JP3277870B2 - Organic coated steel sheet with excellent corrosion and alkali resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic-coated steel sheet which is most suitable for use in automobiles, home appliances, and building materials, and has an effect on workers and users who handle products, measures for wastewater treatment during production, and products in use environments. Environmentally-friendly organic coating that does not contain any heavy metals such as chromium, lead, cadmium, and mercury that are harmful to the environment and the human body in coating compositions and films in order to adapt to environmental problems such as volatilization and elution of harmful substances from the environment. It relates to a steel plate.

[0002]

2. Description of the Related Art Organic composite coated steel sheets for home appliances, building materials, and automobiles have the advantage of being excellent in corrosion resistance, and are widely used as high-performance steel sheets with paintability and lubricity depending on the application. ing. Here, the organic composite coated steel sheet is a treatment containing chromic acid, bichromic acid or salts thereof as a main component for the purpose of improving corrosion resistance (white rust resistance, red rust resistance) on the surface of a zinc-based coated steel sheet. It is obtained by performing a chromate treatment with a liquid and further forming a thin organic resin film on the surface thereof. Such organic composite coated steel sheets include, for example, Japanese Patent Publication No. 4-1070 and Japanese Patent Publication No. 3-326.
No. 38.

[0003] In these organic composite coated steel sheets, basically, the chromate film formed on the surface of the base plating exhibits excellent rust-preventive properties even in a severe corrosive environment such as salt water spray and the like, and the surface of the surface thereof has a good corrosion resistance. The organic resin film layer enhances rust prevention and paintability as a protective film. Further, by adding a rust preventive additive and a solid lubricant to the organic resin, a variation as a highly corrosion-resistant steel plate or a lubricated steel plate becomes possible.
By the way, the above-mentioned chromate treatment performed on the plating surface is a very economical rust prevention treatment method that can impart a rust prevention effect at low cost.

However, since chromate treatment uses hexavalent chromium, which is a pollution control substance, chromate salts have an adverse effect on the human body in the treatment process, and it is difficult to dispose of chromium sludge after wastewater treatment. In addition, there are various problems, for example, that hexavalent chromium may be eluted from the product after the chromate treatment. For this reason, as the use control standards for chromic acids have become stricter, the management of chromate treatment plants, wastewater treatment, and secondary contamination by chromate treatment have become problems, and in response to this, each plant has closed drainage relations. In addition, measures are taken to minimize the emission of chromium ions to the outside.
In addition, in the process of degreasing the rust-preventive oil and press oil attached to the chromate-treated steel sheet by the user, when using an alkaline degreasing solution, the elution of chromium into the degreasing solution is considerably increased. Dechrome treatment is required.

[0005] In view of the above, in order to prevent the generation of white rust on galvanized steel sheets, a number of pollution-free treatment techniques not based on chromate treatment have been proposed. For example,
There is a method of using an inorganic compound, an organic compound, an organic polymer material, or a combination thereof to form a thin film by a method such as immersion, coating, or electrolytic treatment. In particular,
The following methods are known. (1) A method using an oxide of a metal such as molybdenum or tungsten (for example, JP-A-57-5875). (2) A method using tannic acid (for example, JP-A-51-5875).
(3) A pollution-free chromate treatment method comprising only trivalent chromium and not containing hexavalent chromium (for example, see JP-A-61-5).
No. 87)

[0006]

However, in the above method (1), the stable area against corrosion of metal oxides such as molybdenum and tungsten is narrower than that of chromium.
It is impossible to obtain the same level of corrosion resistance as chromate treatment. In the method (2), only a film having insufficient corrosion resistance and having uneven coloring is obtained.
Furthermore, in the above method (3), since soluble chromium is used, it cannot fundamentally meet the need for chromium-free. Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide an organic-coated steel sheet which can obtain excellent corrosion resistance and alkali resistance without containing hexavalent chromium in a film.

[0007]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a polymer having a specific chelate-forming group on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet. By forming a film containing a chelating agent as a main component (polymer chelating agent film) and forming an organic resin-based film thereon, it is possible to perform chromate treatment that may adversely affect the environment and the human body. It has been found that an organic-coated steel sheet which is non-polluting and excellent in corrosion resistance and alkali resistance can be obtained. The present invention has been made based on such findings, and the features thereof are as follows.

[1] A polymer chelating agent having a chelating group in an organic polymer matrix on a surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet, wherein the chelating group contains at least one sulfur atom. Characterized in that a polymer chelating agent film mainly comprising a polymer chelating agent having a thickness of 0.01 to 5 μm is formed, and an organic resin film or an organic composite silicate film is formed thereon. Organic coated steel sheet with excellent corrosion resistance and alkali resistance.

[2] In the organic coated steel sheet according to the above [1], the chelating group possessed by the polymer chelating agent is a thiol group, a thioether group, a thioketone group, a thioamide group, a thiocarboxylic acid group, a dithiocarbamic acid group, a thiosinate group. An organic-coated steel sheet excellent in corrosion resistance and alkali resistance, characterized in that it is at least one member selected from the group consisting of isothiosinate, thiol, thiocarboxylate and dithiocarbamate.

[3] On the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet, a polymer chelating agent film containing the following (A) as a main component and further containing the following component (B) has a thickness of 0.0
An organic-coated steel sheet having excellent corrosion resistance and alkali resistance, wherein the organic-coated steel sheet has a thickness of 1 to 5 μm and an organic resin film or an organic composite silicate film formed thereon. (A) The organic polymer matrix is selected from a thiol group, a thioether group, a thioketone group, a thioamide group, a thiocarboxylic acid group, a dithiocarbamate group, a thiosinate group, an isothiosinate group, a thiol base, a thiocarboxylate group, and a dithiocarbamate group. Polymer chelating agent having one or more chelating groups (B) Silica, polyphosphate, phosphate, molybdate, phosphomolybdate based on 100 parts by weight of polymer chelating agent Phytic acid, phytate, phosphonic acid, 1 to 100 parts by weight of one or more rust preventive additives selected from phosphonates

[4] The organic coated steel sheet according to any of [1] to [3] above, wherein the number average molecular weight of the organic polymer matrix of the polymer chelating agent is 300 or more. Organic coated steel sheet with excellent alkalinity. [5] In the organic-coated steel sheet according to any one of the above [1] to [3],
An organic coated steel sheet having excellent corrosion resistance and alkali resistance, wherein the number average molecular weight of the organic polymer matrix of the polymer chelating agent is 1000 or more. [6] The organic-coated steel sheet according to any one of [1] to [5],
The organic polymer matrix of the polymer chelating agent is polyethylene, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyamino compound, polyvinyl chloride, polyacrylic acid, epoxy resin, phenol resin, styrene-divinylbenzene resin, acrylic resin, starch An organic-coated steel sheet having excellent corrosion resistance and alkali resistance, comprising one or more selected from the group consisting of:

[7] In the organic-coated steel sheet according to any one of the above [1] to [6], the organic resin film or the organic composite silicate film is composed of silica, polyphosphate, phosphoric acid and phosphoric acid per 100 parts by weight of the organic resin. A salt, molybdate, phosphomolybdate, phytic acid, phytate, phosphonic acid, 1 to 100 parts by weight of one or more rust preventive additives selected from phosphonates, and a film thickness Is an organic-coated steel sheet having excellent corrosion resistance and alkali resistance.

[8] In the organic-coated steel sheet according to any one of the above [1] to [6], the organic resin film or the organic composite silicate film is formed by adding a hydrocarbon compound such as polyolefin wax to 100 parts by weight of the organic resin. , Fluororesin-based compounds,
1 to 80 parts by weight of one or more solid lubricants selected from fatty acid amide compounds, metal sulfides, metal soaps, graphite, fluorinated graphite, boron nitride, polyalkylene glycols, and alkali metal sulfates An organic-coated steel sheet having excellent corrosion resistance and alkali resistance, characterized in that it has a thickness of 0.1 to 10 μm.

[9] In the organic-coated steel sheet according to any one of the above [1] to [6], the organic resin film or the organic composite silicate film is composed of silica, polyphosphate, phosphoric acid and phosphoric acid per 100 parts by weight of the organic resin. 1 to 100 parts by weight of one or more rust preventive additives selected from salt, molybdate, phosphomolybdate, phytic acid, phytate, phosphonic acid, phosphonate, polyolefin wax, etc. One or two selected from hydrocarbon compounds, fluororesin compounds, fatty acid amide compounds, metal sulfides, metal soaps, graphite, graphite fluoride, boron nitride, polyalkylene glycols, and alkali metal sulfates The solid lubricant contains 1 to 80 parts by weight, and the film thickness is 0.1 to 10 μm.
m, an organic-coated steel sheet having excellent corrosion resistance and alkali resistance.

[10] In the organic coated steel sheet according to any one of the above [1] to [9], the chelate-forming group of the polymer chelating agent is selected from dithiocarbamic acid groups, thiol groups, dithiocarbamic acid bases, and thiol bases. An organic-coated steel sheet excellent in corrosion resistance and alkali resistance, characterized in that it is at least one member selected from the group consisting of:

In such an organic coated steel sheet of the present invention, the polymer chelating agent film having a specific chelate-forming group formed on the surface of a zinc-based steel sheet or an aluminum-based steel sheet has a high polymer matrix. In addition to forming a film in the same way as an organic resin to suppress corrosion, a specific chelate-forming group adsorbs or reacts with the surface of the plating film to form a dense protective film layer. The metal ions eluted from the metal are captured by the chelate-forming group to form a complex structure, which forms a dense barrier layer, which exhibits a rust-preventive effect.Furthermore, even in a corrosive environment, metal eluted from the plating film by corrosion Free chelate-forming groups in the film capture the ions and form a stable metal complex structure to suppress accelerated corrosion Exert an effect of a very good corrosion resistance and alkali resistance by corrosion effects of these composite effects and the upper organic resin film is obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention and the reasons for limiting the same will be described below. The zinc-coated steel sheet serving as a base of the organic coated steel sheet of the present invention includes a zinc-coated steel sheet, Zn-Ni
Alloy plated steel sheet, Zn-Fe alloy plated steel sheet (electroplated steel sheet and galvannealed steel sheet), Zn-Cr
Alloy plated steel sheet, Zn-Mn alloy plated steel sheet, Zn-C
o alloy plated steel sheet, Zn-Co-Cr alloy plated steel sheet,
Zn-Cr-Ni alloy plated steel sheet, Zn-Cr-Fe alloy plated steel sheet, Zn-Al alloy plated steel sheet (for example, Z
n-5% Al alloy-plated steel sheet, Zn-55% Al alloy-plated steel sheet), and a zinc-based composite plated steel sheet (for example, Zn-SiO ₍₂ dispersion-plated steel sheet) or the like can be used.

[0018] Of the above-mentioned platings, a multi-layer plated steel sheet obtained by plating two or more layers of the same type or different types may be used. In addition, as the aluminum-plated steel sheet serving as the base of the organic-coated steel sheet of the present invention, an aluminum-plated steel sheet, an Al—Si alloy-plated steel sheet, or the like can be used. Alternatively, the steel plate surface may be preliminarily plated with a thin coating of Ni or the like, and the various platings as described above may be performed thereon. As a plating method, any practicable method can be adopted among an electrolysis method (electrolysis in an aqueous solution or electrolysis in a non-aqueous solvent), a melting method, and a gas phase method.

Next, a polymer chelating agent film having a specific chelate-forming group formed on the surface of the zinc-based plated steel sheet or the aluminum-based plated steel sheet will be described. The chelate-forming group forms a dense protective film layer by chemisorption or reaction on the plating film surface, and further reacts with metal ions eluted from the plating film at the time of film formation to form an insoluble dense chelate complex on the plating surface. It has the function of forming a Techniques for preventing corrosion of metal surfaces by a chemical adsorption method using such a corrosion inhibitor (inhibitor) have been known for a long time. As methods for preventing corrosion of iron, mainly, cooling water systems, boiler systems, water supply / hot water supply systems, etc. In such an environment where water and metal are constantly in contact, a method of adding an amine-based or phosphate-based adsorbent into water has been put to practical use.

The present invention is intended to prevent corrosion of steel pipes for use in building materials, home appliances, automobiles, and the like, as well as the purpose and application thereof, in addition to the corrosion prevention of plumbing systems around water. However, heretofore, as a surface treatment film of such a rust-preventive steel plate, there has been almost no practical application of a film mainly composed of a compound having a chelate-forming group. This is because (1) the adsorption capacity differs depending on the type of metal, and it is difficult to obtain a stable and dense adsorption film from a zinc-based plated steel sheet and an aluminum-based plated steel sheet. (2) The chelating agent generally has a low molecular weight. (Normal,
The molecular weight is less than 300), so that it is difficult to form a continuous film such as a polymer resin for a coating, and a sufficient anticorrosion function cannot be obtained due to the reason.

As a result of extensive studies by the present inventors to overcome the above-mentioned problems, it has been found that a film mainly composed of a polymer chelating agent having a specific chelating group added to an organic polymer matrix is formed of zinc. They have been found to have an excellent anticorrosion function as a surface treatment film of a system-coated steel sheet or an aluminum-based steel sheet. Although the anticorrosion mechanism by such a polymer chelating agent film is not always clear,
(1) Stable and strong adsorption on the surface of galvanized steel sheet and aluminum-based steel sheet by specific chelating group
Formation of a reaction film (a film formed by the adsorption or reaction of a specific chelating group on the surface of a plating film); (2) an organic material, not a low molecular weight chelating agent as conventionally used; By using a polymer chelating agent mainly composed of a polymer, a function as an organic film such as a resin for paint is imparted. (3) In addition to the effects of the above (1) and (2), The polymer chelating agent having a chelating group of the type described above captures metal ions eluted from the plating film during film formation to form a film having a three-dimensional polymer complex structure, and forms a dense and stable three-dimensional ion. (4) When a steel sheet having the formed film is exposed to a corrosive environment,
It is considered that a superior anticorrosion effect can be obtained by, for example, suppressing the progress of corrosion by capturing and stabilizing metal ions eluted by anodic dissolution and stabilizing them.

Incidentally, the organic coated steel sheet of the present invention is premised on being used unpainted or overcoated on the user side. Here, the typical process on the user side is cutting → processing (oiling or no oiling) / assembly → alkali degreasing to remove surface oil and dirt → washing and drying → topcoating (depending on the application)・ Bake-in, and it becomes a product through these steps. Therefore, the rust preventive film coated on the steel sheet surface must not be damaged or peeled off in an alkaline environment, but a thin chrome-free rust preventive film excellent in alkali resistance has been known so far. Absent.

The present inventors have studied a wide variety of chelating groups with the aim of obtaining a rust-preventive film having excellent alkali resistance. As a result, the specific chelating group, that is, at least one sulfur atom, It has been found that by using a polymer chelating agent having a chelating group contained therein, a rust preventive film having excellent corrosion resistance and alkali resistance can be obtained, which has led to the present invention. Such a polymer chelating agent having a specific chelating group forms a strong and stable adsorption / reaction layer with a zinc-based plated steel sheet and an aluminum-based plated steel sheet.

The reason why such a specific chelate-forming group imparts excellent corrosion resistance and alkali resistance to the rust-preventive film is not necessarily clear, but the sulfur-based chelate-forming group may be used in the above-mentioned mechanism (1) to (4). This is considered to be because it is excellent in the reactivity with metal ions or the adsorbing power to metal ions at the time of film formation, and thereby, a stable film that is hard to be broken down even during alkali degreasing can be formed.

Examples of such a chelating group containing one or more sulfur atoms include thiol, thioether, thioketone, thioamide, thiocarboxylic acid, dithiocarbamic acid, thiosinate, isothiosinate, thiol base and thiocarboxylate. Acid bases, dithiocarbamic acid bases, and the like can be mentioned. By using a polymer chelating agent having one or more chelating groups selected from these, excellent corrosion resistance and alkali resistance can be imparted to the film. Among these, dithiocarbamic acid groups, thiol groups, dithiocarbamic acid groups, and thiol bases are particularly preferable.

In the present invention, the structure and synthesis method of the organic polymer serving as the matrix of the polymer compound having a chelate-forming group are not limited, and any structure or synthesis method may be used. For example, examples of the organic polymer matrix include polyethylene, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyamino compounds, polyvinyl chloride, polyacrylic acid, epoxy resin, phenol resin, styrene-divinylbenzene resin, acrylic resin, starch, and the like. And one or more selected from these can be used.

The number average molecular weight of the organic polymer matrix is not particularly limited, but is preferably at least 300, more preferably at least 1,000, further preferably at least 10,000, particularly preferably at least 50,000 to 1,000,000. When the molecular weight is less than 300, the effect of improving corrosion resistance is small, while when the molecular weight exceeds 1,000,000, problems such as gelation of the coating composition occur, which is not preferable.

As the polymer chelating agent as described above, for example, a heavy metal collecting agent industrialized for the purpose of collecting heavy metals in wastewater and heavy metals in fly ash can be used. For example, Epofloc L-1 and Epofloc L-2 manufactured by Miyoshi Oil & Fats Co., Ltd., and Welklin K-100 and Welklin K-200 manufactured by Kurita Industry Co., Ltd. can be applied. Goods may be used.

For the purpose of further enhancing the anticorrosion effect, the polymer chelating agent film may contain silica, polyphosphate, phosphate, molybdate, phosphomolybdate, phytic acid, phytate if necessary. And one or more rust-preventive additives selected from the group consisting of sulfonic acid, phosphonic acid, phosphonate and the like.

As the silica, either colloidal silica or fumed silica may be used. Examples of the colloidal silica include Snowtex O, Snowtex N, Snowtex 20, Snowtex 30,
Snowtex 40, Snowtex C, Snowtex S (all manufactured by Nissan Chemical Industries, Ltd.) and the like can be used. Also, as a fume dredica, for example, A
EROSIL R971, AEROSIL R812, A
EROSIL R811, AEROSIL R974, A
EROSIL R202, AEROSIL R805, A
EROSIL130, AEROSIL 200, AER
OSIL 300, AEROSIL 300CF (or more,
Nippon Aerosil Co., Ltd.) can be used.

The silica added to the film contributes to the formation of a dense and stable metal corrosion product in a corrosive environment, and the corrosion product is densely formed on the plating surface to promote corrosion. Is considered to be suppressed. In addition, as a rust preventive additive other than silica, known polyphosphates (for example, aluminum polyphosphate: Teika K-WHITE 8)
0, Takeka K-WHITE 84, Takeka K-WHIT
E 105, Takeka K-WHITE G105, Takeka K
-WHITE 90 (all manufactured by Teica Co., Ltd.)), phosphates (eg, zinc phosphate, aluminum dihydrogen phosphate, zinc phosphite, etc.), molybdate, phosphomolybdate (eg, phosphomolybdenum) Aluminum acid), phytic acid, phytate, phosphonic acid, phosphonate and the like can also be used.

The amount of the rust preventive additive is 1 to 100 parts by weight based on 100 parts by weight of the polymer chelating agent in terms of solid content. If the amount is less than 1 part by weight, the effect of improving corrosion resistance is small. On the other hand, if the amount is more than 100 parts by weight, the coatability and processability are undesirably reduced. The more preferable amount of the rust preventive additive is 5 to 80 parts by weight.

The polymer chelating agent film as described above is formed on the surface of a zinc-based steel sheet or an aluminum-based steel sheet without a chromate treatment film. The dry film thickness of the polymer chelating agent film is optional, but is preferably 0.01 to 5 μm. The film thickness is 0.0
If the thickness is less than 1 μm, the corrosion resistance is insufficient. On the other hand, in applications requiring weldability, the weldability decreases when the film thickness exceeds 5 μm. More preferably, the thickness is 0.05 to 3 μm, and still more preferably 0.1 to 2 μm.

The polymer chelating agent film is formed by applying a coating composition containing the above-mentioned polymer chelating agent as a main component to the surface of a zinc-based steel sheet or an aluminum-based steel sheet and drying. Before applying the coating composition, the surface of the plated steel sheet may be subjected to an alkali degreasing treatment, if necessary, and may be subjected to a pretreatment such as a surface conditioning treatment in order to improve adhesion and corrosion resistance.

As a method of applying the coating composition containing a polymer chelating agent as a main component to the surface of a zinc-based steel sheet or an aluminum-based steel sheet, any method such as a coating method, a dipping method, and a spray method is employed. it can. As a coating method, any method such as a roll coater (three-roll system, two-roll system, etc.), a squeeze coater, a die coater, and the like may be used. In addition, after the coating, dipping, or spraying with a squeeze coater or the like, it is also possible to adjust the coating amount, uniform the appearance, and uniform the film thickness by an air knife method or a roll drawing method.

Usually, after application of the coating composition, heating and drying are performed without washing with water. However, a water washing step may be performed after application of the coating composition. For the heating and drying treatment, a dryer, a hot blast furnace, a high-frequency induction heating furnace, an infrared furnace, or the like can be used. The heat treatment is performed at a plate temperature of 50 to 30.
It is desirably performed at 0 ° C., preferably in the range of 80 ° C. to 250 ° C. If the heating temperature is lower than 50 ° C., a large amount of water in the film remains, and the corrosion resistance becomes insufficient. When the heating temperature is 3
If the temperature is higher than 00 ° C., it is not only uneconomical, but also there is a possibility that a defect occurs in the film and the corrosion resistance is reduced.

Next, an organic resin-based film (organic resin film or organic composite silicate film) formed on the polymer chelating agent film will be described. As the organic resin constituting the organic resin-based film, any of a water-soluble resin, a water-dispersible resin, and a thermosetting resin can be used. In addition, when high corrosion resistance is expected, it is preferable to select a thermosetting resin.

An organic composite silicate obtained by compounding these water-dispersible resins with silica via a silane coupling agent is also suitable. In the present invention, such an organic composite silicate film is subjected to polymer chelation. It may be formed on the upper layer of the agent film. In the following description, such an organic composite silicate film is referred to as “organic resin film”.

As the water-dispersible resin, for example, the following can be used. (1) Acrylic resin For example, polyacrylic acid and its copolymer, polyacrylic acid ester and its copolymer, polymethacrylic acid ester and its copolymer, polymethacrylic acid ester and its copolymer, urethane-acryl Acid copolymers (or urethane-modified acrylic resins), styrene-acrylic acid copolymers, and the like, and resins obtained by modifying these resins with other alkyd resins, epoxy resins, phenol resins, and the like can be used.

(2) Ethylene resin (polyolefin resin) For example, ethylene copolymers such as ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, carboxyl-modified polyolefin resin, and ethylene-unsaturated carboxylic acid copolymer A resin obtained by modifying these resins with another alkyd resin, an epoxy resin, a phenol resin, or the like can be used. (3) Alkyd resin For example, oil-modified alkyd resin, rosin-modified alkyd resin, phenol-modified alkyd resin, styrenated alkyd resin, silicon-modified alkyd resin, acryl-modified alkyd resin, oil-free alkyd resin, high-molecular-weight oil-free alkyd resin, etc. Can be used.

(4) Epoxy resin For example, straight epoxy resins such as epichlorohydrin type and glycidyl ether type, fatty acid modified epoxy resin (epoxy ester resin), polybasic acid modified epoxy resin, acrylic resin modified epoxy resin, alkyd (or polyester) ) Modified epoxy resins, polybutadiene-modified epoxy resins, phenol-modified epoxy resins, amine or polyamine-modified epoxy resins, urethane-modified epoxy resins, and the like can be used. (5) Urethane resin For example, a polycarbonate-based polyurethane resin, a polyester-based polyurethane resin, a polyether-based urethane resin, or the like can be used. Further, two or more water-dispersible resins selected from these may be mixed and used.

In order to lower the drying temperature of the organic resin film, a core-shell type water-dispersible resin in which the core portion and the shell portion of the resin particles are made of different resin types or resins having different glass transition temperatures is used. It can also be used. Further, a water-dispersible resin having a self-crosslinking property, for example, by providing an alkoxysilane group to the resin particles, the production of silanol groups by hydrolysis of the alkoxysilane during heating and drying of the resin film and the formation of silanol groups between the resin particles. A water-dispersible resin in which cross-linking between particles using a dehydration condensation reaction is generated can also be used.

Among the water-dispersible resins described above, ethylene resins are particularly preferable from the viewpoints of corrosion resistance, processability and coatability, and ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, Preference is given to ethylene copolymers such as modified polyolefin resins, ethylene-unsaturated carboxylic acid copolymers, ethylene ionomers and the like. Among them, ethylene ionomers exhibit excellent blackening resistance as well as excellent corrosion resistance and processability. Also, a mixture of such an ethylene resin and one or more of a water-dispersible epoxy resin, a water-dispersible acrylic resin, and a water-dispersible urethane resin can be used.

Further, for these water-dispersible resins,
It is effective to mix at least one of a water-soluble epoxy resin, a water-soluble phenol resin, a water-soluble butadiene rubber (SBR, NBR, MBR), a melamine resin, a blocked isocyanate, and an oxazoline compound as a crosslinking agent.

As the thermosetting resin, for example, the following can be used. (1) Epoxy resin For example, straight epoxy resin such as epichlorohydrin type, glycidyl ether type, etc., fatty acid modified epoxy resin (epoxy ester resin), polybasic acid modified epoxy resin, acrylic resin modified epoxy resin, alkyd (or polyester) modified epoxy Resins, polybutadiene-modified epoxy resins, phenol-modified epoxy resins, amine or polyamine-modified epoxy resins, urethane-modified epoxy resins, and the like can be used. By using these epoxy resins or modified epoxy resins, excellent corrosion resistance and paintability can be imparted to the organic resin film.

(2) Urethane resin For example, oil-modified polyurethane resin, alkyd-based polyurethane resin, polyester-based polyurethane resin, polyether-based urethane resin and the like can be used. (3) Alkyd resin For example, oil-modified alkyd resin, rosin-modified alkyd resin, phenol-modified alkyd resin, styrenated alkyd resin, silicon-modified alkyd resin, acryl-modified alkyd resin, oil-free alkyd resin, high-molecular-weight oil-free alkyd resin, etc. Can be used.

(4) Acrylic silicone resin For example, an acrylic copolymer containing a hydrolyzable alkoxysilyl group on the side chain or terminal of an acrylic copolymer and a curing agent added thereto can be used. When a suitable acrylic silicone resin is used, excellent weather resistance can be obtained. (5) Fluororesins There are fluoroolefin-based copolymers, for example, one of monomers such as alkyl vinyl ether, synchroalkyl vinyl ether, carboxylic acid-modified vinyl ester, hydroxyalkyl allyl ether, and tetrafluoropropyl vinyl ether. There is a copolymer of the above and a fluorine monomer (fluoroolefin).
When such a fluororesin is used, excellent weather resistance and hydrophobicity can be obtained.

Further, two or more kinds of resins selected from these may be mixed and used. Further, a soluble phenol resin may be used in combination with these resins. further,
For the purpose of improving the corrosion resistance and workability of the resin film with respect to these resin base materials (base resins), urea resins (butylated urea resins, etc.), melamine resins (butylated melamine resins), butylated urea, melamine One or more of resins, amino resins such as benzoguanamine resins, block isocyanates, oxazoline compounds, phenol resins and the like can be blended as a curing agent. Among them, particularly, in consideration of the corrosion resistance of the film, blocked isocyanates and amino resins are preferable.

The curing method of the base resin is particularly preferably a urethane reaction between the isocyanate and the hydroxyl group in the base resin. However, in order to stably preserve the coating composition before forming the film, the curing method is preferred. It is necessary to protect the isocyanate of the agent. As a method for protecting the isocyanate, a protection method in which the protecting group is eliminated during heat treatment and the isocyanate group is regenerated can be employed. Examples of the polyisocyanate compound used in this case include an aliphatic, alicyclic (including heterocyclic) or aromatic isocyanate compound having at least two isocyanate groups in one molecule, or a polyhydric alcohol containing such a compound. Compounds that have been partially reacted, or compounds such as burette-type adducts and isocyanuric ring-type adducts of these compounds are mentioned. For example,

M- or p-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate, or p-xylylene diisocyanate, hexamethylene diisocyanate, dimer acid diisocyanate, isophorone diisocyanate, triphenylmethane-4,4 ' , 4 "-triisocyanate, 1,3,5-triisocyanatobenzene,
Polyisocyanate compounds having three or more isocyanate groups, such as 2,4,6-triisocyanatotoluene and 4,4'-dimethyldiphenylmethane-2,2 ', 5,5'-tetraisocyanate;

A single or mixture of the above compounds and polyhydric alcohols (dihydric alcohols such as ethylene glycol and propylene glycol; trihydric alcohols such as glycerin and trimethylolpropane; tetrahydric alcohols such as pentaerythritol; sorbitol and dipentane A compound in which at least two isocyanate groups remain in one molecule as a reaction product with a hexahydric alcohol such as erythritol, hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylene diisocyanate, 4,4'-diphenylmethane diisocyanate , 4,4'-methylenebis (cyclohexyl isocyanate) and the like, and isocyanuric ring type adducts.

Further, for example, when iron rust coexists in a corrosive environment and the resin barrier property in the organic film greatly contributes to the suppression of corrosion, a polyisocyanate compound having at least three isocyanate groups in one molecule It is preferable to use a polyisocyanate compound having more than 4, more preferably 6 or more isocyanate groups as a curing agent.

Examples of the polyfunctional polyisocyanate compound having at least three isocyanate groups in one molecule include a compound having three or more isocyanate groups in one molecule and an isocyanate compound having at least two isocyanate groups in one molecule. Is reacted with a polyhydric alcohol, or a compound such as a burette type adduct or an isocyanuric ring type adduct thereof. For example, triphenylmethane-4,4 ', 4 "-triisocyanate, 1,3,5-triisocyanatobenzene,
Polyisocyanate compounds having three or more isocyanate groups such as 2,4,6-triisocyanatotoluene and 4,4'-dimethyldiphenylmethane-2,2 ', 5,5'-tetraisocyanate; ethylene glycol, propylene glycol An adduct obtained by reacting an amount of a polyisocyanate compound in which an isocyanate group is in excess with respect to a hydroxyl group of a polyol such as 1,4-butylene glycol, polyalkylene glycol, trimethylolpropane, or hexanetriol; hexamethylene diisocyanate; Isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4 '
Buret-type adducts such as diphenylmethane diisocyanate and 4,4'-methylenebis (cyclohexylisocyanate); isocyanuric ring-type adducts;

In the adduct obtained by reacting an amount of the polyisocyanate compound in which the amount of the isocyanate group is excessive with respect to the hydroxyl group of the polyol, the polyisocyanate compound may be a polyisocyanate compound having three or more isocyanate groups. Aliphatic diisocyanate compounds such as hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, dimer acid diisocyanate and lysine diisocyanate; isophorone diisocyanate, 4,4'-methylene bis (cyclohexyl isocyanate), methylcyclohexane-
2,4- (or -2,6-) diisocyanate, 1,3
Aliphatic diisocyanate compounds such as-(or 1,4-) di (isocyanatomethyl) cyclohexane; and xylylene diisocyanate, tolylene diisocyanate, m
Examples thereof include aromatic diisocyanate compounds such as-(or p-) phenylene diisocyanate, diphenylmethane diisocyanate, and bis (4-isocyanatophenyl) sulfone.

Among polyfunctional polyisocyanate compounds having at least six isocyanate groups in one molecule (hexafunctional polyisocyanate compound),
Hexamethylene diisocyanate polyfunctional is most effective. The polyfunctional polyisocyanate compound to be used may be a mixture of homologous compounds having different numbers of isocyanate groups in one molecule. Further, two or more of the above polyfunctional polyisocyanate compounds may be used in combination.

As described above, as a method for protecting the isocyanate of the curing agent in order to stably store the film-formed product, a protection method in which a protective group (blocking agent) is eliminated during heat curing to regenerate the isocyanate group. Can be adopted. The protective agent (blocking agent) includes, for example, the following. An isocyanate compound which is stably protected at least at room temperature by reacting one or more of these with the polyisocyanate compound Can be obtained.

(1) Aliphatic monoalcohols such as methanol, ethanol, propanol, butanol and octyl alcohol (2) Monoethers of ethylene glycol and / or diethylene glycol, for example, methyl, ethyl, propyl (n-, iso) , Butyl (n-, iso, se
Monoethers such as c) (3) Phenols such as phenol and cresol (4) Oximes such as acetoxime and methyl ethyl ketone oxime

The polyisocyanate compound as a curing agent is used in an amount of 5 to 80 parts by weight based on 100 parts by weight (solid content) of the base resin.
It is preferable to mix in a ratio of 10 parts by weight (solid content), preferably 10 to 50 parts by weight (solid content). If the amount of the curing agent is less than 5 parts by weight, the crosslinked density of the formed film becomes insufficient, and the effect of improving the corrosion resistance is small. On the other hand, if it is more than 80 parts by weight, unreacted residual isocyanate absorbs water, and the corrosion resistance (perforation resistance) and the adhesion are impaired.

Further, a monohydric alcohol having 1 to 5 carbon atoms is reacted with part or all of a methylol compound obtained by reacting formaldehyde with at least one selected from melamine, urea and benzoguanamine as a curing agent. May be used in combination with an isocyanate compound. The resin is sufficiently crosslinked with the above-mentioned curing agent, but it is preferable to use a known curing promoting catalyst in order to further increase the low-temperature crosslinking property. Examples of the curing accelerating catalyst include N-ethylmorpholine, dibutyltin dilaurate, cobalt naphthenate, stannous chloride, zinc naphthenate, bismuth nitrate and the like.

For the purpose of suppressing corrosion, the organic resin film contains the same rust-preventive additives as those of the lower polymer chelating agent film, ie, silica, polyphosphate, phosphate, molybdate. One or more rust-preventive additives selected from salts, phosphomolybdate, phytic acid, phytate, phosphonic acid, and phosphonate can be blended.

As the silica, either colloidal silica or fumed silica may be used. Further, water-dispersible and organic solvent-dispersible silica can be selected as necessary.
Examples of the water-dispersible colloidal silica include Snowtex O, Snowtex N, and Snowtex 2
0, Snowtex 30, Snowtex 40, Snowtex C, Snowtex S (manufactured by Nissan Chemical Co., Ltd.), and organic solvent dispersible silica include, for example,
Organosilica sol MA-ST-M, organosilica sol IPT-ST, organosilica sol EG-ST,
Organosilica sol EG-ST-ZL, Organosilica sol NPC-ST, Organosilica sol DMAC-
ST, organosilica sol DMAC-ZL, organosilica sol XBA-ST, organosilica sol MIB
K-ST (all made by Nissan Chemical Co., Ltd.), OSCAL 1
132, OSCAL 1232, OSCAL 1332,
OSCAL 1432 (both manufactured by Catalyst Chemical Industry Co., Ltd.)
Can be used.

As fumed silica, for example, AEROSIL R971, AEROSIL R81
2, AEROSIL R811, AEROSIL R97
4, AEROSIL R202, AEROSIL R80
5 (above, fumed silica having a hydrophobic surface), or AEROSIL 130, AEROSIL 200,
AEROSIL 300, AEROSIL 300CF
(Above, manufactured by Nippon Aerosil Co., Ltd.).

As a method of incorporating silica into the resin composition, a method of dispersing with a usual disperser may be used. Further, an organic composite silicate obtained by reacting a water-dispersible resin with colloidal silica in advance using a silane coupling agent may be used. In this case, for example, an organic composite silicate of an acrylic resin and silica and an organic composite silicate of an epoxy resin and silica can be mixed and used.

As rust preventive additives other than silica, known polyphosphates (for example, aluminum polyphosphate: Takeka K-WHITE 80, Takeka K-WHITE 84, Takeka K-WHITE 105, Takeka K-WHITE G)
105, Teika K-WHITE 90 (all manufactured by Teika Co., Ltd.)), phosphates (for example, zinc phosphate, aluminum dihydrogen phosphate, zinc phosphite, etc.), molybdate, phosphomolybdate ( For example, aluminum phosphomolybdate), phytic acid, phytate, phosphonic acid, phosphonate and the like can be used.

The amount of the rust preventive additive is from 1 to 100 parts by weight based on 100 parts by weight of the organic resin in terms of the solid content. If the amount is less than 1 part by weight, the effect of improving corrosion resistance is small. On the other hand, if the compounding amount exceeds 100 parts by weight, the coatability and workability deteriorate, which is not preferable. The more preferable amount of the rust preventive additive is 5 to 80 parts by weight.

Further, a solid lubricant may be added to the organic resin film for the purpose of improving the processability of the film. Examples of the solid lubricant include the following. (1) Hydrocarbon compounds such as polyolefin wax:
For example, polyethylene wax, synthetic paraffin, natural paraffin, microwax, chlorinated hydrocarbon, etc. (2) Fluororesin compounds: For example, polyfluoroethylene resin (polytetrafluoroethylene resin, etc.), polyvinyl fluoride resin, polyfluoride (3) Fatty acid amide compounds: for example, stearic acid amide, palmitic acid amide, methylenebisstearamide, ethylenebisstearamide, oleic acid amide,
Esylamide, alkylenebisfatty acid amide, etc.

(4) Metal soaps: for example, calcium stearate, lead stearate, calcium laurate, calcium palmitate, etc. (5) Metal sulfides: for example, molybdenum disulfide, tungsten disulfide (6) Others: for example, graphite , Fluorinated graphite, boron nitride, polyalkylene glycol, alkali metal sulfate, etc.

Among the above solid lubricants, polyethylene wax, fluororesin compounds (among others, poly-4
Fluorinated ethylene resin fine particles) are preferred. Examples of the polyethylene wax include Seridust 9615A, Seridust 3715, and Seridust 36 manufactured by Hoechst.
20, Celidust 3910, Sunwax 131-P and Sunwax 161-P manufactured by Sanyo Chemical Co., Ltd., Chemipearl W-100, Chemipearl W-200, Chemipearl W-500, Chemipearl W-500, Chemipearl manufactured by Mitsui Petrochemical Co., Ltd.
W-800, Chemipearl W-950 and the like can be used.

As the fluororesin-based compound, fine particles of tetrafluoroethylene are preferable. For example, Lubron L-2 and Lubron L-5 manufactured by Daikin Industries, Ltd., MP1100 and MP1200 manufactured by DuPont Mitsui, and Asahi IC Fluon Dispersion AD1, Fluon Dispersion AD2 manufactured by iFluoropolymers Co., Ltd.
Fullon L140J, Fullon L150J, Fullon L155J and the like can be used.

[0070] Among these solid lubricants, a particularly excellent lubricating effect can be expected by adding a polyolefin wax and tetrafluoroethylene in combination. The amount of the solid lubricant is the ratio of the organic resin to the solid content.
1 to 80 parts by weight based on 00 parts by weight. If the amount of the solid lubricant is less than 1 part by weight, the lubricating effect is poor.
If it exceeds 80 parts by weight, the coatability will be reduced. The preferred compounding amount of the solid lubricant is 3 to 40 parts by weight.

Further, a coloring dye (for example, an organic solvent-soluble azo metal complex salt dye, a water-soluble azo metal complex salt dye, etc.) and an organic coloring pigment (for example, condensed polycyclic type Organic pigments, phthalocyanine-based organic pigments, etc.), inorganic pigments (eg, titanium oxide, etc.), chelating agents (eg, thiol, etc.), conductive pigments (eg, metal powders such as zinc, aluminum, nickel, etc., iron phosphide,
Antimony-doped tin oxide or the like), a coupling agent (for example, a silane coupling agent, a titanium coupling agent, or the like), a melamine / cyanuric acid adduct, or the like can be added.

The dry film thickness of the organic resin film as described above is arbitrary, but is preferably 0.1 to 10 μm.
If the film thickness is less than 0.1 μm, the corrosion resistance is insufficient. On the other hand, if the film thickness exceeds 10 μm, the workability is reduced in applications requiring workability. A more preferred film thickness is 0.3-3.
μm. The organic resin film is formed by applying an organic resin coating composition of the above-described components on the surface of the polymer chelating agent film and drying the coating.

The coating method of the organic resin coating composition includes:
Any method such as a coating method, a dipping method, and a spray method can be adopted. As a coating method, a roll coater (3 roll method,
Any method such as a two-roll system), a squeeze coater, and a die coater may be used. In addition, after the coating process with a squeeze coater, etc., dipping process or spraying process, adjustment of the coating amount by air knife method or roll drawing method,
It is also possible to make the appearance uniform and the film thickness uniform.

In the heating and drying treatment, a dryer, a hot air oven,
A high-frequency induction heating furnace, an infrared furnace, or the like can be used.
The heat treatment is performed at a plate temperature of 50 to 300 ° C., preferably 8 ° C.
It is desirable to carry out in the range of 0 ° C to 250 ° C. If the heating temperature is lower than 50 ° C., a large amount of water in the film remains, and the corrosion resistance becomes insufficient. On the other hand, if the heating temperature exceeds 300 ° C., it is not only uneconomical, but also there is a possibility that a defect occurs in the film and the corrosion resistance is reduced.

The present invention includes a steel sheet having an organic composite coating comprising a polymer chelating agent film and an organic resin film as described above on both surfaces or one surface. Therefore, examples of the form of the steel sheet of the present invention include the following. (1) One side: plating film-polymer chelating agent film-organic resin film, one surface: plating film (2) One surface: plating film-polymer chelating agent film-organic resin film, one surface: polymer chelating agent film (3) Both surfaces: plating film-polymer chelating agent film-organic resin film (4) One surface: plating film-polymer chelating agent film-organic resin film, one surface: known phosphate treatment film, etc.

[0076]

[Example] As an organic-coated steel sheet for home appliances, building materials, and automobile parts, the surface of a zinc-based steel sheet or an aluminum-based steel sheet is subjected to alkali degreasing treatment, washed with water, and dried.
A coating composition for a lower layer film (such as a polymer chelating agent film) was applied by a roll coater and dried by heating. Further, an organic resin coating composition for an upper layer film (organic resin film) was applied to the upper layer, and dried and heated. In addition, the film thickness of the lower layer film and the upper layer film was adjusted according to the solid content concentration of the coating composition or the application conditions (roll rolling force, rotation speed, etc. of the roll coater). About the obtained organic coated steel sheet,
Evaluations of the film appearance and corrosion resistance (white rust resistance), corrosion resistance after alkali degreasing (white rust resistance), paint adhesion and workability were evaluated. The results are shown in Tables 10 to 37 together with the type of plated steel sheet used, the composition of the lower layer coating and the upper layer coating, the film thickness, and the drying temperature.

The manufacturing conditions of the organic coated steel sheet in this example are shown below. (1) Plated steel sheet A cold-rolled steel sheet having a thickness of 0.8 mm and a surface roughness (Ra) of 1.0 μm was subjected to various types of zinc-based plating or aluminum-based plating and used as a base-plated steel sheet. Table 1 shows the used plated steel sheets. (2) A coating composition containing a polymer chelating agent as a main component A coating composition dispersing machine mainly comprising an aqueous solution of a polymer chelating agent described below and, if necessary, adding a rust preventive additive thereto. (Sand grinder) to disperse the required time,
A coating composition was obtained.

(2-1) Polymer chelating agent 1 to No. A polymer chelating agent consisting of an organic polymer matrix and a chelating group having at least one sulfur atom, denoted as 12, was used. Also,
As a comparative example, No. 1 in the table. 13, No. An aqueous solution of EDTA (ethylenediaminetetraacetic acid), which is a low molecular weight chelating agent, and an aqueous solution of tannic acid, which has been conventionally used as a rust preventive, were used. (2-2) Rust prevention additives Rust prevention additives such as silica shown in Table 3 and polyphosphate shown in Table 4 were used as needed.

(3) Paint Composition for Organic Resin Film Silica shown in Table 6 and a solid lubricant shown in Table 7 were added to the organic resin shown in Table 5, if necessary, to prepare a paint dispersing machine ( Using a sand grinder), the mixture was dispersed for a required time to obtain a resin composition shown in Tables 8 and 9.

The evaluation of the quality performance of the organic-coated steel sheet was performed as follows. (1) Appearance of Film For each sample, the uniformity of the film appearance (with or without unevenness) was visually evaluated. The evaluation criteria are as follows. ：: uniform appearance without any unevenness △: appearance with some unevenness ×: appearance with unevenness

(2) Corrosion resistance (white rust resistance) For each sample, a salt spray test (JIS-Z-23)
71) was carried out, and evaluated by the area ratio of white rust occurrence after a predetermined time. In addition, the film formed without the rust-preventive additive was evaluated by the white rust resistance after 96 hours, while the film containing the rust-preventive additive (silica or a rust-preventive additive other than silica) was formed. As for those obtained, the white rust resistance after 96 hours alone did not show a difference superior to that without the rust-preventive additive. Therefore, the white rust resistance after 120 hours, which is a more severe test condition, was also evaluated. The evaluation criteria are as follows. ◎: No white rust generated ○ +: White rust generation area ratio less than 5% ○: White rust generation area ratio 5% or more and less than 10% ○-: White rust generation area ratio 10% or more and less than 25% △: White rust Generated area rate 25% or more, less than 50% ×: White rust generated area rate 50% or more

(3) Corrosion resistance after alkali degreasing (white rust resistance) Each sample was spray-degreased with an alkali degreasing solution (CLN-364S manufactured by Nippon Parkerizing Co., Ltd.), and then immediately washed with water and dried. This sample was subjected to a salt spray test (JIS-Z-2371), and evaluated by a white rust generation area ratio after a predetermined time. In addition, about 96 which formed the film which does not contain a rust preventive additive,
Evaluation was made on the white rust resistance after a lapse of time. On the other hand, when a film containing a rust-preventive additive (silica or a rust-preventive additive other than silica) was formed, the rust-prevention was obtained only with the white rust resistance after 96 hours. Since there was no significant difference with respect to those without additives, the white rust resistance after 120 hours, which is a more severe test condition, was also evaluated. The evaluation criteria are as follows. ◎: No white rust generated ○ +: White rust generation area ratio less than 5% ○: White rust generation area ratio 5% or more and less than 10% ○-: White rust generation area ratio 10% or more and less than 25% △: White rust Generated area rate 25% or more, less than 50% ×: White rust generated area rate 50% or more

(4) Adhesion of paint For each sample, a melamine baking paint (film thickness 30
μm), then immersed in boiling water for 2 hours, immediately cut in a grid (10 × 10 grids at 1 mm intervals), adhered and peeled off with adhesive tape, and peeled the coating film The evaluation was based on the area ratio. The evaluation criteria are as follows. ：: No peeling ○: Peeling area rate less than 5% △: Peeling area rate 5% or more, less than 20% ×: Peeling area rate 20% or more

(5) Workability Deep drawing was performed with a blank diameter of φ120 mm and a die diameter of φ50 mm (oil-free condition), and evaluated by the molding height until cracks occurred. The evaluation criteria are as follows. ◎: Draw-out ○: Molding height 30 mm or more △: Molding height 20 mm or more, less than 30 mm ×: Molding height less than 20 mm

[0085]

[Table 1]

[0086]

[Table 2]

[0087]

[Table 3]

[0088]

[Table 4]

[0089]

[Table 5]

[0090]

[Table 6]

[0091]

[Table 7]

[0092]

[Table 8]

[0093]

[Table 9]

[0094]

[Table 10]

[0095]

[Table 11]

[0096]

[Table 12]

[0097]

[Table 13]

[0098]

[Table 14]

[0099]

[Table 15]

[0100]

[Table 16]

[0101]

[Table 17]

[0102]

[Table 18]

[0103]

[Table 19]

[0104]

[Table 20]

[0105]

[Table 21]

[0106]

[Table 22]

[0107]

[Table 23]

[0108]

[Table 24]

[0109]

[Table 25]

[0110]

[Table 26]

[0111]

[Table 27]

[0112]

[Table 28]

[0113]

[Table 29]

[0114]

[Table 30]

[0115]

[Table 31]

[0116]

[Table 32]

[0117]

[Table 33]

[0118]

[Table 34]

[0119]

[Table 35]

[0120]

[Table 36]

[0121]

[Table 37]

[0122]

As described above, the organically coated steel sheet of the present invention contains no hexavalent chromium in the processing solution during production or in the film component of the product, and furthermore, the organic coated steel sheet for use in building materials, home appliances, automobiles, etc. As a steel sheet, it has high corrosion resistance and alkali resistance, and is also excellent in film appearance, paint adhesion, and the like.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masaru Sagiyama 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Kokan Co., Ltd. (56) References JP-A-11-158649 (JP, A) JP-A-11 JP-A-11-131253 (JP, A) JP-A-11-5061 (JP, A) JP-A-11-5062 (JP, A) JP-A-11-166151 (JP, A) JP-A-11-158647 (JP, A) JP-A-11-158646 (JP, A) JP-A-54-43142 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 22/00-22/86 B05D 7/14 C09D 125/18

Claims (10)

(57) [Claims] 1. A polymer chelating agent having a chelating group in an organic polymer matrix, wherein the chelating group contains at least one sulfur atom on a surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet. A polymer chelating agent film having a polymer chelating agent as a main component is formed in a thickness of 0.01 to 5 μm, and an organic resin film or an organic composite silicate film is formed thereon. Organic coated steel sheet with excellent corrosion resistance and alkali resistance. 2. The chelating group of the polymer chelating agent has a thiol group, a thioether group, a thioketone group,
2. The composition according to claim 1, which is one or more selected from a thioamide group, a thiocarboxylic acid group, a dithiocarbamate group, a thiosinate group, an isothiosinate group, a thiol base, a thiocarboxylate group, and a dithiocarbamate group. Organic coated steel sheet with excellent corrosion and alkali resistance. 3. A polymer chelating agent film containing the following (A) as a main component and further containing the following component (B) on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet.
An organic-coated steel sheet having excellent corrosion resistance and alkali resistance, wherein the organic steel sheet has a thickness of about 5 μm and an organic resin film or an organic composite silicate film is formed thereon. (A) The organic polymer matrix is selected from a thiol group, a thioether group, a thioketone group, a thioamide group, a thiocarboxylic acid group, a dithiocarbamate group, a thiosinate group, an isothiosinate group, a thiol base, a thiocarboxylate group, and a dithiocarbamate group. Polymer chelating agent having one or more chelating groups (B) Silica, polyphosphate, phosphate, molybdate, phosphomolybdate based on 100 parts by weight of polymer chelating agent Phytic acid, phytate, phosphonic acid, 1 to 100 parts by weight of one or more rust preventive additives selected from phosphonates 4. The organic coated steel sheet having excellent corrosion resistance and alkali resistance according to claim 1, wherein the organic polymer matrix of the polymer chelating agent has a number average molecular weight of 300 or more. 5. The organic coated steel sheet having excellent corrosion resistance and alkali resistance according to claim 1, wherein the number average molecular weight of the organic polymer matrix of the polymer chelating agent is 1,000 or more. 6. The organic polymer matrix of the polymer chelating agent is polyethylene, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyamino compound, polyvinyl chloride, polyacrylic acid, epoxy resin, phenol resin, styrene-divinylbenzene resin. , Acrylic resin, starch selected from one or two or more selected from starch, 2, 3,
The organic-coated steel sheet having excellent corrosion resistance and alkali resistance according to 3, 4, or 5. 7. An organic resin film or an organic composite silicate film, based on 100 parts by weight of the organic resin, silica, polyphosphate, phosphate, molybdate, phosphomolybdate, phytic acid, phytate, 3. The composition according to claim 1, further comprising 1 to 100 parts by weight of one or more rust preventive additives selected from phosphonic acids and phosphonates, and having a film thickness of 0.1 to 10 [mu] m. The organic-coated steel sheet excellent in corrosion resistance and alkali resistance described in 3, 4, 5, or 6. 8. An organic resin film or an organic composite silicate film, based on 100 parts by weight of an organic resin, a hydrocarbon compound such as a polyolefin wax, a fluororesin compound, a fatty acid amide compound, a metal sulfide, a metal soap,
1 selected from graphite, fluorinated graphite, boron nitride, polyalkylene glycol, and alkali metal sulfate
1 to 80 parts by weight of one or more solid lubricants,
The organic-coated steel sheet having excellent corrosion resistance and alkali resistance according to claim 1, 2, 3, 4, 5, or 6, having a thickness of 0.1 to 10 µm. 9. An organic resin film or an organic composite silicate film, based on 100 parts by weight of the organic resin, silica, polyphosphate, phosphate, molybdate, phosphomolybdate, phytic acid, phytate, 1 to 100 parts by weight of one or more rust preventive additives selected from phosphonic acids and phosphonates, hydrocarbon compounds such as polyolefin wax, fluororesin compounds, fatty acid amide compounds, metal sulfide 1 to 80 parts by weight of one or more solid lubricants selected from the group consisting of a product, metal soap, graphite, fluorinated graphite, boron nitride, polyalkylene glycol, and alkali metal sulfate. 1 to 10
3. The method according to claim 1, wherein
Or an organic coated steel sheet excellent in corrosion resistance and alkali resistance according to 6. 10. The chelating group of the polymer chelating agent is one or more selected from dithiocarbamic acid groups, thiol groups, dithiocarbamic acid bases, and thiol bases. 1, 2,
The organic-coated steel sheet excellent in corrosion resistance and alkali resistance according to 3, 4, 5, 6, 7, 8, or 9.