JPH07227933A - Resin-laminated material plate and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a resin-laminated metal plate, which does not develop a noxious gas at waste disposal and is equipped with excellent weatherability and suitable for external packaging, and its manufacturing method. CONSTITUTION:On chemically treated metal plate 1, an adhesive layer 2, the dry film thickness of which is 2-20mum, a polyester film layer 3, the film thickness of which is 10-100mum, a primer layer 4, the dry film thickness of which is 0.1-20mum, and a paint layer 5 containing either one or more of pigment, an antioxidant and a UV-absorber, the dry film thickness of which is 5-40mum, are formed in the order named. In order to form the resin coating film layer, under the condition that the metal plate, on which an adhesive is applied, is heated up to and kept at 150-250 deg.C, a polyester film is laminated onto the metal plate. Next, a primer is applied onto the polyester film and dried. Finally, a weatherproof paint is applied onto the primer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated metal sheet having excellent weather resistance for exterior use, and particularly to a method for producing the resin-coated metal sheet suitable for coil coating.

[0002]

2. Description of the Related Art Conventionally, as a resin-coated metal plate for an exterior, one coated with a vinyl chloride resin is generally used in consideration of weather resistance and economy. However, since vinyl chloride resin generates harmful hydrogen chloride gas in the incineration process at the time of disposal, it has drawbacks such as polluting the environment and shortening the life of the incinerator.

In order to solve this drawback, a resin-coated metal plate using a film such as polyethylene phthalate (PET) as a coating resin is also known. For example, Japanese Patent Publication 61-
51988, JP-B-63-13828, JP-A-63-236640, etc., a print pattern layer also having an adhesive function is sandwiched between a polyester film and a metal plate, and a pattern is formed through this film. A resin-coated metal plate formed to be visible is disclosed. However,
In this layer structure, the polyester film, which has poor weather resistance, is formed as the outermost layer that is exposed to the outside air directly, so that the material deteriorates when exposed to ultraviolet rays, heat, water, etc. for a long period of time.
Not suitable for exterior use.

Further, in Japanese Patent Laid-Open No. 5-245969, 9 to 7 which are adhered to the surface of a metal plate via an adhesive layer is disclosed.
A decorative metal plate has been proposed in which a colored polyester film having a thickness of 5 μm, a printing layer and a clear protective layer are laminated and formed, and the total thickness of the coating layers up to the adhesive layer and the clear protective layer is set to 90 μm or less. However, when this decorative metal plate is used as an exterior, ultraviolet rays pass through the printing layer through the clear protective layer and reach the polyester film layer on the lower surface, so that the weather resistance is not sufficient.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. The purpose of the present invention is to produce no harmful gas at the time of disposal. Another object of the present invention is to provide a resin-coated metal plate suitable for an exterior having excellent weather resistance and a method for producing the same.

[0006]

The resin-coated metal plate according to the present invention for achieving the above object is a resin-coated metal plate in which a plurality of resin coating films are formed on a metal plate subjected to chemical conversion treatment. The resin coating layer has a dry film thickness of 2 on the metal plate surface.
˜20 μm adhesive layer, 10 to 200 μm film thickness polyester film layer, dry film thickness 0.1 to 20 μm primer layer and dry film thickness 5 to 40 μm pigment, antioxidant and / or UV protection agent A structural feature is that a coating layer containing the above is sequentially formed.

FIG. 1 is a partially enlarged sectional view showing a layer structure of a resin-coated metal plate according to the present invention. An adhesive layer 2 and a polyester film layer 3 are provided on the upper surface of a metal plate 1 which has been subjected to a chemical conversion treatment as a base material. The primer layer 4 and the paint layer 5 are sequentially laminated and integrally formed.

In the present invention, examples of the metal plate which is the target substrate for resin coating include cold rolled steel plate, zinc steel plate, zinc-aluminum plated steel plate, aluminum plate and stainless steel plate. A known chemical conversion treatment is performed before use. Further, in order to improve the rust prevention effect, it is preferable to apply a primer to the surface of the metal plate subjected to the chemical conversion treatment. As the primer, a commercially available epoxy-based primer [for example, "Superlac DIFP-01" manufactured by Nippon Paint Co., Ltd.] or a polyester-based primer [for example, Nippon Paint Co., Ltd.]
Manufactured by "Superlac DIFP-600" can be used, and it is preferable that the dry film thickness is 1 to 10 μm.

An adhesive layer is first formed on the upper surface of the metal plate. As the adhesive, epoxy resin, acrylic resin,
At least one selected from rubber, polyester resin, amino resin, imino resin and polyurethane resin is used. Commercially available products of these adhesives include polyurethane adhesives manufactured by Nippon Paint Co., Ltd. (“Power Tight 20
1 "], a polyester adhesive (" SC-611 ") manufactured by Sony Chemicals Co., Ltd., and the like.

The film thickness of the adhesive layer to be formed must be set to a dry film thickness of 2 to 20 μm. This film thickness is 2μ
If it is less than m, the adhesive strength may be too low and peeling may occur.
If the thickness exceeds μm, problems such as “arming” during baking and deterioration of workability may occur.

The rustproofing effect can be further improved by adding at least one rustproofing pigment selected from chromate-based, aluminum phosphate-based, phosphorus-vanadate-based, and lead-based adhesives to the adhesive. Examples of preferable rust preventive pigments are zinc chromate, strontium chromate and the like. The amount of these rust preventive pigments added is in the range of 1 to 30% by weight, and preferably 10 to 20% by weight, based on the total amount of the adhesive. If the addition amount is less than 1% by weight, the rust preventive effect is small, and if it exceeds 30% by weight, the workability may deteriorate.

Examples of the polyester film formed on the adhesive layer include polyethylene terephthalate film (PET film) and polybutylene terephthalate film (PBT film). Although any polyester film can be used regardless of whether it is stretched or not, a film whose adhesion or weather resistance is improved as described below is effectively used. (1) A polyester film whose both surfaces have been subjected to corona discharge treatment in order to improve adhesion. (2) A primer containing at least one component selected from urethane-based, polyester-based, polyimide-based, polybutadiene-based, organic titanium-based primers and epoxy resin-containing primers on a polyester film in order to improve adhesion. A polyester film having a dry film thickness of 0.1 to 20 μm. (3) A polyester film containing a pigment in order to improve weather resistance. (4) A polyester film added with an ultraviolet absorber or an antioxidant in order to improve weather resistance.

The thickness of the polyester film formed is
It is set to 10 to 200 μm. When the film thickness is less than 10 μm, it causes corrosion such as rusting on the metal plate which is the base material. On the other hand, when the film thickness exceeds 200 μm, the workability is deteriorated.

The primer layer formed on the upper surface of the polyester layer is made of one or more materials selected from polyurethane-based, polyester-based, polyimide-based, polybutadiene-based, organic titanium-based primers and epoxy resin-containing primers, and dried. 0.1-20μ as film thickness
It is laminated so that it becomes m. If the thickness of the primer layer is less than 0.1 μm, the adhesive strength will be insufficient, and if it exceeds 20 μm, the workability will be poor.

The coating layer formed on the outermost surface contains at least one selected from oil-free polyester resin, oil-modified polyester resin, acrylic resin, silicon-modified polyester resin, silicon-modified acrylic resin and fluororesin as a resin component. Composed of paint. Such a paint can be applied in any form of solvent type, aqueous type and powder type.

The above paint may contain a pigment. The pigment is not limited in kind as long as it can be used for exterior packaging, and any of organic pigments and inorganic pigments can be used. Examples of such pigments include inorganic pigments such as titanium oxide, iron oxide yellow, iron oxide red, carbon black and aluminum paste, and organic pigments such as phthalocyanine blue and quinacridone red.

When the pigment is not added to the paint, at least one of the antioxidant and the ultraviolet absorber is added. As an example of the antioxidant, hindered amine [Ciba Geigy Co., Ltd., "Sanol LS292",
"Sanol LS770"]. Such an antioxidant is usually added in an amount of 0.
3 to 3.0 parts by weight are added. Examples of the ultraviolet absorber include those containing benzotriazole as a main component [Ciba Geigy, "Tinuvin 900"] and those containing benzophenone as a main component [Cypro Kasei Co., Ltd., "Seethap 103"]. It is commercially available, and, like the above-mentioned antioxidants, it has an amount of 0.
It is preferably added in the range of 3 to 3.0 parts by weight.

The dry film thickness of the paint layer is 5 to 40 μm, preferably 10 to 20 μm. If the film thickness is less than 5 μm, the ultraviolet rays pass through the paint layer and reach the polyester film layer, which impairs the weather resistance.
If it exceeds the range, pinholes are generated during baking, resulting in poor appearance.

In the manufacturing method according to the present invention for obtaining the above-mentioned resin-coated metal plate, an adhesive is applied to the metal plate subjected to the chemical conversion treatment so that the dry film thickness becomes 2 to 20 μm, and then the metal plate is coated with 150 To 250 ° C., and while maintaining this temperature, a polyester film having a film thickness of 10 to 200 μm is laminated, and then a primer is applied to the polyester film surface so that the dry film thickness is 0.1 to 20 μm and dried. , And a dry film thickness of 5-4 on top of the primer layer
A structural feature is that a coating material containing at least one of a pigment, an antioxidant and an ultraviolet absorber is applied so as to have a thickness of 0 μm.

The adhesives, polyester films, primers and paints used for layer formation are of the types and components described above. The adhesive is applied by a roll coater, a curtain flow coater or the like. A roll coater or a curtain coater is preferable as the coating method of the paint, but other general-purpose coating means such as electrostatic coating, spray coating, airless spray coating, roller coating can be adopted. The method for curing the paint layer is usually dry curing, baking curing, depending on the properties of the resin for the paint layer,
UV curing, electron beam curing, etc. can be appropriately selected and applied.

In the above manufacturing method, a primer is applied to a polyester film having a film thickness of 10 to 200 μm so as to have a dry film thickness of 0.1 to 20 μm and dried, and a coating having weather resistance on the upper surface thereof. The dry film thickness 5
To 40 μm to form a coating film, which is heated to 150 to 250 ° C. and laminated to the adhesive layer surface on the metal plate while maintaining this temperature. It is also possible to apply a process of forming a laminate on the.

In this way, a resin-coated metal plate in which an adhesive layer, a polyester film layer, a primer layer and a paint layer are successively formed integrally on a target metal plate can be obtained.

The present invention has the structure described in the claims, and the preferred embodiments are listed below. (A) The adhesive layer contains at least one polymer selected from epoxy resin, acrylic resin, rubber, polyester resin, amino resin, imino resin, and polyurethane resin. (A) The adhesive layer further contains at least one rust preventive pigment selected from chromate-based, aluminum phosphate-based, phosphorus-vanadate-based, and lead-based pigments. (C) Between the chemical conversion treated metal plate and the adhesive layer,
In addition, a primer layer has been formed. (D) The primer layer applied to the polyester film contains at least one material selected from polyurethane-based, polyester-based, polyimide-based, polybutadiene-based, organic titanium-based primers and epoxy resin-containing primers. (E) The paint layer contains at least one resin selected from oil-free polyester resin, oil-modified polyester resin, acrylic resin, silicon-modified polyester resin, silicon-modified acrylic resin, and fluororesin.

[0024]

In the resin-coated metal plate of the present invention, an adhesive layer, a polyester film layer, a primer layer and a paint layer are sequentially laminated on a metal plate which has been subjected to a chemical conversion treatment in a film thickness within a specific range. Among them, the polyester film layer is firmly adhered via the adhesive layer, so that it functions effectively for rust prevention of the metal plate and corrosion resistance during processing, and the primer layer interposed between the polyester film layer and the paint layer. Acts to prevent delamination. Furthermore, the outermost paint layer is a pigment,
Since it contains at least one of an antioxidant and an ultraviolet absorber and is formed to have a dry film thickness of 5 to 40 μm, external ultraviolet rays are blocked by the paint layer and penetrate to the polyester film layer. The phenomenon of deterioration is effectively prevented. Therefore, long-term stable weather resistance is provided for the exterior. Moreover, since the resin layer does not contain a component that generates a harmful gas such as hydrogen chloride upon heating, no harmful pollution occurs during the disposal process.

Further, according to the manufacturing method of the present invention, the desired resin-coated metal plate can always be obtained with good workability by virtue of the above-mentioned layer structure and the function of limiting the film thickness.

[0026]

EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples. Each of the coating layer configurations in each example had the laminated structure shown in FIG. 1, and the quality of the resin-coated metal plate was evaluated as follows.

S-WOM (Sunshine-Weather-O-Meter): A test piece (50 mm x 150 mm) was cut out from a resin-coated metal plate, and JIS was used.
Light irradiation and water spraying were alternately repeated according to the method specified in K5400-9,1 and the test piece before the test and 2000
Color difference (ΔE) and gloss retention [G. R (%)] was compared. SST: Using the above-mentioned test piece of S-W-O-M after 2000 hours of testing, the appearance of the blister of the flat portion and the blister of the 2T bent portion of the test piece was visually checked and judged according to the following criteria. In addition, ⊚ and ∘ are acceptable, and Δ and × are unacceptable. No blisters; ◎ Slight blisters; ○ Partial blisters; △ Full blisters; ×

Examples 1 to 25: A coating type chromate treatment agent [manufactured by Nippon Paint Co., Ltd., "Surfcoat NC", on the upper surface of a metal plate (A) having a thickness of 0.5 mm.
R300 ″] was used to perform a chemical conversion treatment with a chromium content of 40 mg / m ^2. A polyester adhesive (B) containing 15% by weight of strontium chromate (rust preventive pigment) in solid content on the chemical conversion treatment surface. Was applied by a bar coater and baked in a gas furnace so that the plate temperature of the metal plate was 230 ° C. An adhesive layer was formed.The PET film (C) treated by corona discharge was continuously maintained at this temperature. After being laminated by dry lamination, a polyester film layer was laminated, and after cooling, a polyester primer (D) was applied and dried to form a primer layer, and then a coating material (E) was applied thereon and baked at a plate temperature of 210 ° C. After that, it was cooled to manufacture a resin-coated metal plate.

Metal plate, adhesive, polyester film,
The following were used as the primer and the paint (the types of materials shown in Tables 1 to 4 have the following symbols). (A) Metal plate; A-1: Z27 hot-dip galvanized steel plate A-2: # 5052 aluminum plate A-3: SUS # 304 A-4: Galvalume (B) adhesive; B-1: Polyester adhesive [ Made by Nippon Paint Co., Ltd.
"Power Tight MPO-039"] B-2: Polyester adhesive [Nogawa Chemical Co., Ltd.,
"Diabond DA3080"] (C) Polyester film; C-1: PET film ["Emblet S" manufactured by Unitika Ltd.) (D) Primer; D-1: Polyester-based primer [Dainippon Ink and Machinery Co., Ltd. ), "Dickseal A-970"] D-2: Polyester type primer [Dainippon Ink & Co., Inc., "Dickseal A-930"] D-3: Polyester type primer [Nippon Paint Co., Ltd.]
"Power tight MPO-039" manufactured by D-4: Polyester primer [Nippon Paint Co., Ltd.]
"Power Tight MPO-040" manufactured by D-5: Polyester primer [Nogawa Chemical Co., Ltd.]
"Diabond DA3080"] (E) paint; E-1: Oil-free polyester resin paint [Nippe Super Coat 300 "gray color" made by Nippon Paint Co., Ltd. E-2: Silicon polyester resin paint [Nippon Paint] "Superlac DIF S-30" gray color manufactured by Co., Ltd. E-3: Vinylidene fluoride resin coating [Nippon Paint Co., Ltd.]
Made by "Uniflon C" gray color] E-4: Water based acrylic emulsion paint [Nippon Paint Co., Ltd., "Aude Color 100" gray color] E-5: Oil free polyester resin paint [Nippon Paint Co., Ltd., "Nippe Super Court 300 Clear"]

With respect to each of the obtained resin-coated metal plates, the results of performance evaluation were compared with the variable factors, and the results are shown in Tables 1 to 3.
It was shown to. As is clear from the table, all the resin-coated metal plates of the examples showed good results. Especially Example 2
When the silicon-based paint of Example 2 and the fluorine-based paint of Example 23 were used, ΔE of the SWOM test and G.I. R was excellent. Further, in Example 8, slight blister occurred due to the relatively thin film thickness of the polyester film layer, but in other examples, the flat portion blister,
No occurrence of blisters at the 2T bend was observed.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

Comparative Examples 1 and 2 A resin-coated metal plate was formed in the same manner as in Example 1 except that the dry film thickness of the adhesive layer was outside the specified range of the present invention. Example 1 for the obtained resin-coated metal plate
The results of performance evaluation performed in the same manner as in Table 4 are shown in Table 4. In Comparative Example 1 in which the dry film thickness was 1 μm, blisters were generated on the coated surface, and Comparative Example 2 in which the dry film thickness was 25 μm
Then, the 2T bent portion was cracked and a large amount of blisters were generated.

Comparative Examples 3 to 4 A resin-coated metal plate was formed in the same manner as in Example 1 except that a polyester film having a thickness outside the specific range of the present invention was used for layer formation. The performance of the test piece was evaluated for the obtained resin-coated metal plate, and the results are also shown in Table 4.
In Comparative Example 3 in which the film thickness was 9 μm, rust prevention was poor and blister occurred, and in Comparative Example 4 in which the film thickness was 300 μm, cracks were formed in the 2T bent portion, and blister generation was observed.

Comparative Examples 5 to 6 A resin-coated metal plate was formed in the same manner as in Example 1 except that the dry film thickness of the primer layer was outside the specified range of the present invention. The performance evaluation results of the obtained resin-coated metal plate are also shown in Table 4. In Comparative Example 5 in which the dry film thickness was 0.05 μm, the polyester film layer was peeled from the adhesive layer, and in Comparative Example 6 in which the dry film thickness was increased to 25 μm, cracks were generated in the 2T bent portion and a large amount of blisters were generated. .

Comparative Examples 7 to 8 Resin-coated metal plates were formed in the same manner as in Example 1 except that the dry film thickness of the paint layer was outside the specified range of the present invention. The performance evaluation results of the obtained resin-coated metal plate are also shown in Table 4. In Comparative Example 7 in which the dry film thickness was thinned to 3 μm, ΔE, G. R was significantly reduced, and in Comparative Example 8 in which the dry film thickness was increased to 50 μm, a large amount of blisters were generated during baking.

Comparative Example 9 A resin-coated metal plate was formed in the same manner as in Example 1 except that the primer layer and the paint layer were not formed. The performance evaluation results of the obtained resin-coated metal plate are also shown in Table 4. In this case, ΔE, G. Both R were bad.

[0039]

[Table 4]

[0040]

As described above, according to the layer structure of the resin-coated metal sheet according to the present invention, the polyester film layer is adhesively formed on the metal sheet subjected to the chemical conversion treatment through the adhesive layer. The polyester film layer effectively prevents rusting of the metal plate and corrosion resistance during processing. Also,
Since the polyester film layer covers the roughness of the metal plate, the sharpness of the coating film is improved. Secondly, a primer layer is provided between the polyester film layer and the paint layer to prevent peeling of the paint layer. Thirdly, the outermost paint layer shields the polyester film layer from the outside air, so that the polyester film layer, which originally has no weather resistance, is protected from ultraviolet rays, wind and rain. Combined with such features,
It is possible to form an integral resin-coated metal plate having excellent weather resistance as a whole.

Further, since the resin-coated metal plate constituted by the present invention does not contain a component such as vinyl chloride, which produces a harmful gas when incinerated, there is no problem in disposal. In addition, in terms of work, when the polyester film itself is not colored, it is sufficient to prepare only a colorless film, which is advantageous in that the stock quantity of the film can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a partially enlarged cross-sectional view illustrating a layer structure of a resin-coated metal plate according to the present invention.

[Explanation of symbols]

 1 Metal plate subjected to chemical conversion treatment 2 Adhesive layer 3 Polyester film layer 4 Primer layer 5 Paint layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Kimura, Koichi Kimura 2-1-2, Oyodokita, Kita-ku, Osaka City, Osaka Prefecture Nippon Paint Co., Ltd. Osaka Office (72) Noriyasu Noda 4-chome, Minami-Shinagawa, Shinagawa-ku, Tokyo No. 1-15 Japan Paint Co., Ltd. Tokyo office

Claims (3)

[Claims] 1. A resin-coated metal plate in which a plurality of resin coating films are formed on a chemical conversion-treated metal plate, wherein the resin coating film layer has a dry film thickness of 2 to 20 μm with respect to the metal plate surface. An adhesive layer, a polyester film layer having a thickness of 10 to 200 μm,
A primer layer having a dry film thickness of 0.1 to 20 μm and a coating layer containing one or more of a pigment, an antioxidant and an ultraviolet absorber having a dry film thickness of 5 to 40 μm are sequentially formed. Resin coated metal plate to be used. 2. A dried film having a thickness of 2 is formed on the metal plate subjected to the chemical conversion treatment.
After applying the adhesive so that the thickness becomes ~ 20 μm, the metal plate is heated to 150 to 250 ° C., a polyester film having a film thickness of 10 to 200 μm is laminated while maintaining this temperature, and then a dry film thickness is formed on the polyester film surface. Of 0.1 to 20 μm is applied and dried, and the dry film thickness is 5 to 40 on the upper surface of the primer layer.
A method for producing a resin-coated metal plate, which comprises applying a coating material containing at least one of a pigment, an antioxidant and an ultraviolet absorber so as to have a thickness of μm. 3. A dry film thickness of 2 on a metal plate subjected to chemical conversion treatment.
After applying the adhesive so that the thickness becomes ˜20 μm, the metal plate is heated to 150 to 250 ° C., and while maintaining this temperature, the primer is dried to a film thickness of 0.1 in advance on a polyester film having a thickness of 10 to 200 μm. It is formed by coating and drying so as to have a thickness of ˜20 μm, and further coating with a coating containing at least one of a pigment, an antioxidant and an ultraviolet absorber so as to have a dry film thickness of 5 to 40 μm. A method for producing a resin-coated metal plate, which comprises laminating a coated film.