JPS61267933A - Manufacturing device for magnetic recording medium - Google Patents

Abstract

PURPOSE:To orient an acicular magnetic powder of a medium in a prescribed direction with a high orientation rate by providing in advance plural orienting devices for generating a magnetic field of a prescribed direction in a section which is dried to some extent between an applying machine and a drying machine, when a magnetic recording liquid is applied to a nonmagnetic base by using the applying machine and it is brought to a dry processing by the drying machine. CONSTITUTION:A nonmagnetic base 2 of polyester, etc., which has been supplied from a supply roller 1 is fed to an applying machine 3, and in this machine, a magnetic recording liquid consisting of a solvent which has dispersed an acicular magnetic powder is applied, and if necessary, the applying surface is flattened by a smoothing device 4. Subsequently, this base 2 is made to pass through the inside of a drying machine 5 for blowing out a warm air or a hot air, cooled by a cooling device 7, and thereafter, wound by a winding roll 8. In this constitution, plural pieces of orienting devices 9a-9n are provided at an interval in the drying machine 5, and before the drying is ended completely, the orienting direction of the acicular magnetic powder 10 contained in the applying liquid is made uniform, and also an orientatoin disorder generated on the way is corrected, and the S/N of the recording medium is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for manufacturing magnetic recording media, and in particular to an apparatus for manufacturing highly oriented magnetic recording media that can obtain a large 8N ratio and high reproduction output. .

"Prior Art" Generally, magnetic recording media are manufactured by applying a magnetic recording liquid containing magnetic powder to a uniform layer thickness on a non-magnetic base such as polyester, followed by orientation and drying treatment. but,
In the conventional orientation, even if the orientation is once done, or even if the orientation magnetic field is increased to achieve complete orientation, the restraint of the external magnetic field is released before the drying process, as shown in Figure 3. Due to the magnetic force of the acicular magnetic powder 15, they repel and attract each other, causing the magnetic powder to aggregate A at various locations, which may disrupt the orientation of the magnetic powder, and the magnetic powder is almost completely oriented. This is not easy, and as a result, it is not possible to obtain a large 8N ratio when reading out information recorded on a magnetic recording medium, and the orientation ratio is still insufficient, especially for high-density recording and reproduction. There was such a problem.

``Problems to be Solved by the Invention'' In view of the above circumstances, the present invention aims to record and reproduce information with high density by orienting the acicular magnetic powder of the W1 recording medium in a certain direction with a high orientation rate. An object of the present invention is to provide a manufacturing apparatus for a magnetic recording medium that can improve the 8N ratio when the magnetic recording medium is produced.

"Means to be Solved by the Invention" In order to achieve the above object, the present invention provides a manufacturing apparatus that applies a magnetic recording liquid to a non-magnetic base using a coating machine and then performs a drying process using a dryer. This is a magnetic recording medium manufacturing apparatus that is equipped with an orientation device that generates a magnetic field in a fixed direction until it is dried to a certain extent by magnetic recording liquid force (magnetic recording liquid force) in the dryer downstream of the machine. .

"Embodiment" Hereinafter, an embodiment of the magnetic recording medium manufacturing apparatus according to the present invention will be described based on the drawings. In FIG. 1, reference numeral 1 denotes a feed roll around which a non-magnetic base 2 made of polyester or the like is wound. The non-magnetic base 2 is fed into a coating machine 3 and is coated with a magnetic recording liquid made of magnetic powder, solvent, etc.

In a coating machine 3 that applies coating according to the gravure grain, such as in a gravure coating method, the magnetic recording liquid is sent to a dryer 5 via a smoothing device 4 that makes the layer thickness of the magnetic recording liquid on the nonmagnetic base 2 uniform. Of course, if a coating machine that applies the magnetic recording liquid to a uniform layer thickness is used, there is no need to insert the smoothing device 4''4. The length of the magnetic recording liquid is long enough to dry the magnetic recording liquid, and the dryer 5 is configured to dry the magnetic recording liquid by blowing warm air or hot air through the duct 6. In addition to drying, it is of course possible to carry out a drying process using electric heat or steam heat.After the drying process, it is cooled by a cooling device 7 and wound onto a winding roll 8. .

An orientation device 9 is disposed downstream of the coating machine 3. When using smoothing device f14, smoothing device 4
Placed after the . The orientation device [9 is configured to generate a magnetic field sound directed in the direction of transport of the non-magnetic base 2 using a solenoid coil. The orientation device 9 may be a permanent magnet. The orientation device 9 is.

A plurality of them are arranged along the transfer direction of the non-magnetic base 2 from the latter stage of the coating machine 3 to the smoothing device.

The final stage orientation device 9n is disposed at a position where the magnetic recording liquid on the non-magnetic base 2 is dried to a certain extent by the dryer 5 so as to be immovable.

After the magnetic recording liquid is applied to the non-magnetic base by the coating machine 3, it is first sent to the first alignment device 9a via the smoothing device 4. As shown in FIG. 2, the first orienting device 9a applies a magnetic force to the magnetic powder in the magnetic recording liquid, and orients the acicular magnetic powder 101 to face the traveling direction of the non-magnetic base 2.

In the conventional method, when separated from the magnetic field of the first orientation device 9a, since the magnetic particles in the magnetic recording liquid are naturally magnetized, the magnetic particles attract each other due to the magnetic force of the magnetic particles.
Moreover, not only do they repel each other, forming agglomerated groups of magnetic powder at various locations on the non-magnetic base 3, but also the orientation may be disturbed and the surface of the magnetic tape may become rough. In order to prevent this, the orientation of the magnetic powder in the magnetic recording liquid coated on the non-magnetic base 2 is adjusted to a certain degree by the dryer 5 in the second to final stage orientation devices 9b to 9n so that the magnetic powder becomes immovable. Hold until dry. Therefore, in the magnetic recording medium after the drying process, as shown in FIG. 2, the magnetic powder is oriented in a uniform direction.

``Effects of the Invention'' As described above, according to the magnetic recording medium manufacturing apparatus according to the present invention, the magnetic recording liquid can be heated in a fixed direction at the downstream stage of the coating machine and until the magnetic recording liquid is dried to some extent by the dryer. Since we have installed an orientation device that generates a field, it is possible to orient the magnetic powder in a magnetic recording medium in a fixed direction with a higher orientation rate than with conventional orientation methods. It is possible to perform good recording without waste, improve the signal-to-noise ratio, and exhibit great effects in recording and reproducing information at high density.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a magnetic recording medium manufacturing apparatus according to the present invention, FIG. 2 is an explanatory diagram showing the orientation state of a magnetic recording medium manufactured by the manufacturing apparatus, and FIG. , conventional orientation device fa! FIG. 2 is an explanatory diagram of a state in which agglomeration occurs in magnetic powder of a magnetic recording medium manufactured by an apparatus equipped with t't'.

Claims (1)

[Claims] In manufacturing equipment that applies a magnetic recording liquid to a non-magnetic base using a coating machine and then dries it using a dryer, the period after the coating machine and until the magnetic recording liquid is dried to some extent in the dryer. 1. An apparatus for manufacturing a magnetic recording medium, characterized in that an orientation device that generates a magnetic field in a constant direction is disposed therein.