JPS63282925A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To produce the title magnetic recording medium having excellent magnetic characteristic and durability by generating the vapor currents of the different ferromagnetic metals from two vaporization sources toward a moving polymeric film to form the thin film of the ferromagnetic metals, and joining the maximum vapor current parts on the polymeric film. CONSTITUTION:Two vessels 14 and 15 are arranged below a rotary carrier 12 adjacently to each other in a vacuum vessel 27, and the vaporization materials different from each other are vaporized by electron-beam heating sources 16 and 17. The generating condition of the vaporized ferromagnetic metals can be easily controlled, the electron beam is adjusted by a deflecting magnetic field, and the maximum vapor currents 20 and 21 generated from the respective vessels 14 and 15 are joined at the point P on the polymeric film 22 moving on the rotary carrier 12. AS a result, the thin film of the ferromagnetic metals is formed on the polymeric film 22 with the composition uniform in the thickness direction, the magnetic characteristic and mechanical strength of the thin film are also uniformized, and the characteristics preferable as the magnetic recording medium can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a magnetic recording medium suitable for high-density magnetic recording.

Conventional technology Magnetic recording media with ferromagnetic metal thin films as the magnetic recording layer have large short wavelength output, so they are indispensable for future progress in increasing density [Foreign journal: IEE Transactions on Magneto , (ri, z, (IEE
E TRANSACTIONS ONMAGNET I
C3) vo 71-MAG-21, p, p, 1
217-2-/1220 (1985)], and its practical application is strongly desired.

Generally, in a magnetic recording medium having such a structure, a ferromagnetic metal thin film is magnetically recorded by a sputtering method, an electric field evaporation method, an ion blating method, an electron beam evaporation method, etc. while winding a polymer film along a cylindrical can. Manufactured by forming a layer [JP-A-53-42010, Institute of Electronics and Communication Engineers, Magnetic Recording Research Group Material MR81-2,
See Japanese Patent Application Laid-open No. 51-186475, etc.]. Among them,
Electron beam evaporation is superior in terms of productivity, and Co-
Oblique deposition of Ni, vertical deposition of Co-Cr, etc. are being considered.

Fig. 2 shows the configuration of an example of a conventionally used vapor deposition apparatus. In Fig. 2, 1 is a polymer film, 2 is a rotating support, 3 is a feeding shaft, and 4 is a winding shaft. ,
5 is an evaporation source, 6 is an accelerated electron beam, 线 is a mask for limiting the incident angle of the vapor flow, 8 is the minimum incident angle θ, and 9
1 is a gas introduction port, 10 is a vacuum chamber, and 11 is a vacuum exhaust system.

3B-7 In the apparatus shown in Figure 2, the ferromagnetic metal to be evaporated is Co-N.
In the case of i-alloys, compositional changes can be ignored even if long tapes are manufactured, but if the vapor pressures of the alloys are significantly different, such as in Co-Cr alloys, the method of supplying Cr must be devised. Improvements are being attempted.

Problems to be Solved by the Invention However, with the above conventional configuration, it is difficult to obtain long tapes with good reproducibility for ternary alloys and binary alloys whose magnetic properties and durability are greatly affected by the composition ratio. Since this is not possible, the so-called binary evaporation method, in which two evaporation sources are prepared, has been used to further improve the stabilization of the composition, but the magnetic properties.

In terms of durability, it is not as good as when short length tapes are obtained using a single evaporation source, so improvements are desired.

In view of the above problems, the present invention aims to provide a method for manufacturing a magnetic recording medium having excellent magnetic properties and durability.

Means for Solving the Problems In order to achieve the above object, the method for manufacturing a magnetic recording medium of the present invention involves the use of two evaporation sources to evaporate different types of ferromagnetic metals onto a polymer film moving along a rotating support. A ferromagnetic metal thin film is formed by generating a vapor flow, and the maximum vapor flow portions are made to coincide on the polymer film.

Effect: With the above manufacturing method, the conditions for generating the evaporated ferromagnetic metal can be easily controlled, and the maximum vapor flow portions coincide on the polymer film, so that the formed ferromagnetic metal thin film is uniform in the thickness direction. The magnetic properties and mechanical strength properties of the thin film are uniform, and desirable properties as a magnetic recording layer can be obtained.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the main part of a vapor deposition apparatus used to carry out the manufacturing method of the present invention.

In FIG. 1, 12 is a rotating support, 13 is an evaporation source, which is a two-tank type, and the first tank 14 and the second tank 155 are arranged adjacent to each other and evaporate different evaporation materials. used for. 16 is a first electron beam heating source;
Reference numeral 7 indicates a second electron beam heating source, and reference numerals 18 and 19 schematically indicate electron beam trajectories. 20.21
are schematic representations of the maximum steam flow generated from the tanks 14 and 15, respectively, and the maximum steam flow 20.21 is:
They intersect at point P of the polymer film 22 moving on the rotating support 12. 23 is a mask that determines the minimum incident angle, 24 is a gas introduction port, 25 is an unwinding shaft, 26
2 is a winding shaft, 27 is a vacuum chamber, and 28 is an exhaust system.

A rotating support 1 with a diameter of 1 m is placed, for example, directly below a cylindrical can, 32 cm from the end of the cylindrical can, and from that position 3 to the opposite side of the moving direction of the polymer film 22 (to the right in the figure).
The first tank 1 of the two types of evaporation sources 13 is located 2 cm apart.
4 and the center of the second tank 16 at the position of 24CrrT, the 25 KV electron beam was adjusted by the deflection magnetic field, and the vapor flow was maximized at the position of 1Q = 30''. 6 A vane magnetic recording medium was manufactured.

In addition, as a comparative example for the examples of the present invention, a magnetic recording medium was formed using a method of irradiating an electron beam perpendicularly to the surface to be deposited, which has conventionally been considered a preferable condition.

31 pieces of 100 mm diameter each on a polyethylene terephthalate film with a thickness of 10.611 m under the above conditions.
Co-Ni-Pr was applied in oxygen [oxygen partial pressure 7
0.157 zm was deposited at 0.157 zm.

In both comparative examples, the wt ratio of Co-Ni-Pr is 79.5:
19: Adjusted to 1.5. Then, each film was deposited to a width of 50 cy++ and a length of 2,600 m, and was finally processed into a magnetic tape with a width of 8 mm. In addition, 70 perfluoroaracic acid was applied as a lubricant layer.

In both Examples and Comparative Examples, one roll was an arbitrary length of 90 m, and 25 rolls of tape were used with a commercially available 8 mm video tape [VX-
801, manufactured by Kishita Denki] to measure the high frequency output characteristics. In the example, the output level difference in the longitudinal direction of the Te7 Bee Arp was within 7 (dB), whereas in the comparative example, it was 3.2 (dB).
The range of variation was large.

In addition, when the stealth characteristics were measured at 10 arbitrary points under the conditions of 20°C and 12% RH, the time for the output to decrease by 3 (dB) was 31 to 34 minutes in the example, whereas in the comparative example. There was a clear difference between 2 minutes and 14 minutes.

As described above, according to this embodiment, excellent high frequency output characteristics and methyl characteristics can be uniformly obtained.

In the above examples, polyethylene terephthalate was used as the polymer film, but polyphenylene sulfide and polyethylene naphthalate were also used.

Polyimide or the like may also be used.

The trenched ferromagnetic metal thin film may be either a perpendicular magnetization film or an obliquely deposited film (Go-Cr, Co-Ti, Co-W, etc.).

Co-Mo, Co-N1-B, Co-N1-P, C
o-Ni-La.

Co-Cr-Nb, Co-Cr-Ru, etc., and their partial oxide films are used.

Effects of the Invention According to the present invention, since the ferromagnetic metal is evaporated from two evaporation sources and the maximum vapor flows are matched on the polymer film, each vapor flow can be easily adjusted. This has an excellent practical effect in that it is possible to mass-produce magnetic recording media with a stable composition ratio and uniform durability and magnetic properties.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of main parts of a magnetic recording medium manufacturing apparatus used to carry out the present invention, and FIG. 2 is a block diagram of main parts of a conventional magnetic recording medium manufacturing apparatus. 12... Rotating support body, 13... Evaporation source, 1
4...First tank, 15...Second tank, 2
0,21...Maximum vapor flow, 22...Polymer film. Name of agent: Patent attorney Toshio Nakao and 1 other person/2
-11 rotation prayer 4 pieces 73--1 evaporation source υ2I---most

Claims (1)

[Claims] Vapor flows of different types of ferromagnetic metals are generated from two evaporation sources toward a polymer film moving along a rotating support to form a ferromagnetic metal thin film, and the maximum vapor flow portion is on the polymer film. A method of manufacturing a magnetic recording medium characterized by matching.