JPH04332933A - Optical information recording medium and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an optical information recording medium where adhesion strength and shelf life are improved and productivity is improved and then its manufacturing method. CONSTITUTION:After forming a coloring matter film 2 by a spinner, a coloring matter film dissolution liquid is discharged from a lower portion of a rotary disk, a nozzle 4 is pulled upward from a recording layer surface while the dissolution liquid is being discharged, the nozzle 4 is moved to a target position and then the dissolution liquid is discharged to the coloring matter film outside a recording area, and then the nozzle 4 is moved away from and downward from the disk while the dissolution liquid is being discharged, thus enabling discharge to be stopped.

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 a method for manufacturing the same, and more particularly to an optical information recording medium with improved adhesive strength and storage stability and a method for manufacturing the same.

0002

2. Description of the Related Art It is a well-known technique to provide a recording layer in an organic dye-based optical disk by spinner coating. Usually, the recording media obtained in this way are bonded together to form an air sandwich structure, but a photocurable adhesive is used as the adhesive because of its high productivity.

Problems at this time include 1) a decrease in adhesive strength due to the pigment film applied to the adhesive area, and 2) deterioration of the recording material during storage due to uncured monomers associated with a decrease in the degree of adhesive curing. . These improvements include (A) improvements in adhesives with high dye solubility, and (B) methods for wiping off dyes adhering to adhesive areas (JP-A-63-47194 and JP-A-6
3-234429) and (C) a method of washing away the dye adhering to the adhesive part with a solvent (Japanese Patent Laid-Open No. 63-234428).

0004

[Problems to be Solved by the Invention] However, each of the above-mentioned methods has the following problems, and a solution has been desired. It is difficult for (A) to achieve both adhesive strength and storage stability. Further, in the wiping method (B), there are problems with the absorbency of the wiping material, problems with replacing the wiping material, and the boundary between recording film removal is significantly blurred. For (C), a dye recording film dissolving agent is also used, so there are problems such as splashing of the dissolving material on the disk substrate, a pool of solvent at the tip of the solvent outflow pipe (nozzle), and pressure fluctuations at the start of solvent injection. Due to this, the solvent scatters at the tip of the nozzle at the end of solvent injection, which dissolves the recording film in the recording area.

The present invention is intended to solve the above-mentioned problems, and its first purpose is to provide an optical information recording medium with improved adhesive strength and storage stability.

A second object of the present invention is to manufacture an optical information recording medium in which an unnecessary recording layer existing on the adhesive surface of the disk outside the recording area can be easily removed without damaging the recording layer inside the recording area. The purpose is to provide a method.

[0007]

[Means for Solving the Problems] The above objects of the present invention are achieved by the following means. That is, the first optical information recording medium of the present invention is a disk-shaped optical information recording medium containing an organic dye as a main component, in which the dye film outside the recording area at the outer peripheral edge of the optical information recording medium is removed. It is characterized by

A second method for manufacturing an optical information recording medium of the present invention is a method for manufacturing an optical information recording medium having a recording layer containing an organic dye as a main component, in which the dye layer is formed by a spinner and then during rotation. The first step is to discharge the dye film solution from below the disk, the second step is to lift the nozzle slightly above the recording layer surface while discharging the solution, and the second step is to move the nozzle to the target position and remove the dye film outside the recording area. The method is characterized by comprising a third step of discharging the dissolving solution, and a fourth step of moving the nozzle far away from and below the disk while discharging the dissolving solution, and then stopping the discharging.

The optical information recording medium of the present invention and its manufacturing method will be explained in detail below. The substrate used in the optical information recording medium of the present invention must be transparent to the laser beam used only when recording and reproducing is performed from the substrate side.
If it is done from the recording layer side, it does not need to be transparent. As the substrate material, for example, plastics such as polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, polyimide, glass, ceramic, or metal can be used.

[0010] Note that guide grooves and pits for tracking, as well as preformats for address signals, etc., may be formed on the surface of the substrate.

The organic dyes used as the main components of the recording layer are those that cause some kind of optical change when irradiated with laser light and record information based on the change, and include polymethine dyes, naphthalocyanine dyes, phthalocyanine dyes, squarylium dyes, Examples include croconium-based, pyrylium-based, naphthoquinone-based, anthraquinone-based, xanthene-based, and triphenylmethane-based metal complex compounds, and the above dyes may be used alone or in combination of two or more types.

[0012] Furthermore, spiropyran or fulkydo-based photochromic materials may be used.

[0013] The optical information recording medium using the organic dye in the recording layer may be of any type such as phase change, bubble, or perforation type. The recording layer thickness is 100 Å to 10 μm,
Preferably it is 200 Å to 2 μm.

FIGS. 1 to 3 are explanatory diagrams of the optical information recording medium of the present invention and its manufacturing method. A disk coated with an organic dye film 2 on the entire surface of a substrate 1 is rotated by a turntable 3, and then a dye film dissolving agent is continuously sprayed from a nozzle 4 having a discharge and stop function at a distance from the disk and below the disk surface. . After slowly moving the nozzle 4 to the target position (the nozzle moves in the direction of the arrows indicated by ■ to ■ in Figure 1) and removing the outer peripheral edge of the pigment film 2, the dissolving agent is applied to the far side of the disk and below the disk surface. move without stopping (Figure 1).

At this time, the angle θ of the nozzle 4 with respect to the disk surface at the target position shown in FIG. If factors such as the injection method (injection pressure) are not selected appropriately, the solvent may splash on the disk surface or splash from the nozzle, and the splash may melt the recording layer in the recording area, resulting in large defects. You may end up creating a .

For example, in terms of the injection method, if the solvent injection nozzle is fixed as in the past, the solvent that accumulates at the tip of the nozzle at the start and end of the solvent injection may be removed. Because the flow rate (pressure) at the start of injection is unstable, the solvent may scatter in all directions at the nozzle end, reaching into the recording area and causing defects (even if suckback is applied, (Because the nozzle vibrates due to the strong suction force, there is a high possibility that the dissolving agent will scatter.)

In the present invention, as described above, the dissolving agent injection starts and ends far from the disk and below the disk surface, and the dissolving agent injection with a very stable flow rate (pressure) can be obtained near the disk. Destruction of the recording layer due to splashes from the nozzle tip can be prevented. At this time, when the dissolving agent is applied to the end surface of the disk due to movement of the nozzle, scattering of the dissolving agent occurs, but this can be repelled to the outside of the disk by centrifugal force by selecting the angle of the nozzle.

The angle of this nozzle is preferably inclined in the direction in which the dissolving agent is injected toward the outer circumference of the disk, as shown in FIG. , 0°<θ<180°, more preferably θ=3
The most stable results can be obtained between 0 and 60 degrees.

The nozzle diameter φ and the distance w between the nozzle and the disk surface are not very important factors as long as the dissolving agent spray pattern (FIG. 1) is implemented, but the nozzle height w is preferably w=2. 3 mm, and the nozzle diameter is related to the amount and type of solvent sprayed, but considering the finish of the recording layer removal boundary (the boundary between the area with and without the recording film), φ<0.
3mm is appropriate. The number of revolutions of the disk varies slightly depending on the injection pressure of the solvent and the type of solvent, but in general it is 1.
A speed of 500 to 2000 rpm is preferable because the finish at the boundary of the recording layer removal is fine.

It is desirable to set the ejection pressure to the lowest pressure that will dissolve the recording layer on the rotating disk (select a solvent that will dissolve the recording layer without applying too much pressure). By the way, when an organic dye is actually applied to the entire surface of a disk substrate using a spinner, the dye ends up going around to the back side of the disk substrate (the surface without a recording area) due to the slow rotation of the spinner when dye application starts.

[0021] Therefore, when two disks are bonded together to form an air sandwich structure, the dye is attached to both surfaces and the end face of the outer periphery, and the appearance is unappealing. Therefore, it is desirable to remove the adhered dye on the back surface and the outer edge of the disk at the same time as removing the unnecessary recording layer outside the outer edge recording area, or separately.

For the above purpose, as shown in FIG. 3, it is preferable to provide a nozzle 4' for cleaning the dye deposited on the back side in addition to the nozzle 4 for removing unnecessary recording layers at the spacer bonding area at the outer peripheral edge of the disk. Unlike the nozzle 4, this nozzle 4' may be a fixed type, and factors such as nozzle diameter and injection amount may be selected appropriately (if it is made movable, splattering will occur, so it must be a fixed type). Further, since the dye attached to the outer peripheral edge of the disk is removed by the solvent jet from the nozzles 4 and 4', unnecessary recording layers on both sides of the disk can be easily removed using the apparatus shown in FIG.

In the present invention, dye coating, outer peripheral edge removal, and back surface removal may all be performed by one spinner, or each may be performed by independent spinners.

The optical information recording medium of the present invention may be provided with the following subbing layer and protective layer, if necessary.

[0025] The undercoat layer has the following functions: (a) improving adhesion; (b)
) barrier against water or gas, (c) improvement of storage stability of the recording layer and (d) improvement of reflectance, (e) protection of the substrate from solvents, (f) protection of guide grooves, guide pits, and preformats. Used for purposes such as formation. For the purpose of (a), various polymer materials such as ionomer resins, polyamide resins, vinyl resins, natural resins, natural polymers, silicones, liquid rubbers, and silane coupling agents may be used. For the purposes of (b) and (c), inorganic compounds such as SlO2, MgF2, SiO, TiO2, ZnO can be used in addition to the above polymer materials.
, TiN, SiN, etc., metals or semi-metals such as Zn, C
U, S, Ni, Cr, Ge, Se, Au, Ag, Al, etc. can be used. Furthermore, for the purpose of (d), metals such as Al, Ag, etc., and organic thin films with metallic luster, such as methine dyes, xanthene dyes, etc., can be used; For the purpose of
Ultraviolet curing resin, thermosetting resin, thermoplastic resin, etc. can be used.

The protective layer (reading surface side hard coat layer) is (
a) Protecting the light reflecting/absorbing layer from scratches, dust, dirt, etc. (b) It is used for the purpose of improving the storage stability of the light reflection/absorption layer, (c) improving the reflectance, etc. For these purposes, the materials listed above for the undercoat layer can be used. In addition, SiO, SiO2, etc. can be used as inorganic materials, and polymethyl acrylate, polycarbonate, epoxy resin, polystyrene, polyester resin, vinyl resin, cellulose, fatty acid hydrocarbon resin, aromatic hydrocarbon resin can be used as organic materials. , natural rubber,
Heat-softening and heat-melting resins such as styrene-butadiene resin, chloroprene rubber, wax, alkyd resin, drying oil, and rosin can also be used.

Further, a reflective layer may be provided on or below the dye film if necessary, and the reflective layer is desirably made of a material with high reflectance and resistant to corrosion, and examples include glossy metals, preferably Al, Examples include Au, and the film thickness is 10
The film thickness is 0 Å to 50 μm, preferably 200 Å to 20 μm, and examples of the film forming method include vapor deposition sputtering.

The optical information recording medium obtained according to the present invention may have a tightly bonded structure in which the recording layer is placed inside and is bonded to the other substrate, or may have an air sandwich structure, or may have a single-plate structure.

[0029]

[Examples] The present invention will be explained below with reference to Examples. Example 1 A dye having the structural formula shown below [Chemical formula 1] was dissolved in 2,2,2-trifluoroethanol on a φ130 mm polycarbonate substrate with a guide tank, and the solution was spin-coated to a film thickness of 900 Å. Next, unnecessary dyes on the outer peripheral edge and back surface of the disk were removed by the method shown in FIGS. 1 and 3.

[0030]

[Chemical formula 1]

Comparative Example 1 A pigment film was formed in the same manner as in Example 1, and
cm, and from a location 2 mm above the disk surface, the dissolving solution was discharged and stopped to remove unnecessary dye from the outer peripheral edge.

Comparative Example 2 A dye film was formed in the same manner as in Example 1, the nozzle was fixed as shown in FIG. 2, and unnecessary dye was removed from the outer peripheral edge.

[0033] In both Examples and Comparative Examples, the unnecessary dye removing solution was 2-
Ethoxyethanol was used and the disk rotation speed at that time was 1800 rpm.

The Examples and Comparative Examples were carried out on 100 disks each, and Table 1 shows the results of the scattering of the solution in the recording area.

[0035]

[Table 1]

[0036]

Effects of the Invention The optical information recording medium and the method for manufacturing the same of the present invention provide the following effects. 1) When the disk has an air sandwich structure, since there is no unnecessary dye in the bonded portion of the outer spacer, the adhesive strength and storage stability are significantly improved, and an optical disk with excellent sealing reliability can be obtained. 2) Unwanted dye can be easily removed using a compact spinner, resulting in an optical disc with excellent productivity. 3) When the disk has a single-plate structure, there is no unnecessary pigment,
An optical disc with excellent appearance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a method for manufacturing an optical information recording medium of the present invention.

FIG. 2 is a partial explanatory diagram showing an example of the method for manufacturing an optical information recording medium of the present invention.

FIG. 3 is an explanatory diagram showing another example of the method for manufacturing an optical information recording medium of the present invention.

[Explanation of symbols]

1 Board 2 Pigment film 3 Turntable 4 Nozzle 4´　　Nozzle

Claims (4)

[Claims] 1. A disk-shaped optical information recording medium having a recording layer containing an organic dye as a main component, characterized in that the dye film outside the recording area at the outer peripheral edge of the optical information recording medium is removed. Information recording medium. 2. A method for manufacturing a disk-shaped optical information recording medium having a recording layer containing an organic dye as a main component, which comprises forming a dye film using a spinner and then discharging the dye film solution from below the rotating disk. The first step, the second step of pulling the nozzle slightly above the recording layer surface while discharging the solution, the third step of moving the nozzle to the target position and discharging the solution onto the dye film outside the recording area, and dissolving. A method for producing an optical information recording medium, comprising a fourth step of moving the nozzle to a distance and below the disk while discharging the liquid, and then stopping the discharge. 3. In the third step, the angle θ between the nozzle and the disk surface at the target position is 0°<θ<180°.
The method for manufacturing an optical information recording medium according to claim 2. 4. Claim 2, further comprising the step of discharging the dye solution onto a surface of the optical information recording medium opposite to the surface on which the dye film is coated.
A method of manufacturing the optical information recording medium described above.