JP2008266663A - Aluminum material for laminate, resin-coated aluminum material, and manufacturing method of the sames - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum material for laminate having excellent adhesiveness to a resin coating film without performing any chemical conversion or adhesive primer coating, and to provide a resin-coated aluminum material provided with a resin coating film and having excellent adhesiveness. <P>SOLUTION: The aluminum material for laminate comprises an aluminum base material, aluminum oxide film formed on at least one surface of the base material, and an organic silicon compound film formed on a surface of the aluminum oxide film and having a predetermined structure. The aluminum oxide film has the thickness of 6-20 nm, and the forming amount of the organic silicon compound film is 1-10 mg/m<SP>2</SP>in terms of silicon. The resin-coated aluminum material has a resin film provided thereon. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an aluminum material for lamination having an aluminum oxide film and an organosilicon compound film on at least one surface of an aluminum substrate, and a resin-coated aluminum having a resin coating film on the aluminum material for lamination and having excellent adhesion. The present invention relates to materials and methods for producing them.

  In recent years, aluminum alloy plates have been widely adopted as resin coatings for food containers, furniture, and building materials. This is because aluminum is more recyclable than other metal materials and has excellent workability and aesthetics.

  Conventionally, phosphoric acid chromate treatment or chromate chromate treatment has been used as a base surface treatment method for a resin-coated aluminum material. The chromate conversion coating formed by these chromate surface treatment liquids is excellent in the corrosion resistance of the coating alone, and also has the characteristics of excellent adhesion and corrosion resistance after various resin coatings are applied. However, in recent years, from the viewpoint of environmental protection, chromium-containing wastewater during chromate treatment leads to environmental pollution, and wastewater treatment also has a disadvantage that requires cost. In recent years, it has become necessary to abolish the use of chromate-based treatment liquids because valent chromium is harmful to the human body.

Therefore, a treatment liquid containing no hexavalent chromium is desired, and various studies have been conducted so far. For example, Patent Document 1 discloses a treatment containing at least one of hydrofluoric acid or fluoride containing 500 ppm or less of an oxidizing agent and 2000 ppm or less of fluorine in a pH 2 to 4 solution containing phosphate ions and a zirconium compound. A surface treatment method using a liquid has been proposed.
JP 7-48677 A

  By the treatment using such a non-chromate treatment solution, a chemical conversion film mainly composed of zirconium oxide is formed on the surface of the aluminum substrate. However, in the non-chromate treatment method, the reaction between oxygen in the atmosphere and the top surface of the conversion coating during the process of storing the aluminum oxide formed on the top surface of the conversion coating at the same time as the formation of the conversion coating or the aluminum substrate subjected to the conversion treatment. The aluminum oxide grown by this forms a weak boundary layer. Such a weak boundary layer has a drawback that it can be used only for limited applications as compared with the conventional chromate treatment method because it affects the lowering of the adhesion of the resin coating film.

Patent Document 2 uses a treatment liquid containing 0.06 to 3% carboxyl group-containing resin, 0.07 to 3.6% zirconium compound, and 0.06 to 3% imidazolesilane compound. Proposed surface treatment methods.
JP 2001-342578 A

  According to Patent Document 2, since an organic-inorganic composite chemical conversion film containing zirconium oxide as a main component and containing an organic component is formed on the surface of an aluminum base, it provides adhesion as well as corrosion resistance of the coating film. It becomes possible. However, in this treatment method, since the non-chromate treatment solution contains a silane compound, the chemical bonding reaction between the silane compound and the zirconium compound gradually proceeds in the treatment solution, and the treatment solution is stable. Cannot be provided.

  As a method for forming a resin coating film using a thermoplastic resin or the like, a method of thermally bonding a thermoplastic resin film is generally used. The method using a thermoplastic resin film does not require a drying and baking step performed in the case of coating, can be resin-coated only by thermal bonding, and is continuous along the surface direction of the thermoplastic film. Therefore, it has been widely adopted because it has advantages such as the uniformity of the resin coating film thickness being maintained.

However, when the thermoplastic resin film is directly thermocompression bonded onto the aluminum chemical conversion film, the resulting adhesive strength generally decreases. In view of this, a method of performing thermal bonding by applying a coating called an adhesion primer on either the upper part of the chemical conversion film or the bonding surface of the thermoplastic resin film is employed. For example, in Patent Document 3, a thermosetting powder coating is applied on a metal plate, and a polyethylene terephthalate film is laminated and pressure-bonded at a temperature not lower than the melting point of the paint and not higher than a curing start temperature, and thereafter, not lower than a curing start temperature of the paint. And a method for producing a thermoplastic resin-coated metal sheet by heating to a temperature below the melting point of polyethylene terephthalate.
Japanese Patent Laid-Open No. 1-154746

  By forming such an adhesion primer layer, even when an aluminum oxide layer that is a weak boundary layer is formed on the outermost surface of the chemical conversion film, a resin-coated aluminum material having excellent adhesion to a thermoplastic resin is provided. can do. However, in the laminated structure of the chemical conversion film / thermosetting adhesive primer layer / thermoplastic resin film, although the interface breakdown between the adhesive primer layer and the thermoplastic resin film can be suppressed, the interface breakdown between the chemical conversion film and the adhesive primer layer, It has often been confirmed that adhesive failure occurs due to cohesive failure of the adhesive primer layer itself.

  The present invention has been made in order to solve the above-described problems. An aluminum material for laminating excellent in adhesion to a resin coating film without performing chemical conversion treatment and adhesion primer coating treatment, and An object of the present invention is to provide a resin-coated aluminum material provided with a resin-coated film. Another object of the present invention is to provide a method for producing each of the laminating aluminum material and the resin-coated aluminum material having the above-described excellent characteristics.

  As a result of studying the above problems, the present inventors have found that the decrease in the adhesion between the aluminum base material and the resin coating film is due to the aluminum oxide inevitably formed on the outermost surface of the chemical conversion film during the chemical conversion treatment. I found out that it was caused. Therefore, as a result of intensive studies based on such findings, it is possible to suppress the growth of aluminum oxide by providing an organosilicon compound film by treating at least one surface of an aluminum substrate with an organosilicon compound solution, It was found that the amino group, vinyl group, methacryl group, epoxy group, and mercapto group contained as the organic functional group Y of the organosilicon compound reinforces the bond with the resin coating film. That is, the present invention provides an aluminum material for laminating excellent in adhesion to a resin coating film and a resin-coated aluminum material using the same without performing conventional chemical conversion treatment or adhesive primer coating treatment. is there.

The present invention according to claim 1 is an aluminum substrate made of aluminum or an aluminum alloy, an aluminum oxide film formed on at least one surface of the aluminum substrate, and a surface of the aluminum oxide film formed by the following formula (1) The aluminum oxide film has a thickness of 6 to 20 nm, and the formation amount of the organic silicon compound film is 1 to 10 mg / m ² in terms of silicon. It was set as the aluminum material for lamination characterized.

In the formula, Y is an organic functional group selected from the group consisting of an amino group, a vinyl group, a methacryl group, an epoxy group, and a mercapto group, R is an alkyl group having 1 to 5 carbon atoms, OR ′ is an alkoxyl group, n is 0, 1 or 2.

  The present invention provides a resin-coated aluminum material according to claim 3, wherein a resin film is further provided on the organosilicon compound film in the aluminum material for lamination according to claim 1.

According to a third aspect of the present invention, there is provided the step of cleaning at least one surface of an aluminum substrate made of aluminum or an aluminum alloy with an alkaline solution, the step of cleaning the cleaning surface with the alkaline solution with an acidic solution, and the acidic solution. Treating the cleaning surface with an organosilicon compound solution, wherein the aluminum oxide film formed on the surface of the aluminum substrate after the cleaning step with the acidic solution has a thickness of 6 to 20 nm, and the organosilicon compound solution The organic silicon compound film having the following formula (1) is formed on the aluminum oxide film by the treatment step according to the above, and the amount of the organic silicon compound film formed is 1 to 10 mg / m ² in terms of silicon. It was set as the manufacturing method of the aluminum material for lamination.

In the formula, Y is an organic functional group selected from the group consisting of an amino group, a vinyl group, a methacryl group, an epoxy group, and a mercapto group, R is an alkyl group having 1 to 5 carbon atoms, OR ′ is an alkoxyl group, n is 0, 1 or 2.

  The present invention provides a method for producing a resin-coated aluminum material according to claim 4, comprising a step of coating a resin film on the organosilicon compound film after the treatment step with the organosilicon compound solution according to claim 3. .

  An aluminum material for laminating with excellent adhesion to a resin coating film and a resin-coated aluminum material using the same without performing a conventional chromate-based or non-chromate-based chemical conversion treatment, or even an adhesive primer layer forming treatment. Can be provided.

A. Suppression of aluminum oxide Conventionally, when the surface of a base material made of aluminum or an aluminum alloy (hereinafter referred to as "aluminum base material") is subjected to zirconium phosphate-based non-chromate treatment, the structure of the surface layer is an aluminum base. There is an aluminum oxide film consisting of aluminum fluoride, oxide, oxyhydroxide, etc. at the interface between the material and the chemical conversion film, on which zirconium phosphate, hydroxide, oxide and their hydrates A model has been proposed in which a chemical conversion film composed of, for example, is formed.

  As a result of detailed elemental analysis in a depth direction of a chemical conversion film formed by a conventional method, a so-called depth profile, the present inventors used an analytical instrument based on Auger electron spectroscopic analysis and secondary ion mass spectrometry. The main component of the aluminum oxide film does not have a uniform structure in the depth direction or a layered structure consisting of several substances, but has a so-called gradient structure in which the element concentration continuously changes in the depth direction. I confirmed.

  Specifically, as the surface of the aluminum base material subjected to chemical conversion treatment moves from the surface of the aluminum base material toward the surface layer, the aluminum oxide film component increases as the chemical conversion film components (zirconium component and phosphorus component) increase. Furthermore, it has an inclined structure such that the aluminum oxide film component shows a maximum value and then decreases as the aluminum base material component decreases in the direction of the surface layer. Moreover, it was confirmed that the aluminum oxide film component inevitably produced | generated in the chemical conversion film formation process remains with the zirconium and phosphorus film components in the outermost surface of a chemical conversion film.

  Moreover, the aluminum oxide which exists in the chemical conversion film surface layer influences adhesiveness with a resin coating film, and this adhesiveness falls, so that there is much aluminum oxide amount. Therefore, in order to obtain a chemical conversion film having good coating performance, the formation of aluminum oxide on the outermost surface of the chemical conversion film must be suppressed. The present inventors tried to form various chemical conversion films by strictly controlling the chemical conversion treatment conditions or the concentration of the chemical conversion liquid composition, etc., but obtaining a good chemical conversion film in which the formation of aluminum oxide was suppressed. Was difficult.

  Therefore, the present inventors first cleaned the surface of the aluminum substrate with an alkaline solution, then washed with an acidic solution, and then treated with an organosilicon compound solution without a chemical conversion treatment to provide an organosilicon compound film. It has been found that by applying a resin coating thereon, a resin-coated aluminum material having excellent adhesion can be obtained while maintaining the state in which the formation of aluminum oxide serving as a weak boundary layer is suppressed.

  That is, by treating with an organosilicon compound solution after treatment with an acidic solution and providing an organosilicon compound film, a hydroxyl group resulting from aluminum oxide on the surface of the aluminum substrate and an alkoxyl group contained as a functional group in the organosilicon compound Is covalently bonded to form a strong bond, and the organic silicon compound layer serves as a barrier layer, and an effect of suppressing the growth of aluminum oxide can be expected.

B. Laminating Aluminum Material According to the present invention, the laminating aluminum material is prepared by washing the surface of an aluminum substrate with an alkaline solution and then washing with an acidic solution, and then treating the surface with an organic silicon compound-containing solution. Manufactured by forming. As shown in FIG. 1, an aluminum material 1 for laminating according to the present invention is typically made of aluminum that is homogeneous on the surface of an aluminum substrate 2 by such washing with an alkaline solution and subsequent washing with an acidic solution. Oxide film 3 (film thickness: 20 nm or less) is formed, and further treated with a solution containing an organosilicon compound to form a structure in which organosilicon compound film 4 is formed on the aluminum oxide film.

B-1. Aluminum substrate The aluminum substrate is made of aluminum or an aluminum alloy, and an Al-Mn JIS 3000 alloy, an Al-Mg JIS 5000 alloy, or the like is preferably used.

B-2. Cleaning with alkaline solution The aluminum substrate is first cleaned with an alkaline solution. Cleaning with an alkaline solution is performed for the purpose of removing contaminants such as wear and rolling oil adhering to the surface of the aluminum substrate. As a cleaning method, alkali cleaning conventionally used in alkali cleaning treatment of metals such as an aluminum substrate can be performed. As the alkaline solution for washing with alkali, an alkaline cleaner composed of an alkaline aqueous solution or an alkaline solution in which an alkaline component is dissolved or dispersed in an organic solvent is usually used, and an alkaline cleaner composed of an alkaline aqueous solution is preferably used. It does not specifically limit as an alkaline cleaner, What is used for normal alkali cleaning can be used. For example, commercially available caustic soda, Surf Cleaner EC370, EC371, 420N-2 manufactured by Nippon Paint Co., Ltd., FC4498-SK3 manufactured by Nippon Parkerizing Co., Ltd., and the like can be given.

  The conditions for washing with the alkaline solution are not particularly limited, and a condition that allows efficient removal of contaminants may be selected. Since contaminants are removed by a weak etching action on the surface of the aluminum base material, the treatment can usually be performed in a shorter time as the cleaning temperature and concentration are higher. When washing with an alkaline solution is not sufficient, contaminants on the surface of the aluminum substrate remain even after treatment, and hydrophilicity of the surface of the aluminum substrate cannot be ensured. Conditions will be limited. On the other hand, if washing with an alkaline solution is performed at a high temperature, a high concentration, and for a long time, contaminants on the surface of the aluminum substrate are removed well, but this is not preferable because it leads to an increase in cost. In washing with an alkaline solution, a treatment is usually performed at 40 to 70 ° C. for 2 to 20 seconds using a 0.5 to 5% by weight alkaline aqueous solution.

B-3. Washing with an acidic solution Washing with an alkaline solution is followed by washing with an acidic solution. The purpose of the cleaning with the acidic solution is to remove magnesium oxide called smut concentrated on the surface of the aluminum base material and the aluminum oxide that grows simultaneously with the etching. Also in the cleaning method using an acidic solution, conventional acidic cleaning used for acidic cleaning treatment of metals such as an aluminum substrate can be performed. As the acidic solution, an acidic aqueous solution or an acidic solution in which an acid component is dissolved or dispersed in an organic solvent is used. As the acidic solution, an aqueous solution is preferably used, and an aqueous sulfuric acid solution, an aqueous nitric acid solution and the like are particularly preferable. Also in the cleaning with an acidic solution, the higher the cleaning temperature and concentration, the shorter the processing time becomes possible. When washing with an acidic solution is not sufficient, smut and aluminum oxide on the surface of the aluminum substrate remain even after the treatment, which adversely affects the processability with the organic compound solution in the next step. For removal of smut and aluminum oxide, it is preferable to use an acidic aqueous solution of 0.5 to 5% by weight for handling, and when an acidic aqueous solution having a concentration of about 2% by weight is used, a temperature of 40 to 60 ° C. Then, the treatment is performed for 3 to 10 seconds.

B-4. Aluminum oxide film A uniform aluminum oxide film 3 is formed on the surface of the aluminum substrate 2 by such washing with an alkaline solution and subsequent washing with an acidic solution. The aluminum oxide film needs to be 6 to 20 nm, preferably 8 to 16 nm. By setting the aluminum oxide film to 20 nm or less, good hydrophilicity can be ensured, and the treatment with the organosilicon compound solution in the next step can be easily and uniformly performed. Moreover, although an aluminum oxide film is formed by alkaline solution treatment and acidic solution treatment, 6 nm is the minimum thickness that is inevitably formed.

  On the other hand, if the aluminum oxide film after the acid solution treatment exceeds 20 nm, sufficient hydrophilicity cannot be obtained, and uneven coating tends to occur during the treatment with the organic compound solution. In order to make the aluminum oxide film after washing with an acidic solution 20 nm or less, for example, an acidic aqueous solution having a concentration of about 2% by weight is used and treated at 40 ° C. to 60 ° C. for 3 to 10 seconds. Is preferred.

  The thickness of the aluminum oxide film defined in the present invention refers to the intersection of the Al depth direction profile and the oxygen depth direction profile in the depth profile of Auger electron spectroscopy analysis, and the intersection position from the outermost surface. Expressed as distance.

  For example, when an aluminum substrate (JIS-A3004 alloy) is washed with a 2% by weight alkaline aqueous solution at 60 ° C. for 5 seconds and then treated with a 2% by weight sulfuric acid aqueous solution at 30 ° C. for 1 second, A measurement example of the profile in the depth direction of oxygen (O) and Mg is shown in FIG. In this case, the thickness of the aluminum oxide film is 29 nm. In this case, since the acid treatment temperature is short and the treatment time is short, the aluminum oxide film is not sufficiently removed.

  Also, the depth direction of Al, oxygen (O), and Mg when washed with a 2 wt% aqueous alkaline solution at 60 ° C for 5 seconds and then treated with a 2 wt% aqueous sulfuric acid solution at 50 ° C for 3 seconds An example of profile measurement is shown in FIG. In this case, the aluminum oxide film thickness is 6 nm. In this case, since the acid treatment temperature and treatment time are appropriate, the aluminum oxide film can be sufficiently removed.

  For the washing treatment with the alkaline solution and the washing treatment with the acidic solution, a spray method, a dipping method or the like can be used, but the spray method is preferable from the viewpoint of processability. Furthermore, after washing the alkaline solution and after washing the acidic solution, it is preferable to perform a water washing treatment in order to remove the alkaline component and acidic component remaining on the surface of the aluminum substrate. As the water washing treatment, an immersion treatment or a spray treatment is performed using a sufficient amount of water of 5 to 25 ° C. with an electric conductivity of 40 mS / m or less.

B-5. Organosilicon compound film By forming a predetermined organosilicon compound film on the surface of the aluminum oxide film, the adhesion of the resin coating film provided thereon can be improved. As such an organosilicon compound, those represented by the following formula (1) can be used.
In the formula, Y is any organic functional group of amino group, vinyl group, methacryl group, epoxy group, and mercapto group. R is an alkyl group having 1 to 5 carbon atoms, OR ′ is an alkoxyl group, and R ′ is preferably an alkyl group having 1 to 5 carbon atoms. n is 0, 1 or 2.

  Since the amino group, vinyl group, methacryl group, epoxy group, and mercapto group form a strong bond with the hydroxyl group, carboxyl group, etc. of the resin coating film, good adhesion with the resin coating film layer Sex is imparted.

  In the organosilicon compound represented by the above formula (1), 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyl are assumed as the functional group Y is an amino group. Examples include trimethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane, and 3-phenylaminopropyltrimethoxysilane.

  In the organosilicon compound represented by the above formula (1), it is assumed that the functional group Y is a vinyl group, vinyltriacetoxysilane, vinyltri (methoxyethoxy) silane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxy. Silane, allyltrimethoxysilane, etc. are mentioned.

  The organosilicon compound represented by the above formula (1) includes methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, etc., assuming that the functional group Y is a methacryl group. Can be mentioned.

  In the organosilicon compound represented by the above formula (1), the functional group Y is an epoxy group, and 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycid Examples include xylpropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like.

  Furthermore, examples of the functional group Y comprising a mercapto group include 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.

  The organosilicon compound film is formed by applying a solution containing the above-described organosilicon compound to the surface of the aluminum oxide film. As the solvent, water or a polar or nonpolar organic solvent is used, and an organosilicon compound solution is prepared by dissolving or dispersing the organosilicon compound in these solvents. As the solvent, water is preferably used.

In order to obtain good uniformity and adhesion of the formed film, it is necessary to define the amount of the organic silicon compound film formed by the silicon amount. As a result of various studies, the formation amount of the organosilicon compound film after drying should be 1 to 10 mg / m ^{2 in} terms of silicon, that is, as the amount of silicon present in the organosilicon compound film after drying. found.

If the amount of silicon in the organosilicon compound film is less than 1 mg / m ² , it is not possible to form an organosilicon compound film that covers the entire surface of the aluminum substrate after the acid cleaning. In such a case, the aluminum oxide grows due to the reaction between the surface of the aluminum substrate and oxygen in the atmosphere at a location not covered with the organosilicon compound film. As a result, the adhesiveness with the resin coating film formed on the organosilicon compound film after that becomes poor.

On the other hand, if the amount of silicon in the organosilicon compound film exceeds 10 mg / m ² , the aluminum substrate surface can be completely covered with the organosilicon compound film. Growth can be suppressed. However, when the amount of the organic silicon compound film is increased, cohesive failure occurs inside the organic silicon compound film, resulting in a decrease in adhesion to the aluminum substrate.

  In order to obtain such an amount of silicon in the film, it is necessary to control the concentration of the organosilicon compound in the organosilicon compound solution and the amount of solution applied. Usually, the organosilicon compound concentration is 1 to 20% by weight, preferably 5 to 10% by weight. If it is less than 1% by weight, a large amount of solution must be applied, and a film having a desired thickness may not be formed. On the other hand, if it exceeds 20% by weight, the amount of solution to be applied becomes small and it becomes difficult to control the film thickness. Specifically, the amount of silicon in the organosilicon compound film is achieved by appropriately selecting the coating amount of the organosilicon compound solution having a concentration within the above range. As a result, the formed organosilicon compound has good uniformity, and even if there are irregularities on the surface of the aluminum substrate due to rolling marks, etc., stable and good adhesion to the aluminum substrate is obtained. It is done.

  The formation method of the organosilicon compound film is not particularly limited, and a roll coating method, a spray coating method, a bar coating method, a dip coating method, or the like is used. After coating, it is dried at a temperature of 50 to 200 ° C, preferably 80 to 180 ° C. The drying time is appropriately selected according to the drying temperature and the like. That is, it is desirable to shorten the drying time when the drying temperature is high, and lengthen the drying time when the drying temperature is low. However, when drying at low temperature for a short time, the dehydration reaction between the aluminum substrate and the organosilicon compound film becomes incomplete, the covalent bond cannot be promoted, and sufficient adhesion to the aluminum substrate is obtained. I can't.

  On the other hand, when dried at high temperature for a long time, the aluminum oxide film is cracked, and the adhesion of the organosilicon compound film to the aluminum substrate is lowered. Therefore, as drying conditions, for example, when the drying temperature is 60 ° C., the drying time is preferably 40 seconds, and when 150 ° C., the drying time is preferably 15 seconds. By this drying treatment, a dehydration reaction proceeds from the hydrogen bonding portion formed between the aluminum substrate formed after applying the organosilicon compound solution and the organosilicon compound, and good covalent bonding with the aluminum substrate is achieved. A formed organosilicon compound film can be provided.

  The aluminum material for laminating according to the present invention includes an aluminum oxide film and an organosilicon compound film formed thereon on at least one surface of an aluminum substrate. That is, the aluminum oxide film and the organosilicon compound film formed thereon are formed only on one surface of the aluminum base material, and the aluminum oxide film and the aluminum oxide film are formed on both surfaces of the aluminum base material, respectively. And an organosilicon compound film.

C. Resin-coated aluminum material As shown in FIG. 4, a resin-coated aluminum material 5 according to the present invention is typically formed by forming a resin film 6 on an aluminum material 1 for laminating. A resin film 6 as a resin coating film is formed on the organosilicon compound film 4 in the aluminum material 1 for laminating comprising the aluminum oxide film 3 on the material 2 and the organosilicon compound film 4 formed on the aluminum oxide film 3. It is coated.

C-1. Resin film Any resin film may be used as long as it exhibits thermal adhesiveness to an aluminum substrate, and a resin film having various properties can be selected according to various properties required for a resin-coated aluminum material. It is. Examples of such resin films include polyethylene terephthalate, polyethylene naphthalate, nylon 6, nylon 11, polycarbonate, polyarylate, and the like.

  Such a resin film is coated on the aluminum base material after the formation of the organic silicon compound film by thermocompression bonding or heat bonding. For example, the aluminum substrate is heated by high-frequency induction heating or direct flame heating, and the thermocompression bonding method of pressing the film on the surface of the aluminum substrate, or the aluminum substrate surface heated while extruding the resin film. A thermal bonding method for bonding is used. These methods are all conventional methods, and can be appropriately selected according to the purpose, application, and the like.

  The resin film is pressure-bonded or bonded onto the organosilicon compound film at 150 to 300 ° C. In addition, the above-mentioned organosilicon compound film is formed on the surface of the aluminum substrate, and since this film forms a strong contact with the resin film, it adheres to the resin film or the aluminum chemical conversion treatment material surface that has been conventionally performed. There is no need to provide a primer.

  The resin-coated aluminum material produced in this manner is excellent in the adhesion of the resin-coated film and excellent in corrosion resistance even after molding such as press molding.

  The resin-coated aluminum material according to the present invention comprises an aluminum oxide film on at least one surface of an aluminum substrate, an organosilicon compound film formed thereon, and a resin film formed thereon. That is, the resin-coated aluminum material according to the present invention includes an aluminum oxide film only on one surface of an aluminum base, an organosilicon compound film formed thereon, and a resin film formed thereon. And a form provided with an aluminum oxide film, an organic silicon compound film formed thereon, and a resin film formed thereon, respectively, on both sides of the aluminum substrate.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example and a comparative example, this invention is not limited to the Example described below.

Examples 1-6 and Comparative Examples 1-5
JIS-A3004 alloy was used as the aluminum substrate. This was cast, processed and tempered as follows. That is, the A3004 alloy was cast by a DC casting method, homogenized at 560 ° C. for 3 hours, hot-rolled at 460 ° C., and then cold rolled at 120 ° C. to a plate thickness of 0.30 mm and then 250 ° C. The final annealing process was performed.

  The alloy plate processed as described above is subjected to a cleaning treatment (etching treatment) at 60 ° C. for 10 seconds using 2% by weight aqueous caustic soda solution as an alkaline solution, and water having an electric conductivity of 40 mS / m and 20 ° C. After washing, a washing treatment (smut treatment) was carried out at 30 to 50 ° C. for 1 to 5 seconds using a 2% by weight sulfuric acid aqueous solution. Next, aqueous solutions of various organosilicon compounds represented by the formula (1) were adjusted to 1 to 5% by weight, bar-coated with a # 4 bar coater, and dried at 80 ° C. for 1 minute. In this way, a sample of an aluminum material for laminating was prepared.

  A thermoplastic polyethylene terephthalate resin film (model number: MX-850) manufactured by Teijin DuPont with a film thickness of 15 μm was thermocompression-bonded on the surface of each sample at 250 ° C. to prepare a resin-coated aluminum material.

  Table 1 shows acid washing conditions (temperature, time) with a 2% by weight sulfuric acid aqueous solution and an organosilicon compound of the formula (1) (the parentheses indicate the organic functional group Y in the formula (1)).

  Table 2 shows the film thickness of the aluminum oxide film after the treatment with the pickling aqueous solution, the amount of silicon in the organosilicon compound film, and the adhesion evaluation results of the resin-coated aluminum material. In addition, the measuring method of the film thickness of an aluminum oxide film, the adhesiveness evaluation method and evaluation criteria of a resin-coated aluminum material are shown below.

Measurement of film thickness of aluminum oxide film The depth profile of Al and oxygen (O) on the surface of the sample after treatment with an acidic aqueous solution was measured by Auger electron spectroscopy to obtain the intersection on the graph of both profiles. The depth from the surface was taken as the film thickness of the aluminum oxide film.

Measurement of the amount of silicon in the organosilicon compound film The formation amount of the organosilicon compound was measured by a fluorescent X-ray analyzer (manufactured by Rigaku) as the amount of silicon present in the organosilicon compound film.

Adhesion performance of resin-coated aluminum material A can lid material was molded into a can lid and subjected to a retort treatment at 125 ° C. for 30 minutes. Thereafter, the remaining width of the resin film in the opening after the tab was pulled was measured. Here, ◎ if the remaining width was less than 0.4 mm, ◯ if the remaining width was 0.4 mm or more and less than 0.7 mm, and x if the remaining width was 0.7 mm or more. ◎ and ○ were accepted, and x was rejected.

As shown in Table 1, in Examples 1-6, what has an amino group, an epoxy group, a vinyl group, a mercapto group, and a methacryl group in the functional group Y was apply | coated as an organosilicon compound. Moreover, as shown in Table 2, in these examples, the aluminum oxide film thickness after smut treatment with an acidic solution was 20 nm or less. Furthermore, as shown in Table 2, in these examples, the silicon amount in the organosilicon compound film is in the range of 1 to 10 mg / m ^{2 in} terms of Si, and the silicon amount limited in the present invention (1 to 10 mg / m 2). ² ) was achieved. As a result, as shown in Table 2, it was confirmed that the adhesion (feathering property) of the resin film in the resin-coated aluminum material was extremely good.

On the other hand, in Comparative Example 1, since the cleaning with the acidic aqueous solution was insufficient, the aluminum oxide film remained on the surface of the aluminum base material by 20 nm or more. Accordingly, the adhesion of the resin film of the resin-coated aluminum material was inferior despite the fact that the organosilicon compound and the amount of the coating were appropriate.
In Comparative Examples 2 and 3, although the aluminum oxide was well removed, the silicon content in the organosilicon compound film was out of the limited range, so the adhesion of the resin film was inferior.
Moreover, in Comparative Examples 4-5, although the aluminum oxide was removed favorably and the amount of silicon in the organosilicon compound film was appropriate, the organosilicon compound is not limited to the present invention. Therefore, the adhesiveness of the resin film was inferior.

As described above, the aluminum material for laminating according to the present invention has an aluminum oxide film thickness of 6 to 20 nm, and an organic silicon compound film formation amount of 1 to 10 mg / m ^{2 in} terms of silicon. By providing the above, it is possible to obtain an aluminum material for laminating that maintains high adhesion without performing conventional chromate-based and non-chromate-based chemical conversion treatment, and further, an adhesive primer layer forming treatment. Furthermore, a resin-coated aluminum material having the same effect can be obtained by forming a resin film as a resin coating film on the organosilicon compound film in the aluminum material for laminating.

Sectional drawing of the aluminum material for lamination which concerns on this invention is shown. It is a graph which shows the depth direction profile of Al, oxygen, and Mg in the aluminum base material acid-treated after alkali treatment. It is a graph which shows the depth direction profile of Al, oxygen, and Mg in the aluminum base material acid-treated after alkali treatment. Sectional drawing of the resin-coated aluminum material which concerns on this invention is shown.

Explanation of symbols

1 ... Aluminum material for laminating 2 ... Aluminum substrate 3 ... Aluminum oxide film 4 ... Organic silicon compound film 5 ... Resin coated aluminum material 6 ... Resin film

Claims (4)

An aluminum substrate made of aluminum or an aluminum alloy, an aluminum oxide film formed on at least one surface of the aluminum substrate, and an organosilicon compound formed on the surface of the aluminum oxide film and having a chemical structure represented by the following formula (1) An aluminum material for laminating, wherein the aluminum oxide film has a thickness of 6 to 20 nm, and the amount of the organic silicon compound film formed is 1 to 10 mg / m ² in terms of silicon.
Here, Y is any organic functional group selected from the group consisting of amino group, vinyl group, methacryl group, epoxy group and mercapto group, R is an alkyl group having 1 to 5 carbon atoms, OR ′ is an alkoxyl group, n is 0, 1 or 2.   A resin-coated aluminum material, wherein a resin film is further provided on the organosilicon compound film in the aluminum material for laminating according to claim 1. A step of cleaning at least one surface of a base material made of aluminum or an aluminum alloy with an alkaline solution, a step of cleaning the cleaned surface with the alkaline solution with an acidic solution, and treating the cleaned surface with the acidic solution with an organosilicon compound solution Including the steps of:
The thickness of the aluminum oxide film formed on the surface of the aluminum substrate after the washing step with the acidic solution is 6 to 20 nm, and the following formula (1) is formed on the aluminum oxide film by the treatment step with the organosilicon compound solution. A method for producing an aluminum material for laminating, characterized in that an organic silicon compound film having a thickness of 1 to 10 mg / m ² in terms of silicon is formed.
Here, Y is any organic functional group selected from the group consisting of amino group, vinyl group, methacryl group, epoxy group and mercapto group, R is an alkyl group having 1 to 5 carbon atoms, OR ′ is an alkoxyl group, n is 0, 1 or 2. A method for producing a resin-coated aluminum material, comprising a step of coating a resin film on the organosilicon compound film after the treatment step with the organosilicon compound solution in claim 3.