WO2017170015A1

WO2017170015A1 - Aluminum material surface treatment method, surface treatment apparatus, and treated surface aluminum material

Info

Publication number: WO2017170015A1
Application number: PCT/JP2017/011342
Authority: WO
Inventors: 徹也小島; 陽介太田
Original assignee: 株式会社神戸製鋼所
Priority date: 2016-03-29
Filing date: 2017-03-22
Publication date: 2017-10-05

Abstract

A coating is formed by coating a treatment solution containing a 20-400 ppm total, calculated as titanium and calculated as zirconium, of a titanium fluoride compound and/or a zirconium fluoride compound on the surface of an aluminum material so that the total of titanium and zirconium is 4-25 mg/m², and drying.

Description

Surface treatment method of aluminum material, surface treatment apparatus, and surface treated aluminum material

The present invention is obtained by a surface treatment method of an aluminum material using a treatment liquid containing at least one of a titanium fluoride compound and a zirconium fluoride compound, a surface treatment apparatus used in the surface treatment method, and the surface treatment method. The present invention relates to a surface-treated aluminum material that is suitably used for transportation equipment such as automobiles, ships, and airplanes, particularly automobile panels.

In recent years, in the automobile industry, improvement in fuel consumption has been demanded by reducing the weight of members due to global environmental problems such as CO ₂ emission regulations. Aluminum material is attracting attention as a material that replaces the part where the iron material has been used so far, because the specific gravity is as light as about 1/3 that of the iron material. As the aluminum material, an Al—Mg based alloy or an Al—Mg—Si based alloy is used depending on the characteristics. As a method for joining aluminum materials, in addition to a welding method such as brazing, a mechanical joining method such as caulking or rivet, a joining method using adhesion is also frequently used.

Bonding with an adhesive is a surface bonding suitable for increasing rigidity, and has a feature that not only bonding of aluminum materials but also bonding of different materials with different metals or resins can be performed with less restrictions. In addition, it is possible to suppress electric corrosion, and to easily bond regardless of the thickness of the material to be bonded, the bonding location, and the like. However, since the joint portion joined by the adhesive deteriorates due to the intrusion of moisture, oxygen, chloride ions, etc., and the adhesive strength is lowered, sufficient adhesion durability is required. Conventionally, as a technique for improving the adhesion durability of an aluminum material, a surface treatment method for forming a film on the surface of the aluminum material with a treatment liquid containing titanium and zirconium has been proposed.

For example, Patent Document 1 proposes a pretreatment method for applying an adhesive for a metal material. And the adhesive coating pretreatment method of Patent Document 1 includes a step (I) of treating an object to be treated comprising an aluminum-based substrate with a chemical conversion treatment solution containing a zirconium fluorine complex and / or a titanium fluorine complex, and a silane cup. And a step (II) of applying a surface treatment liquid containing a hydrolyzed polycondensate of a ring agent.

Patent Document 2 proposes a method of forming a chromium-free chemical conversion coating on the surface of an aluminum alloy by a non-rinsing method. Then, the method of forming a chromium-free chemical conversion coating of Patent Document 2 is such that a solution containing a predetermined organic film-forming agent is brought into contact with the surface of the aluminum alloy without rinsing after a contact time of 1 to 40 seconds. The surface solution is dried at a temperature of 50 to 125 ° C.

Japanese Unexamined Patent Publication No. 2006-152267 Japanese National Table No. 9-511548

As a surface treatment method of an aluminum material, there is a reactive type treatment in which a treatment liquid is attached to an aluminum material and reacted, and then washed and dried to form a film. Since the reactive type treatment is mainly performed by spraying a treatment liquid on an aluminum material or immersing the aluminum material in the treatment liquid, an excess amount of the treatment liquid is generally used. Moreover, the reaction type treatment requires securing the reaction time of the treatment solution before washing with water. For this reason, the reactive type treatment is difficult in terms of productivity, environmental suitability, etc., because the amount of treatment liquid used and the amount of waste liquid tend to be bulky, take a long processing time.

Even in the case of reaction type processing, it is possible to reduce the amount of processing liquid used and the amount of waste liquid by collecting the processing liquid once used and reusing it in the next processing. However, when the treatment liquid is attached to the aluminum material, the aluminum on the surface is etched and eluted, and the aluminum concentration of the treatment liquid increases. When the aluminum concentration of the treatment liquid is increased, an increase in pH is suppressed in the vicinity of the surface of the aluminum material, so that it is difficult to form a sufficient amount of film. If the temperature of the treatment liquid is increased, the amount of the film can be improved without increasing the amount of the treatment liquid, but it takes energy cost to heat the treatment liquid.

On the other hand, as a surface treatment method for an aluminum material, there is also a coating type treatment in which a coating liquid is formed without applying water washing after applying a treatment liquid to the aluminum material. According to the coating type processing, the amount of processing liquid used and the amount of waste liquid can be reduced, and the processing time can be shortened. In addition, since the aluminum concentration of the treatment liquid is difficult to increase, energy costs and environmental loads can be reduced. However, the film formed by the coating-type process tends to have lower adhesion durability than the film formed by the reactive-type process. An aluminum material having a film formed by coating-type surface treatment is desired to improve the adhesion durability because the adhesion strength is significantly lowered when it is bonded to other materials and placed in a wet environment.

Therefore, the present invention was devised to solve the above problems, and the problem is that the surface on which the film having excellent adhesion durability can be formed on the surface of the aluminum material while reducing the energy cost and the environmental load. It is in providing a processing method and a surface treatment apparatus. Another object of the present invention is to provide a surface-treated aluminum material having excellent adhesion durability.

In order to solve the above problems, a surface treatment method for an aluminum material according to the present invention includes a step of applying a treatment liquid containing at least one of a titanium fluoride compound and a zirconium fluoride compound to the surface of the aluminum material; Forming a film by drying the treatment liquid applied to the surface of the material, and the treatment liquid applied to the surface of the aluminum material comprises the concentration of the titanium fluoride compound and the zirconium fluoride compound. The total concentration was 20 to 400 ppm in terms of titanium and zirconium, and the treatment liquid was applied to the surface of the aluminum material so that the total of titanium and zirconium was 4 to 25 mg / m ² .

According to such a surface treatment method, since the titanium concentration and the zirconium concentration of the treatment liquid are appropriate amounts, when the treatment liquid is dried, it is derived from the treatment liquid containing a titanium fluoride compound, a zirconium fluoride compound, or the like. Unreacted fluorine compound does not remain, and the amount of fluorine compound distributed on the surface of the film is reduced. And a film | membrane exhibits favorable adhesion durability by the quantity of a fluorine compound being reduced. Moreover, since it is a coating type surface treatment method, it is not necessary to wash the treatment liquid reacted on the surface of the aluminum material or the film formed on the surface. Therefore, the treatment time for the surface treatment is shortened, and the amount of waste liquid after washing is also reduced. That is, productivity and environmental compatibility are improved, and energy costs can be suppressed. In general, when the applied treatment liquid is dried, 0 to 40% of the titanium fluoride compound or the zirconium fluoride compound contained in the treatment liquid is volatilized and lost. Since the treated liquid is applied by adjusting the total coating amount of titanium and zirconium, the coating amount of the coating formed by drying is also appropriate. Therefore, the coating amount is not too small, and the corrosion resistance and adhesion to the adhesive are not impaired, and the coating amount is too weak to cause the coating to become brittle. As a result, the film exhibits excellent adhesion durability.

An aluminum material surface treatment apparatus according to the present invention is applied to a surface of an aluminum material, a coating part that applies a treatment liquid containing at least one of a titanium fluoride compound and a zirconium fluoride compound to the surface of the aluminum material. The treatment liquid applied to the surface of the aluminum material has a total concentration of the titanium fluoride compound and the zirconium fluoride compound of titanium. 20 to 400 ppm in terms of conversion and zirconium, and the application unit applied the treatment liquid to the surface of the aluminum material so that the total of titanium and zirconium was 4 to 25 mg / m ² .

According to such a surface treatment apparatus, since the application part applies a treatment liquid having appropriate titanium concentration and zirconium concentration, the unreacted fluorine compound derived from the treatment liquid does not remain in the drying part, and the surface of the film The amount of the fluorine compound distributed in is reduced. And a film | membrane exhibits favorable adhesion durability by the quantity of a fluorine compound being reduced. Moreover, since a coating part forms a film | membrane by apply | coating a process liquid, it is not necessary to wash the process liquid which reacted on the surface of the aluminum material, and the film | membrane formed on the surface with water. Therefore, the treatment time for the surface treatment is shortened, and the amount of waste liquid after washing is also reduced. That is, productivity and environmental compatibility are high, and energy costs can be suppressed. In addition, since the application part applies the treatment liquid having appropriate titanium concentration and zirconium concentration by adjusting the total application amount of titanium and zirconium, the coating amount of the formed film is also appropriate. Therefore, the coating amount is not too small, and the corrosion resistance and adhesion to the adhesive are not impaired, and the coating amount is too weak to cause the coating to become brittle. As a result, the film exhibits excellent adhesion durability. In addition, fluorine compounds that desorb in the drying section can be treated reliably if a scrubber or the like is installed in the drying section, and it is not necessary to install a washing device after the drying section. Therefore, it is possible to easily realize a highly compact and small surface treatment apparatus.

In the surface treatment apparatus for an aluminum material according to the present invention, it is preferable that the aluminum material is an aluminum plate, and includes a transport unit that passes the aluminum plate through the application unit and the drying unit.

According to such a surface treatment apparatus, the processing capability of the coating type surface treatment is improved and the productivity is further improved.

The surface-treated aluminum material according to the present invention is a coating-type surface-treated aluminum material comprising an aluminum material and a film containing at least one of titanium and zirconium formed on the surface of the aluminum material, The total amount of the titanium coating amount and the zirconium coating amount is 3 to 17 mg / m ² , and the ratio of the fluorine amount on the surface to the sum of the titanium amount and the zirconium amount (fluorine amount / titanium amount and zirconium amount) ) Was 4.0 or less.

According to such a surface-treated aluminum material, the coating formed on the surface of the aluminum material has a predetermined titanium coating amount and zirconium coating amount, so that the coating adhesion durability is excellent.

According to the surface treatment method and the surface treatment apparatus of the present invention, a film having excellent adhesion durability can be formed on the surface of an aluminum material while reducing energy cost and environmental load. Moreover, according to the surface treatment aluminum material of this invention, the adhesion durability of a film | membrane will be excellent.

It is a figure which shows typically the process of the surface treatment method which concerns on this invention. It is a figure which shows typically the surface treatment apparatus used with the surface treatment method of this invention. It is sectional drawing which shows typically the structure of the surface treatment aluminum material which concerns on this invention. It is a figure which shows typically the procedure of the adhesiveness evaluation test of a surface treatment aluminum material.

Embodiments of a surface treatment method, a surface treatment apparatus, and a surface-treated aluminum material according to the present invention will be described. First, the surface treatment apparatus used in the surface treatment method of the present invention will be described. As shown in FIG. 2, the surface treatment apparatus 21 includes a treatment liquid coating apparatus (application section) 11, a drying apparatus (drying section) 12, and a transport roll (transport section) 20. In the surface treatment apparatus 21, the treatment liquid coating apparatus 11 and the drying apparatus 12 are arranged adjacent to each other so that the treatment by the drying apparatus 12 can be performed after the treatment by the treatment liquid coating apparatus 11. Hereinafter, each structure with which the surface treatment apparatus 21 is provided is demonstrated.

(Processing liquid application equipment)
The treatment liquid coating apparatus 11 is an apparatus that applies a treatment liquid to the surface of the aluminum material 1. In the treatment liquid coating apparatus 11, a treatment liquid containing at least one of a titanium fluoride compound and a zirconium fluoride compound is applied to the surface of the aluminum material 1. The “coating” performed here is a processing operation for the coating type surface treatment, and differs from the coating for the reactive type surface treatment in accordance with the amount of the processing liquid adhered to the surface of the aluminum material 1. The coating amount means a treatment operation obtained after drying the coating. Although FIG. 2 shows a form by a coating method in which the treatment liquid is applied to the aluminum material 1, the treatment liquid is sprayed and applied to the aluminum material 1 as long as the apparatus is used for the purpose of a coating type surface treatment. The apparatus which performs a spraying method may be sufficient, and the apparatus which performs the immersion method which immerses and apply | coats the aluminum material 1 to a process liquid may be sufficient. However, it is preferable that the treatment liquid coating apparatus 11 does not include a water washing apparatus for rinsing unnecessary reaction products remaining after the reaction of the treatment liquid.

The treatment liquid coating apparatus 11 may be any apparatus that can apply the treatment liquid to the surface of the aluminum material 1. For example, a roll coater as shown in FIG. 2 or various coaters (coating machines) such as a conventionally known bar coater or die coater may be used. Moreover, when it is set as the apparatus which performs the spraying method, you may provide a spray, and when setting it as the apparatus which performs an immersion method, you may provide a processing bath.

Specifically, the treatment liquid applied by the treatment liquid coating apparatus 11 has a total concentration of the titanium fluoride compound and the zirconium fluoride compound of 20 to 400 ppm in terms of titanium and zirconium. The treatment liquid coating apparatus 11 needs to apply the treatment liquid onto the surface of the aluminum material 1 so that the total coating amount of titanium and zirconium is 4 to 25 mg / m ² . Therefore, it is preferable that the treatment liquid coating apparatus 11 is operated so as to apply the treatment liquid at a coating amount of 20 to 100 mL / m ² . The concentration of the treatment liquid, the total coating amount of titanium and zirconium, and the coating amount of the treatment liquid will be specifically described in the surface treatment method of the present invention described later.

(Drying device)
The drying device 12 is a device that dries the aluminum material 1 carried in from the treatment liquid coating device 11. In the drying device 12, the coating liquid 2 is formed by drying the processing liquid applied to the surface of the aluminum material 1 by the processing liquid coating apparatus 11. The drying device 12 may be any device that can perform a drying process on the aluminum material 1 coated with the treatment liquid. For example, it may be a device that applies heat treatment (treatment temperature: 50 to 150 ° C., treatment time: 10 to 60 seconds) to the applied treatment liquid, or a device that blows hot air or dry air onto the applied treatment liquid. It may be. In addition, a scrubber can be installed for the treatment of the desorbing fluorine compound. As will be described later, the aluminum material 1 processed in the drying device 12 has a reduced amount of fluorine on the surface of the coating 2 when the drying of the treatment liquid is completed. Therefore, a water rinsing device for rinsing the formed film 2 does not have to be provided between the drying device 12 and the winding device 13.

(Transport roll)
The transport roll 20 transports the aluminum material 1 to the treatment liquid coating device 11 and the drying device 12. In FIG. 2, the processing object in the processing liquid coating apparatus 11 and the drying apparatus 12 is a long strip-shaped aluminum plate, and the transport roll 20 performs each processing while passing (moving) the aluminum plate. (Structure which performs surface treatment) is shown. With such a configuration, the processing capability is improved, and the productivity of the aluminum material 1 (surface-treated aluminum material) having the film 2 formed on the surface can be increased.

Further, in FIG. 2, the surface treatment device 21 includes a dispensing device 10 and a winding device 13. With such a configuration, the aluminum plate dispensed from the dispensing device 10 is continuously processed in the length direction and collected by the winding device 13. Therefore, the processing performed while the sheet is passed by the transport roll 20 becomes more efficient, and the productivity is improved. However, in the case of processing the aluminum material 1 in the shape of a cast or extruded material, a conveyor or the like may be used instead of the transport roll 20, or the dispensing device 10 and the winding device 13 may not be provided. Good.

The surface treatment apparatus 21 configured as described above further includes a conventionally known alkali cleaning apparatus and pickling apparatus in the previous stage of the treatment liquid coating apparatus 11, and each of the alkali cleaning apparatus and the pickling apparatus is provided with a water washing apparatus. (Not shown). The alkali cleaning device and the pickling device are devices for removing the oil remaining on the surface of the aluminum material 1 and the aluminum oxide film and magnesium oxide film formed on the surface.

Next, the surface treatment method according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the surface treatment method of the present invention includes a treatment liquid coating step S5 and a drying step S6. The surface treatment method of the present invention may include an alkali washing step S1, a water washing step S2, an acid washing step S3, and a water washing step S4 before the treatment liquid coating step S5. Hereinafter, each step will be specifically described. In addition, about the structure of the surface treatment aluminum material obtained with the surface treatment method of this invention, FIG. 3 is referred as an example.

(Alkali cleaning process)
The alkali cleaning step S1 is a step of removing oil remaining on the surface of the aluminum material 1 by cleaning the surface of the aluminum material 1 with alkali. Here, the oil component is lubricating oil or the like attached to the surface of the aluminum material 1 when the aluminum material 1 is produced. As the alkali cleaning device and the alkali cleaning conditions, conventionally known devices and conditions provided along the carry-in route of the aluminum material 1 are used. In addition, when the adhesion amount of the oil remaining on the surface of the aluminum material 1 can be ignored, the alkali cleaning step S1 can be omitted.

(Washing process)
The water washing step S2 is a step of removing alkali remaining on the surface of the aluminum material 1 by washing the surface of the aluminum material 1 with water. Conventionally known apparatuses and conditions are used for the rinsing apparatus and rinsing conditions. In addition, when the alkali washing step S1 is omitted, the water washing step S2 may also be omitted.

(Acid cleaning process)
The acid cleaning step S3 is a step of removing the aluminum oxide film and the magnesium oxide film remaining on the surface of the aluminum material 1 by cleaning the surface of the aluminum material 1 with an acid. Here, the aluminum oxide film and the magnesium oxide film are oxide films formed on the surface of the aluminum material 1 when the aluminum material 1 is produced. As the acid cleaning apparatus and the acid cleaning conditions, conventionally known apparatuses and conditions are used. If the amount of aluminum oxide film or magnesium oxide film remaining on the surface of the aluminum material 1 can be ignored, the acid cleaning step S3 can be omitted.

(Washing process)
The water washing step S4 is a step of removing the acid remaining on the surface of the aluminum material 1 by washing the surface of the aluminum material 1 with water. Conventionally known apparatuses and conditions are used for the rinsing apparatus or rinsing conditions. When the acid washing step S3 is omitted, the water washing step S4 may be omitted.

(Processing liquid application process)
The treatment liquid application step S5 is a step of applying a treatment liquid containing at least one of a titanium fluoride compound and a zirconium fluoride compound to the surface of the aluminum material 1. In the treatment liquid coating step S <b> 5, the treatment liquid applied to the surface of the aluminum material 1 reacts with the aluminum material 1 to form a film 2 containing at least one of titanium and zirconium on the surface of the aluminum material 1. The application in the treatment liquid application step S5 is a treatment operation for the application type surface treatment, and differs from the application for the reaction type surface treatment according to the amount of the treatment liquid adhered to the surface of the aluminum material 1. The coating amount means a treatment operation obtained after drying the coating. The coating in the treatment liquid coating step S5 may be in any form of a coating method, a spray method, and a dipping method as long as it is a processing operation for a coating type surface treatment. However, the application in the treatment liquid application step S5 preferably does not include a water washing step for rinsing unnecessary reaction products remaining after the reaction of the treatment liquid.

Here, the titanium fluoride compound is, for example, fluorotitanate such as K ₂ TiF ₆ , (NH ₄ ) ₂ TiF _6, or fluorotitanate such as H ₂ TiF ₆ . Examples of the zirconium fluoride compound include fluorozirconates such as K ₂ ZrF ₆ and (NH ₄ ) ₂ ZrF ₆ and fluorozirconate acids such as H ₂ ZrF ₆ .

The film 2 containing at least one of titanium and zirconium is formed, for example, by the following series of reactions.
Al ⇔ Al ³⁺ + 3e ^- ··· reaction formula (I)
_{_{O 2 + 2H 2 O + 4e}} - ⇔ 4OH - ··· reaction formula (II)
2H ⁺ + 2e ⁻ ⇔ H _2. Reaction formula (III)
Al ³⁺ + TiF ₆ ²⁻ ⇔ AlF ₆ ³⁻ + Ti ⁴⁺・・・ Reaction formula (IV)
Al ³⁺ + ZrF ₆ ²⁻ ⇔ AlF ₆ ³⁻ + Zr ⁴⁺ ... Reaction formula (V)
Ti ⁴⁺ + 3H ₂ O⇔TiO ₂ · H ₂ O + 4H ⁺ ... Reaction formula (VI)
Zr ⁴⁺ + 3H ₂ O⇔ZrO ₂ .H ₂ O + 4H ⁺ ... Reaction formula (VII)

In the treatment liquid applied to the surface of the aluminum material 1, the total concentration of the titanium fluoride compound and the zirconium fluoride compound is 20 to 400 ppm in terms of titanium and zirconium. In addition, titanium conversion and zirconium conversion mean converting the concentration (mass / volume) of each compound into the concentration of titanium atom or zirconium atom contained in each compound. By using the treatment liquid having such a concentration, titanium applied to the aluminum material 1 when the treatment liquid is applied at a coating amount (20 to 100 mL / m ² ) in a range as described later (amount equivalent to titanium metal). And the total amount (g / m ² ) of zirconium (in terms of metal zirconium), that is, the coating amount in terms of the mass of metal atoms, can be within an appropriate range for the formation of the film 2. On the other hand, when the converted value of the total concentration is less than 20 ppm, the film 2 having a sufficient film amount cannot be formed. When the total converted value exceeds 400 ppm, it becomes difficult for fluorine compounds such as hydrogen fluoride derived from the treatment liquid to be detached, and the amount of fluorine compounds on the surface of the film 2 increases, and the adhesion durability of the film 2 increases. Sex is reduced.

The converted value of the total concentration of the titanium fluoride compound and the concentration of the zirconium fluoride compound may be 40 ppm or more, 80 ppm or more, or 120 ppm or more from the viewpoint of increasing the coating amount of the coating 2. Also good. Further, from the viewpoint of improving the adhesion durability, it may be 360 ppm or less, 320 ppm or less, or 280 ppm or more.

The coating amount of the treatment liquid on the surface to be coated of the aluminum material 1 is preferably 20 to 100 mL / m ² . When the coating amount of the treatment liquid is less than 20 mL / m ² , it is necessary to set the concentration of the treatment liquid high when forming the coating film 2 having an appropriate coating amount. However, if the concentration of the treatment liquid is too high, the amount of the fluorine compound generated on the surface of the film 2 increases, and the adhesion durability of the film 2 decreases. On the other hand, when the coating amount of the treatment liquid exceeds 100 mL / m ² , the reaction efficiency and the uniformity of the film 2 are deteriorated, and it is difficult to form an appropriate film 2. The amount of application of the aluminum material 1 to the surface to be applied can be adjusted by adjusting the amount of treatment liquid to be applied, the conveyance speed of the aluminum material 1, and the like.

In the treatment liquid application step S5, specifically, the treatment liquid is applied to the surface of the aluminum material 1 so that the total of titanium and zirconium is 4 to 25 mg / m ² . In addition, this total amount is the sum of the metal titanium conversion amount converted into the mass of the titanium atom, and the metal zirconium conversion amount converted into the mass of the zirconium atom. When the treatment liquid is applied in such a total amount, when a part of titanium atoms and zirconium atoms contained in the treatment liquid is volatilized and lost by drying, the film amount of the film 2 is also in an appropriate range. . On the other hand, when the total of titanium and zirconium is less than 4 mg / m ² , the coating 2 having a sufficient coating amount cannot be formed. On the other hand, if the total of titanium and zirconium exceeds 25 mg / m ² , the coating amount of the coating 2 becomes too thick, and the fluorine compound increases accordingly, so that the adhesion durability of the coating 2 is lowered.

The total of titanium and zirconium is more preferably 5 mg / m ² or more from the viewpoint of increasing the coating amount of the coating 2. When the total amount is increased in this way, corrosion resistance and adhesion durability are improved. Further, the total of titanium and zirconium is more preferably 20 mg / m ² or less from the viewpoint of improving adhesion durability. With such a total amount, the coating amount of the coating 2 does not become excessive, and the coating 2 is difficult to become brittle, so that peeling and the like are also prevented. In order to apply the treatment liquid by adjusting the total of titanium and zirconium, the concentration of the treatment liquid and the application amount of the treatment liquid to the coated surface of the aluminum material 1 may be adjusted.

(Drying process)
The drying step S6 is a step of forming the film 2 by drying the treatment liquid applied to the surface of the aluminum material 1 in the treatment liquid application step S5. The drying process in the drying step S6 may be, for example, a process of heating the applied processing solution (processing temperature: 50 to 150 ° C., processing time: 10 to 60 seconds), or hot air is applied to the applied processing solution. Or a process of blowing dry air. As will be described later, the aluminum material 1 treated in the drying step S6 has a reduced amount of fluorine on the surface of the coating 2 when the drying of the treatment liquid is completed. Therefore, after the drying step S6, a surface-treated aluminum material having excellent adhesion durability can be produced without performing a water washing step of washing the film 2 with water.

Next, the surface-treated aluminum material obtained by the surface treatment method of the present invention will be described. As shown in FIG. 3, the surface-treated aluminum material includes an aluminum material 1 and a film 2 formed on the surface of the aluminum material 1. Here, the surface of the aluminum material 1 means at least one surface of the aluminum material 1, and includes a so-called single side, double side, or a plurality of sides.
Each configuration will be described below.

(Aluminum material)
The aluminum material 1 is provided in the form of a coiled or sheet-like plate material, or a cast or extruded material, and is preferably provided as a plate material. The aluminum alloy constituting the aluminum material 1 is preferably an Al—Mg alloy or an Al—Mg—Si alloy. The Al—Mg based alloy is a 5000 series alloy specified by JIS, and the Al—Mg—Si based alloy is a 6000 series alloy specified by JIS.

The thickness of the aluminum material 1 is 0.7 to 3.0 mm. When the thickness is less than 0.7 mm, the strength is insufficient, and when the thickness exceeds 3.0 mm, the manufacturing cost is increased. The thickness of the aluminum material 1 is preferably 0.8 mm or more from the viewpoint of strength, and preferably 2.3 mm or less from the viewpoint of manufacturing cost.

(Film)
The film 2 is a film containing a predetermined amount of titanium and zirconium. The titanium in the film 2 is preferably at least one of titanium oxide and titanium fluoride, and the zirconium in the film 2 is preferably at least one of zirconium oxide and zirconium fluoride. The coating 2 is made of aluminum and impurities in addition to titanium and zirconium. Here, the remaining aluminum includes aluminum oxide, aluminum fluoride, and the like.

In the coating 2, the total amount of the titanium coating amount in terms of metal titanium and the zirconium coating amount in terms of metal zirconium is 3 to 17 mg / m ² . The coating 2 preferably satisfies at least one of a titanium coating amount of 1 to 10 mg / m ² in terms of metallic titanium and a zirconium coating amount of 1 to 10 mg / m ^{2 in} terms of metallic zirconium. . Thereby, the stability with respect to deterioration factors, such as water, oxygen, and a chloride ion, increases, and the hydration in the surface of the aluminum material 1 in a humid environment is suppressed. Moreover, the adhesion durability of the film 2 is improved.

The total amount of titanium layer weight and zirconium coating amount of the coating 2 is less than 3 mg / m ^2, the effect of suppressing hydration at the surface of the aluminum material 1 is not sufficient, the film interior at the time of bonding exceeds 17 mg / m ² It becomes easy to cause destruction. Further, from the viewpoint of suppressing hydration on the surface of the aluminum material 1, the lower limit of the total amount of the titanium film and the zirconium film of the film ² is preferably 5 mg / m ² , and the destruction of the inside of the film during bonding is suppressed. Therefore, the upper limit of the total amount of the titanium film amount and the zirconium film amount of the film ² is preferably 15 mg / m ² .

When the amount of the titanium film of the film 2 is less than 1 mg / m ² , the above effect is not obtained. When the amount of the titanium film exceeds 10 mg / m ² , the above effect is saturated and the manufacturing cost is increased. In addition, the inside of the film is easily broken during bonding. From the viewpoint of suppressing hydration on the surface of the aluminum material 1, the amount of the titanium film is preferably ² mg / m ² or more. On the other hand, 8 mg / m ² or less is preferable from the viewpoint of suppressing an increase in the manufacturing cost of the film 2 and the destruction of the inside of the film.

Further, if the amount of the zirconium film of the film 2 is less than 1 mg / m ² , the above effect is not obtained, and if the amount of the zirconium film exceeds 10 mg / m ² , the above effect is saturated and the manufacturing cost is increased. It becomes easy to cause destruction. The amount of the zirconium film is preferably ² mg / m ² or more from the viewpoint of suppressing hydration on the surface of the aluminum material 1. On the other hand, 8 mg / m ² or less is preferable from the viewpoint of suppressing an increase in the manufacturing cost of the film 2 and the destruction of the inside of the film.

The thickness of the coating 2 is not particularly limited as long as the titanium coating amount and the zirconium coating amount are predetermined amounts, but it is preferably 10 to 150 nm. When the thickness of the film 2 is less than 10 nm, it is difficult to maintain the adhesion durability. On the other hand, if the thickness of the film 2 exceeds 150 nm, the durability of the adhesion is saturated and the manufacturing cost is likely to increase.

The coating 2 has a ratio of “fluorine conversion amount (fluorine amount)” and “sum of metal titanium conversion amount (titanium amount) and metal zirconium conversion amount (zirconium amount)” on the surface (fluorine amount / titanium amount and zirconium amount). Is less than or equal to 4.0. Hereinafter, the value of this ratio is expressed as “surface F / (Ti + Zr)”. The film 2 is formed by a drying process and takes such a value of the surface F / (Ti + Zr) when not yet washed with water. This is because the amount of the fluorine compound on the surface of the film 2 is reduced by setting the concentration of the treatment liquid low and adjusting the coating amount of the treatment liquid. The film 2 has excellent adhesion durability because the amount of the fluorine compound is thus reduced.

If the surface F / (Ti + Zr) of the film 2 exceeds 4.0, the amount of fluorine compound on the surface of the film 2 is too large, so that the adhesive strength between the aluminum material 1 and other materials such as iron material becomes low. Also, the adhesion durability is lowered. Further, the adhesive that bonds the aluminum material 1 and the other material easily peels off, and it is difficult to maintain the adhesive state particularly in a wet environment. The surface F / (Ti + Zr) of the film 2 is preferably 3.0 or less, more preferably 2.5 or less, and even more preferably 2.0 or less, from the viewpoint of improving adhesion durability and the like.

The surface F / (Ti + Zr) of the coating 2 can be adjusted by adjusting the concentration of the titanium fluoride compound or the zirconium fluoride compound in the treatment liquid. Further, the surface F / (Ti + Zr) can be obtained by measuring the atomic concentration distribution of fluorine equivalent, metal titanium equivalent, and metal zirconium equivalent by X-ray photoelectron spectroscopy (XPS: X-ray Photoelectron Spectroscopy). it can. The measurement conditions of X-ray photoelectron spectroscopy can be measured using, for example, aluminum Kα as a radiation source, data collection time (Dwell): 100 ms, pass energy (pass): 30 eV, and no etching. The converted amount of each element can be quantified based on the peak intensity.

The titanium coating amount and the zirconium coating amount of the coating 2 can be measured by fluorescent X-ray (XRF: X-ray Fluorescence Analysis). Further, the thickness of the coating 2 can be measured by a glow discharge optical emission spectrometer (GD-OES: Glow Discharge Optical Emission Spectroscopy). Further, the method for measuring the coating amount and thickness is not limited to XRF and GD-OES, and any measuring method having the same accuracy as the measuring method may be used.

Next, the surface treatment method and the surface-treated aluminum material of the present invention will be specifically described by comparing an example that satisfies the requirements of the present invention with a comparative example that does not satisfy the requirements of the present invention.

First, an aluminum plate having a width of 150 mm, a length of 200 mm, and a thickness of 1.0 mm was produced using a JIS-defined 6016 series alloy. The aluminum plate was alkali degreased and washed with water, then acid washed and washed with water.

The treatment liquid (25 ° C.) having the concentrations shown in Table 1 was applied in various coating amounts to the surface of the aluminum plate washed with water after acid cleaning. Thereafter, a coating type surface-treated aluminum material (No. 1 to 11) was produced by performing a drying treatment at 110 ° C. for 30 seconds.

On the other hand, a treatment liquid (50 ° C.) containing 150 ppm of fluorotitanate acid as a titanium fluoride compound and 250 ppm of fluorozirconate acid as a zirconium fluoride compound was sprayed on the surface of the aluminum plate washed with water after acid cleaning for 3 seconds. . Then, after performing the water washing process for 25 second with 25 degreeC water, the reactive type surface treatment aluminum material (No. 12) was produced by performing room temperature drying.

For the coating formed on the surface of the produced surface-treated aluminum material (No. 1 to 12), the titanium coating amount and the zirconium coating amount were measured by fluorescent X-rays (XRF). The coating amount of the surface-treated aluminum material was measured on one plate randomly taken out from a plurality of surface-treated aluminum materials treated under the same conditions. The measurement position per plate is a surface having a width of 150 mm and a length of 200 mm, and is a circular region with a diameter of 30 mm centered on four points 50 mm inside and one point at the center of the plate diagonally from the four corners. , A total of 5 locations. The coating amount of the surface-treated aluminum material was determined as an average value of the measured values at a total of five locations. Further, the atomic concentration of fluorine equivalent amount, metal titanium equivalent amount, and metal zirconium equivalent amount on the surface of the coating formed on the surface of the surface-treated aluminum material (No. 1 to 12) was measured by X-ray photoelectron spectroscopy (XPS). The surface F / (Ti + Zr) was calculated. Similarly, the surface F / (Ti + Zr) of the surface-treated aluminum material was measured for one plate randomly taken out from a plurality of surface-treated aluminum materials treated under the same conditions. The measurement position per one plate was a surface of 150 mm width × 200 mm length, and a total of 5 square areas of 1 mm square located at each of the four corners and the center of the plate. The surface F / (Ti + Zr) of the surface-treated aluminum material was determined as an average value of the measured values at a total of five locations.

Next, using a surface-treated aluminum material (No. 1 to 12), an adhesion test body 34 in which a lower test piece 31 and an upper test piece 33 as shown in FIG. Were prepared. And the following adhesion durability tests were done using these adhesion test bodies 34. A specific method for producing the adhesion test body 34 is as follows.

As shown in FIG. 4, the lower test piece 31 and the upper test piece 33 were laminated and pasted with a thermosetting epoxy resin adhesive 32 so as to have a wrap length of 10 mm (adhesion area: 25 mm × 10 mm). . At this time, glass beads (particle size 250 μm) were added to the adhesive 32 and adjusted so that the thickness of the adhesive 32 was 250 μm. Thereafter, it was baked and cured at 170 ° C. for 20 minutes. Then, it left still at room temperature for 24 hours, and was set as the adhesion test body 34.

(Adhesion durability test)
After the produced adhesion test body 34 was held in neutral salt spray for 14 days, unbonded portions of the lower and

upper test pieces

31 and 33 were grasped, and a shear tensile test was performed at a speed of 10 mm / min. For the tensile test, an AG-50kNI autograph manufactured by Shimadzu Corporation was used. And the observation of the fracture | rupture form of the adhesion test body 34 and calculation of adhesion strength were performed in the following procedures, and adhesion durability was evaluated. Three adhesion test specimens 34 were prepared, and the following cohesive failure rate and adhesive strength were average values of the three.

(Adhesion durability test: failure mode)
The peeled state of the adhesion test body 34 after the tensile test is observed, the fracture inside the adhesive 32 is agglomerated, the interface between the lower test piece 31 and the adhesive 32, and the upper test piece 33 and the adhesive 32. Peeling at the interface was defined as interfacial fracture, and the cohesive failure rate as an index of fracture mode was calculated by the following equation (1).
Cohesive failure rate (%) = 100 − {(interface peeling area of lower test piece 31 / bonding area of lower test piece 31) × 100 + (interface peeling area of upper test piece 33 / bonding area of upper test piece 33) × 100)} (1)
Further, the evaluation criteria for the fracture mode were a failure “x” when the cohesive fracture rate was less than 90% and a good “◯” when 90% or more.

(Adhesion durability test: Adhesive strength)
The maximum stress at break was determined from the stress-strain diagram obtained during the tensile test, and was used as the adhesive strength.

The following Table 1 shows the method used for the surface treatment, the titanium equivalent and zirconium equivalent concentrations of the treatment liquid applied to the surface of the aluminum plate, the application amount of the treatment liquid, the coating amount, and the results of the surface F / (Ti + Zr). The evaluation results of the form and the results of the adhesive strength are shown respectively.

As shown in Table 1, No. Since the surface-treated aluminum material according to No. 12 has a film formed by a reactive surface treatment and is washed with water, the value of “surface F / (Ti + Zr)” is low. For this reason, the adhesive strength is high, the form of fracture due to peeling hardly occurs, and the adhesion durability of the film is excellent.

On the other hand, No. in which a film was formed by coating type surface treatment. Since the coating-type surface-treated aluminum materials according to 1 to 7 have a concentration and a coating amount of the coated treatment liquid in an appropriate range, the value of “surface F / (Ti + Zr)” is kept small. The film was formed by the surface treatment of the coating type, and although it was not washed with water, it was washed with water. As in the case of the reactive surface-treated aluminum material according to No. 12, the adhesive strength is high, the form of fracture due to peeling is less likely to occur, and the adhesion durability of the film is excellent.

On the other hand, No. The coating-type surface-treated aluminum materials according to 8 to 9 have a high value of “Surface F / (Ti + Zr)” because the concentration of the applied treatment liquid is not in an appropriate range and the concentration is too high. For this reason, the adhesive strength is low, and a destructive form due to peeling is likely to occur, and the adhesion durability of the film is not improved.

No. The coating type surface-treated aluminum materials according to Nos. 10 to 11 have a low value of “Surface F / (Ti + Zr)” because the coating amount of the treatment liquid is not in an appropriate range and a film having an appropriate film amount is not formed. However, the film is fragile. For this reason, the adhesive strength is low, and a destructive form due to peeling is likely to occur, and the adhesion durability of the film is not improved.

As described above, the surface treatment method, the surface treatment apparatus, and the aluminum surface treatment material according to the present invention have been described in detail with reference to the embodiments and examples. However, the gist of the present invention is not limited to the above-described contents. The scope of rights should be construed based on the claims. Needless to say, the contents of the present invention can be modified and changed based on the above description.

This application is based on a Japanese patent application filed on March 29, 2016 (Japanese Patent Application No. 2016-066564) and a Japanese patent application filed on November 29, 2016 (Japanese Patent Application No. 2016-231695). Incorporated herein by reference.

The aluminum agent of the present invention has a film having excellent adhesion durability while reducing energy cost and environmental load, and is useful for transportation equipment such as automobiles, ships, and aircraft, particularly automobile panels.

S1 Alkali washing step S2 Water washing step S3 Acid washing step S4 Water washing step S5 Treatment liquid application step S6 Drying step 1 Aluminum material 2 Film 3 Surface treatment aluminum material 11 Treatment liquid application device 12 Drying device 21 Surface treatment device 31 Lower test piece 32 Adhesive 33 Upper test piece 34 Adhesive specimen

Claims

Applying a treatment liquid containing at least one of a titanium fluoride compound and a zirconium fluoride compound to the surface of the aluminum material;
Drying the treatment liquid applied to the surface of the aluminum material to form a film,
The treatment liquid applied to the surface of the aluminum material has a total concentration of the titanium fluoride compound and the zirconium fluoride compound of 20 to 400 ppm in terms of titanium and zirconium,
A surface treatment method for an aluminum material, wherein the treatment liquid is applied to the surface of the aluminum material so that the total of titanium and zirconium is 4 to 25 mg / m 2 .
An application part for applying a treatment liquid containing at least one of a titanium fluoride compound and a zirconium fluoride compound to the surface of the aluminum material;
A drying unit that forms a film by drying the treatment liquid applied to the surface of the aluminum material,
The treatment liquid applied to the surface of the aluminum material has a total concentration of the titanium fluoride compound and the zirconium fluoride compound of 20 to 400 ppm in terms of titanium and zirconium,
The application unit is a surface treatment apparatus for an aluminum material that applies the treatment liquid to the surface of the aluminum material so that the total of titanium and zirconium is 4 to 25 mg / m 2 .
The aluminum material is an aluminum plate;
The surface treatment apparatus for an aluminum material according to claim 2, further comprising a transport unit that passes the aluminum plate through the coating unit and the drying unit.
A coating-type surface-treated aluminum material comprising: an aluminum material; and a film containing at least one of titanium and zirconium formed on the surface of the aluminum material,
The film has a total amount of titanium film amount and zirconium film amount of 3 to 17 mg / m 2 , and the ratio of the fluorine amount on the surface and the sum of the titanium amount and the zirconium amount (fluorine amount / titanium amount and A coating type surface-treated aluminum material having a sum of zirconium amounts of 4.0 or less.