JPS6021546B2 - Highly weather resistant composite coated metal plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly weather resistant composite coated metal plate suitable as an outdoor building material, and its purpose is to improve the weather resistance, corrosion resistance, adhesion over time, etc. of an organic resin coated metal plate. It is an object of the present invention to provide a composite coated metal plate which has excellent outdoor durability and has excellent processing adhesion even in applications where it is processed after coating.

Conventionally, there are colored galvanized iron plates, PVC laminated steel plates, and acrylic film laminated steel plates as organic resin-coated metal plates for outdoor building materials, but none of them are necessarily satisfactory in terms of economy and durability. In other words, if a colored galvanized steel sheet made by applying an organic paint to a hot-dip galvanized steel sheet is used as a roof for a general residential building in an industrial area or an area near the coast, the painted surface will develop abnormalities within 3 to 6 years. This may cause peeling or blistering of the paint film, and corrosion of the underlying galvanized layer may progress, making it necessary to repaint. In addition, a hard, semi-hard, or hostile PVC film is laminated on a metal slope such as a hot-dip galvanized steel sheet, an electrogalvanized steel sheet, or a thin steel sheet, or a PVC film is coated with a PVC film using a plastisol coating method. It is already well known that metal plates exhibit much better corrosion resistance than the colored galvanized steel plates mentioned above in relatively corrosive environments such as industrial areas and coastal areas.
If you are exposed to strong ultraviolet rays and heat from sunlight for a long time,
PVC resin deteriorates and gradually loses its properties as a protective coating. Therefore, it has not always been satisfactory for roof applications in low-latitude regions exposed to strong sunlight. In addition, acrylic film-laminated steel sheets, which are made by laminating an acrylic resin film with a thickness of 50 to 100 mm on metal plates such as hot-dip galvanized steel sheets, electrogalvanized steel sheets, and thin steel sheets, are durable against ultraviolet rays and heat from sunlight. However, it is known to have excellent corrosion resistance in industrial areas and coastal areas, especially in processed areas and scratches that occur when used as an outdoor building material, resulting in peeling of the film and blistering. This may cause corrosion of the underlying galvanized layer.

Therefore, it has not always been satisfactory for roof applications in industrial areas or coastal areas. The present invention eliminates these drawbacks, improves the outdoor customer resistance of the coating layer, particularly the stability against ultraviolet rays and heat, and the protective effect on the base metal plate, and provides a resin-coated metal plate with excellent moldability. As a result of various studies, we have decided to use flaky aluminum powder, zinc, tin, or lead metal powder, or an alloy containing one or more of these metals, as the main component of the coating along with PVC resin on the base metal slope. By coating a composite material layer containing the powder as an inner layer and a coating layer such as an acrylic resin as an outer layer, a coating-coated metal plate that satisfies all of the above objects is completed.

Hereinafter, the content of the present invention will be explained in detail.

Here, the base metal plate includes a steel plate, an electrolytic chromic acid treated plate, a plate plated with zinc, aluminum, copper, chromium, tin, etc., or a plate plated with an alloy thereof. Of course, the surface of these metal plates may be subjected to chemical conversion treatment such as chromate treatment or IJ phosphate treatment. Next, first of all, let's talk about the PVC resin that is the main component for forming the inner layer coating.Any resin polymerized by commonly used suspension polymerization, emulsion polymerization, or solution polymerization can be used. . Moreover, not only a vinyl chloride straight polymer but also a copolymer resin may be used. The aluminum powder in the present invention is
Any scaly powder finely pulverized by a normal industrial method and having a thickness of loAm or less is sufficient; a thickness of 10 rm or more is not suitable because film-forming properties deteriorate.

There are no particular restrictions on the particle size of the flaky aluminum powder, but the smaller the particle size, the better.

Further, there is no need to particularly consider particle size distribution. Powders other than scaly aluminum powder preferably have a particle size of 70 mm or less, and if the particle size is 70 mm or more, film-forming properties are poor. The purity of the metal powder may be such that it is a powder that can be easily obtained industrially, and may contain small amounts of oxides and impurities.

The thickness of the coating layer using the PVC resin-metal powder composite composition should be determined depending on its protective performance, processing characteristics, economic efficiency, usage environment, etc., and is not particularly limited, but is preferably 30 to 300 m. The range is good, and this range is sufficient to exhibit excellent performance.

Metal powder is generally used as a coloring agent to give various plastic products a metallic color or luster, but this is essentially different from the purpose of the present invention.

That is, the characteristics of the composite material of the present invention comprising a PVC resin and a scaly aluminum powder, or a zinc, tin, lead powder, or an alloy powder thereof can be shown by the following points. The first feature is that the inner layer is a composite material layer containing PVC resin and scaly aluminum powder, or zinc, tin, lead powder, or an alloy powder of these, which makes it more durable than the outer coating layer such as acrylic resin. It has been discovered that this material exhibits a synergistic effect and has a remarkable effect on weather resistance.

The reason for this is presumed to be the following effects: A. The flaky aluminum powder can significantly improve the stability of PVC resin against light and heat. B: Elongation strain and shrinkage strain of PVC resin can be reduced. The second feature is that it not only has excellent performance in blocking the base metal plate from corrosive gases and corrosive substances, but also has an excellent electrochemical protective effect on the base metal plate. Therefore, if there are pinholes, cracks, or scratches in the coating layer that reach the base metal, the corrosion of the conventional resin-coated metal plate will progress significantly, resulting in pitting corrosion, pitting, general corrosion, and coating peeling. However, due to the composite material layer made of PVC resin and metal powder in the inner layer according to the present invention,
It has a protective effect against the above-mentioned defects. On the other hand, acrylic, polyester, silicone, or fluorine resin paints used for the outer coating are known to have excellent weather resistance, but cracks in the paint film during processing and molding,
Due to the occurrence of scratches during construction, the thickness of the coating was increased from 3 to 60 mm.
Due to its thinness, it has poor corrosion resistance. Furthermore, due to its inferior corrosion resistance, corrosion products such as iron and zinc may adhere to it.
The weather resistance of the paint film is significantly reduced. By having the composite material layer made of PVC resin and metal powder according to the present invention in the inner layer,
The film resistance of the outer coating film is significantly improved.
Z As mentioned above, the inner layer is a composite material layer containing flaky aluminum powder of PVC resin, zinc, tin, chain powder, or alloy powder containing one or more of these metals, and acrylic, polyester, silicone. Furthermore, it has never been discovered that a composite coating consisting of a fluorine-based resin coating and an outer layer can exhibit many excellent effects at the same time, and this is also a feature of the present invention. It is here. Next, the formulation of the composite material according to the present invention will be explained. For 10 parts by weight of PVC resin, 5 to 7 parts by weight of scaly aluminum powder, or one or more powders of zinc, tin, bell powder, or alloys containing one or more of these metals (hereinafter referred to as metal) powder) in a proportion of 30 to 150 parts by weight. Further, when using 5 to 7 parts by weight of the flaky aluminum powder and 1 to 145 parts by weight of the metal powder, the total must not exceed 150 parts by weight. If the amount of scaly aluminum powder is less than 5 parts by weight, the effect on the deterioration of the vinyl chloride film is significantly reduced, and at the same time, the electrochemical protection and rust prevention effects are also significantly reduced, which is not preferable.

In addition, if the total amount of metal powder is 150 parts by weight or more, there is no particular problem in film formation, but it goes against the purpose of providing a flexible coating, which is one of the objectives of the present invention, and When molding, the processability of the coating layer decreases, which is undesirable. Preferably, the amount of scaly aluminum powder or metal powder or the total amount thereof is 10 to 12 parts by weight per 10 parts of PVC resin. Other additives for forming the coating according to the present invention include plasticizers and stabilizers, but the plasticizer may be a general-purpose plasticizer for PVC resins and is not particularly related to the type or base. . Generally 10~
8 parts by weight is sufficient. However, when using the plastisol method, fluidity during coating is important, so if a small amount of plasticizer is used, a diluent (such as kerosene or mineral spirit) should be used to give the plastic appropriate fluidity. ) may be added. A stabilizer for general-purpose vinyl chloride resins may also be used. Furthermore, if necessary, an appropriate amount of coloring pigments or fillers may be added. On the other hand, the resin coating film used for the outer layer of the composite coating according to the present invention can be made by applying a paint whose main component is acrylic resin, polyester resin, silicone resin, or fluorine resin. Obtained as 3 to 60 m.

An ultraviolet absorber, an antioxidant, a pigment, etc. may be added to the paint. Further, the adhesive used for bonding the base metal plate and the composite coating of the inner layer may be any of the known commercially available acrylic, epoxy, urethane, and rubber adhesives.

Further, in order to improve corrosion resistance, zinc, aluminum powder, or chromic acid-based mirror-proofing pigment may be included in the adhesive. Next, the method for manufacturing the coating according to the present invention will be explained in detail.

0 The coating of the composite composition for the inner layer can be produced by either the pinyl plastisol method (including the so-called modified plastisol method or organosol method5) or the film lamination method.

In the case of the plastisol method, the composite material made into a paste by adding a general-purpose plasticizer to the PVC resin and metal powder according to the present invention is roll coated or bonded onto a base metal slope that has been coated with an adhesive and dried. , knife coating, curtain flow coating, etc., and heat film formation. o If the inner layer is formed by a film method, a composite material of PVC resin and metal powder is molded into a film or sheet in advance by a general-purpose PVC resin film or sheet molding method, such as a calendar method or a T-die method.
Then, it is laminated by heat-pressing and bonding to the base metal plate.

In this case, the adhesive for bonding the base metal plate and the composite film or sheet should be applied to the base metal plate, film or sheet in advance. After forming the inner layer, the outer coating layer is formed using a liquid paint whose main component is acrylic, polyester, silicone, or fluorine resin by spray coating, roll coating, concentrated coating, knife coating, or curtain flow coating. By methods such as
After drying, the coating is applied to a coating thickness of 3 to 60 mm, and heated to form a film.

At this time, when the inner layer is formed by the plastisol method, the coating for the outer layer may be applied immediately after the paste-like composite material is applied, or after it is applied and heated to form a film. When the inner layer is formed by the film method, the coating for the outer layer is applied after the composite film is heat-pressed. Further, the adhesion between the inner layer film and the outer layer film can be achieved by heat fusion, solvent adhesion, etc., and does not particularly require an adhesive, but does not include the use of an adhesive.
After the outer layer is formed and heated, embossing treatment can be performed if necessary.

Next, the effects of the present invention will be explained in detail using examples.

Example 1 After uniformly dispersing and kneading a composite material composition having the composition shown in Table 1 using a pony mixer, a composite electrogalvanized steel sheet (Zn
Apply acrylic resin adhesive to approx.
After coating with 3 mm of sand and sand in a hot air heating furnace at 300°C, the 3 composite materials were coated with a knife coater to a coating thickness of 200 mm, After heating the 260006 sand in a hot air heating furnace and cooling it, an acrylic paint (product name: Corona Paint, manufactured by Nikko Bix Corporation) is applied to the upper layer of this composite coating.
was coated with a bar coater 31 to give a dry coating thickness of 8 mm, heated with sand in a hot air heating furnace at 20 mm, and then cooled to produce a composite coated steel sheet.

The obtained coated steel plate was subjected to DuPont impact processing (tip diameter 12
7 arc, weight 1 kg, height 5 ratio 1), no cracking or peeling of the four composite coating layers was observed, demonstrating excellent workability and adhesion.

In addition, in order to evaluate the outdoor durability, the obtained coated steel plate was subjected to a sunshine weather meter test (J
ISA 1415) over a test time of 800q hours.

As a result, as shown in Table 1, there was no abnormality such as clutching or discoloration of the composite coating.It has excellent weather resistance, no pristal formation, excellent corrosion resistance, and excellent adhesion of the composite coating. Obtained. The adhesion strength is evaluated by JISK.
The test was carried out according to the Eriksen test of 6744. (Score is 5 points (good) ← -1 point (poor).
After 800 feeding hours, salt water mist test (JIS Z 23
71) was carried out for 30 q hours, and the peeling of the coating by forced peeling was evaluated.

As a result, the peeling process was evaluated. As a result, 1 during peeling.
It showed excellent corrosion resistance within the ribs. Comparative Example 1 As shown in Table 1, instead of the scaly aluminum powder in the composite material formulation of Example 1, a PVC coating containing titanium oxide, which is used as a coloring agent for ordinary PVC coatings, was used as an inner layer. A PVC steel plate coated with an acrylic paint was prepared in the same manner as in Example 1 with all other conditions.

The obtained coated steel plate was subjected to a sunshatine weatherometer test in the same manner as in Example 1.

As a result, both the paint film and the vinyl chloride film were cracked and discolored. Also, blisters were formed in the cross-cut portions, and the film was lifted. The adhesion of the film was also significantly inferior. As in Example 1, continue to 0,
A salt water fog test was conducted for 30 hours, but during peeling it was 5-17
Compared to Example 1, the ribs showed significantly inferior corrosion resistance. Example 2 As shown in Table 1, the five coatings of the inner layer and outer layer have the composition as shown in Table 1.
A composite coated steel plate was prepared in the same manner as in Example 1, except that it was obtained from a polyester paint (trade name: SPDIFH-3, manufacturer: Nippon Paint ■).

After confirming that the obtained coated steel plate had excellent workability and adhesion as in Example 1, a sunshine weather meter test was conducted for 800 feeding hours.

As a result, as shown in Table 1, it showed extremely excellent outdoor durability. Continued saltwater fin fog test 30 as in Example 1.
Field time was carried out, and during peeling, it showed excellent corrosion resistance within one side. Example 3 All coatings were used except that the inner layer and outer layer coatings with the formulation shown in Table 1 were obtained from silicone-based paint (product name: Ji.800, manufacturer: Nippon Paint ■). A composite coated steel plate was produced under the same conditions as in Example 1.

After confirming that the obtained coated steel sheet had excellent workability and adhesion as in Example 1, a sunshine weatherometer test was conducted.

As a result, as shown in Table 1, it showed extremely excellent outdoor durability. Continued salt water mist test 30 in the same manner as in Example 1.
During the feeding period, it showed excellent corrosion resistance with less than one leg during peeling. Example 4 As shown in Table 1, all of the compositions were the same, except that the inner layer and outer layer coatings were obtained from a fluorine-based paint (product name: Torgarmet F-150u, manufacturer: Toa Paint ■). A composite coated steel plate was produced under the same conditions as in Example 1.

After confirming that the obtained coated steel sheet had excellent workability and adhesion as in Example 1, a sunshine weatherometer test was conducted. As a result, as shown in Table 1, it showed extremely excellent outdoor durability. As in Example 1, a salt water fog test was subsequently carried out for 30 feeding hours, and during peeling, the corrosion resistance was within one rib, showing excellent corrosion resistance. Example 5 After uniformly mixing a composite material composition having the composition shown in Table 1, it was heated at 160 pm using two rolls for heating and kneading.
The mixture was kneaded for 10 minutes and formed into a film with a thickness of 200 rm.

The obtained film was heat-pressed onto a base metal plate similar to that of Example 1, which was coated with an adhesive. The obtained composite-coated steel plate was spray-coated with acrylic paint (product name: Corona Paint, manufacturer: Nikko Bix Corporation) to a dry coating thickness of 15 mm, and heated in a hot air heating furnace to 200 q.
o.6 The bait sand was heated and then cooled to create a composite coated steel plate. After confirming that the obtained coated steel sheet had excellent workability and adhesion as in Example 1, a sunshine weatherometer test was conducted.

As a result, as shown in Table 1, it showed extremely excellent outdoor durability. Continued salt spray test 30 in the same manner as in Example 1.
A feeding period was conducted, and during peeling, it showed excellent corrosion resistance within one side. Example 6 A composite coated steel plate was prepared using a composite material composition having the composition shown in Table 1 and in the same manner as in Example 5 except for all other conditions.

After confirming that the obtained coated steel sheet had excellent workability and adhesion as in Example 1, a sunshine weatherometer test was conducted.

As shown in Table 1, the results showed remarkable outdoor durability. Continued salt spray test 30G in the same manner as in Example 1.
Although the test was carried out for several hours, it showed excellent corrosion resistance, showing less than one side during peeling. Table 1

Claims (1)

[Scope of Claims] 1. A composite material having a thickness of 30 to 30 μm and containing 100 parts by weight of polyvinyl chloride resin and 5 to 70 parts by weight of scaly aluminum powder having a thickness of 10 μm or less, placed on a base metal plate via an adhesive layer. The inner layer is an acrylic layer with a thickness of 3 to 60 μm,
A highly weather resistant composite coated metal plate with a polyester, silicone or fluorine resin coating layer as the outer layer. 2. On the base metal plate, 100 parts by weight of polyvinyl chloride resin, zinc, tin, with a particle size of 70 μm or less,
The inner layer is a composite material layer with a thickness of 30 to 300 μm containing 30 to 150 parts by weight of one or more powders of lead or an alloy containing one or more of these metals, and a composite material layer with a thickness of 3 to 60 μm.
A highly weather-resistant composite coated metal plate formed with a μm acrylic, polyester, silicone or fluorine resin coating layer as the outer layer. 3. On the base metal plate, via an adhesive layer, 100 parts by weight of polyvinyl chloride resin, 5 to 70 parts by weight of scaly aluminum powder with a thickness of 10 μm or less, zinc with a particle size of 70 μm or less,
The inner layer is a composite material layer with a thickness of 3 to 300 μm containing 1 to 145 parts by weight of one or more powders of tin, lead, or an alloy containing one or more of these metals.
A highly weather resistant composite coated metal plate with a 60 μm acrylic, polyester, silicone or fluorine resin coating layer as the outer layer.