KR20110097661A - Precoating aluminum plate for electronic equipment - Google Patents

Abstract

The present invention provides a pre-coated aluminum sheet for electronic devices that is excellent in conductivity, lubricity, fingerprint resistance, damage resistance and corrosion resistance and is harmless to the environment. As the precoat aluminum plate 10 in which the resin film 12 was formed without providing the base treatment film containing chromium on at least one surface of the aluminum platen 11 whose arithmetic mean roughness Ra is 0.3 micrometer or more and 0.5 micrometer or less, The film 12 does not contain a metal element, contains an acrylic resin component, a urethane resin component, a silica component, and a particulate lubricating component, and the content of the silica component in the resin film 12 exceeds 12% by mass. Content of the lubricating component contained in the resin film 12 exceeds 8 mass%, the average film thickness of the resin film 12 is 0.15 micrometer or more and 1.0 micrometer or less, and the resistance value measured by the specific method is 10 ohm or less. .

Description

Pre-coated aluminum plate for electronic equipment {PRECOATING ALUMINUM PLATE FOR ELECTRONIC EQUIPMENT}

The present invention relates to a pre-coated aluminum plate that is molded and used as a case, structural member, or the like of an electronic device.

Aluminum plates (including aluminum alloy plates) have high strength and formability, and can be significantly lighter than steel sheets. Therefore, by forming a variety of moldings, containers, foils, electrical appliances, automotive products, or It is applied to various uses such as building materials.

The molded article of an aluminum plate may be surface-treated in order to improve external appearance, corrosion resistance, etc. according to the use and environment to be used. Here, as a method of surface-treating, the precoating method which uses the pre-coated aluminum plate which previously surface-treated the aluminum plate before press molding and formed the film from a viewpoint of mass productivity, the simplification of a manufacturing process, cost reduction, etc. is preferable. Do.

In addition, such pre-coated aluminum sheet has recently been subjected to various functions, such as fingerprint resistance, damage resistance, conductivity (earth connectivity), heat dissipation, and thermal insulation, in order to meet the diversification and quality of products and devices. The functional pre-coated aluminum sheet provided with antimicrobial, antifungal, hydrophilic, water repellent, and lubricity has been developed and widely used. Among them, as the pre-coated aluminum sheet for electronic devices, the pre-coated aluminum sheet having electroconductivity, fingerprint resistance, damage resistance and lubricity is most widely employed.

Patent Document 1 discloses a surface treatment excellent in anti-fingerprint and damage resistance that does not make fingerprints adhered to the surface or fine scratches formed on the surface by coating a resin containing a lubricant on an aluminum plate to form a resin film. An aluminum plate is proposed.

According to this invention, although the rubbing resistance and damage resistance of an aluminum plate improve to some extent, since the surface of the aluminum plate coated with the resin film which is an insulating material shows insulation, when taking earth from the case or structural member of the said electronic device, The post-processing, such as scraping off a part of the said resin film and providing the electrically conductive part which exposed the metal part of the aluminum plate, is needed.

Then, in order to solve the problem of ensuring the electroconductivity on the surface of such a precoated aluminum plate, the technique of coating the resin film containing an electroconductive substance is proposed by patent document 2, patent document 3, etc.

However, in the method of coating the resin containing the conductive material on the surface of the aluminum plate, it is necessary to uniformly disperse the particles of the conductive material in the resin, and the particles of the conductive material in the resin film formed on the surface of the aluminum plate. When the contact between each other is not fully secured, or at the interface between the resin film and the aluminum plate, when the contact between the conductive material and the aluminum plate is not sufficiently secured, a problem arises that the desired conductivity cannot be obtained. Therefore, in order to obtain desired electroconductivity, it is necessary to increase the component amount of electroconductive substance. By the way, when the amount of the component of the conductive material is increased, the resin film becomes hard and receded, and thus, a problem arises in that cracking (peeling) of the resin film easily occurs when press working on the aluminum plate on which the resin film is formed.

MEANS TO SOLVE THE PROBLEM In order to solve the problem of the invention of the structure which adds these electroconductive substances in a resin film, this inventor focused on the relationship between the surface roughness which an aluminum plate has, and the average film thickness of a resin film, and used a conductive material in patent document 4. The technique which ensures electroconductivity without providing is proposed. That is, in this patent document 4, as shown in FIG. 5, the predetermined | prescribed corrosion-resistant film 42 and predetermined | prescribed average film thickness on at least one surface of the aluminum platen 41 which has predetermined centerline average roughness Ra. A pre-coated aluminum sheet for electronic equipment, in which a resin film 43 having a film is formed and exposed to the surface of the resin film 43 in a state in which fine convex and convex portions of the aluminum plate 41 are covered with the corrosion resistant film 42. (40) is described, thereby satisfying other requirements while improving high conductivity.

Since the pre-coated aluminum sheet for electronic devices described in Patent Document 4 having the above-described structure is excellent in conductivity, fingerprint resistance, damage resistance, and lubricity, the cover of the optical disk drive, the frame of the liquid crystal panel, the back panel of the liquid crystal panel, and the in-vehicle audio Various electronic devices, such as an inner case, are employ | adopted.

[Prior Art Literature]

[Patent Documents]

Patent Document 1: Japanese Patent Application Laid-open No. Hei 6-70870

Patent Document 2: Japanese Patent Application Laid-Open No. 7-313930

Patent Document 3: Japanese Patent No. 3245696

Patent Document 4: Japanese Patent No. 4237975

However, the corrosion resistant film used in the pre-coated aluminum sheet for electronic devices described in Patent Document 4 is a conventionally known corrosion resistant film mainly composed of chromium (Cr) or zirconium (Zr), and the corrosion resistant film is mainly composed of Cr. In this case, Patent Document 4 discloses that a phosphoric acid chromate treated film, a chromate chromate treated film, or a coated chromate treated film can be suitably used.

For example, a phosphate chromate treatment for forming a phosphate chromate treatment film is a chemical reaction between a chemical solution having hexavalent chromium and aluminum, and since the hexavalent chromium is reduced to trivalent in the course of the reaction, the obtained chemical conversion film (corrosion resistant film) Is known as a treatment that does not contain hexavalent chromium. In addition, the reaction liquid containing hexavalent chromium used for the chemical liquid has a so-called "closed system" design which does not drain the wastewater and waste from the facility, including the water washing water, and the environment. It is well known that care for is a completed and well-equipped technology.

However, from the point of view of the general consumer, it is hard to think that the difference between trivalent chromium and hexavalent chromium is accurately understood, and the feeling of the word `` chromium '' may lower the image of the product.

In recent years, in the field of electronic devices, the EU Directive on the Restriction of the Use of Certain Hazardous Substances in Electronic and Electrical Equipment (RoHS Directive) and the EU Directive on Generators and Electronic Products (WEEE Directive) are considered in terms of environmental protection. And the like, raw materials used tend to be restricted, and hexavalent chromium corresponds to this.

As described above, the phosphate chromate treated film does not contain hexavalent chromium, but trivalent chromium is included. If it is used as a product and disposed of, it is not possible to control what environment it will be exposed to after disposal. For this reason, it is difficult to assert that 100% is not completely satisfied with the question of whether or not trivalent chromium is changed to hexavalent chromium under special circumstances.

To reach this level and open 100% from the safety of hexavalent chromium, it is now necessary to secure a certain performance without using chromium itself at all.

This invention is made | formed in view of the said subject, The objective is excellent in electroconductivity, lubricity, anti-fingerprint, and damage resistance, and is excellent in corrosion resistance, even if it does not integrally form the chromium containing base treatment film represented by chromium phosphate. Another object is to provide a pre-coated aluminum sheet for electronic equipment which is harmless to the environment.

In the precoated aluminum sheet for electronic devices according to the present invention, which has solved the above problems, a resin film is formed on at least one surface of an aluminum platelet whose arithmetic mean roughness Ra is 0.3 µm or more and 0.5 µm or less without providing a base treatment film containing chromium. A pre-coated aluminum sheet for electronic equipment, wherein the resin film does not contain a metal element, but contains an acrylic resin component, a urethane resin component, a silica component, and a particulate lubricating component, and the content of the silica component in the resin film is increased. Spherical terminal exceeding 12 mass%, content of the said lubricating component contained in the said resin film exceeds 8 mass%, the average film thickness of the said resin film is 0.15 micrometer or more and 1.0 micrometer or less, and the tip part is 10 mm in radius. Is pressed at a load of 0.4 N against the aluminum platen on which the resin film is formed. The resistance value between the spherical terminal and the aluminum platelets the stand and is characterized in that not more than 10Ω.

Since the pre-coated aluminum sheet for electronic devices according to the present invention regulates the arithmetic mean roughness Ra of the aluminum platelets and the average film thickness of the resin film within a specific range without forming a base treatment film containing chromium, respectively, the aluminum platelets The fine convex portion of the film is formed to protrude higher than the average height of the resin film, and the film thickness of the resin film covering the convex portion is almost the same as in the case of forming the base treatment film of the prior art. Therefore, the outstanding electroconductivity like the resistance value measured by the said method to be 10 ohms or less can be ensured.

In addition, the pre-coated aluminum sheet for electronic devices according to the present invention defines the resin component for forming the resin film as described above, and includes a silica component and a lubricating component with a predetermined content as essential components, thereby requiring it as an electronic device. In addition to ensuring corrosion resistance, lubricity, fingerprint resistance and damage resistance are ensured. In addition, since the base treatment film containing chromium is not included, and the resin film does not contain metal elements such as chromium, a pre-coated aluminum sheet for electronic devices which is harmless to the environment is realized.

It is preferable that the precoat aluminum plate for electronic devices which concerns on this invention does not provide a base treatment film integrally between the said aluminum platen and the said resin film.

Thus, if it consists of a base process film which does not contain chromium between aluminum platelets and a resin film, and does not provide a base process film at all, the process of forming a base process film and the chemical | medical agent used for base process film formation Since it is omitted, it is possible to greatly simplify the configuration of the equipment for manufacturing a pre-coated aluminum plate for an electronic device of the present invention, the cost can be reduced and the productivity of the pre-coated aluminum plate for electrical equipment is implemented.

In the pre-coated aluminum sheet for electronic devices according to the present invention, the particle diameter of the lubricating component contained in the resin film is preferably 2.5 μm or less.

In this case, even if the film thickness of the resin film formed on the pre-coated aluminum sheet for electronic devices according to the present invention is made thin, the lubrication component is less likely to fall even if the thickness is near the lower limit, thereby ensuring even higher lubricity while maintaining high conductivity. A precoated aluminum plate for an electronic device is implemented.

It is preferable that the said resin film of the precoat aluminum plate for electronic devices which concerns on this invention contains 1 mass% or more and 30 mass% or less of optical characteristic adjustment microparticles | fine-particles whose average particle diameters are 0.3 micrometer or more and 15 micrometers or less further.

In this way, the optical properties of the surface are further optimized to provide a precoated aluminum sheet for electronic devices with further improved fingerprint resistance.

In the pre-coated aluminum sheet for electronic devices according to the present invention, it is preferable that the chromium content as the additive element for the alloy contained in the aluminum platen is less than 0.1% by mass.

In this case, since the chromium is not included not only in the resin film or the base treatment film but also in the aluminum plate itself, a pre-coated aluminum plate for electronic devices which is harmless to the environment is further realized.

According to the pre-coated aluminum sheet for electronic devices according to the present invention, the arithmetic mean roughness Ra of the aluminum platelets and the average film thickness of the resin film are respectively regulated within a specific range, so that the components of the resin film are more appropriate. It is excellent in anti-fingerprint, damage resistance and corrosion resistance.

In addition, according to the pre-coated aluminum sheet for electronic devices according to the present invention, since the resin film and the base treatment film do not contain chromium, it is harmless to the environment.

1 is an enlarged cross-sectional view of a main part schematically showing the configuration of a pre-coated aluminum sheet for electronic equipment according to the present invention;
2 is a schematic diagram schematically showing a method of measuring a resistance value of a pre-coated aluminum sheet for electronic equipment;
3 is an enlarged cross-sectional view of an essential part schematically showing the configuration of another example of the pre-coated aluminum sheet for electronic equipment according to the present invention;
4 is a schematic diagram schematically showing a shear bending test method for measuring damage resistance of a pre-coated aluminum sheet for electronic equipment;
Fig. 5 is an enlarged cross sectional view of an essential part schematically showing the configuration of a pre-coated aluminum sheet for electronic equipment according to the prior art;

Hereinafter, the pre-coated aluminum sheet for electronic devices according to the present invention will be specifically described with reference to the drawings.

As shown in FIG. 1, the precoat aluminum plate 10 for electronic devices which concerns on this invention has the aluminum platen 11 and the resin film 12 formed in at least one surface of this aluminum platen 11. In addition, between the aluminum platelet 11 and the resin film 12, a chemical conversion film (base treatment film) containing chromium such as phosphate chromate, which is commonly used at least, is not formed. However, as long as it is a base treatment film which does not contain chromium as shown in FIG. 3, it is permissible to form this between the aluminum platen 11 and the resin film 12.

The resin film 12 formed on the surface of this aluminum platen 11 does not contain a metal element, but contains an acrylic resin component, a urethane resin component, a silica component, and a particulate lubricating component. The content of the silica component in the solution exceeds 12% by mass, and the content of the lubricating component contained in the resin film 12 exceeds 8% by mass.

Moreover, since fine unevenness | corrugation is formed in the surface of the aluminum platen 11, the said resin film 12 is formed relatively thick with respect to the recessed part of the unevenness | corrugation of the surface of the aluminum platen 11, and a convex part is formed. It is formed relatively thin, and the average film thickness is 0.15 micrometer or more and 1.0 micrometer or less.

Since the pre-coated aluminum sheet 10 for electronic devices according to the present invention has such a resinous coating 12, the spherical terminal 23 (see FIG. 2) having a tip of 10 mm in radius is used for the resinous coating 12. It is possible to set the resistance value between the above-described spherical terminal 23 and the aluminum plate 11 to be 10 Ω or less when pressed against a formed aluminum plate 11 with a load of 0.4 N.

Moreover, the description regarding the above-mentioned precoat aluminum plate 10 for electronic devices concerning this invention, the structure of the precoat aluminum plate 10 for electronic devices which concerns on this invention shown in FIG. 1, and the prior art shown in FIG. As can be seen by comparing the configuration of the pre-coated aluminum plate 40 for electronic devices according to the present invention, the resin coating 12 of the pre-coated aluminum plate 10 for electronic devices according to the present invention, the pre-coating for electronic devices according to the prior art The structure and role which integrated the corrosion-resistant film 42 and the resin film 43 of the aluminum plate 40 are integral. Therefore, although described in detail later, it is possible to provide the base treatment film 13 which does not contain chromium as shown in FIG.

Hereinafter, each structural requirement of the precoat aluminum plate 10 for electronic devices which concerns on this invention is demonstrated.

[Aluminum Platen]

The aluminum platelets 11 usable in the present invention are made of aluminum or an aluminum alloy, and the varieties which can be used are not particularly limited, and can be arbitrarily selected according to the product shape, the molding method, the strength required during use, and the like. Generally, a non-heat treatment type aluminum plate, that is, a 1000 industrial pure aluminum plate, a 3000-based Al-Mn alloy plate, and a 5000-based Al-Mg alloy plate can be preferably used. In particular, when producing a case having a deep container shape with ironing, an aluminum plate such as A1050, A1100, A3003, A3004, etc. specified in JISH4000 is recommended. In addition, when manufacturing the case of a comparatively shallow container shape, or when manufacturing the case of a bending process main body, aluminum plates, such as A5052 and A5182, which are prescribed | regulated to JISH4000 are recommended. Various types of thermal refining and sheet thickness can be selected and used depending on the purpose.

In addition, although the aluminum platen 11 does not contain chromium most preferably, when it contains chromium, it is preferable to make the content into less than 0.1 mass%. The reason stated above is not a performance problem, but in order to make the product more harmless to the environment, chromium is not actively added except for the chromium component which is inevitably mixed by a recycled base metal or the like. Because it is in the position. Furthermore, not allowing this amount of chromium not only impairs the excellent recycling properties of aluminum alloys, but also makes it impossible to use new ones each time, requiring enormous energy and resources. It becomes a harmful product.

In view of this, the above-mentioned aluminum alloy A5052 has a chromium content of 0.15 to 0.35 mass% in the alloy, and corresponds to an alloy to which chromium must be actively added as an alloy component. The use of such an alloy is not preferable as the present invention, and it is preferable to use alternative alloys having similar performance if possible. For example, 5K52 (produced by Kobe Steel Co., Ltd.) which contains about 2.5 mass% magnesium which is equivalent to A5052, and does not contain chromium actively and adds about 0.45 mass% of manganese instead of chromium as an alternative alloy of A5052. Can be employed in aluminum platelets.

(Arithmetic mean roughness Ra of aluminum platelets: 0.3 µm or more and 0.5 µm or less)

Arithmetic mean roughness Ra of the aluminum platen 11, together with the average film thickness of the resin film 12 described later, is conductive, corrosion resistance, anti-fingerprint, damage resistance in the pre-coated aluminum plate 10 for electronic devices of the present invention. It is an important parameter that contributes to the expression of various properties such as.

When the arithmetic mean roughness Ra of the aluminum platen 11 is less than 0.3 µm, the glossiness of the surface of the precoated aluminum plate 10 for electronic devices becomes too large, and fingerprints attached to the surface and minute scratches on the surface are easily visible. , Anti-fingerprint and damage resistance. In this case, the height of the convex portion of the base of the aluminum platen 11 having the fine concavities and convexities is lowered, and as a result, the film thickness of the resin film 12 covering the convex portion becomes thick, so as to secure desired conductivity. Becomes difficult.

On the other hand, when the arithmetic mean roughness Ra of the aluminum platen 11 exceeds 0.5 micrometer, since the height of the convex part of the aluminum platen 11 will become too high, the top of the convex part will be easy to be exposed from the resin film 12. As a result, since the exposed surface of the aluminum plate 11 is abraded by the mold, the damage resistance is lowered and the lubricity is also lowered. Moreover, when the convex part is exposed from the resin film 12, corrosion will generate | occur | produce there from the starting point, and since it spreads around, the corrosion resistance falls.

That is, by defining the arithmetic mean roughness Ra of the aluminum platen 11 in a range of 0.3 µm or more and 0.5 µm or less, excellent conductivity, anti-fingerprint resistance, damage resistance and corrosion resistance can be provided.

In addition, as a method of adjusting the arithmetic mean roughness Ra of the aluminum platen 11 within the above-mentioned range, for example, in the rolling step of the aluminum platen 11, the final (finishing) of cold rolling is performed using a rolling roll whose surface roughness is appropriately set. The method of rolling, the method of performing an etching process on the surface of the aluminum platen 11 after rolling, and the blasting method of hardening fine particles etc. are mentioned.

In this invention, since the arithmetic mean roughness Ra is adjusted in this way and the resin film 12 which specified the component and average film thickness on the aluminum platen 11 in which the fine unevenness | corrugation was formed is formed, it covers the fine convex part of the aluminum platen 11. The film thickness of the resin film 12 does not become too thick, nor does it become too thin. Therefore, the desired electroconductivity, lubricity, fingerprint resistance, and damage resistance are ensured, and the precoat aluminum plate 10 for electronic devices with high corrosion resistance can be obtained.

In addition, if it is a base process film which does not contain chromium, it is permissible to form this between the aluminum platen 11 and the resin film 12, but when not forming a base process film integrally, the process of forming a base process film and Since the chemical agent used for forming the base treatment film can be omitted, it is possible to greatly simplify the equipment configuration for manufacturing the pre-coated aluminum sheet 10 for electronic devices of the present invention, thereby reducing costs and increasing productivity. Can increase.

[Resin film]

(Structural Components of Resin Film: Contains Acrylic Resin Components, Urethane Resin Components, Silica Components, and Particle Lubrication Components)

As mentioned above, the resin film 12 used for the precoat aluminum plate 10 for electronic devices of this invention contains an acrylic resin component, a urethane resin component, a silica component, and a granular lubrication component as a structural component. in need.

By using together an acrylic resin component and a urethane resin component as a resin component, since not only the concave part but the convex part of the surface of the aluminum platen 11 which has a fine unevenness | corrugation can be covered with a thin film, the corrosion resistance, damage resistance, and fingerprint resistance are favorable The coated aluminum sheet 10 can be obtained.

Here, as for the content ratio of the acrylic resin component and a urethane resin component only in a resin component, 5: 95-95: 5 are preferable for the acrylic resin component: urethane resin component by mass ratio, More preferably, it is 10: 90-90. : 10, more preferably 50:50 to 85:15. More acrylic resin components than 95: 5 are inferior to corrosion resistance. In addition, when the urethane resin component is larger than 5:95, the corrosion resistance and the damage resistance are inferior.

Since both the silica component and the lubricating component are dispersed in the resin component in which the acrylic resin component and the urethane resin component are used together, the concave portion as well as the convex portion of the surface of the aluminum platen 11 having fine concavities and convexities as described above can be covered thinly. Compared with the resin film using the resin component, the effect of improving corrosion resistance and lubricity is great. In particular, since the effect of improving corrosion resistance is greatly increased, for example, a base treatment film 42 such as a phosphate chromate treated film which has been responsible for providing corrosion resistance in a conventional pre-coated aluminum plate 40 (see FIG. 5) for electronic devices is not used. However, even if it is a thin film thickness (average film thickness) like this invention, high corrosion resistance can be ensured.

(Component of resin film: does not contain metal element)

Since the present invention aims to provide a pre-coated aluminum sheet 10 for electronic devices that is harmless to the environment, the base treatment film containing chromium is not provided. By not containing a metal element, the precoat aluminum plate 10 for electronic devices which is harmless to an environment can be provided further. For example, as a rust preventive pigment (water repellent pigment) which is often added for the purpose of improving corrosion resistance, there are a lead rust preventive pigment, a zinc rust preventive pigment, and a phosphate rust preventive pigment. Examples of lead-based rust preventive pigments include lead, lead nitrite, basic lead chromate, lead cyanamide, calcium lead, basic lead sulfate, and the like, and contain Pb, Cr, and Ca. Zinc-based rust preventive pigments contain Zn, and examples of the phosphate-rust rust preventive pigments include zinc phosphate, magnesium phosphate, sodium polyphosphate, zinc calcium phosphate, tripolyphosphate, aluminum phosphomolybdate, and the like. Zn, Mg, Na, K , Al and Mo are contained. In addition, as a coloring pigment which is often added for the purpose of coloring, there are titanium oxide, zinc oxide pigment, iron oxide pigment, etc. of white pigment, but these contain Ti, Zn, Fe, and the extender pigment, Calcium carbonate, barium sulfate, alumina, kaolin, talc, bentonite, mica, and the like, and Ca, Ba, Al, Mg, Na are contained. Alternatively, conductive powders include nickel powder, aluminum powder, stainless steel powder, zinc powder, cadmium yellow, cobalt violet, molybdenum orange, and the like, but these contain Ni, Al, Fe, Zn, Cd, Co, and Mo. .

Therefore, the resin film 12 should not add rust-preventive pigments, coloring pigments, and conductive paints containing these metal elements, but as will be described later, the resin film 12 has sufficient performance even if it does not contain these for corrosion resistance and conductivity. Because it can exert, it does not matter at all about not containing these.

(Content of the silica component in the resin film: 12 mass% or more)

The silica component dramatically improves the corrosion resistance. Therefore, by including this in excess of a certain amount, it becomes possible to equip the pre-coated aluminum sheet 10 for electronic devices with a corrosion resistance that can not be obtained only by the acrylic resin component and the urethane resin component.

If content of a silica component is 12 mass% or less, corrosion resistance will fall. Therefore, compared with the conventional precoat aluminum plate 40 (refer FIG. 5) for electronic devices which used the base process film (corrosion-resistant film 42 (refer FIG. 5)) containing chromium, such as a phosphate chromate treated film, It will fall. Moreover, as for content of a silica component, 15 mass% or more is preferable.

In addition, when the fluidity | liquidity etc. of resin at the time of coating are considered, it is preferable to make content of a silica component into 50 mass% or less.

(Content of lubricating component contained in resin film: exceeds 8 mass%)

As the name suggests, the lubricating component plays a role of improving lubricity and improving moldability.

When the content of the lubricating component is 8% by mass or less, sufficient lubricity is not obtained, and thus, when the press work is performed continuously, the amount of abrasion powder is increased, which causes a defect that the peeling of the resin film is likely to occur. . Therefore, content of a lubrication component needs to exceed 8 mass%. In addition, it is preferable to make content of a lubrication component into 12 mass% or more.

Moreover, since there exists a tendency for the film forming property of a resin film to fall and damage resistance to fall that content of a lubricating component increases, it is preferable to make content of a lubricating component into 30 mass% or less.

(Preferable particle diameter of lubricating component: 2.5 μm or less)

As described above, the lubricating component has a particle shape. It is preferable that the particle diameter is 2.5 micrometers or less. When the particle diameter of a lubricating component exceeds 2.5 micrometers, when the average film thickness prescribed | regulated by this invention becomes near a lower limit, a lubricating component will fall easily from a resin film. As for the particle diameter of the lubrication component used by this invention, 0.6 micrometer or less is more preferable. In order to raise the lubricity and to effectively exhibit the effect of improving the moldability, the particle diameter of the lubricating component is preferably 0.1 μm or more.

As the lubricating component, from the viewpoint of appropriately harmonizing the improvement of moldability and economical efficiency, for example, one selected from polyethylene wax, polyalkylene wax, microcrystalline wax, fluorine wax, lanolin wax, carnauba wax, paraffin wax, and graphite The above can be utilized.

(Preferred component: optical properties adjustment fine particles)

In the precoat aluminum plate 10 for electronic devices of this invention, it is preferable to add optical property adjustment microparticles | fine-particles. In the present invention, since fine particles such as a silica component and a lubricating component are originally included, they have excellent anti-fingerprint properties. However, the addition of optical property-adjusting fine particles further optimizes the optical properties of the surface, further improving anti-fingerprint properties. The aluminum plate 10 may be implemented.

As such optical property adjustment microparticles | fine-particles, 1 or more types chosen from inorganic microparticles | fine-particles, such as various organic microparticles | fine-particles, such as acrylic resin microparticles | fine-particles, microparticles | fine-particles of nylon resin, microparticles of a urethane resin, microparticles of polyolefin resin, microparticles | fine-particles of fluororesin type, and glass microparticles | fine-particles, are mentioned, for example. Can be used.

(Preferable particle diameter of optical property adjustment fine particles: 0.3 micrometer or more and 15 micrometers or less)

When adding optical property adjustment microparticles | fine-particles, it is preferable that the particle diameter of optical property adjustment microparticles should be 0.3 micrometer or more and 15 micrometers or less. Since the effect of improving an optical characteristic can hardly be acquired when the particle diameter of an optical characteristic adjustment microparticle is less than 0.3 micrometer, it has no meaning to add this. On the other hand, when the particle diameter of optical property adjustment microparticles | fine-particles exceeds 15 micrometers, it will become easy to fall out from the resin film 12. The lower the chemical activity, such as the fluorine resin beads and the polyolefin resin beads, the easier it is to fall off the resin film 12, so that the particle diameter is more preferably 5 µm or less. Moreover, assuming that the average film thickness prescribed | regulated to this invention becomes near a lower limit, it is more preferable that a particle diameter shall be 2.5 micrometers or less.

(Preferred amount of components of the optical property adjusting fine particles: 1% by mass or more and 30% by mass or less)

In addition, when adding optical property adjustment microparticles | fine-particles, it is preferable to make the component amount of optical property adjustment microparticles 1 mass% or more and 30 mass% or less. Since the effect which improves an optical characteristic is hardly acquired when the amount of components of an optical characteristic adjustment microparticle is less than 1 mass%, it does not mean adding this. On the other hand, when the amount of components of the optical property-adjusting fine particles exceeds 30% by mass, the number of the fine particles in the resin film 12 becomes too large, so that the fine particles are formed between the electrode and the aluminum platelet 11 when the conductivity is to be secured. Since it enters a lot and inhibits both from coming close, electroconductivity falls. Therefore, it is more preferable that the component amount of optical property adjustment fine particles shall be 10 mass% or less.

(Average film thickness of resin film: 0.15 micrometers or more and 1.0 micrometers or less)

The resin film 12 formed on the aluminum plate 11 is provided to impart desired lubricity, corrosion resistance, anti-fingerprint resistance and damage resistance to the precoated aluminum plate 10 for electronic devices according to the present invention. In the present invention, the average film thickness of the resin film 12 is specified in a specific range of 0.15 µm or more and 1.0 µm or less, thereby achieving desired conductivity as well as lubricity, corrosion resistance, fingerprint resistance, and damage resistance.

When the average film thickness of the resin film 12 is less than 0.15 micrometer, since the convex part of the aluminum platen 11 cannot be fully covered, there exists a possibility that sufficient corrosion resistance may not be obtained. In addition, since the film thickness of the resin film 12 formed in the concave portion of the aluminum plate 11 is also thin, the silica component and the lubricating component are also reduced, resulting in inferior rubbing resistance and damage resistance and insufficient lubricity. Therefore, the molding process becomes difficult.

On the other hand, when the average film thickness of the resin film 12 exceeds 1.0 micrometer, even if it roughens so that the surface roughness (arithmetic mean roughness Ra) of the aluminum platen 11 may become near the upper limit prescribed | regulated by this invention, Since the film thickness of the resin film 12 which covers the convex part is too thick, it becomes difficult to ensure desired electroconductivity.

(Formation method of resin film)

Such a resin film 12 is applied continuously to one or both surfaces of the coil-shaped aluminum platelet 11 by a roll coating method, for example, a liquid film-forming agent containing the resin component specified in the present invention. After that, the oven can be formed by firing by passing through a continuous oven formed in a single or a plurality of ovens. This makes it suitable for productivity because the pre-coated aluminum sheet 10 for electronic devices can be manufactured continuously and quickly.

At this time, since the resin film 12 initially applied on the surface of the aluminum platen 11 is in a liquid form, the convex portion of the surface of the aluminum platen 11 is thinly coated, and the concave portion is preferentially filled. The concave portion is thickly coated. Subsequently, a hard resin film 12 is formed on the convex portion with a thin film thickness by the subsequent firing treatment, and a hard resin film 12 is formed on the concave portion with a thick film thickness. It is possible to have an average film thickness defined in the present invention.

In addition, the average film thickness of the resin film 12 can be calculated | required relatively easily from the area of the part in which this resin film 12 was formed, and its resin amount.

[Performance of Pre-coated Aluminum Plate for Electronic Devices]

(Resistance value: 10Ω or less)

As the pre-coated aluminum sheet 10 for electronic devices according to the present invention, it is necessary to set the resistance value measured by the method described later to 10 Ω or less. When such a resistance value is 10 Ω or less, it is possible to take earth directly from above the resin film 12 of the pre-coated aluminum plate 10 for electronic equipment. In addition, the electromagnetic noise can be sufficiently removed. Therefore, when the electronic device uses the pre-coated aluminum plate 10 for electronic devices according to the present invention as a drive device such as an optical disk drive, and the structural members such as the case and the chassis of the drive device, writing or reproduction errors are caused. When the electronic device uses the precoated aluminum plate 10 for electronic devices according to the present invention as a liquid crystal panel, and the structural members such as the fixing frame and the rear cover of the liquid crystal panel, the image noise hardly occurs. .

On the other hand, when the resistance value exceeds 10 Ω, it is impossible to take earth directly from the resin film 12 or to sufficiently remove the electromagnetic noise.

In the present invention, the arithmetic mean roughness Ra of the aluminum platen 11 is within a specific range defined by the present invention (0.3 µm or more and 0.5 µm or less), and the average film thickness of the resin film 12 is defined in the present invention. By setting it within a specific range (0.15 micrometer or more and 1.0 micrometer or less), the resistance value measured by a specific method is set to 10 or less. That is, in the pre-coated aluminum plate 10 for electronic devices according to the present invention, the aluminum plate 11 is formed by forming the resin film 12 in a suitable uniformity with respect to the aluminum plate 11 having a specific range of arithmetic mean roughness Ra. The fine convex part of ()) protrudes higher than the average height of the resin film 12. Thus, in the convex part which protruded higher than the average height of the resin film 12, the film thickness of the resin film 12 is substantially the same as the coating base process film (corrosion-resistant film 42 (refer FIG. 5)) of a prior art. Since it stays at about the film thickness, a resistance value can be 10 ohms or less and electroconductivity can be ensured.

However, defining the arithmetic mean roughness Ra of the aluminum platen 11 within a specific range (0.3 µm or more and 0.5 µm or less) and the average film thickness of the resin film 12 within a specific range (0.05 µm or more and 1.0 µm or less), Even if it is a necessary condition for satisfying the condition of making the resistance value 10Ω or less, it is not a sufficient condition, and even if these conditions are satisfied, the resistance value may not be 10Ω or less. For example, when the arithmetic mean roughness Ra of the aluminum platen 11 is near the lower limit, and the average film thickness of the resin film 12 is near the upper limit, the unevenness of the aluminum platen 11 is small and the film thickness is thick. It is easy to become

Therefore, in this invention, it is a requirement that the resistance value measured by the specific method mentioned later is 10 ohm or less.

As a specific example, the comparative example C3 of Unexamined-Japanese-Patent No. 2004-68042 has described the example which apply | coats a coating material 0.62 micrometer using the aluminum alloy plate of 0.4 micrometer of surface roughness.

Although the surface roughness Ra of the aluminum platen 11 and the coating amount (average film thickness) of the coating film both satisfy the requirements of the present invention, the resistance value is 23?, Which does not satisfy the requirements of the present invention. It is also necessary to consider the influence of the difference in the measurement method, but in this Comparative Example C3, since the load at the time of measuring the resistance value is 100 g, the electrode is pressed against the test piece with a force stronger than 0.4 N (≒ 40 gf) of the present application. From the measurement method, a resistance value lower than the method specified in the present invention will be measured, but a result is disclosed in which only a high resistance value not satisfying the requirements of the present invention is obtained.

As can be seen from this example, within the range of the arithmetic mean roughness Ra of the aluminum platen 11 (0.3 μm or more and 0.5 μm or less) and the average film thickness of the resin film 12 (0.15 μm or more and 1.0 μm) In the present invention, since the resistance value measured by the specific method described later is a necessary condition to satisfy the requirement of 10 Ω or less, it is not a sufficient condition. Only those that can be confirmed to satisfy the requirement of 10 Ω or less are considered as the present invention.

2 is a diagram schematically showing a method of measuring the resistance value of the pre-coated aluminum sheet for electronic devices according to the present invention. This measuring method is the same method and the measurement method of the same conditions as what was disclosed by patent document 4, Unexamined-Japanese-Patent No. 2005-297290, Unexamined-Japanese-Patent No. 2002-206178, etc.

In the measuring method of the resistance value in this invention, one terminal 21 of the tester 20 is made to conduct direct contact with the aluminum platen which exposed the resin film of the part of the precoated aluminum plate for electronic devices by sand paper, and exposed. The other terminal 22 of the tester 20 is measured from the resin film of the pre-coated aluminum sheet for electronic equipment through the brass spherical terminal 23 formed in a substantially spherical shape having a tip of 10 mm radius. It measures by the one-point contact system performed by making contact by the load of 0.4N (# 40gf). In addition, since the terminal 21 (terminal opposite to the spherical terminal 23) of the tester 20 has to be brought into direct contact with the aluminum plate of the precoated aluminum sheet for electronic equipment, the resin film is polished and removed by sandpaper or the like. Direct contact with the part. In addition, since the natural oxide film on the surfaces of the terminal 21 and the spherical terminal 23 also causes irregular distribution of the measured value of the resistance value, the terminal 21 and the spherical terminal 23 before the resistance value is measured. It is preferable to polish the surface of the film with sandpaper or the like beforehand to sufficiently remove the natural oxide film. In addition, the tip of the terminal 21 and the tip of the spherical terminal 23 are contacted before the resistance is measured so as to eliminate the influence of the internal resistance of the tester 20 in measuring the resistance. It is preferable to carry out the zero point correction in the state in which it is made, and then use the most sensitive range of the tester 20 to set the value when the display of the tester 20 is stabilized as a measured value. In order to sufficiently ensure the reliability of the resistance value, the resistance value is measured at least 10, if possible, at least 50 at a random position with respect to one sheet of precoated aluminum sheet for electronic equipment, and the average value is viewed. It is preferable to employ | adopt as a resistance value prescribed | regulated by this invention.

[Base Treatment Film]

The role of the base treatment film formed on a general precoated aluminum plate is to improve the adhesion between the resin film and the aluminum platen and to improve the corrosion resistance. For this purpose, in most cases, an inorganic single coating or an inorganic organic composite coating containing Cr or Zr is used. Among them, a trivalent chromium phosphate chromate treated film is often used as the base treated film. However, since the resin film 12 of this invention has the role which the base process film played as mentioned above, it is not necessary to necessarily provide a base process film. One of the objects of the present invention is to provide a precoated aluminum plate 10 for electronic devices that is good for the environment, and thus, such as a conventionally known phosphate chromate treated film, chromic acid chromate treated film, coated chromate treated film, and the like, It is unacceptable to provide a base treatment film containing chromium. Therefore, in order to further improve the adhesion between the resin film 12 and the aluminum platelet 11 and to improve the corrosion resistance, when the base treatment film is formed, if the base treatment film does not contain chromium, Allowed.

When forming the base treatment film which does not contain chromium, the precoat aluminum plate 10 'for electronic devices which concerns on this invention becomes a structure as shown, for example in FIG.

As shown in FIG. 3, the pre-coated aluminum plate 10 ′ for an electronic device includes an aluminum plate 11, a resin film 12 formed on at least one surface of the aluminum plate 11, and an aluminum plate 11. The base treatment film 13 which does not contain chromium is formed between the resin film 12 and the resin film 12.

As such a base process film 13, a zirconium phosphate (PZr) process film, a titanium phosphate (PTi) process film, etc. are mentioned, for example. Of course, it is needless to say that the base treatment film 13 should not contain environmental load substances other than chromium, for example, substances whose use is restricted in RoHS or WEEE.

The pre-coated aluminum sheet 10 for electronic devices according to the present invention described above can also be understood as follows.

The pre-coated aluminum plate for electronic devices 10 according to the present invention is a pre-coated aluminum plate for electronic devices, in which a resin film 12 is formed on at least one surface of an aluminum platelet 11 having a centerline average roughness Ra of 0.3 µm or more and 0.5 µm or less. The base treatment film (corrosion-resistant film 42 in Fig. 5) is not formed between the aluminum platen 11 and the resin film 12, and the resin film 12 does not contain a metal element. An acrylic resin component, a urethane resin component, a silica component, and a particulate lubricating component, wherein the content of the silica component in the resin film 12 is greater than 12% by mass, and the lubrication component contained in the resin film 12 The resin film 12 contained a spherical terminal 23 (see FIG. 2) in which the content exceeded 8% by mass, and the average film thickness of the resin film 12 was 0.15 µm or more and 1.0 µm or less, and the tip was 10 mm in radius. Aluminum cow The resistance value between 11 sphere-shaped terminal 23 and the aluminum plate piece 11 in when pressed with a load of 0.4N with respect to not more than 10Ω (see Fig. 1).

It is also possible to provide a base treatment film 13 (see FIG. 4) that does not contain chromium between the aluminum platen 11 and the resin film 12.

According to the precoat aluminum plate 10 for electronic devices which concerns on this invention demonstrated above, the following effects are exhibited.

(1) According to the pre-coated aluminum sheet 10 for electronic devices according to the present invention, the arithmetic mean roughness Ra of the aluminum platen 11 and the average film thickness of the resin film 12 are defined in a specific range, and the resin component and silica Content of a component and content of a lubrication component were prescribed | regulated. Thereby, the convex part of the aluminum platen 11 which has a fine unevenness | corrugation protrudes higher than the average height of the resin film 12, and the film thickness of the resin film 12 which covers this convex part is a coating base of the prior art. It becomes almost the same degree as the process film (corrosion-resistant film 42 (refer FIG. 5)), and can maintain electroconductivity, fingerprint resistance, and damage resistance to the same extent as the prior art. In particular, by specifying the resin component of the resin film 12 as a specific one, excellent corrosion resistance can be ensured even without forming a base treatment film (corrosion resistant film 42 (see Fig. 5)) containing chromium. In addition, since the base treatment film containing chromium is not formed, the precoated aluminum plate 10 for electronic devices of the present invention is better for the environment than the precoated aluminum plate for electronic devices of the prior art.

(2) According to the pre-coated aluminum plate 10 for electronic devices according to the present invention, the base treatment film not containing chromium, as well as the base treatment film containing chromium between the aluminum platelet 11 and the resin film 12. Since the base treatment film is not provided at all, the process of forming the base treatment film and the chemical agent used for forming the base treatment film can be omitted, and thus the precoated aluminum plate 10 for electronic devices of the present invention is The configuration of the equipment to be manufactured can be greatly simplified, thereby reducing costs and increasing productivity.

(3) According to the pre-coated aluminum sheet 10 for electronic devices according to the present invention, since the particle diameter of the lubricating component contained in the resin film 12 is configured to be 2.5 µm or less, the film thickness of the resin film 12 Can be made difficult to drop off the lubricating component even when the temperature is in the vicinity of the lower limit within the above range, it is possible to ensure even higher lubricity while maintaining high conductivity.

(4) According to the pre-coated aluminum sheet 10 for electronic devices according to the present invention, the resin film 12 contains 1% by mass or more and 30% by mass or less of the optical property adjusting fine particles having an average particle diameter of 0.3 µm or more and 15 µm or less. As a result, the optical properties of the surface are further optimized to further improve anti-fingerprint properties.

(5) According to the pre-coated aluminum plate 10 for electronic devices according to the present invention, the aluminum plate 11 used for the pre-coated aluminum plate has a chromium content of 0.1 as an additive element for the alloy contained in the aluminum plate 11. Since it was less than mass%, it can be made more harmless to an environment.

The pre-coated aluminum plate 10 for electronic devices according to the present invention can be suitably used for cases and structural members of various electronic devices such as a case and chassis of an optical disc drive device, a frame for fixing a liquid crystal panel, and a back cover.

In addition, since the pre-coated aluminum sheet 10 for electronic devices according to the present invention has excellent lubricity, it is excellent in formability, thereby reducing the occurrence rate of quality defects in press molding in the process of manufacturing molded articles for electronic devices, The yield of the product can be improved. Thereby, this invention can reduce the overall cost of the molded article for electronic devices, and as a result, it contributes greatly to the cost reduction of an electronic device product.

Example

Next, the pre-coated aluminum sheet for electronic devices according to the present invention will be described in more detail in preparation for an embodiment that satisfies the requirements defined by the present invention and a comparative example that does not satisfy the requirements.

The pre-coated aluminum sheets of Examples 1 to 23 and Comparative Examples 1 to 14 were produced as follows.

First, aluminum slabs having a composition of A5182 prescribed in JISH4000 were dissolved, and after adjusting the alloying components, a slab for rolling was produced by casting. The segregation layer on the surface of the slab is faced, subjected to the homogenization process, and then subjected to each step of hot rolling, cold rolling, and heat treatment to form an aluminum plate (plate thickness: 0.5 mm, alloy type: A5182-H34). Was produced. In addition, in the final (finishing) step of the cold rolling, an aluminum platelet having various surface roughnesses (arithmetic mean roughness) shown in Tables 1 and 2 was produced by appropriately changing the surface roughness of the rolling rolls.

Thereafter, the manufactured aluminum platelets were degreased using a commercially available weak alkaline degreasing solution for aluminum to prepare a coating pretreatment. Subsequently, as shown in Table 1 and Table 2, Example 4 is subjected to a base treatment using zirconium phosphate (PZr) as a coating base, and Example 5 is subjected to a base treatment using titanium phosphate (PTi), and Comparative Example 3 , 4 was subjected to a base treatment using phosphoric acid chromate (PCr), but Examples 1 to 3, 6 to 23, and Comparative Examples 1, 2 and 5 to 14 were usually used as coating bases of precoated aluminum plates. Base treatment such as phosphate chromate was not performed. In addition, the comparative example 4 is corresponded to the Example of patent document 4 (Unexamined-Japanese-Patent No. 4237975).

Subsequently, on the surface of these aluminum platelets, the resin components shown in Tables 1 and 2, the content of the silica component (mass%), the content of the lubricating component (mass%), the particle diameter of the lubricating component (μm), and the optical property adjustment fine particles Table 1 and the film forming agent having a particle diameter (μm) and optical property adjusting fine particles (mass%) of the optical property adjusting fine particles were applied by a roll coating method and baked at a heating temperature of 230 ° C. for 30 seconds. The resin film which has an average film thickness (micrometer) shown in Table 2 was formed, and it was set as the precoat aluminum plate for electronic devices of Examples 1-23 and Comparative Examples 1-14 (Hereinafter, it is simply "Example 1" and "Comparison." Example 1 ", etc.).

Polyethylene wax was used as a lubricating component of Examples 1-23 and Comparative Examples 1-14.

In addition, in the resin component of Table 1 and Table 2, A represents acrylic resin, U represents urethane resin, P represents polyester resin, E represents epoxy resin, and the numerical value shown in parentheses shows a composition ratio.

In addition, in the kind of optical property adjustment particle | grains of Table 1, A represents acrylic resin microparticles | fine-particles, P represents polyethylene resin microparticles | fine-particles (polyolefin type), and G represents glass microparticles | fine-particles.

In addition, the surface roughness (arithmetic mean roughness Ra) of the aluminum platen is a direction perpendicular to the rolling direction of the aluminum platen using a surface roughness measuring instrument (manufactured by Kosaka Laboratory Ltd., SURFCORDER SE-30D). It measured by measuring by arithmetic mean roughness Ra (JIS B0601).

In addition, with respect to Examples 1-23 and Comparative Examples 1-14 which were manufactured, electroconductivity (resistance value (ohm)), lubricity (friction coefficient), rubbing resistance (color difference ((DELTA) E)), damage resistance, and corrosion resistance (rating number ( RT No.)) was evaluated. These were measured and evaluated as follows.

<Conductive>

As shown in FIG. 2, the electroconductivity is an LCR meter (4263B manufactured by HEWLETT PACKARD) as the tester 20. As shown in FIG. 2, one terminal 21 of the tester 20 The resin film was subjected to direct conductive contact with the aluminum platen, which was polished with sandpaper and exposed, and the other terminal 22 of the tester 20 was connected to the spherical terminal 23 (this spherical terminal 23 has a radius of the tip end). It was measured by contacting with a load of 0.4 N (로 40 gf) from the top of the resin film of the pre-coated aluminum sheet for electronic equipment to a measurement point through a 10 mm, approximately spherical brass measuring rod. . At the time of measurement, the surface of the terminal 21 and the spherical terminal 23 is polished with sandpaper in advance, and zero point correction is performed in a state where the tip of the terminal 21 and the tip of the spherical terminal 23 are brought into contact with each other. It was done. These measurements were measured while randomly changing the positions of the spherical terminals 23 at 50 places, and the average value was calculated. When the average value of the resistance value passed 10 Ω or less and exceeded 10 Ω, the result was failed.

Lubrication

Lubricity is randomly applied on the surface of each precoated aluminum sheet for electronic equipment by the Bowden Leben method (steel ball φ16 / 16 inch (4.7625 mm), load 2N (200 gf), sliding speed 200 mm / min). The friction coefficient of three selected places was measured, and the average value was computed.

If the average value of the friction coefficient is 0.2 or less, there is no particular problem in the molding process usually performed in various electronic devices, and if it is 0.1 or less, it can be evaluated as particularly good, so that these were passed and the case of exceeding 0.2 was rejected.

Fingerprint resistance

Anti-fingerprint uses the color difference (ΔE) before and after the fingerprint adheres by touching the surfaces of Examples 1 to 23 and Comparative Examples 1 to 14 with bare hands using a spectrophotometer (CM-600d) manufactured by Konica Minolta Co., Ltd. It was measured by.

When the color difference ΔE value was 0.5 or less, the fingerprint attached to the surface could hardly be confirmed by the naked eye, and the test was passed. When the color difference ΔE was exceeded, the fingerprint attached to the surface could be visually confirmed.

<Damage resistance>

Damage resistance was evaluated by the shear bending test method. That is, as shown in FIG. 4, the surface which formed the resin film of the test piece was punched by the upper metal mold | type 31 and the lower metal mold | die 32 between the test pieces of Examples 1-23 and Comparative Examples 1-14. The bending process was carried out so that 33 slides, thereby attempting to reproduce the process scratches generated during the forming process by the press. The space | interval (mould space | interval) which arises between the lower metal mold | die 32 and the punch 33 was made into the space which added 10% clearance to the plate | board thickness of the used test piece.

The slide surface of the test piece which performed the bending process was visually observed, scored 0 (bad)-5 points (good) according to the degree of the bending process scratch with respect to each test piece, and numerically evaluated, and the damage resistance was evaluated. The same experiment was carried out five times, and the average value of two points or more was given as the pass, and the average value was less than two points.

Corrosion Resistance

Corrosion resistance was tested and evaluated in accordance with the neutral salt spray test specified in JISZ2271. That is, 5 mass% sodium chloride aqueous solution was used as the spray liquid sprayed to a stretch test sample, spraying environment temperature was 35 degreeC, and the spraying quantity was 1.5 milliliter every 1 hour in area 80cm <2>. In addition, the test time was made into 100 hours maximum.

In accordance with the rating number method of quantifying the degree of corrosion by the corrosion area ratio, the corrosion generated in the stretch test sample that was tested is quantified, and the rating number (RT No.) is 9.0 or more, and the rating number is 9.0 Less than was rejected.

These evaluation results are shown in Table 3 and Table 4.

(result)

From the contents shown in Tables 1-4, the following became clear.

(Influence of surface roughness (arithmetic mean roughness Ra) of aluminum platen)

Since the arithmetic mean roughness Ra is less than the lower limit of the range prescribed | regulated by this invention, the comparative example 1 brought the result which a fingerprint-proof and a damage resistance do not satisfy an acceptance criterion. Moreover, since the arithmetic mean roughness Ra exceeded the upper limit regulated by this invention in the comparative example 2, lubricity, damage resistance, and corrosion resistance did not satisfy the acceptance criteria.

(Influence of Average Film Thickness of Resin Film)

Since the average film thickness of the resin film is less than the lower limit of the range prescribed | regulated by this invention, the comparative example 5 brought a result which fingerprint-proof, damage resistance, and corrosion resistance do not satisfy an acceptance criterion. Moreover, since the average film thickness of the resin film exceeded the upper limit of the range prescribed | regulated by this invention, the comparative example 6 brought the result that a resistance value does not satisfy | fill an acceptance criterion.

(Influence of the resin component of the resin film)

Since the comparative example 7 uses only the acrylic resin, since the comparative example 8 uses only the urethane resin, since the comparative example 9 uses only the polyester resin, and the comparative example 10 uses only the epoxy resin, As a result, the corrosion resistance did not satisfy the acceptance criteria. In addition, about the comparative example 8, since only urethane resin was used, damage resistance also resulted in not satisfying a passing criterion.

Moreover, about Example 1 and Examples 18-23 which used together the acrylic resin component and the urethane resin component as a resin component, the ratio of the acrylic resin component and a urethane resin component, and the result of corrosion resistance were compared. As a result, in the mass ratio, Example 23 in which the acrylic resin component: urethane resin component was 5:95 and Example 1 in which the acrylic resin component: urethane resin component was 95: 5 had a rating number of 9, but an acrylic resin component: urethane Example 22 in which the resin component is 10:90, Acrylic resin component: Example 21 in which the urethane resin component is 15:85, and Example 18 in which the urethane resin component is 90:10 are preferred with a rating number of 9.3. As a result, in addition, in Example 20 in which the acrylic resin component: urethane resin component was 50:50 and Example 19 in which the acrylic resin component: urethane resin component = 85: 15 had a rating number of 9.5, the result was more preferable.

(Influence of the content of the silica component of the resin film)

In Comparative Examples 11 and 12, since the content of the silica component was less than the lower limit of the range specified in the present invention, the corrosion resistance did not satisfy the acceptance criteria.

(Influence of Content of Lubrication Component of Resin Coating)

Since the comparative example 13 content of the lubrication component is less than the lower limit of the range prescribed | regulated by this invention, lubricity did not satisfy | fill the acceptance criterion.

On the other hand, Examples 1 to 17 in which the surface roughness (arithmetic mean roughness Ra), the average film thickness, the resin component in the resin film, the content of the silica component, and the content of the lubricating component of the aluminum platen all satisfy the range specified by the present invention. In this case, there was no problem in all of the conductivity, lubricity, fingerprint resistance, damage resistance and corrosion resistance.

In addition, about the comparative example 14, the surface roughness (arithmetic mean roughness Ra), the average film thickness, the resin component in a resin film, content of a silica component, and content of a lubrication component of an aluminum platen all satisfy | fill the range prescribed | regulated by this invention. Although there existed, only electroconductivity did not satisfy the acceptance criteria of this invention. This is considered to be the result because arithmetic mean roughness Ra is near a lower limit and an average film thickness is near an upper limit. Therefore, the various parameters defined in the present invention may be said to be sufficient conditions, although they are necessary conditions for securing the conductivity, and therefore the desired effects of the present invention, that is, conductivity, lubricity, fingerprint resistance, damage resistance, and corrosion resistance In order to reliably show the effect of being excellent, it is necessary to define that the resistance value measured by a specific method is 10 Ω or less.

Although the comparative examples 3 and 4 satisfy | fill all the acceptance criteria of this invention in terms of the effect obtained, since it contains chromium in a base process film, it is a comparative example which does not satisfy the criteria of this invention for the purpose of this invention. do.

As mentioned above, although the precoat aluminum plate for electronic devices which concerns on this invention was demonstrated by the detailed description of this invention, the meaning of this invention is not limited to the above-mentioned content, It changes suitably in the range based on the technical idea of this invention. It should be understood that such a range is naturally included in the technical idea of the present invention.

10, 10 ': pre-coated aluminum sheet for electronic devices
11: aluminum platen
12: resin film
13: Base treatment film which does not contain chromium

Claims (5)

A pre-coated aluminum sheet for electronic equipment, in which a resin coating is formed on at least one surface of an aluminum platelet having an arithmetic mean roughness Ra of 0.3 µm or more and 0.5 µm or less, without forming a base treatment coating containing chromium.
The said resin film does not contain a metal element, but contains an acrylic resin component, a urethane resin component, a silica component, and a granular lubrication component,
Content of the said silica component in the said resin film exceeds 12 mass%,
Content of the said lubrication component contained in the said resin film exceeds 8 mass%,
The average film thickness of the said resin film is 0.15 micrometers or more and 1.0 micrometers or less,
The resistance value between the said spherical terminal and the said aluminum platen at the time of pressing the spherical terminal of which the front-end | tip part is a radius of 10 mm with the load of 0.4 N with respect to the said aluminum platen which formed the said resin film is 10 ohm or less
Pre-coated aluminum plate for electronic devices, characterized in that.
The method of claim 1,
A pre-coated aluminum sheet for electronic equipment, characterized in that a base treatment film is not integrally provided between the aluminum platen and the resin film.
The method of claim 1,
The particle size of the said lubricating component contained in the said resin film is 2.5 micrometers or less, The precoat aluminum plate for electronic devices characterized by the above-mentioned.
The method of claim 1,
The said resin film further contains 1 mass% or more and 30 mass% or less of optical characteristic adjustment microparticles | fine-particles whose average particle diameter is 0.3 micrometer or more and 15 micrometers or less, The precoat aluminum plate for electronic devices characterized by the above-mentioned.
The method of claim 1,
The chromium content as an additive element for alloys contained in the said aluminum platen is less than 0.1 mass%, The precoat aluminum plate for electronic devices characterized by the above-mentioned.

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