A curable composition contains: a) functionalized colloidal silica
obtained from the reaction of surface hydroxyl groups of colloidal silica
with at least one functionalizing silane of the general formula:
(Rl)aSi(OR2)4-a wherein each R1 is, independently, a monovalent alkyl,
cycloalkyl, aryl, alkaryl or aralkyl group of up to 18 carbon atoms,
optionally possessing at least one chemically reactive functionality
selected from the group consisting of alkenyl, acrylate and epoxy; b) at
least one first curable monomer possessing at least one of alkenyl and
acrylate functionality; c) at least one second curable monomer possessing
epoxy functionality; d) at least one third curable monomer possessing at
least one of alkenyl and acrylate functionality together with epoxy
functionality, the third curable monomer replacing or supplementing the
first and/or second curable monomer, provided, that when the third
curable monomer replaces both the first and second curable monomers, the
functionalized colloidal silica possesses at least one of alkenyl and
acrylate functionality together with epoxy functionality; and,
optionally, e) at least one curing agent for the curable monomer(s).The
composition when cured exhibits scratch and abrasion resistant properties
making it particularly well-suited for use as a coating for many
different kinds of substrates, e.g., DVD discs and especially the more
recent Blu-ray Discs, where these properties are highly desirable or even
necessary.