JPH05128514A - Manufacture of vapor-deposited magnetic recording medium - Google Patents

Abstract

PURPOSE:To stably introduce oxygen even when an oxygen introduction nozzle at the tip of a shutter is exposed to any high radiant heat for many hours and to obtain a magnetic characteristic which is stable with respect to a width and a length by a method wherein the oxygen introduction nozzle is cooled. CONSTITUTION:A cooling-water circulation pipe 11 is installed around an oxygen introduction nozzle 10 installed at the tip part of a shutter; cooling water is supplied. The oxygen introduction nozzle 10 is formed in the following manner: e.g. holes 0.02mm in diameter are made in 50 places at intervals of 10mm in a pipe whose main body has a length of 600mm and a diameter of 10mm. When the oxygen introduction nozzle 10 is cooled in this manner, the blowoff holes in the nozzle are not changed even when they are exposed to any radiant heat in a vapor-deposition operation for many hours, and it is possible to form a vapor-deposited magnetic recording medium provided with a magnetic characteristic which is stable with respect to its width and its length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a metal thin film type vapor deposition magnetic recording medium most suitable for high density magnetic recording.

[0002]

2. Description of the Related Art In recent years, in the field of magnetic recording, high performance such as digitalization, miniaturization, and long time has been progressing, but the demand for a high density magnetic recording medium has increased accordingly, and a magnetic recording layer has been formed. A metal thin film type magnetic recording medium composed of a ferromagnetic metal thin film has been actively studied because it is extremely advantageous for short wavelength recording. Performances required of the magnetic recording medium include sensitivity, noise, distortion, erasing characteristics and the like, which are characteristics peculiar to the magnetic material, and running performance and durability performance obtained by treating the front and back surfaces of the magnetic layer.

The conventional oblique vapor deposition method will be described below. FIG. 6 shows a vapor deposition section in a conventional vacuum vapor deposition tank, where 1 is a winding section, 2 is an unwinding section, 3 is a cooling can, 4 is an oxygen introduction nozzle, 5 is a shutter, and 6 is an evaporation source. , 7 is an electron gun, 8 is a deposition preventive plate, and 9 is a polyethylene terephthalate film substrate.

A vapor deposition method of the vapor deposition apparatus configured as described above will be described. First, the film substrate 9 of polyethylene terephthalate to be vapor-deposited is set on the unwinding side, and after evacuation, the vapor deposition material is melted by the electron gun 7. afterwards,
A prescribed amount of oxygen is introduced from the oxygen introduction nozzle 4, and after the line speed reaches the prescribed speed, the shutter 5 is opened and closed to perform vapor deposition. At this time, the magnetic characteristics greatly change depending on the minimum incident angle regulated by the shutter 5 and the position of the oxygen nozzle, and it is known that the magnetic characteristic is better when the minimum incident angle is high and the oxygen nozzle is at the tip of the shutter. There is. Furthermore, depending on the blowing angle and the blowing amount of the oxygen nozzle, the magnetic characteristics,
It is generally known that the durability of the vapor deposition film is affected and the stability of the oxygen nozzle occupies an important weight for performance and quality.

[0005]

However, as the productivity of the vapor-deposited magnetic recording medium is improved, the Powe of the electron gun is increased.
It is necessary to increase r, and in order to further increase the evaporation efficiency, efforts are being made to increase the evaporation rate by widening the opening of the evaporation section or moving the evaporation source.
As a result, the effect of radiant heat increases, and even in the oxygen introduction nozzle, the oxygen blowing holes of the nozzle are deformed by this radiant heat, and the oxygen nozzle width direction distribution and oxygen blowing angle vary, and stable oxygen introduction in the width direction and longitudinal direction. However, there is a problem in that a vapor-deposited magnetic recording medium having a stable magnetic property cannot be obtained.

The present invention solves the above-mentioned problems of the prior art. It aims to stably introduce oxygen even if the radiant heat rises with the improvement of the vapor deposition rate, and the vapor-deposited magnetic recording medium has a stable magnetic characteristic in plane. Aim to get.

[0007]

In order to achieve this object, a method of manufacturing a vapor-deposited magnetic recording medium according to the present invention cools an oxygen introducing nozzle provided at a tip portion of a shutter.

[0008]

[Function] By cooling the oxygen introducing nozzle, no matter how it is exposed to radiant heat during vapor deposition for a long time, as long as it is not covered with the vapor deposition material, the nozzle blowing hole does not change,
Even in the width and the length, the initial distribution of the nozzle holes and the flow rate of the blown air can be maintained, and stable oxygen introduction can be always achieved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an oxygen introducing nozzle used in the present invention, 10 is an oxygen introducing nozzle main body, and 11 is a cooling water circulation pipe. Oxygen introduction nozzles are 600 mm long and have a diameter of 10 mm at intervals of 10 mm in a pipe with a diameter of 10 mm.
It has a hole in it. Using this oxygen introduction nozzle, vapor deposition was performed with the configuration of FIG.

The vapor deposition conditions are as follows: minimum incident angle 10 degrees, vapor deposition material C
_o , vapor deposition substrate PET, vapor deposition width 500 mm, vapor deposition rate 100
Adjust the power of the electron gun so that the transmittance becomes constant at 2% at m / min, oxygen flow rate of 3.0 L / min, cooling water flow rate to the oxygen introduction nozzle of 2 L / min, and cooling water temperature of 20 ° C.
It was treated for 0000 m.

FIG. 2 shows the results of measuring the flow rate of oxygen blown out from each blowout hole of the oxygen introducing nozzle before and after the vapor deposition process with a flowmeter. The vertical axis represents the oxygen flow rate, and the horizontal axis represents the blowing hole in the width direction of the oxygen introducing nozzle. The oxygen supply compression to the oxygen introduction nozzle body was 1 kg / cm ² . In addition, the magnetic characteristics of the magnetic recording medium obtained in this way are measured by VSM.
The result measured by the method is shown in FIG. The vertical axis represents the holding power, and the horizontal axis represents the width direction of the vapor deposition substrate, with 10 measurement points. The solid line on the graph indicates the start of vapor deposition and the broken line indicates the end of vapor deposition, which represents the length of vapor deposition. Next, the cooling water of the oxygen introducing nozzle was stopped, and the treatment was performed for 10000 m under the same vapor deposition conditions as above. Similarly to the above, the magnetic characteristics in the width direction are shown in FIG. 4, and the flow rate distribution in the width direction of the oxygen introducing nozzle is shown in FIG.

From the above results, by cooling the oxygen introducing nozzle, it is possible to obtain a magnetic recording medium having stable magnetic characteristics in the longitudinal and width directions even if it receives high radiant heat at a high rate.

In this embodiment, the cooling pipe is brazed in parallel with the oxygen introducing nozzle, but the cooling pipe is spirally attached to the oxygen introducing nozzle or the oxygen introducing nozzle having the jacket structure is used. You may use.

[0015]

As described above, according to the present invention, by cooling the oxygen introduction nozzle provided at the tip of the shutter, stable oxygen introduction can be achieved even if exposed to any high radiant heat for a long time. It is possible to obtain a vapor-deposited magnetic recording medium having stable magnetic properties (width, length).

[Brief description of drawings]

FIG. 1 is a sketch of an oxygen introduction nozzle with a cooling pipe used in an embodiment of the present invention.

FIG. 2 is a flow rate distribution diagram in the width direction of the oxygen introducing nozzle before and after vapor deposition when the oxygen introducing nozzle of one embodiment of the present invention is cooled.

FIG. 3 is a characteristic diagram showing coercive force measurement results of vapor deposition width and length when an oxygen introducing nozzle of one embodiment of the present invention is cooled.

FIG. 4 is a characteristic diagram showing measurement results of coercive force in the width and length of vapor deposition when the conventional oxygen introduction nozzle is not cooled.

FIG. 5 is a characteristic diagram showing a flow rate distribution in the width direction of the oxygen introducing nozzle after vapor deposition when the conventional oxygen introducing nozzle is not cooled.

FIG. 6 is a schematic diagram showing the structure of a vacuum vapor deposition machine.

[Explanation of symbols]

 10 Oxygen introduction nozzle body 11 Cooling water circulation pipe

Claims (1)

[Claims] 1. A method for producing a vapor-deposited magnetic recording medium, which comprises cooling an oxygen introducing nozzle when forming a vapor-deposited layer of the vapor-deposited magnetic recording medium.