JPS60204320A - 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 painted laminate with excellent weldability, workability, and corrosion resistance, and in particular, a coated laminate with excellent continuous spot weldability suitable for steel parts for automobile bodies, and with high workability and high corrosion resistance. It is related to painting @ figure.

From the point of view of spot welding of steel sheets, it is necessary for the coating film to have electrical conductivity, and conventionally, this purpose has generally been achieved by using conductive pigments.

However, continuous spot weldability is an important issue in high-speed, high-volume, labor-saving lines such as automobile body production lines. Continuous spot welding is important because as the number of welds increases, the electrode becomes contaminated with steel plates, plating films, paint compositions, etc., and must be cleaned or replaced. It is evaluated by the number of times.

Techniques for imparting conductivity to coating films using conductive pigments (e.g., Japanese Patent Publication No. 52-44569, Japanese Unexamined Patent Publication No. 583-1138758, 1) Publication No. 58-174582, etc.)
Alternatively, spot welding is possible at 2,000 or more points using techniques that roughly improve the conductivity of the coating film by devising face size (e.g., JP-A-51-79138, JP-B-Sho 58-19706). There is no consideration given to the requirement of ensuring weldability to continuous slits 1, that is, electrode contamination, resulting in unsatisfactory results. Moreover, in recent automobile production processes, 4T is as large as possible, for example, 2000 to 5
000 continuous spot weldability is required.

In addition, in the press or deep drawing process of coating 8 hori, the coating film peels off into powder during processing and adheres to the press machine, causing processing scratches and requiring frequent cleaning of the press machine. Also, the coating film peels off from the base during processing.
In addition, cracks must not be formed and the corrosion resistance of the area must not be reduced.

It is known to add an inorganic or organic lubricant for the purpose of improving the workability of this coating film.

However, originally, weldable coatings tend to have a distinct composition in order to ensure conductivity. There is a problem in that adding an amount that will give the desired effect will conversely lead to a decrease in the strength and processability of the coating film.

In addition, in the production of automobiles, body parts such as rocker panels, doors, fenders, etc. are usually made from steel plates by press processing, assembled by spot welding, and then degreased, treated with phosphate, and then painted by electrodeposition. Therefore, it is required to have good workability and spot weldability, as well as good adhesion to electrodeposited coatings and corrosion resistance. Corrosion resistance becomes a problem, especially in areas where electrodeposition coating is insufficient, such as the joints and edges of parts. In general, when paints containing relatively large amounts of conductive pigments or lubricants are applied, the corrosion resistance of the paint film tends to decrease, and some conductive pigments themselves or their decomposition products can promote corrosion. The type and conditions of use are particularly important in obtaining highly corrosion-resistant coatings.

Therefore, one of the objects of the present invention is to provide a coated laminate having excellent workability, corrosion resistance, and continuous spot weldability. Another objective of the present invention is that it is excellent in workability, corrosion resistance, and continuous weldability, and it also improves coating adhesion in post-coating processes such as electrodeposition coating11, or in cases where the coating is insufficiently coated. It is an object of the present invention to provide a plate coated steel sheet which is excellent in corrosion resistance f1 at parts and is particularly suitable for automatic production.

As a result of research into the relationship between continuous sprocket weldability and coating film composition, the present inventors found that the thermal decomposition of the paint film binder resin is greatly involved in this continuous sprocket weldability. It changes depending on the aromatic ring content in the resin molecule and the presence or absence of a thermally decomposable substance. Continuous spot weldability can be improved by blending appropriate amounts of substances.
I found out that it can be reduced by 1-U. Add 1.1 again! Regarding the improvement of l, since inorganic pigments coexist in a considerable amount, it is preferable to use a lubricant with a small amount, low specific gravity, and large volume, that is, an organic lubricant, and it is suitable for high-level processing such as automobile bodies. I learned that it is important to select the appropriate type and amount of lubricant, as well as the total amount of conductive pigments and other inorganic pigments.

In order to make it weldable, a conductive pigment is naturally required to be included, but the present inventors have greatly improved the corrosion resistance of the laminate by providing a specific corrosion-resistant layer under the paint layer containing the conductive pigment. Among scales and conductive materials, those containing phosphorus as a main component have particularly excellent corrosion resistance and processability, and have stable low electrical resistance, do not melt during welding, and have high hardness. By using a phosphorus starch decomposition inhibitor in combination and controlling the inorganic pigment concentration, it is possible to obtain a laminate with higher corrosion resistance and excellent workability, weldability, and paint film adhesion. Heading: The present invention has been completed.

According to the present invention, at least one compound containing hexavalent chromium having a solubility of 20 to 10-6 is added to a metal substrate that has been subjected to a corrosion-resistant chemical pretreatment or has not been pretreated. Contains water-based silica and/or water-based resin binder as an essential component, and optionally has a solubility of 20%.
A corrosion-resistant layer of a composition containing a larger water-soluble chromium compound and a conductive coating layer are sequentially laminated, and the coating layer is laminated in sequence. The solid content of the paint in one layer is (A> Paint resin with aromatic ring content in the molecule of 0 to 50 parts by weight, 10 to 35 parts by weight, organic aV + lubricant 4 to 50 parts by weight, and J: and conductive pigments
15 to 86% by weight or (B) Paint resin with an aromatic ring content in the molecule of O to 50% by weight 10 to 35% by weight Organic lubricant 4 to 30% by weight Conductive material mainly composed of iron phosphide Pigment 15-85% by weight Phosphorous wheat decomposition inhibitor 1-71% by weight Other inorganic face fit 0-70% by weight However, conductive pigments, phosphorus raw wheat decomposition inhibitors and other inorganic pigments are included.
A corrosion-resistant painted laminate is provided, the layer having a composition of 35 to 86% by weight of 1/v.

The metal base material in the laminate of the present invention is an iron/zinc/aluminum metal material, particularly a cold rolled steel plate, a galvanized 8-metal steel plate, an alloy galvanized steel plate, an aluminized steel plate, a lead and zinc alloy plate, aluminum and aluminum. These include alloy plates, stainless steel plates, and electrogalvanized steel plates containing nickel or iron.

These metal substrates may be simply cleaned and degreased, or may be pretreated to provide corrosion resistance. Such pretreatment for chemical conversion is a general chemical conversion treatment for forming a phosphate film, a chromate film, etc., and is well known to those skilled in the art, and there is no need to explain its details.

In the present invention, the solubility on this metal base material is 20 to 1.
At least one chromium compound containing 0-5 hexavalent chromium
A corrosion-resistant layer of a composition comprising a seed, an aqueous silica and/or an aqueous resin binder as essential components, and optionally a water-soluble chromium compound having a solubility of greater than 20 is provided. This corrosion-resistant layer has a solubility of 20 to 10-5 as an essential component.
Included are chromium compounds containing valent chromium and optionally water-soluble chromium compounds with solubility greater than 20. Typical examples of the former are calcium chromate with a solubility of 2 () to 10, zinc chromate with a solubility of 10 to 10-1, zinc chromate with a solubility of 1, and chromic acid with a solubility of 10 to 10. There are barium, lead chromate, etc. Also, it is a mixture of a hexavalent chromium compound and its metal, or a reaction product with an organic substance, and it is a compound with a solubility of 20 to 10-!1. Compounds that exceed 100% are active in the reactions of coating resins, so they are highly effective in improving the corrosion resistance of coatings over time.
Compounds with a solubility of less than 10 -5 or less than 10 -5 have insufficient anticorrosion ability. Such chromium compounds usually contain 1
Metallic chromium conversion latitude 0.01 by species or a combination of two or more species
It is present in the corrosion-resistant layer at a ratio of about 1 (]/m2. If desired, water-soluble chromium compounds with a solubility exceeding 20, such as CrO3, Cr(NO3 )3・9H20,C
rz (SO4)3 ・181-120, Cv PO4
- On the 6th, 20, other materials such as murate, dichromate, etc. are added.Aqueous silica and/or aqueous resin is used as a binder compatible with the chromium in the corrosion-resistant layer.

Water-based silica is typically colloidal silica or water-dispersible silica with a particle size of 100 mμ or less. A specific example of such colloidal silica is Snowtex 0 (colloidal silica, trade name manufactured by Nissan Chemical Co., Ltd. Solid content 20% average) Particle size 20mμ, pl-13,0), Snowtex N
(the same, pl-19), Snowtex PL (the same, particle size 40-50 mμ, r) l-13), and the water-dispersible silica is Aerosil 300, a trade name manufactured by Nippon Aerosil Co., Ltd. (particle size 100IIlμ or less). ), Aerosil TT
-600 (particle size 0.1-0.3μ), Imucil A10
8 (particle size 5 It , trade name manufactured by Illinois Minerals), etc. are preferably used. In addition, water-based resins include water-soluble resins and water-dispersible resins that are compatible with chromium, and specific examples of water-soluble resins include polyvinyl alcohol, alkylhydroxyalkyl cellulose, polyacrylic acid and its derivatives, polyacrylamide and its derivatives. derivative,
Examples of water-dispersible resins include alkyd resins, phenolic resins, amino resins, and vinyl acetate emulsion polymers. , styrene, butane-based synthetic latte trimmers, acrylic-based emulsion polymers, and natural and synthetic rubber-based emulsion polymers.

These binders can be used alone or in combination of two or more, and are effective in tightly fixing the above-mentioned 1M compound to the metal surface.

By adding the above-mentioned corrosion-resistant layer, a laminate that does not react with the resin component in the top coat, is stable against thermal deterioration, and exhibits excellent corrosion resistance over a long period of time can be provided. still,
It has also been found that particularly good results are obtained when hexavalent nm accounts for 10 to 90% by weight of the total water-soluble chromium in the corrosion-resistant layer.

The laminate of the present invention has workability, weldability,
A specific conductive paint layer with excellent corrosion resistance is created.

This paint layer is made of a paint resin having a -12= aromatic ring content of O or up to 50% by weight in the molecule as a binder resin, such as an epoxy resin, an alkyd resin, an acrylic resin, a melamine resin, Urethane resin, phenolic resin, vinyl resin, polyvinyl butyral resin, polyvinyl acetate resin, chlorinated rubber, oil-free polyester resin, phthalic acid resin, styrene resin,
It is characterized by using polyolefin resin etc. in organic solvent type or water-based type.

These resins can be used alone or in combination of two or more types, but in the case of a combination, it is expressed by the average content,
As mentioned above, the aromatic ring content must be less than 50% by weight, most preferably 0%.

The present inventors have found that the aromatic ring content in the resin molecule is closely related to continuous spot weldability, and that when it exceeds 50%, the thermal decomposition rate is measured by the following method.The resin weight after heating...from room temperature to 550℃. 'c20℃
Syrup the resin at a rate of tη/min (in a N2 gas flow) and measure the weight with a heated wheel hanging analyzer when the sample temperature reaches 0°C (5 to 101 + 1 (]) between rims). At the same time, the continuous spot weldability is also markedly reduced.When the aromatic ring content is 0 to 50% by weight, the weight loss rate due to thermal decomposition of the resin is 70 to 100%, and 5000 It has been found that it can sufficiently withstand continuous spot welding up to the point.

In addition, the content of resin in the solid content of the paint is 10 to 35% by weight,
It has also been found that when the amount is less than 10% by weight, workability is significantly reduced, and when it exceeds 335% by weight, continuous spot weldability is reduced.

The paint layer contains an organic lubricant as a second component. Organic lubricants are known as slip agents, which are used to reduce the friction between the jig and the paint film, weaken the force applied to the paint film, and reduce damage to the paint film during processing. It is not only an organic substance with a low specific gravity and a large volume fraction in the coating film even in small amounts, but also has good thermal decomposition (decomposition temperature 30
It is preferable that the resin exhibits an exothermic reaction at a temperature of 0 to 500°C, and most of it volatizes and coexists without leaving any carbon that would adversely affect continuous sprocketing or welding. Polyolefin compounds, such as polyethylene, isotactic bolyb [lpyrene, bolybdenum, etc., polymers of unsaturated aliphatic olefin hydrocarbons (preferably those with a molecular weight of about 1000 to 10,000); carboxylic acid ester compounds, e.g. Carboxylic acids such as stearic acid, oleic acid, adipic acid, azelaic acid, and sebacic acid, n-butanol, and sea.

- Seven-, di- or poly-esters with alcohols such as butanol, 3-methylbutanol, 2-ethylhexanoate, neopentyl alcohol; polyalkylene glycol compounds such as polypropylene glycol, polyethylene glycol, etc. are particularly preferred substances. Recommended.

From the viewpoint of processability, thermal decomposition, corrosion resistance, adhesion of the top coat, etc., polyethylene waxes are particularly preferred, and the most preferred are polyethylene waxes with a molecular weight of 1,000 to 10,000;
It is a fine polyethylene powder with a particle size of 50μ or less.

Such organic lubricants can be used alone or in combination of two or more, and the amount added is 4 to 30% by weight based on the solid content of the paint.
, preferably from 4 to 20% by weight; if it is less than 4% by weight, the processability decreases and no effect of promoting thermal decomposition of the resin is observed; on the other hand, even if the weight exceeds 30 weights, no further improvement in processability is observed. On the contrary, there is a tendency for corrosion resistance to decrease as the amount increases.

The coating composition used in the present invention also contains a conductive pigment for the purpose of imparting conductivity.

Such conductive pigments can be of any conventional type, but
Examples include the following: Metal powders - metal carbides such as stainless steel, gold, silver, cadmium, aluminum, zinc, tin, copper, and graphite - carbides such as iron, nickel, titanium, tanges, niobium, manganese, etc. I ~ Ferromanganese, ferromolybdenum,
One type or a mixture of two or more of these compounds, such as ferrosilicon, theerochrome, ferrotitanium, and ferrophosphor, is used.

It is necessary to select a conductive pigment that has a small negative effect on corrosion resistance and processability, and it is preferable to exclude metal powder that exhibits a higher potential than iron.

In addition, it is preferable for a conductive pigment to have a stable and low electrical resistance, to not melt even when heat is generated during welding (no reduction in current density and no electrode contamination), and to have a hardness that does not shatter during welding pressure. . Furthermore, since it is used in relatively large quantities, it is important that it is inexpensive.

From these viewpoints, it is preferable to use iron carbide and phosphorus raw wheat.

The conductive pigment has a particle size of 20μ or less, preferably 10μ or less, in an amount of 15 to 86% by weight, preferably 30% by weight of the solid content of the paint.
It is contained in an amount of up to 70% by weight.

If the pigment concentration is less than 30% by weight, conductivity may be insufficient if the coating thickness is 10 μm or more, and if it is less than 1% by weight, there will be a clear lack of electric current and welding will not be possible. If it exceeds 70 wt%, the coating film addition IT and tel- may be lowered, and if it exceeds 86 wt%, the film processability clearly deteriorates, making it impractical.

In a particularly preferred embodiment, a pigment containing iron phosphide as a main component is used as the conductive pigment, and in order to ensure even better corrosion resistance, a phosphorus raw product decomposition inhibitor is used in combination. Phosphite is the most preferred conductive IMi in terms of its good balance of various performances such as corrosion resistance, workability, and weldability.
As mentioned above, it is present in an amount of 15 to 86% by weight in the paint solids. However, even if the conductive surface R1, which is mainly composed of iron phosphide and has the least negative effect on corrosion resistance, is selected, under a corrosive environment, especially when the coating film is exposed to an acidic atmosphere, phosphatic ore will decompose and the decomposed products will cause corrosion. It was found that this can be promoted. Whether or not the coating film becomes an acidic atmosphere depends on the coating composition, the base metal, and the corrosive environment conditions; however, it is especially suitable for severe tests such as complex corrosion tests where several types of corrosive environments and alternating wet and dry conditions are set. On the other hand, if it is possible to obtain a composition J that exhibits a higher degree of corrosion resistance, there is nothing better than this composition. In order to obtain such a composition, the present inventors believe that it is necessary to suppress the decomposition of phosphorite or to render the decomposed products harmless.
For that purpose, the coexistence of a pigment with a suspension water pl-1 of 6 to 13, preferably 7 to 11 is an extremely effective means as it keeps the coating film on the neutral or alkaline side. I discovered that.

Therefore, the coating composition of the present invention contains, as an essential component, a conductive pigment mainly composed of iron phosphide and a phosphorus product decomposition inhibitor. As described above, such decomposition inhibitors are those which are intended to keep the coating film on the neutral or alkaline side continuously, and pigments having a suspension water 1) l-1 of 6 to 13 are conveniently used. Specific examples include the following compounds.

■Alkaline earth metal petroleum sulfonates ■Chromium-19-acid pigments such as zinc chromate, potassium zinc chromate, zinc chromate, basic lead chromate, calcium chromate, strontium chromate ■Zinc phosphate Phosphate pigments such as , iron phosphate, aluminum 1-ribolyphosphate ■ Lead compound pigments such as calcium leadate and lead silicate ■ Extender pigments such as talc, calcium oxate, and silica ■ Zinc powder (same as phosphate ore) However, the amount of these pigments to be added shall be 1% or less in the solid content of the paint, and the amount shall not exceed the total disintegration of the inorganic pigments described below.

Although these compounds are sometimes classified as antirust pigments or extender pigments, in the present invention they are recognized as phosphorus product decomposition inhibitors in terms of suspension water p1-1.

In this way, the phosphorus raw wheat decomposition inhibitor is 1% by weight in the solid content of the paint.
From the above, it is easily understood that the conductive pigment containing iron phosphide as a main component is in the range of 15 to 85% by weight when both are used in combination.

The paint layer of the present invention may optionally contain other inorganic pigments, such as chromium pigments for improving corrosion resistance, zinc chromate-based, lead chromate-based, calcium chromate-based, strontium chromate-based pigments. etc.), phosphorus M salt pigments (zinc phosphate, iron phosphate, aluminum tripolyphosphate pigments, etc.), lead compound pigments (calcium leadate, lead silicate, etc.): For adjusting the amount of resin and adjusting the pH of the coating film. Extender pigments (silica, calcium carbonate, talc, alumina, etc.); coloring pigments (oxidized aluminum, iron oxide, lead oxide, etc.) can be added. When adding these inorganic pigments, the total amount of inorganic pigments listed below must not be exceeded.

1. That is, in the coating composition used in the present invention, the total amount of the conductive pigment mainly composed of iron phosphide, the phosphorus product decomposition inhibitor, and other inorganic pigments added as desired is 35 to 86% by weight, preferably 35 to 86% by weight, based on the solid content of the coating material. It is important that the amount is within the range of 35 to 70% by weight. This is because if the total amount is less than 35% by weight, the processability of the coating will decrease;
Even if it exceeds 8% by weight, a decrease in workability may be observed.
This is because when the amount of ink exceeds 6%, a significant decrease in lJ strength is clearly observed. Therefore, according to the most preferred embodiment g, the coating $11 layer consists of a coating resin with a molecular aromatic ring content of 0 to 50% by weight (10 to 35% by weight) and an organic lubricant 1.- 301F amount % Conductive pigment mainly composed of iron phosphide 15-85% Phosphate decomposition inhibitor 1-71 m1% Other inorganic pigments O.~7070% However, conductive pigment, phosphate mineral decomposition inhibitor and The composition comprises a total amount of other inorganic pigments of 35-86% by weight.

In any case, the thickness of the paint layer is 1 to 20 .mu.m, preferably 2 to 10 .mu.m during the baking process.

The laminate of the present invention exhibits extremely excellent adhesion properties, corrosion resistance, continuous spot weldability, and coating film tightness, and is particularly useful for use in industrial production lines for automobiles and the like.

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

In the examples below, the following metal IJ blades τ were used.

Metal base 1A that has not been subjected to corrosion-resistant chemical pretreatment: Electric 11i 11 nickel alloy plated steel plate (plating area: 140 Q/m2) cleaned with a commercially available alkaline degreaser, washed with water, and dried.

Metal base material subjected to corrosion-resistant chemical pretreatment: An electrolytic zinc-nickel alloy plated steel sheet that has been treated with alkali 1112 oil, washed with water, and dried is treated with 5% aqueous solution of anhydrous chromium M at 50%.
Spray at ℃ for 30 seconds, then wash and dry.

Example 1 The following chromate treatment solution was applied by roll coating to an electrolytic zinc-nickel alloy plated steel sheet that had not been subjected to chemical pretreatment, and then dried in a gas furnace for 1 minute to reach a maximum plate temperature of 150°C. A chromate film with a chromium content of 60m0/112 was made.

In addition, the 1M treatment solution includes zinc chromate with a solubility of 6 to 8 (metallic chromium equivalent: 150), polyacrylic @ (
Dicolymer AC-101-1 Nippon Pure Chemical Industries, Ltd. 11111) (solid content: 10 g) and water were blended in a total amount of 1e, and a liquid obtained by dispersing glass beads in a paint shaker for 1 hour was used. The following coating composition was separately prepared.

Urethane modified 1 poxy resin (Japanese Patent Application Laid-Open No. 57-30717,
Adjusted according to Example 3, benzene ring content in molecule 45w
t%) to 16 parts (Ii', i-type valve equivalent), resol type phenol resin (manufactured by Showa Union Gosei ■, BKS-3)
16. Melt 4 parts by weight (in terms of solid content) of benzene ring content in the molecule (55V 1t%) in cyclohexanone, and add 60 parts by weight of Ferobos HR82132 (iron phosphide-based conductive pigment manufactured by Tsuka Chemicals and Plastics). , strontium chromate N (Kikuchi pigment product, chromate pigment of phosphate mineral decomposition inhibitor) 5 Tabatabe is added,
Using a paint shaker, disperse 2 #181 steel beads. Filter the paint, add 15 parts by weight of Ceridust 3620 (manufactured by Hoechst, micronized polyethylene wax), mix uniformly with a disper, and adjust with cyclohexanone so that the non-volatile content is about 60%.

The chromate-treated steel sheet was coated with the coating composition 24- by the 1-ru coating method, and baked in a gas furnace at a maximum plate temperature of 200°C for 1 minute to form a film with a coating thickness of 7 μm to improve corrosion resistance. A painted laminate was obtained.

Examples 2 to 7 and Comparative Examples 1 to 4 Same method as Example 1, except that metal MCI, corrosion-resistant layer composition,
The coating composition was changed as shown in Table 1 below to obtain coatings.

The chromate treatment solution containing a water-soluble chromium compound having a solubility of more than 20, which is used in Example 2, was prepared, for example, as follows.

Anhydrous chromium acid (metallic chromium equivalent: 20Q) water: 500+[
', add formalin and reduce a predetermined percentage of the total chromium, for example 40%, to Cr3+ to make a partially reduced chromic acid aqueous solution, then add, for example, Aerosil 300 (manufactured by Nippon Aerosil Co., Ltd., Huumed Silica) to 1501 dissolution marks 6- Add zinc chromate (metallic chromium equivalent: 15g) from step 8, and add water to make the total omega
Disperse the glass beads in a paint shaker for 1 hour.

The following performance tests were conducted on the 1q laminates of each Example and Comparative Example (3 days after preparation). A bond as shown in Table 2 was obtained.

Test method and evaluation criteria 1, continuous spora 1 - Weldability Electrode diameter 5 mm, pressurizing force 200 kQ, energization time 10 cycles, current BOOOA, spot welding was carried out with strip 1'1, and the number of 11 points that could be continuously welded was investigated. Ta.

Evaluation: ◎: 5,000 points or more - little dirt ○: 5,000 points or more - V Electric 14! Dirty Δ: 3000 points to 5000 points
Point
142 type), wrinkle presser pressure 31 to
0111IIlφ, die diameter 52.4tnn+φ, drawing depth 4Qmm, blank diameter 95mm), and the coating film was inspected for scratches and peeling 1.

Evaluation: ◎: No abnormalities on the painted surface ○: There are scratches on the painted surface (not reaching the base metal) (10% or more) △: There are scratches that reach the base metal, and there are many scratches on the painted surface ×: Original plate cracks 3, corrosion resistance ■Combined corrosion test (1 cycle - salt water jet 1 (5% NaC +
, 35° C.), 2 hours→drying (60° C.), 2 hours->wetting (98% RH≦, 50° C.) for 4 hours, and after 200 cycles, the occurrence of red rust and white rust on the flat surface was examined.

Evaluation ◎: No natural rust or red rust O: 5% or less area of white rust, no red rust △: 6% or more ×: 1% or more of red rust ■Salt water spray test (according to JTS-22371) 2000
After a period of time, the state of red rust and white rust on the flat surface was examined.

Evaluation: ◎: White 4J-vinyl, no red rust O: White 4J-vinyl 5% or less, no red rust Δ:
6% or more” 2, ×: Occurs in 1% or more of the red squares (blank below) 30- Table 2 Patent application agent Takeo Ito

Claims (11)

[Claims] (1) Solubility 2 in metal M440 which has been subjected to corrosion resistance chemical conversion half-width treatment or which has not been subjected to pre-treatment.
0 to 10"5 containing at least one hexavalent 11m compound and a water-based silica/or a water-based resin binder as essential components, and optionally has a solubility of 20J: water-soluble ↑ ( A corrosion-resistant layer and a conductive paint layer of a composition containing a chromium compound are sequentially laminated, and the paint layer is
Coating 1'+1 solid content (A) Coating resin with aromatic ring content in the molecule of 0 to 50% by weight 10 to 35 weight% Organic lubricant 4 to 50il1ff1% and conductive face 13
1 15-86% by weight or (B) Paint resin with aromatic ring content in the molecule of O-50% by weight 10-35% by weight Organic Fitl lubricant 4-30% by weight Iron phosphate main electrolyte Face 11 15-85% by weight Iron phosphide decomposition inhibitor 1-71% by weight Other inorganic pigments 0-70% by weight However, the total amount of conductive pigments, phosphate mineral decomposition inhibitors and other inorganic pigments is 35-86% by weight. A corrosion-resistant painted laminate characterized in that the layer comprises a composition of % by weight. (2) The laminate according to claim 1, wherein the metal base material is an electrogalvanized steel sheet containing iron, zinc, aluminum metal, or nickel or iron. (3) The corrosion-resistant layer contains a chromium compound of 0.0 in terms of metallic chromium.
1 to 1 (1/rn2, laminate according to claim 1. (4) In the corrosion-resistant layer, the hexavalent 0 chromium is 10 to 10 of the water-soluble total chromium.
The laminate according to claim 1, which accounts for 90% by weight. (5) The laminate according to claim 1, wherein the paint layer has a thickness of 1 to 20 μm. (6) Paint resins include epoxy resin, alkyd resin, acrylic resin, melamine resin, urethane resin, phenol resin, vinyl resin, polyvinylbutyral resin, and polyvinyl 71'! The laminate according to claim 1, which is a resin, a chlorinated rubber, an oil-free polyester resin, a phthalic acid resin, a styrene resin, or a polyolefin resin. (7) Yes 11! The laminate according to claim 1, wherein the lubricant is a compound selected from polyolefin compounds, carboxylic acid ester compounds, and polyalkylene glycol compounds. (8) The laminate according to claim 7, wherein the organic lubricant is a compound that exhibits exothermic decomposition at 300 to 500°C. (9) The laminate according to claim 1, wherein the phosphate mineral decomposition inhibitor is a pigment having a suspension pH of lll-16 to lll-13. (10) Other inorganic pigments 1] Mu pigments, phosphate pigments, lead pigments, or colored Mrj l! 1. The laminate according to claim 1, which is 1. (11) The laminate according to claim 1, wherein the total amount of the conductive pigment, phosphorite decomposition inhibitor, and other inorganic pigments is 35 to 70% by weight in the solid content of the paint.