JPH04175158A - Laminated steel plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a laminated steel sheet laminated with a fluororesin film, which exhibits excellent weather resistance and is suitable for use as a building material, particularly as an outdoor building material.

(Conventional technology) Paint containing polyvinylidene fluoride (PVdF) as a main component is applied to a copper plate (usually There is a coated steel plate that is coated with a plated mesh plate. Such P
VdF coated steel sheets are sold on the market by various steel sheet manufacturers with a guarantee that red rust will not occur in the flat plate portion for 20 or 30 years.

However, painted steel plates are usually subjected to bending processing, etc. during construction, and the coating film may be damaged during this process.

Furthermore, even if a treatment such as caulking agent is applied, rusting from the end face cannot be completely prevented. Therefore, the corrosion resistance of the scratched portion and the end face corrosion resistance of the painted steel plate is insufficient.

On the other hand, in recent years, polyvinyl fluoride (PVF) or PV
A highly corrosion-resistant laminate mesh plate, which is a plated steel plate laminated with a fluororesin film containing dF as a main component, has been applied. Such laminated mackerel boards have better workability than painted steel boards and do not generate pinholes when baking the paint, so they are expected to be highly reliable in terms of corrosion resistance. In particular, for those using turnnote as the base material,
The technique is disclosed in Japanese Patent No. 1424.

However, although fluororesin films have excellent chemical durability, on the other hand, it is difficult to adhere them to base materials due to their chemical stability. As a method for improving this, for example, when the base material is an aluminum plate, a method is disclosed in which a fluororesin film is laminated after anodizing treatment (see Japanese Patent Publication No. 10304/1983).

Regarding adhesion between resins, it has been disclosed that saturated polyester-based or polyolefin-based hot melt adhesives exhibit excellent adhesion when laminating a fluororesin film to a vinyl chloride-based resin material (Tokuko Showa). 64-366
(See Publication No. 6).

(Problem to be solved by the invention) The above-mentioned prior art has the following problems.

■Special Publication No. 60-51423 and No. 60-514
In the method described in Publication No. 24, a turnnote, that is, a lead-tin plated steel plate is used as the base plated steel plate, but since the plated layer is stronger than the base iron, it does not have end face corrosion protection.

■When the lamination method described in Japanese Patent Publication No. 64-3666 is applied to laminated (laminated) liil plates, it is possible to
It is a combination of vinyl chloride resin adhesive/vinyl chloride resin film/hot melt adhesive/fluororesin film, and requires at least two coats and two laminations, making the production process complicated and the cost high. . Also,
If the amount of plasticizer in the vinyl chloride resin film is large, the adhesion will be poor (but if the amount of plasticizer is reduced, the processability will be significantly reduced, so the present invention is suitable for lamination of fluororesin films). By providing an adhesive with excellent initial and durable secondary adhesion, and by using this adhesive to laminate a bifluorocarbon resin film on a galvanized steel plate, we can improve weather resistance, corrosion resistance, and processability. Our aim is to provide superior laminated steel sheets.

Another object of the present invention is to provide a colored laminated steel sheet that is excellent in weather resistance, corrosion resistance, and workability, and can also meet requests for various or subtle color tones, with little change in brown color.

(Means for Solving the Problems) In order to achieve the above object, the inventors of the present invention have conducted various studies, and have found that: (1) using a turn-plated steel plate as a base material has poor end face corrosion resistance, and (2) adhesion of fluororesin film. As a means of resolving the known fact that fluorine film is difficult to adhere to, we found that using adhesives containing epoxy, acrylic, and fluorine resins can provide good adhesion between various base materials and fluorine films. However, the present invention has been completed.

That is, the present invention applies adhesives such as epoxy, acrylic, and fluorine resins to the surface of a zinc-plated steel sheet, aluminum-plated steel sheet, or stainless steel copper sheet that has been subjected to phosphate treatment and/or chromate treatment. The gist of the invention is a laminated steel sheet characterized by a fluororesin film laminated via a layer of adhesive contained as a component.

Furthermore, the present invention provides an epoxy-based,
Acrylic and fluorine resins are used as adhesive components,
The present invention also relates to a laminated mesh board characterized in that a fluororesin film containing no colored pigment is laminated via an adhesive layer containing a colored pigment.

In the laminated steel sheet of the present invention, the adhesive layer may be provided via a polyester-based or epoxy-based primer layer.

(effect) The structure and operation of the present invention will be explained.

As the base material of the laminated steel sheet of the present invention, a zinc-based plated copper plate, an aluminum-based plated copper plate, and a stainless steel plate are used in order to ensure end face corrosion resistance.

The zinc-based plated steel sheet may be either pure zinc plated or zinc alloy plated steel sheet, and includes electroplated steel sheet, hot-dip galvanized steel sheet, and alloyed hot-dip galvanized steel sheet. Furthermore, a multilayer plated steel sheet having a zinc or zinc alloy plating layer and another plating layer can also be used.

Aluminum-based plated steel sheets include pure aluminum plated and aluminum alloy plated steel sheets. An example of the aluminum alloy plated steel plate is a Zn-Q alloy plated steel plate containing 5% or 55% aluminum.

The base steel plate is subjected to one or both of phosphate treatment and chromate treatment as a base treatment in order to improve the adhesion of the resin film.

This treatment can be carried out in the same manner as before (the treatment conditions are not particularly limited. When treated with zinc phosphate, it is usually 0.
A coating weight of 5 to 2 g/m2 is preferred, and in the case of chromate treatment, a coating weight of 5 to 150 mg/m2 (as metal Cr) is preferred. If the amount is too small, it will be difficult to treat the entire surface, and corrosion resistance will also deteriorate. On the other hand, if it is too large, it may lead to a decrease in workability.

In addition to the surface treatment, a polyester or epoxy primer layer may be provided to further improve the adhesion of the film. The primer layer is provided by applying and baking a primer paint according to a conventional method, and the film thickness thereof may be within a conventional range.

First, adhesive is applied to a plated steel plate that has been subjected to a base treatment, or a base treatment and a primer treatment.

The adhesive used in the present invention contains epoxy, acrylic, and fluorine resins as adhesive components.

The epoxy resin is necessary to ensure adhesion to the underlying steel plate. In order to accelerate the curing of the epoxy resin, well-known epoxy crosslinking agents such as amines and isocyanates can also be added.

The type of epoxy resin is not particularly limited, but examples include bisphenol A type epoxy resins that are commonly used for adhesives.

The fluororesin is essential to ensure adhesion to the fluororesin film to be laminated.

Examples of the fluororesin that can be used include polyvinyl fluoride and polyvinylidene fluoride.

Furthermore, the compatibility between the epoxy resin component and the 7-carbon resin component in the adhesive is not good, and in order to uniformly mix the two, it is essential to add an acrylic resin. As the acrylic resin, one having excellent compatibility with the fluororesin is preferable, and examples thereof include methacrylic acid polymers, but acrylic acid polymers can also be used.

The blending ratio of each resin component in the adhesive cannot be specified because it varies depending on the resin type of the film to be laminated, but usually the weight ratio of acrylic resin / fluorine resin = 0
．． Desirably, the weight ratio of epoxy resin/(acrylic resin + fluororesin) is -0, about 2 to 0.4. If it deviates from this range, the effects of each resin shown above may not be sufficient. For example, if the amount of epoxy resin is small, the adhesion between the adhesive and the base treatment will be insufficient, and if the amount of fluororesin is small, the adhesion between the adhesive and the laminate film will be reduced.

Such a resin mixture is diluted with a suitable solvent to form an adhesive coating solution of a coatable viscosity. A preferred solvent is a mixture of an aromatic hydrocarbon solvent (nonner) such as toluene or xylene with a polar solvent such as a ketone solvent (eg, cyclohexanone or methyl isobutyl ketone) or a cellosolve type solvent.

The adhesive coating liquid can contain, in addition to the adhesive component, various additive components that are included in ordinary adhesive coating liquids. Examples of formulations of adhesive coating liquids useful in the present invention are shown below (units are % by weight).

Adhesive resin solid content (total) 30-60%, solvent 30%
~50%, anti-rust pigment a few percent, extender pigment 30% or less, antifoaming agent about 1%.

Antirust pigments can be added to adhesives to improve corrosion resistance. Examples of anticorrosive pigments include strontium chromate and zinc chromate.

Addition of an extender pigment is effective in improving the physical properties of the adhesive layer, particularly the processability, and an example thereof is calcium carbonate.

An example of an antifoam agent is a polymeric acrylic resin.

In the present invention, a colored laminated steel sheet can also be obtained by further containing a colored pigment in the adhesive coating liquid to form a colored adhesive layer.

In recent years, there has been a demand for a variety of colored laminated steel sheets, such as a demand for delicate hues that take into account the harmony of the exterior appearance of buildings. However, using a resin film made by kneading pigments into resin as a laminate film,
In the conventional method of obtaining a desired color tone, unless a certain amount of loft is available, the cost increases significantly, which is economically disadvantageous. Furthermore, depending on the type of pigment, even if there is no color change due to deterioration of the resin component, color change may occur due to ultraviolet deterioration of the pigment itself. In particular, in the case of dark blue or deep red, it is necessary to use organic pigments and the color change is large.

Since the adhesive is made by dissolving or dispersing a resin in a solvent, it is in a liquid state, and various kinds and amounts of pigments can be easily dispersed therein. Therefore, delicate color matching is easy, and even small lots can be prepared relatively easily, which is advantageous in terms of cost. Furthermore, since the outermost layer includes a fluororesin film with excellent weather resistance, deterioration of the colored pigment in the adhesive layer is suppressed, and a colored laminate film with little color change can be obtained.

Coloring pigments that can be used include ultramarine, iron oxide pigments, and the like.

The adhesive coating solution prepared as described above, which may or may not contain a colored pigment, is then applied onto the base plated plated steel plate using a suitable coating means. The coating thickness of this adhesive layer is 1 to 40 g/r in coating weight after drying.
It is preferably within the range of rr. If it is too thin, it will not be possible to ensure sufficient adhesive strength for the overlying fluorine-based resin film, and the corrosion resistance will also decrease. If it is too thick, not only will the cost increase, but also the workability of the laminated metal plate will decrease.

Thereafter, the applied adhesive film is baked at a temperature of 150°C or higher, preferably 200-230°C, to form a dry adhesive layer.

A fluororesin film is laminated on this adhesive layer. The laminate film may be a film made of any fluororesin as long as it can be formed into a film, and may be either a colored film containing a colored pigment or a transparent film containing no colored pigment. Usable fluororesins include polyvinylidene fluoride and polyvinyl fluoride (PvdF and PVF), copolymers of these fluorinated monomers with olefin monomers such as ethylene, and copolymers of these fluororesins with acrylic resins. Examples include mixtures. In the case of a mixture, one containing 80% or more of fluororesin is preferred from the viewpoint of weather resistance.

The thickness of the fluororesin film to be laminated is lO~
100/Jl11 is preferable. If it is too thin, the effect of blocking ultraviolet rays will be small, leading to deterioration of the adhesive component resin of the adhesive layer. If it is too thick, the blocking effect will increase, but it will also increase the cost and may also cause a decrease in workability. The film thickness is particularly preferably about 30-100p.

The thickness of the laminate film is to a certain extent, for example 30pm.
If the above is present, the effect of blocking ultraviolet rays reaching the adhesive layer is great, but in addition, by incorporating an ultraviolet absorber into the film resin to reduce the transmission of ultraviolet rays to the adhesive layer, the resin of the adhesive layer Alternatively, it is also possible to prevent the deterioration of pigments and create a film with better weather resistance.

Lamination is done by layering a fluororesin film on a steel plate on which a dried adhesive layer has been formed as described above, and then using an appropriate pressure/heating method such as a real press to adhere the film to the metal plate through the adhesive layer. This is done by Hot press conditions vary depending on the type of film and adhesive used, but are usually pressure 1 (1-50 kg/cm, temperature 170-220°C, line speed 5-20 m/mi).
It can be carried out with about n.

When the adhesive layer contains a colored pigment, in order to take advantage of this color, the laminated resin film is preferably a transparent film that does not contain any colored pigment. Such films are also advantageous in that they can be mass produced.

(Example) Examples of the present invention will now be described.

The materials and methods used for the following resins are as follows.

■As base material (a) Hot-dip galvanized steel plate (120g/rr
r coating amount), (b) aluminum-containing zinc plating (5
%AQ-95%Zn) M plate (90g/+n” adhesion amount)
, (C) Zinc-containing M plating (55%AQ-45%Zn)
A tlA plate (90g7m2 adhesion amount) and the same stainless steel mesh plate (SUS410L) were used. The thickness of each steel plate is 0.5 mm.

■For the base material (a), after applying zinc phosphate treatment at 1 g/m2, chromate rinse (5 + ng as Cr)
/m2). For base materials (b) to (d), coating type chromate treatment (100 mg7m2 as Cr)
I did it. When providing a primer layer, only zinc phosphate treatment was used.

(2) Primer layer When providing a primer layer, a commercially available epoxy primer paint was baked at a maximum temperature of 210°C for about 60 seconds to a dry film thickness of 3F.

In the primer, 5rCrO was mixed as a rust-preventing pigment so that the amount of 4C was 5%.

■Adhesive layer Apply the following adhesive to one side of the steel plate that has been subjected to base treatment or base treatment and primer treatment to a dry film thickness of 15/m.
It was coated using a bar coater so that the coating amount was 1. After application,
Baking was performed for 50 to 90 seconds at a maximum temperature of 230'C to dry the adhesive.

The adhesive was prepared by mixing the following adhesive components.

Epoxy resin (E): Ebicoat 1004 (made by Yuka Shell Epoxy ■) Acrylic resin (A): High Bay) HPS-000
(manufactured by Mitsubishi Rayon ■) Fluorine resin (F): Neoflon VDF 850 (manufactured by Daikin) When using the adhesive layer as a colored layer, the above components are 20 parts by weight, 30 parts by weight, and 50 parts by weight, respectively, in terms of solid content. 30 parts by weight of ultramarine (blue pigment) was kneaded and used as a pigment.

When an epoxy resin is blended, isocyanate 1, which is an isocyanate crosslinking agent, is used as an epoxy crosslinking agent.
1-550 (manufactured by Dainippon Ink Chemical Co., Ltd.) was added at a ratio of 20% (solid content weight ratio) of the epoxy resin component.

In addition, if the coating viscosity is too high, use cyclohexanone/Turupetz (registered trademark) 150 t7) 1:
It was diluted appropriately with 1 thinner.

■Lamination As a laminate film, (1) vinylidene fluoride film, (2) 80% by weight vinylidene fluoride and acrylic resin (Highvent I (PS-000) manufactured by Mitsubishi Rayon) 2
Clear film containing 0% by weight, (3) (2)
A colored film in which 20% by weight of ultramarine blue was added to the resin component was used. Layer this film on top of the dry coating film of the above adhesive, and
It was hot-pressed to the base steel plate by hot pressing under the condition of g/-.

■Evaluation method The primary and secondary adhesion, corrosion resistance, workability, and weather resistance of the obtained laminated steel sheets were evaluated using the following methods.

(a) After applying force to the laminate film side of the adhesion test piece to a depth that reaches the base material, a goblin (5 x 5 with 2 pitches) was applied, an Erichsen 7 mm was extruded, and a tape peel test was performed to determine whether the primary ( Initial) adhesion was evaluated.

After another test piece was immersed as a flat plate in boiling water for 2 hours, the same cross-cut, Erichsen, and tape peeling tests were conducted to evaluate secondary adhesion.

(b) Corrosion resistance The cross-canted test piece was subjected to a salt spray test of Mg as specified in JIS Z 2371. Corrosion resistance was evaluated by observing the end faces, cross force, blisters on the edges, and the degree of rust after the 480-hour test.

When the blistering width of the film was 0.5 mm or less and the amount of white rust generated was slightly less than a certain amount, the film was considered to have good corrosion resistance.

However, in Example 2, the degree of white rust or blistering on the end surface was observed after 1,000 hours.

(C) Weather resistance Based on JIS K 5500, weather resistance was evaluated by measuring color change after 3000 hours of exposure using a sunshine weather meter.

(d) Processability is 23mm with the laminated film on the outside.
The evaluation was based on the minimum number of sheets that would not cause cracks when bent at 180°C.

Example 1 An adhesive having a compounding ratio of adhesive components (all solid content weight ratios) as shown in Table 1 was applied to various base materials by the method (2) above.
Dry. The vinylidene fluoride film described in (1) above was used as the laminate film.

Table 1 shows the performance of the obtained laminated steel sheet.

(Margins below) Table 1 Primer: Epoxy Primer Example 2 A colored laminated steel plate was obtained using the colored adhesive in (2) above as the adhesive and the clear film (2) in (2) above as the laminate film. Table 2 shows the base material, surface treatment, primer treatment, type of adhesive, and test results for bending workability, corrosion resistance, and weather resistance of this steel plate.

For reference, the same table also shows the performance of a copper plate in which the above-mentioned colored adhesive was used for the adhesive layer and a pigmented colored film was used for the laminate film.

(The following is a blank space) As shown in Table 1, the base material steel sheet is It showed good adhesion between the film and the fluororesin film, and also showed good corrosion resistance on both the edge, cross force, and scratched areas. On the other hand, even if any of the force components of the resin components are lacking, as shown in the comparative example, the adhesion between the film and the base material is insufficient and the laminated steel sheet is not satisfactory.

In addition, from Table 2, the colored laminated copper plate obtained using the colored adhesive layer also shows no significant difference in physical properties, especially weather resistance, compared to the reference example, indicating that it has high performance. I understand that.

(Effects of the Invention) The laminated steel sheet of the present invention is manufactured by a simple process of 1 coat + 1 lamination, in which a specific adhesive is applied once after conventional surface treatment, and then a fluororesin film is laminated. Despite this, satisfactory film adhesion can be obtained, and the corrosion resistance of the end faces and scratched parts is also good.

As described above, according to the present invention, a laminate mesh plate laminated with a fluororesin film and having excellent weather resistance, corrosion resistance, and workability can be provided through a simple manufacturing process, and is very useful industrially.

In addition, when the above-mentioned laminated steel sheet requires coloring, the fluororesin film may be colored, but if the adhesive layer is used as a colored layer, it is possible to create a variety of subtle color tones while maintaining excellent physical properties. Moreover, it is also possible to efficiently produce small loads.

[Brief explanation of the drawing]

FIG. 1(A) is a cross-sectional view of the laminated steel sheet of the present invention without a primer layer, and FIG. 1(B) is a cross-sectional view of the laminated steel sheet of the present invention with a primer layer provided. 1 - Base material steel plate 2 - Base treatment layer 3 - Primer layer 4 - Adhesive layer 5 - Fluorine resin laminate film (△) (B)

Claims (3)

[Claims] (1) Epoxy, acrylic, and fluorine resins are contained as adhesive components on the surface of a zinc-plated steel sheet, aluminum-plated steel sheet, or stainless steel sheet that has been subjected to phosphate treatment and/or chromate treatment. A laminated steel sheet characterized by being laminated with a fluororesin film via an adhesive layer. (2) Epoxy, acrylic, and fluorine resins are used as adhesive components on the surface of a zinc-plated steel sheet, aluminum-plated steel sheet, or stainless steel sheet that has been subjected to phosphate treatment and/or chromate treatment, and A laminated steel sheet characterized in that a fluororesin film containing no color pigment is laminated with a layer of adhesive containing a color pigment interposed therebetween. (3) The laminated steel sheet according to claim 1 or 2, wherein the adhesive layer is provided through a polyester-based or epoxy-based primer layer.