Stabilization of thiolene compositions
AssigneeLoctite Corporation
InventorDavid M. Glaser
Life of this patent
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Abstract
A combination of free radical retarding agent and an active iodine species selected from the group consisting of molecular iodine, iodide ion, and mixtures thereof provides synergistic stabilization of thiol-ene compositions which cure by addition of thiol groups to olefinic carbon-carbon double bonds. The combination is particularly suitable for thiol-ene formulations employing norbornenyl functional polyenes. A preferred stabilization system employs an N-nitrosoarylhydroxylamine salt and a mixture of an alkali iodide and I.sub.2 in the range of 0.6-1 mole I.sub.2 per equivalent I.sup..crclbar..
Claims18
In a curable thiol-ene formulation comprising a polythiol, a polyene and a free radical retarding agent the improvement comprising that the free radical retarding agent is a N-nitrosoarylhydroxylamine or salt thereof and the formulation includes a stabilizing effective amount of an active iodine species selected from the group consisting of I.sup..crclbar., I.sub.2 and mixtures thereof.
A composition comprising
- (a) a polythiol,
- (b) a polyene,
- the ratio of polyene to polythiol being between about 0.7:1 and 1.3:1 on an equivalents basis,
- (c) a metal salt of an N-nitrosoarylhydroxylamine at a level of between 50 ppm and 2%, and
- (d) between 1 and 5000 ppm of an active iodine species selected from the group consisting of I.sub.2, I.sup..crclbar. and mixtures thereof.
Dependencies are inferred from the claim text.