JP2002241959A - Water dispersible metallic surface treatment agent, surface treated metallic material and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface treated metallic material which has excellent properties, a water dispersible metallic surface treatment agent which can obtain the surface treated metallic material, and has storage stability, and a production method therefor. SOLUTION: In the water dispersible metallic surface treatment agent to be used, the total concentration of solid contents is 10 to 80 mass%, and, in the solid contents, the treatment agent consists of, by mass, a 40 to 90% ionomer resin, a 1 to 10% water soluble multifunctional epoxy group-containing compound, and 9 to 50% ammonium ion-adsorbed silica. The ionomer resin is an ethylene-unsaturated carboxylic acid polymer whose glass transition point is 50 to 70 deg.C, and also, 40 to 60% of a carboxylic group contained therein is neutralized by a univalent metallic cation. Further, the content of chlorine contained in the water soluble multifunctional epoxy group-containing compound is <1 mass%. The treatment agent is applied to the upper layer of the surface of the metallic material, and is subjected to baking treatment to form an organic- inorganic composite film by 0.3 to 5.0 g/m2 in terms of dry mass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates not only to basic performance such as corrosion resistance, paint adhesion and alkali resistance, but also to solvent resistance,
The present invention relates to a surface-treated metal material excellent in scratch resistance, a water-dispersible metal surface treatment agent excellent in storage stability capable of obtaining the surface-treated metal material, and a production method.

[0002]

2. Description of the Related Art The demand level of so-called surface appearance quality, such as fingerprint resistance, corrosion resistance, and scratch resistance, has been increasing year by year for surface treated metal materials for home appliances, particularly zinc-based plated steel sheets. Accordingly, the development of a surface treatment agent capable of enhancing the practical function of the surface is being promoted at a rapid pace. Therefore, for example, in recent years, chromate treatment has become the mainstream in place of phosphate treatment in metal post-treatment and coating undercoat treatment techniques, but recently, from the viewpoint of environmental problems, this chromate is hardly dissolved, and furthermore, Fingerprints do not stick even when touched, are not noticeable, do not rust from there, are not easily scratched, surface function does not deteriorate even if wiped with solvent,
The tendency of multifunctional and high-performance metal surfaces, such as good post-painting properties, is only increasing year by year. In particular, surface treatment agents for metal post-treatment have been remarkably improved in recent years, and surface treatment agents with high functionality in non-extra (no price increase) and high-performance metal materials with them Is now available on the market.

[0003] Examples of measures for improving the scratch resistance are disclosed in JP-A-7-171498 and JP-A-10-171498.
No. 130861. The former is a paint made by adding a spherical polyethylene wax particle size and silica particle whose particle size and melting point are specified, to a resin obtained by blending a normal temperature crosslinking type epoxy resin with a urethane resin having active hydrogen in the molecule. The present invention relates to a resin-coated metal material excellent in punching workability, characterized in that a thin film is formed on an upper layer of a metal material using a composition. In addition, the latter relates to a surface-treated metal material which is characterized in that alkali metal silicate, colloidal silicate, solid lubricant and organic resin (silane coupling agent) are blended in specific amounts. Both of these technologies are intended to be marketed as deep drawing metal materials for home appliance audio products.

Japanese Patent Application Laid-Open No. H10-176119 discloses an example in which a phosphate or a chromate is not used, which is pollution-free and imparts excellent corrosion resistance and paint adhesion to a metal surface. This technology involves polymerizing an ethylenically unsaturated monomer into a water-dispersible resin of an aqueous polyester resin having a specified average molecular weight and an ethylene-ethylenically unsaturated carboxylic acid copolymer alkali metal neutralized product (ionomer). With respect to the obtained metal surface treating agent, it is intended to improve the metal corrosion resistance and paint adhesion by specifying the compounding ratio of the resin.

It is also important to take measures to prevent the blackening of the zinc or zinc-based plated steel sheet subjected to chromate treatment with time.
For example, JP-A-6-246229, JP-A-8-3972
5, JP-A-9-187883 and JP-A-9-1878
No. 84 discloses a technique for preventing corrosion of a galvanized layer and preventing discoloration to black by applying a thin film of an organic composite clear resin on a base chromate treatment.

However, using any of the above prior arts,
It has been difficult to obtain a surface-treated metal material that simultaneously satisfies solvent resistance, scratch resistance, and mold galling resistance without impairing corrosion resistance, paint adhesion, and alkali resistance.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to improve solvent resistance, scratch resistance, mold galling, deep drawing workability, etc. without impairing basic performance such as corrosion resistance, paint adhesion, alkali resistance and the like. At the same time, it is an object of the present invention to provide a surface-treated metal material satisfying a high level, a water-dispersible metal surface treatment agent having excellent storage stability, and a production method capable of obtaining the surface-treated metal material.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive research and development in order to solve the above-mentioned problems. Silica using an ionomer resin neutralized with a multivalent metal cation and further adsorbing an amino group or an ammonium ion or both (hereinafter, may be simply referred to as "ammonium ion-adsorbed silica"). And a water-soluble polyfunctional epoxy group-containing compound (hereinafter, simply referred to as a "water-soluble epoxy compound") having a chlorine content controlled within a specific range, thereby providing basic properties such as corrosion resistance, paint adhesion, and alkali resistance. Surface-treated metal material with excellent solvent resistance and scratch resistance in addition to performance, and water with excellent storage stability that can obtain the surface-treated metal material The diffusing metal surface treatment agent is obtained know, it has been led to completion of the present invention.

The gist of the present invention is that (1) the total solid content is 10 to 80% by mass and 40 to 90% in the solid content.
Water-dispersible metal surface composed of an ionomer resin of 1% by mass, 1 to 10% by mass of a water-soluble polyfunctional epoxy group-containing compound, and 9 to 50% by mass of silica adsorbing one or both of an amino group and an ammonium ion. A treating agent, wherein the ionomer resin has a glass transition point of 50 to 70 ° C.
Is an ethylene-unsaturated carboxylic acid polymer of which 40 to 60% of the carboxyl groups contained are neutralized with a monovalent metal cation, and further contained in the water-soluble polyfunctional epoxy group-containing compound. A water-dispersible metal surface treatment agent having a chlorine content of less than 1% by mass, and (2) a water-dispersible polyolefin in which 0.5 to 20% by mass of the water-dispersible metal surface treatment agent in the solid content is further added. The water-dispersible metal surface treatment agent according to the above (1), wherein the metal surface treatment agent is formed of a resin.
An organic-inorganic composite film composed of an ionomer resin in an amount of 1% by mass, a water-soluble polyfunctional epoxy group-containing compound in an amount of 1 to 10% by mass, and silica having one or both of an amino group and an ammonium ion adsorbed in an amount of 9 to 50% by mass. has 0.3 to 5.0 g / m ² as dry weight, the ionomer resin is a glass transition point 50-70 ° C. ethylene - 40-6 carboxyl groups with an unsaturated carboxylic acid polymer, and includes
A surface-treated metal material, wherein 0% is neutralized with a monovalent metal cation, and the chlorine content in the organic-inorganic composite film is less than 0.1% by mass; )
0.5-20% by mass in solid content of organic-inorganic composite film
Is a water-dispersible polyolefin resin, wherein the surface-treated metal material according to the above (3),
(5) The water-dispersible metal surface treating agent according to (1) or (2) is applied to the upper surface of the metal material surface and baked to give the organic-inorganic composite film in a dry mass of 0.3 to 5.0 g / dry.
m ² , a method for producing a surface-treated metal material.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The basic idea of the development of the main resin used in the metal surface treatment agent of the present invention is that, in addition to basic performance such as corrosion resistance, paint adhesion and alkali resistance, (1) a solvent having a strong polar group such as ethanol or methyl ethyl ketone (MEK). On the other hand, it does not easily dissolve or peel or swell. In addition, (2) it does not easily have scratches, does not easily die in a severe process such as press working, and can sufficiently follow the processing elongation of the substrate metal. And (3) a water-dispersible resin having excellent storage stability without gelling and precipitation as a binder resin.

Therefore, in the present invention, a resin obtained by neutralizing a carboxyl group of an ethylene-unsaturated carboxylic acid copolymer with a monovalent metal cation within a specific range is used as a main resin for a binder. As a method to stabilize the alkalinity, secondary adhesion after melamine coating, and storage stability of the treating agent to a high level, ammonium ion-adsorbed silica and a water-soluble polyfunctional epoxy group-containing compound in which the amount of chlorine is controlled to a specific amount or less. (Hereinafter, simply referred to as “water-soluble epoxy compound”) in an appropriate amount.

[0012] The ionomer resin neutralized with a monovalent metal cation used in the present invention is prepared by subjecting ethylene and an unsaturated carboxylic acid to 150 to 270 ° C and 98 to 245 MPa (1000 MPa).
2,500 Kg / cm ² ) at a high temperature and a high pressure, and the obtained carboxylic acid of the ethylene-unsaturated carboxylic acid copolymer is reacted with a metal hydroxide or the like at a high temperature of 150 to 300 ° C. 40-60 carboxyl groups in the chain
% Is neutralized with a monovalent metal cation. The ethylene-unsaturated carboxylic acid copolymer constituting the main skeleton of the ionomer resin may be a graft copolymer, but is preferably a random copolymer in terms of transparency.

The unsaturated carboxylic acid which is a component of the ethylene-unsaturated carboxylic acid copolymer includes an unsaturated carboxylic acid having 3 to 8 carbon atoms. Specific examples include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, isocrotonic acid, citraconic acid,
Allyl succinic acid, mesaconic acid, glutaconic acid, nadic acid, methylnadic acid, tetrahydrophthalic acid, methylhexahydrophthalic acid are exemplified. Of these, methacrylic acid is preferred.

The ethylene-unsaturated carboxylic acid copolymer constituting the main skeleton of the ionomer resin may contain a third component in addition to ethylene and the unsaturated carboxylic acid.
Examples of such a third component include unsaturated carboxylic esters such as methyl (meth) acrylate, ethyl (meth) acrylate and isobutyl (meth) acrylate, and vinyl esters such as vinyl acetate. .

The content of ethylene in the ethylene-unsaturated carboxylic acid copolymer is from 8 to 95% by mass,
Preferably it is 8 to 25% by mass. When the ethylene-unsaturated carboxylic acid copolymer contains the third component, its amount is preferably limited to 40% by mass or less. As the metal cation used for neutralization of the ionomer resin, monovalent metal cations such as Li ⁺ , Na ⁺ , and K ⁺ are recommended in that an ionomer resin having good emulsifiability is obtained. Na (sodium) ions are preferred. The proportion of carboxyl groups neutralized by metal cations,
That is, the degree of neutralization is set to 40 to 60%, and more preferably 45 to 55%. If it is less than 40%, it is difficult to obtain a good aqueous dispersion, and if it exceeds 60%, the adhesion of the coating film is inferior.

The glass transition point of the ethylene-unsaturated carboxylic acid copolymer neutralized and adjusted to 40 to 60% (hereinafter referred to as "the glass transition point").
Tg) must be 50 to 70 ° C, and preferably 50 to 60 ° C. If the Tg is less than 50 ° C., the flaw resistance of the resin film is reduced, the film is easily broken by press working or the like, and the mold is apt to form.
If the temperature exceeds ℃, the flexibility of the film becomes insufficient, and cracking or the like of the film due to processing occurs, which is not preferable. In the present invention, the glass transition point (Tg) is measured according to JIS K7121.

The amount of the water-dispersible ionomer resin (in terms of solid content) is from 40 to 90 as a percentage of the total solid content.
% By mass, preferably 60 to 80% by mass. If this proportion is less than 40% by mass, it is difficult to form a uniform film on the metal coated object, so that the corrosion resistance is significantly reduced. On the other hand, if the content exceeds 90% by mass, it becomes difficult to uniformly control the film thickness due to the effect of the increase in the viscosity of the processing solution, which causes problems such as inferior press workability. It is not preferable because it causes a problem in the painting operation such as a long time.

On the other hand, the water-soluble epoxy compound used in the present invention is used to stably obtain a high level of alkali resistance and secondary adhesion of a coating film at the time of post-coating. The percentage of the total solid content of the water-soluble epoxy compound is from 1 to 10% by mass, preferably from 3 to 7% by mass. If the compounding ratio is less than 1% by mass, the base adhesion of the film and the secondary adhesion of boiling water of a low-grade post-coat such as a melamine alkyd paint will be insufficient. On the other hand, when the content exceeds 10% by mass, the coating film becomes excessively hard, so that cracking is easily caused by processing and the coating film is easily peeled.

In the above water-soluble epoxy compound, the glycidyl group contained therein reacts with the carboxyl group of the ionomer resin by heating after coating, and adheres to a base metal or a one-coat one-bake (1C1B) coating post-coat for home appliances. There is an advantage of improving the performance. The number of functional groups is preferably from 3 to 4 functional groups, and examples thereof include pentaerythritol glycidyl ether and glycerol polyglycidyl ether in which the amount of chlorine is adjusted to less than 1% by mass. However, in the case of monofunctional epoxy compounds, it is necessary to improve the function of secondary adhesion with low-grade post-coats such as melamine alkyd resin coatings in coating films formed from metal surface treatment agents blended with ionomer resins. It is difficult. On the other hand, when the number of functional groups exceeds 5, the crosslink density becomes too high, the coating becomes harder, and the workability is remarkably reduced, so that the corrosion resistance may be deteriorated.

Regarding the viscosity of the water-soluble epoxy compound,
From the viewpoint of coating workability, those having a pressure of 25 mC or less, preferably 400 mPas or less, and more preferably 350 mPas or less. Epoxy equivalents in the range of 6.0 to 7.5 eq / kg, and more preferably in the range of 6.2 to 7.1 eq / kg, are preferable from the viewpoint of reactivity. Here, in the conventionally used polyfunctional epoxy compound, a large amount of chlorine derived from epichlorohydrin as a raw material remains. Therefore, the metal surface treating agent containing a large amount of chlorine has problems such as poor storage stability, precipitates with the passage of time, and inferior performance such as corrosion resistance of the film formed with this treatment solution. .

Therefore, in the present invention, a water-soluble polyfunctional epoxy compound whose chlorine content is adjusted to less than 1% by mass at the time of production is used. In addition, by adjusting the amount of chlorine contained in the water-soluble polyfunctional epoxy resin to 1% by mass or less and the amount of chlorine contained in the treated film to 0.1% by mass or less, the long-term stability of the treating agent can be improved. In addition, it becomes possible to improve the corrosion resistance of the surface-treated metal material obtained by treating this treating agent.

The ammonium ion-adsorbing silica used in the present invention is adjusted to pH 9.0 to 10.5 by adsorbing amino groups and / or ammonium ions on the surface of fine particle silica having a particle diameter of 10 to 20 nm. However, colloidal silica dispersed in water is optimal. In adjusting the pH, either an organic amino compound or aqueous ammonia may be used, but the use of an organic amino compound is preferred in terms of workability and work environment. Examples of such an organic amino compound include amino alcohol and diethanolamine.

The amount of the silica (in terms of solid content) is 9 to 50% by mass, preferably 15% by mass, based on the total solid content.
４０40% by mass. If the silica content is less than 9% by mass, the film has poor scratch resistance and corrosion resistance. If it exceeds 50% by mass, the coating film becomes too hard and the flexibility is reduced. Corrosion resistance also decreases because hair cracks and the like easily occur.

The water-dispersible metal surface treatment agent of the present invention contains a water-dispersible olefin resin-based wax for the purpose of imparting other functions, for example, lubricating property in a ratio of 0.5 to the total solid content. -20% by mass can be added. Further, in addition to the above components, a rust inhibitor can be appropriately added. Examples of such rust preventives include zinc dust, sodium nitrite, ammonium phosphate, zinc phosphate, ammonium vanadate, silicate tungstic acid hydrate, and the like.

The water-dispersible metal surface treating agent of the present invention containing the above components can be used at a total solid content of 10 to 80% by mass. The composition other than the solid content is mostly water, but also includes everything that does not remain in the film composition after painting and baking, such as a volatile pH adjuster. If the total solid content is less than 10% by mass, a sufficient film thickness cannot be ensured. If the total solids concentration exceeds 80% by mass, coating workability deteriorates, and it becomes difficult to secure a stable film thickness.

In the method for preparing the water-dispersible metal surface treating agent of the present invention, for example, a predetermined amount of ammonium ion-adsorbing silica is added to an aqueous dispersion of an ionomer resin, and the pH is adjusted by adding water and an alkali component. The alkali component to be added is preferably an organic amino compound or an alkaline aqueous solution such as aqueous ammonia in order to prevent gasification during the drying process so that no alkali component remains in the solid film. The pH of the treating agent of the present invention is not limited as long as it is alkaline, but it is preferably adjusted to about 10 and then a predetermined amount of a water-soluble epoxy compound is added. Mix well with a disperser. In addition,
There is also a method of heating and melting a mixture of an ionomer resin and a water-soluble epoxy compound to emulsify all at once, but this method is not preferable especially when an inorganic rust preventive is coexisted, and a precipitate may be generated. Better.

According to the treatment method of the present invention, a metal material is treated with the water-dispersible metal surface treating agent of the present invention, and then baked. The treatment method is not particularly limited, but a roll coater method is preferable, and other examples include a dipping method and a spray method. The coating weight of the coating film is 0.3 to 5.0 g / m ^{2 in} dry mass.
And If it is less than 0.3 g / m ² , corrosion resistance deteriorates, which is not preferable. Further, those exceeding 5.0 g / m ² are not economically preferable. The baking temperature is 80 to 180.
C. and baking time are preferably 5 seconds to 30 minutes, more preferably 10 seconds to 10 minutes.

The metal material is not particularly limited, and may be a plate or other untreated steel, an electrogalvanized steel, a galvanized steel, a galvalume steel, an aluminum material, an aluminum alloy material, or other metal such as a copper material. Applicable to materials. Furthermore, the metal material of the present invention includes a metal-plastic composite material in which various metals are laminated on a plastic material.

[0029]

[Examples 1 to 28, Comparative Examples 1 to 12]

<Preparation of water-dispersible metal surface treatment agent> 100 g of ethylene-methacrylic acid copolymer [melt flow index (MFR) is 19
0.8 g / 10 min at 0 ° C., methacrylic acid content 15% by mass], and sodium hydroxide as a neutralizing agent were melted at 250 ° C. to prepare an ionomer resin melt.
After adding 0 g, the mixture was charged into a 1 liter internal pressure-resistant homomixer heated to 170 ° C. over about 2 hours while stirring at 1000 rpm. After completion of the charging, stirring was further continued for 1 hour to cool to room temperature to obtain an aqueous dispersion of an ionomer resin. The resin solid content concentration of this aqueous dispersion was 25% by mass.

Next, pentaerythritol polyglycidyl ether (denacol EX-14) having a chlorine content of less than 1.0% by mass and a water solubility of 100% as an epoxy compound.
10, manufactured by Nagase Kasei Kogyo Co., Ltd.), and colloidal silica (silica content: 20% by mass) whose surface adsorbs ammonium ions and whose alkalinity is controlled as silica is prepared, and an ionomer aqueous dispersion resin, an epoxy compound and silica are prepared. Various blends were prepared at the mass percentages shown in Tables 1 and 2, and they were stirred in a disper at 500 rpm for 60 minutes. The mass% of the ionomer resin and the colloidal silica in Tables 1 and 2 is a value converted into a solid content.

After the stirring, the pH was adjusted to 10 with amino alcohol. After the stirring for a total of 60 minutes was completed, the mixture was filtered with a 200 mesh filter, and the filtrate was adjusted with pure water (if necessary). The water-dispersible metal surface treating agent of this example or a comparative example was used. <Coating on steel plate> The amount of chromium adhered by a known electrolytic chromating method is 50 mg / m2 as metal chromium per side.
On the surface of the electro-galvanized steel sheet of controlled thickness 1.0mm to ² (one surface weight per unit area 20 g / m ^2), a solid film of the water-dispersible metal surface treatment agent is 0.3 to 5.0 g / m ² After coating with a bar coater, the coating film was baked in a gas furnace so that the outlet side plate temperature became 120 ° C. in 20 seconds in the furnace, thereby preparing a test piece. The measurement of the amount of adhesion was performed by a gravimetric method.

<Performance evaluation test> 1) Alkali resistance 2% of alkali degreasing agent (SC53, manufactured by Nippon Paint Co., Ltd.)
Half of the test piece was immersed in an aqueous solution at a liquid temperature of 55 ° C. for 10 minutes, washed with water and dried, and the soundness of the coating film appearance and the film removal resistance were compared and observed with the non-immersed portion. ：: No abnormality in coating film, ○: Slight discoloration of appearance, Δ: Partial film removal, ×: Complete film removal 2) Whitening resistance (boiling water resistance test of coating film) Half of test piece in boiling water of pure water 2 After immersion for a period of time, the test piece was lifted, and after waiting for natural drying, the difference in appearance between the immersed part and the non-immersed part was visually determined. ◎: No difference in appearance, ：: Slight discoloration in immersion part, △:
Partially whitened, ×: whitened all over 3) Mold resistance to galling A cylindrical Ericssen press is used. 50 mm diameter cylinder, drawing ratio 2.4, plate thickness 1.0 mm, clearance 0.0 mm,
The test piece was squeezed out with no oil at a wrinkle holding pressure of 1.5 ton, and the state of die squeezing of the cylindrical body was observed. ：: No galling, ○: Slight galling, Δ: Partial galling, ×: Full galling 4) Corrosion resistance A salt spray test in accordance with JIS Z2371 was performed. A test piece having an Erichsen 6 mm extruded portion and a flat portion (tape seal on the end face and the back face) was prepared, and 168 hours after spraying with salt water, the state of white rust generation was evaluated. ：: no rust, ：: area ratio 5% or less, Δ: 5 to 30%,
×: 30% or more 5) Post-coat secondary adhesion A melamine alkyd resin-based paint (white) was baked on a test piece under the conditions of a dry film thickness of 20 to 25 μm, 125 ° C. for 20 minutes, and then added to boiling pure water. After immersion for 30 minutes and leaving indoors for 24 hours, in a grid test in accordance with JIS K5400, 100 pieces of 1 mm square grids were closely adhered to the test piece and scribed, using an adhesive tape ("Cellotape", manufactured by Nichiban). Forcible peeling was performed in the 45 ° direction, and the peeled portion was evaluated. ◎: No peeling, ○: Slight peeling, Δ: Partial peeling, ×: Full peeling 6) Solvent resistance Eight layers of gauze impregnated with ethanol on the SUS round bar end face were loaded 1 kg x 10 times (reciprocating), After the coating was impregnated with MEK (methyl ethyl ketone) and rubbed with a load of 1 kg x 50 times (reciprocating), the dissolved appearance of the coating film was dyed with a special dye, and judged from the difference in the degree of dyeing. ◎: No abnormality, ○: Slightly dissolved, Δ: Partially dissolved, ×:
Total dissolution (substrate exposure) 7) Storage stability of treating agent After the addition of epoxy compounds having different amounts of chlorine, a change in the properties of the treating agent was observed at 40 ° C. for 30 days. ◎: no abnormality, ○: slightly turbid but no precipitation, Δ: turbidity increased but no precipitation, ×: large precipitation.

[0033]

[Table 1]

[0034]

[Table 2] From the above results, it can be seen that if the amount of silica in the treating agent is out of the range of the present invention, corrosion resistance is damaged on the lower limit side, and press workability such as drawing is damaged on the upper limit side, and it is better to avoid it. Further, when the amount of the ionomer resin is out of the range of the present invention, the lower limit side is inferior in corrosion resistance, press-type galling property, the secondary adhesion of the post coat by melamine alkyd is inferior, and the upper limit side is press working such as drawing. Is slightly inferior, and thus it is not preferable.

Further, it can be seen that, with the passage of time, the precipitate generated in the treatment liquid becomes cloudy or precipitates when the chlorine content in the water-soluble epoxy compound exceeds 1% by mass. Further, with respect to the water-soluble epoxy compound whose chlorine content is controlled, when the amount is out of the range of the present invention, the secondary adhesion of the post coat is deteriorated on the lower limit side, and the alkali resistance, whitening resistance, It is understood that the overall performance of the coating film such as galling resistance is lowered. Further, when the Tg of the ionomer resin is out of the range of the present invention, the film becomes soft and the anti-galling property is inferior at the lower limit, and the flexibility of the film is insufficient and the anti-galling property is inferior at the upper limit. When the degree of neutralization of the ionomer is out of the range of the present invention, it can be seen that the stability of the treatment liquid is deteriorated on the lower limit side, and the secondary adhesion of the post coat is deteriorated on the upper limit side. When the amount of the organic-inorganic composite film is out of the lower limit range of the present invention, not only the corrosion resistance but also the mold galling resistance and the secondary adhesion deteriorate. [Examples 29 to 57 (when a water-dispersible polyolefin resin is added as an aqueous wax)] In addition to the ionomer resin aqueous dispersion, epoxy compound, and ammonium ion-adsorbed silica prepared for each of the above-described Examples and Comparative Examples. A water-dispersible polyolefin resin having a number average molecular weight of 1500 and a particle size of 0.7 μm was mixed in various amounts at a mass percentage (in terms of solid content) shown in Table 3, and was stirred for 30 minutes at 500 rpm for 30 minutes. After finely adjusting the pH with an amino alcohol, the mixture was filtered through a 200 mesh filter, and the filtrate was used as a water-dispersible metal surface treatment agent having a lubricating function. Table 3 shows the compositions and evaluation results.

[0036]

[Table 3] From the above results, the addition of the polyolefin resin as a lubricant has little effect on other performances within the scope of the present invention,
It can be seen that the effect of the ionomer resin and silica constituting the treating agent is the same as before the addition of the polyolefin resin.

[0037]

Since the water-dispersible metal surface treating agent of the present invention is prepared by combining a specific ionomer resin, a water-soluble epoxy compound and silica, it has a high storage stability of 1 month or more at 40 ° C. or less. Have. In addition, the surface-treated metal material of the present invention such as a post-plating treated product has solvent resistance, scratch resistance, mold galling resistance, deep drawability, post-coating resistance without impairing alkali resistance, paint adhesion and corrosion resistance. Has properties and the like. Therefore, the surface-treated metal material of the present invention is suitable as a constituent member of household electric appliances, building materials, automobile parts, and the like.

Continued on the front page (72) Inventor Atsushi Morishita 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Corporation Kimitsu Works (72) Inventor Yujiro Miyauchi 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Corporation Kimitsu Inside the steelworks (72) Inventor Akira Takahashi 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Corporation Inside the Kimitsu Works (72) Inventor Motoo Kabeya 4-1-115 Minamishinagawa, Shinagawa-ku, Tokyo Japan Paint stock In-house F-term (reference) 4J038 CB061 CG011 CG031 CG111 DB002 GA15 HA446 KA08 KA15 MA08 MA10 MA13 NA03 NA04 NA11 NA12 PA19 PB02 PB09 PC02 4K044 AA02 AA06 BA10 BA14 BA21 BB01 BB03 BB11 BC01 CA05 BC06

Claims (5)

[Claims] 1. An ionomer resin having a total solid content concentration of 10 to 80% by mass and 40 to 90% by mass of the solid content,
0 mass% is a water-soluble polyfunctional epoxy group-containing compound, 9 to 5
0% by mass is a water-dispersible metal surface treatment agent composed of silica to which one or both of an amino group and an ammonium ion are adsorbed, wherein the ionomer resin has a glass transition point of 50 to 70 ° C. An acid polymer in which 40 to 60% of the carboxyl groups contained therein are neutralized with a monovalent metal cation, and the water-soluble polyfunctional epoxy group-containing compound has a chlorine content of 1 mass%. % Of a water-dispersible metal surface treatment agent. 2. The aqueous dispersion according to claim 1, wherein 0.5 to 20% by mass of the water-dispersible metal surface treatment agent in the solid content is composed of a water-dispersible polyolefin resin. Metal surface treatment agent. 3. In the surface layer of the metal material, 40 to 90% by mass of the solid content is an ionomer resin, 1 to 10% by mass is a water-soluble polyfunctional epoxy group-containing compound, and 9 to 50% by mass is one of an amino group and an ammonium ion. Or an organic-inorganic composite film composed of silica having both adsorbed thereon, having a dry mass of 0.3 to 5.0 g / m ² , wherein the ionomer resin has a glass transition point of 50 to 70 ° C. 40-60 of the carboxyl group contained in the polymer
% Is neutralized with a monovalent metal cation.
A surface-treated metal material, wherein the chlorine content in the organic-inorganic composite film is less than 0.1% by mass. 4. The organic-inorganic composite coating further contains 0.1% of solid content.
The surface-treated metal material according to claim 3, wherein 5 to 20% by mass is composed of a water-dispersible polyolefin resin. 5. The method according to claim 1, wherein the upper layer of the surface of the metal material is provided.
The water-dispersible metal surface treating agent described in the above item is applied and baked to obtain an organic-inorganic composite film having a dry mass of 0.3 to 5.0 g.
/ Method for producing a surface-treated metal material characterized by m ² formed.