阅读说明：本技术 低粘度双固化增材制造树脂 (Low viscosity dual cure additive manufacturing resin ) 是由 A·G·赖特 陈凯 B·E·斐乐 于 2020-04-21 设计创作，主要内容包括：根据一些实施方案,本文提供一种双固化增材制造树脂,包含：(i)光可聚合组分,(ii)光引发剂,(iii)热可聚合组分以及(iv)非反应性稀释剂,所述树脂通过增材制造可用于三维物体的生产。还提供了使用其的方法。(According to some embodiments, provided herein is a dual cure additive manufacturing resin comprising: (i) a light-polymerizable component, (ii) a photo-initiator, (iii) a thermally polymerizable component and (iv) a non-reactive diluent, said resin being useful for the production of three-dimensional objects by additive manufacturing. Methods of using the same are also provided.)

1. A dual cure additive manufacturing resin, comprising:

(i)a photopolymerizable component (e.g., from 30 or 50 weight percent to 80 or 90 weight percent),

(ii) photoinitiators (e.g. from 0.2 or 0.3 weight percent)To 2 or 4 weight percent),

(iii) a thermally polymerizable component (e.g., from 2 or 5 weight percent to 20 or 25 weight percent), and

(iv) a non-reactive diluent (e.g., from 1, 2,4, or 6 weight percent to 20, 60, 80, or 90 weight percent).

2. The resin of claim 1, the non-reactive diluent having a boiling point of from 80 or 100 degrees Celsius to 250 degrees Celsius (at standard temperature and pressure).

3. The resin of any preceding claim, wherein the resin has a viscosity of no more than 3500 centipoise, 3000 centipoise, or 2500 centipoise at 40 degrees celsius (e.g., when measured according to the procedure given in example 3 herein).

4. The resin of any of the preceding claims, wherein the non-reactive diluent is included in the resin in an amount from 1 or 5 weight percent to 10, 15, or 20 weight percent.

5. The resin of any of the preceding claims, wherein the non-reactive diluent comprises a glycol ether (e.g., dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, propylene glycol methyl ether, diethylene glycol monomethyl ether, ethylene glycol ethyl ether, propylene glycol monomethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol butyl ether, and the like, including combinations thereof).

6. The resin of any of the preceding claims, wherein the non-reactive diluent comprises an ester (e.g., butyl acetate, hexyl acetate, octyl acetate, decyl acetate, dodecyl acetate, and the like, including combinations thereof).

7. The resin of any of the preceding claims, wherein the non-reactive diluent comprises an alcohol (e.g., butanol, pentanol, hexanol, 1-octanol, 2-ethylhexanol, decanol, dodecanol, and the like, including combinations thereof).

8. The resin of any of the preceding claims, wherein the non-reactive diluent comprises N-methyl-2-pyrrolidone, N-dimethylformamide, heavy naphtha, toluene, xylene, mineral spirits or mineral spirits, or a combination thereof.

9. The resin of any of the preceding claims, wherein the non-reactive diluent comprises dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, or a combination thereof.

10. The resin of any of the preceding claims, wherein the non-reactive diluent has:

(i)a boiling point of less than 160, 200 or 240 degrees celsius at a pressure of 1 bar; and/or

(ii)An auto-ignition temperature of less than 300, 400, or 600 degrees celsius (i.e., measured according to the procedure described in ASTM E659); and/or

(iii)Flash points as measured by the Pensky-Martens closed cup method are less than 50, 80, 100, or 140 degrees Celsius (e.g., ASTM D93, EN ISO 2719 or IP 34).

11. A resin according to any preceding claim, the photopolymerizable component comprising a monomer, a prepolymer or both a monomer and a prepolymer which are polymerizable by exposure to actinic radiation or light.

12. The resin of claim 11, said monomer, prepolymer, or both of said photopolymerizable components comprising a reactive end group selected from the group consisting of acrylates, methacrylates, α -olefins, N-vinyls, acrylamides, methacrylamides, styrenics, epoxides, thiols, 1, 3-dienes, vinyl halides, acrylonitriles, vinyl esters, maleimides, and vinyl ethers.

13. A resin according to any preceding claim, wherein the thermally polymerisable component comprises a precursor of: polyurethanes, polyureas, copolymers of polyurethanes and polyureas, silicone resins, epoxy resins, cyanate resins, copolymers of epoxy and cyanate resins, or natural rubber.

14. The resin of any of the preceding claims, wherein the photopolymerizable component comprises a reactive end-capping monomer, a reactive end-capping prepolymer, or a combination thereof.

15. A resin according to any preceding claim, wherein the photopolymerizable component comprises a polyisocyanate prepolymer end-capped by reaction of a polyisocyanate oligomer and an amine (meth) acrylate, alcohol (meth) acrylate, maleimide or n-vinylformamide monomer end-capping agent.

16. The resin of any of the preceding claims, wherein the thermally polymerizable component comprises a polyol and/or polyamine in liquid or solid form, including encapsulated solids or liquids, dissolved or suspended in the resin.

17. The resin of any of the preceding claims, wherein the resin further comprises at least one, any combination, or all of the following:

(v)a chain extender;

(vi)a reactive diluent;

(vii)a pigment or dye; and

(viii)and (4) filling.

18. The resin of any of the preceding claims, wherein the resin further comprises an antioxidant (e.g., from 0.1 weight percent to 3 or 5 weight percent).

19. The resin of any of the preceding claims, wherein the resin further comprises a plasticizer (e.g., from 1, 2, or 4 weight percent to 10, 15, 25, 30, or 40 weight percent).

20. A method of fabricating a three-dimensional (3D) object from a photopolymerizable resin, comprising the steps of:

(a) providing a dual cure resin of any of the preceding claims;

(b) producing an intermediate 3D object from the resin by photopolymerizing the resin in an additive manufacturing process (e.g., bottom-up or top-down stereolithography);

(c) optionally cleaning the intermediate 3D object; and then

(d) Heating the intermediate 3D object (e.g., to a temperature of from 80 to 250 degrees celsius) to volatilize the diluent, polymerizing the thermally polymerizable component, and producing the three-dimensional object.

21. The method of claim 20, wherein the producing step is performed by bottom-up stereolithography (e.g., continuous liquid interface production).

22. The method of claim 20 or claim 21, wherein the cleaning step is included (and is performed, for example, by washing, spinning, rubbing, blowing, or a combination thereof).

23. The method of any one of claims 20 to 22, wherein the object has:(i) a Shore A hardness of at least 60 or 70;(ii)a Young's modulus of at least 15 or 16 MPa;(iii)a percent elongation at break of at least 200 or 250;(iv)an ultimate tensile strength of at least 16, 18 or 20 MPa, or(v)Any combination of the foregoing (each determined, for example, according to the procedures set forth in example 4 herein).

24. The method of any one of claims 20 to 23, wherein the heating step is performed on the intermediate object in an inert atmosphere.

25. The method of claim 24, further comprising:

(e) condensing out a sufficient amount of volatile diluent from the inert atmosphere to reduce the duration of the heating step concurrently with the heating step.

26. A product produced by the method of any one of claims 20 to 25.

27. The product of claim 26, comprising an open cell lattice (e.g., a strut lattice or a three-period surface lattice).

Technical Field

The present invention relates generally to additive manufacturing and in particular to dual cure resins that provide both enhanced printability and good functional properties in the fabricated object.

Background

A group of additive manufacturing techniques, sometimes referred to as "stereolithography," create three-dimensional objects by sequential polymerization of photopolymerizable resins. Such techniques may be "bottom-up" techniques, in which light is projected through a light-transmissive window into the resin at the bottom of the growing object, or "top-down" techniques, in which light is projected onto the resin at the top of the growing object, which is then dipped down into a pool of resin.

The recent introduction of faster stereolithography techniques, known as Continuous Liquid Interface Production (CLIP), in combination with the introduction of "dual cure" resins for additive manufacturing, has expanded the utility of stereolithography from prototype research to manufacturing (see, e.g., U.S. patent nos. 9,211,678, 9,205,601, and 9,216,546 to DeSimone et al, and j. Tumbleston, D. Shirvanyants, n. Ermoshkin et al, continuous liquid interface production of 3D objects,Science 347, 1349-; see also Rolland et al, U.S. Pat. Nos. 9,676,963, 9,453,142, and 9,598,606).

While dual cure additive manufacturing resins can produce objects with functional properties that are satisfactory for consumers and other end uses, they can be highly viscous, resulting in slower production speeds in additive manufacturing processes such as CLIP. Thus, there is a need for dual cure resins that have enhanced printability during production without sacrificing the functional properties of the resulting product.

Disclosure of Invention

According to some embodiments, provided herein is a dual cure additive manufacturing resin comprising:(i)a photopolymerizable component (e.g., from 30 or 50 weight percent to 80 or 90 weight percent),(ii)a photoinitiator (e.g., from 0.2 or 0.3 weight percent to 2 or 4 weight percent),(iii)a thermally polymerizable component (e.g., from 2 or 5 weight percent to 20 or 25 weight percent) and(iv)a non-reactive diluent (e.g., from 1, 2,4, or 6 weight percent to 20, 60, 80, or 90 weight percent).

In some embodiments, the non-reactive diluent has a boiling point from 80 or 100 degrees celsius to 250 degrees celsius (at standard temperature and pressure).

In some embodiments, the resin has a viscosity of no more than 3500 centipoise, 3000 centipoise, or 2500 centipoise at 40 degrees celsius (e.g., when measured according to the procedure given in example 3 herein).

In some embodiments, a non-reactive diluent is included in the resin in an amount from 1 or 5 weight percent to 10, 15, or 20 weight percent.

In some embodiments, the non-reactive diluent comprises a glycol ether (e.g., dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, propylene glycol methyl ether, diethylene glycol monomethyl ether, ethylene glycol ethyl ether, propylene glycol monomethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol butyl ether, and the like, including combinations thereof).

In some embodiments, the non-reactive diluent comprises an ester (e.g., butyl acetate, hexyl acetate, octyl acetate, decyl acetate, dodecyl acetate, and the like, including combinations thereof).

In some embodiments, the non-reactive diluent comprises an alcohol (e.g., butanol, pentanol, hexanol, 1-octanol, 2-ethylhexanol, decanol, dodecanol, and the like, including combinations thereof).

In some embodiments, the non-reactive diluent comprises N-methyl-2-pyrrolidone, N-dimethylformamide, heavy naphtha, toluene, xylene, mineral spirits or mineral spirits, or a combination thereof.

In some embodiments, the non-reactive diluent comprises dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, or a combination thereof.

In some embodiments, the non-reactive diluent has:(i)a boiling point of less than 160, 200 or 240 degrees celsius at a pressure of 1 bar; and/or(ii)An auto-ignition temperature of less than 300, 400, or 600 degrees celsius (i.e., measured according to the procedure described in ASTM E659); and/or(iii)Flash points as measured by the Pensky-Martens closed cup method are less than 50, 80, 100, or 140 degrees Celsius (e.g., ASTM D93, EN ISO 2719 or IP 34).

In some embodiments, the photopolymerizable component comprises a monomer, a prepolymer, or both a monomer and a prepolymer that can be polymerized by exposure to actinic radiation or light.

In some embodiments, the monomers, prepolymers, or monomers and prepolymers of the photopolymerizable component comprise reactive end groups selected from the group consisting of acrylates, methacrylates, alpha-olefins, N-vinyls, acrylamides, methacrylamides, styrenics, epoxides, thiols, 1, 3-dienes, vinyl halides, acrylonitriles, vinyl esters, maleimides, and vinyl ethers.

In some embodiments, the thermally polymerizable component comprises a precursor of: polyurethanes, polyureas, copolymers of polyurethanes and polyureas, silicone resins, epoxy resins, cyanate resins, copolymers of epoxy and cyanate resins, or natural rubber.

In some embodiments, the photopolymerizable component comprises a reactive end-capping monomer, a reactive end-capping prepolymer, or a combination thereof.

In some embodiments, the photopolymerizable component comprises a polyisocyanate prepolymer end-capped by the reaction of a polyisocyanate oligomer and an amine (meth) acrylate, alcohol (meth) acrylate, maleimide, or n-vinyl formamide monomer end-capping agent.

In some embodiments, the thermally polymerizable component comprises a polyol and/or a polyamine. In some embodiments, the polyol and/or polyamine may be in liquid or solid form, including encapsulated solids or liquids, dissolved or suspended in the resin.

In some embodiments, the resin further comprises at least one, any combination, or all of the following:(v)a chain extender;(vi)a reactive diluent;(vii)a pigment or dye; and(viii)and (4) filling.

Also provided is a method of fabricating a three-dimensional (3D) object from a photopolymerizable resin, comprising the steps of: (a) providing a dual cure resin as taught herein; (b) producing an intermediate 3D object from the resin by photopolymerizing the resin in an additive manufacturing process (e.g., bottom-up or top-down stereolithography); (c) optionally cleaning the intermediate 3D object; and then (D) heating the intermediate 3D object (e.g., to a temperature of from 80 to 250 degrees celsius) to volatilize the diluent, polymerize the thermally polymerizable component, and produce the three-dimensional object.

In some embodiments, the production step is performed by bottom-up stereolithography (e.g., continuous liquid interface production).

In some embodiments, a cleaning step is included (and is performed, for example, by washing, spinning, wiping, blowing, or a combination thereof).

In some embodiments, the object has:(i)a Shore A hardness of at least 60 or 70;(ii)a Young's modulus of at least 15 or 16 MPa;(iii)a percent elongation at break of at least 200 or 250;(iv)an ultimate tensile strength of at least 16, 18 or 20 MPa, or(v)Any combination of the foregoing (each determined, for example, according to the procedures set forth in example 4 herein).

In some embodiments, the heating step is performed on the intermediate object in an inert atmosphere.

In some embodiments, the method further comprises: (e) condensing out a volatile diluent from the inert atmosphere in an amount sufficient to reduce the duration of the heating step concurrently with the heating step.

Further provided are products produced by the methods described herein. In some embodiments, the product comprises an open cell lattice (e.g., a strut lattice, a three-cycle surface lattice).

The foregoing and other objects and aspects of the present invention are explained in more detail in the drawings herein and in the detailed description set forth below. The disclosures of all U.S. patent references cited herein are hereby incorporated by reference.

Detailed Description

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

As used herein, the term "and/or" includes any and all possible combinations of one or more of the associated listed items and, when interpreted in the alternative ("or"), does not include combinations.

1. Resin composition

Dual cure resins are preferred for use in the practice of the present invention. Such resins are known and described, for example, in U.S. patent nos. 9,676,963, 9,453,142, and 9,598,606 to Rolland et al and 10,316,213 to Arndt et al, the disclosures of which are incorporated herein by reference in their entirety.

Dual cure additive manufacturing resins as taught herein may comprise:(i)a photopolymerizable component (e.g., from 30 or 50 weight percent to 80 or 90 weight percent),(ii)a photoinitiator (e.g., from 0.2 or 0.3 weight percent to 2 or 4 weight percent),(iii)a thermally polymerizable component (e.g., from 2 or 5 weight percent to 20 or 25 weight percent) and(iv)a non-reactive diluent (e.g., from 1, 2,4, or 6 weight percent to 20, 60, 80, or 90 weight percent).

Non-reactive diluents useful in the present invention are typically organic liquids, which may be polar or non-polar, and protic or aprotic. The diluent is preferably non-flammable, non-hygroscopic, low odor and low viscosity.

In some embodiments, the non-reactive diluent has a boiling point from 80 or 100 degrees celsius to 250 degrees celsius (at standard temperature and pressure). In some embodiments, the non-reactive diluent has a boiling point of less than 160, 200, or 240 degrees celsius at a pressure of 1 bar. In some embodiments, the non-reactive diluent autoignition temperature is less than 300, 400, or 600 degrees celsius (i.e., measured according to the procedure described in ASTM E659). In some embodiments, the non-reactive diluent has a flash point of less than 50, 80, 100, or 140 degrees celsius as measured by the Pensky-Martens closed cup method (e.g., ASTM D93, EN ISO 2719, or IP 34).

In some embodiments, the resin has a viscosity of no more than 3500 centipoise, 3000 centipoise, or 2500 centipoise at 40 degrees celsius (e.g., when measured according to the procedure given in example 3 herein).

In some embodiments, a non-reactive diluent is included in the resin in an amount from 1 or 5 weight percent to 10, 15, or 20 weight percent.

Specific examples of suitable diluents include, but are not limited to: glycol ethers (e.g., dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, propylene glycol methyl ether, diethylene glycol monomethyl ether, ethylene glycol ethyl ether, propylene glycol monomethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol butyl ether, and the like, including combinations thereof); esters (e.g., butyl acetate, hexyl acetate, octyl acetate, decyl acetate, dodecyl acetate, and the like, including combinations thereof); alcohols (e.g., butanol, pentanol, hexanol, 1-octanol, 2-ethylhexanol, decanol, dodecanol, and the like, including combinations thereof); n-methyl-2-pyrrolidone, N-dimethylformamide, heavy naphtha, toluene, xylene, mineral spirits or mineral spirits, or combinations thereof; and dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, or combinations thereof.

The photopolymerizable component may comprise a monomer, a prepolymer, or both a monomer and a prepolymer that can be polymerized by exposure to actinic radiation or light. In some embodiments, the photopolymerizable component comprises reactive end groups selected from the group consisting of acrylates, methacrylates, alpha-olefins, N-vinyls, acrylamides, methacrylamides, styrenics, epoxides, thiols, 1,3 dienes, vinyl halides, acrylonitriles, vinyl esters, maleimides, and vinyl ethers.

The photopolymerizable component may comprise a reactive end-capping monomer, a reactive end-capping prepolymer, or a combination thereof. For example, the photopolymerizable component may comprise a polyisocyanate prepolymer end-capped by reaction of a polyisocyanate oligomer and an amine (meth) acrylate, alcohol (meth) acrylate, maleimide or n-vinylformamide monomer end-capping agent.

According to some embodiments, the thermally polymerizable component may include a polyol and/or a polyamine, which may be provided in liquid or solid form, including encapsulated solids or liquids, dissolved or suspended in the resin. In some embodiments, the thermally polymerizable component comprises a precursor of: polyurethanes, polyureas, copolymers of polyurethanes and polyureas, silicone resins, epoxy resins, cyanate resins, copolymers of epoxy and cyanate resins, or natural rubber.

The resin may further comprise at least one, any combination or all of the following:(v)a chain extender;(vi)a reactive diluent;(vii)a pigment or dye; and(viii)and (4) filling.

The resin may further comprise an antioxidant and/or a plasticizer. Examples of antioxidants include, but are not limited to, phenols, hindered phenols, phosphites, thiosynergists (thiosynergists), and combinations thereof (available from Mayzo, Suwanee, Georgia). Specific examples of plasticizers include, but are not limited to, phthalate plasticizers such as di (2-ethylhexyl) phthalate (DEHP), di (2-propylheptyl) phthalate (DPHP), diisononyl phthalate (DINP); trimellitate plasticizers, such as tris- (2-ethylhexyl) trimellitate (TEHTM) (TOTM); adipate plasticizers, such as di (2-ethylhexyl) adipate (DEHA), diisononyl adipate (DINA); sebacate plasticizers such as dibutyl sebacate (DBS), maleate plasticizers such as diisobutyl maleate (DBM), and the like. Examples also include plasticizers of natural origin, such as epoxidized soybean oil (ESBO) or other epoxidized vegetable oils (e.g., cashew oil).

2. Additive manufacturing

Techniques for producing intermediate objects, or "green" intermediates, from such resins by additive manufacturing are known. Suitable techniques include bottom-up and top-down additive manufacturing, commonly referred to as stereolithography. Such methods are known and described, for example, in U.S. Pat. No. 5,236,637 to Hull, U.S. Pat. Nos. 5,391,072 and 5,529,473 to Lawton, U.S. Pat. No. 7,438,846 to John, U.S. Pat. No. 7,892,474 to Shkolnik, U.S. Pat. No. 8,110,135 to El-Siblani, U.S. patent application publication No. 2013/0292862 to Joyce, and U.S. patent application publication No. 2013/0295212 to Chen et al. The disclosures of these patents and applications are incorporated herein by reference in their entirety.

In some embodiments, the additive manufacturing step is carried out by one of a series of methods sometimes referred to as Continuous Liquid Interface Production (CLIP). CLIP is known and describedFor example, U.S. patent nos. 9,211,678; 9,205,601, respectively; 9,216,546, respectively; and others; continuous liquid interface production of 3D objects in J. Tumbleston et al,Science 347, 1349-; and in r. janussziewcz et al, by continuous liquid interface production,Proc. Natl. Acad. Sci. USA113, 11703-11708 (2016). Other examples of specific embodiments for implementing additive manufacturing steps (sometimes referred to as CLIPs), and which may be used to implement the methods and apparatus of the present invention, include, but are not limited to: batchelder et al, U.S. patent application publication No. US 2017/0129169; sun and Lichkus, U.S. patent application publication No. US 2016/0288376; willis et al, U.S. patent application publication No. US 2015/0360419; lin et al, U.S. patent application publication No. US 2015/0331402; D. castanon, U.S. patent application publication No. US 2017/0129167; B. beller, U.S. patent application publication No. US 2018/0243976 (published on 30/8 in 2018); m, Panzer and j, Tumbleston, U.S. patent application publication No. US 2018/0126630 (published 5/10 in 2018); and k. Willis and b. Adzima, U.S. patent application publication No. US 2018/0290374 (10 months and 11 days 2018).

3. Further curing

Once the intermediate object is formed and optionally cleaned (e.g., by wiping, blowing, spinning, washing, and the like, including combinations thereof), the object is then further cured, such as by heating. The heating may be active heating (e.g., baking in an oven, such as an electric, gas, solar, or microwave oven, or combinations thereof), or passive heating (e.g., at ambient (room) temperatures). Active heating will generally be faster than passive heating, and is generally preferred, but passive heating, such as merely holding the intermediate at ambient temperature for a sufficient time to cause further curing, may also be applied in some embodiments.

Inert atmosphere and oven. In some embodiments using active heating or baking, the object is heated in an inert atmosphere (i.e., an atmosphere containing less oxygen than air). Inert atmosphere ovens in which the oven chamber is purged with an inert gas (such as nitrogen or argon) are known and available from Gruenberg/Thermal Products Solutions, 2821 Old Route 15, new columbia, usa at 17856 pa; despatch Thermal Processing Technology, 8860207^thStreet, minneapolis, 55044 usa, minnesota, and others. In some embodiments, the oven may include a condenser to cool a portion of the oven atmosphere during the toasting step and to separate the volatized solvent from the oven atmosphere by condensation (and thereby accelerate the volatization of additional inert diluent from the heated object into the oven atmosphere). Any suitable condenser configuration may be employed, such as a cooling coil in the oven chamber itself (with a liquid collector, e.g., a drip pan or funnel with a drain operatively connected to the condenser); an assembly for removing a gas side stream from the oven chamber, condensing out the volatilized solvent, and returning the gas side stream into the oven chamber; and so on. A number of such condensing systems are known (see, e.g., U.S. patent No. 5,220,796) and are available from oven manufacturers such as those mentioned above.

4. Three-dimensional product

In some embodiments, the three-dimensional product produced by the methods herein may include one or more repeating structural elements, including, for example, being (or substantially corresponding to) closed cavities, partially closed cavities, repeating cells or cell networks, foam cells, kelvin foam cells or other open cell or closed cell foam structures, staggered structures, overhanging structures, cantilevers, microneedles, fibers, paddles, protrusions, pins, pits, rings, tunnels, tubes, shells, panels, beams (including I-beams, U-beams, W-beams, and cylindrical beams), struts, tie rods, channels (whether open, closed, or partially closed), waveguides, triangular structures, tetrahedral or other pyramidal shapes, cubes, octahedrons, octagonal prisms, triacontahedrons, rhombohedrons, or other polyhedral shapes or modules (including kelvin mini-surface tetradecahedrons, tetragons, and other polyhedral shapes or modules (including kelvin-surface tetradecahedrons), Prismatic or other polyhedral shape), pentagonal, hexagonal, octagonal, and other polygonal structures, or structures of prismatic, polygonal mesh, or other three-dimensional structures. In some embodiments, the object may comprise a combination of any of these structures or an interconnected network of these structures. In an example embodiment, all or a portion of the structure of the 3D shaped object may correspond to (or substantially correspond to) one or more Bravais lattice or unit cell structures, including cubic (including simple, body-centered or face-centered), tetragonal (including simple or body-centered), monoclinic (including simple or bottom-centered), orthorhombic (including simple, body-centered, face-centered or bottom-centered), rhombohedral, hexagonal and triclinic structures. In some embodiments, the object may comprise a shape or surface equivalent to (or substantially equivalent to) a catenoid (catenoid), helicoid (helicoid), gyroid or lidinoid, other three-cycle minimal surface (TPMS), or other geometry, diamond or diamond pattern, lattice or other pattern or structure from a related family (or Bonnet family) or Schwarz P ("original") or Schwarz D ("diamond"), Schwarz H ("hexagonal"), or Schwarz CLP ("parallel cross-ply") surface.

In some embodiments, the three-dimensional products produced by the methods herein can include an arrangement of lattice cells (e.g., an open cell lattice) interconnected on one or more portions (e.g., surface portions) thereof. In some embodiments, the product may comprise three-cycle units (i.e., units that repeat in three dimensions), such as three-cycle surfaces or three-cycle minimal surfaces (see, e.g., Ryan US 9,440,216 and Robb et al, US 7,718,109).

The invention is explained in further detail in the following non-limiting examples.

Examples 1 to 2

(comparative example A)

Preparation of resin containing non-reactive solvent (and control)

The materials used in the examples herein, their abbreviations and their sources are given in table 1 below.

ABPU, 68.48% PEG600DMA, Irganox 245, and TPO were added to a 200 mL vessel. After 30 minutes of mixing at 2000 rpm via a THINKY chamber-mixer, the remaining PEG600DMA, TMPTMA, DINA and DMM were added. The vessel was closed for mixing via a THINKY chamber-mixer for 4 minutes. The pigment was added and mixed again for 4 minutes. MACM was added and mixed via a THINKY-mixer at 2000 rpm for 4 minutes and then 2200 rpm for 30 seconds. The parts by weight of the formulation are given in table 2 below. Formulation 2 and control formulation (a) were prepared similarly to above, with the corresponding components shown in table 2 below.

Example 3

Viscosity of resin formulation

The viscosity of the resin formulation was measured at 40 degrees celsius using a Brookfield viscometer (model DV 1) equipped with a spindle at SC 4-31. Bubble free sample (9.0 g) was poured into the sample chamber and the temperature was allowed to equilibrate for 15 minutes. After equilibration, the RPM of the spindle was adjusted to about 50% of the target torque (RPM approximately 3.0-1.5, depending on the sample viscosity), where the viscosity was measured. The results are given in table 3 below.

Example 4

Properties of objects produced from resin formulations

Each resin was printed immediately after mixing on a Carbon inc. M1 additive manufacturing apparatus (Carbon, inc., redwood city, california) to produce a 0.8 mm thick board. The panels were baked as received (without a washing step) at 90 ℃ for 2 hours and then at 128 ℃ for 2 hours. Tensile samples were cut into ASTM D412 dog bone specimens using Die C and tested for tensile properties at a strain rate of 500 mm/min. The results are given in table 4 below.

Despite the significant difference in viscosity during printing and the substantial loss of solvent from the object during the subsequent curing step, it was surprisingly seen that the final mechanical properties of the parts produced from formulations 1 and 2 were very similar to those of the parts produced from the control resin. Accordingly, the use of inert volatile solvents to enhance the printability of the resin seems to be without any drawbacks, based on the final mechanical properties of the object produced.

Example 5

Cyclohexanone as a non-reactive solvent

When the formulation of the above example was repeated using cyclohexanone instead of DMM, the resin viscosity rapidly increased to form a gel within 1 hour after mixing all the components and heating at 40 ℃, making it unable to be successfully processed/printed under these conditions. It is currently believed that this is due to the chemical incompatibility of MACM and cyclohexanone, thus making cyclohexanone a "reactive" diluent in this case. However, if the curable is a polyol rather than a polyamine (MACM), it is possible that cyclohexanone (and other ketones/aldehydes) may be used as a "non-reactive" diluent.

Example 6

Additional examples of resin formulations

The ABPU may be composed of:

the foregoing is illustrative of the present invention and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.