JP2004272967A - Method for manufacturing magnetic tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a magnetic tape, which can minimize an irregular pattern of a cutting surface of the obtained magnetic tape when the magnetic tape is manufactured by cutting the wide magnetic tape longitudinally, and which can effectively prevent a part of the cutting surface of the magnetic tape from being peeled off and dropped from the cutting surface of the magnetic tape, due to the irregular pattern of the cutting surface of magnetic tape, when the data are recorded or reproduced. <P>SOLUTION: The wide magnetic tape is cut, by setting the cutting start angle θ defined by the upper blade and the lower blade so as to be 6-12°, when the cutting of the wide magnetic tape supplied between the disk-like upper blade 6 and the disk-like lower blade 7, which overlap each other and are rotated in the opposite directions, is started, and the magnetic tape is manufactured. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a magnetic tape, and more particularly, to supply a wide magnetic tape between an upper blade and a lower blade that overlap each other and rotate in opposite directions, Along the longitudinal direction, a wide magnetic tape is cut, and when manufacturing a magnetic tape, an irregular uneven pattern of a cut surface of the obtained magnetic tape can be suppressed to a minimum. When the data is reproduced, it is possible to effectively prevent a part of the cut surface of the magnetic tape from peeling and dropping off from the cut surface of the magnetic tape due to the irregular uneven pattern of the cut surface of the magnetic tape. The present invention relates to a method for manufacturing a magnetic tape that can be prevented.
[0002]
[Prior art]
Normally, the magnetic tape has a magnetic recording layer formed on one surface of a wide support, a back coat layer formed on the other surface, and then between a rotating upper blade and a lower blade of the cutting device. It is manufactured by supplying a wide magnetic tape and cutting it to the width of the product.
[0003]
However, in the case where a wide magnetic tape is supplied between the upper and lower blades of a disk that overlap with each other and rotate in opposite directions, and cut to the width of a product, and a magnetic tape is manufactured, It is known that an irregular pattern is likely to occur on the cut surface, and if a large irregular pattern is generated on the cut surface of the magnetic tape, the cut surface of the magnetic tape becomes a guide surface. When recording data on a magnetic tape, guide the magnetic tape when guiding a cut surface of the magnetic tape by a guide member of a data recording device that guides the magnetic tape, or when reproducing data from the magnetic tape. When the cut surface of the magnetic tape is guided by the guide member of the data reproducing apparatus, a part of the cut surface may peel off from the cut surface of the magnetic tape and fall off. There is Ruosore.
[0004]
[Problems to be solved by the invention]
Conventionally, a wide magnetic tape was cut to cut the wide magnetic tape and to manufacture the magnetic tape so as to prevent the occurrence of such a defect and reduce the irregular uneven pattern of the cut surface of the magnetic tape. Methods of adjusting the degree of overlap between the disk-shaped upper blade and the disk-shaped lower blade to be cut, and chamfering the upper blade or the lower blade have been proposed.
[0005]
By such a method, the irregular concavo-convex pattern of the cut surface of the magnetic tape can be improved to some extent, but in order to improve the irregular concavo-convex pattern of the cut surface of the magnetic tape, a disc to be set must be set. The degree of overlap between the disk-shaped upper blade and the disk-shaped lower blade depends on the diameter of the disk-shaped upper blade and the disk-shaped lower blade, and is used for cutting. It is indispensable to experimentally set the degree of overlap between the disk-shaped upper blade and the disk-shaped lower blade according to the diameter of the lower blade. Developing a method that can improve the irregular asperity pattern of the magnetic tape cut surface as desired because chamfering alone cannot sufficiently improve the irregular asperity pattern of the magnetic tape cut surface. Was desired.
[0006]
Therefore, the present invention provides a wide magnetic tape between the upper blade and the lower blade, which are mutually overlapping and rotate in opposite directions, and cuts the wide magnetic tape along the longitudinal direction. Then, when manufacturing the magnetic tape, the irregular concavo-convex pattern of the cut surface of the obtained magnetic tape can be minimized, and the cut surface of the magnetic tape can be cut at the time of data recording or data reproduction. Provided is a method of manufacturing a magnetic tape capable of effectively preventing a part of a cut surface of a magnetic tape from being separated from a cut surface of a magnetic tape due to an irregular concavo-convex pattern. It is intended for that purpose.
[0007]
[Means for Solving the Problems]
The present inventor has conducted intensive studies in order to achieve the object of the present invention. As a result, the irregular asperity pattern of the cut surface of the magnetic tape was changed to the diameter of the disk-shaped upper blade, the disk-shaped lower blade. Regardless of the degree of overlap and the degree of overlap between the upper blade and the lower blade of the disk, the upper blade and the lower blade of the disk which overlap each other and rotate in the opposite direction By this, it is found that it depends on the cutting start angle of the disk-shaped upper blade and the disk-shaped lower blade when the cutting of the wide magnetic tape supplied in the meantime is started. When the upper blades whose opposing surfaces are chamfered are used, the wide width supplied between the disk-shaped upper blade and the disk-shaped lower blade that overlap with each other and rotate in the opposite direction. The disk-shaped upper blade and the disk-shaped lower blade when the cutting of the magnetic tape is started The start angle, and set to a 12 ° free 6 °, and cut the broad magnetic tape, by manufacturing the magnetic tape, found that the object of the present invention are achieved.
[0008]
According to the study of the present inventor, when an upper blade having a chamfered surface facing the lower blade is used as the upper blade, the disk-shaped upper blade overlaps with each other and rotates in the opposite direction. When setting the cutting start angle between the disk-shaped upper blade and the disk-shaped lower blade when the cutting of the wide magnetic tape supplied between the disk-shaped lower blade and the disk-shaped lower blade is started to be less than 6 ° It has been found that a large concave-convex pattern occurs on the cut surface of the magnetic tape, particularly on the cut surface on the lower blade side.
[0009]
On the other hand, according to the research of the present inventor, when an upper blade having a chamfered surface facing the lower blade is used as the upper blade, a disk-shaped upper blade that overlaps with each other and rotates in the opposite direction. When the cutting start angle between the disk-shaped upper blade and the disk-shaped lower blade when the cutting of the wide magnetic tape supplied between the disk-shaped lower blade and the disk-shaped lower blade is started exceeds 12 ° It has been found that a large irregular asperity pattern occurs on the cut surface of the magnetic tape, especially on the cut surface on the upper blade side.
[0010]
In this specification, the cutting surface of the upper blade side of the magnetic tape refers to the cutting surface of the magnetic tape that is in contact with the upper blade after cutting the magnetic tape, and the cutting surface of the lower blade side of the magnetic tape is Refers to the cut surface of the magnetic tape in contact with the lower blade after cutting the magnetic tape.
[0011]
Therefore, when an upper blade having a chamfered surface facing the lower blade is used as the upper blade, a disc-shaped upper blade and a disk-shaped lower blade that overlap each other and rotate in opposite directions are used. When the cutting start angle formed by the disc-shaped upper blade and the disc-shaped lower blade when the cutting of the wide magnetic tape supplied therebetween is started is set to less than 6 °, and the cutting start angle is 12 °. In any case, when the data is recorded on the magnetic tape, the guide member of the data recording device for guiding the magnetic tape contacts the cut surface of the magnetic tape, or When data is reproduced from the magnetic tape, the guide member of the data reproducing device that guides the magnetic tape comes into contact with the cut surface of the magnetic tape, and a part of the cut surface is separated from the cut surface of the magnetic tape and falls off. May occur is there.
[0012]
On the other hand, according to the research of the present inventor, when an upper blade having a chamfered surface facing the lower blade is used as the upper blade, the disk-shaped upper blade which rotates in the opposite direction is circular. As the cutting start angle formed by the disc-shaped upper blade and the disc-shaped lower blade when the cutting of the wide magnetic tape supplied between the disc-shaped lower blade is started, the magnetic tape becomes The irregular concavo-convex pattern generated on the cutting surface on the upper blade side becomes large, but if the cutting start angle is 12 ° or less, the guide member of the data recording device and the data reproducing It has been found that there is little possibility that a convex portion which is peeled off and comes off when the guide member of the device comes into contact with the cut surface is formed.
[0013]
On the other hand, according to the study of the present inventor, when an upper blade having a chamfered surface facing the lower blade is used as the upper blade, irregularities generated on the cut surface on the lower blade side of the magnetic tape are used. The concavo-convex pattern is a disk-shaped upper blade and a disk when cutting of the wide magnetic tape supplied between the disk-shaped upper blade and the disk-shaped lower blade rotating in opposite directions is started. It has been found that when the cutting start angle formed by the lower blade becomes 6 ° or more, the value sharply decreases, but becomes substantially constant when the cutting start angle is around 12 °.
[0014]
Therefore, when an upper blade having a chamfered surface facing the lower blade is used as the upper blade, the upper blade is supplied between the disk-shaped upper blade rotating in the opposite direction and the disk-shaped lower blade. The cutting start angle between the disc-shaped upper blade and the disc-shaped lower blade when the cutting of the wide magnetic tape is started is set to 6 ° to 12 °, and the magnetic tape is cut. When recording data on the magnetic tape or reproducing data from the magnetic tape, a part of the cut surface of the magnetic tape is reduced due to contact with the guide member for guiding the magnetic tape. It is possible to effectively prevent the problem of peeling off from the cut surface and falling off.
[0015]
In the present invention, preferably, the cutting start angle formed by the disc-shaped upper blade and the disc-shaped lower blade when cutting of the wide magnetic tape is started is set to 7 ° to 11 °, and Is cut, and a magnetic tape is manufactured.
[0016]
According to the study of the present inventor, when an upper blade having a chamfered surface facing the lower blade is used as the upper blade, a disk-shaped upper blade and a disk-shaped lower blade rotating in opposite directions are used. As the cutting start angle between the disk-shaped upper blade and the disk-shaped lower blade when the cutting of the wide magnetic tape supplied between them starts, the upper edge of the magnetic tape becomes The irregular concavo-convex pattern generated on the cutting surface becomes large, but when the cutting start angle is 11 ° or less, the guide member of the data recording device or the guide member of the data reproducing device is provided on the cutting surface on the upper blade side of the magnetic tape. It has been found that a contact portion that does not form on the cut surface due to contact does not occur.
[0017]
On the other hand, according to the study of the present inventor, when an upper blade having a chamfered surface facing the lower blade is used as the upper blade, an irregular asperity pattern generated on the cut surface on the lower blade side of the magnetic tape. The disk-shaped upper blade and the disk-shaped upper blade when the cutting of the wide magnetic tape supplied between the disk-shaped upper blade and the disk-shaped lower blade rotating in opposite directions are started. It has been found that when the cutting start angle formed by the lower blade is 7 ° or more, the value sharply decreases, but no significant decrease is recognized even when the cutting start angle exceeds 11 °.
[0018]
Therefore, when an upper blade having a chamfered surface facing the lower blade is used as the upper blade, the upper blade is supplied between the disk-shaped upper blade rotating in the opposite direction and the disk-shaped lower blade. The cutting start angle formed by the disc-shaped upper blade and the disc-shaped lower blade when cutting of the wide magnetic tape is started is set to 7 ° to 11 °, and the magnetic tape is cut. When recording data on the magnetic tape or reproducing data from the magnetic tape, a part of the cut surface of the magnetic tape is reduced due to contact with the guide member for guiding the magnetic tape. It is possible to reliably prevent the occurrence of the problem of peeling off from the cut surface and falling off.
[0019]
In a further preferred embodiment of the present invention, the cutting start angle between the disk-shaped upper blade and the disk-shaped lower blade when the cutting of the wide magnetic tape is started is set to 8 ° to 10 °. Then, the wide magnetic tape is cut, and the magnetic tape is manufactured.
[0020]
In a preferred embodiment of the present invention, the upper blade is chamfered at 1 to 20 °.
[0021]
In a further preferred embodiment of the present invention, the upper blade is chamfered at 1 to 15 °.
[0022]
In a further preferred embodiment of the present invention, the upper blade is chamfered at 1 to 5 °.
[0023]
In a preferred embodiment of the present invention, the upper blade is chamfered with a width of 3.5 μm or less.
[0024]
In a further preferred embodiment of the present invention, the upper blade is chamfered with a width of 2 μm or less.
[0025]
In a further preferred embodiment of the present invention, the upper blade is chamfered with a width of 1 μm or less.
[0026]
In the present invention, the type of magnetic tape is not particularly limited, and includes a general magnetic tape such as a data backup tape for a computer, a magnetic tape for audio, a magnetic tape for video, a magnetic tape for 8 mm video, and a single-layer magnetic recording. Layers may be formed, or multiple magnetic recording layers may be formed.
[0027]
In the present invention, the magnetic tape includes a support, a single or multilayer magnetic recording layer formed on one surface of the support, and a back coat layer formed on the other surface of the support. In order to improve the adhesion between the magnetic recording layer and the support, an undercoat layer may be provided between the magnetic recording layer and the support.
[0028]
In a preferred embodiment of the present invention, the magnetic tape is configured as a data backup tape for a computer.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0030]
FIG. 1 is a schematic cross-sectional view of a magnetic tape produced by ideally cutting a wide magnetic tape along its longitudinal direction.
[0031]
The magnetic tape 1 according to the present embodiment is used as a computer data backup tape. As shown in FIG. 1, the computer data backup tape 1 includes a support 2. , An undercoat layer 3 and a magnetic recording layer 4 for recording data, and a backcoat layer 5 is formed on the other surface.
[0032]
In this embodiment, the support 2 of the computer data backup tape 1 has a thickness of 6.0 to 6.5 μm, preferably 6.1 to 6.3 μm, and one surface of the support 2 An undercoat layer 3 having a thickness of 0.5 to 2.5 μm and a magnetic recording layer 4 having a thickness of 0.05 to 0.5 μm are formed on the other surface of the support 2. A back coat layer 5 having a thickness of about 0.7 μm is formed.
[0033]
In the computer data backup tape 1 shown in FIG. 1, an undercoat layer 3 and a magnetic recording layer 4 are formed on one surface of a wide support 2 by coating or the like, and the other surface is coated by coating or the like. A wide magnetic tape (not shown) on which the back coat layer 5 is formed is formed by being cut into a predetermined width in the longitudinal direction.
[0034]
FIG. 2 is a schematic cross-sectional view of a magnetic tape cutting device according to a preferred embodiment of the present invention, and FIG. 3 is a partially enlarged cross-sectional view of a portion indicated by A in FIG.
[0035]
As shown in FIG. 2, the magnetic tape cutting device according to the present embodiment includes an undercoat layer 3 having a thickness of about 2 μm on one surface of a wide support 2 having a thickness of about 6.2 μm. A wide magnetic tape (not shown) in which a magnetic recording layer 4 having a thickness of about 0.15 μm is formed, and a back coat layer 5 having a thickness of about 0.5 μm is formed on the other surface of the support 2. ) Is cut into a predetermined width, so that the computer data backup tape 1 can be manufactured. Each of the cutting units includes a disk-shaped upper blade 6 and a disk-shaped lower blade 7. The upper blade 6 and the lower blade 7 of each cutting unit 8 are rotatable.
[0036]
In FIG. 3, OL is the length of the overlapping portion of the upper blade 6 and the lower blade 7.
[0037]
FIG. 4 is a schematic enlarged cross-sectional view of the upper blade 6.
[0038]
As shown in FIG. 4, in the present embodiment, as the upper blade 6, the angle α between the surface facing the lower blade 7 and the surface facing the upper blade 6 of the lower blade 7 is about 4.5 °. The upper blade 6 is chamfered so that the chamfer width W is about 0.5 μm, and is inclined on the surface opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. An upper blade 6 having a surface is used.
[0039]
FIG. 5 is a schematic longitudinal sectional view of each cutting unit 8 constituting the magnetic tape cutting device shown in FIG.
[0040]
As shown in FIG. 5, in each of the cutting units 8 constituting the magnetic tape cutting device according to the present embodiment, the disc-shaped upper blade 6 and the disc-shaped lower blade 7 rotate in directions opposite to each other. The wide magnetic tape has a disc-shaped upper blade 6 and a disc-shaped lower blade 7 such that the magnetic recording layer 4 is located on the upper blade side and the back coat layer 5 is located on the lower blade side. The wide magnetic tape is cut to a predetermined width by the upper blade 6 and the lower blade 7 adjacent to each other and constituting the magnetic tape cutting device and constituting the magnetic tape cutting device, and the computer data backup tape 1 is manufactured. You.
[0041]
In this embodiment, the disc-shaped upper blade 6 and the disc-shaped lower blade 7 and the disc-shaped upper blade 6 when the cutting of the wide magnetic tape supplied therebetween is started. The angle θ formed by the lower blade 7 (hereinafter referred to as “cutting start angle”) is set to 6 ° to 12 °, preferably 7 ° to 11 °.
[0042]
Here, the cutting start angle θ between the upper blade 6 and the lower blade 7 is set by adjusting the length OL of the overlapping portion between the upper blade 6 and the lower blade 7.
[0043]
FIG. 6 is a schematic cross-sectional view of a computer data backup tape 1 generated by cutting a wide magnetic tape into a predetermined width along its longitudinal direction.
[0044]
As shown in FIG. 6, a wide magnetic tape is cut to a predetermined width along its longitudinal direction, and the cut surface on the upper blade side of the generated computer data backup tape 1 has irregular irregularities. It has a pattern and usually protrudes at a portion near the surface of the magnetic recording layer 4, while a cut surface on the lower blade side usually protrudes at a portion near the backcoat layer 5.
[0045]
Here, when recording data on the magnetic recording layer 4 of the computer data backup tape 1, both sides of the computer data backup tape 1, that is, both sides are guided by guide members, and the computer data backup tape 1 is guided. The tape 1 is fed through the data recording device. On the other hand, in reproducing the data recorded on the magnetic recording layer 4 of the computer data backup tape 1, the double-sided cross section of the computer data backup tape 1 is guided by a guide member. Then, the computer data backup tape 1 is configured to be sent through the data reproducing apparatus.
[0046]
Therefore, when the projecting amount of the cut surface of the computer data backup tape 1 exceeds a predetermined amount, the guide member of the data recording device or the data reproducing device is used when the data recording device or the data reproducing device reproduces the data. Due to the contact with the projection of the cut surface, the projection of the cut surface may peel off from the data backup tape 1 for a computer and drop off.
[0047]
However, in the present embodiment, as the upper blade 6, the surface facing the lower blade 7 of the upper blade 6 has an angle α of about 4.5 ° with the surface facing the upper blade 6 of the lower blade 7, and the chamfer is formed. The width W is chamfered so as to be about 0.5 μm, and on the surface of the upper blade 6 opposite to the surface facing the lower blade 7, the thickness of the upper blade 6 decreases toward the tip. By using the upper blade 6 having the inclined surface formed thereon and adjusting the length OL of the portion where the upper blade 6 and the lower blade 7 overlap, the cutting start angle θ formed by the upper blade 6 and the lower blade 7 However, since the angle is set to 6 ° to 12 °, preferably 7 ° to 11 °, the protrusion amount of the cut surface of the generated computer data backup tape 1 can be suppressed to a predetermined amount or less, When recording data or reproducing data, the data recording device or data reproducing device It is possible to effectively prevent the protrusion of the cut surface from peeling off and falling off from the data backup tape for computer 1 due to the contact of the guide member with the protrusion of the cut surface of the data backup tape for computer 1. Can be prevented.
[0048]
【Example】
Hereinafter, examples will be given to further clarify the effects of the present invention.
[0049]
Example
On one side of a wide support 2 made of polyethylene naphthalate having a width of 500 mm and a thickness of 6.1 μm, an undercoat layer 3 having a thickness of 2 μm and a magnetic recording layer 4 having a thickness of 0.15 μm are provided. At the same time, a backcoat layer 5 having a thickness of 0.5 μm was formed on the other surface of the support 2 to produce a wide magnetic tape.
[0050]
Next, a wide magnetic tape was cut using a pair of cutting units 8 each having an upper blade 6 and a lower blade 7 having a diameter of 100 mm, thereby producing a computer data backup tape 1 having a width of 12.65 mm. .
[0051]
Here, as the upper blade 6, the angle α between the surface facing the lower blade 7 of the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °, and the chamfer width W is 0.5 mm. An inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. The upper blade 6 is used to change the length OL of the overlapping portion between the upper blade 6 and the lower blade 7 of the pair of cutting units to change the cutting start angle θ formed by the upper blade 6 and the lower blade 7. Then, in each case, the magnetic tape was cut, and the state of both cut sections of the generated computer data backup tape 1 was inspected.
[0052]
FIG. 7 is a graph showing the relationship between the maximum protrusion amount PU of the cutting surface on the upper blade side of the computer data backup tape 1 and the cutting start angle θ formed by the upper blade 6 and the lower blade 7, and FIG. 4 is a graph showing the relationship between the maximum protruding amount PL of the cutting surface on the lower blade side of the computer data backup tape 1 and the cutting start angle θ formed by the upper blade 6 and the lower blade 7.
[0053]
As shown in FIG. 7, when the diameter of the upper blade 6 and the lower blade 7 is 100 mm, the maximum protrusion amount PU (μm) of the cut surface on the upper blade side of the computer data backup tape 1 is determined by the cutting start angle θ. Was found to increase almost linearly with increasing.
[0054]
On the other hand, as shown in FIG. 8, as the upper blade 6, the angle α between the surface facing the lower blade 7 of the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °, The surface of the upper blade 6 is chamfered so that the chamfering width W is 0.5 μm, and the thickness of the upper blade 6 decreases toward the front end portion on the surface of the upper blade 6 opposite to the surface facing the lower blade 7. When the upper blade 6 having an inclined surface is used and the diameter of the upper blade 6 and the lower blade 7 is 100 mm, the maximum projection PL (μm) of the cut surface on the lower blade side of the computer data backup tape 1. Decreases substantially linearly as the cutting start angle θ increases in an angle region where the cutting start angle θ is about 10 ° or more, and suddenly decreases when the cutting start angle θ is between about 7 ° and about 10 °. Was observed to decrease.
[0055]
As shown in FIG. 8, as the upper blade 6, the angle α between the surface facing the lower blade 7 of the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °, The surface of the upper blade 6 is chamfered so that the chamfering width W is 0.5 μm, and the thickness of the upper blade 6 decreases toward the front end portion on the surface of the upper blade 6 opposite to the surface facing the lower blade 7. When the upper blade 6 having an inclined surface is used, even when the cutting start angle θ is about 7 °, the maximum projection PL (μm) of the cut surface on the lower blade side of the computer data backup tape 1 is , 1.25 μm, but the maximum protrusion PL (μm) of the cutting surface on the lower blade side of the computer data backup tape 1 tends to increase as the cutting start angle θ decreases. Was done.
[0056]
According to the research of the present inventor, when the maximum protrusion amount PU (μm) or PL (μm) of the cut surface of the computer data backup tape 1 exceeds 1.50 μm, the data is recorded or the data is not recorded. At the time of reproduction, the projection of the cut surface of the data backup tape 1 is caused by the guide member of the data recording device or the data reproduction device coming into contact with the projection of the cut surface of the data backup tape 1 for computer. It has been found that there is a high possibility that a problem of peeling and falling off from the cut surface occurs.
[0057]
Therefore, as the upper blade 6, the surface facing the lower blade 7 of the upper blade 6 has an angle α of 4.5 ° with the surface facing the upper blade 6 of the lower blade 7, and the chamfer width W is 0.5 μm. An inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When the blade 6 is used, as shown in FIG. 7, when the cutting start angle θ formed by the upper blade 6 and the lower blade 7 exceeds 12 °, the maximum of the cut surface on the upper blade side of the data backup tape 1 for a computer is obtained. The protrusion amount PU (μm) may exceed 1.50 μm, and the projection of the cut surface on the upper blade side of the data backup tape 1 for computer may cause the data backup tape 1 for computer to be used during data recording or data reproduction. Is likely to peel off from the cut surface of Therefore, the protrusion of the cut surface on the upper blade side of the computer data backup tape 1 is prevented from peeling off and falling off from the cut surface of the computer data backup tape 1 during data recording or data reproduction. To do so, it has been found that it is necessary to cut the wide magnetic tape and set the computer data backup tape 1 by setting the cutting start angle θ to 12 ° or less.
[0058]
On the other hand, as the upper blade 6, an angle α between the surface facing the lower blade 7 of the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °, and the chamfer width W is 0.5 μm. An inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When the blade 6 is used, as shown in FIG. 8, when the cutting start angle θ between the upper blade 6 and the lower blade 7 is less than 6 °, the maximum of the cut surface on the lower blade side of the computer data backup tape 1 is reduced. The projecting amount PL (μm) may exceed 1.50 μm, and the protrusion of the cut surface on the lower blade side of the computer data backup tape 1 may cause the computer data backup tape to be lost when data is recorded or data is reproduced. It may peel off from the cut surface of 1 and fall off Further, the projection of the cut surface on the lower blade side of the computer data backup tape 1 is prevented from peeling off and falling off from the cut surface of the computer data backup tape 1 during data recording or data reproduction. For this purpose, it has been found that it is necessary to cut the wide magnetic tape by setting the cutting start angle θ to 6 ° or more and to generate the computer data backup tape 1.
[0059]
Therefore, as the upper blade 6, the surface facing the lower blade 7 of the upper blade 6 has an angle α of 4.5 ° with the surface facing the upper blade 6 of the lower blade 7, and the chamfer width W is 0.5 μm. An inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When the blade 6 is used, it can be seen from FIGS. 7 and 8 that the projection of the cut surface of the computer data backup tape 1 peels off from the cut surface of the computer data backup tape 1 during data recording or data reproduction. In order to effectively prevent the magnetic tape from falling off, the cutting start angle θ formed by the upper blade 6 and the lower blade 7 is set to 6 ° to 12 °, and a wide magnetic tape is cut. The need to create a data backup tape 1 It was bought.
[0060]
Further, as the upper blade 6, an angle α between the surface facing the lower blade 7 of the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °, and the chamfer width W is 0.5 μm. An inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When the blade 6 is used, from FIG. 7, when the cutting start angle θ formed by the upper blade 6 and the lower blade 7 becomes 11 ° or less, the maximum protrusion amount PU ( μm) is sufficiently smaller than the critical value of 1.50 μm, the cutting start angle θ is set to 11 ° or less, the wide magnetic tape is cut, and the computer data backup tape 1 is cut. By generating the data, when recording data or reproducing data, Protrusion of the cutting face of the upper blade side Yuta data backup tape 1, and peeled from the cut surface of the computer for data backup tapes 1, it was found that it is possible to reliably prevent the falling off.
[0061]
On the other hand, as the upper blade 6, an angle α between the surface facing the lower blade 7 of the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °, and the chamfer width W is 0.5 μm. An inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When the blade 6 is used, as shown in FIG. 8, when the cutting start angle θ formed by the upper blade 6 and the lower blade 7 becomes 7 ° or more, the maximum protrusion amount PL of the cut surface on the lower blade side of the computer data backup tape 1 ( μm) rapidly decreases, the cutting start angle θ is set to 7 ° or more, the wide magnetic tape is cut, and the computer data backup tape 1 is generated. At the time of data reproduction, the data backup tape 1 for computer It has been found that the protruding portion of the cut surface on the lower blade side can be reliably prevented from peeling off from the cut surface of the data backup tape 1 for a computer and falling off.
[0062]
Therefore, as the upper blade 6, the surface facing the lower blade 7 of the upper blade 6 has an angle α of 4.5 ° with the surface facing the upper blade 6 of the lower blade 7, and the chamfer width W is 0.5 μm. An inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When the blade 6 is used, the cutting start angle θ formed by the upper blade 6 and the lower blade 7 is set to 7 ° to 11 ° from FIG. 7 and FIG. By generating the tape 1, it is possible to prevent the projection of the cut surface of the computer data backup tape 1 from peeling off from the cut surface of the computer data backup tape 1 during data recording or data reproduction. It turns out that it can be reliably prevented
[0063]
FIG. 9 is a drawing showing the relationship between the profile of the cut surface on the upper blade side of the data backup tape for computer 1 and the cutting start angle θ formed by the upper blade 6 and the lower blade 7, and FIG. 4 is a diagram showing a relationship between a profile of a cutting section on a lower blade side of a backup tape 1 and a cutting start angle θ formed by an upper blade 6 and a lower blade 7.
[0064]
9 and 10, the right side indicates the side on which the magnetic recording layer 4 of the computer data backup tape 1 is formed, and the left side indicates the side on which the back coat layer 5 of the computer data backup tape 1 is formed. pointing.
[0065]
From FIG. 9, as the upper blade 6, the surface facing the lower blade 7 of the upper blade 6 has an angle α of 4.5 ° with the surface facing the upper blade 6 of the lower blade 7, and the chamfer width W is 0.5 mm. An inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When the upper blade 6 is used, as the cutting start angle θ between the upper blade 6 and the lower blade 7 increases, the maximum protrusion amount PU (μm) of the cutting surface on the upper blade side of the computer data backup tape 1 increases. When the cutting start angle θ exceeds 12 °, the maximum protruding amount PU (μm) of the cut surface on the upper blade side of the data backup tape for computer 1 becomes extremely large, and the upper blade side of the data backup tape for computer 1 becomes larger. The shape of the protruding part of the cut surface of the It can be seen that the guide member has a shape that is easily peeled off from the cut surface of the data backup tape for a computer 1 when it comes into contact with the guide member of the reproducing apparatus.
[0066]
On the other hand, from FIG. 10, as the upper blade 6, the angle α between the surface facing the lower blade 7 of the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °, and the chamfer width W is The inclined surface is chamfered so as to have a thickness of 0.5 μm, and an inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When the formed upper blade 6 is used, as the cutting start angle θ formed by the upper blade 6 and the lower blade 7 becomes smaller, the maximum protruding amount PL (μm) of the cut surface on the lower blade side of the data backup tape for computer 1 becomes smaller. When the cutting start angle θ is less than 6 °, the maximum protrusion PL (μm) of the cut surface on the lower blade side of the computer data backup tape 1 becomes extremely large, and The shape of the protruding part of the cutting surface on the blade side is also It can be read that the guide member has a shape that is easily peeled from the cut surface of the computer data backup tape 1 when the guide member comes into contact with the guide member of the data reproducing apparatus.
[0067]
Therefore, from FIGS. 9 and 10 showing the profile of the cut surface of the computer data backup tape 1, the surface facing the lower blade 7 of the upper blade 6 faces the upper blade 6 of the lower blade 7 as the upper blade 6. Is chamfered so that the angle α with the surface to be cut is 4.5 ° and the chamfer width W is 0.5 μm, and the surface of the upper blade 6 opposite to the surface facing the lower blade 7 faces the tip. When the upper blade 6 having the inclined surface is used so that the thickness of the upper blade 6 decreases, the projection of the cut surface of the data backup tape 1 for computer is used when recording data or reproducing data. However, in order to prevent the computer data backup tape 1 from being separated from the cut surface and falling off, the cutting start angle θ formed by the upper blade 6 and the lower blade 7 is set to 6 ° to 12 °. , Cut wide magnetic tape, It has been found that it is necessary to generate a computer for data backup tapes 1.
[0068]
Further, from FIG. 9, as the upper blade 6, the angle α between the surface facing the lower blade 7 of the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °, and the chamfer width W is The inclined surface is chamfered so as to have a thickness of 0.5 μm, and an inclined surface is formed on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When the formed upper blade 6 is used, when the cutting start angle θ formed by the upper blade 6 and the lower blade 7 is 11 ° or less, the maximum protrusion amount of the cut surface on the upper blade side of the computer data backup tape 1. The PU (μm) becomes smaller, the shape of the projection of the cut surface on the upper blade side of the data backup tape for computer 1 becomes smooth, and even if it comes into contact with the guide member of the data recording device or the data reproducing device, the guide member is formed. From the cut surface of the computer data backup tape 1 It can be seen that become hard to shape.
[0069]
On the other hand, from FIG. 10, the angle α between the surface facing the lower blade 7 of the upper blade 6 as the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °, and the chamfer width The surface of the upper blade 6 is chamfered so that W is 0.5 μm, and is inclined on the surface of the upper blade 6 opposite to the surface facing the lower blade 7 so that the thickness of the upper blade 6 decreases toward the tip. When using the upper blade 6 having a surface formed thereon, when the cutting start angle θ formed by the upper blade 6 and the lower blade 7 becomes 7 ° or more, the maximum protrusion amount of the cut surface on the lower blade side of the computer data backup tape 1 The PL (μm) rapidly decreases, and even if the shape of the projection of the cut surface on the lower blade side of the data backup tape for computer 1 contacts the guide member of the data recording device or the data reproducing device, Difficult to peel from the cut surface of the computer data backup tape 1 It can be read to become a shape.
[0070]
Therefore, from FIGS. 9 and 10, as the upper blade 6, the angle α between the surface facing the lower blade 7 of the upper blade 6 and the surface facing the upper blade 6 of the lower blade 7 is 4.5 °. The surface of the upper blade 6 is chamfered so that the chamfering width W is 0.5 μm, and the thickness of the upper blade 6 decreases toward the front end portion on the surface of the upper blade 6 opposite to the surface facing the lower blade 7. When the upper blade 6 having an inclined surface is used, the cutting start angle θ formed by the upper blade 6 and the lower blade 7 is set to 7 ° to 11 °, and the wide magnetic tape is cut. When the backup tape 1 is generated, the projection of the cut surface of the computer data backup tape 1 separates from the cut surface of the computer data backup tape 1 and drops off when recording or reproducing data. Can be surely prevented It was.
[0071]
The present invention is not limited to the above embodiments, and various changes can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.
[0072]
For example, in the above-described embodiment and the above-described embodiment, a case has been described in which a wide magnetic tape is cut to manufacture a data backup tape for a computer, but the present invention cuts a wide magnetic tape. It is not limited to the manufacture of data backup tapes for computers, but a wide variety of magnetic tapes such as audio magnetic tapes, video magnetic tapes, and 8 mm video magnetic tapes are manufactured by cutting wide magnetic tapes. The present invention can be applied not only to the case where the magnetic recording layer 4 is a single layer, but also to the case where a magnetic tape having a multilayer magnetic recording layer 4 is manufactured.
[0073]
【The invention's effect】
According to the present invention, a wide magnetic tape is supplied between a disk-shaped upper blade and a lower blade that overlap with each other and rotate in opposite directions, and the wide magnetic tape is cut along the longitudinal direction. As a result, it is possible to minimize the irregular pattern of the cut surface of the magnetic tape obtained, and to reduce the irregular pattern of the cut surface of the magnetic tape during data recording or data reproduction. Thus, it is possible to provide a magnetic tape cutting method capable of effectively preventing a part of the cut surface of the magnetic tape from being separated from the cut surface of the magnetic tape and falling off.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a computer data backup tape generated by ideally cutting a wide magnetic tape along its longitudinal direction.
FIG. 2 is a schematic cross-sectional view of a magnetic tape cutting device according to a preferred embodiment of the present invention.
FIG. 3 is a partially enlarged sectional view of a portion indicated by A in FIG. 2;
FIG. 4 is a schematic enlarged cross-sectional view of the upper blade.
FIG. 5 is a schematic longitudinal sectional view of each cutting unit constituting the magnetic tape cutting device shown in FIG. 1;
FIG. 6 is a schematic cross-sectional view of a computer data backup tape generated by cutting a wide magnetic tape along its longitudinal direction.
FIG. 7 is a graph showing the relationship between the maximum protrusion amount of the cutting surface on the upper blade side of the computer data backup tape and the cutting start angle θ formed by the upper blade and the lower blade.
FIG. 8 is a graph showing the relationship between the maximum protruding amount of the cutting surface on the lower blade side of the computer data backup tape and the cutting start angle θ formed by the upper blade and the lower blade.
FIG. 9 is a diagram showing a relationship between a profile of a cutting section on an upper blade side of a data backup tape for a computer and a cutting start angle θ formed by an upper blade and a lower blade.
FIG. 10 is a diagram showing a relationship between a profile of a cutting section on a lower blade side of a data backup tape for a computer and a cutting start angle θ formed by an upper blade and a lower blade.
[Explanation of symbols]
1 Data backup tape for computer
2 Support
3 Undercoat layer
4 Magnetic recording layer
5 Back coat layer
6 Upper blade
7 Lower blade
8 Cutting unit

Claims (5)

A wide magnetic tape having a magnetic recording layer formed on one surface of a wide support and a back coat layer formed on the other surface is overlapped with each other and placed on a circular disk rotating in the opposite direction. A method for producing a magnetic tape, wherein a surface facing the lower blade is chamfered as the upper blade by supplying the material between the blade and the lower blade and cutting it to a predetermined width to produce a magnetic tape. Cutting of the wide magnetic tape supplied between the disk-shaped upper blade and the disk-shaped lower blade overlapping with each other and rotating in opposite directions is started by using the upper blade thus set. The cutting start angle formed by the disc-shaped upper blade and the disc-shaped lower blade at that time is set to 6 ° to 12 °, and the wide magnetic tape is cut to produce a magnetic tape. A method for producing a magnetic tape. The disk-shaped when the cutting of the wide magnetic tape supplied between the disk-shaped upper blade and the disk-shaped lower blade that overlap with each other and rotate in opposite directions is started. 2. The magnetic tape according to claim 1, wherein a cutting start angle formed by an upper blade and the disc-shaped lower blade is set to 7 ° to 11 °, and the wide magnetic tape is cut to manufacture a magnetic tape. A method for producing the magnetic tape according to the above. The method according to claim 1, wherein the upper blade is chamfered at 1 ° to 20 °. The method according to claim 1, wherein the upper blade is chamfered with a width of 3.5 μm or less. 5. The method of manufacturing a magnetic tape according to claim 1, wherein the magnetic tape is configured as a computer data backup tape.

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