WO2017068590A1 - Impression 3d par jet d'encre à l'aide de composés dicyclopentadiéniques polymérisables par polymérisation par métathèse avec ouverture de cycle - Google Patents

Impression 3d par jet d'encre à l'aide de composés dicyclopentadiéniques polymérisables par polymérisation par métathèse avec ouverture de cycle Download PDF

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Publication number
WO2017068590A1
WO2017068590A1 PCT/IL2016/051142 IL2016051142W WO2017068590A1 WO 2017068590 A1 WO2017068590 A1 WO 2017068590A1 IL 2016051142 W IL2016051142 W IL 2016051142W WO 2017068590 A1 WO2017068590 A1 WO 2017068590A1
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WIPO (PCT)
Prior art keywords
romp
catalyst
monomer
modeling material
formulation
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Application number
PCT/IL2016/051142
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English (en)
Inventor
Yuval VIDAVSKY
Ira Yudovin-Farber
Norberto Gabriel LEMCOFF
Amos BEN ASULY
Yakov GINZBURG
Sukdeb SAHA
Original Assignee
Stratasys Ltd.
B.G. Negev Technologies & Applications Ltd., At Ben-Gurion University
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Application filed by Stratasys Ltd., B.G. Negev Technologies & Applications Ltd., At Ben-Gurion University filed Critical Stratasys Ltd.
Publication of WO2017068590A1 publication Critical patent/WO2017068590A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/485—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by the process of building-up characters or image elements applicable to two or more kinds of printing or marking processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/10—Processes of additive manufacturing
    • B29C64/106—Processes of additive manufacturing using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
    • B29C64/112—Processes of additive manufacturing using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material using individual droplets, e.g. from jetting heads
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/10—Processes of additive manufacturing
    • B29C64/188—Processes of additive manufacturing involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B25/00—Layered products comprising a layer of natural or synthetic rubber
    • B32B25/16—Layered products comprising a layer of natural or synthetic rubber comprising polydienes homopolymers or poly-halodienes homopolymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y10/00—Processes of additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y70/00—Materials specially adapted for additive manufacturing
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
    • C07D233/54—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members
    • C07D233/56—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, attached to ring carbon atoms
    • C07D233/60—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, attached to ring carbon atoms with hydrocarbon radicals, substituted by oxygen or sulfur atoms, attached to ring nitrogen atoms
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
    • C07D233/54—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members
    • C07D233/64—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with substituted hydrocarbon radicals attached to ring carbon atoms, e.g. histidine

Definitions

  • the present invention in some embodiments thereof, relates to three- dimensional inkjet printing and, more particularly, but not exclusively, to systems, methods and compositions employing ring-opening metathesis polymerization (ROMP) for producing three-dimensional objects, while using DCPD-based monomer.
  • ROMP ring-opening metathesis polymerization
  • Three-dimensional (3D) inkjet printing is a known process for building three dimensional objects by selectively jetting chemical compositions, for example, polymerizable compositions, via ink-jet printing head nozzles onto a printing tray in consecutive layers, according to pre-determined image data.
  • 3D inkjet printing is performed by a layer by layer inkjet deposition of chemical formulations, which form together a building material formulation.
  • a chemical formulation is dispensed in droplets from a dispensing head having a set of nozzles to form layers on a receiving medium.
  • the layers may then be cured or solidified using a suitable methodology, to form solidified or partially solidified layers of the building material.
  • the chemical formulations used for forming the building material may be initially liquid and subsequently hardened (cured or solidified) to form the required layer shape.
  • the hardening may be effected, for example, by exposing the building material to a curing energy such as thermal energy (e.g., by heating the building material) or to irradiation (e.g., UV or other photo-irradiation), or may be activated chemically, for example, by acid or base activation.
  • the chemical (e.g., polymerizable) formulations utilized in inkjet 3D printing processes are therefore selected so as to meet the process requirements, namely, exhibiting a suitable viscosity during jetting (thus being non-curable under jetting conditions) and rapid curing or solidification, typically upon exposure to a stimulus, on the receiving medium.
  • the formulations should have a relatively low viscosity, of about 10-25 cPs, at the jetting temperature, in order to be jettable.
  • the building material is selectively jetted from one or more printing heads and deposited onto a fabrication tray in consecutive layers according to a pre-determined configuration as defined by a software file.
  • a printing system utilized in a 3D inkjet printing process may include a receiving medium and one or more printing heads.
  • the receiving medium can be, for example, a fabrication tray that may include a horizontal surface to carry the material dispensed from the printing head.
  • the printing head(s) may be, for example, an ink jet head having a plurality of dispensing nozzles arranged in an array of one or more rows along the longitudinal axis of the printing head. The jetting nozzles dispense material onto the receiving medium to create the layers representing cross sections of a 3D object.
  • the printing system may include a leveling device for leveling and/or establishing the height of each layer after deposition and at least partial solidification, prior to the deposition of a subsequent layer.
  • the building materials may include modeling materials and support materials, which form the object and optionally the temporary support constructions supporting the object as it is being built, respectively.
  • the modeling material (which may include one or more material(s)) is deposited to produce the desired object/s and the support material (which may include one or more material(s)) is used, with or without modeling material elements, to provide support structures for specific areas of the object during building and assure adequate vertical placement of subsequent object layers, e.g., in cases where objects include overhanging features or shapes such as curved geometries, negative angles, voids, and so on.
  • Both the modeling and support materials are preferably liquid at the working temperature at which they are dispensed, and subsequently hardened, upon exposure to a condition that affects curing of the materials, to form the required layer shape. After printing completion, support structures are removed to reveal the final shape of the fabricated 3D object.
  • the uncured building material should feature the following characteristics: a relatively low viscosity (e.g., Brookfield Viscosity of 10 to about 30 cps, preferably from 10 to 20 cps) at the working (e.g., jetting) temperature; Surface tension of from about 20 to about 40 Dyne/cm; and a Newtonian liquid behavior and high reactivity to a selected curing energy, to enable immediate solidification of the jetted layer upon activation (e.g., application of curing energy).
  • a relatively low viscosity e.g., Brookfield Viscosity of 10 to about 30 cps, preferably from 10 to 20 cps
  • Surface tension e.g., from about 20 to about 40 Dyne/cm
  • a Newtonian liquid behavior and high reactivity to a selected curing energy e.g., application of curing energy
  • a thin layer (5-40 microns) of the building material should be sufficiently cured within about 200 milliseconds when exposed to UV radiation (of 0.5 W/cm , 340-390 nm), in order to enable the building of subsequent layers.
  • the cured material When a cured rigid modeling material forms the final object, the cured material should preferably exhibit heat deflection temperature (HDT) which is higher than room temperature, in order to assure its usability. Typically, the cured modeling material should exhibit HDT of at least 35 °C. For an object to be stable in variable conditions, a higher HDT is desirable.
  • HDT heat deflection temperature
  • UV-curable materials such as acrylic based materials.
  • UV-curable modeling material formulations for forming rigid objects by inkjet printing which exhibit the properties required for 3D inkjet printing, while being jetted, as described herein, are acrylic -based materials, which typically exhibit HDT in the range of 35-50 °C. Exemplary such formulations are generally described, for example, in U.S. Patent No. 7,479,510, to the present Assignee.
  • Such modeling material formulations when cured, typically feature impact resistance in the range of 20-25 J/m.
  • a cured modeling material should feature both high HDT and high toughness, i.e., impact resistance.
  • Ring-opening metathesis polymerization is a type of olefin metathesis chain-growth polymerization.
  • the driving force of the reaction is the relief of strained cyclic structures, typically cyclic olefins (e.g., norbornenes or cyclopentenes) or dienes (e.g., cyclopentadiene-based compounds).
  • the polymerization reaction typically occurs in the presence of organometallic catalysts, and the ROMP catalytic cycle involves formation of metal-carbene species, which reacts with the double bond in the cyclic structure to thereby form a highly strained metallacyclobutane intermediate.
  • the ring then opens, giving a linear chain double bonded to the metal with a terminal double bond as well.
  • the as formed metal-carbene species then reacts with the double bond on another cyclic monomer, and so forth.
  • ROMP reactions in reaction injection molding has been described, for example, in U.S. Patent Application Publication Nos. 2011/0171147, 2005/0691432, U.S. Patent No. 8,487,046, EP Patent Application Publication No. 2452958, and EP Patent No. 2280017.
  • One of the ROMP materials used in ROMP- based RIM is dicyclopentadiene (DCPD).
  • Poly-DCPD-based materials exhibit good mechanical properties and combine both good toughness and high thermal resistance.
  • polymeric materials based on DCPD were used to produce Telene 1810, which features a viscosity of about 200 cps at room temperature, HDT of 120 °C and impact of 300 J/m; and Metton M15XX, which features a viscosity of 300 cps at room temperature, Tg of 130 °C and impact of 460 J/m [see, for example, www(dot)metton(dot)com/index(dot)php/metton- lmr/benefits].
  • DCPD-based formulations are highly toxic and have an extremely unpleasant, irritating, odor, which often limits their use to sealed industrial environments.
  • Kotha S. et al. disclose the hydroxy derivative of DCPD and its propargylic ether.
  • Kotha S. et al. (Beilstein J. Org. Chem. 2015, 11, 1503-1508) disclose the ketone derivative of DCPD and two stereoisomer ⁇ oximes prepared therefrom.
  • Kotha S. and Ravikumar O. (Eur. J. Org. Chem. 2014, 5582-5590 and Tetrahedron Letters 55 (2014) 5781-5784) disclose several enone, O- allyl and N-allyl derivatives of DCPD.
  • Gong L. et al. (RSC Adv., 2015, 5, 26185- 26188) disclose the acetoxy derivative of DCPD and linear polymer thereof.
  • Additional background art includes WO 2013/128452; Adv. Funct. Mater. 2008, 18, 44-52; Adv. Mater. 2005, 17, 39-42; and Pastine, S. J.; Okawa, D.; Zettl, A.; Frechet, J. M. J. J. Am. Chem. Soc. 2009, 131, 13586-13587; Vidavsky and Lemcoff, Beilstein J. Org. Chem.
  • ROMP read-only memory
  • RIM room temperature
  • a formulation polymerizable by ROMP immediately solidifies once a catalyst is added and/or activated. This limits the use of ROMP formulations in 3D inkjet processes, where liquid formulations that feature viscosity within a predetermined range are required to be passed through inkjet printing heads.
  • DCPD dicyclopentadiene
  • ppb parts per billion
  • DCPD is considered highly toxic.
  • DCPD is considered a volatile compound, and its vapor pressure is 1.4 mmHg at 20 °C (see, National Institute for Occupational Safety and Health (NIOSH) Pocket Guide to Chemical Hazards).
  • the present inventors have now designed various methodologies which enable using ROMP formulations containing DCPD-based monomers in 3D inkjet printing, while circumventing the limitations associated with the malodorous and/or toxicity commonly used DCPD.
  • Embodiments of the present invention therefore relate to methods (processes) and systems designed for practicing ROMP-based methodologies with DCPD-based monomers, as defined herein, while meeting the technological and environmental requirements of 3D inkjet printing processes.
  • Embodiments of the present invention further relate to objects formed upon utilizing DCPD-based monomers as described herein in a 3D inkjet printing process.
  • Embodiments of the present invention further relate to polymeric materials comprising polymerized DCPD-based monomers as described herein.
  • a method of fabricating a three-dimensional object comprising sequentially forming a plurality of layers in a configured pattern corresponding to the shape of the object, thereby forming the object,
  • each layer comprises dispensing by at least one inkjet printing head at least one modeling material formulation, the at least one modeling material formulation comprising an unsaturated cyclic monomer polymerizable by ring opening metathesis polymerization (ROMP) and a catalyst for initiating ROMP of the monomer; and
  • ROMP ring opening metathesis polymerization
  • the dashed lines independently indicate a configuration at a respective position
  • Y is selected from -0-, -S-, and NH-R' , wherein R' is selected from hydrogen, alkyl, cycloalkyl and aryl, each being substituted or unsubstituted,
  • A is hydrogen or is selected from:
  • curled line indicates an attachment point to LI ;
  • a L2-D group wherein L2 is a linking moiety or absent, and D is a NR 10 R 11 group, wherein Rio and Rn are each independently selected from hydrogen, alkyl, aryl, alkaryl and cycloalkyl, or alternatively, Rio and Rn form together a heteroalicyclic or heteroaryl group, or, alternatively, D is a NRioRiiRi 2 + Q , with Rio, Rn and R12 being each independently selected from hydrogen, alkyl, aryl, alkaryl and cycloalkyl, or alternatively, Rio, Rn and Ri 2 form together a nitrogen-containing heteroaryl group, and Q " is an anion; and
  • Y is O.
  • A is an alkyl
  • the alkyl is a linear alkyl selected from the group consisting of methyl, ethyl, n-propyl and n-octyl.
  • A is an alkylaryl.
  • A is benzyl
  • R9 is aryl
  • R9 is an alkaryl, and the aryl is substituted by an amine or an ammonium salt.
  • A is a L2-D group, and wherein D is a NRioRiiRi 2 + Q , wherein Rio, Rn and R12 form together a nitrogen-containing heteroaryl group, and Q " is an anion.
  • A is selected from the group consisting of 3 -pentylene-1 -methyl-imidazolium bromide, 3-hexylene-l- methyl-imidazolium bromide, 3 -heptylene-1 -methyl-imidazolium bromide and 3- pentylene- 1 ,2-dimethyl-imidazolium bromide.
  • the catalyst prior to the exposing the catalyst does not initiate ROMP of the monomer.
  • the modeling material formulation is such that the catalyst is active towards initiating ROMP of the monomer, and wherein prior to the exposing, the catalyst and the monomer are physically separated in the modeling material formulation.
  • the condition comprises removing the physical separation between the catalyst and the monomer.
  • At least one of the monomer and the catalyst is enveloped by a capsule and the condition affects a release of the monomer or the catalyst from the capsule.
  • the condition is selected from heat, irradiation, and shear forces.
  • the modeling material formulation is such that the catalyst is inactive towards initiating ROMP of the monomer.
  • the catalyst is activatable upon exposure to the condition.
  • the condition is selected from heat, and radiation.
  • the formulation further comprises an activator for chemically activating the catalyst towards initiating ROMP of the monomer, and wherein prior to the exposing, the activator is incapable of activating the catalyst.
  • the activator is physically separated from the catalyst and/or the monomer in the modeling material formulation.
  • the condition comprises removing the physical separation between the activator and the catalyst and/or the monomer.
  • the activator is enveloped by a capsule, and the condition affects a release of the activator from the capsule.
  • the condition is selected from heat, radiation, and shear forces.
  • the activator prior to the exposing, the activator is chemically inactive in the modeling material formulation.
  • the activator is activatable upon exposure to the condition, such that exposing to the condition activates the activator, thereby activating the catalyst towards initiating ROMP of the monomer.
  • the modeling material formulation further comprises a ROMP inhibitor.
  • the at least one modeling material formulation further comprises at least one material polymerizable or curable via a non-ROMP reaction, and wherein the exposing further comprises exposing the at least one modeling material formulation to a condition for inducing polymerization or curing of the at least one material.
  • the material comprises a monomer and/or an oligomer polymerizable by free-radical polymerization, cationic polymerization, anionic polymerization, or polycondensation.
  • the material is polymerizable or curable upon exposure to radiation (photopolymerizable).
  • the polymerizable material and the cyclic olefin monomer polymerizable by the ROMP are included in the same modeling material formulation.
  • At least one of the non-ROMP polymerizable or curable material, an initiator of the non-ROMP reaction, the monomer polymerizable by the ROMP, and the catalyst is physically separated from other components in the formulation.
  • each layer comprises dispensing at least two modeling material formulations by at least two inkjet printing heads, each head jetting one of the at least two modeling material formulations.
  • At least one of the modeling material formulations comprises the unsaturated cyclic monomer polymerizable by ROMP, and at least another one of the modeling material formulations comprises the catalyst.
  • at least one of the modeling material formulations which comprises the monomer polymerizable by ROMP further comprises an activator for chemically activating the catalyst towards initiating ROMP of the monomer.
  • At least one of the modeling material formulations comprises the unsaturated cyclic monomer polymerizable by ROMP, and the catalyst, and at least another one of the modeling material formulations comprises an activator for chemically activating the catalyst towards initiating ROMP of the monomer.
  • the material polymerizable or curable by the non-ROMP reaction is comprised in at least one modeling material formulation which is devoid of the monomer polymerizable by the ROMP.
  • At least one of the modeling material formulations further comprises an initiator of the non-ROMP reaction.
  • the initiator is comprised in at least one modeling material formulation which is devoid of the material polymerizable or curable via the non-ROMP reaction.
  • condition for inducing ROMP of the unsaturated cyclic monomer and the condition for inducing polymerization or curing of the chemical group or material polymerizable or curable via a non-ROMP reaction are the same.
  • each layer comprises dispensing at least two modeling material formulations by at least two inkjet printing heads, each head jetting one of the at least two modeling material formulations, wherein at least two of the modeling material formulations independently comprise the unsaturated cyclic olefin monomer polymerizable by ROMP, and wherein at least one of the modeling material formulations comprises the catalyst.
  • At least one of the modeling material formulations comprises the monomer and the catalyst.
  • the catalyst is activatable by the condition.
  • the catalyst is activatable by an activator, and at least one of the modeling material formulations comprises the activator and is devoid of the catalyst.
  • At least one of the formulations comprises the monomer and the activator and at least another one of the formulations comprises the monomer and the catalyst.
  • At least one of the formulations comprises a ROMP inhibitor.
  • the at least one modeling material formulation further comprises an impact modifying agent, a stabilizing agent, a surface active agent, an elastomeric component or composition, an antioxidant, a filler, a pigment, and a dispersant.
  • the method further comprises dispensing a support material formulation by at one additional inkjet printing head.
  • the method further comprises exposing the support material formulation to a condition for inducing polymerization or curing of the support material formulation.
  • a temperature of an inkjet printing head for dispensing the at least one modeling material formulation ranges from 25 °C to 65 °C.
  • a temperature of an inkjet printing head for dispensing the at least one modeling material formulation ranges from 65 °C to about 95 °C.
  • condition is heat and wherein the exposing to the condition comprises heating the at least one modeling material formulation following the dispensing.
  • the heating is by infrared radiation. According to some of any of the embodiments described herein, the heating is by a ceramic radiation source.
  • the dispensing is in a chamber, and wherein the heating comprises heating the chamber to a temperature of from 25 °C to 65 °C.
  • the plurality of layers are formed on a working tray, and the method comprises heating the working tray to a temperature of from 25 °C to 65 °C.
  • the dispensing and/or the exposing are performed under inert atmosphere.
  • the method further comprises straightening the layer by a leveling device.
  • the method further comprises removing cured or partially cured formulation off the leveling device.
  • the straightening is while the at least one formulation is at a cured or partially cured state.
  • the straightening comprises milling.
  • a method of fabricating a three-dimensional object comprising: sequentially forming a plurality of layers in a configured pattern corresponding to a shape a mold of the object;
  • a molding composition comprising an unsaturated cyclic monomer polymerizable by ROMP as defined in claim 1, and a catalyst for initiating ROMP of the monomer, thereby obtaining the object.
  • the method further comprises exposing the mold to a condition for inducing initiation of ROMP of the monomer by the catalyst.
  • a method of fabricating a three-dimension object comprising: introducing to a mold having a shape of the object a molding composition comprising an unsaturated cyclic monomer polymerizable by ROMP as defined in claim 1 and respective embodiments, and a catalyst for initiating ROMP of the monomer, thereby obtaining the object.
  • the method further comprises introducing to the mold a molding composition comprising a curable material that is polymerizable by a non-ROMP reaction, and an initiator for initiating a non-ROMP polymerization.
  • the curable material is a UV-curable material.
  • Implementation of the method and/or system of embodiments of the invention can involve performing or completing selected tasks manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of embodiments of the method and/or system of the invention, several selected tasks could be implemented by hardware, by software or by firmware or by a combination thereof using an operating system.
  • a data processor such as a computing platform for executing a plurality of instructions.
  • the data processor includes a volatile memory for storing instructions and/or data and/or a non-volatile storage, for example, a magnetic hard-disk and/or removable media, for storing instructions and/or data.
  • a network connection is provided as well.
  • a display and/or a user input device such as a keyboard or mouse are optionally provided as well.
  • FIG. 1A presents a TGA curve of hydroxydicyclopentadiene (DCPD-OH).
  • FIG. IB presents a HMQC spectrum of hydroxyl-dicyclopentadiene (DCPD- OH) in CDC1 3 .
  • FIGs. 2A and 2B present HRMS spectra of the sodium salt of compound 1.
  • FIG. 2C presents a TGA curve of compound 1.
  • FIG. 2D presents a COSY NMR spectrum of compound 1 in CDC1 3 .
  • FIG. 2E presents a HMQC NMR spectrum of compound 1 in CDCI 3 .
  • FIGs. 3 A and 3B present HRMS spectra for the sodium salt of compound 3.
  • FIG. 3C presents a TGA curve of compound 3.
  • FIG. 3D presents a COSY NMR spectrum of compound 3 in CDC1 3 .
  • FIG. 3E presents a HMQC NMR spectrum of compound 3 in CDCI 3 .
  • FIGs. 4A and 4B present HRMS spectra for the sodium salt of compound 4.
  • FIG. 4C presents a TGA curve of compound 4.
  • FIG. 4D presents a COSY NMR spectrum of compound 4 in CDC1 3 .
  • FIG. 4E presents a HMQC NMR spectrum of compound 4 in CDCI 3 .
  • FIG. 5 presents a HRMS spectrum of compound 6.
  • FIGs. 6 A and 6B present HRMS spectra for the sodium salt of compound 11.
  • FIG. 6C presents a TGA curve of compound 11.
  • FIG. 7 presents HRMS spectra for compound 12.
  • FIG. 8 presents HRMS spectra for compound 13.
  • FIG. 9A presents a COSY NMR spectrum of compound 14 in CDC1 3 .
  • FIG. 9B presents a HMQC spectrum of compound 14.
  • FIG. 9C presents a HRMS spectrum of compound 14.
  • FIG. 9D presents a TGA curve of compound 14.
  • FIG. 10 presents a TGA curve of endo-OCPO.
  • FIG. 11 A presents a DSC curve of pDCPD (the polymer of endo-OCPO).
  • FIG. 1 IB presents a TGA curve of pDCPD (the polymer of endo-OCPO), after 2 hours of curing.
  • FIG. 12A presents a DSC curve of pDCPD-OH (the polymer of hydroxy-DCPD (DCPD-OH)).
  • FIG. 12B presents a TGA curve of pDCPD-OH (the polymer of hydroxy-DCPD (DCPD-OH)), after 2 hours of curing.
  • FIG. 13A presents a DSC curve of pDCPD-OMe (the polymer of compound 1).
  • FIG. 13B presents a TGA curve of pDCPD-OMe (the polymer of compound 1), after 2 hours of curing.
  • FIG. 14A presents a DSC curve of pDCPD-OPr (the polymer of compound 3).
  • FIG. 14B presents a TGA curve of pDCPD-OPr (the polymer of compound 3), after 2 hours of curing.
  • FIG. 15A presents a DSC curve of pDCPD-OOc (the polymer of compound 4).
  • FIG. 15B presents a TGA curve of pDCPD-OOc (the polymer of compound 4), after 2 hours of curing.
  • FIG. 16A presents a DSC curve of pDCPD-OAc (the polymer of compound 14).
  • FIG. 16B presents a TGA curve of pDCPD-OAc (the polymer of compound 14), after 2 hours of curing.
  • FIG. 17 presents a DMA plot for pDCPD-OCH 2 Ph (the polymer of compound
  • FIG. 18 presents a TGA curve of pDCPD-OBz (the polymer of compound 11), after 2 hours of curing.
  • FIG. 20 presents a photograph of the following polymers: (i) pDCPD (the polymer of endo-DCPD), (ii) pDCPD-OH (the polymer of DCPD-OH), (iii) pDCPD- OAc (the polymer of compound 14), (iv) pDCPD-OBz (the polymer of compound 11), (v) pDCPD-OMe (the polymer of compound 1), (vi) pDCPD-OPr (the polymer of compound 3) and (vii) DCPD-OOc (the polymer of compound 4).
  • the transparency of the polymers is shown by the lines drawn under the polymers.
  • FIG. 21 presents an image for wetting of pDPCD-OH (the polymer of DCPD-
  • FIG. 22 presents a DMA plot for pDCPD (the polymer of endo-DCPD). DMA storage tensile modulus E' and mechanical loss factor tan6 as a function of temperature for pDCPD.
  • FIG. 23 presents a DMA plot for pDCPD-OH the polymer of DCPD-OH).
  • FIG. 24 presents a DMA plot for pDCPD-OAc (the polymer of compound 14). DMA storage tensile modulus E' and mechanical loss factor tan6 as a function of temperature for pDCPD-OAc.
  • FIG. 25 presents a DMA plot for pDCPD-OBz (the polymer of compound 11). DMA storage tensile modulus E' and mechanical loss factor tan6 as a function of temperature for pDCPD-OBz.
  • FIG. 26 presents a DMA plot for pDCPD-OMe (the polymer of compound 1).
  • FIG. 27 presents a DMA plot for pDCPD-OPr (the polymer of compound 3). DMA storage tensile modulus E' and mechanical loss factor tan6 as a function of temperature for pDCPD-OPr.
  • FIG. 28 presents a DMA plot for pDCPD-OOct (the polymer of compound 4). DMA storage tensile modulus E' and mechanical loss factor tan6 as a function of temperature for pDCPD-OOc.
  • FIG. 29 presents the FTIR for DCPD-OH monomer.
  • FIG. 30 presents the FTIR for DCPD-OAc monomer (compound 14).
  • FIG. 31 presents the FTIR for DCPD-OPr monomer (compound 3).
  • FIG. 32 presents the FTIR for pDCPD-OH thin film (the polymer of DCPD-OH) formed in the presence of Grubb's 2 nd generation catalyst.
  • FIG. 33 presents the FTIR for pDCPD-OAc thin film (the polymer of compound 14) formed in the presence of Grubb's 2 nd generation catalyst.
  • FIG. 34 presents the FTIR for pDCPD-OPr thin film (the polymer of compound 3) formed in the presence Grubb's 2 nd generation catalyst.
  • FIG. 35 presents the FTIR for pDCPD-OAc thin film (the polymer of compound 14), formed in the presence of Grubb's 1 st generation catalyst.
  • FIG. 36 presents the FTIR for pDCPD-OPr thin film (the polymer of compound 3), formed in the presence of Grubb's 1 st generation catalyst.
  • FIG. 37 presents the expanded FTIR spectra for polymeric films obtained using Grubb's 1 st and 2 nd generation catalysts.
  • FIG. 38 presents images of an exemplary polymeric material formed of an acrylic resin and an exemplary DCPD derivative according to some embodiments of the present invention, demonstrating an elongation of the formulation.
  • FIG. 39 is a flowchart describing an exemplary method according to some embodiments of the present invention.
  • FIG. 40 is a schematic illustration of a system suitable for 3D inkjet printing of an object according to some embodiments of the present invention.
  • FIGs. 41A-C are schematic illustrations of printing heads according to some embodiments of the present invention.
  • FIG. 42 is a schematic illustration of a self-cleaning leveling device, according to some embodiments of the present invention. DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION
  • the present invention in some embodiments thereof, relates to three- dimensional inkjet printing and, more particularly, but not exclusively, to systems, methods and compositions employing ring-opening metathesis polymerization (ROMP) for producing three-dimensional objects, while using DCPD-based monomer.
  • ROMP ring-opening metathesis polymerization
  • ROMP ring-opening metathesis polymerization
  • DCPD-based ROMP curable monomers Materials obtained by ring-opening metathesis polymerization (ROMP), of DCPD-based ROMP curable monomers, are characterized by exceptional mechanical and other properties.
  • ROMP chemistry in 3D inkjet printing requires solving problems associated with, for example, fast propagation of the polymerization reaction, immediately once a catalyst contacts a DCPD-based ROMP monomer.
  • pre-mixing a DCPD ROMP monomer and catalyst before jetting leads to substantial increase in viscosity when such a formulation passes through the inkjet printing head and nozzle plate, resulting in clogging due to polymerization of the composition on the nozzle plate.
  • ROMP chemistry in 3D inkjet printing further requires solving problems associated with, for example, the malodorous and/or toxic DCPD-based materials commonly used in ROMP methodologies, which require performing the printing processes in industrial environment and/or in printing systems that are completely sealed to the operator' s environment.
  • the present inventors have now designed and successfully practiced novel methodologies for utilizing the valuable properties of materials prepared by ROMP of DCPD in the fabrication of three-dimensional objects in 3D inkjet printing processes.
  • the present inventors have designed 3D inkjet processes and systems which utilize DCPD-based ROMP monomers which are less volatile that the commonly used DCPD, and are therefore less toxic and free of the irritating odor characterizing DCPD-based curable materials usable in ROMP processes yet provide 3D printed objects which exhibit a desired performance.
  • Embodiments of the present invention therefore relate to the use of DCPD-based curable materials, s defined herein, which are free of an irritating odor, as ROMP monomers in the fabrication of three-dimensional objects in 3D inkjet printing processes.
  • the 3D inkjet printing processes and systems disclosed herein allow practicing ROMP-based 3D inkjet printing with DCPD-based materials, as defined herein, in non-industrial environment, using commonly used methods and systems, while circumventing a need for adjusting the evacuation system used in these processes and systems so as to handle highly-volatile hazardous materials.
  • Embodiments of the present invention further relate to curable hybrid formulations which combine the non-volatile DCPD-based curable materials as described herein and other materials (e.g., elastomeric materials), which exhibit exceptional mechanical and thermal properties.
  • curable hybrid formulations which combine the non-volatile DCPD-based curable materials as described herein and other materials (e.g., elastomeric materials), which exhibit exceptional mechanical and thermal properties.
  • Such formulations can be utilized in 3D inkjet printing processes as described herein, and in other methodologies for fabricating three-dimensional objects, such as molding (e.g., reactive injection molding).
  • ROMP monomer encompasses a single monomer or a plurality (two or more) of ROMP monomers, which are polymerizable by ring opening metathesis polymerization.
  • a ROMP monomer or a plurality of ROMP monomers as described herein in any one of the present embodiments comprises at least one DCPD-based ROMP monomers as defined by Formula I* herein, or by Formula I herein or by Formula II herein.
  • DCPD-based monomer namely, a derivative of DCPD in which the malodor characterizing DCPD is reduced or even diminished or nullified, by introducing a modification at the alpha position of the cyclopentene ring of DCPD, as defined herein Formulae P, Pa, I and/or II.
  • DCPD Dicyclopentadiene
  • substitution is effected at least at the secondary carbon at position alpha to the double bond.
  • a ROMP monomer according to the present embodiments is also referred to herein as a DCPD-based ROMP monomer, as it has a basic skeleton as DCPD.
  • a ROMP monomer according to the present embodiments is a DCPD-based compound, or a DCPD derivative, which is polymerizable by ROMP in the presence of a catalyst or a catalyst system, as described herein.
  • the DCPD-based ROMP monomers described herein exhibit a vapor pressure which is reduced compared to DCPD by at least 20 %, or at least 30 %, or at least 40 %, or at least 50 %, or at least 60 %, or by more.
  • a vapor pressure of DCPD is reported in the art as being at least 1.4 mmHg at 20
  • a vapor pressure of a DCPD-based ROMP monomer of the present embodiments is lower than 1 mmHg, preferably lower than lower than 0.8 mmHg, or lower than 0.7 mmHg, or lower than 0.5 mmHg, at 20 °C.
  • a DCPD-based ROMP monomer as described herein is characterized by maximum rate of weight loss temperature higher than 200 °C.
  • a DCPD-based ROMP monomer as described herein is characterized by a boiling temperature higher than 200 °C.
  • the dashed lines independently indicate a configuration at a respective position
  • Y is selected from -0-, -S-, and NH-R', wherein R' is selected from hydrogen, alkyl, cycloalkyl and aryl, each being substituted or unsubstituted,
  • A is hydrogen or is selected from:
  • curled line indicates an attachment point to LI
  • a L2-D group wherein L2 is a linking moiety or absent, and D is a NR 1 0R 11 group, wherein Rio and Rn are each independently selected from hydrogen, alkyl, aryl, alkaryl and cycloalkyl, or alternatively, Rio and Rn form together a heteroalicyclic or heteroaryl group, or, alternatively, D is a NRioRiiRi 2 + Q , with Rio, Rn and R 12 being each independently selected from hydrogen, alkyl, aryl, alkaryl and cycloalkyl, or alternatively, Rio, Rn and Ri 2 form together a nitrogen-containing heteroaryl group, and Q " is an anion; and
  • Embodiments of the present invention encompass DCPD-based ROMP monomers featuring any configuration at the indicated position, and any combination thereof. These include en o-configuration, ejco-configuration, and racemic mixtures thereof. While in some embodiments, compounds are presented in an endo- configuration, it is to be understood that ejco-configuration and a racemic mixture are also contemplated and these embodiments are not to be regarded as limiting.
  • the configuration of the bond linking variable Y to the DCPD skeleton can adopt any configuration and a racemic mixture of these configurations.
  • Embodiments of the present invention encompass any stereomers, enantiomers, and diastereomers, encompassed by Formula I* herein.
  • embodiments of the present invention encompass polymeric (cured) materials obtained upon subjecting the DCPD-based ROMP monomer, or a mixture of monomers comprising same, to curing conditions.
  • the polymers or copolymers obtained can adopt any tacticity.
  • the DCPD-based ROMP monomer has an en o-configuration, although an exo configuration is also contemplated.
  • Y is O.
  • Y is an oxygen-containing polar group
  • the DCPD-based monomer is an ether derivative, or an ester derivative, of DCPD.
  • A is hydrogen
  • the ROMP monomer is DCPD-OH:
  • Y is O and A is alkyl (linear or branched alkyl), alkenyl, cycloalkyl, or aryl, each being optionally substituted, as described herein, and the DCPD-based ROMP monomer is an ether derivative of DCPD.
  • Exemplary such compounds are Compounds 1, 2, 3 and 4, as described herein.
  • Y is O and A is or comprises an aryl, for example, phenyl.
  • the aryl comprises at least one aromatic ring and may be connected to the DCPD skeleton (or moiety) via an alkylene linker, such that A is an alkaryl.
  • the aryl may be optionally substituted with one or more of alkyl, halogen, nitro and carbonyl chloride (acyl chloride) group.
  • A is alkaryl, and in some embodiments, the alkaryl
  • An exemplary compound is compound 5 (presented as its endo -configuration):
  • the aryl may be substituted by one or more positively charged groups, for example, amine, including tertiary amine and quaternary ammonium (e.g., an ammonium salt).
  • positively charged groups for example, amine, including tertiary amine and quaternary ammonium (e.g., an ammonium salt).
  • A is or comprises an alkyl and the alkyl is substituted by a positively-charged group, as defined herein.
  • Exemplary such compounds are compounds 6-9:
  • Z is O
  • the DCPD-based monomer is a DCPD ester derivative.
  • R9 is alkyl (linear or branched alkyl), cycloalkyl, alkaryl or aryl, each being optionally substituted, as defined herein.
  • Exemplary such compounds are compounds 11 and 14:
  • R9 is alkyl (linear or branched alkyl), cycloalkyl, alkaryl or aryl, substituted by a positively charged group, as defined herein.
  • R9 is or comprises a positively charged group.
  • Exemplary such compounds include as R9 an aryl, substituted by a quaternary ammonium and a counter anion (e.g., as defined herein for Q " ).
  • Exemplary such compounds include compounds 12 and 13:
  • A is a Ll-B group, as defined herein, wherein LI is an alkylene chain, optionally interrupted by one or more heteroatoms, for example, one or more of O, N and S.
  • Such a compound is a kind of "dimer” of DCPD, in which two DCPD moieties are linked to one another via said LI.
  • LI is methylene.
  • LI is a longer alkylene, comprising, for example, 2-4 carbon atoms in length.
  • the alkylene is interrupted by an oxygen atom or by -NR'-, and in some embodiments R' is hydrogen.
  • A is a L2-D group, wherein L2 is a linking moiety or absent, and D is a NRioRn group, wherein Rio and Rn are each independently hydrogen, alkyl, aryl, cycloalkyl, or alternatively, Rio and Rn form together a heteroalicyclic or heteroaryl group.
  • D is a NRioRnRi 2 + Q ⁇ wherein Ri 2 is as defined herein for Rio and Rn, or Rio, Rn and Ri 2 form together a nitrogen-containing heteroaryl group, and Q " is a counter anion.
  • D is a nitrogen-containing group which can be an amine (e.g., secondary or tertiary amine), or a nitrogen-containing heteroalicyclic.
  • D is a positively charged, nitrogen-containing
  • a "positively charged group” describes a chemical group which is characterized by a positive electrostatic charge.
  • a positively charged group typically comprises one or more atoms having at least one electron less than the number of protons in this atom.
  • Positively charged groups include, for a non-limiting example, ammonium and sulfonium groups.
  • Quaternary ammonium groups are known to be positively charged at any pH range.
  • quaternary ammonium refers to a nitrogen atom which forms a part of a molecule that is attached to four non-hydrogen substituents and thus is positively charged.
  • a quaternary ammonium groups can be defined by a NRioRiiRi 2 + Q group, or can be a cyclic nitrogen-containing group in which two of Rio, Rn and Ri 2 are joined together to form a heterocyclic group, for example, a heteroaryl.
  • a counter anion is also present.
  • the anion e.g., Z "
  • the anion may be a halide, e.g. chloride, bromide or iodide, hexafluorophosphate or tetrafluoroborate, or organic anion such as, for non-limiting examples, oxalate, maleate, mesylate. Any other anions are contemplated.
  • DCPD derivatives as described herein, which comprise a positively charged group and a counter anion are also referred to herein as "ionic" DCPD derivatives.
  • Other DCPD derivatives as described herein, are also referred to herein as “neutral” DCPD derivatives.
  • the DCPD derivative (specifically, endo-DCPD derivative) is of general formula (I):
  • R is selected from the group consisting of a linear alkyl (C n H 2n+ i), branched alkyl (C n H 2n+ i), a substituted or unsubstituted aryl, a substituted or unsubstituted alkylaryl, a positively charged nitrogen-containing group (in which case the compound of Formula (I) is provided in a form of a salt with a suitable counter-ion), DCPD-O-Me- and ester-forming group of a general formula -C(0)-R', wherein R' is an organic moiety.
  • R is linear or branched alkyl.
  • the linear alkyl is a chain consisting of 1-20 carbon atoms, e.g. CI to C8 alkyls are preferred.
  • the linear alkyl is selected from the group consisting of methyl, ethyl, n-propyl or n-octyl (e.g., Compounds 1-4).
  • R is an aryl.
  • the aryl comprises at least one aromatic ring and may be connected to the DCPD moiety via an alkylene linker.
  • the aryl may be optionally substituted with one or more of alkyl, halogen, nitro and carbonyl chloride group.
  • R is a positively charged nitrogen-containing group, wherein the positively charged nitrogen may form part of a ring system.
  • the compound of general Formula (I) is provided in a form of a salt with a suitable counter-ion.
  • the counter-ion Q " is provided by any suitable anion as described herein.
  • the positively charged nitrogen-containing group is part of a ring system, e.g. imidazole.
  • the positively charged nitrogen of the imidazole ring is connected to the oxygen atom in Formula (I) via a bridging moiety, which is preferably alkylene, such as -(CH 2 ) n -, wherein n is an integer from 2 to 10; most preferably the alkylene bridge is linear C5, C6 or C7 alkylene.
  • the imidazole ring may be substituted at one or more of positions 1, 2, 4 and 5, wherein the substituent is preferably an alkyl group; most preferably the imidazole ring is substituted at one or both of positions 1 and 2.
  • the substituent is preferably a methyl group.
  • R in Formula (I) is a quaternary ammonium having the formula [-R a -N + R b R c R d Q " ].
  • Bridging R a is a moiety that preferably contains an alkylene chain
  • R b , R c and R d are preferably independently selected from the group consisting of an alkyl group and an aryl ring.
  • R is selected from the group consisting of 3-pentylene-l-methyl- imidazolium bromide, 3-hexylene-l-methyl-imidazolium bromide, 3-heptylene-l- methyl-imidazolium bromide and 3-pentylene-l,2-dimethyl-imidazolium bromide (e.g., Compounds 6-9).
  • R is DCPD-O-Me- (Compound 10).
  • the DCPD derivative (for example, an endo-OCPO derivative) is of general Formula (II):
  • R' is an organic moiety which is preferably selected from the group consisting of a linear or branched alkyl, substituted or unsubstituted aryl, e.g. phenyl, and a positively charged nitrogen-containing group (in which case the compound of Formula (II) is provided in a form of a salt with a suitable counter-ion).
  • the linear alkyl is a chain consisting of 1-20 carbon atoms, e.g. C2 to C4 alkyls are preferred.
  • R' is not methyl
  • R' is an unsubstituted phenyl.
  • R' is substituted phenyl, preferably substituted with one or more of alkyl, halogen, nitro and carbonyl chloride group.
  • R' is the positively charged nitrogen-containing group, as defined herein, and the compound of Formula (II) is provided in a form of a salt with a suitable counter- ion Q " .
  • R' is a quaternary ammonium as defined herein, which can be connected to the ester via a linking or bridging group.
  • the bridging group is a moiety that preferably contains an alkylene group such as -(CH 2 ) n -, wherein n is preferably an integer from 2 to 10; or a phenylene group [-(C 6 H 4 )-].
  • a phenylene is a bridging moiety, and is substituted by trimethyl amine positively charged group, along with halogen, preferably ⁇ , or hexafluorophosphate as the anion (see, Compounds 12 and 13).
  • halogen preferably ⁇ , or hexafluorophosphate as the anion (see, Compounds 12 and 13).
  • the DCPD-based ROMP monomers described herein can be prepared in accordance with the synthesis procedure exemplified in the Examples section that follows.
  • neutral DCPD derivatives of Formula (I) as described herein are prepared by dissolving hydroxy-dicyclopentadiene in a suitable solvent in the presence of a base to form a solution; adding a haloalkane R-Hal to the solution of hydroxydicyclopentadiene to form a reaction mixture; stirring the reaction mixture, preferably at room temperature, preferably under inert atmosphere, to form the neutral DCPD derivative of Formula (I); and isolating the neutral DCPD derivative of Formula (I) from the reaction mixture.
  • DCPD derivative of Formula (II) as described herein are prepared by: dissolving hydroxydicyclopentadiene in a suitable solvent in the presence of a base, to form a solution; adding an acyl chloride compound R"-C(0)- Cl, wherein R" is an alkyl or aryl, to the solution of hydroxydicyclopentadiene to form a reaction mixture; stirring the reaction mixture, preferably at a temperature from 0°C to room temperature, preferably under inert atmosphere, to form a DCPD derivative of Formula (II); and isolating the DCPD derivative of Formula (II) from the reaction mixture.
  • a method of three-dimensional (3D) inkjet printing of a three-dimensional object is effected by sequentially forming a plurality of layers in a configured pattern corresponding to the shape of the object, thereby forming the object.
  • formation of each layer is effected by dispensing at least one building material formulation (uncured building material), and exposing the dispensed building material formulation to condition which affect curing of the formulation to thereby obtain a cured building material.
  • the method and system of the present embodiments manufacture three- dimensional objects based on computer object data in a layerwise manner by forming a plurality of layers in a configured pattern corresponding to the shape of the objects.
  • the computer object data can be in any known format, including, without limitation, a Standard Tessellation Language (STL) or a StereoLithography Contour (SLC) format, Virtual Reality Modeling Language (VRML), Additive Manufacturing File (AMF) format, Drawing Exchange Format (DXF), Polygon File Format (PLY) or any other format suitable for Computer-Aided Design (CAD).
  • STL Standard Tessellation Language
  • SLC StereoLithography Contour
  • VRML Virtual Reality Modeling Language
  • AMF Additive Manufacturing File
  • DXF Drawing Exchange Format
  • PLY Polygon File Format
  • CAD Computer-Aided Design
  • Each layer is preferably formed by three-dimensional inkjet printing which scans a two-dimensional surface and patterns it. While scanning, the apparatus visits a plurality of target locations on the two-dimensional layer or surface, and decides, for each target location or a group of target locations, whether or not the target location or group of target locations is to be occupied by building material, and which type of building material is to be delivered thereto. The decision is made according to a computer image of the surface.
  • a building material is dispensed from a dispensing head having a set of nozzles to deposit the building material in layers on a supporting structure.
  • the inkjet printing system thus dispenses building material in target locations which are to be occupied and leaves other target locations void.
  • the inkjet printing typically includes a plurality of dispensing heads, each of which can be configured to dispense a different building material formulation. Thus, different target locations can be occupied by different building materials.
  • the types of building materials can be categorized into two major categories: modeling material and support material.
  • the support material serves as a supporting matrix or construction for supporting the object or object parts during the fabrication process and/or other purposes, e.g., providing hollow or porous objects.
  • Support constructions may additionally include modeling material elements, e.g. for further support strength.
  • the phrases “building material formulation”, “uncured building material”, “uncured building material formulation”, “building material” and other variations therefore collectively describe the materials that are dispensed to sequentially form the layers, as described herein.
  • This phrase encompasses uncured materials dispensed so as to form the object, namely, one or more uncured modeling material formulation(s), and uncured materials dispensed so as to form the support, namely uncured support material formulations.
  • the building material comprises at least one of the DCPD-based ROMP monomers, represented by Formulae P, Pa, I and II, as defined herein.
  • object describes a final product of the additive manufacturing. This term refers to the product obtained by a method as described herein, after removal of the support material, if such has been used as part of the uncured building material.
  • the "object” therefore essentially consists (at least 95 weight percents) of a cured modeling material.
  • object refers to a whole object or a part thereof.
  • cured modeling material describes the part of the building material that forms the object, as defined herein, upon exposing the dispensed building material to curing (and optionally post-treatment), and, optionally, if a support material has been dispensed, removal of the cured support material, as described herein.
  • the cured modeling material can be a single cured material or a mixture of two or more cured materials, depending on the modeling material formulations used in the method, as described herein.
  • cured modeling material or "cured modeling material formulation” can be regarded as a cured building material wherein the building material consists only of a modeling material formulation (and not of a support material formulation). That is, this phrase refers to the portion of the building material, which is used to provide the final object.
  • modeling material formulation which is also referred to herein interchangeably as “modeling formulation”, “modeling material” “model material” or simply as “formulation”, describes a part or all of the uncured building material which is dispensed so as to form the object, as described herein.
  • the modeling material formulation is an uncured modeling formulation (unless specifically indicated otherwise), which, upon exposure to a condition that effects curing, forms the object or a part thereof.
  • a modeling material formulation is formulated for use in three-dimensional inkjet printing and is able to form a three- dimensional object on its own, i.e. , without having to be mixed or combined with any other substance.
  • one or more of the modeling material formulations in a building material comprises at least one of the DCPD-based ROMP monomers, represented by Formulae P, I and II, as defined herein.
  • An uncured building material can comprise one or more modeling formulations, and can be dispensed such that different parts of the object are made, upon curing, of different cured modeling formulations, and hence are made of different cured modeling materials or different mixtures of cured modeling materials.
  • the method of the present embodiments manufactures three-dimensional objects in a layerwise manner by forming a plurality of layers in a configured pattern corresponding to the shape of the objects, as described herein.
  • the final three-dimensional object is made of the modeling material or a combination of modeling materials or a combination of modeling material/s and support material/s or modification thereof (e.g., following curing). All these operations are well- known to those skilled in the art of solid freeform fabrication.
  • an object is manufactured by dispensing a building material that comprises two or more different modeling material formulations, each modeling material formulation from a different dispensing head of the inkjet printing apparatus.
  • the modeling material formulations are optionally and preferably deposited in layers during the same pass of the printing heads.
  • the modeling material formulations and/or combination of formulations within the layer are selected according to the desired properties of the object.
  • FIG. 39 presents a flowchart describing an exemplary method according to some embodiments of the present invention. It is to be understood that, unless otherwise defined, the operations described hereinbelow can be executed either contemporaneously or sequentially in many combinations or orders of execution. Specifically, the ordering of the flowchart is not to be considered as limiting. For example, two or more operations, appearing in the following description or in the flowchart diagrams in a particular order, can be executed in a different order (e.g. , a reverse order) or substantially contemporaneously. Additionally, several operations described below are optional and may not be executed. The method begins at 10 and optionally and preferably continues to 11 at which 3D printing data corresponding to the shape of the object are received.
  • the data can be received, for example, from a host computer which transmits digital data pertaining to fabrication instructions based on computer object data, e.g. , in a form of a Standard Tessellation Language (STL) or a StereoLithography Contour (SLC) format, Virtual Reality Modeling Language (VRML), Additive Manufacturing File (AMF) format, Drawing Exchange Format (DXF), Polygon File Format (PLY) or any other format suitable for Computer- Aided Design (CAD).
  • STL Standard Tessellation Language
  • SLC StereoLithography Contour
  • VRML Virtual Reality Modeling Language
  • AMF Additive Manufacturing File
  • DXF Drawing Exchange Format
  • PLY Polygon File Format
  • CAD Computer- Aided Design
  • the method continues to 12 at which droplets of a building material as described herein are dispensed in layers, on a receiving medium, using at least two different multi- nozzle inkjet printing heads, according to the printing data.
  • the receiving medium can be a tray of a three-dimensional inkjet system or a previously deposited layer.
  • the building material comprises one or more modeling material formulations that can undergo polymerization via ROMP, as described herein.
  • the building material cam optionally further comprise a support material formulation.
  • the dispensing 12 is effected within an environment that is similar in its thermodynamic condition (for example, temperature, humidity, pressure) to the ambient environment.
  • the dispensing 12 can be executed in a generally dry (e.g., relative humidity of less than 60% or less than 50% or less than 40%, or less) and inert environment.
  • the dispensing can be executed in a nitrogen environment.
  • dispensing 12 is executed in a chamber and is optionally and preferably preceded by an operation in which an inert gas, e.g. , nitrogen, helium, krypton and the like is introduced into the chamber.
  • the uncured building material, or a part thereof e.g., one or more formulations of the building material
  • the heating of the formulation(s) is preferably to a temperature that allows jetting the respective formulation through a nozzle of a printing head of a 3D inkjet printing system.
  • the heating is to a temperature at which the respective formulation exhibits a viscosity of no more than X centipoises, where X is about 40 centipoises, or about 35 centipoises, or about 30 centipoises, preferably about 25 centipoises and more preferably about 20 centipoises, or 18 centipoises, or 16 centipoises, or 14 centipoises, or 12 centipoises, or 10 centipoises and even as low as 2 centipoises.
  • X is about 40 centipoises, or about 35 centipoises, or about 30 centipoises, preferably about 25 centipoises and more preferably about 20 centipoises, or 18 centipoises, or 16 centipoises, or 14 centipoises, or 12 centipoises, or 10 centipoises and even as low as 2 cent
  • the heating can be executed before loading the respective formulation into the printing head of the 3D printing system, or while the formulation is in the printing head or while the formulation passes through the nozzle of the printing head.
  • the heating is executed before loading of the respective formulation into the printing head, so as to avoid clogging of the printing head by the formulation in case its viscosity is too high.
  • the heating is executed by heating the printing heads, at least while passing the formulations making up the building material through the nozzle of the printing head.
  • a temperature of an inkjet printing head for dispensing a modeling material formulation as described herein is lower than 70 °C, and ranges, for example, from about 25 °C to about 65 °C, including any subranges and intermediate values therebetween.
  • Modeling material formulations which comprise one or more monomers that undergo polymerization via ROMP, as described herein, and optionally other, non-curable components, are suitable for use in the context of these embodiments.
  • higher temperatures of an inkjet printing head are required, for example, higher than 70 °C, or ranging from about 65 °C to about 95 °C, , including any subranges and intermediate values therebetween.
  • Modeling material formulations which comprise curable materials which are polymerizable by non-ROMP reactions, as described herein (for example, UV-curable acrylates and methacrylates, and/or epoxy monomers useful for cationic photopolymerization), as curable components, optionally in addition to ROMP-curable components, are suitable for use in the context of these embodiments.
  • the method optionally and preferably continues to 13 at which the deposited layers are exposed to a condition (or two or more conditions) that induces ROMP, as defined herein.
  • a condition or two or more conditions that induces ROMP, as defined herein.
  • each individual layer is exposed to this condition following or during the deposition of the layer, and prior to the deposition of the subsequent layer.
  • exposing to conditions that effect curing is performed under a generally dry and inert environment, as described herein.
  • the dry and inert environment is optionally and preferably prepared before the material is dispensed so that 13 can be executed simultaneously with 12 wherein the material is exposed to the environment upon exiting the inkjet printing head.
  • the exposure 13 can include exposing the dispensed layer to radiation, such as, but not limited to, electromagnetic radiation, for example, infrared radiation (e.g., at a wavelength of from about 800 nm to about 4 ⁇ ), ultraviolet radiation (e.g., at a wavelength of from about 200 nm to about 400 nm) and visible or near-visible light radiation (e.g., at a wavelength of from about 400 nm to about 800 nm), or particle radiation, for example in the form of an electron beam, depending on the modeling material being used.
  • electromagnetic radiation for example, infrared radiation (e.g., at a wavelength of from about 800 nm to about 4 ⁇ ), ultraviolet radiation (e.g., at a wavelength of from about 200 nm to about 400 nm) and visible or near-visible light radiation (e.g., at a wavelength of from about 400 nm to about 800 nm), or particle radiation, for example in the form of an electron beam, depending on the modeling material being used.
  • the infrared radiation is applied by a ceramic lamp, for example, a ceramic lamp that produces infrared radiation of from about 3 ⁇ to about 4 ⁇ , e.g. , about 3.5 ⁇ , or of any other wavelength suitable for efficient application of heat, as discussed hereafter.
  • the exposure 13 can include exposing the dispensed layer to elevated temperature (for example, from about 25 °C to about 100 °C, or from about 25 °C to about 65 °C, or from about 65 °C to about 100 °C.
  • the elevated temperatures can be generated by heating the tray on which the layers are dispensed, and/or the chamber within which the printing process is executed or heat- inducing irradiation, using a radiation source as described herein, at a suitable wavelength for providing a required temperature.
  • a ceramic lamp for example, when operated at the above- described wavelengths, may result in heating a dispensed formulation to up to 65 °C.
  • the method can preferably continue to 14 at which the deposited layer is straightened, for example, by a leveling device.
  • the layer is straightened after the dispensed formulation is cured.
  • the layer is straightened while the dispensed formulation is still uncured.
  • the phrase" cured refers to a formulation that underwent curing or at least a partial curing, as defined herein, and encompasses a state of the formulation in which at least 20 % or at least 30 % or at least 40 % or at least 50 % or at least 60 % or at least 70 % of the formulation underwent curing, as defined herein, and a state of a formulation that underwent 100 % curing.
  • a formulation that underwent curing or partial curing is characterized by a viscosity that is substantially higher than an uncured formulation, and preferably, a formulation, or at least a part thereof, solidifies upon curing.
  • Straightening after curing can be achieved by a leveling device that is capable of deforming the solidified portion of the formulation.
  • a representative example of such a leveling device is a roller capable of milling, grinding and/or flaking a solidified formulation or part thereof.
  • Straightening while the formulation is uncured can be achieved by a leveling device that is capable of leveling the formulation in its liquid or gel state.
  • a representative example of such a leveling device is a roller or a blade, which is optionally and preferably, but not necessarily, incapable of effecting milling, grinding and/or flaking.
  • the method continues to 15 at which cured or partially cured formulation is removed off the leveling device.
  • cured or partially cured formulation is removed off the leveling device.
  • a portion of the formulation collected by the leveling device can experience curing or partial curing while the formulation is on the leveling device (for example on the roller, when the leveling device comprises a roller), and the method preferably removes that cured or partially cured formulation from the device.
  • the method can also be useful when the leveling device is applied to the layer while the formulation is cured (for example, when the leveling device effects milling, grinding and/or flaking of the solidified portion of the formulation). In this case the method removes the debris of the milling, grinding and/or flaking process from the leveling device.
  • Operation 15 is preferably executed automatically and optionally also continuously while the leveling device is in motion over the layer.
  • the leveling device can comprise a double roller having a first roller that contacts and straightens the layer and a second that is in contact with the first roller but not with the layer and which is configured to remove the formulation from the first roller.
  • the building material comprises one or more modeling material formulations, as described in further detail hereinafter, and dispensing the building material comprises dispensing one or more modeling material formulations.
  • the building material further comprises one or more support material formulations.
  • dispensing a building material further comprises dispensing the support material formulation(s).
  • Dispensing the support material formulation in some embodiments, is effected by inkjet printing head(s) other than the inkjet printing heads used for dispensing the modeling material formulation(s).
  • exposing the building material to a condition that induces curing includes one or more conditions that affect curing of a support material formulation, to thereby obtain a cured support material.
  • the method further comprises removing the cured support material.
  • Any of the methods usable for removing a support material formulation can be used, depending on the materials employed in the modeling material formulation and the support material formulation. Such methods include, for example, mechanical removal of the cured support material and/or chemical removal of the cured support material by contacting the cured support material with a solution in which it is dissolvable (e.g., an alkaline aqueous solution).
  • curing describes a process in which a formulation is hardened. This term encompasses polymerization of monomer(s) and/or oligomer(s) and/or cross-linking of polymeric chains (either of a polymer present before curing or of a polymeric material formed in a polymerization of the monomers or oligomers).
  • the product of a curing reaction is therefore typically a polymeric material and in some cases a cross-linked polymeric material.
  • a condition that affects curing or "a condition for inducing curing”, which is also referred to herein interchangeably as “curing condition” or “curing inducing condition” describes a condition which, when applied to a formulation that contains a curable material, induces polymerization of monomer(s) and/or oligomer(s) and/or cross-linking of polymeric chains.
  • Such a condition can include, for example, application of a curing energy, as described hereinafter to the curable material(s), and/or contacting the curable material(s) with chemically reactive components such as catalysts, co-catalysts, and activators.
  • a curing energy as described hereinafter to the curable material(s)
  • chemically reactive components such as catalysts, co-catalysts, and activators.
  • exposing to a condition that affects curing means that the dispensed layers are exposed to the curing energy and the exposure is typically performed by applying a curing energy to the dispensed layers.
  • a "curing energy” typically includes application of radiation or application of heat.
  • the radiation can be electromagnetic radiation (e.g., ultraviolet or visible light), or electron beam radiation, or ultrasound radiation or microwave radiation, depending on the materials to be cured.
  • electromagnetic radiation e.g., ultraviolet or visible light
  • electron beam radiation e.g., electron beam radiation
  • ultrasound radiation or microwave radiation e.g., ultrasound
  • a suitable radiation source e.g., an ultraviolet or visible or infrared or Xenon lamp can be employed, as described herein.
  • a curable material or system that undergoes curing upon exposure to radiation is referred to herein interchangeably as "photopolymerizable” or “photoactivatable” or “photocurable”.
  • the curing is also referred to herein and in the art as "thermal curing" and comprises application of thermal energy.
  • Applying thermal energy can be effected, for example, by heating a receiving medium onto which the layers are dispensed or a chamber hosting the receiving medium, as described herein.
  • the heating is effected using a resistive heater.
  • the heating is effected by irradiating the dispensed layers by heat-inducing radiation. Such irradiation can be effected, for example, by means of an IR lamp or Xenon lamp, operated to emit radiation onto the deposited layer. In some embodiments, heating is effected by infrared radiation applied by a ceramic lamp, for example, a ceramic lamp that produces infrared radiation of from about 3 ⁇ to about 4 ⁇ , e.g. , about 3.5 ⁇ .
  • the heat- inducing radiation is selected to emit radiation at a wavelength that results in efficient absorption of the heat energy by a selected ROMP monomer or mixture of monomers, so as to effect efficient application of heat energy (efficient heating or thermal curing).
  • thermoally-curable or “thermally-activatable” or “thermally- polymerizable”.
  • the method further comprises exposing the cured modeling material formulation(s) either before or after removal of a support material formulation, if such has been included in the building material, to a post-treatment condition.
  • the post-treatment condition is typically aimed at further hardening the cured modeling formulation(s).
  • the post- treatment hardens a partially-cured formulation to thereby obtain a completely cured formulation.
  • the post-treatment is effected by exposure to heat or radiation, as described in any of the respective embodiments herein.
  • the post- treatment can be effected for a time period that ranges from a few minutes (e.g., 10 minutes) to a few hours (e.g., 1-24 hours).
  • At least one of the modeling material formulations as described herein comprises a monomer that is polymerizable by ring opening metathesis polymerization (ROMP), which is a DCPD-based ROMP monomers, represented by Formulae P, Pa, I and II, as defined herein.
  • ROMP ring opening metathesis polymerization
  • Such a monomer is also referred to herein interchangeably as a ROMP monomer, a ROMP-polymerizable monomer, a ROMP curable monomer, a ROMP component, a ROMP active component, and similar diversions.
  • one or more of the modeling material formulations in the (uncured) building material comprises a catalyst for initiating a ROMP reaction of the monomer, as described in further detail hereinunder.
  • other ROMP monomers can be used in combination with the DCPD-based monomer of Formulae P, Pa, I or II.
  • Additional ROMP monomers typically include an unsaturated cyclic monomer, preferably a strained unsaturated cyclic olefin, as would be recognized by any person skilled in the art.
  • Exemplary ROMP monomers usable in combination with the DCPD-based ROMP monomer of the present embodiments include, but are not limited to cyclopentadiene trimer, tetramer, pentamer, etc., norbornene, cyclooctene, cyclooctadiene, cyclobutene, cyclopropene and substituted derivatives thereof, for example, substituted norbornenes such as carboxylated norbornenes, butyl norbornene, hexyl norbornene, octyl norbornene.
  • exposing the modeling material formulation to a condition that induces curing comprises exposing the dispensed modeling material formulation(s) to a condition for inducing initiation of ROMP of the monomer by the catalyst, as described in further detail hereinunder. Any of the conditions for effecting curing as described hereinabove are contemplated, depending on the materials selected for the ROMP system.
  • a condition for inducing initiation of ROMP of the monomer by the catalyst is also referred to herein interchangeably as "a ROMP inducing condition” or simply as “inducing condition”, and describes a condition to which a modeling material formulation is exposed so as to effect ROMP of the ROMP monomer (e.g., to effect initiation of ROMP of the ROMP monomer by the catalyst).
  • a building material including the one or more modeling material formulations included therein, can be exposed also to a condition that affects curing via other modes of action (e.g., via other polymerization reactions and/or via cross-linking of polymeric chains), that is, a non-ROMP curing condition, as described in further detail hereinafter.
  • the ROMP inducing condition and a non-ROMP curing condition can be the same or different.
  • a "ROMP system” describes a set of materials and optionally conditions for effecting polymerization, via a ROMP reaction, of an unsaturated cyclic ROMP monomer (or a mixture of ROMP monomers), at least one being a DCPD-based ROMP monomer of Formula P. I or II, as defined herein.
  • the materials included in a ROMP system are also referred to herein as “ROMP components” or “ROMP active components”.
  • a ROMP system requires at least a ROMP monomer as defined herein (e.g., represented by Formula P, or I or II), optionally in combination with other ROMP monomers, and a catalyst for initiating the ROMP reaction.
  • the catalyst is also referred to herein throughout as a "ROMP catalyst” or a "ROMP catalyst system”.
  • a ROMP system consists of a catalyst and a ROMP monomer according to the present embodiments (e.g., represented by Formula P, or I or II), optionally in combination with other ROMP monomers.
  • the catalyst in referred to herein as an "active catalyst", which is active towards initiation of ROMP of the monomer immediately once it contacts the monomer, without a need to apply an external stimulus such as, for example, heat, radiation, or chemical additives.
  • a condition for inducing initiating of ROMP of the monomer by the catalyst requires contacting the catalyst with the ROMP monomer.
  • active towards initiation of ROMP of the monomer it is meant that in the presence of the catalyst, at least 50 % or at least 60 % or at least 70 % or at least 80 % of the monomer polymerizes via ROMP mechanism to provide a respective polymer.
  • a ROMP system consists of a catalyst and a ROMP monomer according to the present embodiments (e.g., represented by Formula P, or I or II), optionally in combination with other ROMP monomers, and a condition for activating the catalyst towards initiation of ROMP of the monomer.
  • the catalyst is referred to herein as a "latent catalyst", which is activatable upon exposure to the condition.
  • the catalyst is inactive towards initiation of ROMP of the monomer when the ROMP system is not exposed to the condition that activates the catalyst, namely, prior to exposure to a ROMP inducing condition.
  • active towards initiation of ROMP of the monomer it is meant that in the presence of the catalyst, no more than 40 % or no more than 30 % or no more than 20 % or no more than 10 % or no more than 5 % of the monomer polymerizes via ROMP mechanism to provide a respective polymer.
  • Latent catalysts as described herein can be thermally-activatable catalysts, which are converted into active catalysts upon exposure to heat (that is, a condition for inducing initiation of ROMP comprises heat or heating a ROMP system, optionally in addition to contacting the catalyst and the ROMP monomer according to the present embodiments).
  • Latent catalysts as described herein can be photo-activatable catalysts, which are converted into active catalysts upon exposure to radiation (that is, a condition for inducing initiation of ROMP comprises exposure to radiation or application of radiation to the ROMP system, optionally in addition to contacting the catalyst and a ROMP monomer according to the present embodiments).
  • the radiation can be, for example, an electromagnetic radiation (e.g., UV or visible or IR light), or ultrasound radiation, or heat-inducing radiation, and can be applied by a suitable source of the radiation, as described herein.
  • Latent catalysts activatable by exposure to other conditions are also contemplated.
  • a ROMP system consists of a ROMP monomer according to the present embodiments (e.g., represented by Formula P, or I or II), optionally in combination with other ROMP monomers, a ROMP catalyst and an activator, for chemically activating the ROMP catalyst.
  • the ROMP catalyst is inactive towards initiation of ROMP of the monomer, as defined herein, in the absence of the activator (when it is not contacted with the activator).
  • a ROMP catalyst that is activatable in the presence of an activator is referred to herein also as a "pre-catalyst", and the activator is referred to herein as a "co-catalyst".
  • a combination of pre-catalyst and an activator is also referred to herein and in the art as a catalyst system, and herein also as a ROMP catalyst system.
  • chemically activating it is meant that the activation of a catalyst is made by an addition of a chemical entity (a chemical additive), e.g., a chemical compound or a chemical species such as an ion.
  • a chemical additive e.g., a chemical compound or a chemical species such as an ion.
  • the catalyst is inactive towards initiation of ROMP of the monomer, as defined herein, in the absence of a respective activator.
  • a condition for initiating ROMP of a monomer requires a contact between the catalyst and the activator and the catalyst and the ROMP monomer.
  • the activator is an activatable activator, which is rendered active towards chemically activating the catalyst when exposed to a certain condition. In such cases, the activator is incapable of chemically activating the catalyst unless it is activated (by exposure to the conditions).
  • activators are also referred to herein as “latent activators”.
  • a latent activator is incapable of activating a catalyst for initiating ROMP of the monomer, and can be converted to an active activator when exposed to an activating condition (which can be the ROMP inducing condition as described herein).
  • the activator is inactive towards chemically activating the catalyst, and the catalyst is therefore inactive towards initiation of ROMP of the monomer when the ROMP system is not exposed to the condition that activates the activator.
  • active towards chemically activating the catalyst it is meant that no chemical reaction between the activator and the catalyst occurs, such that in the ROMP system containing the ROMP monomer according to the present embodiments, a ROMP catalyst which is chemically activatable by the activator, and the latent activator, no more than 40 % or no more than 30 % or no more than 20 % or no more than 10 % or no more than 5 % of the monomer polymerizes via ROMP mechanism to provide a respective polymer.
  • Latent activators as described herein can be thermally-activatable activators, which are converted into active activators upon exposure to heat (that is, a condition for inducing initiation of ROMP comprises heat or heating a ROMP system, optionally in addition to contacting an activator and a catalyst and a ROMP monomer).
  • Latent activators as described herein can be photo-activatable catalysts, which are converted into active activators upon exposure to radiation (that is, a condition for inducing initiation of ROMP comprises exposure to radiation or application of radiation to the ROMP system, optionally in addition to contacting an activator and a catalyst and a catalyst and a ROMP monomer).
  • the radiation can be, for example, an electromagnetic radiation (e.g., UV or visible or IR light), or ultrasound radiation, and can be applied by a suitable source of the radiation.
  • a ROMP system can further comprise a ROMP inhibitor.
  • a "ROMP inhibitor” as used herein refers to a material that slows down a ROMP reaction initiated by a catalyst. ROMP inhibitors can be used with active catalysts, latent catalysts and pre-catalysts, as described herein. In some embodiments, a ROMP inhibitor inhibits a ROMP reaction initiated in the presence of an active catalyst, or once a latent catalyst or pre-catalyst is converted to an active catalyst, by interfering with the chemical reactions that activate a latent catalyst or a pre-catalyst.
  • a ROMP system as described herein refers to the active components and/or conditions that together lead to ROMP polymerization of a ROMP monomer.
  • a formulation that comprises a ROMP system can further comprise other components which can participate in polymerization or curing reactions, and/or form a part of the final polymeric material, as described in further detail hereinbelow.
  • ROMP catalysts typically include metal carbene organometallic complexes, with the metal being typically, but not necessarily, a transition metal such as ruthenium, molybdenum, osmium or tungsten.
  • Ruthenium based ROMP catalysts are more stable on exposure to non carbon- carbon double-bond functional groups, and to other impurities like water and oxygen. These catalysts can typically be used in low loading in the formulation (e.g., in a range of 0.002%-0.05% by weight of the total weight of a modeling material formulation containing same).
  • Ruthenium based ROMP catalysts that are usable in the context of embodiments of the present invention are marketed, for example, by Materia, Umicore, Evonic and BASF.
  • Exemplary ruthenium-based ROMP catalysts include, Grubbs 1 st and 2 nd generation catalysts, Ho veyda- Grubbs catalysts, umicore 41, umicore 42, umicore 61SEVIes, and catMETium RF1.
  • Exemplary catalysts include Grubbs' 2 nd generation catalyst (e.g., 1,3-Bis- (2,4,6-trimethylphenyl)-2-imidazoli-dinylidene] dichloro- (phenylmethylene) (tricyclehexyl-phosphine)ruthenium), commercially available from Sigma Aldrich) or sulfur-chelated ruthenium complex, as described in Ginzburg, Y. et al. Organometallics, 2011, 30, 3430-3437.
  • a ruthenium based catalyst czs-Ru-SPh or czs-Ru-S'Pr described in e.g. Ben- Asuly A. et al. Organometallics, 2009, 28, 4652-4655; Tzur E. et al., J. Organomet. Chem., 2014, 769, 24 -28, is also contemplated.
  • ROMP catalysts can be divided into active catalysts, latent catalysts and pre- catalysts.
  • An active catalyst is a ROMP catalyst that initiates ROMP of a monomer when in contact with the ROMP monomer, without requiring a stimulus.
  • ROMP active catalysts are typically active at room temperature.
  • Exemplary active catalysts usable in the context of the present embodiments are the Grubbs 2 nd generation, Hoveyda-Grubbs 2 nd generation, and Grubbs 3 nd generation catalysts, which are realized by any person skilled in the art.
  • Active catalysts are suitable for use in the context of the present embodiments in dual- or multi-jetting methodologies. Active catalysts are suitable for use in the context of the present embodiments in single-jetting methodologies, when physically separated from the ROMP monomer, and optionally other components in the modeling material formulation.
  • a latent catalyst is a ROMP catalyst that initiates ROMP of a monomer when in contact with the ROMP monomer, upon exposure to a physical stimulus, typically heat or radiation, as described herein.
  • a latent catalyst is inactive in initiating ROMP of a monomer in the absence of a suitable physical stimulus.
  • a latent catalyst typically includes a chelating (e.g., donor) ligand which "blocks" a coordinative site of the metal and thus renders the catalyst inactive. Activating the catalyst is effected by dissociating the chelating ligand from the metal center, to thereby render it active towards metathesis.
  • dissociating the chelating ligand requires a physical external stimulus, as described herein.
  • the type of the external stimulus is determined by the nature of the metal, the chelating ligand and other ligands in the transition metal complex.
  • Latent ROMP catalysts that are activated in response to heat are also referred to as thermally- activatable catalysts.
  • thermally- activatable catalysts include, for example, S -chelated ruthenium catalysts such as described, for example, in Melntig, C. E.; Vidavsky, Y.; Ben- Asuly, A.; Lemcoff, N. G., J. Polym. ScL, Part A: Polym. Chem. 2009, 47, 4209-4213, which is incorporated by reference as if fully set forth herein.
  • An exemplary S-chelated thermally-activatable latent catalyst is:
  • thermally-activatable ROMP catalysts include N-chelated ruthenium catalysts, such as, for example, described in Szadkowska et al., Organometallics 2010, 29, 117-124, which is incorporated by reference as if fully set forth herein.
  • N-chelated thermally-activatable latent catalyst include, without limitation:
  • thermally-activatable ROMP catalysts are contemplated.
  • Latent ROMP catalysts that are activated in response to radiation are also referred to as photoactivatable catalysts.
  • Photoactivatable ROMP catalysts are mostly UV-activatable catalysts, in which dissociation of a chelating ligand is effected in the presence of UV radiation.
  • Exemplary UV-activatable ROMP latent catalysts are described, for example, in Vidavsky, Y. and Lemcoff, N.G. Beilstein J. Org. Chem., 2010, 6, 1106-1119; Ben- Asuly et al., Organometallics, 2009, 28, 4652-4655; Melnscher et al., . Polym. Sci., Part A: Polym. Chem. 2009, 47, 4209-4213; Wang et al., Angew. Chem. Int. Ed. 2008, 47, 3267-3270; and U.S. Patent Application Publication No. 2009-0156766, all of which are incorporated by reference as if fully set forth herein.
  • UV-activatable ROMP catalysts can be, for example, O-chelated and S-chelated Ruthenium catalysts.
  • Non-limiting examples include the following:
  • R Ph, beta-Naph, 1-Pyrenyl, or i-Pr; and all catalysts described in Vidavsky, Y. and Lemcoff, N.G. Beilstein J. Org. Chem., 2010, 6, 1106-1119.
  • UV-activatable ROMP catalysts can be, for example, tungsten catalysts such as, for example:
  • Photoactivatable latent catalyst can also be activated in response to ultrasound radiation.
  • Such catalysts are described, for example, in Piermattei et al., Nature Chemistry, DOI: 10.1038/NCHEM.167, which is incorporated by reference as if fully set forth herein.
  • Latent catalysts as described herein are usable in the context of any of the embodiments described herein, including single jetting methodologies and multi-jetting methodologies.
  • a ROMP pre-catalyst is a ROMP catalyst that initiates ROMP of a monomer when in contact with the ROMP monomer, upon exposure to a chemical stimulus, as described herein, typically an addition of an acid or a proton.
  • a pre-catalyst is inactive in initiating ROMP of a monomer in the absence of the chemical stimulus.
  • a pre-catalyst similarly to a latent catalyst, typically includes a chelating (e.g., donor) ligand which "blocks" a coordinative site of the metal and thus renders the catalyst inactive.
  • Activating the catalyst is effected by dissociating the chelating ligand from the metal center, to thereby render it active towards metathesis.
  • dissociating the chelating ligand requires a chemical stimulus, typically a presence of an acid.
  • a chemical stimulus typically a presence of an acid.
  • the agent that exerts a chemical stimulus that activates the catalyst is referred to herein as an activator or a co-catalyst.
  • a ROMP pre-catalyst and a suitable activator form together a catalyst system.
  • the activator can be, for example, an acid, such as HC1, an acid generator such as, but not limited to, (R n SiCl 4 _ n ), with R being an alkyl or aryl, and n being 1, 2, or 3, or an acid generator as described, for example, in EP Patent No. 1757613 and U.S. Patent No. 8,519,069, the teachings of which are incorporated by reference as if fully set forth herein.
  • the activator is activatable in response to an external stimulus, for example, heat or radiation.
  • an external stimulus for example, heat or radiation.
  • a group of latent activators which are usable in the context of the present embodiments is known in the art as photoacid generators (PAG).
  • PAG photoacid generators
  • Such activators and corresponding pre-catalysts are described for example, in Keitz, B. K.; Grubbs, R. H. J. Am. Chem. Soc. 2009, 131, 2038-2039, which is incorporated by reference as if fully set forth herein.
  • Additional exemplary PAG include sulfonium salts such as tertiary sulfonium chloride and UVI 6976, iodonium salt Uvacure 1600, Speedcure 937, Irgacure 250, Irgacure PAG 103, Irgacure PAG 203, 2-(4-Methoxystyryl)-4,6-bis(trichloromethyl)- 1,3,5-triazine and TMCH.
  • sulfonium salts such as tertiary sulfonium chloride and UVI 6976, iodonium salt Uvacure 1600, Speedcure 937, Irgacure 250, Irgacure PAG 103, Irgacure PAG 203, 2-(4-Methoxystyryl)-4,6-bis(trichloromethyl)- 1,3,5-triazine and TMCH.
  • Other exemplary commercially available PAG are described in Tables 1
  • Acid-activatable ROMP catalysts are described, for example, in U.S. Patent No. 6,486,279.
  • Other catalysts that can be activated by PAG are acid activatable pre- catalysts such as the Schiff base-chelated catalysts described in EP Patent No. 1757613 and U.S. Patent No. 8,519,069.
  • a ROMP catalyst or catalyst as described herein is selected suitable for initiating ROMP of a DCPD-based ROMP monomer according to the present embodiments (e.g., represented by Formula P, I or II) and/or other ROMP monomers, if such ate included in one or more of the modeling formulations described herein.
  • ROMP inhibitors are typically Lewis base compounds such as triphenyl phosphine (TPP), trialkylphosphite and pyridine.
  • TPP triphenyl phosphine
  • pyridine trialkylphosphite
  • Table A below presents a list of exemplary components which can be included, in any combination, in a ROMP system as described herein in any one of the embodiments and any combinations thereof, in combination with a DCPD-based ROMP monomer or a mixture of ROMP monomers, according to the present embodiments.
  • the components can be included in one or more modeling material formulations, as described herein.
  • Ethanox 702 4,4'-Methylenebis(2,6-di- antioxidant Albemarle tert-butylphenol)
  • Umicore 41 [l,3-Bis(mesityl)-2- ROMP catalyst
  • Umicore 42 [l,3-Bis(mesityl)-2- ROMP catalyst
  • Umicore 22 cis-[l,3-Bis(2,4,6- ROMP catalyst Umicore trimethylphenyl)-2- (thermally- imidazolidinylidene] dichloro activatable latent (3 -phenyl- 1 H-inden- 1 - catalyst)
  • Umicore 2 1,3-Bis(2,4,6- ROMP catalyst Umicore trimethylphenyl)-2- (active at room
  • Umicore 61 [1,3-Bis(2,4,6- ROMP catalyst Umicore trimethylphenyl)-2- (active at room
  • Triethyipho sphite Triethyipho sphite ROMP inhibitor Sigma aldrich
  • Ethanox 702 4,4'-Methylenebis(2,6-di- antioxidant Albemarle tert-butylphenol)
  • Umicore 41 [l,3-Bis(mesityl)-2- ROMP catalyst
  • Umicore 42 [l,3-Bis(mesityl)-2- ROMP catalyst Umicore imidazolidinylidene]
  • Umicore 22 cis-[l,3-Bis(2,4,6- ROMP catalyst Umicore trimethylphenyl)-2- imidazolidinylidene] dichloro
  • Umicore 61 [1,3-Bis(2,4,6- ROMP catalyst Umicore trimethylphenyl)-2- imidazolidinylidene] dichloro
  • Triethylpho sphite Triethylpho sphite ROMP inhibitor Sigma aldrich
  • exemplary DCPD derivatives of general Formula (I) or (II) were subjected to ROMP (the reaction took place under heating, e.g. at 70 °C, either with Grubbs' 2 nd generation catalyst (e.g. l,3-Bis-(2,4,6- trimethylphenyl)-2-imidazoli-dinylidene] dichloro- (phenylmethylene) (tricyclehexyl- phosphine)ruthenium), commercially available from Sigma Aldrich) or with sulfur- chelated ruthenium complex, as described in Ginzburg, Y. et al. Organometallics, 2011, 30, 3430-3437), as follows:
  • Grubbs' 2 nd generation catalyst e.g. l,3-Bis-(2,4,6- trimethylphenyl)-2-imidazoli-dinylidene] dichloro- (phenylmethylene) (tricyclehexyl- phosphine)ruthenium
  • n indicates the degree of polymerization
  • m indicates the degree of cross-linking
  • Ru is a catalyst residue, e.g. a coordinated ruthenium group.
  • DCPD derivatives of general Formula (II) were subjected to ROMP (the reaction took place at 100°C, with a ruthenium based catalyst czs-Ru-SPh or cz ' s-Ru-S'Pr, described in e.g. Ben-Asuly A. et al. Organometallics, 2009, 28, 4652- 4655; and Tzur E. et al., J. Organomet. Chem., 2014, 769, 24 -28.
  • DCPD-OH endo-hydroxydicyclopentadiene
  • DCPD derivative compound 14 was co-polymerized by ROMP (the reaction took place at 70°C, with Grubbs' 2 nd generation catalyst).
  • Quaternary ammonium DCPD derivatives of general formula (I) were co- polymerized together with neutral monomers to yield covalent ionic crosslinked polymer.
  • the compound 9 was polymerized together with hydroxyl- DCPD at a ratio exemplified by 1:50, according to the reaction scheme shown below (the reaction took place at 90 C, with the aid of a suitable catalyst):
  • the polymerized materials obtained from Compounds 1-3 were solid, hard homopolymers.
  • the polymerized material obtained from Compound 4 was rubbery, flexible and elastic, stretchable homopolymer.
  • the polymerized material obtained from compound 14 was also relatively soft. Copolymerization reactions of compounds 6-9 with DCPD-OH at a ratio of 1:50, resulted in a solid, hard copolymer.
  • Copolymerization reactions of compounds 6-9 with DCPD-OH at a ratio of 1:50 gave the hardest polymers, whereas, copolymerization reactions of a compound such as 6-9 with DCPD-OH at lower ratios, such as for example, 1: 10 or 1:5 resulted in soft polymers.
  • the DCPD-based ROMP monomers described herein can therefore be selected for providing polymerized (cured) materials featuring diverse properties that go from rubbery thermoset materials to hard glasses and from more hydrophilic surfaces to more hydrophobic.
  • the obtained cured materials are odorless, while retaining the thermomechanical properties of a pDCPD polymer.
  • the building material comprises one or more modeling material formulations which, upon being dispensed, can undergo a ROMP reaction.
  • at least one of these modeling material formulations comprises a DCPD-based ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II).
  • the building material comprises one or more modeling material formulations which form a ROMP system as described herein, which comprises at least one ROMP monomer which is a DCPD-based ROMP monomer as defined herein (e.g., represented by Formula P, I or II).
  • ROMP reactions typically require a catalyst for initiating the polymerization reaction.
  • the polymerization reaction typically starts immediately, sometime without application of a curing energy, and hence modeling material formulations in which an active catalyst, as described herein, is utilized "as is", are inapplicable for 3D inkjet printing.
  • Embodiments of the present invention therefore relate to modeling material formulations which are designed such that, prior to exposure to a suitable condition, the ROMP system is inactive, that is a ROMP catalyst does not initiate ROMP of the monomer, and a ROMP monomer does not polymerize via ROMP to provide a respective polymer, as described herein.
  • Embodiments of the present invention therefore relate to modeling material formulations which are designed such that, prior to exposure to a suitable condition, the catalyst does not initiate the ROMP reaction, that is, prior to exposure to a suitable condition, at least 50 %, preferably at least 60 %, preferably at least 70 %, at least 80 %, at least 90 %, at least 95 % and even 100 % of the ROMP monomers do not undergo polymerization.
  • no more than 40 % or no more than 30 % or no more than 20 % or no more than 10 % or no more than 5 % of the monomer polymerizes via ROMP mechanism to provide a respective polymer.
  • Such modeling material formulations are characterized by a viscosity of no more than 35 centipoises, or no more than 25 centipoises at a temperature of the inkjet printing head during the dispensing.
  • such modeling material formulations are characterized by the indicated viscosity at a temperature lower than 70 °C, or lower than 65 °C, or lower than 60 °C, or lower than 50 °C, or lower than 40 °C, or lower than 30 °C, and even at room temperature (e.g., 25 °C).
  • a viscosity is indicative of the presence (e.g., of more than 80 %) of non-polymerizable ROMP monomers in the formulation, or of the absence (e.g., less than 20 % of the formulation) of polymeric materials obtained by ROMP in the formulation.
  • the modeling material formulations described herein are therefore designed such that ROMP of the ROMP monomers is not effected when the formulations pass through the inkjet printing heads.
  • Embodiments of the present invention further relate to modeling material formulations which are designed such that, upon exposure to a suitable condition (an inducing condition as described herein), the ROMP system becomes active, that is a ROMP catalyst is active towards ROMP of the monomer, and a ROMP monomer undergoes polymerization via ROMP to provide a respective polymer.
  • a suitable condition an inducing condition as described herein
  • Embodiments of the present invention relate to modeling material formulations which are designed such that, upon exposure to a suitable condition, the catalyst initiates the ROMP reaction, that is, upon exposure to a suitable condition, at least 50 %, preferably at least 60 %, preferably at least 70 %, at least 80 %, at least 90 %, at least 95 % and even 100 % of the ROMP monomers undergo polymerization via ROMP reaction.
  • the building material comprises one (single) type of a modeling material formulation.
  • Such embodiments are also referred to herein as “single jetting” methodology or approach.
  • the modeling material formulation comprises only ROMP monomers (at least one being represented by Formula P, I or II), as defined herein, as curable materials. Such embodiments are also referred to herein as “single jetting single curing” methodology or approach.
  • the modeling material formulation comprises in addition to the ROMP monomers, also one or more types of monomers which are polymerizable via a non-ROMP reaction, as curable materials, as described herein. Such embodiments are also referred to herein as “single jetting dual curing” or “single jetting multi-curing” methodology or approach.
  • the building material comprises two or more types of a modeling material formulation.
  • Such embodiments are also referred to herein as “dual jetting” or “multi jetting” methodology or approach, respectively.
  • each of the modeling material formulations comprises only ROMP monomers as curable materials (at least some of the monomers being a DCPD-based monomer as described herein, e.g., represented by Formula P, I or II).
  • ROMP monomers as curable materials
  • Such embodiments are also referred to herein as “dual jetting single curing” or “multi-jetting single curing” methodology or approach.
  • the modeling material formulations comprise in addition to ROMP monomers according to the present embodiments, also one or more types of monomers which are polymerizable via a non-ROMP reaction, as curable materials.
  • Such embodiments are also referred to herein as “multi-jetting multi-curing” or “dual jetting multi-curing” or “dual jetting dual curing” methodology or approach.
  • jetting refers to the number of modeling material formulations included in the building material
  • curing refers to the number of polymerization reactions that occur when the dispensed layers are exposed to a curing condition (e.g., a ROMP inducing condition, or a ROMP inducing condition and one or more additional curing conditions).
  • a curing condition e.g., a ROMP inducing condition, or a ROMP inducing condition and one or more additional curing conditions.
  • dual curing or multi curing refers herein to the type of polymerization reactions and not to the number of conditions applied for inducing curing.
  • the building material comprises a single modeling material formulation, and the single modeling material comprises all the components of a ROMP system, as described herein in any of the respective embodiments, with a ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II).
  • a ROMP monomer of the present embodiments e.g., represented by Formula P, I or II.
  • the ROMP system consists of a ROMP monomer according to the present embodiments (e.g., represented by Formula P, I or II) and an active catalyst, as defined herein.
  • the modeling material formulation comprises a ROMP catalyst and a ROMP monomer according to the present embodiments, and is such that the catalyst is active towards initiating ROMP of the monomer.
  • the ROMP system in the modeling material formulation, according to these embodiments is an active ROMP system, in which the ROMP catalyst initiates ROMP of the monomer when the catalyst contacts the monomer.
  • the active catalyst and the ROMP monomer are physically separated in the modeling material formulation, such that no contact is effected between the catalyst and the ROMP monomer and hence the ROMP system is inactive, and the catalyst does not initiate ROMP of the monomer, as described herein.
  • the ROMP system is inactive in the modeling material formulation due to physical separation between the catalyst and the ROMP monomer.
  • the ROMP system becomes active once the physical separation is removed.
  • the condition is removal of the physical separation between the catalyst and the ROMP monomer.
  • the physical separation results in a contact between the catalyst and the ROMP monomer and in an active ROMP system in which the catalyst initiates ROMP of the monomer.
  • exposing the modeling material formulation to a condition for inducing initiation of ROMP of the monomer by the catalyst comprises removal of a physical separation between a ROMP catalyst and the ROMP monomer.
  • Physical separation can be effected, for example, by encapsulation of one or more components of the ROMP system.
  • encapsulation it is meant that a component is enveloped by a capsule, whereby a capsule is used herein to describe a closed structure by which a component is enveloped.
  • the capsule has a core-shell structure in which the core is the encapsulated component which is enveloped by a shell.
  • each of the ROMP monomer and ROMP catalyst is individually encapsulated (enveloped by a capsule).
  • the capsules encapsulating the ROMP monomer can be the same as or different from the capsules encapsulating the ROMP catalyst.
  • the capsule may have any shape and can be made of any material.
  • the capsule is designed so as to release its content, namely, the encapsulated ROMP component (ROMP monomer or ROMP catalyst) upon being exposed to a condition.
  • the encapsulated ROMP component ROMP monomer or ROMP catalyst
  • exposure to a condition that induces initiation of ROMP monomer by the ROMP catalyst comprises exposure to a condition that affects release of a ROMP component from a capsule. That is, the ROMP including condition is a condition that degrades a capsule and results in contacting the catalyst with the ROMP monomer.
  • the release of a ROMP component from a capsule is effected by exposure to a condition that affects degradation of the capsule.
  • Degradation of the capsule can be effected, for example, mechanically, so as to affect rupture or breaking of the capsule, and the condition is such that causes mechanical degradation of the capsule.
  • the mechanical degradation can be effected, for example, by application of mechanical forces such as shear forces.
  • mechanical degradation is effected by exposing the capsule to shear forces, for example, by passing a modeling material formulation comprising the capsule through one or more inkjet printing heads (e.g., Ricoh Gen 3) which allow jetting at a frequency range of from about 10 kHz to about 30 kHz.
  • inkjet printing heads e.g., Ricoh Gen 3
  • shear forces at such a rate are applied to the dispensed layers of the formulation (e.g., to the receiving tray).
  • Degradation of the capsule can be effected, for example, physically or chemically, by application of, for example, heat or radiation to the capsule so as to decompose capsule or melt the capsule's shell.
  • Degradation of the capsule can thus be effected by exposing the capsule to heat or radiation, to thereby release its content.
  • encapsulation of a ROMP catalyst and/or a ROMP monomer include utilizing capsules made of, for example, wax, degradable polymeric materials, degradable micelles, sol-gel matrices, and/or clays. Exemplary degradable capsules are described, for example, in Adv. Funct. Mater. 2008, 18, 44-52; Adv. Mater. 2005, 17, 39-42; and Pastine, S. J.; Okawa, D.; Zettl, A.; Frechet, J. M. J. J. Am. Chem. Soc. 2009, 131, 13586-13587. doi: 10.1021/ja905378v; all of which are incorporated by reference as if fully set forth herein.
  • one or more of the ROMP catalyst (e.g., an active catalyst) and a ROMP monomer is encapsulated (e.g., individually encapsulated, in case both are encapsulated) in a capsule and exposing a modeling material formulation to the inducing condition comprises passing the formulation through the inkjet printing heads at a shear rate that causes mechanical degradation of the capsule and release on the encapsulated component.
  • one or more of the ROMP catalyst (e.g., an active catalyst) and a ROMP monomer is encapsulated (e.g., individually encapsulated, in case both are encapsulated) in a capsule and exposing a modeling material formulation to the inducing condition comprises exposing the dispensed formulation to heat or radiation to thereby cause degradation of the capsule and release the encapsulated component from the capsule.
  • the formulation comprises a plurality of capsules encapsulating one or both of the ROMP components.
  • the capsules can be the same or different and can release their content when exposed to the same or different inducing condition.
  • the modeling material formulation comprises a ROMP catalyst and a ROMP monomer, and is such that the catalyst is inactive towards initiating ROMP of the monomer upon exposure to the condition.
  • the ROMP system consists of a ROMP monomer as described herein and a latent catalyst, as defined herein, and a condition for activating the catalyst.
  • the catalyst prior to exposing the formulation to the inducing condition, the catalyst is inactive towards initiation of ROMP of the monomer, as explained hereinabove for a latent catalyst.
  • the modeling material formulation prior to exposure to the condition, is an inactive ROMP system, as described herein.
  • the latent catalyst is photo-activatable by, for example, exposure to radiation, as described herein, and in some embodiments the latent catalyst is thermally-activatable by, for example, exposure to heat, as described herein.
  • exposing the modeling material formulation to the inducing condition comprises exposing the formulation to heat or radiation or to any other condition that activates the catalyst, namely, converting a latent catalyst into an active catalyst.
  • the latent catalyst can be physically separated from the ROMP monomer, according to any one of the respective embodiments described herein for physical separation of an active catalyst.
  • the ROMP system comprises a ROMP monomer as described herein, and a catalyst system that comprises a pre-catalyst, as defined herein, and an activator (co-catalyst) for chemically activating the catalyst.
  • the ROMP system consists of a ROMP monomer as described herein, and a catalyst system that comprises a pre-catalyst, as defined herein, and an activator (co-catalyst) for chemically activating the catalyst.
  • the activator chemically activates the catalyst, once it contacts the catalyst and the catalyst initiates the ROMP, once it contacts the ROMP monomer, without a stimulus.
  • the activator is chemically active, that is, is capable of chemically-activating the catalyst, which in turn, becomes active towards initiation of the ROMP.
  • the ROMP system in the modeling material formulation is active.
  • the ROMP system is rendered inactive by physical separation between at least two of its reactive components.
  • the activator when the activator is active in the formulation, the activator is physically separated from the catalyst (e.g., the pre-catalyst) and/or the ROMP monomer in the modeling material formulation. That is, the modeling material formulation is such that there is no contact between the activator and the catalyst, or between the activator and the monomer, or between the catalyst and the monomer, or between the activator and the catalyst and the monomer. Because at least two of the ROMP components composing the active ROMP system according to these embodiments do not contact one another, the ROMP system is inactive.
  • the catalyst e.g., the pre-catalyst
  • the inducing condition renders the ROMP system active, at least by removing the physical separation and allowing contact between all the components composing the ROMP system.
  • the inducing condition is, or comprises, removing the physical separation between the activator and the catalyst (e.g., the pre-catalyst) and/or the monomer.
  • the physical separation is effected by encapsulation, that is, by using a capsule (or a plurality of capsules) enveloping one or more of the catalyst, the activator and the monomer.
  • the capsules can be capsules individually encapsulating the activator, capsules individually encapsulating the ROMP monomer, capsules individually encapsulating the pre-catalyst, or any combination thereof.
  • the capsules can alternatively comprise capsules encapsulating a ROMP monomer and the activator, or capsules encapsulating a ROMP monomer and a catalyst, or capsules encapsulating an activator and a catalyst.
  • the ROMP component not included in such capsules can be individually encapsulated, or non-encapsulated, in the modeling material formulation.
  • the capsule is such that release the ROMP component(s) encapsulated therein upon exposure to a condition.
  • exposing the modeling material to the ROMP inducing condition comprises exposing the formulation to a condition that affects a release of one or more of the ROMP components from a capsule encapsulating same and results in a contact between all the reactive components of the ROMP system.
  • any of the embodiments described herein for degradable capsules are contemplated for the embodiments pertaining to a modeling material formulation that comprises a pre-catalyst and an active activator, as described herein.
  • the activator is enveloped by a degradable capsule and is released from the capsule upon exposure to a condition that affects degradation of the capsule and hence release of the activator.
  • the ROMP inducing condition allows contacting between the activator and the pre-catalyst, to thereby generate an active catalyst, which in turn, contacts the ROMP monomer and initiates ROMP of the monomer.
  • the ROMP system comprises a ROMP monomer as described herein, and a catalyst system that comprises a pre-catalyst, as defined herein, a latent activator (latent co-catalyst) for chemically activating the catalyst, and a condition for activating the activator towards chemically activating the catalyst.
  • a latent activator latent co-catalyst
  • the activator chemically activates the catalyst and the catalyst initiates the ROMP upon exposure to the condition.
  • the activator prior to exposing the formulation to the inducing condition, the activator is inactive towards activating the catalyst (the activator is incapable of chemically activating the catalyst), and hence the catalyst is inactive towards initiation of ROMP of the monomer, as explained hereinabove for a latent activator in an activator-pre-catalyst system.
  • the modeling material formulation comprises a ROMP pre-catalyst, a ROMP monomer, and a latent activator of the catalyst, and is such that the activator is activatable towards activating the catalyst and the pre-catalyst is convertible to an active catalyst for initiating ROMP of the monomer, upon exposure to the condition.
  • the modeling material formulation prior to exposure to the condition, is an inactive ROMP system, as described herein.
  • the ROMP system is activated upon exposure to a condition that activates the latent activator.
  • the latent activator is photo-activatable by, for example, exposure to radiation, as described herein, and in some embodiments the latent activator is thermally-activatable by, for example, exposure to heat, as described herein.
  • exposing the modeling material formulation to the inducing condition comprises exposing the formulation to heat or radiation or to any other condition that activates the activator, namely, converting a latent activator into an active activator, to thereby chemically activating the catalyst towards initiating ROMP of the ROMP monomer.
  • the inducing condition comprises a condition that converts a latent activator to an active activator.
  • one or more of the pre-catalyst, the latent activator and the ROMP monomer can be physically separated in the composition, as described herein in any of the embodiments pertaining to an active activator.
  • a ROMP monomer is encapsulated, a pre-catalyst is encapsulated, and the activator is a latent activator as described herein, and can be encapsulated or not.
  • a latent catalyst is used, and is encapsulated.
  • the ROMP monomer can be encapsulated or not.
  • a latent catalyst is used, and is encapsulated or not, and the ROMP monomer is encapsulated.
  • converting a ROMP system to an active ROMP system is effected by two or more conditions.
  • the ROMP inducing condition comprises a set of conditions and exposing the formulation to these conditions can be effected simultaneously or sequentially.
  • exposure to one condition is effected by passing the formulation through the inkjet printing heads (application of shear forces to degrade a capsule) and exposure to another condition is application of radiation.
  • converting a ROMP system to an active ROMP system is effected by a single condition.
  • a latent catalyst which is photoactivatable can be used in combination with a ROMP monomer that is encapsulated by photodegradable capsules (which undergo degradation upon exposure to radiation such as UV radiation).
  • a pre-catalyst and/or a ROMP monomer are encapsulated in photodegradable capsules and a latent activator that is photoactivatable is used.
  • a UV-activatable ROMP system is provided in the modeling material formulation.
  • a latent catalyst which is thermally- activatable can be used in combination with a ROMP monomer that is encapsulated by thermally-degradable capsules (which undergo degradation upon exposure to heat).
  • a pre-catalyst and/or a ROMP monomer are encapsulated in thermally-degradable capsules and a latent activator that is thermally-activatable is used.
  • a thermally-activatable ROMP system is provided in the modeling material formulation.
  • the modeling material can further comprise a ROMP inhibitor, as described herein.
  • the modeling material formulation can comprise, in addition to the ROMP components, additional, non-curable (non-reactive) materials, as described in further detail hereinunder.
  • Single jetting multi-curing e.g., dual curing
  • a modeling material formulation as described herein for any one of the embodiments of "single jetting single curing” further comprises one or more curable systems which undergo polymerization and/or curing via a non-ROMP reaction.
  • a non-ROMP reaction refers to any polymerization and curing reactions that do not involve ROMP.
  • Such reactions include, for example, chain growth polymerization such as free-radical polymerization, cationic polymerization, anionic polymerization, and step-growth polymerization such as polycondensation.
  • a curable system which undergoes polymerization and/or curing via a non-ROMP reaction comprises monomers and/or oligomers which are polymerizable by a non-ROMP reaction as described herein.
  • Such materials are also collectively referred to herein as non-ROMP polymerizable materials or monomers, or non-ROMP curable materials or monomers.
  • a curable system which undergoes polymerization and/or curing via a non- ROMP reaction can alternatively, or in addition, comprise short-chain polymeric materials which undergo curing by, for example, cross-linking, whereby the curing comprises free-radical cross -linking, cationic or anionic cross-linking, and/or polycondensation.
  • Such materials are also encompassed herein by the expressions non- ROMP polymerizable materials or monomers, or non-ROMP curable materials or monomers.
  • a curable system which undergoes polymerization and/or curing via a non- ROMP reaction may comprise one or more curable materials that undergo polymerization and/or curing via a non-ROMP reaction, and optionally one or more initiators for initiating a respective non-ROMP reaction.
  • such a system further comprises a condition for inducing initiation of the non-ROMP reaction.
  • a curable system which undergoes polymerization and/or curing via a non-ROMP reaction is also referred to herein as a non-ROMP curable system.
  • the modeling material further comprises, in addition to the ROMP components described for the single curing approach, one or more curable materials that undergo polymerization and/or curing via a non-ROMP reaction, and optionally one or more initiators for initiating a respective non-ROMP reaction.
  • the method further comprises exposing the modeling material formulation to a condition for inducing initiation of a respective polymerization and/or curing via a non-ROMP reaction.
  • condition for inducing polymerization and/or curing via a non-ROMP reaction is the same as the ROMP indicting condition, and in some embodiments, it is a different condition.
  • one or more of the components of a curable system e.g., a non-ROMP curable material and/or an initiator of a respective non-ROMP reaction
  • one or more of the ROMP components in the modeling material formulation is/are physically separated from the other components in the formulation.
  • one or more of the ROMP components e.g., a ROMP monomer, a ROMP active catalyst, a ROMP latent catalyst, a ROMP pre- catalyst and/or a ROMP activator (latent or not), if present, is physically separated from other components in the modeling material formulation.
  • one or more of the non-ROMP curable systems e.g., a non-ROMP curable monomer and/or a respective initiator and/or activator, is physically separated from other components in the modeling material formulation.
  • the physical separation can be, for example, by means of a capsule enveloping the component, and the capsule is such that releases the enveloped component upon exposure to the condition that induced curing (a ROMP inducing condition or another curing condition).
  • the capsule and corresponding conditions for releasing an enveloped component and thereby initiating curing can be in accordance with any of the embodiments described herein for a ROMP system.
  • the capsules can be degradable upon exposure to the same or different condition for initiating curing.
  • a modeling material formulation for a single jetting dual curing methodology can comprise a ROMP monomer, a ROMP active catalyst, a non-ROMP curable monomer and a non-ROMP initiator, whereby the ROMP active catalyst is encapsulated.
  • a modeling material formulation for a single jetting dual curing methodology can comprise a ROMP monomer, a ROMP latent or active catalyst, a non-ROMP curable monomer and a non-ROMP initiator, whereby the ROMP latent catalyst is encapsulated and the non-ROMP initiator are individually encapsulated.
  • the capsules of the ROMP catalyst and the non-ROMP initiator can be the same or different, and the condition for degrading the capsules and releasing the encapsulated component can be the same or different.
  • the non-ROMP curable system is polymerizable or curable by free radical polymerization.
  • the modeling material formulation comprises, in addition to a selected inactive ROMP system as described herein in any of the respective embodiments, a monomer and/or oligomer that is polymerizable by a free radical polymerization and a free radical initiator.
  • the non-ROMP curable system is polymerizable or curable by cationic polymerization.
  • the modeling material formulation comprises, in addition to a selected inactive ROMP system as described herein in any of the respective embodiments, a monomer and/or oligomer that is polymerizable by a cationic polymerization and a cationic initiator.
  • the non-ROMP curable system is polymerizable or curable by anionic polymerization.
  • the modeling material formulation comprises, in addition to a selected inactive ROMP system as described herein in any of the respective embodiments, a monomer and/or oligomer that is polymerizable by anionic polymerization and an anionic initiator.
  • the non-ROMP initiator is a latent initiator, which is activatable upon exposure to a curing condition, as described herein.
  • the non-ROMP initiator is chemically activatable by an activator, similarly to the ROMP pre-catalysts and activators described herein.
  • the modeling material formulation further comprises such an activator for chemically activating the non- ROMP initiator.
  • the activator in the formulation can be a latent activator which is activatable upon exposure to a curing condition.
  • the activator can alternatively physically separated, as described herein, from other non-ROMP components in the formulation.
  • the activator, latent or not, can be the same activator that chemically activates a ROMP pre-catalyst or can be a different activator.
  • the non-ROMP curable system is a photo-polymerizable or photo-activatable system, which undergoes polymerization and/or curing upon exposure to radiation as a curing condition.
  • the radiation in these embodiments may affect one or more of initiation of a non-ROMP reaction by activating a latent initiator; initiation of a non-ROMP reaction by activating a latent activator; and/or releasing one or more encapsulated components of the system.
  • the ROMP system in the formulation is a photo- activatable system, as described herein.
  • the radiation required for curing the ROMP system and the non-ROMP system is the same (e.g., UV radiation).
  • a modeling material formulation is cured upon exposure to radiation as a single condition for inducing curing of the formulation.
  • a ROMP monomer which further comprises a group that is polymerizable by a non-ROMP reaction is used in combination with the DCPD-based ROMP monomer as described herein.
  • Such monomers are referred to herein as dual-curing monomers or oligomers or materials.
  • Exemplary such monomers are dicyclopentenyl acrylates, such as, for example, Fancryl FA511 AS, FA512AS, marketed by Hitachi, which contain an acrylic functional group and cyclic olefin structure enabling dual polymerization of the same compound using free radical mechanism and ROMP mechanism, respectively.
  • Other examples for dual-curing monomers are epoxy norbornene derivatives, such as, for example, described in U.S. Patent Nos. 8,362,171 and 7,728,090, which are incorporated by reference as if fully set forth herein.
  • Multi-jetting e.g., dual jetting
  • the building material comprises two or more modeling material formulations which are dispensed from different inkjet printing heads (each formulation is jetted from a different printing head or a different set of printing heads) to form the layers.
  • Such a methodology which is referred to herein as dual jetting, when two different modeling material formulations are used, or as multi-jetting, when more than two modeling material formulations are used, allows dispensing modeling material formulations which are absent of one or more of the components required for a polymerization or curing to occur, whereby when the formulations are dispensed and contact one another, curing and/or polymerization occurs.
  • such a methodology allows separating ROMP components as described herein by including a different combination of components in each formulation, whereby none of the formulations comprises all the components required for the ROMP reaction to occur.
  • a ROMP reaction, and optionally non-ROMP reactions occur only on the receiving medium, and after the building material is dispensed.
  • exposing the formulation to a condition for initiating ROMP can be effected by contacting the different formulations on the receiving medium (receiving tray). In some of these embodiments, exposing to a ROMP inducing condition is effected by dispensing the formulations.
  • Connex 3TM (Stratasys Ltd., Israel) multiple material deposition technology
  • Objet Connex 3TM (Stratasys Ltd., Israel) multiple material deposition system, is a system that allows utilizing such a technology.
  • the building material comprises two or more modeling material formulations, and the two or more modeling material formulations are such that when combined, curing is effected by ROMP reaction.
  • these embodiments are referred to herein as dual jetting single curing or multi-jetting single curing methodology.
  • At least one of these modeling material formulations comprises DCPD-based ROMP monomer according to the present embodiments (e.g., represented by Formula P, or I or II).
  • the building material comprises two or more modeling material formulations, and the two or more modeling material formulations are such that when combined, curing is effected by both a ROMP reaction and a non-ROMP reaction, as defined herein.
  • these embodiments are referred to herein as dual jetting dual curing or multi-jetting multi-curing methodology.
  • At least one of these modeling material formulations comprises a ROMP monomer DCPD-based derivative according to the present embodiments (e.g., represented by Formula P, or I or II).
  • Multi-jetting e.g., dual jetting
  • the building material comprises two or more modeling material formulations, and the two or more modeling material formulations are such that when combined, curing is effected by ROMP reaction.
  • each of the modeling material formulations comprises a ROMP monomer (which can be the same or different). At least one or both of these modeling material formulations comprises a DCPD-based ROMP monomer according to the present embodiments (e.g., represented by Formula P, or I or II).
  • any of the ROMP systems described hereinabove for" single jetting single curing can be used, whereby a different combination of the ROMP components of a respective system is included in each of the modeling material formulations.
  • each of the modeling material formulations comprises a ROMP monomer (which can be the same or different), at least one being a DCPD-based ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II) and one of the formulations further comprises a ROMP catalyst.
  • the building material comprises more than two modeling material formulations, each independently comprising a ROMP monomer (which can be the same or different), at least one being a DCPD-based ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II) and one or two of these formulations further comprises a ROMP catalyst.
  • a ROMP monomer which can be the same or different
  • DCPD-based ROMP monomer of the present embodiments e.g., represented by Formula P, I or II
  • one or more of the modeling material formulations is devoid of a ROMP catalyst, and in some embodiments, one or more of the modeling material formulations comprises a ROMP monomer according to the present embodiments (e.g., represented by Formula P, I or II) and a ROMP catalyst. In some of these embodiments, one or more of the ROMP catalysts is an active catalyst, as described herein.
  • the formulations comprise two or more types of catalysts.
  • the two or more catalysts are active catalysts.
  • the formulations comprise two or more types of ROMP monomers, at least one being a monomer according the present embodiments (e.g., represented by Formula P, I or II).
  • each of the ROMP active catalysts has a different reactivity towards initiation of ROMP of the different monomers.
  • a ROMP system of the modeling material formulations comprises first and second ROMP monomers, at least one being a monomer according the present embodiments (e.g., represented by Formula P, I or II), and first and second ROMP active catalysts.
  • the first ROMP active catalyst has a higher reactivity towards initiation of ROMP of the first monomer
  • the second ROMP active catalyst has a higher reactivity towards initiation of ROMP of the second monomer.
  • one of the formulations comprises a first ROMP monomer and the second active catalyst that is less reactive towards initiation of ROMP of the first monomer and has a higher reactivity towards initiation of ROMP of the second ROMP monomer
  • another one of the formulations comprises the first active catalyst that is less reactive towards initiation of ROMP of the second ROMP monomer and has a higher reactivity towards initiation of ROMP of the first ROMP monomer.
  • At least one of the ROMP monomers being a DCPD-based ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II).
  • Such exemplary embodiments allow using active catalysts while avoiding substantial clogging of the inkjet printing heads.
  • the ROMP catalyst(s) include one or more latent catalysts, which are activatable upon exposure to a ROMP inducing condition, as described herein.
  • a method comprises exposing the dispensed layers to a condition that activates the catalyst, as described herein.
  • the ROMP system further comprises an activator and the catalyst is a pre-catalyst.
  • each of the modeling material formulations independently comprises a ROMP monomer, at least one comprises a DCPD-based ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II), one or more of the formulations further comprise a pre-catalyst, and one or more other formulations further comprise an activator.
  • the one or more formulations that comprise the activator are devoid of the pre-catalyst. In some embodiments, the one or more formulations that comprise the pre-catalyst are devoid of an activator.
  • exposing the dispensed layers to inducing condition is effected by the contacting the formulations on the receiving medium, and hence comprises the formation of the dispensed layers (e.g., by jetting the modeling material formulation by the inkjet printing heads).
  • the ROMP system comprises a latent activator.
  • exposing the dispensed layers to inducing condition is effected by exposing the dispensed formulations to a condition that activates the activator.
  • one or more of the components in one or more of the formulations is physically separated from the other components in the formulation, as described herein in the context of the single jetting single curing embodiments.
  • one or more, or each, of the modeling material formulations further comprises a ROMP inhibitor.
  • one or more, or each, of the modeling material formulations further comprises additional materials, as is described in further detail hereinunder.
  • converting the ROMP system or systems to active ROMP systems is effected by a single condition.
  • activating of a latent catalyst, if present in one or more of the formulations, of a latent activator, if present in one or more of the formulations, and/or release of one or more components that are encapsulated are all effected upon exposing the dispensed formulations to the same condition.
  • the condition can be, for example, radiation (e.g., UV radiation), such that the ROMP system or systems in the two or more modeling material formulations is/are photoactivatable.
  • the condition can be, for example, heat, such that the ROMP system or systems in the two or more modeling material formulations is/are thermally- activatable.
  • Multi e.g., dual
  • jetting multi e.g., dual
  • the two or more modeling material formulations comprise, in addition to ROMP components, components of one or more non-ROMP curable systems, as described herein (for example, under "single jetting multi-curing").
  • the components of such a building material therefore undergo polymerization and/or curing via ROMP polymerization and also by one or more non-ROMP reactions, as described herein.
  • the components of the two or more modeling material formulations form two curable systems, for example, one or more ROMP systems, at least one comprising a DCPD-based ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II), and one or more of free radial polymerization system, cationic polymerization system, anionic polymerization system, etc. Any polymerization system that is usable in 3D inkjet printing is contemplated.
  • the ROMP components can include one or more ROMP monomers, at least one being a DCPD-based ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II), and one or more catalysts, for example, active catalysts.
  • ROMP monomers at least one being a DCPD-based ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II)
  • catalysts for example, active catalysts.
  • the active catalyst when used, is included in a modeling material formulation that is devoid of a ROMP monomer, and which, in some embodiments, comprises a material that polymerizable by a non-ROMP reaction (a non-ROMP curable or polymerizable material) as described herein.
  • one or more of the modeling material formulations comprises a ROMP monomer or monomers, and is devoid of a catalyst
  • other one or more modeling material formulation comprises a ROMP catalyst which is an active catalyst, and is devoid of a ROMP monomer.
  • the catalyst is a latent catalyst.
  • the catalyst is physically separated from the other components in the formulation containing same. Physical separation can be effected by means of degradable capsules, as described herein.
  • the inducing condition comprises a condition which activates the catalyst, as described herein.
  • the inducing condition comprises a condition which degrades the capsule so as to release the active catalyst.
  • the catalyst is a pre-catalyst and the one or more of the modeling material formulations comprises an activator or a latent activator, as described herein.
  • one or more of the modeling material formulations comprise a ROMP monomer according to the present embodiments (e.g., represented by Formula P, I or II) and a pre-catalyst and other one or more modeling material formulations comprise the activator.
  • one or more of the modeling material formulations comprise a ROMP monomer according the present embodiments (e.g., represented by Formula P, I or II) and the activator and other one or more modeling material formulations comprise the pre-catalyst.
  • the inducing condition for effecting ROMP can be contacting the respective formulations on the receiving medium (tray).
  • exposing to the condition is effected by jetting the formulations by the inkjet printing heads (dispensing the layers of the formulations).
  • one or more of the modeling material formulations comprise a ROMP monomer or monomer, at least one being a monomer according the present embodiments (e.g., represented by Formula P, I or II), and other one or more modeling material formulations comprise the activator and the pre-catalyst.
  • the activator is a latent activator and/or one or both of the activator and the pre-catalyst are physically separated from one another, as described herein.
  • one or more of the modeling material formulations further comprises a non-ROMP curable material (a material polymerizable or curable by a non-ROMP reaction as described herein).
  • the non-ROMP curable material is included in a formulation which comprises a ROMP catalyst (active, latent or pre-catalyst, encapsulated or non-encapsulated) and/or a ROMP activator (active or latent, encapsulated or non-encapsulated).
  • a ROMP catalyst active, latent or pre-catalyst, encapsulated or non-encapsulated
  • a ROMP activator active or latent, encapsulated or non-encapsulated
  • one or more formulations comprise a ROMP monomer or monomers at least one being a monomer according the present embodiments (e.g., represented by Formula P, I or II), and one or more other formulations comprise a non-ROMP curable material and a ROMP catalyst (active, latent or pre-catalyst, encapsulated or non-encapsulated) and/or a ROMP activator (active or latent, encapsulated or non-encapsulated), and is devoid of a ROMP monomer.
  • a ROMP monomer or monomers at least one being a monomer according the present embodiments (e.g., represented by Formula P, I or II)
  • one or more other formulations comprise a non-ROMP curable material and a ROMP catalyst (active, latent or pre-catalyst, encapsulated or non-encapsulated) and/or a ROMP activator (active or latent, encapsulated or non-encapsulated), and is devoid
  • one modeling material formulation comprises a ROMP monomer according the present embodiments (e.g., represented by Formula P, I or II) and another modeling material formulation, formulation B comprises a non-ROMP curable material.
  • formulation A further comprises a ROMP pre-catalyst (optionally encapsulated) and formulation B further comprises a ROMP activator (latent or not, encapsulated or non-encapsulated).
  • formulation A further comprises a ROMP activator (latent or not, optionally encapsulated) and formulation B further comprises a ROMP pre-catalyst (optionally encapsulated).
  • formulation B further comprises a ROMP catalyst (latent or active, optionally encapsulated). In some embodiments, formulation B further comprises a ROMP activator (latent or not, encapsulated or non-encapsulated) and a ROMP pre- catalyst (optionally encapsulated).
  • a ROMP monomer in one or more of the modeling material formulations can be replaced by a non-ROMP curable material, as long as there is at least one ROMP monomer according the present embodiments (e.g., represented by Formula P, I or II).
  • one or more of the modeling material formulations, according to any one of the embodiments described herein and any combination thereof, further comprises an initiator of the non-ROMP reaction (a non-ROMP initiator).
  • the initiator is comprised in one or more modeling material formulations which are devoid of a non-ROMP curable material.
  • one or more of the modeling material formulations comprise a ROMP monomer and a non-ROMP initiator.
  • such a formulation is devoid of one or more of the ROMP components of the ROMP system (e.g., a catalyst, an activator, a pre-catalyst).
  • one modeling material formulation, formulation A comprises a ROMP monomer and another modeling material formulation, formulation B comprises a non- ROMP curable material.
  • formulation A further comprises a ROMP pre-catalyst (optionally encapsulated) and a non-ROMP initiator (latent or active, optionally encapsulated), and formulation B further comprises a ROMP activator (latent or not, encapsulated or non-encapsulated).
  • formulation A further comprises a ROMP activator (latent or not, optionally encapsulated) and a non- ROMP initiator (latent or active, optionally encapsulated), and formulation B further comprises a ROMP pre-catalyst (optionally encapsulated).
  • formulation A further comprises a non-ROMP initiator (latent or active, optionally encapsulated) and formulation B further comprises a ROMP catalyst (latent or active, optionally encapsulated).
  • formulation A further comprises a ROMP activator (latent or not, optionally encapsulated) and a non-ROMP initiator (latent or active, optionally encapsulated)
  • formulation B further comprises a ROMP activator (latent or not, encapsulated or non-encapsulated) and a ROMP pre-catalyst (optionally encapsulated).
  • a ROMP monomer in one or more of the modeling material formulations can be replaced by a non-ROMP curable material, and one or more of the formulations further comprises a non-ROMP initiator (latent or active, optionally encapsulated).
  • the method further comprises exposing the formulation to one or more conditions for inducing polymerization and/or curing of the one or more non-ROMP curable systems.
  • the condition for inducing ROMP and the condition for inducing polymerization and/or curing of the non-ROMP curable material(s) are the same.
  • the conditions are different and can be applied simultaneously or sequentially, as desired or required.
  • curable system refers to a system that comprises one or more curable materials, as defined herein.
  • a “curable system” comprises one or more curable materials and optionally one or more initiators and/or catalysts for initiating curing of the curable materials, and, further optionally, one or more conditions (also referred to herein as curing conditions) for inducing the curing, as described herein.
  • a curable material is a monomer or a mixture of monomers and/or an oligomer or a mixture of oligomers which can form a polymeric material upon a polymerization reaction, when exposed to a condition at which curing, as defined herein, occurs (a condition that affects or induces curing).
  • a "bifunctional” or “multifunctional” curable material or monomer is meant to describe curable materials that result in a polymeric material that features two or more functional groups, and hence can act also as a cross-linker, for cross-linking polymeric chains formed of the same and/or different curable materials in the building material.
  • a curable system further comprises an initiator for initiating the curing and/or polymerization of the curable material(s).
  • the initiator can be active towards the initiation of the curing and/or polymerization in the curable system or can be inactive towards this initiation.
  • Inactive initiators can be latent initiators, which are activatable upon exposure to a condition, and this condition induces the curing and/or polymerization.
  • inactive initiators can be inactive due to physical separation from the curable material(s).
  • the physical separation can be effected by means of capsules, preferably degradable capsules as described herein.
  • Such initiators are activatable by a condition that removes the physical separation, e.g., induces release of the initiator from the capsule, as described herein.
  • inactive initiators can be chemically activated by an activator, and become active upon a condition that results in contacting the activator, similarly to any of the embodiments described herein in the context of a pre-catalyst and an activator.
  • a curable system further requires a condition for effecting curing and/or polymerization of the curable materials.
  • the one or more modeling material formulations comprise a curable system that is an active system, namely, the components included in the one or more modeling material formulations can undergo polymerization or curing without a stimulus.
  • the one or more modeling material formulation comprise a curable system that is inactive, namely, the components included in the one or more modeling material formulations can undergo polymerization or curing only when exposed to a condition that induces curing.
  • a curable system as described herein may comprise, in addition to a curable material, an initiator and optionally an activator.
  • a curable system as described herein can be a ROMP system, as described herein in any of the respective embodiments, which comprises one or more ROMP monomers, as described herein in any of the respective embodiments.
  • the modeling material formulation comprises in addition to components of a ROMP system, components of one or more additional curable systems, which are referred to herein also as non-ROMP systems.
  • the two or more modeling material formulations further comprise components of additional, one or more curable systems, either in the same, and preferably, in different formulations.
  • curable systems which comprise curable materials that are curable and/or polymerizable via a polymerization or curing reaction other than ROMP, are referred to herein also as non-ROMP curable systems.
  • non-ROMP components for example, non-ROMP curable materials, non-ROMP initiators, non-ROM- activators, and non-ROMP inducing condition (or condition for inducing non-ROMP polymerization and/or curing or for initiating a non-ROMP reaction).
  • a concentration of a curable material, including a ROMP monomer, in a modeling material formulation containing same ranges from about 50 % to about 99 % by weight of the total weight of the modeling material formulation, including any subranges and intermediate values therebetween.
  • a modeling material formulation comprises a single curable material, at the indicted concentration range.
  • a modeling material formulation comprises two or more curable materials, and the total concentration of curable materials ranges from about 50% to about 99% by weight of the total weight of the formulation.
  • a concentration of additional reactive components in a curable system as described herein including, for example, a ROMP catalyst, a ROMP activator, a non-ROMP initiator, a non-ROMP activator (or co-initiator), in a modeling material formulation containing same individually ranges (for each component) from about 0.001 % to about 10 %, or from about 0.01 % to 5 % by weight of the total weight of the modeling material formulation, including any subranges and intermediate values therebetween.
  • ROMP pre-catalyst in a modeling material formulation containing same independently ranges from about 0.001 % to about 1 %, or from about 0.001 % to about 0.1 % by weight of the total weight of the modeling material formulation, including any subranges and intermediate values therebetween.
  • a concentration of a ROMP inhibitor in a modeling material formulation containing same independently ranges from about 0.001 % to about 1 %, or from about 0.001 % to about 0.1 % by weight of the total weight of the modeling material formulation, including any subranges and intermediate values therebetween.
  • a concentration of a ROMP activator (active or latent) in a modeling material formulation containing same independently ranges from about 0.001 % to about 5 %, or from about 0.001 % to about 1 % by weight of the total weight of the modeling material formulation, including any subranges and intermediate values therebetween.
  • a modeling material formulation comprises a single reactive component, at the indicted concentration range.
  • a modeling material formulation comprises two or more curable materials reactive components, and the total concentration of the reactive components materials ranges from about 0.001 % to about 10 % by weight of the total weight of the formulation, including any subranges and intermediate values therebetween.
  • components which form a curable system as described herein are referred to as reactive components or materials, and curable components are referred to as reactive polymerizable components, materials, monomers, or groups, interchangeably.
  • a curable material can be a monofunctional curable material, which comprises one polymerizable group that participates in the polymerization or curing, or a bifunctional or multifunctional curable material, as defined herein.
  • non-reactive materials or components are also referred to herein as non-reactive materials or components.
  • Non-ROMP curable systems can be, for example, curable systems in which the non-ROMP curable material(s) undergo curing and/or polymerization via free radical polymerization. Such systems are also referred to herein as free-radical curable systems.
  • free-radical polymerizable (curable) components may include mono-functional and/or multi-functional acrylic and/or methacrylic monomers, acrylic and/or methacrylic oligomers, and any combination thereof.
  • Other free-radical polymerizable compounds may include thiols, vinyl ethers and other components (monomers or oligomers) with a reactive double bond.
  • An acrylic or methacrylic oligomer can be, for example, a polyester of acrylic acid or methacrylic acid, oligomers of urethane acrylates and urethane methacrylates.
  • Urethane-acrylates are manufactured from aliphatic or aromatic or cycloaliphatic diisocyanates or polyisocyanates and hydroxyl-containing acrylic acid esters.
  • Oligomers may be mono-functional or multifunctional (for example, di-, tri-, tetra- functional, and others).
  • An example is a urethane- acrylate oligomer marketed by IGM Resins BV (The Netherlands) under the trade name Photomer-6010.
  • An acrylic or metyhacrylic monomer can be, for example, an ester of acrylic acid or methacrylic acid.
  • Momoners may be mono-functional or multifunctional (for example, di-, tri-, tetra-functional, and others).
  • An example of an acrylic mono- functional monomer is phenoxyethyl acrylate, marketed by Sartomer Company (USA) under the trade name SR-339.
  • An example of an acrylic di-functional monomer is propoxylated (2) neopentyl glycol diacrylate, marketed by Sartomer Company (USA) under the trade name SR-9003.
  • Either the monomer or the oligomer might be polyfunctional, and can be, for example, Ditrimethylolpropane Tetra- acrylate (DiTMPTTA), Pentaerythitol Tetra- acrylate (TETTA), Dipentaerythitol Penta- acrylate (DiPEP). Any other curable material that is polymerizable by free radical polymerization is contemplated.
  • DITMPTTA Ditrimethylolpropane Tetra- acrylate
  • TETTA Pentaerythitol Tetra- acrylate
  • DIPEP Dipentaerythitol Penta- acrylate
  • Any other curable material that is polymerizable by free radical polymerization is contemplated.
  • a free-radical polymerizable material is polymerizable or curable by exposure to radiation.
  • Systems comprising such a material can be referred to as photo-polymerizable free-radical systems, or photoactivatable free-radical systems.
  • a free-radical curable system further comprises a free radical initiator, which produces free radicals for initiating the polymerization and/or curing.
  • a condition for initiating free-radical curing and/or polymerization comprises is a condition that induced free radical generation by the initiator.
  • the initiator in such cases is a latent initiator, which produces free radicals when exposed to the condition.
  • the initiator is a free-radical photoinitiator, which produces free radicals when being exposed to radiation.
  • the radiation is UV radiation
  • the system is a UV-curable system.
  • a free -radical photoinitiator may be any compound that produces a free radical on exposure to radiation such as ultraviolet or visible radiation and thereby initiates a polymerization reaction.
  • suitable photoinitiators include benzophenones (aromatic ketones) such as benzophenone, methyl benzophenone, Michler's ketone and xanthones; acylphosphine oxide type photo-initiators such as 2,4,6- trimethylbenzolydiphenyl phosphine oxide (TMPO), 2,4,6- trimethylbenzoylethoxyphenyl phosphine oxide (TEPO), and bisacylphosphine oxides (BAPO's); benzoins and bezoin alkyl ethers such as benzoin, benzoin methyl ether and benzoin isopropyl ether and the like.
  • Examples of photoinitiators are alpha-amino ketone, and bisacylphosphine oxide (BAPO's). Additional
  • a free -radical photo-initiator may be used alone or in combination with a co- initiator.
  • Co-initiators are used with initiators that need a second molecule to produce a radical that is active in the photocurable free -radical systems.
  • a co-initiator of a photoinitiator is also referred to herein as a non-ROMP activator.
  • Benzophenone is an example of a photoinitiator that requires a second molecule, such as an amine, to produce a free radical. After absorbing radiation, benzophenone reacts with a ternary amine by hydrogen abstraction, to generate an alpha-amino radical which initiates polymerization of acrylates.
  • Non-limiting example of a class of co-initiators are alkanolamines such as triethylamine, methyldiethanolamine and triethanolamine.
  • UV curable materials of a free-radical curable system include, but are not limited to, tricyclodecane dimethanol diacrylate SR 833S, Phenoxy ethyl Acrylate SR 339, Isobornyl acrylate SR 506D and etc. Other examples are provided in Table B herein.
  • one or more of the modeling material formulations containing a free-radical curable system comprises a radical inhibitor, for preventing or slowing down polymerization and/or curing prior to exposing to the curing condition.
  • the one or more additional curable systems is/are polymerizable or cured via cationic polymerization, and are referred to herein also as cationic polymerizable or cationic curable systems.
  • curable components or materials of such systems undergo polymerization or curing via cationic polymerization.
  • Exemplary cationically polymerizable components include, but are not limited to, epoxy-containing materials (monomers or oligomers), caprolactams, caprolactones, oxetanes, and vinyl ethers (monomers or oligomers).
  • Non-limiting examples of epoxy-containing curable compounds include Bis-(3,4 cyclohexylmethyl) adipate, 3,4-epoxy cyclohexylmethyl-3,4-epoxycyclohexyl carboxylate, 1,2 epoxy-4-vinylcyclohexane, 1,2-epoxy hexadecane, 3,4-epoxy cyclohexylmethyl - 3,4-epoxy cyclohexane carboxylate, which is available, for example, under the trade name UVACURE 1500 from Cytec Surface Specialties SA/NV (Belgium) and mono or multifunctional silicon epoxy resins such as PC 1000 which is available from Polyset Company (USA).
  • a cationic polymerizable material is polymerizable or curable by exposure to radiation.
  • Systems comprising such a material can be referred to as photo-polymerizable cationic systems, or photoactivatable cationic systems.
  • a cationic curable system further comprises a cationic initiator, which produces cations for initiating the polymerization and/or curing.
  • a condition for initiating cationic curing and/or polymerization comprises is a condition that induced cation generation by the initiator.
  • the initiator in such cases is a latent initiator, which produces cations when exposed to the condition.
  • the initiator is a cationic photoinitiator, which produces cations when exposed to radiation.
  • the radiation is UV radiation
  • the system is a cationic UV-curable system.
  • Suitable cationic photoinitiators include, for example, compounds which form aprotic acids or Bronsted acids upon exposure to ultraviolet and/or visible light sufficient to initiate polymerization.
  • the photoinitiator used may be a single compound, a mixture of two or more active compounds, or a combination of two or more different compounds, i.e. co-initiators.
  • suitable cationic photoinitiators include aryldiazonium salts, diaryliodonium salts, triarylsulphonium salts, triarylselenonium salts and the like.
  • An exemplary cationic photoinitiator is a mixture of triarylsolfonium hexafluoroantimonate salts.
  • Non-limiting examples of suitable cationic photoinitiators include P-
  • the non-ROMP curable system is any other system that is usable in 3D-printing processes and systems. Additional examples include, without limitation, systems based on polyurethane chemistry , in which isocyanate-containing compounds and hydroxyl-containing compounds (e.g., polyols) react via polycondensation in the presence of a catalyst and/or upon exposure to UV radiation,), thiol chemistry, in which mercaptopropionate-based curable materials polymerize when exposed to UV in the presence of a free-radical photoinitiator, and more.
  • polyurethane chemistry in which isocyanate-containing compounds and hydroxyl-containing compounds (e.g., polyols) react via polycondensation in the presence of a catalyst and/or upon exposure to UV radiation
  • thiol chemistry in which mercaptopropionate-based curable materials polymerize when exposed to UV in the presence of a free-radical photoinitiator, and more.
  • the non-ROMP curable systems comprise a combination of two or more non-ROMP curable systems.
  • At least one, and preferably each, of the non-ROMP curable systems in the modeling material formulations described herein is activatable upon exposure to the same condition as does a ROMP system. That is, curing of all the curable systems is effected upon exposure to the same curing inducing condition, as described herein.
  • the ROMP system is a photoactivatable system and the one or more non-ROMP curable systems are also photoactivatable systems.
  • the systems are UV-curable, that is, the condition inducing curing is effected by exposure to UV radiation, as described herein.
  • Photoactivatable ROMP systems are described herein.
  • Photoactivatable non-ROMP systems may include free radical photopolymerizable compounds (e.g., Tricyclodecane dimethanol diacrylate SR 833S, Phenoxy ethyl Acrylate SR 339, Isobornyl acrylate SR 506D and so on), and/or cationic polymerizable compounds (e.g., cycloaliphatic epoxide Uvacure 1500, epoxidized polybutadiene polyBD605E, limonene dioxide Celloxide 3000, Difunctional silicon- containing epoxy resin PC2000, etc.), optionally in combination with a free radical photoinitiator or a cationic photoinitiator, respectively, as described herein.
  • free radical photopolymerizable compounds e.g., Tricyclodecane dimethanol diacrylate SR 833S, Phenoxy ethyl Acrylate SR 339, Isobornyl acrylate SR 506D and so on
  • a modeling material formulation can further comprise a photosensitizer.
  • the photosensitizer can be included in a modeling material formulation that comprises a respective photocurable material (including a ROMP monomer) or in another formulation, that is devoid of the photocurable material.
  • the photosensitizer is included in a modeling material that is devoid of one or more of the components which are activatable by exposure to radiation.
  • Such components include, for example, an active ROMP catalyst that is encapsulated by a photodegradable capsule, a latent ROMP catalyst that is photoactivatable, a latent activator that is photoactivatable, an activator that is encapsulated by a photodegradable capsule, a photoinitiator, as described herein, an initiator or co-initiator that in encapsulated in photodegradable capsule, and so forth.
  • Exemplary photosensitizers include, but are not limited to, 2- isopropylthioxanthone and 4-isopropylthioxanthone, marketed as SPEEDCURE ⁇ and referred to herein also as ITX, 9,10-Dibutoxy anthracene marketed as Anthracure ® UVS-1331, Phenothiazine (253 and 318 nm), Anthracene, and a curcumin compound such as marketed as Ecocol curcumin colour 95%
  • Table B below presents a list of exemplary components which can be included, in any combination, in a UV-curable non-ROMP system as described herein in any one of the embodiments and any combinations thereof.
  • the components can be included in one or more modeling material formulations, as described herein.
  • a modeling material formulation can further comprise one or more additional materials, which are referred to herein also as non-reactive materials.
  • Such agents include, for example, surface active agents, stabilizers, antioxidants, fillers, pigments, dispersants, and/or impact modifying agents (toughening agents or toughness modifiers).
  • the non-reactive agents can be independently included in one or all of the modeling material formulations.
  • filler describes an inert material that modifies the properties of a polymeric material and/or adjusts a quality of the end products.
  • the filler may be an inorganic particle, for example calcium carbonate, silica, and clay.
  • Fillers may be added to the modeling formulation in order to reduce shrinkage during polymerization or during cooling, for example, to reduce the coefficient of thermal expansion, increase strength, increase thermal stability, reduce cost and/or adopt rheological properties. Nanoparticles fillers are typically useful in applications requiring low viscosity such as ink-jet applications.
  • a modeling formulation comprises a surface active agent.
  • a surface- active agent may be used to reduce the surface tension of the formulation to the value required for jetting or for printing process, which is typically around 30 dyne/cm.
  • An exemplary such agent is a silicone surface additive.
  • Suitable stabilizers include, for example, thermal stabilizers, which stabilize the formulation at high temperatures.
  • the modeling formulation comprises one or more pigments.
  • the pigment's concentration is lower than 35%, or lower than 25 % or lower than 15 %, by weight.
  • the pigment may be a white pigment.
  • the pigment may be an organic pigment or an inorganic pigment, or a metal pigment or a combination thereof.
  • the modeling formulation further comprises a dye.
  • combinations of white pigments and dyes are used to prepare colored cured materials.
  • the dye may be any of a broad class of solvent soluble dyes. Some non-limiting examples are azo dyes which are yellow, orange, brown and red; anthraquinone and triarylmethane dyes which are green and blue; and azine dye which is black.
  • one or more of the modeling material formulations comprises a toughening agent.
  • Non- limiting examples of toughening agents include elastomeric materials.
  • Representative examples include, without limitation, natural rubber, butyl rubber, polyisoprene, polybutadiene, polyisobutylene, ethylene-propylene copolymer, styrene- butadiene - styrene triblock rubber, random styrene-butadiene rubber, styrene-isoprene- styrene triblock rubber, styrene-ethylene/butylene- styrene copolymer, styrene- ethylene/propylene- styrene copolymer, ethylene- propylene- diene terpolymers, ethylene- vinyl acetate and nitrile rubbers.
  • Preferred agents are elastomers such as polybutadienes.
  • Toughening agents such as elastomeric materials can be added to the formulation by incorporating in a modeling material
  • a concentration of elastomeric materials may range from about 0.10 phr to about 10 phr, or from about 0.1 phr to about 5 phr, relative to the weight of the formulation containing same.
  • a concentration of elastomeric materials may alternatively range from about 0.1 % to about 20 %, by weight, of the total weight of a formulation containing same.
  • impact modifying agents such as, for example, carbon fibers, carbon nanotubes, glass fibers, aramid Keylar, polyp araphenylene benzobisoxazole Zylon, and other polar and non polar impact modifiers, are also contemplated.
  • kits containing modeling material formulations as described herein containing modeling material formulations as described herein.
  • one or more of the modeling material formulations comprises a DCPD-based ROMP monomer of the present embodiments (e.g., represented by Formula P, I or II).
  • kits as provided herein are identified for use in 3D inkjet printing methods and systems for fabricating a three-dimensional object
  • a kit comprises a modeling material formulation for use in a single jetting single curing methodology, as described herein.
  • the components of the modeling material formulations are packaged together in the kit and include a ROMP monomer or monomers, at least one being a monomer according the present embodiments (e.g., represented by Formula P, I or II), as described in any of the respective embodiments, a ROMP catalyst, which can be active or latent, or can be a system of a pre-catalyst and an activator (latent or active).
  • one or more of the components in the kit can be physically separated from the other components (e.g., encapsulated, as described herein).
  • a kit comprises a modeling material formulation for use in a single jetting dual or multi-curing methodology, as described herein.
  • the components of the modeling material formulations are packaged together in the kit and include a ROMP monomer or monomers, at least one being a monomer according the present embodiments (e.g., represented by Formula P, I or II), as described in any of the respective embodiments, a ROMP catalyst, which can be active or latent, or can be a system of a pre-catalyst and an activator (latent or active), and components of an additional curable system, as described herein in any of the respective embodiments.
  • a ROMP monomer or monomers e.g., represented by Formula P, I or II
  • a ROMP catalyst which can be active or latent, or can be a system of a pre-catalyst and an activator (latent or active)
  • components of an additional curable system as described herein in any of the respective embodiments.
  • one or more of the components in the kit can be physically separated from the other components (e.g., encapsulated, as described herein).
  • a kit comprises a modeling material formulation for use in a single jetting dual or multi-curing methodology, as described herein.
  • the components of each of the modeling material formulations are packaged individually in the kit and include a ROMP monomer or monomers, at least one being a monomer according the present embodiments (e.g., represented by Formula P, I or II), as described in any of the respective embodiments, a ROMP catalyst, which can be active or latent, or can be a system of a pre-catalyst and an activator (latent or active), divided in the formulations in accordance with any one of the respective embodiments.
  • a ROMP monomer or monomers e.g., represented by Formula P, I or II
  • a ROMP catalyst which can be active or latent, or can be a system of a pre-catalyst and an activator (latent or active), divided in the formulations in accordance with any one of the respective embodiments.
  • one or more of the components in one or more formulations can be physically separated from the other components (e.g., encapsulated, as described herein) in a respective formulation.
  • a kit comprises a modeling material formulation for use in a dual or multi-jetting dual or multi-curing methodology, as described herein.
  • the components of each of the modeling material formulations are packaged individually in the kit and include a ROMP monomer or monomers, as described in any of the respective embodiments, a ROMP catalyst, which can be active or latent, or can be a system of a pre-catalyst and an activator (latent or active), and components of one or more additional curable systems, as described herein in any of the respective embodiments.
  • one or more of the components in one or more formulations can be physically separated from the other components (e.g., encapsulated, as described herein), in a respective formulation
  • a three-dimensional object which comprises a polymeric material obtainable by ROMP of a ROMP monomer or combination of ROMP monomers, at least one being a monomer according the present embodiments (e.g., represented by Formula P, I or II).
  • the 3D object further comprises a polymeric material obtainable from any of the other curable systems described herein.
  • the 3D object is obtainable by 3D inkjet printing. In some of these embodiments, the 3D object is odorless.
  • the object is characterized by an impact resistance of at least 100, at least 150, at least 180, at least 200 J/m, and even higher impact resistance
  • impact resistance which is also referred to interchangeably, herein and in the art, as “impact strength” or simply as “impact” describes the resistance of a material to fracture by a mechanical impact, and is expressed in terms of the amount of energy absorbed by the material before complete fracture. Impact resistance can be measured using, for example, the ASTM D256-06 standard Izod impact testing (also known as “Izod notched impact", or as “Izod impact”), and/or as described hereinunder, and is expressed as J/m.
  • the object is characterized by heat deflection temperature
  • HDT which is at least 50, at least 80, at least 100, at least 120 °C, and even higher.
  • HDT heat deflection temperature
  • a method of fabricating a three-dimensional object comprising: sequentially forming a plurality of layers in a configured pattern corresponding to a shape of a mold (e.g., having an inner surface shaped in accordance with an outer surface of the three-dimensional object); and
  • a molding composition which comprises an unsaturated cyclic monomer polymerizable by ROMP, according to the present embodiments, (e.g., represented by Formula P, I or II) and a catalyst for initiating ROMP of the monomer, thereby fabricating the three-dimensional object.
  • an unsaturated cyclic monomer polymerizable by ROMP e.g., represented by Formula P, I or II
  • a catalyst for initiating ROMP of the monomer thereby fabricating the three-dimensional object.
  • the molding composition comprises a ROMP system as described in any of the respective embodiments described herein for single jetting single curing, excluding embodiments in which one or more of the components is physically separated in the formulation.
  • the method further comprises exposing the mold to a condition for inducing initiation of ROMP of the monomer by the catalyst.
  • a condition can include a condition for activating a latent catalyst, or a condition for activating a latent activator, or any other condition for promoting the ROMP.
  • the formation of each of the layers forming the mold comprises dispensing by at least one inkjet printing head at least one modeling material formulation.
  • the modeling material formulation(s) comprise a non-ROMP curable system as described herein in any of the respective embodiments.
  • the non-ROMP curable system is a UV-curable non-ROMP system, as described herein in any of the respective embodiments.
  • a method of fabricating a three-dimension object comprising: introducing to a mold having a shape of the object a molding composition comprising an unsaturated cyclic monomer polymerizable by ROMP which is a DCPD- based monomer according to the present embodiments, and a catalyst for initiating ROMP of said monomer, thereby obtaining the object.
  • the method further comprises introducing to the mold a molding composition comprising a curable material that is polymerizable by a non-ROMP reaction, as described herein and an initiator for initiating a non-ROMP polymerization, as described herein.
  • the curable material is a UV-curable material. Such embodiments result in an hybrid formulation in the mold.
  • the Printing System The Printing System:
  • FIG. 40 is a schematic illustration of a system 110 suitable for 3D inkjet printing of an object 112 according to some embodiments of the present invention.
  • System 110 comprises a printing apparatus 114 having a printing unit 116 which comprises a plurality of printing heads. Each head preferably comprises an array of one or more nozzles 122, as illustrated in FIGs. 41A-C described below, through which a liquid (uncured) building material 124 is dispensed.
  • apparatus 114 is a three- dimensional inkjet printing apparatus.
  • FIGs. 41A-B illustrate a printing head 116 with one (FIG. 41 A) and two (FIG. 4 IB) nozzle arrays 22. The nozzles in the array are preferably aligned linearly, along a straight line.
  • the nozzle arrays are optionally and preferably can be parallel to each other.
  • two or more printing heads can be assembled to a block of printing heads, in which case the printing heads of the block are typically parallel to each other.
  • a block including several inkjet printing heads 116a, 116b, 116c is illustrated in FIG. 41C.
  • Printing heads 116 are optionally and preferably oriented along the indexing direction with their positions along the scanning direction being offset to one another.
  • Each printing head is optionally and preferably fed via a building material reservoir which may optionally include a temperature control unit (e.g. , a temperature sensor and/or a heating device), and a material level sensor.
  • a temperature control unit e.g. , a temperature sensor and/or a heating device
  • a material level sensor e.g., a temperature sensor and/or a heating device
  • a voltage signal is applied to the printing heads to selectively deposit droplets of material via the printing head nozzles, for example, as in piezoelectric inkjet printing technology.
  • the dispensing rate of each head depends on the number of nozzles, the type of nozzles and the applied voltage signal rate (frequency).
  • Such printing heads are known to those skilled in the art of solid freeform fabrication.
  • the overall number of printing nozzles or nozzle arrays is selected such that half of the printing nozzles are designated to dispense support material formulation(s) and half of the printing nozzles are designated to dispense modeling material formulation(s), i.e. the number of nozzles jetting modeling material formulations is the same as the number of nozzles jetting support material formulations.
  • four printing heads 116a, 116b, 116c and 116d are illustrated. Each of heads 116a, 116b, 116c and 116d has a nozzle array.
  • heads 116a and 116b can be designated for modeling material/s and heads 116c and 116d can be designated for support material.
  • head 116a can dispense a first modeling material formulation
  • head 116b can dispense a second modeling material formulation
  • heads 116c and 116d can both dispense a support material formulation.
  • heads 116c and 116d may be combined in a single head having two nozzle arrays for depositing a support material formulation.
  • modeling heads and the number of support material depositing heads (support heads) may differ.
  • the number of modeling heads, the number of support heads and the number of nozzles in each respective head or head array are selected such as to provide a predetermined ratio, a, between the maximal dispensing rate of the support material and the maximal dispensing rate of modeling material.
  • the value of the predetermined ratio, a is preferably selected to ensure that in each formed layer, the height of modeling material equals the height of support material. Typical values for a are from about 0.6 to about 1.5.
  • the overall dispensing rate of support material is generally the same as the overall dispensing rate of the modeling material when all modeling heads and support heads operate.
  • each of the Mxm modeling arrays and Sxs support arrays can be manufactured as a separate physical unit, which can be assembled and disassembled from the group of arrays.
  • each such array optionally and preferably comprises a temperature control unit and a material level sensor of its own, and receives an individually controlled voltage for its operation.
  • Apparatus 114 can further comprise a hardening device 324 which can include any device configured to emit light, heat or any other curing energy that may cause the deposited material to harden.
  • hardening device 324 can comprise one or more radiation sources, which can be, for example, an infrared lamp or any other source emitting heat-inducing radiation, as further detailed hereinabove, a UV radiation source.
  • hardening device 324 serves for applying a curing condition to the modeling material.
  • the printing head and radiation source are preferably mounted in a frame or block 128 which is preferably operative to reciprocally move over a tray 360, which serves as the working surface.
  • Apparatus 114 can further comprise a tray heater 328 configured for heating the tray. These embodiments are particularly useful when the modeling material is hardened by heating (exposure to heat).
  • the radiation sources are mounted in the block such that they follow in the wake of the printing heads to at least partially cure or solidify the materials just dispensed by the printing heads.
  • Tray 360 is positioned horizontally. According to the common conventions an X-Y-Z Cartesian coordinate system is selected such that the X-Y plane is parallel to tray 360. Tray 360 is preferably configured to move vertically (along the Z direction), typically downward.
  • apparatus 114 further comprises one or more leveling devices 132.
  • Leveling device 132 serves to straighten, level and/or establish a thickness of the newly formed layer prior to the formation of the successive layer thereon.
  • Leveling device 132 can comprise one or more rollers 326.
  • Rollers 326 can has a generally smooth surface or it can has a patterned surface.
  • one or more of the layers is straightened while the formulation within the layer is at a cured or partially cured state.
  • leveling device 132 is capable of deforming the solidified portion of the formulation.
  • the roller has a non- smooth surface so as to facilitate the milling, grinding and/or flaking.
  • the surface of the roller can be patterned with blades and/or have a shape of an auger.
  • leveling device 132 can comprise a roller or a blade, which is optionally and preferably, but not necessarily, incapable of effecting milling, grinding and/or flaking.
  • Leveling device 132 preferably comprises a waste collection device 136 for collecting the excess material generated during leveling. Waste collection device 136 may comprise any mechanism that delivers the material to a waste tank or waste cartridge.
  • Leveling device 132 is a self-cleaning leveling device, wherein cured or partially cured formulation is periodically removed from leveling device 132.
  • FIG. 42 A representative Example of a self-cleaning leveling device is illustrated in FIG. 42. Shown in FIG. 42 is a double roller having a first roller 356 that contacts and straightens a layer 358 and a second roller 354 that is in contact with the first roller 356 but not with the layer 358 and which is configured to remove the formulation from the first roller 358.
  • second roller 354 preferably is also non- smoothed wherein the pattern formed on the surface of roller 354 is complementary to the pattern formed on the surface of roller 356, so as to allow roller 354 to clean the surface of roller 358.
  • Apparatus 114 can also comprise a chamber 350 enclosing at least heads 116 and tray 360, but may also enclose other components of system 110, such as, but not limited to, devices 132 and 324, frame 128 and the like.
  • apparatus 114 comprises a chamber heater 352 that heats the interior of chamber 350 as further detailed hereinabove.
  • Chamber 350 is preferably generally sealed to an environment outside chamber 350.
  • chamber 350 comprises a gas inlet
  • gas source 366 configured for filling said chamber by an inert gas through gas inlet 364.
  • Gas source 366 can be a container filled with the inert gas.
  • the gas can be any of the inert gases described above.
  • chamber 350 is also formed with a gas outlet 368 for allowing the gas to exit chamber 350 if desired.
  • Both inlet 366 and outlet 368 are of the present embodiments provided with valves (not shown) so as to controllably allow entry and/or exit of the gas to and from chamber 350.
  • controller 152 generates, continuously or intermittently, inflow and outflow of the inert gas through gas inlet 366 and gas outlet 368.
  • controller 152 can be configured to control at least one of source 366, inlet 364 and outlet 368.
  • system 110 comprises a gas flow generating device 370, placed within chamber 350 and configured for generating a flow of the inert gas within chamber 350.
  • Device 370 can be a fan or a blower.
  • Controller 152 can be configured for controlling also device 370, for example, based on a predetermined printing protocol.
  • apparatus 114 comprises a mixing chamber 362 for preparing the modeling material formulation prior to entry of the modeling material formulation into a respective head.
  • chamber 362 receives materials from different containers, mixes the received materials and introduces the mix to two heads (heads 116b and 116a, in the present example).
  • heads 116b and 116a heads 116b and 116a, in the present example.
  • chamber 362 can receive materials from different containers, mixes the received materials and introduces the mix only to more than two heads of only to one head.
  • the position and fluid communication between mixing chamber 362 and respective head is selected such that at least 80% or at least 85% or at least 90% or at least 95% or at least 99% or the modeling material formulation that enters the respective head or heads (e.g. , heads 116b and 116a in the present example) remains uncured.
  • chamber 362 can be attached directly to the printing head or the printing block, such that motion of the printing head is accompanied by motion of the mixing chamber.
  • System 110 can be used for printing a 3D object using the modeling material formulation described herein.
  • system 110 can exchange air with its immediate environment (e.g., the air surrounding system 110). This is advantageous because in is not necessary to transport gas to a remote location via a system of pipes or the like.
  • the dispensing heads of unit 116 move in a scanning direction, which is referred to herein as the X direction, and selectively dispense building material in a predetermined configuration in the course of their passage over tray 360.
  • the building material typically comprises one or more types of support material and one or more types of modeling material.
  • the passage of the dispensing heads of unit 116 is followed by the curing of the modeling material(s) by radiation source 126.
  • an additional dispensing of building material may be carried out, according to predetermined configuration.
  • the layer thus formed may be straightened by leveling device 326, which preferably follows the path of the dispensing heads in their forward and/or reverse movement.
  • leveling device 326 which preferably follows the path of the dispensing heads in their forward and/or reverse movement.
  • the dispensing heads may move to another position along an indexing direction, referred to herein as the Y direction, and continue to build the same layer by reciprocal movement along the X direction.
  • the dispensing heads may move in the Y direction between forward and reverse movements or after more than one forward-reverse movement.
  • the series of scans performed by the dispensing heads to complete a single layer is referred to herein as a single scan cycle.
  • tray 360 is lowered in the Z direction to a predetermined Z level, according to the desired thickness of the layer subsequently to be printed. The procedure is repeated to form three-dimensional object 112 in a layerwise manner.
  • tray 360 may be displaced in the Z direction between forward and reverse passages of the dispensing head of unit 116, within the layer. Such Z displacement is carried out in order to cause contact of the leveling device with the surface in one direction and prevent contact in the other direction.
  • System 110 optionally and preferably comprises a building material supply system 330 which comprises the building material containers or cartridges and supplies a plurality of building materials to fabrication apparatus 114.
  • a control unit 340 controls fabrication apparatus 114 and optionally and preferably also supply system 330.
  • Control unit 340 typically includes an electronic circuit configured to perform the controlling operations.
  • Control unit 340 preferably communicates with a data processor 154 which transmits digital data pertaining to fabrication instructions based on computer object data, e.g., a CAD configuration represented on a computer readable medium in a form of, for example, a Standard Tessellation Language (STL) format Standard Tessellation Language (STL), StereoLithography Contour (SLC) format, Virtual Reality Modeling Language (VRML), Additive Manufacturing File (AMF) format, Drawing Exchange Format (DXF), Polygon File Format (PLY) or any other format suitable for CAD.
  • STL Standard Tessellation Language
  • SLC StereoLithography Contour
  • VRML Virtual Reality Modeling Language
  • AMF Additive Manufacturing File
  • DXF Drawing Exchange Format
  • PLY Polygon File Format
  • control unit 340 controls the voltage applied to each printing head or nozzle array and
  • control unit 340 receives additional input from the operator, e.g., using data processor 154 or using a user interface 118 communicating with unit 340.
  • User interface 118 can be of any type known in the art, such as, but not limited to, a keyboard, a touch screen and the like.
  • control unit 340 can receive, as additional input, one or more building material types and/or attributes, such as, but not limited to, color, characteristic distortion and/or transition temperature, viscosity, electrical property, magnetic property. Other attributes and groups of attributes are also contemplated.
  • compositions, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.
  • a compound or “at least one compound” may include a plurality of compounds, including mixtures thereof.
  • range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.
  • method refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts.
  • linking moiety or “linking group” describes a group that connects two or more moieties or groups in a compound.
  • a linking moiety is typically derived from a bi- or tri-functional compound, and can be regarded as a bi- or tri-radical moiety, which is connected to two or three other moieties, via two or three atoms thereof, respectively.
  • linking moieties include a hydrocarbon moiety or chain, optionally interrupted by one or more heteroatoms, as defined herein, and/or any of the chemical groups listed below, when defined as linking groups.
  • end group When a chemical group is referred to herein as "end group" it is to be interpreted as a substituent, which is connected to another group via one atom thereof.
  • hydrocarbon collectively describes a chemical group composed mainly of carbon and hydrogen atoms.
  • a hydrocarbon can be comprised of alkyl, alkene, alkyne, aryl, and/or cycloalkyl, each can be substituted or unsubstituted, and can be interrupted by one or more heteroatoms.
  • the number of carbon atoms can range from 2 to 20, and is preferably lower, e.g., from 1 to 10, or from 1 to 6, or from 1 to 4.
  • a hydrocarbon can be a linking group or an end group.
  • Bisphenol A is An example of a hydrocarbon comprised of 2 aryl groups and one alkyl group.
  • amine describes both a -NR'R” group and a -NR'- group, wherein R' and R" are each independently hydrogen, alkyl, cycloalkyl, aryl, as these terms are defined hereinbelow.
  • the amine group can therefore be a primary amine, where both R' and R" are hydrogen, a secondary amine, where R' is hydrogen and R" is alkyl, cycloalkyl or aryl, or a tertiary amine, where each of R' and R" is independently alkyl, cycloalkyl or aryl.
  • R' and R" can each independently be hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, carbonyl, C-carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, N-carbamate, O-carbamate, C- amide, N-amide, guanyl, guanidine and hydrazine.
  • amine is used herein to describe a -NR'R" group in cases where the amine is an end group, as defined hereinunder, and is used herein to describe a -NR'- group in cases where the amine is a linking group or is or part of a linking moiety.
  • alkyl describes a saturated aliphatic hydrocarbon including straight chain and branched chain groups.
  • the alkyl group has 1 to 20 carbon atoms. Whenever a numerical range; e.g., " 1-20", is stated herein, it implies that the group, in this case the alkyl group, may contain 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms. More preferably, the alkyl is a medium size alkyl having 1 to 10 carbon atoms. Most preferably, unless otherwise indicated, the alkyl is a lower alkyl having 1 to 4 carbon atoms (C(l-4) alkyl).
  • the alkyl group may be substituted or unsubstituted.
  • Substituted alkyl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, N-carbamate, O-carbamate, C- amide, N-amide, guanyl, guanidine and hydrazine.
  • the alkyl group can be an end group, as this phrase is defined hereinabove, wherein it is attached to a single adjacent atom, or a linking group, as this phrase is defined hereinabove, which connects two or more moieties via at least two carbons in its chain.
  • a linking group it is also referred to herein as "alkylene” or "alkylene chain”.
  • Alkene and Alkyne are an alkyl, as defined herein, which contains one or more double bond or triple bond, respectively.
  • cycloalkyl describes an all-carbon monocyclic ring or fused rings (i.e., rings which share an adjacent pair of carbon atoms) group where one or more of the rings does not have a completely conjugated pi-electron system. Examples include, without limitation, cyclohexane, adamantine, norbornyl, isobornyl, and the like.
  • the cycloalkyl group may be substituted or unsubstituted.
  • Substituted cycloalkyl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C- carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, N-carbamate, O-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine.
  • substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloal
  • the cycloalkyl group can be an end group, as this phrase is defined hereinabove, wherein it is attached to a single adjacent atom, or a linking group, as this phrase is defined hereinabove, connecting two or more moieties at two or more positions thereof.
  • heteroalicyclic describes a monocyclic or fused ring group having in the ring(s) one or more atoms such as nitrogen, oxygen and sulfur.
  • the rings may also have one or more double bonds. However, the rings do not have a completely conjugated pi-electron system.
  • Representative examples are piperidine, piperazine, tetrahydrofuran, tetrahydropyrane, morpholino, oxalidine, and the like.
  • the heteroalicyclic may be substituted or unsubstituted.
  • Substituted heteroalicyclic may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C- carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, O- carbamate, N-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine.
  • substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl
  • the heteroalicyclic group can be an end group, as this phrase is defined hereinabove, where it is attached to a single adjacent atom, or a linking group, as this phrase is defined hereinabove, connecting two or more moieties at two or more positions thereof.
  • aryl describes an all-carbon monocyclic or fused-ring polycyclic
  • the aryl group may be substituted or unsubstituted.
  • Substituted aryl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, N-carbamate, O-carbamate, C-amide, N-amide, N-amide,
  • the aryl group can be an end group, as this term is defined hereinabove, wherein it is attached to a single adjacent atom, or a linking group, as this term is defined hereinabove, connecting two or more moieties at two or more positions thereof.
  • heteroaryl describes a monocyclic or fused ring (i.e., rings which share an adjacent pair of atoms) group having in the ring(s) one or more atoms, such as, for example, nitrogen, oxygen and sulfur and, in addition, having a completely conjugated pi-electron system.
  • heteroaryl groups include pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, pyrimidine, quinoline, isoquinoline and purine.
  • the heteroaryl group may be substituted or unsubstituted.
  • Substituted heteroaryl may have one or more substituents, whereby each substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heteroalicyclic, amine, halide, sulfonate, sulfoxide, phosphonate, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, cyano, nitro, azo, sulfonamide, C-carboxylate, O-carboxylate, N-thiocarbamate, O-thiocarbamate, urea, thiourea, O-carbamate, N-carbamate, C-amide, N-amide, guanyl, guanidine and hydrazine.
  • substituent group can independently be, for example, hydroxyalkyl, trihaloalkyl, cycloalkyl
  • the heteroaryl group can be an end group, as this phrase is defined hereinabove, where it is attached to a single adjacent atom, or a linking group, as this phrase is defined hereinabove, connecting two or more moieties at two or more positions thereof.
  • Representative examples are pyridine, pyrrole, oxazole, indole, purine and the like.
  • halide and "halo" describes fluorine, chlorine, bromine or iodine.
  • haloalkyl describes an alkyl group as defined above, further substituted by one or more halide.
  • diisulfide refers to a -S-SR' end group or a -S-S- linking group, as these phrases are defined hereinabove, where R' is as defined herein.
  • phosphinyl describes a -PR'R" end group or a -PR'- linking group, as these phrases are defined hereinabove, with R' and R" as defined hereinabove.
  • hydroxyl describes a -OH group.
  • alkoxy describes both an -O-alkyl and an -O-cycloalkyl group, as defined herein.
  • aryloxy describes both an -O-aryl and an -O-heteroaryl group, as defined herein.
  • thiohydroxy describes a -SH group.
  • thioalkoxy describes both a -S-alkyl group, and a -S-cycloalkyl group, as defined herein.
  • thioaryloxy describes both a -S-aryl and a -S-heteroaryl group, as defined herein.
  • hydroxyalkyl is also referred to herein as "alcohol”, and describes an alkyl, as defined herein, substituted by a hydroxy group.
  • cyano describes a -C ⁇ N group.
  • nitro describes an -N0 2 group.
  • peroxo describes an -O-OR' end group or an -O-O- linking group, as these phrases are defined hereinabove, with R' as defined hereinabove.
  • carboxylate as used herein encompasses C-carboxylate and O- carboxylate.
  • a carboxylate can be linear or cyclic.
  • R' and the carbon atom are linked together to form a ring, in C-carboxylate, and this group is also referred to as lactone.
  • R' and O are linked together to form a ring in O-carboxylate.
  • Cyclic carboxylates can function as a linking group, for example, when an atom in the formed ring is linked to another group.
  • thiocarboxylate encompasses C-thiocarboxylate and O-thiocarboxylate.
  • a thiocarboxylate can be linear or cyclic.
  • R' and the carbon atom are linked together to form a ring, in C-thiocarboxylate, and this group is also referred to as thiolactone.
  • R' and O are linked together to form a ring in O- thiocarboxylate.
  • Cyclic thiocarboxylates can function as a linking group, for example, when an atom in the formed ring is linked to another group.
  • carbamate encompasses N-carbamate and O- carbamate.
  • a carbamate can be linear or cyclic.
  • R' and the carbon atom are linked together to form a ring, in O-carbamate.
  • R' and O are linked together to form a ring in N-carbamate.
  • Cyclic carbamates can function as a linking group, for example, when an atom in the formed ring is linked to another group.
  • carbamate encompasses N-carbamate and O- carbamate.
  • thiocarbamate encompasses N-thiocarbamate and O- thiocarbamate.
  • Thiocarbamates can be linear or cyclic, as described herein for carbamates.
  • dithiocarbamate encompasses S-dithiocarbamate and N-dithiocarbamate.
  • amide as used herein encompasses C-amide and N-amide.
  • An amide can be linear or cyclic.
  • R' and the carbon atom are linked together to form a ring, in C-amide, and this group is also referred to as lactam.
  • Cyclic amides can function as a linking group, for example, when an atom in the formed ring is linked to another group.
  • hydrazine describes a -NR'-NR"R" ' end group or a -NR'-NR"- linking group, as these phrases are defined hereinabove, with R', R", and R'" as defined herein.
  • alkylene glycol describes a -0-[(CR'R") z -0] y -R'" end group or a -0-[(CR'R") z -0] y - linking group, with R', R" and R" ' being as defined herein, and with z being an integer of from 1 to 10, preferably, 2-6, more preferably 2 or 3, and y being an integer of 1 or more.
  • R' and R" are both hydrogen.
  • z is 2 and y is 1, this group is ethylene glycol.
  • z is 3 and y is 1, this group is propylene glycol.
  • a poly(alkylene glycol) group or moiety can have from 10 to 200 repeating alkyelene glycol units, such that z is 10 to 200, preferably 10-100, more preferably 10-50.
  • Yields refer to isolated compounds featuring purity greater than 95 %, as determined by proton Nuclear Magnetic Resonance spectroscopy ( 1 H-NMR) analyses.
  • HR-MS data were obtained using a thermoscientific LTQU XL Orbitrap HR-MS equipped with APCI (atmospheric pressure chemical ionization).
  • the cross-linked thermoset polymers were also subjected to the differential scanning calorimetric analysis (DSC) with a METTLER-TOLEDO DSC 823 and results were evaluated with the STAR 6 software. Each sample was subjected to a 2-3 heating cooling cycles. Each cycle contained a heating segment followed by a cooling segment at a heating rate of 5 °C/minute.
  • DSC differential scanning calorimetric analysis
  • the viscoelastic properties of the polymerized materials were evaluated from 25 °C to lowest storage modulus ( ⁇ ') temperature with the heating rate of 2 °C/minute using dynamic mechanical analysis (DMA) (METTLER TOLEDO DMA 1 STARe system) at different frequencies, e.g., 0.1 Hz, 1 Hz and 10 Hz, while experimental results were evaluated using the STAR 6 software version 14.00.
  • Very soft materials like pDCPDOOc were analyzed in a temperature range of from -100 °C to 10 °C until the E' reached a minimum value at the same frequencies.
  • FTIR for the thin films was measured by using a Jasco FT/IR-460 Plus Fourier transform infrared spectrometer.
  • Thermo-mechanical properties of polymerized materials were determined by measuring the impact strength and HDT according to respective ASTM procedures, as follows: The impact strength of polymerized (cured) materials was measured by a Resil 5.5 J type instrument (CEAST Series, Instron ® (USA)) using an Izod impact test (notched Izod) according to the ASTM International organization D-256 standard.
  • the Heat deflection temperature (HDT) of the samples was determined according to the ASTM International organization D-648 standard using a HDT 3 VICAT instrument (CEAST Series, Instron ® (USA)).
  • DCPD-OH endo-hydroxydicyclopentadiene
  • Endo-dicyclopentadiene (40.0 grams, 0.303 mol) was dissolved in
  • TGA curve of hydroxydicyclopentadiene is provided in Figure 1A.
  • HMQC spectrum of hydroxydicyclopentadiene (DCPD-OH) in CDCI 3 is provided in Figure IB.
  • TGA curve of compound 1 is provided in Figure 2C.
  • TGA curve of compound 3 is provided in Figure 3C.

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Abstract

L'invention concerne des procédés pour la fabrications d'objets 3D par une technologie d'impression 3D, qui utilise des matériaux durcissables à base de dicyclopentadiène (DCPD) qui polymérisent via une polymérisation par métathèse avec ouverture de cycle (ring-opening metathesis polymerization - ROMP) pour fabriquer l'objet. L'invention concerne également des formulations durcissables et des matériaux durcis formés à partir ceux-ci, contenant les matériaux durcissables à base de dicyclopentadiène (DCPD). Les matériaux durcissables à base de dicyclopentadiène (DCPD) et les matériaux durcis formés à partir de ceux-ci sont caractérisés par une réduction ou une absence de mauvaise odeur.
PCT/IL2016/051142 2015-10-21 2016-10-20 Impression 3d par jet d'encre à l'aide de composés dicyclopentadiéniques polymérisables par polymérisation par métathèse avec ouverture de cycle WO2017068590A1 (fr)

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WO2020006345A1 (fr) 2018-06-29 2020-01-02 Promerus, Llc Monomères de polycyclooléfine et catalyseur activé par un composé capable de générer un photo-acide en tant que matériaux d'impression 3d
WO2020065654A1 (fr) 2018-09-28 2020-04-02 Stratasys Ltd. Procédé de fabrication additive à durcissement partiel
WO2020065655A1 (fr) 2018-09-28 2020-04-02 Stratasys Ltd. Impression à jet d'encre en trois dimensions d'un objet thermiquement stable
WO2020132665A1 (fr) 2018-12-21 2020-06-25 Promerus, Llc Matériaux d'impression 3d à haute résistance aux chocs dérivés de monomères de polycyclo-oléfine et d'agents de réticulation
WO2020136654A1 (fr) 2018-12-27 2020-07-02 Stratasys Ltd. Fabrication additive à l'aide de matériaux renforcés
WO2021014434A1 (fr) 2019-07-19 2021-01-28 Stratasys Ltd. Fabrication additive d'objets tridimensionnels contenant un matériau transparent
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WO2022232309A1 (fr) * 2021-04-27 2022-11-03 Inkbit, LLC Matériaux pour une polymérisation par métathèse d'ouverture de cycle et leurs utilisations
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US11118004B2 (en) 2016-04-26 2021-09-14 Stratasys Ltd. Three-dimensional inkjet printing using ring-opening metathesis polymerization
WO2020006345A1 (fr) 2018-06-29 2020-01-02 Promerus, Llc Monomères de polycyclooléfine et catalyseur activé par un composé capable de générer un photo-acide en tant que matériaux d'impression 3d
WO2020065654A1 (fr) 2018-09-28 2020-04-02 Stratasys Ltd. Procédé de fabrication additive à durcissement partiel
WO2020065655A1 (fr) 2018-09-28 2020-04-02 Stratasys Ltd. Impression à jet d'encre en trois dimensions d'un objet thermiquement stable
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US11235511B2 (en) 2018-09-28 2022-02-01 Stratasys Ltd. Three-dimensional inkjet printing of a thermally stable object
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WO2020132665A1 (fr) 2018-12-21 2020-06-25 Promerus, Llc Matériaux d'impression 3d à haute résistance aux chocs dérivés de monomères de polycyclo-oléfine et d'agents de réticulation
WO2020136654A1 (fr) 2018-12-27 2020-07-02 Stratasys Ltd. Fabrication additive à l'aide de matériaux renforcés
WO2021014434A1 (fr) 2019-07-19 2021-01-28 Stratasys Ltd. Fabrication additive d'objets tridimensionnels contenant un matériau transparent
US11286338B2 (en) 2019-09-18 2022-03-29 Promerus, Llc Two component mass polymerizable compositions containing polycycloolefin monomers and organoruthenium carbide precatalyst
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US11732086B2 (en) 2019-09-18 2023-08-22 Promerus, Llc Two component mass polymerizable compositions containing polycycloolefin monomers and organoruthenium carbide precatalyst
WO2021067558A1 (fr) * 2019-10-01 2021-04-08 3D Systems, Inc. Matériaux de construction optiquement actifs pour impression 3d
US11377538B2 (en) 2019-10-01 2022-07-05 3D Systems, Inc. Optically active build materials for 3D printing
US11780989B2 (en) 2019-10-01 2023-10-10 3D Systems, Inc. Optically active build materials for 3D printing
US11725077B2 (en) 2019-10-10 2023-08-15 PolySpectra, Inc. Olefin metathesis photopolymers
WO2021202485A1 (fr) * 2020-04-01 2021-10-07 3M Innovative Properties Company Compositions comprenant un catalyseur romp et un dispersant, cartouches et procédés
US11718710B2 (en) 2020-10-14 2023-08-08 The Board Of Trustees Of The University Of Illinois Method of light-promoted frontal ring-opening metathesis polymerization
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WO2022232309A1 (fr) * 2021-04-27 2022-11-03 Inkbit, LLC Matériaux pour une polymérisation par métathèse d'ouverture de cycle et leurs utilisations
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