UV-curing thiolenes for pressure sensitive and hotmelt adhesives
Thiolene-curing adhesive formulations, methods of preparation, and uses thereof are provided.
1 . A UV-curable adhesive composition comprising:
a vinyl-ether terminated urethane; and
a poly-functional mercaptan.
2 . The UV-curable adhesive composition, according to claim 1 , wherein said urethane is synthesized from at least one polyester polyol and at least one aliphatic diisocyanate.
3 . The UV-curable adhesive composition, according to claim 1 , wherein said urethane has a molecular weight, <Mn>, in the range of 1000 to 50,000, more preferably 2000 to 12,000 and most preferably 3000 to 7000.
5 . The UV-curable adhesive composition, according to claim 1 , wherein said polyol has a molecular weight in the range of from about 1000 to about 3200 AMU.
6 . The UV-curable adhesive composition, according to claim 1 , wherein said diisocyanate is selected from the group consisting of Desmodur W, IPDI, and TMDI.
7 . The UV-curable adhesive composition, according to claim 1 , wherein said poly-functional mercaptan has at least 2 thiol groups.
8 . The UV-curable adhesive composition, according to claim 1 , wherein said poly-functional mercaptan is selected from the group consisting of
ethylene bis(3-mercaptopropionate),
trimethylolpropane tris(2-mercaptoacetate),
trimethylolpropane tris(3-mercaptopropionate),
triethyl-1,3,5,-triazine-2,4,6-trione tris(3-mercaptopropionate),
pentaerythritol tetrakis(2-mercaptoacetate),
pentaerythritol tetrakis(3-mercaptopropionate),
dimethyl bis(3-mercaptopropyl)silane,
1,6-hexanedithiol,
1,10-decanedithiol, and
3,6-Dioxaoctane-1,8-dithiol.
9 . The UV-curable adhesive composition, according to claim 1 , wherein said poly-functional mercaptan is a 3-mercaptopropionic acid ester of a polyhydroxy compound.
10 . The UV-curable adhesive composition, according to claim 9 , wherein said polyhydroxy compound is selected from the group consisting of glycols, propylene glycol, butanediol, hexanediol, cyclohexanedimethanol, glycerol, polyethylene glycol, polypropylene glycol, and polyester polyols.
11 . The UV-curable adhesive composition, according to claim 1 , wherein said poly-functional mercaptan is trimethylpropane tris(trimercaptopropionate).
12 . The UV-curable adhesive composition, according to claim 1 , further comprising at least one additive selected from the group consisting of polymerization inhibitors, antioxidants, tackifiers, flow and leveling agents, pigments, fillers, odor-masking agents, and UV-stabilizers.
13 . A thiolene composition comprising the reaction product of:
a vinyl-ether terminated urethane; and
a poly-functional mercaptan, wherein
said composition is crosslinked with a curing agent.
14 . The thiolene composition, according to claim 11 , wherein said curing agent is ultraviolet light.
15 . A thiol-ene formulation curable to a crosslinked polymer comprising:
a polyfunctional mercaptan; and
a vinyl-terminated urethane.
16 . An adhesive product comprising
a layer of a backing material; and
a layer of a curable thiol-ene formulation comprising:
a polyfunctional mercaptan, and
a vinyl-terminated urethane, wherein said thiol-ene formulation is cured to a crosslinked polymer.
17 . A method of using a curable thiol-ene formulation comprising:
providing a backing material;
providing on said backing material a layer of a curable thiol-ene formulation comprising:
a polyfunctional mercaptan, and
a vinyl-terminated urethane; and
curing said thiol-ene formulation.
18 . The method of using a curable thiol-ene formulation, according to claim 17 , further comprising applying said formulation with a hot-melt coater.
19 . A hot-melt coater containing the curable thiol-ene formulation of claim 1.