Disclosed is a composition capable of imparting high
hardness, abrasion resistance, excellent
contamination resistance and durability of such
contamination resistance even in the form of a thin film. Specifically disclosed is a composition including an
organic polymer containing 5-30% by
mass of a radically polymerizable
monomer with a perfluoroalkyl group, 0.01-5% by
mass of α,ω-dimercaptopolysiloxane, 5-40% by
mass of a radically polymerizable
monomer with a cationically photopolymerizable
epoxy group and 25-75% by mass of another radically polymerizable
monomer which is copolymerizable with the aforementioned substances. The
organic polymer has a structure corresponding to a radically polymerized
copolymer of the monomer mixture wherein the
molar ratio of the mercapto group to the
epoxy group is 0.0001-0.025 and / or a structure obtained by reacting a (
meth)
acrylic acid with the
epoxy group of the radically polymerized
copolymer.