JPH09192601A - Formation of composite film on aluminum or aluminum alloy surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart excellent lubricity and solvent resistance to the surface of an aluminum alloy by forming ground surface films on the surface, then applying a specific ethylenic ionomer resin, an org. crosslinking agent having a functional group and an aq. org. high-polymer resin compsn. on the surface of the films and drying the coatings, thereby forming coating layers of a type not requiring the removal of the films. SOLUTION: The surface of the aluminum alloy are first treated with an aq. soln. contg. ions of metals such as Cr, Zr and Ti to form the ground surface films on it. Next, the ethylenic ionomer resin of which the resin skeleton is formed of ethylene and α,β-unsatd. carboxylic acid and which is 0.05-0.2 in the weight ratio thereof to ethylene and is neutralized with the metal ions, an org. crosslinking agent which has the functional group, such as epoxy, in the amt. of 10 to 70% of the equiv. to the unneutralized carboxyl group in the resin and the aq. org. high-polymer resin compsn. contg. petroleum wax or polyethylene wax are applied on the ground surface films. The coatings are thereafter dried, by which the coating layers of 0.1 to 10μm of the type of requiring the removal of the films are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a plate material made of aluminum or an aluminum alloy (hereinafter referred to as an aluminum plate material) with moldability and solvent resistance, as well as corrosion resistance, alkali resistance and fingerprint resistance. The present invention also relates to a method for forming a composite film on the surface of aluminum or an aluminum alloy for forming a film removal-unnecessary type film layer having excellent printability. The method for forming a composite film of the present invention is particularly preferably applied to a plate material of aluminum or aluminum alloy that is accompanied by continuous press molding or bending.

[0002]

2. Description of the Related Art Conventionally, aluminum plate materials have been widely used in processing and assembling manufacturers of home appliances (including electronic parts, etc.), automobiles, building materials, etc., but most of them are methods such as pressing and casting according to their respective uses. Are molded, assembled, and then painted and printed. During this forming process, since the aluminum plate material itself has insufficient workability, a lubricant such as press oil or wax is applied on site before the forming process as a countermeasure. However, oil and dust are scattered around the press machine to contaminate the work site, and it must be said that the environment is extremely poor in terms of working environment and pollution prevention. Further, due to recent global environmental problems, a cleaning method using an organic solvent such as freon or trichloroethane for removing lubricants such as press oil and wax has become a problem. In addition, these solvents are prohibited to be used as substances that destroy the ozone layer. A molding method that uses volatile oil that does not require cleaning is also being considered, but it requires high cost because it requires a fairly large-scale drying facility, and problems such as a poor working environment because volatile oil is used. I'm holding.

[0003] Therefore, as a molding technique replacing the press oil application, some techniques relating to a functional surface-treated aluminum plate material having lubricity have been reported so far.
For example, in JP-A-63-83172, a resin composition comprising at least one organic resin selected from an epoxy resin, a polyester resin and an acrylic resin and an amino resin or polyisocyanate as a curing agent component is used as a conductive material. , A rust preventive lubricious coating forming composition containing a chromium compound and a lubricating substance is disclosed. However, by using this composition, a surface-treated steel sheet that can be pressed or welded without application of a press oil and can be coated without film removal can be obtained, and the surface-treated steel sheet is targeted by the present inventors. However, it is still insufficient for strength forming.
Further, in JP-A-6-346178, Mg3.0
~ 6.0% aluminum alloy surface, synthetic resin coating film selected from ethylene acrylic resin coating film, epoxy resin coating film and epoxy acrylic resin coating film, or 3% or less inner wax in the epoxy acrylic resin coating film Disclosed is an aluminum alloy material for a recording medium cassette shutter, which is characterized by forming a synthetic resin coating film containing. Although this coating film has good corrosion resistance, printability, and adhesion, it is still insufficient for the molding process of strength, which is the goal of the present inventors.

On the other hand, in the field where continuous press molding is performed, press oil is still used, and the work of removing the scattered or adhered press oil with a solvent is performed. Further, in the assembly process, there is a work of numbering the surface of the plate material with ink or the like, and washing and removing with a solvent after the assembly. Therefore, even a functional surface-treated aluminum plate material with lubricity requires a cleaning step with these solvents, so it is necessary to perform surface treatment on the aluminum plate material without elution of the coating film by the solvent or appearance change. .

A technique relating to a functional surface-treated aluminum plate material having lubricity is further described in, for example, Japanese Patent Laid-Open No. 6-5513.
In Japanese Patent Laid-Open No. 7, a chromate film is formed on the surface of aluminum or an aluminum alloy, and one or two resins selected from urethane resin, ester resin and epoxy resin and a wax as a lubricating additive are formed on the chromate film. There is disclosed a method for forming a composite film, which comprises applying an organic polymer resin composition containing a silica sol and then drying it to form a film layer. When this method is used, the moldability, the corrosion resistance and the paintability are excellent, so that it is sufficient for the strength molding which is the target of the present inventors, but the solvent resistance is still insufficient. As mentioned above, at present, molding processability and solvent resistance are particularly excellent,
Aluminum plate materials having good corrosion resistance, alkali resistance, fingerprint resistance and printability have not been obtained.

[0006]

SUMMARY OF THE INVENTION The present invention is to solve these problems of the above-mentioned prior art.
In particular, on the surface of the aluminum plate material, a film-removal-free type coating layer that imparts strong moldability, that is, excellent lubricity and solvent resistance, and is also excellent in corrosion resistance, alkali resistance, fingerprint resistance and printability is formed. It is an object of the present invention to provide a method for forming a composite film on the surface of aluminum or an aluminum alloy.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have found that a film-removal-free type coating layer which simultaneously has excellent molding workability, solvent resistance, corrosion resistance, alkali resistance, fingerprint resistance and printability on the surface of an aluminum plate material. As a result of repeated intensive studies on means for forming, after forming a specific undercoat on the surface of the aluminum plate material, an ionomer resin of a specific structure and an organic crosslinking agent,
The present invention has been found to solve the above problems by applying a water-based organic polymer resin composition containing petroleum wax or polyethylene wax as a lubricating additive, and then drying to form a film removal unnecessary type coating layer. It came to completion.

That is, according to the present invention, the surface of aluminum or aluminum alloy is preliminarily subjected to Cr, Zr and Ti.
After treatment with an aqueous solution containing at least one metal ion selected from the above, an undercoat is formed on the surface, a resin skeleton is formed from ethylene and α, β-unsaturated carboxylic acid on the undercoat. So that the weight ratio of the α, β-unsaturated carboxylic acid to ethylene is 0.05 to 0.2 and the degree of neutralization with respect to the carboxyl groups in the unsaturated carboxylic acid is 30 to 70%. Selected from the group of epoxy group, trialkoxysilyl group, oxazolyl group and isocyanato group in an amount of 10 to 70% as an equivalent to the unneutralized carboxyl group in the resin and an ethylene ionomer resin neutralized with a metal ion. Containing an organic cross-linking agent having at least one functional group, and a petroleum wax or a polyethylene wax having a saponification value of 0 or 30 as a lubricating additive. The aqueous organic polymer resin composition is applied, then a composite film forming method of drying to the aluminum or aluminum alloy surface, characterized in that to form the film removal unnecessary type film layer of 0.1 to 10 [mu] m. It is preferable to further contain silica sol in the water-based organic polymer resin composition of the present invention. Further, as the metal ion of the present invention, it is preferable to use at least one selected from Li ⁺ , Na ⁺ , K ⁺ and Zn ²⁺ . The petroleum wax or polyethylene wax of the present invention is preferably contained in the water-based organic polymer resin composition in an amount of 5 to 25% by weight based on the total solid content including the wax itself.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. The aluminum or aluminum alloy targeted by the present invention is
The component composition is not particularly limited. However, when the object requires strength, for example, when it is used as a floppy disk shutter for home electric appliances, a magneto-optical disk shutter, a floppy disk drive case, a hard disk drive case, etc., A1
It is desirable to use a -Mg-based, A1-Mn-based or A1-Mg-Mn-based aluminum alloy. Above all, 1 to 7 wt% of Mg or 0.5 to 2 in the aluminum alloy
Those containing wt% of Mn are preferable. If Mg in the aluminum alloy is less than 1 wt%, the strength is low, and 7 wt%
If it exceeds, rolling becomes difficult and formability such as bending is deteriorated. Further, if Mn in the aluminum alloy is less than 0.5 wt%, the strength is low, and if it exceeds 2 wt%, a coarse intermetallic compound is generated and formability such as bending is deteriorated, which is not preferable.

In the method for forming a composite film of the present invention, the surface of aluminum or aluminum alloy is degreased and washed with water by a conventional method, and then treated with an aqueous solution containing ions of at least one metal selected from Cr, Zr and Ti. However, it is necessary to form an undercoat on the surface. As the aqueous solution, known ones can be used and are not limited to those which react with aluminum to form a chemical conversion film. Examples of the Cr ion-containing aqueous solution treating agent include reactive type, coating type and electrolytic type. First, reactive C
As the r-ion-containing aqueous solution treating agent, chromic acid is 0.4 to 10 g / L, and phosphoric acid is 1.5 to 50 g / L.
L, an aqueous solution containing 0.05 to 5 g / L of three kinds of hydrofluoric acid, or 0.4 to 10 g of chromic acid
/ L, 0.1 to 10 g / L of nitric acid, and 0.05 to 5 g / L of hydrofluoric acid as an aqueous solution containing three kinds of acids. The formation of the undercoat by these is performed by treating the aluminum or aluminum alloy surface after degreasing and washing with water with the above aqueous solution at a treatment temperature of 20 to 60 ° C. and a pH of 0.5 to 2.
It is applied by spraying or dipping in the range of 5, followed by washing with water and drying. Drying is preferably air blowing or heat drying at a temperature of 70 ° C. or lower. If the acid concentration, the treatment temperature and the pH are not within the above ranges, the underlying film cannot be formed efficiently and economically.

Next, the coating type Cr ion-containing aqueous solution treating agent may be an aqueous solution containing 1 to 180 g / L of all Cr ions. The Cr ions contained in this aqueous solution have a trivalent / hexavalent Cr ion ratio (weight ratio) of 0.
An aqueous solution of 25 or more, preferably 0.25 to 1.5 can be used. After forming the composite film of the present invention, continuous pressing and bending are performed, and then coating (top coating, printing, etc.)
In the case of performing the coating, a pretreatment for coating such as degreasing and rinsing is performed prior to coating in order to remove the secondary press oil and the like, but the trivalent / hexavalent Cr ion ratio is less than 0.25. Does not have sufficient chromium elution resistance during pretreatment of coating. The above-mentioned coating type Cr ion-containing aqueous treatment agent contains phosphoric acids such as phosphoric acid and polyphosphoric acid for the stability of trivalent chromium, oxide colloids such as silica sol, alumina sol, titania sol and zirconia sol for improving corrosion resistance, or Powders of these oxides, fluorides such as zirconium fluoride, silicofluoride, and titanium fluoride for promoting insoluble salt formation, metal ions such as zinc ion, cobalt ion, and nickel ion for improving adhesion, molybdic acid,
Oxygen acids such as tungstic acid or their water-soluble salts,
Etc., one or more kinds of additives can be further contained, if necessary, in an individual additive / total Cr ion ratio (weight ratio) of 8.0 or less, preferably 4.0 or less. . If the additive / total Cr ion exceeds 8.0, the desired performance cannot be obtained. The coating type Cr ion-containing aqueous solution treating agent is applied to the object to be treated and heated and dried without washing with water. The drying temperature is not limited, but is preferably 40 to 2
00 ° C.

Next, as an electrolytic type Cr ion-containing aqueous solution treating agent, a treating solution obtained by adding at least one of sulfuric acid, phosphoric acid, halogen ions and the like to chromic acid, or a silica sol, an alumina sol, etc. to this treating solution. Examples of the treatment solution include the colloids, or the ions such as cobalt ion, magnesium ion, zirconium ion, and titanium ion. An example of such a treatment liquid is disclosed in Japanese Unexamined Patent Publication No. 5-179488, which is hexavalent Cr.
Ion 2 g / L or more, sulfate ion 20 to 2000 pp
m is an acidic electrolytic treatment liquid having a pH of 0.5 to 2.0, and silica sol at a concentration of fluorine of 400 ppm or less, at least one ion selected from zirconium ion and titanium ion of 20 to 1000 ppm and a solid content concentration for further improving corrosion resistance. An acidic electrolytic treatment solution which may contain 1 to 5 g / L is proposed and can be used in the present invention. The above-mentioned electrolytic Cr ion-containing aqueous solution treating agent is used to subject the object to be subjected to cathodic electrolysis, washing with water, and drying if necessary to form a base film. For drying, air blowing or heat drying is appropriately selected.

Similarly, examples of the Zr ion or Ti ion containing aqueous solution treating agent include reactive type and coating type. These aqueous solution treating agents contain zircon hydrofluoric acid or titanium hydrofluoric acid instead of chromic acid in the Cr ion-containing aqueous solution treating agent. That is, in the case of the reactive type, an acid such as zircon hydrofluoric acid or titanium hydrofluoric acid, hydrofluoric acid, phosphoric acid (or nitric acid) is contained at the same concentration as in the case of the reactive type Cr ion-containing aqueous solution treating agent. The conditions of the film treatment and the drying may be substantially the same as those in the case of the reactive type Cr ion-containing aqueous solution treating agent. Also in the case of the coating type, the same components and concentrations as in the case of the coating type Cr ion-containing aqueous solution treating agent can be used except that zircon hydrofluoric acid or titanium hydrofluoric acid is used instead of chromic acid, and the coating and drying conditions are also the same. Good. The above-mentioned Cr, Zr and Ti
Specific examples of the aqueous solution containing at least one metal ion selected from No. 1 to No. 1 of Table 1 below. Commercially available agents such as those shown in 1 to 7 can be mentioned, and these may be used according to the instruction manual.

By forming these undercoat films,
It is possible to improve the corrosion resistance of the aluminum plate material and the adhesion between the film-removing unnecessary coating layer of the present invention and the aluminum substrate. The performance of the composite coating is 3 to 300 mg / m ² , and preferably 5 to 150 mg, as the amount of metal adhesion of the underlying coating.
The effective range is / m ² . Undercoat 3m
If it is less than g / m ² , corrosion resistance and adhesiveness will decrease, and 300 mg
If it exceeds / m ² , the adhesiveness will decrease.

Next, the ethylene ionomer resin which is the main component of the water-based organic polymer resin composition will be described.
This resin has an ionomer structure in which a carboxyl group is cross-linked with a metal ion between the molecules of a copolymer of ethylene and an α, β-unsaturated carboxylic acid. Examples of α, β-unsaturated carboxylic acids used herein include acrylic acid,
Methacrylic acid, maleic acid, fumaric acid and the like can be mentioned. These may be used alone or in combination of two or more. First, a method for producing this ethylene-based ionomer resin will be described. Monomer ethylene and α,
β-unsaturated carboxylic acid and α, β-
The unsaturated carboxylic acids are mixed so that the weight ratio is 0.05 to 0.2, the temperature is 150 to 250 ° C., and the pressure is 1000 to 2
Under high temperature and high pressure of 000 kg / cm ² , bulk polymerization is carried out using an organic peroxide such as t-butyl peroxide as a catalyst to produce an acid copolymer. A metal ion is added to the acid copolymer with a basic metal compound such as a metal oxide, a metal hydroxide or a metal carbonate so that the degree of neutralization becomes 30 to 70%, and the acid in the acid copolymer is added. Neutralize the group. As this neutralization operation, a method of neutralizing the acid groups of the acid copolymer with the above-mentioned metal ion source under melting of the acid copolymer in an extruder, the acid copolymer including the metal ion source There is a method of stirring in heated water. In this case, the latter is obtained as an aqueous dispersion, but the former needs to be an aqueous dispersion. As a method for obtaining this aqueous dispersion, a method of stirring the obtained neutralized copolymer in water heated to a temperature equal to or higher than the melting point of the copolymer can be mentioned. An anionic or nonionic surfactant may be used to ensure the stability of the aqueous dispersion obtained by the above method.

What is important here is that the weight ratio of α, β-unsaturated carboxylic acid to ethylene is 0.05 to 0.
2, preferably 0.1 to 0.15, and the degree of neutralization with metal ions is 30 to 70%, preferably 40 to 60%. When the weight ratio of the α, β-unsaturated carboxylic acid to ethylene is less than 0.05, the carboxyl group necessary for the adhesion to the surface of the aluminum plate material is insufficient and the adhesion is deteriorated. If this weight ratio exceeds 0.2, the structure of the ethylene chain is reduced and the lubricity is reduced. The metal ion for neutralizing the carboxyl group in the unsaturated carboxylic acid is 30 to 70%, preferably 40 to 60% of the carboxyl group.
It is necessary to have a crosslinked ionomer structure. This is because the degree of neutralization of carboxyl groups by metal ions is 30.
If it is less than 100%, the coating properties such as solvent resistance are deteriorated, and conversely, if the degree of neutralization exceeds 70%, the adhesion to the surface of the aluminum plate material is deteriorated.

Metallic metals used for the neutralization of carboxyl groups
On, Li⁺, Na⁺ , K⁺, Zn²⁺, Mg²⁺,
Al³⁺, Fe²⁺, Ni²⁺, Mn²⁺, Cu²⁺, Cs²⁺And
And Rb⁺Etc., but especially Li⁺, Na⁺, K⁺,
And Zn²⁺Use at least one or more selected from
It is preferable from the viewpoint of solvent resistance.

Sufficient solvent resistance cannot be achieved with the above resin components alone, so it is necessary to add an organic crosslinking agent in order to improve solvent resistance. This is accomplished by further crosslinking the ionomer resin with an organic crosslinking agent. As described above, the ethylene-based ionomer resin has not only the cross-linking property by the metal ion but also the heat-curing property by the cross-linking by the organic cross-linking agent, and thus the coating film characteristics excellent in the solvent resistance and the corrosion resistance can be obtained. . The organic cross-linking agent has at least one functional group selected from the group consisting of an epoxy group, a trialkoxysilyl group, an oxazolyl group and an isocyanato group capable of undergoing a cross-linking reaction with an unneutralized carboxyl group with a metal ion. Is.

As the organic cross-linking agent having an epoxy group,
Commercially available epoxy compounds used as organic cross-linking agents, such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, sorbitol polyglycidyl ether, allyl glycidyl ether, butyl glycidyl ether, phenylglycidyl Ether, alkylphenol glycidyl ether, polyethylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether,
Neopentyl glycol diglycidyl ether, 1,6
-Hexanediol diglycidyl ether, glycerin polyglycidyl ether, diglycerin polyglycidyl ether, trimethylolpropane polycresyl glycidyl ether, aliphatic diglycidyl ether, polyfunctional glycidyl ether, tertiary fatty acid monoglycidyl ether, epoxy acrylate, bisphenol A Glycidyl ether, propylene oxide adduct of bisphenol A or hydroxylated bisphenol A, butyl glycidyl ether acrylate, ethylene glycol diglycidyl ether acrylate, trimethylolpropane polyglycidyl ether polyacrylate, terephthalic acid diglycidyl ester acrylate, phthalic acid diglycidyl ester, It is possible to use spiroglycol diglycidyl ether etc. Kill.

As the organic cross-linking agent having a trialkoxysilyl group, a commercially available silane coupling agent used as an organic cross-linking agent, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, vinyltri Acetylsilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ
-Mercaptopropyltrimethoxysilane, β-mercaptoethyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, vinyltrichlorosilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane , N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-
Aminopropylmethyldimethoxysilane, γ- (diethylenetriamino) propyltrimethoxysilane, γ-ureidopropyltriethoxysilane, imidazolinetriethoxysilane, γ- [N- (β-methacryloxyethyl) -N, N-dimethylammonium ( Chloride)] propyltrimethoxysilane, bis- (3-triethoxysilylpropyl) -tetrasulfane, γ-chloropropyltriethoxysilane and the like can be used.

As the organic cross-linking agent having an oxazolyl group, vinyl oxazoline / styrene copolymer and the like can be used. As the organic cross-linking agent having an isocyanato group, a commercially available isocyanate used as an organic cross-linking agent, for example, toluylene diisocyanate, a dimer of toluylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluylene diisocyanate, diphenylmethane diisocyanate, Tolylene diisocyanate oxime block, polyisocyanate prepolymer, blocked isocyanate, polyisocyanate,
Two-component polyisocyanate, non-yellowing two-component polyisocyanate, thermosetting polyisocyanate and the like can be used.

The amount of the organic cross-linking agent added is required to be 10 to 70%, preferably 15 to 65%, in terms of the equivalent amount to the unneutralized carboxy groups. If the added amount of the organic cross-linking agent exceeds 70%, it becomes plastic and the solvent resistance decreases, and if it is less than 10%, the cross-linking effect cannot be obtained. Is inferior, which is not preferable. Regarding the method of blending the organic crosslinking agent,
It suffices to simply add it to the ethylene ionomer resin and disperse it.

The above resin component alone cannot achieve the desired moldability of the present invention, and it is necessary to include a lubricating additive. As a lubricating additive for improving the molding processability, hydrocarbon-based, fatty acid amide-based, ester-based, alcohol-based, metal soap-based lubricating additives, etc. are known. In the lubricating additive of, the saponification value is 0 or 30 or less, preferably 0 to 20.
Is a petroleum wax such as paraffin wax or microcrystalline wax, or a polyethylene wax having a saponification value of 0 or 30 and a molecular weight of 1000 or more and a derivative thereof (for example, polyethylene glycol stearate). By including it in the polymer resin composition, excellent moldability and lubricity can be obtained, and performances such as solvent resistance, corrosion resistance after processing, and alkali resistance can be improved.

The amount of the petroleum wax or polyethylene wax to be added is not particularly limited, but it is preferably contained in the water-based organic polymer resin composition in an amount of 5 to 25% by weight based on the total solid content including the wax. . Saponification value is 3
Petroleum waxes or polyethylene waxes exceeding 0 have a large polarity and are easily miscible with the resin, so that they are less likely to be present on the resin surface during film formation and the lubrication effect is insufficient. The content of petroleum wax having a saponification value of 0 or less than 30 is 5
If it is less than 25%, the workability improving effect is small, and if it exceeds 25%, the workability is deteriorated due to the elongation and strength of the resin film, and the solvent resistance is also decreased, which is not preferable. Regarding the method of blending the petroleum wax or the polyethylene wax, it suffices to simply add it to the ethylene ionomer resin and disperse it. The order of addition with the organic cross-linking agent does not have to come first, and either may come first or at the same time.

Silica sol can be further added to the water-based organic polymer resin composition for the purpose of improving corrosion resistance and further improving coating film adhesion in the case of overcoating. The silica sol is not particularly limited, and may be produced by either a gas phase method or a liquid phase method. Specific examples include the liquid phase method Snowtex N and Snowtex N manufactured by Nissan Chemical Industries, Ltd. C, or an aqueous dispersion of AEROSIL 200 manufactured by Nippon Aerosil Co., Ltd. in the vapor phase method, or the like can be used. When adding the silica sol, a particularly important point is to add the silica sol as a solid content in an amount of 30% by weight or less based on the total solid content of the aqueous organic polymer resin composition. If it is added in an amount of more than 30% by weight based on the total solid content, the coating film becomes brittle and the corrosion resistance, molding processability and adhesiveness deteriorate. More preferably, addition of 20% by weight or less improves solvent resistance. The silica sol may be added by simply adding it to the ionomer resin and dispersing it. Further, the order of addition between the organic cross-linking agent and the petroleum wax or the polyethylene wax is not limited, and any of them may be added first or simultaneously.

In addition, in the water-based organic polymer resin composition of the present invention, a conductive material for improving weldability, a coloring pigment for improving design, or an antistatic agent for use in electronic parts. It is also possible to add agents. Also, various additives such as a leveling agent, an anti-settling agent, a thickener, etc. may be added. These additives can be added within a range that can usually achieve the purpose and within a range that does not impair the effects of the present invention.

The water-based organic polymer resin composition of the present invention is applied to the surface of an aluminum plate material and dried. As a coating method, a roll squeeze method, a chemi coater method, a roll coater method,
Well-known coating methods such as an air knife method, a dipping method, a spray method, and an electrostatic coating method can be appropriately used. Drying is performed by heating and drying, but the drying temperature is not preferable because the yellowing phenomenon occurs when the ultimate plate temperature exceeds 200 ° C., and the coating performance deteriorates when the temperature further increases. Preferably, the ultimate plate temperature is 50
To 200 ° C, more preferably 100 to 180 ° C. The thickness of the film-removing unnecessary type coating layer obtained by drying is required to be 0.1 to 10 μm in order to achieve the target performance of the present invention. If it is less than 0.1 μm, the lubricity is inferior, and if it exceeds 10 μm, a poor appearance and processability called powdering phenomenon, in which powdery substances are separated and deposited during processing, and workability are deteriorated, and the cost is increased, which is not economical.

[0028]

The aqueous organic polymer resin composition of the present invention contains an organic crosslinking agent in order to improve the solvent resistance. This is to obtain excellent solvent resistance by further cross-linking the ionomer resin obtained by neutralizing the acid copolymer with metal ions with an organic cross-linking agent.
Generally, an ionomer resin is composed of three phases of a polyethylene crystal part, an amorphous part, and an ionic aggregation part, and the crystal part and the ionic aggregation part form a microphase-separated structure dispersed in an amorphous matrix phase in a small lump. doing. Therefore,
By acting as a hard physical cross-linking point of the ionic aggregation part,
The rigidity, surface hardness and tensile strength are higher than those of acid copolymers. By adding an organic cross-linking agent to the ethylene ionomer resin having such basic characteristics,
Some of the unneutralized carboxyl groups are covalently crosslinked. That is, it is considered that the solvent resistance and the corrosion resistance are improved by adopting a structure in which the ionic bond crosslinks and the covalent bond crosslinks coexist. Thus, the ethylene-based ionomer resin is not only crosslinked by metal ions,
Cross-linking with an organic cross-linking agent gives a thermosetting characteristic, and it is possible to obtain coating film characteristics excellent in solvent resistance and corrosion resistance.

[0029]

EXAMPLES The effects of the present invention will be specifically described below with reference to Examples and Comparative Examples. Two types of performance evaluation tests were carried out: [Test A] using aluminum alloy A5052 as an aluminum material and [Test B] evaluated using various aluminum materials.

[Test A] Aluminum alloy plate material (JIS
A5052, dimensions: 200 mm x 300 mm, plate thickness 0.
3 mm) was degreased with an alkaline degreasing agent (registered trademark: Fine Cleaner N364S) manufactured by Nippon Parkerizing Co., Ltd. under the conditions of a concentration of 20 g / L, a temperature of 60 ° C. and a spraying time of 2 minutes, followed by rinsing with water, followed by surface treatment, and then, The water-based organic polymer resin composition of the present invention is applied, and the temperature is 1
A material that was dried for 5 seconds (maximum plate temperature: 120 ° C.) was used as a test material. The base treatment chemicals are shown in Table 1, the resin species used in the aqueous organic polymer resin composition are shown in Table 2, the organic crosslinking agent species are shown in Table 3, and the organic lubricant species are shown in Table 4. The types of silica sol are shown in Table 5. The treatment process of the base treatment chemical shown in Table 1 differs depending on the type. The chemical molding and anodized film was treated under the conditions shown in Table 1, washed with water and dried at room temperature. The coating-type treated film was treated under the conditions shown in Table 1, baked at 70 to 80 ° C., and dried.

The ionomer resin was produced as follows. Ethylene and methacrylic acid or acrylic acid in a predetermined amount ratio were mixed at a temperature of 1 using a tank reactor with a stirrer.
80-220 ° C, pressure 1300-1800kg / c
Polymerization was carried out under the conditions of m ² and catalyst t-butyl peroxide to prepare an acid copolymer. The obtained acid copolymer and the basic metal compound in an amount such that the degree of neutralization of the acid copolymer is within a predetermined range are melted and stirred at 250 ° C. using an extruder to mix the acid copolymer. A neutralized product of the polymer was prepared, and then charged into a pressure-resistant homomixer heated to 170 ° C. with water, stirred at a rotation speed of 1000 rpm for about 2 hours, and further cooled to room temperature with stirring for 30 minutes to produce an ionomer resin. did. The water-based organic polymer resin composition was prepared as follows. For example, paint No. 1 was prepared by mixing 696 parts by weight of resin A, 15 parts by weight of organic cross-linking agent α, 50 parts by weight of organic lubricant a, and 239 parts by weight of water. Other paints were mixed and prepared according to their contents. The water-based organic polymer resin composition shown in Table 6 was applied to a # 4 bar coater (about 9
cc / m ² ) was applied to the surface of the test material, and the film thickness was adjusted by the concentration of the paint.

The test material prepared by the above method was tested for workability, solvent resistance, corrosion resistance, adhesion, alkali resistance, fingerprint resistance and printability. A1) Workability test The appearance of the film damage on the cylindrical processed portion under the deep-drawing condition of the cylinder was visually evaluated. <Cylindrical deep drawing conditions> Punch diameter; 50 mmφ Die diameter; 51 mmφ Punch shoulder; 5 mmR Die shoulder; 5 mmR Punch speed; 30 m / min Sample diameter; 105 mmφ Test temperature; 30 ° C. <Evaluation criteria>◎; None ○: There is very little film damage after squeezing △: Small film damage due to squeezing ×: Large film damage due to squeezing × ×: Specimen breaks without drawing

A2) Solvent resistance test Rubbing was performed 100 times with gauze impregnated with ethanol, and the appearance of the film was visually evaluated for damage. <Evaluation Criteria> ⊙: No damage to the coating ∘: Damage to the coating is negligible △: Damage to the coating is small ×: Damage to the coating is large A3) Corrosion resistance test 400 hours salt spray test based on JIS Z2371 The white rust generation area after that was measured. <Evaluation criteria> ◎: White rust area less than 3% ○; White rust area 3% or more and less than 10% △; White rust area 10% or more and less than 30% ×; White rust area 30% or more

A4) Adhesion test Using an NT cutter, 100 squares at 1 mm intervals were prepared,
The number of peeled films with a cellophane tape was measured. <Evaluation Criteria> ○: No peeling Δ: Peeling number 1 to 5 ×; Peeling number 6 to 20 XX; Peeling number 21 or more A5) Alkali resistance test Alkaline degreasing agent (registered trademark: Fine Cleaner N364S) manufactured by Nippon Parkerizing Co., Ltd. ), The concentration is 20 g /
It was immersed in L at 50 ° C. for 2 minutes, washed with water and air-dried. Solubility was evaluated by measuring the weight difference before immersion and after air drying. <Evaluation Criteria> ◎: No difference in weight ○: Weight loss of less than 5% △: Weight loss of 5% or more and less than 30% ×; Weight loss of 30% or more

A6) Fingerprint resistance test The state of adhesion of fingerprints when a finger was pressed against was visually determined. <Evaluation Criteria> ◯: No adhesion mark is observed Δ: Adhesion mark is slightly conspicuous ×: Adhesion mark is significantly conspicuous A7) Printability test A silk screen ink was printed and evaluated by ink adhesion evaluation after UV curing. The adhesiveness was evaluated by removing the cellophane tape. As the silk screen ink, a UV metal ink manufactured by Toyo Ink Mfg. Co., Ltd. was used. <Evaluation criteria> ○: Good, no peeling △: Bleeding or peeling X: Printing bleeding

The results of the performance test of Test A are shown in Table 7. Example No. 1 in which a composition within the scope of the present invention was applied by performing chromate treatment. Nos. 1 to 21 are excellent in various properties such as processability, solvent resistance, corrosion resistance, adhesion, alkali resistance, fingerprint resistance and printability. However, Comparative Example No. 3 which does not satisfy the scope of the present invention. 1 to 21 are processability, solvent resistance,
Performance is poor in any of corrosion resistance, adhesion, alkali resistance, fingerprint resistance, and printability. In Comparative Example 1, since no undercoating treatment was performed, the corrosion resistance was insufficient, and the workability and adhesion were inferior. In Comparative Example 2 and Comparative Example 3, the base treatment is not suitable except for the present invention, and the workability and adhesion are inferior. In Comparative Example 4 and Comparative Example 16, the organic cross-linking agent is outside or outside the present invention, and the solvent resistance and alkali resistance are also inferior. In Comparative Example 5 and Comparative Example 6, the amount of the organic cross-linking agent added is outside the scope of the present invention, Comparative Example 5 with less than 10% has reduced solvent resistance, and Comparative Example 6 with more than 70% has solvent resistance and Workability is poor.

In Comparative Examples 7 and 8, the degree of neutralization of the paint by the metal is out of the range of the present invention, Comparative Example 7 in which the paint content exceeds 70% has poor adhesion, and Comparative Example 8 in which the paint content is less than 30%. Solvent resistance is inferior. In Comparative Example 9 and Comparative Example 10, the weight ratio of α, β-unsaturated carboxylic acid to ethylene is out of the range of the present invention, and in Comparative Example 9 in which it exceeds 0.2, the workability is poor, and it is less than 0.05. In Comparative Example 10, the adhesion is poor. Since Comparative Example 11 is not neutralized with a metal, solvent resistance, corrosion resistance and alkali resistance are deteriorated.
In Comparative Examples 12 to 15, since the resin species are outside the present invention, the processability is good, but the solvent resistance and alkali resistance are poor. Comparative Example 17 is an example containing no petroleum wax as an organic lubricant, and is inferior in processability. In Comparative Example 18 and Comparative Example 19, the organic lubricant type is outside the scope of the present invention, or the saponification value is outside the scope of the present invention, the processability is particularly poor, and the solvent resistance, adhesion and alkali resistance are also low. Inferior Comparative Examples 20 and 21 have a coating amount outside the range of the present invention, and Comparative Example 20 having a thickness of less than 0.1 μm is particularly inferior in workability and inferior in fingerprint resistance. Further, in Comparative Example 21, when the film thickness is thicker than 10 μm, the workability and the adhesion are deteriorated.

[Test B] An aluminum alloy having the composition shown in Table 8 was melted by a conventional method and continuously cast into an ingot, which was homogenized at 550 ° C. for 9 hours and then hot-rolled to 2 mm. It was used as a plate material. Then 2 at a temperature of 380 ° C
After performing intermediate annealing for holding for a time, final cold rolling was performed to a thickness of 0.3 mm, and stabilization treatment was performed for holding at 200 ° C. for 2 hours. After that, degreasing in the same process as test A,
After washing with water, phosphoric acid chromate treatment was performed with Alchrome K702 manufactured by Nippon Parkerizing Co., Ltd. so that the Cr deposition amount was 20 mg / m ^2, and the water-based organic polymer resin of No. 1 shown in Table 2 of the present invention. The composition was applied and dried (maximum ultimate plate temperature: 120 ° C) was used as a test material.

In the evaluation test, in addition to the conventional solvent resistance, corrosion resistance, adhesion, alkali resistance, fingerprint resistance, printability,
Bending workability and strength tests were conducted. B1) Bending workability test A 90 ° -OR bending test was performed using the plate thickness of the test material as the bending radius, and the cracking condition of the bending portion was observed. <Evaluation Criteria> ○: No cracks ×: Cracks occurred B2) Strength test A dent resistance test was performed. The test was a static test using a copper ball indenter (curvature radius 20 mm) and a load of 1 kg. <Evaluation criteria> ○: Small deformation ×: Large deformation

The performance test results are shown in Table 9. Material No. 1
Examples 22 to 28 using the aluminum alloys of
It is also good in various properties such as bending workability, strength, solvent resistance, corrosion resistance, adhesion, alkali resistance, fingerprint resistance and printability. On the other hand, the material No. Examples 29 to 31 using the aluminum alloy having the composition of 8 to 10 were inferior in any of bending workability and strength, but solvent resistance, corrosion resistance, adhesion, alkali resistance, fingerprint resistance and printing. The sex was excellent.

[0041]

EFFECTS OF THE INVENTION According to the present invention, the surface of an aluminum plate is provided with strong moldability, that is, excellent lubricity and solvent resistance, and corrosion resistance, alkali resistance, scratch resistance, fingerprint resistance and printability. Also, it is possible to provide a method for forming a composite film on the surface of aluminum or an aluminum alloy on which an excellent film-removal type film layer is formed. Therefore, the practical effect of the present invention is quite large.

[0042]

[Table 1] Table 1 Types of surface treatment

[0043]

[Table 2] Table 2 Test resin types

[0044]

[Table 3] Table 3 Sample organic cross-linking agent

[0045]

[Table 4] Table 4 Organic lubricants tested

[0046]

[Table 5] Table 5 Test silica sol

[0047]

[Table 6] Table 6 Composition of water-based organic polymer resin composition (solid content)

[0048]

[Table 7] Table 7 Performance test results

[0049]

[Table 8] Table 8 Alloy composition

[0050]

[Table 9] Table 9 Performance test results

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location B05D 7/24 302 B05D 7/24 302Y 302R 302T C09D 133/02 PFW C09D 133/02 PFW 191/06 JAK 191/06 JAK C23C 22/00 C23C 22/00 Z 22/24 22/24 (72) Inventor Ryoji Morita 1-15-1, Nihonbashi, Chuo-ku, Tokyo Japan Parkerizing Co., Ltd. (72) Inventor, Jido Bunji 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Takahiro Sato 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (4)

[Claims] 1. A surface of aluminum or an aluminum alloy is previously treated with an aqueous solution containing ions of at least one metal selected from Cr, Zr and Ti,
After forming an undercoat on the surface, a resin skeleton is formed from ethylene and α, β-unsaturated carboxylic acid on the undercoat, and the weight ratio of the α, β-unsaturated carboxylic acid to ethylene is 0. .05 to 0.2 and the degree of neutralization for the carboxyl group in the unsaturated carboxylic acid is 30 to 70.
% Of the epoxy group, trialkoxysilyl group, oxazolyl group and isocyanato group in an amount of 10 to 70% as an equivalent to the unneutralized carboxyl group in the resin. An organic cross-linking agent having at least one functional group selected from the group, and a saponification value of 0 or 30 as a lubricating additive.
Aluminum or aluminum characterized in that a water-based organic polymer resin composition containing the following petroleum wax or polyethylene wax is applied and then dried to form a film-removing unnecessary film layer of 0.1 to 10 μm. A method for forming a composite film on the surface of an alloy. 2. The composite film forming method according to claim 1, wherein the aqueous organic polymer resin composition further contains silica sol. 3. The method for forming a composite film according to claim 1, wherein the metal ion in the ionomer resin is at least one selected from Li ⁺ , Na ⁺ , K ⁺ and Zn ²⁺ . 4. The petroleum wax or polyethylene wax is contained in an amount of 5 to 25% by weight based on the total solid content of the water-based organic polymer resin composition including the petroleum wax or polyethylene wax itself. Item 1
The method for forming a composite film as described.