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EP-3685231-B1 - 3D PRINTING WITH POLYMERIC NANOGEL PARTICLES

EP3685231B1EP 3685231 B1EP3685231 B1EP 3685231B1EP-3685231-B1

Inventors

  • STANSBURY, JEFFREY W.
  • SHAH, Parag K.
  • MCLEOD, ROBERT R.

Dates

Publication Date
20260513
Application Date
20180918

Claims (9)

  1. A method of producing a three-dimensional object from a photoinitiated polymerizable composition, the method comprising sequentially exposing immediately adjacent volumes of the photoinitiated polymerizable composition to curing radiation thereby initiating the polymerization of the polymerizable composition in said volumes to form corresponding sequential immediately adjacent layers of the three-dimensional object until the three-dimensional object is completed; wherein the photoinitiated polymerizable composition comprises, based on the total weight of the photoinitiated polymerizable composition, (a) 40 to 90 wt% of a nanogel component that comprises nanogel particles, wherein the nanogel particles comprise a copolymer with polymerizable reactive groups suitable for reacting with each other or with a reactive diluent monomer, a reactive oligomer, or a combination thereof that is present in the polymerizable composition upon photoinitiation, wherein (i) the copolymer is the polymerized product of a mixture that comprises a monovinyl monomer, a divinyl monomer, and a chain transfer agent, wherein the divinyl monomer is at a concentration in a range of 20 mol% to 80 mol% of the monomer content of the mixture; (ii) the polymerizable reactive groups of the copolymer are at a concentration that is in a range of 5% to 20% of the reactive group density of the divinyl monomer; (iii) at least one of the monovinyl monomer and the divinyl monomer is a glassy polymer when homopolymerized and at least one of the monovinyl monomer and the divinyl monomer is a rubbery polymer when homopolymerized; (iv) the nanogel component has a glass transition temperature (T g ), corresponding to the peak of a tan delta plot created via Dynamic Mechanical Analysis (DMA), is in a range of -50 °C and 20 °C; (v) the nanogel component has a number average molecular weight (M n ), determined with triple-detector gel permeation chromatography (TD-GPC) analysis, that is in a range of 10 kg/mol and 100 kg/mol; and (vi) the nanoparticles have an average hydrodynamic radius (R h ), determined by light scattering while conducting a TD-GPC analysis, that is in a range of 1 nm to 5 nm; and (b) up to 50 wt% of the reactive diluent monomer, the reactive oligomer, or the combination thereof; (c) 0.01 to 10 wt% of a photoinitiator at an amount effective to initiate said reactions in the presence of curing radiation of appropriate wavelength and irradiance; and; (d) 0.005 to 5 wt% of a wavelength compatible radiation absorber at an amount effective for control of radiation transmission depth of the curing radiation.
  2. The method of claim 1, wherein the photoinitiated polymerizable composition comprises 50 to 80 wt% of the nanogel component; 20 to 50 wt% of the reactive diluent monomer, the reactive oligomer, or the combination thereof; 0.05 to 7 wt% of the photoinitiator; and 0.05 to 2 wt% of the wavelength compatible radiation absorber.
  3. The method of claim 1 or 2, wherein the photoinitiated polymerizable composition comprises 60 to 75 wt% of the nanogel component; 20 to 50 wt% of the reactive diluent monomer, the reactive oligomer, or the combination thereof; 0.1 to 5 wt% of the photoinitiator; and 0.1 to 1 wt% of the wavelength compatible radiation absorber.
  4. The method of any one of claims 1-3, wherein the chain transfer agent is selected from the group consisting of aliphatic and aromatic monofunctional thiols, difunctional thiols, trifunctional thiols, tetrafunctional thiols, pentafunctional thiols, hexafunctional thiols, octafunctional thiols, and bis(borondifluorodimethylglyoximate) cobaltate (II).
  5. The method of any one of claims 1-3, wherein the monovinyl monomer is selected from the group consisting of (meth)acrylates, styrene and derivatives thereof (styrenics), vinyl acetate, maleic anhydride, itaconic acid, N-alkyl (aryl) maleimides and N-vinyl pyrrolidone, vinyl pyridine, acrylamide, methacrylamide, N,N-dialkylmethacrylamides and acrylonitrile, and combinations thereof; the divinyl monomer is selected from the group consisting of ethylene glycoldi(meth)acrylate, urethane di(meth)acrylate (UD(M)A), 2,2'-bis [4-(3-(meth)acryloxy-2-hydroxy propoxy)-phenyl] propane (bis-G(M)A), ethoxylated bisphenol-A-di(meth)acrylate (BisEMA), hexanediol di(meth)acrylate, poly(ethylene glycol) di(meth)acrylate, tripropylene glycol di(meth)acrylate, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, allyl (meth)acrylate, divinyl benzene, 1,3-diglycerolatediacrylate, N,N-methylene bisacrylamide, and combinations thereof; and the chain transfer agent is selected from the group consisting of is selected from the group consisting of propyl-mercaptan, butyl-mercaptan, hexylmercaptan, octyl-mercaptan, dodecanethiol, thioglycolic acid, methylbenzenethiol, dodecanethiol, mercaptopropionic acid, 2-ethyl-hexyl-thioglycolate, octylthioglycolate, mercaptoethanol, mercaptoundecanoic acid, thiolactic acid, thiobutyric acid, trimethylol-propane-tris(3- mercaptopropionate), pentaerythritol tetra(3-mercaptopropionate), pentaerythritol-tetrathioglycolate, pentaerythritol-tetrathiolactate, pentaerythritol-tetrathiobutyrate; dipentaerythritol-hexa(3-mercaptopropionate), dipentaerythritol-hexathioglycolate; tripentaerythritol- octa(3-mercaptopropionate), and tripentaerythritol-octathioglycolate, and combinations thereof.
  6. The method of claim 5, wherein the monovinyl monomer is one or more (meth)acrylates selected from the group consisting of methyl(meth)acrylate, ethyl(meth)acrylate (EMA), propyl(meth)acrylate, n-butyl(meth)acrylate, iso-butyl(meth)acrylate, t-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate octyl(meth)acrylate, dodecyl(meth)acrylate, isodecyl-methacrylate (IDMA), isostearyl(meth)acrylate, isobornyl-methacrylate (IBMA), 2-ethylhexyl-methacrylate (EHMA), hybrid acrylate/methacrylate prepared by the reaction of hydroxyethyl-acrylate and isocyanatoethyl-methacrylate (HEA+IEM), 2-phenoxyethyl(meth)acrylate, phenyl(meth)acrylate, p-t-butylphenyl(meth)acrylate, p-methoxyphenyl(meth)acrylate, p-tolyl(meth)acrylate, p-cyclohexylphenyl(meth)acrylate, p-nitophenyl(meth)acrylate, and benzoyl(meth)acrylate, 2-napthyl(meth)acrylate, (meth)acrylic acid, and combinations thereof.
  7. The method of any one of claims 1-6, wherein the photoinitiator is selected from one or more of an alpha-hydroxyketone, a benzophenone, a thioxanthone, an alkylaminoacetophenone, an acyl phosphine oxide, a benzyl-ketal, a benzoin-ether, a ketocoumain, a 1,2-diketone, and combinations thereof.
  8. The method of claim 7, wherein the photoinitiator is one or more acyl phosphine oxides selected from the group consisting of bis-acylphosphine-oxide (BAPO), 2,4,6-trimethylbenzolyldiphenylphosphine-oxide (TPO), ethyl(2,4,6-trimethylbenzolyldiphenylphosphine-oxide) (TPO-L), tris[1-(2-methyl)aziridinyl]phosphine-oxide (MAPO), 2,2-dimethoxy-2-phenylacetophenone (DMPA), benzyl-dimethylketal (BDK), cyclohexylphenylketone (CPK), 2-hydroxy-2-methyl-1-phenyl-propanone (HDMAP), isopropylthioxanthrone (ITX), hydroxyethyl-substituted alpha-hydroxyketone (HMPP), 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MMMP), 2-benzyl-2-dimethylamino-1-(4-morpholinopheny1)-1-butanone (BDMB), benzophenone (BP), methylthiophenyl-morpholinoketone (TPMK), 4-methylbenzophenone, 2-methylbenzophenone, 1-hydroxy-cyclohexyl phenyl-ketone, 2-benzy1-2-(dimethylamino)-144-(4-morpholinyl)pheny1]-1-butanone, diphenyl-iodonium-hexafluorophosphate, bis(p-tolyl)-iodonium-hexafluorophosphate, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-hydroxy-2-methyl-phenyl-propan-1-one, 1,7-bis(9-acridinyl)heptane, 2-hydroxy-4'-hydroxyethoxy-2-methylpropiophenone, 2,2 1 -bis(0-chloropheny1-4,4',5,'-tetrapheny1-1,2'-diimidazole, 9-phenylacridine, N-phenylglycine, 2-(4-methoxyphenyl-4,6-bis(trichloromethyl)-1,3,5-triazine, p-toluene-sulfonylamine, tris-(4-dimethylaminophenyl)methane, tribromo-methylphenyl-sulfone, 2,4-bis(trichloromethyl)-6-(p-methoxy)styryl-s-triazine, 2,4-bis(trichloromethyl)-6-(3,4-dimethoxy)styryl-s-triazine, 4-(2-aminoethoxy)methyl-benzophenone, 4-(2-hydroxyethoxy)methylbenzophenone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 4-hydroxybenzophenone, 4-methyl-acetophenone, 4-(4-methylphenylthiophenyl)-phenylmethanone, dimethoxyphenylacetophenone, camphorquinone, 1-chloro-4-propoxythioxanthone, 2-chlorothioxanthone, 2,2-diethoxyacetophenone, 2,4-diethylthioxanthone, 2-dimethyl-aminoethylbenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, ethyl-4-(dimethylamino)-benzoate, 2-isopropylthioxanthone, methyl-o-benzoyl benzoate, methylphenylglyoxylate, 4,4'-bis(diethylamino)-benzophenone, 4-phenylbenzophenone, 2,4,6- and ethyl-(2,4,6-trimethylbenzoyl)-phenylphosphinate.
  9. The method of any one of claims 1-8, wherein the wavelength compatible radiation absorber is selected from the group consisting of benzophenones, benzotriazoles, triazines, titanium dioxide, zinc oxide, carbon black, and combinations thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a PCT application claiming the benefit of U.S. Prov. Application Ser. No. 62/559,794, filed September 18, 2017. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with government support under R01 DE022348 (identify the contract) awarded by (identify the Federal agency). The government has certain rights in the invention. BACKGROUND OF INVENTION Photopolymer-based three-dimensional printing is used widely with conventional techniques including the stereo lithography apparatus (SLA), digital light processing (DLP), continuous liquid interface production (CLIP), and polyjet/inkjet printing. Problems or concerns with current 3D printing operations and resulting products include, for example, anisotropy in mechanical properties, volumetric shrinkage and shrinkage stress, diffusion of monomer and radical species across interfaces, which tends to results in distortion of edges, conversion gradients in formed layers. US 2015/051310 mentions an adhesive polymer with increased polymer wet flexural strength obtained by (a) reacting a monovinyl monomer and a divinyl monomer in the presence of a chain transfer agent and an initiator to obtain a copolymer, (b) reacting the copolymer with a reactive olefinic compound to form a reactive nanogel with pendant olefinic groups, and (c) reacting the reactive nanogel comprising pendant olefinic groups with an adhesive resin but does not make any reference to three dimentional printing. Cong C et al. RSC Advances, 2015, 5(43), 33729-33736, is directed to the use of nanogels incorporating different polysiloxane chain lengths for photopolymerization stress reduction and modification of polymer network properties. 3D printing is mentioned as a field of use - among many other fields of use. It does not disclose a method using a polymerizable composition comprising 40 to 90 wt.-% nanogel. Thus, a need still exists for polymerizable materials suitable for 3D printing and/or methods of 3D printing that addresses one or more of these problems. SUMMARY OF INVENTION Another embodiment of tThe present invention is directed to a method of producing a three-dimensional object from a photoinitiated polymerizable composition, the method comprising sequentially exposing immediately adjacent volumes of the photoinitiated polymerizable composition to curing radiation thereby initiating the polymerization of the polymerizable composition in said volumes to form corresponding sequential immediately adjacent layers of the three-dimensional object until the three-dimensional object is completed; wherein the photoinitiated polymerizable composition comprises, based on the total weight of the photoinitiated polymerizable composition, (a) 40 to 90 wt% of a nanogel component that comprises nanogel particles, wherein the nanogel particles comprise a copolymer with polymerizable reactive groups suitable for reacting with each other or with a reactive diluent monomer, a reactive oligomer, or a combination thereof that is present in the polymerizable composition upon photoinitiation, wherein (i) the copolymer is the polymerized product of a mixture that comprises a monovinyl monomer, a divinyl monomer, and a chain transfer agent, wherein the divinyl monomer is at a concentration in a range of 20 mol% to 80 mol% of the monomer content of the mixture;(ii) the polymerizable reactive groups of the copolymer are at a concentration that is in a range of 5% to 20% of the reactive group density of the divinyl monomer;(iii) at least one of the monovinyl monomer and the divinyl monomer is a glassy polymer when homopolymerized and at least one of the monovinyl monomer and the divinyl monomer is a rubbery polymer when homopolymerized;(iv) the nanogel component has a glass transition temperature (Tg), corresponding to the peak of a tan delta plot created via Dynamic Mechanical Analysis (DMA), is in a range of -50 °C and 20 °C;(v) the nanogel component has an average molecular weight (Mn), determined with triple-detector gel permeation chromatography (TD-GPC) analysis, that is in a range of 10 kg/mol and 100 kg/mol; and(vi) the nanoparticles have an average hydrodynamic radius (Rh), determined by light scattering while conducting a TD-GPC analysis, that is in a range of 1 nm to 5 nm; and(b) up to 50 wt% of the reactive diluent monomer, the reactive oligomer, or the combination thereof;(c) 0.01 to 10 wt% of a photoinitiator at an amount effective to initiate said reactions in the presence of curing radiation of appropriate wavelength and irradiance; and;(d) 0.005 to 5 wt% of a wavelength compatible radiation absorber at an amount effective for control of radiation transmission depth of the curing radiation. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 depicts a chemical reaction between monovinyl and divinyl comonomers in a solvent with a chain transfer agent to form a nanogel.Fig. 2 depicts the copolymerization of isodecyl