JPS6079532A - Manufacture of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording medium whose rectangular ratio does not become too small even if iron is used as a vapor depositing source, and which has excellent performance, by using gaseous hydrogen atmosphere as the atmosphere of a diagonal vapor deposition, when vapor-depositing diagonally iron to a nonmagnetic base material in vacuum. CONSTITUTION:A vacuum tank 1 becomes a prescribed degree of vacuum, for instance, <=5X10<-5>Torr. by executing a vacuum exhaust through a valve 10, and a nonmagnetic base material 3 fed from a winding-out roll 2 is wound around a cooling drum 4 and carried, vapor-deposited by a vapor deposition source 5, and wound by a winding roll 6. A shielding plate 7 controls an incident angle theta when a vapor depositing substance is made incident, and it is installed so as to be moved in the horizontal direction. A gas leading-in system 9 having a valve 8 is used for adjusting artificially the vapor depositing atmosphere, and raises an H2 gas partial pressure in the vacuum tank 1 by leading in an H2 gas of a suitable flow rate. Also, when a nozzle 10' is provided, the H2 gas partial pressure in the vicinity of an outlet of the nozzle, namely, in an area related directly to a vapor deposition can be further raised.

Description

Detailed Description of the Invention (Technical Field) The present invention provides an improved magnetic recording medium that uses iron as a deposition source but does not have an excessive squareness ratio and can provide a magnetic recording medium with excellent performance. Relating to a manufacturing method.

(Prior art) In recent years, in response to the increasing demand for high-density magnetic recording, metal thin-film type magnetism, in which a thin film of ferromagnetic metal is formed on a non-magnetic substrate by methods such as vacuum evaporation, sputtering, and ion blating, has been developed. Recording media are being developed. These metal thin film magnetic recording media are capable of higher density recording than coated magnetic recording media, in which magnetic materials are dispersed in a binder and formed by coating, and they also have various advantages. Efforts are being made to put it into practical use.

Generally, in order to manufacture metal thin film type magnetic recording media, ferromagnetic metals such as Fe, Co, Ni5Cr, etc., or alloys mainly composed of these metals are used, and alloys mainly composed of Co and CO are used. Often used. but,
Among the above metals, Fe is C.

Although it has the advantages of low price and low S/N distortion when compared with alloys mainly composed of Co and Co, it is difficult to use it for high-density recording because of its small squareness ratio. Therefore, few attempts have been made to utilize Fe for high-density recording.

(Objective of the Invention) Therefore, an object of the present invention is to solve the problem of a small squareness ratio when using Fet.

(Structure of the Invention) In the method for manufacturing a magnetic recording medium of the present invention, when iron is obliquely deposited on a nonmagnetic substrate in vacuum to form an iron thin film, the atmosphere for the oblique deposition must be a hydrogen gas atmosphere. This is a characteristic feature.

FIG. 7 and FIG. 2 are schematic diagrams showing examples of the apparatus used in the method of the present invention. The vacuum chamber L has a predetermined degree of vacuum, for example, S The shielding plate 7 is used to control the incident angle θ when the deposition substance is incident, and the shielding plate 7 is moved horizontally in FIGS. 7 and 8 and 2. Here, the gas introduction system with valve 1 is used to artificially adjust the deposition atmosphere.
By introducing H2 gas at an appropriate flow rate, the partial pressure of H2 gas in the vacuum chamber 1 can be increased. In FIG. 2, 10 indicates a nozzle/'Y, and by providing such a nozzle, it is possible to further increase the H2 gas partial pressure near the exit of the nozzle, that is, in a region directly involved in vapor deposition.

Hereinafter, the present invention will be explained more specifically using Examples and Comparative Examples.

Example Using the apparatus shown in Figure 1, a gas introduction system? 5o H2 gas
By introducing at a flow rate of cc1 min and evacuation via valve IO, the vacuum degree of 1 yen of tank tg A, OX
/ O-1' Torr, the minimum angle of incidence lI on the polyethylene terephthalate film! A Fe vapor deposited film with a thickness of 1000X was formed by diagonal filtration.

Using the apparatus of Comparative Example 1@, no gas was introduced from the outside,
The vacuum degree was maintained at OX/0-'' Torr, and the other procedures were the same as in the examples.

The magnetostatic properties of the magnetic recording media obtained in the above Examples and Comparative Examples are summarized in a table.

As is clear from the above table, the magnetic recording medium obtained according to the present invention has improved magnetostatic properties, especially the squareness ratio.

[Brief explanation of drawings]

FIGS. 1 and 1 are schematic diagrams illustrating an example of the apparatus used in the method of the present invention. l......Vacuum tank......Unwinding roll 3...Φ
・・・・・・Non-magnetic base material・・・・・・・・・e cooling drum! ...... Vapor deposition source 60...00... Winding port + Lua ......... Shielding plate t, io-@
・・・・・・Valve 9・・・・・・・・・Gas introduction system

Claims (1)

[Claims] (1) A method for manufacturing a magnetic recording medium, characterized in that when forming an iron thin film by obliquely depositing iron on a nonmagnetic substrate in vacuum, the atmosphere for the obliquely depositing is a hydrogen gas atmosphere.