JPH01196725A - Production of metallic thin film magnetic recording medium - Google Patents

Abstract

PURPOSE:To remove foreign matters stuck to a medium without damaging the medium by bringing a lapping tape into contact with both faces of the medium. CONSTITUTION:A medium 1 where a metallic magnetic thin film layer is formed on a substrate consisting of a polyester or the like is led out from a supply roll 2 and is brought into contact with lapping tapes 5 and 9 in a magnetic face treating part A and a rear face treating part B and is wound around a take-up roll 3. A lapping tape where a grinding member is coated on a polyester film or the like can be used, and it is preferable that tapes 5 and 9 of >=5,000 surface roughness are brought into contact with the medium 1 with <=20g/cm<2> contacting pressure. It is preferable that blow-off devices 13 and suction devices 14 for clean air are provided in the vicinity of treating parts to prevent foreign matters floating in air from being stuck to the medium 1 again.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a metal thin film type magnetic recording medium using a cleaning tape particularly suitable for removing attached foreign matter.

BACKGROUND OF THE INVENTION In general, magnetic recording media are required to minimize blemishes and dropouts, which cause deterioration in image and sound quality. These performance deteriorations are mainly caused by foreign matter (dust, missing matter, deposits, etc.) generated or mixed in during the manufacturing process adhering to the surface of the magnetic layer. Conventionally, therefore, as countermeasures against these problems, removal using non-woven wiping paper, removal by blowing clean air, etc. have been adopted.

Problems to be Solved by the Invention In conventional coating-type magnetic recording media, the above-mentioned measures have been sufficiently effective and led to a significant performance improvement, but the surface smoothness is even better and the surface is made of a metal material. In metal thin film magnetic recording media, the adhesion between foreign particles and the surface of the magnetic layer is stronger than in conventional media, and the above measures do not prevent foreign particles, especially those with a diameter of several μm or more.
There was a problem in that foreign matter of several tens of micrometers could not be completely removed.

An object of the present invention is to provide a manufacturing method for effectively removing foreign matter adhering to the surface of a metal thin film magnetic recording medium without damaging the medium.

Means for Solving the Problems In order to solve the above problems, the present invention runs a wrapping tape in pressure contact with the surface of a metal thin film type magnetic recording medium.

Operation The present invention, with the above-described configuration, can process the surface roughness and contact pressure of the wrapping tape under conditions that are optimized from the viewpoint of the balance between the foreign matter removal effect and the damage to the medium.

Example The present invention will be specifically explained below based on Examples.

In FIG. 1, a magnetic recording medium 1 (hereinafter referred to as a raw material) in which a metal magnetic thin film layer is formed on a substrate made of synthetic resin such as polyester is first wound around an unwinding roll 2, and is sequentially wound in the direction of the arrow. It is pulled out and moved, passes through a guide roller 4, and is wound again on a winding roll 3. During this time, the magnetic surface processing section A and the back surface processing section B are brought into contact and both surfaces are processed simultaneously. The main purpose is to remove foreign matter from the surface of the magnetic layer, but since there is a possibility that foreign matter adhering to the back side may also be transferred and adhere to the surface of the magnetic layer, double-sided treatment is basically used. Both the magnetic surface treatment section A and the back surface treatment section B each include a wrapping tape 6.9 in which an abrasive material is applied to a substrate made of synthetic resin such as polyester, and its unwinding roll 6.
, 10. Take-up roll 7.11 and also contact roll 8,
It consists of 12. Raw material 1 is generally a wide 500
It may be of mW to 1000 mW, or may be a narrow width slit of Bm, 3A inch, 1 inch, etc., and the thickness is not particularly limited to 5 to 100 μm. The running speed is generally 30m/i~300171/s
However, it can be handled by considering the contact area, the number of processing stages, and the degree of foreign matter adhesion, and is not limited to this.

On the other hand, it is desirable that the wrapping tape 6.9 has a width υ wider than the original roll 1, and the running speed is
It is slower than the speed of , and there is a constant speed difference. This speed difference is determined based on the running stability, how dirty the wrapping cheese is, and the economy of wrapping tape consumption. //6o~54
゜. We are considering the extent. Regarding the running direction, both the same direction and the opposite direction to the original fabric running direction are effective, but the opposite direction shows a particularly good tendency. The dependence of the lapping tapes 5 and 9 on the abrasive material removal ability of alumina.

We investigated chromium oxide, iron oxide, silicon carbide, etc., but no particularly significant differences were found.

Next, parameters that affect processing performance obtained from various studies will be explained using Table 1.

C-space T-4. #L) [No.] 1st table Contact pressure C? /crlJ There are two important parameters in this process: (1) the contact pressure between the wrapping cheese and the original fabric, and (11) the surface roughness of the wrapping tape.

First, regarding the first contact pressure, it can be inferred that it is important since this process removes adhered foreign matter by physical force. At this time, the removal ability increases as the contact force increases, but if a certain limit is exceeded, scratches and damage occur, and the amount of foreign matter increases. This limit value is 20! /cri
l, and in this region it becomes independent of the type of wrapping tape. Therefore, the contact pressure must be within a range that does not cause damage.

This contact pressure is controlled by (1) the strength of the tension on the web, and (11) the clinging state of the web and wrapping tape (this is determined by the diameters of the contact rolls 8 and 12 and the vertical positional relationship of the center axes). (determine).

Next, regarding the surface roughness of the second wrapping tape, 6
It was found that when the surface was treated with a surface roughness of No. 000 or less, the limit of the contact pressure at which damage occurred was lowered. The reason for this is not clear, but in any case, in order to maximize the foreign matter removal effect, use wrapping tape with a roughness of No. 6000 or higher and a limit contact pressure of 20 y/w.
It is necessary to process at a high temperature below cnl.

These are summarized in Table 1 above. The horizontal axis shows the contact pressure, and the vertical axis shows the surface roughness of the wrapping tape. The upper row of each square shows the foreign matter removal effect (○: completely removed, △: 8
Approximately 0 can be removed. X: 30-40% can be removed. −;
The degree of scratch damage (○: no scratch damage, 61 weak discontinuous 1 to 2 occurrences, ×: strong continuous 4 to 2) 6 occurrences).

Next, in order to further complete the treatment, a clean air blower 13 and a suction device 14 are provided near the treatment section. This is done to prevent foreign matter from re-adhering to the original fabric, as most foreign matter will adhere to the wrapping tape, but some may become loose depending on the material and size. This is especially effective when there is a lot of foreign matter attached.

Effects of the Invention As is clear from the above explanation, according to the present invention, foreign substances with strong adhesion strength can be almost completely removed from metal thin film magnetic recording media that are easily damaged by scratches, without causing such side effects. Therefore, clogging and dropouts are reduced, and good sound and image quality can be provided, contributing to higher performance of metal thin film recording media. Furthermore, this treatment is economical because it can be introduced into other processes and does not require any special process.

[Brief explanation of the drawing]

The figure is a side view of an apparatus that embodies a manufacturing method according to an embodiment of the present invention. 1...Metal thin film magnetic recording medium (original film), 2.
...Original fabric unwinding roll, 3...Original fabric winding υ roll, 4...Guide roll, 5, 9.
...Wrapping tape, 6,10...Wrapping tape unwinding roll, 7,11...
Wrapping tape winding roll, 8.12...
・Contact roll, 13...Clean air blowout, 14
...Suction device, A...Magnetic surface processing section,
B... Back side processing section.

Claims (3)

[Claims] (1) A method for manufacturing a metal thin film magnetic recording medium, which comprises running a long metal thin film magnetic recording medium, and during the running, wrapping tape is brought into contact with both sides of the magnetic recording medium. (2) The metal thin film type magnetic recording medium according to claim 1, wherein a lapping tape having a surface roughness of No. 5000 or more is brought into contact with the magnetic recording medium at a contact pressure of 20 g/cm^2 or less. Production method. (3) A method for manufacturing a metal thin film type magnetic recording medium according to claim 1, characterized in that a clean air blowing and suction device is provided near the wrapping tape contact processing section.