JPH01264631A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the performance of the recording medium without impairing the high-density recording adaptability thereof by setting the winding angle of a nonmagnetic substrate with a substrate support so as to coincide with the track angle of a magnetic recording format at the time of depositing a magnetic layer by vapor deposition on the nonmagnetic substrate. CONSTITUTION:The nonmagnetic substrate (b) which travels from a delivery roll (a) in a vacuum film forming vessel A toward a take-up roll (c) is held on the rotatable substrate support (d) and the magnetic material (f) in a crucible (e) is continuously evaporated and deposited on the nonmagnetic substrate (b). The substrate (b) is wound diagonally across the support 1(d) in such a manner that the angle (winding angle) between the perpendicular plane H orthogonal with the axis of rotation of the support and the inlet side center line Lin and exit side center line Lout of the substrate 2(b) coincides with the track angle of the magnetic recording format in this case.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a method for manufacturing a magnetic recording medium, and more particularly, to a method for manufacturing a magnetic recording medium, and more specifically, it is possible to produce a magnetic recording medium that can be used for high-density recording without impairing the inherent suitability for high-density recording of a metal thin film magnetic layer. The present invention relates to a method by which high performance magnetic recording media can be manufactured.

[Prior art and inventions or problems to be solved] In recent years,
The performance of magnetic recording devices is rapidly increasing, and magnetic recording media are desired to have even higher densities.

To meet this demand, when manufacturing magnetic recording media particularly suitable for high-density recording, a magnetic layer is formed by applying a magnetic paint containing ferromagnetic powder and a binder onto a non-magnetic substrate. Instead of the manufacturing method of magnetic recording media (hereinafter referred to as coating type recording media forming method), magnetic material is deposited on a non-magnetic substrate by a method such as vacuum evaporation, sputtering, or ion brate ink. As a result, a method of continuously forming a magnetic layer made of a thin metal film on a nonmagnetic substrate (hereinafter referred to as a thin film recording medium formation method) has been adopted.

In other words, in the conventional coating type recording medium forming method, there is a limit to the filling rate of ferromagnetic powder, so the direction of recording density is -1.
However, the φu IIA type short recording medium formation method has the advantage that it is easy to form a magnetic layer with high recording density.

To manufacture a magnetic recording medium by this method of forming a thin film type recording medium, for example, an apparatus as shown in FIG. 3 is used.

In FIG. 3, a strip-shaped non-magnetic substrate wound around a delivery roll a is taken up by a take-up roll C. A vacuum film forming tank A is provided between the delivery roll a and the take-up roll C. A rotatable substrate support d for holding a non-magnetic substrate running from a delivery roll a toward a take-up roll C is installed in the vacuum film forming tank A. Depositing the magnetic material f in the crucible e on the non-magnetic substrate held by the substrate support d while introducing a gas such as oxygen gas, helium gas, -oxidizing gas, etc. as necessary. By this method, a metal thin film magnetic layer is continuously formed on a nonmagnetic substrate. Note that the magnetic material f in the crucible e is heated by, for example, a heating electron beam generator g to generate a flying vapor flow toward the nonmagnetic substrate held on the substrate support d.

Further, the inside of the vacuum film forming tank A is kept in a vacuum by an exhaust system (not shown). Furthermore, in the figure, h and h' are free rolls for guiding the traveling non-magnetic substrate.

However, in the conventional method for forming a thin film type recording medium, as shown in FIG. The angle formed by the entrance side center line Lin or the exit side center line of the non-magnetic substrate.ut is shown as α in the figure. The center line of the non-magnetic substrate facing toward the winding roll is the longitudinal center line of the non-magnetic substrate. Therefore, the crystal growth direction of the magnetic material, that is, the easy axis of magnetization of the magnetic layer in the resulting magnetic recording medium, is along the longitudinal direction of the nonmagnetic substrate.

However, in general, in a magnetic recording device, the trough angle with respect to the magnetic recording medium A during running (
In the figure, it is indicated by γ. Example: Track angle γ in standard mode of VH3 video cheap recorder: 5 degrees 58 minutes 9.9
seconds. ), when using a magnetic recording medium obtained by the conventional thin film recording medium formation method, an angular difference will occur between the recording direction by the magnetic head and the axis of easy magnetization of the magnetic recording medium. Become.

This angular difference is a cause of recording loss, and impairs the inherent suitability for high-density recording of a magnetic recording medium formed with a metal thin film magnetic layer.

Furthermore, in the azimuth recording method, the angular difference between the axis of easy magnetization in the magnetic recording medium and the azimuth angle (the angle between the gap line of the magnetic head and the scanning line) is added to this angular difference, so it can be ignored. This may result in unbearable recording loss.

In other words, the problem with conventional thin-film recording medium forming methods is that it is not possible to manufacture a magnetic recording medium that can fully exhibit the inherent high-density recording suitability of a magnetic recording medium having a metal thin-film magnetic layer. There is.

This invention has been made based on the above circumstances.

An object of the present invention is to provide a method for efficiently manufacturing a high-performance magnetic recording medium without impairing the inherent suitability for high-density recording of a magnetic recording medium having a thin metal V magnetic layer. It's about doing.

[Means for Solving the Problems] In order to solve the problems described above, the inventor has made extensive studies and found that while the strip-shaped non-magnetic substrate wound around the delivery roll is wound up by the take-up roll, , a magnetic recording medium in which a magnetic layer consisting of a thin film of magnetic material is continuously formed on a non-magnetic substrate by depositing evaporated particles of magnetic material on the non-magnetic substrate wrapped around a rotatable substrate support. In the manufacturing method, by wrapping a non-magnetic substrate around the substrate support at a specific angle, it is possible to achieve high performance without impairing the inherent suitability for high-density recording of magnetic recording media with magnetic thin films. The inventors have discovered that it is possible to provide a method for efficiently manufacturing magnetic recording media, and have arrived at this invention.

The configuration of the present invention is such that while a strip-shaped nonmagnetic substrate held by a delivery roll is wound up by a take-up roll via a substrate support, the nonmagnetic substrate is wound around the outer peripheral surface of the substrate support. A method for manufacturing a magnetic recording medium, in which a thin magnetic layer made of the magnetic material is continuously formed on the non-magnetic substrate -1- by depositing evaporated particles of a magnetic material on the substrate support. This method of manufacturing a magnetic recording medium is characterized in that the winding angle of the magnetic substrate is made to match the track angle of the magnetic recording format.

One of the important points in this invention is that the angle at which the nonmagnetic substrate is wound around the substrate support corresponds to the track angle of the magnetic recording format.

Specifically, as shown in FIG. 1, for example, a vertical plane H perpendicular to the rotational axis of the base support 1 and a center line on the entrance side of the non-magnetic base 2, n or a center line on the exit side. 11. The nonmagnetic substrate 2 may be wound around the substrate support 1 in a cross-fold shape so that the angle .alpha. of the magnetic recording format matches the rack angle of the magnetic recording format.

In this invention, it is preferable that the angle α completely coincides with 1 to Herak's angle, or if the angle difference between angle α and 1 to Herak's angle is within the range of ±1 degree, the object of the invention can be achieved. It is possible to achieve.

Such winding can be achieved by appropriately setting the angle between the delivery roll 3, the base support 1, and the take-up roll 4, as shown in FIG. It is. In addition, in the figure, 5.5' is a free roll that guides the nonmagnetic substrate 2.

The track angle of the magnetic recording format, which should have the same winding angle, is not particularly limited and can be appropriately set depending on the use of the magnetic recording medium obtained by the method of the present invention. - For example, the track angle in the standard mote of the VH3 tape recorder is 5 degrees 58 minutes 9.
．． 9 seconds, track angle 5 degrees 56 minutes 48.1 seconds with 3x mode.

1 in β-I mode 1 of β-type video recorder
Herak angle 5 degrees old minute 42 seconds, track angle 5 degrees 00 minutes 51 seconds in β-■ mode, track angle 5 degrees 00 minutes 34 seconds in β-■ mode 1, track angle 4 degrees in 8 ■ video format A 54 minutes 13.2 seconds, DA
The T-video track angle is 6 degrees, 22 minutes, and 59.5 seconds.

Examples of materials for forming the nonmagnetic substrate used in the method of the present invention include polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate; polyolefins such as polypropylene; Examples include cellulose derivatives such as acetate, and plastics such as polycarbonate. Further CLI, An, Z
Metals such as n, glass, so-called new ceramics (
For example, various ceramics such as boron nitride, silicon carbide, etc. can also be used.

There is no particular restriction on the final form of the non-magnetic substrate as a magnetic recording medium, and it may be in the form of a disk, car, tape, sheet, drum, etc., depending on the recorder used. It is possible to create a corresponding format.

The thickness of the nonmagnetic substrate is usually in the range of 20 to 80 gm when it is disk-shaped or cart-shaped. In addition, in the case of a tape or sheet, usually 3~
It is within the range of 1 flOgm, preferably within the range of 5 to 30 pLm.

A metal thin film magnetic layer is formed on the nonmagnetic substrate.

The metal thin film magnetic layer in the present invention may be formed by, for example, a physical vapor deposition method (PVD) such as a vacuum evaporation method, an ion Brede ink method, a sputter link method, a physicochemical method such as a plasma CVD method, or a laser photochemical vapor deposition method. Hightsuri 1~
Method): The magnetic metal thin film material can be formed on the non-magnetic substrate by depositing it on the non-magnetic substrate by a method such as chemical vapor deposition (CVD).

Examples of the magnetic metal thin film material include Fe, Go,
Ni, Gd and other magnetic metals; Fe-Ba, Fc
-Go, Fc-Al, Go-Ni, Fc-3i,
Fc-R1+, Fc-V, Fe-Cu, Fe
-Au, Go-Cr, Go-P, Go-V,
Go-8i, Co-Y, Co-La,
Go-Pr, Go-3g+, Co-Mn, Go-
Pt, Ni-Cu, Go-Ni-Fe, F
e -A11-Ni, Ni0-Ni-Ag, Go-N
i-Cr, Go-Ni-Zn, Go-3i −
1, Fe-3i-AJL, Mn-B1. Mn-3
Examples include alloy-based magnetic metals such as Mn-B and Mn-H.

The layer thickness of the metal thin film magnetic layer cannot be determined unconditionally as it varies depending on the use of the magnetic recording medium, the type of the magnetic metal thin film material, etc., but it is usually within the range of 0.03 to 0.6 p, m. It is. By keeping this layer thickness within the above range, a magnetic recording medium with excellent electromagnetic conversion characteristics and production efficiency can be obtained.

In the present invention, a protective layer such as a lubricant layer may be formed on the metal thin film magnetic layer, if necessary.

By providing the lubricant layer, the running properties of the magnetic recording medium obtained by the method of the present invention can be improved, and the wear resistance and weather resistance of the metal thin film magnetic layer can be improved. I'll come.

Examples of the lubricant used to form the lubricant layer include fatty acids, fatty acid esters, hydrocarbons, aliphatic amines, silicone oils, and modified silicone compounds.

These may be used alone or in combination of two or more.

When the lubricant layer is provided, the thickness of the lubricant layer is usually 0.001 to 0.000. 0.001 to 0.007 gm. By setting the layer thickness within the above range, it is possible to improve the runnability of the magnetic recording medium obtained by the method of the present invention without deteriorating the electromagnetic conversion characteristics, and to improve the running properties of the metal thin film magnetic layer. The effect of improving wear resistance and corrosion resistance is fully exhibited.

The lubricant layer can be formed, for example, by a method of applying the lubricant onto the metal thin film magnetic layer using a solvent or without using a solvent.

When applying the lubricant, for example, hearth roll coating, gravure roll coating, wire bar coating, doctor blade coating,
Application methods such as dip coating, air knife coating, calendar coating, squeegee coating, kiss coating and fantine coating may be employed.

Furthermore, a back coat layer may be formed on the surface (back surface) of the nonmagnetic substrate on which the metal thin film magnetic layer is not provided.

The magnetic recording medium obtained by the method of the present invention can be used, for example, as a magnetic tape such as a video tape or audio tape by cutting it into a long shape, or as a floppy disk by cutting it into a disk shape. Ru.

Furthermore, like a normal magnetic recording medium, it can also be used in a card-like or cylindrical form.

[Example] Next, Examples and Comparative Examples of the present invention will be shown to further specifically explain the present invention.

(Example 1) While running a non-magnetic substrate made of polyethylene terephthalate with a thickness of 12.5 pLm at a speed of 50 m/min, winding was carried out at an angle of 4 degrees and 54 minutes on the non-magnetic substrate that was wound around the substrate support. □By depositing evaporated particles of Go-Ni alloy (Ni content: 20% by weight) while introducing gas, a Go-Ni alloy thin film with a thickness of 0.15 ILm is continuously formed on a non-magnetic substrate. The original fabric of the recording medium was obtained.

The evaporated particles were generated by heating the Co--Ni alloy in the crucible using a heating electron beam generator.

The obtained original magnetic recording medium was cut into tapes having a width of 8 mm to form 8 mm video tapes.

This 8 mm type video tape was recorded and played back, and the brightness signal (white peak 5.4 M
H7) and color signals (modulation frequency 743kHz) were measured.

The results are shown in Table 1.

Note that the luminance signal and color signal were each measured as follows.

Luminance signal: Signal generator [rTG-7/1 manufactured by Shibaku Co., Ltd.
” was used to generate a 100% white signal, and an 8-inch video deck [manufactured by Sony, rEV-A300. ] recorded in Techi. The recorded tape was reproduced, and the reproduction signal voltage value was determined in comparison with a reference tape [manufactured by Sony ■, rP5-90MP].

Color signal, signal generator [Sibaku rTG-771,
A 100% chroma signal was generated using an 8II type video deck [manufactured by Sony, rEV-A300. ] recorded in Techi. The recorded tape was reproduced, and the reproduction signal voltage value was determined in comparison with a reference tape [manufactured by Sony ■, rP6-90MP].

(Example 2) In Example 1, the wrapping around the substrate support was carried out in the same manner as in Example 1 except that the angle was changed from 4 degrees 54 minutes to 3 degrees 30 minutes.

The results are shown in Table 1.

(Example 3) In Example 1, the wrapping around the substrate support was carried out in the same manner as in Example 1 except that the angle was changed from 4 degrees 54 minutes to 5 degrees 30 minutes.

The results are shown in Table 1.

(Comparative Example 1) An 8 mm videotape was produced in the same manner as in Example 1 except that the angle of wrapping around the substrate support was changed from 4 degrees 54 degrees to 0 degrees. 8m
An M-type videotape was recorded and played back, and the brightness signal and color signal in the playback signal were measured.

The results are shown in Table 1.

(Comparative Example 2) An 8-inch videotape was produced in the same manner as in Example 1 except that the angle of wrapping around the substrate support was changed from 4 degrees 54 minutes to 6 degrees 3 minutes. The resulting 8 mm videotape was recorded and played back, and the brightness signal and color signal in the playback signal were measured.

The results are shown in Table 1.

Table 1 (Evaluation) As is clear from Table 1, the magnetic recording medium obtained by the method of the present invention has a higher color signal in the reproduced signal and less recording loss than the magnetic recording medium of the comparative example. are doing.

- On the other hand, no improvement was seen in the color signal with respect to the luminance signal. The inventor conjectures that the reason for this is that the luminance signal is more susceptible to the surface properties of the magnetic recording medium than the color signal.

[Effects of the Invention] According to the present invention, (1) When forming a metal thin film magnetic layer by depositing evaporated particles of a magnetic material on a non-magnetic substrate, the direction of crystal growth of the metal thin film is set according to the track of the magnetic recording format. By matching the angle, the recording loss caused by the angular difference between the recording direction by the magnetic spatula and the axis of easy magnetization in the magnetic recording medium is reduced, and the high-density recording inherent to the metal thin film magnetic layer is achieved. It is possible to manufacture a magnetic recording medium that does not deteriorate in aptitude, and (2) it is necessary to efficiently manufacture a high-performance magnetic recording medium that exhibits excellent high-density recording aptitude, especially in the azimuth recording method. An object of the present invention is to provide a method for manufacturing a magnetic recording medium that has advantages such as:

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the relationship between a nonmagnetic substrate and a substrate support in the method of the present invention, and FIG. 2 is a conceptual diagram showing an example of a manufacturing apparatus that can be suitably used in the method of the present invention. 3 is a schematic diagram showing an example of a manufacturing apparatus used in the conventional method, and FIG. 4 is an explanatory diagram showing the relationship between the nonmagnetic substrate and the substrate support in the conventional method, FIG. 5 is an explanatory diagram showing the track angle of the magnetic recording format. 1... Base support, 2... Nonmagnetic substrate, 3... Delivery roll, 4... Winding roll, α... Winding angle. Figure 3 Figure 4 Whistle q M

Claims (1)

[Claims] (1) A strip-shaped non-magnetic substrate held on a delivery roll,
While winding up with a take-up roll via the base support, evaporated particles of the magnetic material are deposited on the non-magnetic base wound around the outer peripheral surface of the base support to form a thin film magnetic layer made of the magnetic material. A method for producing a magnetic recording medium in which the non-magnetic substrate is continuously formed on the non-magnetic substrate, wherein a winding angle of the non-magnetic substrate with respect to the substrate support is made to match a track angle of a magnetic recording format. Method of manufacturing media.