JPH05242530A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To eliminate the need for an operation to wipe away the dyestuff material constituting a light absorptive layer and to improve merchandise value by forming the dyestuff material so as to be soluble in a top coating material constituting a protective layer. CONSTITUTION:The dyestuff material of the light absorptive layer 3 is so formed as to be soluble in the top coating material prior to curing of the protective layer 5. The dyestuff material in the outer peripheral part 20A of the optical information recording medium 20 is cleanly washed away with the top coating material flowing on the front surface thereof at the time of a spin coating stage and the outer peripheral part 5C of the protective layer 5 is directly adhered at the layer boundary 21 of the substrate 2 and the 5th layer. The outer peripheral edge 3A of the light absorptive layer 3 is thus coated with the outer peripheral part 5L of the protective layer 5 and is partly dissolved, thereby, the securely integrated state is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium, and in particular, a dye material constituting a light absorbing layer can be applied to a top coat material constituting a protective layer before curing. The present invention relates to a soluble optical information recording medium.

[0002]

2. Description of the Related Art Conventionally, in a recordable compact disc type optical information recording medium, a light absorbing layer (recording layer) and a light reflecting layer are formed on a transparent substrate, and a laser beam is applied to this light absorbing layer. The optical information is recorded by applying (recording light), and the optical information is read by applying laser light (reading light) to the light absorbing layer and the light reflecting layer.

FIG. 4 shows a conventional general optical information recording medium 1
FIG. 5 is a partially cutaway perspective view of the optical information recording medium 1, and FIG.

This optical information recording medium 1 comprises a transparent substrate 2
And a light absorption layer 3 (recording layer) formed on the substrate 2,
It has a light reflection layer 4 formed on the light absorption layer 3 and a protective layer 5 formed on the light reflection layer 4.

In particular, as shown in FIG. 5, a pre-groove 6 is formed on the substrate 2 in a spiral shape or a concentric shape. To the left and right of the pre-groove 6, parts other than the pre-groove 6, that is, lands 7 are located.

The substrate 2 and the light absorption layer 3 are in contact with each other by the first layer boundary 8. Light absorbing layer 3 and light reflecting layer 4
Are in contact with the second layer boundary 9. The light reflecting layer 4 and the protective layer 5 are in contact with each other by the third layer boundary 10.

When the recording laser light (recording light) L is irradiated onto the optical information recording medium 1 as shown by the phantom line in FIG.
The light absorbing layer 3 absorbs the energy of the recording laser light L to generate heat, and thermal deformation occurs on the substrate 2 side, so that the pits 11 can be formed. Note that an optical change may occur in the light absorption layer 3.

The substrate 2 is made of a transparent material such as polycarbonate.
In addition, it is composed of a resin having excellent impact resistance.

The light absorbing layer 3 is a layer made of a light absorbing substance formed on the tracking guide means by the pre-groove 6, and by irradiating the recording laser light L,
It is a layer accompanied by heat generation, melting, sublimation, deformation or modification.

The light absorbing layer 3 is formed by uniformly coating the surface of the substrate 2 with an organic dye such as a cyanine dye dissolved in a solvent by means of spin coating or the like.

In this case, the forming means is a vapor deposition method, L
Examples of the method include the B method, the spin coating method, and the like. The spin coating method is preferable because the layer thickness can be controlled by adjusting the concentration, viscosity, and solvent drying rate of the light absorption layer 3.

Next, the light reflection layer 4 is a metal film, and gold, silver, copper, aluminum, or an alloy containing these is formed by means of vapor deposition, sputtering or the like.

Next, the protective layer 5 is formed of a top coat material such as a resin having the same excellent impact resistance as that of the substrate 2 For example, an ultraviolet curable resin is applied as a top coat material by a spin coat method, and this is formed by irradiating it with ultraviolet rays to cure it.

Regarding the recordable compact disc type optical information recording medium 1 having such a constitution, conventionally, regarding the solubility of the dye material of the top coat material such as the ultraviolet curable resin before the protection layer 5 is cured on the light reflection layer 4, , No comparison was made.

The problem relating to the solubility of the dye material in the top coat material will be described with reference to FIGS. 6 and 7 in relation to the state of the light absorption layer 3 in the outer peripheral portion 1A of the optical information recording medium 1.

FIG. 6 is a cross-sectional view of the main part of the outer peripheral portion 1A showing the step of spin coating the last protective layer 5 in the manufacturing process of the optical information recording medium 1, and FIG. 7 is the outer peripheral portion 1A with the protective layer 5 formed. FIG.

First, as shown in FIG. 6, when the pigment material of the light absorbing layer 3 is insoluble in the top coat material (UV curable resin) 5A of the protective layer 5, this top coat material 5 is used.
By flowing A in the centrifugal direction of the optical information recording medium 1 by spin coating, the outer peripheral portion 1A of the optical information recording medium 1 is
The light absorption layer 3 located on the outer side of the light reflection layer 4 in the centrifugal direction
Is not washed away and remains intact.

Therefore, as shown in FIG. 7, the top coat material 5A is cured by ultraviolet rays without being in direct contact with the substrate 2, and as a result, the outer peripheral portion 5B of the protective layer 5 is formed.
Are in contact with the light absorption layer 3 by the fourth layer boundary 12.

When the dye material (light absorbing layer 3) remains between the protective layer 5 and the substrate 2, the outer peripheral portion 1A of the optical information recording medium 1 is not completely covered with the resin, and the light absorbing layer 3 is formed. There is a problem that the outer peripheral edge portion 3A is exposed to the outside, the adhesive strength between the protective layer 5 and the substrate 2 is impaired, and the outer peripheral portion 1A is easily peeled off.

Further, if the coloring material remains on the outer peripheral portion 1A or the outer peripheral portion 5B, there is a problem in that the appearance is unfavorable and the value as a product is significantly impaired.

Therefore, regarding the dye material adhered to the adhesive portion between the substrate 2 and the protective layer 5 on the outer peripheral portion 1A, a pad or the like soaked with a solvent soluble in the dye material is used before the top coat process. Often wiped off.

This is because if the top coat is performed without wiping off the pigment material on the outer peripheral portion 1A, the pigment material on the outer peripheral portion 1A may remain without flowing, as described above.

The reason for this is that the topcoat is performed without considering the mutual solubility of the dye material and the topcoat material 5A, and the solubility parameter (δ value or SP value) and hydrogen bonding force (γ) of the dye material are used. This is because those values of the topcoat material are not within the soluble range of (value), and as a result, the dye material in the outer peripheral portion 1A is not washed off during the topcoat.

In order to avoid the above problems, there is a case where the outer peripheral portion 1A is wiped off before the top coat by using a pad or the like soaked with a solvent for dissolving the dye material as described above. However, there is a problem that the whole process becomes complicated and the yield and the like decrease due to a work mistake.

[0025]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and includes a step of wiping a dye material in the outer peripheral portion of an optical information recording medium or the outer peripheral portion of a light reflecting layer in the centrifugal direction. It is an object of the present invention to provide an optical information recording medium that is unnecessary, improves the adhesive strength of the outer peripheral portion, and is transparent and clean.

[0026]

That is, the present invention focuses on the solubility of the topcoat material with respect to the dye material. The first invention is to form a substrate having a light-transmitting property on the substrate and a substrate having a light-transmitting property. A light absorbing layer composed of a dye material,
An optical information recording medium having a light reflecting layer formed on this light absorbing layer and a protective layer formed on this light reflecting layer and made of a top coat material, wherein the dye material of the light absorbing layer is The optical information recording medium is characterized in that it is soluble in the top coat material before curing of the protective layer.

A second invention is characterized in that the solubility parameter of the top coat material of the protective layer is set within the range of the solubility parameter of the dye material of the light absorbing layer. This is an information recording medium.

In a third aspect of the invention, the solubility region of the topcoat material of the protective layer, which is represented by the relationship of the solubility parameter to the hydrogen bonding force, is the hydrogen bonding force of the dye material of the light absorbing layer. It is an optical information recording medium characterized in that it has a common part with a dissolution region expressed by the relationship of solubility parameters.

The present invention will be described in more detail below. The physical structure of the optical information recording medium 20 according to the present invention is the same as that of the conventional optical information recording medium 1 shown in FIGS. 4 and 5, except for the outer peripheral portion 20A, except that the light absorbing layer 3 and the protective layer are provided. 5
It is a combination of the constituent materials of and.

More specifically, a combination is selected in which the dye material forming the light absorbing layer 3 is soluble in the top coat material 5A forming the protective layer 5 before curing (during the top coat step). To do.

Alternatively, the top coat material 5 of the protective layer 5
A combination is selected so that the solubility parameter (δ value or SP value) of A is within the range of the solubility parameter of the dye material of the light absorption layer 3.

Alternatively, the solubility parameter and hydrogen bond strength (γ value) ranges of the topcoat material 5A and the range of these values of the dye material are common in the solubility parameter / hydrogen bond strength dissolution region diagram. Select a combination that has parts.

[0033]

In the optical information recording medium according to the present invention, the dye material becomes soluble in the top coat material. Therefore, when the top coat material is spin-coated, the dye material in the outer peripheral portion of the optical information recording medium is protected by this top coat material. It can be washed off, and only the light absorption layer of the portion whose upper surface is covered by the light reflection layer remains, the protective layer and the substrate are directly adhered to each other at their outer peripheral portions, and the outer peripheral edge portion of the dye material is It becomes possible to dissolve in the topcoat material.

Therefore, not only the work of wiping the dye material around the outer peripheral portion is not required, but also the adhesive strength can be improved, and the adhesive portion can be colorless and transparent and has an excellent commercial value.

[0035]

EXAMPLES Next, examples of the present invention will be described.

[Example] Thickness 1.2 mm, outer diameter 120 m
A substrate made of polycarbonate and having an inner diameter of 15 mm and an inner diameter of 15 mm was molded by an injection molding method.

On this substrate, a material containing an indodicarbocyanine dye material as a main material was added to ethanol in an amount of 40 g /
A solution dissolved in 1 liter was applied by a spin coating method to form a dye film (light absorbing layer).

An Au film having a thickness of 60 mm was formed up to an outer diameter of 117 mm on the substrate having the dye film by a sputtering method to form a light reflection layer.

Further, an ultraviolet curable resin (SN-0676 manufactured by San Nopco Co., Ltd.) is applied on the light reflecting layer by a spin coating method, and is irradiated with ultraviolet rays to be cured, thereby forming a protective layer having a thickness of 10 μm. Formed.

In the thus obtained optical information recording medium, FIG. 1 shows a dissolution region diagram of the applied pigment material and the ultraviolet curable resin before curing. This dissolution region diagram is a graph showing the relationship between the solubility parameter and the hydrogen bonding force.

As shown in FIG. 1, the solubility parameter of the ultraviolet curable resin is 8.5 to 13.5, which is within the range of the solubility parameter (9 to 16.5) of the dye material. Since the dye material and the UV-curable resin before curing have a common part in their mutual dissolution region (soluble region), the dye material is soluble in the UV-curing resin before curing.

Therefore, as shown in FIG. 2, the dye material on the outer peripheral portion 20A of the optical information recording medium 20 is thoroughly washed off by the top coat material flowing on the upper surface during the spin coating process, and the outer peripheral portion 5C of the protective layer 5 is formed. Is substrate 2
And a fifth layer boundary 21, the outer peripheral edge portion 3A of the light absorption layer 3 is covered with the outer peripheral portion 5C of the protective layer 5, and a part of the outer peripheral edge portion 3A is melted to form a solid state. Could be realized.

A heat seal film having a width of 1 cm was attached to this portion, and the adhesive strength was measured to be 25 fg /
It was mm ² .

Further, when the coloring material was added to the top coat material used at this time, the coloring material was easily dissolved.

Comparative Example 1 Tetra tert. A solution in which a butylphthalocyanine Cr complex was dissolved in cyclohexane at 30 g / liter was spin-coated and a film was formed to form a light absorption layer.

On this substrate, an Au layer and a top coat layer (SN-067 manufactured by San Nopco Co., Ltd.) were prepared as described above.
6) was formed.

FIG. 3 shows a dissolution region diagram of the dye material applied at this time and the ultraviolet curable resin before curing.

As shown in the figure, the solubility parameter (8.5 to 13.5) of the ultraviolet curable resin is not within the range of the solubility parameter (7 to 9.5) of the dye material, and
The dye material and the UV curable resin before curing do not have a common part in the dissolution region.

The dye material on the outer peripheral portion of the optical information recording medium thus constructed remained almost unwashed (see FIG. 7).

A heat-seal film having a width of 1 cm was attached to this portion, and the adhesive strength was measured to be 3.3.
It was fg / mm ² .

Furthermore, when the dye material used at this time was added to the top coat material, it did not dissolve at all.

[0052]

As described above, according to the present invention, the dye material forming the light absorbing layer is made soluble in the top coat material forming the protective layer. Therefore, the dye material in the outer peripheral portion of the optical information recording medium is used. This eliminates the need for the wiping work and makes the outer peripheral part transparent and clean, which can enhance the commercial value and further improve the adhesive strength of the outer peripheral part.

[0053]

[Brief description of drawings]

FIG. 1 is a dissolution region diagram of a dye material applied and an ultraviolet curable resin before curing in an optical information recording medium 20 according to an example of the present invention.

FIG. 2 is a sectional view of relevant parts in an outer peripheral portion 20A of the optical information recording medium 20 of the same.

FIG. 3 is a dissolution region diagram of a dye material applied and an ultraviolet curable resin before curing in a comparative example.

FIG. 4 is a partially cutaway perspective view of a conventional general optical information recording medium 1.

FIG. 5 is a longitudinal sectional view of the main part of the optical information recording medium 1.

FIG. 6 shows a process of manufacturing a conventional optical information recording medium 1.
Outer peripheral portion 1 showing the step of spin-coating the last protective layer 5.
It is a principal part sectional view of A.

FIG. 7 is a sectional view of relevant parts of the outer peripheral portion 1A with the protective layer 5 formed thereon.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Optical information recording medium 1A Peripheral part of optical information recording medium 1 2 Translucent substrate 3 Light absorbing layer (recording layer) 3A Outer peripheral part of light absorbing layer 4 Light reflecting layer 5 Protective layer 5A Top of protective layer 5 Coating material (ultraviolet curable resin) 5B Outer peripheral portion of protective layer 5 5C Outer peripheral portion of protective layer 5 Pre-groove 7 Land 8 First layer boundary (between substrate 2 and light absorbing layer 3) 9 Second layer Interface (between light absorbing layer 3 and light reflecting layer 4) 10 Third layer boundary (between light reflecting layer 4 and protective layer 5) 11 Pit 12 Fourth layer boundary (outer peripheral portion 5B of protective layer 5) And light absorption layer 3
20 optical information recording medium 20A outer peripheral part of optical information recording medium 20 fifth layer boundary (between substrate 2 and outer peripheral part 5C of protective layer 5) L recording laser light (recording light)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Mutsumi Arai Mutsumi Arai 6-16-20 Ueno Taito-ku, Tokyo Taiyo Denki Inc.

Claims (3)

[Claims] 1. A light-transmitting substrate, a light-absorbing layer formed on the substrate and made of a dye material, a light-reflecting layer formed on the light-absorbing layer, and formed on the light-reflecting layer. And an optical information recording medium having a protective layer composed of a top coat material, wherein the dye material of the light absorbing layer is soluble in the top coat material before curing of the protective layer. An optical information recording medium characterized by: 2. A transparent substrate, a light absorbing layer formed on the substrate and made of a dye material, a light reflecting layer formed on the light absorbing layer, and a light reflecting layer formed on the light reflecting layer. And an optical information recording medium having a protective layer composed of a top coat material, wherein the solubility parameter of the top coat material of the protective layer is within the range of the solubility parameter of the dye material of the light absorbing layer. An optical information recording medium characterized in that 3. A light-transmitting substrate, a light-absorbing layer formed on the substrate and made of a dye material, a light-reflecting layer formed on the light-absorbing layer, and formed on the light-reflecting layer. And an optical information recording medium having a protective layer composed of a top coat material, wherein the dissolution region represented by the relationship of solubility parameter to hydrogen bonding force of the top coat material of the protective layer is the optical absorption An optical information recording medium, wherein the dye material of the layer has a common part with a dissolution region expressed by a relationship of a solubility parameter with respect to a hydrogen bonding force.