JP7074382B1 - Aluminum satin treatment liquid and aluminum satin treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a satin finish treatment liquid and a satin finish treatment method capable of imparting a satin finish to the surface of aluminum. An aluminum satin-finished liquid comprising (A) an aluminum salt, (B) an alkali metal salt, and (C) a sugar alcohol having 4 to 9 hydroxyl groups. [Selection diagram] None

Description

The present invention relates to a satin finish treatment liquid for aluminum and a satin finish treatment method for aluminum.

Various articles are manufactured by processing aluminum (including aluminum alloys; hereinafter also referred to as "aluminum and the like"). Aluminum and the like are subjected to various surface treatments depending on the purpose during processing.

As a surface treatment liquid for surface treatment of aluminum, a surface treatment liquid containing an alkali, a zinc ion source, a chelating agent and a metal salt has been proposed (see Patent Document 1).

However, since the surface treatment liquid described in Patent Document 1 is a surface treatment liquid for improving the bondability of the aluminum material to the resin, the appearance of the treated aluminum material has not been studied.

The surface of aluminum and the like is required to have various appearances depending on the article to be manufactured. Examples of such an appearance include a satin-finished appearance. The surface treatment agent described in Patent Document 1 has a problem that a satin finish cannot be formed on the surface of aluminum or the like.

Further, a surface treatment is performed in which a surface treatment liquid containing a halogen-containing compound such as hydrofluoric acid is immersed and aluminum or the like is subjected to a satin finish treatment. However, since the method uses a surface treatment liquid containing a halogen-containing compound, there is a problem that the human body is adversely affected and the environment is also burdened.

Therefore, it is desired to develop a satin finish treatment liquid and a satin finish treatment method capable of forming a satin finish on the surface of aluminum.

Japanese Unexamined Patent Publication No. 2019-70185

An object of the present invention is to provide a satin finish treatment liquid and a satin finish treatment method capable of imparting a satin finish to the surface of aluminum.

As a result of diligent research, the present inventors have made an aluminum satin-finished liquid containing (A) an aluminum salt, (B) an alkali metal salt, and (C) a sugar alcohol having 4 to 9 hydroxyl groups. According to this, it was found that the above object could be achieved, and the present invention was completed.

That is, the present invention relates to the following aluminum satin treatment liquid and aluminum satin treatment method.
1. 1. (A) Aluminum salt,
(B) Alkali metal salt and
(C) A satin-finished liquid for aluminum, which contains a sugar alcohol having 4 to 9 hydroxyl groups.
2. 2. The aluminum salt is a group consisting of sodium aluminate, aluminum silicate, aluminum formate, aluminum acetate, aluminum sulfate, aluminum nitrate, aluminum phosphate, aluminum hydroxide, aluminum carbonate, aluminum chloride, aluminum bromide, and aluminum myoban. Item 2. The satin-finished treatment liquid according to Item 1, which is at least one selected from the above.
3. 3. Item 2. The satin-finished liquid according to Item 1 or 2, wherein the content of the aluminum salt is 10 g / L or more.
4. Item 6. The item according to any one of Items 1 to 3, wherein the alkali metal salt is at least one selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, alkali metal hydrogen carbonates, and salts thereof. Pear-skin treatment liquid.
5. Item 2. The satin-finished liquid according to any one of Items 1 to 4, wherein the content of the alkali metal salt is 60 to 600 g / L.
6. Item 2. The satin-finished liquid according to any one of Items 1 to 5, wherein the sugar alcohol content is 100 g / L or more.
7. It is a satin finish method for aluminum.
Step 1 to prepare a satin finish by mixing (1) (A) aluminum salt, (B) alkali metal salt, and (C) sugar alcohol having 4 to 9 hydroxyl groups.
(2) Step 2 of immersing aluminum in the satin finish.
A satin finish method, characterized in that it has.
8. A satin-finished aluminum material produced by using the satin-finished treatment liquid according to any one of Items 1 to 6.

By treating aluminum with the satin finish treatment liquid of the present invention, a satin finish can be formed on the surface of the aluminum. Further, by treating the aluminum by the satin finish treatment method of the present invention, the satin finish can be formed on the surface of the aluminum.

It is an SEM image of the surface of the test piece in the state of pear-skin degree 0. It is an SEM image of the surface of the test piece in the state of satin degree 1. It is an SEM image of the surface of the test piece in the state of pear-skin degree 2. It is an SEM image of the surface of the test piece in the state of pear-skin degree 3.

1. 1. Pear-skin treatment liquid The pear-skin treatment liquid of the present invention is an aluminum pear-skin treatment liquid containing (A) an aluminum salt, (B) an alkali metal salt, and (C) a sugar alcohol having 4 to 9 hydroxyl groups. The satin finish treatment liquid of the present invention having the above-mentioned characteristics can form a satin finish on the surface of aluminum by treating aluminum by containing the above (A), (B) and (C). According to the satin finish treatment liquid of the present invention, the satin finish can be applied to the surface of aluminum without using a halogen-containing compound such as hydrofluoric acid, so that adverse effects on the human body and burden on the environment are suppressed. ..

((A) Aluminum salt)
The (A) aluminum salt (hereinafter, also referred to as “component (A)”) is not particularly limited, and a known aluminum salt can be used. Examples of such aluminum salts include sodium aluminate, aluminum sulfate (III), aluminum nitrate (III), aluminum silicate (III), aluminum formate (III), aluminum acetate (III), and primary aluminum phosphate. (III), secondary aluminum phosphate (III), tertiary aluminum phosphate (III), aluminum hydroxide (III), aluminum carbonate (III), aluminum chloride (III), aluminum bromide (III), aluminum myoban And so on. Among these, sodium aluminate, aluminum sulfate (III), and aluminum nitrate (III) are preferable, and sodium aluminate is more preferable, because it is easier to form a satin finish on the surface of aluminum.

The above component (A) can be used alone or in combination of two or more.

The content of the component (A) in the satin-finished liquid is preferably 10 g / L or more, preferably 10 to 300 g / L, more preferably 25 to 250 g / L, and even more preferably 50 to 200 g / L. When the lower limit of the content of the component (A) is within the above range, it becomes easier to form a satin finish on the surface of aluminum. Further, when the upper limit of the component (A) is within the above range, the uniformity of the satin finish appearance is further improved.

((B) Alkali metal salt)
Examples of the (B) alkali metal salt (hereinafter, also referred to as “component (B)”) include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; sodium carbonate, potassium carbonate, and carbonic acid. Alkali metal carbonates such as lithium; examples thereof include alkali metal hydrogen carbonates such as sodium hydrogencarbonate, potassium hydrogencarbonate, and lithium hydrogencarbonate. Further, these hydrates may be used. Among these, sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferable, and sodium hydroxide is more preferable, because it is easier to form a satin finish on the surface of aluminum.

The above component (B) can be used alone or in combination of two or more.

The content of the component (B) in the satin-finished liquid is preferably 60 to 600 g / L, more preferably 75 to 450 g / L, and even more preferably 90 to 300 g / L. When the lower limit of the content of the component (B) is within the above range, it becomes easier to form a satin finish on the surface of aluminum. Further, when the upper limit of the component (B) is within the above range, the uniformity of the satin finish appearance is further improved.

((C) Sugar alcohol having 4 to 9 hydroxyl groups)
The sugar alcohol used in the satin-finished liquid of the present invention is a sugar alcohol having 4 to 9 hydroxyl groups (hereinafter, also referred to as “component (C)”).

The sugar alcohol as the component (C) is not particularly limited as long as the number of hydroxyl groups is 4 to 9, and known sugar alcohols can be used. Such sugar alcohols are not particularly limited as long as the number of hydroxyl groups is 4 to 9, and examples thereof include sorbitol, mannitol, lactitol, xylitol, erythritol, and maltitol. Among these, sorbitol, mannitol and lactitol are preferable, and sorbitol and lactitol are more preferable.

Specific examples of the sugar alcohol having 4 to 9 hydroxyl groups include sorbitol having 6 hydroxyl groups, xylitol having 5 hydroxyl groups, and lactitol having 9 hydroxyl groups.

From the viewpoint of the properties of the satin-finished liquid (for example, the presence or absence of separation, stability, etc.), the sugar alcohol preferably has, for example, 4 to 12 carbon atoms, and more preferably 4 to 6 carbon atoms.

The above component (C) can be used alone or in combination of two or more.

The content of the component (C) in the satin-finished liquid is preferably 100 g / L or more, more preferably 100 to 1000 g / L, further preferably 200 to 850 g / L, and particularly preferably 300 to 750 g / L. When the lower limit of the content of the component (C) is within the above range, it becomes easier to form a satin finish on the surface of aluminum. Further, when the upper limit of the component (C) is within the above range, the uniformity of the satin finish appearance is further improved.

It is preferable that the satin-finished liquid of the present invention contains the above-mentioned component (A), component (B) and component (C), and the balance is water. That is, the satin-finished liquid of the present invention is preferably an aqueous solution containing the above-mentioned component (A), component (B) and component (C).

When the satin-finished liquid of the present invention is an aqueous solution, the mass ratio (alkali metal salt / water) of the alkali metal salt to water is preferably 0.075 or more, more preferably 0.1 or more, and further more preferably 0.125 or more. preferable. When the lower limit of the mass ratio is in the above range, it becomes easier to form a satin finish on the surface of aluminum. The upper limit of the mass ratio is preferably 0.5 or less.

(Other ingredients)
The satin-finished liquid of the present invention may contain other components in addition to the above-mentioned (A) component, (B) component and (C) component. Examples of other components include surfactants, mist inhibitors, defoamers and the like.

2. 2. Pear -skin treatment method The pear-skin treatment method of the present invention is a satin treatment method for aluminum, which comprises (1) (A) an aluminum salt, (B) an alkali metal salt, and (C) a sugar having 4 to 9 hydroxyl groups. It is a satin finish method having a step 1 of mixing alcohol to prepare a satin finish and (2) a step 2 of immersing aluminum in the satin treatment solution.

Pure aluminum or an aluminum alloy can be used as the aluminum to be treated in the satin finish method of the present invention. The aluminum alloy is not particularly limited, and various aluminum-based alloys are exemplified. Specific examples of aluminum alloys include, for example, wrought alloys specified in JIS-A 1,000 to 7,000 series, casting materials shown in each of AC and ADC, and die casting materials. Examples thereof include various alloy groups mainly composed of aluminum.

(Step 1)
Step 1 is a step of mixing (A) an aluminum salt, (B) an alkali metal salt, and (C) a sugar alcohol having 4 to 9 hydroxyl groups to prepare a satin-finished liquid.

As the satin finish treatment liquid used in step 1, a satin finish treatment liquid containing the above-mentioned components (A), (B) and (C) may be used.

In step 1, the component (A), the component (B), and the component (C) may be sequentially mixed to prepare a satin finish. The order in which the component (A), the component (B) and the component (C) are mixed is not particularly limited.

In step 1, for example, the component (A), the component (B) and the component (C) may be sequentially added to water and mixed, or the component (A), the component (B) and the component (C) may be added to water. May be sequentially added and mixed, and further water may be added and diluted to prepare a satin finish. The satin-finished liquid prepared in the above step 1 is a satin-finished liquid containing the component (A) from the beginning. By containing the component (A) at the time of preparation, the satin finish treatment liquid of the present invention can stably perform the satin finish from the start of the satin finish. In the satin-finished treatment liquid of the present invention, as a result of treating aluminum as a object to be treated with a treatment liquid containing the component (B) and the component (C), the aluminum to be treated is dissolved and aluminum ions are eluted. However, it is different from the treatment liquid containing aluminum ions, the component (B) and the component (C).

In step 1, in addition to the above-mentioned (A) component, (B) component and (C) component, the above-mentioned other components may be added as needed.

(Step 2)
Step 2 is a step of immersing the aluminum in the satin finishing liquid.

The method of immersing the aluminum in the satin-finished liquid is not particularly limited, and a conventionally known method such as a method of fixing the aluminum to be treated to a jig and immersing it in the satin-treated liquid can be used.

The liquid temperature (treatment temperature) of the satin-finished liquid in step 2 may be appropriately adjusted, for example, 40 ° C. or higher is preferable, 50 to 90 ° C. is more preferable, and 60 to 80 ° C. is further preferable.

The processing time in step 2 may be appropriately set according to the desired degree of satin finish appearance, and is, for example, about 1 to 45 minutes.

The film thickness (dissolved film thickness) of aluminum melted in step 2 can be appropriately adjusted according to the material, purpose of use, and the like. For example, if the aluminum is an A6063 material, the melt film thickness is about 10 to 30 μm.

In step 2, the satin-finished treatment liquid may be agitated or the aluminum to be treated may be shaken, if necessary. The stirring method and the shaking method are not particularly limited, and conventionally known stirring methods and shaking methods may be used.

(Other processes)

The satin finish treatment method of the present invention may include a degreasing treatment step before the step 2. The purpose of the degreasing treatment is, for example, to remove dirt and oil adhering to the aluminum surface. The degreasing treatment method is not particularly limited, and a conventionally known degreasing treatment method can be carried out.

The satin finish method of the present invention may include an etching treatment step before the step 2. The purpose of the etching treatment is, for example, to remove a natural oxide film formed on the aluminum surface. The etching treatment method is not particularly limited, and a conventionally known etching treatment method can be carried out.

The satin finish method of the present invention may include a desmat treatment after the etching treatment step and / or the step 2. The purpose of the desmat treatment is, for example, an etching treatment step, removal of the smut generated by the step 2, and the like. The desmat treatment method is not particularly limited, and conventionally known desmat treatment methods can be implemented.

The satin finish method of the present invention may include an anodizing treatment step after the step 2. The purpose of the anodizing treatment is, for example, to improve the corrosion resistance of the surface of aluminum. The anodizing treatment method is not particularly limited, and conventionally known anodizing treatment methods can be carried out.

The satin finish method of the present invention may include a dyeing treatment step after the step 2. The purpose of the dyeing process is, for example, to dye aluminum and impart designability. The dyeing treatment method is not particularly limited, and a conventionally known dyeing treatment method can be carried out.

The satin finish method of the present invention may include a sealing treatment step after the step 2 and / or the dyeing treatment. The purpose of the sealing treatment is, for example, to improve the corrosion resistance of aluminum, to suppress the color loss of aluminum dyed by the dyeing step, and the like. The sealing treatment method is not particularly limited, and conventionally known sealing treatment methods can be implemented.

3. 3. Pear-skin aluminum material The pear-skin aluminum material of the present invention is a pear-skin aluminum material produced by using the pear-skin treatment liquid. Since the satin-finished aluminum material of the present invention is produced by using the satin-finished treatment liquid of the present invention described above, the satin-finished appearance is sufficiently formed on the surface.

As the aluminum for producing the satin-finished aluminum material, aluminum which is the above-mentioned object to be treated may be used. Further, as a method for producing a satin-finished aluminum material using the satin-finished aluminum material of the present invention, the method described in the above-mentioned satin-finished treatment method of the present invention can be mentioned.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

Aluminum metal pieces (A6063S material, A1050 material, A5052 material, A7075 material) were prepared as objects to be treated in Examples and Comparative Examples. The aluminum metal piece was treated with Top ADD-100 (manufactured by Okuno Pharmaceutical Industry Co., Ltd.) at 55 ° C. for 2 minutes to perform degreasing treatment. Next, an etching treatment was performed at 55 ° C. for 30 seconds using an etching treatment liquid containing 100 g / L of sodium hydroxide and 5 ml / L of Alsatin SK (manufactured by Okuno Pharmaceutical Industry Co., Ltd.). Next, an aluminum test piece was prepared by treating with Top Desmat N-20 (manufactured by Okuno Pharmaceutical Industry Co., Ltd.) at 25 ° C. for 1 minute and then performing Desmat treatment.

(Examples and comparative examples)
The satin-finished liquids of Comparative Examples 2 to 5 and Examples 1 to 17 were prepared according to the formulations shown in Tables 1 and 2. The pear-skin treated liquid was prepared by sequentially adding each component shown in Tables 1 and 2 to water. The aluminum test pieces shown in Tables 1 and 2 were immersed under the conditions shown in Tables 1 and 2 and subjected to satin finish treatment. In Comparative Example 1, the test piece was not subjected to satin treatment. Finally, the test pieces prepared in Comparative Examples 2 to 5 and Examples 1 to 17 were subjected to desmat treatment again under the same conditions as the above conditions to prepare the test pieces of Examples and Comparative Examples.

(Evaluation method)
The following evaluations were performed on Examples and Comparative Examples.

Dissolution film thickness The weight of the test piece before and after the satin finish treatment was measured, and the dissolution film thickness (μm) was calculated from the weight difference, the area of the test piece, and the specific gravity of aluminum.

Pear-skin degree evaluation The surface of the test pieces of Examples and Comparative Examples was observed visually and by SEM to evaluate the pear-skin degree. In general, the satinness increases as the dissolution film thickness increases. Therefore, in the examples, the evaluation was performed when the dissolution film thickness reached 15 to 20 μm. Further, in the comparative example, the dissolution film thickness was not 15 to 20 μm.

For the evaluation using SEM, the SEM images of FIGS. 1 to 4 were used as a reference. FIG. 1 is an SEM image of a test piece that has not been subjected to satin finish, and is flat as a whole. do not have. 2 to 4 are SEM images of the test pieces subjected to the satin finish. In FIG. 2, the surface of the test piece is roughened, but extruded marks and defects still remain, and it is not satin finished by visual observation. In FIG. 3, the extruded marks and defects of the aluminum itself, which is the object to be treated, have disappeared, and it is a satin finish by visual observation. In FIG. 4, the extruded marks and defects of the aluminum itself, which is the object to be treated, have disappeared, and it is a satin finish by visual observation. Further, in FIG. 4, a particularly large unevenness is formed.

Evaluation was made according to the following evaluation criteria. If the pear-skin texture is 2 or more, it can be evaluated that there is no problem in actual use.
Pear-skin degree 0: The SEM image is close to FIG. 1, and it is not pear-skinned by visual observation.
Pear-skin degree 1: The SEM image is close to FIG. 2, and it is not pear-skinned by visual observation.
Pear-skin degree 2: The SEM image is in a state close to that of FIG. 3, and is pear-skinned by visual observation.
Pear-skin degree 3: The SEM image is in a state close to that of FIG. 4, and is pear-skinned by visual observation.

From the results in Table 1, it was found that the satin finish was sufficiently formed in Comparative Examples 2 and 3. However, in Comparative Examples 2 and 3, acidic fluoride ammonium fluoride containing fluorine is used as the satin finish, and the adverse effect on the human body and the burden on the environment are not suppressed.

From the results in Table 2, in Examples 1 to 17, the satin finish was sufficiently formed, and the satin finish treatment equivalent to that in Comparative Examples 2 and 3 using the acidic fluoride ammonium fluoride containing fluorine as the satin finish treatment liquid was possible. It turned out that there was. Further, in Comparative Examples 4 and 5, it was found that the satin finish did not contain the (A) aluminum salt and the satin finish was not sufficiently formed.

Claims (4)

(A) Aluminum salt,
(B) Alkali metal salt and
(C) Contains a sugar alcohol having 4 to 9 hydroxyl groups,
The content of the aluminum salt is 10 g / L or more, and the content is 10 g / L or more.
The content of the alkali metal salt is 60 to 600 g / L, and the content is 60 to 600 g / L.
The content of the sugar alcohol is 100 g / L or more.
A satin finish of aluminum, which is characterized by that. The aluminum salt is a group consisting of sodium aluminate, aluminum silicate, aluminum formate, aluminum acetate, aluminum sulfate, aluminum nitrate, aluminum phosphate, aluminum hydroxide, aluminum carbonate, aluminum chloride, aluminum bromide, and aluminum myoban. The satin-finished treatment liquid according to claim 1, which is at least one selected from the above. The satin-finished treatment according to claim 1 or 2 , wherein the alkali metal salt is at least one selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, alkali metal hydrogen carbonates, and salts thereof. liquid. It is a satin finish method for aluminum.
Step 1 to prepare a satin finish by mixing (1) (A) aluminum salt, (B) alkali metal salt, and (C) sugar alcohol having 4 to 9 hydroxyl groups.
(2) Step 2 of immersing aluminum in the satin finish.
Have,
The content of the aluminum salt in the satin-finished liquid in the step 1 is 10 g / L or more, the content of the alkali metal salt is 60 to 600 g / L, and the content of the sugar alcohol is. 100 g / L or more,
A pear-skin texture treatment method characterized by this.

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