JPH0721554A - Smoother for forming lubricating layer of magnetic recording medium - Google Patents

Abstract

PURPOSE:To impart excellent lubricity to a magnetic recording medium at the time of smoothing a lubricant deposited on a magnetic layer to form a lubricant layer by press-bonding the lubricant with a flexible member. CONSTITUTION:A cobalt-nickel alloy, etc., are vacuum-deposited on one side of a base film 3 consisting of polyethylene terephthalate, etc., to form a magnetic layer. The film is then placed in a housing 8 contg. a heating can 4, nozzle 6 and ultrasonic spraying device 7 to form the magnetic layer. Namely, the film 3 coated with the magnetic layer is traveled on the can 4, and a lubricant such as denatured alcohol is then atomized by the device 7 and sprayed on the film 3 from the nozzle 6. The film 3 is then passed through a smoother 5, and the lubricant surface is smoothed. In this case, the smoother 5 is formed with a flexible metallic film and set at a position where a slight load is applied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a smoother used for forming a lubricating layer of a metal thin film type magnetic recording medium.

[0002]

2. Description of the Related Art As a conventionally known magnetic recording medium,
There is a so-called metal thin film type magnetic recording medium in which a magnetic metal material is directly attached to a non-magnetic support by a method such as vapor deposition and sputtering to form a magnetic layer.

In the case of a metal thin film type magnetic recording medium, a method such as roller transfer in air with a lubricant is used for the purpose of lowering the friction coefficient between the magnetic recording medium and the head to improve the running property and protecting the magnetic layer. To form a lubricating layer (overcoat layer) on the magnetic layer by coating on the magnetic layer or by impregnating a nonmagnetic support in a lubricant solution.

[0004]

However, it is difficult to obtain a lubricating layer having a more uniform surface state by the method of applying a lubricant on the magnetic layer as in a metal thin film type magnetic recording medium. Lubrication performance is not demonstrated. Therefore,
It is desired to provide a metal thin film type magnetic recording medium with further excellent lubricating performance.

[0005]

The present inventors have completed the present invention as a result of earnestly researching a method for solving the above problems and producing a magnetic recording medium having excellent lubricating performance. .

That is, the present invention is a smoother which is arranged along a conveying path of a magnetic recording medium and smoothes the lubricant adhered on the magnetic layer to form a lubricant layer, which can be pressure-bonded to the lubricant. The present invention provides a smoother for forming a lubricating layer of a magnetic recording medium (hereinafter referred to as the smoother of the present invention), which includes a flexible member.

The smoother of the present invention can be applied to a so-called coating type magnetic recording medium and a metal thin film type magnetic recording medium, and is particularly preferably used for forming a lubricating layer of a metal thin film type magnetic recording medium. .

The smoother of the present invention includes a flexible member which is pressure-bonded to the lubricant adhered on the magnetic layer formed on the non-magnetic support, and the flexible member is attached to the magnetic recording medium by a suitable fixture. Are arranged along the conveying path of the manufacturing process of.

As the flexible member used in the present invention,
It is necessary to select a shape and material that allows the lubricant deposited on the magnetic layer to spread uniformly. For example, a thickness of 1 μm to 5 mm made of metal or plastic such as polyamide.
A plate-shaped material having a degree of flexibility can be used. By smoothing after applying the lubricant, the unevenness of the adhesion of the lubricant can be eliminated and a lubricating layer having a uniform surface state can be obtained, so that the running property of the magnetic recording medium is improved.

FIG. 1 shows a smoother of the present invention which is pressure-bonded to a non-magnetic support on a conveying path, and FIG. 2 is a schematic cross-sectional view thereof, which are schematic views, and the positional relationship and scale are not the actual ones. Is different. In FIG. 1, 1 is a flexible member, and 2 is a fixture for the flexible member. The flexible member is fixed by screws and attached to an appropriate portion inside the housing. Further, 3 is a non-magnetic support to which a lubricant is attached, which runs in the direction of the arrow. The mounting position of the flexible member 1 may be appropriately determined in consideration of the material of the member, the type of lubricant, the traveling speed of the non-magnetic support, and the like.

In the present invention, examples of the method for depositing the lubricant on the magnetic layer include, but are not limited to, a method of applying a lubricant and a method of spraying a lubricant. The smoother attachment position and the amount of lubricant adhered are preferably adjusted so that the finally formed lubricating layer has a thickness of about 50 to 200 Å.

The lubricant to be adhered on the magnetic layer may be fatty acid type or fluorine type, but perfluoropolyether is particularly preferable. As the perfluoropolyether, those having a molecular weight of 2000 to 5000 are preferable, for example, “FOMBLIN Z DIAC” [carboxyl group-modified,
A product commercially available under the trade name of "Montecatini Co., Ltd." or "FOMBLIN Z DOL" [alcohol modified, Montecatini Co.] can be used. Since these have a hydroxyl group or a carboxyl group at the terminal, they can enhance the binding between the lubricant and the magnetic layer, and are therefore particularly preferably used in the present invention.

Besides this, a fluorine-based lubricant containing a benzene ring, a double bond, a branched chain, etc. can also be used. Fluorine-based lubricants are particularly preferably used in the present invention because they improve not only durability but also corrosion resistance as compared with fatty acid-based lubricants.

The lubricant is a fluorine-based inert solvent (for example, perfluorocarbon such as "Fluorinert" manufactured by Sumitomo 3M Limited), an aromatic hydrocarbon solvent such as toluene, an alcohol-based solvent, a suitable solvent such as a ketone-based solvent. It is preferably used as a solution of about 0.001 to 10% by weight dissolved in. When perfluoropolyether is used as the lubricant, perfluorocarbon can be used as the solvent, and the concentration in that case is preferably about 0.001 to 1.0% by weight.

As the non-magnetic support, polyesters such as polyethylene terephthalate and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; cellulose derivatives such as cellulose triacetate and cellulose diacetate; polycarbonates;
Polyvinyl chloride; polyimide; plastics such as aromatic polyamide are used. The thickness of these non-magnetic supports is about 3 to 200 μm.

[0016]

According to the smoother of the present invention, the surface state of the lubricating layer on the magnetic layer of the magnetic recording medium can be made more uniform, and the running property of the magnetic recording medium is improved.

[0017]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 A magnetic layer was formed on one surface of a 10 μm thick base film (made of polyethylene terephthalate) by vapor deposition in vacuum (5 × 10 ⁻⁵ Torr). As the magnetic material for the magnetic layer,
A cobalt-nickel alloy (Co: Ni = 80%: 20%) was used, and the thickness of the magnetic layer was 0.2 μm.

Next, a lubricating layer was formed by an apparatus for forming a lubricant installed in the housing 8 as shown in FIG. That is, the base film 3 having the magnetic layer formed as described above is run on a heating can 4 and "FOMBLIN Z DOL" [alcohol modified by Montecatini Co.] is used as a lubricant by an ultrasonic spraying device 7. The lubricant was made into fine particles and sprayed onto the base film 3 from the spray nozzle 6. The inside of the housing 8 is maintained at a vacuum degree of 2 × 10 ^-2 Torr by a vacuum pump (not shown).

The base film 3 sprayed with the lubricant is
After passing through the smoother 5 of the present invention, the surface of the lubricating layer is smoothed. The flexible member of the smoother 5 has a thickness of 0.1.
It is made of a flexible metal film of mm, and is installed at a position where a slight load is applied to the base film 3.

Example 2 A flexible polyamide film having a thickness of 0.1 mm was used as the flexible member of the smoother, and the position of the lubricant spray nozzle was changed as shown in FIG. The lubricant was sprayed in the same manner as in No. 1 to smooth the lubricating layer.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the smoother of the present invention.

FIG. 2 is a schematic sectional view of the smoother of the present invention.

FIG. 3 is a schematic view of an example of an apparatus for forming a lubricating layer including the smoother of the present invention.

FIG. 4 is a schematic view of another example of a lubricating layer forming apparatus including a smoother of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flexible member 2 ... Fixing device 3 ... Non-magnetic support body 4 ... Heating can 5 ... Smoother 6 ... Nozzle 7 ... Ultrasonic spraying device 8 ... Housing

Claims (1)

[Claims] 1. A smoother which is arranged along a conveying path of a magnetic recording medium and smoothes a lubricant adhered on a magnetic layer to form a lubricant layer, which is a flexible member press-bonded to the lubricant. A smoother for forming a lubricating layer of a magnetic recording medium, which comprises: