JPS59112436A - Manufacture of magnetic tape - Google Patents

Abstract

PURPOSE:To prevent a magnetic tape from being curved by setting the magnetic metallic film side inward, and to obtain a tape having high performance by curving a supporting body consisting of polymer moldings, and forming a ferromagnetic metallic thin film on its projecting surface. CONSTITUTION:A polymer supporting body 3 of polyester film, etc. is moved from a feed roll 3a to a winding roll 3b by rotating a can 4 in the direction as indicated with an arrow A, along a cooling can 9 (4 in a separate figure) whose side face 9a is curved to the outside, a crucible 6 is heated by a polymer beam, and a metallic magnetic film 3c of Co-Ni, etc. is formed under an atmosphere of O2 whose pressure is reduced. In this case, an incident angle of the Co-Ni alloy and an interval in the longitudinal direction of vapor deposition are prescribed by using vapor deposition area prescribing masks 7a, 7b and 7c, and vapor deposition area prescribing plates 8a, 8b and 8c. In this way, d/l of length l of a magnetic tape 3 and a deformation degree (d) of the magnetic film 3c is set to <=0.01.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing a magnetic tape by forming a thin metal film by vapor deposition on a support such as a molded polymer.

BACKGROUND ART AND PROBLEMS Conventionally, a ferromagnetic metal layer is formed on a non-magnetic support made of a polymer molded material by diagonally depositing a metal magnetic material within a predetermined incident angle range. As a method of manufacturing a magnetic tape, a manufacturing method using a manufacturing apparatus as shown in FIG. 1 has been proposed.

In FIG. 1, (1) generally shows a magnetic tape manufacturing apparatus for producing a magnetic tape by so-called oblique deposition.
The interior (1a) of this magnetic tape manufacturing apparatus (1) can be evacuated using a vacuum pump (2). (3) indicates a non-magnetic support such as a 6 μm thick IJ ethylene terephthalate film tape. This non-magnetic support (3) is wound for a predetermined length around a cooling can (4) which rotates around a rotating shaft (4a) and has a cylindrical appearance to reduce its temperature. It is designed to move at speed in the direction indicated by the arrow. here,
The non-magnetic support (3) is supplied with a non-magnetic support supply roll (3a
), is wound around the cooling can (4) by a predetermined length, and is supplied to the winding roll (3b). (5) is a metal magnetic material such as cobalt.
A nickel alloy (80% cobalt, 20% nickel) is shown, and this cobalt-nickel alloy (5) Fi crucible (6)
It is placed in Then, when this crucible (6) is heated by an electron gun (not shown), an oxygen atmosphere of, for example, 5X10-5 torr is created using a vacuum pump (2) inside the manufacturing equipment (la) K. , the cobalt-nickel alloy (5) is evaporated and evaporated onto the non-magnetic support (3). On the other hand, the incident angle θ, which is the angle between the normal direction of the circumference as a horizontal cross section of the cooling can (4) and the direction of the non-magnetic support (3) from which the cobalt (5) is flying, is determined as a predetermined incident angle. In order to ensure that the cobalt-nickel alloy is diagonally deposited only within the corner range, masks for defining the deposition area (7m) (7b) (7a) are used.
) and vapor deposition area defining plates (8a), (8b), and (8c) are provided as shown. Here, the regulation plate (8a) and (
8b) respectively define the interval in the longitudinal direction of the non-magnetic support (3) in order to define the range of the incident angle in the vapor deposition region, and the defining plate (8C) defines the lower part in the width direction of the non-magnetic support. Although not shown, a regulation plate for defining the upper side is also provided corresponding to the regulation plate (8C). Also, masks (7a) (7b) (7c)
is provided in an arc shape close to the non-magnetic support, and the mask (
7a) and (7b) define the interval in the longitudinal direction to define the range of the incident angle, and the mask (7C) defines one side in the width direction of the non-magnetic support (3). A mask defining the other side of the magnetic support (3) in the width direction is provided corresponding to the mask (7C). Therefore, these regulation plates (8a) (8bX8c) and mask (7a)
(7b) (7c), cooling can (4) and crucible (6)
), the angle of incidence of the cobalt-nickel alloy onto the non-magnetic support (3) can be limited, resulting in the desired oblique deposition.

If magnetic tape is manufactured using this oblique deposition method,
A ferromagnetic metal thin film is formed by magnetic powder with a good acicular ratio,
It is known that high-performance magnetic tapes can be manufactured that can realize high-density recording by increasing the coercive force He of the magnetic tapes and making it possible to record short wavelength signals.

By the way, in the manufacturing method using this conventional device, the non-magnetic support (3) is continuously placed in the cooling can (4).
), and the non-magnetic support (3) is made flat in the width direction on the cooling can (4).

For stable movement, a predetermined tension is applied to the non-magnetic support (3). Therefore, the non-magnetic support (
3) is elongated in the longitudinal direction and contracted in the width direction during the vapor deposition process, causing a problem that curvature occurs on the inside.

In order to eliminate this curvature, attempts have been made to run the vehicle between heated rollers, but since the rollers are flat in the width direction, the same tension is applied when moving between the rollers, making it difficult to sufficiently remove the deformation. could not be done and the problem was not resolved.

OBJECTS OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a method for manufacturing a magnetic tape that can manufacture a magnetic tape without curvature.

Summary of the Invention The method for producing a magnetic tape of the present invention involves, when forming a ferromagnetic metal thin film on a support made of a polymer molded product, the support is curved to form a convex surface, and a ferromagnetic metal film is formed on the convex surface. A thin metal film is formed on the magnetic tape, making it possible to manufacture a magnetic tape without curvature.

X Application (5) An embodiment of the method for manufacturing the magnetic tape of the present invention will be described below with reference to FIG. This third diagram (including δω) shows the cooling can used in this embodiment, and the side surface (9a) of this cooling can (9) is a curved surface that curves outward.

In the example, the radius of curvature ρ of this curved surface is set to 0.3 m. In other respects, the structure is similar to that of the conventional magnetic tape manufacturing method.

Since this embodiment is configured in this manner, the non-magnetic support (3) is supplied from the non-magnetic support supply roll (3a), is wound around the cooling can (9) by a predetermined length, and is sequentially wound for winding. It is made such that it is fed to the roll (3b).

On the other hand, the crucible (6) is heated by the electron beam of the electron gun, and the cobalt-nickel alloy (5) is evaporated and ejected into an oxygen atmosphere of, for example, 0-5 torr, forming a mask for defining the vapor deposition area and a vapor deposition area. At an incident angle not defined by the area defining plate, the vapor is deposited on the surface of the non-magnetic support (3) wrapped around the cooling can (9). At this time, the non-magnetic support (3) is wrapped around a curved cooling can (9), and the non-magnetic support (3) is formed into a curved surface so that the side to be vaporized is convex, and is cooled at a predetermined speed. As the can (9) rotates, the nonmagnetic support (3) travels along a predetermined path, and a ferromagnetic metal thin film having a thickness of, for example, 04 Jim is formed on this convex surface.

Then, the degree of deformation per unit length is d in Figure 2.

If defined as dll per l, the degree of deformation according to the example shown in Table 1 was ODI. By the way, in the conventional case where the sides of Ri IJ Song Gang (9) were flat,
The degree of deformation was 0.08.

Table 1 In this example, when the radius of curvature of the curved surface in the width direction of the support body was manufactured by changing the radius of curvature ρ = 0.3 m to 05 m m 1.0 m + 20 m, the degree of deformation of the completed magnetic tape was 01). 5, OD7, 04)8, the curvature of the completed magnetic tape can be eliminated by adjusting the radius of curvature ρ.

According to this embodiment, the support is curved when wrapped around the cooling can (9) to form a convex surface, and a ferromagnetic metal thin film is formed on the convex surface. So, there is an advantage to being able to eliminate the curvature of the magnetic tape.

Next, as in the above embodiment, the cooling can (9) shown in FIG.
Another example of manufacturing a magnetic tape using the following will be described. In this embodiment, first a magnetic tape is obtained in the same manner as in the conventional example shown in FIG.
9) The process of wrapping the paper around the paper for a predetermined length and sending it is performed. By forcibly curving the magnetic tape in the opposite direction to the direction of curvature in this vapor deposition step and then performing a heat treatment, a magnetic tape from which such curvature has been removed can be obtained.

For example, the temperature of the cooling can (9) is set to 100°C, the radius of curvature of the curved side surface (9a) of the cooling can (9) is 05 m, and the vapor deposition layer side of the magnetic tape % is the side not in contact with the cooling can (9), and this heat treatment is performed. The process shall be carried out. As shown in Table 2, the running speed of the magnetic tape after vapor deposition process Table 2 was V [m/rmyr].
= 0.5, the degree of deformation was d/'t-0, and the curvature formed during the deposition process was completely eliminated.

As described above, this embodiment has the advantage that by bending the magnetic tape to a predetermined curvature and heating it, the curvature of the magnetic tape formed in the vapor deposition process can be released.

In this example, the running speed of the magnetic tape v=1 m/m
When the degree of deformation d/z-o, o 1, vtg'lJm
When dll-0,02, V W 3 m/m, dll-0,04, vm4@/m'
/l-o, 07, and in both examples, the curvature was improved compared to d/l = o, o s when no heat treatment step was performed, similar to the above-mentioned example.

Further, in each of the above-mentioned embodiments, it is possible to perform a heat treatment by running a concave curved side surface with the vapor deposition surface of the magnetic tape in contact with the side surface (9).

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various other configurations can be made without departing from the gist of the present invention.

Effects of the Invention As described above, the method for manufacturing a magnetic tape of the present invention has the advantage that a magnetic tape without any curvature can be manufactured.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a conventional magnetic tape manufacturing method, FIG. 2 is a line diagram for explaining the example in FIG. FIG. (3) is a support body, (9) is a cooling can, (9a)
is an aspect of cooling can. (10)

Claims (1)

[Claims] When forming a ferromagnetic metal thin film on a support made of a molded polymer, the support is curved to form a convex surface, and the ferromagnetic metal thin film is formed on the convex surface. A method of manufacturing magnetic tape.