JPH0551155A - Roll body, winding method and winding device, and magnetic recording medium and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent the generation of lateral and longitudinal creases to a banded body wound onto a winding shaft by controlling the thickness of a gaseous layer, interposed between the banded body wound onto the winding shaft and the banded body wound thereon, always to be the specific value. CONSTITUTION:The rotating speed of a winding shaft 1 is detected by a rotating speed detecting means 5. The length of a roll body wound onto the winding shaft 1 is computed by a roll length computing means 7. An arithmetic means 8 receives the roll length information from the roll length computing means 7 so as to perform specified operation. A control means formed of a touch roll 3, a tension roll 4, actuators 3a, 4a, and the like controls the thickness of a gaseous layer, existing between the banded body wound onto the winding shaft and the banded body wound thereon, always to be approximately 0.1-0.7mu by an output signal from the means 8. As a result, lateral and longitudinal creases are not generated to the banded body wound onto the winding shaft 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, photographic film,
The present invention relates to a photographic light-sensitive material such as photographic paper, a belt-shaped body such as a magnetic tape, a winding method and a winding device.

[0002]

BACKGROUND OF THE INVENTION For example, various techniques have been proposed as a winding device for winding a photographic light-sensitive material such as photographic film and photographic paper, and a belt-shaped body such as a magnetic tape (JP-A-48-98268 and JP-A-61). -238638, JP-A-62-2
No. 44849, JP-A No. 62-259953,
JP-A-62-264154 and JP-A-63-37.
055 publication). However, the winding devices that have been proposed so far have not sufficiently solved the problems of horizontal wrinkles and vertical wrinkles when winding a belt-shaped body such as a photographic photosensitive material or a magnetic tape.

[0003]

DISCLOSURE OF THE INVENTION As a result of earnestly studying the above-mentioned problems, the present inventor has found that when winding a photographic light-sensitive material such as photographic film or photographic paper or a belt such as a magnetic tape, If the thickness of the air layer that is caught between the belt and the belt is large, the winding becomes loose, and as a result, winding misalignment and widthwise wrinkles occur, and conversely, the thickness of the air layer that is trapped is thin. In this case, it was found that the winding was too tight, resulting in vertical wrinkles in the longitudinal direction. Then, as a result of earnestly conducting further research, the thickness of the air layer caught between the strips is always about 0.1 to 0.
It has been found that the occurrence of horizontal wrinkles and vertical wrinkles can be significantly reduced by controlling and winding to 7 μm.

The present invention has been made on the basis of the above findings, and an object of the present invention is to provide a technique for preventing horizontal wrinkles and vertical wrinkles from occurring in a band-shaped body wound around a winding shaft. Is. An object of the present invention is a winding body obtained by winding a strip-shaped body around a winding shaft, and a thickness of a gas layer interposed between the strip-shaped body wound around the winding shaft and the strip-shaped body. Is always about 0.1 to 0.7 μm.

The thickness of the gas layer interposed between the strips wound on the winding shaft is preferably about 0.2 to 0.5 μm. A method for winding a belt-shaped body in which a belt-shaped body is wound around a winding shaft, wherein the thickness of the gas layer interposed between the belt-shaped bodies wound around the winding shaft is always about 0. This can be achieved by a winding method for a strip, which is controlled to be 1 to 0.7 μm and is wound.

The gas layer interposed between the strips wound on the winding shaft can be controlled to be wound so that the thickness of the gas layer is about 0.2 to 0.5 μm. preferable.
Further, the thickness of the gas layer interposed between the band-shaped magnetic recording medium materials in which the magnetic layer is formed on the non-magnetic band-shaped support is 0.1 to
The product wound on the take-up shaft so as to have a thickness of 0.7 μm should be left as it is in a high-temperature chamber at 40 ° C or higher for 4 hours or longer, and then allowed to cool and punched into slits or discs. Is achieved by a magnetic recording medium.

In addition, when the magnetic layer is formed on the non-magnetic strip-shaped support and is continuously wound around the winding shaft, the thickness of the gas layer interposed between the strips is 0.1 to 0.7 μm. The winding conditions are controlled so that the winding state is 40 ° C after completion of winding.
This is achieved by a method for producing a magnetic recording medium, which is characterized by leaving in the above high temperature chamber for 4 hours or more, allowing to cool, and then slitting or punching into a disk shape.

The gas layer interposed between the strips wound on the winding shaft may be controlled and wound so that the thickness of the gas layer is about 0.2 to 0.5 μm. preferable. Then, the winding operation of the winding body is a winding device in which a strip-shaped body is wound around a winding shaft, and a rotation speed detecting means for detecting a rotation speed of the winding shaft and the winding shaft. The winding length calculation means for calculating the winding length of the wound strip, the rotation speed information from the rotation speed detection means, and the winding length information from the winding length calculation means are input and a predetermined calculation is performed. And a control means for controlling the thickness of the gas layer interposed between the strip-shaped body wound around the winding shaft and the strip-shaped body according to the output signal from the calculating means. It is achieved by the winding device.

That is, the rotation speed n _i of the winding shaft is obtained by counting the pulses of the winding shaft motor,
Further, the winding length l _i of the strip-shaped body wound on the winding shaft is calculated by the running speed detected by the contact or non-contact type linear encoder × time until the rotation speed of the winding shaft is n _i. Based on these information, (thickness of the strip wound on the winding shaft + thickness of the air layer caught between the strips) is t _i

[0010]

[Equation 1]

Since the thickness of the strip is subtracted from this t _i , the thickness of the air layer caught between the strips can be obtained. By the way, according to the above equation, it is not necessary to consider the dimensions of the winding shaft at all, and the rotation speed n _i and the winding length l _i can be accurately measured. The thickness can be controlled accurately, that is, on the submicron order, which is a problem in the present invention.

According to the present invention, it is not necessary to consider the size of the winding shaft in calculating the thickness of the air layer wound between the strips, but the size of the winding shaft is large. If it is too large, the number of windings will be reduced for the same winding length, so it is difficult to obtain control with high accuracy, and therefore the winding shaft preferably has a diameter of 400 mm or less. However, if the size of the winding shaft is too small, the rotation speed will be very high in the initial stage of winding, and winding disorder will easily occur, and the strength of the winding shaft itself will also decrease. It becomes easy to receive. Therefore, considering the material and shape of the winding shaft, the diameter of the winding shaft is preferably 50 mm or more.

The thickness of the air layer caught between the strips is
Strictly speaking, since it changes from moment to moment, it is preferable to seek and feed back at each time point. Therefore, when the difference between the winding length (l _i -l _i-1) is too long, difficult to obtain control of a high precision, therefore (l _i -l _i-1) is preferably at 1000m or less .. Also, since the number of revolutions n varies greatly with a slight difference, ti is not calculated in a large unit such as one revolution.
It is preferably ½ rotation or less, more preferably ¼ rotation or less, and particularly preferably 1/20 to 1/6. This is because the lower limit of 1/20 is practically meaningless even if it is detected in units smaller than this, in view of the winding length detection accuracy.

Further, the thickness of the air layer caught between the strips can be obtained by subtracting the thickness of the strip from t _i , and the thickness of this strip can be regarded as substantially constant. Although it does not matter, the thickness of this strip is, for example, X
It is possible to obtain a more accurate air layer thickness by measuring with a line thickness meter or β-ray thickness meter and subtracting this value, and as a result, more beautiful winding can be performed. ..

When the above invention is applied to the production of a magnetic recording medium, extremely great features are exhibited. That is, when subjected to a high temperature treatment, the non-magnetic support such as a magnetic tape is usually
Since it is made of polyester or the like, heat contraction occurs, so that the deformation of the support such as wrinkles caused by winding becomes more severe. Therefore, it is extremely important to satisfy the conditions of the present invention. This high temperature treatment has the effect of preventing the non-magnetic support from deforming over time, and substantially guarantees the tracking accuracy during recording and reproduction for a long period of time. Further, the effect of accelerating the cross-linking reaction of the cross-linking agent in the magnetic layer is also expected, which is indispensable in the current production of magnetic recording media. Since this heat treatment needs to be maintained at a high temperature for a certain time (at a temperature of 40 ° C. or higher for 4 hours or more), the heat treatment is performed on the wound body in view of production efficiency such as space problem. Therefore, the band-shaped body is thermally contracted while the movement is restricted in the winding, and the deformation is emphasized as described above. Therefore, in order to prevent this, it is important not to create a condition that causes deformation at the time of winding, and it is necessary to always wind while winding an air layer having an appropriate thickness. Therefore, even if the high temperature treatment is performed, the preferable thickness of the air layer at the time of winding is not particularly different from that at the time of winding. That is, if it is wound so as not to be deformed originally, it will not be deformed even if it is subjected to a high temperature treatment, which is a point when applied to the manufacture of a magnetic recording medium.

[0016]

【Example】

[Embodiment 1] FIG. 1 is a schematic view showing an embodiment of a winding device according to the present invention. In the figure, A is the winding device of the present invention,
Reference numeral 1 is a winding shaft made of resin having a diameter of 300 mm, 2 is wound on the winding shaft 1 (winding speed is 400 m / min), thickness 18
A strip (web) having a size of μm, a width of 1 m, and a length of 15000 m, 3 is a touch roll arranged so as to be pressed against the surface of the winding shaft 1, and 4 is a tension roll for controlling the winding tension of the web 2. ..

Reference numeral 5 is a rotation speed detecting sensor for detecting the rotation speed of the winding shaft 1, and 6 is a web 2 wound around the winding shaft 1.
Is a contact or non-contact type linear encoder for detecting the traveling speed of, and the signal n _i from the rotation speed detection sensor 5 and the signal from the linear encoder 6 are input to the calculating means 7, and based on these signals. The winding length l _i is calculated, and the signal of the winding length l _{i and} the signal of the rotation speed n _i are input to the calculating means 8.

[0018]

[Equation 2]

Is calculated (thickness of the web wound on the winding shaft + thickness of the air layer caught between the webs) t _i or between the webs with the web thickness reduced The thickness of the air layer entrained in is required. Then, when the thickness of the air layer caught between the webs thus obtained is out of the range of about 0.2 to 0.5 μm, that is, the value is larger than 0.5 μm. In this case, a command signal for increasing the contact pressure of the touch roll 3 and / or for increasing the tension by the tension roll 4 is output to each of the actuators 3a, 4a, and with a value smaller than 0.2 μm. In some cases, to reduce the contact pressure of the touch roll 3, and /
Alternatively, a command signal for lowering the tension by the tension roll 4 is output to each of the actuators 3a, 4a, and the thickness of the air layer wound between the wound webs 2 is about 0.2 to 0.5 μm. It is controlled to be within the range of.

According to such control, the thickness of the air layer caught between the webs when the webs such as photographic light-sensitive materials such as photographic film and printing paper and webs such as magnetic tapes are wound. Loose winding, which does not occur when the thickness is thick, winding misalignment and widthwise wrinkles, on the contrary,
The winding is done neatly without the winding being too tight and vertical wrinkles occurring when the thickness of the air layer involved is small.

Since the tightening is controlled so that the tightening does not become stronger as the winding progresses, buckling is less likely to occur. [Comparative Example 1] In Example 1, the contact pressure of the touch roll and the tension were fixed under constant conditions (60 kg each).
/ M width, 5 kg / m width) and when wound up, the average thickness of the air layer was about 0.8 μm.

When this winding was unwound, horizontal wrinkles were generated over the entire length except about 1500 m on the winding core and about 1500 m outside the winding. [Comparative Example 2] Similar to Comparative Example 1, a constant condition (100 kg / m width, 100 kg / m width,
When wound up at a width of 10 kg / m), the average thickness of the air layer was 0.05 μm.

And in this case, about 1000 of the winding core
Longitudinal wrinkles had occurred near the outside of the roll except for m. [Embodiment 2] FIG. 2 is a schematic view of a part of an apparatus used for manufacturing a magnetic recording medium according to the present invention.

In the figure, B is a magnetic recording medium manufacturing apparatus, 1
Reference numeral 1 is a feeding roll around which a belt-shaped non-magnetic support 10 is wound, 12 is a gravure roll, 13 is a backup roll, 14 is a smoother, 15 is a drying mechanism, and 16 is a guide roller. Reference numeral 17 denotes a β-ray thickness gauge for measuring the thickness of the strip-shaped non-magnetic support 10, and the output from the β-ray thickness gauge 17 is input to the calculating means 8 in FIG. ..

Reference numeral 18 is an X-ray film thickness meter for measuring the coating layer thickness, and the output from the X-ray film thickness meter 18 is input to the calculating means 8 in FIG. Then, a strip-shaped non-magnetic support 10 made of a polyester film having a thickness of 14 μm, a width of 1 m, and a length of 11000 m was coated with magnetic powder,
A magnetic coating material in which a binder resin and further various additives are dispersed in an organic solvent is applied by a gravure roll 12 at a coating speed of 350 m / mim to a dry thickness of 4 μm, dried by a drying mechanism 15, and then shown in FIG. Take-up is automatically controlled by a device (further equipped with a β-ray film thickness meter 17 and an X-ray film thickness meter 18) so that the thickness of the air layer is always 0.2 to 0.5 μm. Was done.

Then, the 100 wound rolls were continuously stored in a high temperature chamber kept at 55 ° C. for 36 hours, allowed to cool, and then slit to a 1/2 inch width to prepare a magnetic tape. As a result of observing this magnetic tape, occurrence of deformation such as wrinkles that would cause a problem in all windings was not recognized. [Comparative Example 3] In Example 2, the winding condition of the magnetic tape was constant (touch roll contact pressure 80 kg / m width, tension 7).
(kg / m width) and wound.

In this case, 13 out of 100 windings had horizontal wrinkles and 10 had vertical wrinkles. In the former case, the thickness of the air layer at the time of winding is 0.7μ at the location where horizontal wrinkles occur.
In the latter case, the thickness of the air layer at the time of winding was less than 0.1 μm at the location where vertical wrinkles occurred.

[0028]

[Effects] According to the present invention, there is a feature that winding is not loosened or tightened too much, horizontal wrinkles or vertical wrinkles do not occur, and the winding condition is excellent.

[Brief description of drawings]

FIG. 1 is a schematic view of a winding device.

FIG. 2 is a schematic view of a part of an apparatus used for manufacturing a magnetic recording medium.

[Explanation of symbols]

 A winding device 1 winding shaft 2 web 3 touch roll 4 tension roll 5 rotation speed detection sensor 6 encoder 7 computing means 8 computing means B magnetic recording medium manufacturing device 10 non-magnetic support 11 feeding roll 12 gravure roll 15 drying mechanism 17 β-ray film thickness meter 18 X-ray film thickness meter

Claims (5)

[Claims] 1. A winding body having a winding shaft wound with a belt-shaped body, wherein the thickness of a gas layer interposed between the belt-shaped body wound with the winding shaft is constant. About 0.1-0.7μ
A winding body characterized by being of m. 2. A method for winding a belt-shaped body around a winding shaft, wherein the thickness of a gas layer interposed between the belt-shaped body wound around the winding shaft is always constant. About 0.1-0.7
A method for winding a belt-shaped body, which comprises controlling the winding to a value of μm and winding. 3. A winding device for winding a belt around a winding shaft, comprising: a rotation speed detecting means for detecting a rotation speed of the winding shaft; and a belt wound around the winding shaft. A winding length calculating means for calculating a winding length, a calculating means for performing a predetermined calculation by inputting the rotation speed information from the rotation speed detecting means and the winding length information from the winding length calculating means, and this calculation. A winding device comprising: a strip-shaped body wound around the winding shaft and a control means for controlling the thickness of a gas layer interposed between the strip-shaped body according to an output signal from the winding means. 4. A magnetic layer is formed on a non-magnetic strip-shaped support,
The winding conditions are controlled so that the thickness of the gas layer interposed between the strips when the film is continuously wound on the winding shaft is 0.1 to 0.7 μm. 40 ℃ as it is
A method for producing a magnetic recording medium, which is characterized by leaving in the above high temperature chamber for 4 hours or more, allowing to cool, and then slitting or punching into a disk shape. 5. The winding shaft is wound such that the magnetic layer has a thickness of 0.1 to 0.7 μm of a gas layer interposed between the strip-shaped magnetic recording medium materials formed on the non-magnetic strip support. A magnetic recording medium characterized by being left in a high-temperature chamber at 40 ° C. or higher for 4 hours or more as it is, and then slitting or punched into a disk shape after being left to cool.