JPS60141549A - Corrosion-resistant coated laminate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a corrosion-resistant painted laminate, and more specifically to a corrosion-resistant painted laminate in which a chromium compound-containing corrosion-resistant layer and a chromium compound-free paint layer are laminated on a zinc, iron, or alumina 11 metal base material. Regarding a painted laminate.

Zinc, iron, and aluminum metals are coated for aesthetic and other functional purposes, and are often pretreated to improve coating adhesion and corrosion resistance. Such pretreatments include phosphate treatment, chromate treatment, anodic oxidation treatment, etc. Among them, chromate treatment is considered to be useful for forming a highly corrosion-resistant coating film. This chrome
1- Regarding treatment techniques, various proposals have been made for the purpose of improving coating film corrosion resistance and sealability. In other words, technology to form a poorly soluble film by regulating the amount of hexavalent chromium relative to the total chromium in the liquid composition (for example, Japanese Patent Publication No. 39-1
No. 8217, No. 54-37567, etc.), technology using colloidal silica or water-dispersible silica as a binder to increase the amount of chromium deposited as a coating type chromate (for example, Japanese Patent Application Laid-open No. 511.0834, No. 53-92339, etc.) ), techniques that similarly use water-soluble resins or water-dispersible resins (for example, JP-A-52-30235, JP-A-53-49)
029, etc.), technology of adding phosphoric acid or fluorine salt as a reaction accelerator (for example, Japanese Patent Publication No. 44-26525, Japanese Patent Publication No. 524)
2135, etc.), N], Co, Mn as film modifiers.
, Zn.

Techniques for adding metal salts such as Ra (for example, JP-A-56-1
No. 05486, No. 5B-34178, etc.), or a technique of treating with a chromate solution containing a reaction accelerator, followed by treatment with a coating type chromate-1 solution, etc. have been proposed. However, although these all improve the initial corrosion resistance performance, they may cause deterioration of corrosion resistance due to thermal alteration or deterioration of corrosion resistance over time due to the reaction between the active chromium of the chrome-1 film and the coating film components. This did not solve the wood-related problems of chromate-based films.

On the other hand, it is often done to incorporate rust preventive pigments such as solid chromate pigments and button pigments, which have relatively low solubility, into paints that require high corrosion resistance; However, deterioration of corrosion resistance over time has been a problem. In addition, although it is not as strong as water-soluble chromium compounds, there are some paints in which pigments cannot be added because these chromate pigments react with paint components, and even if they can be added, there are restrictions on the chromate I pigments that can be used. In order to provide corrosion resistance, a relatively large amount of pigment is required, and furthermore, it is complicated and difficult to select an appropriate combination of pigment and paint.

Therefore, it is possible to fix a chromium compound that has a sufficient protective film function on the metal surface, has excellent heat resistance, does not react with the coating resin, and exhibits long-term corrosion protection, and can also be used with any paint. ), it must be said that it would be of great benefit to the industry if the technology was established.

As a result of intensive research, the present inventors have developed a combination of a hexavalent chromium-containing chromium compound with solubility within a specific range and a certain binder, and a paint pretreatment agent containing a water-soluble chromium compound in the combination. It has been discovered that all of these problems can be solved by using the following, and the present invention has been completed.

In other words, the purpose of the present invention is to provide excellent corrosion resistance and coating adhesion to zinc, iron, and aluminum base metals, and in particular to prevent thermal deterioration and/or
Another object of the present invention is to provide a corrosion-resistant paint laminate, which forms a corrosion-resistant paint film that does not deteriorate over time due to reaction with a paint resin, and further laminates a paint containing no chromium compound on the corrosion-resistant paint film.

The purpose of the present invention is basically to use metallic materials that have undergone or have not been subjected to corrosion-resistant chemical conversion treatment.Second, at least one chromium-11 compound containing hexavalent chromium-11 having a solubility of 20 to 10-5 As a metal chronograph, 10-! ~1.
A corrosion-resistant layer is formed by treatment with a chromate-1 treatment solution containing 10-2 to 500 g/] of a binder compatible with chromate pigment in terms of solid content, and a paint layer that is substantially free of chromate pigments. This is achieved by a corrosion-resistant painted laminate made of In a particularly preferred embodiment, the corrosion-resistant layer composition further contains a water-soluble chromium compound of 10-' to 100.0% in terms of metallic chromium. /] Contain.

Solubility 20-10-5 used in the present invention 6
Specifically, chromium compounds containing valent chromium have a solubility of 20 to 1
Typical calciuno romate with 0 and solubility 10-10
Typical examples include zinc chromate and strontium chromate with a solubility of 10-1 to +05, and barium chromate and lead chromate with a solubility of 10-1 to +05. Also, it is a mixture of hexavalent talo-11 compound and other metals or a reaction product with an organic substance.
This also includes compounds having a solubility of 20 to 10-5.

Compounds with a solubility of more than 20 are too active in the coating resin reaction and do not sufficiently improve the corrosion resistance of the coating over time.On the other hand, compounds with a solubility of less than 10-5 do not have sufficient anti-corrosion ability and cannot be used properly. The effect of the invention is not demonstrated. still.

Calcium chromate, which has a solubility of 20 to 10, is particularly useful when the applied material is active or the corrosion environment of the paint film is low humidity.
It tends to be somewhat corrosion resistant and lacks sustainability.

Typical entry point 11 acid button with solubility of 10-1 to 10-5 is high humidity rot 111! I! It exhibits high corrosion resistance under environmental conditions, but its anticorrosion ability is slightly inferior under low humidity conditions. On the other hand, typical zinc chloride and strontium chromate, which have a solubility of 10-1 to 10, are particularly useful because they have appropriate solubility and exhibit a high degree of corrosion resistance in corrosive environments.
There is one compound.

The chromium compounds may be used alone or in combination of two or more, as appropriate, depending on the coating type of the material and the required coating capacity.

As mentioned above, "11. The concentration of the compound in the pretreatment agent of the present invention must be within the range of 10-1 to too, /1 in terms of metal chloride 11. This means 10-'r, /1. , less than L is 5 for the purpose of the present invention, too dilute for normal use U,
The method of use can achieve the inventive effect, on the other hand, 100 g/l
This is because, if it exceeds this, the stability of the processing agent itself will deteriorate.

In the present invention, the above compound is used in combination with a binder that is compatible with chromium. The indizer is typically water-based silica or water-based resin.

Typical water-based silica is colloidal silica or water-dispersible silica with a particle size of 100IllI) or less, and a specific example of such colloidal silica is Snowtex 0(
Colloidal silica, product manufactured by Nissan Chemical Co., Ltd., solid content 20%, average particle size 20+++ 7z, p+13.0), Snowtex N (same, pH 9), Snowtex Yen, (same,
Particle size 40-50m 7L, (+Il Gil brand name Aerosil 300 (particles 1M, +00mμ or less) Aerosil TT-600 (particle size 01...0.3
μ), Inno 1 Sil Δ1.0B (l (diameter 5 μ, trade name manufactured by Illinois Mineral Ne), etc. Resins are included, and specific examples of water-soluble resins are listed in Bo.
Vinyl alnitol, alkylhydroxyalkyl 1-allulose, polyacrylic acid and its derivatives, polyacrylamide and its derivatives, polyvinyl bi-Dridone,
It is a reaction product of polyvinyl methyl maleic anhydride and beer or acrylic compound, and specific examples of the dispersible resin include alkyd resin, phenol resin, amino resin,
Hinyl acetate emulsion polymer, S'gL.

Examples include butadiene-based synthetic latex polymers, acrylic-based emulsigone polymers, and natural and synthetic rubber-based emulsion polymers.

These binders can be used alone or in combination of two or more kinds, and are effective in closely fixing the chromium compound to the metal surface.

Binder component is 10-2 to 500g/ in terms of solid content]
be selected within the range of Especially in the case of water-based silica, 1
Selected from 0-2 to 500 ratio/1] 11.10-”g/
], the sufficient effect of the present invention cannot be obtained;
g/] - no particular effect is expected from increasing the dose. In the case of water-based resin, 10"-50g
Selected from /l A waist 10-1, If it is less than /1, the sufficient effect of the present invention cannot be obtained, and if it exceeds 50g/l, fJ
The stability of one component tends to deteriorate.

It is preferable that pl+ of the pretreatment agent of the present invention is adjusted within the range of 1 to 10. This is because if it is lower than Pll, excessive dissolution of the metal will occur during film formation, which is undesirable.
Moreover, if the pretreatment agent's p
For l+ adjustment, various ordinary inorganic acids or organic acids,
Volatile bases such as aqueous ammonia and amines are used.

The pretreatment agent of the present invention is applied to a cleaned zinc, iron, or aluminum metal surface by a conventional method, such as a dipping method, a spray method, or a roll coating method, and is allowed to dry without washing with water. Drying conditions are the maximum temperature reached on the metal surface of 60 to 200.
It may be selected as appropriate under the conditions of °C.

The weight of the dry film formed by the pretreatment liquid is usually 0.05 to 5 g/
If the amount is less than this, the protective film function will be insufficient and sufficient corrosion resistance cannot be expected, and if it exceeds 5 g/m'', no significant effect can be expected by increasing the amount. Incidentally, the amount of metal chromium (2) is preferably 0.01 g to Ig/m2.

The protective film thus obtained is stable against thermal deterioration and exhibits excellent corrosion resistance, and provides excellent corrosion resistance over a long period of time without reacting with the resin component of the clear or top coat.

The present inventors further discovered that by adding a water-soluble chromium compound to the pretreatment agent of the present invention, in terms of metallic chromium, 1O-I to 100g/], significantly superior additive initial corrosion resistance and corrosion resistance over time were obtained. I also found that. Follow me
C According to a preferred embodiment of the present invention, the solubility is 20-1
At least one chromium compound containing 0-5 hexavalent chromium
1.0-1 to 100 g as metallic chromium seeds, and 1.0-1 to 100 g of metallic chromium as seeds, and at least one of the water-soluble chromium 11 compounds as metallic chromium.
0-' = 100 g/l, (preferably hexavalent chromium is more than 10 g/l of water-soluble chromium) 10-2 to 500 g/l of binder compatible with chromium in terms of solid content,
A metal coating pretreatment agent containing L is used. Note that the water-soluble chromium compound means a water-soluble chromium-11 compound having a solubility of greater than 20, preferably greater than 40.

The water-soluble chromium compound used here is any water-soluble chromium compound conventionally used in chromate treatment agents, such as CrOF(, Cr(No 3 ) 91120,
Cr2 (SO4)3・1'8+120, CrPO4・
6+i2o and other famous chromates or dichromates, and one of them or a silk combination is preferably used.

In the present invention, these water-soluble chromium-11 compounds are used in a range of 10-1 to 100E/1 in terms of metal chromium, and the amount of hexavalent chromium-11 is 10% by weight or more of the water-soluble chromium. This is because if it is less than 10-',/1, no additive effect of the water-soluble chromium compound can be expected, and even if it exceeds 100 g/l, no particular effect will be observed.

The method of applying the pretreatment liquid, the application ratio, ie, the weight of the dry film, etc., are as described above. In addition, when using a pretreatment agent containing a water-soluble chromium-11 compound, the content of the water-soluble compound in the film should be in the range of 0.01 to 0.5 g/m2 in terms of metallic chromium. It is desirable in order to sufficiently exhibit the protective film function and to improve the adhesion of the coating film.

The pretreatment agent according to the present invention may optionally contain one or more of phosphoric acid, hydrofluoric acid, silicic acid, borofluoric acid, zirconium hydrofluoric acid, titanium hydrofluoric acid, and salts thereof as a reaction accelerator.
By adding more than one species, the protective film function of the chromate film can be improved and the corrosion resistance can be further improved. The amount of reaction accelerator is, for example, 5 to 20 g/l in the case of phosphoric acid (phosphate).
degree, 0.03~ for hydrofluoric acid, complex hydrofluoric acid (salt)], Og
/ ], it is also recognized that it is preferable for the effect to be fully exhibited.

The metal materials treated with the pretreatment agent of the present invention are then coated with various paints, including clear ones, which do not substantially contain chromium-pigments, and these can be hydrogen, solvent-based, or powder paints. It is also possible to perform electrostatic coating or electrodeposition coating.

Since such paints do not substantially contain chromate pigments, paint resins and other components can be arbitrarily selected in the applied paints, and if a pretreatment agent containing a water-soluble chromium compound is used, for example, the paint resin etc. and the chromium compound may be mixed together. Even if it may react, it contains a less reactive and less soluble taro compound as an essential component, which is expected to provide sufficient corrosion resistance, and since chromium will not be eluted from the paint film. It can exhibit excellent corrosion resistance over time. Among such paints, paints based on epoxy resin vinyl butyral resin, oil-free polyester resin, and carboxylated polyethylene resin are suitable because of their low film-forming temperature and good adhesion when painting. be. The coating film thickness can be appropriately selected depending on the expected quality, but a coating thickness of about 1 to 10 μm can sufficiently exhibit the effects of the present invention.

The present invention will be explained below with reference to Examples.

Example 1 Zinc chromate with solubility of 6 to 8 (15 g in terms of metallic chromium)
, polyacrylic acid Jurimer AC-10! , (solid content equivalent: 10g) and water total amount is 1j! Mix as desired,
Glass peas dispersed for 1 hour with Red Devils, P112
-3 metal coating pretreatment agents were obtained.

Examples 2-4 and Comparative Examples 1 to 3 Pretreatment agents were obtained in the same manner as in Example 1, but with the formulations listed in Table 1. Acetic acid was used to adjust PL+ to the acidic side, and aqueous ammonia was used to adjust the alkaline side.

Electrogalvanized copper plates (EG) were coated with the various pretreatment agents described above, and after drying, a clear paint was applied to a dry film thickness of 2μ, and after drying by heating, the coated plates were tested for taro, elution, and corrosion resistance.

Corrosion resistance was evaluated by the Tsuru 1-spray method based on the time until white rust appeared after the coating was applied and after the coating was held at room temperature for a predetermined period of time.

The results of these tests are shown in Table 1 below.

Regarding chromium elution, after sealing the back edge of the Fj for painting, immerse it in pure water at 40'C for 72 hours, measure the amount of chromium deposited on the painted surface using fluorescent X-ray analysis, and make a judgment based on the amount of chromium eluted. did. In the table, O is not eluted and △ is 5 mg/m”
× indicates elution of 5 mg/m” or more.

(Leaving space below) Procedural amendment August 31, 1980 Title of invention Corrosion-resistant painted laminate 3 Corrosion-resistant painted laminate Relationship to the case of the person making the amendment Patent applicant address 2-f'I''I-m, Inuyodo Kita, Oyodo-ku, Osaka City 2
Name: Nippon Pain Co., Ltd.Representative: Masao Suzuki 4Agent address: 3-571 Kyobashi, Higashi-ku, Osaka 540 Ji Building River Center 〇 [Name: Patent Attorney J: (6871) Ito Nik ((5 Supplement 1)
Number of inventions increased by the 6th amendment attached to 1-1 of the instruction 7. Subject of the 7th amendment Section 1 of the detailed description of the invention in the written statement, page 7, line 20 of the specification [Snowtex l) T,, J and Correct that to ``Snowtex OI-Tears.''

2. In the same article, page 8, lines 2 to 3, the statement [Made by Jill Co., Ltd., caterpillar] is corrected as follows.

"Aerosil 300 (trade name manufactured by Jill Corporation) (particles of approximately 1 rnμ
) Aerosil TT-600 (Deguri company product, particle size 40 mμ), corrected as Imushi Yu.

3. Same, page 14, lines 5-6 "Roll coat" “Roll coat and correct it to 1.

4. On the same page, lines 10-11 1 predetermined period j Ir2 Power Month,” he corrected.

5. On the same page, line 13 [It says chromium leachability “Corrected to be chromium eluting.

Claims (6)

[Claims] (1) Metal base material that has been subjected to corrosion-resistant chemical pretreatment or has not been pretreated.Secondly, solubility of 20 to 1
Corrosion-resistant layer of a composition containing at least one chromium compound containing 0-5 hexavalent chromium 11, an aqueous silica and/or an aqueous resin binder, and optionally a water-soluble chromium 11 compound having a solubility of greater than 20. and a corrosion-resistant paint laminate comprising successive paint layers substantially free of chromium compounds. (2) The laminate according to claim 1, wherein the metal base material is an iron, zinc, or aluminum metal. (3) The corrosion-resistant layer has a chromium compound converted to metal chromium 11 of 0.
01 to I (H/ +++ 2, laminate according to claim 1. (4) In the corrosion-resistant layer, hexavalent chromium 11 is 10 of the total water-soluble chromium.
~90Ir1. % of the laminate according to claim 1. (5) Claim 1, wherein the paint is characterized by an epoxy resin, a vinyl butyral resin, an oil-free polyester resin and/or a carboxylated polyethylene resin.
Laminated body as described in section. (6) The laminate according to claim 1, wherein the coating film thickness is 1 to 10 μm.