JP3082387B2 - Fluororesin film laminated metal plate - Google Patents

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 laminated with a fluororesin film, which exhibits excellent weather resistance and is suitable for building materials, especially for outdoor building materials.

[0002]

2. Description of the Related Art As a coated steel sheet for outdoor building materials having better weather resistance, corrosion resistance and stain resistance than conventional colored tin, a base material steel sheet (usually plated) which is mainly composed of polyvinylidene fluoride (PVdF). Steel plate).
Such PVdF-based coated steel sheets have been put on the market by steel sheet manufacturers, guaranteeing that no red rust will occur on the flat part for 20 or 30 years.

[0003] However, the coated steel sheet is usually subjected to bending or the like at the time of application, and at that time, the coating film may be damaged or fine cracks may occur. Furthermore, rusting from the end face cannot be completely prevented even though a treatment such as a caulking agent is performed. Therefore, the corrosion resistance and the end face corrosion resistance of the processed part and the damaged part of the coated steel sheet are important.

On the other hand, in recent years, a highly corrosion-resistant laminated steel sheet obtained by laminating a fluororesin film containing polyvinyl fluoride (PVF) or PVdF as a main component on a plated steel sheet has been put on the market. Since such a laminated steel sheet has better workability than a coated steel sheet and does not generate pinholes at the time of paint baking, high reliability regarding corrosion resistance is expected.

[0005] Fluororesin film laminated steel sheets using a turn sheet as a base material are disclosed in Japanese Patent Publication Nos. 60-51423 and 60-51424. However, in this laminated steel sheet, the base metal plated steel sheet is a turn sheet,
That is, it is limited to a lead-tin-plated steel sheet, and since this plating layer is more noble than the base iron, the end face has low corrosion resistance.

In general, a fluororesin film has excellent chemical durability, but on the other hand, it is difficult to adhere to a base material due to its chemical stability. As an improvement method, for example,
When the base material is an aluminum plate, a method of laminating a fluororesin film after anodizing treatment has been disclosed (see Japanese Patent Publication No. 59-10304).

However, in this method, the base material is limited to an aluminum plate, and an extra step of anodizing the base aluminum plate is required.

[0008] Regarding the adhesion between resins, it is disclosed that when a fluororesin film is laminated on a vinyl chloride resin material, a saturated polyester-based or polyolefin-based hot melt adhesive exhibits excellent adhesiveness (see, for example, Japanese Patent Application Laid-Open No. H10-157,837). Kosho 64-
No. 3666). When this lamination method is applied to a laminated steel sheet, the base treatment of the plated steel sheet / adhesive for vinyl chloride resin / vinyl chloride resin film / hot melt adhesive /
It becomes a combination of many materials called fluororesin film,
At least two coats and two lamination steps are required, the production process becomes complicated, and the cost is large. When the amount of the plasticizer in the vinyl chloride resin film is large, the adhesiveness is poor, and when the amount of the plasticizer is reduced, the processability is significantly reduced.

Further, as pointed out in JP-A-63-168333, when a fluororesin film is laminated, there is no adhesive for the fluororesin film which is effective at a low temperature. The fact is that it has to be laminated at high temperatures. When the bonding temperature is higher than the melting point of the film, manufacturing problems such as wrinkling, breakage, and elongation of the film during lamination are caused.

[0010] Further, among the fluororesin film laminated metal plates for building materials, those having a low gloss and a calm and high-grade feeling with a fine unevenness formed on the film surface are preferred. However, when the laminating temperature is increased as described above, the film resin is leveled and fine irregularities on the film surface disappear, resulting in an increase in gloss, which significantly impairs the commercial value.

[0011]

SUMMARY OF THE INVENTION The object of the present invention is to
An object of the present invention is to provide a fluororesin film-laminated metal sheet excellent in weather resistance, corrosion resistance and workability by using an adhesive excellent in (initial) and secondary (durable) adhesion.

Another object of the present invention is to provide a fluororesin film-laminated metal in which the surface state imparted to the film is preserved by using an adhesive capable of low-temperature bonding without causing wrinkles, breakage, and elongation of the film. Is to provide a board.
In an ordinary metal plate laminating line, after an adhesive is applied onto a metal plate, the adhesive is baked and dried, and immediately thereafter, the film and the metal plate are bonded by a laminator. Therefore, the temperature at the time of lamination with the film (hereinafter referred to as lamination temperature) is only slightly lower than the baking drying temperature of the adhesive (hereinafter referred to as baking temperature). It is necessary to use a low adhesive.

[0013]

As a result of repeated studies to achieve the above object, the present inventors have found that using an adhesive containing an epoxy resin, a crosslinking agent thereof, an acrylic resin, and a fluororesin, The inventors of the present invention have found that they can be bonded at a low temperature, and can obtain extremely good adhesion between various base materials subjected to a base treatment and a fluorine film, and therefore excellent corrosion resistance.

That is, according to the present invention, a composition containing an epoxy resin and its crosslinking agent, an acrylic resin, and a fluororesin is formed on one or both of a phosphate-based and a chromate-based chemical conversion coating. The gist of the present invention is a fluororesin laminated metal plate in which a fluororesin film is laminated via one or more adhesive layers.

The composition for forming the adhesive layer may further contain, if necessary, one or both of a catalyst for a crosslinking reaction between an epoxy resin and a crosslinking agent thereof and a silane coupling agent. Therefore, it is possible to lower the baking temperature and the laminating temperature.

[0016]

The construction of the present invention will be described in detail below together with its operation. The type of the base material of the laminated metal plate of the present invention is not particularly limited, but the manufactured laminated metal plate is often used outdoors because of its excellent weather resistance, and the base material also has excellent corrosion resistance. Things are often applied. An example of a suitable base metal plate is zinc-based
(That is, pure zinc or a zinc alloy). Also, stainless steel plate,
An aluminum plate, a titanium plate, etc. can also be used.

As a base treatment, one or both of a phosphate-based and a chromate-based chemical conversion coating is formed on such a metal plate to secure the adhesiveness of the adhesive / metal plate.
This base chemical conversion treatment film may be formed by an ordinary method. The amount of the chemical conversion coating is not particularly limited, but is 0.1 to 2.0 g / m ² by zinc phosphate treatment, phosphate chromate treatment,
In the coating type chromate treatment, 5 each as chromium metal
~70 mg / m ^2, is a 20~150mg / m ^2. If the amount of the base treatment is too small, the uniformity is poor. If the amount is too large, the adhesion of the processed portion is reduced.

The fluororesin film to be laminated on the undercoated metal plate is a film of a known fluororesin containing PVF or PVdF as a main component or a mixed resin of a fluororesin and another resin. One or more kinds of pigments, fillers, reinforcing agents, ultraviolet absorbers, antioxidants, and other various additives may be contained. The thickness of the fluororesin film is not particularly limited.

The undertreated metal plate and the fluororesin film are laminated via an adhesive layer. The present invention is characterized by an adhesive composition used for forming the adhesive layer. That is,
In the present invention, by using an adhesive composition containing four components of an epoxy resin, a cross-linking agent, an acrylic resin and a fluororesin, lamination is performed, whereby strong primary adhesion to both the fluororesin film and the undercoating layer is achieved. And secondary adhesion. If low-temperature baking (around 180 ° C) or low-temperature lamination (around 160 ° C) of the adhesive is required due to restrictions on the production line or the type of fluororesin film, a catalyst for the crosslinking reaction between the epoxy resin and the crosslinking agent or silane It is advantageous to blend one or both of the coupling agents into the adhesive composition to reduce the temperature.

The epoxy resin in the adhesive is effective for securing adhesion to a metal surface or its underlying treatment, and by curing the epoxy resin together with a crosslinking agent,
Both primary adhesion (adhesion immediately after adhesion) and secondary adhesion (adhesion after aging) are expected to be improved.

On the other hand, it is often difficult to secure the adhesion to the fluororesin film at a low temperature in a short time, but the adhesion to the fluororesin film is improved by adding the fluororesin to the adhesive. can do.

Since the acrylic resin is compatible with the fluororesin, it is added to ensure the adhesion between the epoxy resin and the fluororesin. This is because an adhesive film made of only an epoxy resin and a fluororesin hardened by a cross-linking agent undergoes layer separation after baking as it is, resulting in poor adhesion.

The catalyst for the cross-linking reaction between the epoxy resin and the cross-linking agent and the silane coupling agent are effective for lowering the baking temperature of the adhesive and for improving the adhesion to the base material which is an inorganic material. It is added as needed.

In order to ensure these performances, the above resin components are 5 to 90% of epoxy resin, 0.25 to 30% of crosslinking agent, 5 to 90% of acrylic resin,
Preferably, the fluororesin is present in the composition in an amount of 5 to 90%. It is more preferable that the amount of the fluororesin is 50% by weight or more, but adding an excessive amount of the fluororesin leads to an increase in cost.

If the amount of the epoxy resin or the cross-linking agent is too small, the adhesion to the base material surface such as a base treatment, particularly the secondary adhesion, is reduced. Adhesion decreases. If the amount of the acrylic resin is too small, the adhesion between the fluororesin and the epoxy resin cannot be exhibited as described above.

The amounts of the crosslinking reaction catalyst and the silane coupling agent are not particularly limited as long as they can achieve the above-mentioned purpose of addition, and vary depending on the resin composition.
The crosslinking reaction catalyst is 0.05 to 5%, and the silane coupling agent is 0.1%.
It is usually preferred to use amounts in the range of from 01 to 5% (all by weight based on total solids).

Examples of the epoxy resin include an epoxy compound obtained by reacting a bisphenol such as bisphenol A, bisphenol F, bisphenol AD with epihalohydrin or β-methylepohalohydrin, and a copolymer thereof. . Further, monocarboxylic acid or dicarboxylic acid modified products, mono-, di- or polyalcohol-modified products, mono- or diamine-modified products, mono-, di-, or polyphenol-modified products of these epoxy compounds can also be used as the epoxy resin.

As the crosslinking agent for the epoxy resin, various known crosslinking agents for epoxy resins can be used. Preferred crosslinking agents are polyisocyanate resins and amino resins, and may be used alone or as a mixture of two or more. The crosslinking agent is desirably used in an amount of 5 to 40 parts by weight based on 100 parts by weight of the epoxy resin.

Polyisocyanate resins useful as a crosslinking agent include aromatic diisocyanates such as xylylene diisocyanate, tolylene diisocyanate, and 4,4'-diphenylmethane diisocyanate, and aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate. Diisocyanates, alicyclic diisocyanates such as isophorone diisocyanate,
Furthermore, polyisocyanate compounds such as multimers of these diisocyanates and adducts with polyhydric alcohols,
In addition, these polyisocyanate compounds are used as blocking agents (eg, phenolic, lactam, alcohol, active methylene, mercaptan, imine, amine,
There is a blocked polyisocyanate resin in which an isocyanate group is blocked by reacting with an imidazole-based, oxime-based or sulfite-based blocking agent. When such a blocked polyisocyanate resin is used, an organotin compound such as dibutyltin dilaurate can be added together as a dissociation catalyst.

Examples of amino resins useful as crosslinking agents include:
For example, there are condensates of formaldehyde or paraformaldehyde alkylated with an alcohol having 1 to 4 carbon atoms and urea, N, N′-ethylene urea, dicyandiamide, aminotriazine and the like.Specifically, methoxylated methylol urea, Methoxylated methylol
N, N'-ethylene urea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine and the like.

Catalyst for crosslinking reaction between epoxy resin and crosslinking agent
Examples of the (i.e., curing catalyst) include an acid catalyst, a titanium chelating agent, and a titanate coupling agent. As the acid catalyst, phosphoric acid, phosphoric acid butyl ester, paratoluenesulfonic acid, dinonylnaphthalenesulfonic acid, cyclohexylsulfamic acid and the like can be used. As the titanium chelating agent, titanium acetylacetonate, tetra-n-butyl titanate and the like can be used. Examples of titanate-based coupling agents include isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, and tetraoctyl bis (ditridecyl phosphite) titanate , Tetra
(2,2-diallyloxymethyl-1-butyl) bis (di-
Tridecyl) phosphite titanate, bis (dioctyl pyrophosphate) oxyacetate titanate,
Bis (dioctyl pyrophosphate) ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearyl titanate, isopropyl isostearyl diacryl titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, isopropyl tri (N-aminoethyl -Aminoethyl) titanate, dicumylphenyloxyacetate titanate,
And diisostearoylethylene titanate.

Examples of the silane coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldichlorosilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane. Silane, γ-aminopropyltriethoxysilane, N- (β
-Aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ- Glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, vinyltris (β-methoxy-ethoxy) silane,
β- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane and the like.

As the fluororesin, homopolymerization of a fluorine-containing monomer such as tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene, vinyl fluoride, and vinylidene fluoride or copolymerization with another monomer can be used. Any fluoropolymer obtained can be used, and either a thermoplastic or thermosetting resin may be used. Specifically, for example,
Examples thereof include polyvinyl fluoride and polyvinylidene fluoride. Examples of commercially available products include Kynar 500 (polyvinylidene fluoride manufactured by Atochem North America) as a thermoplastic fluororesin and Lumiflon 200 (made by Asahi Glass) as a thermosetting fluororesin.

When using a thermosetting fluororesin,
As a cross-linking agent, one or more of melamine resin, polyisocyanate and urea resin are added
It is contained in an amount of up to 30% by weight.

As the acrylic resin, those having high compatibility with the fluororesin to be used are preferable, and these may be either thermoplastic or thermosetting. Examples of the thermoplastic acrylic resin include polymers and copolymers of acrylate or methacrylate such as methyl methacrylate and ethyl acrylate. In this case, the ester group of the ester product is methyl, ethyl, propyl, butyl,
It may be an alkyl group such as isobutyl, n-hexyl, lauryl and stearyl. In the case of a copolymer, the ester group may be one type or two or more types. Thermosetting acrylic resins include monomers having functional groups (carboxyl group, hydroxyl group, amino group, methylol group, epoxy group, etc.) that form a crosslinked structure in the molecule, such as acrylic acid, methacrylic acid, acrylamide, Selected from the group consisting of methacrylamide, N-methylolacrylamide, allyl glycidyl ether, glycidyl methacrylate and the like, and the group of styrene and the above-mentioned acrylic acid or methacrylic acid ester which do not have such a functional group. Examples include, but are not limited to, polymers obtained by copolymerizing two or more monomers.

The above-mentioned adhesive components are mixed at a predetermined ratio,
Usually, it is diluted with a thinner to obtain a liquid composition having a viscosity suitable for application, and used for forming an adhesive layer. Various pigments may be added to the adhesive composition, if desired, in addition to the above components. Examples of pigments that can be added include general pigments such as titanium white, silica, iron oxide, talc, clay, calcium carbonate, and barium sulfate. Further, in order to improve the end face corrosion resistance of the laminated metal plate, a rust preventive pigment, for example, strontium chromate, zinc chromate or the like may be added to the adhesive. When these pigments are added, the amount of addition is preferably not more than 250 parts by weight based on 100 parts by weight of the total resin in the adhesive, and the addition of more than this significantly lowers the workability of the adhesive film.

In order to manufacture the laminated metal sheet of the present invention, the adhesive composition thus prepared is applied to an undercoat layer of a base metal sheet subjected to an undercoat treatment using a suitable coating apparatus such as a roll coater. Apply to. The coating amount is preferably about ² to 30 g / m ^{2 in} terms of the adhesion amount of the adhesive after baking and drying. When a pigment is added to the adhesive, the coating amount is larger than when no pigment is added. The metal plate coated with the adhesive is then heated and the adhesive is baked and dried. Usually, a fluororesin film is immediately supplied onto the metal plate and pressed against the metal plate under pressure to produce a laminated metal plate. Is done. The laminate may be provided on both sides of the base metal plate or on one side.

When a crosslinking catalyst or a silane coupling agent is added to the adhesive composition, the baking temperature of the adhesive is 160
~ 200 ℃ (usually around 180 ℃), plate temperature during lamination
(Lamination temperature) is 140-180 ° C (usually around 160 ° C) and the melting point of fluororesin film (usually 170-190 ° C).
(Approximately ° C.) lower temperature, and wrinkles, breakage, and elongation of the film during the operation can be avoided. In addition, since leveling of the film during lamination can be avoided, even if the film is of a low gloss type having fine irregularities on the surface, this surface structure is maintained even during lamination, and there is no danger of reducing the commercial value.

[0039]

【Example】

(Example 1) Hot-dip galvanized steel sheet (coated amount: 1 g / m ² ) treated with zinc phosphate base
120 g / m ² , a plate thickness of 0.6 mm) and a vinylidene fluoride / acrylic mixed resin film (0.040 mm) manufactured by Sumitomo Bakelite Co., Ltd. as a fluororesin laminating film, to produce a laminated steel plate.

The adhesive used had the composition shown in Table 1-1.
(Parts by weight), and prepared by dissolving and dispersing each resin together with a crosslinking reaction catalyst and a silane coupling agent in a thinner (mixed solvent of xylene / isophorone (1/1)) with a paint conditioner. . The solids concentration of the resulting adhesive was in the range of 20-60% by weight.

Epoxy resin manufactured by Dainippon Ink and Chemicals, Inc.
(Trade name: Epicron), melamine resin (trade name: Super Beckamine) manufactured by Dainippon Ink and Chemicals, Ltd., and acrylic resin manufactured by Mitsubishi Rayon Co., Ltd.
(Trade name: Hipet), vinylidene fluoride resin (trade name: Kynar) manufactured by Atochem North America, Inc. as a fluororesin, p-toluenesulfonic acid, silane coupling agent manufactured by Wako Pure Chemical Industries, Ltd. as a catalyst for crosslinking reaction Used was vinyltrichlorosilane.

After drying the obtained adhesive with a bar coater, it was coated on one side of the hot-dip galvanized steel sheet so as to have an adhesion amount of 10 g / m ^2, and was heated for about 1 minute in a conveyer type hot air oven at 250 to 350 ° C. After baking to dry the adhesive film, the film and the steel plate were bonded by a laminator arranged on the exit side of the oven. Due to the short bake, the actual bake temperature was much lower than this oven temperature. Laminating speed is
At this speed, the crimping time between the nips of the laminator was about 0.1 second. The temperature immediately before entering the laminator was taken as the lamination temperature. Immediately after lamination, the resulting laminated steel sheet was water-cooled.

The primary adhesion of the laminated steel sheet thus manufactured was determined by inserting a 5-mm-wide cross slit into the sample.
An Erichsen overhang of 5 mm was performed and evaluated by examining the adhesion of the film or adhesive. The secondary adhesion was examined by immersing the sample in boiling water for 2 hours and then performing the same Erichsen overhang. 5 points with no film peeling at both primary and secondary adhesion (excellent)
, 4 points when the edge of the cut part slightly peeled off (good)
In addition, one having a large peeling was evaluated as one point (poor), and evaluated according to five levels according to the degree of film peeling. Practically, it is considered that the adhesion is good if the number is 3 or more, preferably 4 or more.

Further, a salt spray test based on JIS Z2371 was performed for 1000 hours using the obtained 0T bending test piece of the laminated steel sheet to investigate corrosion resistance. Corrosion status is 0
Both the T-bend and the cut end face were examined. The bent portion was evaluated on a scale of 1 to 5 where no white rust was generated (excellent) and 1 where much white rust was generated (poor).
The cut end face was evaluated by measuring the blister width (mm) from the end face. The test results are shown in Table 1-2.

(Example 2) Hot-dip galvanized steel sheet (coating amount 120 g / m ² , plate thickness) treated as a base metal plate by a coating type chromate treatment (Cr adhesion amount 50 mg / m ² ) 0.5
mm) and the same fluororesin film as in Example 1 was used as a laminate film to produce a laminated steel sheet. The adhesive used was prepared in the same manner as in Example 1 so as to have the composition (parts by weight) shown in Table 2-1. This adhesive contained a pigment and did not add a catalyst for crosslinking reaction.

Dainippon Ink and Chemicals as epoxy resin
Epicron (trade name) manufactured by Co., Ltd., and blocked polyisocyanate (trade name: Vernock D-
550), and dibutyltin dilaurate in an amount corresponding to 2% by weight of the added amount of the blocked polyisocyanate was added as a dissociation catalyst for the blocking agent. The fluororesin is the same as in Example 1 (trade name: Kainer), γ-aminopropyltriethoxysilane is used as a coupling agent, and a titanium dioxide pigment manufactured by Ishihara Sangyo is used as a pigment.
(Trade name).

After drying the adhesive with a bar coater, the adhesion amount is 25 g.
/ m ^{2 on} one side of the hot-dip galvanized steel sheet, baked for about 1 minute in a conveyor-type hot-air oven at 250-300 ° C to dry the adhesive, and filmed with a laminator provided on the exit side of the oven. And a steel plate. The laminating speed was 10 m / min and the crimping time was about 0.2 seconds. The temperature immediately before entering the laminator was taken as the lamination temperature. The laminated steel sheet obtained immediately after lamination was water-cooled.

The results of the evaluation of the primary adhesion, secondary adhesion and corrosion resistance of this laminated steel sheet in the same manner as in Example 1 are shown in Table 2-2.

(Example 3) As a base metal plate, a stainless steel plate (SUS304, DF material, plate thickness 0.5 mm) which had been subjected to coating type chromate treatment (Cr adhesion amount: 50 mg / m ² ) was used and laminated. As the film, a polyvinylidene fluoride film (0.040 mm thick) manufactured by Electrochemical Co., Ltd. was used.

An adhesive having the composition shown in Table 3-1 was prepared and used in the same manner as in Example 1. Although not shown in Table 3-1, the adhesive contained a pigment. As the pigment, the same titanium dioxide pigment as used in Example 2 was added at a ratio of 180 parts by weight with respect to 100 parts by weight of the resin, and dispersed in the adhesive.

Epoxy resin is Epicron (trade name) manufactured by Dainippon Ink and Chemicals, a melamine resin (trade name Super Beckamine) manufactured by Dainippon Ink and Chemicals as an amino resin as a cross-linking agent, and Mitsubishi resin as an acrylic resin. Using a high-pet (trade name) manufactured by Rayon, p-toluenesulfonic acid, a fluororesin, and a silane coupling agent as other crosslinking reaction catalysts were all the same as those used in Example 1.

The laminating conditions and evaluation method were as described in Example 1.
And 2 (Adhesive adhesion amount 5 g / m ² , laminating speed 20 m / min). The test results are shown in Table 3-2. In this example, in the salt spray test, all the samples showed good corrosion resistance, and no blisters were observed from the end faces.

(Example 4) Aluminum alloy plate (Al-Mg type, A5052P, mill finish) as base metal plate 0.8 m thick
m was used. As a base treatment, phosphoric acid chromate (Nippon Paint, Alodine 405, 30 mg / m ² ) was applied. The laminated fluororesin film was the same as that used in Example 1. The adhesive shown in Table 4-1 was prepared in the same manner as in Example 3. That is, in the same manner as in Example 3, the titanium dioxide pigment was added at a ratio of 180 parts to 100 parts by weight of the resin and dispersed in the adhesive.

As a fluororesin, a thermosetting fluororesin (trade name: Lumiflon) manufactured by Asahi Kasei Corporation, other epoxy resins, a crosslinker amino resin, an acrylic resin, a crosslinking reaction catalyst (p-toluenesulfonic acid), The silane coupling agent was the same as in Example 3.

The laminating conditions and the evaluation method were as described in Example 1.
And 2. (Adhesive adhesion amount 25 g / m ² , laminating speed 10 m / min). The test results are shown in Table 4-2.

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

[Table 3]

[0059]

[Table 4]

[0060]

As can be seen from the examples, in the fluororesin film-laminated metal plate of the present invention, the film and the metal plate are firmly adhered to each other, and the film itself has good corrosion resistance in addition to excellent weather resistance. Therefore, corrosion from the end face is also effectively prevented. Therefore, the present invention provides a laminated metal sheet that is sufficiently resistant to outdoor use and is suitable for high-quality building materials having excellent weather resistance and corrosion resistance. In addition, the laminated metal sheet of the present invention does not use a special base material, and can be easily manufactured in the same manner as a normal laminated metal sheet only by the steps of preparing the base metal sheet and laminating a film via an adhesive. can do. In addition, when one or both of a crosslinking catalyst and a silane coupling agent are added to the adhesive composition, low-temperature baking and low-temperature lamination can be performed, and not only deterioration of the surface appearance is prevented, but also fluororesin is added during lamination. Since the film is not softened or melted, the film does not wrinkle, break or elongate, and the possibility of lamination failure is significantly reduced.

Continuation of the front page (72) Inventor Toshiaki Shioda 4-33, Kitahama, Chuo-ku, Osaka-shi Inside Sumitomo Metal Industries, Ltd. (56) References JP-B-59-43226 (JP, B2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B32B 15/08 102 C09J 163/00

Claims (2)

(57) [Claims] 1. One or more layers formed from a composition containing an epoxy resin and a crosslinking agent thereof, an acrylic resin, and a fluororesin on one or both of a phosphate-based and a chromate-based chemical conversion coating. A fluororesin laminated metal plate on which a fluororesin film is laminated via an adhesive layer. 2. The composition for forming an adhesive layer further comprises one or both of a catalyst for a crosslinking reaction between an epoxy resin and a crosslinking agent thereof and a silane coupling agent. 2. The fluororesin film-laminated metal plate according to 1.