JPH05229055A - Manufacture of laminated metal plate - Google Patents

Abstract

PURPOSE:To prevent an organic resin film from becoming deteriorated and thereby enhance corrosion-inhibitive properties by sandwiching a polymer resin layer as an intermediate layer between metal plates and then coating the external surface of the metal plate with an organic substance. CONSTITUTION:A polymer resin 4 such as deformed polypropylene is sandwiched between metal plates 2, 3 of galvanized steel plate to form a product in one piece. Next, a film 5 of organic paint containing soluble chromate pigment such as zinc chromate, that is, an organic paint of epoxy resin, is formed on the external surface of the metal plates 2, 3. This organic paint film 5 is formed by heating a laminated plate 1a, then baking the organic paint containing zinc chromate and forming a chromate layer 5a on the surface of the metal plates 2, 3. Alternatively, the organic substance film 6 of the same type can be formed on the metal surface adjoining the polymer resin 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a laminated metal plate in which a polymer resin is sandwiched between two metal plates and bonded.
Particularly, it relates to improvement of corrosion resistance on the surface of a metal plate.

[0002]

2. Description of the Related Art A laminated metal plate is a thin metal plate such as a steel plate which is a skin material and is tightly integrated by sandwiching a polymer resin. It has a vibration damping function and is excellent in lightness and workability. ing. Therefore, it is often used in automobiles, home appliances, building materials, etc. for the purpose of noise prevention, vibration prevention, and weight reduction.

A steel sheet or the like, which is a skin material of the laminated metal sheet, is required to have corrosion resistance because its surface easily rusts. Therefore, for example, as disclosed in JP-A-63-158242, the surface of a steel sheet which is a skin material is subjected to an iron-zinc alloy plating treatment, or in order to enhance the effect of the plating treatment, Corrosion resistance is given by chemical conversion treatment. Further, in order to further improve the corrosion resistance of the laminated metal plate, a steel plate which has been surface-treated and further coated with an organic resin film is used as a skin material.

When manufacturing a laminated metal sheet using such a steel sheet, the steel sheet which has been surface-treated in advance and coated with an organic resin film is degreased and washed on a line, and then, for example, 18
A laminated metal plate having a polymer resin as an intermediate layer is formed by heating the steel plate to about 0 ° C., sandwiching the polymer resin between the heated steel plates, and pressing it down.

[0005]

As described above, in the past,
Since an organic resin film is formed on the surface of a steel plate that is a skin material, and then degreasing cleaning and thermocompression bonding are performed to manufacture a laminated metal plate, the organic resin film deteriorates due to degreasing cleaning and heating, and corrosion resistance decreases. There was a fear.

[0006] Further, there is also a disadvantage that the amount of the organic resin film which is softened by heating when it is pressure-bonded is reduced due to contact with the roll, so that a predetermined rust preventive effect cannot be obtained. there were.

The present invention has been made in order to solve the above drawbacks, and provides a method for producing a laminated metal plate which can prevent deterioration of an organic resin film and can improve corrosion resistance. The purpose is to do.

[0008]

The method for producing a laminated metal sheet according to the present invention is such that a polymer resin layer as an intermediate layer is sandwiched between metal sheets to be joined, and then the laminated surface is formed on at least one outer surface of the metal sheet. It is characterized by performing an organic coating treatment.

[0009]

According to the present invention, the polymer resin is sandwiched between the two metal plates and heat-pressed, and then the organic film is formed on the outer surface of the metal plate, and heat or pressure is applied to the organic film. Prevents and suppresses deterioration of organic coatings.

[0010]

1 and 2 are sectional views showing a laminated metal plate 1 according to an embodiment of the present invention. As shown in the figure, the laminated metal plate 1 includes thin metal plates 2 and 3, a polymer resin 4 that is sandwiched between the metal plates 2 and 3 and integrated, and the outer surfaces of the metal plates 2 and 3. The organic coating film 5 is formed on both or one of them.

As the metal plates 2 and 3, cold rolled steel plates, alloyed hot-dip galvanized steel plates, zinc-nickel alloy electroplated steel plates, iron-zinc alloy electroplated steel plates, and other aluminum plates, aluminum alloy plates, magnesium alloy plates, etc. are used. ing. In particular, a zinc-nickel alloy electroplated steel sheet is excellent in bare corrosion resistance, and by forming the organic coating 5, the corrosion resistance is further improved, which is preferable.

The polymer resin 4 is a thermoplastic resin such as polyolefin or polyamide represented by modified polypropylene or modified polypropylene, or a thermosetting resin such as an epoxy resin or an acrylic resin from the viewpoints of heat-sealing property and moldability. Is used. If conductive particles such as nickel powder are mixed into the polymer resin 4 as needed to ensure conductivity, spot welding or the like can be made possible. Further, as shown in FIG. 2, metal plates 2 and 3 each having a polymer resin 4 side coated with an organic coating 6 are used on the joint surfaces of the polymer resin 4 and the metal plates 2 and 3, respectively. The polymer resin 4 and the polymer resin 4 may be closely attached and integrated.

The organic coating 5 and the organic coating 6 are composed of a coating of an organic coating material containing a chromate-based soluble pigment such as zinc chromate and strontium chromate, and a resin coating. The resin that constitutes the resin coating may be any of solvent-based resin, water-soluble resin, and water-dispersed resin. For example, epoxy resin, acrylic resin, polyester resin, amino resin, polyurethane resin , Fluorine resin, silicon resin, phenol resin and their copolymers are used.

The manufacturing process of the laminated metal plate 1 configured as described above includes a pressure-bonding process in which the polymer resin 4 is pressure-bonded between the metal plates 2 and 3 to form the laminated plate 1a, and an organic coating film is applied to the laminated plate 1a. 5 comprises a coating step. In the pressure-bonding step for forming the laminated plate 1a, plating or chemical conversion treatment is performed in advance, or the metal plates 2 and 3 having the joint surface with the polymer resin 4 coated with the organic coating 6 are heated while degreasing and cleaning on the line, The polymer resin 4 is sandwiched between the heated metal plates 2 and 3 and pressed down to tightly integrate the metal plates 2 and 3 and the polymer resin 4 to form the laminated plate 1a. Immediately thereafter, the step of coating the organic coating 5 is started.

In the step of coating the organic coating 5, an organic coating material containing zinc chrome or the like is baked while heating the laminated plate 1a at a constant temperature, and the chrome layer is formed on the surfaces of the metal plates 2 and 3 as shown in FIG. 5a is formed. After that, Krome
An organic resin is baked on the surface of the insulating layer 5a to form the organic resin layer 5b. When baking the organic coating 5, a heating method according to the type of the polymer resin 4 is adopted. For example, in the case of using the polymer resin 4 which is made conductive by mixing conductive particles such as nickel powder, the polymer resin 4 which is heated by electromagnetic induction heating or warm air heating and is not made conductive is used. In some cases, it is heated with warm air. If electromagnetic induction heating is used when a polymer resin 4 that does not impart conductivity is used, a spark is generated between the upper and lower metal plates 2 and 3, and pinholes are generated in the polymer resin 4 in the intermediate layer. This is because the polymer resin 4 may be deteriorated. The thickness of the organic coating 5 can be adjusted to an arbitrary value by adjusting the heating temperature and the immersion time in the organic resin.

Since the organic film 5 thus formed is not subjected to extra heat or pressure after the film is completed, it does not cause deterioration of the organic film 5 or decrease in the amount of adhesion, and has desired characteristics. The laminated metal plate 1 can be manufactured.

Next, a specific example of the above embodiment will be described. As a specific example 1, the upper and lower metal plates 2 and 3 are coated with zinc-nickel alloy with a basis weight of 20 g / m ^{2 on} the surface of a steel plate made of ultra-low carbon steel and having a thickness of 0.5 mm and the polymer resin 4 respectively. Using a zinc-nickel alloy-plated steel sheet prepared as above, a polymer resin 4 made of a thermoplastic resin such as polyethylene mixed with conductive particles such as nickel powder is sandwiched and pressure-bonded to form a laminated plate 1a. The surface of the upper metal plate 2 was coated with the organic coating 5 to form the laminated metal plate 1.

As a second specific example, the upper and lower metal plates 2 and 3 are also made of extremely low carbon steel and the surface and the polymer resin 4
A 0.4 mm thick zinc-nickel alloy-plated steel sheet with a basis weight of 20 g / m ² is used for the joint surface with and the organic material is used for the joint surface with the polymer resin 4 on the metal plates 2 and 3. After coating the coating film 6, a polymer resin 4 made of a thermosetting resin such as acrylic resin mixed with conductive particles such as nickel powder is pressure-bonded to form a laminated plate 1a, and then the upper and lower metal plates 2 are formed. , 3 were coated with an organic coating 5 to form a laminated metal plate 1.

In both the first and second specific examples, the organic coating 5 is coated with the laminated plate 1a running at a line speed of 70 m / min, and in the first coating step, the surface temperature on the exit side of the laminated plate 1a is 11%.
The chrome layer 5a is coated while controlling the heating temperature so as to be 0 ° C. In the subsequent second coating step, an epoxy compounded with silica while controlling the heating temperature so that the surface temperature on the outlet side is 113 ° C. An organic resin layer 5b made of resin was coated. The organic coating 5 formed under these conditions had a chromate deposition amount of 55 mg / m ² and a resin deposition amount of 1.1 g / m ² .

As a comparative example, the same steel plates as in Example 1 were used as the upper and lower metal plates 2 and 3, and the organic film 5 was coated on the outer surfaces of the metal plates 2 and 3, and then the polymer resin 4 of the intermediate layer was used.
Was sandwiched and pressure-bonded to form a laminated metal plate 1. In this case, the organic coating 5 is coated with the chromium layer 5a by heating at the surface temperature 110 ° C. on the outlet side while running the metal plates 2 and 3 at a line speed of 39 m / min. 112 ° C
Organic resin layer 5 made of epoxy resin containing silica
coated b. The organic coating 5 formed under these conditions has a chromate deposit of 46 mg / m ² and a resin deposit of 1.14 g / m ² .
^{Was 2} .

In the step of pressure-bonding the polymer resin 4, the metal plates 2 and 3 are run at a line speed of 5 m / min while being degreased and washed at an alkali concentration of 19.5 g / liter and a temperature of 50 ° C., and subsequently at a temperature of 183 ° C. Polymer resin 4 made of a thermoplastic resin such as polyethylene was pressure-bonded between the metal plates 2 and 3 while being heated. In this crimping process, chrome after degreasing and cleaning
As a result of examining the adhesion amount of the coating layer 5a, it was reduced to 28 mg / m ² . Further, as a result of examining the amount of the organic resin layer 5b attached after the pressure-bonding step, the amount of the resin attached was reduced to 0.88 g / m ² .

As a result, the organic coating 5 coated on the surface of the laminated metal plate 1 is a comparative diagram showing the amount of adhesion of the chromate layer in FIG. 4 and a comparative diagram showing the amount of adhesion of the organic resin layer in FIG. As shown in FIG. 2, in the case of the comparative example, both the adhesion amounts B of the chromate layer 5a and the organic resin layer 5b are removed in the pressure-bonding step. The adhesion amount A of the organic resin layer 5b both has a predetermined adhesion amount.

[0023]

As described above, according to the present invention, after a polymer resin is sandwiched between two metal plates and heat-pressed,
Since the organic film is coated on the outer surface of the metal plate, it is possible to prevent heat and pressure from being applied to the organic film, and it is possible to prevent the organic film from being deteriorated or dropped.

Further, it is possible to always manufacture a laminated metal plate coated with an organic coating having a predetermined adhesion amount, and it is possible to greatly improve the corrosion resistance of the laminated metal plate.

[Brief description of drawings]

FIG. 1 is a sectional view showing a laminated metal plate according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing another example of a laminated metal plate.

FIG. 3 is a cross-sectional view showing the structure of an organic coating.

FIG. 4 is a comparative diagram showing the amount of adhesion of the chromate layer.

FIG. 5 is a comparative diagram showing an adhesion amount of an organic resin layer.

[Explanation of reference numerals] 1 laminated metal plate 2 metal plate 3 metal plate 4 polymer resin 5 organic coating 5a chrome layer 5b organic resin layer

Claims (1)

[Claims] 1. A method for producing a laminated metal plate, which comprises sandwiching a polymer resin layer as an intermediate layer between metal plates to bond them, and then subjecting at least one outer surface of the metal plates to an organic coating treatment. ..