JP3798906B2 - Method for producing multicolored painted metal sheet - Google Patents

Description

【００３２】
Ｎo.４は、従来法により得られた塗装鋼板であるが、境界部の盛り上がりが著しく、使用上の支障を招いた。
【００３３】
これに対して本発明法で得られた二色刷り塗装鋼板（Ｎo.１〜Ｎo.３）は、境界部分を含め全体の塗膜厚さが均一なものが得られた。更にロールのラップ代を本発明の好ましい範囲に制御すれば境界部の滲みも少なくなり、より好ましい範囲に制御したＮo.１では境界部での滲みも全くなく、表面外観に極めて優れるものであった。
【００３４】
【発明の効果】
本発明は上記の様に構成されているので、色の異なる二色が接触する境界部分の塗膜が肉厚となって盛り上がることもなく、全体の塗膜厚さが均一であり、該境界部分の色同士は滲むことなく鮮明にストライプ状に塗り分けられた表面美麗な多色刷り塗装金属板を効率よく提供することができた。
【図面の簡単な説明】
【図１】ラップ代の概念を説明する為のロール断面概略説明図。
【図２】本発明の二色刷り塗装金属板を製造する為の概略説明図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coated metal plate (pre-coated steel plate) frequently used in household electrical appliances and the like and a method for manufacturing the same. Specifically, the coated metal plate of the present invention can be obtained by painting with a roll coater, but the surface of the metal plate is divided into multicolor stripes, and two different colors contact each other. The coating film at the boundary portion is a multicolored coated metal plate having a uniform overall coating thickness without being raised.
[0002]
In addition, the metal plate of the present invention includes various types such as a cold rolled steel plate, a hot dip galvanized steel plate, an electrogalvanized steel plate, an alloyed hot dip galvanized steel plate, a stainless steel plate, a copper plated steel plate, and a tin plated steel plate in addition to an aluminum plate and a copper plate. Applied to steel plate. In the following description, a steel plate will be mainly described as a representative example, but it is not intended to be limited to this.
[0003]
[Prior art]
Conventionally, coated steel sheets obtained by applying spray coating, electrodeposition coating, powder coating, etc. to zinc-based plated steel sheets have been widely used for household electrical appliances. However, in recent years, pre-coated steel sheets for the purpose of omitting the painting process in home appliance manufacturers have been frequently used.
[0004]
In coating the steel sheet surface, a method using a roll coater in which several rolls are combined is employed. As the roll coater used, a three-roll coater is widely used in place of the conventional two-roll coater from the viewpoint that there are few coating defects. As a typical example, a pick-up roll for pumping up the paint, and the paint on a steel plate There is a so-called V-type three-roll coater comprising an applicator roll (also known as a coating roll) to be coated on and a doctor roll that scrapes paint on a pickup roll. For example, Japanese Patent Laid-Open No. 6-134372 discloses a method of manufacturing a double-side coated steel sheet having a beautiful surface appearance using such a three-roll coater. The first coating on the front surface and the second and subsequent surfaces on the back surface are disclosed. It is described that the coating defects such as roping, repellency, and dent can be greatly reduced by changing the coating of the conventional two-roll coater to the three-roll coater.
[0005]
Recently, with the diversification of needs on the user side, instead of painting the entire surface in a single color, it is desired to provide a multicolored coated steel sheet that is divided into two colors or three colors. However, the conventional roll coater coating method including the above method is applied once or twice to improve the corrosion resistance and appearance quality, and in general, the entire surface is coated in a single color. However, in order to obtain a steel sheet that is separately applied in two colors or three colors, a method such as partial printing is separately required, resulting in high costs. Accordingly, the present inventors diligently studied a method for efficiently obtaining a multicolor-coated steel sheet without printing or the like.
[0006]
[Problems to be solved by the invention]
However, according to the results of the study by the present inventors, when the coating is performed for the second time after the coating is dried as in the conventional case, the coating film at the boundary portion where the two different colors come into contact with each other; As a result, it was found that when the coil was wound up, a streak-like shape defect occurred at the boundary portion, and the aesthetic appearance was significantly impaired. In addition, if the coating film at the boundary portion rises, it will adversely affect the subsequent coating process by the roll coater.
[0007]
The present invention has been made paying attention to the above circumstances, and the purpose of the present invention is to achieve a total coating thickness without increasing the thickness of the boundary coating film even in a coated metal plate coated with a roll coater. A multi-colored metal plate with a beautiful surface and a multi-colored metal plate that has a uniform surface and is clearly divided into multi-colored stripes without blurring between the border colors, and such a multi-colored metal plate It is to provide a method of manufacturing well.
[0009]
The method for producing a coated metal sheet of the present invention that has solved the above problems is a method for producing a multicolored coated metal sheet by performing coating with a three-roll coater using a grooving roll as an applicator roll at least twice. Te, after first coating by grooving roll, and has a gist where the coating film surface are sequentially repeating the steps of performing a second coating by grooved rolls in less drying.
[0010]
Here, the lapping of the grooved roller for use in the grooved roll and the second paint used for the first coating is that control in the range of 0～1.0Mm. This makes it possible to more effectively suppress the rising of the coating thickness at the boundary , the coating thickness is uniform, and the surface is beautifully painted in a striped pattern with multiple colors. Can be obtained efficiently.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have produced a coated metal sheet by coating at least twice with a roll coater. By sequentially repeating the second coating (more preferably, by appropriately adjusting the lapping margin between the roll used for the first coating and the roll coater used for the second coating) As a result, it was found that a rise in the thickness of the coating film can be effectively suppressed, and a multi-colored coated metal sheet having a beautiful surface can be obtained, and the present invention has been completed.
[0012]
The multicolored coated metal plate obtained in this way has the metal plate surface coated in multicolor stripes, and the maximum coating thickness T ( mm) is the relational expression (1) below.
| T−t ₁ | ≦ 0.004
| T−t ₂ | ≦ 0.004
| T ₂ −t ₁ | ≦ 0.008
[Wherein t ₁ and t ₂ mean the average coating thickness (mm) of both side portions sandwiching the boundary portion]
Satisfy or
Relational expression (2) below
0.8t ₁ ≦ T ≦ 1.2t ₂
[Wherein t ₁ and t ₂ mean the average coating thickness (mm) of both side portions sandwiching the boundary portion]
We are satisfied. Thus, according to the manufacturing method of the present invention , the surface of the metal plate to be coated with the roll coater is divided into multicolor stripes, and the entire coating including the thickness of the boundary portion is applied. A coated metal plate having a uniform film thickness can be obtained .
[0013]
The relational expression (1) above shows that the difference between the maximum coating thickness (T) of the boundary portion and the average coating thickness (t ₁ , t ₂ ) of both side portions sandwiching the boundary portion, The difference between t ₁ and t ₂ is specified, and is one of the aspects in which “the entire coating film thickness including the film thickness at the boundary portion is uniform” is quantified.
[0014]
On the other hand, the relational expression (2) is another aspect in which “the entire coating film thickness including the film thickness at the boundary portion is uniform” is quantified by another expression, and T and t ₁ , it is to identify with the relationship of t ₂ in the ratio.
[0015]
If the manufacturing method of this invention is used, the coating-metal thickness which satisfy | fills either of the said (1) or (2) relational expression , ie, the coating-film thickness of the boundary part and the both-sides part which pinches | interposes this boundary part will be substantially the same. Thus, it is possible to obtain a coated metal plate with a clear and beautiful surface appearance without being mixed or smeared with the colors of the boundary portion. Next, a method for producing the painted metal plate will be described.
[0016]
The method of the present invention is a method for producing a coated metal plate by applying at least twice with a roll coater, and after the first coating, the second coating is performed before the coating surface is dried. Are sequentially repeated.
[0017]
That is, the method of the present invention is to obtain a multicolored coated metal sheet by repeating the coating, but after the first coating, the second coating is performed before the coating surface is dried. It is necessary to carry out this process, and a coated metal sheet with a beautiful surface can be obtained only by repeating this process sequentially. As in the conventional method, in the method in which the coated film after coating is dried and then the next coating is performed, the boundary portion where colors overlap is raised, and this cannot be performed well by the roll coater.
[0018]
Furthermore, for the purpose of obtaining a more beautiful appearance, it is recommended that the wrap cost of the roll used for the first coating and the roll used for the second coating be -0.5 to 1.0 mm. Here, the “lapping allowance” means the roll overlap allowance where the rolls overlap (see the roll cross-sectional schematic explanatory diagram of FIG. 1).
[0019]
By controlling the wrap allowance within the above range, the coating film at the boundary will not rise, and the two colors will not mix or bleed, so a multicolored metal sheet with a beautiful surface and a clear surface can be obtained. It is done. The range of the overlap allowance may be negative, and if it is −0.5 mm or more, a clear boundary region can be formed by the penetration of the paint. On the other hand, when the thickness exceeds 1.0 mm, the boundary portion is mixed or smeared, the surface appearance is remarkably deteriorated, and coating with a roll coater cannot be smoothly advanced. More preferably, it is 0 mm or more and 0.5 mm or less.
[0020]
In the present invention, it is recommended to use a roll having grooves in order to apply two or more colors on the surface of the metal plate. In FIG. 2, an example of the roll used in order to manufacture a two-color printing metal plate is shown. By using the two types of grooving roll A and grooving roll B shown in FIG. 5A, the color of the hatched portion 1 is given to the coated plate when the grooving roll A is used, and the grooving roll B is used. Sometimes the shaded area 2 is colored on the painted plate. In addition, the state of the coating metal plate when these rolls are removed is shown in FIG.
[0021]
The preferred groove depth in the present invention may vary depending on the use conditions. For example, since the groove is also deformed by the pressing pressure of the roll, if the pressing pressure is reduced (0.1 to 0.3 kg / mm is preferable in the present invention), the suitable groove depth also changes. It is recommended to control within the range of 2-4 mm. As for the lower limit of the groove depth, it is possible to paint with different colors as long as it is at least 0.5 mm or more, but at this level, the base metal plate is rubbed and the appearance of the painted surface is significantly reduced. This is not preferable. Therefore, in order to obtain a beautiful coating appearance, the depth of the groove is preferably at least 2 mm. On the other hand, when it exceeds 4 mm, there is a problem that the basic unit of the roll deteriorates.
[0022]
In addition, it is recommended that the roll coater to be used be a three roll coater. This is because with the two-roll coater, the paint is picked up in the groove and cannot be painted well.
[0023]
The material of the roll is not particularly limited as long as it can be used to produce a normal coated metal plate, but urethane rubber, fluorine rubber, nitrile rubber, chloroprene rubber, butyl rubber, ethylene propylene Use of rubber, silicon rubber, polyethylene rubber, acrylic rubber, polybutadiene rubber, polyisoprene rubber and the like is preferable.
[0024]
The paint resin used for the coating film in the present invention is not particularly limited, and solvent-diluted paints such as fluorine-based, epoxy-based, polyester-based, acrylic-based, melamine-based, urethane-based, and silicon-based; acrylic-styrene-based, epoxy -Water based emulsion type paints such as ester type, acrylic type, urethane type, polyvinyl acetate type, polyethylene type, ethylene vinyl acetate type and the like can be mentioned. These may be used alone or in combination of two or more.
[0025]
The viscosity of the paint is preferably 30 to 140 seconds with a Ford Cup No. 4. If the viscosity is too low, the appearance of the painted surface is deteriorated, resulting in an increase in the cost associated with an increase in the amount of solvent and an increase in the load on the drying furnace. On the other hand, when the viscosity is too high, the appearance of the coating such as rolls is deteriorated, and the appearance of the wrap portion is raised, and the appearance is remarkably impaired.
[0026]
In addition, this invention has the characteristics in the coating process by a roll coater, and the baking process after coating should just employ | adopt a normal method, and is not specifically limited.
[0027]
The present invention is described in detail below based on examples. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the preceding and following descriptions are included in the technical scope of the present invention.
[0028]
【Example】
Example: By the following method, the two-color coated steel sheet of the present invention and the conventional two-color coated steel sheet were produced, and both the surface appearances were observed with the naked eye, and the maximum coating thickness T (mm) at the boundary portion, The average film thicknesses t ₁ and t ₂ (mm) of both side portions sandwiching the boundary portion were measured.
[0029]
[Method of the present invention]
After the first coating by applying and drying with two rolls under normal conditions, the second coating is carried out by the three-roll method with a grooving roll, and three rolls with a grooving roll before the paint is dried. The coating was dried for the third time by the method. In addition, as shown in Table 1, the roll used for the second coating and the roll used for the third coating were variously changed.
[0030]
[Conventional method]
It was carried out in the same manner as the above-mentioned method of the present invention except that the second coating was carried out and the third coating was carried out after drying.
The surface appearance of the coated steel sheet thus obtained was observed with the naked eye, centering on the degree of blurring at the boundary where two different colors contact.
These results are listed in Table 1.
[0031]
[Table 1]

[0032]
No. 4 is a coated steel sheet obtained by a conventional method, but the rise of the boundary portion is remarkable, causing a problem in use.
[0033]
On the other hand, the two-color coated steel sheets (No. 1 to No. 3) obtained by the method of the present invention were obtained with a uniform overall coating thickness including the boundary portion. Further, if the roll wrap allowance is controlled within the preferred range of the present invention, the bleeding at the boundary portion is reduced, and No. 1 controlled to a more preferable range has no bleeding at the boundary portion, and the surface appearance is extremely excellent. It was.
[0034]
【The invention's effect】
Since the present invention is configured as described above, the coating film at the boundary portion where two different colors contact each other is not thickened and rises, and the entire coating film thickness is uniform. It was possible to efficiently provide a multicolored coated metal sheet with a beautiful surface in which the colors of the portions were clearly painted in stripes without bleeding.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional explanatory view of a roll for explaining the concept of a lapping margin.
FIG. 2 is a schematic explanatory diagram for producing a two-color coated metal plate of the present invention.

Claims (1)

A method of producing a multicolored coated metal sheet by performing coating with a three-roll coater using a grooving roll as an applicator roll at least twice,
The lapping cost of the grooving roll used for the first coating and the grooving roll used for the second coating is 0 to 1.0 mm,
After performing the first coating by grooving roll, a method of coating the surface to produce a multi-color coated metal plate, characterized in that successively repeating the step of performing a second coating by grooved rolls in less drying.

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