JPH091731A - 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 100 to 170 deg.C, pressing and sticking matted vinylidene fluoride film having a mean roughness of the surface of 1.0μm or more to the plate by a laminating roll, reheating the plate to 100 to 160 deg.C to stick the film to the plate, and forcibly 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 producing such a laminated metal plate, a thermosetting resin adhesive is applied to a metal plate, and then the adhesive is heated and dried at a plate temperature of about 200 ° C. By cooling type laminating roll,
The vinylidene fluoride film was heat-bonded by pressing it against a metal plate under a bonding temperature (plate temperature) higher than its melting point (document unknown). As the above-mentioned adhesive, a thermosetting resin adhesive such as acrylic, epoxy, polyester, etc. having long-term durability is used. In the case of this thermosetting resin adhesive, even if it is heated and dried at a low temperature, it is bonded. Since no activity is imparted, the adhesive is heated and dried at a plate temperature of about 200 ° C. With this conventional method, it is possible to well prevent the generation of wrinkles during lamination and obtain a laminated metal plate having excellent adhesive strength.

[0003]

However, since the metal plate is heated to a high temperature of 200 ° C. or higher in the heating and drying step immediately before lamination, the bonding temperature (plate temperature) is still high even when the vinylidene fluoride film is bonded. It is higher than the melting point of the film. 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 disappeared.

Therefore, the present inventor replaced the thermosetting resin adhesive applied to the metal plate with heating at 200 ° C. or higher, instead of heating the metal plate in two steps before and after the step of laminating the vinylidene fluoride film on the metal plate. Upon heating at a low temperature of 170 ° C. or lower, it was found that the adhesive strength of the film to the metal plate can be secured in comparison with the conventional example, and the present invention has been completed. That is, an object of the present invention is to obtain a laminated metal sheet in which a matt vinylidene fluoride film is securely bonded to a metal sheet while maintaining the matte performance.

[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 resin adhesive applied to the metal plate at a plate temperature of 100 to 100. 1
A step of baking and drying at 70 ° C., and a step of pressing a matte vinylidene fluoride film having an average surface roughness of 1.0 μm or more with a laminating roll to adhere it onto the adhesive layer formed on the metal plate. , Plate temperature 100
It is to manufacture a laminated metal plate through a step of controlling the heating to ˜160 ° C. and adhering a vinylidene fluoride film to the metal plate, and a step of forcibly cooling the metal plate. At this time, it is desired that the first heating temperature and the second heating temperature are set high when one is low in order to secure the adhesive strength.

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 to have a thickness of 3 to 8 μm by applying an epoxy resin-based or polyester resin-based coating material and baking it.

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 the first heating furnace 3, where the plate The thermosetting resin adhesive is baked and dried by heating at a temperature of 100 to 170 ° C., and the film thickness of the dried adhesive is formed to 3 to 10 μm.

Next, the metal plate 1 discharged from the first 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. And glue. The plate temperature is lowered by 5 to 10 ° C. until it comes out of the first 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 upper roll 4a contacting the film 5 is a rubber winding roll, and the lower roll 4b contacting the metal plate 1 is a steel roll. Has become. The roll rolling force by the laminating roll 4 is a linear pressure of 14 to 18 kg /
Set to cm. Since both rolls 4a and 4b increase in temperature over time during the work, it is desirable to cool them to room temperature (30 ° C.).

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 multilayer structure in order to improve the adhesiveness. That is, as the vinylidene fluoride film 5, a co-integrated multi-layer film having a surface layer made of polyvinylidene fluoride resin and a back layer made of, for example, an acrylic resin is used, and the surface layer has weather resistance, stain resistance, and corrosion resistance. The chemical property is secured and the backing layer improves the adhesiveness with the metal plate. 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 passed through a second heating furnace 6, where the plate temperature 1
The temperature of the film 5 is controlled to be 00 to 160 ° C., so that the film 5 is completely adhered to the metal plate 1.

The laminated metal plate 1 exiting the second heating furnace 6 is immediately passed through a water-cooled forced cooling device 7 to be cooled. In the forced cooling device 7, water is sprayed on the laminated metal plate 1 to cool it. The laminated metal plate 1 that has exited the forced cooling device 7 is wound in a coil after the attached water is dried in a dryer 8 with hot air. In FIG. 1, 1b shows the product coil.

When the laminating roll 4 and the second heating furnace 6 cannot be connected to each other due to the facility, the metal plate 1 after laminating is forcibly cooled and once wound up, and thereafter, the metal plate 1 is placed on another line. 2 Heating furnace 6 Laminated metal plate 1
May be passed through, and forced cooling may be performed again to wind the coil.

[0013]

In the first heating furnace 3, the thermosetting resin adhesive is baked on the metal plate 1 at a plate temperature of 100 to 170 ° C.
This is because if the temperature is lower than 100 ° C, the curing is insufficient and the degree of cross-linking is small, and the adhesive strength is lowered.
It becomes close to the melting point of vinylidene fluoride, which is the substance of film 5, and the roughening treatment of the film surface disappears and it becomes smooth (mirror surface).
Because it begins to turn. In this case, it is desirable to set the upper limit of the heating temperature to 165 ° C. in consideration of safety. Since the upper limit of the heating temperature is kept low in this way, when the vinylidene fluoride film is laminated on the metal plate 1 by the laminating roll 4, it is still in a temporary adhesion state.

Under the same purpose, the metal plate 1 is placed in the second heating furnace 6.
Is controlled to a plate temperature of 100 to 160 ° C. However, the upper limit (160 ° C.) here is for safety in order to secure matte performance.
By this second heating step, the vinylidene fluoride film 5 is permanently bonded to the metal plate 1.

Laminated metal plate 1 discharged from the second heating furnace 6
Is cooled by the forced cooling device 7 before the coil is wound, so that the roughened film surface is crushed when the coil is wound and a pressure mark is attached to the vinylidene fluoride film 5 to cause uneven gloss. This is to prevent it.

[0016]

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 explained, the first heating furnace 3,
Laminating roll 4, second heating furnace 6, forced cooling device 7,
Each was passed through the dryer 8 in order and wound on a coil. In the laminating roll 4, the vinylidene fluoride film 5 was laminated on the primer of the metal plate 1. 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 the adhesive layer with a roll rolling force of 14 kg / cm ( Laminated by linear pressure).

At that time, as shown in Table 1, the first heating plate temperature in the first heating furnace 3 and the second heating plate temperature in the second heating furnace 6 were printed with a vinylidene fluoride film 5 on the metal plate 1. . Then, the surface appearance and the adhesive strength were checked.

[0018]

[Table 1]

(Judgment Method) As a method of judging the surface appearance, a sample of 50 × 50 cm was cut out from the product, and the surface roughness at the place where the gloss was high was visually observed. This surface roughness is an average roughness. The ○ marks indicate that the surface roughness of the vinylidene fluoride film is maintained at 0.9 μm or more and the glossiness is 5% or less at all the measurement points, and the X marks indicate that the surface average roughness of the vinylidene fluoride film is 0%. It is less than 0.5 μm and the glossiness is 1
It indicates that there are multiple portions of 5% or more. The glossiness is a value measured by the 60-degree specular reflection method in Method 2 of JIS Z8741.

The adhesive force was measured by 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 it 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 are shown in Table 1 above, and good results were obtained in each of Examples 1 to 4 of the present invention.

On the other hand, in Comparative Example 1 (Conventional Example), since the heating temperature in the first heating furnace 3 was 220 ° C., which was too high, the surface roughness of the vinylidene fluoride film was crushed during lamination, and the surface appearance was It became extremely bad. In Comparative Example 2, since the second heating plate temperature was 170 ° C., which was close to the melting point of the vinylidene fluoride film, it seems that the high temperature heating in the second heating furnace 6 promoted the disappearance of the surface roughness, There was a problem with the surface appearance. Further, in Comparative Example 3, the first heating plate temperature was 90 ° C., and in Comparative Example 4, the second heating plate temperature was 90 ° C., and one heating plate temperature was 10 ° C.
The surface appearance was good but the adhesive strength could not be secured, probably because the temperature was below 0 ° C.

[0023]

According to the present invention, the baking temperature of the thermosetting resin adhesive to the metal plate is lower than the conventional temperature of 100.
After the temperature is set to ~ 170 ° C, heating is controlled at 100 to 160 ° C after the vinylidene fluoride film is laminated, and the latter heating is used to compensate for the insufficient baking temperature of the former, and the thermosetting resin bonding is performed in two steps of heating. We are trying to activate the agent. Therefore, the adhesive strength of the vinylidene fluoride film to the metal plate can be secured well. 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. . Further, since the laminated metal plate after heating is forcibly cooled, it is possible to prevent the occurrence of uneven luster due to pressure marks on the vinylidene fluoride film even when the product is coiled.

[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 First Heating Furnace 4 Laminating Roll 5 Vinylidene Fluoride Film 6 Second Heating Furnace 7 Forced Cooling Device 8 Dryer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B32B 31/12 7148-4F B32B 31/12 31/20 7148-4F 31/20 // B29K 27: 12 B29L 9:00

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 100 to 170 ° C. and drying, and a metal plate. In addition, the average roughness of the surface on the formed adhesive layer is 1.
A step of pressing and adhering a matte vinylidene fluoride film set to 0 μm or more with a laminating roll; and a step of heating and controlling the metal plate to a plate temperature of 100 to 160 ° C. to adhere the vinylidene fluoride film to the metal plate, A method for producing a laminated metal sheet of vinylidene fluoride film, which is obtained by sequentially performing the step of forcibly cooling the metal sheet.