JPS6141311B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention involves coating and forming an adhesive layer on an electrolytic lead-plated steel plate, then coating and forming a sol paint containing a reinforcing material on the adhesive layer, and then laminating a film with good weather resistance on the surface. The purpose of the reinforced laminated steel sheet is to provide a method for manufacturing a reinforced laminated steel sheet that can produce a laminated steel sheet that is hard to get scratches and has good corrosion resistance and weather resistance through a simple process. As one of the main methods for imparting corrosion resistance to steel materials, surface-coated steel materials have been widely used, and metal-plated and painted steel materials are particularly representative. However, recently, steel materials have been used for various purposes and are increasingly being used under harsh conditions, so conventional single plating, such as zinc plating, may not always provide satisfactory results. Since this was not possible, a technology was developed to improve the appearance and corrosion resistance by painting and coloring the galvanized layer after galvanizing, and it has been put into practical use as decorative steel sheets and colored galvanized iron. It is well known that However, the problem with these conventional galvanized/painted surface coatings is that zinc itself becomes a sacrificial anode due to corrosive factors such as moisture and oxygen passing through the coating, and it corrodes easily. The products also tend to increase, and corrosion under the paint film tends to progress quickly. On the other hand, the plated steel plate that has been electrolytically plated is
It is a typical cathodic type galvanized steel sheet and differs from galvanized steel sheet in this respect because the lead layer is electrochemically more noble than the base iron. For this reason, lead has better corrosion and chemical resistance than zinc, and even if the paint film deteriorates or defects occur, the highly corrosion-resistant lead will protect the base metal for many years. Even if the lead disappears, corrosion will remain in this area and will not promote peeling of the surrounding coating. The reason why painted steel sheets based on electrolytic lead-galvanized steel sheets with excellent corrosion resistance have not been commercialized until now is that the adhesion with the paint film and corrosion resistance could not be improved as in the case of galvanized steel sheets. It was not put to practical use because there was no suitable pretreatment such as zinc phosphate treatment or chromic acid treatment, and no suitable primer. That is, the present invention provides coating adhesion equal to or higher than that of galvanized steel sheets by subjecting electroplated steel sheets to a specific pretreatment, and then forms an adhesive layer containing rust-preventing pigments on top of the adhesion of the electroplated steel sheets. A method for manufacturing a reinforced laminated steel sheet that has excellent corrosion resistance and weather resistance and is resistant to scratches on the base material by laminating a synthetic resin film with good weather resistance and heat resistance on one or both sides of the agent layer via a sol paint containing reinforcing material. It is. The present invention will be explained in detail below. First, the electrolytic lead-plated steel sheet that is the object of the present invention can be easily plated to a predetermined thickness using conventional electrolytic lead plating methods such as a boufating bath, a silicate bath, a sulfamic acid bath, and an alkaline bath. However, in the present invention, the plating thickness needs to be 0.1μ or more. If the thickness is less than this, there will be no corrosion resistance under the corrosion-resistant coating, and the function of the electrolytic leaded layer/organic coating system will deteriorate.
Regarding the upper limit of the plating thickness, there is no problem even if it is quite thick, but since it is an electroplating method, the standard is 10μ, and making it thicker than this will require a long time for plating, which will be disadvantageous in terms of the process. . Of course, even if the plating thickness is greater than this, there will be no problem in terms of corrosion resistance and workability. Also, the electrolytic lead plating layer itself contains tin, copper,
It is also possible to use nickel, cobalt, antimony, etc. as the eutectoid plating layer or to use various metal oxides as the dispersion type eutectoid plating layer, and as long as the electrolytic lead plating layer is used as the base material, it works effectively. In addition, the steel sheet referred to in the present invention is a cold-rolled steel sheet or pickled hot-rolled steel sheet of copper-containing steel such as ordinary low carbon steel or weathering steel, low alloy steel such as sulfuric acid-resistant steel, or seawater-resistant steel. Both items are eligible. Next, as a pretreatment, an alkaline aqueous solution with a pH of 9 or higher is preferable, but mere immersion cleaning is insufficient and activation of the plated layer surface by alkaline electrolytic cleaning or a strong brushing polishing effect is required. For example, a method of activating the surface of a lead-plated layer by brushing cleaning with a 3% aqueous solution of sodium orthosilicate (PH 13.5) at 90°C, followed by electrolytic cleaning with the same solution, followed by hot water cleaning with brushing. It has been found that by employing this method, adhesion of the primer and paint film can be obtained that is equal to or better than that obtained when zinc phosphate treatment is applied to a galvanized steel sheet as a base. In addition, in the case of electroplating as in the present invention, other than alkaline electrolytic cleaning, there is also a method in which the oxide film on the surface of the plating layer is scraped off using a brushing roll containing an abrasive material or a buff roll containing an abrasive material to expose an active surface. . In addition, electrolytic lead-plated steel sheets usually have defects in the plating film such as pinholes, so anti-corrosion pigments are used to protect the film defects with a primer coating layer.
For example, zinc chromate, strontium chromate,
Apply a primer containing anti-rust pigment such as calcium molybdate (e.g. one-component epoxy system, acrylic epoxy system, two-component acrylic/phenol modified vinyl system, etc.) to a thickness of 1 to 15μ and heat at 175 to 240℃. The adhesive layer is formed by baking at a baking temperature of . A synthetic resin film with good weather resistance and heat resistance is laminated on one or both sides of this adhesive layer via a reinforcing material-containing sol paint. Here, Fig. 1 shows an example in which a film such as an acrylic film is directly laminated on a sol paint containing a reinforcing material, and Fig. 2 shows an example in which a film such as an acrylic film is laminated directly on a sol paint containing a reinforcing material. This is an example in which films such as polyvinyl resin are laminated. In addition, when laminating a sol paint containing a reinforcing material and a film on only one side, a similar or different type of film may be laminated on the other side as shown in Figure 1, or a film of a different type may be laminated on the other side as shown in Figure 2. A sol paint may also be applied. Here, any suitable sol paint containing reinforcing material can be used, but
For example, a polyvinyl chloride sol paint containing about 0.3 to 30% of inorganic fibers such as glass wool or rock wool with a wire diameter of 1 to 100 μ and a length of 5 to 1000 μ as a reinforcing material has a thickness of 50 to 400 μ, preferably 130 to 200 μ.
It is preferable to apply it at 180 to 220°C and bake it. The film may be an acrylic film with a thickness of 25 to 200μ, preferably 50 to 75μ.
Use a material with good weather resistance, such as a 25-100μ vinyl fluoride resin film. The lamination molding temperature for this film is 175 to 240 if the film is acrylic.
℃, or 190 to 240℃ in the case of vinyl fluoride film. When a fluorinated vinyl film is used here, it is preferable to use an adhesive as it has low thermal adhesiveness. When a vinyl chloride resin sol is applied as a sol paint to one side, it may be applied to a thickness of 50 to 350 microns, and when a color top coat is applied, it may be baked to a thickness of 7 to 25 microns at 180 to 240°C. In addition, in the above, baking was performed sequentially for each layer, but
It may be done all at once after the final layer is formed. Further, the coating may be applied by roll (pressure) spraying or the like as appropriate. In the present invention, after the adhesive layer is applied and formed on the electrolytic leaded steel plate as described above, the sol paint containing reinforcing material is applied and formed on the adhesive layer.
The layer of sol paint containing reinforcing material is firmly adhered by the adhesive layer, and this layer of sol paint containing reinforcing material forms a hard layer with high hardness, making it possible to apply a scratch-resistant makeup. Since a weather-resistant film is laminated on top of the reinforcing material-containing sol paint layer, it is possible to obtain a highly durable decorative surface with little property deterioration even when used outdoors for a long period of time.
Furthermore, since the reinforcing material is mixed into the sol paint beforehand, the reinforcing layer can be easily removed by a simple painting process, without the need for complicated processes such as pasting reinforcing mats or spraying with a roving cutter. There are benefits that can be provided. The present invention will be specifically described below based on examples. Example 1 After cleaning a steel plate with a thickness of 0.35 mm, electrolytic lead plating was applied to both sides under the conditions shown below.
A reinforced laminated steel plate having a coating structure as shown in FIG. 1 was manufactured.

[Table] First, 3% sodium orthosilicate solution (PH13.5) heated to 90℃ was applied to the surface of the electrolytic leaded steel plate 3, which consists of the steel plate 1 and the electrolytic leaded layer 2, with a nylon brushing roll. After spray cleaning while brushing, electrolytic cleaning with a solution of the same concentration, and then hot water cleaning, an activation layer 4 is formed on both surfaces of the lead-plated layer 2, and strontium,
Apply a two-component acrylic/phenol modified vinyl adhesive containing chromate anti-corrosion pigment to a thickness of 10μ.
Primer layer 5 was obtained by baking at 220° C. for 1.5 minutes. Next, a polyvinyl chloride sol paint containing glass wool with a wire diameter of 20μ and a length of 100μ is applied to one side of the adhesive layer 5 to a thickness of 150μ, baked at 200℃ for 1.5 minutes, and glass wool reinforcement is added. A vinyl chloride coating layer 6 was formed. Here, the vinyl chloride sol paint used was a white one whose main components were 100 parts of PVC (=1700), 50 parts of DOP, 3 parts of dibasic lead phosphite, and 15 parts of titanium white. Next, an acrylic film having a thickness of 60 μm was placed on top of the glass wool-containing vinyl chloride coating layer 6 and laminated by heating and pressing at 200° C. for 1.5 minutes to form an acrylic film layer 8. On the other hand, on other surfaces where acrylic film is not laminated,
Use the same adhesive as above as the primer layer 5'.
After coating to a thickness of μ and baking under the same conditions, the same vinyl chloride sol paint as above was applied to a thickness of 150 μ and baked at 200° C. for 1.5 minutes to form a back coating layer 7. Comparing the performance of the reinforced laminated steel sheet manufactured in this manner with that of a vinyl chloride-coated steel sheet with a conventional galvanized steel sheet as a base, the results are shown in the attached table. These results show that reinforced laminated steel sheets based on electrolytic lead-plated steel sheets plated to a thickness of 0.1 to 10μ have excellent corrosion resistance and weather resistance, and do not cause flaws or cracks even when bent. It was hot.

[Table] Example 2 Example 1 on both sides of weather-resistant copper-containing steel with a thickness of 0.5 mm
Electrolytic lead plating with a thickness of 5 μm was applied to each plate under the same conditions as above to produce a reinforced laminated steel plate having a coating structure as shown in FIG. First, both sides of an electro-leaded steel plate 3 consisting of a weather-resistant copper-containing steel plate 1 and an electro-leaded layer 2 are polished with hot water and washed with a Scotch brite roll containing an abrasive to make both surfaces of the lead-plated layer 2 active. Form layer 4, and apply 5 μm of acrylic adhesive containing calcium and molybdate rust-preventing pigments to one side, which will become the surface.
The adhesive layer 5 was formed by applying the adhesive layer 5 to a thickness of 200° C. and baking it at 220° C. for 1.5 minutes. Next, on this adhesive layer, the same glass wool-containing vinyl chloride sol paint as in Example 1 was applied to the adhesive layer 5 to a thickness of 100μ, and baked at 200°C for 1.5 minutes to form a glass wool reinforcement-containing coating layer 6. ’, apply 5 μm of acrylic epoxy adhesive to the surface of the coating layer containing glass wool reinforcement.
Apply the adhesive layer with a thickness of
A vinyl fluoride resin film with a thickness of 38 μm was layered on the surface of the vinyl fluoride resin film 8′, and a vinyl fluoride resin film layer 8′ was formed by heating and pressing at 210°C for 1.5 minutes. On other surfaces that will not be laminated, apply the same adhesive as above to a thickness of 5μ as a primer layer 5', bake under the same conditions, and then apply vinyl chloride sol paint to a thickness of 150μ without glass wool reinforcement. 1.5 at 200℃ after coating
A back coating layer 7 was obtained by baking for a minute. The performance of the reinforced laminated steel sheet manufactured in this way is as shown in Example 1.
It achieved the same performance as the previous one, was resistant to scratches, and had excellent corrosion resistance and weather resistance.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing embodiments of the reinforced laminated steel sheet of the present invention. DESCRIPTION OF SYMBOLS 1... Steel plate, 2... Electroplated layer, 3... Electrolytic lead plated steel plate, 4... Activation layer, 5, 5', 5''... Primer layer, 6, 6'... Glass wool reinforced vinyl chloride coating layer, 7... Back coating layer, 8, 8'... Film layer.

Claims (1)

[Scope of Claims] 1. The surface of the lead-plated layer of an electro-leaded steel plate obtained by plating lead on a thin steel plate to a thickness of 0.1 to 10 μm by electroplating method is subjected to brushing polishing or alkaline electrolytic cleaning. After applying and forming an adhesive layer containing anti-corrosion pigments on the surface, a sol paint containing reinforcing material is applied and formed on the adhesive layer, and then a weather-resistant film is laminated on the surface. A method for manufacturing a reinforced laminated steel sheet, characterized by forming it. 2. The method for manufacturing a reinforced laminated steel sheet according to claim 1, wherein the laminate film is an acrylic film. 3. The method for manufacturing a reinforced laminated steel sheet according to claim 1, wherein the laminate film is a vinyl fluoride resin film.