JPS63217522A - Magnetic recording body - Google Patents

Abstract

PURPOSE:To improve magnetic recording performance and mechanical strength by providing Al-Si alloy alloy film having a specified compsn. on a substrate, providing anodized films on the surface of said films and packing a magnetic material into the fine pores of the anodized films. CONSTITUTION:The Al-Si alloy films 2 are provided on the substrate 1. The Al-Si alloy films 2 are formed of an aluminum alloy which consists of 10-1,000ppm Si and the balance Al and is formed in the form of a film on the substrate 1. Magnetic films 3 are integrally provided on the Al-Si alloy films 2. The films 3 are subjected to an anodic oxidation treatment using an electrolytic bath and the magnetic material such as iron, nickel, cobalt or the alloy thereof is electrolytically deposited and packed into the fine pores formed in the anodized films integrally formed on the surface of the films 2 at the time of the chemical conversion thereof. The recording medium is formed by polishing such surfaces. The magnetic recording performance and mechanical strength are thus improved.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a magnetic recording body particularly suitable for perpendicular magnetic recording, in which an anodic oxide film is provided on a substrate and a magnetic material is inserted into the fine pores of the anodic oxide film. By using an Al-Si alloy film as a substrate in a magnetic recording material filled with aluminum and made into a magnetic film, the mechanical strength and surface hardness of the magnetic film are increased, and the durability of the magnetic film is improved. It's Nishichino.

"Conventional technology" Conventionally, high-purity aluminum of 99°99% or higher is adhered to a film several micrometers thick on a hard substrate such as a glass plate using a thin film forming method such as vacuum evaporation or sputtering. This aluminum film is anodized to form an anodized film, and a magnetic material such as iron (Fe), nickel (Ni), cobalt (Co), or an alloy thereof is injected into the micropores of this anodic oxide film. A magnetic recording material formed by electrolytic deposition and filling is
It is known to be particularly suitable for perpendicular magnetic recording systems.

``Problems to be Solved by the Invention'' However, the magnetic recording medium in which a high-purity aluminum film is provided on a substrate as described above has the following problems.

■8 When high-purity aluminum is vapor-phase deposited on a substrate such as glass, the aluminum crystals deposited on the substrate tend to grow abnormally, so when anodizing this aluminum film, this oxidation treatment is If the anodic oxide film is not filled with magnetic material, defective portions are likely to occur in the fine pores of the produced anodic oxide film, which deteriorates the magnetic recording performance of the magnetic recording body.

(2) High-purity aluminum has poor adhesion to glass substrates or plastic substrates such as polyethylene terephthalate, so the aluminum film on the substrate and the anodic oxide film filled with magnetic material are likely to peel off due to impact or friction.

■Although the surface of the magnetic recording medium described above is composed of a hard anodic oxide film, the base is made of relatively soft high-purity aluminum, so the surface hardness is affected by the soft base. The surface of the magnetic recording medium is easily scratched when the magnetic recording medium is used.

The present invention aims to solve the above-mentioned problems, improve the mechanical strength of the aluminum film and anodized film on the substrate, and provide a magnetic recording medium with excellent magnetic recording performance. .

"Means for Solving the Problems" In this invention, an Al-Si alloy film is provided on a substrate, an anodized film is provided on this film, and a magnetic material is filled in the micropores of this anodized film. The above Al-Si alloy is Si 10-
The solution was to set the composition to 1,000 ppm with the remainder of AI.

FIG. 1 shows a first example of the magnetic recording body of the present invention, and reference numeral l in the figure represents a substrate. The substrate 1 is formed into a plate shape from a material such as hard glass, an inorganic nonmetallic hard material such as ceramics, or a synthetic resin material such as polyethylene terephthalate.

On this substrate 1, an Al-Si alloy film 2 is provided. This A I-S i alloy film contains Si of 10 to I,
Using an aluminum alloy containing 000 ppm and the remainder of AI as a material, a film is formed on the substrate 1 by a thin film forming method such as a vacuum evaporation method, a sputtering method, an ion blasting method, or a CVD method, or a thin film of the above alloy is formed on the substrate 1. Obtained by pressing on top.

The Si-containing insects in the above Al-Si alloy are IO ~ 1,0
00 ppm, but if the Si content is less than 10 ppm, the effect of making crystals finer and improving the hardness of the anodic oxide film cannot be obtained during vapor phase precipitation on the substrate.

Additionally, if the Si content exceeds 1,000 ppm, high-resistance Al-5i compounds (AlsSi, etc.) are generated in the anodic oxide film during anodizing, making it impossible to electrolytically deposit magnetic materials. It becomes possible.

This Al-Si alloy film becomes the base for the anodic oxide film provided on it, and also serves as a power supply member during anodizing treatment and magnetic substance deposition. The thickness is adjusted so that the thickness is about 0.1 to 2 μl. If this remaining thickness is less than 0.1 μm, the electrical resistance during power supply will increase, which is disadvantageous.
If it exceeds 2 μm, the apparent mechanical strength and surface hardness of the anodic oxide film decreases, which is disadvantageous. It is preferable to use aluminum (A1) and silicon (Si) highly purified by zone refining etc. as materials for this Al-Si alloy.

A magnetic film 3 is integrally provided on this Al--Si alloy film 2. This magnetic film 3 is formed integrally on the surface of the Al-Si alloy film 2 by anodizing the Al-Si alloy film 2 using an electrolytic bath such as an oxalic acid electrolytic bath or a sulfuric acid electrolytic bath. In the film, iron (Pe), nickel (Ni), cobalt (
It is made by electrolytically depositing and filling a magnetic material such as Go) or an alloy thereof, and then grinding the surface, and its thickness is 0.
The thickness is approximately 5 to 1.5 μm. The anodic oxidation treatment and magnetic substance deposition are carried out by connecting a power supply electrode to the inner or outer peripheral edge of the substrate 1 and supplying power through the Al--Si alloy film 2.

On this magnetic film 3, a protective film made of silica, graphite, etc., a lubricating film made of fluorocarbon lubricant, etc. can be provided as appropriate.

The above-mentioned magnetic recording body is made of Si 10-1,0 on a substrate such as glass, which serves as a base for an anodic oxide film and also serves as a power supply member during anodizing treatment and magnetic substance deposition.
By providing an Al-Si alloy film having a composition of 0.00 ppm and the remainder being AI, it is possible to improve the magnetic recording performance and mechanical strength of the magnetic recording medium.

To explain the factors behind this performance improvement, first,
Even if the l-Si alloy is deposited on a substrate in a vapor phase, there is no abnormal crystal growth that occurs with high-purity aluminum, and the Al-Si alloy
Since the Si alloy precipitates on the substrate with very fine crystal grains and forms an Al-Si alloy film, the anodic oxidation treatment of this Al-Si alloy film is performed uniformly, and the anodic oxidation film is produced. This prevents the occurrence of defects in which the magnetic material is not filled into the fine holes, and as a result, the magnetic recording performance of the magnetic recording body can be improved.

Furthermore, the Al-Si alloy has excellent adhesion to materials used as substrates, such as glass. This is Al-S
This is thought to be because the Si contained in the i-alloy makes it easier to adhere to a substrate such as glass containing 5ift. Therefore, with the Al-Si alloy, the alloy film is less likely to peel off from the substrate due to impact or friction, and the mechanical strength of the magnetic recording medium can be improved. In addition, high-purity aluminum has poor adhesion with polyethylene terephthalate and easily peels off, making it difficult to use polyethylene terephthalate as a substrate, but Al-Si alloy has good adhesion with polyethylene terephthalate. As a result, a substrate made of polyethylene terephthalate can be used.

Furthermore, since the above-mentioned AI-Si alloy has higher mechanical strength than high-purity aluminum, it increases the surface hardness of the anodic oxide film that is based on it, and as a result, improves the mechanical strength of the surface of the magnetic recording body. be able to.

FIG. 2 shows a second example of the magnetic recording body of the present invention. In this example, the substrate l is made of aluminum or an aluminum alloy, and a first base material 1a formed on the base material 1a. It consists of an anodic oxide film 1b. The first anodic oxide film 1b is formed integrally on the substrate la by anodizing the substrate 1a using an electrolytic bath such as an oxalic acid electrolytic bath or a sulfuric acid electrolytic bath. 1
It is about 0 to 20 μm. This first anodic oxide film! b is for hardening the substrate 1, and therefore, if its thickness is less than 108 m, it does not contribute to hardening the substrate 1, and a thickness of at least 5 μm is required. Further, the first anodic oxide film tb is preferably electrolytically treated in a low temperature bath at high voltage in order to harden it. On this substrate l, as in the previous example, an Al-Si alloy film (S
i10 to LOOOppm, remainder of AI), and a magnetic film 3 is similarly provided.

The magnetic recording body of this example can obtain the same effects as the previous example, such as being able to improve magnetic recording performance and mechanical strength.

"Example" Si content 30 ppm (remaining Al) on a glass substrate
The magnetic recording device of the present invention is composed of an Al-Si alloy film (thickness: 1 μm) having a composition of A body (Example 1) was prepared by the following operations.

In addition, a comparative example using 99.999% high-purity aluminum instead of the Al-Si alloy was created using the same procedure, and the performance of both samples was first measured by vacuum evaporation on a glass substrate whose surface had been cleaned. 2μm Al-Si alloy film (
1st Example) or high-purity aluminum (Comparative Example) were formed. The photographs shown in Figures 3 and 4 show the state of crystal growth on these substrates. Figure 3 shows the state of crystal growth on these substrates. (Remaining AI) containing Al-Si alloy (Example 1), and Figure 4 shows high-purity aluminum (Comparative Example 1).As is clear from these photographs, the Al-Si alloy of Example 1
It can be seen that the -Si alloy film does not have irregularities caused by abnormal growth of crystals as seen in high-purity aluminum films, and fine crystal grains are precipitated in a uniform state.

Next, using the substrates on which the 2 μm thick Al-Si alloy film or high-purity aluminum film was formed, a peel test was conducted using a tape.

As a result of performing this test 10 times for each of Example 1 and Comparative Example 1, the peeling rate was 7/1 for Comparative Example 1.
In contrast, in Example 1, the rate was as low as 2/10.

In addition, a 60 μm thick polyethylene terephthalate substrate was used instead of the glass substrate in Example I and Comparative Example 1, and 30 ppm of Si was applied on this substrate.
An Al-Si alloy film (referred to as Example 2) and the above-mentioned high-purity aluminum film (referred to as Comparative Example 2) containing A (remaining part of I) were each formed to a thickness of 2 μm, and a peel test using the above-mentioned tape was conducted. As a result, the peeling rate of Comparative Example 2 was 10
/10, whereas in Example 2 the rate was as low as 3/10.

Next, power supply terminals were connected to the inner and outer edges of each substrate on which the Al-Si alloy film or high-purity aluminum film was formed, and the Al-Si alloy film and high-purity aluminum film were soaked in a 3% oxalic acid electrolytic bath. Medium, DC 45V, bath temperature 10
An anodic oxidation treatment was performed at ℃ to form an anodic oxide film with a thickness of 1 μm. Next, this was electrolyzed in a ferrous ammonium sulfate electrolytic bath, and the fine pores of the anodic oxide film were electrolytically deposited and filled with iron to form a magnetic film.

As a result of inspecting the surfaces of Example 1 and Comparative Example 1 prepared in this way, it was found that in Example I, less than half of the defective areas where iron (magnetic material) was not filled in the micropores of the anodic oxide film were found. It was confirmed that in Example 1, the occurrence of the defective portions described above was small.

Furthermore, as a result of measuring the surface hardness of each of Example 1 and Comparative Example 1, the surface hardness of Comparative Example 1 was 250 HV (Vickers hardness), while that of Example 1 was 300 Hv.
Met.

"Effects of the Invention" As explained above, the magnetic recording body of the present invention includes an Al-Si alloy film provided on the surface of the substrate 3, a magnetic material filled in the fine pores of this anodic oxide film, and the Al-Si alloy film Si alloy
Since the composition was set to O ~ 1,000 ppm and the balance was AI,
An Al-Si alloy film can be formed on the substrate in a uniform state, and this AI-Si alloy film is anodized,
When filling the micropores with a magnetic material, defective portions where the magnetic material is not filled are less likely to occur, thereby improving the magnetic recording performance of the magnetic recording body.

In addition, Al-Si alloy has excellent adhesion to substrate materials such as glass, ceramics, or polyethylene terephthalate, and has higher mechanical strength than high-purity aluminum. The mechanical strength of the magnetic recording medium can be improved, such as by making the film less likely to peel off and increasing the surface hardness of the magnetic film.

[Brief explanation of the drawing]

1 and 2 are both schematic cross-sectional views showing examples of the magnetic recording medium of the present invention, FIG. 3 is a micrograph showing the metal structure of the surface on which the Al-Si alloy of the present invention is deposited, and FIG. Figure 4 is a micrograph showing the metal structure of the surface on which high-purity aluminum was deposited. ■...Substrate 2...Al-Si alloy film 3...Magnetic film.

Claims (1)

[Scope of Claims] A recording medium in which an Al-Si alloy film is provided on a substrate, an anodic oxide film is provided on the surface of this film, and a magnetic material is filled in the fine pores of the anodic oxide film, the recording medium comprising: -Si alloy with 10 to 1,000 ppm of Si, A
A magnetic recording material having a composition of l remainder.