Compositions polymerizable/crosslinkable by cationic/radical irradiation
Compositions that can be polymerized and/or crosslinked into coatings by cationic and/or radical irradiation contain at least one photoinitiator and at least one compound having at least one isocyanate function.
1. A composition that can undergo cationic polymerization when irradiated, comprising:
A) at least one base compound having at least two polymerizable functional groups selected from the group consisting of epoxy-epoxy, oxetane-oxetane , and dioxolane-dioxolane;
B) at least one cationic photoinitiator;
C) optionally, at least one compound having an alcohol or thiol or carboxylic acid function; and
D) at least one compound having at least one isocyanate function.
2. The composition as defined by claim 1 , wherein said composition is irradiated with actinic radiation and/or with an electron beam.
3. The composition as defined by claim 1 , comprising at least one base compound with epoxy groups selected from the group consisting of:
4. The composition as defined by claim 1 , comprising a compound C containing a thiol or alcohol function.
5. The composition as defined by claim 1 , wherein the at least one compound comprising an isocyanate function is a polyisocyanate of formula (I):
Y—(—N═C═O) n
in which Y is a substituted or unsubstituted aromatic, aliphatic, cycloaliphatic or heterocyclic multivalent group optionally comprising heteroatom(s) and n is at least equal to 1.
6. The composition as defined by claim 5 , wherein the polyisocyanate comprises a diisocyanate or a triisocyanate.
7. A process for coating a support substrate, comprising depositing thereon a composition as defined by claim 1 .
8. The process as defined by claim 7 , comprising the following steps:
coating the support substrate with the composition to form at least one coating layer, whether partial or total, on the support substrate, and,
polymerizing the coating layer by irradiation.