JP4920625B2 - Surface-treated metal plate - Google Patents

Description

  The present invention relates to a surface-treated metal plate that does not contain hexavalent chromium, which has high environmental impact, and has excellent corrosion resistance, solvent resistance, alkali resistance, and adhesion to a top coating.

  In various fields such as home appliances, automobiles, and building materials, hexavalent chromate is applied to surface-treated metal plates such as zinc-based plated steel and aluminum-based plated steel for the purpose of providing corrosion resistance or adhesion to top coating. In general, a technique for performing a chromate treatment using the like has been used. However, against the background of the recent increase in environmental problems, there has been an active movement to eliminate hexavalent chromium, which has a high environmental impact, from the procurement materials, and the demand for chromate-free is increasing day by day. Some industries have already begun to be abolished.

  Because of this movement, various alternatives to chromate coatings have been studied and many have been proposed. In many of them, a coating layer mainly composed of an organic resin having excellent barrier properties is formed on an upper layer of a metal plate. Although it has excellent barrier properties, it has a certain degree of corrosion resistance, but there has been a problem that the coating layer is damaged or removed in the cleaning process using various solvents and alkaline cleaning liquids. That is, there is a problem that not only the corrosion resistance is deteriorated by deteriorating the inherent barrier property of the coating layer but also the appearance design is remarkably lowered. Therefore, it has been required to form a coating layer having excellent cleaning liquid resistance such as solvent resistance and alkali resistance as well as corrosion resistance.

  Patent Document 1 discloses an aqueous resin composition obtained by reacting an aqueous polyurethane resin, an aqueous polyolefin resin, water-dispersible silica, and a composition containing a silane coupling agent and / or a hydrolysis condensate thereof, A rust-proof coating agent containing a thiocarbonyl group-containing compound and phosphate ions, a rust-proof treatment method for coating the same, and a rust-proof metal material coated therewith are disclosed. However, in the above method, since the reaction between the silane coupling agent and each resin is insufficient, the degree of compounding between the components in the obtained coating film is low, and the solvent resistance and alkali resistance are inferior. There is.

  Patent Document 2 describes an organic composite-coated steel sheet having a composite coating containing two types of resins having different solubility parameters and an inorganic component. However, since a coating film with insufficient crosslinking is formed, for example, there is a problem that the solvent rubbing test is seriously damaged.

  Patent Document 3 discloses a surface-treated galvanized steel sheet having a coating layer formed by applying an aqueous composition containing a metal compound, a water-soluble organic resin and an acid to the surface of a galvanized steel sheet. ing. However, since the amount of carboxyl groups in the water-soluble resin is relatively large, there is a problem that the alkali resistance is poor.

  In Patent Document 4, (a) a water-dispersible resin and / or a water-soluble resin, (b) a silane coupling agent, (c) phosphoric acid and / Alternatively, a surface-treated steel sheet having a surface-treated coating film formed from a surface-treating composition containing hexafluorometal acid is disclosed. However, there is a problem that the stability of the treating agent and the solvent resistance of the obtained coating film are insufficient.

  Patent Document 5 describes a coated steel sheet on which a coating film containing a crosslinked resin matrix and an inorganic rust inhibitor is formed. However, since satisfactory performance is not always obtained in solvent resistance and alkali resistance, a surface-treated metal plate with improved performance is required.

JP 2001-164182 A Japanese Patent Laid-Open No. 2001-199003 JP 2001-214283 A JP 2003-105555 A JP 2005-281863 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a surface-treated metal plate that ensures a good balance of corrosion resistance, solvent resistance, alkali resistance, adhesion to a top coating, and the like.

  In order to ensure adhesion to the top coat of a coating film containing an organic resin, it is common to introduce a polar functional group or a skeleton having polarity into the resin skeleton. In the case of an aqueous surface treatment agent, a highly hydrophilic functional group is used as the polar functional group, and this plays an important role in ensuring the stability of the surface treatment agent. In particular, current water-based resins have anionic functional groups, and those obtained by water-solubilization or water-dispersion by neutralization with amines, ammonia, alkali metal elements or the like are widely used.

  For these organic resins having an anionic functional group, increasing the amount introduced is advantageous for the stability of the surface treatment agent and the adhesion to the top coating material or the base, but on the other hand, after the coating film is formed When it comes in contact with an alkali component, the coating film surface is thereby neutralized and hydrophilicity is increased, and there is a problem that the alkali resistance is greatly reduced. In addition, the organic resin containing a large amount of anionic functional groups has a problem that the polar solvent resistance is inferior because of its high compatibility with polar solvents.

  In order to solve these problems, by using an alkali metal element as the neutralizing agent for the anionic functional group, after forming the coating film, an ion cluster is formed in the coating film to improve the cohesive strength of the coating film. In addition, a technique for cross-linking functional groups with a cross-linking agent to improve the cross-linking density, or a technique using both of them has been used, but their improvement effect is not always sufficient.

  The method of using an alkali metal element as a neutralizing agent has a problem in that the alkali resistance and the polar solvent resistance are improved, while the corrosion resistance and the adhesion with the top coating are lowered. The technique of increasing the crosslinking density with a crosslinking agent improves the coating performance such as solvent resistance and alkali resistance, but on the other hand, the stability of the bath is drastically reduced, and it is difficult to find a composition that is industrially practical. Further, there is a problem that the flexibility is lowered and the corrosion resistance after processing is also lowered.

  Therefore, as a result of intensive studies, the inventors have included a specific cationic metal element in the coating layer containing an organic resin having an anionic functional group, and further in the depth direction in the coating layer. By controlling the concentration appropriately, the present inventors have succeeded in finding a coating film having unprecedented solvent resistance and alkali resistance without impairing the corrosion resistance and adhesion to the top coating.

  As mentioned above, alkali metal elements are considered to ionically bond with anionic functional groups to form ion clusters, and certain cationic metal elements including alkali metal elements are also ionically bonded to anionic functional groups in the coating film. It is thought that an ion cluster is formed. While these are effective in solvent resistance and alkali resistance, they promote the permeability of corrosion factors and may adversely affect the corrosion resistance.

  Therefore, the present invention appropriately concentrates the specific cationic metal element only on the outer surface that comes into contact with the solvent or alkaline cleaning liquid used during cleaning, so that only the anionic functional group in the outermost layer is the cationic metal element. By forming an ion cluster by ionic bonding with (B), the alkali resistance and solvent resistance of the outermost layer portion of the coating film are remarkably improved, and the resistance of the entire coating film to alkali and solvent can be improved. In addition, since the ion clusters are unevenly distributed only in the outermost layer portion of the coating film, the permeability of the corrosion factor can be minimized, and the corrosion resistance does not deteriorate.

  The surface-treated coating film formed in this way was invented based on the idea that alkali resistance and solvent resistance can be improved without reducing corrosion resistance.

That is, the main point of the present invention is that
(1) A surface-treated metal plate having at least one coating layer on a metal plate or a plated metal plate, and the coating layer (X) formed on the outermost surface has an anionic functional group (A) And at least one cationic metal element (B) selected from Li, Na, K, Mg, Ca and Sr, and the distance in the depth direction from the outer surface of the coating layer (X) is Y ( μm), when the distance from the outer surface of the coating layer (X) to the interface with the lower layer in contact with the coating layer (X) in the depth direction is Z (μm), 0 ≦ Y ≦ (Z / A surface-treated metal plate characterized by having a maximum value of the concentration of the cationic metal element (B) in the range of 5),
(2) The cationic metal element (B) defined by the following formula (I) obtained from the element concentration measurement result in the depth direction in the high frequency discharge glow discharge optical emission spectrometry of the coating layer (X) The surface-treated metal plate according to (1), wherein the maximum value of M is 3 to 10 when the intensity ratio is M,
M = [M] / [C] (I)
Here, [M] is the sum of the spectral intensities of the cationic metal element (B) (calculated as the sum of the spectral intensities of the respective cationic metal elements when a plurality of cationic metal elements are contained), [C] Is the spectral intensity of carbon.
(3) The surface-treated metal plate according to (1) or (2), wherein the anionic functional group contains a carboxyl group,
(4) The surface-treated metal plate according to any one of (1) to (3), wherein the organic resin (A) is an aqueous resin,
(5) The surface-treated metal plate according to any one of claims 1 to 3, wherein the organic resin (A) is a crosslinked resin matrix formed by a reaction between an aqueous resin and a crosslinking agent.
(6) The surface according to (4) or (5), wherein the aqueous resin contains at least one selected from an aqueous polyester resin, an aqueous polyurethane resin, an aqueous epoxy resin, an aqueous acrylic resin, and an aqueous polyolefin resin. Processing metal plate,
(7) Any of (4) to (6), wherein the aqueous resin contains an alkali metal neutralized product of an ethylene-unsaturated carboxylic acid copolymer, and the neutralization rate is 30 to 90%. The surface-treated metal plate according to
(8) The crosslinking agent is at least one selected from amino resins, polyisocyanate compounds, block bodies of polyisocyanate compounds, epoxy compounds, carbodiimide compounds, silane compounds, crosslinkable zirconium compounds, and crosslinkable titanium compounds. The surface-treated metal plate according to (5),
(9) The surface-treated metal plate according to any one of (1) to (8), wherein the coating layer (X) contains an inorganic rust inhibitor.
(10) The surface-treated metal plate according to (9), wherein the inorganic rust preventive agent contains at least one selected from silica, a phosphoric acid compound, a vanadium compound, a molybdenum compound, and a niobium compound.
(11) The surface-treated metal plate according to any one of (1) to (10), wherein the coating layer (X) contains a wax component,
(12) The surface-treated metal according to any one of (1) to (11), wherein a base coating film layer is provided between the coating film layer (X) and the metal plate or the plated metal plate. Board,
(13) The surface-treated metal plate according to (12), wherein the base coating layer contains at least one selected from an organic resin, a silane coupling agent, and a polyphenol compound,
(14) The surface-treated metal plate according to (12) or (13), wherein the undercoating layer contains at least one selected from silica, a phosphoric acid compound and hexafluorometal acid,
(15) The surface-treated metal plate according to any one of (1) to (14), wherein the plated metal plate is a zinc-based plated steel plate or an aluminum-based plated steel plate,
It is.

  The surface-treated metal plate of the present invention has excellent corrosion resistance despite not containing chromium in the coating film, and is excellent in solvent resistance, alkali resistance, and adhesion to the top coat. For this reason, the surface-treated metal plate of the present invention is very promising as a future environment-friendly material, and the contribution to each industrial field is very large.

  The details of the present invention and the reasons for limitation will be described below.

  The present invention is a surface-treated metal plate having at least one coating layer, wherein the coating layer (X) formed on the outermost surface has an anionic functional group (A) and Li, Na, K, It contains at least one cationic metal element (B) selected from Mg, Ca, Sr, and the component (B) is concentrated in a region close to the outer surface of the coating layer (X). And

  By concentrating the component (B) in a region close to the outer surface of the coating layer (X), it is possible to improve the solvent resistance and alkali resistance without reducing the corrosion resistance. Since these cationic metal elements (B) have high electrical positivity, they are easily ionically bonded to an anionic functional group and are suitable for forming an anionic functional group and an ion cluster. Moreover, these cationic metal elements (B) can be supplied from a relatively inexpensive compound.

  The coating layer (X) has a distance in the depth direction from the outer surface to Y (μm), and the interface between the outer surface of the coating layer (X) and the lower layer in contact with the coating layer (X) in the depth direction. Is Z (μm), it is preferable to have a maximum value of the concentration of the component (B) in the range of 0 ≦ Y ≦ (Z / 5). Z (μm) represents the film thickness of the coating film layer (X), and the concentration of the component (B) in the range of 1/5 of the film thickness from the outer surface particularly suppresses the decrease in corrosion resistance. preferable.

  A method for verifying whether or not the maximum value of the concentration of the component (B) is in the range of 0 ≦ Y ≦ (Z / 5) is not particularly limited. For example, high frequency GDS (high frequency discharge type glow discharge emission spectroscopy) Examples thereof include a measuring method and a cross-sectional TEM (field emission transmission electron microscope) observation method. The verification method will be described below.

<High-frequency GDS method>
In this method, System 3860 manufactured by Rigaku Denki Kogyo Co., Ltd. is used, the discharge voltage is 30 W, the argon flow rate is 250 ml / min, and the sampling interval is 0.5 seconds. , The component (B), and the spectral intensity of the element (zinc in the case of zinc-based plating) contained in the lower layer are measured, and a graph representing the relationship between the sampling time T and the spectral intensity of each element is created. The sampling time during which the spectral intensity of the element contained in the lower layer is greatly increased is defined as the interface between the coating layer (X) and the lower layer, and is expressed as Tz. Since the distance in the depth direction of the coating film from the outer surface of the coating layer (X) and the GDS sampling time are directly proportional, the sampling in the depth direction of the coating film from the outer surface of the coating layer (X). When time is Ty,
0 ≦ Ty ≦ (Tz / 5)
If there is a maximum value of the spectral intensity of the component (B) in the range of
0 ≦ Y ≦ (Z / 5)
It is possible to determine that it has a maximum value of the concentration of the component (B).

<Section TEM observation method>
In this method, first, a surface-treated metal plate is embedded in an epoxy resin to cure the epoxy resin. Next, in order to confirm the layer structure of the coating film, the cross-sectional direction is trimmed as an observation surface, and an ultrathin section having a thickness of about 50 nm is cut out with an ultramicrotome apparatus. The cross section of the cut ultrathin slice was observed with a field emission transmission electron microscope (FE-TEM, JEM2100F manufactured by JEOL Ltd.), and the coating layer in the depth direction from the outer surface of the coating layer (X) ( Read the distance Z (μm) to the interface with the lower layer in contact with X). Next, using an EDS analyzer (JED2100T manufactured by JEOL Ltd.), the component (B) is line-analyzed in the depth direction of the coating film, and the outer surface of the coating layer (X) having a maximum detected intensity. It is possible to determine whether or not it is included in the range of 0 ≦ Y ≦ (Z / 5) by measuring the distance from.

Furthermore, the intensity ratio of the component (B) defined by the following formula (I) obtained from the element concentration measurement result in the depth direction in the high frequency discharge type glow discharge optical emission spectrometry of the coating layer (X) is expressed as M. In this case, it is preferable that the maximum value of M is 3 to 10.
M = [M] / [C] (I)

Here, [M] is the total spectral intensity of the cationic metal element (B), and [C] is the spectral intensity of carbon.
If the maximum value of M is less than 3, the formation of ion clusters in the coating film is insufficient, and the solvent resistance and alkali resistance are not sufficient. If it exceeds 10, the formation of ion clusters in the coating film becomes excessive, and the top coat is applied. There is a risk that paint adhesion may be reduced.

  The anionic functional group is not particularly limited, and examples thereof include a carboxyl group, a sulfone group, a phosphate group, and a mercapto group. In particular, when a carboxyl group is contained, the effect of improving solvent resistance and alkali resistance is great, and in the case of an aqueous resin, it is also suitable for making it aqueous.

  When the organic resin (A) is formed of an aqueous resin, the effect of improving solvent resistance and alkali resistance is particularly great. Here, the aqueous resin includes, in addition to the water-soluble resin, a resin (water-dispersible resin) that is insoluble in water and can be finely dispersed in water like an emulsion or a suspension.

  When the organic resin (A) is formed by a cross-linked resin matrix formed by a reaction between an aqueous resin and a cross-linking agent, the solvent resistance and alkali resistance are further improved as compared with a coating film formed by the aqueous resin alone. Can do. The crosslinked resin matrix is formed by a reaction between an aqueous resin and a crosslinking agent. The reaction (crosslinking reaction between the aqueous resin and the crosslinking agent) may be performed when the coating film is formed, or a part of the reaction is performed before the coating film is formed, and the reaction is completed when the coating film is formed. You may let them.

  The aqueous resin is not particularly limited, but at least one of the aqueous resins to be used is preferably selected from an aqueous polyester resin, an aqueous polyurethane resin, an aqueous epoxy resin, an aqueous acrylic resin, and an aqueous polyolefin resin.

  The aqueous polyester resin is not particularly limited. For example, ethylene glycol, propylene glycol, diethylene glycol, 1,6-hexanediol, neopentyl glycol, triethylene glycol, bisphenol hydroxypropyl ether, glycerin, trimethylolethane, trimethylolpropane. Dehydration condensation of polyhydric alcohols such as phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, adipic acid, sebacic acid, maleic anhydride, itaconic acid, fumaric acid, and hymic anhydride And those obtained by neutralizing with ammonia or an amine compound and dispersing in water.

  The aqueous polyurethane resin is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, diethylene glycol, 1,6-hexanediol, neopentyl glycol, triethylene glycol, bisphenol hydroxypropyl ether, glycerin, trimethylolethane, and trimethylolpropane. And the like obtained by reacting a polyhydric alcohol such as hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate and the like, further extending the chain with diamine or the like, and dispersing in water.

  The aqueous epoxy resin is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, resorcin type epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, resorcin type epoxy resin. , An epoxy resin such as a novolak-type epoxy resin is reacted with an amine compound such as diethanolamine or N-methylethanolamine and neutralized with an organic acid or an inorganic acid, or in the presence of the epoxy resin, Examples thereof include those obtained by radical polymerization of an acid value acrylic resin, neutralized with ammonia or an amine compound, and then dispersed in water.

  The aqueous acrylic resin is not particularly limited, and examples thereof include unsaturated monomers such as styrene, alkyl (meth) acrylates, (meth) acrylic acid, hydroxyalkyl (meth) acrylates, and alkoxysilane (meth) acrylates. Can be obtained by radical polymerization in an aqueous solution using a polymerization initiator. The polymerization initiator is not particularly limited, and for example, persulfates such as potassium persulfate and ammonium persulfate, and azo compounds such as azobiscyanovaleric acid and azobisisobutyronitrile can be used.

  The aqueous polyolefin resin is not particularly limited. For example, after radical polymerization of ethylene and an unsaturated carboxylic acid such as methacrylic acid, acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid or the like under high temperature and high pressure, ammonia And amine compounds, metal compounds such as KOH, NaOH, and LiOH, or those obtained by neutralizing and dispersing in water with ammonia or amine compounds containing the metal compounds.

  The aqueous resin may be used alone or in combination of two or more. An aqueous composite resin obtained by modifying with at least one selected from an aqueous polyester resin, an aqueous polyurethane resin, an aqueous epoxy resin, an aqueous acrylic resin and an aqueous polyolefin resin in the presence of at least one of the aqueous resins. You may use 1 type (s) or 2 or more types.

  When the aqueous resin contains an alkali metal neutralized product of the ethylene-unsaturated carboxylic acid copolymer, the effect of improving solvent resistance and alkali resistance is large, which is preferable. Here, the alkali metal neutralized product of the ethylene-unsaturated carboxylic acid copolymer means that a part of the carboxyl group contained in the ethylene-unsaturated carboxylic acid copolymer is a metal such as KOH, NaOH or LiOH. It means that it has been neutralized by the alkali metal element supplied by the compound.

  The alkali metal neutralized product of the ethylene-unsaturated carboxylic acid copolymer preferably has a neutralization rate of 30% lower limit and 90% upper limit. A neutralization rate of 30% at the lower limit and 90% at the upper limit means that 30 to 90% of the carboxyl groups contained in the ethylene-unsaturated carboxylic acid copolymer are neutralized. When the neutralization rate is less than 30%, the alkali resistance of the obtained coating film and the stability of the coating agent for forming the coating film are not sufficient, and when the neutralization rate exceeds 90%, it was obtained. There is a risk of impairing the adhesion between the coating film and the top coat. The lower limit is more preferably 40%, and the upper limit is more preferably 80%. In the neutralization of the ethylene-unsaturated carboxylic acid copolymer, ammonia, an amine or the like may be used in combination with the alkali metal element.

  The crosslinking agent is not particularly limited as long as it has a plurality of reactive functional groups, but is not limited to amino resin, polyisocyanate compound, blocked product thereof (blocked product of polyisocyanate compound), epoxy compound, carbodiimide compound, silane compound. , At least one selected from a crosslinkable zirconium compound and a crosslinkable titanium compound is preferable. By using these to obtain a crosslinked resin matrix, the solvent resistance and alkali resistance can be further improved.

  The amino resin is not particularly limited, and examples thereof include a melamine resin, a benzoguanamine resin, a urea resin, and a glycoluril resin.

  It does not specifically limit as said polyisocyanate compound, For example, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, tolylene diisocyanate etc. can be mentioned. Examples of the blocked product include a blocked product of hexamethylene diisocyanate, a blocked product of isophorone diisocyanate, a blocked product of xylylene diisocyanate, and a blocked product of tolylene diisocyanate, which are blocked products of the polyisocyanate compound. The said amino resin may be used independently and may use 2 or more types together.

  The epoxy compound is not particularly limited as long as it is a compound having a plurality of oxirane rings. For example, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, sorbitan polyglycidyl ether, pentaerythritol polyglycidyl ether Glycerin polyglycidyl ether, trimethylpropane polyglycidyl ether, neopentyl glycol polyglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol glycol diglycidyl ether, polypropylene glycol glycol diglycidyl ether, 2,2-bis -(4'-glycidyloxyphenyl) propane, tris (2,3-epoxypropyl) isocyanurate DOO, bisphenol A diglycidyl ether, and hydrogenated bisphenol A diglycidyl ether and the like. The said epoxy compound may be used independently and may use 2 or more types together.

  As the carbodiimide compound, for example, after synthesizing an isocyanate-terminated polycarbodiimide by a condensation reaction involving decarbonization of a diisocyanate compound such as aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate, the reactivity with an isocyanate group is further achieved. Examples include a compound to which a hydrophilic segment having a functional group having a group is added. The said carbodiimide compound may be used independently and may use 2 or more types together.

  The silane compound is not particularly limited as long as it is a silane compound having a plurality of reactive functional groups. For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylethoxysilane, N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ -Methacryloxypropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltri Toxisilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane and the like. The said silane agent may be used independently and may use 2 or more types together.

  The crosslinkable zirconium compound is not particularly limited as long as it is a zirconium-containing compound having a plurality of functional groups capable of reacting with an anionic functional group, but is preferably a compound that is soluble in water or an organic solvent. More preferably, it is a zirconium compound. An example of such a compound is zirconyl ammonium carbonate.

  The crosslinkable titanium compound is not particularly limited as long as it is a titanium-containing compound having a plurality of functional groups capable of reacting with an anionic functional group, but dipropoxy bis (triethanolaminato) titanium, dipropoxy bis (diethanolaminato). ) Titanium, propoxy tris (diethanolaminato) titanium, dibutoxy bis (triethanolaminato) titanium, dibutoxy bis (diethanolaminato) titanium, dipropoxy bis (acetylacetonato) titanium, dibutoxy bis (acetylacetonato) Titanium, dihydroxy bis (lactato) titanium monoammonium salt, dihydroxy bis (lactato) titanium diammonium salt, propanedioxytitanium bis (ethylacetoacetate), oxotitanium bis (monoammonium Kisareto) include isopropyl tri (N- amidoethyl-aminoethyl) titanate and the like. The said crosslinkable titanium compound may be used independently and may use 2 or more types together.

  The cross-linked resin matrix comprises (1) the water-based polyolefin resin and an epoxy compound as a cross-linking agent from the viewpoint of improving adhesion with the lower layer (undercoat film or metal plate), adhesion with the top coating, and improving corrosion resistance. More preferable are those comprising a silane compound, (2) the aqueous polyurethane resin, a silane compound as a crosslinking agent, or a composite thereof.

  Although the content rate in the said coating-film layer (X) of the said organic resin (A) is not specifically limited, The lower limit is 50 mass% and the upper limit is 90 mass% in 100 mass% of coating films. If it is less than 50% by mass, the adhesion to the base or the top coat and the alkali resistance may be reduced. If it exceeds 90% by mass, the corrosion resistance may decrease. The lower limit is more preferably 65% by mass, and the upper limit is more preferably 85% by mass.

  The coating layer (X) preferably contains an inorganic rust preventive agent to enhance corrosion resistance. The inorganic rust preventive agent is not particularly limited, and a known inorganic rust preventive agent can be used, but it may contain at least one selected from silica, a phosphate compound, a vanadium compound, a molybdenum compound, and a niobium compound. More preferred.

  By containing the silica, the barrier property of the coating film can be improved, and the permeability of the corrosion factor can be suppressed. Although it does not specifically limit as said silica, It is preferable that they are silica fine particles, such as colloidal silica with a primary particle diameter of 5-50 nm, and a fumed silica. Examples of commercially available products include Snowtex O, Snowtex N, Snowtex C, Snowtex IPA-ST (Nissan Chemical Industry), Adelite AT-20N, AT-20A (Asahi Denka Kogyo), Aerosil 200 (Nippon Aerosil) Etc.

  By containing the phosphoric acid compound, when the base is a metal, it reacts with the surface to form a phosphate layer to passivate, and it forms a sparingly soluble coating film and has a barrier property against corrosion factors. The effect to exhibit, the effect which demonstrates the barrier property etc. by supplementing the metal ion eluted from the base metal plate, forming a hardly soluble compound with a metal ion, etc. are anticipated. The phosphoric acid compound is not particularly limited, but phosphoric acids such as orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid and tetraphosphoric acid, ammonium salts such as triammonium phosphate and diammonium hydrogen phosphate, Metal salts with Na, Mg, Al, K, Ca, Mn, Ni, Zn, Fe, etc., aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), Examples thereof include phosphonic acids such as diethylenetriaminepenta (methylenephosphonic acid) and their salts, organic phosphoric acids such as phytic acid and their salts, and the like. These may be used alone or in combination of two or more.

  By including the vanadium compound, molybdenum compound, and niobium compound, the same corrosion resistance improvement effect as that of the phosphoric acid compound can be expected. By containing the phosphoric acid compound at the same time, the effect of increasing the ability to supplement metal ions eluted from the underlying metal plate and forming a poorly soluble compound with the metal ions is obtained. The action can be secured.

  The vanadium compound is not particularly limited. For example, vanadium pentoxide, metavanadate, ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride, vanadium trioxide, vanadium dioxide, oxysulfuric acid, vanadium oxyacetylacetonate, vanadium acetyl Examples include acetonate, vanadium trichloride, phosphovanadomolybdic acid, and the like. Further, a pentavalent vanadium compound is formed by an organic compound having at least one functional group selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, a primary to tertiary amino group, an amide group, a phosphoric acid group, and a phosphonic acid group. Those reduced to tetravalent to divalent can also be used. These may be used alone or in combination of two or more.

  It does not specifically limit as said molybdenum compound, A conventionally well-known molybdenum containing compound can be used, For example, a molybdate etc. can be used. The molybdate is not limited in its skeleton and degree of condensation, and examples thereof include orthomolybdate, paramolybdate, and metamolybdate. Moreover, all salts, such as a single salt and a double salt, are included, and a phosphate molybdate etc. can be mentioned as a double salt. These may be used alone or in combination of two or more.

  The niobium compound is not particularly limited, and a conventionally known niobium-containing compound can be used. Examples thereof include niobium oxide, niobic acid and its salt, fluoroniobate, and fluorooxoniobate. Among these, niobium oxide is preferable from the viewpoint of improving corrosion resistance. The niobium compound is more preferably niobium oxide colloidal particles. The niobium oxide colloidal particles are more stable when the average particle diameter is smaller, and a coating film containing dense niobium oxide is formed. More preferable.

  The niobium oxide colloidal particles in the coating agent are those in which niobium oxide is dispersed in water in the form of fine particles. For example, niobium oxide is not formed strictly, but in the intermediate state between niobium hydroxide and niobium oxide. It may be in an amorphous state.

  Although content in the said coating-film layer (X) of the said inorganic rust preventive agent is not specifically limited, It is preferable to contain 0.01-20 mass% in 100 mass% of coating films. If the amount is less than 0.01% by mass, the content may be small and the effect of improving the corrosion resistance may not be obtained. If the amount exceeds 20% by mass, the coating film becomes brittle and the corrosion resistance may be lowered.

  By containing a wax component in the coating film layer (X), the lubricity of the coating film surface is improved, and the workability and scratch resistance of the coating film can be improved.

  Although it does not specifically limit as said wax component, Although a well-known wax component can be used, it is preferable to use at least 1 type changed from a fluororesin type | system | group and a polyolefin resin type | system | group. Examples of fluororesins include polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polychlorotrifluoroethylene (PCTFE). ), Polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and the like can be used. Of these, one type may be used alone, or two or more types may be used in combination.

  The polyolefin resin is not particularly limited, and examples thereof include hydrocarbon waxes such as paraffin, microcrystalline, and polyethylene, and derivatives thereof. The derivative is not particularly limited, and examples thereof include carboxylated polyolefin and chlorinated polyolefin. Of these, one type may be used alone, or two or more types may be used in combination.

  The surface-treated metal plate of the present invention has at least one coating layer, and the configuration is not limited as long as the coating layer (X) is formed on the outermost surface. A structure in which the film layer (X) is coated one layer, or a two-layer structure in which a base coating layer is provided on the upper layer of the metal plate and the coating layer (X) is further coated thereon is preferable. Although the total film thickness of the coating layer formed on the upper layer of the metal plate is not particularly limited, it is preferably 0.1 μm to 5 μm. If the thickness is less than 0.1 μm, sufficient corrosion resistance may not be obtained. If the thickness exceeds 5 μm, the performance is saturated and economically disadvantageous, and it may not be used for applications requiring conductivity and weldability. In view of the above matters, the thickness is more preferably in the range of 0.3 μm to 3 μm.

  When it has a base coating film layer in the lower layer of the said coating-film layer (X), the adhesiveness of the said coating-film layer (X) can further be improved and corrosion resistance can further be improved.

  Although the said base coating film layer is not specifically limited, Adhesiveness of the said coating film layer (X) and a base metal plate is included by including at least 1 sort (s) chosen from a silane coupling agent, organic resin, and a polyphenol compound. The corrosion resistance can be further improved.

  The silane coupling agent contained in the base coating layer is not particularly limited. For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ sold by Shin-Etsu Chemical, Nippon Unicar, Chisso, Toshiba Silicone, etc. -Aminopropyltrimethoxysilane, γ-aminopropylethoxysilane, N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltri Methoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltri Metoki Silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, N Examples include -β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane. The said silane coupling agent may be used independently and may use 2 or more types together.

  The organic resin contained in the base coating layer is not particularly limited, and the same organic resin as that of the coating layer (X) can be used. The organic resin used for the base coating layer preferably contains at least one selected from a water-based epoxy resin, a water-based polyester resin, and a water-based phenol resin, and good adhesion can be obtained.

  The aqueous polyester resin is not particularly limited. For example, ethylene glycol, propylene glycol, diethylene glycol, 1,6-hexanediol, neopentyl glycol, triethylene glycol, bisphenol hydroxypropyl ether, glycerin, trimethylolethane, trimethylolpropane. Dehydration condensation of polyhydric alcohols such as phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, adipic acid, sebacic acid, maleic anhydride, itaconic acid, fumaric acid, and hymic anhydride And those obtained by neutralizing with ammonia or amine compound and dispersing in water.

  The aqueous epoxy resin is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, resorcin type epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, resorcin type epoxy resin. In the presence of an epoxy resin such as a novolac-type epoxy resin, which is obtained by reacting with an amine compound such as diethanolamine or N-methylethanolamine and neutralizing with an organic acid or inorganic acid, or in the presence of the epoxy resin, Examples thereof include those obtained by radical polymerization of an acrylic resin, neutralized with ammonia or an amine compound, and dispersed in water.

  The aqueous phenol resin is not particularly limited. For example, a methylol phenol resin obtained by addition reaction of aromatics such as phenol, resorcin, cresol, bisphenol A, paraxylylene dimethyl ether and formaldehyde in the presence of a reaction catalyst. And the like obtained by reacting a phenol resin such as diethanolamine with N-methylethanolamine and neutralizing with an organic acid or an inorganic acid.

  The polyphenol compound contained in the undercoat layer refers to a compound having two or more phenolic hydroxyl groups bonded to a benzene ring, or a condensate thereof. Examples of the compound having two or more phenolic hydroxyl groups bonded to the benzene ring include gallic acid, pyrogallol, catechol and the like. The condensate of the compound having two or more phenolic hydroxyl groups bonded to the benzene ring is not particularly limited, and examples thereof include polyphenol compounds that are widely distributed in the plant kingdom, usually called tannic acid. Tannic acid is a general term for aromatic compounds having a complex structure having a large number of phenolic hydroxyl groups widely distributed in the plant kingdom. The tannic acid may be hydrolyzable tannic acid or condensed tannic acid. The tannic acid is not particularly limited, and examples thereof include hameli tannin, oyster tannin, chatannin, pentaploid tannin, gallic tannin, mylobarantannin, dibidi tannin, algarobilatannin, valonia tannin, catechin tannin, and the like. . Examples of the tannic acid include commercially available ones such as “tannic acid extract A”, “B tannic acid”, “N tannic acid”, “industrial tannic acid”, “purified tannic acid”, “Hi tannic acid”, "F tannic acid", "local tannic acid" (all manufactured by Dainippon Pharmaceutical Co., Ltd.), "tannic acid: AL" (manufactured by Fuji Chemical Industry Co., Ltd.) and the like can also be used. The said polyphenol compound may be used by 1 type, and may use 2 or more types together.

  The content of at least one selected from a silane coupling agent, an organic resin, and a polyphenol compound in the undercoating layer is not particularly limited, but it is preferably 1% by mass or more in 100% by mass of the undercoating layer. If the amount is less than 1% by mass, the content may be small and the effect of improving adhesion and corrosion resistance may not be obtained.

  The undercoat layer further contains at least one selected from silica, a phosphoric acid compound, and hexafluorometal acid, so that the adhesion to the undercoat metal plate can be further enhanced, and the corrosion resistance can be further enhanced.

  By including the silica, a chemical bond is formed with at least one selected from the silane coupling agent, organic resin, and polyphenol compound, and the cohesive force of the coating film is improved and adhesion is improved. The barrier property of the coating film can be improved, and the permeability of the corrosion factor can be suppressed.

  Although it does not specifically limit as said silica, It is preferable that they are silica fine particles, such as colloidal silica with a primary particle diameter of 5-50 nm, and a fumed silica. Examples of commercially available products include Snowtex O, Snowtex N, Snowtex C, Snowtex IPA-ST (Nissan Chemical Industry), Adelite AT-20N, AT-20A (Asahi Denka Kogyo), Aerosil 200 (Nippon Aerosil) Etc.

  By containing the phosphoric acid compound and hexafluorometal acid, the surface of the metal plate is activated by etching, and the action of silane coupling agent, organic resin, and polyphenol compound on plating is promoted.

  The phosphoric acid compound contained in the undercoat layer is not particularly limited, but phosphoric acids such as orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, triammonium phosphate, dihydrogen phosphate Ammonium salts such as ammonium, metal salts with Na, Mg, Al, K, Ca, Mn, Ni, Zn, Fe, aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (Methylenephosphonic acid), phosphonic acids such as diethylenetriaminepenta (methylenephosphonic acid) and their salts, organic phosphoric acids such as phytic acid and their salts, and the like. These may be used alone or in combination of two or more. In addition to the above-described action, the phosphate compound has an action of forming a phosphate layer on the surface of the metal plate to passivate it, and thus has an action of improving corrosion resistance.

  The hexafluorometal acid contained in the base coating layer is not particularly limited, and examples thereof include hexafluorophosphoric acid, hexafluorotitanic acid, hexafluorozirconic acid, hexafluorosilicic acid, hexafluoroniobic acid, hexafluoroantimonic acid. And ammonium salts, potassium salts, sodium salts, calcium salts, magnesium salts and the like thereof. In addition to the above effects, hexafluorometal acid has the effect of improving corrosion resistance because a stable metal oxide coating layer is formed on the plating surface by the metal supplied from hexafluorometal acid. In particular, a metal containing Ti, Zr, Si, or Nb is preferable. The hexafluorometal acid may be used alone or in combination of two or more.

  The content in at least one undercoating layer selected from silica, phosphoric acid compound and hexafluorometal acid is not particularly limited, but is 0.1 to 50% by mass in 100% by mass of the undercoating layer. It is preferable to contain. If the amount is less than 0.1% by mass, these amounts are insufficient, and thus the corrosion resistance improvement effect may not be obtained. If it exceeds 50% by mass, the underlying coating film layer becomes brittle, and the adhesiveness may deteriorate due to the cohesive failure of the coating film.

Although the adhesion amount of the said base coating-film layer is not specifically limited, It is preferable to exist in the range of 10-1000 mg / m < ² >. If it is 10 mg / m ² or less, sufficient effect of the undercoat film layer cannot be obtained, and if it exceeds 1000 mg / m ² or more, the undercoat film layer tends to cohesively break down, resulting in a decrease in adhesion. From the stable effect and economical viewpoint, a more preferable adhesion amount range is 50 to 500 mg / m ² .

  The metal plate applicable in the present invention is not particularly limited, and examples thereof include iron, iron-base alloy, aluminum, aluminum-base alloy, copper, copper-base alloy, and the like, and optionally plated on the metal plate. A plated metal plate can also be used. Among them, the most preferable ones in the application of the present invention are zinc-based plated steel sheets and aluminum-based plated steel sheets. Zinc-coated steel sheets include galvanized steel sheets, zinc-nickel plated steel sheets, zinc-iron plated steel sheets, zinc-chromium plated steel sheets, zinc-aluminum plated steel sheets, zinc-titanium plated steel sheets, zinc-magnesium plated steel sheets, zinc-manganese. Galvanized steel sheets such as plated steel sheets, zinc-aluminum-magnesium plated steel sheets, zinc-aluminum-magnesium-silicon-plated steel sheets, and cobalt, molybdenum, tungsten, nickel as a small amount of different metal elements or impurities in these plated layers Examples include those containing titanium, chromium, aluminum, manganese, iron, magnesium, lead, bismuth, antimony, tin, copper, cadmium, arsenic and the like, and those in which inorganic substances such as silica, alumina, and titania are dispersed. Examples of the aluminum-based plated steel sheet include aluminum or an alloy composed of aluminum and at least one of silicon, zinc, and magnesium, such as an aluminum-silicon plated steel sheet, an aluminum-zinc plated steel sheet, and an aluminum-silicon-magnesium plated steel sheet. . Furthermore, the present invention can also be applied to multilayer plating in combination with the above plating and other types of plating such as iron plating, iron-phosphorus plating, nickel plating, cobalt plating and the like. The plating method is not particularly limited, and any known method such as an electroplating method, a hot dipping method, a vapor deposition plating method, a dispersion plating method, and a vacuum plating method may be used.

  The coating method for forming the coating layer (X) is not particularly limited as long as the cationic metal element (B) can be concentrated near the outer surface. A method of simultaneously applying multiple surface treatment agents having different element (B) concentrations, and a roll coat, air spray, airless spray, and dipping, in which surface treatment agents having different concentrations of the cationic metal element (B) are generally used. A method of applying and baking by a multi-stage process combining one or two of the above methods, and applying the surface treatment agent by commonly used roll coat, air spray, airless spray, dipping, etc. For example, a method of forming a concentrated layer on the outer surface by contacting with an aqueous solution containing the metal cation immediately after forming by heating and drying.

  In any method, the baking temperature (the reached plate temperature of the metal plate) when the coating layer (X) is thermally dried is not particularly limited, but is preferably 100 ° C. or higher. Further, the upper limit is preferably less than 250 ° C. When the temperature is lower than 100 ° C, the curability of the coating film to be formed becomes insufficient. When the temperature exceeds 250 ° C, the coating film is thermally decomposed and the corrosion resistance is deteriorated or yellowing occurs and the appearance is deteriorated. There is. The drying time for heat drying is preferably 1 second to 5 minutes.

  In the case of the method in which the surface treatment agents having different cationic metal element concentrations presented in the first and second methods are applied in multiple layers or in multiple stages, the thickness of the uppermost layer film, which is a concentrated layer of the cationic metal element, is particularly determined in multiple layers or multiple stages. It is preferable that it is 1/5 or less of the total film thickness by application.

  The method for adding a cationic metal element to the surface treatment agent in the multi-layer coating or multi-stage coating method is not particularly limited. For example, carbonate, phosphate, sulfate, nitrate, acetate, fluoride salt, oxide salt Can be added as a hydroxide salt. It is preferable that the addition amount to the surface treatment agent for treating the upper layer film that becomes the concentrated layer of the cationic metal element is 0.1% by mass to 10% by mass as the concentration of the cationic metal element with respect to the solid content. If it is less than 0.1% by mass, the cationic metal element (B) concentrated layer formation in the surface layer portion of the coating film is insufficient, and the effect of improving alkali resistance and solvent resistance may not be sufficient. In some cases, the cationic metal element (B) is excessively concentrated, ion clusters are excessively formed, and the adhesion to the top coating is lowered.

  In the case of the third method of contacting the cation-containing aqueous solution, it is preferable that the surface treatment agent is applied, heated and dried, and then immediately contacted with the aqueous solution. The method for supplying the metal cation contained in the aqueous solution is not particularly limited. For example, carbonate, phosphate, sulfate, nitrate, acetate, fluoride, oxide, hydroxide, etc. are dissolved in ion-exchanged water. And the concentration of the metal cation contained in the aqueous solution is preferably 30 to 1000 ppm or more. If it is less than 30 ppm, the cationic metal element (B) concentrated layer formation in the coating surface layer portion may be insufficient, and if it exceeds 1000 ppm, the cationic metal element (B) concentration may be excessive. The pH of the aqueous solution is preferably 3-11.

  EXAMPLES Hereinafter, although the manufacture example and Example which concern on this invention are shown and this invention is demonstrated further in detail, this invention is not limited only to the following Example. In the examples, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

  As a coating agent for forming the coating layer (X), an aqueous resin shown in Table 1 is used as an organic resin, and a crosslinking agent (Table 2), an inorganic rust preventive agent (Table 3), and a wax component (Table). 4) was blended in the blending amounts shown in Table 5 and adjusted by stirring using a paint disperser.

  The aqueous resin shown in Table 1 was produced as follows.

(Production of aqueous resin 1 Production of aqueous polyester resin)
Prepared by heating and reacting neopentyl glycol, trimethylolpropane, and Cardura E10 (manufactured by Japan Epoxy Resin) to phthalic anhydride, isophthalic acid and adipic acid, neutralizing with dimethylethanolamine and dispersing in water. did.

(Production of aqueous resin example 2 Production of aqueous polyurethane resin)
A polyester diol obtained from bisphenol A type diol, neopentyl glycol and isophthalic acid, 2,2 dimethylolpropionic acid and isophorone diisocyanate were reacted, then neutralized with triethylamine and dispersed in water.

(Aqueous resin production example 3 Production of aqueous epoxy resin)
Prepared by modifying bisphenol A type epoxy resin with acrylic resin obtained by radical copolymerization of acrylic acid, 2-ethylhexyl methacrylate and butyl acrylate with peroxide, then neutralizing with dimethylethanolamine and dispersing in water did.

(Water Resin Production Example 4 Production of Ethylene-Unsaturated Carboxylic Acid Copolymer Resin)
An ethylene-methacrylic acid copolymer resin (Nucleel N2060 manufactured by Mitsui DuPont Polychemical Co., Ltd.) was neutralized with sodium hydroxide (60 equivalent% with respect to the total carboxyl groups) and dispersed in water.

(Water Resin Production Example 5 Production of Ethylene-Unsaturated Carboxylic Acid Copolymer Resin)
An ethylene-methacrylic acid copolymer resin (Nucleel N2060 manufactured by Mitsui DuPont Polychemical Co., Ltd.) was neutralized with dimethylethanolamine (80 equivalent% with respect to the total carboxyl groups) and dispersed in water.

(Water Resin Production Example 6 Production of Ethylene-Unsaturated Carboxylic Acid Copolymer Resin)
An ethylene-acrylic acid copolymer resin (Nucleel N5130H manufactured by Mitsui DuPont Polychemical Co., Ltd.) was neutralized with sodium hydroxide (40 equivalent% with respect to the total carboxyl groups) and dispersed in water.

  Coating agents for forming the undercoat layer are organic resins (Table 1), silane coupling agents (Table 6), polyphenol compounds (Table 7), phosphate compounds (Table 8), hexafluorometal acids ( Table 9) was blended in the blending amounts shown in Table 10 and adjusted by stirring using a paint disperser.

  After the surface of the metal plate shown in Table 11 is subjected to alkaline degreasing treatment, washed with water and dried, if necessary, the coating agent for the base coating film having the composition shown in Table 10 is applied by a roll coater so that the ultimate plate temperature becomes 120 ° C. Then, after drying by heating in ion exchange water and cooling, it was dried by blowing warm air. The amount of adhesion was adjusted depending on the non-volatile content (heating residue) of the coating agent or application conditions. Thereafter, a coating agent for forming a coating layer (X) having the composition shown in Table 5 and a coating agent obtained by adding a predetermined amount of a carbonate of a cationic metal element (B) to the coating agent to each predetermined film thickness In this way, multiple layers were simultaneously applied by a slide coater, and dried by heating so that the ultimate plate temperature was a predetermined temperature.

  Coating composition of the surface-treated metal plate obtained, concentration of the cationic metal element (B) in the coating layer (cationicity in the range of 0 ≦ Y ≦ (Z / 5) defined in claim 2) Table 12 shows the presence or absence of the maximum value of the concentration of the metal element (B), and the value of M defined in claim 3. The concentration state of the cationic metal element (B) in the coating layer and the value of M defined in claim 3 were investigated by measuring the depth direction of the high frequency GDS.

  Furthermore, after the surface of the metal plate shown in Table 11 is subjected to alkaline degreasing treatment, washed with water and dried, the coating agent for the base coating film having the composition shown in Table 10 is applied by a roll coater as necessary, and the ultimate plate temperature reaches 120 ° C. It was dried by heating, soaked in ion exchange water and cooled, and then dried by blowing warm air. The amount of adhesion was adjusted depending on the non-volatile content (heating residue) of the coating agent or application conditions. Thereafter, a coating agent for forming a coating film layer (X) having the composition shown in Table 5 was applied by a roll coater, heat-dried so that the ultimate plate temperature was a predetermined temperature, and then the cationic metal (B ) In an aqueous solution (the solvent is ion-exchanged water) for 5 seconds and then dried by blowing warm air.

Coating composition of the surface-treated metal plate obtained, treatment conditions of the cationic metal element (B) aqueous solution, concentration of the cationic metal element (B) in the coating layer (0 ≦ Y defined in claim 2) Table 13 shows the maximum value of the concentration of the cationic metal element (B) within the range of ≦ (Z / 5) and the value of M defined in claim 3. In addition, about the concentration state to the coating-film layer of a cationic metal element (B) and the value of M defined in Claim 3, it investigated by measuring the depth direction of the high frequency GDS on the following conditions. Using a System 3860 manufactured by Rigaku Denki Kogyo Co., the carbon and cation in the depth direction of the coating film from the outer surface of the coating layer (X) under the conditions of a discharge voltage of 30 W, an argon flow rate of 250 ml / min and a sampling interval of 0.5 seconds The spectral intensity of the conductive metal element (B) and the element contained in the lower layer (zinc in the case of zinc-based plating) were measured, and a graph showing the relationship between the sampling time T and the spectral intensity of each element was created. The sampling time during which the spectral intensity of the elements contained in the lower layer was greatly increased was taken as the interface between the coating layer (X) and the lower layer, and expressed as Tz. Since the distance in the depth direction of the coating film from the outer surface of the coating layer (X) and the GDS sampling time are directly proportional, the sampling in the depth direction of the coating film from the outer surface of the coating layer (X). When time is Ty,
0 ≦ Ty ≦ (Tz / 5)
If there is a maximum value of the sum of the spectral intensities of the cationic metal element (B) in the range of
0 ≦ Y ≦ (Z / 5)
Was determined to have a maximum concentration of the cationic metal element (B). The value of M was obtained from the sum of the spectral intensities of the cationic metal element (B) at the sampling time and the spectral intensity of carbon having the maximum value of the sum of the spectral intensities of the cationic metal element (B).

Table 15 shows the results of evaluating the quality performance (corrosion resistance, solvent resistance, alkali resistance, adhesion to the top coat) of the obtained surface-treated metal sheet. In addition, quality evaluation was performed as follows.
(1) Corrosion resistance The edge and back surface of the test plate were tape-sealed, and an SST (JIS-Z-2371) test was conducted. The state of white rust generation after 120 hours was observed and evaluated in terms of white rust generation area%.
(2) Solvent resistance After installing the test plate on a rubbing tester, the coating state after rubbing the absorbent cotton impregnated with ethanol 10 times (reciprocating) with a load of 0.5 kgf / cm ² was evaluated according to the following evaluation criteria. did.
4: No trace on the rubbing surface 3: Slight trace on the rubbing surface 2: White trace on the rubbing surface 1: No coating on the rubbing surface (3) Alkali resistance Degreasing agent (Fine Cleaner L4460, manufactured by Nihon Parkerizing Co., Ltd.) A agent 1.8%, B agent 1.2% aqueous solution (pH 12.0) after stirring for 30 minutes while observing the coating state The remaining area% was evaluated.
(4) Adhesion with topcoat paint Melamine alkyd paint (Amirac # 1000 White, manufactured by Kansai Paint Co., Ltd.) was applied to the test plate surface with a bar coater to a dry film thickness of 20 μm, and baked at 120 ° C. for 25 minutes. Was made. After being left for a day and night, immersed in boiling water for 30 minutes, taken out and left for 1 day, put a grid cut cut at 1 mm intervals, extrude Eriksen 7 mm, and paste cellophane tape (manufactured by Nichiban) on the extruded part, The state of the coating film after forced peeling was observed, and a rating of 10 (no peeling) to 1 (complete peeling) was given according to the remaining rate of the coating film according to the following criteria.
Score 10: Survival rate 100%
Score 9: 95% ≤ remaining rate <100%
Score 8: 90% ≤ remaining rate <95%
Score 7: 80% ≤ remaining rate <90%
Score 6: 70% ≤ remaining rate <80%
Score 5: 60% ≤ remaining rate <70%
Score 4: 50% ≤ remaining rate <60%
Score 3: 30% ≤ remaining rate <50%
Score 2: 0% <remaining rate <30%
Score 1: 0% survival rate

  From Tables 12 to 14, all of the examples of the present invention are excellent in corrosion resistance, solvent resistance, alkali resistance, and adhesion to the top coat. However, in Examples 10, 24, 65, 121, and 149 in which the value of M defined in claim 3 exceeds 10, the adhesion with the top coating tends to be slightly lowered.

  On the other hand, the alkali resistance is inferior in the comparative example in which the cationic metal element (B) concentration on the outer surface is not recognized and the present invention is not satisfied. Moreover, when compared with the presence or absence of the concentration of the cationic metal element (B) on the outer surface with the same upper layer coating composition, the comparative example in which the concentration of the cationic metal element (B) is not recognized is also reduced in solvent resistance. (For example, comparison between Example 24 and Comparative Example 25).

As mentioned above, although preferred embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

Claims (15)

  A surface-treated metal plate having at least one coating layer on a metal plate or a plated metal plate, wherein the coating layer (X) formed on the outermost surface has an anionic functional group (A) and Li, Containing at least one cationic metal element (B) selected from Na, K, Mg, Ca and Sr, and the distance in the depth direction from the outer surface of the coating layer (X) is Y (μm), When the distance from the outer surface of the coating layer (X) to the interface with the lower layer in contact with the coating layer (X) in the depth direction is Z (μm), 0 ≦ Y ≦ (Z / 5) A surface-treated metal sheet having a maximum value of the concentration of the cationic metal element (B) in a range. The intensity ratio of the cationic metal element (B) defined by the following formula (I) obtained from the element concentration measurement result in the depth direction in the high-frequency discharge glow discharge optical emission spectrometry of the coating layer (X) The surface-treated metal sheet according to claim 1, wherein the maximum value of M is 3 to 10, where M is M.
M = [M] / [C] (I)
Here, [M] is the sum of the spectral intensities of the cationic metal element (B) (calculated as the sum of the spectral intensities of the respective cationic metal elements when a plurality of cationic metal elements are contained), [C] Is the spectral intensity of carbon.   The surface-treated metal sheet according to claim 1, wherein the anionic functional group contains a carboxyl group.   The surface-treated metal plate according to claim 1, wherein the organic resin (A) is an aqueous resin.   The surface-treated metal sheet according to any one of claims 1 to 3, wherein the organic resin (A) is a crosslinked resin matrix formed by a reaction between an aqueous resin and a crosslinking agent.   6. The surface-treated metal plate according to claim 4, wherein the aqueous resin contains at least one selected from an aqueous polyester resin, an aqueous polyurethane resin, an aqueous epoxy resin, an aqueous acrylic resin, and an aqueous polyolefin resin.   The surface according to any one of claims 4 to 6, wherein the aqueous resin contains an alkali metal neutralized product of an ethylene-unsaturated carboxylic acid copolymer, and the neutralization rate is 30 to 90%. Processing metal plate.   The cross-linking agent is at least one selected from amino resins, polyisocyanate compounds, block bodies of polyisocyanate compounds, epoxy compounds, carbodiimide compounds, silane compounds, cross-linkable zirconium compounds, and cross-linkable titanium compounds. Item 6. The surface-treated metal sheet according to Item 5.   The surface-treated metal plate according to any one of claims 1 to 8, wherein the coating layer (X) contains an inorganic rust inhibitor.   The surface-treated metal sheet according to claim 9, wherein the inorganic rust inhibitor contains at least one selected from silica, a phosphoric acid compound, a vanadium compound, a molybdenum compound, and a niobium compound.   The surface-treated metal plate according to any one of claims 1 to 10, wherein the coating layer (X) contains a wax component.   The surface-treated metal plate according to any one of claims 1 to 11, further comprising a base coating layer between the coating layer (X) and the metal plate or the plated metal plate.   The surface-treated metal sheet according to claim 12, wherein the undercoat layer contains at least one selected from an organic resin, a silane coupling agent, and a polyphenol compound.   The surface-treated metal sheet according to claim 12 or 13, wherein the undercoating layer contains at least one selected from silica, a phosphoric acid compound and hexafluorometal acid. The surface-treated metal plate according to claim 1, wherein the plated metal plate is a zinc-based plated steel plate or an aluminum-based plated steel plate.