JP2016137623A - Double-side precoated aluminum plate for press working and method of manufacturing press product using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-side precoated aluminum plate for press working having improved coated film scraping property and excellent conductivity and a method of manufacturing a press product using the same.SOLUTION: A double-side precoated aluminum plate 10 for press working is constituted by; sequentially laminating on one surface of an aluminum plate 12, an undercoat later 16 composed of a first organic resin-based coating containing no pigment, and a topcoat layer 18 composed of a second organic resin-based coating containing a matting agent of 1 to 15 wt.% in a coloring pigment and a resin component same as that in the first organic resin-based coating, thereby forming a lubricative coated film 20 with a two layer structure; and forming on the other surface of the aluminum plate 12, a conducive coated film 24 with a thickness of 0.05 to 1.0 μm and composed of a third organic resin-based coating containing one or more kind of an urethane resin, an ionomer resin, a polyethylene resin, an epoxy resin, a fluorine resin and a polyester resin and no conducive material.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a double-sided pre-coated aluminum plate for press working having improved coating shaving properties and excellent electrical conductivity, and a method for producing a press product using the same, and more particularly to electronic devices such as personal computers and mobile phones. It can be suitably used for casings in electric devices such as wireless devices and televisions, battery cases for electric vehicles and hybrid vehicles, etc., while realizing an excellent antistatic effect, The colored coating film is advantageously prevented from occurrence of peeling of the coating film, realizing extremely excellent moldability and capable of effectively grinding / polishing a required portion of the colored coating film. A double-sided pre-coated aluminum plate that can advantageously display the letters, symbols, figures, patterns, etc. made of the gloss of the base aluminum plate under the background of A method of manufacturing a press product with a double-sided precoated aluminum plates.

  Conventionally, aluminum plates have excellent corrosion resistance and are light in weight, so they are formed into desired shapes by pressing such as drawing or bending, and are used in home appliances and OA equipment. It has been widely used as a component in various fields such as automobile products. Also, the surface of such an aluminum plate is generally coated with an organic resin paint in order to ensure excellent design, but a coating film made of such an organic resin paint is formed. In the pre-coated aluminum plate, since most of the organic resin-based coatings are insulative, their characteristics cannot be fully exhibited in electronic and electrical equipment products that require antistatic performance. The problem was inherent.

  For this reason, in order to solve such problems, a conductive paint containing a conductive material such as iron phosphide, graphite, carbon black, metal oxide, flake-like or scale-like nickel filler is used as an aluminum material. Many methods have been proposed so far for imparting electrical conductivity to an aluminum coating material by applying a coating to the surface and forming a conductive coating film on the surface thereof.

  However, a conductive coating film containing such a conductive substance generally has characteristics such as flexibility, flexibility, and stretchability as compared with an organic resin-based coating film that does not contain any conductive substance. From the point where it becomes inferior, using a pre-coated aluminum plate on which such a conductive coating film is formed, when performing press processing such as drawing and bending, in particular, the outer surface after molding, that is, There is a risk of problems such as cracking of the coating film, peeling of the coating film, or deterioration of the surface properties of the aluminum plate on the surface that comes into contact with the die during press processing. It was not achievable at a high level.

  Therefore, in Japanese Patent Application Laid-Open No. 2003-286585 (Patent Document 1), a lubricating coating film made of an organic resin-based paint is formed on one surface of an aluminum plate, while the other surface contains a conductive substance. A method has been proposed in which press-formability and conductivity are made compatible by forming a conductive coating film with an organic resin-based paint.

  And about the press product obtained from such a double-sided pre-coated aluminum plate, in order to improve the aesthetics, when the pigment was included in the lubricating coating film, the adhesion of the lubricating coating film tended to deteriorate. Thus, it has become clear that there is a risk of wrinkles due to peeling of the coating film in corner portions that are exposed to particularly severe processing conditions during press working.

  Further, in Japanese Patent Application Laid-Open No. 2004-195753 (Patent Document 2), a lubricating coating film on such a double-side pre-coated aluminum plate is composed of a layer containing no pigment and a layer containing a predetermined pigment. On the one side of the aluminum plate, based on the knowledge that the adhesion of the lubricating coating is improved and the occurrence of defects such as wrinkles due to peeling of the coating can be advantageously prevented. In addition, the undercoat layer made of the first organic resin-based paint containing no pigment and the overcoat layer made of the second organic resin-based paint containing the pigment are sequentially laminated, so that the lubricating coating having a two-layer structure is formed. A double-sided pre-coated aluminum plate has been proposed in which a conductive coating film made of a third organic resin-based paint containing a conductive substance is formed on the other surface while a film is formed.

Thus, on the outer surface (design surface) of a press product made of such a double-sided pre-coated aluminum plate, a relatively light color tone such as silver or pearl has been conventionally used depending on the pigment contained in the overcoat layer. Since dirt and scratches on the surface are conspicuous, a dark color and a moist color tone that suppresses the gloss of the coating film typified by black have been demanded. In order to meet such a color tone, it is necessary to add a matting agent typified by silica (SiO ₂ ) to the overcoat layer containing the pigment.

  By the way, it is generally done to print letters and patterns on the obtained press product after press molding. However, it is dark and has a contrast based on a tone that suppresses gloss. Therefore, there is a problem that the target character or pattern cannot be clearly shown. For this, it can be said that it is preferable to employ a solution means for scraping the overcoat layer and causing characters and patterns made of a base aluminum color to appear on the background of a dark color tone. At that time, as a method of removing a desired portion of such an overcoat layer by partially cutting so as to give a shape such as a character, a character or a pattern is raised by press molding, and the overcoating portion is overcoated. For example, a method of mechanically scraping the layer while rotating it with a disc-shaped or rod-shaped polishing body mounted on a grinder may be used. However, in the case of mechanically shaving, since the overcoat layer is originally a coating film made of an organic resin having lubricity for press molding, the polishing body is slippery and uncut material is generated. There is a defect that cannot be cut.

JP 2003-286585 A Japanese Patent Laid-Open No. 2004-195753

  Here, as a result of intensive studies to solve the problems in the prior art as described above, the present inventors have obtained a lubricity coating formed on one surface of an aluminum plate while ensuring excellent conductivity. By appropriately controlling the content of the matting agent contained in the overcoat layer constituting the film, the coating film can be easily cut off when mechanically shaved, thereby realizing good coating abrasion characteristics. As a result, it has been found that preferable characters, symbols, figures and the like with clear outlines can be advantageously displayed, and the present invention has been completed.

  Therefore, the subject of the present invention is to provide a double-sided pre-coated aluminum plate for press working having improved coating shaving properties and excellent conductivity, and a method for producing a press product using the same, Another problem is that, during press processing, the occurrence of coating film cracking and coating film peeling is advantageously prevented, and extremely excellent formability is achieved while the required portion of the colored coating film is obtained. The double-sided pre-coated aluminum plate that can advantageously reveal characters, symbols, figures, patterns, etc. made of the gloss of the base aluminum plate under the background of such a colored coating film, and its An object of the present invention is to provide a method for producing a pressed product using such a double-side precoated aluminum plate.

  In the present invention, in order to solve the above-described problems, the present invention can be suitably implemented in various modes as listed below, but each mode described below can be arbitrarily combined. Can be used. It should be understood that aspects or technical features of the present invention are not limited to those described below, and can be recognized based on the description of the entire specification and the inventive concept disclosed in the drawings. It should be.

(1) A matting agent is contained in a proportion of 1 to 15% by weight in one surface of an aluminum plate together with an undercoat layer made of a first organic resin-based paint containing no pigment and a colored pigment. On the other side, a two-layered lubricating coating film is formed by sequentially laminating an overcoat layer composed of a second organic resin-based paint having the same resin component as that of the organic resin-based paint. In addition, the resin component comprises a third organic resin-based paint containing one or more of urethane resin, ionomer resin, polyethylene resin, epoxy resin, fluororesin and polyester resin, and no conductive material. A double-side precoated aluminum plate for press working, wherein the conductive coating film is formed in a thickness of 0.05 to 1.0 µm.
(2) Each of the first and second organic resin-based paints is composed of a polyester resin-based paint containing, as a main component, a polyester resin having 400 to 1000 carbon atoms as a resin component. The undercoat layer is formed in a thickness of 5 to 20 μm using the first organic resin-based paint, while the overcoat layer is formed in a thickness of 3 to 15 μm using the second organic resin-based paint. The double-side pre-coated aluminum plate for press working as set forth in the aspect (1), wherein the double-side pre-coated aluminum plate is formed in a thickness of 5 mm.
(3) The double-side precoated aluminum plate for press working as described in the aspect (1) or the aspect (2), wherein the color pigment is a dark color pigment.
(4) The double-side precoated aluminum sheet for press working according to any one of the above aspects (1) to (3), wherein the color pigment is carbon black.
(5) The double-side pre-coated aluminum plate for press working according to any one of the aspects (1) to (4), wherein the matting agent has an average particle diameter of 1 to 15 μm.
(6) The double-side precoated aluminum plate for press working according to any one of the above aspects (1) to (5), wherein the matting agent is silica powder.
(7) The said aspect (1) thru | or before the said 2nd organic resin-type coating material contains the inner wax in the ratio of 0.2-5.0 weight part with respect to 100 weight part of the said resin component. The double-sided pre-coated aluminum plate for press processing as described in any one of the description aspect (6).
(8) Any one of the above aspects (1) to (7), wherein the conductive coating film contains an inner wax in a ratio of 0.1 to 4.0 parts by weight. A double-sided precoated aluminum plate for press working as described in 1.
(9) In the aspect (8), the blending ratio of the inner wax in the third organic resin-based paint is 0.2 to 0.8 times the blending ratio of the inner wax in the second organic resin-based paint. The double-sided precoated aluminum plate for press working as described.
(10) The lubricating coating and the conductive coating are respectively formed on the surface of an aluminum plate on which a coating type or reactive type chromate layer or non-chromate layer is formed by a base treatment. The double-side pre-coated aluminum plate for press working according to any one of the above aspects (1) to (9), wherein
(11) When producing a pressed product by performing press working using the double-side pre-coated aluminum plate for press working according to any one of the above-described aspects (1) to (10), the double-side pre-coated A method for producing a pressed product, wherein the surface of the aluminum plate on which the lubricious coating film is formed is positioned on the die side, and the surface on which the conductive coating film is formed is positioned on the punch side.
(12) The topcoat layer of the press product obtained by the pressing process, wherein the surface on which the lubricious coating film is formed is subjected to grinding or polishing treatment to constitute the lubricious coating film. The method for producing a pressed product according to the aspect (11), wherein a required part of the product is removed.

  Thus, in the double-side pre-coated aluminum plate for press work according to the present invention, the content of the matting agent contained in the outer top coat layer constituting the two-layered lubricating coating is 1 to 15% by weight. Thus, by being controlled, the coating shaving property of the overcoat layer can be effectively improved, and therefore, the background aluminum color of the base color layer is used to change the aluminum color of the substrate. Good characters, figures, symbols, patterns, etc. that were made use of can be advantageously displayed.

  In addition, the other surface of the double-side pre-coated aluminum plate is made good by controlling the thickness of the coating film to 0.05 to 1.0 μm without containing a conductive material such as Ni filler as in the prior art. Since a conductive coating film exhibiting conductivity is formed, good coating film properties can be advantageously ensured, and press moldability can be advantageously enhanced, while making a significant contribution to cost reduction. .

  Moreover, according to the manufacturing method of the press product according to the present invention, among the coated surfaces of the double-side pre-coated aluminum plate, the lubricating coating film forming surface is positioned on the die side, and the conductive coating film forming surface is on the punch side. In addition to being able to obtain the desired press product with good press formability by performing the press working so that it is positioned, lubrication located on the outer surface side of such a press product The effective coating film can be effectively ground / polished at the required site, so that the desired characters, symbols, figures, patterns and the like can be advantageously displayed.

It is sectional explanatory drawing by which one specific example of the double-sided precoat aluminum plate according to this invention is shown in the state set to the press molding machine. FIG. 2 is an enlarged partial sectional explanatory view showing in detail a coating structure of the double-side precoated aluminum plate of FIG. 1. It is an expanded sectional fragmentary explanatory view showing an example of the form which grinds the required part of the top coat layer of the press product obtained by press-molding the double-sided precoat aluminum board according to the present invention.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings. However, in the drawings to be described later, their thicknesses are exaggerated and shown in a larger ratio than actual so that the presence of each layer such as a coating film formed on the surface of the aluminum plate can be easily recognized. It should be understood.

  First, FIG. 1 shows a specific example of a double-side precoated aluminum plate according to the present invention set in a press molding machine. In this case, the double-side pre-coated aluminum plate 10 is composed of two layers of an undercoat layer 16 and an overcoat layer 18 on the surface on the die 14 side (the lower surface in FIG. 1), using the aluminum plate 12 as a base. The conductive coating film 20 has a form in which a conductive coating film 24 having conductivity is formed on the surface on the punch 22 side (the upper surface in FIG. 1).

  More specifically, a surface treatment layer 26 is provided on the surface of the aluminum plate 12 on the side of the die 14 between the undercoat layer 16 of the lubricating coating film 20 as shown in FIG. ing. Then, a pigment-free first organic resin-based paint is applied to the surface of the aluminum plate 12 on which such a base treatment layer 26 is formed, and is cured, whereby the undercoat layer 16 is formed. On top of that, by applying and curing a second organic resin-based paint containing a predetermined color pigment, the topcoat layer 18 is formed, and the two-layered lubricating coating film 20 is laminated. is there.

  By the way, as the first organic resin-based coating material for forming the undercoat layer 16 of the lubricating coating film 20, in order to improve the adhesion of the lubricating coating film 20, a coating containing no pigment is adopted. Become. In addition, as such a first organic resin-based coating material, it is desirable to have excellent flexibility and excellent corrosion resistance after curing (after drying). For example, the first organic resin coating material is mainly used as a coating resin (organic resin). Conventional component such as polyester resin paint, epoxy resin paint, acrylic resin paint, fluorine resin paint, or urethane resin paint, in which the component is polyester resin, epoxy resin, acrylic resin, fluorine resin, or urethane resin In the present invention, among them, a polyester resin paint containing a polyester resin having 400 to 1000 carbon atoms as a main component is preferable. By adopting such a paint, the undercoat layer 16 of the lubricating coating film 20 can be softened. Sex and flexibility, whereby a composition with remarkably superior properties of stretchability and the like.

  As described above, the reason why the desirable range of the carbon number of the polyester resin is set to 400 to 1000 is that, when the carbon number of the polyester resin is less than 400, the coating is performed after the curing process (after the drying process). This is because the film may be excessively cured and the flexibility of the coating film may be reduced, and as a result, there is a possibility that a crack in the coating film or peeling of the coating film may be caused in the processed portion by press working. Because. Further, when the number of carbon atoms exceeds 1000, the coating film tends not to be sufficiently cured after the curing treatment, which may lead to problems such as a decrease in corrosion resistance and weather resistance.

  In addition, the first organic resin-based paint as described above may be mixed with an additive such as an inner wax as appropriate, if necessary.

  On the other hand, the second organic resin-based paint for forming the overcoat layer 18 of the lubricating coating film 20 includes more than the conventionally known color pigments in order to improve the appearance of the press-molded product and enhance the design. At least one kind or two or more kinds are appropriately selected and added and contained in an appropriate amount. Specifically, inorganic pigments such as oxides, sulfides, chromates, ferrocyanides, ultramarine, and carbon black, C.I. I. Organic pigments such as azo pigments and phthalocyanine pigments named by Name (C.I.No.) can be mentioned. In particular, in the present invention, dark pigments such as red, blue and black are used. Color-based color pigments are preferably employed, and among these, carbon black is advantageously used.

  In addition, the second organic resin-based paint in which such a colored pigment is contained in the same manner as in the past further provides a predetermined matte to improve the design of the color tone of the outer surface of the pressed product. In the present invention, the amount of such a matting agent added is 1 to 15 parts by weight in 100 parts by weight of the solid content of the paint. In other words, the matting agent content in the topcoat layer 18 is adjusted so as to be a ratio of 1 to 15% by weight, whereby the topcoat layer 18 in the lubricating coating 20 is good. It was possible to realize a good paint film shaving property. If the content of the matting agent is less than 1% by weight, it is difficult to achieve good coating shaving of the target topcoat layer 18 and exceeds 15% by weight. As a result, the matting agent is likely to aggregate during storage of the paint, causing a problem that the original matting effect of the matting agent is reduced. In particular, in the present invention, the content of such a matting agent is suitably employed in the range of 5 to 10% by weight.

In addition, such a matting agent is basically one in which white or transparent particles are dispersed in a paint to diffuse incident light or reflected light from a base aluminum plate to obtain a matting effect. Various types of organic matting agents and inorganic matting agents are known. For example, as organic matting agents, fine resin particles such as fluororesin, polyamide, acrylic resin, polyurethane, phenol resin, silicon resin, polyethylene, polypropylene, polyamide, and fine powder such as aluminum stearate are known. Further, silica (SiO ₂ ), mica, alumina, talc, clay, calcium carbonate, barium sulfate, aluminum hydroxide, titanium oxide and the like are known as inorganic matting agents. In the present invention, one or more of these known matting agents are appropriately selected and used, but advantageously, silica particles are preferably employed. Become.

  Furthermore, in the present invention, such a matting agent having an average particle diameter of 1 to 15 μm and having a size smaller than the film thickness of the overcoat layer 18 is advantageously used. . This is because when the average particle size of the matting agent is less than 1 μm, it becomes difficult to sufficiently exhibit the original matting effect, and the coating film scraping property is also lowered. In addition, when the average particle size of the matting agent exceeds 15 μm, the particle size of the matting agent becomes larger than the coating thickness of the overcoat layer 18, and the lubricity deteriorates due to friction caused by the matting agent during press molding. As a result, it becomes possible to cause problems that make it difficult to perform press forming effectively.

  And even in the second organic resin-based paint in which a specific amount of a predetermined matting agent is contained together with such a colored pigment, as in the case of the first organic resin-based paint described above, after curing (drying In the latter), it is desirable to have excellent flexibility and corrosion resistance, and various known organic resin-based paints as described above can be appropriately selected and used. Among them, carbon A polyester resin-based paint containing a polyester resin having a number of 400 to 1000 as a main component can be particularly preferably employed for the same reason as the first organic resin-based paint, and such a paint is employed. As a result, the overcoat layer 18 of the lubricating coating film 20 is extremely excellent in properties such as flexibility, flexibility and stretchability. Thus, the paint resin that is the main component of the second organic resin-based paint and the paint resin that is the main component of the first organic resin-based paint described above further improve the adhesion of the lubricating coating. In the present invention, the same resin component is used in the present invention.

  Further, in the lubricating coating film 20, it is desirable that the second organic resin-based paint forming the top coat layer 18 serving as the outer surface layer contains an inner wax in a predetermined ratio. Further, the press formability of the lubricating coating film 20 can be improved more effectively. As the inner wax, various conventionally known waxes can be used, for example, animal waxes such as lanolin; plant waxes such as carnauba; synthetic waxes such as polyethylene wax and Fischer-Tropsch wax; paraffin wax And petroleum waxes such as microcrystalline wax and petrolatum, and one or more of them can be appropriately selected and used.

  Further, the blending ratio of the inner wax: A is a ratio of 0.2 to 5.0 parts by weight with respect to 100 parts by weight of the above-described coating resin (preferably a polyester resin having 400 to 1000 carbon atoms). Can be suitably employed. However, if the blending ratio of the inner wax: A is too small, the lubricity of the surface of the lubricating coating film 20, that is, the overcoat layer 18, may be reduced, and the coating film may be peeled off during molding. On the contrary, if the amount is excessive, the flexibility of the overcoat layer 18 is lowered and the corrosion resistance may be lowered.

Then, the first organic resin-based paint containing no pigment as described above and the second organic resin-based paint containing a predetermined pigment and a matting agent are sequentially applied and cured, as shown in FIG. The undercoat layer 16 and the overcoat layer 18 are laminated to form a lubricating coating film excellent in press moldability. The thickness of the undercoat layer 16 (D _{1 in} FIG. 2) ) And the thickness of the overcoat layer 18 (D _{2 in} FIG. 2) are preferably 5 to 20 μm and 3 to 15 μm, respectively. It is more desirable to form so that it may become 10-15 micrometers and 5-13 micrometers. More preferably, the thickness of the two layers including the undercoat layer 16 and the overcoat layer 18, that is, the film thickness (D ₁ + D ₂ ) of the lubricating coating 20 is 15 to 25 μm. It is desirable that

Because the thickness of the undercoat layer 16 as described above: D ₁ is, if less than 5μm is reduced adhesion between the overcoat layer 18 containing a pigment or a delustering agent, the coating film peeling is caused In addition, if it exceeds 20 μm and becomes too thick, the film thickness of the entire lubricating coating film 20 becomes too large, and the bending processability of the lubricating coating film 20 is increased. This is because there is a risk that coating film cracking or peeling of the coating film may be caused in the processed part. Further, the thickness of the overcoat layer 18 which pigments or matting agents are allowed to exist: D ₂ is not less than 3 [mu] m, if too thin, when forming the bending or the like, it becomes difficult to hold the pigment This is because there is a risk of coating film cracking, peeling of the coating film, and the like in the overcoat layer 18. On the contrary, when the thickness exceeds 15 μm and becomes too thick, the entire lubricating coating film 20 is bent. This is because the processability is lowered, and there is a risk of coating film cracking, coating film peeling, and the like being caused in the processed part.

  On the other hand, on the surface opposite to the surface on which the lubricating coating film 20 is formed as described above, that is, the surface in contact with the punch 22, as shown in FIG. Although the coating film 24 is formed, a ground treatment layer 30 is also provided between the conductive coating film 24 and the aluminum plate 12, and such a ground treatment layer 30 is formed. The surface of the aluminum plate 12 is made of a resin component containing one or more organic resins of urethane resin, ionomer resin, polyethylene resin, epoxy resin, fluororesin, and polyester resin that do not contain a conductive substance. An organic resin coating is applied and cured to form a conductive coating 24 having a thickness of 0.05 to 1.0 μm. In addition, when the thickness of this electroconductive coating film 24 exceeds 1.0 micrometer, there exists a possibility that the electrical resistance of the electroconductive coating film 24 may become large and electroconductivity may fall. Further, the lower limit value of the thickness of the conductive coating film 24 is required to be 0.05 μm because the press formability is maintained. And as an organic resin-type coating material which forms such a conductive coating film 24, an epoxy resin-type coating material can be suitably employ | adopted among the above, By using such a coating material, it is electroconductive. Therefore, the conductive coating film 24 excellent in the above can be formed advantageously.

  Even in the third organic resin-based paint as described above, it is desirable that the inner wax is contained in a predetermined ratio as in the second organic resin-based paint described above. Thus, the press formability of the conductive coating film 24 can be further effectively improved. As the blending ratio B of the inner wax, a ratio of 0.1 to 4.0 parts by weight with respect to 100 parts by weight of the coating resin in the paint can be suitably employed. This is because when the blending ratio B of the inner wax is too small, the lubricity of the conductive coating film 24 may be reduced, and the coating film may be peeled off during molding. This is because if the amount is too large, the bending processability of the conductive coating film may decrease, and problems such as coating film cracking and coating film peeling may occur in the processed portion.

  In particular, as shown in FIG. 1, the inner wax described above is disposed in the press molding machine so that the conductive coating 24 is formed on the double-side precoated aluminum plate 10 so that the surface of the conductive coating 24 is on the punch 22 side. The blending ratio of the inner wax contained in the second organic resin-based paint as described above among B: the blending ratio that is 0.2 to 0.8 times that of A, that is, the second organic resin The proportion of the inner wax in the third organic resin-based paint with respect to A: The proportion of the inner wax in the third organic resin-based paint: B (= B / A) is preferably 0.2 to 0.8. It can be adopted. This is because, in press working such as deep drawing, by reducing the friction coefficient on the upper surface 34 of the die 14, the pulling force on the die shoulder 36 can be reduced, while the friction on the punch shoulder 38 is reduced. By making the coefficient larger than the friction coefficient of the die shoulder portion 36, the fracture risk portion can be moved away from the punch center, that is, the portion of the aluminum plate 10 that is in contact with the die shoulder portion 36 is pulled by the upper surface 34 of the die 14. This is because it is advantageously prevented that the wall thickness becomes thin and breaks, thereby improving the deep drawing limit. In addition, when such (B / A) is less than 0.2 times, the lubricity in the conductive coating film 24 is lowered, and there is a risk of peeling of the coating film, and when it exceeds 0.8 times. Thus, the above effect cannot be obtained.

  By the way, using the first, second and third organic resin-based paints as described above, the lubricating coating 20 (the undercoat layer 16 + the topcoat layer 18) and the conductive coating 24 are provided on each side. In order to obtain the double-sided precoated aluminum plate 10, first, it is desirable to perform a predetermined ground treatment on the surface of the aluminum plate 12, whereby the ground treatment layers 26 and 30 are formed on the surface of the aluminum plate 12. Each will be formed.

  In addition, as such a base treatment, a chemical film such as chromate treatment with chromate chromate or phosphate chromate; non-chromate treatment with titanium phosphate other than chromium compounds, zirconium phosphate, molybdenum phosphate, zinc phosphate, etc. A so-called chemical conversion treatment is preferably employed. Further, due to the presence of the base treatment layers 26 and 30 formed by such a base treatment, the adhesion between the aluminum plate 12 and the lubricating coating 20 and the adhesion between the aluminum plate 12 and the conductive coating 24 are improved. In addition, both can be improved effectively, and further excellent corrosion resistance can be realized, and corrosion under the coating caused when corrosive substances such as water and chlorine compounds penetrate the surface of the aluminum plate. It is suppressed, and film swelling and film peeling can be advantageously prevented.

  In addition, the chemical conversion treatment methods such as the chromate treatment and the non-chromate treatment described above include a reaction type and a coating type. However, in the present invention, any method can be adopted. In addition, it is possible for each surface of the aluminum plate 12 to be subjected to different ground treatments separately. However, it is preferable that the same ground treatment is performed at the same time.

  Furthermore, after the base treatment layers 26 and 30 are formed by the base treatment as described above, a lubricating coating film 20 composed of two layers of the undercoat layer 16 and the overcoat layer 18 is formed on one surface. The conductive coating 24 is formed on the other surface, respectively. Here, the lubricating coating film 20 is prepared by applying the first organic resin-based paint as described above on the base treatment layer 26 on the surface of the aluminum plate 12 in accordance with a conventional method, and then curing it. The layer 16 is formed, and the second organic resin-based paint is applied and cured on the undercoat layer 16, and the overcoat layer 18 is laminated to form a two-layer structure. The conductive coating film 24 is also formed by applying and curing the third organic resin-based paint as described above on the base treatment layer 30 on the surface of the aluminum plate 12 in accordance with a conventional method. Thus, by forming the lubricating coating film 20 and the conductive coating film 24, a double-side pre-coated aluminum plate excellent in press formability, designability and conductivity is produced.

  Here, the coating method of the first to third organic resin-based paints is not particularly limited, and conventionally known methods such as a roll coating method, a bar coating method, a dip coating method, and a spray method are known. Various techniques can be employed as appropriate, and even in the curing conditions (baking conditions) when forming the lubricating coating film 20 and the conductive coating film 24, depending on the type of coating resin, etc. Each will be selected appropriately. If the coating resin constituting the first or second organic resin coating and the coating resin constituting the third organic resin coating are of the same resin system, the first and third organic resins It is also possible to carry out baking of the second paint or the second and third organic resin paint at the same time, which is advantageous in terms of cost.

  In the double-sided precoated aluminum plate 10 produced as described above, an undercoat layer 16 made of a pigment-free first organic resin paint and a pigment-containing second layer are formed on one surface. On the other side, a conductive coating film 24 made of a third organic resin-based paint is formed. Thus, the top coat layer 18 of the lubricating coating film 20 can ensure a very high design or aesthetic appearance, and the presence of the undercoat layer 16 of the lubricating coating film 20 allows the coating film adhesion. Generation of defects such as coating film cracking and coating film peeling is extremely advantageously prevented, and excellent press formability can be realized. On the other hand, by the conductive coating film 24, Antistatic performance is effective It is of being brought improvement in manner.

  By the way, the double-side pre-coated aluminum plate 10 as described in detail above is formed into a desired shape by a press process such as a drawing process or a bending process in accordance with an ordinary method, and is used in electronic devices such as personal computers and mobile phones. It is advantageously used as a casing part in electric equipment such as radio equipment and television, and battery casing parts of electric cars and hybrid cars. 1, the double-side precoated aluminum plate 10 according to the present invention is formed so that the lubricating coating 20 is formed on the die 14 side, and the conductive coating 24 is formed on the punch 22. It is desirable to install it in a press molding machine so that it is on the side. As a result, even on the outer surface of the molded product where problems are likely to occur, the occurrence of coating film cracking or peeling of the coating film can be effectively prevented, and the pigment 28 is present on the outer surface that enters the human eye. An excellent design property is imparted by the formed overcoat layer 18, and excellent conductivity can be imparted to the inner surface by the conductive coating film 24, so that an antistatic effect is advantageously achieved.

  And in the press product which is a press-molded product obtained by press molding in this way, the top coat layer 18 constituting the lubricating coating film 20 located on the outer surface thereof is improved in the coating shaving property. Therefore, by removing such an overcoat layer 18 and making the aluminum color of the substrate appear through the transparent undercoat layer 16, characters, symbols, figures, patterns, etc. with clear outlines are obtained. It can be advantageously formed against the background of the colored topcoat layer 18.

  For example, as shown in FIG. 3, the portion of the topcoat layer 18 located on the convex portion 32 formed at a required portion of the press product 30 is removed by a mechanical deletion operation such as grinding or polishing with a grinder. Thus, the base of the aluminum plate 12 is exposed through the undercoat layer 16, so that characters, figures, symbols, patterns, etc. constituted by such convex portions 32 are clearly defined on the outer surface of the press product 30. It becomes possible to make it appear with a contour.

  The exemplary embodiments of the present invention have been described in detail above. However, the embodiments are merely examples, and the present invention is limited in any way by specific descriptions according to such embodiments. It should be understood that it is not interpreted.

  For example, in the above-described embodiment, the surface treatment layers 26 and 30 are provided on each surface of the aluminum plate 12, thereby improving the adhesion between the lubricating coating 20 and the conductive coating 24. However, the ground treatment layers 26 and 30 are not necessarily required in the present invention.

  Moreover, even if it exists in the aluminum plate 12 to which a precoat is given, if it exhibits a plate shape, the aluminum plate or aluminum alloy plate which consists of various conventionally well-known aluminum or aluminum alloy is included widely, The object It can be done.

  In addition, although not listed one by one, the present invention can be implemented in a mode with various changes, modifications, improvements, and the like based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the invention.

  Hereinafter, some experimental examples including examples of the present invention will be shown to clarify the present invention more specifically. However, the present invention is not limited by the description of such experimental examples. It goes without saying that it is not something that you receive.

  First, as an aluminum plate as a test material, an Al-4.5% Mg alloy O material having a plate thickness of 1.0 mm, which is generally used in press working, was prepared. And as shown in following Table 1 and Table 2, the surface treatment of any of ae shown in following Table 3 was performed with respect to the surface of this prepared aluminum plate. Among the a to e ground treatments, the aluminum plate on which the d and e ground treatments are performed is preliminarily degreased and then subjected to the ground treatment by the bar coating method. As for the aluminum plate to which the ground treatment is applied, since the degreasing effect is obtained by the ground treatment, the ground treatment is carried out as it is by the soaking method, and both are dried in an atmosphere of about 100 ° C. The treatment layer was formed on both sides of the aluminum plate.

  Further, as a first organic resin-based paint for forming a transparent undercoat layer of a lubricating coating film, a polyester resin-based paint made of a polyester resin having an average carbon number as shown in Table 1 below is used in each experimental example. A polyester having an average carbon number similar to that of the first organic resin-based paint as the second organic resin-based paint for forming an overcoat layer of a desired color tone of the lubricating coating 15 parts by weight of the color pigment shown in Table 1 was added to 100 parts by weight of the polyester resin in the polyester resin-based paint made of resin. Furthermore, various matting agents having a particle size shown in Table 1 below are added at a blending ratio consisting of parts by weight shown in Table 1 below with respect to 100 parts by weight as a whole based on the solid content, and an inner wax is obtained. Polyethylene wax was added so as to have a ratio shown in Table 1 below: A, and they were mixed uniformly for 5 minutes with a stir bar for each experimental example. Further, as a third organic resin-based paint for forming a conductive coating film, in the polyester resin-based paint composed of a polyester resin having the same average carbon number as the first and second organic resin-based paint, Polyethylene wax, which is an inner wax, was added to 100 parts by weight of the polyester resin so as to have a ratio shown in Table 2 below, and these were uniformly mixed with a stirring bar for 5 minutes. Each experimental example was prepared.

  And with respect to one side of the aluminum plate of Experimental Examples 1-15, predetermined amount of 1st organic resin-type coating materials were apply | coated using the bar coater, respectively, and the temperature of the surface of an aluminum plate is 230 degreeC. In an oven at 240 ° C., the coating was cured by heating for 40 seconds to form an undercoat layer (excluding Experimental Example 13), and further, as an overcoat, A predetermined amount of the second organic resin paint is applied using a bar coater, while a predetermined amount of the third organic resin paint (conductive paint) is applied in the same manner to the other surface. Then, by heating under the same conditions as in the case of the first organic resin-based paint, the second and third organic resin-based paints on both sides are cured, and the double-side precoated aluminum plates according to Experimental Examples 1-15 Was made. In addition, the film thickness of the formed lubricous coating film (overcoat layer, undercoat layer) and the conductive coating film is shown together in the following Table 1 and Table 2, respectively.

  Next, using the precoated aluminum plates according to Experimental Examples 1 to 15 produced as described above, press formability (press workability), paint film scraping property, electrical conductivity, and paint film adhesion are as follows. The evaluation test of the property and the corrosion resistance was carried out, and the evaluation was made in 5 stages, with 2 or more being acceptable levels, except for the film shaving property. Regarding the film shaving property, the evaluation was made in four stages of ◎, ○, Δ, and ×, and ○ or more was regarded as an acceptable level.

-Press formability-
The double-side pre-coated aluminum plates according to Experimental Examples 1 to 15 produced as described above were positioned on the die side with the surface on which the lubricating coating film was formed, and subjected to deep drawing under the following conditions, The press formability was evaluated by obtaining the maximum depth (molding height) at which no cracks occurred on the die side surface. Such evaluation was performed according to the following evaluation criteria, and the obtained results are shown in Table 4 below. In addition, in the double-sided precoated aluminum plate of Experimental Example 13 in which no undercoat layer containing no pigment was formed, peeling of the coating film on the die side was observed from the initial stage of pressing.
[Processing conditions]
Die diameter: φ52.8 mm, punch diameter: φ50 mm, radius of curvature of punch shoulder: 5 mm, radius of curvature of plate pressing die shoulder: 5 mm, plate pressing force: 34 kN, lubricating oil: not used.
[Evaluation criteria]
Evaluation 5: Over 15 mm Evaluation 4: Over 14 mm and 15 mm or less Evaluation 3: Over 13 mm and 14 mm or less Evaluation 2: Over 12 mm and 13 mm or less Evaluation 1: 12 mm or less

-Paint shaving properties-
Press-molded Gothic H letter (vertical bar width 3 mm, horizontal bar width 2 mm) with a size of 13 mm × 13 mm on the precoated aluminum plates of Experimental Examples 1 to 15 to a height of 0.5 mm The surface of the top surface (letter) is lifted and polished by attaching a felt disc impregnated with abrasive (outer diameter 30 mm) to the grinder and rotating it. Was evaluated in four stages as follows. The number of H characters evaluated was five. The obtained results are shown in Table 4 below. Experimental Example 9 having no matting agent and Experimental Examples 10 to 12 in which the blending ratio of the matting agent was less than 1 part by weight were evaluated as Δ or less.
[Evaluation criteria]
A: By polishing in a short time of 10 to 15 seconds per character, all the five characters were able to reveal the undercoat layer in a state where there was no uncut portion of the overcoat layer.
○: 10-15 seconds of polishing per character left uncut material, and by polishing for more than 30 seconds, all 5 characters appeared undercoat without remaining overcoated layer. .
Δ: Uncut residue could not be eliminated in 1 to 2 of the 5 characters, and when further scraped, the undercoat layer was scraped off, and a base aluminum plate appeared.
X: Uncut residue could not be eliminated in 3 to 5 characters out of 5 characters, and when further scraped, the undercoat layer was scraped off, and the base aluminum plate appeared.

-Conductivity-
Each of the precoated aluminum plates of Experimental Examples 1 to 15 (however, in this evaluation test, those prepared only with the conductive coating film shown in Table 2 were prepared separately) were used. The surfaces on which the conductive coating films were formed were stacked one above the other, and the upper and lower sides were sandwiched between ^two copper electrodes (tip area: about 3 mm ² ), and a pressure of about 10 kg / cm ² was applied. Then, a voltage is applied between the pre-coated aluminum plates with a constant voltage power source of 5 V, the electric resistance is obtained from the current value flowing through the circuit, and evaluated according to the following evaluation criteria. The results are shown in Table 4 below. Experimental Example 15 in which the film thickness of the conductive coating film was 1.2 μm had an electric resistance of 20Ω or more, although it conducted electricity a little.
[Evaluation criteria]
Evaluation 5: Less than 0.01Ω Evaluation 4: 0.01Ω or more and less than 0.5Ω Evaluation 3: 0.5Ω or more and less than 2Ω Evaluation 2: 2Ω or more and less than 10Ω Evaluation 1: 10Ω or more

-Coating film adhesion-
Each of the double-sided precoated aluminum plates of Experimental Examples 1 to 15 was immersed in boiling water for 2 hours, and then a cross-cut tape peeling test was performed. The remaining number of coating films in a total of 100 cross-cuts (1 mm × 1 mm each) The coating film adhesion was evaluated. This evaluation was performed according to the following evaluation criteria, and the obtained results are shown in Table 4 below.
[Evaluation criteria]
Evaluation 5: 100 Evaluation 4: 90 to less than 100 Evaluation 3: 80 to less than 90 Evaluation 2: 60 to less than 80 Evaluation 1: Less than 60

-Corrosion resistance-
Using a cutter knife, a cross-cut is made on the lubrication coating surface where the design properties of the double-side precoated aluminum plates of Experimental Examples 1 to 15 are required, and after performing a salt spray test for 720 hours, the lubrication coating film The appearance was evaluated according to the following evaluation criteria, and the obtained results are shown in Table 4 below.
[Evaluation criteria]
Evaluation 5: No change Evaluation 4: Coating film swelling of less than 0.5 mm Evaluation 3: Coating film swelling of 0.5 mm or more and less than 1 mm Evaluation 2: Coating film swelling of 1 mm or more and less than 3 mm Evaluation 1: Coating film swelling of 3 mm or more

  As is apparent from the results in Table 4, the double-sided precoated aluminum plates according to Experimental Examples 1 to 8 according to the present invention consist of an undercoat layer containing no pigment and an overcoat layer containing a pigment and a matting agent on one side. While a two-layered lubricating coating film is formed on the other side, a conductive coating film is formed on the other surface. With such a two-layered lubricating coating film, an extremely While ensuring designability, the occurrence of coating cracking and coating film peeling is extremely advantageously prevented, and excellent press formability can be realized, and the conductive coating effectively improves antistatic performance. You will be harassed.

  In addition, as the first organic resin-based paint for forming the above-described undercoat layer, in particular, a pigment-free polyester resin-based paint having a polyester resin having 400 to 1000 carbon atoms as a paint resin is used. In such a first organic resin paint, an undercoat layer having a thickness of 5 to 20 μm is formed, and a pigment and a specific amount of matting agent are used as a second organic resin paint for forming an overcoat layer. A polyester resin paint containing a polyester resin having a carbon number of 400 to 1000 and containing an inner wax in a predetermined ratio, and further to such a second organic resin paint. If an overcoat layer with a thickness of 3 to 15 μm is formed, the properties such as flexibility, flexibility and stretchability are further effective for the lubricating coating composed of the undercoat layer and the overcoat layer. It is understood that even better press formability can be enjoyed.

  In addition, as a third organic resin-based paint (conductive paint) for forming a conductive coating film, a more advanced conductivity can be realized by a coating film having a specific resin and film thickness, The metal luster of the aluminum plate on which such a conductive coating film is formed can be sufficiently secured. Moreover, even such conductive coatings can be imparted with more excellent properties such as flexibility, flexibility, stretchability, etc., and press formability can be advantageously improved. .

  Furthermore, according to the present invention, the double-sided pre-coated aluminum plate is placed on the die side while the surface on which the lubricating coating film is formed, while the surface on which the conductive coating film is formed is positioned on the punch side. If carried out, it becomes a place that is particularly excellent in press formability, and the occurrence of coating film cracking, coating film peeling and the like can be effectively prevented even on the outer surface side of the molded product where problems are likely to occur. In addition, the outer surface of the molded product produced by press working has a coating layer containing a matting agent consisting of a pigment and a specific content, such as carbon black, so it has excellent coating shaving properties. In addition, an extremely effective design surface is imparted, and conductivity is imparted to the inner surface, so that an antistatic effect can be exhibited.

DESCRIPTION OF SYMBOLS 10 Double-sided precoat aluminum plate 12 Aluminum plate 14 Die 16 Undercoat layer 18 Topcoat layer 20 Lubricating coating film 22 Punch 24 Conductive coating film 26,30 Ground treatment layer 32 Convex part 34 Upper surface 36 Die shoulder part 38 Punch shoulder part

Claims (12)

  The first organic resin in which a matting agent is contained in a proportion of 1 to 15% by weight together with an undercoat layer made of a first organic resin-based paint containing no pigment and a colored pigment on one surface of the aluminum plate. A two-layer lubricating coating film is formed by sequentially laminating a top coat layer made of a second organic resin-based paint having the same resin component as that of the resin-based paint, while the resin component is formed on the other surface. As a conductive coating film made of a third organic resin-based paint containing one or more of urethane resin, ionomer resin, polyethylene resin, epoxy resin, fluororesin and polyester resin, and no conductive substance. A double-side precoated aluminum plate for press working, wherein the double-sided precoated aluminum plate is formed in a thickness of 0.05 to 1.0 μm.   Each of the first and second organic resin-based paints is composed of a polyester resin-based paint containing a polyester resin having 400 to 1000 carbon atoms as a main component as a resin component, and the undercoat layer, While the first organic resin-based paint is used to form a thickness of 5 to 20 μm, the overcoat layer is formed using the second organic resin-based paint to a thickness of 3 to 15 μm. The double-side precoated aluminum plate for press working according to claim 1, wherein the double-side precoated aluminum plate is used for press working.   The double-side precoated aluminum plate for press working according to claim 1 or 2, wherein the colored pigment is a dark colored pigment.   The double-side precoated aluminum plate for press working according to any one of claims 1 to 3, wherein the color pigment is carbon black.   The double-side precoated aluminum plate for press working according to any one of claims 1 to 4, wherein the matting agent has an average particle diameter of 1 to 15 µm.   The double-side precoated aluminum plate for press working according to any one of claims 1 to 5, wherein the matting agent is silica powder.   The said 2nd organic resin-type coating material contains the inner wax in the ratio of 0.2-5.0 weight part with respect to 100 weight part of the said resin component. 2. A double-side precoated aluminum plate for press working according to item 1.   The both surfaces for press working according to any one of claims 1 to 7, wherein the conductive coating film contains an inner wax in a proportion of 0.1 to 4.0 parts by weight. Pre-coated aluminum plate.   The press working process according to claim 8, wherein a blending ratio of the inner wax in the third organic resin-based paint is 0.2 to 0.8 times a blending ratio of the inner wax in the second organic resin-based paint. Double-side pre-coated aluminum plate.   The lubricating coating film and the conductive coating film are respectively formed on the surface of an aluminum plate on which a coating or reaction type chromate layer or non-chromate layer is formed by a base treatment. The double-sided precoated aluminum plate for press working according to any one of claims 1 to 9. When manufacturing a press product by performing press processing using the double-side pre-coated aluminum plate for press processing according to any one of claims 1 to 10,
The surface of the double-side pre-coated aluminum plate on which the lubricating coating film is formed is positioned on the die side, while the surface on which the conductive coating film is formed is positioned on the punch side. Method. In the press product obtained by the press working, the surface on which the lubricious coating film is formed is subjected to grinding or polishing treatment, and the required portion of the top coat layer constituting the lubricating coating film The manufacturing method of the press product of Claim 11 from which is removed.

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