JP5416625B2 - Pre-coated aluminum plate - Google Patents

Description

  The present invention relates to an aluminum plate and an aluminum alloy plate used in a high-temperature environment such as automobile exhaust system members and heat-resistant structural members of home appliances, and a precoated aluminum plate having a heat-resistant coating provided on the surface of the aluminum plate by painting. About.

Surface treatment of aluminum plates (including aluminum alloy plates; the same applies hereinafter) used at high temperatures, such as automotive exhaust system members and heat-resistant structural members of home appliances, has been conventionally performed after forming the aluminum plate into a product shape. It has been carried out by a post-coating method that forms a highly inorganic film or silicone resin film. However, the surface treatment is preferably performed by a pre-coating method in which a resin film is formed in advance on the surface of the aluminum plate before molding from the viewpoints of mass productivity, simplification of the manufacturing process, and cost reduction.
The following are mentioned as a precoat material manufactured by the precoat method and excellent in heat resistance.

  For example, Patent Document 1 describes an oil-free organic-coated metal plate having excellent press workability and post-processing heat resistance by containing a polyolefin wax and silica in an ether / ester type urethane resin and an epoxy resin. ing.

  Patent Document 2 describes a pre-coated steel sheet having good workability and excellent heat resistance by dispersing a low melting point frit and aluminum powder, graphite powder, and nickel powder in a silicone resin.

  Further, in Patent Document 3, a primer coating film based on a heat-resistant resin selected from a polyethersulfone resin, a polyphenylsulfide resin, and a polyamideimide resin is laminated with a top coating film having a fluorine resin surface concentrated. The precoat steel plate which can express heat-resistant non-adhesiveness by this is described.

JP-A-8-192102 JP 2002-361794 A JP 2005-262465 A

The exhaust system members of automobiles and heat-resistant structural members of home appliances may have a temperature of 400 ° C. or higher during actual use.
However, the heat-resistant temperature of the urethane resin and epoxy resin described in Patent Document 1 is about 200 ° C. at the highest, and the resin begins to decompose in a high temperature environment higher than that.

  In addition, the precoat material mainly composed of a silicone resin described in Patent Document 2 has high heat resistance, and can be used even when the use temperature exceeds 200 ° C. However, the silicone resin is generally used as a urethane resin or an epoxy resin. It is necessary to perform baking for a long time at a temperature higher than a typical resin, and a baking time of at least 1 minute is required at a temperature of 300 ° C. or higher. If the baking is insufficient, the required heat resistance and workability will not be ensured, and there will be problems such as blocking when winding the plate in a coil shape. Sex is reduced.

  The polyethersulfone resin and polyphenylsulfide resin used as the primer coating described in Patent Document 3 are known as engineering plastics, but it is not easy to make a paint, and even if it can be realized, the cost is high. there is a possibility. Furthermore, since the fluororesin used for a top coating film is also expensive, the cost of a precoat steel plate becomes high and is not preferable.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a precoated aluminum plate that can withstand a high temperature of 400 ° C. or more, has good mass productivity, is inexpensive, and has excellent workability.

  As a result of intensive studies to solve the above problems, the present inventors can solve the above problems by setting the addition ratio (mass ratio) and film thickness of the aqueous resin and silicate compound to a specific range. As a result, the present invention has been completed.

That is, the precoated aluminum plate of the invention according to claim 1 is a precoated aluminum plate in which a heat resistant film is formed on the surface of an aluminum plate or an aluminum alloy plate, and the heat resistant film includes an aqueous resin and a silicate compound. from it, further lubricant as an optional component, fluidity modifiers, leveling agents, popping agents, preservatives, stabilizers, seeing containing at least one of the anti-blocking agent, the aqueous resin / silicate compound The mass ratio is 0.8 or more and 7 or less, and the film thickness is 0.2 μm or more and 20 μm or less.

  By including an aqueous resin and a silicate compound in the heat resistant film, it is possible to withstand a high temperature environment of 400 ° C. or higher. By setting the mass ratio of the aqueous resin / silicate compound in the heat resistant film to 0.8 or more and 7 or less, the appearance of the heat resistant film can be kept good. Furthermore, by making the thickness of the heat resistant film 0.2 μm or more and 20 μm or less, a heat resistant film can be continuously formed on a coiled aluminum plate using a roll coater. It is excellent in productivity and desirable in terms of cost. In addition, since the heat-resistant film of the precoated aluminum plate is a resin film containing an aqueous resin and a silicate compound, when the maximum temperature reached is less than 300 ° C. and the baking time is less than 50 seconds However, heat resistance and workability are not deteriorated, and the mass productivity is excellent. Both the aqueous resin and the silicate compound contained in the heat-resistant film are available at a low price, and no special method is required for the adjustment of the coating solution, so that the cost is excellent.

The precoated aluminum plate of the invention according to claim 2 is characterized in that a topcoat film is formed on the heat resistant film.

  By forming the top coat film on the heat resistant film, functions such as processability, lubricity, fingerprint resistance, and blocking resistance can be imparted while maintaining high heat resistance.

  Since the precoated aluminum plate according to the present invention forms a heat-resistant film with a specific range of addition ratio (mass ratio) and film thickness of the aqueous resin and silicate compound, it withstands high temperatures of 400 ° C. or higher, Good mass productivity, low cost, and excellent workability.

It is a cross-sectional schematic diagram of the precoat aluminum plate which concerns on 1st Embodiment. It is a cross-sectional schematic diagram of the precoat aluminum plate which concerns on the 1st modification in 1st Embodiment. It is a cross-sectional schematic diagram of the precoat aluminum plate which concerns on the 2nd modification in 1st Embodiment. It is a cross-sectional schematic diagram of the precoat aluminum plate which concerns on the 3rd modification in 1st Embodiment. It is a cross-sectional schematic diagram of the precoat aluminum plate which concerns on 2nd Embodiment. It is a cross-sectional schematic diagram of the precoat aluminum plate which concerns on the 1st modification in 2nd Embodiment. It is a cross-sectional schematic diagram of the precoat aluminum plate which concerns on the 2nd modification in 2nd Embodiment. It is a cross-sectional schematic diagram of the precoat aluminum plate which concerns on the 3rd modification in 2nd Embodiment.

Hereinafter, the precoated aluminum plate according to the present invention will be described in detail with reference to the drawings as appropriate.
First, a precoated aluminum plate according to a first embodiment of the present invention will be described with reference to FIG.

[First Embodiment]
As shown in FIG. 1, the precoat aluminum plate 1 which concerns on 1st Embodiment forms the heat resistant film 3 on the surface of the aluminum plate 2. As shown in FIG.

[Aluminum plate]
The aluminum plate 2 used in the present invention is made of aluminum or an aluminum alloy. For example, 1000 series industrial pure aluminum specified in JIS, 3000 series Al—Mn alloy, 5000 series Al—Mg alloy, etc. can be used. In particular, when drawing or ironing, A1050, A1100, A3003, and A3004 defined in JIS H4000 are recommended. In addition, A5052 and A5182 are recommended for use in applications where strength is desired. There is no restriction | limiting in particular about tempering and board thickness, According to the objective, various tempering and board thickness can be selected.

[Heat resistant film]
In the precoated aluminum plate 1 of the present invention, the heat-resistant film 3 is provided for imparting workability as well as heat resistance. In consideration of productivity and cost, the heat-resistant coating 3 is preferably one that can be continuously coated with a roll coater and can be baked for a short time of about 20 to 50 seconds in a baking furnace.

  In order to form the heat-resistant film 3 of the precoated aluminum plate 1 according to the first embodiment, it is essential that the mass ratio of the aqueous resin / silicate compound is 0.8 or more and 7 or less. By setting the mass ratio of the aqueous resin / silicate compound within this range, the appearance of the heat resistant film can be kept good.

  As the aqueous resin, acrylic resin, ethylene resin, epoxy resin, polyester resin, urethane resin, PVA (polyvinyl alcohol), PEO (polyethylene oxide), CMC (carboxymethylcellulose), or a mixture thereof can be used.

  As the silicate compound, lithium silicate, sodium silicate, potassium silicate, or a mixture thereof can be used.

If the mass ratio of the aqueous resin / silicate compound is less than 0.8, since a film crack occurs immediately after baking of the coating, a sound film cannot be formed. On the other hand, if the mass ratio exceeds 7, the heat resistance is lowered, which is not realistic. In addition, the coating becomes difficult due to thickening.
The mass ratio of the aqueous resin / silicate compound is preferably 0.9 or more, more preferably 2.8 or more, and still more preferably 3.7 or more. The mass ratio of the aqueous resin / silicate compound is preferably 6.8 or less.
The total content of the aqueous resin and the silicate compound is preferably 25% by mass or more (as solid content) of the heat-resistant film. By setting it as 25 mass% or more, workability becomes favorable and excellent heat resistance can be obtained.

  Moreover, it is essential that the film thickness of the heat resistant coating 3 is 0.2 μm or more and 20 μm or less. By making the film thickness of the heat-resistant film 3 in this range, the heat-resistant film 3 can be continuously formed on the coiled aluminum plate 2 using a roll coater, so that mass productivity is excellent. It is also preferable in terms of cost.

When the film thickness of the heat-resistant film 3 is less than 0.2 μm, it is difficult to control the film thickness, it is difficult to apply the film uniformly, and as a result of forming an unpainted portion, the appearance is not uniform and the appearance is poor. Further, it is necessary to increase the pressure between the pickup roll and the applicator roll, and the roll is easily worn. On the other hand, when the film thickness of the heat-resistant film 3 exceeds 20 μm, blisters and repellency are generated by baking after coating, and the appearance is deteriorated. Moreover, since the liftability of the paint by the pick-up roll of the roll coater becomes insufficient, the obtained heat-resistant film 3 has extremely large variations in film thickness.
The film thickness of the heat resistant coating 3 is preferably 2 μm or more, and more preferably 7 μm or more.

[First Modification in First Embodiment]
The precoated aluminum plate 1 according to the first embodiment can form the topcoat film 4 on the heat resistant film 3 as in the first modification shown in FIG. In this way, functions such as workability, lubricity, fingerprint resistance, and blocking resistance can be imparted while maintaining high heat resistance.

[Top coat film]
The top coat film 4 is preferably formed by applying an aqueous resin such as an acrylic resin, an ethylene resin, or an epoxy resin. Further, the top coat film 4 can contain additives according to the purpose. For example, carnauba wax, polyethylene wax, etc. can be included to improve lubricity, optical adjustment fine particles can be included to improve fingerprint resistance, and blocking prevention is improved to improve blocking resistance. An agent can be included. These can be selected according to the purpose of use, and the kind thereof is not particularly limited. The top coat film 4 preferably has a film thickness of 0.2 to 5 μm in order to reliably exhibit the above-described effects.

[Second Modification of First Embodiment]
The precoated aluminum plate 1 according to the first embodiment can form a base treatment film 5 between the aluminum plate 2 and the heat resistant film 3 as in the second modification shown in FIG. In this way, the corrosion resistance and adhesion of the heat resistant coating 3 to the aluminum plate 2 can be improved.

[Undercoat film]
When the ground treatment film 5 is formed, the corrosion resistance and the adhesion between the aluminum plate 2 and the heat resistant film 3 can be improved as compared with the case where the ground treatment film 5 is not formed.
As the ground treatment film 5, a conventionally known film containing Cr, Zr or Ti can be used. For example, a phosphate chromate film, a chromate chromate film, a zirconium phosphate film, a zirconium oxide film, a titanium phosphate film, a coating type chromate film, a coating type zirconium film, and the like can be appropriately formed. Moreover, you may make these contain an organic component as needed. From the viewpoint of environmental consideration in recent years, it is desirable to form a phosphate chromate film that does not contain hexavalent chromium, a zirconium phosphate film, a zirconium oxide film, a titanium phosphate film, a coating-type zirconium film, or the like.

The amount of Cr, Zr or Ti deposited on the aluminum plate 2 by the ground treatment film 5 (Cr, Zr or Ti converted value) is measured comparatively simply and quantitatively using, for example, a conventionally known fluorescent X-ray method. can do. Therefore, quality control of the aluminum plate 2 can be performed without hindering productivity. The adhesion amount of the ground treatment film 5 is preferably about 10 to 50 mg / m ^{2 in} terms of Cr, Zr or Ti. When the adhesion amount is less than 10 mg / m ² , the effect of improving the corrosion resistance and adhesion cannot be expected as compared with the case where the base treatment film 5 is not formed. In addition, when the adhesion amount of the base treatment film 5 exceeds 50 mg / m ² , cracks are likely to occur in the base treatment film 5, which is not preferable.

[Third Modification of First Embodiment]
The precoated aluminum plate 1 according to the first embodiment forms a base treatment film 5 between the aluminum plate 2 and the heat resistant film 3 as in the third modification shown in FIG. The coat film 4 can be formed. In this way, functions such as processability, lubricity, fingerprint resistance, and blocking resistance can be imparted by the top coat film 4 while maintaining high heat resistance by the heat resistant film 3, and further, the surface treatment. The adhesion of the heat-resistant film 3 to the aluminum plate 2 can be improved by the film 5.
The top coat film 4 is the same as that described in the first modified example, and the ground treatment film 5 is the same as that described in the second modified example, and thus detailed description thereof is omitted.

[Second Embodiment]
Next, a precoated aluminum plate according to a second embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 5, the precoated aluminum plate 1 according to the second embodiment is obtained by forming a heat resistant coating 3 containing an inorganic pigment 6 on the surface of an aluminum plate 2. By containing the inorganic pigment 4 in the heat resistant film 3, the heat resistant film 3 can be colored.
In addition, since it is the same as that of 1st Embodiment about the silicate compound of the aluminum plate 2, the corrosion-resistant film | membrane 3, and aqueous resin, detailed description is abbreviate | omitted.

[Inorganic pigments]
As the inorganic pigment 6, it is preferable to use a pigment having heat resistance that does not decompose or discolor even in a high temperature atmosphere of 400 ° C. As such an inorganic pigment 4, titanium oxide, carbon black, black fired pigment (cobalt black, manganese bismuth) Black, copper / chromium black, copper / manganese / iron black, etc.) and extender pigments such as calcium carbonate, barite powder, talc, and kaolin can be used. As the inorganic pigment 6, any one selected from these can be used, and two or more kinds can be mixed and used.

  Further, as the inorganic pigment 6, rust preventive pigments such as lead oxide, zinc powder and phosphate, metal powder pigments such as aluminum pigment, nickel powder and zinc powder, or Au, Ag, Pt, Cu, Ni, etc. Conductive pigments can be used.

The addition amount of the inorganic pigment 6 is preferably 20% by mass or more, and more preferably 40% by mass or more in order to obtain a good appearance. When the added amount of the inorganic pigment 6 is less than 20% by mass, uneven color tends to occur due to poor dispersion of the pigment.
The addition amount of the inorganic pigment 6 is preferably less than 62% by mass, more preferably 58% by mass or less, and even more preferably 55% by mass or less in order to ensure heat resistance.

  In addition, in the precoat aluminum plate 1 which concerns on 2nd Embodiment which adds the inorganic pigment 6, in order to obtain a favorable external appearance, it is necessary to make a film thickness into 2 micrometers or more and 20 micrometers or less.

When the film thickness of the heat-resistant film 3 in the second embodiment is less than 2 μm, color unevenness occurs due to insufficient coating of the aluminum plate 1. On the other hand, when the film thickness of the heat-resistant film 3 in the second embodiment exceeds 20 μm, blisters and repellency are generated by baking after coating, and the appearance deteriorates. Moreover, since the liftability of the paint by the pick-up roll of the roll coater becomes insufficient, the obtained heat-resistant film 3 has extremely large variations in film thickness.
The film thickness of the heat resistant coating 3 in the second embodiment is preferably 7 μm or more, and preferably 18 μm or less.

  Moreover, the heat resistant film 3 in the second embodiment needs to have a mass ratio of aqueous resin / silicate compound of 2.0 or more and 5 or less in order to obtain excellent processability and heat discoloration. In this way, even if an inorganic pigment is added, it can be processed without any problem, and further, the heat-resistant film 3 is heated to 400 ° C. in an air atmosphere and the surface of the heat-resistant film 3 has a fine diameter of 200 nm or less. Since no pores are formed and the film is dense, excellent heat discoloration can be obtained.

When the mass ratio of the aqueous resin / silicate compound in the second embodiment is less than 2.0, the surface of the heat-resistant film 3 after heating the heat-resistant film 3 to 400 ° C. in an air atmosphere has a pore diameter of 200 nm or less. Therefore, the surface of the heat-resistant film 3 is roughened to cause whitening and gloss reduction, resulting in inferior heat discoloration. Moreover, since the ratio of aqueous resin is small, workability is also inferior. On the other hand, when the mass ratio of the aqueous resin / silicate compound in the second embodiment exceeds 5, since the amount of the inorganic pigment 6 added is large, the viscosity of the paint becomes high and coating becomes difficult. Moreover, it is not preferable because the paint life is reduced.
The mass ratio of the aqueous resin / silicate compound in the second embodiment is preferably 2.3 or more, and more preferably 2.8 or more. The mass ratio of the aqueous resin / silicate compound in the second embodiment is preferably 4.6 or less.

[First Modification to Third Modification in Second Embodiment]
The precoated aluminum plate 1 according to the second embodiment can also be implemented in the same modified example as in the first embodiment.
For example, as shown in FIG. 6, it can be set as the precoat aluminum plate 1 which formed the topcoat film | membrane 4 on the heat resistant film | membrane 3 to which the inorganic pigment 6 was added as a 1st modification.
For example, as shown in FIG. 7, as a second modification, a precoated aluminum plate 1 in which a base treatment film 5 is formed between an aluminum plate 2 and a heat resistant film 3 to which an inorganic pigment 6 is added is used. Can do.
Further, for example, as shown in FIG. 8, as a third modification, a base treatment film 5 is formed between the aluminum plate 2 and the heat resistant film 3 to which the inorganic pigment 6 is added. It can be set as the precoat aluminum plate 1 in which the topcoat film | membrane 4 was formed.

  In addition, components other than the heat resistant coating 3 of the precoated aluminum plate 1 according to the first to third modifications in the second embodiment are the same as those in the first embodiment and the first to third modifications. Therefore, detailed description is omitted.

As mentioned above, although the 1st Embodiment and 2nd Embodiment and these modifications were shown and the precoat aluminum plate 1 which concerns on this invention was demonstrated, the precoat aluminum plate 1 which concerns on this invention inhibits the desired effect of this invention. Other components may be included as necessary.
For example, one or more lubricants such as palm oil, carnauba wax, polyethylene wax, and microcrystalline wax can be included in the heat resistant coating 3 in order to further improve press moldability. The heat-resistant film 3 is a commonly used pigment, pigment dispersant, fluidity modifier, leveling agent, anti-skid agent, preservative, in order to ensure the paint performance and general performance as a pre-coated metal plate. , Stabilizers, anti-blocking agents and the like can be contained.

Furthermore, an undercoat layer may be provided between the heat-resistant coating 3 and the metal plate and / or the ground treatment coating 5 in order to improve the adhesion between the heat-resistant coating 3 and the aluminum plate 2. Thereby, the moldability of the precoat aluminum plate 1 can be improved more.
Examples of the undercoat layer include an acrylic resin, an epoxy resin, a polyester resin, and a silica-based film.

  The pre-coated aluminum plate 1 according to the present invention described above can be molded into a predetermined shape and used as an exhaust system member of an automobile such as a muffler, or a heat-resistant structural member of home appliances such as a gas stove, a microwave oven, and an oven. it can.

  Next, the pre-coated aluminum plate according to the present invention will be described more specifically by exemplifying examples that satisfy the requirements of the present invention and comparative examples that are not.

[First embodiment]
First, the precoated aluminum plate on which a heat-resistant film without adding an inorganic pigment is formed will be specifically described.

First, an aluminum plate (JIS 1100H26 material, plate thickness 0.3 mm) was subjected to a phosphoric acid chromate treatment as a base treatment to form a phosphate chromate film of 20 mg / m ^{2 in} terms of Cr on both sides.

Subsequently, each paint was prepared by mixing the silicate compound and the aqueous resin shown in Table 1 below at a mass ratio shown in Table 1. The prepared paint was applied to an aluminum plate using a roll coater and baked under conditions of a baking temperature of 200 ° C. and a heating time of 30 seconds to form a heat resistant film having the film thickness shown in Table 1. Example 1 Precoated aluminum plates of -6 and Comparative Examples 1-7 were prepared. The film thickness of the heat-resistant film of each precoated aluminum plate was measured using an eddy current film thickness meter. The results are also shown in Table 1 below.
In Example 4, a top coat film was formed on the heat resistant film using the resins shown in Table 1. The top coat film was formed by using a roll coater and baking treatment at 200 ° C. for 30 seconds in the same manner as the heat resistant film. The film thickness of the top coat film was 2 μm.
Further, in Example 6, in addition to the aqueous resin and the silicate compound, polyethylene wax was added, and heat resistance was obtained using a paint prepared so that the total content of the aqueous resin and the silicate compound was 25%. Formed an adhesive film.

  The heating method for the aluminum plate coated with the paint is a continuous baking method in which the aluminum plate coated with the paint moves from the inlet to the outlet of the oven, and the time for the aluminum plate to pass through the oven is the heating time. Adjusted to seconds. Moreover, the highest reached temperature of the aluminum plate confirmed with the heat label affixed on the aluminum plate was made into baking temperature, and it adjusted so that this might be set to 200 degreeC.

  The appearance, heat resistance and workability of the heat-resistant film of the prepared precoated aluminum plate were evaluated as follows.

<Appearance evaluation>
The appearance of the pre-coated aluminum plate immediately after the heat-resistant film was formed was visually evaluated. If any of blisters, repellencies, or unpainted parts was found, it was judged as bad (x), and if none, good (◯).

<Evaluation of heat resistance>
The heat resistance was evaluated by heating the prepared pre-coated aluminum plate at 400 ° C. for 24 hours in the air atmosphere. If the heat-resistant film disappeared compared to before heating, the heat-resistant film was Those that discolored but remained were rated good (◯), and those that did not discolor the heat-resistant film were rated excellent (◎).

<Evaluation of workability>
For the evaluation of workability, 0T 180 degree bending process and 3T 180 degree bending process specified in JIS K5400 are performed, and the heat-resistant film on the 3T 180 degree bending part is peeled off with a cellophane tape. The product was evaluated as good (◯), and the heat resistant film of the 0T 180 ° bent portion was not exfoliated with the cellophane tape.

<Evaluation of corrosion resistance>
Corrosion resistance was evaluated by conducting a neutral salt spray test specified in JIS Z2371 for 100 hours. Corrosion was observed in the flat part and the crosscut part as defective (x), and corrosion was seen only in the crosscut part. Was good (◯), and no flat part or cross cut part was corroded.

  Table 1 shows the types of silicate compounds, types of aqueous resins, mass ratios of aqueous resins / silicate compounds, film thickness [μm], presence / absence of top coat film, appearance, heat resistance and processability. An evaluation result is shown. The underline in Table 1 indicates that the requirements of the present invention are not satisfied.

As shown in Table 1, since Examples 1 to 6 satisfied the requirements of the present invention, the evaluation results of appearance, heat resistance, and workability were all good or excellent. In particular, since the top coat film was formed in Example 4, the workability was more excellent as compared with Examples 1-3, 5, and 6.
On the other hand, since Comparative Examples 1-7 did not satisfy any of the requirements of the present invention, any of the appearance, heat resistance, and workability was poor.

Specifically, in Comparative Example 1, the heat-resistant film was not formed because the mass ratio of the aqueous resin / silicate compound was less than the lower limit.
In Comparative Example 2, since the mass ratio of the aqueous resin / silicate compound exceeded the upper limit, it could not be applied.
Since the film thickness of Comparative Example 3 was less than the lower limit, the appearance was poor.
In Comparative Example 4, since the film thickness exceeded the upper limit, the appearance was poor.
In Comparative Example 5, since the heat resistant film was formed of the epoxy resin, the heat resistance was poor.
In Comparative Example 6, since the heat resistant film was formed with an acrylic resin, the heat resistance was poor.
In Comparative Example 7, the heat resistance film was formed with the silicone resin, so the processability was poor.

[Second Embodiment]
Next, the precoated aluminum plate on which a heat resistant film to which an inorganic pigment has been added is formed will be specifically described.

First, a phosphate chromate film was formed on both surfaces of an aluminum plate under the same conditions as in the first embodiment.
And the silicate compound and aqueous resin which are shown in following Table 2 are mixed by the mass ratio shown in Table 2, and also an inorganic pigment (copper * chromium black) is added with content [mass%] shown in Table 2, A paint was prepared.

The prepared coating material was applied to an aluminum plate using a roll coater in the same manner as in the first example, and baked in a continuous baking type oven at a baking temperature of 200 ° C. for a heating time of 30 seconds. forming a heat-resistant coating having a thickness, to prepare a pre-coated aluminum plate of example 7-1 4. The film thickness of the heat-resistant film of each precoated aluminum plate was measured using an eddy current film thickness meter. The results are also shown in Table 2 below.
Note that the Example 1 2, to form a topcoat film using the resin shown in Table 2. The top coat film was formed by baking at 200 ° C. for 30 seconds using a roll coater. The film thickness of the top coat film was 2 μm.
Moreover, in Example 13, in addition to the aqueous resin and the silicate compound, polyethylene wax was added, and heat resistance was obtained using a paint prepared so that the total content of the aqueous resin and the silicate compound was 25%. Formed an adhesive film.

And the external appearance of the heat resistant film of the produced precoat aluminum plate, heat resistance, and workability were evaluated similarly to 1st Example. In addition, regarding the evaluation of the appearance, if there was any of blistering, repelling, or color unevenness, it was judged as bad (x), and if there was none, it was judged as good (◯).
Table 2 shows the types of silicate compound, type of aqueous resin, mass ratio of aqueous resin / silicate compound, film thickness [μm], presence or absence of top coat film, and appearance, heat resistance, and processability. Results are shown .

As shown in Table 2, since Examples 7 to 14 satisfied the requirements of the present invention, the evaluation results of appearance, heat resistance, and workability were all good or excellent. In particular, since the top coat film was formed in Example 12, the workability was more excellent as compared with Examples 7 to 11, 13, and 14 .

  As mentioned above, although the precoat aluminum plate which concerns on this invention was demonstrated in detail by the form and Example for inventing, the meaning of this invention is not limited to these description, Description of a claim Should be interpreted widely.

DESCRIPTION OF SYMBOLS 1 Precoat aluminum plate 2 Aluminum plate 3 Heat resistant film 4 Topcoat film 5 Undercoat film 6 Inorganic pigment

Claims (2)

A pre-coated aluminum plate in which a heat-resistant film is formed on the surface of an aluminum plate or an aluminum alloy plate,
The heat-resistant film is composed of an aqueous resin and a silicate compound , and further includes at least one of a lubricant, a fluidity modifier, a leveling agent, an anti-waxing agent, an antiseptic, a stabilizer, and an anti-blocking agent as optional components. one only contains the mass ratio of the aqueous resin / silicate compound is 0.8 or more and 7 or less, pre-coated aluminum plate having a thickness and wherein the at 0.2μm or 20μm or less.   The precoat aluminum plate according to claim 1, wherein a topcoat film is formed on the heat resistant film.

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