Patent ID: 7361393
Filing Date: 2008-04-22
Classification: G11B,Y10T

Abstract:
1. An optical disk of a system wherein a recording layer and a thin film cover layer with a thickness of from 5 to 200 μm, are laminated on a substrate in this order, and the recording layer is to be irradiated through the thin film cover layer with a blue laser beam to be used for recording and/or retrieving data, wherein a hard coat layer (X) is formed on the thin film cover layer, and the hard coat layer (X) is made of a cured product of an active energy ray curable composition (Q) comprising an active energy ray curable polymerizable monomer (A), a colloidal silica (B) having an average particle size of from 1 to 200 nm, a lubricity-imparting agent (C) and an active energy ray polymerization initiator (D), provided that the polymerizable monomer (A) contains at least 20 mass % of a polyfunctional polymerizable monomer (a-1) having at least two polymerizable functional groups selected from the group consisting of an acryloyl group and a methacryloyl group in one molecule, in the total mass of the polymerizable monomer (A) contained in the curable composition (Q), and the lubricity-imparting agent (C) contains a lubricity-imparting agent (C-T) having, in one molecule, a moiety (c-1) made of a portion represented by the following formula (1), at least one moiety (c-2) selected from the group consisting of portions represented by the following formulae (2) to (5), and an active energy ray curable functional group (c-3): wherein each of R wherein R