TW201348517A - Surface treated aluminum material, method for producing same, and resin-coated surface treated aluminum material - Google Patents

Abstract

To provide: a surface treated aluminum material which has excellent bondability and adhesion over the entire surface of the aluminum material; and a method for producing the surface treated aluminum material. A surface treated aluminum material which is provided with an oxide coating film on at least one surface. The surface treated aluminum material is characterized in that the oxide coating film is composed of a porous aluminum oxide coating layer that is formed on the surface side and has a thickness of 20-500 nm and a barrier aluminum oxide coating layer that is formed on the base side and has a thickness of 3-30 nm. The surface treated aluminum material is also characterized in that the porous aluminum oxide coating layer is provided with fine pores each having a diameter of 5-30 nm and that the fluctuation range of the total thickness of the porous aluminum oxide coating layer and the barrier aluminum oxide coating layer is within ±50% of the arithmetic mean of the total thickness in the whole surface of the aluminum material. Also provided is a method for producing the surface treated aluminum material.

Description

Surface treated aluminum and its manufacturing method, and resin coated surface treated aluminum

The present invention relates to an aluminum material which has been subjected to surface treatment, a method for producing the same, and a resin-coated surface-treated aluminum material, and more particularly to a surface treatment which is excellent in adhesion and adhesion to an aluminum oxide film on the surface. The aluminum material, the method of making it stable, and the surface-treated aluminum material are coated with a resin using a surface-treated aluminum material.

A pure aluminum material or an aluminum alloy material (hereinafter referred to as "aluminum material") is lightweight and has appropriate mechanical properties, and is excellent in aesthetics, moldability, corrosion resistance, etc., and is widely used in various containers. Structural materials, mechanical parts, etc. These aluminum materials are sometimes used directly. In addition, various surface treatments are often applied to add and enhance corrosion resistance, abrasion resistance, resin adhesion, hydrophilicity, water repellency, antibacterial property, new style, and infrared. It is used for functions such as radioactivity and high reflectivity.

For example, in the surface treatment method for improving corrosion resistance and wear resistance, anodizing treatment (so-called Alumite treatment) is widely used. Specifically, as described in Non-Patent Documents 1 and 2, the aluminum material is immersed in acidity. The electrolytic solution is subjected to electrolytic treatment by a direct current, and an anodized film having a thickness of several tens of μm is formed on the surface of the aluminum material. Therefore, various treatment methods have been proposed in accordance with the use.

Further, in particular, in the surface treatment method for improving the resin adhesion, the alkali exchange electrolysis method of Patent Document 1 has been proposed. I.e., basic solution using a liquid temperature of 40 ~ 90 ℃ carried out at a current density of 4 ~ 50A / dm ² amount of more than 80C / dm ² time, the AC electrolysis. Thereby, an aluminum alloy coating plate for a can lid having an oxide film having a film thickness of 500 to 5,000 angstroms was obtained.

However, according to the technique of Patent Document 1, even when the treatment is performed under the same electrolysis conditions, the adhesion may be extremely low by the timing of the electrolysis treatment. Specifically, a change in hue (often a brownish or white turbid color) is exhibited for a portion of the surface of the aluminum material, and the adhesion of the portion is extremely low.

[Previous Technical Literature]

[Non-patent literature]

[Non-Patent Document 1] Aluminum Handbook, 7th Edition, 179-190 pages, 2007, General Association of Japan Aluminum Association

[Non-Patent Document 2] Japanese Industrial Standard JIS H8601 "Anodized Film of Aluminum and Aluminum Alloys" (1999)

[Patent Document]

[Patent Document 1] Special Kaiping No. 3-229895

[Summary of the Invention]

An object of the present invention is to provide a surface-treated aluminum material which is excellent in overall adhesion and adhesion of aluminum, a method for producing such a surface-treated aluminum material, and a resin-coated surface-treated aluminum using a surface-treated aluminum material. material.

In order to solve the above-mentioned problems, the present inventors have intensively studied the results, and the reduction in adhesion or adhesion is a change in the total thickness of the porous aluminum oxide film layer and the barrier aluminum oxide film layer on the entire surface of the aluminum material. The reason for the appropriateness is that the formation of the oxide film on the entire surface of the aluminum material is uneven, and in order to prevent this, it has been found that it is effective to control the concentration of dissolved aluminum contained in the electrolytic treatment liquid used for the alkali alternating current electrolysis treatment.

That is, the present invention is the first aspect of the patent application, a surface-treated aluminum material characterized by forming an aluminum oxide film on at least one surface, the oxide film being porous from a thickness of 20 to 500 nm formed on the surface side. The aluminum oxide film layer is formed of a barrier aluminum oxide film layer having a thickness of 3 to 30 nm formed on the substrate side, and a pore having a diameter of 5 to 30 nm is formed in the porous aluminum oxide film layer, and the entire surface of the aluminum material is formed. The variation in the total thickness of the porous aluminum oxide film layer and the barrier aluminum oxide film layer in the middle is within ±50% of the arithmetic mean of the total thickness.

The present invention is the surface treated aluminum material of claim 2, wherein the surface-treated aluminum material is bent at 180 degrees by 5R in such a manner that the oxide film side is convex, and the aluminum substrate is The exposure rate is 5% or less.

The present invention is in the third aspect of the patent application, a method for producing a surface-treated aluminum material, which is a method for producing a surface-treated aluminum material according to claim 1 or 2, which is characterized in that the surface-treated aluminum material is used. The electrode and the counter electrode are used as an electrolytic solution at a pH of 13 to 13 at a liquid temperature of 35 to 80 ° C and an aqueous solution having a dissolved aluminum concentration of 5 ppm or more and 1000 ppm or less, at a frequency of 20 to 100 Hz and a current density of 4 to 50 A/ The dm ² and the electrolysis time are subjected to an alternating current electrolysis treatment under conditions of 5 to 60 seconds, and an oxide film is formed on the surface of the aluminum material opposite to the counter electrode.

The present invention is a method for producing a surface-treated aluminum material according to the fourth aspect of the patent application, wherein the counter electrode is a graphite electrode.

The present invention is a method for producing a surface-treated aluminum material according to claim 5, wherein the electrode and the counter electrode of the surface-treated aluminum material are in a flat shape.

Further, the present invention is the sixth aspect of the patent application, which is a resin-coated surface-treated aluminum material characterized by coating a resin layer on the surface of an oxide film of a surface-treated aluminum material according to claim 1 or 2.

According to the present invention, a high-adhesive oxide film is uniformly formed on the surface of an aluminum material with high adhesion to a resin or the like. Therefore, it is possible to obtain a surface-treated aluminum material having an overall aluminum material and excellent adhesion and adhesion.

Specifically, the oxide film on the surface of the aluminum material forms a two-layer structure of a porous aluminum oxide film layer and a barrier aluminum oxide film layer. Then by having The porous aluminum oxide film layer having a thickness of 20 to 500 nm formed on the surface side of the aluminum material and having a small hole diameter of 5 to 30 nm can suppress the agglomeration damage itself and increase the surface area thereof, thereby increasing the adhesion. Sex. Further, by having a barrier type aluminum oxide film layer having a thickness of 3 to 30 nm formed on the substrate side of aluminum, the agglomeration damage of the aluminum oxide film layer is suppressed, and the aluminum substrate is bonded to the porous aluminum oxide film layer to enhance adhesion. Sex and confidentiality. Further, the variation in the total thickness of the oxide film in the entire surface of the aluminum material is within ±50% of the arithmetic mean of the total thickness, and the entire surface of the aluminum material is covered, and the resin layer to be joined can be excellent. Adhesion and adhesion.

The aluminum material obtained in this way is excellent in adhesion, and when the various adhesives according to the existing technology are used in the above resin layer, great adhesion strength can be obtained. Further, the excellent adhesion, for example, various coatings according to the existing technology, and the like, are used as a base for coating an aqueous coating, a solvent coating, a powder coating, an electrocoat, or the like as the resin layer. The treatment can obtain a great coating film adhesion strength.

Specifically, the resin-coated surface-treated aluminum material of the bonded body in which the surface of the oxide film of the surface-treated aluminum material of the present invention is provided with a resin layer such as a thermoplastic resin or a thermosetting resin is used in the past. Various uses of aluminum. For example, in recent years, for example, it has been used as a printed wiring board having a high thermal conductivity with an aluminum plate. In other words, in recent years, miniaturization and weight reduction of electric motors and electronic equipment have been demanded for multilayering, high integration, and high density of printed circuit boards. Then, the substrate using the conventional insulator is continuously emitted from the electronic components of the high-density package. The heat generated caused the circuit to be unstable. However, by using an aluminum plate having excellent thermal conductivity as a substrate, the electronic components of the substrate itself can be cooled, and the performance of the entire circuit can be improved.

Such a printed circuit board is manufactured by attaching a metal foil such as an aluminum plate to a copper foil. In this case, an epoxy resin, a polyimide resin, or the like can be used as the adhesive. Therefore, since the surface of the oxide film of the surface-treated aluminum material of the present invention is coated with the resin-coated surface-treated aluminum material as the resin layer of the above-mentioned adhesive, the surface treatment can be particularly enhanced by the intervention of the oxide film of the above specific structure. The aluminum material and the resin layer are adhered to each other, and the aluminum material is adhered to the metal foil by the resin layer.

Further, in the production method of the present invention, the surface-treated aluminum material can be stably produced by appropriately setting the conditions of the alternating current electrolysis treatment.

1‧‧‧Surface treated aluminum

2‧‧‧Oxide film

3‧‧‧Porous aluminum oxide coating

31‧‧‧ hole

4‧‧‧Barrier aluminum oxide coating

5‧‧‧Substrate

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of a surface treated aluminum material of the present invention.

[Formation for implementing the invention]

Hereinafter, the contents of the present invention will be described in order. As shown in Fig. 1, the surface-treated aluminum material 1 of the present invention forms an oxide film 2 on one surface, which is formed of a porous aluminum oxide film layer 3 formed on the surface side and a side formed on the substrate 5 side. The barrier type aluminum oxide film layer 4 is composed of. Then, the porous aluminum oxide film layer 3 forms small holes 31.

A. Aluminum

Pure aluminum or aluminum alloy can be used for the aluminum material used in the present invention. The composition of the aluminum alloy is not particularly limited, and various alloys including an alloy specified by JIS can be used. The shape is not particularly limited, but a stable film can be formed, so that a flat plate can be suitably used. The thickness may be appropriately selected depending on the application, but from the viewpoint of light weight and formability, it is preferably 0.05 to 2.0 mm, more preferably 0.1 to 1.0 mm.

B. Oxide film

The surface of the aluminum material used in the present invention is provided with a porous aluminum oxide film layer formed on the surface side and a barrier aluminum oxide film layer formed on the substrate side. That is, an oxide film composed of a porous aluminum oxide film layer and a barrier aluminum oxide film layer is provided on the surface of the aluminum material. The porous aluminum oxide film layer exhibits strong adhesion or adhesion, and the entire aluminum oxide film layer and the aluminum substrate are firmly bonded by the barrier aluminum oxide film layer.

B-1. Porous aluminum oxide film layer

The thickness of the porous aluminum oxide film layer is 20 to 500 nm. When the thickness is less than 20 nm, the thickness is insufficient, so that the formation of the pore structure described later is insufficient, and the adhesion or adhesion is lowered. On the other hand, when it exceeds 500 nm, the porous aluminum oxide film layer itself is liable to be agglomerated and destroyed, and the adhesion or adhesion is lowered.

As shown in Fig. 1, the porous aluminum oxide film layer 3 has a small hole 31 extending in the depth direction from the surface thereof. The diameter of the small hole is 5 to 30 nm, preferably 10 to 20 nm, and the small hole is formed by increasing the resin layer or the adhesive and the aluminum oxide film. The contact area exerts the effect of increasing the adhesion or adhesion. If the diameter of the small hole is less than 5 nm, sufficient adhesion or adhesion cannot be obtained due to insufficient contact area. Further, when the diameter of the small pores exceeds 30 nm, the entire porous aluminum oxide film layer becomes brittle and causes aggregation failure, and the adhesion or adhesion is lowered.

The ratio of the total pore area of the small pores to the surface area of the porous aluminum oxide coating layer is not particularly limited. The ratio of the total pore area of the pores to the surface area of the porous aluminum oxide film layer (the area indicated by the multiplication of the length and the width without considering the minute irregularities of the surface) is preferably 25 to 75%. When it is less than 25%, the contact area may be insufficient to obtain sufficient adhesion or adhesion. On the other hand, when it exceeds 75%, the entire porous aluminum oxide film layer becomes brittle and aggregates and breaks, and the adhesion or adhesion may be lowered.

B-2. Barrier aluminum oxide film layer

The thickness of the barrier aluminum oxide film layer is 3 to 30 nm. When the thickness is less than 3 nm, the adhesion of the porous aluminum oxide film layer to the aluminum substrate cannot be sufficiently bonded to the intervening layer, and in particular, the bonding strength in a severe environment such as high temperature and high humidity is insufficient. Further, if it exceeds 30 nm, the barrier property of the aluminum oxide film layer is liable to be agglomerated and destroyed, and the adhesion or adhesion is lowered.

B-3. Wide variation in thickness of the oxide film

The thickness of the entire oxide film is the total thickness of the porous aluminum oxide film layer described in B-1 and the barrier aluminum oxide film layer described in B-2, and the measurement width is wide even when measured in any place of the aluminum material. Must be within ±50%, preferably within ±20%. That is, making any of the aluminum surfaces In the plural (preferably 10 or more, even if it is more than 10 points in these places), the average thickness of the oxide film measured is T (nm), and must be measured at these multiple points. The total thickness of the oxide film in all is in the range of (0.5 × T) ~ (1.5 × T). If it does not reach (0.5 × T), the oxide film at this place is thinner than its surroundings. As a result, in this thin portion, a gap is likely to occur between the adhesive to be adhered or a resin layer to be adhered to the oxide film, and a sufficient contact area cannot be secured, and the adhesion or adhesion is lowered.

In addition, if there is more than (1.5 × T), the oxide film at this place is thicker than the surrounding. In this case, the stress concentration of the resin layer or the like which is adhered to the thick portion causes the aggregation of the oxide film to be broken, and the adhesion or the adhesion is lowered.

Further, as the thickness of the oxide film as described above is extremely thin or thick, the optical characteristics are different from those of the surroundings, and thus the color change of the brownish or white turbid color can be visually observed.

B-4. Softness

When the surface-treated aluminum material of the present invention can be used for a printed circuit board or the like, it may be used in a state of being bent. Generally, in the state where the aluminum material is bent, the oxide film attached to the surface is liable to be cracked. The oxide film of the surface-treated aluminum material of the present invention has the above-described specific structure, and the niobium oxide film is hardly aggregated and broken, and is excellent in flexibility. Therefore, even if the surface-treated aluminum material is used in a state of being bent, cracking of the oxide film can be suppressed.

Such a softness is, for example, when the surface-treated aluminum material is bent at a degree of 5R by 180 degrees to form a convexity on the side of the oxide film, which may occur depending on the crack of the oxide film layer. The exposure rate of the aluminum substrate was evaluated. Specifically, in the curved portion, the total length of the crack is L, which is divided by the total length T of the bend, and (L/T)×100 (%) is the exposure rate of the aluminum substrate according to the crack occurrence. By. At this time, in order to prevent the adhesion of the oxide film layer from occurring, the exposure rate based on the crack is preferably 5% or less, more preferably 2% or less.

C. Manufacturing method

One method for producing a surface-treated aluminum material having an oxide film satisfying the above conditions on the surface is, for example, an electrode using a surface-treated aluminum material and an electrode as a counter electrode described later, at pH 9 ~13 and the liquid temperature is 35~80 °C, and the alkaline aqueous solution with the dissolved aluminum concentration of 5ppm or more and 1000ppm or less is used as the electrolytic solution, with the frequency of 20~100Hz, the current density of 4~50A/dm ² and the electrolysis time of 5~60 seconds. The condition is subjected to an alternating current electrolytic treatment to form an oxide film on the surface of the aluminum material opposite to the counter electrode.

In the alternating electrolysis treatment step, an alkali aqueous solution used as an electrolytic solution may be a phosphate such as sodium phosphate, potassium hydrogen phosphate, sodium pyrophosphate, potassium pyrophosphate or sodium metaphosphate; or sodium hydroxide or potassium hydroxide. An alkali metal hydroxide; or a carbonate of sodium carbonate, sodium hydrogencarbonate, potassium carbonate or the like; or ammonium hydroxide; or an aqueous solution of a mixture of such. As described later, since the pH of the electrolytic solution must be stored in a specific range, it is preferred to use an aqueous alkali solution containing a phosphate-based substance having a desired buffering effect. The concentration of such an alkali component can adjust the pH of the electrolytic solution to a desired value, but is generally 1 x 10 ^-4 to 1 mol/liter. Moreover, in such an alkaline aqueous solution, the ability to remove a dirt component can be improved, and a surfactant can also be added.

The pH of the electrolytic solution must be 9 to 13, preferably 9.5 to 12. When the pH is less than 9, the alkali etching force of the electrolytic solution is insufficient, so that the porous structure of the porous aluminum oxide film layer is incomplete. Further, when the pH exceeds 13, the alkali etching force becomes excessive, so that the porous aluminum oxide film layer is hard to grow, and further, the formation of the barrier aluminum oxide film layer is also hindered.

The temperature of the electrolytic solution must be 35~80 °C, preferably 40~70 °C. When the temperature of the electrolytic solution is less than 35 ° C, the porous etching property of the porous aluminum oxide film layer is incomplete due to insufficient alkali etching force. On the other hand, when the temperature exceeds 80 ° C, the alkali etching force becomes excessive, and the growth of the porous aluminum oxide film layer and the barrier aluminum oxide film layer are all hindered.

The concentration of dissolved aluminum contained in the electrolytic solution must be 5 ppm or more and 1000 ppm or less. When the concentration of the dissolved aluminum is less than 5 ppm, the formation reaction of the oxide film in the initial stage of the electrolysis reaction is rapidly generated, and thus it is susceptible to the unevenness of the treatment step (the state of the dirt on the surface of the aluminum material or the state in which the aluminum material is mounted). As a result, a thick oxide film is locally formed. Further, when the dissolved aluminum concentration exceeds 1000 ppm, the viscosity of the electrolytic solution increases, and in the electrolysis step, the pair of flows in the vicinity of the surface of the aluminum material is hindered, and at the same time, the action of the dissolved aluminum suppresses the formation of the film. As a result, a thin oxide film is locally formed. When the concentration of the dissolved aluminum exceeds the above range, it is difficult to make the variation width of the total thickness of the oxide film in the entire surface of the aluminum material within ±50% of the arithmetic mean of the total thickness. As a result, the adhesion and adhesion of the obtained oxide film may be lowered, or good flexibility at the time of bonding to the resin layer may not be obtained.

The thickness of the entire oxide film containing the porous aluminum oxide film layer and the barrier type aluminum oxide film layer in the alkali exchange electrolysis is controlled by the electric quantity, that is, the product of the current density and the electrolysis time, and the electric quantity is substantially increased, and the oxide film is formed. The thickness of the whole is increasing. From such a viewpoint, the AC electrolysis conditions of the porous aluminum oxide film layer and the barrier aluminum oxide film layer are as follows.

The frequency used is 20~100Hz. As a result of the improvement of the DC element of the electrolytic system when the temperature is less than 20 Hz, the formation of the porous structure of the porous aluminum oxide film layer is not progressed, and it becomes a dense structure. In addition, if it exceeds 100 Hz, since the anode and the cathode are reversed too quickly, the formation of the entire oxide film is extremely slow, and both the porous aluminum oxide film layer and the barrier aluminum oxide film layer have a specific thickness, which requires a very long time. .

The current density must be 4~50A/dm ² . When the current density is less than 4 A/dm ² , only the barrier aluminum oxide film layer is preferentially formed, so that the porous aluminum oxide film layer cannot be obtained. On the other hand, when it exceeds 50 A/dm ² , the current becomes excessively large, and the thickness control of the porous aluminum oxide film layer and the barrier aluminum oxide film layer becomes difficult, which tends to cause uneven processing.

The electrolysis time must be 5 to 60 seconds. In the processing time of less than 5 seconds, the formation of the porous aluminum oxide film layer and the barrier aluminum oxide film layer is too intense, so that the oxide film layer of either one cannot be sufficiently formed, and is oxidized by amorphous aluminum. An oxide film composed of matter. In addition, when it exceeds 60 seconds, not only the porous aluminum oxide film layer and the barrier aluminum oxide film layer become too thick or redissolved, but productivity is also lowered.

Among the electrodes used in one of the alternating current electrolytic treatments, one of the electrodes is an aluminum material which is surface-treated by electrolytic treatment. The other pair of electrodes can Although a known electrode such as graphite, aluminum, or a titanium electrode is used, in the present invention, it is not deteriorated with respect to the alkali component or temperature of the electrolytic solution, and it is necessary to use a material having excellent conductivity and further causing no electrochemical reaction. From this point of view, a graphite electrode can be suitably used as the counter electrode. The graphite electrode is chemically stable, inexpensive and easy to obtain. Moreover, due to the action of many pores in the graphite electrode, the electric power line is moderately diffused in the alternating current electrolysis step, so the porous aluminum oxide film layer and the barrier type aluminum oxide film are formed. Layers tend to become more uniform.

In the present invention, the aluminum material to be electrolytically treated and the counter electrode system are each in the form of a flat plate, and the dimensions of the longitudinal and transverse directions between the opposing aluminum material and the counter electrode are approximately the same, and it is preferable to make the two electrodes stand still. Electrolysis operation. At this time, an oxide film is formed on the surface of the aluminum material opposite to the counter electrode. Here, an oxide film is formed on the other surface of the counter electrode, and an oxide film is formed on the other surface to temporarily terminate the AC electrolysis treatment, and then the other surfaces are opposed to the counter electrode. The configuration is similar to the AC electrolysis treatment.

Further, even when the shape of the aluminum material is a rod shape or an angle material other than the plate material, the electrolysis step is not performed in the opposite direction to the surface of the counter electrode, and the electrolysis step is repeated, so that oxidation can be formed on the desired surface. Membrane.

The structural observation and thickness measurement of the porous aluminum oxide film layer and the barrier type aluminum oxide film layer of the present invention can be suitably used for cross-sectional observation by a transmission electron microscope (TEM). Specifically, the thickness of the porous aluminum oxide film layer and the barrier aluminum oxide film layer, and the diameter of the pores of the porous aluminum oxide film layer are made by an ultramicrotome. The sheet sample was measured by TEM observation.

D. Resin coated surface treated aluminum

The treated surface of the surface-treated aluminum material of the present invention is further coated with a resin layer to form a resin-coated surface-treated aluminum material, which can be further used for many purposes. Here, the resin layer may be either a thermosetting resin or a thermoplastic resin, and it is compatible with the oxide film of a specific structure defined by the present invention, and various effects can be obtained. In general, the bonding system between the aluminum material and the resin layer has a large thermal expansion coefficient of the resin compared to the aluminum material, so that peeling, cracking, cracking, and the like are likely to occur at the interface between the aluminum material and the resin layer. However, the resin-coated surface-treated aluminum-based surface-treated aluminum material of the present invention has a thin oxide film and a specific structure, and has excellent flexibility and easy to follow the expansion of the resin layer, and at the interface between the aluminum material and the resin layer. The above characteristics are difficult to occur.

The above-mentioned damage occurrence is, for example, an electrolytic aqueous solution in which a resin-coated surface-treated aluminum material is bent at a thickness of 180 degrees by 5 degrees so that the resin layer becomes convex, and the electrolytic solution can be evaluated by the magnitude of the electric resistance. The larger the damage of the peeled portion or the like, the smaller the electric resistance due to the electrolytic solution.

A resin-coated surface-treated aluminum material using a thermoplastic resin as a resin layer can be suitably used as a lightweight, highly rigid composite material. The resin layer is formed by subjecting the heated thermoplastic resin to a flow state, and then contacting and infiltrating the porous aluminum oxide film layer to cool and cure the thermoplastic resin. Instead, the aluminum laminated thermoplastic resin film can also be surface treated. The thermoplastic resin may be a polyolefin such as polyethylene or polypropylene; polyvinyl chloride; polyethylene terephthalate or polybutylene terephthalate; Polyester; polyphenylene sulfide; polyetheretherketone, polyether ketone, etc. aromatic polyether ketone; polystyrene; fluororesin of polytetrafluoroethylene, polychlorotrifluoroethylene, etc.; polymethyl Acrylic resin such as methyl acrylate; ABS resin; polycarbonate; thermoplastic polyimide. The resin-coated surface-treated aluminum material coated with such a thermoplastic resin can be used for various types of moving bodies that require light weight and high rigidity, and is specifically used for components such as aerospace, the universe, automobiles, ships, trains, and the like.

A resin-coated surface-treated aluminum material using a thermosetting resin as a resin layer can be suitably used as a printed wiring board. In the method of forming the resin layer, the thermosetting resin is in a flowing state, and then contacted and infiltrated into the porous aluminum oxide film layer, and then the thermosetting resin is cured by heating. A thermosetting resin may be a phenol resin; an epoxy resin such as a bisphenol A type or a novolac type; a melamine resin; a urea resin; an unsaturated polyester resin; an alkyd resin; a polyurethane; Polyimine and the like.

Further, the thermoplastic resin and the thermosetting resin may be used alone or in combination of two or more kinds of polymer gels. Further, by adding various fillers to the thermoplastic resin and the thermosetting resin, the physical properties such as the strength of the resin and the coefficient of thermal expansion can be improved. As such a filler, various fibers such as glass fiber, carbon fiber, and linaloamide fiber; inorganic substances such as calcium carbonate, magnesium carbonate, cerium oxide, talc, and glass; clay; and the like can be used.

[Examples]

Hereinafter, the appropriateness of the present invention will be specifically described based on examples and comparative examples. Implementation form.

Examples 1 to 15 and Comparative Examples 1 to 13

A JIS 5052-H34 alloy plate having a length of 200 mm × a width of 400 mm × a plate thickness of 1.0 mm was used as the aluminum material. This aluminum alloy plate was used for one electrode, and a flat plate shape graphite plate or titanium plate having a length of 300 mm × a width of 500 mm × a plate thickness of 2.0 mm was used for the counter electrode system. The single surface of the aluminum alloy is faced to the counter electrode, and the opposite surface layer of the opposite side forms a porous aluminum oxide film layer on the surface side and a barrier aluminum oxide film layer on the substrate side, and two electrodes are disposed. As the electrolytic solution, an aqueous alkali solution containing sodium pyrophosphate as a main component was used. The alkali component concentration of the electrolytic solution was 0.5 mol/liter, and the pH was adjusted by hydrochloric acid and an aqueous sodium hydroxide solution (any one of which was 0.1 mol/liter). The electrolytic aluminum electrolytic treatment was carried out under the electrolysis conditions shown in Table 1 to form a porous aluminum oxide film layer and a barrier aluminum oxide film layer. Further, in Comparative Example 13, a sulfuric acid anodizing treatment (2.5 μm thick, with a sealing treatment) according to the prior art was carried out instead of the alkaline AC electrolytic treatment.

For the test materials prepared as described above, cross-sectional observation was carried out by TEM. Specifically, the thickness of the porous aluminum oxide film layer and the barrier aluminum oxide film layer and the diameter of the pores of the porous aluminum oxide film layer are measured, so that the cross section observation sheet is prepared from the test material using an ultramicrotome test material. Then, in the sheet sample, any 10 points in the observation area (1 μm × 1 μm) were selected and observed by the TEM cross section, and the thickness of the porous aluminum oxide film layer and the barrier type aluminum oxide film layer were measured at each point, and porous. Diameter of the pores of the aluminum oxide film layer (first measurement). The arithmetic mean of the measured values of 10 points for the thickness and diameter of these is shown in the first measurement of Table 2.

Then, in order to investigate the variation in the total thickness of the porous aluminum oxide film and the barrier aluminum oxide film on the surface of the entire test material, the second measurement was performed. In the second measurement, the sample material supplied to the first measurement was used, and the sheet sample prepared in the first measurement was individually prepared, and nine sheet samples were further prepared by an ultramicrotome in the same manner. Then, even about these 9 The sheet samples were measured in the same manner as in the first measurement, and the thickness of the 10-point porous aluminum oxide film layer and the barrier type aluminum oxide film layer was measured. Then, the measurement result of the thickness of the 100-degree porous aluminum oxide film layer and the barrier type aluminum oxide film layer in all the above-mentioned 10 sample samples was added to the porous aluminum oxide film layer and the barrier in each point. The thickness of the aluminum oxide film layer was determined to determine the total thickness and the thickness of the oxide film at each point. The maximum value, the minimum value, and the arithmetic mean value of the oxide film thickness at 100 points obtained in this manner are shown in the second measurement in Table 2. Further, it is also studied whether or not the fluctuation of the oxide film thickness of these 100 points is within ±50% of the arithmetic mean. Specifically, when the arithmetic mean value is T (nm), the total thickness including all of the maximum value and the minimum value is (0) in the range of (0.5 × T) to (1.5 × T), and is not in the range. The unqualified (x) is shown in the second measurement of Table 2.

With respect to the above test materials, the adhesiveness using the adhesive, the adhesion to the coating film, and the flexibility in the bending test were evaluated in the following manner. Further, evaluation of the resin-coated surface-treated aluminum material was also carried out.

[Adhesive evaluation]

Two pieces of the test piece were prepared and cut into a length of 50 mm and a width of 25 mm. The two test pieces were made to have a width of 10 mm in the width direction to overlap the oxide film to form the surface, and a commercially available two-liquid epoxy adhesive (main agent = modified epoxy resin, hardener) = modified polyimine, weight mixing ratio = main agent 100 / hardener 100) and the overlapping portion was adhered to prepare a shear test piece. The end portion of the length of the test piece of the two pieces is subjected to a tensile tester The speed of 100 mm/min was pulled in the opposite direction along the longitudinal direction, and the adhesion was evaluated on the basis of the following by the load (converted to shear stress) and the peeling state. Further, the shear test piece was prepared from 10 test pieces of the same test piece and evaluated separately.

○: the shear stress is 20 N/mm ² or more and the adhesive layer itself is agglomerated and destroyed.

△: The shear stress is 20 N/mm ² or more, but the interface between the adhesive layer and the test material has been peeled off.

×: the shear stress is less than 20 N/mm ² and the interface between the adhesive layer and the test material has been peeled off.

The results are shown in Table 3. The number of the above-mentioned groups of ○, △, and × in the test pieces of the ten groups was shown in the same table, but all of them were judged to be acceptable when they were ○, and were judged to be unsatisfactory.

[Adhesion assessment]

On the surface of the oxide film side of the test material, "V Flon #2000" manufactured by Dainippon Co., Ltd. was applied, and dried (160 ° C, 20 minutes) to prepare a resin coating film having a thickness of 30 μm. Test piece. According to the method of JIS-K5600-5-6, the resin coating film of the adhesion test piece was placed with a checker blade of 1 mm ² and a score of 1 mm ² was placed. Then, after the test piece was subjected to a sterilization immersion treatment at 125 ° C for 30 minutes, it was immediately taken out from the treatment liquid to wipe off the water. For this test piece, a peeling test was performed using a transparent pressure-sensitive adhesive tape. The adhesion was evaluated on the basis of the following basis by the coating film residual ratio. Further, in the adhesion test piece, 10 test pieces were produced from the same test piece, and evaluated separately.

○: The residual rate of the coating film is 100%.

△: The residual rate of the coating film is 75% or more and less than 100%.

×: The residual rate of the coating film is less than 75%.

The results are shown in Table 3. The number of the above-mentioned ○, △, and × in the test pieces of the ten test pieces was shown in the same table, but all of them were judged to be acceptable when they were ○, and were judged to be unacceptable.

[softness assessment]

It is prepared to cut from the above-mentioned test material into a length of 50 mm and a width of 25 mm. The mold was used and bent at 180 degrees by 5R to make the oxide film forming surface convex. Then, the bent portion was immersed in a test liquid (20% aqueous copper sulfate solution) for 5 minutes, and then taken out, washed with water, and dried at room temperature. When the oxide film of the bent portion is cracked, copper is attached to the surface of the cracked aluminum substrate. Therefore, a magnifying glass or a measuring ruler is used to visually observe the place where the copper is adhered along the entire length of the curved portion, and the specific crack generating portion is formed. Specifically, the total length of adhesion of copper observed in the bent portion is L (mm), and divided by the total length of the bend (25 mm), so that (L/25) × 100 (%) is used as the exposure of the aluminum substrate according to the crack occurrence. rate. The softness test piece was prepared from the same test piece for 10 tests. The sheets were evaluated separately to determine the respective exposure rates of the aluminum substrates.

The results are shown in Table 3. The exposure ratio of the table indicates the average exposure ratio of the ten test pieces. Here, the exposure rate was 5% or less, and it was judged that it was unacceptable.

[Evaluation of Resin-Coated Surface-treated Aluminum]

On the surface of the oxide film side of the test material, "9K-564S" (aqueous acrylic resin paint) manufactured by DIC Co., Ltd. was applied, and dried (250 ° C, 1 minute) to form a resin coating film having a thickness of 2 μm (resin Layer), made of resin coated surface treated aluminum. The film was further cut to a length of 100 mm and a width of 30 mm, and the film layer was bent at a thickness of 35 R using a mold to make the resin layer side convex, thereby producing a test piece. The curved apex portion of the test piece was brought into contact with a sponge having a width of 20 mm containing a 1% sodium chloride aqueous solution while the test piece side was positive and the sponge side was negative, and a DC voltage of 6.0 V was applied for 4 seconds, and the voltage application was measured. The maximum current value. When there is no damage such as peeling at the interface between the test material and the resin layer, since the test piece becomes an insulator, current does not flow. Further, when there is a damaged portion, a current flows by the aqueous sodium chloride solution present therein. Then, the larger the damage portion, the larger the amount of the sodium chloride aqueous solution present therein, the lower the electric resistance and the larger the maximum current value. When the maximum current value is less than 5 mA, the damage such as peeling is not small or small, and is acceptable. In addition, when it is 5 mA or more, damage such as peeling is large, and it is unacceptable. The results are shown in Table 3.

In any of Examples 1 to 15, since the oxide film satisfies the requirements of the present invention, adhesion evaluation, adhesion evaluation, and softness of the surface-treated aluminum material are satisfied. The evaluation, and the evaluation of the resin-coated surface treated aluminum were judged as qualified. However, in Comparative Examples 1 to 13, it was judged to be unacceptable for the following reasons.

In Comparative Example 1, since the pH of the electrolytic solution in the AC electrolytic treatment was too low, the alkali etching force was insufficient. Therefore, the pore diameter of the porous aluminum oxide film layer is insufficient, and the adhesion, the adhesion, and the flexibility are unacceptable.

In Comparative Example 2, since the pH of the electrolytic solution in the AC electrolytic treatment was too high, the alkali etching force became excessive. Therefore, the thickness of the porous aluminum oxide film layer and the barrier type aluminum oxide film layer is insufficient, and the pore diameter of the porous aluminum oxide film layer is too large, and the total thickness of the oxide film is wide, adhesive, adhesive, and soft. To be unqualified.

In Comparative Example 3, since the temperature of the electrolytic solution in the alternating current electrolytic treatment was too low, the alkali etching force was insufficient. Therefore, the porous aluminum oxide film layer has an incomplete porous structure and a small pore diameter, and the adhesion, the adhesion, and the flexibility are unacceptable.

In Comparative Example 4, since the temperature of the electrolytic solution in the AC electrolytic treatment was too high, the alkali etching force became excessive. Therefore, the thickness of the porous aluminum oxide film layer and the barrier aluminum oxide film layer is insufficient, and the total thickness of the oxide film is wide, and the adhesion, adhesion, and flexibility are unacceptable.

In Comparative Example 5, the electrolytic solution in the alternating current electrolytic treatment was a completely new bath, and the dissolved aluminum did not exist, so that the formation reaction of the oxide film in the initial stage of the electrolytic reaction was rapidly generated. Therefore, where a thick oxide film is formed in part, the total thickness of the oxide film is wide, and the adhesion, adhesion, and flexibility are unacceptable.

In Comparative Example 6, the dissolution of the electrolytic solution in the AC electrolytic treatment was performed. The aluminum concentration is too high and a part of a thin oxide film is formed. Therefore, the change in the total thickness of the oxide film is wide, and the adhesiveness, adhesion, and flexibility are unacceptable.

In Comparative Example 7, since the frequency in the AC electrolysis treatment was too low, the electrical state was close to DC electrolysis. Therefore, the porous aluminum oxide film layer is not formed, and the thickness of the barrier aluminum oxide film layer becomes excessively large. Therefore, adhesion, adhesion, and softness are unacceptable.

In Comparative Example 8, since the frequency in the AC electrolytic treatment was too high, the anode and the cathode were reversed too fast. Therefore, the formation of the porous aluminum oxide film layer is extremely slow, the thickness thereof is insufficient, and the adhesion, the adhesion, and the flexibility are unacceptable.

In Comparative Example 9, the current density in the alternating current electrolysis treatment was too low, so that the barrier type aluminum oxide film layer was preferentially formed. Therefore, the thickness of the porous aluminum oxide film layer is insufficient, and the adhesion, the adhesion, and the flexibility are unacceptable.

In Comparative Example 10, since the current density in the AC electrolytic treatment was too high, a spark or the like was generated in the electrolytic solution in the electrolytic treatment, and the control became unstable. Therefore, the entire oxide film is excessively formed, and the thickness of the porous aluminum oxide film layer and the barrier aluminum oxide film layer is excessively large, and the thickness of the oxide film is extremely small. As a result, the total thickness of the oxide film was wide, and the adhesion, adhesion, and flexibility were unacceptable.

In Comparative Example 11, the electrolytic treatment time in the alternating current electrolysis treatment was too short, so that the porous aluminum oxide film layer and the barrier type aluminum oxide film layer were not sufficiently formed. Therefore, the thickness of the porous aluminum oxide film layer and the barrier aluminum oxide film layer is insufficient, and the adhesion, the adhesion, and the flexibility are unacceptable.

In Comparative Example 12, the electrolytic treatment time in the alternating current electrolysis treatment was too long, so that the entire oxide film was excessively formed. Therefore, the porous aluminum oxide film The layer and the barrier type aluminum oxide film layer are too thick, and the adhesion, the adhesion and the softness are unacceptable.

In Comparative Example 13, the sulfuric acid anodizing treatment according to the prior art did not have the oxide film structure defined in the present invention, so that the adhesion, the adhesion, and the flexibility were unacceptable.

In any of Comparative Examples 1 to 13, the oxide film of the present invention did not have the characteristics of the present invention, so that the resin-coated surface-treated aluminum material had a large bending damage and the coating was evaluated as unacceptable.

[Industrial use possibility]

According to the present invention, it is possible to obtain a surface-treated aluminum material having excellent adhesion and adhesion in an aluminum material, and a surface-treated aluminum material coated with the resin.

1‧‧‧Surface treated aluminum

2‧‧‧Oxide film

3‧‧‧Porous aluminum oxide coating

31‧‧‧ hole

4‧‧‧Barrier aluminum oxide coating

5‧‧‧Substrate

Claims (6)

A surface-treated aluminum material characterized by an aluminum material having an oxide film formed on a surface thereof, wherein the oxide film is formed of a porous aluminum oxide film layer having a thickness of 20 to 500 nm formed on the surface side and a thickness of 3 to 30 nm formed on the substrate side. The barrier aluminum oxide film layer is formed on the porous aluminum oxide film layer to form a small hole having a diameter of 5 to 30 nm, and the porous aluminum oxide film layer and the barrier aluminum oxide film layer on the entire surface of the aluminum material The variation width of the total thickness is within ±50% of the arithmetic mean of the total thickness. The surface-treated aluminum material according to the first aspect of the invention, wherein the surface-treated aluminum material is bent by 180 degrees by 5R so that the oxide film side becomes convex, and the aluminum substrate has an exposure ratio of 5% or less. A method for producing a surface-treated aluminum material, which is a method for producing a surface-treated aluminum material according to claim 1 or 2, which is characterized in that an electrode of a surface-treated aluminum material and a counter electrode are used at a pH of 9 to 13 The liquid temperature is 35 to 80 ° C, and an alkaline aqueous solution having a dissolved aluminum concentration of 5 ppm or more and 1000 ppm or less is used as an electrolytic solution at a frequency of 20 to 100 Hz, a current density of 4 to 50 A/dm ^{2 ,} and an electrolysis time of 5 to 60 seconds. An alternating current electrolytic treatment is performed to form an oxide film on the surface of the aluminum material opposite to the counter electrode. A method of producing a surface-treated aluminum material according to claim 3, wherein the counter electrode is a graphite electrode. The method for producing a surface-treated aluminum material according to claim 3, wherein the electrode of the surface-treated aluminum material and the counter electrode are in a flat shape. A resin-coated surface-treated aluminum material characterized by coating a resin layer on the surface of an oxide film of a surface-treated aluminum material as disclosed in claim 1 or 2.