JPH0938560A - Coating device - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide a coating device capable of high-speed coating and thinning of a coating film, and capable of obtaining a favorable coating film. A die (2) having a paint pool (pocket (9)) to which the paint (6) is supplied is provided, and the paint (6) is supplied from a slit (5) provided at the tip of the die (2) on a continuously running support (1). An extrusion type coating apparatus for coating while extruding, wherein the tips are adjacent to each other and the magnetic gap 1
The magnet portion 3 composed of 5 is provided on the side opposite to the die 2 with the support body 1 interposed therebetween, and the magnetic gap 15 is provided on the die 2 side.
An upper lip 7 and a lower lip 8 forming the slit 5 at the tip of the die 2 are arranged so as to be opposed to the tip, and are arranged in non-contact with the support 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called extrusion type coating device, and more particularly to a coating device suitable for coating a magnetic paint or the like when manufacturing a magnetic recording medium.

[0002]

2. Description of the Related Art Generally, as an audio tape or a video tape, a magnetic paint is prepared by dispersing and kneading a magnetic powder, a binder, a dispersant, a lubricant, etc. in an organic solvent on a non-magnetic support such as a polyester film. A so-called coating type magnetic recording medium in which a magnetic layer is formed by coating is used.

In manufacturing this coating type magnetic recording medium, as a device for coating a magnetic coating on a support, a coating device using a roll such as a gravure roll or a reverse roll has been conventionally used. In particular, an apparatus using a direct gravure method capable of coating a wide range of structural viscosities (thixotropic properties) is generally used.

The gravure roll is subjected to surface treatment such as hard chrome treatment in consideration of abrasion resistance. Depending on the structural viscosity of the magnetic paint, the transferability of the paint from the roll onto the base film as the support is impaired, and output fluctuations due to uneven coating thickness and dropout due to paint scattering tend to occur. These problems tend to become more pronounced as the coating speed increases.

In particular, when a magnetic paint having a high structural viscosity or a metal-based magnetic paint is transferred onto a support having a thickness of 50 μm or more as in the case of forming a magnetic layer of a floppy disk, the gravure roll cell is used. An air layer is likely to be formed between the groove and the support, and transfer failure is likely to occur.

On the other hand, as a new coating device capable of solving such a problem, an extrusion (die) type coating device has attracted attention and has already been partially put into practical use.

This extrusion type coating apparatus is
It has a wide slit facing the tip surface, and the vicinity of the tip is equipped with a doctor edge die, and the magnetic paint continuously extruded toward the surface of the running support is the doctor. The edge is applied so as to have a uniform thickness on the support. In addition, a coating liquid reservoir is provided on the back side of the slit,
The coating material supplied from both sides of the die is sent out into the slit through the coating liquid reservoir.

[0008] Such an extrusion type coating apparatus can easily form a coating film having a uniform film thickness, and since the roll having a large diameter is not used, the apparatus is low in cost and downsized. It is advantageous in that it is not necessary to circulate the paint around the die because all the paint supplied in the die is applied, so it has been used in the field of photographic film and photographic paper. ing.

By the way, in recent years, in the coating type magnetic recording medium, it has been desired to develop a coating technique which can sufficiently cope with high-speed coating for improving productivity and thinning of the magnetic coating film.

Therefore, in the above-mentioned extrusion type coating apparatus, in order to form a thinned magnetic coating film without causing unevenness of the film thickness, for example, Japanese Patent Laid-Open No. Sho 62-62.
As disclosed in Japanese Patent Laid-Open No. 95170, a slit formed at the tip of the die is pressed against the support without supporting the back surface of the traveling support, and 50 is provided on the opposite side of the slit with the support interposed. A method has been proposed in which a permanent magnet having a magnetic force of ˜5000 gauss is arranged and magnetic coating is extruded from the slit to apply the magnetic coating. Also, as started in Japanese Patent Laid-Open No. 4-214229, a method has been proposed in which an electromagnet is used instead of a permanent magnet and the direction of the magnetic flux is defined by the angle formed with the surface of the support. The tip of the die in these coating devices is made of a non-magnetic material.

[0011]

However, even if the above-mentioned method is applied, the movement of the magnetic coating material cannot be retained during high-speed coating, stable coating is difficult, and uneven film thickness occurs.

As described above, in the conventional coating apparatus, it is the actual situation that sufficient effects cannot be obtained for high-speed coating and thinning of the coating film.

Therefore, the present invention has been proposed in view of the above-mentioned conventional circumstances, and provides a coating apparatus capable of achieving high-speed coating and thinning of a coating film, thereby obtaining a favorable coating film. With the goal.

[0014]

DISCLOSURE OF THE INVENTION A coating apparatus according to the present invention is proposed in order to achieve the above-mentioned object, and is provided with a die having a paint reservoir to which paint is supplied, An extruding type coating apparatus for coating while coating material is extruded from a slit provided at the tip of the die on a support that travels in a moving manner, wherein the magnet portion has a magnetic gap formed by the tips being adjacent to each other, The magnetic gap is disposed on the opposite side of the die with the support interposed therebetween, and the upper lip and the lower lip forming the slit at the die tip respectively have the above-mentioned It is arranged in non-contact with the support.

Usually, in the extrusion type coating apparatus, a wide slit is formed so as to face the front end surface, and a die having a doctor edge in the vicinity of the front end surface is used to form a support that is running. The coating material continuously extruded toward the surface is applied onto the support by the doctor edge so as to have a uniform thickness. However, in this coating device, the lower lip does not function as a doctor edge, and the support body runs in contact with the lower lip. When the lip is not in contact with the support, the lip will not scratch or scrape the surface of the support, and the formed coating film will have chip lines due to dust, foreign matter, scraped powder of the support, etc. It becomes difficult to make it.

As described above, in this coating apparatus, the magnet portion is arranged on the side opposite to the die with the support interposed therebetween. Therefore, if the coating material contains a magnetic material, the magnetic flux from the magnet portion causes , The movement of the paint extruded from the slit is retained. In this case, the upper lip and the lower lip may each be made of a non-magnetic material, but if they are made of a magnetic material, the direction of the magnetic flux can be well controlled.

Further, when the magnet portions are configured such that their tips are adjacent to each other to form a magnetic gap, the magnetic flux can be concentrated from the magnetic gap toward both lips. As long as the magnet portion has a magnetic gap formed by adjoining the ends thereof, even if the magnet portion is made entirely of a permanent magnet, the permanent magnet is sandwiched between the yokes made of a high magnetic permeability material. It may be. As the permanent magnet, any conventionally known one represented by alnico magnet, rare earth magnet, ferrite magnet and the like can be used. An electromagnet may be used instead of the permanent magnet.

Here, it is preferable that the gap between the tip of the magnet portion and the tip of the die is 0.2 to 3 mm. If this gap is too small, the magnetic flux will not go to both lip directions, and conversely, if the gap is too large,
It becomes impossible to concentrate the magnetic flux.

The arrangement position of the magnet portion with respect to the die is
It is preferable that the upper end surface of the magnetic gap is set to be located within a range of ± 1 mm with respect to the height of the upper end surface of the slit in the die. If the arrangement position of the magnet portion deviates from the above range, the effect of holding the movement of the paint by the magnetic flux deteriorates.

Further, the magnetic force in the vicinity of the tip of the die, that is, the magnetic force in the vicinity of both lips may be appropriately selected according to the coating speed and the coating characteristics (viscosity, surface tension, etc.), but if it is too small,
If the paint cannot keep its movement and is too large, the resulting coating film becomes rough. For this reason, 500 to 6000 gausses, especially 3000 to
It is preferable to have a magnetic force of 6000 gauss.

Further, the coating apparatus according to the present invention comprises a die having a paint reservoir to which the paint is supplied, and the paint is extruded from a slit provided at the tip of the die on a continuously running support. In an extrusion type coating device for coating while a magnet portion having tips adjacent to each other to form a magnetic gap is provided on the opposite side of the die with the support interposed, and the magnetic gap is provided on the die tip. The upper lip and the lower lip, which are arranged so as to face each other and which form the slit at the tip of the die, are made of a magnetic material, respectively, and are arranged so that the lower lip comes into contact with the support. It may be one.

That is, in a coating device in which the lower lip functions as a doctor edge and the support is run while being in contact with the lower lip via a coating material to perform coating, a magnet portion is provided on the opposite side of the die with the support sandwiched. And each of the upper lip and the lower lip is made of a magnetic material. In this case as well, similar to the coating device in which the above-mentioned lip is arranged in non-contact with the support, the magnetic flux from the magnet section causes
The movement of the paint extruded from the slit can be well maintained.

Also in this coating apparatus, the positional relationship between the die and the magnet portion and the magnitude of the magnetic force to be applied near the lip are set by the coating apparatus in which the lip is arranged in a non-contact manner with the support. The same applies.

By the way, in the coating apparatus as described above, in any case where the lip is arranged in a non-contact manner with the support, or the lip is arranged in contact with the support, the die and If the relative arrangement of the magnet portions is ensured, the traveling direction of the support and the arrangement direction of the die and the magnet portion can be set arbitrarily. Therefore, in this specification, the terms "upper" and "lower" do not necessarily indicate the upper side and the lower side in the vertical direction, but indicate the upstream side and the downstream side in the traveling direction of the support. Therefore, the terms "upper lip" and "lower lip" do not necessarily mean that the upper lip is vertically above the lower lip.

The above-mentioned coating apparatus is suitable for coating a magnetic coating material on a coating type magnetic recording medium. In that case, the magnetic powder, resin binder, etc. constituting the support and the magnetic coating material are conventionally known. Any of the above can be used without any limitation.

For example, as the above-mentioned support, polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, cellulose derivatives such as cellulose triacetate, cellulose diacetate and cellulose butyrate, polyvinyl chloride, polychlorine, etc. Polymer substrates formed of vinyl resins such as vinylidene, plastics typified by polycarbonates, polyimides, polyamideimides, metal substrates composed of Al alloys and titanium alloys, ceramics substrates composed of alumina glass, etc., Examples include glass substrates. The shape is not limited at all, and may be any shape such as a tape shape, a sheet shape, and a drum shape. When a rigid substrate such as an Al alloy plate or a glass plate is used, an oxide film such as an alumite treatment or a Ni-P film may be formed on the surface of the substrate to harden the surface. However, a tape-shaped or sheet-shaped flexible support is preferable in consideration of continuous running of the support.

On the other hand, as the magnetic powder constituting the magnetic paint, a ferromagnetic metal material such as Fe, Co or Ni, or Fe-C is used.
o, Fe-Ni, Fe-Co-Ni, Co-Ni, Fe
-Mn-Zn, Fe-Ni-Zn, Fe-Co-Ni-
Cr, Fe-Co-Ni-P, Fe-Co-B, Fe-
Fe, Co, Ni such as Co-Cr-B and Fe-Co-V
Various ferromagnetic alloy materials containing Mn as a main component, Mn-Bi, Mn
Ferromagnetic metal particles made of an alloy material such as -Al are suitable. Also, for the purpose of improving various characteristics, Al, Si, T
Elements such as i, Cr, Mn, Cu, Zn, Mg, and P may be added. In addition, γ-Fe ₂ O ₃ and Co-containing γ-F
e ₂ O ₃ , Fe ₃ O ₄ , Co-containing γ-Fe ₃ O ₄ , Co
It may be a conventionally known oxide magnetic powder such as γ-Fe ₃ O ₄ , CrO ₂ or the like.

As the binder, a polymer of vinyl chloride, vinyl acetate, vinyl alcohol, vinylidene chloride, acrylic acid ester, methacrylic acid ester, styrene, butadiene, acrylonitrile, or the like, or a copolymer combining two or more of these, Polyurethane resin, polyester resin, epoxy resin and the like are exemplified. In particular, vinyl-based copolymers, polyester-polyurethane-based copolymers, polycarbonate-polyurethane-based copolymers, nitrocellulose and the like are suitable.

As the solvent for dispersing the binder and the magnetic powder, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketones, methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, glycol acetate mono are used. Esters such as ethyl ether, glycol ethers such as glycol dimethyl ether, glycol monoethyl ether and dioxane, aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as hexane and heptane, methylene chloride, ethylene chloride, Carbon tetrachloride, chloroform,
Chlorinated hydrocarbons such as ethylene chlorohydrin and dichlorobenzene are exemplified.

Further, a dispersant, a lubricant, an abrasive, an antistatic agent, a rust preventive and the like may be added as additives to the magnetic paint.

In addition to the magnetic layer, a back coat layer, a top coat layer or the like may be formed on the support described above, if necessary. In this case, the film forming conditions for the back coat layer, the top coat layer and the like are not particularly limited as long as they are the methods usually applied to the manufacturing method of this type of magnetic recording medium.

The coating apparatus of the present invention can be used not only for coating a magnetic coating material but also for coating a backcoat layer or a topcoat layer in the manufacturing process of such a coating type magnetic recording medium. It is possible.

The coating apparatus of the present invention can also be applied to the field of manufacturing photographic film, photographic paper, and the like.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described below with reference to the drawings.

First Embodiment In the coating apparatus according to the present embodiment, as shown in FIGS. 1 and 2, the lip 4 forming the slit 5 at the tip of the die 2 does not come into contact with the support 1. It is provided.

Specifically, in this coating device, a predetermined nonmagnetic and flexible support 1 is provided at a predetermined portion in the middle of the unwinding side to the winding side in the direction of A in FIG. A die (extruder) 2 made of a substantially rectangular parallelepiped metal block having a width is provided, and a magnet portion 3 having a predetermined width is provided on the opposite side of the die 2 with the support 1 interposed therebetween. .

The die 2 is disposed on the side of the support 1 which runs in the direction A in the figure, and the lip 4 attached to the tip of the die 2 has a predetermined distance from the surface of the support 1. It is arranged.

The lip 4 is made of a non-magnetic material or a magnetic material, and has a slit 5 having a width corresponding to the coating width facing the tip surface. The slit 5 is a gap through which the paint 6 made of a magnetic material is extruded, and is usually a very narrow gap of about 0.01 to 2.0 mm.

In this coating apparatus, the tip of the lower lip 8 is set back from the tip of the upper lip 7. Further, since both lips 7 and 8 are not in contact with the support 1, the vicinity of the tip of the upper lip 7 does not function as a front blade, and the vicinity of the tip of the lower lip 8 does not function as a smoothing blade.

A pocket (coating liquid reservoir) 9 communicating with the slit 5 is formed on the back side of the slit 5.
The pocket 9 has a length substantially equal to the width of the slit 5 and is formed as an orifice-shaped space.

A coating liquid supply port (not shown) is provided at both ends of the pocket 9 so as to open on both end faces of the die 2, and the coating liquid for introducing the coating liquid 6 is introduced into these coating liquid supply ports. The supply pipe is connected. Further, a pump 10 is attached to an intermediate portion of the coating liquid supply pipe, and the pump 10 is configured to pump the paint 6 from the coating liquid supply pipe into the pocket 9 at a predetermined pressure. .
Therefore, the pocket 9 becomes a space for receiving the paint 6 to be pumped, and has a function of an accumulator. Then, the paint 6 pumped into the pocket 9 is
It is supplied into the slit 5 and is further extruded from the front end portion of the slit 5 to the surface of the supporting body 1 running.

On the other hand, the paint 6 is applied by the die 2 as described above.
The support 1 to which is applied is supported by guide rolls (not shown), and an appropriate tension is applied by these guide rolls so that smooth traveling is performed. In addition, the guide roll is movably arranged so that the distance between the support 1 and the tip of the lip 4 can be adjusted, and the angle of the support 1 with respect to the die 2 can be adjusted.

In the magnet portion 3 provided on the opposite side of the support 1 with a gap having a predetermined distance from the die 2, the permanent magnet 11 has an N pole on the upper side and an S pole on the lower side. It is sandwiched between yokes 12 made of magnetic material. The upper side of the yoke 12 (the upper yoke 13) and the yoke 1
One end of each of the lower sides (lower yokes 14) of the two 2 projects from the permanent magnet 11, and the thickness thereof is reduced toward the tip. The lower yoke 14 is bent so that its tip is adjacent to the tip of the upper yoke 13.

Therefore, in the magnet portion 3, a magnetic gap 15 is formed between the tip of the upper yoke 13 and the tip of the lower yoke 14, and the lip 4 is directed toward the paint 6 containing the magnetic material. When it is made of a magnetic material, a magnetic flux can be generated toward the lip 4.

Although not shown, the above-mentioned magnet portion 3 is fixed to a support table that allows the magnet portion 3 to move in any direction, and a gap d between the tip of the yoke 12 and the tip of the lip 4 is provided.
The height position h of the magnetic gap 15 with respect to the slit 5 is adjustable. Here, the height of the lower surface of the upper yoke 13 (corresponding to the upper end surface of the magnetic gap 15) in the magnet portion 3 is the height of the lower surface of the upper lip 7 (corresponding to the upper end surface of the slit 5) in the die 2. The height position of the magnetic gap 15 is defined as 0, and the direction in which the height of the magnet portion 3 with respect to the die 2 is increased is plus, and the direction in which the height of the magnet portion 3 with respect to the die 2 is decreased is minus. Set h.

With the above-mentioned structure, in this coating apparatus, the support 1 traveling in the direction A in the drawing is used.
When the paint 6 extruded from the slit 5 formed facing the tip surface of the lip 4 in the die 2 is attached to the surface of the
Hold the movement of the paint 6 by the magnetic flux from
Good coating will be performed.

Further, in this coating apparatus, the lip 4
Since the tip does not come into contact with the support 1, the surface of the support 1 is not scratched or scraped, and chipping streaks due to dust, foreign matter, scraped powder of the support, etc. are unlikely to occur in the formed coating film.

By the way, in FIGS. 1 and 2, the die and the magnet portion are arranged so that the coating material is applied to the support 1 traveling downward from the vertical direction. The coating device according to the embodiment is not limited to this. Specifically, the traveling direction of the support 1 with respect to the disposition positions of the die 2 and the magnet portion 3 is a surface on which the center of the slit 5 extends (hereinafter, referred to as a slit center plane) and a main surface of the support 1. The angle at which the center plane of the slit and the main surface of the support 1 are perpendicular to each other is 0 °,
It may be rotated within 15 °.

If the relative arrangement of the traveling support 1 and the die 2 and the magnet portion 3 is within the above range, the traveling direction of the support 1 and the arrangement direction of the die 2 and the magnet portion 3 are It can be set arbitrarily. That is, as shown in FIG.
The slit center plane in may be inclined by 45 ° with respect to the horizontal plane, or as shown in FIG. 4, the slit center plane may be rotated by 90 ° with respect to the horizontal plane,
Similarly, it may be rotated at any angle of 360 °.

Second Embodiment In the coating apparatus according to this embodiment, as shown in FIGS. 5 and 6, the structure of the die 22 is different from that of the first embodiment, and a slit is formed at the tip. Lip 2 that makes up 5
4 are arranged so that they come into contact with the support 1.

In this coating apparatus, the upper lip 27 and the lower lip 28 forming the slit 5 are made of a magnetic material. Further, the upper lip 27 has a so-called wedge shape in which the vicinity of the tip surface is linearly shaved off, functions as a front blade, and functions as a front blade to apply the coating amount of the paint 6 extruded onto the support 1 through the slit 5. regulate. On the other hand, the lower lip 28 is formed so that its tip end surface projects and contacts the support 1, and functions as a smoothing blade to flatten the surface of the coating material 6 supplied onto the support 1.

The support 1 to which the coating material 6 is applied by the die 22 having such a structure is appropriately tensioned by the guide rolls, and the guide rolls are movably arranged so that the support 1 is supported. The amount of hugging of the support 4 on the lip 4 side (hugging amount of the support 1 on the lip 4) is adjusted.

The rest of the configuration is the same as that of the coating apparatus shown in the first embodiment, and therefore, the same members as those used in FIGS. Is omitted.

By virtue of having the above-mentioned structure, in this coating apparatus, the support 1 traveling in the direction A in the drawing is used.
The lip 24 of the die 22 is brought into contact with the surface of the die 22, the paint 6 is extruded from the slit 5 formed facing the tip end surface of the lip 24 at the abutment surface, and the magnetic gap 15 in the magnet portion 3 is magnetized. Both lips made of material 7,
Due to the magnetic flux toward 8, the coating film is formed while maintaining the movement of the paint 6 extruded from the slit 5.

[0055]

EXAMPLES In order to investigate the coating performance of the coating apparatus shown in the above-mentioned first and second embodiments, a magnetic coating material was actually coated on the non-magnetic support 1. did.

Example 1 Here, in order to investigate the coating performance of the coating apparatus shown in the first embodiment, the magnetic coating material was coated by making various settings in the coating apparatus.

Specifically, the magnetic coating material was applied to the traveling support 1 under the following conditions using the application device as shown in FIGS.

Settings in Coating Device <Die> Overall Width: 130 mm Coating Width: 110 mm Lip 4: Cemented Carbide (Magnetic Material) Upper Lip 7 Thickness 5 mm, Lower Lip 8 Thickness 3 mm Lower Lip to Upper Lip 7 8 retreat 1 mm Gap of slit 5: 0.3 mm Distance between support 1 and tip of lip 4: 0-3.5 mm <Magnet part> Width: 150 mm Permanent magnet 11: Neodium alloy magnet Magnetic force of 4000 gauss near lip 4. Yoke 12: S10C (high magnetic permeability material) Size of magnetic gap 15: 1 mm Height of magnetic gap 15 relative to slit 5: 0
mm Distance between the support 1 and the tip of the yoke 12: 0.5 mm <Paint> Type: VHS video tape magnetic layer forming coating thickness: 2-3 μm (after drying) <Support> Width: 127 mm Thickness: 14. 5 μm Material: Polyethylene terephthalate Tension during coating: 3 kgf in the entire width of the support Running speed: 400 to 1000 m / min The running speed of the support 1 is changed in the range of 400 to 1000 m / min. The distance from the tip of the lip 4 of the support 1 was adjusted so as to be possible.

When the coating was carried out in this way, it was possible to carry out the coating without any problems even when the running speed of the support 1 was increased to 1000 m / min. Further, when the coating device shown in the first embodiment is used as in the present embodiment, the tip of the lip 4 does not contact the support 1,
Without scratching or scraping the surface of the support 1,
The formed coating film did not have streaks due to dust, foreign matter, shavings of the support 1, and the like.

For comparison, when the magnetic coating material was applied under the same conditions as described above except that the magnet portion 3 was not provided, the magnetic coating material adhered to the support 1 in a sloping manner, and a good coating was obtained. No film could be formed.

In place of the magnetic coating material applied in this example, a magnetic coating material (using iron oxide type magnetic powder) for forming a magnetic layer of an audio tape was used, and the other conditions were the same as in this example. When coating was carried out, it was possible to carry out coating without causing any problems even when the running speed of the support 1 was increased to 1000 m / min, as in this example.

Further, the thickness of the support 1 is 12 to 14.5.
Both the lips 7 and 8 forming the slit 5 at the tip of the die 2 are made of a non-magnetic material, even if the coating thickness after drying of the magnetic coating is changed within the range of 2 to 4 μm, even if it is changed within the range of μm. Even if it changes, even if the interval of the slit 5 is changed to 0.26 μm,
Similar to this example, good coating could be performed until the traveling speed of the support 1 reached a high speed of 1000 m / min.

As a result, when the magnetic coating material is applied by using the coating device in which the magnet portion 3 having the magnetic gap 15 is provided on the side opposite to the lip 4 with the support body 1 sandwiched between them, there is no overflow or chipping streaks. It was found that the coating film can be formed at high speed.

Example 2 In this example, the width of the support 1, the coating width of the magnetic coating, the type of the magnetic coating, etc. were different from those of Example 1, and the magnetic coating was applied.

Specifically, a magnetic coating material was applied to the traveling support 1 under the following conditions by using the application device as shown in FIGS.

Settings in Coating Device <Die> Overall Width: 700 mm Coating Width: 600 mm Slit 5 Gap: 0.26 mm <Magnet Part> Same Configuration as in Example 1 <Paint> Type: 8 mm For forming magnetic layer of video tape ( Metal magnetic powder is used) Coating thickness: 1.5 to 2 μm (after drying) <Support> Width: 620 mm Thickness: 8 to 12 μm Material: Polyethylene terephthalate And, in order to enable good coating under these conditions, When the traveling speed of the support 1 was adjusted, it was 350 m /
It was possible to carry out the coating without any problem even in the minute.

As a result, the coating apparatus according to the first embodiment can form a good coating film at a high speed even if the coating width of the magnetic coating material, the type of the magnetic coating material, and the like are changed, even if it is very thin. all right.

Example 3 Also in this case, the magnetic coating material was applied with the width of the support 1 and the coating width of the magnetic coating material, the type of the magnetic coating material and the like different from those of the first embodiment.

Specifically, the magnetic coating material was applied to the traveling support 1 under the following conditions using the application device as shown in FIGS.

Settings in Coating Device <Die> Overall Width: 1320 mm Coating Width: 1220 mm Lip 4: Cemented Carbide (Non-Magnetic Material) Slit 5 Gap: 0.26 mm <Magnet Part> Same Configuration as in Example 1 <Paint> Type: For forming magnetic layer of VHS video tape Coating thickness: 2 to 2.7 μm (after drying) <Support> Width: 1240 mm Thickness: 12 to 14.5 μm Material: Polyethylene terephthalate And good coating under these conditions When the traveling speed of the support 1 was adjusted to be possible, 600 m /
It was possible to carry out the coating without any problem even in the minute.

From this, it was found that the coating apparatus according to the first embodiment can form a good coating film at high speed even if the coating width of the magnetic coating material, the type of the magnetic coating material, etc. are changed.

Example 4 In this example , the magnetic coating material was applied by changing the running direction of the support 1 with respect to the positions where the die 2 and the magnet portion 3 were provided.

Specifically, the magnetic coating material was applied to the traveling support 1 under the following conditions using the application device as shown in FIGS.

Settings in Coating Device <Die> Same configuration as in Example 1 except that both lips 7 and 8 are made of non-magnetic material <Magnet part> Same configuration as in Example 1 <Paint> Kind is as in Example 1. Same coating thickness: 2 μm (after drying) <Support> Width, thickness, and material are the same as in Example 1 Running direction: Centered on a line at which the slit center plane and the main surface of the support intersect, and the slit center plane is supported. The angle at which the main surface of the body is vertical is 0 °, and the traveling speed is ± 30 °: 250 to 800 m / min. The traveling direction of the support 1 is changed within ± 30 °,
Further, the traveling speed of the support 1 was also changed within the above range under each condition.

Table 1 shows the results of coating with such settings. In Table 1, the case where good coating was performed is indicated by ◯, the support body 1 is defined by either of the lips 7 or 8, or
The case where it comes into contact with either of the two yokes 13 and 14 of the magnet part 3 is indicated by x.

[0076]

[Table 1]

From Table 1, when the traveling direction of the support 1 with respect to the die 2 and the magnet portion 3 is ± 20 ° or more, either the die 2 or the magnet portion 3 comes into contact, whereas
If the traveling direction of the support 1 is within ± 15 °, 800
It was found that high-speed coating up to m / min can be satisfactorily performed.
However, it is merely a design problem that the support 1 comes into contact with either the die 2 or the magnet portion 3 when the support 1 is set to a traveling direction of ± 20 ° or more.

From this, it was found that a good coating film can be formed at high speed even if the traveling direction of the support 1 with respect to the die 2 and the magnet portion 3 changes.

Embodiment 5 Here, the traveling direction of the support 1, the die 2 and the magnet portion 3 are used.
The magnetic coating material was applied by changing the arrangement direction of.

Specifically, as shown in FIG. 3, the coating device as shown in FIGS. 1 and 2 is arranged such that the slit center plane of the die 2 is inclined at 45 ° with respect to the horizontal plane. The magnetic coating was applied to the running support 1 under the following conditions.

Settings in Coating Device <Die> Overall Width: 1320 mm Coating Width: 1220 mm Lip 4: Cemented Carbide (Nonmagnetic Material) Gap between Slits: 0.26 mm <Magnet Part> Same Configuration as in Example 1 <Paint> Type: For forming a magnetic layer of audio tape Coating thickness: 4 to 6 μm (after drying) <Support> Width: 1240 mm Thickness: 8 to 12 μm Material: Polyethylene terephthalate And good coating is possible under these conditions. When the traveling speed of the support 1 was adjusted, 600 m /
It was possible to carry out the coating without any problem even in the minute.

As a result, the coating apparatus according to the first embodiment forms a good coating film at high speed even when the traveling direction of the support 1 and the disposing direction of the die 2 and the magnet portion 3 are inclined by 45 °. I knew I could do it.

Example 6 Here again, the traveling direction of the support 1, the die 2 and the magnet portion 3 are used.
The magnetic coating material was applied by changing the arrangement direction of.

Specifically, as shown in FIG. 3, the coating apparatus as shown in FIGS. 1 and 2 is used as shown in FIG. 3, and the center plane of the slit in the die 2 is 45 with respect to the horizontal plane.
The magnetic coating material was applied to the traveling support 1 under the following conditions by arranging so as to be inclined.

Settings in Coating Device <Die> Overall Width: 1320 mm Coating Width: 1220 mm Lip 4: Cemented Carbide (Non-magnetic Material) Slit 5 Gap: 0.26 mm <Magnet Part> Same Configuration as in Example 1 <Paint> Type: 8 mm for forming magnetic layer of video tape Coating thickness: 2 μm (after drying) <Support> Width: 1240 mm Thickness: 8 to 12 μm Material: Polyethylene terephthalate And, in order to enable good coating under these conditions, When the traveling speed of the support 1 was adjusted, it was 350 m /
It was possible to carry out the coating without any problem even in the minute.

As a result, the coating apparatus according to the first embodiment provides good coating even when the traveling direction of the support 1 and the arranging directions of the die 2 and the magnet portion 3 are inclined, and the types of magnetic paint are different. It was found that the film can be formed at high speed.

Embodiment 7 Here, the traveling direction of the support 1, the die 2 and the magnet portion 3 are used.
The magnetic paint was applied by further changing the arrangement direction of.

Specifically, as shown in FIG. 4, the slit center surface of the die 2 is 90 ° with respect to the horizontal plane as shown in FIG.
The support 1 is arranged so as to tilt and runs under the following conditions.
A magnetic paint was applied to.

Settings in Coating Device <Die> Overall Width: 700 mm Coating Width: 600 mm Lip 4: Cemented Carbide (Nonmagnetic Material) Gap between Slits: 0.26 mm <Magnet Part> Same Configuration as in Example 1 <Paint> Type: For forming magnetic layer of VHS video tape Coating thickness: 2 μm (after drying) <Support> Width: 620 mm Thickness: 12 to 14.5 μm Material: Polyethylene terephthalate And good coating is possible under these conditions. When the traveling speed of the support 1 was adjusted to 600 m /
It was possible to carry out the coating without any problem even in the minute.

As a result, the coating apparatus according to the first embodiment forms a good coating film at high speed even when the traveling direction of the support 1 and the arranging direction of the die 2 and the magnet portion 3 are inclined by 90 °. I knew I could do it.

Example 8 In this example, in order to investigate the coating performance of the coating apparatus shown in the second embodiment, the magnetic coating material was coated by making various settings in the coating apparatus.

Specifically, the magnetic coating material was applied to the traveling support 1 under the following conditions using the application device as shown in FIGS. 5 and 6.

Settings in Coating Device <Die> Full Width: 160 mm Coating Width: 110 mm Lip 24: Cemented Carbide (Magnetic Material) Thickness of Upper Lip 27: 5 mm Thickness of Lower Lip 28: 3 mm Thickness of Slit 5: 0.3 mm < Magnet part> Full width: 150 mm Permanent magnet 11: Neodium alloy magnet Magnetic force of 500 to 4000 gauss is generated in the vicinity of lip 24. Yoke 12: S10C (high magnetic permeability material) Size of magnetic gap 15: 1 mm Yoke 12 tip and lip 24 tip Gap d: 0.2
~ 3 mm Height position h of the magnetic gap 15 with respect to the slit 5:
± 1.0 mm <Paint> Type: For forming magnetic layer of VHS video tape Coating thickness: 2 to 3 μm (after drying) <Support> Width: 125 mm Thickness: 14 μm Material: Polyethylene terephthalate Tension: 3 to full width of support 4 kgf Running speed: 400 to 600 m / min The magnetic force generated in the vicinity of the lip 24 is 500 to 4
It was changed in the range of 000 gauss. In addition to the amount of the support 1 held, the gap d between the yoke 12 and the lip 24 and the magnetic gap 15 with respect to the slit 5 are adjusted so that good coating can be performed with the magnetic force. The height position h and the traveling speed of the support 1 were also adjusted.

In this way, when the magnetic coating material was coated while changing the magnetic force, the maximum coating speed at which good coating was possible was examined, and the results shown in Table 2 were obtained. Table 2 also shows the range of the height d of the magnetic gap 15 with respect to the slit 5 and the gap d between the tip of the yoke 12 and the tip of the lip 24 that can achieve the highest coating speed. In addition, for comparison, the maximum coating speed in the case of using the coating apparatus having the same settings as described above except that the magnet portion 3 is not provided is also shown.

[0095]

[Table 2]

From Table 2, the magnet portion 2 is made to face the die 22.
By disposing No. 3, the maximum coating speed can be increased, and as the magnetic force generated near the lip 24 is increased, the gap d between the tip of the yoke 12 and the tip of the lip 24 is increased.
It can be understood that the maximum coating speed can be increased even if the height position h of the magnetic gap 15 with respect to the slit 5 is rough. However, it can be seen that even if the magnetic force is set to 3000 Gauss or more, the maximum coating speed is not further increased.

From this, a magnetic force of 3000 gauss or more is generated in the vicinity of the lip 24, and the tip of the yoke 12 and the lip 24.
It is understood that the magnetic paint can be applied at a high speed when the gap d from the tip is 0.2 to 3.0 mm and the height position h of the magnetic gap 15 with respect to the slit 5 is ± 1.0 mm.

Although the lip 24 is made of a magnetic material here, the lip 24 is made of a non-magnetic material for comparison, and the magnetic paint is applied in the same manner. Specifically, a magnetic paint of 3000 gauss was generated in the vicinity of the lip 24 to apply the magnetic paint, and the maximum application speed at this time was examined.

As a result, when the lip 24 is made of a magnetic material, the maximum coating speed is 6 as shown in Table 2.
While it was 00 m / min, when the lip 24 was made of a non-magnetic material, the maximum coating speed was 500 m / min.

From this, as shown in the second embodiment, the lip 2 which forms the slit 5 at the tip of the die 22.
In the coating device in which 4 is disposed so as to come into contact with the support 1, it is preferable that the lip 24 is made of a magnetic material, whereby the magnetic flux from the magnet portion 3 can be concentrated and the magnetic paint It can be seen that the movement can be held well.

Although the coating apparatus according to the present invention has been described above, the coating apparatus according to the present invention is not limited to the configuration shown in the above-mentioned embodiment, and the conditions shown in the above-mentioned example are not limited. The present invention is not limited to the above, and various modifications and changes are possible.

For example, although the neodymium alloy magnet is used as the permanent magnet 11 in the magnet portion 3 in the above-mentioned embodiment, any other material may be used as long as it has a desired magnetic force. An electromagnet may be used instead of the permanent magnet 11. Also, the shape of the yoke 12 in the magnet portion 3 does not necessarily need to bend the lower yoke 14 as long as the tips of the magnet portion 3 are adjacent to each other and a magnetic gap 15 of a desired size can be formed between the tips.

Further, even in the die 2, the lip 4 is moved to the S
Although the magnetic material is 10C, other magnetic materials may be used, and the entire die 2 as well as the lip 4 may be made of a magnetic material.

Further, in the coating apparatus in which the lip 24 is arranged in non-contact with the support 1 as shown in the first embodiment, the die 2 and the magnet are used in Examples 5, 6 and 7. The case where the arrangement direction of the portion 3 is tilted at 45 ° and 90 ° has been described, but it may be tilted at any angle of 360 °.
Furthermore, as shown in the second embodiment, the lip 2
Even in the coating device in which 4 is brought into contact with the support 1, the die 2
Also, the arrangement direction of the magnet portion 3 can be arbitrarily changed.

In addition, the kind of the coating material 6 applied to the support 1 and the applied field are not limited.

[0106]

As is apparent from the above description, in the coating apparatus according to the present invention, the movement of the paint supplied onto the support is maintained by the magnetic flux narrowed by the magnetic gap of the magnet section. be able to. Therefore, when the coating apparatus according to the present invention is used, abnormal coating behavior can be prevented from occurring and stable coating can be performed even when performing high-speed coating and thin film coating.

Therefore, by applying the present invention, a good coating film can be formed with high productivity.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration example of a coating apparatus according to the present invention.

FIG. 2 is a perspective view of an essential part showing a configuration example of a coating apparatus according to the present invention.

FIG. 3 is a schematic cross-sectional view showing a state in which the coating device of FIG. 1 is arranged such that the traveling direction of the support body and the arrangement direction of the die and the magnet portion are inclined by 45 °.

FIG. 4 is a schematic cross-sectional view showing a state in which the coating device of FIG. 1 is arranged such that the traveling direction of the support body and the arrangement direction of the die and the magnet portion are inclined by 90 °.

FIG. 5 is a schematic cross-sectional view showing another configuration example of the coating apparatus according to the present invention.

FIG. 6 is a main part perspective view showing another example of the configuration of the coating apparatus according to the present invention.

[Explanation of symbols]

 1 Support 2 Die 3 Magnet Part 4 Lip 5 Slit 6 Paint 7 Upper Lip 8 Lower Lip 9 Pocket 11 Permanent Magnet 12 Yoke 13 Upper Yoke 14 Lower Yoke 15 Magnetic Gap

Claims (9)

[Claims] 1. An extrusion type coating, which comprises a die having a paint reservoir to which the paint is supplied, and which applies the paint while extruding the paint from a slit provided at the tip of the die onto a continuously running support. In the apparatus, a magnet portion having tips adjacent to each other to form a magnetic gap is arranged on the opposite side of the die with the support interposed therebetween so that the magnetic gap faces the tip of the die. The coating device, wherein an upper lip and a lower lip that form the slit at the tip of the die are respectively arranged in non-contact with the support. 2. The coating apparatus according to claim 1, wherein each of the upper lip and the lower lip is made of a magnetic material. 3. The coating apparatus according to claim 1, wherein a gap between the tip of the magnet portion and the tip of the die is 0.2 to 3 mm. 4. The magnet portion has an upper end surface of the magnetic gap of ± 1 m with reference to a height of an upper end surface of the slit.
The coating apparatus according to claim 1, wherein the coating apparatus is arranged so as to be located in a range of m. 5. The magnet part is provided near the both lips.
The coating apparatus according to claim 1, which has a magnetic force of 00 to 6000 gauss. 6. An extrusion type coating comprising a die having a coating material reservoir to which the coating material is supplied, and applying the coating material on a continuously running support while extruding the coating material through a slit provided at the tip of the die. In the apparatus, a magnet portion having tips adjacent to each other to form a magnetic gap is arranged on the opposite side of the die with the support interposed therebetween so that the magnetic gap faces the tip of the die. The coating device is characterized in that an upper lip and a lower lip forming the slit at the tip of the die are made of a magnetic material and are arranged so as to come into contact with the support. 7. The coating apparatus according to claim 6, wherein a gap between the tip of the magnet portion and the tip of the die is 0.2 to 3 mm. 8. The magnet portion has an upper end surface of the magnetic gap of ± 1 m with respect to a height of an upper end surface of the slit.
The coating apparatus according to claim 6, wherein the coating apparatus is arranged so as to be located in a range of m. 9. The magnet part is provided in the vicinity of both the lips.
The coating device according to claim 6, wherein the coating device has a magnetic force of 00 to 6000 gauss.