JPH1136081A - Aqueous resin-containing chromate composition for metallic material and production of functional galvanized steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a treating soln. composition for producing a surface treated galvanized steel sheet excellent in white rust-resistance, blacking resistance and fingerprint resistance in one stage by allowing the comps. to contain organic components having a specified comps. and organic components contg. resin and a surfactant. SOLUTION: The inorganic components contain Cr<6+> and Cr<3+> in the range of 1/10 to 8/10 by weight and contain one or more kinds among NO3 <-> , SO4 <2-> and BO3 <3-> by 0.1 to 4.0 by the molar ratio to all Cr ions. The organic components contain resin contg. one or more kinds of high polymer compds. and either or both surfactants of a nonionic surfactant and a nonionic-anionic composite surfactant, in which the resin is stably dispersed into water by the surfactant, and the weight ratio of the solid content expressed by (the surfactant)/(the resin + the surfactant) is regulated to the range of 0.05/100 to 40/100. Then, the weight ratio of (the resin + the surfactant)/(Cr<6+> +Cr<3+> ) is regulated to the range of (2/1) to (300/1), and the pH is regulated to <=3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chromate composition containing an aqueous resin for a metal material and a method for producing a functional zinc-coated steel sheet. More specifically, the present invention does not require a preliminary pretreatment of Co, Ni or the like or a resin coat, and achieves corrosion resistance (white rust resistance), blackening resistance, and fingerprint resistance by one-step chromate treatment. Excellent galvanized steel sheet, etc. (Electro-galvanized, hot-dip galvanized, hot-dip zinc-5% aluminum-containing plated, hot-dip zinc 55%
The present invention relates to an aqueous resin-containing chromate composition for a metal material for producing aluminum-containing plating, vapor-deposited zinc plating, and the like, and a method for producing a functional zinc-coated steel sheet.

[0002]

2. Description of the Related Art Since sacrificial corrosion protection by galvanizing steel is the most effective and economical, currently about 10% of the annual crude steel production in Japan is produced as galvanized steel sheet, and it is used for building materials, automobiles and home appliances. It is used in a wide range of fields. The sacrificial corrosion protection by zinc is based on the formation of a battery in a situation where two metals, zinc and steel, are in contact with each other, and zinc, which is a more noble metal, serves as an anode, turns iron into a cathode, and forms a local battery in the case of iron alone. It is to prevent anodic dissolution and corrosion of steel. Therefore, the rust prevention action ends when the zinc in contact with the steel disappears, so it is necessary to suppress the corrosion of the zinc layer in order to maintain its action and effect. Processing has been performed.

[0003] However, although rust prevention by chromate treatment of zinc-based plating remarkably prevents the generation of white rust, black rust (referred to as blackening reduction) which is a problem in appearance during the stock period or during transportation occurs. There is a problem that is easy to do. In recent years, in the field of construction materials, in order to be maintenance-free, hot-dip galvanized steel sheet is more excellent in corrosion resistance than hot-dip galvanized steel sheet (referred to as galfan or super zinc) or hot-dip galvanized steel sheet (55% aluminum). (Galvalume) has been widely used, and it is known that these materials are very susceptible to blackening. Black discoloration (black rust) is considered to be a basic zinc carbonate represented by (ZnCO). [Zn (OH)] like white rust, but it is oxygen deficient in stoichiometry. It is said to be different from white rust. Blackening is a corrosion product in a situation of lack of oxygen, and particularly in the case of a hot-dip galvanized steel sheet, blackening is promoted by the added aluminum.

As a method for solving this problem, that is, a problem of black rust after chromate treatment, a method disclosed in Japanese Patent Application Laid-Open No. S59-17738 is currently available.
It is known that a flash treatment using an aqueous solution containing Ni and Co (a treatment for chemically depositing a trace amount of metal, the same applies hereinafter) is effective, as seen in Japanese Patent Publication No. 1 (1993) -107, etc. However, although the blackening resistance (suppression of the generation of black rust) is certainly improved by this method, white rust is more likely to be generated, so that there is a problem that the original purpose of the chromate treatment is lost. This is a process in which the flash treatment is performed to replace Ni and Co, which are more noble metals with respect to the zinc metal in the plating, in a metallic state on the surface of the galvanized plating. It is considered to form a local cell with a metal.

[0005] As a method for solving this problem by one-step processing, (1) Japanese Patent Application Laid-Open No. Hei 5-331659 and (2) Japanese Patent Application Laid-Open No. 7-54156 are disclosed. According to these, it is disclosed that white rust resistance and black rust resistance can be improved in a well-balanced manner by adding a specific amount of a specific anion or cation to a chromate treatment solution. However, there is no description or even suggestion of further increasing the corrosion resistance or imparting functions (fingerprint resistance, lubricity, etc.) by adding a resin or the like.

[0006] In addition to the above-mentioned chromate-treated steel sheet for the purpose of temporary rust prevention, a zinc-based plated steel sheet, as well as a fingerprint-resistant steel sheet or a lubricated steel sheet (pressed without press oil) as a functional surface-treated steel sheet having higher corrosion resistance. Processing is possible).

As these surface-treated steel sheets, those subjected to a two-process treatment in which a zinc-plated surface is subjected to a chromate treatment and then coated with an organic resin are mainly used.
Recently, a one-step process (chromate treatment containing a resin) has been put to practical use in order to reduce the surface treatment process.

Various techniques have been disclosed so far for the one-step process of the prior art, for example, (3) JP-B-7-6070, (4) JP-A-3-219086,
(5) JP-A-5-279867, (6) JP-A-6-1
No. 92850, (7) JP-A-6-93461, (8)
JP-A-9-3657, (9) JP-A-7-11453 and JP-A-5-287548 are mentioned.

The above prior arts (3) to (9) relate to a resin-containing aqueous chromate treatment composition containing a chromate component, a resin and a nonionic activator as main components. The surface-treated galvanized steel sheet produced by these treatments was excellent in white rust resistance and fingerprint resistance, but was completely insufficient in blackening resistance.

[0010] Further, (10) relates to a chromate treatment mainly comprising an aqueous resin polymerized by using a chromate component and an anionic emulsifier and a water-soluble polymer polyol. Since this aqueous resin does not substantially contain a nonionic emulsifier, the stability of the emulsion against the oxidizing power of chromic acid is not good, so that the pot life was insufficient.

Therefore, a surface treatment composition and a production method capable of producing a galvanized steel sheet having excellent white rust resistance, blackening resistance and fingerprint resistance in one step have not been obtained at present.

[0012]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has a high resistance to white rust.
The object of the present invention is to provide a method for producing a water-based resin-containing chromate composition for a metal material and a functional galvanized steel sheet used for producing a surface-treated galvanized steel sheet having excellent blackening resistance and fingerprint resistance in one step. Is what you do.

[0013]

The inventors of the present invention have conducted intensive studies on means for solving the problems of the prior art, and as a result, have found that an aqueous resin-containing chromate containing an inorganic component and a resin component having a specific composition. By using the composition,
The inventor has newly found that the above-mentioned problem can be solved, and has completed the present invention.

That is, the aqueous resin chromate treatment composition for a metal material of the present invention comprises (1) a hexavalent chromium ion (Cr) and a trivalent chromium ion (Cr) in a weight ratio of Cr / (Cr + Cr) of 1 / And at least one inorganic acid ion selected from the group consisting of nitrate ions (NO), sulfate ions (SO) and borate ions (BO) in moles relative to total chromium ions (Cr + Cr). An inorganic component having a ratio of 0.1 to 4.0, and (2) (a)
Nonionic surfactant having at least one nonionic moiety selected from a resin containing at least one polymer compound and (b) a polyethylene glycol group and a polyethylene oxide group formed by addition polymerization of two or more molecules of ethylene oxide. Or a surfactant containing any one or both of a nonion-anion composite surfactant having the nonionic portion and the anion portion, wherein the resin is stably dispersed in water by the surfactant, and (b) ) / ((A) + (b)) (solid content weight ratio) is 0.0
An organic component in the range of 5/100 to 40/100, and a weight ratio of ((a) + (b)) / (Cr + Cr) ((a) + (b) is a weight as a solid content. Is in the range of 2/1 to 300/1 and the pH is 3 or less.

The inorganic component further comprises Zn, Ni, Co, A
It preferably contains at least one metal ion selected from the group consisting of l, Ti, and Zr.

[0016] The method for producing a functional zinc-coated steel sheet of the present invention comprises the step of applying an aqueous treatment liquid containing the aqueous resin-containing chromate composition for a metal material to the surface of the zinc-coated steel sheet;
It is characterized by drying to form a resin chromate film of 5 to 100 mg / m in chromium deposition amount (in terms of chromium metal) on the surface of the steel sheet.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail. Although the aqueous resin-containing chromate composition for a metal material of the present invention can be applied to various metal materials, it is particularly preferably used for a galvanized steel sheet. Examples of the galvanized steel sheet include an electrogalvanized steel sheet, a hot-dip galvanized steel sheet, a hot-dip galvanized steel sheet containing 5% aluminum, and a hot-dip galvanized steel sheet.
55% aluminum-containing plated steel sheet, vapor-deposited galvanized steel sheet and the like.

The aqueous resin-containing chromate composition for a metal material of the present invention is an aqueous composition for subjecting a galvanized steel sheet to a chromate treatment and a resin treatment in one step, and therefore basically contains a chromate component (inorganic component). Resin component (organic component)
It is composed of

First, the chromium component of the inorganic component (1) will be described. The inorganic component (1) is hexavalent chromium ion (C
r) and trivalent chromium ions (Cr), and the weight ratio Cr / (Cr + Cr) thereof is preferably 1/10 to 8/10, more preferably 1/10 to 7/10. . If this ratio is less than 1/10, the amount of trivalent chromium component that serves as the skeleton of the chromate film is small, so that the chromate film is easily eluted, which may lead to a decrease in corrosion resistance and environmental pollution. Exceeding the ratio is not preferable because the hexavalent chromium ion is small and the corrosion resistance may be insufficient.

Next, the inorganic component (1) of the present invention comprises nitrate ion (NO), sulfate ion (SO) and borate ion (B
O), at least one inorganic acid ion selected from the group consisting of the above-mentioned at least one inorganic acid ion / (C
(r + Cr) (molar ratio) is preferably 0.1 to 4.0, more preferably 0.3 to 3.0.
If the molar ratio to the total chromium ions is less than 0.1, the effect of preventing blackening is insufficient, and if it exceeds 4.0, the effect is saturated, which is economically disadvantageous. The addition is usually nitric acid,
The reaction is carried out in the form of sulfuric acid or boric acid, but metal salts containing these acids may be used.

The pH of the aqueous resin-containing chromate treatment composition for a metal material of the present invention is preferably 3 or less,
More preferably, it is 0.1 to 2.5. This is because, since the trivalent chromium in the chromate component is present as a cation ion, if the pH exceeds 3, it becomes unstable in the treatment solution, and may form a precipitate or gel. The acid for adjusting the pH of the treatment liquid to 3 or less is not particularly limited. For example, phosphoric acid, chromic acid, dichromic acid, nitric acid, boric acid, hydrofluoric acid, inorganic acids such as hydrogen fluoride compound, formic acid, Organic carboxylic acids such as acetic acid, glycolic acid, citric acid, tartaric acid, malic acid, acrylic acid, methacrylic acid, maleic acid, acrylic acid, methacrylic acid,
A homopolymer or a copolymer of a carboxylic acid having vinyl polymerizability such as maleic acid can be applied. Phosphoric acid, hydrofluoric acid, and hydrogen fluoride compounds have the effect of slightly coloring the chromate film and improving the corrosion resistance, but reduce the blackening resistance. It is necessary to

The inorganic component (1) of the present invention preferably further contains a metal ion, as long as it can be dissolved in the chromate solution of the present invention, and is particularly selected from the group consisting of Zn, Ni, Co, Al, Ti, and Zr. At least one metal ion is effective for improving corrosion resistance and is preferred. Alkali metals such as Na and K are not preferred because they lower the water resistance of the film and consequently the corrosion resistance. The addition amount of the metal ion is added in consideration of the balance between the anion component and the cation component in the treatment liquid. Although the amount of addition is not particularly limited, the molar ratio to the total chromium ions, that is, the specific metal ion / total chromium ion molar ratio is 0.1%.
It is preferably from 0.5 to 4, and more preferably from 0.1 to 3. If it is less than 0.05, the effect of improving the corrosion resistance is small, and if it is more than 4, the stability of the treatment liquid may be reduced (generation of precipitates or gelation). The method of adding metal ions is not particularly limited, but inorganic salts such as nitrates, sulfates, chromates, carbonates, hydroxides, and oxides are preferably used because they are simple and convenient.

Next, the aqueous resin component which is the main component of the organic component (2) will be described. The type of the resin used in the present invention is not particularly limited, but most of general-purpose aqueous resin emulsions cannot be stably dispersed in an acidic chromate solution, and thus are stably dispersed with an emulsifier containing a nonionic portion. It must be a resin emulsion (a). As the type of the resin, an acrylic resin, a polyester resin, an epoxy resin, a urethane resin, or the like can be used.

The acrylic resin used in the present invention is not particularly limited. Examples thereof include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate,
Ethylhexyl acrylate, methyl methacrylate,
Ethyl methacrylate, isopropyl methacrylate,
Butyl methacrylate, isobutyl methacrylate, n
-Hexyl methacrylate, lauryl methacrylate,
Maleic acid, itaconic acid, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, acrylamide, N-methylol acrylamide, diacetone acrylamide, glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile, etc. And a polymer obtained from the above monomer. Known polymerization methods include solution polymerization, suspension polymerization, and emulsion polymerization, but are not particularly limited in the present invention.

The polyester resin used in the present invention is not particularly limited. Examples thereof include ethylene glycol, diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, hexamethylene glycol, hydrogenated bisphenol A, trimethylolpropane, glycerin, etc. Reaction of low molecular weight polyols with polybasic acids such as succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, endmethylenetetrahydrophthalic acid, hexahydrophthalic acid There is a polymer obtained.

The epoxy resin used in the present invention is not particularly limited. Examples thereof include bisphenol A, bisphenol F, an addition polymerization product obtained by reacting tetrabromobisphenol A with epichlorohydrin, phenol novolak resin, and orthophenol. Addition product obtained by the reaction of cresol novolak resin with epichlorohydrin, cycloaliphatic epoxy resin having a functional group such as cyclohexene oxide group, tricyclodecene oxide group, cyclopentene oxide group, diglycidyl phthalate, tetrahydrophthalic acid Glycidyl ester resins such as diglycidyl ester, hexahydrophthalic acid diglycidyl ester, diglycidyl p-oxybenzoic acid, glycidyl dimer acid,
Glycidylamine resins such as N, N-diglycidylaniline, tetraglycidyldiaminodiphenylmethane, and triglycidyl p-aminophenol are exemplified.

As the urethane resin used in the present invention, there is a polymer obtained by reacting at least one polyol selected from a polyester polyol and a polyether polyol with a polyisocyanate.

The polyester polyol used for the urethane resin is not particularly limited, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, and 1,3.
-Low molecular weight polyols such as propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, hexamethylene glycol, hydrogenated bisphenol A, trimethylolpropane, glycerin and succinic acid, glutar Acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, endmethylenetetrahydrophthalic acid, compounds having a hydroxyl group at the terminal obtained by reaction with a polybasic acid such as hexahydrophthalic acid. Can be

The polyether polyol used for the urethane resin is not particularly limited, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3
-Low molecular weight polyols such as propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, hexamethylene glycol, a polyol having a bisphenol skeleton, hydrogenated bisphenol A, trimethylolpropane, and glycerin And polyether polyols such as polyethylene glycol, polypropylene glycol, and polyethylene / propylene glycol, polycaprolactone polyols, polyolefin polyols, and polybutadiene polyols.

Examples of the polyisocyanate used as a crosslinking agent during the polymerization of the urethane resin include aliphatic, alicyclic and aromatic polyisocyanates. Specifically, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate ester, hydrogenated xylylene diisocyanate, 1,4-
Cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 3,3 'dimethoxy-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5- Tetrahydronaphthalene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, phenylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, etc. No.

The emulsifier (b) containing a nonionic moiety used in the present invention includes a polyethylene glycol group and 2
It refers to a surfactant having at least one nonionic hydrophilic group selected from addition polymerization groups of ethylene oxide having at least one molecule. The amount of the surfactant is not particularly limited, but (b) / ((a) + (b)) (weight ratio of solid content) is preferably 0.05 / 100 to 40/100, and 1/100. It is more preferably used so as to be 100 to 30/100, and even more preferably used so as to be 5/100 to 20/100. If the weight ratio is less than 0.05, the stability when mixed with the chromate component is insufficient, and if it exceeds 40/100, the water resistance of the film is reduced, and the corrosion resistance may be deteriorated.

The emulsifier used in the present invention is not particularly limited except that it has the nonionic hydrophilic group, and one or a mixture of two or more thereof can be used.
Nonionic surfactants that can be used in the present invention include:
(A) Higher aliphatic alcohol ethylene oxide adduct, fatty acid ethylene oxide adduct, polyhydric aliphatic alcohol fatty acid ester ethylene oxide adduct, higher alkylamine ethylene oxide adduct, fatty acid amide ethylene oxide adduct, polypropylene glycol ethylene oxide adduct And polyethylene oxide adducts of the following compounds: glycerol fatty acid ester type compounds, pentaerythritol and sorbitan fatty acid ester type compounds, polyhydric alcohol alkyl ether type compounds, and alkanolamine fatty acid amides Nonionic compounds having no aromatic nucleus, such as type compounds, (b)
Phenols, alkylated phenols, ethylene oxide adducts of styrenated phenols, polyethylene oxide adducts of the following compounds: nonionic compounds having a polynuclear aromatic group such as naphthalenes and anthracenes; Polyethylene oxide adduct of a compound of the formula: mononuclear aromatic compounds such as condensates of styrenated phenols, polyvinylphenols, phenols with aldehydes such as formaldehyde and acetaldehyde, or ketones such as acetone and methyl ethyl ketone And a compound having a plurality of benzene nuclei obtained by adding, condensing, or polymerizing them, a polynuclear aromatic compound such as naphthalenes and bisphenols, and an aldehyde such as formaldehyde and acetaldehyde, or Tons, obtained by the condensation polymerization of ketones such as methyl ethyl ketone, in various forms, such as nonionic compound having a nonionic compound and a combined group thereof having a plurality of benzene nucleus.

Further, a hydrophilic acid such as sulfuric acid, phosphoric acid, or carbonic acid is added to the nonionic surfactant to form a sulfate (-OSOH) group, a sulfonic acid (-SOH) group, A nonionic-anion composite surfactant to which an acid ester (-OPOH) group, a carboxylic acid (-COOH) group, or a salt group thereof is added can also be used.

Further, the nonionic surfactant may be a reactive surfactant having a carbon-carbon double bond (C = C) in its hydrophobic group, and is commercially available for emulsion polymerization of acrylic resin and the like. Reactive emulsifiers that have been used can be used. The reactive surfactant may be used alone, used for emulsion polymerization of the resin, and may be contained as it is in the treatment liquid composition of the present invention, or may be used in a mixed form thereof. Examples of the reactive surfactant include, but are not particularly limited to, a double bond such as a -CH = CHCH group or a -CHOCHCH = CH group in the skeleton structure of the ethylene oxide adduct of the alkylated phenol. Those having a group added, an ester compound of acrylic acid or methacrylic acid monomer and polyethylene glycol or polypropylene glycol, or a polyethylene glycol group on a skeleton having a double bond such as a styrene monomer,
And those obtained by addition polymerization of two or more molecules of ethylene oxide.

The organic component (2) of the present invention may contain a wax (c). This is preferable because lubricity can be imparted. There is no particular limitation on the wax, but paraffin, microstatin,
And at least one selected from petroleum waxes such as polypropylene and a fluorine-containing organic compound. Wax is not limited, but JIS K2
The softening point defined by 351 is preferably from 50 to 160 ° C. If the softening point is outside these ranges, lubricity may be insufficient and the effect of addition may not be obtained.
Further, the fluorine-containing organic compound is not particularly limited. For example, the repeating unit of polyethylene (PE)-(C
Polymers in which hydrogen atoms of (H—CH) — have been replaced with fluorine atoms, ie, polyvinyl fluoride (PVF), polyvinylidene fluoride (PVdF), polytrifluoroethylene (PT
Various high-molecular fluorine-containing organic compounds such as rFE), polytetrafluoroethylene (PTFE), and copolymers of these polymers with olefins or modified products thereof. The particle size of the wax is small (1μ
m or less) is more excellent in the stability of the processing solution, but is larger in terms of matting and lubrication (several μm to several tens of μm). Is preferred. The compounding amount of the wax (c) is 1/10 in terms of the solid content weight ratio of the wax (c) / the resin (a).
It is preferably 0 to 40/100, and 5/100 to
More preferably, it is 20/100. 1/100
If it is less than 10%, the lubricity may be insufficient.
If it exceeds 0, the effect is saturated and it is not economical.

These waxes need to be stably dispersed in water with a surfactant containing a nonionic portion or a resin emulsion dispersed with a surfactant containing a nonionic portion, similarly to the above-mentioned resin emulsion.

The chromate liquid composition containing an aqueous resin for a metal material of the present invention may further contain a conventionally known lubricant such as graphite, molybdenum disulfide, oils and fats. However, since most of them have sedimentation in water, it is necessary to take care such as increasing the viscosity of the treatment liquid and performing sufficient stirring when coating the treatment liquid.

As described above, the water-based resin-containing chromating composition of the present invention has a Cr / (Cr + Cr) weight ratio of 1 /.
10-8 / 10 chromate component, nitric acid, sulfuric acid,
An inorganic component (1) containing at least one selected from the group of boric acid in a molar ratio of 0.1 to 4.0 with respect to all chromium ions (Cr + Cr), and an emulsifier (b) having a nonionic portion
And (b) / ((a) + (b)), wherein the weight ratio of solids is 0.1.
And the organic component (2) is in the range of 0.05 / 100 to 40/100, and the weight ratio between the chromate component (1) and the organic component (2) is ((a) + (b)) (solid content ) /
The weight ratio of (Cr + Cr) is preferably 2/1 to 300/1. If the weight ratio is less than 2/1, sufficient corrosion resistance and fingerprint resistance cannot be obtained, and if it exceeds 300/1, the effect is saturated and not only is economically disadvantageous, but also the chromium component is too small to lower the corrosion resistance. is there.

Next, a method for producing a zinc-based plated steel sheet having excellent corrosion resistance, blackening resistance and fingerprint resistance according to the present invention will be described. In the production method of the present invention, the application and drying methods are not particularly limited, and generally known methods such as immersion and shower can be applied. The treatment liquid coating layer is formed using these methods. At this time, the treatment liquid application amount may be adjusted by air blow, a roll, or the like, or a desired amount may be obtained by an arbitrary method such as a roll coating method or a spray coating method. It can also be adjusted to the amount of application. Further, drying after applying the treatment liquid composition of the present invention to the surface of the steel sheet may be basically performed by evaporating water, and there is no particular limitation on the method. Drying methods such as high-frequency induction heating can be used. Therefore, the heating temperature and the heating time are not particularly limited.

Thus, the aqueous treatment liquid containing the aqueous resin-containing chromate composition of the present invention is applied to the surface of a steel sheet and dried to deposit 5 to 10 chromium on the surface (in terms of chromium metal).
A resin chromate film of 0 mg / m is formed. If the amount of chromium is less than 5 mg / m, the corrosion resistance of the resulting film may be insufficient. If the amount exceeds 100 mg / m, the effect of the corrosion resistance is saturated, which is not economical.

[0041]

Next, the function and effect of the present invention will be described. The aqueous resin-containing chromate treatment composition for a metal material of the present invention,
Chromate component (trivalent chromium ion, hexavalent chromium ion) that gives basic corrosion resistance to galvanized steel sheet
And an inorganic acid component (nitric acid, sulfuric acid, boric acid) for improving blackening resistance and a resin component for providing high corrosion resistance and fingerprint resistance, and emulsification for stably dispersing the resin component in the inorganic chromate component ( Surfactant), containing p
It is adjusted to H3 or less.

Although the functions and actions of the present invention are not always clear, the action mechanism of the inorganic component will be described first. The mechanism for preventing the formation of white rust in a chromate film is generally understood as an inhibitory effect of suppressing corrosion of zinc by hexavalent chromium ions, and is further found in "Materials and Environment, 41, 244-245, 1992". As described above, it is considered that hexavalent chromium ions eluted from the film repair the damaged portion of the film, thereby causing self-repair. Further, it is considered that the added inorganic acid suppresses the formation of oxygen-deficient corrosion products (black rust) by forming a salt of each inorganic acid with zinc.

Next, regarding the coexistence of the resin component and the inorganic component, the hydrophilic resin particles generally have an anionic functional group or a hydrophilic group such as a hydroxyl group or a polyethylene glycol group in the resin skeleton, so that the resin particle has a self-adhesive function. Emulsification and emulsification, and hydrophobic resins are emulsified by inversion emulsification with a surfactant or emulsification polymerization with a reactive surfactant, and these resin emulsions are emulsified. It is stably dispersed in a neutral to alkaline pH range. Consider the case where these resin emulsions are mixed with an inorganic chromate component. First, trivalent chromium ions act as polyvalent cations, and have the effect of neutralizing the charge on the surface of the emulsion particles. In general, neutralizing the surface charge of a particle destabilizes its dispersion and tends to agglomerate. For this reason, self-emulsified emulsions and anionic surfactants having anionic functional groups are neutralized by trivalent chromium ions. It cannot be dispersed.

In addition, 6 present in the treatment liquid composition at the same time
Chromium ion is a strong oxidizing agent and the pH of the processing solution is 3
When the inorganic chromate component and the resin component are mixed, the Jeta (急 激) potential on the surface of the resin emulsion also changes rapidly due to a sudden change in pH, causing its dispersion instability and causing a tendency of aggregation. Occurs. Under such circumstances, in order to prevent instability of dispersion of the resin component and maintain a stable dispersion state, an emulsifier containing a nonionic (non-ionic) portion is used. It is effective to use. In other words, if the nonionic portion provides sufficient hydrophilicity to stably disperse the resin component in water, neutralization of the charge by trivalent chromium ions and the change of the resin component by a change in surface charge due to a rapid pH change Agglomeration is prevented, and a one-pack type composition in which the inorganic chromate component and the resin component are stably present can be obtained. The same can be considered for the additive component (dispersion of wax or the like).

[0045]

Next, examples of the present invention will be described together with comparative examples.
The effect will be described in more detail. It should be noted that these examples are described for describing the present invention, and do not limit the present invention in any way.

1. Preparation of treatment liquid composition (1-1) Preparation of chromate component A chromate component having the composition shown in Table 1 was prepared.
For example, B1 is prepared by adding 200 g of chromic anhydride to 50 parts of pure water.
0 g, and methanol was added to reduce a part of hexavalent chromium, and then pure water was added to adjust to 1 kg. The ratio of Cr / (Cr + Cr) was adjusted by the amount of methanol added. (1-2) Preparation of Inorganic Component (1) Inorganic component (1) shown in Table 2 was prepared by adding an inorganic acid component, a metal component and other additives to the chromate component of Table 1. (1-3) Preparation of aqueous resin component Table 3 shows an aqueous resin, Table 4 shows an emulsifying (surfactant) agent, and Table 5 shows an additive (wax). These were mixed at the ratios shown in the resin components in Table 6. After mixing, the mixture was sufficiently stirred. (1-4) Preparation of treatment liquid composition of the present invention While the prepared aqueous resin fat component was being stirred, the prepared chromate component (Tables 1 and 2) was gradually added, and the results are shown in Table 6. A treatment liquid composition was prepared.

2. Preparation of test plate (2-1) Test materials The following commercially available materials were used as test materials. (1) Double-sided electrogalvanized steel sheet (EG) Sheet thickness = 0.8 mm, basis weight = 20/20 (g / m) (2) Hot dip galvanized steel sheet regular spangle (GI
-R) Sheet thickness = 0.8 mm, basis weight = 120/120 (g /
m) (3) Lead-containing hot-dip galvanized steel sheet zero spangle (GI
-Z) Sheet thickness = 0.8 mm, basis weight = 100/100 (g /
m) (4) Zero spangle (Pb)
Less GI) Sheet thickness = 0.8 mm, basis weight = 180/180 (g /
m) (5) 5% aluminum-containing hot-dip galvanized steel sheet (G
F) Sheet thickness = 0.5 mm, basis weight = 90/90 (g / m) (6) Hot-dip galvanized steel sheet containing 55% aluminum (G
L) Thickness = 0.8mm

(2-2) Degreasing treatment The test material was fine cleaner 4336 (registered trademark: Nippon Parkerizing Co., Ltd.) of a silicate-based alkaline degreasing agent.
Degreasing treatment was performed. (Concentration = 20 g / L, temperature = 60
(2 ° C., sprayed for 20 seconds) (2-3) Production of galvanized steel sheet having excellent corrosion resistance, blackening resistance and fingerprint resistance The aqueous resin compositions for galvanized steel sheet of Examples and Comparative Examples were applied with a bar coater. It was manufactured under the manufacturing conditions shown in Table 6. For drying, the temperature of the drying oven, the wind speed, and the time were adjusted, and the indicated maximum plate temperature (PMT = Peak M) was displayed.
et al Temperature).

3. Performance Test (3-1) Corrosion Resistance of Flat Plate Part The salt spray test (SST) according to JIS-Z2731
The test was performed for 20 hours and 240 hours, and the occurrence of white rust was observed and evaluated according to the following evaluation criteria. <Evaluation criteria> ◎ = Rust generation is 0% of total area ○ = Rust generation is less than 5% of total area △ = Rust generation is 5% or more and less than 10% of total area 全 = Rust generation is 10% or more of total area Less than 30% × = Rust generation is 30% or more of the whole area

(3-2) Corrosion resistance of flawed part After the flaw was made by NT cutter until it reached the galvanized (steel plate) substrate, a salt spray test was carried out in the same manner as in 2-1 and evaluated according to the following evaluation criteria. <Evaluation Criteria> ◎ = Rust width from cut portion is less than 0.5 mm ○ = Rust width from cut portion is 0.5 mm or more and less than 1 mm △ = Rust width from cut portion is 1 mm or more and less than 3 mm ▽ = From cut portion Rust width of 3 mm or more and less than 10 mm × = Rust width of 10 mm or more from cut part

(3-3) Corrosion Resistance of Processed Parts The Ericksen test extruded 6 mm so that the test object side became convex, performed a salt spray test for 120 hours, and evaluated according to the following evaluation criteria. <Evaluation Criteria> ＝= Area of rust generation in processed part is less than 10% ○ = Area of rust generated in processed part is 10% or more and less than 20% △ = Area of rust generated in processed part is 20% or more and less than 40% ▽ = Processed part Area ratio of 40% or more and less than 70% in X == 70% or more of rust generation area in processed part

(3-4) Blacking resistance The blackening acceleration test (Method A, Method B) was carried out and evaluated by the following visual evaluation. Method A: Prepare two test plates (of 70 × 150 mm size) for each test level,
This was packed (two wraps) with single-sided vinyl coated paper to form a stack, and tightened with a torque wrench at a load of 70 kg · f. This is a 50 ° C., 95% RH constant temperature wet box.
For 10 days. Method B: A test plate (of 70 × 150 mm size) of each level was placed on a commercially available slide glass stand with the test surface facing upward, and allowed to stand in a constant temperature wet box at 70 ° C. and 90% RH for 1 day. . <Visual judgment criteria> ◎ = No abnormality ○ = Chromate The color of the film appearance is missing, but no blackening is observed △ = Very thin, partial blackening ▽ = Thin blackening X = Notable blackening over the entire surface

(3-5) Fingerprint Resistance The fingerprint resistance of the test plate was evaluated by the following method. Method I: Vaseline is applied to the surface of a test plate and wiped off with clean gauze. At this time, the parts before and after the application of Vaseline were treated with a color computer (SM-3, manufactured by Suga Test Instruments).
The value, a value, and b value were measured, and the color difference ΔE was calculated (the smaller the value, the better). Method II: A test plate was actually imprinted, and its appearance was evaluated according to the following evaluation criteria. <Evaluation> ◎ = Fingerprint trace is not visible at all ○ = Fingerprint trace is not visible when viewed from above, but is only visible when the angle is changed △ = Fingerprint trace is only visible when viewed from above and when the angle is changed Easy to see ▽ = Fingerprint traces are visible from any angle × = Fingerprint traces are clearly visible

(3-6) Lubricity At the level to which the lubricating component (WAX) was added, using a Bowden friction and wear tester, a load of 1 kg and an indenter SUJ-2 (1) were used.
0 mmφ), room temperature, a sliding speed of 10 mm / sec, a sliding distance of 20 mm, and a friction coefficient μ at the time of sliding 10 times was evaluated. Also, the drawing ratio was 2.1, the wrinkle pressure was 1 ton, the punch diameter was 50 mm, the punch shoulder R was 5 mm, and the die diameter was 52.
High-speed deep drawing was performed under the conditions of 0 mmφ, die shoulder R5 mm, test temperature of 30 ° C., and processing speed of 30 m / min, and then a corrosion resistance test (72 hours of salt spray) was performed and evaluated according to the following evaluation criteria. <Evaluation Criteria> ◎ = Rust generation is less than 5% of the processing area ○ = Rust generation is 5% to less than 20% of the processing area △ = Rust generation is 20% to less than 40% of the processing area ▽ = Rust generation is the processing area × 40% or more and less than 70% × = Rust generation is 70% or more of the processing area

(3-7) Coatability A melamine alkyd paint (trade name: Delicon # 700) manufactured by Dainippon Paint Co., Ltd. was coated on a test plate with a bar coat so as to have a coating thickness of 25 μm, and baked at 140 ° C. for 30 minutes. After drying, a coated plate was prepared, and in the following tests, primary and secondary adhesion tests (immersion in boiling pure water for 2 hours, removal, and standing for 24 hours, and an adhesion test) were performed. Cross cut test: 10 mm square on the coating surface with a cutter knife
After making zero crosscuts, cellophane tape peeling was performed, and the number of remaining crosscuts was evaluated. The evaluation is better when the remaining number is large. Cross-cut Erichsen test: After the cross-cut test, the sample was extruded by 5 mm with an Erichsen tester, and cellophane tape was peeled off again, and the remaining state of the coating film was evaluated according to the following evaluation criteria. <Judgment criteria> ＝= There is almost no peeling (peeling of less than 3%) ○ = Very slight peeling is seen (peeling of 3% or more and less than 10%) Δ = Slight peeling is seen (10% or more and 30%剥離 = peeling is observed (peeling of 30% or more and less than 60%) × = significant peeling (peeling of 60% or more)

[0056]

[Table 1] Table 1 Chromate component Total Cr = (Cr + Cr), and phosphoric acid used was orthophosphoric acid.

[0057]

[Table 2]

[0058]

[Table 3] Table 3 Aqueous resin components

[0059]

Table 4 Emulsifier

[0060]

Table 5 Wax

[0061]

[Table 6]

4. Test results Table 7 shows the test results.

[0063]

[Table 7]

As shown in Table 7, Examples 1 to 3 using the aqueous resin-containing chromate-treating compositions for metal materials of the present invention.
Sample No. 2 was excellent in corrosion resistance, blackening resistance, fingerprint resistance and paintability, and Examples 15, 21 to 29, 31, and 32 were particularly excellent in corrosion resistance. Further, Examples 18, 19, 30, 31, and 32 were excellent in lubrication (working) properties and also in corrosion resistance after working. On the other hand, Comparative Examples 1 to 6, and 10 and 13 using the aqueous resin-containing chromate treatment composition outside the scope of the present invention had good corrosion resistance, fingerprint resistance, and paintability, but had very poor blackening resistance. Was inferior. In Comparative Example 11, the corrosion resistance was poor. Comparative Example 12 had good blackening resistance, but all other properties were inferior. Comparative Example 13 had workability but was inferior in post-processing corrosion resistance and blackening resistance. Furthermore, in Comparative Examples 7 to 9 and 14, no treatment liquid was obtained, and no test was possible.

[0065]

As described above, the aqueous resin-containing chromate-treated composition of the present invention has excellent corrosion resistance and blackening resistance in a single step, and is functional zinc plating excellent in fingerprint resistance, lubricity and coating properties. Since steel plates can be manufactured, the practical value is extremely large.

Claims (3)

[Claims] (1) It contains hexavalent chromium ion (Cr) and trivalent chromium ion (Cr) in a weight ratio of Cr / (Cr + Cr) in the range of 1/10 to 8/10, and further contains nitrate ion (Cr). NO), an inorganic component containing at least one inorganic acid ion selected from the group consisting of sulfate ions (SO) and borate ions (BO) in a molar ratio of 0.1 to 4.0 with respect to all chromium ions (Cr + Cr); (2) a nonionic moiety of at least one member selected from (a) a resin containing at least one polymer compound and (b) a polyethylene glycol group and a polyethylene oxide group formed by addition polymerization of two or more molecules of ethylene oxide. A nonionic surfactant having at least one of a nonionic surfactant having the nonionic portion and an anionic portion; or It includes square surfactant, wherein the resin is dispersed stably in water by a surfactant, and (b) / ((a) + (b)) (solid content weight ratio) 0.0
An organic component in the range of 5/100 to 40/100, and a weight ratio of ((a) + (b)) / (Cr + Cr) ((a) + (b) is a weight as a solid content. Is in the range of 2/1 to 300/1 and the pH is 3 or less. 2. The method according to claim 1, wherein the inorganic component is Zn, Ni, Co,
The aqueous resin-containing chromate composition for a metal material according to claim 1, wherein the chromate composition contains at least one metal ion selected from the group consisting of Al, Ti, and Zr. 3. An aqueous treatment solution containing the aqueous resin-containing chromate composition for a metal material according to claim 1 or 2 is applied to the surface of a zinc-based plated steel sheet, dried, and the amount of chromium deposited on the surface of the steel sheet ( 5 to 100 mg / m (in terms of metal chromium)
A method for producing a functional galvanized steel sheet, comprising forming a resin-containing chromate film according to (1).