JPH0329111A - Magnetic recording medium with oriented surface - Google Patents

Abstract

PURPOSE:To obtain a medium showing good sliding and contact property against a magnetic head and having high reproduction output, improved durability and reliability by specifying the thickness and Young's modulus of a flexible substrate which constitutes the recording medium film. CONSTITUTION:The magnetic recording medium having oriented surfaces is formed by using recording medium films 3, 4 each comprising a flexible sub strate and a magnetic recording layer formed on the substrate, drawing these films to generate specified tensile stress and fixing the films as drawn with an adhesive to a rigid supporting body 5 of a desired shape. The film substrate is specified to have 10 - 50 mum thickness and 5 X 10<8> - 2 X 10<10> N/m<2> Young's modulus. Thereby, the obtd. magnetic recording medium having oriented surfaces is flexible with little deformation during rotation and has excellent sliding and contact property against a magnetic head, high durability and reliability.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording medium, and more specifically, the present invention relates to a magnetic recording medium, and more specifically, it has a flat and flexible recording surface with an elongated surface, and has a smooth sliding contact with a magnetic head. This invention relates to a surface-stretched magnetic recording medium that is extremely good, has excellent durability, and is mass-producible.

[Conventional technology]

Typical methods for forming a magnetic recording layer made of a metal magnetic thin film on a flexible substrate include physical vapor deposition methods such as vacuum evaporation and sputtering.

Among these, the vacuum evaporation method has a faster film formation rate and is superior in mass production than the sputtering method, but unlike the sputtering method, it is not possible to form a film on both sides of the substrate at the same time. There was a problem that the magnetic head was easily warped and the sliding contact with the magnetic head was poor.

By the way, in recent years, in order to improve the flatness of the surface of magnetic recording media, a new form of stretching the surface of a Hokuro media film provided with a magnetic recording layer and holding and fixing it with a rigid support has been developed. Research is being conducted on surface-stretched magnetic recording media (hereinafter referred to as surface-stretched recording media). 9 8
September 3rd), pages 15l1 to 15l4 [IEEE
, Trans. Magnetics, MAG,
Vol. 2 1 , Na 5 , (Septen+
ber 1 9 8 3) pp 1 5 1 1~1
514)).

This surface-stretched recording medium has the characteristics that the amount of deformation of the recording disk surface during rotation is smaller than that of conventional floppy disks, and flexibility can be maintained with respect to contact with a magnetic head. Therefore, it has the advantage of extremely good sliding contact with the magnetic head, excellent durability as a recording disk, and better mass productivity than hard disks.

[Problem to be solved by the invention]

As mentioned above, surface-stretched recording media have a small amount of surface deformation during rotation and can maintain flexibility, so they have good sliding contact with the magnetic head, are durable, and are easy to mass-produce. It has the advantage of being excellent. However, when producing a surface-stretched recording medium, if the thickness and Young's modulus (elongation modulus) of the recording medium film (substrate) provided with the magnetic recording layer are not limited, the recording medium film cannot be stretched with uniform tension. It was difficult.

In other words, if the thickness of the substrate on which the magnetic recording layer is provided is too thin or the Young's modulus of the substrate is small, cracks may occur in the magnetic recording layer, and conversely, if the substrate is too thick or the Young's modulus of the substrate is too small, cracks may occur in the magnetic recording layer. If the ratio is too large, there is a problem that it is difficult to fix the recording medium film provided with the magnetic recording layer to the support with uniform tension. The object of the present invention is to limit the thickness and Young's modulus of the substrate of the recording medium film provided with the magnetic recording layer to a specific range, thereby reducing the amount of deformation during rotation, making the film flexible and capable of sliding contact with the magnetic head. The object of the present invention is to provide a surface-stretched magnetic recording medium that has extremely good properties, durability, and reliability. [Means for Solving the Problems] In order to achieve the above object of the present invention, a recording medium film in which a magnetic recording layer is provided on a flexible substrate is used, and the film is set under a specific tension. In the case of producing a magnetic recording medium with a stretched surface by adhesively fixing it to a rigid support having a shape, the recording medium can be The entire film can be fixed to the rigid support with uniform tension, and good sliding contact with the magnetic head can be obtained.

The substrate constituting the surface-stretched magnetic recording medium of the present invention has a thickness in the range of 10 to 50 μm, and a Young's modulus of 5 × 10” to 2 × 101 IN/m2.
It is desirable that it be within the range of . The thickness of the above board is 10
If the thickness is less than μm and the Young's modulus is less than 5×10 3 N/m 2 , cracks will occur in the magnetic recording layer when the recording medium film is surface-stretched on a rigid support, which is undesirable. If it exceeds 50 μm and Young's modulus exceeds 2×10 10 N/m 2 , the tension of the recording medium film tends to be uneven, which is not preferable.

The ferromagnetic material constituting the magnetic recording layer of the surface-stretched magnetic recording medium of the present invention is. Single metals such as Co, Fe, Ni, etc.
Or alloys containing these as main components, such as Co-Ni
, Co-Cr, Co-P, Co-10, Co-Ni-P, etc., or iron oxide-based, iron nitride-based ferromagnetic materials can be used. Any ferromagnetic material that satisfies the performance and characteristics of the magnetic recording medium can be suitably used.

The flexible substrate material constituting the surface-stretched magnetic recording medium of the present invention may be a synthetic resin film such as polyester, polyimide, or polyethylene, or a composite synthetic resin film prepared by adding various reinforcing materials to these films. etc. can be used.

When producing the surface-stretched magnetic recording medium of the present invention, the method for stretching a recording medium film is as follows: (1) A method in which upper and lower recording medium films are bonded together in a stretched state with a rigid support in between. (2) A method in which a sealed air chamber is provided inside the upper and lower recording medium films, and the pressure of the air chamber is adjusted to apply a predetermined tension to the recording medium film.

Then, as a method for adhering and fixing the recording medium film to a rigid support with a predetermined shape, the tension of the recording medium film is kept constant using methods such as ionization welding, ultrasonic welding, and methods using various adhesives. Any method that can maintain the temperature can be suitably used.

The recording medium film on which the magnetic recording layer used in the surface-stretched magnetic recording medium of the present invention is formed can be prepared by depositing a ferromagnetic material on various flexible substrates by vacuum evaporation, sputtering, etc.
It can be manufactured by any method such as vapor deposition (physical vapor deposition) or various plating methods such as ion plating. Among these methods, the vacuum evaporation method, which has a high film formation rate, is considered to be a preferable method in terms of mass production of recording medium films.

〔Example〕

An embodiment of the present invention will be described below in more detail based on the drawings. FIGS. 1(a) and 1(b) are explanatory diagrams showing an example of a method for manufacturing a surface-stretched magnetic recording medium of the present invention. As shown in FIG. 1(a), first, recording medium films 3 and 4 held at a certain tension are brought into contact with both sides of a rigid support 5 made of aluminum. Next, as shown in FIG. 1(b), when the tightening tools 1 and 2 are pressed against both sides of the recording medium films 3 and 4, stronger tension is applied to the recording medium films 3 and 4. In this state, the contact areas between the recording medium films 3 and 4 and the rigid support 5 are ultrasonically welded. After fixing,
Remove the tightening tools 1 and 2, and remove the recording medium films 3 and 4.
By cutting off the excess portion, a double-sided recording type surface-stretched magnetic disk 6 shown in FIG. 1(C) is obtained. The recording medium films 3 and 4 used were a polyimide film substrate with a thickness of 40 μm and a Young's modulus of 7×10′N/m2, on which a ferromagnetic alloy thin film made of Go-Cr alloy was deposited by vacuum evaporation. After forming the film to a thickness of .27 μm, a thin C (carbon) film was formed as a protective film to a thickness of 0.03 μm.

(Comparative Example 1) Except that the thickness of the polyimide film substrate was 5 μrn,
A surface stretched magnetic disk was produced in the same manner as in the above example.

(Comparative Example 2) Young's modulus of polyimide film substrate was 3×10”N/m
2. A surface-stretched magnetic disk was produced in the same manner as in the above example except that the thickness was 60 μm.

The reproduction output of the surface-stretched magnetic disks produced in the above Examples and Comparative Examples 1 and 2 was measured to evaluate the performance. In addition,
A magnetic head of a commercially available floppy disk device was used to measure the reproduction output, and the measured value was 41 (dB) based on the output value of the surface-stretched magnetic disk produced in the example of the present invention.
=o), and the reproduction output (dB) of the surface-stretched magnetic disks produced in Comparative Examples 1 and 2 is shown. The results are shown in the first
Shown in the table.

As is clear from Table 1, the thickness of the polyimide film substrate is 40 μm, and the Young's modulus is 7×10'N/
It can be seen that the surface-stretched magnetic disk of the present invention with a diameter of m'' exhibits good sliding contact with the magnetic head and improves the reproduction output.

〔Effect of the invention〕

As explained in detail above, the surface-stretched magnetic recording medium of the present invention, in which the thickness and Young's modulus of the flexible substrate constituting the recording medium film are limited to a specific range, is suitable for sliding movement with a magnetic head. Since contact properties are extremely good and high reproduction output can be obtained, magnetic recording media with excellent durability and reliability can be produced.

[Brief explanation of drawings]

FIG. 1(.) and FIG. 1(b) are explanatory diagrams showing an example of the manufacturing process of a surface-stretched magnetic recording medium exemplified in the embodiment of the present invention, and FIG. FIG. 2 is a schematic diagram showing a cross-sectional structure of a surface-stretched magnetic recording medium produced in an example. 1, 2...Tightening tool 3.4...Recording medium film 5...Rigid support 6...Surface stretched magnetic disk

Claims (1)

[Scope of Claims] 1. A magnetic recording medium in which the surface of a recording medium film in which a magnetic recording layer is provided on a flexible film substrate is held and fixed in a stretched state by a rigid support having a predetermined shape. In the above, the thickness of the substrate is in the range of 10 to 50 μm, and the Young's modulus of the substrate is in the range of 5 × 10^5 to 2 × 10^.
A surface-stretched magnetic recording medium characterized in that the tension is in the range of 1^0N/m^2. 2. In the surface-stretched magnetic recording medium according to claim 1, the magnetic recording layer formed on the flexible film substrate is formed by a vacuum deposition method. magnetic recording media.