JPS6233783A - Coating layer for metallic magnesium molding and its production - Google Patents

Abstract

PURPOSE:To improve the corrosion- and wear resistance of an Mg molding by forming a porous anodized film on the surface of the Mg molding then forming an inorg. cured material film insoluble in water thereon. CONSTITUTION:The molding consisting of metallic Mg is immersed into an anodic oxidation treatment liquid of which the essential components contain acidic ammonium fluoride, sodium dichromate and phosphoric acid and electricity is conducted thereto as an anode to form the porous anodized film having the excellent corrosion resistance on the surface thereof. Such molding is rinsed and dried and thereafter the inorg. cured film insoluble in water is formed thereon to seal the many fine pores opened to the surface of the anodized film; at the same time, the molding is heated to a suitable temp. to cure the film. The glassy cured material film consisting of a metallic alkoxide ceramic coating agent contg. the alkoxide of a specific metal or polycrystalline cured material film of an alkali metal salt ceramic coating material having a specific oxide or silica sol ceramic coating agent is used for the inorg. cured material film to improve the corrosion- and wear resistance of the Mg molding.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a coating layer of a magnesium metal molding and a method for producing the same υ.

[Background of the Invention] Magnesium metal (including magnesium alloys) has the lowest specific gravity among practical metals and high mechanical strength, so it is used for various purposes by taking advantage of these properties. It is also true that metals have limited applications because of their high chemical activity and susceptibility to corrosion through normal use, and because magnesium metal has an inherently low hardness. .

Magnesium metal has the above-mentioned drawbacks in terms of wood quality, so when using magnesium metal, it is necessary to perform a treatment to compensate for its corrosion resistance and hardness. Many proposals have been made and many have already been implemented.

[Prior Art and its Problems] Conventionally, chemical conversion treatment and anodic oxidation treatment have been known as surface treatment methods for magnesium metal.

The chemical conversion treatment method is a method of forming an oxide film or the like on a metal surface through a chemical reaction between the metal and a chemical conversion treatment liquid component. As this method, phosphate treatment, chromate treatment, etc. are known. As a specific example, JIS-H-86
51 (1978).

However, since the obtained film is usually used as a temporary food, it cannot impart long-term corrosion resistance to the treated magnesium metal surface.In addition, this method generally hardens the surface of the magnesium metal to a high degree. It won't happen.

The anodic oxidation treatment method is a method in which magnesium metal is immersed in an electrolytic bath, and a voltage is applied using the magnesium metal as an anode to form a resistant film by oxidation reaction on the fully curved surface of magnesium, which is the anode. A specific example of this method is JI
5-H-8651 (1978), methods described in types 5 and 6 of
Mention may be made of the HAE method and the Dow-17 method described in B).

Among the anodic oxide films obtained by anodizing treatment methods, there are methods that can impart good corrosion resistance to magnesium metal, such as the HAE method and the Dow-17 method. Furthermore, the anodic oxide film obtained by this method has relatively high hardness and relatively good wear resistance.

However, the anodic oxide film is porous with openings on its surface, and since the skin in these areas is thin, there is a problem in that corrosion may occur from these openings after long-term use.

[
As one method, a method is used in which a paint with good weather resistance, which is mainly composed of acrylic resin, urethane resin, or epoxy resin, is applied onto the anodic oxide film.

However, 1. In order to achieve the corrosion resistance required for magnesium metal by this method, it is generally necessary to:
It must be painted 4iL, and usually one coat of paint is applied. Therefore, there is a problem that the work becomes complicated. Furthermore, since the coating film is mainly composed of organic substances, there is also the problem that the coating film deteriorates at high temperatures.

Furthermore, since the hardness of the paint film is generally lower than that of the anodic oxide film, the surface hardness obtained by this method is the hardness of the paint film, and no increase in the hardness of the treated product can be expected.

As a post-treatment method for maintaining the high hardness of the anodized film and further improving its corrosion resistance, a method of sealing the anodic oxide film using hydraulic lath or chromic acid has been proposed. This pore sealing treatment is a method for improving the corrosion resistance of magnesium metal by sealing the pores in the anodic oxide film and suppressing corrosion from the open parts.

However, for example, what about sealing using water glass?
If this happens, it depends on whether the glass is dry or soluble in water, so when the dried water lath that forms on the surface of the anodic oxide film comes into contact with water during the sealing process, the water will dissolve ( The problem is that it is soluble in magnesium metal and therefore cannot impart sufficient #1 properties to magnesium metal over long periods of time, which necessarily limits its use.

On the other hand, in order to improve the corrosion resistance and abrasion resistance of the metal surface, a film of a hardened inorganic substance insoluble in water such as ceramic, such as ceramic, is applied to the metal surface +11i. It is already known that immersion is effective. When applying this film to a metal surface to improve corrosion resistance and wear resistance,
(Inorganic hardened bodies and metals have different thermal expansion and ball coefficients, and the compatibility between the two is poor, so they often do not exhibit good adhesion. The problem is that the cured product tends to peel off.

Therefore, usually, the metal surface is made rough by degreasing or pickling, and then the metal surface is roughened by sun blasting or the like.

Methods are being used to improve the adhesion between the metal surface and the inorganic cured body.

However, even if magnesium metal is subjected to the above-mentioned treatment, since the activity of magnesium metal is high, a thin oxide film is formed on the surface of magnesium metal, and the adhesion between this oxide film and the inorganic hardened material is poor. Therefore, the attached inorganic cured material peels off from the oxide film, making it impossible to provide effective coating. Therefore, this method has not been put to practical use with magnesium metal.

[Purpose of the invention]

The main object of the present invention is to provide a coating layer for a magnesium metal molded article that has excellent corrosion resistance and heat control properties, high hardness, and excellent wear resistance, and a method for producing the coating layer.

[9, Summary of Ming] The present invention provides a method for forming a porous anodic oxide film formed on the surface of a magnesium metal molded article and having an opening on the surface, and covering the surface of the anodic oxide film while sealing the opening. The coating layer of a magnesium metal molded article consists of a water-insoluble inorganic cured body film.

Such a coating layer is formed by a step of anodizing the surface of the magnesium metal molding to form an anodized film.
Apply ceramic coating agent to the oxide film.Y
It can be easily produced by a method comprising two steps and one step of curing the coating agent.

[Effects of the Invention] Since the coating layer of the magnesium metal molded article 1- of the present invention is coated with a water-insoluble inorganic hardened material on the surface of the anodic oxide film, there is no corrosion from the surface portion, and there is no possibility of corrosion. [The large number of pores in the anodic oxide film that were the cause of the problem are sealed with a water-insoluble inorganic hardened material that has penetrated into the pores near the surface of the anodic oxide film, so corrosion from the pores is also possible. It shows good corrosion resistance with almost no occurrence of corrosion.

Furthermore, the coating layer of the present invention is a water-insoluble inorganic material. 1. Because the cured product has high hardness, it not only shows good side abrasion resistance, but also the water-insoluble inorganic cured product that penetrates into the pores and seals them, and the anodic oxide film act synergistically. Shows excellent wear resistance.

The water-insoluble inorganic hardened film attached to the anodic oxide film adheres to the anodic oxide film, and the hardened material penetrates into the blank tag and firmly adheres to the inner wall surface of the sealing hole. - Since the anodic oxide film is tightly adhered to the body, there is almost no chance of it peeling off.

Furthermore, the water-insoluble inorganic cured product has good properties such as #thermal properties due to its inorganic nature.

Although the coating layer of undeveloped IJil has excellent properties as described in L, it is not particularly necessary to apply multiple coats as in the case of paint application, for example.
Its formation is easy.

[Detailed Description of the Invention] The coating layer of the present invention basically consists of an anodized film and a water-insoluble inorganic cured film that are integrally provided on the surface of a magnesium metal molded article.

The anodic oxide film has a large number of pores with openings on its surface. Generally, the pores of such an anodized film have a depth of 1 to 30 gm and a diameter of 1 to 40 gm.

An anodized film is an oxide film that is created by anodizing magnesium metal, and its hardness depends on the type of oxide, but it is usually very hard. Because it grows directly from metal, it has excellent adhesion and is known to not peel off easily.

The water-insoluble, Ja-free, hardened material covers the surface of the anodic oxide film and seals the openings in the surface of the anodic oxide film near the surface. Usually, it penetrates into the pores through the openings on the surface.

And 1 ton of anodized skin! The water-insoluble cured inorganic film of No. 27 is a water-insoluble film that has a part on the anodic oxide film that is bonded to the anodic oxide film and seals the pores due to the adhesive force between the water-insoluble inorganic cured product and the anodic oxide film. The effect of firmly holding the inorganic cured film (anchor effect) provides a strong bond.

Such a covering layer can be manufactured by the following method.

The first step is a step of anodizing the magnesium metal molded product to form an anodized film.

Ordinary magnesium metal moldings can be used.

Examples of magnesium metal include those consisting essentially only of magnesium and alloys containing about 70% by weight or more of magnesium, which are generally used as industrial materials.

Examples of metals other than magnesium that form alloys include:
Mention may be made of aluminum, zinc, manganese, zirconium, silicon and rare earth atoms.

The anodic oxide film can be obtained according to a known anodic oxidation treatment method.

Examples of anodizing treatment methods include the Dow-17 method and the HAE method.

Examples of anodizing solutions used include anodizing solutions whose main components include acidic ammonium fluoride, sodium dichromate and phosphoric acid, aluminum ions, fluorine ions, phosphate ions and permanganate ions. Anodizing solutions, anodizing solutions containing aluminum ions, fluoride ions, and citric acid, anodizing solutions containing acidic ammonium fluoride, and anodizing solutions containing aluminate ions, iodine ions, and borate ions. I can do it.

−・Generally, anodizing treatment is carried out at an anodizing treatment voltage of lO~
within the range of 150V, and the electric density from 0.1 to IO
1 within the range of A/dm', processing time 10-90
Set within minutes. Note that the treatment time and the like can be appropriately set depending on the thickness of the anodic oxide film to be obtained.

Usually, the composition of the oxide film obtained by anodic oxidation treatment under the above conditions varies depending on the type of anodic oxidation solution, etc.
, MgF, MgO11A! ;L2O1, Cr2O, etc.

The second step is to apply a coating agent (that is, a ceramic coating agent) that forms a water-insoluble inorganic cured film onto the anodic oxide film.

The ceramic coating agent is such that when the applied coating agent is cured, the cured product covers the surface of the anodic oxide film and further seals the openings on the surface of the anodic oxide film near the surface of the anodized film 1. to be painted. It should be noted that it is sufficient to apply the ceramic coating agent so as not to seal the pores near the surface of the anodic oxide film.
For example, when using a coating agent with a low viscosity, such as the metal alkoxylate ceramic coating agent described later, it may be possible to penetrate deep into the pores, and the coachib agent should be applied so that it can penetrate deep into the pores. By applying the coating, the water-insoluble inorganic cured body of this coating agent and the anodic oxide film cooperate with phase m to exhibit good wear resistance and at the same time, good corrosion resistance.

A method of applying the coating agent under reduced pressure can be used as a method for penetrating the coating agent deeply. In addition, by using this method, even if the coating agent does not penetrate deep, the air in the pores can be removed, and the N corrosion resistance is favorable.

Usually, the coating agent is applied after washing the anodized magnesium metal in step 1 with water and drying it.

The coating agent used is one that is cured in the next third step to become a water-insoluble inorganic cured product. Even if a material such as water glass which cannot form a water-insoluble inorganic hardened material is used, it is not possible to impart long-term corrosion resistance to magnesium metal.

Examples of such coating agents include Sj, Ti,
A metal alkoxide ceramic coating agent containing as one component an alkoxide of at least one metal selected from the group consisting of AI, Zr, Sr, Sn and Ba, S
iO2. SiO2・Al12O3. At least one kind of powder selected from the group consisting of ZrO2, SiN and BN and/or! a Alkali metal salt-based ceramic coating agent mainly composed of male and SiO2/MgO1S
Examples include silica sol ceramic coating agents whose main component is at least one kind of powder obtained from the group consisting of iO2, MgO, TiO2 and 5io2, Cr2O, and these can be used alone or in combination. can.

To explain these coating agents in more detail, metal alkoxide-based ceramic coating agents usually contain metal alkoxides [metals (e.g., Si,
a reaction product of Ti, Al, Zr, Sn, Ba, etc.) and alcohol (e.g., methyl alcohol, ethyl alcohol, propyl alcohol), and a solvent such as the alcohol mentioned above that dissolves or disperses the reaction product, and a metal alkoxide. Refers to a coating agent having a pH value within the range of 3 to 9 and consisting essentially of a catalyst that controls the hydrolysis reaction or polycondensation reaction of .

After application, the neating agent changes from a sol to a gel at a temperature around room temperature and becomes a glassy film by air drying or heating to a temperature of room temperature to 30°C.

Alkali gold) IskiA-based ceramia ceramic coating agent or fiber M1 component (e.g., SiO2.5in2@A
n2O. , ZrO2,5i)N4,BN) as the main component, and a binder [e.g., alkali metal 1(R2O*S
iO2, R are Na, Li and SiO2/R2O
=n, l≦n≦4)].

Hardeners [metal oxides (e.g. ZnO1M g O and S
102), silicon 7, compounds (e.g. Na25iF6), hydroxides (e.g. Adan (OH) 3), phosphates (e.g. 2
ZnO-P2Os) and U*a salt (N, H3BO3, Na2BaO7)] refers to a coachib agent having a pH value of 10 or more that is substantially formed from the following, and after coating, the binder This is a coating agent in which a condensation reaction occurs between the coating agent and heated water, and upon further heating, for example, siloxane bonds are formed and the coating agent becomes polycrystalline.

And what is silica sol ceramic coating agent?
The main component is a chemically resistant powder (e.g., SiO2.MgO1Cr2O38 and T i O2), and a binder (e.g.,
It is a coating agent that exhibits a pH (fi of 9 or less) and is essentially composed of a dispersant (colloidal silica) and a dispersant (example 1, water). It is a coating agent that becomes polycrystalline.

Note that the pH (i/i) of the coachib agent is preferably 3 or more and 1-.For example, a coachib agent with a pH lower than 3, such as an acidic metal salt-based ceramic coating agent, reacts with magnesium metal. Sometimes.

There is no particular restriction on the method of applying the coating agent to the surface of the anodic oxide film, and any conventional method can be used. Coating can be carried out using conventional methods such as dipping, spraying, rolling, and coating.

The coating thickness of the coachib agent is usually 50 gm or more, and the thickness of the water-insoluble inorganic cured product is, for example, 50 gm or more.
When the thickness is 0 μm or more, the coating thickness is usually 50 pm or more, and the process consisting of curing the coating and then coating and curing is repeated.
The thickness shall be .

Also, when laminating one or more types of coating agents, it is preferable to perform the same operation as described in 1-1.

The first method [the culm is hardened with the applied coating agent]
It's mostly fl.

Usually, curing is carried out by applying and drying the coating agent, and then leaving it for a predetermined period of time at a temperature of 1-10 degrees below the curing temperature of the coating agent used.

The usual curing temperature is, for example, a temperature within the range of room temperature to 300° C. for the metal alkoxide-based ceramic coating agent, the alkali metal salt-based ceramic coating agent, and the silica sol-based ceramic coating agent. Especially 1
Curing by heating I7 at 00 to 200°C shortens the curing time, which is preferable.

The curing time should be selected appropriately depending on various conditions such as the type of coating agent used, coating thickness, temperature, etc., and should not be particularly limited. For example, when using a metal alkoxide ceramic coating agent, The curing time is 1 to 30 hours at a curing temperature of 1°C to 20°C.

The water-insoluble inorganic cured product thus cured covers the surface of the anodic oxide film and closes the openings on the surface of the anodic oxide film. And it has penetrated into the inside of the pores.

And, as a coating agent, the above-mentioned Si, Ti, AM
The water-insoluble inorganic cured body layer obtained by curing using a metal alkoxide ceramic coating agent containing metal alkoxides such as Zr, Sr, Sn, and Ba as the t component is generally a metal alkoxide ceramic coating. Due to the low viscosity of the agent, the thickness of the film covering the surface of the anodized film is usually less than 1 m, and compared to other coatings,
The coating agent has penetrated relatively deep into the pores and hardened. The obtained cured body usually contains Si, Ti,
It is a glassy substance made of oxides of metals such as AM, Zr, Sn, Ba, 5 and/or Sn, and under normal use, corrosive components such as moisture will be absorbed by this skin. The YQ layer exhibits very good corrosion resistance because it does not pass through the anodic oxide layer I.Since the thickness of the anodized layer I-like layer is usually thin as described above, a water-insoluble hardened layer is attached. This method does not require an increase in the number of covering methods, and is particularly useful when used for parts that require dimensional accuracy.

In addition, due to the highly hard water-insoluble inorganic hardened material that penetrates into the pores and hardens, the degree of (i3I!) of the anodic oxide film is also increased.
and exhibits excellent wear resistance.

Add the metal alkoxide ceramic coating agent and measure the thickness of the film by several pieces! i1-tile m can also be 1-
It is 1f ability and is multilayered like this! Abrasion resistance is further improved by adding Hj.

Furthermore, a cured product of another coating agent such as an alkali metal m-based and/or silica sol-based ceramic coating agent is laminated on the cured product of the metal alkoxide-based ceramic coating agent to improve the wear resistance of the surface. You can also do that.

On the other hand, Sioz, SiN, Zr as a coating agent
O2, S i O2' A 'l 2O ) and BN
"i-A cured product obtained by curing an alkali metal salt-based ceramic coating agent whose main component is any powder and/or fiber, or SiO2, MgO1S i02,
The cured product obtained by curing a silica sol-based ceramic coating agent mainly composed of powders such as MgO TiO2 and 5in2 Cr2O3 generally has a high viscosity, so the cured product is formed on the anodic oxide film. The film is thicker than when a metal alkoxide ceramic coating agent is used, and the thickness of the cured film is usually in the range of 1 to 2 O0 gm. Usually, this film is polycrystalline and has very high hardness, mainly consisting of the above components. Therefore, the coating layer consisting of the anodic oxide film and this water-insoluble inorganic hardened film has particularly good wear resistance. It is. On the other hand, since it is polycrystalline, a small amount of water etc. tends to penetrate deep into the cured film. If this penetrating water reaches the magnesium metal, it may cause corrosion. Therefore, by forming a film of a glassy hardened material on the surface of the water-insoluble inorganic hardened material of such a coating layer using the metal alkoxide ceramic coating agent described above, it is possible to prevent the penetration of wood, etc. as mentioned above. corrosion resistance is further improved.

The water-insoluble cured inorganic film according to the present invention differs from water glass in that the alkali content in the constituent components is extremely small and it is substantially insoluble in water.

Furthermore, the coating layer of the present invention is aa-free.

For example, it goes without saying that it has extremely superior heat resistance compared to paints whose main component is organic.

Next, Examples and Comparative Examples of the present invention will be shown.

Corrosion resistance of each product was determined by spraying salt water on the coating layer (or anodic oxide film) at a specified interval and observing the surface condition with the naked eye in accordance with the method described in JIS-Z-2371 "Salt water spray test". The surface has no corrosion spots! A sample with a good E rating was labeled as A, a sample with few corrosion points was labeled as B, and a sample with many corrosion points and part of the film peeled off was labeled as C.

The abrasion resistance was measured by a surface abrasion test ( The load is 400 gf, the number of reciprocating frictions is 60 DS/min, the roughness of the abrasive paper is #32O, and the material of the abrasive is 5iC), and the number of reciprocating frictions (DS number) required to wear out 1 m of film thickness is determined. It was measured by the method.

Further, the adhesion was tested according to the JIS-6852r adhesive compression shear adhesive strength testing method.

[Example 1] Magnesium alloy AZ91 (die-cast product) was subjected to normal pretreatment consisting of alkaline degreasing and pickling to clean the surface, and then treated with KOH [165 g/ac], A!
;L(OH)3 [35g/l], KF [35g/l]
! ;L], KMnO4 [2Og/cross] and Na
s POa [35g/Jlj] and 2A/dm? using AC. 60 at a constant current of
Anodic oxidation was performed for a minute to form an anodic oxide film having a thickness of 23 pm and having pores.

Next, after washing with water and drying, this anodic oxide film is coated with a metal alkoxide ceramic coating agent (] 1 Board Research Institute ■
Nigelascar 90 (trade name, manufactured by Manufacturer, Inc.) was applied and cured by heating at 150° C. for 30 minutes to form a water-insoluble inorganic cured film on the anodic oxide film F.

When the thickness of the obtained coating layer was measured, it was found to be 237°Cm, and a very thin film of water-insoluble inorganic cured material was formed on the anodic oxide film. Since it was less than 1 gm, the film thickness could not be measured with the film thickness measuring device used. but,
As a result of observation using an electron microscope, a film of a vitreous water-insoluble inorganic hardened material was formed on L of the anodic oxide film, and the hardened material had penetrated into the pores, and the pores were one layer near the surface.
It was confirmed that one hole had been drilled.

Table 1 shows the results of the salt spray test and the NL abrasion test for this coating layer.

[Example 2] In Example 1, KOH [1
Anodizing was carried out in the same manner for 30 minutes except that a treatment solution consisting of KF [25 g/, Q) and potassium citrate [2 Og/i] was used. An anodic oxide film having pores with a thickness of 11 m was formed.

After washing with water and drying, a metal alkoxylate ceramic coating agent (manufactured by +-] Ita Institute Co., Ltd., trade name Nigelascar 401) was applied, and air-dried for 24 hours at room temperature. 2. A film of a water-insoluble inorganic cured product was formed on h.

When the thickness of the displaced coating layer was measured, it was 11.Lm
A very thin film of water-insoluble inorganic hardened material was formed on the anodized film, but since the film thickness of this water-insoluble inorganic hardened material was less than lpm, the film thickness measuring device used could not measure the film thickness. It was not possible to measure the film thickness. However, 'Ichi T-Kenga! As a result of observation using an L mirror, it was found that a skin 1 of the vitreous insoluble aluminous hardened material was observed on the anodic oxide film L.
To! was formed, and it was confirmed that the cured material had penetrated into the V and pores, and the pores were sealed near the surface of the anodic oxide film.

Table 1 shows the results of the salt spray test and abrasion resistance test of this composite film.

[Example 3] In Example 1, using magnesium alloy AZ31,
As the positive J4i oxidation treatment solution, NaA 0□ [100g/
i'l, NaOH [150 g/i] and NaI [2
Using a treatment solution consisting of
drn', anodization treatment was performed in the same manner except that the treatment time was changed to 30 minutes.

The thickness of the anodic oxide film formed was 40 μm.

After washing with water and drying, apply an alkali metal salt-based ceramic coating agent (Higashi) ■ manufactured by Gosei Kagaku Rigyo Co., Ltd., product name Nearon Ceramic D) with a glass rod, and leave it at room temperature for 24 hours.
After air drying for 1 hour, heat at 90℃ for 2 hours, and then heat for 150℃.
A coating layer was formed in the same manner except that it was cured by heating for 1 hour at .degree.

The thickness of the coating layer was 90-150 pm. Table 1 shows the results of the salt spray test and abrasion resistance test of this coating layer.

The compressive shear adhesive strength of this coating layer is 70Kg.
f/cm'.

[Example 4] In Example 3, an alkali metal salt-based ceramic coating agent (manufactured by Sumitomo Chemical Co., Ltd.) was used instead of the alkali metal salt-based ceramic coating agent.

Using Sumiceram 318-A), apply it with a glass rod, air dry at room temperature for 1 hour, and then apply at 100°C for 1 hour.
It was cured by heating for more than an hour.

11) The thickness of the coating layer was 55 to 60 pm.

Table 1 shows the results of the salt spray test and abrasion resistance test of this coating layer.

[Example 5] In Example 3, instead of the alkali metal salt-based ceramic coating agent, Shoshu water glass was added to the silica sol-based ceramic coating agent [(manufactured by Catalyst Kasei Kogyo ■, trade name: 5I-30)]. A coating layer was formed in the same manner, except that a coating film with a pH value of 10.5 was applied using a cup, air-dried at room temperature for 1 hour, and then heated at 150° C. for 1 hour to cure.

The thickness of the resulting coating layer was 50 pm.

Table 1 shows the results of the salt spray test and abrasion resistance test of this coating layer.

[Comparative Example 1] A water-insoluble inorganic cured body was formed in the same manner as in Example 1 except that the anodic oxidation treatment was not performed.

The film thickness of the water-insoluble inorganic cured product was less than 1 μm, and the film thickness could not be measured.

Table 1 shows the results of a salt spray test conducted on this film.

[Comparative Example 2] Magnesium alloy AZ91 (die-cast product) was pretreated and anodized according to the method of Example 1, and then washed with water.
After drying, an anodized skin was obtained.

Table 1 shows the results of the salt spray test and abrasion resistance test of this anodized film.

[Comparative Example 3] A water-insoluble inorganic cured body was formed in the same manner as in Example 3 except that the anodic oxidation treatment was not performed.

The film thickness of the water-insoluble inorganic cured product is 50 to 100 μm.
Met.

Table 1 shows the results of a salt spray test conducted on this film.

The compressive shear adhesive strength was 35Kgf/Cm'. Table 1 below has margins +6h 48h 12Oh (O5/g
m) Example Covering layer Anodic oxide film IA
AA 30 15 2AAA 40 33 3AAA-1 1 layer 700 Do layer 7017 4AAAL layer 700 Do layer 6017 5AABJ=layer 100 Do layer 5017 Comparative example I C Medium Correct --2ABC1
5 30 discontinued --Note) In Table 1, the upper layer is a ceramic coating layer, and the lower layer is a composite layer of an anodized film and a ceramic film.
Moreover, the anodic oxide film refers to the abrasion resistance of the anodic oxide film before the water-insoluble inorganic hardened material is attached.

From Table 1, corrosion resistance is poor when using only the water-insoluble inorganic cured product (Comparative Examples 1 and 3) or using only the anodic oxide film (Comparative Example 2). On the other hand, the coating layer according to the present invention (Examples 1 to 5)
It is clear that this material has excellent corrosion resistance and wear resistance.

The thickness of the film of the water-insoluble inorganic cured material attached using the metal alkylcoside ceramic coating agent (Examples 1 and 2) according to the present invention is extremely thin, and the coating layer itself has approximately the same thickness as the anodic oxide film, and the dimensions Accuracy is extremely good. Despite the thin film of the water-insoluble inorganic cured material, it exhibits excellent corrosion resistance and abrasion resistance.

= On the other hand, an RFF coating having a water-insoluble 'V texture cured body (Examples 3 to 5) by an alkali metal salt-based ceramic coating agent and a silica sol-based ceramic coating agent
The layer has good corrosion resistance and, in particular, very good wear resistance.

The water-insoluble inorganic hardened body layer of the magnesium alloy according to the present invention has an anodic oxide film as a lower layer, thereby greatly improving the '/F:R properties of the magnesium alloy. Furthermore, since the surface of the coating layer of the present invention is made of a water-insoluble inorganic hardened material, it has particularly excellent corrosion resistance and wear resistance as described above. Of course, it also has excellent properties such as heat resistance and insulation that wood has.

Patent Applicant Ube Industries Co., Ltd. Representative Patent Attorney Yasuo Yanagawa - F Zenri Ne Yamazumi 11-) September 181, 1985
115, -. 151 1. Kfl's Indication 1986 [゛ Pat.
, Relationship with 1 case of Nagisa with sleeves + f- Special seller name (02O) Ube Industries Co., Ltd. 4, agent address J-So "6th floor, 8th floor, Mitsuya Yotsuya Hill, 2-14 Yotsuya, Shinjuku-ku, Tokyo, amended The number of inventions increases due to None 7
8. Subject of sleeve if- (1) “Claims” column of the specification (2) “Detailed description of the invention “yl” column 8 of the specification
, Contents of Supplement IF As shown in the attached document, (1) the "Scope of Claims" column of the specification will be amended as follows.

110 A porous anodic oxide film having an opening on one surface formed on the surface of a magnesium metal molded product.

A coating layer of a magnesium metal molded article comprising a water-insoluble inorganic cured film covering the surface of the anodic oxide film while sealing the opening.

2. The coating layer according to claim 1, wherein the water-insoluble inorganic cured material coating nt2 is a vitreous cured material coating.

3゜The glassy hardened body is Si, Ti, Al, Zr, Sr.
2. The coating layer according to claim 2, wherein the coating layer is a cured product of a metal alkoxide-based ceramic coating agent containing an alkoxide of at least one metal selected from the group consisting of , Sn, and Ba.

4. A coating layer as described in which the water-insoluble inorganic cured film is polycrystalline.

The 5° polycrystalline hardened body is made of SiO2. SiO2・A l
A cured product of an alkali metal salt-based ceramic coating agent whose main component is at least one kind of powder and/or fiber selected from the group consisting of 2Oy, ZrO2, Si, N, and BN, and/or SiO2. MgO1S self 0
Claim 4, characterized in that it is made of a cured body of a silica sol-based ceramic coating agent whose main component is at least one kind of powder selected from the group consisting of 2.MgO-TiO2 and SiO2-Cr2O3. Covering layer.

6. The step of anodizing the surface of the magnesium metal molding to form an anodized film, the step of coating the anodic oxide film with a ceramic coating agent, and the step of curing the coating agent. A method for producing a coating layer of a gnesium metal molded article.

7. A method for producing a coating layer according to claim 6, wherein the anodizing is carried out using an anodic oxidizing solution.

8. Ceramic coating agent is Si, Ti, Al,
The method for producing a coating layer according to claim 6, which is a metal alkoxide ceramic coating agent containing an alkoxide of at least one metal selected from the group consisting of Zr, Sr, Sn, and Ba. .

9. Ceramic coating agent is SiO2, Si
O2・A l 2 0 3, Z r O
2. An alkali metal salt-based ceramic coating agent whose main component is at least one kind of powder and/or fiber selected from the group consisting of Si3N4 and BN, and/or the material is S i02 *MgO, S i02 *Mg
0eT i 02 OJ: and SiO2*Cr2O,J:
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Claims (1)

[Scope of Claims] 1. A porous anodic oxide film having an opening on the surface formed on the surface of a magnesium metal molded product, and a water-insoluble anodic oxide film that seals the opening and covers the surface of the anodic oxide film. A coating layer of a magnesium metal molded article consisting of an inorganic cured body film. 2. The coating layer according to claim 1, wherein the water-insoluble inorganic cured film is a vitreous cured film. 3. Glassy hardened body is Si, Ti, Al, Zr, Sr
3. The coating layer according to claim 2, which is a cured product of a metal alkoxide-based ceramic coating agent containing an alkoxide of at least one metal selected from the group consisting of , Sn, and Ba. 4. The coating layer according to claim 1, wherein the water-insoluble inorganic cured body film contains a polycrystalline cured body. 5. Polycrystalline hardened body is SiO_2, SiO_2・Al
_2O_3, ZrO_2, a cured body of an alkali metal salt-based ceramic coating agent whose main component is at least one kind of powder and/or fiber selected from the group consisting of SiN and BN, and/or SiO_2・MgO, Si
O_2・MgO・TiO_2 and SiO_2・Cr_
5. The coating layer according to claim 4, wherein the coating layer is made of a cured product of a silica sol ceramic coating agent whose main component is at least one kind of powder obtained from the group consisting of 2O_3. 6. The method includes the steps of anodizing the surface of the magnesium metal molding to form an anodic oxide film, applying a ceramic coating agent on the anodic oxide film, and curing the coating agent. A method for producing a coating layer for a gnesium metal molded article. 7. The method for producing a coating layer according to claim 6, wherein the anodic oxidation is performed using an anodic oxidizing solution. 8. Ceramic coating agent is Si, Ti, Al,
The method for producing a coating layer according to claim 6, which is a metal alkoxide ceramic coating agent containing an alkoxide of at least one metal selected from the group consisting of Zr, Sr, Sn, and Ba. . 9. Ceramic coating agent is SiO_2, SiO_
2. At least one kind of powder selected from the group consisting of Al_2O_3, ZrO_2, SiN and BN and/
Or an alkali metal salt-based ceramic coating agent mainly composed of fibers, and/or SiO_2・MgO,
SiO_2・MgO・TiO_2 and SiO_2・C
7. The method for producing a coating layer according to claim 6, wherein the coating layer is a silica sol-based ceramic coating agent whose main component is at least one kind of powder obtained from the group consisting of r_2O_3.