JPS62128037A - Optical recording medium - Google Patents

Abstract

PURPOSE:To obtain a high-reliability optical recording medium which has less defects and is superior in durability and moisture resistance by providing the plasma polymerized film of hexamethyl disilazane between a resin layer, where tracking grooves are formed, and a plane base material which constitutes a substrate. CONSTITUTION:The plasma polymerized film 12 (5-50nm) of hexamethyl disilazane is provided on a washed glass plane base material 11 on the conditions of 0.1-5Torr degree of vacuum and 10-50W polymerization power in a plasma polymerizing device. After this base material is pressed to a photopolymer 13 applied on a stamper, ultraviolet rays are irradiated from the side of the glass plane base material 11 to cure the photopolymer 13, and this base material is peeled off the stamper to produce the substrate where tracking grooves are formed. An SiO film 14 (50-200nm), a ferrimagnetic film 15 (100nm) consisting of a rare earth element-transition element metal, and the SiO film 14 (50-200nm) are formed successively on the substrate by the vapor-deposition or sputtering method. Two substrates of the same structure obtained in this manner are adhered to each other by an adhesive 16 so that SiO films 14 are on the inside.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical recording medium for recording and reproducing information using light such as a laser beam.

2. Description of the Related Art In recent years, with the rapid increase in the amount of information processed in information processing systems, recording media with large recording capacities, particularly optical recording media, have been attracting attention, particularly in the fields of data processing systems and office automation. In optical recording media, recording is performed by irradiating a light beam onto the medium to induce a local temperature rise or chemical change due to light absorption. Reproduction is performed by irradiating a light beam with a different intensity or wavelength from that during recording and detecting the reflected or transmitted light to detect local changes on the medium induced by recording. Optical recording media have optical uniformity. , moisture resistance, heat resistance, etc., and these requirements are particularly severe in relation to reliability in data processing systems. For this reason, conventional optical recording media often use glass as a substrate, and are configured, for example, as shown in FIG. 3.

That is, a silane coupling agent 32 is applied as a primer to a glass flat substrate 31 to improve adhesion, and after drying, tracking grooves are formed thereon using a photopolymer 33. An underlayer 34 is formed to prevent heat damage to the substrate or improve recording characteristics, and a tellurium alloy film, thermoplastic resin, rare earth-transition metal ferrimagnetic film, etc. is provided as a recording film 35 on this underlayer.
(In some cases, a protective layer is also formed.) Furthermore, two sheets of the same structure made in this way are pasted together with an adhesive 36 with the recording film inside.

Recording and reproduction are performed by irradiating a recording film with a light beam such as a laser beam from the glass side of the moving optical recording medium.

Problems to be Solved by the Invention However, in the optical recording medium configured as described above, the wetting state of the applied silane coupling agent is greatly influenced by the surface condition of the glass, and it is difficult to apply it uniformly. Ta. Therefore, there have been problems in that the substrate is likely to be defective, the error rate during playback is high, and the adhesive strength between the glass and the photopolymer is likely to vary, resulting in a lack of long-term reliability.

Moreover, many silane coupling agents are water-soluble and acidic or alkaline, which has the problem of poor moisture resistance and the possibility of causing corrosion of the recording film.

In view of the above problems, the present invention has low defectivity and durability.

The present invention provides a highly reliable optical recording medium that has excellent moisture resistance and is free from corrosion of the recording film.

Means for Solving the Problems In order to achieve this object, the optical recording medium of the present invention has a substrate comprising a resin layer on which tracking grooves are formed and a flat base material supporting the resin layer. It has a structure in which a plasma polymerized film of hexamethyldisilazane is provided between flat base materials.

Function The plasma-polymerized film of hexamethyldisilazane is a uniform film with no pinholes, excellent moisture resistance, and good adhesion to glass. Therefore, by forming a plasma-polymerized film of hexamethyldisilazane on a flat glass substrate and forming tracking grooves using a photopolymer on top of the plasma-polymerized film, high reliability of the optical recording medium can be achieved over a long period of time. It is something to do.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. In FIG. 1, 11 is a glass flat plate base material, 12
13 is a plasma polymerized film prepared using hexamethyldisilazane as a monomer, 13 is an epoxy photopolymer with tracking grooves formed, 14 is a SiO film as a base layer and a protective layer, 16 is TbFe as a recording film,
GdTbFe, TbFeC.

16 is an adhesive.

Next, a method for manufacturing the optical recording medium of this example will be briefly described. First, a plasma polymerized film 12 (6 to 60 nm) of hexamethyldisilazane was provided on a cleaned glass flat substrate 11 in a plasma polymerization apparatus under the conditions of a vacuum degree of 0.1 to 5 Torr and a polymerization power of 10 to 50 W, and a stamper. −
After pressing against the photopolymer 13 coated on top, the photopolymer 13 is cured by irradiating ultraviolet rays from the glass flat substrate 11 side, and is peeled off from the stamper to produce a substrate on which tracking grooves are formed. A 5SiO film 14 (50 to 20
0 nm), rare earth-transition metal ferrimagnetic film 15 (
100 nm), SiO film 14 (50 to 200 nm)
), and then two sheets of the same structure thus formed are bonded together with an adhesive 16 with the SiO film 14 inside.

As a result of comparing the optical recording medium according to the present invention shown in FIG. 1 with the conventional optical recording medium shown in FIG. The error rate during playback has been halved. In addition, as a result of a durability test in an environment of 80° Cao% RH, optical recording media with conventional configurations were found to be defective due to local peeling between the glass flat substrate and the photopolymer within 1000 hours. However, in the optical recording medium according to the present invention in which a plasma polymerized film of hexamethyldisilazane is provided between a glass flat substrate and a photopolymer,
Even after the passage of time, no defects occurred.

As described above, according to this embodiment, an optical recording medium with few defects, excellent durability, and moisture resistance can be realized.

In this example, the photopolymer was epoxy-based, the underlayer and protective layer were Siq, and the recording film was a rare earth-transition metal ferrimagnetic film, but the photopolymer was acrylic-based, and the underlayer and protective layer were other transparent oxide films. or transparent nitride film,
The recording film may be a tellurium alloy film or a thermoplastic resin film.

Furthermore, by utilizing the excellent uniformity and moisture resistance of the plasma polymerized film of hexamethyldisilazane, it is possible to form a plasma polymerized film 22 on the protective layer as shown in FIG. A recording medium is obtained.

In FIG. 2, the same parts as in FIG. 1 are given the same numbers.

Effects of the Invention The present invention provides a plasma-polymerized film of hexamethyldisilazane between the resin layer on which tracking grooves are formed and the flat base material, which constitutes the substrate, thereby achieving less defects, durability, and moisture resistance. This makes it possible to realize a highly reliable optical recording medium with excellent performance.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an optical recording medium in one embodiment of the present invention, FIG. 2 is a block diagram of an optical recording medium in another embodiment of the present invention, and FIG. 3 is a block diagram of a conventional optical recording medium. be. 11...Glass flat plate base material, 12.22...
...Plasma polymerized film, 13...Photopolymer, 14...SiO film, 16...Rare earth-transition metal ferrimagnetic film, 16...Adhesion agent.

Claims (2)

[Claims] (1) A plasma-polymerized film of hexamethyldisilazane is provided between the resin layer and the flat substrate of a substrate consisting of a resin layer on which tracking grooves are formed and a flat substrate that supports the resin layer. Characteristic optical recording media. (2) The optical recording medium according to claim 1, wherein a photopolymer is used as the resin layer, and glass is used as the flat substrate.