Dual cure 3D printing resins
Provided is a composition comprising: A) an aliphatic polyurethane which comprises a reaction product of a first aliphatic polyisocyanate, a first polyol, and a thiol, optionally in the presence of a catalyst, and B) a urethane (meth)acrylate prepolymer, optionally a reactive diluent, and a photoinitiator, wherein the urethane (meth)acrylate prepolymer comprises a reaction product of a second aliphatic polyisocyanate, a second polyol and an acrylate, wherein the reactive diluent comprises a (meth)acrylate monomer, wherein the first aliphatic polyisocyanate and second aliphatic polyisocyanate may be identical or different, and wherein the first polyol and the second polyol may be identical or different. Also provided is a process comprising combining: A) a polyurethane which comprises a reaction product of a first aliphatic polyisocyanate, a first polyol, and a thiol, optionally in the presence of a catalyst, and B) a urethane (meth)acrylate prepolymer, a reactive diluent, and a photoinitiator, wherein the urethane (meth)acrylate prepolymer comprises a reaction product of a second aliphatic polyisocyanate, a second polyol and an acrylate, wherein the reactive diluent comprises a (meth)acrylate monomer, wherein the first aliphatic polyisocyanate and second aliphatic polyisocyanate may be identical or different, and wherein the first polyol and the second polyol may be identical or different. The compositions of the invention may find use in 3D printing applications.
1 . A composition comprising:
A) an aliphatic polyurethane which comprises a reaction product, formed by a thermal curing process, of a first aliphatic polyisocyanate, a first polyol, and a thiol, optionally in the presence of a catalyst,
and
B) a urethane (meth) acrylate prepolymer, optionally a reactive diluent, and a photoinitiator, which upon a UV curing process prior to the thermal curing process forms UV-cured urethane (meth) acrylate,
wherein the urethane (meth) acrylate prepolymer comprises a reaction product of a second aliphatic polyisocyanate, a second polyol and an acrylate, wherein the reactive diluent comprises a (meth) acrylate monomer, wherein the first aliphatic polyisocyanate and second aliphatic polyisocyanate may be identical or different, and wherein the first polyol and the second polyol may be identical or different.
2 . The composition according to claim 1 , wherein the first aliphatic polyisocyanate and the second aliphatic polyisocyanate are each independently selected from the group consisting of 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 1,12-dodecamethylene diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 1-isocyanato-2-isocyanato-methyl cyclopentane, 5-isocyanato-1-(isocyanatomethyl) -1,3,3-trimethylcyclohexane, bis-(4-isocyanatocyclohexyl) methane, 1,3-bis (isocyanatomethyl)-cyclohexane, 1,4-bis (isocyanatomethyl)-cyclohexane, bis-(4-isocyanato- 3-methyl-cyclohexyl)-methane, 1-isocyanato-1-methyl-4 (3)-isocyanato-methyl cyclohexane,dicyclohexylmethane-4,4-diisocyanate, pentane diisocyanate, trimers of any of these, prepolymers of any of these, isomers of any of these, allophanates of any of these, and combinations of any of these.
3 . The composition according to claim 1 , wherein the first polyol and the second polyol are each independently selected from the group consisting of acrylic polyols, polyester polyols, polyether polyols, polyurethane polyols, and polycarbonate polyols.
4 . The composition according to claim 1 , wherein the photoinitiator is selected from the group consisting of benzophenones in combination with tertiary amines, alkylbenzophenones, 4,4′-bis (dimethylamino) benzophenone, anthrone, halogenated benzophenones, benzoin, benzil ketals, acylphosphine oxides, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bisacylphosphine oxides, phenylglyoxylic esters, camphorquinone, a-aminoalkylphenones, α,α-dialkoxyacetophenones and a-hydroxyalkylphenones, phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, oligo-[2-hydroxy-2-methyl-1-[4-(1-methylvinyl) phenyl] propanones, bis (4-methoxybenzoyl) diethylgermanium, and combinations thereof.
5 . The composition according to claim 1 , wherein the first aliphatic polyurethane comprises 10 wt. % to 50 wt. % of the composition, wherein wt. % is based on the weight of the composition.
6 . The composition according to claim 1 , wherein the reactive diluent is selected from the group consisting of phenoxy ethyl (meth) acrylate, phenoxy-2-methylethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, 3-hydroxy-2- hydroxypropyl (meth) acrylate, benzyl (meth) acrylate, phenylthio ethyl acrylate, 2-naphthylthio ethyl acrylate, 1-naphthylthio ethyl acrylate, 2,4,6-tribromophenoxy ethyl acrylate, 2,4-dibromophenoxy ethyl acrylate, 2-bromophenoxy ethyl acrylate, 1-naphthyloxy ethyl acrylate, 2-naphthyloxy ethyl acrylate, phenoxy 2-methylethyl acrylate, phenoxyethoxyethyl acrylate, 3-phenoxy-2-hydroxy propyl acrylate, 2,4-dibromo-6-sec-butylphenyl acrylate, 2,4-dibromo-6-isopropylphenyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, alkoxylated tetrahydrofurfuryl acrylate, ethoxylated nonyl phenol (meth) acrylate, alkoxylated lauryl (meth) acrylate, alkoxylated phenol (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, octadecyl (meth) acrylate, tridecyl (meth) acrylate, ethoxylated (4) nonyl phenol (meth) acrylate, caprolactone (meth) acrylate, cyclic trimethylolpropane formal (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, isobutyl (meth) acrylate, n-butyl (meth) acrylate, ethyl hexyl (meth) acrylate, isobornyl (meth) acrylate, and 2,4,6-tribromophenyl (meth) acrylate.
7 . The composition according to claim 1 , wherein the thiol is selected from the group consisting of trimethylol propane tri-(3-mercapto propionate), pentaerythritol tetra-(3-mercapto propionate), glycol di-(3-mercapto propionate), glycol dimercapto acetate, trimethylol propane trithioglycolate, mercapto diethyl ether, ethane dithiol, thiolactic acid, mercapto propionic acid and esters thereof, thiophenol, thio acetic acid, 2-mercapto ethanol, 1,4-butanedithiol, 2-3-dimercapto propanol, toluene-3,4-dithiol, α, α′-dimercapto-p-xylene, thiosalicylic acid, mercapto acetic acid, dodecane dithiol, didodecane dithiol, di-thio phenol, di-p-chlorothiophenol, dimercapto benzothiazole, 3,4-dimercapto toluene, allyl mercaptan, benzyl mercaptan, 1,6-hexane dithiol, 1-octane thiol, p-thiocresol, 2,3,5,6-tetrafluorothiophenol, cyclohexyl mercaptan, methylthioglycolate, mercapto pyridines, dithioerythritol, 6-ethoxy-2-mercaptobenzothiazole, d-limonene dimercaptan, and mixtures thereof.
8 . The composition according to claim 1 , wherein the thiol is included in a molar ratio to the catalyst of >2:1 to 500:1.