JPS5812127A - Cleaning tape - Google Patents

Abstract

PURPOSE:To obtain a satisfactory cleaning effect without damaging and wearing a head, by setting properly the type, size and quantity of abrasives. CONSTITUTION:Alumina (Al2O3) powder is used for abrasives of a cleaning tape. The mean grain size of the alumina powder is set at about <=0.7mum and preferably at <=0.5mum. The ratio of the alumina powder in the cleaning layer of the cleaning tape is set so that the ratio between the quantity of the alumina powder and the total sum of magnetic powder and the alumina powder is <=0.07. Furthermore the quantity of the alumina powder to be added as abrasive particles is set at about <=5 in terms of P/B ratio, i.e., the ratio of the total sum of the alumina powder and the magnetic powder to the quantity of a binder. The surface coarseness of the film of the cleaning layer is set at <=0.19mu in terms of the standard deviation 6 of the amplitude of coarseness. No calendering process is applied for the control of the surface coarseness.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning tape, and more particularly to a cleaning tape that does not damage or wear out the head (has a sufficient leaning effect).

Conventionally, cleaning tapes have used abrasive particles with a particle size of 200 μm or less and a Mohs hardness of less than 5, and the cleaning layer has a friction coefficient of 0.14 or more (Japanese Patent Application Laid-Open No. 102017/1983). , a particle size of 5 μm or less and a Mohs hardness of 5.5 or less is mixed with a particle size of 6 to 200 μm and a Mohs hardness of 5 or less and dispersed on a support using a binder, resulting in a surface roughness of 100 tones or less. (41 Kaisho 53-77612).

Both of these cleaning tapes use abrasive particles having a Mohs hardness of approximately 5 or less.

Therefore, by using such soft abrasive particles, the head surface is prevented from being damaged. Furthermore, by mixing fine hard particles, it also has the effect of removing clogging of the head. However, since it is a mixture of brittle and soft particles, the brittle particles are broken and fall off when they slide against the head, contaminating the head chip and the drum periphery, and also causing dropouts. Furthermore, since brittle particles with a low Mohs hardness are manufactured from natural ores by a crushing method rather than by a synthetic method, it is inevitable that particles with high hardness will be mixed in as impurities. Therefore, the head surface is damaged by these hard particles.

In addition, the surface roughness and center line average roughness are 0.04 to 0.10.
A cleaning tape designed to have μ has also been proposed.
~ No. 6). The larger the abrasive particle diameter, the greater the cleaning effect, but it also damages the head, so the surface is smoothed by calendering and the surface roughness is reduced to prevent the head from being damaged. However, if the surface roughness is around 0.04 to 0.10μ, the cleaning effect is not sufficient (it is too weak, and if calender treatment is applied, even if it is a weak calender, the cleaning effect will be significantly reduced). Since it is possible to record an image on a material with this level of surface roughness, the cleaning layer contains magnetic powder, and the degree of cleaning can be confirmed by the reproduced image. It is also known that it is composed of

There are also known tapes that record test patterns using a mixture of abrasive particles and magnetic powder, and video cleaning tapes that have a layer on a substrate made of a mixture of magnetic recording material and abrasive material. Utility Model Publication No. 55-5481
No. 9, Utility Model Publication No. 5l-14237i1). However, none of these have sufficient cleaning effects.

The present invention can greatly improve the drawbacks of the prior art, and in particular provides a cleaning tape that can reliably clean a video head and does not cause wear or damage to the head.

To avoid damaging or wearing the head (in order to obtain a sufficient leaning effect, the type and size of the abrasive are extremely closely related to the leaning effect, and the factors that can stably control this head wear are the abrasive It was found that the amount of

In addition, we conducted one actual driving test using a video tape recorder.
As a result, it was found that simply removing the deposits on the head chip was insufficient in its cleaning effect.

Therefore, we investigated what kind of abrasive could be used to minimize damage to the head, and found that particles with a small Mohs hardness and brittle particles, or particles obtained by a grinding method from natural ores, are suitable for video cleaning tape. It turned out that it wasn't.

The cleaning tape according to the present invention uses alumina (AJzOi) powder as an abrasive. Since the alumina powder has a light specific gravity, it is concentrated on the surface of the cleaning layer and contributes to improving the polishing ability. Further, the alumina powder used has an average particle size of about 0.7 μm or less, preferably 0.5 μm or more. By using alumina powder having a particle size within this range, excellent properties such as stability with the head and sustainability of the cleaning effect can be obtained. If the particle size is significantly larger than this range, the head will be damaged and the 8/N ratio of the video will be lowered, which is not appropriate. In addition, the proportion of alumina powder in the cleaning layer of the cleaning tape is
It is necessary to ensure that the ratio of alumina powder to the total amount of magnetic powder and alumina powder is not greater than approximately 0.07. If it is too thick than this value, the headwear will become extremely thick (which is not desirable).

'Furthermore, the amount of alumina powder added as abrasive particles is
Suitably, the P/B ratio, ie, the ratio of the total amount of alumina powder and magnetic powder to the amount of binder, is less than about 5, preferably less than about 3.5.

If the P/B ratio of C is too large, it is undesirable to cause a phenomenon of powder falling and clogging of the head.

Further, if an image can be recorded on the cleaning tape at the same time and the cleaning status can be checked while monitoring the reproduced image, the user number will be extremely convenient. In order to reproduce the reproduced image on the cleaning tape and obtain a good image quality, the surface roughness of the coating film should be such that the standard deviation σ of the roughness amplitude is 0.1 mm or less, preferably 0.1 mm. It is preferable that the thickness be 15μ or less.

Even if a cleaning tape is made using alumina powder that satisfies the conditions described above, if it is calendered to adjust its surface roughness, the cleaning effect will be significantly reduced, which is undesirable. . Therefore, the cleaning tape according to the present invention satisfies the above-mentioned conditions such as surface roughness without being subjected to such calender treatment, and is capable of producing the desired cleaning effect and producing reproduced images of high quality. This is an extremely useful device that allows you to record and check the cleaning effect while playing back the reproduced image.

In the present invention, the magnetic powder used in the cleaning layer must be capable of recording and reproducing reproduction information for determining the cleaning effect. Either can be used. The amount of magnetic powder to be used may also be set to satisfy the above-mentioned conditions.

Alumina powder and magnetic powder are mixed into a paint for forming a cleaning layer so as to satisfy the conditions described above. A binder is also added to this paint to achieve the P/B ratio described above.

The binder that can be used is not limited in any way and can be used as a binder for the magnetic layer or back coat layer of a magnetic recording medium. Furthermore, various additives such as a curing agent, a dispersant, and a lubricant can be added to the paint.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 The composition of the cleaning layer forming paint was as follows.

Composition Jusen comb magnetic powder (Cor-PelOH) 95
Alumina powder (0.5j1m) 5 Polyurethane resin 10.2 Hardening agent
7.6 Dispersant
0.5 lubricant
0.5 methyl ethyl ketone 2
00 Toluene 100 The mixture having the above composition was mixed and well dispersed to prepare a paint.

This paint was applied onto a polyethylene terephthalate film having a thickness of 14 fim to a thickness of 35 μm to form a cleaning layer.

With the above composition, cleaning tapes 1.2 and 3 were created by varying the particle size and amount of alumina powder added.
Y-87N and head output (
RF output) was measured using a Sony home video tape recorder (VTR) that was actually driven for 30 seconds. The results are shown in Figure 1A and Figure 1.
As shown in Figure B, these results were obtained by using the same sample on a VTR.
The measurements were taken while changing the playback speed. The vertical axis of the figure shows the degree to which the electromagnetic characteristics of the VTR have deteriorated due to spacing caused by scratches on the head after running.

From these results, the particle size of the alumina powder is approximately 0.7 f.
It has been found that if it is less than im, there is no problem in terms of damage to the head.

Example 2 Among the coating compositions of Example 1, the particle size of the alumina powder was 0.
Use alumina powder with a 4μ ratio and increase the amount of alumina powder added to the second level.
A cleaning tape was made with the changes shown in the figure.

Using this tape, a VTR was run for 10 minutes to measure the degree of head wear, and the results are shown in FIG. From this result, the amount of alumina powder added is approximately 796vE.
It turned out that there was no problem with the headwear.

Experimental Example 1 Using the cleaning tapes having various surface roughness obtained in Examples 1 and 2, the surface roughness σ (standard deviation of roughness)
The relationship between this and video S/N playback output was investigated. The results are shown in FIG. From this result, the roughness that satisfies the image quality of the reproduced image is approximately σ<0.19 μm, and σ<0.15
It has been found that μm is desirable.

Experimental Example 2 Using the cleaning tapes having various surface roughnesses σ obtained in Examples 1 and 2 described above, the relationship between the surface roughness σ and head wear was investigated. The results are shown in FIG. These results revealed that there is no clear relationship between surface roughness σ and head wear.

From the above results, if it is just a cleaning tape,
Although the optimum conditions can be determined depending on the alumina particle size and the amount added, it has been found that there are certain restrictions on the surface roughness when used as a leaning tape that can record and reproduce images.

However, when calendering is performed to smooth the roughness, it has been shown that even with a weak calender that causes almost no change in the roughness, head wear is significantly reduced and the cleaning effect is significantly degraded. For example, when alumina powder was added as much as 25% by weight and the surface roughness σ was approximately 2 pm, the surface roughness was slightly calendered, and the surface roughness was 2 μm, which hardly changed.

However, the non-calendered head wear after 10 minutes of actual VTR running was about 12fi111, while the calendered one was 2μm weaker.

[Brief explanation of the drawing]

Figures 1A and 1B are graphs showing the relationship between the particle size and amount of alumina powder added and Y-8/N and RF output, and Figure 2 is a graph showing the relationship between the amount of alumina powder added and headwear. , FIG. 3 is a graph showing the relationship between surface roughness and Y-8/N, and FIG. 4 is a graph showing the relationship between surface roughness and head wear. Agent Saturn Masaru Pine Wood Modification Figure 1A Figure 1B 0.5 0.70.5-1.5 2.0 (uJ”)
Ar4,,-1'-'L(turr) 1 x
(,,, -1r, - ((Voluntary) Procedural Amendment 1, Indication of Case 1982 Patent Application No. 107912 6 Number of Inventions Increased by Amendment 1) Separate the scope of the pointer claims of Ming #1 Yu 2) Correct Mho's invention of IT - Ichinohe's explanation - as in Hisashi. (Correct ``The effect is unreasonable'' in line 14*ia of specification 11 to ``unsuitable as a tape.'' (2) [Alumina...
・・・・・・・・・・・・Also, add -1 to ``. (3) On the 18th line of the same 9m, to the monkey "From Wi rice," [-
Since the i'F valley can be formed up to the deterioration of LUdH, insert ". (4) In the 7th line of the 10th line, “10
If it is within 1υ1184 minutes, there will be no delay.''
Insert. (5) Correct ``up to 7-'' to ``rZsg down'' in line 8 of the same 10th line. (6) After "show" in the 20th position of the 11th member, insert "The numbers in the figure are the alumina addition amount (-)." (7) In the 7th line of the 11th line, “Determined by...
Correct "...however" to "can be determined, and the constraints on the surface 11[ are not great.However," (8) 1lijl 1 jaFor the punishment of "surface magnetism" in the 9th line, 1- 1 As shown in Figure 6, #<ul
9μm+1 reassembly is preferable.'' (9) Correct the word ``shown'' in the 11th and 14th subtitles to ``from our red sea bream''. 4 Correct "2" in line 15 of 11-15 to [LL2J. I The 11th line of 16th to the 18th line of ``% of the... song...but'' has been subjected to a calendar treatment that makes it weak, so the surface cover is tJ, 2 μm, and it hardly becomes a clump. The head wear was measured on the same item. En 11 members lines 20-12lijl “Weak...
・・・・・・・・・・・・・・・・・・・・・・・Corrected ``I was prayed for'' to ``It was only good and the cleaning effect was poor.'' 3) Amend the brief description of the drawing as follows. (1) "Y-8..." on page 12, line 4 of the specification
. . . output" is corrected to "amount of decrease in Y-8/N and RF output due to head damage during 60 seconds of actual running." (2) 1lij12tj 5th line “Alumina...
・・・・・・・・・・・・・The words ``with fists and irises'' have been supplemented with ``by 4 μm of Iu alumina powder and 1 u bunkakusho''. (3) Insert [by running for 1υ minutes] into the - of "head" on the 8th line of the 12th line. One or more one or two, time 1'? Billing letter.

Claims (1)

[Claims] The ratio of the amount of alumina powder to the total amount of alumina powder and magnetic powder will be 0.07 or less, and the coating surface roughness σ of the cleaning layer will be less than 0.19. A cleaning tape characterized in that a cleaning layer is provided on the cleaning tape.