JP5125284B2 - Aluminum coating material and manufacturing method thereof - Google Patents

Description

The present invention relates to an aluminum coating material having a coating film excellent in corrosion resistance on the surface of an aluminum material made of aluminum or an aluminum alloy, and a method for producing the same .

Methods for using chromium surface treatment agents such as chromate treatment and phosphoric acid chromate treatment are well known for corrosion resistance treatment of aluminum materials, and these methods are still widely practiced (see Patent Documents 1 to 3). .
However, in recent years, there has been a global increase in the desire to regulate the use of environmentally hazardous substances. For example, in the EU, laws and regulations relating to hexavalent chromium have begun due to the directive on scrapped automobiles.

  In addition, the inventor proposed that trivalent chromium (chromium nitrate) be used by using a trihydric or higher polyhydric alcohol having three or more primary alcoholic hydroxyl groups in the molecule (patent) Furthermore, although there is no legal regulation for this trivalent chromium at present, there is a report that a part of the trivalent chromium changes to hexavalent chromium when heated. Aluminum coating that has a silicon-containing coating (a coating that contains silicon element) and is substantially free of hexavalent and trivalent chromium, so-called “non-chromium” that is environmentally friendly and excellent in corrosion resistance A material was developed and proposed (see Patent Document 5).

  Furthermore, as an example of the non-chromate type coating treatment, the surface of a metal plate such as a galvanized steel plate is coated with 50 to 90% by mass of a specific cross-linked resin matrix (A) and an inorganic protection such as colloidal silica, phosphoric acid and niobium oxide sol. By forming a film containing 10-50% by mass of rusting agent (B), we provide a non-chromate organic coated metal plate with excellent corrosion resistance, alkali resistance, solvent resistance, scratch resistance and adhesion. It has been proposed (see Patent Document 6).

JP-A-1-299,877 Japanese Patent Publication No.02-42,389 Japanese Patent Publication No. 03-77,440 JP 2000-256,868 JP 2004-283,824 JP 2005-281,863 A

As a result of further investigation on an aluminum coating material in which a coating film having such an anti-chrome and environmentally friendly and excellent corrosion resistance is formed, the present inventor has unexpectedly found that the surface of the aluminum material and the coating material of this coating material A film (inorganic film) containing a predetermined silicon oxide at a predetermined silicon amount and silicon content and containing a phosphorus compound derived from phosphoric acid at a predetermined phosphorus content and phosphorus content is interposed between the film and the film. Thus, it was found that the corrosion resistance of the obtained aluminum coating material can be remarkably improved, and the present invention has been completed.

  Accordingly, an object of the present invention is to provide an aluminum coating material that has a coating film on the surface of an aluminum material made of aluminum or an aluminum alloy, is non-chromium, and is environmentally friendly and exhibits excellent corrosion resistance.

That is, the present invention is formed by applying a film-forming treatment liquid containing water-dispersible silica and phosphoric acid to the surface of an aluminum material made of aluminum or an aluminum alloy , and silicon oxide has a silicon content of 5 to 200 mg / m ^2. And a silicon content of 25 to 46.7% by weight and a phosphoric acid-derived phosphorus compound in a range of 0.1 to 20 mg / m ² of phosphorus and 0.2 to 10% by weight of phosphorus. In addition, the aluminum coating material is characterized in that a coating film is formed through an inorganic film substantially not containing chromium. Here, “substantially free of chromium” means that chromium is below the detection limit (usually 0.5 mg / m ² or less) in fluorescent X-ray analysis of inorganic coatings. Means not added.

  In the present invention, as an aluminum material, a rolled material made of aluminum or an aluminum alloy, an extruded shape material, a die-cast material, a cast material, a processed material obtained by appropriately processing these materials, and a combination of these materials as appropriate. The obtained combination material and the like can be mentioned.

In the present invention, the inorganic film formed on the surface of the aluminum material contains silicon oxide in a silicon amount of 5 mg / m ² or more and 200 mg / m ² or less, preferably 10 mg / m ² or more and 100 mg / m ² or less. It is necessary. If the amount of silicon in the inorganic coating is less than 5 mg / m ² , there is a problem that the yarn rust resistance is inferior. On the other hand, if it exceeds 200 mg / m ^2, there arises a problem that the adhesion is poor. In addition, this inorganic film is preferably substantially free of organic substances such as an organic binder from the viewpoint of achieving superior corrosion resistance. Here, “substantially free of organic substances” means a trace amount of carbon (C amount) or less (usually 10 mg / m ² or less) detected by surface contamination in fluorescent X-ray analysis. This means that no organic substance such as an organic binder is added.

  The inorganic coating of the present invention usually has a thickness of 5 nm to 500 nm, preferably 20 nm to 300 nm, and the silicon content in the coating is 25 wt% to 46.7 wt%. Hereinafter, it is preferably 30% by weight or more and 46.7% by weight or less. If the film thickness of the inorganic film is less than 5 nm, the yarn rust resistance may be insufficient. Conversely, if the film thickness is greater than 500 nm, the adhesion may be insufficient. In addition, if the silicon content in the film is less than 25% by weight, the problem of poor yarn rust resistance occurs, and if it exceeds 46.7% by weight, it is difficult to form a film with a general-purpose raw material and the cost increases. Problems arise.

Furthermore, the inorganic film containing the silicon oxide of the present invention is a film formed using water-dispersible silica as a raw material , and examples of the water-dispersible silica include colloidal silica and vapor phase silica, and more preferably colloidal. Silica. The colloidal silica is not particularly limited. Specifically, for example, spherical colloidal silica includes SNOWTEX-C, SNOWTEX-O, SNOWTEX-N, SNOWTEX-N, manufactured by Nissan Chemical Industries, Ltd. There are Tex-S, Snowtex-OL, Snowtex-XS, Snowtex-XL, etc. Also, as chain colloidal silica, there are Snowtex-UP and Snowtex-OUP manufactured by Nissan Chemical Industries. Gas phase silica includes Aerosil 130, Aerosil 200, Aerosil 200CF, Aerosil 300, Aerosil 300CF, Aerosil 380, Aerosil MOX80, etc. manufactured by Nippon Aerosil Co., Ltd.

Furthermore, this inorganic film, for the purpose of more such further improve corrosion resistance, the time of the film formation process for forming the inorganic film, phosphoric acid in addition to the silicon oxide in the film forming solution to be used As a result , a phosphorus compound is added to the inorganic film. The added phosphoric acid reacts with the surface of the aluminum material during the film formation treatment to produce a phosphate such as aluminum phosphate, and is contained in the inorganic film as a phosphorus compound derived from phosphoric acid . The amount of phosphorus compound added to the inorganic film for this purpose is 0.1 mg / m ² or more and 20 mg / m ² or less, preferably 0.5 mg / m ² or more and 10 mg / m ² as the amount of phosphorus in the film. The phosphorus content in the film should be 10% by weight or less. Regarding the amount of phosphorus compound added, if the amount of phosphorus in the film is less than 0.1 mg / m ² , the purpose of adding the phosphorus compound is not achieved, and if it exceeds 20 mg / m ² , the adhesion is increased. The problem that it is defective arises, and if the phosphorus content in the film exceeds 10% by weight, there arises a problem that the adhesiveness is lowered.

The phosphoric acid added to the film-forming treatment solution for this purpose is not particularly limited, but preferably, for example, one or a mixture of two or more selected from orthophosphoric acid, phosphonic acid, pyrophosphoric acid, and tripolyphosphoric acid . Can be mentioned.

  In addition to the silicon oxide, an inorganic compound may be added to the inorganic film in the same manner as the phosphorus compound, if necessary, for the purpose of further improving corrosion resistance. The term “inorganic compound” as used herein refers to an inorganic compound other than the above silicon oxide and phosphorus compound, and the amount of the inorganic compound added to the film is preferably 35% by weight or less. When the added amount of the inorganic compound in the film exceeds 35% by weight, the corrosion resistance is lowered. Examples of inorganic compounds added to the film-forming treatment liquid include metal oxide sols such as alumina sol, zirconia sol, and titania sol, and inorganic pigments such as zinc oxide, titanium oxide, barium sulfate, alumina, kaolin, and iron oxide. Can be mentioned.

  In the present invention, the coating film formed on the surface of the aluminum material via an inorganic film is not particularly limited. Examples of the coating material for forming this coating film include acrylic coatings and polyester coatings. Silica sol using paint, urethane paint, acrylic urethane, acrylic polyester, epoxy paint, fluorine paint, acrylic silicone paint, urethane silicone paint, acrylic urethane silicone paint, alkali silicate paint, colloidal silica, etc. Paints, titanium oxide paints, ceramic paints, silicon-containing paints of the present invention, and the like, and any paints such as organic paints, inorganic paints, and organic / inorganic hybrid paints may be used.

  The coating film formed on the surface of the aluminum material through an inorganic film is formed by applying a silicon-containing paint containing silicon element (Si), and the silicon-containing coating containing silicon element (Si) in the coating film. It may be a film, and the silicon-containing paint for forming this silicon-containing coating film is not particularly limited. The silicon-containing paint is specifically a paint containing a monomer or polymer having a siloxane bond, or a paint containing an alkoxysilane and / or silanol group. Specific examples of such paints include acrylic silicone paints, urethane silicone paints, acrylic urethane silicone paints, alkali silicate paints, silica sol paints, silica paints, ceramic paints, and the like. Examples of the paint system include solvent-based, water-based emulsion, and water-based paints, and water-based emulsion paints are particularly preferable.

  In the present invention, the coating film formed on the surface of the aluminum material through the inorganic film may be a top coating film that itself forms the outermost surface of the aluminum coating material. It may be a primer coating film that functions as a primer layer for laminating films. And about the film thickness of the coating film formed on the inorganic film, it is appropriately selected according to the purpose of use of the aluminum coating material, etc. In general, the thickness should be 0.1 μm or more and 20 μm or less, preferably 0.5 μm or more and 15 μm or less. If the thickness is less than 0.1 μm, sufficient corrosion resistance is not exhibited. The problem that adhesiveness falls arises.

  And, when the coating film of the present invention is used as a primer layer, a top coating film is formed by further applying a top coating composition on the coating film, but there is no particular limitation on the top coating composition used here, For example, acrylic paint, polyester paint, urethane paint, acrylic urethane, acrylic polyester, epoxy paint, fluorine paint, acrylic silicone paint, urethane silicone paint, acrylic urethane silicone paint, alkali silicate paint And silica sol-based paints using colloidal silica, titanium oxide-based paints, ceramics-based paints, silicon-containing paints of the present invention, etc., and any of organic, inorganic, organic / inorganic hybrid paints, etc. There may be. Moreover, about this top coat film, not only a single layer coating film but a multilayer coating film of two or more layers may be used, and the film thickness is not particularly limited, but usually 1 to 100 μm is preferable.

The aluminum coating material of the present invention is obtained by applying a film forming treatment liquid containing silicon oxide to the surface of an aluminum material to obtain a silicon amount of 5 to 200 mg / m ^{2, a} silicon content of 25 to 46.7% by weight, and phosphoric acid. A film forming treatment for forming an inorganic film having a phosphorus content of 0.1 to 20 mg / m ² and a phosphorus content of 0.2 to 10% by weight is performed, and then a coating is applied on the obtained inorganic film. Manufactured by forming a film.

  In the production of the aluminum coating material of the present invention, preferably, prior to the film formation treatment, an acid treatment with an acid solution, preferably an acid solution having a pH of 6 or less, on the surface in advance for the purpose of degreasing or surface adjustment, And / or a pretreatment comprising an alkali treatment with an alkaline solution, preferably an alkaline solution having a pH of 8 or higher, may be applied.

  Here, examples of the acid solution used for this pretreatment include those prepared with commercially available acid degreasing agents, mineral acids such as sulfuric acid, nitric acid, hydrofluoric acid, and phosphoric acid, organic acids such as acetic acid and citric acid, and the like. What was prepared using acid reagents, such as mixed acid obtained by mixing acid of this, etc. can be used, Preferably it is an acid solution below pH 6, and as an alkaline solution, for example, Those prepared with a commercially available alkaline degreasing agent, those prepared with an alkaline reagent such as caustic soda, or those prepared by mixing these materials can be used, and preferably an alkaline solution having a pH of 8 or more. .

  Moreover, the acid solution and / or alkali solution used for pretreatment may contain a silicon compound. By performing the pretreatment using an acid solution and / or an alkali solution containing a silicon compound, there is an effect that the adhesion between the surface of the aluminum material and the inorganic film formed thereon becomes stronger. Be expected. Examples of the acid solution and / or alkali solution containing such a silicon compound include an acid solution containing colloidal silica and an alkali solution containing a silicate such as sodium metasilicate.

  Regarding the operation method and treatment conditions of the pretreatment performed using the above acid solution and / or alkali solution, the operation method and treatment conditions of the pretreatment conventionally performed using this kind of acid solution or alkali solution, and For example, by a method such as dipping or spraying, the temperature is from room temperature to 90 ° C., preferably from room temperature to 70 ° C., one step for about 1 second to about 15 minutes, preferably about 5 seconds to about 10 minutes. However, it is preferable that the time is 5 seconds to 3 minutes.

In the pretreatment performed using this acid solution and / or alkali solution, the surface of the aluminum material may or may not be etched.
And after pre-treating the surface of the aluminum material, it may be washed with water if necessary, and industrial water, ground water, tap water, ion-exchanged water, etc. can be used for this washing treatment and manufactured. It is suitably selected according to the aluminum coating material. Further, the pretreated aluminum material is subjected to a drying treatment if necessary. This drying treatment may be natural drying left at room temperature, or may be forced drying using an air blower, a dryer, an oven, or the like. .

Next, the surface of the aluminum material or, if necessary, the surface of the aluminum material pretreated by the acid treatment and / or alkali treatment, preferably contains water-dispersible silica such as colloidal silica and phosphoric acid . Then, if necessary, a film forming treatment solution to which a predetermined inorganic compound is added is applied, and the silicon amount is 5 to 200 mg / m ² and the silicon content is 25 to 46.7% by weight. A film forming treatment for forming an inorganic film having 1 to ²⁰ mg / m ² and a phosphorus content of 0.2 to 10% by weight is performed.

  The film forming treatment liquid is preferably an aqueous solution or an alcohol solution, and an organic substance such as an alcohol, a solvent, or a surface conditioner may be added as necessary. The organic substance added here is preferably one that vaporizes and disappears from the coating during the formation of the inorganic coating and does not substantially remain in the coating as a component of the coating. As an approximate standard, the organic substance that substantially disappears when vaporized from the film during film formation is one having a boiling point of 150 ° C. or lower.

  Regarding the operation method and treatment conditions of the film formation treatment for forming the inorganic film by applying the above film formation treatment liquid on the surface of the aluminum material, for example, the roll coating method, spray coating method, dipping method, bar coating method, static coating method, etc. Even a pre-coating method such as an electrocoating method, or a post-coating method such as a spray coating method, a spin coating method, a dipping method, an electrostatic coating method or the like, usually from room temperature to 80 ° C., preferably from room temperature to 50 ° C. In the temperature range up to 1 second to about 10 minutes, preferably 2 seconds to 5 minutes, and after the coating, if necessary, the drying treatment is carried out at room temperature. In addition to natural drying, the forced drying may be performed using an air blower, a dryer, an oven, or the like. In the case of forced drying, it is preferable to dry at room temperature to 250 ° C. for about 1 second to 10 minutes, preferably about 2 seconds to 5 minutes.

  After a predetermined inorganic film is formed on the surface of the aluminum material as described above, a paint is applied on the inorganic film to form a coating film. As for the coating method of this paint, for example, a pre-coating method such as a roll coating method, a spray coating method, a dipping method, a bar coating method, an electrostatic coating method, etc., or a spray coating method, a spin coating method, a dipping method, A post-coating method such as an electrostatic coating method may be used. The drying process after painting may be performed by a drying method corresponding to the paint, for example, a method of performing air blowing, a dryer, an oven, etc. in the range of room temperature to 300 ° C. for 5 seconds to 24 hours. can do.

  In addition, when the above-mentioned coating film is used as a primer layer and a top coating film is provided thereon, it is not different from the case where a top coating film is formed on a conventional primer layer, for example, it is formed. Post-coating by roll coating method, spray coating method, dipping method, bar coating method, electrostatic coating method, etc., spray coating method, spin coating method, dipping method, electrostatic coating method, etc. A top coating material may be applied by a coating method, and then dried by a drying method corresponding to the top coating material.

  According to the present invention, there is provided an aluminum coating material which has a coating film on the surface of an aluminum material made of aluminum or an aluminum alloy, is non-chromium substantially free of chromium, and is environmentally friendly and exhibits excellent corrosion resistance. Can do.

Hereinafter, preferred embodiments of the present invention will be specifically described based on examples , reference examples, and comparative examples.

[Examples 2, 5, 8, 9, 13 to 17, Reference Examples 1, 3, 4, 6, 7, 10 to 12, and Comparative Examples 1 to 7]
An aluminum plate (JIS 5052) having a size of 70 mm × 150 mm × 0.8 mm was prepared as an aluminum material, and the aluminum plates of these examples, reference examples, and comparative examples 1 to 6 were pretreated as follows. Inorganic film formation and coating film formation were performed.

〔Preprocessing〕
In Reference Examples 1 and 11, the sample was immersed in a 10 wt% sulfuric acid aqueous solution at 40 ° C. for 3 minutes, washed with water, and dried.

In Example 2, Reference Example 12 and Comparative Example 1, the sample was immersed in a 10 wt% -sulfuric acid aqueous solution at 40 ° C. for 3 minutes, washed with water, then immersed in a 5 wt% -sodium hydroxide aqueous solution at 40 ° C. for 3 minutes, and washed with water. Then, it was immersed in a 10 wt% -sulfuric acid aqueous solution at room temperature for 1 minute, washed with water and dried.

In Example 17 and Reference Example 3 and Comparative Example 2, they were immersed in a 30 wt% aqueous nitric acid solution at room temperature for 5 minutes, washed with water and dried.

In Example 9 and Reference Examples 4 and 10, they were immersed in a 2 wt% -phosphoric acid aqueous solution at 60 ° C. for 30 seconds, washed with water, and dried.

  In Example 5, a 60 wt% nitric acid solution containing 2 wt% colloidal silica prepared using Snowtex-O (ST-O) manufactured by Nissan Chemical Industries was used as an acid solution containing a silicon compound. It was soaked at 30 ° C. for 30 seconds, washed with water and dried.

In Example 8, Reference Examples 6 and 7, and Comparative Examples 3-7, as an alkaline solution containing a silicon compound, a degreasing agent containing sodium metasilicate (degreasing agent A: Nippon Paint Co., Ltd., trade name: Surf Cleaner 155 ) Was used for 30 seconds, and then washed with water and dried.

  In Examples 13 to 16, a 2 wt% aqueous solution of a degreasing agent containing sodium metasilicate (degreasing agent B: product name: Surf Cleaner 53) containing sodium metasilicate was used as an alkaline solution containing a silicon compound, and the temperature was 60 ° C. After being immersed for 3 minutes, it was washed with water and dried.

[Film formation treatment]
As a treatment liquid containing silicon oxide, a film-forming treatment liquid having the composition shown in Table 2 ( each Example and each Reference Example ) and Table 3 (Comparative Examples 1 to 6) containing water-dispersible silica shown in Table 1. Was used.

In each example, each reference example, and each comparative example , after the pretreatment, a film forming treatment liquid having the composition shown in Tables 2 and 3 was applied with a bar coater # 3 and dried at 200 ° C. for 1 minute.

  At this time, in Examples 2, 5, 8, 9, and 13 to 17 and Comparative Examples 2 and 5, in addition to water-dispersible silica, phosphoric acid (Wako Pure Chemical Industries, Ltd.) was used at the ratios shown in Tables 2 and 3. A reagent special grade manufactured by the company (phosphoric acid content 85 wt%) and / or aluminum phosphate (for reagent chemistry manufactured by Wako Pure Chemical Industries, Ltd.) was added.

In Examples 5 and 13 to 15 , Reference Examples 11 and 12, and Comparative Examples 1, 2, and 6, in addition to water-dispersible silica, alumina sol (manufactured by Nissan Chemical Industries: Alumina Sol-100, solid content 10 wt%) ) Or zirconia sol (manufactured by Nissan Chemical Industries, solid content 30 wt%) or boehmite (manufactured by Nissan Chemical Industries: AS-100, solid content 10 wt%).

  Furthermore, in Comparative Example 6, the film forming process for forming this inorganic film was not performed.

The amount of silicon (Si amount: mg / m ² ) and the amount of phosphorus (P amount) contained in the coating unit area for the inorganic coatings of Examples, Reference Examples, and Comparative Examples formed as described above. : Mg / m ² ) was measured by X-ray fluorescence analysis. For the measurement, an inorganic film was prepared on a 99.999% pure aluminum plate in the same manner as in each example, each reference example, and each comparative example, and the amount of silicon contained in the film unit area ( Si amount: mg / m ² ) and phosphorus amount (P amount: mg / m ² ) were quantitatively analyzed. Similarly, for chromium (Cr) and carbon (C), the amount of chromium (Cr amount) and the amount of carbon (C amount) are quantitatively analyzed by fluorescent X-ray analysis, and they are not detected (below the detection limit: the detection limit of Cr is 0.5). It was mg / m ² , and the detection limit of C was 10 mg / m ² ).

  Furthermore, for the silicon content (Si content: wt%) and phosphorus content (P content: wt%) in the inorganic film, a certain amount of the coating material for forming the silicon-containing film was taken out at 200 ° C. After heating for a minute, the weight of the formed silicon-containing film was measured, and the amount of Si and the amount of P were quantitatively analyzed by chemical analysis to determine the content.

[Formation of coating film]
The coating film formed through the inorganic film was formed using the paint shown in Table 4 below. For the formation of the silicon-containing coating film, paints F, G, H and I which are silicon-containing paints in Table 4 were used.

[Examples 2, 5, 13, 14, 16 and 17 , Reference Examples 1, 3, 4, 6, 7 and 12, and Comparative Examples 1 to 4, 6 and 7]
Examples 2, 5, 13, 14, 16 and 17 after the above pretreatment and film formation treatment were performed , Reference Examples 1, 3, 4, 6, 7 and 12, and Comparative Examples 1 to 4, About each aluminum plate of 6 and 7, the coating film was formed with the following method and each test piece (aluminum coating material) was prepared.

In Reference Example 1, the coating material A was bar-coated, baked for 40 seconds at a peak metal temperature (PMT) of 210 ° C. and dried to form a coating film having a thickness of 5 μm. Next, paint J was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a thickness of 20 μm, and a test piece (aluminum coating material) of Reference Example 1 was prepared.

  In Example 2, paint B was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a 10 μm-thick film, and the test piece (aluminum coating material) of Example 2 was prepared. did.

In Reference Example 3, paint C was bar-coated, baked at PMT 210 ° C. for 40 seconds and dried to form a coating film having a thickness of 10 μm. Next, the paint K was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a 10 μm-thick coating film, and a test piece (aluminum coating material) of Reference Example 3 was prepared.

In Reference Example 4, the coating material D was bar-coated, baked at PMT 210 ° C. for 40 seconds and dried to form a coating film having a thickness of 2 μm. Next, the paint C was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a thickness of 10 μm, and a test piece (aluminum coating material) of Reference Example 4 was prepared.

  In Example 5, the coating material E was bar-coated, baked at PMT 210 ° C. for 40 seconds and dried to form a coating film having a thickness of 1 μm. Next, the paint M was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a film thickness of 15 μm, and a test piece (aluminum coating material) of Example 5 was prepared.

In Reference Example 6, paint F was bar-coated, baked at PMT 230 ° C. for 40 seconds, and dried to form a coating film having a thickness of 0.5 μm. Next, the paint K was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a thickness of 30 μm, and a test piece (aluminum coating material) of Reference Example 6 was prepared.

In Reference Example 7, paint G was bar-coated, baked at PMT 230 ° C. for 100 seconds, dried to form a 20 μm-thick film, and the test piece (aluminum coating material) of Reference Example 7 was prepared. did.

In Reference Example 12, paint F was bar-coated, baked at PMT 230 ° C. for 40 seconds and dried to form a coating film having a thickness of 5 μm. Next, the coating material K was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a thickness of 10 μm, and a test piece (aluminum coating material) of Reference Example 12 was prepared.

  In Example 13, the coating material C was bar-coated, baked at PMT 220 ° C. for 40 seconds, and dried to form a coating film having a thickness of 10 μm. Subsequently, the coating material L was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a thickness of 20 μm, and a test piece (aluminum coating material) of Example 13 was prepared.

  In Example 14, paint F was bar-coated, baked at PMT 230 ° C. for 40 seconds and dried to form a coating film having a thickness of 1 μm. Next, the paint J was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a film thickness of 15 μm, and a test piece (aluminum coating material) of Example 14 was prepared.

  In Example 16, the coating material C was bar-coated, baked at PMT 220 ° C. for 40 seconds and dried to form a coating film having a thickness of 10 μm. Subsequently, the coating material L was bar-coated, baked for 60 seconds at PMT 225 ° C. and dried to form a coating film having a thickness of 20 μm, and a test piece (aluminum coating material) of Example 16 was prepared.

  In Example 17, paint F was bar-coated, baked at PMT 230 ° C. for 40 seconds and dried to form a coating film having a thickness of 0.2 μm. Next, the paint K was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a thickness of 10 μm, and a test piece (aluminum coating material) of Example 17 was prepared.

  In Comparative Example 1, paint C was bar-coated, baked at PMT 220 ° C. for 40 seconds and dried to form a coating film having a thickness of 10 μm. Next, the paint K was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a thickness of 10 μm, and a test piece (aluminum coating material) of Comparative Example 1 was prepared.

  In Comparative Examples 2 and 4, paint D was bar-coated, baked at PMT 220 ° C. for 40 seconds and dried to form a coating film having a thickness of 5 μm. Next, paint K was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a 10 μm-thick coating film, and test pieces (aluminum coating materials) of Comparative Examples 2 and 4 were prepared. .

  In Comparative Example 3, paint G was bar-coated, baked at PMT 230 ° C. for 40 seconds and dried to form a coating film having a thickness of 2 μm. Next, the paint K was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a thickness of 10 μm, and a test piece (aluminum coating material) of Comparative Example 3 was prepared.

  In Comparative Examples 6 and 7, paint C was bar-coated, baked at PMT 230 ° C. for 40 seconds and dried to form a coating film having a thickness of 10 μm. Next, paint K was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a 10 μm-thick coating film, and test pieces (aluminum coating materials) of Comparative Examples 6 and 7 were prepared. .

[ Examples 8, 9 and 15 , Reference Examples 10 and 11, and Comparative Example 5]
In Example 8, paint H was spray-coated, baked at PMT 170 ° C. for 20 minutes, and dried to form a silicon-containing coating film having a film thickness of 30 μm. Thus, a test piece (aluminum coating material) of Example 8 was prepared.

  In Example 9, the coating material I was spray-coated, baked at PMT 100 ° C. for 20 minutes, and dried to form a silicon-containing coating film having a thickness of 5 μm. Next, the coating material K was bar-coated, baked at PMT 225 ° C. for 60 seconds and dried to form a coating film having a thickness of 10 μm, and a test piece (aluminum coating material) of Example 9 was prepared.

In Reference Example 10 and Example 15, the paint I was spray-coated, baked at PMT 100 ° C. for 20 minutes, and dried to form a silicon-containing coating film having a thickness of 50 μm, and the specimens of Reference Example 10 and Example 15 ( Aluminum coating material) was prepared.

In Reference Example 11, paint I was spray-coated, baked at PMT 100 ° C. for 20 minutes and dried to form a silicon-containing coating film having a thickness of 10 μm, and a test piece (aluminum coating material) of Reference Example 11 was prepared.

  In Comparative Example 5, paint I was spray-coated, baked at PMT 100 ° C. for 20 minutes, and dried to form a silicon-containing coating film having a thickness of 50 μm, and a test piece (aluminum coating material) of Comparative Example 5 was prepared.

[Corrosion resistance test]
About the test piece of each Example, each reference example, and each comparative example which were prepared as mentioned above , the following salt spray test, the yarn rust resistance test, and the boiling water immersion test were done, and corrosion resistance performance was evaluated.

  The salt spray test was carried out for 1000 hours with a cross cut made according to the method of JIS K5600. The coating after 1000 hours has no generation of corrosion or blisters at the cut part, and the cut part has good adhesion, and the cut part has corrosion of 1 mm or less, no blister, and good adhesion. The evaluation was evaluated as “Good”, and “X” when the corrosion of the cut portion was 1 mm or more, or the occurrence of blistering or poor adhesion was observed.

  In the yarn rust resistance test, a 7 cm crosscut is put into a test piece, immersed in a 3 wt% -hydrochloric acid solution at 35 ° C. for 2 minutes, and placed in a constant temperature and humidity bath at 40 ° C. and 85% RH for 1500 hours (hr). Left to stand. The maximum rust length generated at this time was measured, and the evaluation was evaluated as ◎ for less than 1 mm, ○ for 1 mm or more and less than 2 mm, △ for 2 mm or more and less than 3 mm, and × for 3 mm or more.

In the boiling water immersion test, the test piece was immersed in boiling water for 5 hours, and after observing the abnormalities such as swelling and peeling after completion of the test, the adhesion of the coating film was evaluated as a secondary physical property. Evaluation was made with no abnormality in the appearance after completion of the test, and with X where abnormality such as swelling or peeling occurred. Secondary physical properties are JIS K5600 adhesion (cross-cut method). The cross-cut area where peeling occurs is 5% or less (category 1 or less) ◎ More than 5% and 15% or less ○ , More than 15% and 35% or less, and Δ, more than 35%.
The results of the salt spray test, the yarn rust resistance test, and the boiling water immersion test are shown in Table 5 ( each example and each reference example ) and Table 6 ( each comparative example ).

  The aluminum coating material of the present invention is a so-called non-chromium that contains substantially no hexavalent and trivalent chromium, and has excellent corrosion resistance, and is an environmentally friendly material. It can be used with peace of mind and has high industrial value.

Claims (3)

It is formed by applying a film-forming treatment solution containing water-dispersible silica and phosphoric acid to the surface of an aluminum material made of aluminum or an aluminum alloy . The silicon oxide is made of silicon in an amount of 5-200 mg / m ² and silicon content of 25- 46.7% by weight , a phosphoric acid-derived phosphorus compound containing 0.1 to 20 mg / m ² of phosphorus and a phosphorus content of 0.2 to 10% by weight, and chromium. An aluminum coating material, characterized in that a coating film is formed through an inorganic coating substantially not contained. The aluminum coating material according to claim 1 , wherein the water-dispersible silica is colloidal silica. A method for producing an aluminum coating material having a coating film substantially free of chromium on the surface of an aluminum material made of aluminum or an aluminum alloy, the surface of the aluminum material containing water-dispersible silica and phosphoric acid and chromium A film-forming treatment solution substantially free of silicon is applied, and the silicon amount is 5 to 200 mg / m. ² And a silicon content of 25 to 46.7% by weight and a phosphorus content of 0.1 to 20 mg / m ² And an inorganic film having a phosphorus content in the range of 0.2 to 10% by weight and substantially free of chromium, and then forming the film on the inorganic film. A manufacturing method of paint.