Optical recording media and manufacturing thereof

Abstract

In an optical recording medium, a recording layer is formed by coating a substrate with a solution of coloring matter comprising a coloring matter dissolved in a solvent comprising a mixture of cyclooctane and at least one hydrocarbon having 6 to 9 carbon atoms other than cyclooctane. The obtained optical recording medium enables the suppression of leakage of the land prepit signal for address information into the RF signal for recorded data at the time of recorded data reproduction, thereby attaining a lowering of error rate.

Description

Field of Invention

[0001] The present invention relates to an optical recording medium in which a colorant film is provided as a recording layer, and a method for producing the same. Background of the Invention

[0002] With the development of the electronic industry, large-capacity storage recording discs for optical recording such as CD·R, DVD·R, and DVD·RW are widely used as external storage of personal computers or as imaging recording media to replace video, and more recently as a large-scale storage medium. Capacity storage optical recording medium. Among various media capable of optical recording, the write-once-read (WOR) compact disc has repeated exchange with the ordinary reproduction-only (read-only) CD-ROM (recording only once), and this type of optical disc is called CD·R, many people use this kind of disc. Furthermore, the development of a medium capable of recording even with a Digital Versatile Disc (DVD) having a recording density greater than that of a CD...

Examples

Embodiment 1

[0093] A polycarbonate sheet for DVD·R with a diameter of 120 mm and a thickness of 0.6 mm was used as a transparent resin substrate on which periodic Z-shaped tracking grooves (pitch: 0.74 μm, depth: 160 nm, width (half-wave width) were provided. ): 350 nm).

[0094] In forming the recording layer, in a solvent comprising 1,2-dimethylcyclohexane (DMCH) mixed with 10% by weight of cyclooctane, a dipyrrolemethylene metal complex dye of the following formula is dissolved in an amount of 20g / L:

[0095] The obtained solution was filtered and applied on the above-mentioned substrate by spin coating, and the thickness of the dye film in the central area of ​​the groove (the thickness of the recording layer) was 120 nm by adjusting the rotational speed.

[0096] The dye thin film thus formed was dried at 80° C. for 1 hour, and a 100 nm-thick Au film was applied as a reflective layer using a sputtering apparatus (model CDI 900, manufactured by Balzers).

[0097] Then, a UV-curabl...

Embodiment 2

[0101] The same substrates and dyes as described in Example 1 were used. The dye was dissolved in a mixed solvent comprising ethylcyclohexane (ECH) and 3% by weight of o-xylene and 10% by weight of cyclooctane at a concentration of 25 g / L. The prepared solution was coated on a substrate, and the rotation adjustment was adjusted so that the film thickness (recording layer thickness) in the central region of the groove was 120 nm. In the same manner as in Example 1, an optical recording medium was prepared, and its signal evaluation was performed. The results are listed in Table 1.

Embodiment 3

[0103] The same substrate as described in Example 1 was used. The pyrrole methylene metal complex of the following formula (3) was dissolved in a mixture comprising a mixture of ethylcyclohexane (ECH) and cyclohexane (mixed in a weight ratio of 3:1) mixed with 5% by weight of cyclooctane. In the solvent, the concentration is 15g / L. The prepared solution was coated on the substrate, and the rotation adjustment was adjusted so that the film thickness (recording layer thickness) in the central region of the groove was 120 nm. In the same manner as in Example 1, an optical recording medium was prepared, and its signal evaluation was performed. The results are listed in Table 1.

Field of Invention

[0001] The present invention relates to an optical recording medium in which a colorant film is provided as a recording layer, and a method for producing the same. Background of the Invention

[0002] With the development of the electronic industry, large-capacity storage recording discs for optical recording such as CD·R, DVD·R, and DVD·RW are widely used as external storage of personal computers or as imaging recording media to replace video, and more recently as a large-scale storage medium. Capacity storage optical recording medium. Among various media capable of optical recording, the write-once-read (WOR) compact disc has repeated exchange with the ordinary reproduction-only (read-only) CD-ROM (recording only once), and this type of optical disc is called CD·R, many people use this kind of disc. Furthermore, the development of a medium capable of recording even with a Digital Versatile Disc (DVD) having a recording density greater than that of a CD...

Examples

Embodiment 1

[0093] A polycarbonate sheet for DVD·R with a diameter of 120 mm and a thickness of 0.6 mm was used as a transparent resin substrate on which periodic Z-shaped tracking grooves (pitch: 0.74 μm, depth: 160 nm, width (half-wave width) were provided. ): 350 nm).

[0094] In forming the recording layer, in a solvent comprising 1,2-dimethylcyclohexane (DMCH) mixed with 10% by weight of cyclooctane, a dipyrrolemethylene metal complex dye of the following formula is dissolved in an amount of 20g / L:

[0095] The obtained solution was filtered and applied on the above-mentioned substrate by spin coating, and the thickness of the dye film in the central area of ​​the groove (the thickness of the recording layer) was 120 nm by adjusting the rotational speed.

[0096] The dye thin film thus formed was dried at 80° C. for 1 hour, and a 100 nm-thick Au film was applied as a reflective layer using a sputtering apparatus (model CDI 900, manufactured by Balzers).

[0097] Then, a UV-curabl...

Embodiment 2

[0101] The same substrates and dyes as described in Example 1 were used. The dye was dissolved in a mixed solvent comprising ethylcyclohexane (ECH) and 3% by weight of o-xylene and 10% by weight of cyclooctane at a concentration of 25 g / L. The prepared solution was coated on a substrate, and the rotation adjustment was adjusted so that the film thickness (recording layer thickness) in the central region of the groove was 120 nm. In the same manner as in Example 1, an optical recording medium was prepared, and its signal evaluation was performed. The results are listed in Table 1.

Embodiment 3

[0103] The same substrate as described in Example 1 was used. The pyrrole methylene metal complex of the following formula (3) was dissolved in a mixture comprising a mixture of ethylcyclohexane (ECH) and cyclohexane (mixed in a weight ratio of 3:1) mixed with 5% by weight of cyclooctane. In the solvent, the concentration is 15g / L. The prepared solution was coated on the substrate, and the rotation adjustment was adjusted so that the film thickness (recording layer thickness) in the central region of the groove was 120 nm. In the same manner as in Example 1, an optical recording medium was prepared, and its signal evaluation was performed. The results are listed in Table 1.

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