JPH06282884A - Manufacture of writable optical information recording medium - Google Patents

Abstract

PURPOSE:To obtain a writable optical information recording medium having no fear of peeling between layers by dissolving to remove a light absorption layer on a peripheral edge of a board and so forming a protective layer as to bring the edge of the board into contact with that of the protective layer. CONSTITUTION:A light absorption layer 14 and an enhancement layer 16 are formed on a light transmissive board 12. A reflecting layer 18 is so formed as not to cover an outer peripheral edge of a surface of the board 12 at the layer 14 side. The layers 14, 16 of the edge of the board 12 are dissolved to be removed, and a protective layer 20 is formed on the layer 18 and the edge of the board 12. With this structure, since the edge of the board 12 can be rigidly connected to the edge of the layer 20, a writable optical information recording medium 10 with high reliability and having no fear of peeling between the layers can be manufactured. When the layers 14, 16 at the edge of the board 12 are dissolved to be removed, it is preferable to dissolve to remove it by using resin liquid for forming the layer 20 while rotating the board 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention irradiates a light absorbing layer containing an organic dye with a recording laser beam on which information is superimposed to form a pit having an optical phase difference with a background portion. The present invention relates to a method of manufacturing a writable optical information recording medium.

[0002]

2. Description of the Related Art Various writable optical information recording media have been proposed. The applicant of the present invention has improved such a writable optical information recording medium and
As a writable optical information recording medium which can be adapted to the standard of a compact disc (CD) which is a type optical information recording medium, a writable optical information recording medium disclosed in JP-A-2-87342 is proposed.

This writable optical information recording medium is an enhancement between the light absorption layer and the light reflection layer which is transparent to the wavelength of the reproducing laser light (imaginary part of complex refractive index k _ehs = 0).
(enhance) layer is provided. Since this writable optical information recording medium has such an enhancement layer between the light absorption layer and the light reflection layer, the reflectance of the reproducing laser light is as high as 70% or more.

[0004]

However, this writable optical information recording medium has a light absorbing layer, an enhance layer and a light reflecting layer which have a weak adhesive force to other layers between the transparent substrate and the protective layer. Since it is interposed between the layers, there is a risk of peeling between the layers, particularly between the layers at the peripheral portion, and there is a problem of lack of reliability.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method of manufacturing a highly reliable writable optical information recording medium which is free from peeling between layers.

[0006]

In the method for producing a writable optical information recording medium according to the present invention, a light absorbing layer containing an organic dye is formed directly or through another layer on a transparent substrate. And a step of forming a reflective layer on the light absorbing layer directly or through another layer so as not to cover the outer peripheral edge portion of the surface of the light transmissive substrate on the light absorbing layer side, and the transparent layer. A step of dissolving and removing the light absorption layer on the peripheral portion of the light-transmitting substrate and a layer adjacent thereto, and forming a protective layer on the reflective layer and on the peripheral portion of the light-transmitting substrate directly or via another layer. And a step of performing.

Here, the light absorbing layer and the layer adjacent thereto may be dissolved and removed by using a resin liquid for forming the protective layer.
Alternatively, the light absorbing layer and the layer adjacent thereto may be dissolved and removed while rotating the transparent substrate.

[0008]

[Action]

In the present invention, a step of forming a light absorbing layer containing an organic dye directly or through another layer on a transparent substrate, and a step of forming a reflecting layer directly or other on the light absorbing layer. The step of forming the outer peripheral edge of the surface of the light-transmissive substrate on the light-absorption layer side through the layer of (1) and the light-absorption layer on the peripheral edge of the light-transmissive substrate and a layer adjacent thereto. Since the step of dissolving and removing and the step of forming a protective layer on the reflective layer and on the peripheral portion of the translucent substrate directly or via another layer, the protective layer covers the outer peripheral portion thereof. It is formed in a state of being adhered to the outer peripheral edge portion of the surface of the transparent substrate on the side of the light absorption layer.

When the resin solution for forming the protective layer is used to dissolve and remove the light absorbing layer and the layer adjacent thereto, only one step of dropping the resin solution for forming the protective layer,
The removal of the light absorbing layer and the formation of the protective layer on the outer peripheral portion of the surface of the transparent substrate on the side of the light absorbing layer are performed.

Further, when the light absorbing layer and the layer adjacent thereto are dissolved and removed while rotating the light transmitting substrate, the light absorbing layer on the outer peripheral edge of the surface of the light transmitting substrate on the light absorbing layer side is removed. And the formation of the protective layer is efficiently performed.

[0012]

1 is a partially cutaway perspective view of an example of an optical information recording medium according to the present invention, and FIG. 2 is an enlarged view of portion A in FIG. In this optical information recording medium 10, as shown in the figure, the light absorption layer 14 and the enhancement layer 1 are provided on one surface of the transparent substrate 12.
6, the reflective layer 18 and the protective layer 20 are laminated in this order.

Here, examples of the translucent material include polycarbonate, acrylic resin, polyolefin, glass, and the like, but even materials other than these materials have a refractive index of 1.4 to 1. No. 6 can be used as long as it has excellent impact resistance.

The transparent substrate 12 can be molded by means such as injection molding. In addition, the transparent substrate 1
The 2 may have pregrooves formed in a spiral shape in advance. The pregroove may be under any condition that is usually considered, but the depth is 50
It is preferably about 300 nm. The pre-groove is generally formed by pressing a stamper when manufacturing the transparent substrate 12 by injection molding, but the pre-groove is not necessarily limited to this method.

As the material of the light absorbing layer 14, a light absorbing organic dye is preferable. Specific examples of the light absorbing organic dyes include cyanine dyes, triarylmethane dyes, pyrylium dyes, phenanthrene dyes, tetradehydrocholine dyes, triarylamine dyes, squarylium dyes, croconic methine dyes, and phthalocyanine dyes. , And azurenium dyes,
Other light-absorbing organic dyes can also be used. The above description is based on Te, Bi, Mn.
Well-known materials such as are not excluded from the material of the light absorption layer 14.

The light absorbing layer 14 may contain other dyes, resins (for example, thermoplastic resin such as nitrocellulose, thermoplastic elastomer), liquid rubber and the like. Light absorbing layer 14
Is a translucent substrate 12 on which a pre-groove is formed by dissolving the above-described dye and any additive in an organic solvent (for example, alcohol, acetylacetone, methyl cellosolve, toluene, etc.), or of the translucent substrate 12. Coated on top of the other layers coated above.

The coating method of the light absorbing layer 14 includes vapor deposition method, LB method, spin coating method and the like. The layer thickness is controlled by adjusting the concentration, viscosity and solvent drying rate of the light absorbing layer 14. The spin coating method is preferable because it is possible.

The enhancement layer 16 can be formed of, for example, an organic dielectric such as silicon resin. Enhance layer 1
When 6 is formed of an organic dielectric, the raw material liquid is spin-coated on the light absorption layer 14 directly or through another layer.

The thickness d _ehs of the enhancement layer 16 is the real part n _abs of the complex refractive index of the light absorption layer 14, the thickness d _abs of the light absorption layer 14, the real part n of the complex refractive index of the enhancement layer 16.
_ehs, the film thickness d _ehs and reproducing Les enhancement layer 16 - the value given by the wavelength of the laser light _{λ ρ = (n abs · d} abs
+ N _ehs · d _ehs ) ÷ λ is set so that 0.05 ≦ ρ ≦ 1.6. Further, the imaginary part _kabs of the complex refractive index of the light absorption layer 14 is set to 0.04 or less.

Although the enhancement layer 16 is provided between the light absorption layer 14 and the reflection layer 18 in the example of FIG. 2, the enhancement layer 16 is provided between the transparent substrate 12 and the light absorption layer 14. May be. Further, the enhancement layer 16 may not be provided.

The reflective layer 18 is preferably a metal film such as gold, silver, aluminum, or an alloy containing these.
The reflective layer 18 is formed smaller than the translucent substrate 12. The metal film can be formed by means such as vapor deposition and sputtering. The reflective layer 18 may be coated with an oxidation resistant layer in order to prevent its oxidation.

The protective layer 20 is preferably formed of an ultraviolet curable resin having excellent impact resistance such as polyacrylate resin. Although the protective layer 20 is directly adhered to the translucent substrate 12 at the peripheral portion, it can be so configured by any of the following methods.

In one method, a cleaning liquid made of an organic solvent is dropped on the outer peripheral edge of the transparent substrate 12 while the transparent substrate 12 is rotated, and the cleaning liquid is placed on the outer peripheral edge of the transparent substrate 12. The light absorption layer 14 and the enhancement layer 16 are dissolved and removed. Then, the resin liquid forming the protective layer 20 is spin-coated on the reflective layer 16. The resin liquid forming the protective layer 20 is coated on the reflective layer 16 by centrifugal force and then on the outer peripheral edge of the translucent substrate 12. As the cleaning liquid composed of an organic solvent, alcohol such as methanol or ethanol can be used.

In another method, while rotating the translucent substrate 12, the resin liquid for forming the protective layer 20 is excessively dropped on the reflection layer 18, and the resin liquid is coated on the reflection layer 18 by centrifugal force. Then, the resin liquid is allowed to flow to the outside of the reflective layer 18, and the resin liquid thus flowed out is used to absorb the light absorption layer 1 on the outer peripheral edge of the transparent substrate 12.
4 and the enhancement layer 16 are dissolved and removed. Then, the resin liquid remaining on the reflective layer 18 and on the outer peripheral edge of the transparent substrate 12 is dried to form the protective layer 20.

In the example of FIG. 2, the outer peripheral edge portion of the protective layer 20 and the outer peripheral edge portion of the transparent substrate 12 are adhered in a state of facing each other, but the outer peripheral edge portion of the protective layer 20 is transparent. The outer peripheral edge of the substrate 12 may be adhered so as to wrap it.

Example 1 First, a disk-shaped light-transmitting substrate 12 having spiral pre-grooves was formed by an injection molding method. Here, polycarbonate was used as the material of the transparent substrate 12. The transparent substrate 12 has a thickness of 1.2 m.
m, outer diameter 120 mmφ, and inner diameter 15 mmφ. The pre-groove has a width of 0.8 μm, a depth of 0.08 μm and a pitch of 1.6 μm, and the diameter of the transparent substrate 12 is 46 to 117 m.
It was formed in the range of mφ.

Next, 1,1'dibutyl 3,3,3 ', 3' tetramethyl 4,5,4'5 'is formed on the transparent substrate 12.
A diacetone alcohol solution of dibenzoindodicarbocyanine perchlorate (manufactured by Japan Photosensitive Dye Research Institute, Inc .: NK3219) was applied by a spin coating method to form a light absorption layer 14 having a film thickness d _abs = 130 nm.

Here, this diacetone alcohol solution contained 0.65 g of 1,1'dibutyl 3,3,3 ', 3'.
Tetramethyl 4,5,4'5 'dibenzoindodicarbocyanine perchlorate dissolved in 10 cc of diacetone alcohol was used.

Next, 1.2 g of monomethyl siloxane (KR-220 manufactured by Shin-Etsu Chemical Co., Ltd.) dissolved in 100 ml of cyclohexane was applied onto the light absorption layer 14 by spin coating, and then at 80 ° C. Curing was performed for 30 minutes to obtain an enhancement layer 16. The film thickness d _ehs of the enhancement layer 16 is 52 nm, and the real part n of the complex refractive index is n.
_{The ehs} was 1.41.

Next, Al is coated on the enhancement layer 16 by a sputtering method to form a reflection layer 1 having a film thickness of 100 nm.
8 was formed.

Next, a polyacrylate resin is excessively spin-coated on the reflective layer 18 so that the light absorbing layer 14 on the peripheral portion is formed.
The enhancer layer 3 was dissolved and removed, and the peripheral portion of the translucent substrate 12 and the reflective layer 18 were coated with this resin liquid. Then, the polyacrylate resin liquid was cured by irradiation with ultraviolet rays to form a protective layer 20 having a film thickness of 10 μm.

When the laminated state of the peripheral portion of the optical information recording medium 10 formed as described above is observed, it is found that the optical information recording medium 10 is completely integrally bonded and is in a state where there is no fear of peeling. all right.

Example 2 The same as Example 1 except that the light absorbing layer 14 and the enhancement layer 3 on the outer side of the reflective layer 18 were removed by washing with a cleaning agent (methanol) before forming the protective layer 20. An optical information recording medium was manufactured in the above manner, and the laminated state of the peripheral portion of this optical information recording medium was observed in the same manner as in Example 1 above. It turns out that it is in a state of no.

[0034]

According to the present invention, since the outer peripheral edge portion of the transparent substrate and the outer peripheral edge portion of the protective layer are firmly bonded to each other, a highly reliable optical information recording medium in which the layers are not easily peeled off is provided. There is an effect that can be obtained.

Further, according to the present invention, there is an effect that the optical information recording medium having the outer peripheral edge portion of the protective layer adhered to the outer peripheral edge portion of the transparent substrate can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of an example of an optical information recording medium according to the present invention.

FIG. 2 is an enlarged view of part A of FIG.

[Explanation of symbols]

 10 Optical Information Recording Medium 12 Translucent Substrate 14 Light Absorbing Layer 16 Enhance Layer 18 Light Reflecting Layer 20 Protective Layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chiharu Tsukamoto 6-16-20 Ueno Taito-ku, Tokyo Taiyo Induction Co., Ltd.

Claims (3)

[Claims] 1. A step of forming a light absorbing layer containing an organic dye directly or through another layer on a transparent substrate, and a reflecting layer directly or on another layer on the light absorbing layer. Through the step of forming so as not to cover the outer peripheral edge of the surface of the transparent substrate on the side of the light absorbing layer, and dissolving and removing the light absorbing layer on the peripheral edge of the transparent substrate and the layer adjacent thereto. A method of manufacturing a writable optical information recording medium, comprising: a step of forming a protective layer on the reflective layer and on a peripheral portion of the translucent substrate either directly or via another layer. 2. The method for producing a writable optical information recording medium according to claim 1, wherein the light absorbing layer and a layer adjacent thereto are dissolved and removed by using a resin liquid for forming a protective layer. Manufacturing method of possible optical information recording medium. 3. The method for manufacturing a writable optical information recording medium according to claim 1, wherein the light absorbing layer and a layer adjacent thereto are dissolved and removed while rotating the transparent substrate. Manufacturing method of possible optical information recording medium.