JPH091732A - Manufacture of laminated metal plate of vinylidene fluoride film - Google Patents

Abstract

PURPOSE: To obtain the adhesion strength of a film to a metal plate and to eliminate the vanishment of matting effect on the film surface in a method for manufacturing the metal plate laminated with a matted vinylidene fluoride film. CONSTITUTION: The method for manufacturing a laminated metal plate comprises the steps of coating the surface treated metal plate with thermosetting resin adhesive, baking and drying the adhesive to the plate at the plate temperature of 120 to 170 deg.C, pressing and sticking a matted vinylidene fluoride film having a mean roughness of the surface of 1.0μm or more to the plate by a laminating roll controlled at the surface temperature of the side in contact with the film to 90 to 130 deg.C, and forcedly cooling the plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated metal sheet suitable for use as a building exterior material, a soundproof wall material for highways, etc., and in particular, a laminate laminated with vinylidene fluoride film having excellent weather resistance and stain resistance. Regarding metal plates.

[0002]

2. Description of the Related Art As a conventional technique for manufacturing such a laminated metal plate, a thermosetting resin adhesive is applied to a metal plate and then the adhesive is heated at a plate temperature of about 200 ° C. to secure the adhesive strength. After drying, a vinylidene fluoride film was heat-bonded to the metal plate via the adhesive by a pair of upper and lower cooling type laminating rolls (literature unknown). As the adhesive, a thermosetting resin adhesive such as acrylic, epoxy, or polyester that has long-term durability is used, and in the case of this thermosetting resin adhesive, it adheres even if it is heated and dried at a low temperature. Since no activity is imparted, the adhesive is heated and dried at a plate temperature of about 200 ° C. In the laminating roll there, the surface temperature of the roll on the side in contact with the film was controlled to be cooled to 30 to 80 ° C. In this conventional method,
It is possible to obtain a laminated metal plate that can well prevent wrinkling during lamination and has excellent adhesive strength.

[0003]

However, since the metal plate is heated to a high temperature of 200 ° C. or higher in the heating / drying step immediately before lamination, the plate temperature is still higher than the melting point of the film when the vinylidene fluoride film is adhered. It has become. The melting point of the vinylidene fluoride film depends on the mixture, but it is usually around 170 ° C. Therefore, when laminating a vinylidene fluoride film that has been subjected to a matte treatment with an average roughness of the film surface of 1.0 μm or more, the surface roughness of the film is melted and smoothed by heat, and the original matte effect is exhibited. There was a problem where it would not be done.

Therefore, an object of the present invention is to improve the baking temperature of a thermosetting resin adhesive on a metal plate and the temperature of a laminating roll so that a vinylidene fluoride film having a matte treatment has a matte effect on a metal plate. The purpose is to obtain a laminated metal plate that is securely bonded while holding.

[0005]

The manufacturing method of the present invention comprises a step of applying a thermosetting resin adhesive to a surface-treated metal plate, and a thermosetting on the adhesive layer formed on the metal plate. A step of baking and drying the mold resin adhesive at a plate temperature of 120 to 170 ° C., and a metal plate with a matte vinylidene fluoride film having an average surface roughness of 1.0 μm or more on at least the side in contact with the film. Roll surface temperature is 90-1
A laminated metal plate is manufactured through a step of adhering a thermosetting resin adhesive with a laminating roll controlled at 30 ° C. and a step of forcibly cooling the metal plate. That is, in the present invention, the baking temperature of the thermosetting resin adhesive on the metal plate is lowered, while the temperature of the laminating roll is increased, as compared with the conventional type.

Specifically, as the metal plate, a galvanized steel plate, an aluminum-zinc alloy plated steel plate, various other plated steel plates, and a stainless plate can be used. This metal plate is subjected to a chemical conversion treatment with chromic acid or the like as a surface treatment, and a primer is formed if necessary. The primer is formed by coating and baking an epoxy resin-based or polyester resin-based paint to a thickness of 3 to 8 μm.

FIG. 1 shows a production line in which a coiled metal plate 1 is 20 to 40 per minute from the metal plate coil 1a.
At a line speed of m, a roll coater 2 is used to apply a thermosetting resin adhesive such as an epoxy resin type, an acrylic resin type, or a polyester resin type, and then the metal plate 1 is passed through a heating furnace 3 at a plate temperature of 120. The thermosetting resin adhesive is baked and dried by heating to ˜170 ° C. to form a film thickness of the adhesive after drying to 3 to 10 μm. Here, an epoxy resin type adhesive is most suitable as the thermosetting resin adhesive.

Next, the metal plate 1 discharged from the heating furnace 3 is passed through a laminating roll 4, a vinylidene fluoride film 5 is pressed against the metal plate 1, and the thermosetting resin adhesive applied in the previous step is used for bonding. To do. The plate temperature is lowered by 5 to 10 ° C. until it comes out of the heating furnace 3 and reaches the laminating roll 4. The laminating roll 4 includes a pair of rolls 4a and 4b arranged above and below the metal plate 1, and the upper roll 4a in contact with the film 5 is a rubber winding roll.
The lower roll 4b in contact with is a steel roll.
The roll rolling force by the laminating roll 4 is 12 to 12 in linear pressure.
Set to 18 kg / cm. Of the two rolls 4a and 4b, the roll 4a on the side in contact with the film 5 is an electric heat roll having a built-in induction coil and a temperature sensor, and its surface temperature is controlled to 90 to 130 ° C.
However, the lower roll 4b may be a similar heat roll.

The vinylidene fluoride film 5 has a roughened surface so as to exert a matting effect. That is, the average roughness of the film surface is 1.0 μm or more (the glossiness is 5% or less when measured by the 60 ° specular reflection method in Method 2 of JIS Z8741).

The film 5 may have only one layer of vinylidene fluoride resin, but it is desirable that the film 5 has a plurality of layers in order to improve the adhesiveness. That is, in the vinylidene fluoride film 5, the surface layer is made of polyvinylidene fluoride resin and the back layer is made of acrylic resin, for example.
Using a multi-layer film that is co-integrated, weather resistance on the surface layer,
Ensures stain resistance and chemical resistance, and improves adhesion to the metal plate with the back layer. According to such a co-extrusion film, the boundary portion between the front layer and the back layer is infiltrated and fused and integrated. In that case, if the total thickness of the film is less than 20 μm, it becomes difficult to obtain a uniform thickness in the production of the film, and the laminating work becomes difficult, and if it exceeds 100 μm, the cost becomes high. Therefore, the thickness of 20 to 100 μm is used.

Next, the metal plate 1 laminated with the vinylidene fluoride film 5 is immediately passed through a water-cooled forced cooling device 6 to be cooled. For example, in the forced cooling device 6, the water sprayed from the water cooling nozzle can be dropped onto the entire surface of the vinylidene fluoride film 5 of the laminated metal plate 1 to cool it. Laminated metal plate 1 exiting forced cooling device 6
After the attached water is dried with hot air by the dryer 7 in the device 6, it is coiled. In FIG. 1, 1b shows the product coil.

[0012]

In the heating furnace 3, the thermosetting resin adhesive is baked on the metal plate 1 at a plate temperature of 120 to 170 ° C.
This is because if the temperature is lower than 0 ° C., the curing is insufficient, the degree of cross-linking is small, the activation is insufficient, and the adhesive force cannot be secured.
On the other hand, when the temperature exceeds 170 ° C, the plate temperature during lamination becomes close to the melting point of vinylidene fluoride, which is the material of the film 5,
This is because the roughening treatment of the film surface disappears and the film becomes smooth (mirror surface).

In the laminated film 4, at least the roll 4a on the side in contact with the film 5 is a heat roll, so the film 5 immediately before being laminated on the metal plate 1 is preheated. The preheating temperature therefor, that is, the surface temperature of the roll 4a is 90 to 13
The reason why the temperature was set to 0 ° C. is that when the temperature is lower than 90 ° C., the adhesive surface side of the film 5 is not activated due to insufficient preheating and the baking temperature of the above adhesive is suppressed to 170 ° C. or lower. The adhesive force of the film 5 to the plate 1 cannot be secured. On the other hand, when the roll surface temperature exceeds 130 ° C., the adhesive strength can be obtained, but the roughening treatment of the surface of the film 5 disappears and the film 5 is smoothed, and wrinkle shrinkage easily occurs.

The forced cooling device 6 cools the laminated metal sheet 1 from the laminating roll 4 before coiling it. The film surface roughened during coiling is crushed and the vinylidene fluoride film is crushed. This is to prevent uneven glossiness from being caused by the pressure mark on 5.

[0015]

EXAMPLE A 0.45 mm thick galvanized steel sheet (metal sheet 1) is treated with chromic acid, and an epoxy resin coating is applied to the surface of the steel sheet to form a primer having a dry thickness of 5 μm. This coiled steel plate was fed at a line speed of 30 m / min, and a roll coater 2 was used to apply an epoxy adhesive as a thermosetting resin adhesive to a dry film thickness of 6 μm as shown in FIG. As described, the coil was wound through the heating furnace 3, the laminating roll 4, the forced cooling device 6, and the dryer 7 in that order. In the laminating roll 4, the vinylidene fluoride film 5 was laminated on the primer of the metal plate 1 via the adhesive. This vinylidene fluoride film 5 is a 40 μm thick co-extruded multilayer film in which the surface layer is polyvinylidene fluoride and the back layer is made of acrylic resin, and the back layer side is overlaid on a primer and the roll rolling force is 14 kg / cm (linear pressure). ).

At that time, the vinylidene fluoride film 5 was laminated on the metal plate 1 while changing the baking plate temperature in the heating furnace 3 and the roll surface temperature of the upper roll 4a of the laminating roll 4 as shown in Table 1. Then, the surface appearance and adhesive strength of the product were examined by the following test methods.

[0017]

[Table 1]

(Judgment method) As a method of judging the surface appearance, a 50 × 50 cm sample was cut out from the product, and the surface roughness at the place where the gloss was high was measured visually. This surface roughness is an average roughness. The ∘ marks indicate that the surface roughness of the vinylidene fluoride film at all measurement points was maintained at 0.9 μm or more and the glossiness was 5% or less. The cross indicates that the vinylidene fluoride film has a surface roughness of 0.5 μm or less and a gloss of 15
It indicates that there are multiple parts of% or more. The glossiness is a value measured by the 60-degree specular reflection method in Method 2 of JIS Z8741.

The method for measuring the adhesive force was based on the # type Erichsen test. That is, a # -shaped cut having a width of 5 mm was inserted with a knife, Erichsen was extruded by 7 mm, and the film was pulled from the cut portion of the mountain portion with tweezers to perform forced peeling. Here, the mark ◯ indicates that the film was broken up to the middle of the Erichsen part (within 3 mm), and the mark x indicates that the film was peeled off beyond the middle of the Erichsen part (3 mm or more).

The results of determining the surface appearance and the adhesive strength were as shown in Table 1 above. According to this, in Examples 1 to 4 of the present invention, the baking plate temperature in the heating furnace 3 was 120 to 1.
Roll surface temperature of laminating roll 4 to 70 ° C
Since the temperature was controlled to 0 to 130 ° C., good results were obtained in both surface appearance and adhesive strength.

On the other hand, in Comparative Example (Conventional Example) 1, the temperature of the baking plate in the heating furnace 3 was 220 ° C., which was too high.
Even when the roll surface temperature was set low, the surface roughness of the vinylidene fluoride film was melted during lamination, and the surface appearance was extremely poor. Further, in Comparative Example 2, since the roll surface temperature was as low as 80 ° C. with respect to the baking plate temperature of 170 ° C., the adhesive strength became insufficient. Further, in Comparative Example 3, the roll surface temperature is 140 ° C. with respect to the baking plate temperature of 170 ° C.
And the surface appearance was poor because it was too high. In Comparative Example 4, the baking plate temperature was too low at 110 ° C., so even if the roll surface temperature was set as high as 130 ° C., the surface appearance was good, but the adhesive strength could not be secured.

[0022]

According to the present invention, the baking plate temperature of the thermosetting resin adhesive to the metal plate is lower than that of the conventional one.
While setting to 0-170 degreeC, the roll surface temperature of the lamination roll was set to 90-130 degreeC higher than before. Therefore, the latter roll temperature can make up for the insufficient baking temperature of the former, and the adhesive force of the vinylidene fluoride film to the metal plate can be well secured. Moreover, since the plate temperature during lamination is kept lower than the melting point of the vinylidene fluoride film, the roughened surface of the film is not crushed and the surface appearance (matte) of the film can be well secured. .

[Brief description of the drawings]

FIG. 1 is a schematic front view of a production line for carrying out the method of the present invention.

[Explanation of symbols]

 1 Metal Plate 2 Roll Coater 3 Heating Furnace 4 Laminating Roll 5 Vinylidene Fluoride Film 6 Forced Cooling Device 7 Dryer

Claims (1)

[Claims] 1. A step of applying a thermosetting resin adhesive to a surface-treated metal plate, a step of baking the thermosetting resin adhesive on the metal plate at a plate temperature of 120 to 170 ° C. and drying, and a metal plate. On the adhesive layer formed on, the average surface roughness is
Step of adhering a matte vinylidene fluoride film set to 1.0 μm or more with a thermosetting resin adhesive with a laminating roll in which the surface temperature of the roll on the side in contact with the film is controlled to 90 to 130 ° C. And a step of forcibly cooling the metal plate, and a method for producing a laminated metal plate of a vinylidene fluoride film obtained by sequentially performing the steps.