JPH07254147A - Polishing device for magnetic recording medium - Google Patents

Abstract

PURPOSE:To form a polishing device for a magnetic recording medium capable of efficiently removing an unequally existing org. matter layer existing on the extreme surface of a magnetic layer without impairing the smoothness of the magnetic recording medium. CONSTITUTION:A cleaning mechanism consisting of a felt revolving roll 4 having a circular columnar or cylindrical shape and a driving system for driving the roll is installed between an un-winging shaft 1 and take-up shaft 7 for a magnetic tape 10. The felt material is impregnated and fixed with a polishing agent consisting of inorg. powder dispersed by using an org. binder. While the felt revolving roller 4 is kept rotated at a high speed in a direction reverse from the traveling direction of the magnetic tape 10, the roll is brought into contact with the magnetic layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating type magnetic recording medium manufacturing apparatus which is widely used as a storage medium for video, audio and information equipment, and more particularly to magnetic recording for continuously cleaning the magnetic recording medium. The present invention relates to a medium polishing device.

[0002]

2. Description of the Related Art A coating type magnetic recording medium is produced by applying a magnetic coating material and drying it, and then calendering it to give a mirror finish and punching or cutting it into a predetermined shape. In the process of passing through the steps of (1) and (2), paint or coating dust, foreign matter, or cutting chips when cutting may be attached or buried in the magnetic layer, which may lead to deterioration of signal quality as a defect of the magnetic layer. There is

In order to improve this, various studies have been made on a cleaning process performed after each step. In particular, a method using a wiping cloth, a cleaning tissue, or the like can be given as a method that has been used for a long time after each step including the final step of the magnetic recording medium. These methods are for wiping off dust and dirt that are lightly in contact with the magnetic recording medium, and remove foreign matter buried in the magnetic layer or foreign matter strongly adhered to the magnetic layer. Has no effect on.

Therefore, a cleaning method using a polishing sheet or a polishing tape formed by applying a polishing agent, or a method of bringing a blade of a crystalline material having a sharp edge into contact with the magnetic layer has become mainstream. In addition, as a relatively new technology, as a technology derived from metal processing technology, a diamond grindstone in which diamond abrasive grains are bound with a metal binder is processed into a roll shape, while rotating in the direction opposite to the transport direction of the magnetic recording medium. A method of contacting the magnetic layer is known. Further, with improvements in ceramic forming technology and processing technology for super steel, blades and the like having sharp edges made of these materials have begun to be widely used.

All of these methods are intended to forcibly remove foreign matter, and the cleaning degree can be adjusted according to the roughness of the magnetic layer, the size of the foreign matter, or the state of adhesion. There are features.

However, due to recent advances in magnetic layer constituent materials, paint refining techniques, and cleansing techniques, the probability of occurrence of large-sized coating film defects, which has been a problem in the past, has been greatly reduced.

On the other hand, as the demand for recording / reproducing characteristics in a region where the recording wavelength is short has increased, a magnetic recording medium itself has been required to have a considerably excellent surface roughness. In order to meet this demand, investigations are being made in the fields of material technology, coating technology, coating technology, and mirror finishing technology that support the coating type magnetic recording medium.

[0008]

The surface roughness of appearance has been considerably improved by the above-mentioned measures.
It has become clear that air gap loss is newly caused by factors other than surface roughness, which hinders recording / reproducing characteristics in the short wavelength region. This is because it exists inside the magnetic layer, and specifically, it is due to the fact that there are many organic substances ubiquitously in the extremely surface layer of the magnetic layer, and the magnetic powder is not firmly filled. Then, such an organic substance ubiquitous layer acts as a layer in which a magnetic signal cannot be effectively recorded in a section up to a depth where the density of the magnetic powder is stable. The thickness of the organic substance ubiquitous layer is very thin, and is estimated to be 300 to 1000 angstroms from the recording characteristics.

Attempts have been made to thin the organic substance ubiquitous layer by a processing method applying a conventional technique after forming a magnetic layer, but a wiping cloth or a cleaning tissue has no effect, and a whetstone roll, various blades, Even if a positive cleaning method using a polishing tape or the like is used, it cannot be reduced efficiently. The cause is the contact state between the magnetic recording medium to be processed and these cleaning elements, and the excellent surface property of the magnetic layer is impaired under the condition that the organic substance ubiquitous layer can be effectively cleaned. Further, if the required removal work is performed under the condition that the surface of the magnetic layer can be maintained, the cleaning efficiency is extremely lowered, so that the number of treatments is increased or the removal cannot be performed sufficiently. In particular, these cleaning elements are inorganic materials such as alumina particles, chromium oxide particles, diamond abrasive grains and sharp edges, and physically scrape off foreign matters and dirt. The scraping action has the following features. That is, the sharp edge of the blade is a one-time treatment in a state close to line contact, and the element formed by the abrasive grains has a form in which the contact probability is gained by the abrasive grain density and the relative speed. Therefore, even if the contact probability is sufficient for the purpose of scraping off a specific foreign substance, it is an inefficient mechanism for precisely cleaning the organic component of the pole surface layer existing over the entire surface of the magnetic layer without leakage. There is.

In order to solve the above-mentioned problems in the prior art, the present invention can efficiently remove the organic substance ubiquitous layer existing in the pole surface layer of the magnetic layer without impairing the smoothness of the magnetic recording medium. An object is to provide a polishing apparatus for a magnetic recording medium.

[0011]

In order to achieve the above-mentioned object, a polishing apparatus for a magnetic recording medium according to the present invention has a structure in which a rotating shaft is provided at the center of a felt material having a cylindrical shape or a cylindrical shape. A cleaning mechanism including a roll and a drive system for driving the felt rotation roll is provided, and the felt rotation roll is brought into contact with the magnetic layer while being rotated at a high speed in a direction opposite to the traveling direction of the magnetic recording medium. .

Further, in the above construction, the felt material is preferably made of animal hair. Further, in the above constitution, it is preferable that an inorganic powder abrasive is dispersed with an organic binder, and this is impregnated and fixed to the felt material. In this case, the abrasive further has an average particle diameter of 0.1 to 1. It is preferably at least one selected from 0 μm chromium oxide, aluminum oxide and iron oxide.

Further, in the above-mentioned constitution, it is preferable to disperse the inorganic powder abrasive in an aliphatic oil and fat, and to impregnate and fix it on the felt material. It is preferably at least one selected from chromium oxide, aluminum oxide and iron oxide having a thickness of 0.1 to 1.0 μm.

Further, in the above structure, the conveying speed and the felt rotation of the magnetic recording medium such that the ratio of the cumulative contact lengths of the felt materials contacting each other while processing the unit length of the magnetic recording medium satisfies 5 to 400. It is preferable to set the rotation speed of the roll and the roll diameter.

Further, in the above structure, it is preferable that air is blown from the non-treated surface side of the magnetic recording medium toward the felt rotating roll. Further, in the above structure, a cleaning mechanism using a polishing tape is provided on at least one of the front and rear sides of the cleaning mechanism using the felt rotation roll, and the polishing tape is run such that its polishing surface contacts the magnetic layer of the magnetic recording medium. Is preferred.

Further, in the above construction, a blade made of cemented sapphire or diamond having a sharp edge is provided on at least one of the front and rear sides of the cleaning mechanism using the felt rotating roll, and the sharp edge is a magnetic recording medium. It is preferable to run so as to contact the magnetic layer.

Further, in the above construction, a cylindrical or cylindrical abrasive grain rotating roll having diamond abrasive grains bonded with a metal binder is provided on at least one of the front and rear sides of the cleaning mechanism using the felt rotating roll, It is preferable to bring the grain rotation roll into contact with the magnetic layer while rotating the grain rotation roll at a high speed in a direction opposite to the traveling direction of the magnetic recording medium. In this case, it is further preferable that the grain size of the diamond abrasive grains is 2 to 20 μm. .

[0018]

According to the structure of the present invention, the fibers of the felt material having excellent lipophilicity slide on the surface of the magnetic layer at a high speed, thereby producing a brushing effect when the cross-sectional directions of the fibers come into contact with each other. Since the wiping effect is produced when the lengthwise directions of the two come into contact with each other, the organic substance on the extreme surface layer can be efficiently removed. Further, due to the flexibility of the fiber itself, physical damage to the surface of the magnetic layer can be suppressed, and excellent surface properties can be maintained.

Further, in the above-mentioned constitution, according to the preferable constitution in which the felt material is animal hair, it is possible to obtain sufficient hardness and flexibility of the fiber for efficiently removing the organic substance in the outermost layer.

Further, in the above-mentioned constitution, an inorganic powder abrasive is dispersed with an organic binder, and this is impregnated into a felt material.
According to the preferable constitution of fixing, not only the organic floating components such as the binder resin in the surface layer of the magnetic recording medium are removed by the brushing action and the wiping action of the animal hair fiber, but also the fine abrasive adhered to the fiber surface is removed. The ubiquitous organic layer can be effectively cut without causing damage on the surface of the magnetic layer while being appropriately controlled by the flexibility of the fiber.

Further, in the above-mentioned constitution, according to a preferable constitution in which the inorganic powder abrasive is dispersed in an aliphatic oil and fat, and the felt is impregnated and fixed to the felt material, the aliphatic abrasive in which the abrasive is dispersed is used. The oil and fat can be transferred when the surface of the magnetic layer is treated, and can act as a lubricant for the magnetic layer.

Further, when the abrasive is used, according to a preferred constitution, the abrasive is at least one selected from chromium oxide, aluminum oxide and iron oxide having an average particle size of 0.1 to 1.0 μm. Excellent in matching the surface properties of the layers and the hardness of the magnetic layer and the outermost layer, and can suppress grinding damage.

Further, in the above structure, according to the preferable structure in which air is blown from the non-processed surface side of the magnetic recording medium toward the felt rotating roll, the contact pressure on the felt rotating roll can be varied. Even when the cleaning process is performed at high speed, the contact between the magnetic recording medium and the felt rotation roll can be stably maintained.

Further, in the above construction, a cleaning mechanism using a polishing tape is provided on at least one of the front and rear sides of the cleaning mechanism using the felt rotating roll, and the polishing tape is run such that its polishing surface contacts the magnetic layer of the magnetic recording medium. According to the preferred construction, the felt material exerts an effect of removing large foreign matters and dusts before the brushing action and the wiping action brought about by the high-speed sliding of the felt material, and the short fibers and the abrasive removed from the felt material. And the like can be removed so as not to be adversely affected. Further, in the above configuration, a blade made of cemented sapphire or diamond having a sharp edge is provided on at least one of the front and rear sides of the cleaning mechanism by the felt rotating roll, and the sharp edge is in contact with the magnetic layer of the magnetic recording medium. A preferred configuration of running as described above, or in the above configuration, at least one of the front and rear sides of the cleaning mechanism using the felt rotation roll, a cylindrical or cylindrical abrasive roll having diamond abrasive grains bonded with a metal binder. The same effect can be obtained by a preferable configuration in which the abrasive grain rotating roll is brought into contact with the magnetic layer while being rotated at a high speed in a direction opposite to the traveling direction of the magnetic recording medium.

[0025]

EXAMPLES The present invention will be described in more detail below with reference to examples. (Embodiment 1) FIG. 1 is a block diagram of a 1/2 inch VTR magnetic tape polishing apparatus showing an embodiment of a magnetic recording medium polishing apparatus according to the present invention. In FIG. 1, 10 is a magnetic tape, 1 is an unwinding shaft of the magnetic tape 10, 2 is a tape regulating roll for regulating the running of the magnetic tape 10, and 3 is a length measuring roll for detecting the speed of the magnetic tape 10. Four
Is a felt rotating roll made of felt material, 5
Is an air nozzle for pressing the magnetic tape 10 against the felt rotation roll 4, 6 is a tape tension detecting roll for detecting the tension of the magnetic tape 10, 7 is a winding shaft of the magnetic tape 10, 8 is a winding touch roll,
9 is a touch roll arm. Specifically, a commercially available video tape cleaner is used as the polishing apparatus main body, and the felt rotation roll 4 and a drive system for driving the same are provided in the video tape cleaner.

As the felt rotation roll 4, the ratio of the cumulative contact length of the felt material during the processing of the unit length of the magnetic tape 10 calculated from the roll diameter and the number of rotations and the running speed of the magnetic tape 10 is 5 to 5. It is effective to set the condition to be 400. This is, for example, 200 m / mi
For the magnetic tape 10 running at n, the roll diameter is 30 mm, and the rotation speed is 1061 to 84882 rpm. As long as the rotation accuracy and the contact state with the magnetic tape 10 can be secured, it is preferable to perform the processing at a high speed of 20000 rpm or more.

The felt rotation roll 4 has a roll diameter of 30.
mm, the width is 20 mm, and a rotating shaft having a diameter of 3 mm is provided at the center thereof. The felt rotation roll 4 itself is formed by punching a sheet-like felt having a thickness of 20 mm into which a rotation shaft is driven at the center of a cylinder. Here, as the felt material, animal hair is preferable from the viewpoint of the hardness and flexibility of the fiber, and among them, wool felt and fur felt are preferable. In particular, farfelt containing a large amount of oil component contained in the fiber itself is preferable.

A DC motor used in a commercially available micro grinder or the like is used to drive the felt rotation roll 4, and 2500 rpm to 100000 rpm is used.
It has a structure that can be set up to stepless variable. Here, the tip of the DC motor has a diameter of 3 mm.
Is provided, and the felt rotation roll 4 can be freely replaced.

The air nozzle 5 is installed according to the roll diameter of the felt rotation roll 4, and is configured to supply / stop the primary compressed air by controlling it with a regulator. And the air nozzle 5 is provided in this way,
By blowing air from the non-treated surface side of the magnetic tape 10, the contact pressure on the felt rotating roll 4 can be changed, so that even when the cleaning process is performed at ultra-high speed rotation, the magnetic tape 10 and the felt rotating roll 4 can be changed. The contact with can be kept stable. Even if this method is not used, the contact state can be controlled by adjusting the tension on the entrance side and the exit side when the magnetic tape 10 is passed through the felt rotation roll 4, but like the magnetic tape 10. This method is effective when processing a magnetic recording medium having a very small thickness.

The tension of the magnetic tape 10 is electrically detected by the tape tension detection roll 6 and fed back to the drive system of the unwinding shaft 1 and the winding shaft 7. The tension of the magnetic tape 10 was set to 60 g according to the conventional conditions, and the running speed of the magnetic tape 10 was set to 200 m / min according to the conventional conditions.

FIG. 2 is a model diagram showing the action of the rotating roll of the felt material of the present invention. FIG. 2A shows the brushing action when the fiber cross section in the felt material comes into contact with the surface of the magnetic tape 10. (B) shows the wiping action when the fiber side surface in the felt material comes into contact with the surface of the magnetic tape 10. In FIG. 2, 11 is a felt fiber, 12 is an organic substance ubiquitous in the magnetic surface layer (hereinafter referred to as “electrode layer”),
Reference numeral 13 is a magnetic layer stable region. Brushing action (a)
As a result, dirt and organic components on the outermost surface layer are scraped off, and the dirt components scraped off by the wiping action (b) are wiped off or swept out. These two effects are brought about by the felt rotating roll 4 rotating at a high speed, and the organic component existing on the extreme surface layer of the magnetic tape 10 can be effectively cleaned.

Further, a greater effect can be obtained by dispersing the inorganic powder abrasive with an organic binder and impregnating and fixing the inorganic binder on the felt material. By doing so, not only the organic floating components such as the binder resin existing on the outermost layer of the magnetic tape 10 are removed by the brushing action (a) and the wiping action (b) of the felt fiber 11, but also the felt fiber 11 is removed. This is because the finely divided abrasive adhered to the surface is appropriately controlled by the flexibility of the fiber, and the ubiquitous organic layer is effectively cut without damaging the extreme surface. In Example 1, the impregnation of the felt material with the abrasive was performed in a sheet state before being processed into a roll shape.

As an abrasive, chromium oxide having an average particle diameter of 0.1 to 1.0 μm is used because it has excellent matching with the surface properties of the magnetic layer and the hardness of the outer surface layer and is less likely to cause grinding damage.
It is preferably at least one selected from aluminum oxide and iron oxide.

Further, it is also effective to disperse the above-mentioned abrasive with an aliphatic fat and oil, and to impregnate and fix this to a felt material. The reason is that the aliphatic fats and oils in which the abrasive is dispersed are transferred when the surface of the magnetic layer of the magnetic tape 10 is treated and act as a lubricant for the magnetic layer.

As the aliphatic fat and oil, it is preferable to use a saturated or unsaturated one having 14 to 22 carbon atoms. When the felt material impregnated with the abrasive is used as described above, the fine abrasive adhered to the surface of the felt fiber 11 removes dirt in both the contact state of the brushing action (a) and the wiping action (b). The action to put out can be enhanced.

(Embodiment 2) FIG. 3 shows a 1/2 inch VTR of another embodiment of the polishing apparatus for a magnetic recording medium according to the present invention.
It is a block diagram of the polishing apparatus of the magnetic tape for use. As shown in FIG. 3, the polishing apparatus according to the second embodiment includes a felt rotation roll 4
Example 1 except that a blade 14 made of cemented carbide sapphire having a sharp edge is provided in front of the polishing unit by the air nozzle 5 via the tape regulation roll 2.
Is the same as the configuration (FIG. 1). In such a configuration, if the blade 14 is run so that its sharp edge contacts the magnetic layer of the magnetic tape 10 before the magnetic tape 10 contacts the felt rotation roll 4, the surface of the magnetic layer is damaged. Since such foreign matter is not captured by the felt material, the effect of the present invention by the felt rotating roll 4 is not impaired.

In the second embodiment, the blade 14
The cleaning mechanism based on the felt rotating roll 4 is provided before the cleaning mechanism based on the felt rotating roll 4, but the cleaning mechanism is not necessarily limited to this configuration, and may be provided after the cleaning mechanism based on the felt rotating roll 4. It may be provided at two positions before and after the cleaning mechanism. If the cleaning mechanism using the blade 14 is provided after the cleaning mechanism using the felt rotation roll 4, the short fibers and abrasives and the like that have fallen off from the felt material can be removed, so that they are caught in the magnetic tape 10 and have an adverse effect. There is no such thing.

Further, although the blade 14 made of cemented carbide sapphire is used in the second embodiment, the material is not limited to this. For example, a blade made of diamond is also used. The effect can be obtained.

(Embodiment 3) FIG. 4 is a block diagram of a 1/2 inch VTR magnetic tape polishing apparatus showing still another embodiment of the magnetic recording medium polishing apparatus according to the present invention. As shown in FIG. 4, the polishing apparatus of the third embodiment is the same as that of the first embodiment except that the polishing tape unit is provided via the tape regulating roll 2 in front of the polishing unit including the felt rotation roll 4 and the air nozzle 5. Is the same as the configuration (FIG. 1).
Here, the polishing tape unit includes a polishing tape 18, a polishing tape post 15 on which the polishing tape 18 is hung, a polishing tape unwinding shaft 16 and a polishing tape winding shaft 17. Further, as the polishing tape 18,
Carborundum abrasive grains having a roughness of # 10000 were used according to the conventional conditions. Then, in such a configuration, if the polishing tape 18 is made to travel so that its polishing surface contacts the magnetic layer of the magnetic tape 10 before the magnetic tape 10 contacts the felt rotation roll 4, in the case of the second embodiment Similarly to the above, since the foreign material that damages the surface of the magnetic layer is not captured by the felt material, the effect of the present invention by the felt rotation roll 4 is not hindered.

In the fourth embodiment, the polishing tape 1
Although the cleaning mechanism by 8 is provided in front of the cleaning mechanism by the felt rotating roll 4, the cleaning mechanism is not necessarily limited to this configuration.
The cleaning mechanism may be provided after the cleaning mechanism described above, or may be provided before and after the cleaning mechanism provided by the felt rotation roll 4. If the cleaning mechanism using the polishing tape 18 is provided after the cleaning mechanism using the felt rotation roll 4, short fibers and abrasives and the like that have fallen off from the felt material can be removed. Never give.

(Embodiment 4) FIG. 5 is a block diagram of a polishing apparatus for a 1/2 inch VTR magnetic tape showing still another embodiment of the polishing apparatus for a magnetic recording medium according to the present invention. As shown in FIG. 5, the polishing apparatus of the present Example 4 was carried out except that the abrasive grain rotating roll 19 was provided via the tape regulating roll 2 in front of the polishing unit consisting of the felt rotating roll 4 and the air nozzle 5. The configuration is the same as in Example 1 (FIG. 1).
Here, the abrasive grain rotation roll 19 is formed by combining diamond abrasive grains having a grain size of 5 to 10 μm with a metal binder to form a cylindrical shape, and has an outer diameter of 40 mm and a width of 1 mm.
Inches. Then, in such a structure, if the abrasive grain rotation roll 19 is brought into contact with the magnetic layer while being rotated at a high speed in the direction opposite to the traveling direction of the magnetic tape 10, as in the case of the second embodiment, the magnetic layer is formed. Since the foreign material that damages the surface is not captured by the felt material, the effect of the present invention by the felt rotation roll 4 is not hindered.

In the fourth embodiment, the cleaning mechanism using the abrasive rotation roll 19 is used as the felt rotation roll 4.
However, the present invention is not limited to this configuration, and may be provided after the cleaning mechanism by the felt rotation roll 4, or before and after the cleaning mechanism by the felt rotation roll 4. Good. If the cleaning mechanism using the abrasive grain rotation roll 19 is provided after the cleaning mechanism using the felt rotation roll 4, short fibers and abrasives and the like that have fallen off from the felt material can be removed, so that they are caught in the magnetic tape 10. It has no adverse effect.

In the fourth embodiment, diamond abrasive grains having a grain size of 5 to 10 μm are used, but the grain size is not necessarily limited to this range, and the grain size is 2 to 20 μm. The same effect can be obtained as long as it is within the range.

(Comparative Example 1) FIG. 6 shows a typical example 1 of the prior art.
It is a block diagram of the polishing apparatus of the 1/2 inch VTR magnetic tape. As shown in FIG. 6, this polishing apparatus includes a blade 14 made of cemented carbide sapphire having a sharp edge and a polishing tape unit. Here, the polishing tape unit includes a polishing tape 18, a polishing tape post 15 on which the polishing tape 18 is hung, a polishing tape unwinding shaft 16 and a polishing tape winding shaft 17.

Using the above Examples 1 to 4 and Comparative Example 1, the cleaning properties of the magnetic tapes for 1/2 inch VTR were actually compared. Specifically, a coating type metal tape having performance conforming to the latest digital VTR standard for business, D-3 format, was used. In Example 1, the felt material, the rotation speed of the felt rotation roll 4, the presence / absence of the air nozzle 5, the presence / absence and type of the abrasive impregnation, and the impregnation method were compared. Moreover, in Examples 2 to 4, 2
Since various kinds of polishing methods are effectively operated, the tape was carried out under the condition that the tape can be reasonably run in the set tension of 60 g.

A specific comparison was made as follows.
First, samples were prepared by changing the number of treatments with each polishing apparatus configuration, wound into a cassette as a D-3 format 90-minute tape, and the number of treatments satisfying the standard value of dropout was determined.

The standard value of dropout was set as follows. That is, the measurement result of the total length by the D-3 system video tape recorder (Matsushita Electric Industrial, type AJ-D350) shows that the average value and the maximum value per minute are 5
0.5 μs or less and 10 at 0 μsec × −8 dB
400 or less at 0.2 μsec × −8 dB
The number of pieces or less and the number of pieces of 1000 or less were used as reference values.

In the cleaning process by the conventional method, in order to satisfy the dropout reference value, it was necessary to perform 7-pass process with the polishing apparatus having the structure of Comparative Example 1. The processing conditions at this time were that the tape tension was 60 g, the tape speed was 200 m / min, and the polishing tape used was carborundum abrasive grains having a roughness of # 10000.

The processing conditions satisfying this reference value were similarly examined for Examples 1 to 4. In both cases, the tape tension and tape speed were set to the same conditions as in the conventional method.

Further, with respect to the sample tape manufactured under the polishing conditions satisfying the dropout standard value, the C / N characteristics in the high frequency region were also compared with the conventional method. Specifically, using the signal transmission circuit built into the AJ-350, a carrier signal of 33.5 MHz is used.
± 2MH for carrier by recording / reproducing single wave at
The difference between the average value of the reproduction noise level at z and the reproduction level of the carrier signal was defined as the C / N characteristic.

The contents studied in Examples 1 to 4 and the results thereof are shown below (Table 1). Regarding C / N characteristics,
It is shown as a relative value with respect to the C / N value of Comparative Example 1.

[0052]

[Table 1]

As is clear from Table 1, if the cleaning mechanism using the felt rotation roll 4 is adopted, the dropout reference value can be achieved with a smaller number of treatments than in Comparative Example 1. In particular, if the magnetic tape 10 is pressed by the air nozzle 5 together, the cleaning efficiency can be kept high even when the driving rotation speed of the felt rotation roll 4 is high, and as a result, the number of processing times can be further reduced. I understand. Further, when the felt material impregnated with the abrasive is used, the number of treatments is reduced regardless of the kind of the abrasive and the impregnation method, and it is understood that the cleaning efficiency is excellent. Furthermore, polishing tape 18
It can be seen that the number of cleaning processes can be significantly reduced by additionally providing another cleaning mechanism such as the blade 14, the abrasive grain rotating roll 19, or the like.

On the other hand, looking at the comparison of the C / N characteristics, the cleaning mechanism using the felt rotation roll 4 is adopted, and another cleaning mechanism is provided in the second embodiment.
It can be seen that the results are higher than those in Comparative Example 1 in all cases including the cases of 4 to 4.

As is clear from the above results, by adopting the cleaning mechanism using the felt rotation roll 4, the organic component of the polar surface layer which could not be wiped off by the conventional method without physically damaging the surface of the magnetic layer. It can be seen that can be efficiently removed.

In the above embodiment, the polishing apparatus for the magnetic tape of 1/2 inch width was described as an example, but the invention is not necessarily limited to this apparatus and the polishing for magnetic tapes of other widths is possible. It can also be applied to an apparatus or a polishing apparatus for the original width of a magnetic tape.

Further, the magnetic recording medium to be processed is not limited to a long one such as the magnetic tape 10, and for example, a disk-shaped magnetic recording medium such as a floppy disk may be used. As in the case of the magnetic tape 10 or the like, the felt rotary roll having the length of the disk radius is brought into contact with the disk while rotating in a direction opposite to the rotation direction of the disk, thereby effectively cleaning the organic component of the pole surface layer. be able to.

Further, the size and manufacturing method of the felt rotating roll 4 are not limited to those shown in the above-mentioned embodiment, and can be manufactured in various shapes according to the purpose. For example, when processing with the original width, 1
A wide felt rotating roll made by stacking several to several tens of disc-shaped or donut-shaped ones punched from a felt sheet having a thickness of 0 to 30 mm, or a sheet-shaped roll from a metal wide roll. The same effect can be obtained by using a felt rotation roll produced by winding a felt material.

Further, in the above embodiment, the apparatus having only the function of polishing the magnetic recording medium has been described as an example, but the present invention is not necessarily limited to such a configuration, and other It is also possible to incorporate it into a device having the function of. For example, in a slitter device or a tape winding device, the same effect can be exhibited by incorporating the polishing device of the present invention in the traveling path of the magnetic recording medium.

[0060]

As described above, according to the polishing apparatus for a magnetic recording medium of the present invention, the fibers of the felt material having excellent lipophilicity slide on the surface of the magnetic layer at high speed,
When the fibers are in contact with each other in the cross-sectional direction, a brushing effect is produced, and when the fibers are in the longitudinal direction with each other, a wiping effect is produced. Further, due to the flexibility of the fiber itself, physical damage to the surface of the magnetic layer can be suppressed, and excellent surface properties can be maintained. As a result, not only is it possible to reduce dropouts at a very shallow and fine level with a smaller number of processing times than in the past, but also it is possible to greatly improve the recording / reproducing characteristics in the high frequency range.

Further, in the above-mentioned constitution, according to the preferable constitution in which the felt material is animal hair, it is possible to obtain sufficient hardness and flexibility of the fibers for efficiently removing the organic substance in the outermost layer.

Further, in the above constitution, the inorganic powder abrasive is dispersed in the organic binder, and the felt material is impregnated with this.
According to the preferable constitution of fixing, not only the organic floating components such as the binder resin in the surface layer of the magnetic recording medium are removed by the brushing action and the wiping action of the animal hair fiber, but also the fine abrasive adhered to the fiber surface is removed. The ubiquitous organic layer can be effectively cut without causing damage on the surface of the magnetic layer while being appropriately controlled by the flexibility of the fiber.

Further, in the above-mentioned constitution, according to a preferable constitution in which the abrasive powder of the inorganic powder is dispersed in the aliphatic oil and fat and the felt material is impregnated and adhered thereto, the aliphatic oil and fat in which the abrasive material is dispersed is used. Can be transferred when the surface of the magnetic layer is treated, and can act as a lubricant for the magnetic layer.

Further, in the case of using an abrasive, according to a preferable constitution that the abrasive is at least one selected from chromium oxide, aluminum oxide and iron oxide having an average particle diameter of 0.1 to 1.0 μm, Excellent in matching the surface properties of the layers and the hardness of the magnetic layer and the outermost layer, and can suppress grinding damage.

Further, in the above-mentioned structure, according to the preferable structure in which the air is blown from the non-processed surface side of the magnetic recording medium toward the felt rotating roll, the contact pressure to the felt rotating roll can be varied. Even when the cleaning process is performed at high speed, the contact between the magnetic recording medium and the felt rotation roll can be stably maintained.

In the above construction, a cleaning mechanism using a polishing tape is provided on at least one of the front and rear sides of the cleaning mechanism using the felt rotation roll, and the polishing tape is run such that its polishing surface is in contact with the magnetic layer of the magnetic recording medium. According to the preferred construction, the felt material exerts an effect of removing large foreign matters and dusts before the brushing action and the wiping action brought about by the high-speed sliding of the felt material, and the short fibers and the abrasive removed from the felt material. And the like can be removed so as not to be adversely affected. Further, in the above structure, a blade made of cemented sapphire or diamond having a sharp edge is provided on at least one of the front and rear sides of the cleaning mechanism by the felt rotating roll, and the sharp edge is in contact with the magnetic layer of the magnetic recording medium. A preferable configuration of running as described above, or in the above configuration, at least one of the front and rear sides of the cleaning mechanism by the felt rotating roll, a cylindrical or cylindrical abrasive roll having a diamond abrasive grain bonded with a metal binder. The same effect can be obtained by a preferable configuration in which the abrasive grain rotating roll is brought into contact with the magnetic layer while being rotated at a high speed in a direction opposite to the traveling direction of the magnetic recording medium.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a 1/2 inch VTR magnetic tape polishing apparatus showing an embodiment of a magnetic recording medium polishing apparatus according to the present invention.

FIG. 2 is a model diagram showing the action of a rotating roll made of the felt material of the present invention.

FIG. 3 is a block diagram of a 1/2 inch VTR magnetic tape polishing apparatus showing another embodiment of the magnetic recording medium polishing apparatus according to the present invention.

FIG. 4 is a block diagram of a 1/2 inch VTR magnetic tape polishing apparatus showing still another embodiment of the magnetic recording medium polishing apparatus according to the present invention.

FIG. 5 is a configuration diagram of a 1 / 2-inch VTR magnetic tape polishing apparatus showing still another embodiment of the magnetic recording medium polishing apparatus according to the present invention.

FIG. 6 is a typical 1/2 inch VTR in the prior art.
It is a block diagram of a magnetic tape polishing apparatus for use.

[Explanation of symbols]

 1 Magnetic Tape Unwinding Shaft 2 Tape Control Roll 3 Measuring Roll 4 Felt Rotating Roll 5 Air Nozzle 6 Tape Tension Detection Roll 7 Magnetic Tape Winding Shaft 8 Winding Touch Roll 9 Touch Roll Arm 10 Magnetic Tape 11 Felt Fiber 12 Magnetic Layer Pole Surface organic material 13 Magnetic layer stable region 14 Carbide sapphire blade 15 Polishing tape post 16 Polishing tape unwinding shaft 17 Polishing tape winding shaft 18 Polishing tape 19 Abrasive rotation roll

Claims (11)

[Claims] 1. A felt rotating roll comprising a felt material having a cylindrical shape or a cylindrical shape with a rotating shaft provided at the center of the felt material, and a drive mechanism for driving the felt rotating roll. An apparatus for polishing a magnetic recording medium, in which the magnetic recording medium is brought into contact with the magnetic layer while being rotated at a high speed in a direction opposite to the traveling direction of the magnetic recording medium. 2. The polishing apparatus for a magnetic recording medium according to claim 1, wherein the felt material is animal hair. 3. A polishing apparatus for a magnetic recording medium according to claim 1, wherein an inorganic powder abrasive is dispersed with an organic binder, and the felt is impregnated and fixed to the felt. 4. The magnetic recording medium polishing apparatus according to claim 1, wherein an inorganic powder abrasive is dispersed in an aliphatic oil and fat, and the felt is impregnated and fixed. 5. The magnetic recording medium polishing apparatus according to claim 3, wherein the polishing agent is at least one selected from chromium oxide, aluminum oxide, and iron oxide having an average particle diameter of 0.1 to 1.0 μm. 6. A conveyance speed of a magnetic recording medium and a rotation speed of a felt rotation roll such that a ratio of cumulative contact lengths of felt materials contacting each other while processing a unit length of the magnetic recording medium satisfies 5 to 400. The roll diameter is set to 1.
An apparatus for polishing a magnetic recording medium according to 1. 7. The polishing apparatus for a magnetic recording medium according to claim 1, wherein air is blown from the non-treated surface side of the magnetic recording medium toward the felt rotating roll. 8. A cleaning mechanism using a polishing tape is provided on at least one of the front and rear sides of the cleaning mechanism using a felt rotation roll, and the polishing tape is run such that its polishing surface is in contact with the magnetic layer of the magnetic recording medium. An apparatus for polishing a magnetic recording medium according to 1. 9. A blade made of cemented sapphire or diamond having a sharp edge is provided on at least one of the front and rear sides of the cleaning mechanism using the felt rotation roll, and the sharp edge is in contact with the magnetic layer of the magnetic recording medium. The polishing apparatus for a magnetic recording medium according to claim 1, wherein the polishing apparatus is run in the direction of. 10. A columnar or cylindrical abrasive grain rotating roll in which diamond abrasive grains are bonded by a metal binder is provided on at least one of the front and rear sides of a cleaning mechanism using a felt rotating roll, and the abrasive grain rotating roll is magnetically coupled. The polishing apparatus for a magnetic recording medium according to claim 1, wherein the magnetic recording medium is brought into contact with the magnetic layer while being rotated at a high speed in a direction opposite to the traveling direction of the recording medium. 11. The diamond abrasive grain size is 2 to 20 μm.
The polishing apparatus for a magnetic recording medium according to claim 10, wherein m is m.