JPH08252502A - Coated sheet formed with coating films in stripe form and coating method and coating device for the coated sheet - Google Patents

Abstract

PURPOSE: To efficiently and simultaneously coat a sheet material with plural coating films varying in characteristics, colors, etc., in a transverse direction by forming the plural coating films in a stripe form in the transverse direction. CONSTITUTION: The sheet material is selectively coated with the coating films in the direction where the material is passed, by which the coating films 16a to 16aa are formed. The boundary lines of the coating films 16a to 16aa may be in parallel with the pass plate direction or may be curvilinear. At least one layer among the respective coating films 16a to 16aa are subjected to striped coating if the coating films 16a to 16aa are laminated in plural layers. A slide coater 5 is used to form these striped coating films. Namely, the coating materials in coating material tanks 12a to 12d are supplied to nozzles 9a to 9d and coating liquid films are formed as double-layered coating material layers on slide slopes 10. The coating material layers fall freely onto lip parts 18 at the bottom end and forms a coating material curtain liquid film 16. This coating material curtain liquid film 16 is applied on the front surface of a steel strip carried into the coating device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a coating film on both sides of a plate material, such as a steel plate, an aluminum plate, a stainless plate, used for electrical products, building materials, automobile parts, etc.
Metal plate such as copper plate, plastic plate, wood plate, cutting plate,
Or it is used for a continuous coating line for strips.

[0002]

2. Description of the Related Art Metal plates, such as steel plates, aluminum plates, and copper plates, used for electric products, building materials, automobile parts, ornaments, etc. have hitherto been rust-proof, electrically insulating, or aesthetically pleasing. For the purpose of imparting, an organic film is formed on its surface by plating film or coating, but in recent years, with the expansion of applications of the metal plate, the properties required for this metal plate are diverse, and However, there is a growing demand for superior design characteristics (appearance characteristics). Similarly, for resin plates and the like, there are many demands for designability. In order to meet such a demand, various organic films are often formed on the surfaces of these metal plates and resin plates.

Further, the coated plate is often required to have various functions, and a coating film is often formed to impart the function.

Conventionally, when forming an organic film on the surface of a metal plate, generally, a post-coating method in which the metal plate is coated after molding or a pre-coating method in which the metal plate is coated before molding is employed. A roll coater system that combines multiple rolls is often used. As a general roll coater system, there is a three roll coater system as shown in FIG. This roll coater method is excellent in film thickness controllability, and thin film coating is possible, but appearance defects called roping are likely to occur, and since the coating roll and the plate material are in contact, there is roll wear due to the plate material, It also has a drawback that roll scratches due to abrasion are transferred to the coating film and become defective unless the plate material having a wide width is passed.

In addition to this roll coater system, a curtain flow system is known in which coating is performed in a non-contact manner on a metal plate. As shown in FIG. 8, this curtain flow system has the advantage that a coated plate having excellent appearance can be obtained because it can be coated without contact with the plate material.
It is reported in Japanese Patent No. 80877. However, it is necessary for the paint curtain to fall stably without being cut, and it is difficult to form a curtain having a wet film thickness of 30 μm or less, and it is difficult to apply a thin film.

[0006]

Conventionally, by using a coater such as the roll coater system or the curtain flow system described above, after coating the metal plate with the coating material, a hot air baking furnace is used to exert the function of the coating film. The coating film is dried and cured by an induction heating furnace, irradiation with energy rays such as electron beams and near infrared rays, or a combination thereof. Usually, when two or more coating films are formed, after coating the first coating film, drying and curing the coating film,
It is necessary to repeat the coating, coating and drying / curing treatments such as coating the next coating film, curing and drying, a plurality of times, resulting in reduced productivity and increased production cost.

When the surface of the board is to be given a function by painting, if the surface can be efficiently painted and divided to have a different function depending on the place, one material can be used more efficiently. For example, a general coated steel sheet cannot be welded due to the poor conductivity of the coating, but if it is known in advance which part of the plate will be welded, a weldable coating will be formed on that part. It is possible to take measures such as not forming a coating film on that portion. Alternatively, even if adhesive bonding is considered, if it is known in advance which part of the coated plate material will be bonded, for example, an adhesive is applied in advance to the part to be bonded, and It is conceivable that the part will be colored in a string. Also, from the viewpoint of imparting designability, there is a demand for a technique of separately coating the surface of a plate material with different coating films.

In the prior art, there is no efficient coating method that can meet such needs. The present invention provides a coating plate and a coating method in which a plurality of coating films having different characteristics, colors, etc. are formed simultaneously in the width direction efficiently and at low cost.

[0009]

A coated plate having a plurality of coating films formed in a stripe shape in the width direction as set forth in claim 1, and in the thickness direction of the coating film as set forth in claim 2. The above problem can be solved by a coated plate having a plurality of coating layers, in which at least one of the coating layers has different coatings in the width direction formed in stripes.

According to a third aspect of the present invention, the slide surface of the slide hopper is provided with a plurality of slits which are opened at front and rear intervals and extend in the width direction of the slide surface, and means for supplying paint to the slits. Multiple paint films are stacked to form a multi-layer paint film, the multi-layer paint film is allowed to freely fall from the tip of the slide surface to form a paint curtain, and the paint curtain is dropped toward the running plate material to produce a plate material. In the method of coating a plate material that forms a multi-layer paint film on the surface of
5. A method of coating a coating plate, characterized in that at least one slit is provided with a partition wall that divides the slit into a plurality of parts in the width direction, and means for supplying paint to each partition wall is provided. The partition wall for dividing the slit into a plurality of parts in the width direction can be moved in the width direction, and the above-mentioned problem can be solved by the method for coating a coating plate according to claim 3.

Further, the slide surface of the slide hopper according to claim 5 is provided with a plurality of slits which are opened at front and rear intervals at intervals and extend in the width direction of the slide surface, and means for supplying paint to the slits. A plurality of paint films are stacked on top of each other to form a multi-layer paint film, and the multi-layer paint film is allowed to freely fall from the tip of the slide surface to form a paint curtain, and the paint curtain is dropped on the surface of a running plate material. In a method of coating a plate material in which a multi-layer paint film is formed on the surface of a plate material, at least one slit is provided with a partition wall that divides the slit into a plurality of parts in the width direction, and paint is supplied between the partition walls. A coating device is also provided, characterized in that it comprises means. Further, as described in claim 6, the partition wall dividing the slit into a plurality of parts in the width direction is also movable in the width direction.

[0012]

In the coated plate of the present invention, in which a plurality of coating films are formed in stripes in the width direction of the plate material, as shown in FIG. 5, the coating films are applied separately in parallel to the direction of passage of the plate material. It is what has been. In this figure, the boundary line of each coating layer is represented by a straight line parallel to the direction in which the plate material is passed, but this boundary line may be a curved line. Coating films 16ba, 16ca, 1
6aa may be a different type of coating, for example, 1
6ba and 16aa may be the same coating film, and the combination thereof is free. The number of coating films in the width direction is also arbitrary. Figure 5
Although a view of the plate material viewed from the cross-sectional direction is shown in (a), when a plurality of coating films are laminated, at least one of the coating film layers is coated in a stripe shape.

When a striped coating film is formed on the outermost coating film, the function of the surface coating film can be differentiated so that each coating film layer can have a different function. For example, when using a coated plate material, when it is known that the end portions in the width direction of the plate material are joined by adhesion, as shown in JP-A-6-316028, Regarding the required width, by applying a coating film that develops adhesiveness by heating and separately coating the coating from the central portion, subsequent steps can be omitted. If the plate material is divided into three parts and an adhesive is required at the end of each of the three divided parts, the first layer, the third layer, the fourth layer, the sixth layer from the end of the plate material in the width direction, The 7th and 9th layers are used as the adhesive layer, and the other required coatings, such as the required color coating, are applied to the 2nd, 5th and 8th layers between them.
An adhesive layer will be present at the end of each divided plate. As another example, when two-color coated plate materials are required and the coated plate material is divided into two and used, one half in the width direction is used for one color and the other half is used for another. By applying different colors, it becomes possible to manufacture efficiently.

When designability is required, various designs are possible by forming not only the surface layer but also the inner layer coating film in a stripe shape.

When forming a plurality of layers of coating film in the width direction,
An unpainted part may be formed between them. That is, FIG. 5 (b)
And either 16ba, 16ca, 16aa or 2
It is the case that the layers are unpainted.

The thickness of the coating film may be determined as necessary and is not particularly limited. The same applies to the number of coating layers in the thickness direction.

In the present invention, a slide coater is used to form a striped coating film. A slide coater is provided with a plurality of slits that open in the front and back of the slide surface of the slide hopper at intervals and that extends in the width direction of the slide surface, and a means for supplying paint to the slits. A multi-layer paint film is layered on top of each other, and the multi-layer paint film is allowed to fall freely from the tip of the slide surface to form a paint curtain, and the paint curtain is dropped on the surface of a running plate material to form a multi-layer paint film A method of coating a plate material for forming a paint film is disclosed in, for example, Japanese Patent Publication No.
This is disclosed in Japanese Patent Laid-Open No. In the slide coater, the slit extending in the width direction of the slide surface usually has one continuous opening, but in the present invention, a plurality of coating liquids are supplied in the width direction to at least one of the plurality of slits. As possible, a partition wall that divides the slit into a plurality of parts in the width direction is provided, and a means for supplying the paint is provided between the partition walls. Further, it is possible not to supply the coating liquid between a certain partition wall and an adjacent partition wall.

If the partition wall is movable in the width direction of the slit, the boundary line between a plurality of striped coating films in the width direction of the plate material can be curved by moving the partition wall during coating. In an extreme example, the coating is initially started so that three coating layers are formed in the width direction, and then the partition wall is moved to narrow the width of one coating layer, and finally, in the width direction. It is also possible to control so that only two coating layers are formed. Conversely, it is also possible to increase the number of coating layers in the width direction.

The thickness of the coating liquid film can be adjusted by adjusting the amount of coating material delivered by a pump, the slit spacing, the coating material viscosity, and the speed of the loading plate material.

Examples of the plate material include steel plates (cold rolled steel plate, plated steel plate), stainless steel plate, aluminum plate, titanium plate, metal plate such as copper plate, plastic plate, wood plate, paper plate and the like.

The formed coating layer (coating liquid layer) is sent to the drying / curing step. Drying and curing may be performed by a known method. For example, a hot air oven, an induction heating oven, an energy ray curing oven, or a combination thereof may be used. It may be dried and cured at room temperature. Of these, the induction heating furnace, when drying and curing the multilayer coating film laminated in the thickness direction,
Volatile components such as solvents and reaction products are smoothly volatilized, and defects such as armpits are unlikely to occur, which is particularly excellent.

If necessary, a pretreatment for coating may be performed. For example, degreasing, washing with water, zinc phosphate treatment, chromate treatment, composite oxide film treatment and the like.

[0023]

Embodiments of the present invention will be described below together with an embodying apparatus.

FIG. 1 shows an outline of a continuous coating line for steel strips to which the present invention is applied. The steel strip 1 is introduced into the coater chamber 4 from the pay-off reel 2 through the degreasing, cleaning treatment, and pre-coating treatment step 3, and here, the slide coater 5 used in the present invention is used to apply a plurality of coating liquid films to the surface. After being applied, it is introduced into a baking furnace 6, dried and hardened therein, cooled by a cooling device 7, and then wound on a tension reel 8 to be a product as a coiled coated steel strip 1a.

In the present invention, as a coating apparatus, at least one slit is provided with a partition wall for dividing the slit into a plurality of widths so that a plurality of coating liquids can be supplied in the width direction. It is characterized in that the slide coater 5 provided with a means for supplying paint to is used. This slide coater is, for example, Japanese Patent Publication Sho-49-
It is based on the multilayer slide hopper type curtain flow type coating apparatus proposed for coating a photosensitive material such as a photographic film disclosed in Japanese Patent No. 24133.

As shown in FIGS. 2 and 3, the slide coater in this embodiment has a slide inclined surface 10 on which four rows of slit nozzles 9a, 9b, 9c, 9d are provided. Are arranged. Nozzle 9
b and 9d are three nozzles 9b1, 9b2, 9b3 and 9d1, 9d2, 9d3 respectively in the width direction by the partition wall.
Is divided into Paint liquid supply parts 11a, 11b1, 11b2, 11 for supplying respective paint liquids to the respective nozzles.
b3, 11c, 11d1, 11d2, 11d3 are connected, and the respective coating liquid supply sections are provided with supply pipes 13a, 13
b1, 13b2, 13b3, 13c, 13d1, 13d
2, 13d3 and pumps Pa, Pb1, Pb2, Pb
3, Pc, Pd1, Pd2, Pd3 through the coating liquid tank 12a, 12b1, 12b2, 12b3, 12c, 1
It is connected to 2d1, 12d2, and 12d3. In the figure,
14 is a curtain guide that guides the liquid film on the slide slope 10, 10 is a surplus liquid storage pan that stores the excess coating liquid, 16 is a curtain-like liquid film from the lower end lip 18 of the slide slope 10, 17 Is a transport roller. Since the drawing is complicated, the nozzles 9b and 9d, the coating liquid supply units 11b and 11d, the supply pipes 13b and 13d, the pump Pb,
The Pd and the paint tanks 12b and 12d are originally composed of three, but are described as one. 91 of FIG. 3,
Partition plates 92, 93, and 94 are used to change the type of paint to be discharged by the partition plates. The partition plate is movable so as to be movable left and right in this figure. By moving this partition plate left and right during painting, the boundaries between paints can be made curved.

The number of nozzles, the number and spacing of partition walls of each nozzle, the number of paint tanks, etc. may be freely selected according to the number of coating films to be laminated and the number of coating films in the width direction.

Here, the steel strip 1 is horizontally carried into the coating device portion, but it may be carried in at an angle from the horizontal. The loading direction of the steel sheet may be opposite to that shown in FIG. 2, as shown in FIG.

In the continuous coating line for steel strips shown in FIG. 1, the slide coater 5 shown in FIG. 2 is arranged above the strip passage at the latter stage of the coating pretreatment process by degreasing, water washing and chromate treatment. Four layers of coating liquid film were simultaneously formed in the thickness direction on the upper surface of the strip 1. An electrogalvanized steel plate was used as the steel plate. The width of the slide surface was set to 1600 mm, and the height from the tip of the slide surface to the steel plate surface was set to 250 mm. A coating liquid film was formed on the steel sheet such that the first layer of the polyester-based high-processing primer coating “P185” (manufactured by Nippon Paint Co., Ltd.) was a dry film thickness of 5 μm from the side closer to the steel sheet. A coating film was formed as shown in Table 1 from the second layer to the fourth layer. The width of the steel sheet used, the width of each coating layer when the coating is applied in the width direction, and the dry film thickness of the coating film are also described in the table. All paints are made by Nippon Paint. In the case of separately coating the width direction, it is divided into three, the coating layer at one end in the width direction is 1, the coating layer at the center is 2, and the coating layer at the opposite end is Three
As described in the table.

On the back side, a service coat (“Olga 100” manufactured by Nippon Paint Co., Ltd.) was coated with a normal roll coater so that the dry film thickness was 7 μm.

The steel sheet coated with these paints was baked in an induction heating furnace under the conditions that the maximum plate temperature was 230 ° C. and the time required to reach it was 60 seconds, and then it was cooled to form a four-layer coating film in the thickness direction. A coated steel sheet having a layer and a service coat layer on the back surface was obtained.

Table 1 shows the use and usage of each coating film. The adhesion of the coating film is 1 mm square for each part with each coating layer that is applied separately in the width direction.
After putting in 00 pieces with a cutter knife and extruding by 7 mm with an Erichsen tester and peeling with a cellophane tape, it was judged as “good” when the coating film did not adhere to the cellophane tape. In order to improve the designability, Example No. 1 divides the second layer coating film into three in the width direction and respectively coats different colors, and the fourth layer also has the same coating width as the second layer. It was also color coded. Both ends were bent into a U-shape so that the color boundaries would be folds, and used as the outer case of the audio device. The top plate was black + clear layer yellow, and the side plate was gray + clear layer blue, and the design was excellent. No. 4 had the same constitution and was coated while moving the partition walls of the slits of the second layer and the fourth layer in exactly the same manner, and the boundary between the coating films in the width direction was made into a curve. The partition wall was moved so as to draw a sine curve with a steel plate length of 500 mm as one cycle with an amplitude of 50 mm left and right from the initial position. It was used as a partition surface material and had excellent design. No2 is both ends 5 of the steel plate
An adhesive layer was applied to 0 mm and a clear coating was applied to the central portion to provide an adhesive layer for adhesive bonding at the end portion, and to improve gloss and sharpness of the central portion. After press working for a reflector for a fluorescent lamp, it was heated to adhesively bond the adhesive coated portion to the back surface coating film of this steel sheet. Production efficiency is improved compared to the caulking joining method,
In addition, the glossiness and sharpness of the reflector plate were improved. No3 is
It is a coated steel sheet consisting of two layers of a primer coating film and a solid color coating film on the top, which are found in ordinary pre-coated steel sheets, but the top coating film is divided into three colors with the same width.
This coil having a width of 1200 mm was slit into a coil having a width of 400 mm and used as the outer plate of the toaster. Although the lots ordered by customers were small and production efficiency was low in the past, it was possible to paint three colors at a time, improving production efficiency and reducing costs. All of the steel sheets had no problem with the adhesion of the coating film and had a good appearance. The steel sheet manufactured for each application has excellent functionality or design. In addition, it is a highly efficient and low cost coating method that allows a coated plate having a complicated coating film structure to be manufactured by a single coating and drying / curing process.

[0033]

As described above, according to the present invention, the functionality,
This is a technique that enables efficient and low-cost production of a coated plate having a coating layer with excellent design.

[0034]

[Table 1]

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of an example of a continuous coating line for steel strips to which the present invention has been applied.

FIG. 2 is a partial cross-sectional side view showing an embodiment of the present invention.

3A and 3B are enlarged explanatory views of a main part of the slide coater in FIG. 2, where FIG. 3A is a partial sectional side view and FIG. 3B is a plan explanatory view in FIG.

FIG. 4 is a partial cross-sectional side view showing another embodiment (example of carrying-in direction) of the present invention.

FIG. 5 is an explanatory view showing an example of a coated steel strip having a coating film with a striped pattern obtained in the present invention, (a) is a cross-sectional explanatory view,
(B) is a plane explanatory view.

FIG. 6 is an explanatory plan view showing a main part of another embodiment of the present invention.

FIG. 7 is a partial cross-sectional side view showing an example of a conventional coater.

FIG. 8 is a partial cross-sectional explanatory view showing another conventional coater example.

[Explanation of symbols]

1 Steel strip 2 Payoff reel 3 Pretreatment process 4 Coater chamber 5 Slide coater 6 Baking furnace 7 Cooling device 8 Tension reel 9a, 9b, 9ba, 9bb, 9c, 9d Slit nozzle 10 Sliding inclined surface 11a, 11b, 11c, 11d liquid supply part 12a, 12b, 12c, 12d liquid tank 13a, 13b, 13c, 13d supply pipe 14 curtain guide 15 paint pan 16 curtain-shaped paint liquid film 16a primer liquid film 16b, 16c stripe paint liquid film 16d protective liquid film 17 Conveyor roller 18 Lip 19 Paint supply pan 20 Paint 21 Pickup roll 22 Doctor roll 23 Applicator roll 24 Backup roll 25 Paint film 26 Paint hopper 27 Flow control valve 28 Large diameter coating roll 29 Small diameter coating roll 30 Coating film

Claims (6)

[Claims] 1. A coated plate having a plurality of coating films formed in a stripe shape in the width direction. 2. A coating plate having a plurality of coating layers in the thickness direction of the coating layer, characterized in that at least one of the coating layers has different coatings formed in stripes in the width direction. Board. 3. A slide hopper is provided with a plurality of slits which are opened in the front and rear of the slide surface at intervals and extend in the width direction of the slide surface, and a means for supplying paint to the slits is provided. The paint film is laminated to form a multi-layer paint film, and the multi-layer paint film is allowed to freely fall from the tip of the slide surface to form a paint curtain, and the paint curtain is dropped on the surface of the running plate material to cause the surface of the plate material. In the method for coating a plate material for forming a multi-layer paint film, at least one slit is provided with a partition wall that divides the slit into a plurality of parts in the width direction, and the paint is supplied between the partition walls. How to paint a painted plate. 4. The coating method for a coating plate according to claim 3, wherein the partition wall dividing the slit into a plurality of pieces in the width direction is movable in the width direction. 5. A plurality of slits, which are opened at front and rear intervals on the slide surface of the slide hopper, and extend in the width direction of the slide surface, and means for supplying paint of the slits,
Multiple paint films are laminated on the slide surface to form a multi-layer paint film, and the multi-layer paint film is allowed to fall freely from the tip of the slide surface to form a paint curtain, and the paint curtain is formed on the surface of the running plate material. In a plate material coating apparatus that drops a multi-layer paint film on the surface of a plate material, at least one slit is provided with a partition wall that divides the slit into a plurality of parts in the width direction, and paint is applied between the partition walls. A coating device comprising means for supplying. 6. The coating apparatus according to claim 5, wherein the partition wall dividing the slit into a plurality of pieces in the width direction is movable in the width direction.