Optical disk

Abstract

An optical disk (10) has a substrate (12) using a plastic material which is transparent and decomposable in the natural world, and a reflecting film (14) covers the signal recording surface (20) of the substrate (12). The reflecting film (14) is made of a material decomposable in the natural world or a material present in the natural world. And a ground print layer (16) is formed thereon, and a label print layer (18) is printed. These prints use a material decomposable in the natural world or a material present in the natural world.

Description

technical field [0001] This invention relates to an optical disc, and is particularly related to an optical disc with less environmental load such as CD, DVD, Blu-ray Disc, and Advanced Optical Disc (AOD). Background technique [0002] For example, Japanese Unexamined Patent Application Publication No. 2000-11448 published on January 14, 2000 discloses an example of a conventional optical disc of this type. [0003] The substrate and protective layer of the decomposable optical recording medium in this patent document are formed of biodegradable plastics, and aluminum or the like is used as the reflective film. [0004] However, in this prior art, since a protective layer for protecting the reflective film is provided in addition to the substrate, it is necessary to prepare plastic materials for the substrate and the protective layer, and material costs increase. Since the protective layer forming process is required in the manufacturing process of the optical recording med...

AI Technical Summary

Problems solved by technology

[0004] However, in this prior art, since a protective layer for protecting the reflective film is provided in addition to the substrate, it is necessary to prepare plastic materials for the substrate and the protective layer, and the material cost increases.

Since the protective layer formation process is required in the manufacturing process of the optical recording medium, not only in terms of the quality control of the protective layer, but also the number of manufacturing steps of the optical recording medium is increased, the production management and production process are complicated, and the production time is consequently reduced. and cost increase

[0005] In addition, in this optical disc, biodegradable plastics are only used on the substrate and the protective layer, which is not sufficient in terms of reducing the environmental load of the entire optical disc.

[0006] Also, since the heat resistance of this decomposable plastic is generally low, there is a risk of thermal deformation of the disc in a high temperature environment

For example, among degradable plastics, plant-derived biodegradable plastics made of highly transparent polylactic acid, etc., generally have lower heat resistance than petroleum-based resins such as polycarbonate.

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