JP2010053413A - Surface treatment composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonpolluting surface treatment composition which is used instead of the conventional chromate treatment and phosphate treatment and allows a precoated steel sheet to have excellent corrosion resistance in a flat surface part thereof and excellent corrosion resistance and adhesiveness in a processed or end face part thereof and to provide a method for forming a film by using the surface treatment composition and a surface-treated metal sheet. <P>SOLUTION: The surface treatment composition has 1-30 mass% solid content comprising (A) a water-soluble or water-dispersible resin and (B) a following mixture of rustproof components. The mixture (B) is composed of at least one vanadium compound (b1) of vanadium pentoxide, calcium vanadate and ammonium metavanadate, a silicon compound (b2) and calcium phosphate (b3). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention replaces conventional chromate treatment and phosphate treatment, chemical resistance, corrosion resistance of the flat part, corrosion resistance in the processed part and end face part, pollution-free surface treatment composition excellent in adhesion, The present invention relates to a film forming method using a surface treatment composition and a surface-treated metal plate.

  Conventionally, pre-coated metal sheets such as pre-coated steel sheets painted by coil coating, etc., building materials such as roofs, walls, shutters, garages, various household appliances, switchboards, refrigerated showcases, steel furniture, kitchen appliances, etc. Widely used as a housing related product.

  In order to manufacture these housing-related products from a pre-coated metal plate, the pre-coated steel plate is usually cut, press-molded and joined. Therefore, these housing-related products often have a metal exposed portion that is a cut surface and a crack generating portion due to press working. Chromate treatment and phosphate treatment are generally used to improve the corrosion resistance of the metal surface of pre-coated steel sheets in order to improve the corrosion resistance of the exposed metal parts and crack generation parts as compared with other parts. Has been done.

  However, in recent years, the toxicity of chromium has become a social problem. The surface treatment method using chromate has the problem of scattering of chromate fume in the treatment process, the wastewater treatment facility requires a large expense, and further the problem of elution of chromic acid from the chemical conversion treatment film. . Hexavalent chromium compounds are extremely harmful substances as many public institutions, including IARC (International Agency for Research on Cancer Review), have designated as carcinogenic substances for the human body.

  Also, in phosphate treatment, zinc phosphate and iron phosphate surface treatments are usually performed, but in order to provide corrosion resistance, chrome treatment is usually performed after phosphating for rinsing with chromic acid. In addition to the above problems, there are problems such as a reaction accelerator in the phosphate treatment agent, wastewater treatment of metal ions, and sludge treatment by elution of metal ions from the metal to be treated.

  For example, as a treatment method other than chromate treatment or zinc phosphate treatment, (A) an amine obtained by reacting an epoxy compound of an epoxy group-containing acrylic resin with an amine compound having at least one active hydrogen in the molecule From a modified acrylic resin, (B) at least one compound selected from phosphoric acid compounds, hydrofluoric acid, metal hydrofluoric acid and metal hydrofluoric acid salts, (C) molybdenum compounds, tungsten compounds and vanadium compounds There is described a surface treatment composition for a lubricating steel sheet, comprising at least one selected compound, (D) an aqueous organic polymer compound that is stable at a pH of 7 or less, and (E) a lubricant as an essential component. (Patent Document 1).

  And (A) an amine-modified acrylic resin obtained by reacting an epoxy compound of an epoxy group-containing acrylic resin with an amine compound having at least one active hydrogen group in the molecule; (B) a phosphoric acid compound; It contains at least one compound selected from hydroacid, metal hydrofluoric acid and metal hydrofluoride, and (C) at least one compound selected from molybdenum compounds, tungsten compounds and vanadium compounds as essential components. A surface treatment composition for metal materials is disclosed (Patent Document 2).

  Further, (A) at least one titanium compound selected from the group consisting of a hydrolyzable titanium compound, a low condensate of hydrolyzable titanium compound, titanium hydroxide and a low condensate of titanium hydroxide is a hydrogen peroxide solution. Based on 100 parts by weight of the solid content of the titanium-containing aqueous liquid obtained by mixing, 1 to 400 parts by weight of (B) an organic phosphoric acid compound, and 10 to 2 parts of (C) a water-soluble or water-dispersible organic resin in solids. 2,000 parts by weight, (D) 1 to 400 parts by weight of a vanadic acid compound, (E) 1 to 400 parts by weight of a zirconium fluoride compound, and (F) 1 to 400 parts by weight of a zirconium carbonate compound. A metal surface treatment composition is disclosed (Patent Document 3).

  In addition, Patent Document 4 discloses (I) a high corrosion-resistant underlayer film having a dry film thickness of 0.01 to 1 μm and (II) a fingerprint-resistant film having a dry film thickness of 0.2 to 3 μm on a metal steel plate. Is a surface-treated steel sheet in which the high corrosion-resistant underlayer coating (I) is (A) a hydrolyzable titanium compound, a low condensate of a hydrolyzable titanium compound, titanium hydroxide, and titanium hydroxide. Based on 100 parts by weight of a titanium-containing aqueous liquid obtained by mixing at least one titanium compound selected from the group consisting of low-condensates with hydrogen peroxide, (B) 1 to 400 parts by weight of an organophosphate compound , (C) water-soluble or water-dispersible organic resin 10 to 2,000 parts by weight, (D) metavanadate 1 to 400 parts by weight, (E) zirconium fluoride 1 to 400 parts by weight, and (F) zirconium carbonate Lower layer containing 1 to 400 parts by weight of salt A surface-treated steel sheet having a film formed from the surface treatment composition for film is disclosed (Patent Document 4). However, the metal surface treatment composition described in Patent Document 3 or Patent Document 4 is inferior in corrosion resistance and chemical resistance compared to a film using a chromium-based pigment, and in particular, the corrosion resistance at the end face is insufficient. there were.

  Further, in Patent Document 5, internal gelled hard polymer particles (a) having an average particle diameter of 0.4 to 0.6 μm, water-dispersible silica (b), glycidoxyalkyltrialkoxysilane (c), Painted zinc-based plated steel sheet treated with an aqueous rust-proof coating composition containing an organic vanadium compound (d), a water-dispersible urethane resin (e), a zirconium compound (f), and diammonium hydrogen phosphate (g) Is disclosed.

  However, the surface treatment compositions and the like described in Patent Documents 1 to 5 are inferior in corrosion resistance compared to the surface treatment composition using a chromium-based pigment, and in particular, the corrosion resistance and adhesion at the processed part and the end face part are insufficient. is there.

JP 2003-166073 A JP 2003-226882 A Japanese Patent Laid-Open No. 2006-9121 JP 2006-22370 A JP 2008-81785 A

  An object of the present invention is to find a pollution-free surface treatment composition excellent in corrosion resistance and adhesion at a flat portion, processed portion and end face portion, and a pollution-free surface treatment composition and coating excellent in the above-mentioned film performance A forming method and a surface-treated metal plate are provided.

  Therefore, as a result of intensive studies to solve the above-described conventional problems, the present inventors have obtained a specific vanadium compound (b1) as a water-soluble or water-dispersible resin (A) and a rust preventive component mixture (B). ), The surface treatment composition containing a predetermined amount of the silicon compound (b2) and the phosphoric acid calcium salt (b3) is excellent not only in the corrosion resistance of the flat surface portion but also in the corrosion resistance of the processed portion and the end surface portion in the coated metal plate and the like. The present inventors have found a surface treatment composition capable of forming a coating film and have completed the present invention.

That is, the present invention provides a surface treatment composition having a solid content of 1 to 30% by mass containing “1. water-soluble or water-dispersible resin (A) and the following antirust component mixture (B),
Antirust component mixture (B): a composition comprising at least one of vanadium pentoxide, calcium vanadate and ammonium metavanadate (b1), silicon compound (b2), and phosphate calcium salt (b3) Because
1 to 30 parts by mass of the vanadium compound (b1) and 1 to 30 parts by mass of the silicon compound (b2) with respect to 100 parts by mass of the resin solid content of the water-soluble or water-dispersible resin (A). And the amount of the phosphate calcium salt (b3) is 1 to 30 parts by mass, and the amount of the rust preventive component mixture (B) is 3 to 90 parts by mass. Furthermore, the surface treatment composition of 1 which contains 1-30 mass parts of compound (b4) which produces a fluoro metal ion with respect to 100 mass parts of resin solid content of water-soluble or water-dispersible resin (A),
3. The surface treatment composition according to 1 or 2, wherein the water-soluble or water-dispersible resin (A) is an amino group-containing epoxy resin,
4). The surface treatment composition according to any one of 1 to 3, comprising 0.1 to 10 parts by mass of a resol-type phenol resin with respect to 100 parts by mass of the resin solid content of the water-soluble or water-dispersible resin (A). ,
5). A cured coating film having a thickness of 0.01 to 10 μm is formed on the metal substrate using the surface treatment composition according to any one of claims 1 to 4, and the material arrival temperature is 80 ° C. to 120 ° C. for 1 second to 60 seconds. A film forming method characterized by heating and drying;
The surface-treated metal plate obtained by the film forming method according to 6.5 ”.

  The surface treatment composition of the present invention does not contain a chromium-based rust preventive pigment and is advantageous in terms of environmental hygiene. The film obtained by applying the surface treatment composition is not only excellent in corrosion resistance of the flat portion, but also processing of the surface-treated metal plate that was difficult to achieve with the surface treatment composition containing a non-chromium rust preventive pigment. Excellent effect on corrosion resistance and adhesion at the edge and end face.

  The present invention relates to a surface treatment composition containing a specific amount of a water-soluble or water-dispersible resin (A) and an antirust component mixture (B). Details will be described below.

[Metal plate]
The metal plate to be coated with the surface treatment composition of the present invention includes, for example, an electrogalvanized steel sheet, an electrogalvanized nickel plated steel sheet, a hot dip galvanized steel sheet, a zinc-aluminum hot dip plated steel sheet, Examples include hot-rolled steel sheets, cold-rolled steel sheets, stainless steel sheets, copper-plated steel sheets, aluminum sheets, molten tin-zinc (Sn-10% Zn) -plated steel sheets, molten aluminum-plated steel sheets, Al-Mg alloys.

[Water-soluble or water-dispersible resin (A)]
The water-soluble or water-dispersible resin (A) is a resin having a cationizable group such as an amino group, an ammonium base, a sulfonium base, or a phosphonium base in the molecule, and is usually used as a resin type. Examples thereof include an epoxy resin, an acrylic resin, a polybutadiene resin, an alkyd resin, and a polyester resin. In particular, an amino group-containing epoxy resin obtained by addition reaction of an amino group-containing compound with an epoxy resin is not only excellent in the corrosion resistance of the flat portion, but is also preferable from the viewpoint of improving the corrosion resistance and adhesion at the processed portion and the end surface portion. .

  Examples of the amino group-containing epoxy resin include (1) an adduct of an epoxy resin and a primary mono- and polyamine, a secondary mono- and polyamine, or a primary and secondary mixed polyamine (for example, US Patents). (2) Adducts of epoxy resins with secondary mono- and polyamines having ketiminated primary amino groups (see, for example, US Pat. No. 4,017, (3) a reaction product obtained by etherification of an epoxy resin and a ketiminated hydroxy compound having a primary amino group (for example, see JP-A-59-43013), etc. Can be mentioned.

  The epoxy resin used in the production of the amino group-containing epoxy resin is a compound having at least one, preferably two or more epoxy groups in one molecule, and its molecular weight is generally at least 300, preferably 400-4. "Number average molecular weight (Note 1)" in the range of 800, 2,500, more preferably in the range of 800 to 2,500 and epoxy equivalents in the range of at least 160, preferably 180 to 2,500, more preferably 400 to 1,500. In particular, those obtained by the reaction of a polyphenol compound and an epihalohydrin are preferable.

  (Note 1) Number average molecular weight: 4 of “TSK GEL4000HXL”, “TSK G3000HXL”, “TSK G2500HXL”, “TSK G2000HXL” (manufactured by Tosoh Corporation) according to the method described in JIS K 0124-83 Using the book, it was obtained from a chromatogram obtained with an RI refractometer and a standard polystyrene calibration curve at 40 ° C. and a flow rate of 1.0 ml / min using tetrahydrofuran for GPC as an eluent.

  Examples of the polyphenol compound used for forming the epoxy resin include bis (4-hydroxyphenyl) -2,2-propane [bisphenol A], bis (4-hydroxyphenyl) methane [bisphenol F], bis ( 4-hydroxycyclohexyl) methane [hydrogenated bisphenol F], 2,2-bis (4-hydroxycyclohexyl) propane [hydrogenated bisphenol A], 4,4′-dihydroxybenzophenone, bis (4-hydroxyphenyl) -1, 1-ethane, bis (4-hydroxyphenyl) -1,1-isobutane, bis (4-hydroxy-3-tert-butyl-phenyl) -2,2-propane, bis (2-hydroxynaphthyl) methane, tetra ( 4-hydroxyphenyl) -1,1,2,2-ethane, 4,4 ′ Dihydroxydiphenyl sulfone, phenol novolak, and the like cresol novolak.

  Moreover, as an epoxy resin obtained by reaction of a polyphenol compound and epichlorohydrin, the resin of the following formula induced | guided | derived from bisphenol A is suitable especially.

Here, what is shown by n = 0-8 is suitable.
As commercially available products of such epoxy resins, jER828EL, jER1002, jER1004, jER1007 (Japan Epoxy Resin Co., Ltd., trade name), Araldite AER6099 (made by Asahi Ciba, trade name), Epomic R-309 (Mitsui Chemicals, Product name).

The epoxy resin may be a modified epoxy resin obtained by reacting a modifying component such as a polyol, a polyether polyol, a polyester polyol, a polyamidoamine, a polybasic acid, or a polyisocyanate compound, and further, such as ε-caprolactone. It may be a modified epoxy resin obtained by graft polymerization of lactones, acrylic monomers, or the like.
The method for producing the modified epoxy resin by reacting the modified component with the epoxy resin is not particularly limited. The reaction between the modified component and the epoxy resin is usually, for example, 1 to 5 at 100 to 150 ° C. at 100 to 150 ° C. in the presence of a reaction catalyst as necessary in a solvent capable of dissolving these components. It can carry out suitably by making it react for time.

  Examples of the reaction catalyst include quaternary salt catalysts such as tetraethylammonium bromide, tetrabutylammonium bromide, triphenylbenzylphosphonium chloride, and amines such as triethylamine.

  Examples of primary mono- and polyamines, secondary mono- and polyamines, and primary and secondary mixed polyamines used in the production of the amino group-containing epoxy resin of (1) above include monomethylamine, dimethylamine, Mono- or di-alkylamines such as monoethylamine, diethylamine, monoisopropylamine, diisopropylamine, monobutylamine, dibutylamine; alkanolamines such as monoethanolamine, diethanolamine, mono (2-hydroxypropyl) amine, monomethylaminoethanol; Examples include amine compounds such as alkylene polyamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine.

  Examples of the secondary mono- and polyamine having a ketiminated primary amino group used in the production of the amino group-containing epoxy resin of (2) above include the production of an amine-added epoxy resin of (1) above. Among the primary and secondary mixed polyamines used in 1), for example, ketimine compounds of amine compounds produced by reacting ketone compounds with diethylenetriamine or the like can be mentioned.

  Examples of the hydroxy compound having a ketiminated primary amino group used in the production of the amino group-containing epoxy resin of (3) above include, for example, those used in the production of the amine-added epoxy resin of (1) above. Among primary mono- and polyamines, secondary mono- and polyamines or primary and secondary mixed polyamines, compounds having primary amino groups and hydroxyl groups, such as monoethanolamine, mono (2-hydroxypropyl) A hydroxyl group-containing ketimine compound of an amine compound obtained by reacting a ketone compound with an amine or the like can be mentioned.

  In particular, among the amino group-containing epoxy resins, as a more preferable resin from the viewpoint of improving the corrosion resistance of the processed portion for pre-coated steel sheets, a modified epoxy resin by reacting an aliphatic polybasic acid having 4 to 36 carbon atoms with an epoxy resin, An aliphatic polybasic acid-modified amino group-containing epoxy resin formed by adding an amine compound or the like; in addition, an amine compound or the like is added to the modified epoxy resin by reacting a polyisocyanate compound and an epoxy resin. And diisocyanate compound-modified amino group-containing modified epoxy resins.

  The aliphatic polybasic acid having 4 to 36 carbon atoms is preferably a saturated or unsaturated aliphatic polybasic acid having 6 to 36, such as hexahydroisophthalic acid, hexahydroterephthalic acid, hexahydrophthalic acid. Acid, methyl hexahydrophthalic acid, methyl hexahydroterephthalic acid, Δ1-tetrahydrophthalic acid, Δ2-tetrahydrophthalic acid, Δ3-tetrahydrophthalic acid, Δ4-tetrahydrophthalic acid, Δ1-tetrahydroisophthalic acid, Δ 2-tetrahydroisophthalic acid, Δ3-tetrahydroisophthalic acid, Δ4-tetrahydroisophthalic acid, Δ1-tetrahydroterephthalic acid, Δ2-tetrahydroterephthalic acid, methyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthal Acid, hexachloroe Alicyclic dicarboxylic acids such as domethylenetetrahydrophthalic acid and its anhydrides; succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanic acid, dodecanedicarboxylic acid, suberic acid, pimelic acid, maleic acid, fumaric acid Aliphatic dicarboxylic acids such as itaconic acid, brassic acid, citraconic acid, chloromaleic acid, and dimer acid, and anhydrides thereof; trivalent or higher aliphatic polybasic acids such as hexahydrotrimellitic acid; methyl esters of these acids And lower alkyl esters such as ethyl ester.

  Examples of the polyisocyanate compound include tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, diphenylmethane-2,2′-diisocyanate, diphenylmethane-2,4′-diisocyanate, diphenylmethane-4,4′-diisocyanate, crude MDI [ Polymethylene polyphenyl isocyanate], bis (isocyanate methyl) cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, isophorone diisocyanate and the like; cyclization of these polyisocyanate compounds; A polymer or biuret body; or a combination thereof. In particular, hexamethylene diisocyanate is preferable from the viewpoint of improving the corrosion resistance of the processed part and the end face part.

  In addition, in manufacture of an amino group-containing epoxy resin, the addition reaction of an epoxy resin (modified epoxy resin) and an amino group-containing compound is usually performed at 80 to 170 ° C., preferably 90 to 150 ° C. in an appropriate solvent. The temperature can be 1 to 6 hours, preferably 1 to 5 hours. Examples of the solvent include hydrocarbon solvents such as toluene, xylene, cyclohexane, and n-hexane; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone. Ketone solvents; amide solvents such as dimethylformamide and dimethylacetamide; alcohol solvents such as methanol, ethanol, n-propanol, and iso-propanol; or a mixture thereof.

  The use ratio of each reaction component in the above addition reaction is not strictly limited and can be changed as appropriate. Based on the total solid mass of the epoxy resin (modified epoxy resin) and the amino group-containing compound, The epoxy resin is used in the range of 70 to 95% by mass, preferably 80 to 95% by mass; the amino group-containing compound is used in the range of 5 to 30% by mass, preferably 5 to 20% by mass.

  The amount of the amino group-containing compound used is within the range such that the amine value of the cationic resin as the final product of the present invention is 10 to 80 mgKOH / g, preferably 20 to 70 mgKOH / g. From the viewpoint of improving the corrosion resistance of the film.

[Anti-rust component mixture (B)]
The surface treatment composition of this invention can obtain the coating metal plate excellent in the corrosion resistance of a plane part, and the corrosion resistance in a process part and an end surface part by containing a specific amount of specific antirust component mixtures (B). In addition, a rust prevention component mixture (B) consists of a vanadium compound (b1), a silicon compound (b2), and a phosphate calcium salt (b3). Furthermore, the antirust component mixture (B) may contain a compound (b4) that generates a fluoro metal ion, if necessary. Details will be described below.

Vanadium compound (b1):
The vanadium compound (b1) is at least one vanadium compound selected from vanadium pentoxide, calcium vanadate, and ammonium metavanadate. Vanadium pentoxide, calcium vanadate and ammonium metavanadate are excellent in elution of pentavalent vanadium ions into water, and the pentavalent vanadium ions released from the vanadium compound (b1) react with the material metal, It works effectively to improve corrosion resistance by reacting with ions from other anti-rust component mixtures. Among these, vanadium pentoxide is particularly effective in improving corrosion resistance.

Silicon compound (b2):
The silicon compound (b2) contains at least one compound selected from metal silicate salts, silica fine particles, and metal ion exchanged silica fine particles.
The silicate metal salt is a salt made of silicon dioxide and a metal oxide, and may be any of orthosilicate, polysilicate and the like. Examples of silicates include zinc silicate, aluminum silicate, aluminum orthosilicate, aluminum hydrated aluminum silicate, aluminum calcium silicate, sodium aluminum silicate, beryllium aluminum silicate, sodium silicate, calcium orthosilicate, calcium metasilicate, sodium calcium silicate, and silicic acid. Zirconium, magnesium orthosilicate, magnesium metasilicate, magnesium calcium silicate, manganese silicate, barium silicate, olivine, garnet, tortovite, cyllite, benitoite, neptunite, nymphite, turquoise, quartzite, barracite, tosen Stones, zonotorite, talc, gyoganite, aluminosilicate, borosilicate, beryllosilicate, cholite, fluorite and the like. As the metal silicate, calcium orthosilicate and calcium metasilicate are particularly preferable.

  The silica fine particles can be used without particular limitation as long as they are silica fine particles, such as silica fine powder with an untreated surface, silica fine powder with a surface treated with organic matter, calcium ion-exchanged silica fine particles, organic solvent-dispersible colloidal silica, etc. Can be mentioned. Examples of the silica fine particles whose surface is not treated or treated with an organic substance include silica fine powder having an average particle size of 0.5 to 15 μm, preferably 1 to 10 μm, and organic solvent-dispersible colloidal silica. As the fine silica powder, those having an oil absorption of 30 to 350 ml / 100 g, preferably 30 to 150 ml / 100 g can be suitably used, and as commercially available products, silicia 710, silicia 740, silicia 550, Examples include Aerosil R972 (all of which are manufactured by Fuji Silysia Chemical Co., Ltd.), Mizukacil P-73 (manufactured by Mizusawa Chemical Industry Co., Ltd.), Gasil 200DF (manufactured by Crossfield).

  The organic solvent-dispersible colloidal silica is also referred to as an organosilica sol, in which silica fine particles having a particle size of about 5 to 120 nm are stably dispersed in an organic solvent such as alcohols, glycols, and ethers. In addition, examples of commercially available products include the OSCAL series (manufactured by Catalytic Chemicals Co., Ltd.) and organosols (manufactured by Nissan Chemical Co., Ltd.).

  The metal ion exchanged silica fine particles are silica fine particles in which metal ions are introduced into a fine porous silica carrier by ion exchange. Specifically, it is a silica fine particle into which calcium or magnesium is introduced. For example, as commercially available products of calcium ion exchange silica, SHIELDEX (Shielddex, registered trademark) C303, SHIELDEXAC-3, SHIELDEXC-5 (all of which are manufactured by WR Grace & Co.) and the like can be mentioned. it can.

  Alkaline earth metal ions released from metal ion-exchanged silica are involved in electrochemical action and various salt forming actions, and effectively work to improve corrosion resistance. Moreover, the silica fixed in the coating film effectively works to suppress peeling of the coating film in a corrosive atmosphere.

Phosphate-based calcium salt (b3):
The phosphate calcium salt (b3) is a phosphate containing calcium as a metal element. For example, calcium phosphate, calcium ammonium phosphate, calcium monohydrogen phosphate, calcium dihydrogen phosphate, calcium phosphate phosphate, tripoly A calcium phosphate etc. can be mentioned. Phosphate ions and calcium ions released from the phosphate calcium salt (b3) work effectively to improve corrosion resistance.

  In the surface treatment composition of the present invention, the vanadium compound (b1) and the silicon compound (b2) in the antirust component mixture (B) with respect to 100 parts by mass of the resin solid content of the water-soluble or water-dispersible resin (A). ) And phosphate calcium salt (b3) are within the following range.

  Vanadium compound (b1): 1 to 30 parts by mass, preferably 1 to 20 parts by mass, silicon compound (b2): 1 to 30 parts by mass, preferably 1 to 20 parts by mass, phosphate calcium salt (b3): 1 -30 mass parts, preferably 1-20 mass parts.

  Furthermore, in the surface treatment composition of the present invention, the amount of the rust preventive component mixture (B) is preferably 3 to 90 parts by mass, preferably 100 parts by mass of the resin solid content of the water soluble or water dispersible resin (A). 9 to 60 parts by mass is also preferable in order to obtain a film excellent in the corrosion resistance of the flat part, the corrosion resistance in the processed part and the end face part, and the adhesion.

  The surface treatment composition of the present invention synergistically combines the vanadium compound (b1), the silicon compound (b2) and the phosphate calcium salt (b3) in a predetermined amount as the antirust component mixture (B). Corrosion resistance can be improved. Of these, the combination of vanadium pentoxide, calcium metasilicate, and calcium phosphate is suitable for the antirust component mixture (B) from the viewpoint of corrosion resistance.

  Furthermore, in addition to the vanadium compound (b1), the silicon compound (b2) and the phosphoric acid calcium salt (b3), the rust-preventive component mixture (B) includes a compound (b4) that generates a fluoro metal ion, if necessary. ) Can be blended.

Compound (b4) producing a fluoro metal ion:
The compound (b4) that generates a fluoro metal ion is a compound that generates a fluoro metal ion such as zirconium fluorine hydrogen ion, titanium hydrogen fluoride ion, or hydrogen silicofluoride ion. Specifically, for example, zirconium hydrofluoric acid, zirconium Hydrofluoric acid salt (eg, sodium salt, potassium salt, lithium salt, ammonium salt, etc.); Titanium hydrofluoric acid, titanium hydrofluoric acid salt (eg, sodium salt, potassium salt, lithium salt, ammonium salt, etc.), etc. Hydrosilicic acid, hydrosilicic acid salt (for example, sodium salt, potassium salt, lithium salt, ammonium salt, etc.) and the like.

  Further, vanadium compound (b1), silicon compound (b2), phosphoric acid calcium salt (b3), blended as necessary with respect to 100 parts by mass of the resin solid content of the water-soluble or water-dispersible resin (A). Each mixture of the compound (b4) that produces a fluoro metal ion was added to 10,000 parts by weight of a 5% strength by weight sodium chloride aqueous solution at 25 ° C., stirred for 6 hours, and allowed to stand at 25 ° C. for 48 hours. The pH of the filtrate obtained by filtering the supernatant is 3 to 8, preferably 4 to 6. The solubility of the rust preventive component mixture (B) by water and the reaction between the solution of the rust preventive component and the metal plate From the viewpoint of sex.

That is, the filtrate for pH measurement is any amount in the range of 1 to 30 parts by mass of the vanadium compound (b1) with respect to 10,000 parts by mass of a 5% by mass sodium chloride aqueous solution at 25 ° C. The amount of the silicon compound (b2) in the range of 1 to 30 parts by mass, and the amount of the phosphate calcium salt (b3) of 1 to 30 parts by mass. It is a filtrate of a dissolved solution added and dissolved in an amount of 1 to 30 parts by mass.

  The surface treatment composition of the present invention can be prepared by using the antirust component mixture (B), if necessary, a dispersion resin, a pigment such as a color pigment, an extender pigment, an organic tin compound, an ultraviolet absorber, and an ultraviolet stabilizer. Conventionally known additives such as agents, organic solvents, silane coupling agents, anti-settling agents, antifoaming agents, coating surface modifiers, and neutralizing agents (for example, acids, specifically, acetic acid, phosphoric acid, Lactic acid, or a mixture thereof) is blended, and blended as a dispersion paste obtained by dispersing in a dispersion mixer such as a ball mill, sand mill, or pebble mill.

  Use of phosphoric acid in the neutralizing agent is preferable from the viewpoint of improving the corrosion resistance of the obtained surface treatment film. The proportion of phosphoric acid in the surface treatment composition is 0.1 to 1.0 equivalent, preferably 0.3 to 0.8 equivalent, based on the functional group in the water-soluble or water-dispersible resin (A). Is good.

  As the dispersing resin, known ones can be used. For example, a base resin having a hydroxyl group and a cationic group, a surfactant, etc., or a tertiary amine type epoxy resin, a quaternary ammonium salt type epoxy resin, a tertiary sulfonium salt. Resins such as type epoxy resins can be used. The amount of the dispersing resin used is preferably 1 to 150 parts by mass, particularly 10 to 100 parts by mass per 100 parts by mass of the rust preventive component.

  Examples of the colored pigment include organic colored pigments such as cyanine blue, cyanine green, organic red pigments such as azo and quinacridone; and inorganic colored pigments such as titanium white, titanium yellow, bengara, carbon black, and various fired pigments. Among them, titanium white can be preferably used.

  Examples of the extender pigment include talc, clay, silica, mica, alumina, calcium carbonate, barium sulfate and the like. As the organic tin compound, dibutyltin dibenzoate, dioctyltin oxide, dibutyltin oxide and the like can be suitably used.

  The organic solvent described above is blended as necessary for improving the coating properties of the surface treatment composition of the present invention, and those capable of dissolving or dispersing the water-soluble or water-dispersible resin (A) can be used. Specifically, for example, hydrocarbon solvents such as toluene, xylene, high boiling petroleum hydrocarbons, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, ethyl acetate, butyl acetate, ethylene glycol monoethyl Ester solvents such as ether acetate and diethylene glycol monoethyl ether acetate, alcohol solvents such as methanol, ethanol, isopropanol and butanol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether The like can be illustrated ether alcohol solvents such as these can be used alone or in combination of two or more.

  Examples of the silane coupling agent include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycid. X-propyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane , Γ-aminopropyltrimethoxysilane, β-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N- (vinylbenzylamine) -β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane Etc. can be mentioned, which may be used alone or in combination of two or more.

  The surface treatment composition can be adjusted by adding the dispersion paste containing the antirust component mixture (B) as described above to the emulsion to be described later and adjusting with water.

  For the production of the surface treatment composition of the present invention, various compounds such as a water-soluble or water-dispersible resin (A), a blocked polyisocyanate compound, a resol type phenol resin, a surfactant, and a lubricant, as necessary. After thoroughly mixing additives, organic solvents, etc. to prepare a compounded resin, the compounded resin is water-soluble with organic carboxylic acids such as acetic acid, phosphoric acid, formic acid, propionic acid and lactic acid; inorganic acids such as hydrochloric acid and sulfuric acid. Or an aqueous dispersion to obtain an emulsion.

  The blocked polyisocyanate compound is an addition reaction product of a polyisocyanate compound and an isocyanate blocking agent in a substantially theoretical amount. As the polyisocyanate compound used in the blocked polyisocyanate compound, known compounds can be used. For example, tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, diphenylmethane-2,2′-diisocyanate, diphenylmethane-2 , 4′-diisocyanate, diphenylmethane-4,4′-diisocyanate, crude MDI [polymethylene polyphenyl isocyanate], bis (isocyanate methyl) cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, isophorone diisocyanate, and other aromatics, Aliphatic or alicyclic polyisocyanate compounds; cyclized polymers or vinyls of these polyisocyanate compounds Tsu DOO body; or a combination thereof can be mentioned.

In particular, aromatic polyisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, diphenylmethane-2,4′-diisocyanate, diphenylmethane-4,4′-diisocyanate, crude MDI are used from the viewpoint of the corrosion resistance of the planar portion. Is preferred.
In particular, by using hexamethylene diisocyanate as the isocyanate species, it is more preferable for improving the curability and improving the corrosion resistance of the processed part and the end face part in the precoated steel sheet because it can impart flexibility to the coating film.

  On the other hand, the isocyanate blocking agent is added to the isocyanate group of the polyisocyanate compound to block, and the blocked polyisocyanate compound produced by the addition is stable at room temperature, but the baking temperature of the coating film (100 to 200). It is desirable that the blocking agent can be dissociated to regenerate free isocyanate groups when heated to (° C.).

  Examples of the blocking agent used in the blocked polyisocyanate compound include oxime compounds such as methyl ethyl ketoxime, methyl amyl ketoxime, and cyclohexanone oxime; phenol compounds such as phenol, para-t-butylphenol, and cresol; n-butanol Aliphatic alcohols such as 2-ethylhexanol; aromatic alkyl alcohols such as phenyl carbinol and methyl phenyl carbinol; ether alcohol compounds such as ethylene glycol monobutyl ether and diethylene glycol monoethyl ether; ε-caprolactam, γ- And lactam compounds such as butyrolactam; and the like.

  The blending ratio of the blocked polyisocyanate compound blended as necessary is 1 to 60 parts by weight, preferably 10 based on 100 parts by weight of the resin solid content of the component (A). It is preferable in the range of -40 mass parts from a surface of a corrosion-resistant improvement.

The resol type phenol resin blended as necessary is a phenol resin obtained by condensing a phenol such as phenol or bisphenol A and an aldehyde such as formaldehyde in the presence of a reaction catalyst to introduce a methylol group, Also included are those in which part of the introduced methylol group is alkyl etherified with an alcohol having 6 or less carbon atoms.
The resol type phenol resin has a number average molecular weight (Note 1) in the range of 200 to 1,000, preferably 300 to 700, and an average number of methylol groups per nucleus of the benzene nucleus of 0.3 to 2. It is suitable that it is in the range of 5, preferably 0.5 to 2.0. By using the above-mentioned resol type phenolic resin, it is possible to form a coating film having excellent coating performance such as adhesion. As a commercial item of the said resole type phenol resin, Sumilite resin PR-55317 (the Sumitomo Bakelite company make, brand name), Shounol BKS-316, etc. are mentioned.

  For the production of the surface treatment composition, an emulsion containing a water-soluble or water-dispersible resin (A) is blended with a dispersion paste containing a rust preventive component mixture (B), and an additive and a neutralizing agent are added as appropriate. It is obtained by diluting with deionized water and adjusting so that the solid content is in the range of 1 to 30% by mass, preferably 5 to 20% by mass.

About the film formation method The surface treatment composition of this invention can obtain a coating metal plate by coating on a metal plate. The metal plate described above can be used as the metal plate. Here, FIG. 1 is a model diagram of a coating line when the surface treatment composition of the present invention is used as “surface treatment”. FIG. 2 shows a multilayer coating film using the surface treatment composition of the present invention.

  The coating using the surface treatment composition of the present invention can be applied to the metal plate by a known method such as a roll coating method, a curtain flow coating method, a spray method, a brush coating method, or a dipping method.

  Although the cured film thickness of the coating film obtained from a surface treatment composition is not specifically limited, Usually, 0.01-10 micrometers, Preferably it is used in the range of 0.1-5 micrometers. The curing of the coating film may be appropriately set according to the type of resin used, and when the material coated by the coil coating method is continuously baked, the maximum material reaching temperature is preferably 60 to 120 ° C., preferably Is baked under conditions of 80 to 100 ° C. for 1 second to 60 seconds, preferably 5 seconds to 30 seconds. The film formed by coating the surface treatment composition of the present invention on a metal plate exhibits excellent corrosion resistance.

  There are three reasons for this.

1. Directly without oxidation-reduction reaction between metal ions generated by dissolution of raw material metal such as chloride ions in a corrosive environment and pentavalent vanadium ions (VO ₃ ⁻ and VO ₄ ³⁻ vanadate ions) Formation of a precipitating salt, trivalent vanadium ion and raw material metal ion generated by the oxidation-reduction reaction of pentavalent vanadium ion and raw material metal effectively produce a precipitating salt or compound with silicate ion. Effectively covers the exposed surface of the material. Furthermore, it is considered that the corrosion progressing site and its periphery are adjusted to a pH range suitable for the oxidation-reduction reaction between the pentavalent vanadium ion and the material metal by the phosphate ions eluting at the same time.

  2. In the surface treatment composition, a part of the rust inhibitor is dissolved and exists in the form of metal ions. In the coating film obtained by applying this surface treatment composition to a metal material and drying by heating, this dissolved component reacts effectively on the interface of the material metal to form a film that functions as a chemical conversion treatment. To do. Furthermore, even if the surface to be coated is scratched on the coating film, the coating film has a function (self-healing property) to protect the scratches by elution of metal ions resulting from the antirust component mixture (B) from the coating film. Can be formed. The formation of the above-mentioned “film and coating film” can be achieved by a single coating and heat drying, which is considered to contribute greatly to obtaining a coated article having excellent corrosion resistance.

3. By using the vanadium compound (1), the silicate compound (2) and the phosphoric acid calcium salt (3) constituting the rust preventive component mixture in combination, each of the above (1), (2) and (3) Can effectively counteract the weak acid resistance, alkali resistance and water resistance. Furthermore, since calcium ions have an action of suppressing the dissolution of the material metal in a strong alkali atmosphere in which the material metal having a pH exceeding 10 is easily dissolved, excellent chemical resistance and water resistance can be achieved at the same time. The fact that the synergistic effect of the action based on these rust-preventive component mixtures worked greatly also contributes greatly to the excellent corrosion resistance of the surface treatment composition.
In addition, the glass transition temperature of the cured coating film obtained from the surface treatment composition of the present invention is 40 to 115 ° C., preferably 50 to 105 ° C. from the viewpoint of the corrosion resistance, acid resistance, workability, etc. of the coating film. Is preferred.
The glass transition temperature of the coating film was measured using a DINAMIC VISCOELASTOMETER MODEL VIBRON (Dynamic Visco Elastometer Model Vibron) DDV-IIEA (manufactured by Toyo Baldwin, automatic dynamic viscoelasticity measuring machine) at a frequency of 110 Hz. Is the maximum temperature obtained from the change in tan δ.
A top coat film can also be provided on the obtained coating film obtained by baking and drying the surface treatment composition (see FIG. 2). The film thickness of the top coat film is 5 to 100 μm, preferably 10 to 50 μm.
Examples of the above-mentioned top coating material include a known top coating material such as polyester resin-based, alkyd resin-based, silicon-modified polyester resin-based, silicon-modified acrylic resin-based, and fluororesin-based for pre-coated steel sheets. The type of top coating is not particularly limited, but especially when workability is particularly important, a coated steel sheet with particularly excellent workability can be obtained by using a polyester-based top coating for advanced processing. Obtainable.
In addition, when a galvanized steel plate or an aluminum-zinc alloy plated steel plate is used as the metal plate to be coated, the corrosion resistance of the flat surface portion has been considerably improved, but conventionally, the cut end surface portion and the processed processing Although corrosion resistance was insufficient in the parts, excellent corrosion resistance can be obtained also in the chemical resistance, the end face part, and the processed part by coating the surface treatment composition of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. In each example, “parts” indicates mass parts, and “%” indicates mass%.

Production and Production Example 1 of Water-soluble or Water-dispersible Resin (A) Cationic Epoxy Resin No. 1 1 Production example (epoxy resin)
In a flask equipped with a stirrer, thermometer, nitrogen inlet tube and reflux condenser, jER1004 (bisphenol A type epoxy resin, epoxy value 0.108 mol / 100 g, number average molecular weight 1650, manufactured by Japan Epoxy Resin Co., Ltd.) and acetic acid 25 parts of -3-methoxybutyl was heated and mixed at 100 ° C.
After confirming uniform dissolution, 2.75 parts of monoethanolamine was added, and the reaction was allowed to proceed for 2 hours. After confirming that the epoxy value was 0.018 mol / 100 g, 1.89 parts of diethanolamine was added, and the reaction was further continued for 1 hour. When the epoxy value became 0.005 mol / 100 g or less, it was diluted with a mixed solvent previously mixed with methyl ethyl ketoxime / xylene / butanol = 1/1/1 to obtain a cationic epoxy resin No. having a solid content of 65%. . 1 was obtained.

Production Example 2 Cationic Epoxy Resin No. Example 2 (urethane-modified)
In a flask equipped with a stirrer, thermometer, nitrogen inlet tube and reflux condenser, jER1004 (bisphenol A type epoxy resin, epoxy value 0.108 mol / 100 g, number average molecular weight 1650, manufactured by Japan Epoxy Resin Co., Ltd.) and acetic acid 25 parts of -3-methoxybutyl was heated and mixed at 100 ° C. After confirming that the solution was uniformly dissolved, 6.75 parts of n-methylethanolamine was added and the reaction was allowed to proceed for 2 hours. After confirming that the epoxy value was 0.018 mol / 100 g, 11.1 parts of a pre-mixed methyl ethyl ketoxime / xylene = 1/1 mixed solvent was added, and the reaction temperature was cooled to 40 ° C. After confirming that it was uniformly dissolved, 7.56 parts of hexamethylene diisocyanate was added and the reaction was carried out for 1 hour. Thereafter, the reaction temperature was again raised to 100 ° C., 1.89 parts of diethanolamine was added, and the reaction was further continued for 1 hour. When the epoxy value became 0.005 mol / 100 g or less, it was diluted with a mixed solvent previously mixed with methyl ethyl ketoxime / xylene / butanol = 1/1/1 to obtain a urethane-modified cationic epoxy having a solid content of 65%. Resin No. 2 was obtained.

Production Example 3 Cationic Epoxy Resin No. Example 3 (2 basic acid modified system)
In a flask equipped with a stirrer, thermometer, nitrogen inlet tube and reflux condenser, jER1004 (bisphenol A type epoxy resin, epoxy value 0.108 mol / 100 g, number average molecular weight 1650, manufactured by Japan Epoxy Resin Co., Ltd.) and acetic acid 25 parts of -3-methoxybutyl was heated and mixed at 100 ° C. After confirming uniform dissolution, 10 parts of Tsunodim 205 (dimer acid, manufactured by Tsukino Food Industry Co., Ltd.) was added and the reaction was carried out for 2 hours. After confirming that the acid value was 0.5 mgKOH / g or less, 2.36 parts of monoethanolamine was added, and the reaction was continued for 2 hours. After confirming that the epoxy value was 0.018 mol / 100 g, 1.89 parts of diethanolamine was added, and the reaction was further continued for 1 hour. When the epoxy value became 0.005 mol / 100 g or less, it was diluted with a mixed solvent previously mixed in methyl ethyl ketoxime / xylene / butanol = 1/1/1 to obtain a dimer acid-modified product having a solid content of 65%. Cationic epoxy resin no. 3 was obtained.

Emulsion Production Example Production Example 4 Emulsion No. Production Example 1 Cationic Epoxy Resin No. 1 obtained in Production Example 1 After mixing 153.8 parts (solid content 100 parts) and 20 parts of ethylene glycol monobutyl ether, and further mixing 30.3 parts of 10% acetic acid and stirring uniformly, deionized water 129.2
The solution was dripped over about 30 minutes with vigorous stirring, and emulsion No. 30 having a resin solid content of 30% was added. 1 was obtained.

Production Examples 5 to 12 Emulsion No. 2-No. Production Example 9 Emulsion No. 9 was prepared in the same manner as in Production Example 4 except that the contents shown in Table 1 were used. 2-No. 9 was obtained.

  (Note 2) Desmodur BL-3175: Sumika Bayer Urethane Co., Ltd., a solution of hexamethylene diisocyanate nurate blocked with methyl ethyl ketoxime, solid content 75%.

  (Note 3) Duranate MF-K60X: manufactured by Asahi Kasei Chemicals Corporation, a low-temperature curable blocked polyisocyanate resin solution, solid content 60%.

Production Example 13 Production Example of Dispersing Resin jER828EL (Note 4) 1010 parts, 390 parts of bisphenol A, Plaxel 212 (polycaprolactone diol, Daicel Chemical Industries, Ltd., trade name, weight average molecular weight of about 1,250) 240 parts And 0.2 part of dimethylbenzylamine was added and reacted at 130 ° C. until the epoxy equivalent reached about 1,090.
Next, 134 parts of dimethylethanolamine and 150 parts of a 90% aqueous lactic acid solution were added and reacted at 120 ° C. for 4 hours. Next, methyl isobutyl ketone was added to adjust the solid content, and an ammonium salt type resin dispersion resin having a solid content of 60% was obtained. The ammonium salt concentration of the dispersing resin was 0.78 mmol / g.

  (Note 4) jER828EL: Japan Epoxy Resin, trade name, epoxy resin.

Production Example 14 Dispersion Paste No. Production Example 1 1 8.3 parts of a resin having a solid content of 60% obtained in Production Example 10 (5 parts solid content),
Add 2 parts of vanadium pentoxide, 1 part of calcium metasilicate, 2 parts of calcium phosphate, 20 parts of titanium white, 20 parts of barrita and 37.6 parts of deionized water, and disperse in a ball mill for 20 hours. Dispersion was carried out until the particle diameter of the particles became 5 μm or less, and a dispersion paste No. 1 was obtained.

Production Examples 15 to 32
A dispersion paste No. 1 was prepared in the same manner as in Production Example 14 except that the contents of Table 2 were used. 2-No. 19 was obtained.

Comparative Production Examples 1-10
A dispersion paste No. 1 was prepared in the same manner as in Production Example 14 except that the blending contents shown in Table 4 were used. 20-No. 29 was obtained.

Production Example 33 Production of resol type phenolic resin crosslinking agent solution
In a reaction vessel, 100 parts of bisphenol A, 178 parts of 37% formaldehyde aqueous solution and 1 part of sodium hydroxide were blended, reacted at 60 ° C. for 3 hours, and dehydrated at 50 ° C. for 1 hour under reduced pressure. Subsequently, 100 parts of n-butanol and 3 parts of phosphoric acid were added and reacted at 110 to 120 ° C. for 2 hours. After completion of the reaction, the resulting solution was filtered to remove the sodium phosphate produced to obtain a resol type phenolic resin crosslinking agent solution having a solid content of about 50%. The obtained resin had a number average molecular weight of 880, an average number of methylol groups per benzene nucleus of 0.4, and an average number of alkoxymethyl groups of 1.0.

Example 1 Surface treatment agent No. 1 Production of emulsion No. 1 obtained in Production Example 4 1 333.3 parts (solid content 100 parts), 55% dispersion paste No. 1 obtained in Production Example 14. 1 was mixed with 90.9 parts (solid content 50 parts) and deionized water 236.2 parts to obtain a surface treatment agent No. 1 having a solid content of 20%. 1 was obtained.

Examples 2-32 Surface treatment agent No. 2-No. 32 Production of a surface treatment agent No. 32 having a solid content of 20% was performed in the same manner as in Example 1 except that the formulations shown in Tables 5 and 6 below were used. 2-No. 32 was obtained.

(Note 6) KBE-903: γ-aminopropyltriethoxysilane: manufactured by Shin-Etsu Chemical Co., Ltd., trade name, silane coupling agent.

  (Note 7) KBE-603: N-β (aminoethyl) γ-aminopropyltrimethoxysilane: manufactured by Shin-Etsu Chemical Co., Ltd., trade name, silane coupling agent.

  (Note 8) KBM-803: γ-mercaptopropyltrimethoxysilane: manufactured by Shin-Etsu Chemical Co., Ltd., trade name, silane coupling agent.

  (Note 9) KBE-403: γ-glycidoxypropyltrimethoxysilane: manufactured by Shin-Etsu Chemical Co., Ltd., trade name, silane coupling agent.

Comparative Examples 1-10
Except for the formulation shown in Table 7 below, the surface treatment agent No. 33-No. 42 was obtained.

[Preparation of test paint plate]
Each surface treating agent No. obtained in the said Examples 1-32 and Comparative Examples 1-10. 1-No. No. 42 was used, and each test plate was obtained by painting and baking each material according to the following coating specifications 1 and 2.

Paint specification 1
A hot-dip galvanized steel sheet (thickness 0.35 mm, galvanized basis weight 250 g / m ² , abbreviated as “GI steel sheet” in the table), an alkaline degreasing agent “CC-561B” manufactured by Nippon CB Chemical Co., Ltd. with a concentration of 2% After degreasing by spraying for 20 seconds at a liquid temperature of 65 ° C., the solution was sprayed with hot water at a liquid temperature of 60 ° C. for 20 seconds and washed with hot water.
On this degreased steel sheet, each surface treatment agent obtained in Examples and Comparative Examples was coated with a bar coater so as to have a dry film thickness of 2 μm, and placed in a conveyor oven for 20 seconds at 120 ° C. (maximum material arrival temperature). And dried by heating to obtain test plates GI-1 to GI-42.
On these test plates (A), KP color 1580B40 (manufactured by Kansai Paint Co., Ltd., trade name, polyester-based top coating, blue, glass transition temperature of cured coating film about 70 ° C.) was dried with a bar coater. The coating was applied to a thickness of 15 μm and baked for 40 seconds at a maximum material temperature of 220 ° C. to obtain a coating test plate.

Paint specification 2
Electrogalvanized steel sheet (plate thickness: 0.35 mm, plating basis weight: 150 g / m ² , indicated as “EG steel sheet” in the table), alkaline degreasing agent “CC-561B” manufactured by Nippon CB Chemical Co., Ltd. with a concentration of 2% After degreasing by spraying at a liquid temperature of 65 ° C. for 20 seconds, spraying with hot water at a liquid temperature of 60 ° C. for 20 seconds was followed by washing with hot water.
On this degreased steel sheet, each surface treatment agent obtained in Examples and Comparative Examples was coated with a bar coater so as to have a dry film thickness of 1 μm, and then placed in a conveyor oven at 120 ° C. (maximum material arrival temperature) for 20 seconds. And dried by heating to obtain test plates EG-1 to EG-42.
Next, on these test plates EG-1 to EG-42, a Magiclon 1000 (acrylic resin / melamine-based paint) was applied by spraying so as to have a dry film thickness of 30 μm, and a box type set at a furnace temperature of 180 ° C. It was heated and dried for 30 minutes in a drying furnace to obtain a coating test plate.

Coating Film Performance Test Regarding the test plates GI-1 to GI-42 and the respective coating test plates obtained in Examples 1 to 32 and Comparative Examples 1 to 10, the test plates EG-1 to EG-42, and the respective coating test plates. The coating film performance test was conducted according to the following test method. The test results are shown in Tables 8 to 10.

Test method (Note 11) Salt spray test (surface treatment): Each test plate cut to a size of 5 cm x 10 cm (a test plate not coated with a top coating material according to coating specification 1 or a top coating material according to coating specification 2) The back surface and the cut surface of the test plate (uncoated) were sealed with a rust preventive paint, and a cross cut reaching the substrate was put in the center of the surface of the painted plate. The coated plate was subjected to a salt spray test (JIS Z-2371) with 5% saline at 35 ° C. for 168 hours to evaluate the occurrence of white rust and red rust on the coated surface after the test, and the average progressed from the crosscut portion The corrosion width (one side) was evaluated.
A: White rust and red rust are not generated or slight, and the average corrosion width from the cut portion is less than 3 mm.
○: Although occurrence of white rust is recognized, the average corrosion width from the cut is less than 3 mm, or the tape peeling width from the cut portion is less than 7 mm although the white rust is not generated or is slight.
(Triangle | delta): Generation | occurrence | production of white rust is recognized by the whole and the average corrosion width | variety from a cut is 3 mm or more and less than 7 mm.
X: The occurrence of red rust is observed, or the average corrosion width from the cut exceeds 7 mm on one side although no red rust is generated.

(Note 12) Salt spray test (after alkaline degreasing): Each coated test plate cut to a size of 5 cm x 10 cm (test plate not coated with topcoat paint according to coating specification 1 or topcoat paint according to coating specification 2) The back surface and the cut surface of the test plate) were sealed with a rust preventive paint, and a cross cut reaching the substrate was put in the center of the surface of the painted plate.
Next, this coated plate was immersed in a 2% Pulclean N364S (manufactured by Nihon Parkerizing Co., Ltd., alkaline degreasing agent) solution heated to 50 ° C. for 2 minutes, and then taken out and washed. This coated plate was subjected to a salt spray test (JIS Z-2371) with 5% saline at 35 ° C. for 96 hours to evaluate the occurrence of white rust and red rust on the coated surface after the test, and proceeded from the crosscut portion. The corrosion width (one side) was evaluated.
A: White rust and red rust are not generated or slight, and the average corrosion width from the cut portion is less than 3 mm.
○: Although occurrence of white rust is recognized, the average corrosion width from the cut is less than 3 mm, or the tape peeling width from the cut portion is less than 7 mm although the white rust is not generated or is slight.
Δ: Whether white rust is observed on the whole and the average corrosion width from the cut is 3 mm or more and less than 7 mm.
X: The occurrence of red rust is observed, or the average corrosion width from the cut exceeds 7 mm on one side although no red rust is generated.

(Note 13) Adhesion to water: Each test coating plate cut to a size of 5 cm × 10 cm is immersed in boiling water at about 100 ° C. for 2 hours, and then pulled up and the coating film appearance on the surface (front surface) side In addition, a cross-cut tape adhesion test was conducted for evaluation.
The cross-cut tape adhesion test is performed in accordance with JIS K-5600-5-6 (1999) cross-cut tape method, with a gap spacing of cuts of 1 mm, making 100 cross-cuts, and attaching cellophane adhesive tape to the surface. Then, the number of grids remaining on the coated surface after abrupt peeling was examined.
A: There is no abnormality such as blistering or whitening in the coating film, and there are 100 remaining grids,
○: There are no abnormalities such as blistering and whitening in the coating film, and a residual grid number of 91 to 99,
Δ: Slightly abnormalities such as blistering or whitening were observed in the coating film, and the residual grid number was 91 to 99, or the coating film had no abnormality such as blistering or whitening, but the residual grid number was 71 to 99. 90 pieces
X: Generation | occurrence | production of the swelling of a coating film is recognized fairly or remarkably, or the number of remaining grids is 70 or less.

(Note 14) Alkali resistance: The back and cut surfaces of each test paint plate cut to a size of 5 cm × 10 cm were sealed with a rust-proof paint, and a cross cut reaching the substrate was put in the center of the front side of the paint plate. . This coated plate was immersed in a 5% aqueous sodium hydroxide solution at 20 ° C. for 24 hours, then taken out, washed, and evaluated for the appearance of the coating on the surface side of the coated plate dried at room temperature. Was peeled off, and the peel width (one side) from the cut portion in the coating film after peeling off was evaluated.
A: There is no occurrence of swelling, and the tape peeling width from the cut part is 1.5 mm or less.
○: There is no occurrence of blisters, and the tape peeling width from the cut part exceeds 1.5 mm, 3 mm or less,
Δ: Slight occurrence of swelling is observed, but tape peeling width from the cut portion is 3 mm or less, or occurrence of swelling is not recognized, but the tape peeling width from the cut portion exceeds 3 mm,
X: Generation | occurrence | production of a swelling is recognized and the tape peeling width from a cut part exceeds 3 mm.

(Note 15) Acid resistance: The back and cut surfaces of each test paint plate cut to a size of 5 cm × 10 cm were sealed with a rust preventive paint, and a cross cut reaching the substrate was put in the center of the front side of the paint plate. . This coated plate was immersed in a 5% sulfuric acid aqueous solution at 20 ° C. for 24 hours, then taken out, washed, and evaluated for the appearance of the coating on the surface side of the coated plate dried at room temperature. The peel width (one side) from the cut portion in the coating film after being peeled off rapidly was evaluated.
A: There is no occurrence of swelling, and the tape peeling width from the cut part is 1.5 mm or less.
○: There is no occurrence of swelling, and the tape peeling width from the cut part exceeds 1.5 mm and is 3 mm or less.
Δ: Slight occurrence of swelling is observed, but tape peeling width from the cut portion is 3 mm or less, or occurrence of swelling is not recognized, but the tape peeling width from the cut portion exceeds 3 mm,
X: Generation | occurrence | production of a swelling is recognized and the tape peeling width from a cut part exceeds 3 mm.

(Note 16) Combined cycle corrosion test: According to JIS K-5621 (1990). For each test, cut to a size of 6 cm x 12 cm so that the burrs at the edge of the long side of each test coating plate face the front side on the right side toward the front side and the back side on the left side. Insert a cross cut with a narrow angle of 30 degrees and a line width of 0.5 mm into the center of the surface side of the paint board using the back of the cutter knife, and seal the top edge of the paint board with anticorrosive paint. Is provided with a 4T bending portion (processing to bend with the surface side of the coated plate facing outward, sandwiching four plates of the same thickness as the painted plate inside, and bending the painted plate 180 degrees in a vise) About the coated plate (5% saline sprayed at 30 ° C. for 0.5 hour)-(Test for 1.5 hours in a humidity tester of RH 95% or higher at 30 ° C.)-(Dry at 50 ° C. for 2 hours)-(30 Drying at 2 ° C for 2 hours is one cycle and 300 cycles (total Was 1800 hours) test. The state of the edge part, cross cut part, and 4T bending process part of the coating board after this test was evaluated.
(4T process part) The total length of the rust part in a 4T process part was evaluated.
A: No occurrence of rust,
○: White rust is observed, but less than 20 mm,
Δ: White rust is 20 mm or more and less than 40 mm,
X: Generation | occurrence | production of white rust 40 mm or more or red rust is recognized.
(Edge part) The average value of the edge creep widths of the left and right long sides of the coated plate was determined and evaluated according to the following criteria.
A: Less than 5 mm
○: 5 mm or more and less than 10 mm,
Δ: 10 mm or more and less than 20 mm,
X: 20 mm or more.
(Cross cut part) Corrosion state of the cross cut part, by the average value of the white rust occurrence length ratio in the bare metal exposed part of 0.5mm cut width, and the left and right swelling width (sum of both sides) of the cut part, Evaluation was made according to the following criteria.
A: White rust generation length ratio in exposed metal portion is less than 50% and swelling width is less than 3 mm,
○: The white rust generation length ratio in the bare metal exposed portion is 50% or more and less than 3 mm, or the white rust occurrence length ratio in the bare metal exposed portion is less than 50% and the swelling width is 3 mm or more and less than 5 mm,
Δ: White rust generation length ratio in exposed metal portion is 50% or more and swelling width is 5 mm or more and less than 10 mm,
X: The white rust generation length ratio in the bare metal exposed part is 50% or more and the swelling width is 10 mm or more.

(Note 17) Salt spray test: The back and cut surfaces of each test paint plate cut to a size of 5 cm × 10 cm were sealed with a rust-proof paint, and a cross cut reaching the substrate was put in the center of the surface of the paint plate. . The coated plate is subjected to a salt spray test (JIS Z-2371) with 5% saline at 35 ° C. for 360 hours to evaluate the white rust occurrence state of the coated surface after the test, and adhere the cellophane adhesive tape to the crosscut portion. The tape peeling width (one side) from the cut portion in the coating film after being peeled off rapidly was evaluated.
A: There is no or little occurrence of red rust and white rust, and the tape peeling width from the cut part is less than 5 mm,
○: The occurrence of red rust and white rust is slight, but the tape peel width from the cut part is 5 mm or more and less than 10 mm, or the occurrence of red rust and white rust is somewhat recognized, but the tape peel width from the cut part Is less than 5 mm.
Δ: Some occurrence of red rust and white rust was observed in the entire cut part, and the tape peeling width from the cut part was 5 mm or more and less than 10 mm.
X: Generation | occurrence | production of red rust is recognized by the whole cut part, or the tape peeling width from a cut part is 10 mm or more.

  The surface treatment composition of the present invention can provide a coated metal plate or a coated article excellent in the corrosion resistance of the flat portion and the corrosion resistance of the processed portion and the end surface portion.

An example of a continuous coil coating line is shown. The coating-film structure of the coating film containing the surface treatment composition of this invention is shown.

Explanation of symbols

1. Shows the iron surface.
2. A plating layer is shown.
3. The processing layer using the surface treatment composition of this invention is shown.
4). An undercoat film is shown.
5). The top coat film is shown.

Claims (6)

A surface treatment composition having a solid content of 1 to 30% by mass, comprising a water-soluble or water-dispersible resin (A) and the following antirust component mixture (B).
Antirust component mixture (B): a composition comprising at least one of vanadium pentoxide, calcium vanadate and ammonium metavanadate (b1), silicon compound (b2), and phosphate calcium salt (b3) Because
1 to 30 parts by mass of the vanadium compound (b1) and 1 to 30 parts by mass of the silicon compound (b2) with respect to 100 parts by mass of the resin solid content of the water-soluble or water-dispersible resin (A). And the amount of the phosphoric acid calcium salt (b3) is 1 to 30 parts by mass, and the amount of the antirust component mixture (B) is 3 to 90 parts by mass. Furthermore, the surface treatment composition of Claim 1 which contains 1-30 mass parts of compounds (b4) which produce a fluoro metal ion with respect to 100 mass parts of resin solid content of water-soluble or water-dispersible resin (A). . The surface treatment composition according to claim 1 or 2, wherein the water-soluble or water-dispersible resin (A) is an amino group-containing epoxy resin. The surface treatment according to any one of claims 1 to 3, comprising 0.1 to 10 parts by mass of a resol type phenol resin with respect to 100 parts by mass of the resin solid content of the water-soluble or water-dispersible resin (A). Composition. A cured coating film having a thickness of 0.01 to 10 μm is formed on the metal substrate using the surface treatment composition according to any one of claims 1 to 4, and the material arrival temperature is 80 ° C. to 120 ° C. for 1 second to 60 seconds. A film-forming method, characterized by heating and drying. A surface-treated metal plate obtained by the film forming method according to claim 5.

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