WO2007102544A1 - Resin-coated metal plate and surface treatment composition for producing same - Google Patents

Abstract

Disclosed is a resin-coated metal plate having excellent corrosion resistance. Specifically disclosed is a resin-coated metal plate having a resin coating film which is obtained from a surface treatment composition. The surface treatment composition contains 55-95 parts by mass of an olefin-α,β-unsaturated carboxylic acid copolymer and an α,β-unsaturated carboxylic acid polymer in total, and 5-45 parts by mass of colloidal silica (provided that the total of the polymers and silica is 100 parts by mass). The surface treatment composition further contains 7-30 parts by mass of a silane coupling agent per 100 parts by mass of the total of the polymers and silica. The mass ratio between the olefin-α,β-unsaturated carboxylic acid copolymer content and the α,β-unsaturated carboxylic acid polymer content is from 1,000:1 to 10:1.

Description

 Specification

 Resin-coated metal plate and surface treatment composition for producing the same

 TECHNICAL FIELD [0001] The present invention relates to a resin-coated metal plate provided with a resin film used for automobiles, home appliances, building materials, and the like, and a surface treatment composition for producing the same, and more particularly to corrosion resistance, resin film and other coatings. Excellent adhesion to the film (may be abbreviated as “coat film adhesion”) and adhesion between the resin film and the metal plate (may be abbreviated as “resin film adhesion”) The present invention relates to a resin-coated metal plate and a surface treatment composition for producing the same. Background art

 [0002] As materials used in automobiles, etc., zinc-plated steel sheets such as electrogalvanized steel sheets and hot-dip galvanized steel sheets, or chromate on zinc-coated steel sheets for the purpose of further improving corrosion resistance Many inorganic surface-treated steel sheets that have been treated are used. However, due to the recent increase in environmental awareness, the demand for steel sheets not subjected to chromate treatment is increasing.

 [0003] As a means for improving corrosion resistance in place of such chromate treatment, for example, Patent Document 1

 We have proposed a surface treatment agent for metals containing a copolymer emulsion of β-ethylenically unsaturated carboxylic acid and olefin and a crosslinking agent. Patent Document 2 proposes a surface treatment agent containing a carboxyl group-containing resin and an inorganic silicate, and a surface-treated steel sheet obtained therefrom.

 Patent Document 1: Japanese Patent Laid-Open No. 2005-220237

 Patent Document 2: JP 2000-282254 A

 Disclosure of the invention

 Problems to be solved by the invention

[0004] Recently, a higher level of corrosion resistance has been required even for resin-coated steel sheets that have not been subjected to chromate treatment. In the field of resin-coated metal sheets, means for improving corrosion resistance have been demanded. Is constantly being sought. Accordingly, an object of the present invention is to provide a resin-coated metal plate having excellent corrosion resistance. Means for solving the problem

 [0005] The resin-coated metal plate of the present invention that has achieved the above object is a resin-coated metal plate provided with a resin film obtained from a surface treatment composition,

 The surface treatment composition contains 55 95 parts by mass of olefin-β, β-unsaturated carboxylic acid copolymer and β, β-unsaturated carboxylic acid polymer, and

 45 parts by mass of colloidal silica (however, the total of olefin-β, β-unsaturated carboxylic acid copolymer, a, unsaturated carboxylic acid polymer and colloidal silica is 100 parts by mass),

 In addition to 100 parts by mass of a total of 100 parts by mass of olefin fin j3-unsaturated carboxylic acid copolymer, α, unsaturated carboxylic acid polymer and colloidal silica, 30 parts by mass of silane coupling agent 7

 The content ratio of the olefin-unsaturated carboxylic acid copolymer to the α, β-unsaturated carboxylic acid polymer is 1,000: 1 to 10: 1 by mass ratio.

[0006] In the resin-coated metal plate of the present invention, (1) α, unsaturated carboxylic acid polymer strength polymaleic acid, (2) colloidal silica has a surface area average particle size of S4 to 20 nm, and / or ( 3) Silane coupling agent power A glycidyl group-containing silane coupling agent is preferred.

[0007] The surface treatment composition further comprises a vanadium compound with respect to a total of 100 parts by mass of (a) olefin, j3-unsaturated carboxylic acid copolymer, cis, β-unsaturated carboxylic acid polymer and colloidal silica. 0.56 containing 6 parts by mass, and when the total of Ζ or (b) olefin-β, β monounsaturated carboxylic acid copolymer and β, β monounsaturated carboxylic acid polymer is 100 parts by mass, It is also a preferred embodiment of the present invention to contain a carpositimide group-containing compound at a ratio of 0.:!30 parts by mass with respect to 100 parts by mass. In the resin-coated metal plate of the present invention, the amount of the resin film attached is preferably 0.23 g / m ² in terms of dry mass.

[0008] In addition, the present invention provides a total of 55 95 parts by mass of olefin α, β unsaturated carboxylic acid copolymer and α, β-unsaturated carboxylic acid polymer, and 5 45 parts by mass of colloidal silica (provided that Unsaturated carboxylic acid copolymer, ct,; 3-unsaturated carbo The total of the acid polymer and colloidal silica is 100 parts by mass. ), Olefin coupling α, unsaturated carboxylic acid copolymer, a, unsaturated carboxylic acid polymer and colloidal silica in total 100 parts by mass, further containing 7-30 parts by mass of silane coupling agent In addition, the content ratio force S of the olefin and β-unsaturated carboxylic acid copolymer and O, β-unsaturated carboxylic acid polymer is S, and the mass ratio is 1,000 ::! To 10: 1. A featured surface treatment composition is also provided. The surface treatment composition may further comprise a vanadium compound 0.5 to 100 parts by mass in total of olefin 1,3_unsaturated carboxylic acid copolymer, hi, j3-unsaturated carboxylic acid polymer and colloidal silica. 6 to 10 parts by mass, and / or 1 to 9 parts by mass of an oxazoline-containing polymer, and / or 0.5 to 5 parts by mass of spherical polyethylene wax particles having an average particle diameter of 0.6 to 4 zm may be contained. The invention's effect

 [0009] Surprisingly, the combination of the olefin α, β unsaturated carboxylic acid copolymer and the α, β unsaturated carboxylic acid polymer can significantly enhance the corrosion resistance of the resin-coated metal sheet.

 BEST MODE FOR CARRYING OUT THE INVENTION

One of the features of the present invention is that the surface treatment composition is an olefin-β, β-unsaturated carboxylic acid copolymer (hereinafter sometimes referred to as “olefin monoacid copolymer”). And a combination of an α, β-unsaturated carboxylic acid polymer (hereinafter sometimes abbreviated as “carboxylic acid polymer”). As shown in the following examples, a resin-coated metal plate obtained by applying and drying a surface treatment composition containing both of these on a metal plate is a surface treatment composition containing only one of these. Compared to the resin-coated metal plate obtained from

Here, the “olefin α, β unsaturated carboxylic acid copolymer” or “olefinic acid copolymer” in the present invention is a copolymer of olefin and α, β unsaturated carboxylic acid. , A structural unit force derived from olefins means that the copolymer contains 50% by mass or more (that is, the structural unit derived from α, β-unsaturated carboxylic acid is 50% by mass or less), “ct,; 3- The term “saturated carboxylic acid polymer” or “carboxylic acid polymer” refers to a polymer obtained using α, —unsaturated carboxylic acid as a monomer. This means that the conventional structural unit is 90% by mass or more in the polymer. In the examples, “ethylene-acrylic acid copolymer” was used as the “olefin-acid copolymer”, and “polymaleic acid” or “polyacrylic acid” was used as the “strong rubonic acid polymer”. .

 [0012] The exact mechanism by which the corrosion resistance of the resin-coated metal sheet is improved by surface treatment with a composition containing both olefinic monoacid copolymer and carboxylic acid polymer is unknown, but both of these are used in combination. By doing so, it can be presumed that a dense resin film was formed and the permeation of water and oxygen was effectively suppressed. However, the present invention is not limited to this estimation.

 [0013] The olefin monoacid copolymer used in the present invention can be produced by copolymerizing olefin and β, unsaturated carboxylic acid by a known method, and is commercially available. In the present invention, one or more olefin monoacid copolymers can be used.

 [0014] The olefin that can be used for the production of the olefin-acid copolymer is not particularly limited, but ethylene and propylene are preferred, and ethylene is more preferred. As the olefinic acid copolymer, any of those derived from only one olefin having a unit strength of olefin, or one derived from two or more olefins can be used.

 [0015] The α, β unsaturated carboxylic acid that can be used in the production of the olefinic acid copolymer is not particularly limited. For example, monostrength rubonic acid, maleic acid such as acrylic acid, methacrylic acid, crotonic acid, and isocrotonic acid. And dicarboxylic acids such as fumaric acid and itaconic acid. Among these, acrylic acid is preferable. As olefinic acid copolymers, the structural unit of α, β-unsaturated carboxylic acid is derived from only one type of α, β unsaturated carboxylic acid, or from two or more types of α, β unsaturated carboxylic acid. You can use any of the things you do.

[0016] The olefin-acid copolymer used in the present invention may have a structural unit derived from another monomer within a range that does not adversely affect the corrosion resistance and the like that are the effects of the present invention. . In the olefin-acid copolymer, the amount of structural units derived from other monomers is preferably 10% by mass or less, more preferably 5% by mass or less, and the most preferred olefin-acid copolymer is It consists only of olefin, and β-unsaturated carboxylic acid. As preferred olefin monoacid copolymer, ethylene monoacrylic acid copolymer The body is mentioned.

 [0017] The structural unit of α, β unsaturated carboxylic acid in the olefinic acid copolymer improves the adhesion between the resin film and the metal plate, and secures the amount of the carboxyl group serving as a reactive group for crosslinking. Used for. The constituent unit amount of ひ, β-unsaturated carboxylic acid in the copolymer is preferably 5% by mass or more, more preferably 10% by mass or more. However, if the β monounsaturated carboxylic acid unit is excessive, the corrosion resistance and alkali resistance may be lowered. Therefore, the amount of the constituent unit is preferably 30% by mass or less, more preferably 25% by mass or less. .

 [0018] The weight-average molecular weight of the olefinic monoacid copolymer used in the present invention is preferably 1,000 to 100,000, more preferably 3,000 to 70,000, and still more preferably 5,000 to 30,000. This weight average molecular weight can be measured by GPC using styrene as a standard.

 [0019] As the carboxylic acid polymer, a homopolymer or copolymer of one or two or more kinds of j3_unsaturated carboxylic acids, or a copolymer obtained by copolymerizing another monomer. You can use any of them. Such carboxylic acid polymers can be produced by known methods and are commercially available. In the present invention, one or more carboxylic acid polymers can be used.

 [0020] The α, β unsaturated carboxylic acid that can be used for the production of the carboxylic acid polymer is not particularly limited, and examples thereof include monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and isocrotonic acid, maleic acid, and fumaric acid. Examples thereof include dicarboxylic acids such as acid and itaconic acid. Of these, acrylic acid and maleic acid are preferred, and maleic acid is more preferred.

[0021] Carboxylic acid polymers may contain constituent units derived from monomers other than α, unsaturated carboxylic acids, but the amount of constituent units derived from other monomers is A carboxylic acid polymer composed of only a, j3-unsaturated carboxylic acid is more preferable, and the content is 10% by mass or less, preferably 5% by mass or less in the polymer. Preferred examples of the carboxylic acid polymer include polyacrylic acid, polymethacrylic acid, acrylic acid-maleic acid copolymer, polymaleic acid and the like. Among these, coating film adhesion, resin film adhesion, and corrosion resistance From the viewpoint, polymaleic acid is more preferable. The exact mechanism by which the corrosion resistance is improved by using polymaleic acid is unknown. It is considered that the adhesion between the resin film and the metal plate is improved, and the corrosion resistance is improved accordingly. However, the present invention is not limited to this estimation.

 [0022] The weight average molecular weight of the carboxylic acid polymer used in the present invention is preferably 500 to 30,000, more preferably 800 to 10000, more preferably 900 to 3,000, and most preferably 1,000 to 3,000. 2,000. This weight average molecular weight can be measured by GPC using styrene as a standard.

 [0023] The content ratio of the olefinic monoacid copolymer to the carboxylic acid polymer in the surface treatment composition is 1,000 ::! ~ 10: 1, prefer <200 ::! ~ 20: 1, more preferred <100: 1 ~: 100: 3. If the content ratio of the rubonic acid polymer is too low, the combined effect of the olefinic monoacid copolymer and the carboxylic acid polymer is not sufficiently exerted, and conversely, the content ratio of the carboxylic acid polymer is excessive. This is because the olefinic monoacid copolymer and the carboxylic acid polymer are phase-separated in the surface treatment composition, so that a uniform resin film may not be formed and the alkali resistance may be lowered.

 [0024] One of the characteristics of the surface treatment composition of the present invention is that it contains colloidal silica.

 When colloidal silica is present in the resin film, the silica is eluted in a corrosive environment, so that the dissolution and elution of the metal plate is suppressed, and the corrosion resistance is improved.

 [0025] Colloidal silica is commercially available, and general commercial products can be used. Examples of colloidal power include the Snowtex series "ST-40", "ST-XS", "ST-N", "ST-SS", "ST-〇" manufactured by Nissan Chemical Industries, Ltd. . When the surface treatment composition used for forming the resin film is aqueous, it is preferable to select the type of colloidal silica according to the pH of the surface treatment composition in order to disperse the colloidal silica well.

 In the surface treatment composition, the total amount of olefinic monoacid copolymer and carboxylic acid polymer (hereinafter sometimes abbreviated as “resin component”) is 55 to 95 parts by mass, The amount of dull silica is 5 to 45 parts by mass (provided that the total of the resin component and colloidal silica is 100 parts by mass). The amounts of the resin component and colloidal silica specified in the present invention are values converted into solid contents.

[0027] When the amount of colloidal silica exceeds 45 parts by mass, the resin component is reduced and the surface treatment is performed. The film forming property of the chemical composition is lowered, cracks are generated in the resin film, and the corrosion resistance and other properties are lowered. The amount of colloidal silica is preferably 30 parts by mass or less, and more preferably 25 parts by mass or less from the viewpoint of spot weldability (however, the total of the resin component and colloidal silica force is 100 parts by mass). When the amount of colloidal silica is 25 parts by mass or less, accumulation of silica on the electrode is effectively suppressed by spot welding.

 [0028] On the other hand, when the amount of colloidal silica is less than 5 parts by mass, the effect of improving the corrosion resistance of colloidal silica is not sufficiently exhibited, and the alkali resistance is also lowered. The amount of colloidal silica is preferably 10 parts by mass or more, more preferably 15 parts by mass or more (provided that the total of the resin component and the colloidal silica is 100 parts by mass).

 [0029] If the colloidal silica used in the present invention is too large, the film-forming property of the surface treatment composition decreases, silica elution in a corrosive environment becomes insufficient, and the corrosion resistance improving effect also decreases. In addition, alkali resistance and resin film adhesion are also reduced. On the other hand, if the colloidal silica is too small, the effect of improving the corrosion resistance is saturated, and conversely, the activity of the silica becomes too high, and the surface treatment composition may gel, and a good resin film may not be formed. Therefore, the surface area average particle diameter of colloidanol silica is preferably 4 to 20 nm. “The surface area average particle diameter of silica can be measured by the Sears method when the average particle diameter is about 1 to:! Onm, and by the BET method when it is about 10 to: OOnm.

 [0030] One of the characteristics of the surface treatment composition of the present invention is that it contains a silane coupling agent. By using a silane coupling agent, the adhesion between the metal and the resin film is improved, and accordingly the corrosion resistance is also improved. Therefore, the surface treatment composition does not need to contain an acidic compound (for example, a phosphoric acid compound, a nitric acid compound, and a fluorine compound) for the purpose of etching the surface of the metal plate. This is because the adhesion of the resin film can be improved by the silane coupling agent without etching the surface of the metal plate. A surface treatment composition that does not contain an acid compound for etching purposes has improved stability and can form a good resin film.

[0031] The amount of the silane coupling agent in the surface treatment composition is 7 parts by mass or more, preferably 9 parts by mass with respect to 100 parts by mass in total of the olefin-acid copolymer, carboxylic acid polymer and colloidal silica. Part or more, more preferably 11 parts by weight or more, preferably 30 parts by weight or less, preferably 25 parts by mass or less. If the amount is less than parts by mass, the adhesion and corrosion resistance of the resin film will be reduced, and if it exceeds 30 parts by mass, the stability of the surface treatment composition will be reduced, leading to adhesion and corrosion resistance. Decreases.

[0032] Silane coupling agents are commercially available, and general commercial products can be used in the present invention. One or more silane coupling agents can be used. Examples of silane coupling agents include butyltrimethoxysilane, butyltriethoxysilane, butyltris (monomethoxyethoxy) silane, γ-chloropropylmethoxysilane, _γ -aminopropyltriethoxysilane, N- (j3-amino Ethyl) 1 γ-aminopropyltrimethoxysilane, Ν— (j3

-Aminoethyl) -1-γ-aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, y-mercaptopropyltrimethoxysilane, and the like.

 [0033] Among the silane coupling agents, preferred is a glycidyl group-containing silane coupling agent. Glycidyl group-containing silane coupling agents are highly reactive, so they have a significant effect on improving corrosion resistance and alkali resistance. Examples of the glycidinole group-containing silane coupling agent include silane.

[0034] The surface treatment composition of the present invention may contain a vanadium compound. Similarly to colloidal silica, vanadium compounds also have the effect of suppressing the dissolution and dissolution of the metal plate and enhancing the corrosion resistance. In particular, the vanadium compound improves the corrosion resistance, particularly the corrosion resistance of the buttock, of the molten zinc-plated steel sheet and the electrogalvanized steel sheet.

 [0035] Examples of vanadium compounds include vanadium pentoxide (V O) and ammonium metavanadate.

 twenty five

 Nium (NH VO), sodium metavanadate (NaV0), potassium metavanadate (KV)

 4 3 3

 O), vanadium acetylylacetonate (V (C H O)), etc.

3 5 7 2 3

 One or more of these can be used. These vanadium compounds are commercially available and can be easily obtained.

[0036] When the surface treatment composition of the present invention is water-based, a vanadium compound having high solubility in water, "Vanadinic acid solution (IV)" manufactured by Shinsei Chemical Industry Co., Ltd. (VO is tetravalent with oxalic acid). Return to It is preferable to use an aqueous solution containing the original one. If the aqueous surface treatment composition is neutral or alkaline, it is desirable to neutralize the vanadic acid solution with a base (preferably aqueous ammonia) to a pH of 5-7, The pH of the “vanadic acid solution (IV)” is about 3.) However, if the pH of the vanadic acid solution exceeds 7, fine suspension of vanadium hydroxide may be formed.

[0037] The amount of the vanadium compound in the surface treatment composition is preferably 0.5 to 6 parts by mass, more preferably 1 to 100 parts by mass in total of the olefinic monoacid copolymer, the carboxylic acid polymer and the colloidal silica. ~ 3 parts by mass. If the vanadium compound is less than 0.5 parts by mass, the effect of improving the corrosion resistance cannot be exhibited sufficiently. On the other hand, even if the amount exceeds 6 parts by mass, the effect of improving the corrosion resistance is saturated, and the coating film adhesion and the resin film adhesion may be deteriorated. When using the “vanadic acid solution”, the vanadium compound amount specified in the present invention is the V O amount calculated from the V 2 O equivalent concentration (manufacturer indication) of the “vanadic acid solution”.

 2 5 2 5

[0038] The surface treatment composition of the present invention may further contain a carpositimide group-containing compound. The carpositimide group in the compound reacts with the carboxyl group in the olefinic acid copolymer and the carboxylic acid polymer. Therefore, the use of a carpositimide group-containing compound can reduce the amount of carboxyl groups in the resin film and improve the alkali resistance. In the present invention, one kind or two or more kinds of carpositimide group-containing compounds can be used.

[0039] Carpositimide group-containing compounds include isocyanates such as hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (H XDI), 4, 4-diphenyl. It can be produced by heating enylmethane diisocyanate (MDI) or tolylene diisocyanate (TDI) in the presence of a calpositimidization catalyst, and it can also be modified by aqueous (water-soluble, water-emulsifiable) Or water dispersibility). When the surface treatment composition is water-based, an aqueous carpositimide group-containing compound is preferable. Further, a compound containing a plurality of carposimide groups in one molecule is preferable. When a plurality of carposimide groups are contained in one molecule, the corrosion resistance and the like can be further improved by a crosslinking reaction with a carboxyl group in the resin component. [0040] Examples of commercially available polycarbodiimide compounds include N, N dicyclohexyl carbonyl levodiimide, N, N diisopropyl carbodiimide, and "Polycarbodiimide" (polymer having a plurality of carbodiimide groups in one molecule). Among these, “polycarbodiimide” having a plurality of carboxyl groups is preferable.

 [0041] In order to sufficiently exert the effect of the carpositimide group-containing compound, the amount of the compound in the surface treatment composition is as described above when the total of the olefinic monoacid copolymer and the carboxylic acid polymer is 100 parts by mass. The amount is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and further preferably 8 parts by mass or more with respect to 100 parts by mass. On the other hand, if the amount of the compound containing the carpositimide group is excessive, the effect of the combination of olefinic monoacid copolymer and carboxylic acid polymer is reduced. In addition, if an excessive amount of the aqueous carposimide group-containing compound is used in the aqueous surface treatment composition, it may adversely affect water resistance and corrosion resistance. From such a viewpoint, the amount of the carpositimide group-containing compound is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and further preferably 16 parts by mass or less with respect to 100 parts by mass.

 [0042] The surface treatment composition of the present invention may contain a resin and / or a wax other than the olefinic acid copolymer and the carboxylic acid polymer as long as the effects of the present invention are not impaired. The amount of other resin and wax in the surface treatment composition is preferably 10 parts by mass or less with respect to 100 parts by mass when the total amount of olefinic acid copolymer and carboxylic acid polymer is 100 parts by mass. More preferably, it is 5 parts by mass or less. Furthermore, the surface treatment composition is a cross-linking agent, diluent, anti-skinning agent, surfactant, emulsifier, dispersant, leveling agent, antifoaming agent, penetrating agent, structure, and the like as long as the effects of the present invention are not impaired. It can also contain film aids, dyes, pigments, thickeners, lubricants and the like.

The surface treatment composition of the present invention further comprises an oxazoline-containing polymer with respect to a total of 100 parts by mass of an olefin, j3-unsaturated carboxylic acid copolymer, a β-unsaturated carboxylic acid polymer, and colloidal silica. You may contain 1-9 mass parts. The oxazoline-containing polymer can be dried at a low temperature, does not deteriorate the fluidity (viscosity) and wettability of the surface treatment composition, and has good mechanical stability. Furthermore, because it consists of a styrene / acrylic polymer main chain, it forms a very hard film when using an oxazoline-containing polymer, and adheres well to the substrate and the post-coating film (resin film adhesion & coating film adhesion). Property) is also improved. to this Thus, even when roll forming is performed on the resin-coated metal plate, the film is more easily peeled off than in press molding, the film is less likely to be damaged.

Oxazoline-containing polymers include “Epocross κ Series” manufactured by Nippon Shokubai Co., Ltd., “K-2010E”, “K_2020E”, “K_2030E” of styrene / acryl main chain emulsion.

Or the like.

If the oxazoline-containing polymer is less than 1 part by mass with respect to 100 parts by mass of the total of olefin, / 3--unsaturated carboxylic acid copolymer, H, / 3-unsaturated carboxylic acid polymer and colloidal silica, The film is rolled and broken due to contact with the roll during roll forming, resulting in film peeling. If the oxazoline-containing polymer is 9 parts by mass or more with respect to 100 parts by mass of the total of olefin, j3—unsaturated carboxylic acid copolymer, 3 / 3-unsaturated carboxylic acid polymer and colloidal silica, the coating The improvement cannot be obtained, and the coating film adhesion is significantly deteriorated. Preferably, it is 2-6 mass parts, More preferably, it is 3-4 mass parts.

The surface treatment composition of the present invention further has an average particle size of 0. 100 parts by mass in total of olefin 1a, monounsaturated carboxylic acid copolymer, α, β monounsaturated carboxylic acid polymer and colloidal silica. 0.5 to 5 parts by mass of spherical polyethylene wax particles of 6 to 4 μΐη may be contained. As a result, the contact resistance between the roll and the resin-coated metal plate when the resin-coated metal plate is roll-formed is reduced, and the coating is less likely to be damaged. When used in combination with the aforementioned oxazoline-containing polymer, the effect of preventing film damage can be further enhanced. Spherical polyethylene wax particles include Chemipearl (Polyolefin Water Dispersion) “W-100”, “W-400”, “W-500”, “W-700”, “W-900” from Mitsui Chemicals, Inc. Or the like.

In roll forming, unlike press forming, a roll and resin-coated metal are used to gradually form a resin-coated metal sheet with multi-stage rolls while flowing a normal coolant liquid (water-based emulsion liquid in which water is added and dispersed). There is almost no increase in the temperature of the plate, but it is important to reduce the contact resistance between the roll and the resin-coated metal plate during roll forming by exerting the lubricity more efficiently. Therefore, it is necessary to disperse in the film while maintaining the shape of the spherical wax particles, and the temperature at which the surface treatment composition is dried after coating (film formation temperature). The degree) needs to be lower than the soft saddle point of the spherical polyethylene wax particles. When the average particle diameter of the spherical polyethylene wax is 0.6 / m or less, the protrusions of the wax particles covered with the film are not formed on the surface of the film, and the contact resistance with the roll cannot be reduced during roll forming. When the average particle size is 4 zm or more, it becomes difficult to cover the wax particles with a film, which causes deterioration of the adhesion of the paint film after painting when it is repainted.

 [0043] The surface treatment composition of the present invention may be either a solvent-based composition or an aqueous composition that can be applied to the surface of a metal plate, but is an aqueous composition because of environmental problems. Is preferred. There is no particular limitation on the preparation method of the surface treatment composition. Organic solvent (in the case of solvent-based composition) or water, preferably deionized water (in the case of aqueous composition), olefinic acid copolymer, carboxylic acid A surface treatment composition can be prepared by blending a predetermined amount of a polymer, colloidal silica and a silane coupling agent, and if necessary, a vanadium compound, a carpositimide group-containing compound and / or other components and stirring. The When stirring, it may be heated, but if heated, heat before blending the silane coupling agent and, if necessary, the carpositimide group compound, and after these blending, do not heat It is preferable. This is to avoid gelation of the surface treatment composition due to the reaction of the olefinic acid copolymer and carboxylic acid polymer with the silane coupling agent and the carpositimide group-containing compound.

 [0044] When producing an aqueous surface treatment composition, it is preferable to emulsify the olefinic acid copolymer, which is the main component of the resin. The olephinic acid copolymer can be emulsified by using an emulsifier and / or by neutralizing a carboxyl group in the copolymer. When an emulsifier is used, the average particle diameter of the aqueous emulsion of the olefin monoacid copolymer can be reduced, and the film-forming property and thereby the density of the resin film can be improved.

[0045] For emulsification, it is one of preferred embodiments to neutralize carboxyl groups in the olefinic monoacid copolymer. Because by neutralizing and emulsifying carboxyl groups, the amount of emulsifier used can be reduced, or no emulsifier can be used, and the adverse effect of the emulsifier on the water resistance and corrosion resistance of the resin film can be reduced or eliminated. Because. Ole When neutralizing the carboxyl group in the phosphinic acid copolymer, a base of preferably about 0.5 to 0.95 equivalent, more preferably about 0.6 to 0.8 equivalent is used with respect to the carboxyl group. It is preferable to use it. If the degree of neutralization is too low, the emulsifying property will not improve much. On the other hand, if the degree of neutralization is too high, the amount of carboxyl groups reacting with the silane coupling agent will decrease, which will adversely affect corrosion resistance. In addition, the viscosity of the composition containing the olefin-acid copolymer may become too high.

[0046] As a base for neutralization, for example, hydroxides of alkali metals and alkaline earth metals

 (For example, NaOH, KOH, Ca (OH), etc., preferably NaOH)

 2

 Strong base, aqueous ammonia, or primary, secondary or tertiary amines (preferably triethylamine). If a strong base such as NaOH is used, the emulsifying property is improved, but if it is too much, the corrosion resistance of the resin film may be lowered. On the other hand, amines, especially those having a low boiling point, preferably those having a boiling point of 100 ° C. or less at atmospheric pressure (eg, triethylenamine) do not significantly reduce the corrosion resistance of the resin film. This may be because the low-boiling amine is volatilized when a resin film is formed by heating and drying after applying the surface treatment composition. Shikamin has little effect of improving emulsifying properties. Therefore, when neutralizing the carboxynole group of the olefinic acid copolymer and emulsifying, it is preferable to use a combination of the strong base and amine, preferably a combination of NaOH and triethylamine. When the above-mentioned strong base and amine are used in combination, the amount of the strong base is preferably 0.01 to 0.3 equivalents, and the amine is preferable with respect to the amount of the carboxyleno group of the olephinic acid copolymer. Is 0.4 · 0.8 equivalents.

 [0047] When a water-based surface treatment composition is used, a small amount of an organic solvent may be added to reduce interfacial tension and improve wettability to a metal plate. Examples of the organic solvent for this purpose include methanol, ethanol, isopropanol, butanols, hexanol, 2-ethino hexanol, ethylene glycol eno eno enoate, ethylene glycol butyl ether, diethylene glycol, propylene glycol and the like. it can.

[0048] The solid content of the surface treatment composition is not particularly limited, and can be adjusted according to the method for applying the surface treatment composition to the metal plate. The solid content of the surface treatment composition is generally about 5 to 20% by mass. For example, the spray ringer method (the surface treatment composition is applied to the surface of the metal plate). In the case of application by spraying and then squeezing with a roll, it is preferably about 10 to 18 mass%.

 [0049] The metal plate used in the present invention is not particularly limited, for example, a non-plated cold-rolled steel sheet, a molten zinc-plated steel sheet (GI), a molten alloyed zinc-plated steel sheet (GA), or an electrogalvanized steel sheet. Examples include steel plates (EG), aluminum plates and titanium plates. Of these, chromate treatment is used, and nale, galvanized steel sheets are preferred.

 [0050] In the present invention, the method and conditions for forming a resin film on a metal plate are not particularly limited, and the surface treatment composition is applied to one or both surfaces of the metal plate surface by a known coating method, followed by heating. A resin-coated metal plate can be produced by drying. Examples of the method for applying the surface treatment composition include a curtain flow coater method, a roll coater method, a spray method, and a spray ringer method. Among these, the spray ringer method is preferable from the viewpoint of cost and the like. Further, there is no particular limitation on the heating and drying conditions, and the heating and drying temperature is about 50 to 120 ° C, preferably about 70 to 90 ° C. However, an excessively high heat drying temperature is not preferable because the resin film deteriorates.

[0051] If the amount of the resin film deposited on the surface of the metal plate is too small, it is difficult to sufficiently secure corrosion resistance. On the other hand, if the amount of adhesion is too large, the effects such as corrosion resistance are saturated, which is uneconomical and the resin film adhesion may decrease. Therefore, the amount of the resin film deposited on the resin-coated metal plate is preferably 0.2 to 3 g / m ² , more preferably 0.7 to ² g / m ² in terms of dry mass.

 Example

 [0052] Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, and is appropriately within a range that can be adapted to the purpose described above. Of course, it is possible to implement changes in the scope of the present invention, all of which are included in the technical scope of the present invention.

 [0053] (1) Evaluation method of characteristics of resin-coated metal sheet

 (1 1) Flat plate corrosion resistance

A salt spray test was carried out based on JIS Z2371, and the time until it reached the force of white birch generation rate (= area where white birch was generated / total area of specimen X 100) was measured. [0054] (1-2) Cross-cut corrosion resistance

 In order to investigate the corrosion resistance of the buttock, a cross-cut was put into the test material with a cutter knife, and a salt spray test was performed based on JIS Z 2371, and the time until the white candy occurrence rate reached 10% was measured.

 [0055] (1-3) Corrosion resistance in JASO cycle test

 Based on JIS H8502, JASO cycle test (salt spray (temperature 35 ° CX 2 hours) → drying (temperature 35 ° CX humidity 30% or less X 4 hours) → wet (temperature 50 ° CX humidity 95% or more X 2 hours) ) And 1 cycle (each including the transition time)) was conducted for 15 cycles, and the incidence of birch was evaluated according to the following criteria.

 (Evaluation criteria)

 ◎: White birch incidence less than 5%

 ◯: White birch incidence 5% to less than 10%

 Δ: White birch incidence 10% to less than 20%

 X: White birch incidence 20% or more

[0056] (1 4) Coating film adhesion

 The specimen was bar-coated with acrylic paint so that the coating thickness was 20 μm, and baked at 160 ° C for 20 minutes for post-coating. Subsequently, after immersing this test material in boiling water for 1 hour, taking it out and leaving it for 1 hour, 100 mm of the lmm square grid was cut with a cutter knife, and a tape peeling test was carried out on this. The coating film adhesion was evaluated according to the following criteria based on the number of residual cells.

 (Evaluation criteria)

 ◎: Residual coating rate 100%

 ○: Residual rate of paint film 99% or less to 90% or more

 Δ: paint film remaining rate 89% or less to 80% or more

 X: paint film remaining rate 79% or less

[0057] (1_5) alkali resistance

After immersing the test material in alkaline degreasing agent (CL_N364S, manufactured by Nihon Parker Rising Co., Ltd.) 20g / L, adjusted to a liquid temperature of 60 ° C for 2 minutes, lifting, washing and drying, the test material is Based on S Z2371, a salt spray test was conducted to measure the time until 10% white birch was generated.

 [0058] (16) Resin film adhesion

In order to investigate the adhesion between the resin film and the metal plate, a filament tape (# 9510, manufactured by Sliontic) was applied to the surface of the specimen, and the temperature was 40 ° CX RH98. After storing for 168 hours in an atmosphere of / _o , the filament tape was peeled off, and the ratio of the area where the resin film remained (remaining ratio) was measured. The resin film adhesion was evaluated based on the following criteria.

 (Evaluation criteria)

 ◎: Residual rate of film 100%

 ○: Residual rate of film less than 100% to 90% or more

 Δ: Residual rate of film less than 90% to 70% or more

 X: film remaining rate less than 70%

 (17) Roll formability

 As a roll formability evaluation method, the surface of the resin-coated metal plate was slid with stainless steel (SUS) protrusions (line contact) using a roll formability evaluation apparatus, and the damage state of the film was visually observed. The roll formability evaluation device consists of a flat plate die and a die with protrusions (both are made of SUS) and is pulled through a resin-coated metal plate between these dies while applying pressure. The test was carried out with the size of the resin-coated metal plate to be tested set to 40 X 300 mm, the drawing speed 300 mm / min, and the applied pressure 1960 N.

 <Evaluation criteria>

 A: The film is not damaged,

 ○: Slight damage to the film is observed

 Δ: Damage to the film is observed

 X: Damage is observed on the film and metal surface

[0059] (2) Resin composition

The resin-coated metal plate used in the examples was produced by applying a surface treatment composition to a metal plate and drying it. This surface treatment composition is a composition containing an olefin-acid copolymer, a carboxylic acid polymer, and less than a specified amount of a silane coupling agent. (Referred to as “resin composition” in the Examples) was prepared, and this resin composition was prepared by adding colloidal silica and the remaining amount of a silane coupling agent. Then, the resin composition used for preparation of the surface treatment composition in an Example is demonstrated.

 [0060] (2-1) Production of resin composition 1

 An ethylene-acrylic acid copolymer ("Primacol 599 01" manufactured by Dow Chemical Co., Ltd., a structural unit derived from acrylic acid, with an autoclave equipped with a 1.0L emulsification facility equipped with a stirrer, thermometer and temperature controller : 20% by mass, weight average molecular weight: 20,000, melt index: 1300, acid value: 150) 20.0 g, polymaleic acid aqueous solution (“Non-Pole PMA_50W” manufactured by NOF Corporation, weight average molecular weight: about 1100, 50 mass% product) 8.0 g, triethylamine 35.5 g (0.63 equivalent to the carboxyl group of ethylene-acrylic acid copolymer), 4 8% NaOH aqueous solution 6.9 g (ethylene-acrylic acid copolymer) 0.15 equivalents to the carboxyl group of), tall oil fatty acid (Harima Kasei Co., Ltd. “Noichiichi Toll FA3”) 3.5 g, ion-exchanged water 792. 6 g were added and sealed at 150 ° C. and 5 atm. Stir at high speed for 3 hours, then to 30 ° C And retirement. Next, silane coupling agent (GE Toshiba Silicone “TSL8350”, y—glycidoxypropyltrimethoxysilane) 10.4 g, carpositimide group-containing compound (Nisshinbo “Polycarposiimide SV-02”, weight average (Molecular weight: 2,700, solid content: 40% by mass) 31.2 g and 72.8 g of ion exchange water were added and stirred for 10 minutes to prepare resin composition 1 in the form of aqueous emulsion (solid content of 20. 3% by mass, measured according to 3 K6833).

 [0061] (2-2) Production of resin composition 2

In an autoclave with a 1.0L emulsification facility equipped with a stirrer, thermometer and temperature controller, ethylene acrylic acid copolymer ("Primacol 599 01" manufactured by Dow Chemical Co., Ltd.) 20.0g, polymaleic acid aqueous solution (manufactured by NOF Corporation "NONPOL PMA_ 50 W", 50 mass _^0/0 dishes) 8. 0 g, triethyl Chino rare Min 35. 5 g (ethylene - 0.63 equivalents relative to the carboxyl group of the acrylic acid copolymer), 48% NaOH aqueous solution 6.9g (0.15 equivalent to the carboxyl group of ethylene-acrylic acid copolymer), olefin-maleic anhydride copolymer wax ("Diacarna 30" manufactured by Mitsubishi Chemical Corporation) ) 3.5g and 792. 6g of ion-exchanged water were added and sealed. The mixture was stirred at 150 ° C and 5 atm for 3 hours at high speed, and then cooled to 30 ° C. Next, silane coupling simultaneous lj (GE Toshiba Silicone “TSL8350”) 10.4 g, carbo Diimide group-containing compound (Nisshinbo “Polycarposimide SV-02”, solid content 40% by mass) 31.2 g and ion-exchanged water 72.8 g were added and stirred for 10 minutes to form an aqueous emulsion resin. Composition 2 was prepared (solid content 20.1% by weight).

[0062] (2-3) Production of resin composition 3

In an autoclave with a 1.0L emulsification facility equipped with a stirrer, thermometer and temperature controller, ethylene-acrylic acid copolymer ("Primacol 599 01" manufactured by Dow Chemical Co., Ltd.) 20.0g, polymaleic acid Aqueous solution (“Nonpol PMA_ 50W” manufactured by NOF Corporation), 50 mass ⁰ / o product) 16.0 g, 35.5 g of triethylenoleamine (0.63 equivalent to the carboxyl group of ethylene-acrylic acid copolymer) , 48% NaOH aqueous solution 6.9g (0.15 equivalents to the carboxyl group of ethylene-acrylic acid copolymer), tall oil fatty acid (Halima Kasei Co., Ltd. "Noichiichi Toll FA3") 3.5g, ion The solution was sealed with 812.2 g of exchange water, stirred at 150 ° C and 5 atm for 3 hours at high speed, and then cooled to 30 ° C. Next, silane coupling agent (GE TOSHIBA Silicone "TSL8350") 10.7g, Carpositimide group-containing compound (Nisshinbo "Polycarposimide SV-02", solid content 40% by mass) 32.2g, ion-exchanged water 75 g was added and stirred for 10 minutes to prepare a resin composition 3 in the form of an aqueous emulsion (solid content 20.5% by mass).

 [0063] (2-4) Production of resin composition 4

In an autoclave with a 1.0L emulsification facility equipped with a stirrer, thermometer, and temperature controller, ethylene-acrylic acid copolymer (Honeywell “AC5120”, allylic acid-derived structural unit: 15 mass) %, Weight average molecular weight: 5,000, acid value: 120) 20.0 g, polymaleic acid aqueous solution (“Nonpol PMA-50W”, 50% by mass, manufactured by NOF Corporation) 8.0 g, triethylamine 34.6 g (ethylene) —0.8 equivalent to the carboxyl group of acrylic acid copolymer), 5.4 g of 48% NaOH aqueous solution (0.15 equivalent to the carboxylate group of ethylene-acrylic acid copolymer), tall oil fatty acid ( Harima Chemical Co., Ltd. “Hartol FA3”) 3.5 g and ion-exchanged water 799.9 g were filled and sealed, stirred at 150 ° C and 5 atm for 3 hours at high speed, and then cooled to 30 ° C. Next, silane coupling agent (GE Toshiba Silicone “TSL8350”) 10.5 g, Carpositimide group-containing compound (Nisshinbo “Polycarpositimide SV_02”, solid content 40% by mass) 31.5 g, ion-exchanged water 73.5 g Add and stir for 10 minutes Then, a resin composition 4 in the form of an aqueous emulsion was prepared (solid content: 20.1% by mass).

 [0064] (2-5) Production of resin composition 5

In an autoclave with a 1.0L emulsification facility equipped with a stirrer, thermometer and temperature controller, ethylene-acrylic acid copolymer ("Primacol 599 01" manufactured by Dow Chemical Co., Ltd.) 20.0g, polymaleic acid aqueous solution (manufactured by NOF Corporation "NONPOL PMA_ 50 W", 50 mass _^0/0 dishes) 8. 0 g, triethyl Chino rare Min 35. 5 g (ethylene - 0.63 equivalents relative to the carboxyl group of the acrylic acid copolymer) , 48% NaOH aqueous solution 6.9g (0.15 equivalents to the carboxyl group of ethylene-acrylic acid copolymer), tall oil fatty acid (Halima Kasei Co., Ltd. "Noichiichi Toll FA3") 3.5g, ion Exchanged water (774.4 g) was sealed and sealed, stirred at 150 ° C and 5 atm for 3 hours at high speed, and then cooled to 30 ° C. Next, 10.5 g of silane coupling agent (GE TOSHIBA Silicone “TSL8350”) and 10.5 g of ion-exchanged water were added and stirred for 10 minutes to prepare a resin composition 5 in the form of an aqueous emulsion. (Solid content 21.1% by weight).

 [0065] (2-6) Production of resin composition 6

 In an autoclave with a 1.0L emulsification facility equipped with a stirrer, thermometer and temperature controller, ethylene acrylic acid copolymer ("Primacol 599 01" manufactured by Dow Chemical Co., Ltd.) 20.0g, polymaleic acid aqueous solution (Non-Paul PMA-50W, 50% by mass, manufactured by NOF Corporation) 8.0 g, 35.5 g of triethylamine (0.63 equivalents relative to the carboxyl group of the ethylene acrylic acid copolymer), 48% NaOH Add 6.9 g of aqueous solution (0.15 equivalent to the carboxyl group of ethylene acrylic acid copolymer), add 788. lg of ion-exchanged water, seal, and stir at 150 ° C and 5 atm for 3 hours at high speed. Cooled to 30 ° C. Next, 10.4 g of silane coupling agent (GE Toshiba Silicone “TSL8350”), Carpositimide group-containing compound (Nisshinbo “Polycarposimide SV_02”, solid content 40% by mass) 31.2 g, ion-exchanged water 72.8 g was added and stirred for 10 minutes to prepare a resin composition 6 in the form of an aqueous emulsion (solid content 20.6% by mass).

 [0066] (2-7) Production of resin composition 7

In an autoclave with a 1.0L emulsification facility equipped with a stirrer, thermometer and temperature controller, ethylene-acrylic acid copolymer ("Primacol 599 01" manufactured by Dow Chemical Co., Ltd.) 20.0g, polyacrylic Acid aqueous solution (“AC_ 10L” manufactured by Nippon Pure Chemical Industries, Ltd. : 25, 000, 40 mass _^0/0 each entrance port) 10 · 0 g, 0. 63 equivalents relative to the carboxyl group of triethyl Chino rare Min 33 · 5 g (Ethylene one Atarinore acid copolymer), tall oil fatty acid (Harima “Noichi Itoru FA3” manufactured by Kasei Co., Ltd.) 3.5 g, 48% NaH aqueous solution 6.9 g (0.15 equivalents of the ethylene acrylate copolymer). The lg was sealed free of calories, stirred at 150 ° C and 5 atm for 3 hours at high speed, and then cooled to 30 ° C. Next, 10.4 g of silane coupling agent (GE Toshiba Silicone “TSL8350”), Carpositimide group-containing compound (Nisshinbo “Polycarposimide SV-02”, solid content 40% by mass) 31.2 g, ion-exchanged water 72.8 g was added and stirred for 10 minutes to prepare a resin composition 7 in the form of an aqueous emulsion (solid content: 20.2% by mass).

 [0067] (2-8) Production of resin composition 8 (for comparison, without carboxylic acid polymer)

 In a photoclave with a 1.0L emulsification facility equipped with a stirrer, thermometer and temperature controller, ethylene-acrylic acid copolymer ("Primacol 599 01" manufactured by Dow Chemical Co., Ltd.) 20.0g, Triethylamine 35 5g (0 · 63 equivalents relative to the carboxyl group of the ethylene-acrylic acid copolymer), 48% NaOH7 solution 6.9g (0.15 equivalents relative to the carboxyl group of the ethylene acrylic acid copolymer), Toll Oil fatty acid (Hallima Kasei Co., Ltd. “Nool Toll FA3”) 3.5 g, ion-exchanged water 788. lg was added and sealed, stirred at 150 ° C and 5 atm for 3 hours at high speed, then 30 ° C Until cooled. Next, 10.3 g of silane coupling agent (GE Toshiba Silicone “TSL8350”), compound containing carposimide group (Nisshinbo “Polycarposimide SV-02”, solid content 40% by mass) 30.9 g, ion-exchanged water 72 lg was added and stirred for 10 minutes to prepare a resin composition 8 in the form of aqueous emulsion (for comparison) (solid content 20.0% by mass).

 [0068] (2-9) Production of resin composition 9 (for comparison, without carboxylic acid polymer)

In an autoclave with a 1.0L emulsification facility equipped with a stirrer, thermometer and temperature controller, 20.0 g of ethylene-acrylic acid copolymer ("Primacol 599 01" manufactured by Dow Chemical Company), Triethino Reamine 35.5g (0.63 equivalents relative to the carboxyl group of ethylene-acrylic acid copolymer), 48% NaOH7] solution 6.9g (0.1% relative to the carboxyl group of ethylene-acrylic acid copolymer) 15 equivalents), 774. lg of ion-exchanged water was added, and the mixture was sealed. Then silane cutlet Pulling agent (GE Toshiba Silicone “TSL8350”) 10.2 g, Carposiimide group-containing compound (Nisshinbo “Polycarpopositimide SV-02”, solid content 40% by mass) 30.6 g, ion-exchanged water 71. 4 g was added and stirred for 10 minutes to prepare a resin composition 9 (for comparison) in the form of an aqueous emulsion (solid content 19.1% by mass).

[0069] (2-10) Resin composition 10 to 14 (for comparison)

 Resin composition 10 (for comparison): Polyacrylic acid aqueous solution instead of polymaleic acid in resin composition 1 (“AC — 10S” manufactured by Nippon Pure Chemical Industries, Ltd., weight average molecular weight: 5,000, solid content: 40.3 mass% )

 Resin composition 11 (for comparison): Polymaleic acid aqueous solution in place of polymaleic acid in resin composition 1 (Non-Paul PMA_50W manufactured by NOF Corporation, solid content 50.1% by mass)

 Resin composition 12 (for comparison): In place of polymaleic acid of resin composition 1, methyl vinyl ether-maleic anhydride copolymer aqueous solution (ISP Japan "AN_119", weight average molecular weight: 200,000, solid (15.3% by mass)

 Resin composition 13 (for comparison): instead of the ethylene acrylic acid copolymer of resin composition 1, ethylene acrylic acid copolymer resin aqueous emulsion (“HYTEC

S-3121 ”, weight average molecular weight: 40,000, solid content 25.5% by mass)

 Resin composition 14 (for comparison): Polyallylamine aqueous solution (“PAA-01” manufactured by Nitto Boseki Co., Ltd., weight average molecular weight: 5,000, solid content 15.1% by mass) instead of triethylamine in resin composition 1

 [0070] Example 1

 Colloidal silica (“ST_XS” manufactured by Nissan Chemical Industries, Ltd., surface area average particle diameter: 4 to 6 nm) 20 parts by mass is added to 80 parts by mass of the resin components 1 to 14 of the resin composition 1 to 100 in total. It was set as the mass part. Furthermore, 10 parts by mass of a silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd., y-glycidoxypropyltrimethoxysilane) is added to 100 parts by mass in total, and water is added to adjust the solid content. The surface treatment composition was prepared by diluting (solid content: 15 to 16.5% by mass) and stirring at room temperature.

In Examples, “resin component” means “olefin-acid copolymer and carboxylic acid polymer” in resin compositions 1 to 7, and “resin component” in resin compositions 8 and 9. Acid resin ", and resin compositions 10 to 14 represent polymers contained in the respective resin compositions. In addition, when using resin compositions 10 to 12 (for comparison) having an acidic pH, instead of the colloidal silica “ST-XS”, acidic colloidal silica (“ST_0” manufactured by Nissan Chemical Industries, Ltd., surface area average) The surface treatment composition was prepared using a particle diameter of 10 to 20 nm.

[0072] As a metal plate, an alkali degreased hot-dip galvanized steel plate (Zn adhesion amount 45 g / m ² ) was used, and the surface treatment composition was applied to the surface of the steel plate with a bar coat (bar No. 3). The plate was heated and dried at a plate temperature of 90 ° C. for about 12 seconds to produce a resin-coated metal plate with a coating amount of 1. Og / m ² :! -14.

 [0073] The characteristics of the obtained resin-coated metal sheet were evaluated. The results are shown in Table 1. As shown in Table 1 below, the resin-coated metal plates 1 to 7 obtained from the surface treatment composition containing a combination of an olefin monoacid copolymer and a carboxylic acid polymer have good corrosion resistance and coating film. Adhesion, alkali resistance and resin film adhesion.

 [0074] [Table 1]

 [0075] Example 2

Colloidal silica (“ST-XS” manufactured by Nissan Chemical Industries, Ltd.) 5 to 45 parts by mass was added to 55 to 95 parts by mass of the resin component of the resin composition 1 to make a total of 100 parts by mass. Furthermore, silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) 10 Add part by weight and dilute with water to adjust the solid content (solid content 16.5% by mass)

The surface treatment composition was prepared by stirring at room temperature.

[0076] Resin-coated metal plates 15 to 26 were produced in the same manner as in Example 1, and the characteristics thereof were evaluated.

 The results are shown in Table 2. As shown in Table 2 below, the resin-coated metal plates 15 to 23 that satisfy the requirements of the resin component amount and colloidal silica amount specified in the present invention have good corrosion resistance, coating film adhesion, alkali resistance and resin. Has film adhesion.

[0077] [Table 2]

 "Resin ingredients

 = Olefin mono (, jS—unsaturated carboxylic acid) copolymer + α, unsaturated carboxylic acid polymer

 [0078] Example 3

 To 80 parts by mass of the resin component of the resin composition 1, 20 parts by mass of colloidal silica (ST-XS manufactured by Nissan Chemical Co., Ltd.) was added to make a total of 100 parts by mass. Furthermore, 3 to 25 parts by mass of a silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) is added to 100 parts by mass in total (total of silane coupling agent (γ-glycidoxypropyltrimethoxysilane). Is 7 · 1 to 29.1 parts by mass), further diluted with water to adjust the solid content (solid content 15.5 to 18.8% by mass), stirred at room temperature, surface treatment composition A product was prepared.

[0079] Resin-coated metal plates 27 to 36 were produced in the same manner as in Example 1, and their characteristics were evaluated.

The results are shown in Table 3. As shown in Table 3 below, resin-coated metal plates 27 to 33 that meet the requirements for the amount of silane coupling agent specified in the present invention have good corrosion resistance, coating film adhesion, alkali resistance, and resin film adhesion. Have [0080] [Table 3]

 "A white precipitate was generated in one week after the preparation of the surface treatment composition.

* ² Gelled immediately after preparation of the surface treatment composition.

 [0081] Example 4

 20 parts by mass of colloidal silica (“Snowtex series” manufactured by Nissan Chemical Co., Ltd.) having a different surface area average particle diameter was added to 80 parts by mass of the resin component of the resin composition 1 to make a total of 100 parts by mass. Furthermore, 10 parts by mass of a silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) is added to the total of 100 parts by mass, and diluted with water to adjust the solid content (solid content 16.5 (Mass%) and stirring at room temperature to prepare a surface treatment composition.

 [0082] Resin-coated metal plates 37 to 40 were produced in the same manner as in Example 1, and their characteristics were evaluated.

 The results are shown in Table 4. As shown in Table 4 below, the resin-coated metal plates 37 and 38 using colloidal silica having a preferred average particle size have good corrosion resistance, coating film adhesion, ano- ral resistance, and resin film adhesion.

 [0083] [Table 4]

 Colloidal

 Flat plate Cross cut JASO Al

 Metal plate Silica Coated film Corrosion resistance Corrosion resistance Cycle test Caliability

 No. Particle size Adhesion Adhesion

 Corrosion resistance at (hr) (hr) (hr)

 (nm)

 37 4-6 240 120 @ © 120 ◎

38 10-20 240 120 ◎ 120

39 40-60 120 48 厶 0 48 厶

40 70-100 96 <24 厶 o 24 Δ [0084] Example 5

 To 80 parts by mass of the resin component of the resin composition 1, 20 parts by mass of colloidal silica (“ST-XS” manufactured by Nissan Chemical Industries, Ltd.) was added to make a total of 100 parts by mass. Furthermore, 7.5 parts by mass of a silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) is added to 100 parts by mass of the total, and a dilute aqueous solution of a vanadium compound has a VO equivalent of 0.5-6. Part by mass

 twenty five

 In order to adjust the solid content, it was diluted with water (solid content: 16.2 to: 17.0 mass%) and stirred at room temperature to prepare a surface treatment composition.

 The vanadium compound diluted aqueous solution is prepared by diluting “vanadic acid solution (IV)” manufactured by Shinsei Chemical Industry Co., Ltd. with pure water to a predetermined concentration, and then adjusting the pH to 6.5 using aqueous ammonia.

 [0085] Resin-coated metal plates 41 to 51 were produced in the same manner as in Example 1, and the characteristics thereof were evaluated.

 The results are shown in Table 5. As shown in Table 5 below, the resin coated metal plates 41 to 48 containing a proper amount of vanadium compound have particularly good corrosion resistance (cross-cut corrosion resistance) at the buttock.

 [0086] [Table 5]

 After preparation of the surface treatment composition, a suspension of vanadium hydroxide was generated, and the surface treatment composition changed to a white positive color.

 After preparation of the surface-molding treatment composition I: A large amount of floating vanadium hydroxide was generated, resulting in coating unevenness.

 [0087] Example 6

Colloidal silica (Nissan Chemical Industries) with respect to 80 parts by mass of the resin component of the resin composition 1 20 parts by mass of “ST-XS” manufactured by the company was added to make a total of 100 parts by mass. Furthermore, 10 parts by mass of a silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) is added to 100 parts by mass of the total, and further diluted with water to adjust the solid content (solid content 16.5 (Mass%) and stirring at room temperature to prepare a surface treatment composition.

[0088] As the metal plate, an alkaline degreased hot-dip galvanized steel plate (Zn adhesion amount 45 g / m ² ) was used, and the surface treatment composition was applied to the surface of the steel plate with a bar coat (bar No. 3). Then, it was dried by heating at a plate temperature of 90 ° C. for about 12 seconds to produce resin-coated metal plates 52 to 62 with a resin film adhesion amount of 0.:! To 3.5 g / m ² .

 [0089] The properties of the obtained resin-coated metal sheet were evaluated. The results are shown in Table 6. As shown in Table 6 below, the resin-coated metal plates 52 to 59 provided with a resin film with a preferable resin adhesion amount have good corrosion resistance, coating film adhesion, alkali resistance, and resin film adhesion.

 [0090] [Table 6]

 Example 7

 30 parts by mass of colloidal silica (“ST_XS” manufactured by Nissan Chemical Industries, Ltd.) was added to the resin component 70 of the resin composition 1 to make a total of 100 parts by mass. Furthermore, 7 parts by mass of a silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) is added to the total of 100 parts by mass, and sodium metavanadate as a vanadium compound (“Sodium Metavanadate” manufactured by Shinsei Chemical Industry Co., Ltd.) Was added so that the amount converted to VO was 2 parts by mass. In addition, it contains oxazoline

 twenty five

Styrene / acryl main chain oxazoline polymer (Nippon Shokubai Co., Ltd.) as polymer (crosslinking agent) “Epocross K 2030E”) is added to 0 to 15 parts by mass with respect to 100 parts by mass in total, and diluted with water to adjust the solid content (solid content concentration 16.5% by mass) at room temperature. The surface treatment composition was prepared by stirring.

 Resin-coated metal plates 63 to 76 were produced in the same manner as in Example 1 and their characteristics were evaluated. The results are shown in Table 7. As shown in the following metal plates 63 to 72 in Table 6, corrosion resistance and adhesion as well as roll formability are improved by the addition of the polymer containing oxazoline.

[Table 7]

Example 8

 30 parts by mass of colloidal silica (“ST-XS” manufactured by Nissan Chemical Industries, Ltd.) was added to the resin component 70 of the resin composition 1 to make a total of 100 parts by mass. Furthermore, 7 parts by mass of a silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) is added to the total of 100 parts by mass, and sodium metavanadate as a vanadium compound (“Sodium Metavanadate” manufactured by Shinsei Chemical Industry Co., Ltd.) Was added so that the equivalent amount of V 0 was 2 parts by mass. In addition, it contains oxazoline

 twenty five

As a polymer (crosslinking agent), 4 parts by mass of styrene / acryl main chain oxazoline polymer (Nippon Shokubai "Epocross K-2030E") is added to 100 parts by mass in total, and the average particle size is 0 3 μm spherical polyethylene wax particles (“Permarin KUE-17J” manufactured by Sanyo Chemical Industries, Ltd.) and spherical polyethylene wax particles with an average particle size of 0.6-7 μm (Mitsui "Chemical Pearl W900", "Chemical Pearl W700", "Cheminole W500", "Chemipe Norre W300J", "Chemino Monore W400J" On the other hand, 0.5 to 5 parts by mass was added, and further diluted with water to adjust the solid content (solid content concentration: 16.5% by mass) and stirred at room temperature to prepare a surface treatment composition.

 Resin-coated metal plates 77 to 94 were produced in the same manner as in Example 1 and their characteristics were evaluated. The results are shown in Table 8. As shown in the metal plates 77 to 81 and 85 to 90 in the following table, the roll formability was particularly improved by adding the polymer containing oxazoline and adding the spherical polyethylene wax.

[Table 8]

Example 9

30 parts by mass of colloidal silica (“ST_XS” manufactured by Nissan Chemical Industries, Ltd.) was added to the resin component 70 of the resin composition 1 to make a total of 100 parts by mass. Furthermore, 7 parts by mass of a silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) is added to the total of 100 parts by mass, and sodium metavanadate as a vanadium compound (“Sodium Metavanadate” manufactured by Shinsei Chemical Industry Co., Ltd.) Was added so that the equivalent amount of V 0 was 2 parts by mass. In addition, it contains oxazoline Styrene / acryl main chain oxazoline polymer (Nippon Shokubai Co., Ltd.) as polymer (crosslinking agent)

4 parts by mass of “Epocross K-2030E”) is added to 100 parts by mass of the total, and an average particle size of 1.0 / m spherical polyethylene wax particles (“Chemical W700” manufactured by Mitsui Chemicals, Inc.) To 100 parts by mass, 2 parts by mass was added, and further diluted with water to adjust the solid content (solid content concentration: 16.5% by mass), and stirred at room temperature to prepare a surface treatment composition.

Alkali degreased hot-dip galvanized steel sheets (Zn adhesion 45 g / m ² ), alloyed hot-dip galvanized steel sheets (Zn adhesion 45 gZm ² ), electrogalvanized steel sheets (Zn adhesion 20 g / m ²⁾ The surface treatment composition is applied to the surface of the metal plate with a bar coat (bar No. 3) and dried by heating at a plate temperature of 90 ° C for about 12 seconds. :! To 3.5 g / m ² of resin-coated metal plate 95 to 109 were produced.

The characteristics of the obtained resin-coated metal plate were evaluated. The results are shown in Table 9. As shown in Table 9 below, resin-coated metal plates 95 to 102 (hot-dip galvanized steel plate) and 103 to 104 (alloyed hot-dip galvanized steel plate) with a resin coating having a preferable resin adhesion amount, 105-: 10 6 (electrogalvanized steel sheet) all have good corrosion resistance, coating film adhesion, alkali resistance, resin film adhesion, and roll formability.

[Table 9]

Metal plate Resin film Flat plate Cross cut JASO Paint film Anti-roll

No. adhesion amount Corrosion resistance Corrosion resistance Cycle adhesion Adhesiveness Film formability

(g / m ² ) (hr) (hr) (hr) adhesion in test

 95 0.2 168 120 ◎ © 96 ◎ o

96 0.5 240 168 © 120 ◎

 97 0.7 288 216 ◎ 144 ◎

 98 1.0 320 240 168 ◎

 99 1.5 320 240 ◎ 168 @ ©

100 2.0 320 240 ◎ 168 ◎

 101 2.5 344 240 @ ◎ 168 ◎ ©

102 3.0 344 240 ◎ o 168 ◎ ©

103 0.5 120 72 O © 72 ◎ 0

104 1 .0 168 72 0 72 © o

105 0.5 240 168 © 120 @

106 1 .0 288 216 ◎ © 144 © ©

107 0.1 120 72 Δ Δ 48 Δ X

108 3.2 344 240 @ Δ 168 ◎ o

109 3.5 344 240 ◎ Δ 168 厶

* Metal plates 95-102 and 107-109 are steel plates with molten subgrowth

* Metal plates 103 to 104 are galvanized steel plates

* Metal plates 105 to 106 are electrogalvanized steel plates

Claims

The scope of the claims

 [1] A resin-coated metal plate provided with a resin film obtained from a surface treatment composition,

 The surface treatment composition comprises 55 to 95 parts by mass of olefin-β, β-unsaturated carboxylic acid copolymer and β, β-unsaturated carboxylic acid polymer, and

 5 to 45 parts by mass of colloidal silica (provided that the total of olefin-β, β-unsaturated carboxylic acid copolymer, j3_unsaturated carboxylic acid polymer and colloidal silica is 100 parts by mass). ,

 Olefin j3--unsaturated carboxylic acid copolymer, α, unsaturated carboxylic acid polymer and colloidal silica in total 100 parts by weight

Containing 7-30 parts by weight,

 A resin-coated metal sheet, characterized in that the content ratio of the olefin-unsaturated carboxylic acid copolymer and the α, β-unsaturated carboxylic acid copolymer is from 1,000: 1 to 10: 1 by mass ratio.

 [2] The resin-coated metal sheet according to [1], wherein the α, β-unsaturated carboxylic acid polymer is polymaleic acid.

 [3] The resin-coated metal sheet according to claim 1 or 2, wherein the colloidal silica has a surface area average particle diameter of 4 to 20 nm.

 [4] The resin-coated metal sheet according to claim 1 or 2, wherein the silane coupling agent is a daricidyl group-containing silane coupling agent.

[5] The surface treatment composition comprises 100 parts by mass of a olefin, β-unsaturated carboxylic acid copolymer, o, β-unsaturated carboxylic acid polymer, and colloidal silica. The resin-coated metal plate according to claim 1 or 2, which contains 5 to 6 parts by mass.

 [6] When the surface treatment composition comprises 100 parts by mass of the total of olefin-β, β-unsaturated carboxylic acid copolymer and β, β-unsaturated carboxylic acid polymer, 3. The resin-coated metal sheet according to claim 1 or 2, which contains a calpositimide group-containing compound in a ratio of 0.:! To 30 parts by mass.

[7] The adhesion amount of the resin film is 0.2 to 3 g / m ² in dry mass. Resin-coated metal plate.

 [8] 55-95 parts by mass of the olefin α, β unsaturated carboxylic acid copolymer and the α, β unsaturated carboxylic acid polymer, and

 5 to 45 parts by mass of colloidal silica (provided that the total of olefin-β, β-unsaturated carboxylic acid copolymer, j3_unsaturated carboxylic acid polymer and colloidal silica is 100 parts by mass). ,

 It contains 7-30 parts by mass of a silane force pulling agent for a total of 100 parts by mass of olefin-s, j3-unsaturated carboxylic acid copolymer, ss, / 3_unsaturated carboxylic acid polymer and colloidal silica. With

 The content ratio of olefin and β-unsaturated carboxylic acid copolymer to β-unsaturated carboxylic acid polymer is from 1,000: 1 to 10: 1 by mass ratio. Surface treatment composition.

 [9] It contains 0.5 to 6 parts by mass of a vanadium compound with respect to a total of 100 parts by mass of olefin a, unsaturated carboxylic acid copolymer, α,; 3-unsaturated carboxylic acid polymer and colloidal silica, The surface treatment composition according to claim 8.

 [10] The surface treatment composition further comprises an oxazoline-containing polymer with respect to a total of 100 parts by mass of the olefin-a, β-unsaturated carboxylic acid copolymer, a, β-unsaturated carboxylic acid polymer, and colloidal silica. The resin-coated metal plate according to claim 1 or 2, which contains 1 to 9 parts by mass.

 [11] The surface treatment composition further comprises an average particle size of 0 with respect to a total of 100 parts by mass of olefin-α-, β-unsaturated carboxylic acid copolymer, a, β-unsaturated carboxylic acid polymer and colloidal silica. The resin-coated metal sheet according to claim 10, comprising 0.5 to 5 parts by mass of spherical polyethylene wax particles of 6 to 4 zm.