herein are selected based on the similarity or difference of their absorbance, optical density, reduction factor, and / or molar extinction coefficient, including at wavelength λ. For example, in some examples, the amounts of photoinitiator components and noncurable absorbent components provide a desired ratio of various total absorbances at wavelength λ, and / or the desired D PT , D p , E c , or D p / E cA value is selected to provide. 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, and the “total absorbance” of each or component at wavelength λ is understood to be the amount (moles) of each or component multiplied by the molar extinction coefficient of that type or component at wavelength λ.

[0035] Furthermore, it should be noted that the wavelength λ may be any wavelength that is not inconsistent with the purposes of this 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. Furthermore, in some cases, the photoinitiator component and / or non-curable absorbent component of the fabrication material described herein have an absorption peak within the above wavelength range, such as 300 nm to 385 nm or 385 nm to 405 nm.

[0036] Any non-curable absorbent material or component that is not inconsistent with the technical objectives of this disclosure may be used in the molding materials 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 “dyes” may, more specifically, be hydrophilic or water-soluble dyes. For example, in some implementations, the non-curable absorbent component includes a water-soluble yellow dye. Alternatively, water-soluble blue or green dyes may be used.

[0037] In some embodiments, the non-curing absorbent component of the molding material described herein comprises quinoline yellow or sulfonated quinoline yellow. In some examples, the sulfonated quinoline yellow comprises at least one of a monosulfonate species, a disulfonate species, and a trisulfonate species. Furthermore, in some cases, the sulfonated quinoline yellow may be of formula I: [ka] In the formula, M is sodium or hydrogen, and the subscript n is an integer between 1 and 3. It should be further understood that the above formula I may have other structures in resonance or equilibrium. The above formula I can also be understood as representing such structures.

[0038] Furthermore, in some cases, the non-curable absorbent component of the molding 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 may also be used.

[0039] The non-curing absorbent component may be present in the modeling material described herein in any amount not inconsistent with the technical objectives of the present invention. In some embodiments, for example, the non-curing absorbent component may be present in the modeling material in an amount of up to 10% by mass or up to 5% by mass, based on the total weight of the modeling material. For example, in some examples, the modeling material contains 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 material used for molding is based on the total weight of the molding material and is in the following proportions: 0.01-10% by mass, 0.01-5% by mass, 0.01-3% by mass, 0.01-2% by mass, 0.01-1% by mass, 0.05-10% by mass, 0.05-5% by mass, 0.05-3% by mass, 0.05-1% by mass, 0.1-10% by mass, 0.1-7% by mass, 0.1-5% by mass, 0.1-3% by mass, 0.1-2% by mass, 0.1-1% by mass, 0.1-0.5% by mass, 0.2-1% by mass, 0.2-0.5% by mass, 0.5-10% by mass, 0.5-7% by mass, and 0.5-5% by mass. The material contains 0.5-2% by mass, 0.5-1% by mass, 1-10% by mass, 1-7% by mass, 1-5% by mass, or 1-3% by mass of a non-curable absorbent component. In some preferred embodiments, the amount of the non-curable absorbent component is about 1% by mass or less. For example, in some preferred embodiments, the molding material described herein contains 0.0001-1% by mass, 0.0001-0.5% by mass, 0.0001-0.1% by mass, 0.001-1% by mass, 0.001-0.5% by mass, 0.001-0.1% by mass, 0.001-0.05% by mass, 0.01-1% by mass, 0.01-0.5% by mass, 0.01-0.1% by mass, 0.01-0.05% by mass, 0.1-1% by mass, or 0.1-0.5% by mass of a non-curable absorbent component, based on the total weight of the molding material. Since "inert" non-curable absorbent components are not only optically relevant materials during curing but can also act as non-reactive "fillers," the use of relatively small amounts of non-curable absorbent components, such as the amounts mentioned above, can be particularly advantageous in some cases for maintaining or achieving desired mechanical properties of articles formed from a given molding material.Furthermore, in some embodiments, a non-curing absorbent component (such as sulfonated quinoline yellow) is present in the fabricated material in an amount sufficient to limit the penetration of light into the fabricated material to a depth of 30 μm or less, and the light has a peak wavelength of 385 nm to 405 nm.

[0040] The 3D printing materials described herein also include a photoinitiator component for initiating the polymerization of one or more components of the 3D printing material upon exposure to light of an appropriate wavelength. In some embodiments, the photoinitiator component can initiate the polymerization of the acrylate component and / or one or more additional polymerizable or curable material components of the 3D printing material.

[0041] Any photoinitiator that is not inconsistent with the purpose of this disclosure may be used in the fabrication materials described herein. In some embodiments, for example, the photoinitiator component includes an α-cleavage type (monomolecule decomposition process) photoinitiator or a hydrogen abstraction type photosensitizer-tertiary amine synergist that is capable of absorbing 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 cases, photoinitiators include benzoins such as benzoin, benzoin ethers (e.g., benzoin methyl ether, benzoyl ethyl ether, and benzoyl isopropyl ether), benzoin phenyl ether, and benzoin acetate; acetophenones such as acetophenone, 2,2-dimethoxyacetophenone, and 1,1-dichloroacetophenone; benzyl, benzyl ketals (e.g., benzyl dimethyl ketal and benzyl diethyl ketal); anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone; triphenylphosphine; benzoylphosphine oxide (e.g., 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin (TPO) etc.); benzophenones such as benzophenone and 4,4'-bis(N,N'-dimethylamino)benzophenone; thioxanthones and xanthones; acridine derivatives; phenazine derivatives; quinoxaline derivatives or 1-phenyl-1,2-propanedione; 2-O-benzoyloxime; 1-aminophenyl ketones; or 1-hydroxyphenyl ketones such as 1-hydroxycyclohexylphenyl ketone, phenyl 1-hydroxyisopropyl ketone, and 4-isopropylphenyl 1-hydroxyisopropyl ketone.

[0043] Suitable photoinitiators may also include photoinitiators that are operable for use with HeCd laser radiation sources, such photoinitiators include acetophenone, 2,2-dialkoxybenzophenone, and 1-hydroxyphenyl ketones (e.g., 1-hydroxycyclohexylphenyl ketone or 2-hydroxyisopropylphenyl ketone (=2-hydroxy-2,2-dimethylacetophenone)). Furthermore, in some examples, suitable photoinitiators include photoinitiators that are operable for use with Ar laser radiation sources, such photoinitiators include benzyl ketals such as benzyldimethyl ketal. In some embodiments, the photoinitiator includes α-hydroxyphenyl ketone, benzyldimethyl ketal, or 2,4,6-trimethylbenzoyldiphenylphosphine oxide, or a mixture thereof.

[0044] Another class of photoinitiators that may be included in the 3D printing materials described herein includes ionic dye-counterionic compounds that can absorb chemical rays to generate free radicals for polymerization initiation. In some embodiments, 3D printing materials containing ionic dye-counterionic compounds can polymerize when exposed to visible light within a tunable wavelength range of about 400 nm to about 700 nm. Ionic dye-counterionic compounds and their modes of operation are disclosed in European Patent Application Publication No. 0223587, U.S. Patents No. 4,751,102, 4,772,530, and 4,772,541.

[0045] In some cases, the photoinitiators that may be included in the fabrication materials described herein include water-soluble pyrrolidone or phosphine oxides, such as monoacylphosphine oxide (MAPO) salts or bisacylphosphine oxide (BAPO) salts, which in some cases may be sodium or lithium MAPO or BAPO salts. In some embodiments, the photoinitiators included in the fabrication materials described herein have the structure of formula II or formula III: [ka] [ka] In the formula, X is Na or Li, and R1-R 10 Each of these is independently H, CH3, or CH2CH3. For example, in some preferred embodiments, each of R1, R3, and R5 in Formula II is CH3, and R2, R4, R6, R7, R8, R9, and R 10 Each of these is H. Such species may be referred to herein as "NaP", "Na-TPO", "sodium TPO", or "sodium TPO-L" when X is Na, and as "LiP", "Li-TPO", "lithium TPO", or "lithium TPO-L" when X is Li. In other preferred embodiments, R1, R3, R5, R6, R8, and R in formula III are 10 Each of the groups is CH3, and each of R2, R4, R7, and R9 is H. Such species may be referred to herein as BAPO-ONa when X is Na, and as BAPO-OLi when X is Li. Furthermore, referring to equations II and III above, it should be understood that these structures also represent resonance structures, or (for illustrative purposes) structures where the PO single bond and PO double bond "switch places" in the depiction of the structure (for example, the PO double bond points "up" as the two adjacent CO double bonds in equation III, rather than "down" as above).

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

[0047] Furthermore, it should be understood that the amounts (mass percentages) mentioned in the preceding paragraph refer to non-oligomeric and non-polymeric photoinitiators. That is, the amounts above refer to "monomer" or "molecular" photoinitiators having a molecular weight of, for example, less than 400. However, it should also be understood that oligomeric or polymeric photoinitiators may also be used in the fabrication materials and methods described herein. However, in such cases (when oligomeric or polymeric photoinitiators are used), the amounts (mass percentages) above should be calculated without considering the weight of the oligomeric or polymeric portion of the oligomeric or polymeric photoinitiator. That is, in order to determine the total amount (mass percentage) of oligomeric or polymeric photoinitiators present in the fabrication 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 this 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 noncurable absorbent component can be selected by reference to each other. For example, in some examples, the 3D printing material described herein contains up to 5% by mass of the photoinitiator component and up to 1% by mass of the noncurable absorbent component. In other examples, the 3D printing material described herein contains up to 4% by weight of the photoinitiator component and up to 0.5% by mass of the noncurable absorbent component, or up to 5% by mass of the photoinitiator component and up to 0.05% by mass of the noncurable absorbent component. In some particularly preferred embodiments, the 3D printing material described herein contains at least 1% by mass of the photoinitiator component in combination with a certain amount of noncurable absorbent component as described herein, such as up to 0.5% by mass of the noncurable absorbent component. As further described herein, compositions with too little photoinitiator component (especially compared to the amount of noncurable absorbent component) are at a distance D p Unable to adequately react to the hardening radiation inside, as a result D p Sufficient polymerization does not occur within the spatial region defined by . In some examples, the preferred (weight) ratio of the photoinitiator component to the noncurable 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 noncurable absorbent component is 1-200, 1-100, 5-100, 1-200, 10-150, 10-100, 25-200, 25-100, 50-200, 50-150, or 50-100 (where the weight of the photoinitiator component is the numerator and the weight of the noncurable absorbent component is the denominator). Such ratios, in some examples, allow for the formation of a cured polymer network while minimizing the amount of other non-functional or noncurable "filler" materials, while achieving the desired curing effect (e.g., desired D p , E c , or D p / E c It can lead to the achievement of a ratio.

[0049] Furthermore, as described above, the relative amounts of the photoinitiator component and the noncurable absorbent component can be based at least partially (as opposed to being based solely on mass percentage or weight) on the total (optical) absorbance of the photoinitiator component and the noncurable absorbent component at wavelength λ. For example, if the noncurable absorbent component absorbs relatively weakly at wavelength λ, a relatively large amount (molar or mass percentage) of the noncurable absorbent component may be required to achieve the desired "photon competition" with the photoinitiator component, compared to a situation where the noncurable absorbent component absorbs relatively strongly at wavelength λ (in which case a relatively small amount (molar or mass percentage) of the noncurable absorbent component may be required to achieve the same desired "photon competition"). Therefore, in some embodiments, the ratio of the photoinitiator component to the noncurable absorbent component described herein (such as the weight-based ratio described above) is used when the photoinitiator component and the noncurable absorbent component have absorption (or optical density) values ​​within twice each other at wavelength λ. Furthermore, in some examples, the ratios described in the previous paragraph (such as the ratio of photoinitiator components to non-curing absorber components in the range of 10 to 100) are not weight-based ratios, but rather ratios of total absorbance at wavelength λ.

[0050] Referring here to other specific components of the modeling materials described herein, the modeling materials described herein include acrylate components. Any acrylate component that is not inconsistent with the technical purposes of this disclosure may be used. In particular, for the purposes of reference herein, it is observed that the “acrylate” component may include one or more chemical species comprising at least one acrylate, methacrylate, acrylamide, or methacrylamide moiety or functional group. Furthermore, the term “(meth)acrylate” should be understood to include acrylate or methacrylate or mixtures or combinations thereof. Similarly, the term “(meth)acrylamide” should be understood to include acrylamide or methacrylamide or mixtures or combinations thereof. Thus, the term “acrylate component” refers to the entirety of the aforementioned species in the modeling material.

[0051] In some embodiments described herein, the acrylate component comprises hydrophilic (or water-soluble) mono-, di-, and / or tri(meth)acrylate species. The acrylate component may include, for example, one or more of hydroxylalkyl(meth)acrylates (e.g., hydroxypropyl acrylate), hydroxyalkyl(meth)acrylamides (e.g., N-hydroxyethylacrylamide), ethoxylated trimethylolpropane triacrylate ("TAC" or trimethylolpropaneethoxylate triacrylate), acryloylmorpholine, and various combinations or mixtures thereof. In some embodiments, the hydroxyalkyl(meth)acrylate comprises hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, hydroxybutyl(meth)acrylate, and / or mixtures thereof.

[0052] The acrylate components of the molding materials described herein may also include poly(ethylene glycol) diacrylate (PEGDA) components. With respect to the poly(ethylene glycol) diacrylate components used herein, the PEGDA component may include a single poly(ethylene glycol) diacrylate species or multiple poly(ethylene glycol) diacrylate species with different molecular weights. In some embodiments, the species of the PEGDA component have a weight-average molecular weight of 0.1 kilodaltons (kDa) to 20 kDa or 0.2 to 20 kDa. The molecular weights of individual species of PEGDA may be, for example, within one or more ranges shown in Table 1. [Table 1] Any combination or mixture of poly(ethylene glycol) diacrylates with different molecular weights is intended. In some embodiments, the PEGDA component comprises a mixture of two or more PEGDA species, each having a weight-average molecular weight of 0.5 to 5 kDa. The specific composition of the PEGDA component (if PEGDA is used) can be selected according to several considerations, including but not limited to the crosslinking density, elasticity, tensile strength, and / or mesh size of the resulting hydrogel article.

[0053] It should be understood that the acrylate components of the 3D printing materials described herein may include combinations of acrylate species. For example, in some cases, the acrylate component may 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 two or more combinations thereof. In certain 3D printing materials, the acrylate component may include only one hydroxyalkyl (meth)acrylate. In other 3D printing materials, the acrylate component may include multiple (two or more) hydroxyalkyl (meth)acrylates. In yet another 3D printing material, the acrylate component may include at least one hydroxyalkyl (meth)acrylate and at least one hydroxyalkyl (meth)acrylamide. In yet another 3D printing material, the acrylate component may include at least one hydroxyalkyl (meth)acrylate and at least one poly(ethylene glycol) diacrylate. Therefore, this disclosure intends for many combinations and compositions of acrylate components that may be included in exemplary implementations, but these are not expressly enumerated herein.

[0054] In general, the acrylate components of the printing materials described herein may be present in the printing material in any amount that is not inconsistent with the technical objectives of this disclosure. In some embodiments, for example, the acrylate components are present in an amount or concentration of 1 to 90% by mass, based on the total weight of the printing material. In some examples, the acrylate components are present in amounts of 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, and 30 to 80% by mass. 30-75% by mass, 30-60% by mass, 30-50% by mass, 40-90% by mass, 40-80% by mass, 40-70% by mass, 40-60% by mass, 50-90% by mass, 50-85% by mass, 50-75% by mass, 50-70% by mass. Based on the total weight of the molding material, it exists in amounts of 50-60% by mass, 60-90% by mass, 60-80% by mass, 60-75% by mass, 60-70% by mass, 70-90% by mass, 70-85% by mass, 70-80% by mass, or 75-90% by mass.

[0055] Furthermore, in some cases, the molding materials described herein contain acrylate components consistent with the embodiments provided in Table 2 below, where the amounts listed in Table 2 are mass percentages of the specified components based on the total weight of the molding material. [Table 2]

[0056] The 3D printing materials described herein also include, in some cases, additional curable material components, which are added to the acrylate components. Any such additional curable material components that are not inconsistent with the technical purposes of this disclosure may be used. For the purposes of reference herein, a curable material includes a chemical species comprising one or more curable or polymerizable moieties. For the purposes of reference herein, a “polymerizable moiety” includes a moiety that can be polymerized or cured to provide a printed 3D article or object. Such polymerization or curing can be carried out in any manner that is not inconsistent with the purposes of this disclosure. In some embodiments, for example, polymerization or curing includes 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 a reactive species (e.g., a photoinitiator, or another species already “activated” to provide a reactive moiety such as a free radical moiety) that can initiate a polymerization reaction. One non-limiting example of a polymerizable moiety of a curable material described herein is an ethylenically unsaturated moiety, such as a vinyl moiety or an allyl moiety. Furthermore, in some examples, the polymerization reaction includes free radical polymerization reactions, such as reactions between unsaturated points, including ethylenically unsaturated points. Other polymerization reactions may also be used. As will be understood by those skilled in the art, the polymerization reaction used to polymerize or cure the curable materials described herein may include reactions 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] In general, any additional curable material or combination of additional curable materials that is not inconsistent with the purposes of this disclosure can be used in the 3D printing materials described herein. For example, in some cases, additional curable materials suitable for use in the 3D printing 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 wavelengths of wavelength λ or close to wavelength λ (within 30 nm). In some cases, 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 includes a compound having the structure of formula IV or formula V: [ka] [ka] In the formula, n is an integer between 4 and 40 or between 4 and 20. In some embodiments, such compounds have the structure of formula IV or formula V, where n is an integer between 4 and 14, 4 and 20, 6 and 30, 10 and 40, or between 10 and 20. Other values ​​of n are also possible. Compounds of formula IV or formula V can be prepared in any way that is not inconsistent with the technical objectives of this disclosure. For example, in some cases, the compounds described herein are formed from the reaction of poly(ethylene glycol) (PEG) with maleic anhydride (MA). Thus, 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 where n has a value corresponding to the PEG portion having a molecular weight of about 200.

[0059] Additional curable material components, if present, may be used in any amount that is not inconsistent with the technical objectives of this disclosure. In some embodiments, for example, the additional curable material components may be present in amounts of 1-30% by mass, 1-20% by mass, 5-20% by mass, 5-15% by mass, 10-30% by mass, or 10-20% by mass, based on the total weight of the molded material.

[0060] The printing materials described herein may also contain water. Water may be present in any amount that is not inconsistent with the technical purposes of this disclosure. For example, in some cases, water may be present in the printing material in amounts of 5–90% by mass, 10–85% by mass, 20–85% by mass, or 20–80% by mass, based on the total weight of the printing material. In some implementations, water may be present in amounts or concentrations of 10–60% by mass, 20–70% by mass, 20–50% by mass, 30–80% by mass, 30–60% by mass, 40–80% by mass, 40–60% by mass, 50–80% by mass, or 50–70% by mass, based on the total weight of the printing material.

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

[0062] The 3D printing materials described herein may, in some cases, further comprise one or more photosensitizers. Generally, such sensitizers can be added to the 3D printing material to enhance the effectiveness of one or more photoinitiators that may be present. In some examples, the sensitizer comprises isopropylthioxanthone (ITX) or 2-chlorothioxanthone (CTX).

[0063] The sensitizer may be present in the print material in any amount not inconsistent with the purposes of this disclosure. In some embodiments, the sensitizer is present in an amount ranging from about 0.1% to about 2% by mass or about 0.5% to about 1% by mass, based on the total weight of the print material. However, in other examples, the print material described herein excludes such sensitizers.

[0064] With respect to other possible components of the 3D printing material described herein, the 3D printing material described herein may also include at least one colorant, which may be different from the non-curable absorbent component of the 3D printing material. That is, in some examples, the colorant does not have the same photon absorption properties as described above for the non-curable absorbent component, and in particular does not have photon absorption properties that cause “competition” of the colorant for photons with the photoinitiator and / or non-curable absorbent component of the 3D printing material. Such colorants of the 3D printing material described herein may be granular colorants such as granular pigments, or molecular colorants such as molecular dyes. Any such granular or molecular colorants that are not inconsistent with the purpose of this disclosure may be used. In some examples, for example, the colorant of the 3D printing material includes inorganic pigments such as TiO2 and / or ZnO. In some embodiments, the colorant of the 3D printing material is RGB, sRGB, CMY, CMYK, L * a * b * , or colorants for use in Pantone® coloring schemes. Furthermore, in some examples, the granular colorants described herein have an average particle size of less than about 5 μm or less than about 1 μm. In some examples, the granular colorants described herein have 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 granular colorants have an average particle size of about 50 to 5000 nm, about 50 to 1000 nm, or about 50 to 500 nm.

[0065] Colorants may be present in the modeling materials described herein in any amount not inconsistent with the technical objectives of this disclosure. In some examples, the colorants may be present in the modeling materials in amounts up to about 2% by mass, or about 0.005–2% by mass, 0.01–2% by mass, 0.01–1.5% by mass, 0.01–1% by mass, 0.01–0.5% by mass, 0.1–2% by mass, 0.1–1% by mass, 0.1–0.5% by mass, or 0.5–1.5% by mass, based on the total weight of the modeling materials. In some embodiments, the modeling materials described herein exclude such colorants.

[0066] Furthermore, the molding materials described herein, in some embodiments, further comprise one or more polymerization inhibitors and / or stabilizers. Polymerization inhibitors may be added to the molding material to provide additional thermal stability to the composition. Any polymerization inhibitor that is not inconsistent with the purposes of this disclosure may be used. Furthermore, polymerization inhibitors can delay or reduce the polymerization rate and / or prevent polymerization from occurring for a period of time or “induction time” until the polymerization inhibitor is consumed. Furthermore, in some examples, the polymerization inhibitors described herein are “addition-type” inhibitors. The inhibitors described herein may also be “chain-transfer-type” inhibitors. In some examples, a suitable polymerization inhibitor comprises methoxyhydroquinone (MEHQ).

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

[0068] Polymerization inhibitors and / or stabilizers may be present in the print material in any amount not inconsistent with the purposes of this disclosure. In some embodiments, the polymerization inhibitor is present in an amount ranging from about 0.01% to about 2% by mass or about 0.05% to about 1% by mass. Similarly, in some examples, the stabilizer is present in the print material in an amount ranging from about 0.1% to about 5% by mass, about 0.1% to about 2% by mass, about 0.5% to about 4% by mass, or about 1% to about 3% by mass, based on the total weight of the print material. In some embodiments, the print material described herein excludes the polymerization inhibitor and / or stabilizer.

[0069] The morphing materials described herein may have a variety of properties in their cured or uncured states, including properties related to the microstructure of the morphing material, which may be a composite mixture or other composite material system. In some embodiments, such structural features or other properties relate to the morphing material in a cured or polymerized state. The “cured” or “polymerized” morphing materials used throughout this disclosure include morphing materials that are at least partially cured, i.e., morphing materials that contain a curable material or polymerizable component that is at least partially polymerized and / or crosslinked. For example, in some cases, the cured morphing material is polymerized or crosslinked by at least about 70%, or at least about 80%. In some embodiments, the cured morphing material is polymerized or crosslinked by at least about 85%, at least about 90%, at least about 95%, at least about 98%, or at least 99%. In some examples, the cured morphing material is polymerized or crosslinked by about 80% to about 99%. The degree of polymerization or crosslinking can be determined using any protocol or method not inconsistent with the technical objectives of this disclosure, for example, by identifying 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 identifying the amount of monomers that are not incorporated. 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” as defined as the number of repeating units in the polymer molecule.

[0070] In some embodiments, the molding materials described herein, once cured or polymerized, have an elongation at break of more than 150% when measured according to the method of Example 18. For example, certain articles formed from polymerization of the molding materials according to this disclosure may have elongations at break of 150-300%, 150-275%, 150-250%, 200-275%, or 200-250% when measured according to the method of Example 18.

[0071] Furthermore, in some embodiments, the 3D printing materials described herein have 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 examples, the 3D printing materials described herein have 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 3D printing materials described herein have 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 cases, the molding materials described herein exhibit a dynamic viscosity of approximately 200–1600 cP, approximately 200–1200 cP, approximately 200–800 cP, approximately 200–500 cP, or approximately 200–400 cP when uncured and measured in accordance with ASTM standard D2983 at 23 or 30°C.

[0072] The printing materials described herein may individually include, have, or exhibit any combination of the above-mentioned components and / or properties, provided that the combination of components and / or properties is not inconsistent with the principles and technical objectives of the present invention. Furthermore, in some embodiments, the printing materials described herein have a combination of compositional characteristics that may be particularly preferred for improving the accuracy and / or precision of additive manufacturing while maintaining the normal (or faster) speed of the additive manufacturing process, maintaining (or improving) the normal energy efficiency of additive manufacturing (with respect to the energy required for curing), and / or maintaining (or improving) the desired mechanical properties of the printed article. It should be understood that the above-mentioned “normal” or “maintained” properties are compared to printing materials of the present invention that are comparable to, but not included within, the metrics of the present invention identified above, according to the present disclosure / preferred embodiments. Similarly, it should be further understood that the “desired mechanical properties” may vary based on a predetermined selection of the printing material components. Again, however, the preferred printing materials described herein, such as the printing materials described herein, can provide the advantages intended in this disclosure without substantially impairing the mechanical properties that the printing materials offer when they are outside the range of the parameters of the present invention described herein. For example, a printing material formulated to have high elongation (e.g., through the selection of certain acrylate components and / or other components) can maintain such elongation despite containing photoinitiator components and noncurable absorber components in the formulation in a manner consistent with the preferred embodiments described above (e.g., elongation can be achieved using the preferred printing 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 3D printing materials described herein can be manufactured in any manner not inconsistent with the purposes of this disclosure. In some embodiments, for example, a method for preparing a 3D printing material described herein includes the steps of mixing the components of the 3D printing material, optionally melting the mixture, and optionally filtering the (optionally melted) mixture. In some cases, the components are mixed and optionally melted at a temperature of about 25°C to about 35°C, or at temperatures in the range of 25 to 55°C, 35 to 65°C, or 45 to 75°C. In some examples where it is desirable or necessary to melt one or more solid components of the 3D printing material, mixing and / or melting can be carried out at temperatures in the range of about 75°C to about 85°C. In some embodiments, the 3D printing material described herein is manufactured by placing all the components of the 3D printing 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 at temperatures in the range of about 75°C to about 85°C. Stirring (and optionally heating) is continued until the mixture reaches a substantially homogenized liquid (or molten) state. Generally, liquid (or molten) mixtures can be filtered while still in a fluid state to remove any large, undesirable particles that might interfere with the spraying, extrusion, or other printing processes. The filtered mixture can then be cooled to ambient temperature (if necessary) and stored until ready for use in a 3D printing system.

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

[0075] For example, in some cases, the method described herein provides a penetration depth (D) at wavelength λ. p) and critical energy (E c The process includes the steps of: providing a shaping material having; and selectively curing a portion of the shaping material using incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength of wavelength λ, wherein the shaping material has a diameter greater than 200 μm and less than 300 μm. p , and 3-12 mJ / cm² 2 E c It has. Furthermore, in some such cases, the molding material is (μm cm 2 ) / mJ, in units of D greater than 10 or greater than 15 p / E c It has a ratio. In some embodiments, the molding material used in the method described herein is (μm cm 2 ) / mJ units, 15-100, 15-50, 15-25, or 20-50 D p / E c It has a ratio. In other examples, the D of the molding material used in the method described herein. p The thickness is greater than 10 μm and less than 50 μm, and the E of the molding material c The humidity is 5-40 mJ / cm². 2 Or 10-40 mJ / cm 2 Furthermore, in some such cases, the molding material is (μm cm 2 ) / mJ, with a value less than 3, less than 2, or less than 1. p / E c The ratio is, for example, 0.2 to 2, or 0.5 to 1.5. In yet another example, the D of the molding material used in the method described herein. p The thickness is greater than 25 μm and less than 50 μm, and the E of the molding material c The humidity is 5-30 mJ / cm². 2 or 5-10 mJ / cm 2 Furthermore, in some such cases, the molding material is (μm cm 2 ) / mJ, less than 10 D p / E c The ratio is, for example, 2-6 or 3-5. Furthermore, in some embodiments described herein, the molding material is selectively cured according to pre-selected computer-aided design (CAD) parameters, Dp This corresponds to the voxel depth of the CAD parameter. Furthermore, in some examples, one or more layers of the fabrication material described herein have thicknesses of approximately 10 μm to approximately 100 μm, approximately 10 μm to approximately 80 μm, approximately 10 μm to approximately 50 μm, approximately 10 μm to approximately 40 μm, approximately 20 μm to approximately 100 μm, approximately 20 to approximately 80 μm, or approximately 20 to approximately 40 μm. Other thicknesses are also possible.

[0076] Furthermore, in some embodiments, the method described herein can provide high-resolution prints including hydrogel articles. In some cases, for example, a hydrogel article printed by the method described herein includes one or more features having an overgrowth of less than 20 percent or less than 10 percent relative to the computer dimensions of the features. Overgrowth can be measured in any desired direction and / or plane, including the xy plane, xz plane, and / or yz plane. The direction of measurement for overgrowth can be determined by the nature of the structural features of the printed hydrogel article.

[0077] By performing the printing process described herein, it is possible to provide 3D articles printed from the material described herein having high feature resolution. For reference purposes herein, “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 model of the article. In some embodiments, the printed articles described herein have an average voxel size of more than 50 μm per side on average (for example, where the average voxel size corresponds to a volume with an average length of 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 (for example, where 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 methods for printing 3D articles described herein may include, for example, MJP, DLP, or SLA 3D printing methods. For example, in some examples, an MJP method for printing 3D articles includes the step of selectively depositing layers of the build material described herein in a fluid state onto a substrate such as a build pad of a 3D printing system. Furthermore, in some embodiments, the methods described herein further include the step of supporting at least one of the layers of build material with a support material. Any support material that is not inconsistent with the purposes of this disclosure may be used.

[0079] The methods described herein may also include a step of curing a layer of the printing material, which involves using the curing radiation described above (such as curing radiation having a peak wavelength λ). Furthermore, curing may include polymerizing one or more polymerizable moieties or functional groups of one or more components of the printing material. In some examples, a deposited layer of the printing material is cured before the deposition of another or adjacent layer of the printing material. Furthermore, in some embodiments, curing of one or more deposited layers of the printing material is performed by exposing one or more layers to electromagnetic radiation such as UV light, visible light, or infrared light, as described above.

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

[0081] A. Material deposition method In the material deposition method, one or more layers of the morphing material described herein are selectively deposited onto a substrate and then cured. The curing of the morphing material may occur after the selective deposition of one layer, each layer, several layers, or all layers of the morphing material.

[0082] In some examples, the build material described herein is selectively deposited in a fluid state onto a substrate such as a build pad of a 3D printing system. Selective deposition may include, for example, depositing the build material according to pre-selected CAD parameters. For example, in some embodiments, a drawing of a CAD file corresponding to a desired 3D article to be printed is created and sliced ​​into a sufficient number of horizontal slices. Then, the build material is selectively deposited layer by layer according to the horizontal slices of the drawing in the CAD file to print the desired 3D article. A "sufficient" number of horizontal slices is, for example, the number necessary to successfully print the desired 3D article in order to manufacture it accurately and precisely.

[0083] Furthermore, in some embodiments, a pre-selected amount of the material described herein is heated to a suitable temperature and ejected through one or more printheads of a suitable inkjet printer to form layers on the print pad in the print chamber. In some examples, each layer of the material is deposited according to pre-selected CAD parameters. In some embodiments, a piezoelectric printhead is suitable for depositing the material. Further printheads suitable for depositing the material and support materials described herein are commercially available from various inkjet printer manufacturers. For example, in some examples, printheads from Xerox, Hewlett Packard, or Ricoh can be used.

[0084] Furthermore, in some embodiments, the printing material described herein remains substantially fluid upon deposition. Alternatively, in other embodiments, the printing material exhibits a phase change immediately upon deposition and / or solidifies immediately upon deposition. Furthermore, in some embodiments, the temperature of the printing environment can be controlled so that the sprayed droplets of the printing material solidify upon contact with the receiving surface. In other embodiments, the sprayed droplets of the printing material do not solidify upon contact with the receiving surface and remain substantially fluid. Furthermore, in some embodiments, after each layer has been deposited, the deposited material is planarized and cured using electromagnetic radiation (e.g., UV, visible, or infrared) before the deposition of the next layer. Optionally, several layers may be deposited before planarization and curing, or one or more layers may be deposited and then planarized without curing after a number of layers have been deposited and cured. Planarization corrects the thickness of one or more layers before the material hardens by flattening the distributed material, removing excess material, and creating a uniformly smooth exposed or flat upward surface on the printer's support platform. In some embodiments, planarization is achieved using a wiper device, such as a roller that can rotate in the opposite direction in one or more print directions but not in the opposite direction in one or more other print directions. In some examples, the wiper device comprises a roller and a wiper that removes excess material from the roller. Furthermore, in some examples, the wiper device is heated. It should be noted that, in some embodiments, the viscosity of the sprayed molding material described herein before curing is desirable to be sufficient to maintain its shape and not subject to excessive viscous resistance from the planarization device.

[0085] Furthermore, the support material, when used, can be deposited in a manner consistent with that described above for the modeling material. The support material can be deposited, for example, according to pre-selected CAD parameters such that it is adjacent to or continuous with one or more layers of the modeling material. In some embodiments, droplets of the sprayed support material solidify or coagulate upon contact with the receiving surface. In some examples, the deposited support material also undergoes planarization, curing, or both. Any support material that is not inconsistent with the purposes of this disclosure can be used.

[0086] The layering of the build material and support material can be repeated until a 3D article is formed. In some embodiments, the method for printing a 3D article further includes the step of removing the support material from the build material.

[0087] Curing of the printing material may occur after the selective deposition of one layer of printing material, each layer of printing material, several layers of printing material, or all the layers of printing material required to print the desired 3D article. In some embodiments, partial curing of the deposited printing material occurs after the selective deposition of one layer of printing material, each layer of printing material, several layers of printing material, or all the layers of printing material required to print the desired 3D article. For the purposes of reference herein, “partially cured” printing material is one that can undergo further curing. For example, a partially cured printing material is polymerized or crosslinked to a maximum of about 30%, or to a maximum of about 50%. In some embodiments, a partially cured ink is polymerized or crosslinked to a maximum of about 60%, about 70%, about 80%, about 90%, or to a maximum of about 95%.

[0088] Partial curing of the deposited material may include irradiating the material with an electromagnetic radiation source or photocuring the material (including using the curing radiation described above). Any electromagnetic radiation source that is not inconsistent with the purposes of this disclosure may be used, such as an electromagnetic radiation source that emits UV 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 examples, post-curing is performed after selectively depositing all the layers of material necessary to form the desired 3D article, after partially curing all the layers of material, or after performing both of the above steps. Furthermore, in some embodiments, post-curing includes photocuring, including using the curing radiation having a peak wavelength λ. Again, any electromagnetic radiation source that is not inconsistent with the purposes of this disclosure may be used in the post-curing steps 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., shorter wavelength) than the one used for partial curing, a xenon (Xe) arc lamp may be used for partial curing and a mercury (Hg) lamp may be used for post-curing.

[0090] Furthermore, after post-curing, in some examples, the deposited layer of the 3D printing material is polymerized or crosslinked by at least about 80%, or at least about 85%. In some embodiments, the deposited layer of the 3D printing material is polymerized or crosslinked by at least about 90%, at least about 95%, at least about 98%, or at least about 99%. In some examples, the deposited layer of the 3D printing material is polymerized or crosslinked by 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%.

[0091] B. Vat polymerization It is also possible to form 3D articles from the 3D articles described herein using vat polymerization methods such as SLA. Therefore, in some examples, the method for printing 3D articles described herein includes holding the 3D articles described herein in a fluid state in a container, selectively applying energy (in particular, curing radiation having a peak wavelength λ) to the 3D articles in the container to solidify at least a portion of the fluid layer of the 3D articles, thereby forming a solidified layer that defines the cross-section of the 3D article. Furthermore, the method described herein may further include raising or lowering the solidified layer of the 3D articles to provide a new or second fluid layer of unsolidified 3D articles on the surface of the fluid 3D articles in the container, and then selectively applying energy again to the 3D articles in the container to solidify at least a portion of the new or second fluid layer of the 3D articles, thereby forming a second solidified layer that defines the second cross-section of the 3D article. Furthermore, by applying energy to solidify the printing material, the first and second cross-sections of the 3D article can be joined or bonded together in the z-direction (or the printing direction corresponding to the upward or downward direction described above). In addition, 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. Furthermore, in some examples, raising or lowering the solidified layer of the printing material is performed using a lifting platform placed in a container of fluid printing material. The method described herein may also include a step of planarizing the new layer of fluid printing material brought about by raising or lowering the lifting platform. Such planarization can be performed in some examples by a wiper or roller.

[0092] Furthermore, it should be understood that the aforementioned process may be repeated any number of times to provide a 3D object. For example, in some cases, this process may be repeated "n" times, where n may be up to approximately 100,000, up to approximately 50,000, up to approximately 10,000, up to approximately 5,000, up to approximately 1,000, or up to approximately 500. Accordingly, in some embodiments, the method for printing a 3D article described herein may include the steps of: selectively applying energy (e.g., curing radiation with a peak wavelength λ) to a build material in a container to solidify at least a portion of the nth fluid layer of the build material, thereby forming an nth solidified layer defining the nth cross-section of the 3D article; raising or lowering the nth solidified layer of the build material to provide an (n+1)th layer of unsolidified ink on the surface of the fluid build material in the container; selectively applying energy to the (n+1)th layer of ink in the container to solidify at least a portion of the (n+1)th layer of the build material, thereby forming an (n+1)th solidified layer defining the (n+1)th cross-section of the 3D article; raising or lowering the (n+1)th solidified layer of the build material to provide an (n+2)th layer of unsolidified build material on the surface of the fluid build material in the container; and continuing to repeat the above steps to form a 3D article. Furthermore, it should be understood that one or more steps of the methods described herein, such as the step of selectively applying energy (e.g., curing radiation as described herein) to a layer of the material being fabricated, can be performed according to an image of the 3D article in a computer-readable format. Common 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 described above, the molding material can be partially cured, as described in Section IIA above. For example, in some embodiments, selectively applying energy to the molding material in the container to solidify at least a portion of the fluid layer of the molding material may include partially curing at least a portion of the fluid layer of the molding material. In other embodiments, partial curing of at least a portion of the fluid layer of the molding material may occur after providing and solidifying the first layer of the molding material, before or after providing or solidifying the second layer of the molding material, or before or after providing or solidifying one, some, or all subsequent layers of the molding 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 may be, for example, an article corresponding to a design in a CAD file.

[0095] C. Further characteristics of the method In some embodiments of the methods described herein in Section IIA or Section IIB, the method further includes the step of leaching a non-curable absorbent component (e.g., sulfonated quinoline yellow) from the printed three-dimensional hydrogel article produced by the method after completion of the print job. The hydrogel article can be placed in a water bath or other water or aqueous environment before being used, for example, 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 water environment. The water bath or other surrounding water environment containing the leached non-curable absorbent component (e.g., sulfonated quinoline yellow) may have a pH of 6.5 to 8 in the absence of buffer or other pH-controlling species added to the water. In some embodiments, the pH of the water environment containing the leached non-curable absorbent component (e.g., sulfonated quinoline yellow) may have a pH of 7 to 7.5. This represents a fundamental departure from other hydrogel inks and may create a highly acidic aqueous environment during the leaching of components after the article is completed.

[0096] III. Pudding 3D Items In another embodiment, printed 3D articles are described herein. In some embodiments, printed 3D articles are formed from the printing materials described herein. Any of the printing materials described in Section I above may be used. For example, in some examples, the printing material comprises, based on the total weight of the printing material (the total amount of components is equal to 100% by weight), 1 to 90% by mass of acrylate components, 0.5 to 3% by mass of photoinitiator components, 0.1 to 1% by mass of non-curable absorber components, and 10 to 85% by mass of water, wherein the photoinitiator components are operable to initiate curing of the acrylate components when the photoinitiator components are exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ, and the printing material has a penetration depth (D) at wavelength λ. p ) and critical energy (E c ) has, D p It is greater than 200 μm and less than 300 μm, E c The humidity is 3-12 mJ / cm². 2The material used for the molding process is 10-50 μm D p and 5-40 mJ / cm 2 E c It holds.

[0097] Hydrogel articles printed according to the methods described herein can find applications in a variety of fields, including the medical field. Hydrogel articles may, for example, be medical implants. Hydrogel medical implants can be used for tissue regeneration and / or function as scaffolds for cell seeding and / or proliferation.

[0098] Examples Some embodiments of the material for 3D printing will be further described in the following non-limiting embodiments.

[0099] Examples 1-4 Table 3 below shows some specific embodiments of the molding material. 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". Furthermore, in all cases of Table 3 below, water is balanced so that it reaches 100% by mass of the components. 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 mentioned above, it should be further noted that the "PEGDA component" and "other acrylate component" below can also be described collectively as a single "acrylate component". [Table 3]

[0100] Examples 5-10 Table 4 provides formulations of the molding material according to several 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. Please understand that all components of a given example composition total 100 mass percent. Table 5 provides the components of Examples 5-10. Table 6 shows the D of Examples 5-10. p and E c The values ​​are provided. Furthermore, in Table 5, "SQY" refers to sulfonated quinoline yellow. All components of Examples 5 to 10 below, other than the photoinitiator and non-curing absorbent components, are substantially non-absorbent at wavelength λ, and therefore 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 molding material according to several 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 not present (zero mass percentage). 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" (for example, PEGDA 3400 has a weight-average molecular weight of 3400). Furthermore, 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 of Examples 11-17. p and Ec The values ​​are provided. All components of the following Examples 11-17, other than the photoinitiator component and the non-curing absorbent component, are substantially non-absorbent at wavelength λ, and therefore these species were essentially optical spectators as described herein. [Table 7] [Table 8] [Table 9]

[0102] Example 18 Tensile tests of printed articles to measure elongation at break were performed as follows: The test formulation (ink, molding material, or polymerizable liquid) was printed on a horizontally oriented ring in a 20 μm thick layer using a digital photovoltaic (DLP) printer at room temperature (approximately 23-25°C). The ring had a neck region with a specified 1 mm × 1 mm square cross-section. The ring was removed from the printer platform and the uncured material was washed away (e.g., by placing the ring in phosphate-buffered saline (PBS) or water for 10 minutes or less 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 determining the gradient of the first 10% strain.

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

[0104] Embodiment 1. A molding material for forming hydrogel articles, Acrylate component; Photoinitiator component; Non-curing absorbent components; and water Includes, 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 molding material has a penetration depth (D) at wavelength λ. p ) and critical energy (E c ) has; D p It is greater than 200 μm and less than 300 μm; E c The humidity is 3-12 mJ / cm². 2 That is the case.

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

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

[0107] Embodiment 4. A molding material for forming hydrogel articles, Acrylate component; Photoinitiator component; Non-curing absorbent components; and water Includes, 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 molding material has a penetration depth (D) at wavelength λ. p ) and critical energy (E c ) has; D p It is greater than 10 μm and less than 50 μm; E c The humidity is 5-40 mJ / cm². 2 Or 10-40 mJ / cm 2That is the case.

[0108] Embodiment 5. The molding material is (μm cm 2 ) / mJ, with a D of 0.2 to 2 p / E c A molding material according to Embodiment 4, having a ratio.

[0109] Embodiment 6. A molding material for forming hydrogel articles, Acrylate component; Photoinitiator component; Non-curing absorbent components; and water Includes, 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 molding material has a penetration depth (D) at wavelength λ. p ) and critical energy (E c ) has; D p It is greater than 25 μm and less than 50 μm; E c The humidity is 5-30 mJ / cm². 2 or 5-10 mJ / cm 2 That is the case.

[0110] Embodiment 7. The molding material is (μm cm 2 ) / mJ, less than 10 D p / E c A molding material according to Embodiment 6, having a ratio.

[0111] Embodiment 8. The molding material is (μm cm 2 ) / mJ, in units of 2-6 or 3-5 D p / E c A molding material according to Embodiment 6, having a ratio.

[0112] Embodiment 9. The acrylate component is present in amounts of 1-90% by mass, 1-60% by mass, 1-40% by mass, 10-90% by mass, 10-80% by mass, 10-70% by mass, 10-60% by mass, 10-50% by mass, and 15-90% by mass, based on the total weight of the molding material. 15-80% by mass, 15-75% by mass, 15-60% by mass, 15-50% by mass, 15-40% by mass, 20-90% by mass, 20-85% by mass, 20-70% by mass, 20-60% by mass, 20-50% by mass, and 30-90% by mass. 30-80% by mass, 30-75% by mass, 30-60% by mass, 30-50% by mass, 40-90% by mass, 40-80% by mass, 40-70% by mass, 40-60% by mass, 50-90% by mass, 50-85% by mass, 50-75% by mass. present in the building material in an amount of 50-70% by mass, 50-60% by mass, 60-90% by mass, 60-80% by mass, 60-75% by mass, 60-70% by mass, 70-90% by mass, 70-85% by mass, 70-80% by mass, or 75-90% by mass; The photoinitiator component is present in the printed material in amounts of 0.1-5% by mass, 0.1-3% by mass, 0.1-2% by mass, or 0.5-2% by mass, based on the total weight of the printed material; The non-curing absorbent component is present in the modeling material in amounts of 0.1-5% by mass, 0.1-3% by mass, 0.1-2% by mass, 0.1-1% by mass, or 0.1-0.5% by mass, based on the total weight of the modeling material; Water is present in the modeling material in amounts of 10-85% by mass or 20-80% by mass, based on the total weight of the modeling material. The molding material described in any of the embodiments described above:

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

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

[0115] Embodiment 12. A molding 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. A molding material according to any of the above embodiments, wherein the acrylate component comprises one or more hydroxyalkyl acrylates.

[0117] Embodiment 14. The molding material comprises 0.5 to 2% by mass of a photoinitiator component and 0.1 to 1% by mass of a non-curable absorber component. The weight ratio of the photoinitiator component to the non-curing absorbent component is 2-10 or 5-100. A molding material according to any of the embodiments described above.

[0118] Embodiment 15. A fabrication material according to any of the above embodiments, wherein both the non-curable absorbent component and the photoinitiator component have absorption peaks within 30 nm of wavelength λ.

[0119] Embodiment 16. A molding material according to any of the above embodiments, wherein the total absorbance of the non-curable absorbent component at wavelength λ is approximately 0.1 to 10 times the total absorbance of the photoinitiator component at wavelength λ.

[0120] Embodiment 17. A molding material according to any of the above embodiments, wherein the non-curing absorbent component comprises a water-soluble yellow dye.

[0121] Embodiment 18. A molding material according to any of the above embodiments, wherein the non-curing absorbent component contains quinoline yellow.

[0122] Embodiment 19. A molding material according to any of the above embodiments, wherein the non-curing absorbent component comprises sulfonated quinoline yellow.

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

[0124] Embodiment 21. The acrylate component comprises 0 to 50% by mass of PEGDA species; PEGDA species have 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-curing absorbent component is present in an amount of 0.1 to 3% by mass; Water is present in amounts of 5-90% by mass. The molding material described in Embodiment 4.

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

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

[0127] Embodiment 24. A molding 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. A molding material according to Embodiment 21, Embodiment 22, Embodiment 23, or Embodiment 24, wherein a non-curing absorbent component is present in an amount of 0.1 to 1% by mass.

[0129] Embodiment 26. A molding 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 comprises one or more hydroxylalkyl (meth)acrylates; Non-curing absorbent components include UV386A, SQY, or tartrazine. The molding material described in Embodiment 21, Embodiment 22, Embodiment 23, Embodiment 24, Embodiment 25, or Embodiment 26:

[0131] Embodiment 28. A method for forming a three-dimensional article by additive manufacturing, A step of providing a molding material according to any one of Embodiments 1 to 27; and A process of selectively curing a portion of a fabrication material using incident hardening radiation having a Gaussian wavelength distribution and a peak wavelength at wavelength λ. Methods that include...

[0132] Embodiment 29. The molding material is selectively cured according to pre-selected computer-aided design (CAD) parameters; D p This corresponds to the voxel depth of the CAD parameters. The method described in 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 molding material includes a step of selectively depositing layers of the molding material in a fluid state onto a substrate to form a three-dimensional article.

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

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

[0138] Embodiment 35. A printed three-dimensional article formed from a molding material described in any of Embodiments 1 to 27 and / or using the method described in any 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 a therapeutic species to a biological environment, a microfluidic organ on a chip, a nerve graft, or a regenerative organ or tissue scaffold.

[0141] Embodiment 38. A molding material for forming hydrogel articles, Poly(ethylene glycol) diacrylate component; Sulfonated quinoline yellow; Photoinitiator components; and water Modeling materials, including those used in shaping.

[0142] Embodiment 39. The molding 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 molding 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 molding 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 molding material.

[0145] Embodiment 42. The molding 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 molding material.

[0146] Embodiment 43. The molding 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 molding material.

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

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

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

[0150] Embodiment 47. The molding 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 molding material.

[0151] Embodiment 48. The molding 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 molding material.

[0152] Embodiment 49. A method for printing a three-dimensional hydrogel article, A step of providing a molding material according to any one of embodiments 38 to 48; and A process of printing and curing a molding material with light to form a hydrogel article. Methods that include...

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

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

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

[0156] Embodiment 53. The method according to Embodiment 49, further comprising the step of leaching sulfonated quinoline yellow from a 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 referenced herein are incorporated in their entirety by reference. Various embodiments of the present invention have been described in order to achieve various objectives of the present invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A molding material for forming hydrogel articles, Acrylate component; Photoinitiator component; Non-curing absorbent components; and water Includes, The photoinitiator component is operable to initiate curing of the acrylate component when exposed to incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength λ; The aforementioned molding material has a penetration depth (D) at wavelength λ. ｐ ) and critical energy (E ｃ ) has; E ｃ The current level is 5-40 mJ / cm². ２ And, The acrylate component is present in the molding material in an amount of 5 to 80% by mass, based on the total weight of the molding material; The photoinitiator component is present in the molding material in an amount of 0.5 to 2% by mass, based on the total weight of the molding material; The non-curing absorbent component is present in the molding material in an amount of 0.1 to 1% by mass, based on the total weight of the molding material; The water is present in the molding material in an amount of 10 to 85% by mass, based on the total weight of the molding material. The weight ratio of the photoinitiator component to the non-curing absorbent component is 2 to 10. A molding material characterized by the following features.

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

3. The molding material according to claim 2, characterized in that the acrylate comprises a plurality of different PEGDA species having different molecular weights.

4. The molding material according to claim 3, characterized in that the one or more PEGDA species have a weight-average molecular weight of 0.1 kDa to 20 kDa.

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

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

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

8. The molding material according to claim 1, characterized in that the non-curing absorbent component contains a water-soluble yellow dye.

9. The molding material according to claim 1, characterized in that the non-curing absorbent component includes quinoline yellow or sulfonated quinoline yellow.

10. A method for forming a three-dimensional object by additive manufacturing, A step of providing a molding material according to claim 1; and A process of selectively curing a portion of the molding material using incident curing radiation having a Gaussian distribution of wavelengths and a peak wavelength at wavelength λ. A method characterized by including

11. The molding material is selectively cured according to pre-selected computer-aided design (CAD) parameters; D ｐ This corresponds to the voxel depth of the CAD parameters; The voxel depth is 50 μm or less. The method according to claim 10, characterized in that

12. The method according to claim 10, characterized in that the step of providing the molding material includes a step of selectively depositing a layer of the molding material in a fluid state onto a substrate to form the three-dimensional article.

13. The step of providing the molding material includes the step of holding the molding material in a fluid state within a container; The step of selectively curing a portion of the molding material includes the step of selectively applying curing radiation to the molding material in the container to solidify at least a portion of the first fluid layer of the molding material, thereby forming a first solidified layer that defines the first cross-section of the article; A step of raising or lowering the first solidified layer to provide a second fluid layer of the molding material to the surface of the fluid molding material in the container; The process involves selectively applying curing radiation to the molding material in the container to solidify at least a portion of the second fluid layer of the molding 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 bonded to each other in the z-direction. The method according to claim 10, characterized by including the following:

14. The non-curing absorbent component is present in the molding material in an amount that limits the penetration of incident curing radiation into one or more layers of the molding material to a depth of 30 μm or less; λ is between 385 nm and 405 nm. The method according to claim 10, characterized in that

15. A printed three-dimensional article formed from the molding material described in claim 1.

16. The article according to claim 15, characterized in that the article is a medical implant.

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