JPH05334634A - Floppy head cleaning disk - Google Patents

Abstract

PURPOSE:To enhance the cleaning action of a floppy head cleaning disk without using chromium oxide by forming a coating layer contg. magnetic iron oxide and inorg. powder as an abrasive material on a nonmagnetic substrate. CONSTITUTION:Both sides of a nonmagnetic substrate of polyethylene terephthalate, etc., are coated with a coating material contg. magnetic barium ferrite powder and inorg. powder of alumina, etc., under orientation with no magnetic field. The surface roughness of the coated sides can be increased and a floppy head cleaning disk hardly causing environmental pollution is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floppy head cleaning disk (hereinafter abbreviated as FHCD) used for cleaning a head of a floppy disk driver (hereinafter abbreviated as FDD).

[0002]

2. Description of the Related Art As an FHCD used for cleaning an FDD head, one containing a polishing agent such as chromium oxide in its coating layer has been put into practical use in the past (for example, Japanese Patent Laid-Open No. 61-227216). Publication).

This relates to a cleaning disk composed of a coating film containing an abrasive having a Mohs hardness of 4 or more, a lubricant and a resin binder. Here, corundum, chromium oxide and γ-Fe ₂ O ₃ are used as the abrasive. Are used. These inorganic materials are used mainly because the powder material has a Mohs hardness of 4 or more.

[0004]

[Problems to be Solved by the Invention] However, FHC
The grindability of the head of D does not always depend only on the Mohs hardness of the powder contained in the coating layer. FDD
The non-magnetic dirt attached to the head of the
The surface of the FHCD is cleaned by abrasive wear due to the inorganic powder particles. In the case of this abrasive wear, the surface roughness of the FHCD coating film greatly affects the polishing property. That is, the surface roughness of the coating film is FHC
It is believed that D can be used as an excellent FHCD.

Therefore, an FHCD having excellent polishability can be produced without using chromium oxide. Needless to say, it is desirable not to use chromium oxide from the viewpoint of preventing pollution.

An object of the present invention is to prepare FHCD having excellent polishing property without using chromium oxide as an abrasive.

[0007]

To this end, the present invention has a constitution in which a coating layer containing magnetic iron oxide and inorganic powder in the form of particles as an abrasive is formed on a non-magnetic support. Be prepared.

[0008]

[Function] A magnetic paint containing magnetic iron oxide having a needle-like particle shape and inorganic powder having a granular particle shape is prepared, and both surfaces are coated on a non-magnetic support in a non-magnetic field orientation. By making the root mean square roughness of larger than a predetermined value,
It is possible to prepare an FHCD that can be used practically sufficiently.

[0009]

EXAMPLES Examples of the present invention will be described in detail below.

Example 1 A magnetic coating composition was prepared by thoroughly dispersing the material composition shown below with a ball mill and a sand mill, and then filtering and adding a curing agent, a lubricant and a solvent to prepare a coating composition. A coating composition having a nonvolatile content of 40% by weight was prepared. Ba ferrite magnetic powder (particle size = 0.05 μm, plate ratio = 3) ... 100 parts by weight Alumina (manufactured by Uemura Kogyo Co., Ltd., product number; UB-10, particle size = 0.5 μm) 3 parts by weight PVC system Copolymer resin (manufactured by Nippon Zeon Co., Ltd., product number; MR-110) 12 parts by weight Polyurethane resin (manufactured by Toyobo Co., Ltd., product number; UR-8200) 8 parts by weight Curing agent (manufactured by Nippon Polyurethane Co., Ltd.) , Part number; H-101) …… 4 parts by weight Lubricant (oleic acid) ……………………………………………… 5 parts by weight Lubricant (butyl stearate) ……………………………………………… 4 parts by weight Next, using a general-purpose coating machine, put 1 on 75 μm PET.
The coating was performed so that the film thickness was 0 μm, and the opposite surface was similarly coated. This raw fabric was heat-cured (60 ° C.-24 hr), punched out into a 3.5-inch floppy disk, and then casing as it was in a shell to prepare an FHCD.

(Example 2) In Example 1, the magnetic powder was changed to Ba ferrite magnetic powder having a particle size = 0.15 µm and a plate ratio = 10, and otherwise the same procedure as in Example 1 was used.
A CD was made.

(Example 3) In Example 1, the amount of alumina was changed to 7 parts by weight, and the other procedure was the same as in Example 1, except that F
An HCD was made.

Comparative Example 1 In Example 1, both coated surfaces were calendered. Conditions are 90 ℃ -300kg /
The FHCD was produced by the same method as in Example 1 except that cm-50 m / min.

(Comparative Example 2) In Example 1, the Ba ferrite magnetic powder was changed to needle-like α-hematite having a particle size of 0.30 μm, and otherwise FHC was produced in the same manner as in Example 1.
D was prepared.

(Comparative Example 3) An FHCD was prepared in the same manner as in Example 1 except that the Ba ferrite magnetic powder in Example 1 was changed to α-goethite having a major axis of 0.30 μm.

(Reference Example) Further, in Example 1, a sample to which alumina as an abrasive was not added was prepared. Since this sample does not contain alumina, the coating film is particularly weak and it contaminates the FDD head. Therefore, in order to evaluate the polishing property of FHCD, a head with a scraped coating film or the like is required. .. This sample is for preliminarily contaminating the FDD head, and was used as a reference example.

The surface roughness and polishability of each FHCD produced as described above were measured. Surface roughness is WY
The value of root mean square roughness (RMS) was adopted, which was measured at a magnification of 20 times using TOPO-3D manufactured by KO. This is because the surface roughness is shown more accurately than the conventional center line average roughness (Ra). The polishing property was evaluated as follows.

Matsushita Communication Industrial Co., Ltd. under normal temperature and humidity
The reference sample was run for 10 minutes on the FDD manufactured by JFE-253A3, and the head was contaminated. Next, Examples 1 to 3,
The FHCD of Comparative Examples 1 to 3 was run for 30 seconds. The abrasiveness of each FHCD at this time was judged by five-level visual evaluation of how the head was cleaned. An index of 5 was the best, and an index of 1 had almost no effect, and during that time, the evaluation was made in 3 stages. The above results are shown in (Table 1).

[0019]

[Table 1]

As is clear from these results, the coating film which is not subjected to the calendering treatment and which is composed of Ba ferrite magnetic powder, alumina, resin and lubricant is effective as FHCD. Further, the larger the plate ratio of Ba ferrite is, the larger the roughness of the coating film is, but both of them have good polishing properties. The amount of alumina may be about several parts by weight with respect to the magnetic powder.

It has been found that the magnetic powder does not necessarily have to be acicular particles. In particular, in the case of Ba ferrite magnetic powder which is hexagonal plate particles, the magnetic powder tends to stack in the vertical direction of the coating film due to its static magnetic field energy, and thus the surface after coating tends to be rough. This makes it possible to produce an FHCD having excellent polishing properties.

Inorganic powders as abrasives include alumina, chromium oxide, red iron oxide, etc., but the particle shape is not needle-like but granular. However, magnetic iron oxide for a magnetic recording medium is synthesized as acicular particles, and therefore, the particle shape of the magnetic iron oxide makes it highly abrasive in abrasive wear. Furthermore, a magnetic paint containing these particles is added to the P
When FHCD is prepared by coating on a non-magnetic support such as ET (polyethylene terephthalate) base, it is needless to say that magnetic field orientation treatment and calender treatment are not necessary.
This is because it is desired to roughen the surface of the coated surface and improve the polishing property as FHCD.

[0023]

As described above, according to the present invention, an inorganic powder having a granular particle shape is applied as an abrasive rather than a coating material containing an abrasive such as chromium oxide, thereby providing a better cleaning action. FHCDs that have can be prepared.

Claims (1)

[Claims] 1. A floppy head characterized in that a coating layer is provided on a non-magnetic support, and the coating layer contains magnetic iron oxide as magnetic powder and an inorganic powder in the form of granular particles as an abrasive. Cleaning disc.