JPH04155621A - Magnet roll for manufacturing magnetic recording body - Google Patents

Abstract

PURPOSE:To apply a paint containing magnetic particles thick uniformly by arranging a non-magnetic rotor having a solvent resisting resin layer or a solvent resisting rubber layer formed on the surface thereof and a magnet disposed in the rotor. CONSTITUTION:A magnet roll 1 is made up of a non-magnetic rotor 10, silicone rubber layer 11 formed on the surface thereof and a cylindrical bipolar magnet 12 with a soft magnetic body 13 fitted thereinto. The silicone rubber layer 11 can be replaced with a solvent resisting resin or rubber such as fluororesin or acrylic rubber. Then, the rotor 10 having the silicone rubber layer 11 formed thereon applies a paint containing magnetic particles on a tape 4 rotating together with a gravure roll 3 and thus, the magnetic particles applied on the tape 4 is oriented magnetically in a vertical way to the tape surface.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to audio tapes, video tapes (hereinafter referred to as
It's called magnetic tape. ) and other magnetic recording body manufacturing magnet rolls.

[Prior art] Magnetic tape is made by dispersing magnetic particles such as a copolymer of vinyl chloride and vinyl acetate in a solvent on a polymer film base mainly made of polyethylene terephthalate, etc.
It is manufactured by laminating a paint-like product mixed with a coating agent mainly composed of butyl acetate, etc., and is usually manufactured through a dispersion process, a coating process, an orientation process, and a surface treatment process.

As an example of a conventional magnetic tape manufacturing and magnetic orientation method, as shown in FIG. 11 disclosed in Japanese Patent Publication No. 45-21547, a tape 34 is conveyed from nip rolls 30, 31 through guide rolls 32, A paint in which magnetic particles and a binder are mixed and dispersed using a solvent is applied while being pressurized by a gravure roll 33 and a pressure roller 35 while adjusting the thickness with an adjustment blade 36, and then the magnetic material is applied from an auxiliary roll 37 and a guide roll 38. After passing through an alternating current magnetic field device 39 for agitation to make the coating density distribution uniform, a permanent magnet 40 for magnetic orientation, a dryer 41, and a drying process equipped with a magnetic field generating device in the middle, the surface and the next step are carried out. There is a method of manufacturing magnetic tape that involves curing and smoothing its surface.

[Problem to be solved by the invention]

There are two methods for magnetic orientation during magnetic tape production: one is to laminate magnetic particles in a direction parallel to the tape plane (in a plane direction), and the other is to laminate magnetic particles in a direction perpendicular to the tape plane. Conventional magnetic tapes often have acicular magnetic particles laminated parallel to a plane, as in the example above, but in general, when magnetic particles are placed in a magnetic field and magnetized and oriented, a so-called demagnetizing field is generated. There was a problem that the coefficient was thick (and the magnetization was weakened).For this reason, recently, as shown in Fig. 10, magnetic recording has been performed by orienting the magnetic particle layer perpendicular to the plane of the magnetic tape. Perpendicular magnetic recording is becoming more and more popular. However, it is difficult to thickly and uniformly apply a paint mixture of magnetic particles, binder, and solvent to the surface of the base of a magnetic recording medium. There is a demand for faster coating and magnetic orientation processes, but there are many processing steps and it is difficult to increase the conveyance speed.

This invention was made in view of the above problems, and its purpose is to pick up magnetic particles onto a recording body substrate during the production of a magnetic recording body, and to pick up magnetic particles on a recording body surface when applying the magnetic particles to the recording body surface. It is an object of the present invention to provide a magnet roll for manufacturing a magnetic recording body, which can apply magnetically in a predetermined direction and with high density to the entire surface of the magnetic recording body.

[Means to solve the problem]

That is, in order to solve the above-mentioned problems, the present invention provides a magnet roll for manufacturing a magnetic recording body, which includes: (1) a non-magnetic rotating body having a solvent-resistant resin layer or a solvent-resistant rubber layer formed on its surface;
It is characterized by comprising a magnet disposed inside the rotating body. (2) Or, the magnet (2) is a bipolar magnet; It is characterized in that it is a multi-polar magnet, and the magnet (■) or (■) is a multi-polar magnet in which a plurality of magnetic poles with the same polarity are arranged partially adjacent to each other on the circumference and fixedly arranged. do.

[For production]

When the above-mentioned means is used as a magnet roll for producing a magnetic recording body, it works as follows.

First, when the magnet roll for producing a magnetic recording material used as means (2) is used for picking up magnetic particles, the magnetic particles are transferred to the tape by the rotation of the gravure roll and the rotating body on the side of the magnet roll for producing the magnetic recording material in the coater. At the same time, the magnetic particles coated on the tape are magnetically oriented in a predetermined direction with respect to the tape surface by this magnetic recording body manufacturing magnet roll.

In addition, when using the magnet roll for magnetic recording material production as the means of (2) for magnetic orientation, the magnetic particles coated on the tape by the coater are directed in a predetermined direction when passing through the position where this magnet roll is installed. magnetically oriented.

Next, the magnet roll for producing a magnetic recording material according to the means of (1) and (2) or (2) is magnetically oriented in a predetermined direction and magnetically recorded whether it is used for picking up magnetic particles or for magnetic orientation. A magnetic force acts on the body so that the body can be discharged more smoothly, that is, in the transport direction.

(Embodiments) Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front view including a partial axial section of a magnet roll l for producing a magnetic recording body according to the present invention, and FIG. 2 is a sectional view taken along the line A--A in FIG.

This magnet roll 1 is used for applying paint, which is a mixture of magnetic particles placed on the grooves provided on the surface of the gravure roll and a binder with a solvent, onto the tape, or for orienting the magnetic particles applied to the tape. be done.

This magnet roll 1 includes a rotating body 10 made of a non-magnetic material, a silicone rubber layer 11 formed on the surface thereof, and a soft magnetic material 1.
3 and a cylindrical bipolar magnet 12 fitted with the magnet. The bipolar magnet 12 is made of 2-17 samarium cobalt and polyamide elastomer, and is manufactured by mixing these and extrusion magnetic field molding. In addition, other pound magnets, sintered magnets, metal magnets, etc. can be used. The rotating body 10 is manufactured by fitting flanges 10b made of metal such as stainless steel onto both sides of a cylindrical body 10a made of carbon fiber reinforced resin (CFRP). Incidentally, instead of this silicone rubber layer 11, a solvent-resistant resin or rubber such as a fluororesin, ethylene propylene rubber, or acrylic rubber can be used. The silicone rubber layer 11 is made resistant to solvents by the solvent volatilized when applying the paint, which is a mixture of magnetic particles and a binder with a solvent (hereinafter referred to as paint containing magnetic particles), to the tape. This is because they are placed in an atmosphere of Further, the bipolar magnet 12 is disposed inside the rotating body 10 with a certain space 20 therebetween. Incidentally, the cylindrical body 10 a of the rotating body 10
Although non-magnetic metal such as aluminum alloy or copper alloy may be used instead of CFRP, CFRP is preferably used. The soft magnetic body 1 fitted into the inner peripheral surface of the bipolar magnet 12
3 is a flange 12 that allows the lines of magnetic force of the bipolar magnet to pass through well, and is fitted to the bipolar magnet 12.
a and the flange 12a, which is formed integrally with the flange 12a.
It is rotatable together with a shaft 15 supported by bearings 14 and 14 fitted to the shaft 14.

Magnet roll 1 for manufacturing magnetic recording material according to the present invention
The magnet roll 1 has the above-described configuration. Next, an example of use and function of the magnet roll 1 will be explained.

Figure 3 shows paint containing magnetic particles picked up by a gravure roll 3 installed in a coater 2 on a tape 4.
FIG. 3 is a diagram showing an example of the use of the magnet roll 1 in the case of directly applying the coating material to the surface of the magnet. In this case, the rotating body 10 on which the silicone rubber layer 11 of the magnet roll 1 is formed applies paint containing magnetic particles to the tape 4 while rotating together with the gravure roll 3. Magnetically oriented perpendicular to the plane.

FIG. 4 is a diagram showing an embodiment in which the magnet rolls 1 and 1' are used as magnetic orientation rolls. That is, the coater 2 applies paint containing magnetic particles to the gravure roll 3.
The tape 4 applied with the pressure roll 5 is transferred to the auxiliary roll 6,
The tape passes through a guide roll 7 and a magnet roll 1" installed for orientation with a slight gap, but at this time the magnetic particles coated on the tape 4 are magnetically oriented in the vertical direction. It should be noted that this magnetic roll 1.

FIG. 5 also shows an example in which the magnet roll 1 is used for magnetic orientation. In this case, a ferromagnetic roll 8 is installed in place of the magnet roll l' shown in FIG. In this case as well, when the tape 4 coated with paint containing magnetic particles by the coater 2 passes the positions of the magnet roll 1 and the ferromagnetic roll 8, the magnetic particles coated on the tape are magnetically oriented in the vertical direction. Ru.

FIGS. 6 and 7 are cross-sectional views when a bipolar magnet of another shape is used instead of the bipolar magnet 12.

That is, instead of the cylindrical bipolar magnet 12 disposed inside the rotating body 10, a cylindrical bipolar magnet 12 as shown in FIG. 6 may be used, or a cylindrical bipolar magnet 12 as shown in FIG. 7(a) may be used. It may also be a prismatic bipolar magnet 12゛,
Furthermore, as shown in FIG. 2(b), prismatic bipolar magnets 12''', 12''' attached to a support 21 made of iron, aluminum, stainless steel, or the like may be used.

FIG. 8 is a diagram showing an example in which a modified example of the cylindrical bipolar magnet 12 is used. That is, the magnet roll 1 for magnetic orientation is not a bipolar magnet 12, but a multipolar magnet 22 in which an even number of alternating magnetic poles are arranged at uniform intervals on the circumference, and the rotating body 10 is
(Silicone-containing rubber layer 11) and gravure roll 3 are rotated in the tape transport direction as shown by the arrow, but the multipolar magnet 22 is rotated in the opposite direction to the tape transport direction to remove paint containing magnetic particles. This is something to pick up. In this case, the tape 4 is magnetically oriented in a predetermined direction, and is ejected more smoothly to the tape 4 by reverse rotation of the multipolar magnet 22, as shown by the arrow of the ejecting section.
A magnetic force acts to send the material in the transport direction.

FIG. 9 shows an embodiment in which a plurality of multipolar magnets are fixedly arranged, and a part of the multipolar magnets 23 are arranged with the same poles adjacent to each other. When using this magnet roll 23 for pickup, for example, paint containing magnetic particles is applied to the tape 4 at the N1 pole part that emits the strongest lines of magnetic force, and a region with low magnetic force is created between S2 and 83. It is conveyed so that it is separated from the magnet roll 23. In this case as well, the tape 4 is magnetically oriented in a predetermined direction, and the fixed multi-pole magnet 23 applies magnetic force so that the tape 4 is more smoothly ejected, that is, sent out in the transport direction, as shown by the arrow on the ejecting section. acts.

The multipolar magnets of the embodiments shown in FIGS. 8 and 9 may be used in combination with the magnet roll 1 shown in the above embodiments, or may be used by being placed in a known magnetic orientation device. .

〔Effect of the invention〕

Since the magnet roll for producing a magnetic recording material according to the present invention has the structure described in detail above, when magnetically oriented in a predetermined direction and with high density with respect to the plane of a magnetic recording material such as a magnetic tape, it is possible to Containing paint can be applied thickly and evenly.

In particular, when this magnet roll for producing magnetic recording materials is used with a multi-pole magnet built into the rotating body, either rotating or fixed, the magnetic tape coated with paint containing magnetic particles can be transported smoothly. Magnetic particles can be applied efficiently and at high speed.

[Brief explanation of drawings]

FIG. 1 is a front view including a partial axial cross section of a magnet roll for producing a magnetic recording body according to the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG. 3 is a pick-up with a gravure roll. Figure 4 is a diagram showing an example of the use of the magnet roll in the case where a paint containing magnetic particles is directly applied to the tape and magnetically aligned in the perpendicular direction. , Fig. 5 is a diagram of another embodiment in which a magnet roll is used for magnetic orientation, Figs. 6 and 7 are cross-sectional views in the case where a magnet of another shape is used instead of a bipolar magnet, and Fig. 8 9 is an example diagram using a modified example of a cylindrical bipolar magnet, and FIG. 9 is an example in which a plurality of built-in magnets are fixedly arranged.
An example diagram of a case where two magnets are arranged with the same poles adjacent to each other. Figure 10 is a conceptual diagram of a case where magnetic particles are magnetically aligned perpendicularly to a tape. Figure 11 is a diagram showing magnetic particles on a tape. FIG. 1- Magnet roll 10- Rotating body 10a- Cylindrical body 10 b- Flange 11- Urethane rubber layer 1
2...-dipolar magnet 12', 12", 12"'-
Dipolar magnet 12a-Flange 13-Soft magnetic material
14 - Bearing 15 - Shaft 2 - Coater 3 - Gravure roll 4 - Magnetic tape 8 - Ferromagnetic material 22. 23 - Multipolar magnet Applicant Yamauchi Co., Ltd. President and Representative Director Yamauchi City Attorney, Patent Attorney Maki Kawasaki Figure 3 Figure 5 Figure 8 Figure 1n Procedural Amendment November 27, 1990 1990 Patent Application No. 279638 2, Title of Invention Magnet for manufacturing magnetic recording bodies Role 3, Relationship with the case of the person making the amendment Patent applicant address (residence) ■573 2-7 Shodaita Chika, Hirakata City, Osaka Prefecture
Address: “Column for detailed explanation of the invention in the specification” and “Column for brief explanation of the drawings” 8. Contents of amendment 3 (1) r Regarding the column for detailed explanation of the invention in the specification, a. In the 4th line from the top of page 3, the phrase ``...- surface and next process'' is corrected to ``...- surface treatment step.'' The first line from the top of page 5 of the statement is ``in the opposite direction.''
``-'' is corrected to ``is in a stationary state or in the opposite direction 1-1-''. C. In the 20th line from the top of page 6 of the specification, the statement ``... is made of non-magnetic material'' is corrected to ``... is made of non-magnetic material.'' (2) Regarding the "Brief Description of Drawings" column, a. In the 17th line from the top of page 13 of the specification, "11-...-Urethane rubber layer" was replaced with "rll--Silicone rubber layer". to correct. that's all

Claims (4)

[Claims] (1) A magnet roll for manufacturing a magnetic recording material, comprising a non-magnetic rotating body on which a solvent-resistant resin layer or a solvent-resistant rubber layer is formed, and a magnet placed inside the rotating body. . (2) The magnet roll for producing a magnetic recording body according to claim 1, wherein the magnet is a dipole magnet. (3) The magnet is a multi-polar magnet in which an even number of alternating magnetic poles are arranged on the circumference and arranged to be stationary or rotatable in the opposite direction to the rotating body. A magnet roll for manufacturing a magnetic recording body as described in 1. (4) The magnetic recording body according to claim 1, wherein the magnet is a multipolar magnet in which a plurality of magnetic poles, some of which have the same polarity, are arranged on the circumference and fixedly arranged. Magnet roll for manufacturing.