Optical disc and method for manufacturing the same
AssigneeTDK Corporation
InventorsNarutoshi Fukuzawa, Hiroshi Take, Hiroshi Kawahara
Life of this patent
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Abstract
An optical disc is includes a recording layer, a reflective layer, and a protective layer provided, in that order, on one surface of a light-transmissive substrate and a hard coating layer having a thickness in the range of 1 to 5 μm on the other surface of the substrate. The hard coating layer is formed by applying and curing a solution comprising a hard coating agent containing colloidal silica and a UV-curable acrylic resin and a solvent containing propylene glycol monomethyl ether as a principal constituent. The hard coating layer contains 40 mg/cm3 or less of residual solvent.
Claims8
An optical disc comprising:
- a light-transmissive substrate;
- a recording layer, a reflective layer, and a protective layer provided, in that order, on one surface of the substrate;
- and
- a hard coating layer having a thickness in the range of 1 to 5 μm on another surface of the substrate, wherein
- the hard coating layer is produced by a process comprising applying to the substrate and curing a solution comprising a hard coating agent containing colloidal silica, a UV-curable acrylic resin, and a solvent principally containing propylene glycol monomethyl ether;
- and
- the hard coating layer comprises the colloidal silica, a cured resin consisting of the UV-curable acrylic resin after the curing, and 0.5 to 40 mg/cm3 of the solvent.
A method of manufacturing an optical disc, the method comprising
- applying a recording layer, a reflective layer, and a protective layer, in that order, on one surface fo a light-transmissive substrate;
- applying on another surface of the substrate a solution comprising a hard coating agent containing colloidal silica, a UV-curable acrylic resin, and a solvent principally containing propylene glycol monomethyl ether;
- and
- curing the solution, without heating the hard coating agent, to form a hard coating layer containing 0.5 to 40 mg/cm3 of the solvent.
Dependencies are inferred from the claim text.