JPH0798868A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To avoid production of an area where a magnetic layer is not protected, and to prevent the deterioration of performance of the medium by disposing a slitter between a release roll and a cooling roll and cutting the medium into specified width before the material to be treated is coated by vapor deposition. CONSTITUTION:A slitter 15 comprising an upper blade 16 and a lower blade 17 is disposed between a release roll 6 and a cooling roll 8. A tape released from the roll 6 is cut in the traveling direction to have specified width by the slitter 15, and then guided by a roll 8 and introduced to a vapor deposition zone to form a magnetic layer. At the end of the vapor deposition zone, oxygen gas is supplied through an oxygen gas supply tube 19. Oxygen is bonded with the vapor-deposited particles of the magnetic layer to form an oxide layer as a protective layer on the magnetic layer. In this process, the oxygen gas is also bonded with particles on side faces of the magnetic layer so that the whole surface of the magnetic layer is covered with the oxide layer. Therefore, such an area that the magnetic layer is not coated can be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a vapor-deposited magnetic recording medium in which vapor of a magnetic material is vapor-deposited to form a magnetic layer.

[0002]

2. Description of the Related Art A vapor deposition tape, which is one of vapor deposition type magnetic recording media, is a tape made by adhering a vapor of a ferromagnetic material such as iron, nickel or cobalt to a film base surface. The vapor-deposited tape produced in this way does not require the binder required for a coating-type tape, so that a thin magnetic layer can be formed with a high degree of filling, improving the high frequency characteristics and reducing the tape thinness. Stylization can be achieved.

As a conventional apparatus for producing a vapor-deposited magnetic recording medium, a vacuum container, a traveling device for traveling a series of materials to be vapor-deposited disposed in the vacuum container, and a magnetic material disposed below the material to be vapor-deposited. A crucible having a melting tank, an electron beam generator for irradiating the magnetic material of the crucible with an electron beam, and an oxidizing gas supply device arranged at the end of the vapor deposition region for supplying an oxidizing gas. is there. Then, the magnetic material in the melting tank of the crucible was irradiated with an electron beam, whereby the magnetic material was irradiated with the electron beam to be melted and continued to evaporate, and the vapor was deposited on the deposition target material. Further, the oxidizing gas supply device arranged at the end of the vapor deposition region supplies the oxidizing gas so as to form an oxide layer as a protective layer on the magnetic layer.

After the film is formed, the material to be vapor-deposited is taken out of the vacuum container, subjected to various treatments, and then subjected to a slitter and cut into a predetermined width. The material to be vapor-deposited, which has been cut into a predetermined size, is incorporated into a cassette and shipped as a product.

[0005]

Since the cutting process by the slitter is at the end of the magnetic recording medium manufacturing process, the cutting surface becomes a product without any treatment. Therefore, the performance of the magnetic recording medium may start to deteriorate in a shorter period than the cut surface.

FIG. 5 shows a cut surface of a magnetic recording medium cut by a slitter. A magnetic layer 30 is formed on a material to be deposited, that is, a base 33, and an oxide layer 34 is formed on the magnetic layer 30.
Is formed, but the cut surface 3 of the magnetic layer 30 is formed by cutting.
1 results in exposure to the open air. That is, the oxide layer 34 does not function as a protective layer on the cut surface 31. Deterioration of the magnetic recording medium progresses from the cut surface 31.

FIG. 4 shows the state of the deterioration. That is, in the magnetic layer 30 formed on the base 33, cracks 32 enter from the cut surface 31 at the time of cutting, and air, moisture and the like enter from the cracks 32 and deteriorate.

The present invention has been made in view of the above problems, and an object thereof is to prevent the deterioration of the performance of the magnetic recording medium by eliminating the unprotected surface of the magnetic layer, It is an object of the present invention to provide a magnetic recording medium manufacturing apparatus capable of maintaining the initial performance of a magnetic recording medium for a long period of time.

[0009]

A magnetic recording medium manufacturing apparatus according to the present invention comprises a vacuum container, a traveling device for traveling a series of materials to be vapor-deposited disposed in the vacuum container, and a device below the material to be vapor-deposited. A crucible provided with a melting tank for magnetic material, an electron beam generator for irradiating the magnetic material of the crucible with an electron beam, and an oxidizing gas supply provided at the end of the vapor deposition region for supplying an oxidizing gas Device, the traveling device, a feed roll, in a magnetic recording medium manufacturing apparatus including a cooling roll, a slitter for cutting the material to be vaporized fed from the feed roll to a predetermined width in the traveling direction as a feed roll. It is characterized in that it is arranged between the cooling rolls.

According to the present invention, a slitter is arranged between the feed roll and the cooling roll. This slitter acts so as to cut the vapor deposition target material fed from the feed roll into a predetermined width in the traveling direction. Therefore, the material to be vapor-deposited is different from the conventional one and is cut before being vapor-deposited.

The cut material to be vapor-deposited is fed by a traveling device and enters the vapor deposition region where vapor deposition is performed to form a magnetic layer on the material to be vapor-deposited. At the end of the vapor deposition region, oxidizing gas is supplied by the oxidizing gas supply device,
This oxidizing gas combines with the vapor-deposited particles of the magnetic layer to form an oxide layer as a protective layer on the magnetic layer. The oxidizing gas not only bonds with the vapor-deposited particles on the top surface of the magnetic layer,
It also binds to vapor-deposited particles on the side surface of the magnetic layer. In this way, the entire magnetic layer is covered with the oxide layer.

[0012]

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

FIG. 1 is a block diagram of an apparatus for manufacturing a magnetic recording medium according to the present invention. The present apparatus includes a vacuum container 1, a traveling device 2, a crucible 3, an electron beam generator 4, and an oxidizing gas supply device 20. Vacuum container 1
The discharge port 29 is connected to a vacuum pump (not shown), and a traveling device 2 for traveling a series of materials to be vapor-deposited, that is, the synthetic resin tape 5, is arranged in the vacuum container 1. The traveling device 2 includes a feed roll 6, two take-up reel groups 7, a cooling roll 8, and an elastic roll 12 in contact with the cooling roll 8 and the two take-up reel groups 7. . The crucible 3 is arranged at a predetermined position below the cooling roll 8. The crucible 3 is made of MgO and can withstand a high temperature of about 2000 ° C. Further, the crucible 3 includes a melting tank 9, and the magnetic metal 10 is housed in the melting tank 9. The electron beam generator 4 includes an electron gun 11, which emits an electron beam and irradiates the magnetic metal 10 in the melting tank 9 with the electron beam. The shielding plate 24 regulates the vapor deposition area of the magnetic metal vapor on the tape 5, and the position of the shielding plate 24 and the crucible 3 is at an angle θ (normal of the cooling roll and center line of the crucible) shown in FIG. It is installed so that the angle formed by and is about 45 degrees. The oxidizing gas supply device 20 is connected to the oxygen gas supply source 18, the introduction pipe 14 connected to the supply source 18, the flow rate control valve 13 arranged in the introduction pipe 14, and the introduction pipe 14. And an oxygen gas supply pipe 19. The oxygen gas supply pipe 19 is
The tip is disposed at the end of the vapor deposition region so as to form an oxide layer on the magnetic layer.

A slitter 15 is arranged between the feed roll 6 and the cooling roll 8. This slitter 15 is
It consists of upper and lower round blades. A large number of upper blades 16 are juxtaposed on the rotary shaft at a predetermined interval. Also the lower blade 17,
Similar to the upper blade 16, a large number of them are juxtaposed on another rotating shaft at a predetermined interval. The upper blade 16 and the lower blade 17 are sandwiched by the blades being rotated by the power source via the respective rotary shafts in opposite directions, so that the original tape of the magnetic tape 5 is removed. It is designed to be cut. The cutting width can be easily changed by moving the position of the blade. The magnetic tape 5 is cut by the slitter 15 into a predetermined width in the running direction.

FIG. 2 is a plan view of the two take-up reel groups 7 and the elastic roll 12. The tape winding surface 22 of the winding reel group 7 is positioned by the spacer 21, and the tape winding surface 22 between the two winding rolls is arranged alternately. The elastic roll 12 guides the cut tape 5, and the tape winding surfaces 22 of the two winding rolls are in contact with the elastic roll 12. The even-numbered tapes are taken up by one take-up reel 7, and the odd-numbered tapes are taken up by the other take-up reel 7.

In the apparatus of the present invention thus constructed, the tape 5 delivered from the feed roll 6 is cut in the running direction by the slitter 15 to a predetermined width, and then guided by the cooling roll 8 into the vapor deposition area. enter. Electron gun 1
When the electron beam is irradiated onto the magnetic metal 10 by 1, the magnetic metal 10 is irradiated with the electron beam and melts,
Continue to evaporate. The tape 5 that has entered the evaporation region rotates in the circumferential direction on the cooling roll while receiving the vapor deposition of the magnetic metal vapor, and the magnetic layer is formed on the tape in the meantime. At the end of the vapor deposition region, oxygen gas is supplied by the oxygen gas supply pipe 19, and this oxygen gas combines with the vapor deposition particles of the magnetic layer to form an oxide layer as a protective layer on the magnetic layer. The oxygen gas not only bonds with the vapor-deposited particles on the upper surface of the magnetic layer, but also with the vapor-deposited particles on the side surfaces of the magnetic layer. In this way, the entire magnetic layer is covered with the oxide layer. The tape 5 on which the oxide layer is formed is taken up by the take-up reel group 7 via the elastic roll 12.

When using this apparatus, the vapor deposition conditions can be set to the following numerical values.

Degree of vacuum: 4.5 × 10 -5 torr Travel speed: 0.5 m / min Output of electron gun: 16 Kw (10 Kv) Magnetic metal: ..Co-Ni alloy (80-20% by weight) Oxygen gas supply rate ... 100 cm3 / min Thickness of deposited film ... 1200 angstroms FIG. 3 shows the oxidation of the magnetic recording medium manufactured by the device of the present invention. The state of layer formation is shown. A magnetic layer 28 is formed on the tape 5, and an oxide layer 29 is formed thereon. It can be clearly seen that the oxide layer 29 covers the entire magnetic layer including both side surfaces 28a of the magnetic layer.

(Example) A base film having a back coat layer formed thereon was attached to the present apparatus shown in FIG. 1, and a Co-Ni alloy (80-20% by weight) in the crucible was evaporated and oxidized by an electron gun. Oxygen gas was supplied by a reactive gas supply device to form a film having a thickness of about 1500 Å on the film.

Comparative Example On the other hand, as a comparative example, a conventional apparatus was used to perform film formation under the above conditions, and the film after film formation was cut by a slitter.

Each of the two films was placed in an 8 mm cassette, and the cassette was placed in a thermo-hygrostat having a temperature of 40 ° C. and a relative humidity of 80% to perform an accelerated deterioration test. ) Retention rates were compared. The comparison results are shown in the table below.

(The margin below)

[0023]

[Table 1]

From these results, it can be seen that the oxide layer functioning as a protective layer is better in the film formed using the present apparatus than in the film forming using the conventional apparatus.

[0025]

Since the device of the present invention is constructed as described above, the unprotected surface of the magnetic layer can be eliminated, and the entire magnetic layer is protected by the oxide layer. Therefore, the magnetic recording medium manufactured by the manufacturing apparatus of the present invention can maintain its initial performance for a long period of time.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an apparatus for manufacturing a magnetic recording medium according to the present invention.

FIG. 2 is a plan view of a winding roll and an elastic roll included in the present apparatus.

FIG. 3 is a perspective view of a magnetic recording medium manufactured by this manufacturing apparatus.

FIG. 4 is a diagram showing a state of deterioration of a conventional magnetic recording medium cut by a slitter.

FIG. 5 is a view showing a state of a cut surface of a conventional magnetic recording medium cut by a slitter.

[Explanation of symbols]

 1 Vacuum Container 2 Traveling Device 3 Crucible 4 Electron Beam Generator 5 Tape (Material to be Evaporated) 6 Feed Roll 8 Cooling Roll 10 Magnetic Metal 15 Slitter 19 Oxygen Gas Supply Pipe 20 Oxidizing Gas Supply Device

Front page continuation (72) Inventor Akira Shiga 2606 Akabane, Kaigai-cho, Haga-gun, Tochigi Kao Corporation

Claims (1)

[Claims] Claim: What is claimed is: 1. A vacuum vessel, a traveling device for traveling a series of materials to be vapor-deposited arranged in the vacuum vessel, a crucible having a melting tank for magnetic material, which is arranged below the material to be vapor-deposited, and the crucible. The electron beam generator for irradiating the magnetic material with an electron beam, and the oxidizing gas supply device arranged at the end of the vapor deposition region for supplying the oxidizing gas, the traveling device includes a feed roll and a cooling device. In a magnetic recording medium manufacturing apparatus including a roll, a slitter for cutting the material to be vaporized fed from the feed roll to a predetermined width in a traveling direction is disposed between the feed roll and the cooling roll. Recording medium manufacturing device.