JPH0969214A - Cleaning tape for head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively clean a head without scruping the sliding surface of a tape more than required even in the case of cleaning the head mounted on a high-speed rotary drum by forming a cleaning layer which holds lubricant in a tape-like support. SOLUTION: The cleaning tape for a head is constituted by forming a cleaning layer 1 containing carbon as a main body on a tape-like support 2. The tape is of a wet type cleaning tape used by holding cleaning liquid in the cleaning layer. The head is cleaned by feeding the tape in a VTR in a recording or reproducing mode in the shape that the tape is wound in a cassette for the VTR. The tape having such a cleaning layer 1 containing the carbon as the main body has a suitable surface roughness by the shape of the carbon. Further, a back coating layer 3 may be provided at the opposite side of the support 2 to the layer 1 in the tape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head cleaning tape suitable for use in a high-performance VTR used for broadcasting or business.

[0002]

2. Description of the Related Art In a magnetic head mounted on a video tape recorder (VTR) or the like, magnetic powder that has fallen off the magnetic tape or dust particles such as dust from the external environment adhere to the tape sliding surface. Or the lubricant applied to the magnetic tape adheres to the surface, resulting in a baked state. The powdery foreign matter thus adhered and the burned-in lubricant have a bad influence on the recording / reproducing characteristics of the magnetic head when accumulated.

Therefore, conventionally, a cleaning tape has been used to clean the tape sliding surface of the magnetic head.

This cleaning tape includes a wet cleaning tape used by applying a cleaning liquid on the surface,
It is roughly classified into dry cleaning tape that does not use cleaning liquid.

Of these, the wet cleaning tape is widely used because of its excellent cleaning effect and less adverse effect on the head. As such a wet cleaning tape, there is known a film made of a vinyl resin on which a metal film is formed by vapor deposition as a cleaning layer, and a fibrous film. Furthermore, the actual Kaisho 62-1
In Japanese Patent No. 50712, Japanese Unexamined Patent Publication No. 4-349210, and Japanese Unexamined Patent Publication No. 5-163030, the surface of the cleaning tape is formed into a special shape to enhance the retention of the cleaning liquid and improve the cleaning effect. Things have been proposed.

[0006]

However, the wet cleaning tapes proposed so far have a cleaning layer with too high hardness or a rough surface, so that they are high-performance VTRs used for broadcasting or commercial use, for example. When used in, there is a problem that the head is damaged.

That is, in a high-performance VTR used for broadcasting and business use, a rotary head equipped with a large number of magnetic heads is rotated at high speed in order to record and reproduce more information. For example, there is one that uses a rotary head equipped with 10 or more magnetic heads at a rotation speed of 4500 rpm or more.

When a tape or fibrous film on which a metal film is formed is slid on a rotating head which rotates at such a high speed, the tape sliding surface of the head is scraped off more than necessary, or the tape is caught. This causes a problem that the head is chipped by causing For this reason,
In a high-performance VTR used for broadcasting or business, only a dry cleaning tape is used, and the head cannot be sufficiently cleaned in the actual situation.

Therefore, the present invention has been proposed in view of such a conventional situation, and scrapes the tape sliding surface of the head more than necessary even when the head mounted on the high-speed rotary drum is cleaned. An object of the present invention is to provide a head cleaning tape capable of effectively cleaning the head without causing any damage or causing a chip in the head.

[0010]

In order to achieve the above-mentioned object, the cleaning tape of the present invention comprises a carbon-based cleaning layer formed on a tape-shaped support, and a lubricant is added to the cleaning layer. Held and configured.

The surface roughness Ra of the cleaning layer is
It is preferably 1.0 to 10 μm. The surface roughness Ra is the center line average roughness Ra defined in JIS B0601.

A back coat layer may be formed on the surface of the cleaning tape opposite to the side on which the cleaning layer is formed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Specific embodiments of the present invention will be described below.

The head cleaning tape of the present invention comprises:
A cleaning layer composed mainly of carbon is formed on a tape-shaped support.

This cleaning tape is a wet cleaning tape which is used by holding a cleaning liquid in a cleaning layer and is wound around a VTR cassette.
The head is cleaned by running on the VTR in the recording mode or the reproduction mode.

Here, the cleaning tape having such a cleaning layer mainly composed of carbon has an appropriate surface roughness depending on the shape of carbon. Therefore, it has an appropriate polishing performance and effectively cleans the head. In addition, the retention of the cleaning liquid is good,
This also increases the cleaning effect. Moreover, since the protrusions made of carbon have a relatively low hardness, even when used for cleaning the head mounted on a high-speed rotary drum, the tape sliding surface of the head is scraped off more than necessary and Does not cause chipping.

Therefore, the tape sliding surface of the head can be kept in a clean state without lowering the reproduction output of the head after cleaning and shortening the life of the head.

For the cleaning layer mainly composed of carbon, carbon powder and an adhesive are mixed and dispersed with an organic solvent to prepare a coating liquid for cleaning layer, and the coating liquid for cleaning layer is applied on a support, It is formed by drying.

Since the surface roughness of the cleaning layer is determined by the shape and particle size of the carbon powder and the P / B ratio, the kind and the addition amount of the carbon powder used are the optimum surface roughness for obtaining the cleaning effect. It is desirable to adjust so that The surface roughness Ra of the cleaning layer
Is 1.0 to 10 μm, preferably 1.5 to 3.5 μm
It is good. If the surface roughness of the cleaning layer is too low, the cleaning effect may be insufficient, and if it is too high, the polishing amount of the head may be unnecessarily large.

The carbon used for the cleaning layer preferably has a particle size of 19 to 270 nm.
As commercially available products, BP-800, Asahi # 80, Asahi # 3
5, MT, MT-CI, etc. can be used.

As the adhesive, a vinyl chloride-vinyl acetate copolymer, a vinyl chloride-propionic acid copolymer,
Vinyl chloride-vinyl acetate-vinyl alcohol copolymer,
Vinyl chloride-based resins such as vinyl chloride-acrylic copolymers, polyurethane resins such as polyester polyurethane, polyether polyurethane, polycarbonate polyurethane, nitrified cotton, etc. are used in video tapes as a support for cleaning tapes. A polymer support, especially a film made of a polyester resin such as polyethylene terephthalate or a vinyl resin is preferable.

As the cleaning liquid to be held on the surface of the cleaning tape, a cleaning liquid usually used in wet cleaning tapes can be used. For example, fluorine-based cleaning such as perfluoropolyether and carboxylic acid perfluoropolyether. The liquid is suitable. The cleaning liquid may be applied to the surface of the cleaning layer, or may be added in advance to the cleaning layer by adding it at the stage of preparing the coating liquid for the cleaning layer.

The above is the basic structure of the cleaning tape. As shown in FIG. 1, this cleaning tape has a back surface on the side opposite to the side on which the cleaning layer 1 of the support 2 is formed. The coat layer 3 may be provided.

This back coat layer is for improving the slidability between the back side of the tape and the tape running system,
For example, it may have the same composition as the back coat layer provided on the video tape. That is, a back coat coating solution prepared by mixing and dispersing an antistatic agent such as carbon or an adhesive with an organic solvent on the surface of the support opposite to the side where the cleaning layer is formed is applied and dried. Is formed by.

[0025]

EXAMPLES Examples of the present invention will be described based on experimental results.

Experimental Example 1 First, a coating liquid for cleaning layer was prepared according to the following composition.

[0027] That is, an adhesive is mixed with the main powder and dispersed in a ball mill together with an appropriate amount of solvent. Then, depending on the solvent,
The coating solution for the cleaning layer was prepared by further diluting and adjusting to an appropriate solid content.

Then, the cleaning layer coating solution thus prepared is coated on a polyethylene terephthalate support having a thickness of 10 μm in a coating thickness of 0.7 to 0.8 μm and dried to form a cleaning tape. It was made.
The surface roughness Ra of the cleaning layer was 1.02 μm as measured with a surface roughness meter (trade name: ET-30, manufactured by Kosaka Seisakusho KK).

Experimental Example 2 to Experimental Example 11 Except that the cleaning layer was formed with the surface roughness Ra shown in Table 1 by changing the kind and amount of the carbon black as the main powder in the coating liquid for the cleaning layer. Experimental example 1
A cleaning tape was prepared in the same manner as in.

The cleaning tape produced as described above was wound on a VitaCam VTR cassette and applied with a cleaning liquid. And V for BetaCam
It was run on a TR (BVW-75 manufactured by Sony Corporation) and the cleaning effect and the amount of headwear were measured.
The results are shown in Table 1 together with the surface roughness Ra of the cleaning layer.
Shown in

The cleaning effect was evaluated by intentionally clogging the head, running the cleaning tape on the head for 10 seconds, and observing the head surface with an optical microscope after running. ◎ indicates that the head has no stain, ○ indicates that the head has some stain, but there is no problem, △ indicates that the head is stain, but × indicates that the head is usable, × indicates the head Shows the case where the product is extremely dirty and cannot be used.

The amount of headwear was evaluated by running the cleaning tape on the head for 10 seconds and comparing the amount of protrusion of the head after traveling from the cylinder with the amount of protrusion before traveling. The amount of protrusion of the head is
The amount of protrusion was measured by using a protrusion amount measuring device (manufactured by TOHODENSHI Industrial Co., Ltd.). ◎ indicates that the head was scarcely scraped, ○ indicates that the polishing amount of the head was less than 0.1 μm,
Δ indicates the case where the head polishing amount is less than 0.2 μm, and X indicates the case where the head polishing amount is 0.2 μm or more.

The cleaning effect and the amount of headwear were measured in the same manner for a cleaning tape having a metal film as a cleaning layer (Experimental Example 12) and a cleaning tape made of a fibrous film (Experimental Example 13).
The results are also shown in Table 1.

[0034]

[Table 1]

First, in the conventional cleaning tapes (Experimental Examples 12 and 13), the head polishing amount was large, and
The damage done to R is great.

On the other hand, in the cleaning tape having the cleaning layer mainly composed of carbon, the surface roughness Ra of the cleaning layer is set to 1.0 to 10 μm,
A sufficient cleaning effect can be obtained, and the polishing amount of the head can be suppressed to be small.

Therefore, the cleaning tape having the cleaning layer mainly composed of carbon is BetaCa.
It can be seen that it is suitable as a cleaning tape for a high performance VTR such as a VTR for m.

Even in the cleaning layer mainly composed of carbon, the surface roughness Ra was 1 μm as in Experimental Example 9.
If it is made smaller, a sufficient cleaning effect cannot be obtained. When the surface roughness Ra is larger than 10 μm as in Experimental Examples 10 and 11, the head polishing amount becomes too large. That is, it is appropriate that the surface roughness Ra of the cleaning layer is 1.0 to 10 μm, more preferably 1.5 to 3.5 μm.

[0039]

As is clear from the above description, the cleaning tape for head of the present invention is composed of a tape-like support and a cleaning layer mainly containing carbon formed thereon. In addition to its excellent effect, it has a moderate polishing power, so even when used for cleaning the head mounted on a high-speed rotary drum,
The head is not scraped off more than necessary, and the head is not chipped. Therefore, it is suitable as a cleaning tape used for high-performance VTRs for broadcasting and business.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a head cleaning tape to which the present invention is applied.

[Explanation of symbols] 1 cleaning layer 2 support

Claims (5)

[Claims] 1. A head cleaning tape comprising a tape-shaped support, a cleaning layer containing carbon as a main component, and a lubricant retained on the cleaning layer. 2. The surface roughness Ra of the cleaning layer is 1.
The head cleaning tape according to claim 1, which has a thickness of 0 to 10 μm. 3. The head cleaning tape according to claim 1, wherein a lubricant is applied to the surface of the cleaning layer. 4. The head cleaning tape according to claim 1, wherein a lubricant is internally added to the cleaning layer. 5. The head cleaning tape according to claim 1, wherein a back coat layer is formed on the surface of the support opposite to the surface on which the cleaning layer is formed.