JPH06103567A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To carry out a process for forming a protective-lubricative layer on the magnetic layer of a magnetic recording medium in vacuum and to reduce the number of production processes. CONSTITUTION:A magnetic layer is formed in a vacuum vessel 11 of a vacuum deposition device 10 and a silane coupling agent 23 filled into a crucible 22 is evaporated in the vacuum vessel 11. Steam is then blown from a steam introducing pipe 25 on the evaporated silane coupling agent 23 on the magnetic layer of the resulting magnetic tape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic recording medium, and more particularly to a technique for forming a protective / lubrication layer by using a coupling agent in a vacuum atmosphere.

[0002]

2. Description of the Related Art A magnetic recording medium such as a magnetic tape or a hard disk has a structure as shown in FIG. In FIG. 2, for example, an undercoat layer 3, a magnetic layer 4, a protective / lubricating layer 5 are sequentially formed on the surface of a PET (polyethylene terephthalate) film 2 as a base material of the magnetic tape 1, and the back surface of the PET film 2 is also formed. A back coat layer 6 is formed on the.

Conventionally, a combination of carbon, SiO ₂ , fatty acid ester, perfluoropolyether and the like has been used for the protective layer and the lubricating layer. To manufacture such a magnetic recording medium, carbon and SiO ₂ are deposited on the magnetic layer 4 in a vacuum atmosphere, but fatty acid ester and perfluoropolyether cannot be formed in a vacuum atmosphere. When these materials are used, they are formed in air.

[0004]

By the way, in the conventional method of manufacturing a magnetic recording medium, a process in a vacuum atmosphere and a process in air are mixed to manufacture the protective layer and the lubricating layer. Therefore, the manufacturing process was complicated in a vacuum atmosphere, and the number of processes could not be reduced. The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a method of manufacturing a magnetic recording medium capable of forming a protective layer / lubrication layer of the magnetic recording medium in a vacuum atmosphere.

[0005]

Therefore, according to the present invention, after forming a magnetic layer on a base material of a magnetic recording medium in a vacuum chamber in a vacuum atmosphere, a coupling agent that undergoes a hydrolysis reaction is added in the vacuum chamber. Water vapor is sprayed toward the evaporated coupling agent in the vicinity of the magnetic layer, and the coupling agent reacts with the sprayed predetermined amount of water on the surface of the magnetic layer to form a magnetic layer on the magnetic layer. A protective / lubrication layer is formed on the.

[0006]

According to the above construction, the coupling agent evaporated on the surface of the magnetic layer undergoes a hydrolysis reaction with the sprayed water vapor to form a protective / lubricating layer on the magnetic layer. Since this step is performed in a vacuum atmosphere, it is possible to continuously form the protective / lubrication layer in the same vacuum atmosphere from the step of forming the magnetic layer.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The same elements as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 1 showing the present embodiment, the inside of the vacuum chamber 11 of the vacuum vapor deposition apparatus 10 is a vacuum exhaust system 12
Is continuously evacuated, and is maintained in a vacuum atmosphere of, for example, 10 ⁻⁵ to 10 ⁻⁶ (Torr).

Unwinding roll 13, can 14, roller 15,
The can 16 and the take-up roll 17 have a cylindrical shape that rotates about an axis. For example, the magnetic tape 18 having the PET film 2 as a base material is mounted on the take-up roll 13, and the can 14, the roller 15, and the can 15 are wound. It is wound around a winding roll 17 via the peripheral side surface of 16. Crucible containing magnetic material 20
18 is disposed at a position where it is obliquely vapor-deposited on the PET film 2, and the peripheral side surface of the can 14 directly below the rotation axis is covered with a shielding plate 20. An electron beam gun is used for the magnetic material 19 in the crucible 18.
An electron beam 21a is struck from 21 to evaporate the magnetic material 19. The evaporated magnetic material 19 is obliquely vapor-deposited on the surface of the magnetic tape 1 with its evaporation direction being regulated to form the magnetic layer 4 having a column structure.

The crucible 22 is disposed just below the can 16, and a silane coupling agent 23, which will be described later, is placed in the crucible 22 so that the silane coupling agent 23 evaporates in the crucible 22. It has a built-in heater.
In addition, a crucible made of magnetic material is placed between the cans 14 and 16.
A shielding plate 24 is provided for restricting evaporation from 18 toward the can 16 and the crucible 22 and evaporation of the silane coupling agent 23 from the crucible 22 toward the can 14 and the crucible 18.

A magnetic tape 1 is provided just below the can 16.
A water vapor introducing pipe 25 is arranged so as to spray the water vapor onto the coupling agent 23 which evaporates on the magnetic layer 4. Next, the operation will be described. Electron beam 21a with electron beam 21a
When the magnetic material 19 is driven into the magnetic material 19, the magnetic material 19 is evaporated by heating and obliquely deposited on the magnetic tape 1 on the circumferential side surface of the can 14.
As a result, the magnetic layer 4 is formed, and the magnetic tape 1 is a roller.
Move to the peripheral side of the can 16 via 15.

The silane coupling agent 23 contained in the crucible 22 has a boiling point of 144 ° C. and is heated by a heater built in the crucible 22 and evaporated. Water vapor is sprayed from the water vapor introducing pipe 25 toward the evaporated silane coupling agent on the magnetic layer 4 formed on the magnetic tape 1. The silane coupling agent causes the following hydrolysis reaction with the sprayed water vapor on the magnetic tape 1. The YRSi (OH) ₃ produced by this reaction is strongly bound to the magnetic layer 4, which is the surface of the inorganic material. Also, this YRSi (O
H) ₃ has a smooth property and is an optimum material for a protective layer and a lubricating layer.

Next, the evaluation results of the characteristics will be shown. The characteristics were evaluated by a still durability test. That is, the magnetic tape was slit to 8 mm, and the tape was inserted into an 8 mm VTR cassette, and the decrease in output at 4 MHz after the still state for 1 hour was measured. Normal,
The standard output value after the still durability test is 4 MHz before the test.
Within -3 dB of the output value of. After the still durability test, an output decrease of 0.5 dB was measured, and the result was very good.

According to this structure, after forming the magnetic layer 4 in the vacuum vapor deposition apparatus, the coupling agent is evaporated, and steam is sprayed onto the evaporated coupling agent on the magnetic layer 4 for coupling. By hydrolyzing the agent, the protection / lubrication layer 5 can be formed in vacuum, and the protection / lubrication layer 5 can be continuously formed in the same vacuum atmosphere from the step of forming the magnetic layer 4. Therefore, the number of manufacturing steps is reduced.

Further, since all the steps are performed in a vacuum, dust adhesion during the steps is prevented. Furthermore, the result of the still durability test was very good. In this embodiment, the silane coupling agent was used as the coupling agent, but the coupling agent is not limited to this, and any coupling agent that binds to the magnetic layer 4 by a hydrolysis reaction can be used, for example, titanate. A system coupling agent, an aluminate system coupling agent, a zircon system coupling agent, an aluminum zircon system coupling agent, etc. may be used.

[0015]

As described above, according to the present invention, after the magnetic layer 4 is formed, the coupling agent is evaporated in a vacuum chamber and a predetermined amount of water vapor necessary for the reaction is evaporated on the magnetic layer 4. By spraying onto the coupling agent and causing the coupling agent to undergo a hydrolysis reaction, it is possible to continuously form a protective / lubricating layer in the same vacuum atmosphere from the step of forming the magnetic layer. The number of manufacturing steps of the medium can be reduced.

Further, since all the steps are performed in a vacuum, dust adhesion during the steps is prevented. Furthermore, the still durability test was also very good.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a vacuum vapor deposition device of the present invention.

FIG. 2 is a sectional view of a magnetic recording medium.

[Explanation of symbols]

 1 Magnetic Tape 4 Magnetic Layer 5 Protective / Lubricating Layer 10 Vacuum Evaporation Device 11 Vacuum Tank 13 Unwinding Roll 14, 16 Can 17 Winding Roll 23 Silane Coupling Agent 20, 24 Shielding Plate 25 Water Vapor Introducing Pipe

Claims (1)

[Claims] 1. A magnetic layer is formed on a base material of a magnetic recording medium in a vacuum chamber in a vacuum atmosphere, a coupling agent which undergoes a hydrolysis reaction is evaporated in the vacuum chamber, and evaporated in the vicinity of the magnetic layer. Water vapor is sprayed toward the coupling agent, and the coupling agent and a predetermined amount of water sprayed are reacted on the surface of the magnetic layer to form a protective / lubricating layer on the magnetic layer. A method for manufacturing a characteristic magnetic recording medium.