JPH0335448A - Magneto-optical recording element - Google Patents

Abstract

PURPOSE:To enhance adhesion strength between a metal layer and a resin layer and to maintain excellent magneto-optical characteristics by forming an layer comprising of a metal oxide which constitutes the metal protective layer between the metal protective layer and the resin protective layer. CONSTITUTION:On a plastic substrate 6, there are successively formed dielectric layer 7 comprising of silicon nitride, magneto-optical recording layer 8 comprising of rare earth-transition metal amorphous alloy, and metal layer 9. Further, a metal compd. layer 10 comprising of oxide and/or nitride of the metal which constitutes the metal layer 9, and a resin layer 11 comprising of UV-curing resin are formed. Thereby, adhesion strength between the metal layer and the resin layer is enhanced, and the obtd. medium has excellent magneto-optical characteristics and has no decrease in C/N for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rewritable magneto-optical recording element having a magneto-optical recording layer made of, for example, an amorphous alloy of a rare earth metal and a transition metal.

[Prior art and its problems]

FIG. 3 shows the layer structure of a magneto-optical recording element that has already been proposed. A magneto-optical recording layer 3 is sequentially formed, and Ti, AI, Cr+ Ta, Nb+ y1 are further formed on the N3 as a protective layer.
A metal layer 4 made of g+ Cu, Si, or an alloy thereof, and an ultraviolet curable resin layer 5 are sequentially formed.

However, according to the above layer structure, the resin layer 5 is formed directly on the metal layer 4, and therefore there is a problem that the adhesion between the two layers N4 and N5 is poor.

Due to such problems, the resin layer 5 tends to peel off, causing deterioration of the magneto-optical properties and significantly reducing the reliability of the element itself.

In order to solve this problem, it has been proposed to perform primer treatment on the surface of the metal layer 4 before applying the resin.

This primer treatment is to apply an undercoat to the surface of the metal layer 4 with something that connects the metal and resin, and the undercoat material includes, for example, a primer resin (polyester resin, etc.), a hardening agent, and a diluent. There is a mixture of 4 parts, which is applied onto the metal layer 4 using a spin cord and cured at 100°C for 1 hour.

However, when the above-mentioned primer treatment is performed, there are problems in that the manufacturing process becomes complicated and the time required for manufacturing becomes longer, thereby reducing manufacturing efficiency and increasing manufacturing costs.

Another problem is that the adhesion between the substrate 1 and the dielectric N2 decreases due to baking at a high temperature.

The present invention has been devised in view of the above, and its purpose is to increase the adhesion between a metal layer and a resin layer formed as a protective layer, thereby maintaining excellent magneto-optical properties, and An object of the present invention is to provide a magneto-optical recording element with improved manufacturing efficiency and manufacturing cost.

[Means for solving problems]

The magneto-optical recording element of the present invention comprises at least a magneto-optical recording layer, a metal protective layer and a resin protective layer laminated in sequence on a substrate, and a metal protective layer is provided between the metal protective layer and the resin protective layer. It is characterized by forming a layer of oxide and/or nitride of.

The present invention will be explained in detail below.

FIG. 1 shows the basic layer structure of the magneto-optical recording element of the present invention.
FIG. 2 shows the layer structure of the magneto-optical disk shown in the example.

In both figures, the bottom film is on the plastic substrate 6, but the second
In the figure, first a dielectric layer 7 made of silicon nitride is formed. A magneto-optical recording layer 8 made of an amorphous alloy of a rare earth metal and a transition metal, a metal layer 9, a metal compound layer 10 made of an oxide and/or nitride of the metal, and a resin made of an ultraviolet curable resin or the like. 15Ill are sequentially formed.

The present invention combines the metal compound layer 10 with a metal layer 9 and a resin layer 11.
It is characterized in that it is interposed between the layers 9 and 11 to enhance the adhesion between the two layers 9 and 11.

After forming the metal layer 9, such a metal compound layer 10 is
It can be formed by any of the following three methods (i), (ii), and (iii).

(i) After forming the metal layer 9 by sputtering, oxygen gas, nitrogen gas, nitrogen dioxide, air, etc. are introduced into the film forming chamber, and oxide is formed on the surface of N9 by reactive sputtering. and/or forming a nitride layer.

(i i) ... After forming the metal layer 9 by sputtering method, vacuum evaporation method, etc., oxygen gas, nitrogen gas, air, etc. are introduced into the film forming chamber, and these gases are irradiated with ultraviolet rays. An oxide and/or nitride layer is then formed on the surface of layer 9.

(iii) After forming the metal layer 9 by a sputtering method or the like, the metal oxide forming the layer 9 and the metal compound NIO obtained by these methods have a stoichiometry It is thought that it may be either an excess or a deficient substance that deviates from the composition.

There are various metals as constituent elements of the metal layer 9, but passivation-forming elements such as Ti+AI+Cr, Ta, and Nb are particularly desirable, and due to the corrosion resistance of these elements, the oxidation of the metal layer 9 is prevented from forming the nucleation layer. is prevented from reaching the deep depths of
As a result, the magneto-optical recording characteristics of the magneto-optical recording layer 9 are not impaired.

According to experiments repeatedly conducted by the present inventors, the thickness of both the metal layer 9 and the metal compound [10] is 300 to 150.
It is best to set it within the range of 0.If it is within this range, it will have a sufficient blocking effect against ions or molecules such as O", 0"-, HzO, Ox, etc. Peeling of the film due to stress will no longer occur.

Moreover, the layer thickness of the metal compound layer 10 is preferably set within the range of 10 to 200 layers, and within this range, excellent adhesion to the resin layer 11 can be obtained.

Moreover, if the thickness of the metal layer 9 is set as described above, even if a small amount of free oxygen or 'am nitrogen is generated, it will not invade the magneto-optical recording layer 9.

Thus, according to the magneto-optical recording element of the present invention, a metal oxide,
By forming a metal nitride or metal oxynitride layer, the adhesion between the two layers was increased, which resulted in excellent magneto-optical properties and no reduction in C/N over a long period of time. .

〔Example〕

Next, embodiments of the present invention will be described in detail.

(Example 1) A dielectric layer mainly composed of silicon nitride is formed to a thickness of 725 mm on a polycarbonate resin disk substrate (130 mmφ) using a magnetron sputtering device, and amorphous GdDyFeTi is formed on this layer. A perpendicular magnetization film made of the alloy was formed to a thickness of 600 mm, and a Ti metal layer was further formed to a thickness of 800 mm. Then, targeting titanium oxide, a titanium oxide layer with a thickness of 150 mm was laminated, and then an acrylic ester-based ultraviolet curable resin N (
Magneto-optical disk 8 was prepared by applying and forming a magneto-optical disc (trade name: SD-17) manufactured by Dainichi Plastics Co., Ltd. (trade name: SD-17) by a spin code method.

By the way, when a metal oxide layer, metal nitride layer, or metal oxynitride layer is formed as a protective layer, and then an ultraviolet curable resin is applied on the layer, it is better to apply the ultraviolet curable resin as soon as possible. The inventors have experimentally confirmed that this improves the adhesion of the resin layer.

Therefore, in this example, after applying the above-mentioned maintenance i1J'W, it took 10 to 20 hours to apply and form the resin.
The temperature was set within a range of 10 minutes, and the environmental atmosphere at that time was set to room temperature.

Next, in producing the above-mentioned magneto-optical disk A, a Ti metal layer was formed to a thickness of 1000 mm, and a titanium oxide layer was formed in the following manner instead of the sputtering method. That is, the disk was set in an ultraviolet irradiation device, and the surface of the Ti metal layer was irradiated with ultraviolet light (wavelength: 150 to 350n, illuminance: 4mW/cab) for 1 minute using a low-pressure mercury lamp in an oxygen atmosphere.
”) As a result, a titanium oxide layer with a thickness of about 10 to 30 μm could be formed on the surface of the core layer.

Further, in producing this magneto-optical disk, the formation of films other than the above-mentioned titanium oxide layer was the same as in magneto-optical disk A, thus producing a magneto-optical disk.

Next, in producing the above magneto-optical disc, a magneto-optical disc was produced under the same conditions except that ultraviolet irradiation was not performed, and this was designated as magneto-optical disc C.

The three types of magneto-optical disks produced in this way were placed in a high temperature environment (80°C, 85XRH), and their changes over time were checked by peeling off the resin layer, and the results shown in Figure 4 were obtained. Obtained.

The horizontal axis in the figure is time. The vertical axis represents the peeling rate.

This peeling rate was determined by a method in which 10 magneto-optical disks of various types were prepared, cellophane tape was pasted on the resin layer surface of each magneto-optical disk, and when the tape was peeled off, the peeling of the resin layer was confirmed by visual observation. In this case, the degree of delamination at four arbitrary locations on one disk is recognized as 111, and thus 4
It was determined based on the presence or absence of peeling at 0 locations.

When these 40 locations were not peeled off at all, the peeling rate was set as 0χ, and when all of them were peeled off, the peeling rate was set as 10 (H).

In FIG. 4, the *, ■, and ○ marks are the measurement fronts of the magneto-optical disks A, B, and C, respectively.

As is clear from the figure, magneto-optical disk A had a peeling rate of less than IO2 even after 750 hours, and was the least peeled. However, magneto-optical disk C showed a peeling rate of about 502 after 750 hours.

(Example 2) Next, in this example, a magneto-optical disk D-G was manufactured under the following conditions and subjected to the same high temperature and high humidity environment resistance test as in (Example 1), as shown in Figure 5. The results were obtained.

Dielectric material 1i (thickness: 950 mm), which is mainly made of silicon nitride, is placed on the disk substrate as in 1-piece '47LL (Example 1), GdDyFeT.
An i-perpendicular magnetization film (thickness: 300 mm), a dielectric layer (400 mm thick) mainly made of silicon nitride, and an AI metal layer (thickness: 400 mm) are sequentially laminated, and then oxygen gas (0 mm) is added to the deposition chamber.
! > was introduced, and the gas ratio with argon gas (Ar), which is the sputtering gas, was adjusted to approximately 30:1, and the back pressure was adjusted to approximately 5 mTorr.
, and form an aluminum oxide layer (about 10 to 30 people) by sputtering method, followed by (Example 1)
The same acrylic ester-based ultraviolet curable resin layer was applied and formed.

When forming an aluminum oxide layer in the production of a magneto-optical disk, the aluminum oxide layer was formed as follows instead of the sputtering method.
After shaping the A1 metal layer of 0 people by sputtering method, it was placed in the ultraviolet irradiation device used in (Example 1),
The surface of the AI metal layer was irradiated with ultraviolet rays for 5 minutes in an oxygen atmosphere (wavelength 150 to 350 nm, illumination intensity 4IIIW/c11).
2) As a result, an aluminum oxide layer with a thickness of about 10 to 30 mm could be formed on the surface of the core layer. Other than the formation of this aluminum oxide layer, it is the same as a magneto-optical disc.

A magneto-optical disk E with an optical property of 1 and 10 L was prepared under exactly the same conditions except that no ultraviolet irradiation was performed.

Magneto-Optical Disk G In producing the magneto-optical disk, nitrogen gas was introduced into the film forming chamber instead of oxygen gas, thereby forming an aluminum nitride layer, and the other laminated structures were kept exactly the same.

In FIG. 5, the Peng mark, circular mark, mark, and Δ mark are measurement plots of magneto-optical disks D, E, F, and G, respectively.

As is clear from the results shown in the figure, it can be seen that the magneto-optical disks D, E, and G of the present invention had excellent adhesion without deterioration over time.

According to experiments conducted by the inventors in addition to the above examples, titanium oxynitride, aluminum oxide, and aluminum oxynitride were used as targets in place of the titanium oxide target used in the production of magneto-optical disks. Even if used for
It was confirmed that the object of the present invention was achieved.

Furthermore, the object of the present invention could be achieved even when nitrogen dioxide gas or air was used as the gas introduced into the reaction chamber for the super soter when producing the magneto-optical disks D and G.

Furthermore, the present inventors replaced the Ti metal layer and the AI metal layer with C
r metal layer, Ta metal layer, Nb metal layer, Mo metal layer, Cr
Similar to this example, a metal layer, a Cu metal layer, and a Si metal layer are formed, and the oxide layer and nitride layer thereof are formed in the same way as in this example, and various magneto-optical disks are manufactured using this. It was experimentally confirmed that this effect was obtained.

〔Effect of the invention〕

As described above, according to the present invention, the adhesion between the metal layer and the resin layer formed as a protective layer is increased, and thereby,
The excellent initial magneto-optical properties could be maintained, and as a result, a magneto-optical recording element of high quality and long-term reliability could be provided.

Furthermore, in the magneto-optical recording element of the present invention, the above effects can be obtained without performing the above-mentioned brimer treatment, which simplifies the manufacturing process and shortens the required manufacturing time, resulting in increased manufacturing efficiency. has increased, and manufacturing costs have decreased.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing the layer structure of the magneto-optical recording element of the present invention, and FIG. 3 is a cross-sectional view showing the conventional layer structure,
FIGS. 4 and 5 are diagrams showing the results of peeling experiments. 1.6...Plastic substrate 2.7...Dielectric layer 3.8...Magneto-optical recording layer 4.9...Metal layer 10...Metal compound layer 5.11...Resin layer

Claims (3)

[Claims] (1) In a magneto-optical recording element in which at least a magneto-optical recording layer, a metal protective layer and a resin protective layer are sequentially laminated on a substrate,
A magneto-optical recording element, characterized in that a metal oxide layer constituting the metal protective layer is formed between the metal protective layer and the resin protective layer. (2) The magneto-optical recording element according to claim 1, wherein a nitride layer of the metal is formed in place of the oxide layer. (3) The magneto-optical recording element according to claim (1), wherein an oxynitride layer of the metal is formed in place of the oxide layer.