JPH06114316A - Applicator - Google Patents

Abstract

PURPOSE:To improve corrosion resistance and hardness of a metal edge and to control the generation of stripes on a coated layer. CONSTITUTION:The amount of a coating liquid applied on a film 1 is controlled by a blade 6 placed downstream from a coating means or a back edge 16 and a doctor edge 17 of a coating head 11. The blade 6 or the back edge and the doctor edge 17 are made of a cemented carbide in which 0.5-1.0% of Cr is incorporated into WC in addition to Co as a binding metal. If the amount of Cr is below 0.5%, it can not serve for binding. On the other hand, its amount exceeding 1.0% causes the decrease in the strength because of the deposit in the form of CrC.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus for coating a flexible support made of metal foil, plastic film, paper or the like with a coating liquid such as ink, magnetic substance or photographic photosensitive material.

[0002]

2. Description of the Related Art Conventionally, as a coating apparatus for coating a magnetic material or the like on a flexible support (hereinafter referred to as a film), there is a Meyer bar coating system shown in FIGS. 1 and 2, for example. 1 is a schematic configuration diagram of a coating machine, FIG.
FIG. 2 is an enlarged view of a main part of coating means in FIG.
In this machine shown in FIG. 1, a film 1 held in a roll shape is unwound, and a lower roll 3 partially immersed in a storage tank 2 in which a magnetic substance such as a magnetic dispersion liquid is stored, and the lower roll 3 is pressure-bonded thereto. When the film 1 travels and passes between both rolls 3 and 4 of the coating means 5 including the upper roll 4, the magnetic dispersion is continuously applied to one surface of the film 1 by the roll 3. The coating amount of the coating liquid on the film 1 is regulated by a blade 6 (see FIG. 2), that is, a metal edge which is located on the downstream side of the coating means 5 in a direction orthogonal to the film running direction and extends in the width of the film. The thickness will be controlled. Then, the film 1 is further run, the coating layer is dried in the drying furnace 7 and cooled by the cooling roll 8, and then the winding roll 9 is used.
It is supposed to be wound up in.

Further, as another means for controlling the coating amount of the coating liquid on the film 1 to a constant amount, for example, there is an extrusion type coating head 11 shown in FIG. This head 1
1 is inside the main body 12 extending in the width direction of the film 1,
Cylindrical reservoir 14 to which the coating liquid is supplied via the pipe 13.
Is extended in the longitudinal direction of the main body 12 to the length of the film width, and at the upper part of the storage part 14, a slot part 15 that is opened to the film running surface and through which the coating liquid is discharged is formed in communication. Further, on both the upstream side and the downstream side of the slot portion 15 in the film running direction, from the back edge 16 and the doctor edge 17 so that the coating liquid forms a laminar flow with a uniform flow rate and liquid pressure distribution in the width direction of the film 1. A pair of metal edges are formed and partitioned. And the slot portion 15
Thus, the coating liquid applied on the running film 1 is regulated by the doctor edge 17 so that the thickness of the coating layer becomes uniform. Both edges 16 and 17 may be formed integrally with the main body 12.

The metal edge in each of the above coating devices is
Since the WC (tungsten carbide) is composed of a cemented carbide that is bonded by a bonding metal such as Co (cobalt), its straightness and flatness can be increased. Furthermore, since the coating liquid is applied or the coating amount is regulated while the metal edge is pressed against the film 1, it is also useful for improving the wear resistance of the coating head tip with respect to the coating liquid to which the abrasive is added. ing. by the way,
In recent years, with the increase in density and multilayer of magnetic recording media, additives such as lubricants and dispersants have been added to the magnetic dispersion liquid applied on a non-magnetic film to improve magnetic properties and running properties. Improved magnetic recording media and the like are being manufactured.

[0005]

However, when the film 1 is coated with the above-mentioned coating apparatus using the magnetic dispersion liquid to which the additive such as the lubricant is added, the lubricant in the coating liquid is used. Fatty acids such as stearic acid (usually other mistyric acid, aluminic acid, oleic acid, linoleic acid, linolenic acid, etc. contained in the magnetic substance dispersion liquid) contained in the dispersant, metal edge, etc. Co contained in the cemented carbide forming the alloy as a binding metal is oxidized and corroded, which deteriorates the finishing accuracy of the metal edge surface.
Furthermore, the metal edge is corroded on the surface, and WC drops off in particle units, resulting in chipping or wear. Therefore, when the coating liquid is coated or the coating amount is regulated by such a metal edge, the meniscus of the coating liquid on the coating surface of the film 1 may be disturbed due to the chipped portion,
There is a drawback that foreign matter in the coating liquid is trapped in the notch and streaks occur on the surface of the coating layer, so that a good coating layer cannot be obtained. This problem increases as the running speed of the film 1 increases and the thickness of the coating layer decreases.

In view of the above situation, the present invention improves the corrosion resistance of metal edges and suppresses the generation of streaks in the coating layer, even if higher fatty acids are contained in the coating liquid. It is an object of the present invention to provide a coating device capable of obtaining a coating layer.

[0007]

A coating apparatus according to the present invention coats a coating liquid on the surface of a flexible support that continuously runs, and the coating amount of the coating liquid to be coated is regulated by a metal edge. In such a coating apparatus, the metal edge is made of a cemented carbide containing 0.5 to 1.0% of chromium as a binding metal in addition to cobalt.

Further, the metal edges are formed on the upstream side and the downstream side in the running direction of the support in order to partition the slot portion for discharging the coating solution of the coating head for applying the coating solution in the vicinity of the surface of the support. It is characterized by being a back edge and a doctor edge.

Further, the metal edge is a blade located downstream of the coating means for applying the coating liquid on the surface of the support in the support running direction.

[0010]

Since the cemented carbide forming the metal edge contains 0.5 to 1.0% of chromium as a binding metal,
During production, chromium alloys with cobalt and bonds with tungsten carbide, so even if the coating liquid contains acids such as higher fatty acids, the oxidation resistance of chromium suppresses the corrosion of cobalt and cemented carbide. Corrosion resistance is improved. Therefore, the corrosion resistance of the metal edge is enhanced to suppress chipping and wear of the surface, and the coating amount of the coating liquid applied on the running support is regulated by the metal edge, forming a uniform coating layer without streaks. To be done.

The coating liquid is applied to the flexible support by the coating head, and the coating amount is regulated by the doctor edge to form a uniform coating layer having no streaks on the support.

The coating liquid is coated on the surface of the support by the coating means, and then the coating amount is regulated by the blade to form a uniform coating layer having no streaks on the support.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, as the metal constituting the metal edge, a cemented carbide containing 0.5 to 1.0% of Cr (chromium) in addition to Co as a binding metal to WC was used. Cr in such a range is changed to C
By adding to O to produce a cemented carbide, Cr and Co are alloyed and combined with WC. Due to its oxidation resistance and corrosion resistance, Cr suppresses the oxidation of Co by the higher fatty acid in the coating liquid such as the magnetic dispersion liquid, so that the oxidation resistance and corrosion resistance of the cemented carbide can be improved and The hardness of the hard alloy increases and the wear resistance increases. Here, if the content of Cr in the cemented carbide is less than 0.5%, Cr does not serve for bonding the cemented carbide, and if it exceeds 1.0%, it bonds with carbon C of WC. As CrC (chromium carbide), resulting in a decrease in strength of the cemented carbide, which is not preferable.

Therefore, if the blade 6 shown in FIG. 2 or the back edge 16 and the doctor edge 17 shown in FIG. 3 are made of a cemented carbide having such a composition, the surface of each metal edge has the above-mentioned conventional structure. Oxidation resistance and corrosion resistance are improved with respect to higher fatty acids such as stearic acid contained in additives such as lubricants and dispersants in the coating liquid, as compared with those made of cemented carbide. Further, the hardness of the metal edge is increased and the wear resistance is increased. Therefore, chipping or abrasion of the surface of the metal edge is unlikely to occur. Therefore, in the coating means shown in FIG. 2, the blade 6 can uniformly regulate the coating layer of the coating liquid on the running film 1 and prevent the formation of streaks or the like on the coating surface at that time. Also, FIG.
In the coating head 11 shown in FIG. 1, the coating liquid is applied to the film 1 as a uniform laminar flow in the slot portion 15 partitioned by the back edge 16 and the doctor edge 17, and the coating layer is uniformly regulated by the doctor edge 17. . Further, the same effect can be obtained even if the traveling speed of the film 1 in the coating apparatus is increased or the thickness of the coating layer is made thinner.

As described above, in this embodiment, the corrosion resistance and wear resistance of the cemented carbide forming the metal edge can be improved, and the metal edge surface is less likely to be chipped or worn.
It is possible to suppress the generation of streaks on the coated surface of.

The coating apparatus according to the present invention is the same as that shown in FIG.
It is needless to say that the present invention is not limited to the coating device shown in FIG. 3 and is also applicable to other types of coating device using a metal edge.

[0017]

As described above, in the coating apparatus according to the present invention, in addition to cobalt as a binding metal of cemented carbide, 0.5 to
Since 1.0% of chromium is added, it is possible to improve the oxidation resistance and corrosion resistance of the surface of the metal edge, and also improve the wear resistance. Wear can be suppressed. Therefore, it is possible to prevent the occurrence of streaks in the coating layer of the coating liquid on the support.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a coating machine including a coating device.

FIG. 2 is an enlarged view of a main part of the coating device of FIG.

FIG. 3 is a perspective view showing a state in which a part of the coating head is cut and separated.

[Explanation of symbols]

 1 film 5 coating means 6 blade 11 coating head 15 slot portion 16 back edge 17 doctor edge

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Teruyoshi Tanase 1528, Nakashinden, Yokoi, Kobe, Anpachi-gun, Gifu Pref. Mitsubishi Materials Corporation Gifu Works

Claims (3)

[Claims] 1. A coating device in which a coating liquid is applied to the surface of a flexible support that continuously runs and the coating amount of the coating liquid applied to the support is regulated by a metal edge. In the above, the metal edge is 0.5 to
A coating apparatus comprising a cemented carbide containing 1.0% of chromium as a binding metal. 2. The metal edges are formed on the upstream side and the downstream side in the traveling direction of the support in order to partition the slot portion for discharging the coating liquid of the coating head for coating the coating liquid in the vicinity of the surface of the support. The coating device according to claim 1, which is a back edge and a doctor edge. 3. The coating apparatus according to claim 1, wherein the metal edge is a blade located downstream of the coating means for coating the coating liquid on the surface of the support with respect to the traveling direction of the support.