JPH0658740B2 - Magnetic recording liquid coating device - Google Patents

Description

The present invention relates to a coating apparatus for gravure coating a magnetic recording liquid on a base material when manufacturing a magnetic recording medium such as a magnetic tape. The present invention relates to a cup roll. The present invention relates to an apparatus for applying a magnetic recording liquid, which can prevent adhesion unevenness of the magnetic recording liquid and uneven application of the magnetic recording liquid on a substrate.

[Conventional technology]

In general, this type of magnetic recording liquid coating apparatus is one in which a predetermined amount of magnetic recording liquid in a pan is attached to a cup roll and transferred onto a substrate. At this time, the back roll presses the base material against the cup roll.

However, particularly when the coating apparatus is operated at a high speed, air is often introduced into the marks of the cup roll, and coating unevenness may occur on the base material, resulting in a defective product. Also,
Even if the magnetic recording liquid is operated at a constant speed, the amount of the magnetic recording liquid attached to the cup roll varies due to the difference in the viscosity of the magnetic recording liquid, and the magnetic recording liquid is not uniformly transferred to the substrate. In addition, the transfer amount of the magnetic recording liquid was uneven due to the difference in the markings of the plate, that is, the cup roll. Moreover, the operating conditions must be changed according to various conditions such as the operating speed of the coating device, the viscosity of the magnetic recording liquid, and the score of the cup roll, which is extremely troublesome and cannot be easily realized. It was

Furthermore, in detail, since the cup roll is usually applied at a high speed (100 to 500 m / min), an air layer is rotating on the surface of the cup roll as the cup roll rotates, and the marks of the cup roll are Since there are usually 20 to 60 lines per inch and it is extremely fine, it is not easy to push away the air layer on the surface of the notch, remove the air inside the notch, and push in the magnetic recording liquid instead. This tendency becomes significant especially when the viscosity of the magnetic recording liquid is high at a high speed.

Therefore, conventionally, the magnetic recording liquid is pushed into the slits by the twisting roll, or the pressure is pushed in using a nozzle.

[Problems to be Solved by the Invention]

However, in any of the above-mentioned methods, the air on the surface of the cup roll and the air inside the notches are not sufficiently replaced with the magnetic recording liquid, and the bubbles cannot be completely extruded, so that it is difficult to generate coating spots. Was the current situation.

Further, when the magnetic recording liquid in the marks of the cup roll enters the lower part of the base material and is transferred to the base material by the pressure of the back roll, the magnetic recording liquid slightly extruded from the notches forms the cup roll and the base material. It always accumulates continuously in the contact part gap. This liquid pool is affected by the air pressure of the air layer carried by the substrate depending on the coating speed, that is, the number of rotations of the back roll / cup roll, and a part of this liquid pool may drop like water drops. Further, the liquid pool itself fluctuates unevenly in the width direction and the diametrical direction of the cup roll, and this drop or fluctuation affects the transfer force and is a major cause of coating unevenness.

Therefore, in view of the above circumstances, the present invention provides a cup roll surface and a score on the lower portion of the cup roll regardless of the score of the cup roll and the difference in viscosity of the magnetic recording liquid, and without being significantly affected by the operating speed. The replacement of the magnetic recording liquid with the internal air can be performed quickly and completely, and the drop or fluctuation of the liquid pool due to the air pressure carried by the base material on the upper part of the cup roll is eliminated, and the magnetic force on the base material is thereby reduced. It is an object of the present invention to provide a magnetic recording liquid coating device capable of reliably preventing transfer unevenness of the recording liquid.

[Means to be Solved by the Invention]

In order to achieve the above object, the present invention provides a device for supplying a magnetic recording liquid mixed with a magnetic material, a cup roll for applying a magnetic recording liquid from the supplying device to a substrate, and a cup roll for the cup roll. In a magnetic recording liquid coating device having a back roll for pressing a base material, the cup roll is a hollow cup roll main body rotatably supported by a housing unit, and the cup roll main body is inserted from the outside into a cup roll main body. An angle adjusting shaft that is rotatable with respect to the roll body, a magnet that is attached to the angle adjusting shaft so as to be positionally adjustable via a core member, and extends in the axial direction of the cup roll body, and the angle adjusting shaft. A lock member for fixing the base end portion of the cup unit to the housing unit, wherein the magnet is a cup roll outer peripheral surface to which the magnetic recording liquid from the supply device is supplied. It is characterized in that the inner peripheral surface of the corresponding cup roll and the inner peripheral surface of the cup roll corresponding to the outer peripheral surface of the cup roll in front of the contact portion of the cup roll and the back roll are positioned and arranged in proximity to each other. is there.

〔Example〕

An embodiment of a magnetic recording liquid coating apparatus according to the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a cup roll and 2 is a back roll. A part of the cup roll 1 is immersed in the magnetic recording liquid 4 in the pan 3 to attach the magnetic recording liquid to the notches 5, and then the cup roll 1 to the substrate 6
It is designed to be transferred to.

As shown in FIG. 2, in the cup roll 1, headers 9 and 10 are rotatably supported on a frame 7 via a housing unit 8 having a bearing such as a bearing. One of the headers 9 is provided with a rotary shaft 11 that is connected to a power transmission mechanism that is interposed between the motor and the motor. The other header 10 has a fitting hole 13 into which an angle adjusting shaft 12 is inserted.
Has been drilled.

The opposite ends of the headers 9 and 10 are formed in a tapered shape. Ring-shaped receiving seats 14 each having a ring hole are fitted to the tapered ends of the headers 9 and 10, and the headers 9 and 10 and the receiving seats 14 are fixed with a cap nut 15. Has become. Between the seats 14 and 14, a cup roll main body 16 having a notch 5 on the peripheral surface is fixedly installed.

The angle adjusting shaft 12 is used for the bearings 1 of the headers 9 and 10.
It is supported by 7. That is, the bearings 17 support the angle adjusting shaft 12 so that the headers 9 and 10 are rotatable with respect to the angle adjusting shaft 12. Cup roll body 16
The angle adjusting shaft 12 located inwardly of the
As shown in the figure, cores 20 and 21 are mounted via mounting rings 18 and 19, respectively. Both ends of the cores 20 and 21 are fixed to the attachment rings 18 and 19 by means such as welding. The mounting rings 18 and 19 are rotatably loosely fitted to the angle adjusting shaft 12, and the set bolt 2
Each mounting ring 18 and 19 can be fixed to the angle adjusting shaft 12 by 2.

The angle adjusting shaft 12 is exposed from the fitting hole 13 of the header 10 to the outside, and a handwheel 23 is attached to the end of the angle adjusting shaft 12 facing the outside. Further, a lock member 25 is attached to the bearing holder 24 attached to the one housing unit 8, and the lock member 25 tightens the angle adjusting shaft 12 by operating the lock handle 26, so that The angle adjusting shaft 2 is locked so as not to rotate with respect to 7.

Magnets 27, 28 are attached to the tips of the cores 20, 21, respectively.
Are attached continuously in the axial direction of the cup roll body 16, and the magnets 27 and 28 and the cup roll body 1 are attached.
With an appropriate gap between the cup roll body 1 and
It does not come to support the rotation of 6.

If the cup roll having the above structure is used, the back roll 2 can be a commonly used rubber roll.

[Action]

First, the lock handle 26 is operated to unlock the angle adjusting shaft 12 by the lock member 25, and then the hand adjusting handle 23 is rotated to rotate the angle adjusting shaft 12 and accordingly the core. 20, 21 are also rotated, and the magnet 27 is arranged so as to correspond to the position where the cup roll body 16 is immersed in the magnetic recording liquid 4 in the pan 3.
Further, the other magnet 28 is adjusted in advance so that it is arranged slightly before (upstream side) the position where the magnetic recording liquid is transferred from the cup roll 1 to the substrate 6.
After the adjustment, the lock handle 26 is operated to operate the lock member 2
5, the angle adjusting shaft 12 is locked so as not to rotate.

When the headers 9 and 10 and the cup roll body 16 are rotated in the arrow direction A shown in FIG. 1 by the motor, the magnetic recording liquid 4 in the pan 3 adheres to the notches 5,
At this time, the magnetic force of the magnet 27 acts on the magnetic powder contained in the magnetic recording liquid 4, and the magnetic recording liquid 4 is forcibly attached to the inside of the notch 5 together with the magnetic powder.

Here, the normal cup roll is 100 to 500 m / min.
Due to the high-speed coating, an air layer rotates on the surface of the cup roll 1 as the cup roll rotates, and the crevices of this cup roll are usually 20 to 60 lines per inch, which is extremely fine. Although it is not easy to push away the air layer on the surface of the eye and discharge the air inside the notch to push in the magnetic recording liquid instead, in the present invention, the magnetic recording liquid 4 is sucked by the cup roll 1 by the magnet 27. As a result, the air on the surface of the cup roll and the air inside the indentation is quickly and strongly replaced with the magnetic recording liquid. At this time, the attracted magnetic recording liquid is magnetized,
When the magnetic recording liquid 4 is stiffened, its viscosity is increased, and it can be easily extruded against air pressure. Furthermore, bubbles mixed in the magnetic recording liquid 4 are also extruded, and stable application to bubble-free cup rolls becomes possible.

Due to the above action, the magnetic recording liquid in the notch
In the vicinity of the magnet 27, it becomes rigid due to the magnetization and the viscosity increases, but when the cup roll 1 rotates, it is released from the magnetic force of the magnet 27 and falls to the normal viscosity,
Excess magnetic recording liquid is scraped off by the doctor 29.

Scraped by the doctor 29, the cup roll body 1
The magnetic recording liquid 4 remaining on the magnetic recording liquid 6 is transferred to the base material 6. At this time, the magnet 28 exerts a magnetic force on the magnetic powder contained in the magnetic recording liquid 4 in the notches 5, and the magnetic recording liquid 4 4 is stabilized on the cup roll 1 and adhered evenly to the base material 6.

That is, the magnetic recording liquid 4 in the marks of the cup roll 1
When the magnetic recording liquid 4 enters the lower surface of the base material 6 and is transferred to the base material 6 by the pressure of the back roll 2, the magnetic recording liquid 4 slightly extruded from the notches is continuously continuous in the gap between the contact portion between the cup roll 1 and the base material 6. However, depending on the coating speed, that is, the number of rotations of the back roll / cup roll,
Under the influence of the air pressure of the air layer carried by the base material 6, a part of the liquid pool a drops like a water drop, or the liquid pool itself becomes uneven in the width direction and the diameter direction of the cup roll. It fluctuates, and this drop or fluctuation is a major cause of coating spots.

However, in the present invention, the liquid pool a that affects the transfer force is appropriately attracted to the cup roll 1 side by the magnet 28, and the magnetization of the liquid pool a causes the magnetic recording liquid 4 to become rigid (the viscosity increases). However, the adverse effect of the air pressure carried by the base material 6 can be reduced. This allows
The liquid pool a is stabilized, and coating unevenness can be eliminated.

Even if a magnet is not provided on the back roll 2, the magnetic recording liquid 4 in the marks of the cup roll 1 is reliably transferred to the base material 6 by the rolling pressure of the back roll 2. The attraction by the magnetic force of the magnet with the rubber roll body wall of the back roll main body 31 interposed therebetween has almost no effect, and the transfer effect is greater when the back roll is pressed.

When the cores 20 and 21 are assembled in the cup roll body 16, the set bolts 22 are loosened, and the cores 20 and 21 are overlapped and folded, and then inserted into the cup roll body 16.
Next, the cores 20 and 21 are opened by a predetermined angle to adjust their positions, and the set bolt 22 is tightened, whereby the cores 20 and 21 are fixed to the angle adjusting shaft 12. Further, the structures of the headers 9, 10, the receiving seat 14, and the cores 20, 21 are not limited to the structures of the embodiment, and the number of the magnets 27, 28 can of course be increased or decreased as necessary.

Further, the magnetic recording liquid is supplied to the cup roll by immersing the lower part of the roll in the pan, but needless to say, it may be sprayed by a nozzle or the like.

〔The invention's effect〕

As described above, the magnetic recording liquid coating apparatus according to the present invention is a magnetic recording liquid coating apparatus having a cup roll for coating the base material with the magnetic recording liquid and a back roll for pressing the base material against the cup roll. Inside the cup roll, a magnet extending in the axial direction of the cup roll main body is disposed so that it can be positioned in the circumferential direction of the cup roll. Since it is arranged on the upper part of the cup roll in front of the contact point, the magnetic material is attracted to the cup roll by the magnet on the lower part of the cup roll, so that the air on the cup roll surface / notch and the magnetic recording liquid can be replaced. It can be done quickly and strongly, it can adhere to a stable cup roll without bubbles, and the magnet on top of the cup roll It is possible to stabilize the liquid pool between the base material and the cup roll, and to surely apply the liquid to the base material. As a result, it is possible to reliably prevent uneven transfer of the magnetic recording liquid on the substrate.

[Brief description of drawings]

The drawings show one embodiment of a magnetic recording liquid coating apparatus according to the present invention. FIG. 1 is a sectional view of a main part of the coating apparatus, FIG. 2 is a central longitudinal sectional view of a cup roll, and FIG. 3 is a cup roll. FIG. 1 ... Cup roll, 2 ... Back roll, 3 ... Pan, 4 ... Magnetic recording liquid, 5 ... Mark, 6 ... Base material, 7 ... Frame, 8 ... Housing unit, 9, 10 ... Header, 11 ... Rotating shaft 12 ... Angle adjusting shaft, 13 ... Fitting hole 14 ... Seat, 15 ... Cap nut 16 ... Cup roll main body, 17 ... Bearing 18,19 ... Mounting ring, 20, 21 ... Core 22 ... Set bolt, 23 ... Handwheel 24 ... Bearing holder, 25 ... Lock member 26 ... Lock handle 27,28 ... Magnet, 29 ... Doctor

Claims (1)

[Claims] 1. A device for supplying a magnetic recording liquid mixed with a magnetic material, a cup roll for applying a magnetic recording liquid from the supplying device to a substrate, and a back roll for pressing the substrate against the cup roll. In the magnetic recording liquid application device having the above, the cup roll is a hollow cup roll main body rotatably supported by a housing unit, and the cup roll is inserted into the cup roll main body from the outside and is rotatable with respect to the cup roll main body. A shaft for adjusting the angle, a magnet that is attached to the shaft for adjusting the position so as to be positionally adjustable through a core member, and extends in the axial direction of the cup roll main body, and a base end portion of the shaft for adjusting the angle is provided in the housing. A lock member for fixing to the unit is provided, and the magnet is provided inside the cup roll corresponding to the outer peripheral surface of the cup roll to which the magnetic recording liquid from the supply device is supplied. Face and magnetic recording liquid coating device, characterized in that in proximity to the cup roll inner peripheral surface corresponding to a cup roll outer surface is positioned disposed in front of the contact portion of the cup roll and back roll.