JPH0230586A - Manufacture of information recording medium - Google Patents

Abstract

PURPOSE:To improve a signal characteristic by making the film thickness of a recording pigment layer uniform by a method wherein a preformat pattern is formed on the recording pigment layer formed on a substrate. CONSTITUTION:A pretreated device A in which a porous material 3 impregnated with a solvent 5 is provided between a heating plate 4 to which clearances are established meeting a form of a preformat pattern and a support plate 6 is stuck fast to a substrate 2, and solvent vapor 5a is generated from the porous material by heating with the heating plate. In that case, solvent treatment with the vapour is performed for this part of a substrate surface and simultaneously, heating treatment with the heating plate 4 is performed for the other part thereof conforming to the form of the preformed pattern owing to close adhesion. Then, a recording pigment layer 1 is formed by applying a solvent solution of an organic pigment on said substrate 2, and the preformat pattern is formed on the recording pigment layer by changing the quality of the recording pigment layer brought into contact with a solvent treatment part 2a on the substrate surface. Thereby, reflection factor is decreased in the changed quality part of the recording pigment layer by solvent treatment, the reflection factor being increased in the recording part by heating treatment, and a signal characteristic of the title information recording medium is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing an information recording medium, and particularly to a method for manufacturing an information recording medium in which a preformat pattern is formed on the recording dye layer itself.

[Prior Art] Conventionally, as a method for forming a preformat pattern on a substrate for an information recording medium, when the substrate is made of thermoplastic resin, injection molding at a temperature higher than the melting point, hot press molding, etc. A method in which a stamper mold is thermally transferred by a method, or a method in which a photocurable resin composition is applied onto a substrate, a stamper mold is brought into close contact with the substrate, and the photocurable resin composition is cured by irradiating ultraviolet rays or the like. A method of optically transferring a stamper mold is known.

FIG. 3 is a schematic cross-sectional view showing a conventional information recording medium. In the figure, a conventional information recording medium has a recording layer 1 on a resin base material 12 provided with a track portion 13 having an uneven shape.
1, and a base material 1 which also serves as a protective layer on the recording layer 11.
5 are bonded together via an adhesive layer 14.

[Problems to be Solved by the Invention] As described above, conventional information recording media have a structure in which a recording layer is formed on a resin substrate having a track portion having an uneven shape. In the case of manufacturing, first, an uneven shape must be formed on the resin base layer.

In this case, problems such as the transfer yield of the stamper mold, the transfer time, the durability and cost of the stamper mold become problems that make mass production difficult and increase the price.

Furthermore, since the recording sensitivity of the recording layer depends on the film thickness, uniform film formation is required, but since the recording layer is formed on the uneven shape of the track part, it is possible to obtain uniform film thickness. is difficult.

The present invention has been made in order to improve the drawbacks of the prior art, and by forming a preformat pattern on a recording dye layer made of an organic dye-based medium formed on a substrate, the recording dye layer can be improved. An object of the present invention is to provide a method for manufacturing an information recording medium having a uniform film thickness and improved signal characteristics.

[Means for Solving the Problems] That is, the present invention applies solvent treatment to the preformat portion of the preformat pattern and heat treatment to the portions other than the preformat pattern on the surface of the substrate in accordance with the shape of the preformat pattern. At the same time, a recording dye layer is formed on the substrate, and a preformat pattern is formed on the recording dye layer by altering the quality of the recording dye layer in contact with the solvent-treated portion of the substrate surface. This is a method for manufacturing an information recording medium.

The present invention will be explained in detail below.

In the method for manufacturing an information recording medium of the present invention, the surface of the substrate is pretreated in accordance with the shape of the preformat pattern, or
The pretreatment involves simultaneously applying solvent treatment to the preformat portion of the preformat pattern and heat treatment to the portions of the preformat pattern other than the preformat, and then forming a recording dye layer made of an organic dye-based medium on the substrate. However, a preformat pattern is formed on the recording dye layer by altering the quality of the recording dye layer that is in contact with the solvent-treated portion of the substrate surface.

Next, the present invention will be explained based on the drawings.

FIGS. 1(a) and 1(b) are process diagrams showing an example of the method for manufacturing the information recording medium of the present invention. First, in FIG. 1(a), a solvent 5 is placed between the heat plate 4 and the support plate 6, which have a gap formed in accordance with the shape of the desired preformat pattern.
When the pretreatment device A, which is provided with a porous body 3 impregnated with Since the heat plate 4 of the pretreatment device A is in close contact with the
The surface of the substrate 2 is simultaneously subjected to a solvent treatment using a solvent vapor 5a on the preformat portion of the pattern, or a heat treatment using a heat plate 4 on the portion of the pattern other than the preformat, in accordance with the shape of the preformat pattern.

Next, as shown in FIG. 1(b), a recording dye layer l is formed by applying a solution of an organic dye dissolved in a solvent onto the substrate 2 which has been simultaneously subjected to solvent treatment and heat treatment as described above. form.

In FIG. 1(b), 2a indicates a solvent-treated portion where the surface of the substrate 2 has been subjected to solvent treatment, and 2b indicates a heat-treated portion where heat treatment has been performed. Further, la indicates an altered portion, and the organic dye in the portion of the recording dye layer l that is in contact with the solvent-treated portion 2a reacts with the solvent-treated substrate surface to form an altered portion. For example, when an acrylic resin substrate is treated with ethanol vapor, low-molecular-weight acrylic resin is generated on the surface of the substrate, which reacts with the organic dye to change the quality and reduce the reflectance. This makes it possible to read preliminary information such as the AT servo and recording start position by preformatting the portion with low reflectance.

In addition, 1b indicates a recording part, which consists of a recording dye layer 1 formed on a heat-treated part 2b where the substrate is heat-treated.For example, in the case of an acrylic resin substrate, when heat-treated, the recording material on the The signal characteristics of the dye layer can be improved.

FIG. 2(a) is an explanatory view showing an information recording medium subjected to solvent treatment and heat treatment by the above method, and FIG. 2(b) is a partially enlarged view thereof. Reference numeral 7 indicates a substrate processing portion where the substrate has been subjected to solvent treatment, and by forming the recording dye layer 1 on the substrate 2 after the solvent treatment and heat treatment, guide tracks la' and recording tracks are formed in the substrate treatment portion 7. 1' is formed.

In the present invention, the preformat patterning of the recording dye layer itself includes, for example, reducing the reflectance of an organic dye-based medium by solvent treatment when using an acrylic resin substrate;
and the effect of heat treatment on the reflectance of organic dye-based media.”
can be used.

In the present invention, the substrate 2 is made of a material that can be treated with a solvent, such as a plastic plate made of polycarbonate resin, epoxy resin, polymethylpentene resin, acrylic resin, styrene-epoxy copolymer, etc. can be used. Preferably, the substrate is an optically transparent material.

As a solvent, ethanol, isopropyl alcohol (
It is possible to use a general alcohol solvent such as IPA) or methanol.

In addition, heat treatment is usually carried out at 60 to 100°C, preferably at 7°C.
It is preferable to carry out the heating in the range of 5 to 85°C.

Examples of organic dyes forming the recording dye layer 1 include cyanine dyes, polymethine dyes, phthalocyanine dyes, merocyanine dyes, azulene dyes, and squalium dyes, among which the following structural formulas are used: Cyanine dyes shown in (I), and structural formulas (II) and (]II)
The polymethine dyes shown in the following are preferred as they have practicality. In addition, polymethine dyes are excellent in terms of productivity and cost as they are soluble in solvents that are suitable for printing.

Structural formula (I) C2H51eC:2 H5 Structural formula (II) COO4° Structural formula (III) CI! The thickness of the O4° recording dye layer is usually 500 to 2,000, preferably 800 to 1,200.

As described above, the present invention applies solvent treatment and heat treatment to the surface of a substrate in accordance with the shape of a preformat pattern, and then forms a recording dye layer on the substrate and forms a preformat pattern on the recording dye layer. An information recording medium can be easily manufactured by forming a recording dye layer and then adhering a base material that also serves as a protective layer on the recording dye layer via an adhesive layer.

Examples of the adhesive layer include hot-melt type ethylene-vinyl acetate copolymers and modified resins thereof, ethylene ethyl acrylate copolymers, acetic acid and nyl-acrylate copolymers, polyimide resins, epoxy resins, and the like.

The base material can be made of any material such as glass, plastic, metal, etc., but preferably it is made of the same material as the substrate.

[Function] The method for manufacturing an information recording medium of the present invention includes applying solvent treatment to the preformat portion of the preformat pattern on the surface of the substrate in accordance with the shape of the preformat pattern.
A recording dye layer is formed on the substrate after heat treatment is simultaneously applied to areas other than the preformat, and the recording dye is By forming a preformat pattern on the layer, the recording dye layer on which the preformat pattern is formed has a uniform thickness without any unevenness, and the altered portions of the recording dye layer that have been subjected to solvent treatment on the substrate are The reflectance decreases and is reversed in the recording portion of the recording dye layer that has been subjected to heat treatment, thereby improving the signal characteristics of the information recording medium.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 After cleaning and drying an O84 thick casting acrylic resin substrate to remove the mold release agent, etc., the substrate was closely attached to a pretreatment device comprising a porous ceramic body impregnated with ethanol, and heated. The plate was heated at 130° C. for 5 seconds to perform heating and ethanol vapor treatment to form a preformat pattern with 9 recording tracks at the end and 3 guide tracks at 1 end.

Next, a diacetone alcohol solution containing 3 wt % of the polymethine dye represented by the structural formula (II) was applied onto the substrate, and after drying, a recording dye layer of 1000±500 layers was formed.

Next, this was bonded to an acrylic resin base material having a thickness of 0.3 μl using a hot-melt type adhesive made of ethylene-vinyl acetate copolymer to produce an information recording medium.

The obtained information recording medium had a contrast of 0.4 to 0.5 in the track-crossing signal and a reflectance of 13 to 14% in the recording track portion with respect to a laser beam having a spot diameter of 3 ILmφ and a wavelength of 833 nm.

[Effects of the Invention] As explained above, according to the present invention, the surface of the substrate is adjusted to the shape of the preformat pattern without forming irregularities for forming the preformat pattern on the surface of the substrate, and the solvent is removed. By applying treatment and heat treatment at the same time,
By altering the quality of the recording dye layer, a preformat pattern is formed in the recording dye layer, and the reflectance decreases in the altered area of the recording dye layer where the substrate is subjected to solvent treatment, and the recording area subjected to heat treatment. In this case, the reflectance is improved and the signal characteristics of the information recording medium can be improved.

[Brief explanation of the drawing]

1(a) and 1(b) are process diagrams showing an example of the method for manufacturing an information recording medium of the present invention, FIG. 2(a) is an explanatory diagram showing an information recording medium subjected to solvent treatment and heat treatment, and FIG. FIG. 2(b) is a partially enlarged view, and FIG. 3 is a schematic cross-sectional view showing a conventional information recording medium. 1... Recording dye layer 1a... Altered part 1'...
・Recording track 1b...Recording section 2a...Solvent treatment section 3...Porous body 5...Solvent 6...Support plate A...Pretreatment device la...Guy 2... Substrate 2b...Heat processing section 4...Heat plate 5a...Solvent vapor 7...Substrate processing portion Todrak

Claims (1)

[Claims] After simultaneously applying solvent treatment to the preformat portion of the preformat pattern and heat treatment to the non-preformat portions according to the shape of the preformat pattern on the surface of the substrate, a recording dye layer is formed on the substrate. A method for manufacturing an information recording medium, comprising forming a preformat pattern on the recording dye layer by altering the quality of the recording dye layer that is in contact with the solvent-treated portion of the substrate surface.