JPH06277608A - Doctor blade for coating apparatus - Google Patents

Abstract

PURPOSE:To obtain a doctor blade with improved corrosion resistance and wear resistance by making at least the apex part of an alloy prepd. by rolling a Ni alloy with a specified compsn. and heat-treating it. CONSTITUTION:As a metal constituting the apex part 21 of a blade of a doctor blade 17, a Ni alloy obtd. by the following compsn. and a manufacturing condition is used. This alloy is prepd. by a method wherein hot forging and hot rolling are applied on an ingot of a Ni alloy with a compsn. of 14-23% Cr, 14-20% Mo, 0.2-5% W, 0.2-7% Fe, 0.2-2.5% Co and the remaining parts being Ni and irreversible impurities in terms of wt.% to form a hot rolling material and melting treatment is applied on this hot rolling material to make an austenite constitution. Then, under this condition, plastic processing is given by cold roll processing and fine Ni-Mo type intermetal compd. is deposited in a raw material by keeping it at 450-800 deg.C for at least 0.5hr. Corrosion resistance of the apex part of the doctor blade is improved thereby and strength and wear resistance are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible support made of metal foil, plastic film, paper or the like, which is made of an insulating material, a conductive material, an adhesive, an adhesive, an ink, a photographic photosensitive material, a magnetic substance or the like. The present invention relates to a coating device that coats a coating liquid.

[0002]

2. Description of the Related Art Conventionally, as a coating device for coating a coating liquid such as a magnetic substance on a flexible support (hereinafter referred to as a film), there is a Meyer bar coating system shown in FIGS. 6 and 7, for example. FIG. 6 is a schematic configuration diagram of the coating machine, and FIG. 7 is an enlarged view of a main part of the coating means in FIG. In this machine shown in FIGS. 6 and 7, the film 1 held in a roll shape is unwound, and the coating roll 3 is partially immersed in a storage tank 2 in which a magnetic substance such as a magnetic dispersion liquid is stored.
Also, when the film 1 travels and passes between both rolls 3 and 4 of the coating means 5 consisting of the guide rolls 4 pressed onto the magnetic roll, the coating roll 3 continuously transfers the magnetic dispersion liquid to one surface of the film 1. Applied to. The coating amount of the coating liquid on the film 1 is regulated by the doctor blade 6 (see FIG. 7) which is located on the downstream side of the coating means 5 in the direction orthogonal to the film running direction and extends in the film width, so that the coating liquid has a uniform thickness. Will be controlled. Then, the film 1 is further run, the coating layer is dried in the drying furnace 7, cooled by the cooling roll 8, and then wound by the winding roll 9.

Further, as another means for controlling the coating amount of the coating liquid on the film 1 to a constant amount and making the thickness of the coating layer uniform, there is, for example, one shown in FIG. With this coating device,
The coating roll 13 partially immersed in the coating liquid in the storage tank 12 is pressed against the guide roll 11 for guiding the traveling film 1 through the film 1 to form the coating means 1.
4 are configured. In this coating means 14, the coating liquid in the storage tank 12 is attached to the surface of the coating roll 13 and carried by the rotation of the coating roll 13, and the guide roll 1
The coating liquid is applied to the film 1 on 1. In addition, the doctor blade 15 is disposed in close proximity to the coating roll 13 between the coating liquid dipping portion in the storage tank 12 and the pressure-bonding portion to the film 1, so that extra doctor blade 15 that adheres to the coating roll 13 Coating roll 1 by scraping off the coating liquid
It is controlled so that the coating liquid on 3 is made into a uniform layer and a uniform coating layer is formed on the film 1.

The doctor blades 6 and 15 in each of the above-mentioned coating devices are WC (tungsten carbide) C
Since it is made of a cemented carbide that is bonded by a bonding metal such as o (cobalt), its straightness and flatness can be increased. Furthermore, doctor blade 6,1
5 is pressed against the film 1 or the coating roll 13 to control the coating amount of the coating liquid, but it is also useful for improving the wear resistance of the doctor blades 6 and 15 against the coating liquid to which an abrasive is added. Has become. The doctor blades 6 and 15 may be made of stainless steel. 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 the film of non-magnetic material to improve magnetic properties and running properties. Magnetic recording media having improved properties are manufactured.

[0005]

However, when the film 1 is coated with the above-mentioned coating apparatus using the magnetic dispersion liquid to which such an additive as a lubricant is added, the doctor blades 6 and 15 are used. When it is made of cemented carbide, stearic acid, etc. contained in lubricants and dispersants in the coating liquid (usually mistyric acid, aluminic acid, oleic acid, linoleic acid, linolenic acid, etc. are magnetic. The higher fatty acid (included in the body dispersion) oxidizes and corrodes Co contained in the cemented carbide as a binding metal, deteriorating the finishing accuracy of the sharp edge of the blade tip. Further, the doctor blades 6 and 15 may be corroded on the surface thereof, causing WC to drop off in particle units, resulting in chipping, abrasion, etc., and the sharpness of the blade tip may be lost. Therefore, if the coating amount of the coating liquid is regulated by such doctor blades 6 and 15, the meniscus of the coating liquid on the coating surface of the film 1 is disturbed by the notch, and the foreign substance in the coating liquid is present at the notch. If they are captured, streaks may occur on the surface of the coating layer. Further, there is a drawback that sharp edges are lacking and a coating layer having a uniform thickness cannot be obtained. This problem increases as the running speed of the film 1 increases and the thickness of the coating layer decreases. Also, when using a stainless steel doctor blade, the corrosion resistance is lower than that of cemented carbide,
There is a drawback that streaks and unevenness in thickness generated on the surface of the coating layer become large.

In view of such circumstances, the present invention has a higher corrosion resistance and wear resistance of the doctor blade, and suppresses corrosion and wear even when higher fatty acid is contained in the coating liquid,
It is an object of the present invention to provide a doctor blade for a coating apparatus in which generation of streaks in the coating layer is suppressed and a uniform and good coating layer can be obtained.

[0007]

A doctor blade of a coating apparatus according to the present invention is a coating apparatus in which a coating liquid is applied to a surface of a continuously running flexible support by a coating means and is applied to the support. In a coating device in which the coating amount of the liquid is regulated by a doctor blade, at least the tip of the doctor blade has Cr: 14 to 23%, M
o: 14-20%, W: 0.2-5%, Fe: 0.2-
7%, Co: 0.2 to 2.5%, the balance being Ni and an unavoidable impurity, and a Ni alloy having a composition comprising rolling and heat treatment.

Further, the doctor blade is characterized in that it is arranged on the downstream side of the coating means and close to the coating layer on the support.

Further, the doctor blade is characterized in that it is arranged in the vicinity of a coating roll of a coating means for coating the coating liquid on the support.

[0010]

In the Ni alloy forming the doctor blade, since the Ni-Mo intermetallic compound is finely and uniformly dispersed in the base material, the Ni alloy has sufficient hardness and sharp edge for controlling the coating amount, and is high. Since it has corrosion resistance and strength, even if an acid or the like is contained in the coating liquid, it suppresses corrosion of the surface of the doctor blade tip portion and has high wear resistance. Therefore, the sharpness of the edge can be maintained by suppressing chipping and wear of the doctor blade surface, the coating amount of the coating liquid applied on the traveling support is reliably regulated, and a uniform coating layer without streaks is formed. It

The coating solution is applied to the flexible support by the application means, and then the application amount is regulated by the doctor edge to form a uniform coating layer without streaks on the support.

The coating liquid deposited on the coating roll is regulated by a doctor blade to a desired thickness, and then the coating liquid is uniformly coated on the surface of the support to which the roll is pressure bonded.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to FIGS. The doctor blade according to the embodiment of the present invention is arranged and configured in the same manner as shown in FIGS. 6 to 8 described above. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a front view of a doctor blade, and FIG. 2 is a side view of the doctor blade. 1 and 2, the doctor blade 17 is rotatably fixed and held by a coating machine main body (not shown) on both side surfaces of a rectangular plate-shaped body 18 (see FIG. 1) which is slightly wider than the film 1. A pair of arm portions 19 and 20 are formed. Further, on the upper surface and the lower surface of the body 18,
A blade tip portion 21 having a substantially right-angled triangle in a side view, which has the same width as the body 18 and the same bottom length as the thickness of the body 18,
21 (see FIG. 2) are fixed with screws 22 or the like,
It is configured. The tip apex angle is, for example, 60 °. The pair of blade tip portions 21 and 21 have a point-symmetrical shape with respect to the center of rotation of the arm portions 19 and 20, and are attached as such. Therefore, either one of the blade tips 21 can be selectively selected and used to regulate the coating amount on the film 1 or the coating roll 13. The blade tip 21 may be attached to only one surface of the body 18.

In this embodiment, the doctor blade 1
As the metal forming the blade tip portion 21 of No. 7, a Ni alloy obtained under the following composition and manufacturing conditions is used. This alloy has appropriate hardness, high toughness, high corrosion resistance, wear resistance, high strength, heat resistance, and non-magnetism. That is,
This alloy contains Cr: 14 to 23% and Mo: 1 by weight.
4 to 20%, W: 0.2 to 5%, Fe: 0.2 to 7%,
Co: 0.2-2.5%, balance Ni and unavoidable impurities,
The Ni alloy ingot having the composition of is subjected to hot forging and hot rolling under normal conditions to obtain a hot rolled material, and the hot rolled material is subjected to solution treatment under normal conditions (1100 to 1200 ° C.). Austenite structure. And, in the state of austenite structure, the working rate by cold working is 70% or more,
Preferably 80% or more of plastic working is applied, which is then carried out at 450-800 ° C., preferably 500-600 ° C.
By holding for 3 hours or more, preferably 0.5 hours or more,
A fine Ni-Mo-based intermetallic compound can be deposited in the matrix.

Therefore, if the blade tip portion 21 of the doctor blade 17 is molded with the alloy thus manufactured, the lubricant in the coating liquid and the lubricant in the coating liquid can be compared with the conventional cemented carbide. It has high oxidation resistance and corrosion resistance to higher fatty acids such as stearic acid contained in additives such as dispersants. Further, since it has high toughness and an appropriate hardness, the sharpness of the tip of the blade tip 21 can be sharply maintained, and the strength is increased and the wear resistance is increased. Therefore, the blade tip 21 is less likely to be chipped or worn. Therefore, in the coating means shown in FIG. 7, by the doctor blade 6 using the doctor blade 17,
The coating layer of the coating liquid on the running film 1 is uniformly regulated, and at that time, it is possible to prevent the formation of streaks on the coating surface. In addition, in the doctor blade 15 (using the doctor blade 17) shown in FIG.
The excess amount of coating liquid that adheres to the top is removed, and film 1
A uniform coating layer can be applied on top. 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.

Next, the blade tip portion 21 according to the present embodiment.
The reasons for limiting the above-described component composition and manufacturing conditions of the above-described alloy constituting the above will be described. A. Component composition a) Cr The Cr component has a function of significantly improving the passivation ability of the austenite matrix and improving the corrosion resistance, but if the content thereof is less than 14%, the corrosion resistance is particularly remarkable in an oxidizing atmosphere. And the content is 23
%, The austenite structure becomes unstable, and it becomes impossible to stably form a structure in which a fine Ni-Mo-based intermetallic compound is precipitated in the austenite matrix, which causes a decrease in corrosion resistance. Its content was limited to 14-23%.

B) Mo Mo component has an action of improving the strength by forming a Ni-Mo intermetallic compound which binds to Ni and finely disperses and precipitates in the matrix as described above. Amount is 14%
If the content is less than this, the desired effect is not obtained, while if the content exceeds 20%, the hot and cold rollability is deteriorated, so the content is set to 14 to 20%. Limited c) WW component has the action of forming a solid solution in the austenite matrix to improve the strength, but if its content is less than 0.2%, the desired strength improvement effect cannot be obtained, while its content is 5 %, The hot and cold rollability will deteriorate, so the content was limited to 0.2-5%.

D) Fe The Fe component has an effect of improving hot and cold rolling properties, but if the content of Fe is less than 0.2%, the desired effect cannot be obtained in this function, while the content thereof is If the amount exceeds 7%, the strength will decrease, so the content should be 0.2
Limited to ~ 7%. e) Co The Co component has the function of forming a solid solution in the austenite matrix and stabilizing it to promote the stable precipitation of the intermetallic compound during the precipitation hardening treatment. No effect is obtained on the other hand, and on the other hand, even if the content exceeds 2.5%, no further improvement effect is exhibited by this action. Therefore, considering the economic efficiency, the content is set to 0.2-2. 5%
Limited to.

B. Manufacturing conditions a) Cold rolling ratio If the cold rolling ratio is less than 70%, precipitation of the intermetallic compound by precipitation hardening after cold rolling is not sufficiently performed, and in this case,
Since it becomes impossible to obtain a hardness of 48 or more by HRC, the cold rolling rate was limited to 70% or more. Further, particularly when the cold rolling ratio is 80% or more, a hardness of HRC 56 or more can be obtained, which is more preferable. When performing this cold working, cold rolling is carried out with a cold rolling mill at a rolling reduction of 3 to 4% per pass so that the total rolling reduction (working rate) becomes 70% (80%) or more. When the above is continued, a thin plate of Ni alloy is obtained. The hardness of the thin plate at this stage is H due to work hardening.
It becomes 45 (50) or more in RC. The processing rate is more preferably 95% or more. In order to process the Ni alloy having the above-described composition at a processing rate of 95% or more, the processing can be performed by using a cemented carbide roll. 95% like this
A thin plate of 60 or more can be obtained by HRC by processing as described above and subjecting it to precipitation hardening treatment as described later.

B) Precipitation hardening treatment When the above-mentioned thin plate is heated at a temperature of 450 to 800 ° C. for 0.3 hours or more, an intermetallic compound is precipitated and the hardness is HR.
It becomes 48 or more in C Here, if the treatment temperature is lower than 450 ° C., it takes a long time to precipitate the intermetallic compound, which is not desirable in terms of productivity. On the other hand, if the temperature exceeds 800 ° C.,
Since the proportion of the alloy components that form a solid solution in the austenite matrix increases, the precipitation of intermetallic compounds cannot be satisfactorily performed, and it becomes impossible to obtain a hardness of 48 or more by HRC, so the temperature is set to 450 to Limited to 800 ° C.
If the above-mentioned thin plate is held at a temperature of 500 to 600 ° C. for 0.5 hours or more, a hardness of HRC of 56 or more can be obtained, which is more preferable. If the thin plate thus obtained is formed into the shape as the blade tip portion 21, N
It is possible to obtain the alloy having high corrosion resistance, high toughness and high strength, abrasion resistance, heat resistance, non-magnetism, and sharpness of the tip, which are peculiar to i alloy.

As described above, in this embodiment, the metal constituting the blade tip portion 21 of the doctor blade 17 can be improved in corrosion resistance and wear resistance, can maintain a sharp sharp edge, and can be removed from the blade tip portion 21. And abrasion are less likely to occur, so that it is possible to suppress the generation of streaks on the coated surface of the film 1. Further, the strength is high and the durability is also improved.
Further, since the blade tip portion 21 is non-magnetic, it is preferable that the coating liquid is a magnetic substance because it does not adversely affect the magnetic layer when the coating amount is regulated.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 is a front view of the doctor blade according to the second embodiment, FIG. 4 is a side view, and FIG. 5 is an enlarged side view of the blade tip portion in FIG. In the doctor blade 24 of this embodiment, the body 25 is the film 1
It is slightly wider than the above, and has a shape in which one corner of the side view rectangle is cut out by the slope 25a. This slope 25 of body 25
A rectangular notch 25b is formed over the entire width at the upper end of the surface facing a, and a substantially plate-shaped blade tip portion 26 of the same width is fitted in the notch 25b and fixed by screws or the like. The blade tip portion 26 is made of the above-mentioned Ni alloy. Further, the upper part thereof projects from the upper surface of the body 25 (see FIG. 4), and the upper end edge has, for example, an apex angle of 6
It is formed by a vertical surface forming an angle of 0 ° and an inclined surface 26a (see FIG. 5).

In addition, a stepped bolt hole 28 for fixing the doctor blade 24 to a machine body (not shown) is formed in the body 25 in a direction substantially orthogonal to the blade tip 26 direction from the slope 25a. An appropriate number (four in this embodiment) of bolt holes 28 are provided along the width direction of the body 25. Also in this embodiment, the same operation and effect as in the first embodiment can be obtained.

Next, a specific example of the method for manufacturing the Ni alloy blade tips 21 and 26 according to this embodiment will be described. First, using a high frequency induction furnace, Table 1 below
Prepare a molten alloy of Ni alloy having the composition shown in
An ingot having a diameter of 150 mm and a length of 400 mm is cast, and the ingot is subjected to hot forging at a starting temperature of 1200 ° C. to obtain a plate material having a thickness of 50 mm.
Hot rolled at a starting temperature of 200 ° C to a thickness of 20
mm hot-rolled material, and then this hot-rolled material was subjected to solution treatment under the condition of holding at 1150 ° C. for 2 hours.
By performing cold working at the rolling rate shown in Table 1 and subsequently performing precipitation hardening treatment under the conditions shown in Table 1,
The present invention product manufacturing methods 1 to 15 are performed, and the blade tip 2
1, 26 were manufactured.

Next, the tensile strength, hardness (HRC) and corrosion resistance of each of the blade tips 21 and 26 obtained as a result were measured, and the measurement results are shown in Table 1.
Further, in Table 1, for the purpose of comparison, as conventional products 1 and 2, doctor blades made of cemented carbide and stainless steel were also measured under the same conditions under the same conditions, and the obtained properties are also shown. The corrosion resistance is measured according to JIS G 0578.
The ferric chloride corrosion test method for stainless steel was used.

[0026]

[Table 1]

From the measurement results shown in Table 1, the product of the present invention 1
The blade tip portions of the doctor blades manufactured in any of 15 to 15 have higher strength than the doctor blades of the conventional products 1 and 2. Further, it can be understood that in the product of the present invention, no significant weight loss is observed and extremely high corrosion resistance can be obtained. On the other hand, in the conventional product, although the hardness of the cemented carbide is higher than that of the product of the present invention, the strength is low, and a considerable weight loss is observed in the corrosion resistance, and the corrosion resistance is significantly inferior. However, in the case of stainless steel, all the measurement results were significantly inferior to the products of the present invention.

Needless to say, the doctor blade according to the present invention is not limited to the ones shown in the above-mentioned embodiments, but may be applied to doctor blades having other shapes and other types. In addition, the doctor blade 17,
24, only the blade tips 21 and 26 are made of Ni as described above.
Although the alloy blade is made of an alloy, it goes without saying that the entire doctor blade may be made of this Ni alloy.

[0029]

As described above, in the doctor blade of the coating apparatus according to the present invention, at least the tip portion is Cr: 14.
-23%, Mo: 14-20%, W: 0.2-5%, F
e: 0.2 to 7%, Co: 0.2 to 2.5%, balance Ni
And since it is made of an alloy obtained by rolling and heat-treating a Ni alloy having a composition consisting of unavoidable impurities, it is possible to improve the corrosion resistance of the tip portion and also improve the strength and wear resistance of the tip portion. It is possible to suppress chipping and wear due to corrosion and the like. Therefore, it is possible to prevent the occurrence of streaks in the coating layer of the coating liquid on the support. Further, the sharp edge at the tip can be sharply held to form a uniform coating layer and improve the durability. Moreover, since it is non-magnetic, it does not adversely affect the magnetic layer even when the coating liquid is a magnetic substance.

[Brief description of drawings]

FIG. 1 is a front view of a doctor blade according to a first embodiment of the present invention.

2 is a side view of the doctor blade of FIG. 1. FIG.

FIG. 3 is a front view of a doctor blade according to a second embodiment of the present invention.

4 is a side view of the doctor blade of FIG.

FIG. 5 is an enlarged view of portion B in FIG.

FIG. 6 is a diagram showing a schematic configuration of a coating machine including a coating device.

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

FIG. 8 is an enlarged view of a main part of another coating device.

[Explanation of symbols]

 1 film 5,14 coating means 17,24 doctor blade 21,26 blade tip

Front page continuation (72) Inventor Yosuke Orikasa 1-297 Kitabukuro-cho, Omiya City, Saitama Prefecture Mitsubishi Materials Corporation Mechatronics & Manufacturing System Development Center (72) Inventor Masahiro Yokomizo 1-297 Kitabukuro-cho, Omiya City, Saitama Prefecture Mitsubishi Materials Corporation Mechatronics / Production System Development Center

Claims (3)

[Claims] 1. A surface of a flexible support that runs continuously,
In a coating device in which a coating liquid is coated by a coating unit and the coating amount of the coating liquid to be coated on the support is regulated by a doctor blade, the doctor blade has at least a tip portion of Cr:
14-23%, Mo: 14-20%, W: 0.2-5
%, Fe: 0.2 to 7%, Co: 0.2 to 2.5%, the balance being Ni and an unavoidable impurity. blade. 2. The doctor blade of a coating apparatus according to claim 1, wherein the doctor blade is arranged on the downstream side of the coating means and close to the coating layer on the support. 3. The doctor of the coating apparatus according to claim 1, wherein the doctor blade is arranged in the vicinity of a coating roll of a coating means for coating the coating liquid on the support. blade.