KR100391368B1 - Aqueous Chromate Treatment Composition and Processing Method for Metal Materials - Google Patents

Abstract

A chromate coating with excellent corrosion resistance, chromium elution and paint paintability is characterized by (1) an inorganic component consisting of Cr ⁶⁺ and Cr ³⁺ ions, and (2) an organic component consisting of a wax, an organic fluorine compound and / or a polymerizable compound. And (3) an emulsifying component consisting of a nonionic-anionic composite surface active component having an anionic portion and a nonionic portion having a polyethylene glycol and / or polyoxyethylene group, wherein the organic component (2) is an emulsifying component It can be formed on the metal surface in a single coating process by applying a special aqueous chromate treatment composition emulsified by (3).

Description

Aqueous Chromate Treatment Composition and Processing Method for Metallic Materials

Technical Field

The present invention relates to an aqueous chromate treatment composition for metal materials and a treatment method. More specifically, the present invention relates to an aqueous chromate treatment composition for a metallic material such that a lubricant chromate coating having excellent lubricity, excellent moldability, excellent corrosion resistance, good adhesion to a paint coating and reduced chromium elution is formed on the surface of the metal material and It relates to a chromate treatment method. Aqueous chromate treatment compositions exhibit long pot-life.

Background

Usually, metal materials, for example steel materials, are formed by the steel industry in the form of plates, pipes, or rods, and then the use of the shaped material in various products, for example household appliances, vehicles or building materials products. According to the desired shape and size by pressing or forging, and then the shaped article is assembled. In almost all molding processes, the molding operation is performed with lubricating oils such as press oils; Solid lubricants such as calcium soap; Zinc phosphate paints; And applying a lubricant paint to the molded surface of the metal material by a combination of two or more of the above lubricating materials. In the factory for the molding process, the molding machine and its surroundings are sometimes soiled by the lubrication of powders, solids or solids and are not always satisfactory in terms of environmental pollution prevention, worker safety and industrial worker hygiene.

Sacrificial corrosion protection of steel materials by plating with zinc-containing metals is known to be very advantageous and economical. Therefore, about 10 million tons of steel, equivalent to 10% of Japan's total annual crude steel production, is zinc-containing metal plated steel sheet. And are used in various industries, such as the construction, automotive and household appliance industries.

Sacrifice to Zinc In the corrosion protection mechanism, when two kinds of metals, namely zinc and steel, come into contact with each other, local cells are formed and zinc, the base metal more than steel, acts as an anode and steel acts as a cathode. When present alone, it prevents anodization of the steel and prevents corrosion of the steel due to the formation of local cells. Therefore, the corrosion protection effect also disappears when zinc in contact with the steel disappears. It is necessary to control the corrosion of the zinc layer in order to maintain the corrosion protection effect over a long period, and as a corrosion control means, chromate treatment is applied to the steel material after the steel material is plated with zinc-containing metal.

A lubricant, for example press oil, is applied to the zinc-containing metal-plated steel material surface-treated by the chromate treatment, and then the lubricant-coated material undergoes a molding process, for example, a press operation. After the molding operation, the lubricant remaining in the process material, for example press oil and dirt containing metal dust, is removed with a chlorine compound-containing cleaning liquid, for example trichloroethylene. The cleaned surface of the metal is then painted and the painted material is fed into the assembly section to produce the final product.

Recently, there is a need to limit or suspend the use of chlorine and / or fluorine containing solvents due to the increased demand for environmental protection worldwide. Therefore, there is a strong demand for a new lubricant chromate that can be easily formed into a metal material without lubricating oil without applying a lubricant to a conventional lubricant coating surface by applying a metal material with a conventional lubricant chromate coating film.

Many attempts have been made to meet the aforementioned needs. These attempts are described in the following publications.

The prior art disclosed in this publication is briefly described below.

Publication (1) discloses an organic-inorganic composite reaction product consisting of a water-soluble or water dispersible organic resin, an alkoxysilane compound and silica as a main component: and an aqueous composition consisting of a lubricant. The coating film formed from the aqueous composition and composed of the organic-inorganic composite reaction product as a main component exhibits insufficient flexibility, adhesion to metal materials, and insufficient molding processability.

Publications (2) to (6) disclose a method of forming a surface coating film having high corrosion resistance and lubricity for steel sheets. In this method, a chromate coating is formed on the surface of the steel sheet, and then an organic resin component consisting of an aqueous acrylic resin as the base resin: a solid lubricant, for example, graphite or molybdenum disulfide, or α, β-unsaturated carboxylic acid monomer Acrylic resin produced by copolymerizing a monomer with another monomer capable of copolymerizing with an α, β-unsaturated carboxylic acid monomer; And at least one member selected from chromate, silica sol, silane coupling agent, titanate coupling agent and particulate pigment. Because the resulting coating surface exhibits water and oil resistance properties, these methods are disadvantageous in that when the resulting coating surface is painted, the paint cannot be uniformly dispersed on the surface and cannot be tightly bonded to the surface.

The publication 7 is a coating liquid prepared by mixing a composition comprising a curable component consisting of an organic resin selected from an epoxy resin, a polyester resin and an acrylic resin and an amino resin or a polyisocyanate resin with an electrically conductive material, a chromium compound and a lubricating material. Discloses a method of coating a metal material. In this method, when the electrically conductive material is carbon black or graphite, the resulting coating is colored black so that the resulting product can only be used for limited applications. In addition, when the electrically conductive material is a metal powder, a semiconductor oxide, or iron phosphite, the resulting coating film exhibits insufficient molding processability.

In the method disclosed in the publication (8), a coating film comprising a composite or mixed material consisting of a polyurethane resin and silicon dioxide, or another coating film composed of the composite or mixed material mixed with zinc powder as a main component is a zinc-containing metal plated steel sheet. Is formed on the surface of the plating layer. However, this method is disadvantageous in that the resulting coating film does not impart sufficient moldability to the coated metal material.

In the method of publication 9, a chromate coating film is formed on a plated steel sheet or a cold rolled steel sheet, and then the organic composite resin composition consisting of carboxylated polyolefin resin, liquid epoxy resin, fluorine-containing resin and silica is coated on the surface of the chromate coating film. Since the fluorine-containing resin has not only waterproof properties but also oil-repellent property, the paint coating film cannot be uniformly and firmly attached to the composite resin coated surface when the paint coating film is applied to the composite resin coated surface. Further, when the coated coromate treatment liquid is applied to the metal material to form the undercoat, and then the composite resin compositions of the publication 9 are applied to the undercoat, the composite resin composition is an aqueous composition, so that the chromium compound is applied. It is eluted from the undercoat to the aqueous composite resin in the middle and the safety of the aqueous resin composition is disrupted.

In the method disclosed in publication 10, the chromate coating film is formed in a specific amount on a steel plate plated with zinc, zinc alloy or aluminum alloy and is a mixture of resin, silica and fluorine-containing resin powder having hydroxyl and / or hydroxyl groups. The formed dendritic coating film is formed on the front and back surfaces of the chromate coated steel sheet. This dendritic mixture is disadvantageous in that the paint layer produced can become uneven when paint is applied to the dendritic coating surface and has poor adhesion to the dendritic coating surface.

In the method disclosed in publication 11, the chromate coating is plated with zinc, zinc alloy or aluminum alloy; Resin having hydroxyl and / or carboxyl group, silica, and resins having a high resistance to powdering in high-speed press operations, formed in a specific amount on the front and back surfaces of steel sheets coated with a resinous mixture of polyolefin wax having a melting point of 110 ° C. or higher. To produce a steel sheet. However, the method of publication 11 is still insufficient in that it does not provide the steel sheet with sufficient lubricity and adhesion to the paint.

Merits 12 consist of an inorganic component consisting of sixth chromium ion alone or sixth chromium ion and trivalent chromium ion, an organic component consisting of a special acrylic polymer emulsion, and a lubricating component dispersion dispersed by a nonionic emulsifier and having high lubricity. And metal surface treatment compositions having a pH value of 5 or less.

The composition of the publication 12 has sufficient surface treatment stability, corrosion resistance, paint adhesion and molding processability. However, the resulting applied metal material is still insufficient in weldability and electrical grounding.

The publication 13 discloses a chromate treated steel sheet containing an organic lubricant material and silica and coated with a chromate coating having excellent corrosion resistance, lubricity and electrical conductivity. However, in the disclosed chromate treatment compositions, the stability of the organic lubricant mixed with silica is low because the organic lubricating material is emulsified by a nonionic surfactant so that the resulting treatment liquid contains precipitates or aggregates. In addition, since the treatment liquid has high foamability, the continuous operability of the treatment liquid is poor. Moreover, because the resulting coating contains silica, the resulting coated steel sheet exhibits insufficient weldability.

Thus, a coating film having a process that can be molded in a single step with the treatment composition, excellent corrosion resistance, paint adhesion, weldability, treatment liquid stability and sufficient lubricity has not been achieved yet.

As described above, when the paint coating is applied directly to the molded metal material without undercoating, the metal material is treated with a phosphating liquid or chromate liquid before the molding operation. Also referred to as finger mark-resistant steel sheets, surface treated steel sheets having excellent paint overcoating properties and high corrosion resistance in their non-painted parts are commonly used for various applications. Also referred to as lubricating steel sheets, other surface treated steel sheets which can be molded by a lubricating forming process without lubricating oil and which have excellent paint coating properties similar to finger mark resistant steel sheets have recently been put into practical use. These lubricant steel sheets do not require a deoiling process and are therefore useful for simplifying the process, reducing the total processing cost and improving the working environment.

Typically, finger mark-resistant steel sheets and lubricant steel sheets are produced in a two-step process consisting of applying a chromate treatment to the surface of a zinc-containing metal plated steel sheet, and then applying the chromate treatment surface with an organic resin. In a recent improved process, the resin containing chromate solution is applied to the plated steel plate surface in a single step. It is also referred to as a lubricant chromate steel sheet when the degree of deformation of the forming work process is relatively low, for example in a bending operation, and another surface treated steel sheet produced by a single surface treatment with a lubricant containing chromate solution is fed to the hard forming work process. .

Various single chromate treatment processes are disclosed in the following publications.

Publications 14 and 15 disclose resin-containing aqueous chromate compositions consisting of a chromate component as a main component and an acrylic resin emulsified with a nonionic surfactant. If this composition is used to prepare a single step treatment solution, the resulting treatment solution exhibits insufficient portlife. In addition, when the composition is applied to a metallic material, the resulting coating shows poor paint paintability, while the coating film is excellent in corrosion resistance. The inventors of the present invention found that when the treatment liquid containing the nonionic surfactants indicated in the publications (14) and (15) is mixed with silica, the resulting mixture is agglomerated to increase the viscosity of the mixture or to produce a precipitate. In view of the disadvantages of the composition was confirmed.

Publications (16) and (17) disclose chromate treatment liquids composed of a chromate component, a polyurethane resin, and a nonionic surfactant as main components. The coating film produced from the chromate treatment liquid is disadvantageous in that the paint coatability of the coating film is poor, the port life of the chromate treatment liquid is insufficient, and the mixture stability of the liquid and silicon is poor.

The publication 18 discloses a chromate treatment composition for steel sheets composed of a silica-containing chromate component and lubricant particles as main components. This composition is disadvantageous in that the resulting coating has very poor paint coatability.

Publication 19 discloses a method of forming a water-poorly soluble chromate coating on a metal material by using a treatment liquid composed of a chromate component, an aqueous resin liquid (emulsion) and a water-soluble polymerizable polyol as main components. The aqueous resin liquid is substantially free of nonionic emulsifiers, and therefore the aqueous resin emulsion becomes unstable due to the oxidative activity of chromium ions and exhibits poor stripe. In addition, when the treatment liquid of the publication 19 is converted to a dry coating film, hexavalent chromium ions are insufficiently reduced, and thus the resulting coating film exhibits an unfavorable solution of chromium solution from the coating film. In order to solve the above problems, reduction of hexavalent chromium ion is promoted by adding a polymerizable material produced by addition reaction of a glycol compound with a polyfunctional polyol compound having a skeletal structure formed from a novolak phenol resin. The inventors of the present invention confirmed that in the chromate compositions described above, the stabilization of the aqueous resin emulsion is insufficient, and the port life of the treatment liquid is reduced because the reduction reaction of the hexavalent chromium ion proceeds in the treatment liquid.

Therefore, the composition has sufficient stability and long pot life, and resin-containing for metal materials that can form a chromate coating film having excellent corrosion resistance and paint overcoating properties and low chromium elution similar to those obtained by conventional two-step treatment in a single process. An aqueous treatment composition has not yet been obtained.

Disclosure of the Invention

It is an object of the present invention to achieve superior performance similar to or higher than that obtained by a conventional two-step process comprising a chromate undercoating step that improves the corrosion resistance of the metal material and an organic resin application step that improves the corrosion resistance and paint overcoating properties of the metal material. It is to provide an aqueous chromate treatment composition and method for a metal material that can form a coating film having a single step.

It is another object of the present invention to provide an aqueous chromium treatment composition and method for metal materials having a high stability of the treatment liquid and capable of forming a coating film having excellent corrosion resistance, paint overcoating properties and low chromium elution in a single step process. .

This object can be achieved by the aqueous chromate treatment compositions and methods of the present invention.

The aqueous chromium treatment composition for metal materials of the present invention has a pH of 3.0 or less:

(1) an inorganic component consisting of (a) hexavalent chromium ions and (b) trivalent chromium ions dissolved in water;

(2) an organic component consisting of at least one member selected from the group consisting of (c) a wax, (d) a fluorine-containing organic component and (e) an organic polymerizable compound;

(3) nonionics having at least one hydrophobic segment and a hydrophilic composite segment consisting of anionic moiety and a nonionic moiety having at least one member selected from the group consisting of polyethylene glycol groups and addition polymerization ethylene oxide groups. Consisting of an emulsifying component consisting of an anionic composite surfactant,

The organic component 2 is present in the form of an aqueous emulsion in which the organic component 2 is stably emulsified with the aid of the emulsifying component 3 in the aqueous composition.

The method of the present invention for surface treatment of metallic materials is:

Forming a layer of an aqueous coating liquid composed of the aqueous chromate treatment composition as described above on the surface of the metal material, and drying the aqueous coating liquid layer to form a lubricant chromate coating film on the surface of the metal material.

Best Mode for Carrying Out the Invention

The aqueous chromate treatment compositions and methods of the present invention can be applied to a variety of metal materials, including steel materials such as steel sheets, zinc-containing metal plated steel materials such as sheets, aluminum alloy sheets, and stainless steel materials, which are merely It is illustrative only and does not limit the scope of the metal material.

The aqueous chromate treatment composition of the present invention has a pH value of 3.0 or less and consists of an inorganic component (1), an organic component (2) and an emulsifying component (3) for the organic component (2).

The inorganic component (1) consists of hexavalent chromium ion (a) and trivalent chromium ion (b) dissolved in water. The concentration of hexavalent chromium ion and trivalent chromium ion is not particularly limited. Usually, when the chromium treatment composition is used as the chromium treatment liquid, the total concentration of the hexavalent and trivalent chromium ions in the treatment liquid is preferably 1 to 100 g / liter, more preferably 1 to 40 g / liter. If the total concentration is less than 1 g / liter, the resulting coating film may have insufficient corrosion resistance. In addition, if the total concentration exceeds 100 g / liter, the resulting aqueous chromate treatment composition may have insufficient port life and the corrosion resistance of the resulting coating may be saturated, which can be an economic disadvantage.

The actual acceptable potlife of the aqueous chromate treatment composition is that when the closed container is filled with the aqueous chromate treatment composition and left at a temperature of 50 ° C. for at least 5 days, no precipitates and / or coagulum are generated in the composition, The composition is set at such a level that it can be applied directly to the metal surface without the need for cleaning.

The trivalent chromium ion (Cr ³⁺ ) and the hexavalent chromium ion (Cr ⁶⁺ ) in the inorganic component (1) of the chromate treatment composition of the present invention have a weight ratio (Cr ³⁺ / Cr ⁶⁺ ) of 2/8 to 7/3. It is preferable to exist as). If the weight ratio (Cr ³⁺ / Cr ⁶⁺ ) is less than 2/8, the content of hexavalent chromium in the resulting coating film becomes too large, resulting in insufficient water resistance. In addition, if the weight ratio (Cr ³⁺ / Cr ⁶⁺ ) exceeds 7/3, the content of hexavalent chromium in the resulting coating film is too small, resulting in too low corrosion resistance.

The source of hexavalent chromium ions is not limited to a specific group of chromium compounds.

For example, hexavalent chromium ions can be derived from chromic acid, dichromic acid and salts of these acids. In addition, the source of trivalent chromium ion is not limited to the specific group of chromium compounds. Trivalent chromium ions can be derived, for example, from reduction products of chromium nitrate, chromium phosphate, chromium fluoride and chromic acid.

In order to keep the aqueous chromate treatment liquid of the present invention stable, it is important to stabilize the trivalent chromium ion contained in the aqueous treatment liquid. For this purpose, the pH of the aqueous treatment liquid is adjusted to a level below 3.0. The kind of acid to be used for adjusting the pH value of the aqueous treatment liquid is not limited. Typically, preferably the acid for pH adjustment is an inorganic acid such as phosphoric acid, chromic acid, and dichromic acid; Organic carboxylic acids such as formic acid, acetic acid, glycolic acid, citric acid, tartaric acid, malic acid, acrylic acid, methacrylic acid and maleic acid; And at least one member selected from polymers and copolymers of ethylenically unsaturated polymerizable carboxylic acids such as acrylic acid, methacrylic acid and maleic acid. When the pH value of the chromate treatment liquid is adjusted to one or more of the above-mentioned specific acids, the paint coatability and corrosion resistance of the resulting coating film are not affected. The pH-adjusting acid may be contained in the inorganic component (a) of the chromate treatment composition or may be immersed when the aqueous treatment liquid is prepared from the composition.

In the aqueous chromate treatment composition of the present invention, the inorganic component (1) comprises (i) phosphoric acid, (ii) inorganic fluoride compound, (iii) granular silica and (iv) zinc, iron, nickel, cobalt, aluminum, titanium and zirconium ions. Optionally further comprising (g) an additive component consisting of at least one member selected from the composed class.

Preferably the inorganic fluoride compound (ii) is selected from hydrogen fluoride (hydrofluoric acid) and salts thereof and fluoride complexes such as silico-fluoric acid and salts thereof, zirconium-fluoric acid and salts thereof, and Titanium-fluoric acid and salts thereof. Preferably the phosphoric acid (i) and inorganic fluoride compounds (ii) have an equivalent weight ratio of the total amount of trivalent chromium ions to the phosphoric acid (i) and inorganic fluoride component (ii) of at least 1/3, more preferably from 1/3 to Present at 50/1. If the equivalent weight ratio is less than one third, the resulting treatment liquid has an acid content that is too high such that the resulting coating film may exhibit insufficient water resistance and poor corrosion resistance.

Preferably the granular silica (iii) for the additive component (g) consists of at least one member selected from colloidal silica, silica sol and fumed silica, with a particle size of 5 to 30 nm. If the particle size of the silica (iii) is 300 nm or more, the surface of the resulting coating film formed from the silica (iii) containing treatment liquid may be rough and may have insufficient appearance and reduced gloss. In addition, if the particle size is less than 5 nm, the silila particles may have too large a specific surface area and the resulting treatment liquid may exhibit insufficient stability upon storage and use. Granular silica (iii) may be added in the preparation of the aqueous treatment liquid.

Granular silica (iii) added to the aqueous chromate treatment liquid effectively improves the corrosion resistance and finger mark resistance of the resulting coating film.

Granular silica (iii) is preferably used in an amount such that the resulting coating does not exhibit too large electrical resistance and thus reduced weldability.

The granular silica (iii) in the aqueous chromate treatment composition can be stably contained for a long time due to the intention of the emulsifying component (3).

The inorganic component 1 optionally contains at least one kind of additional metal ions selected from zinc, iron, nickel, cobalt, aluminum, titanium and zirconium ions which can effectively improve the corrosion resistance of the resulting coating film.

The organic component (2) in the aqueous chromate treatment composition of the present invention consists of at least one member selected from the group consisting of (c) waxes, (d) fluorine-containing organic compounds and (e) organic polymerizable compounds.

The organic component 2 effectively improves the lubricity, corrosion resistance and water resistance of the resulting coating film.

Preferably, at least one member selected from the group consisting of wax (c) and fluorine-containing organic compounds (d) has a weight ratio of 1/50 to 100/1 relative to the total amount of hexavalent and trivalent chromium ions. . If the weight ratio is less than 1/50, the effect of the wax (c) and / or the fluorine-containing organic compound (d) may be insufficient in improving lubricity, corrosion resistance and water resistance.

In addition, if the weight ratio exceeds 100/1, the resulting coating film may exhibit insufficient corrosion resistance, weldability and electrical grounding.

The wax (c) is preferably selected from paraffin wax, microcrystalline wax and polyethylene wax. Preferably the wax has a softening temperature of 50 to 160 ° C, preferably 50 to 150 ° C. If the softening temperature is less than 50 ° C, the wax cannot impart sufficient lubricity to the resulting coating film. If the softening temperature is 160 ° C. or higher, the wax may be difficult to emulsify, and the resulting coating film formed from the treatment liquid containing the high melting point wax may contain the wax unevenly and may exhibit insufficient lubricity.

The wax (c) is preferably in the form of fine particles having an average size of 0.1 to 5 mu m. If the average size is less than 0.1 μm or more than 5 μm, the resulting coating film may have insufficient lubricity.

Preferably, the fluorine-containing organic compound (d) for the organic component (2) is a polymer having a repeating ethylenic unit (-(CH ₂ -CH ₂ )-) in which at least one hydrogen atom is replaced with a fluorine atom, for example Polyvinyl fluoride (PVF), polyvinylidene fluoride (PVdF), polytrifluoroethylene (PTrFE), polytetrafluoroethylene (PTFE); Copolymers of at least one olefin monomer and at least one fluorine containing monomer such as vinyl fluoride, vinylidene fluoride, trifluoroethylene and tetrafluoroethylene: and from modified products of the fluorine containing polymers and copolymers Is generated. In particular, PTFE is advantageously used in the present invention because it has a low coefficient of friction.

The fluorine-containing organic compound (d) may be supplied in an aqueous dispersion or emulsion state, which may be produced by emulsion polymerization.

The organic component 2 optionally further comprises an additional lubricant consisting of graphite, molybdenum disulfide, and at least one member selected from lubricating oils and fats and oils. The addition of additional lubricants sometimes results in non-uniformity due to non-uniform distribution of additional lubricants when the resulting coating is colored black or gray when graphite or molybdenum disulfide is used, and when oil or fat or oil is used, It may be disadvantageous in that an economic disadvantage arises because the paint coating must be removed from the resulting coating before it is applied.

The organic polymerizable compound (e) for the organic component (2) is not limited to a specific group of compounds as long as the polymerizable compound (e) can effectively improve the lubricity, corrosion resistance and paint coatability of the resulting coating film.

Preferably, the organic polymerizable compound (e) is selected from those recognized as useful as coating polymers in conventional two-stage chromate treatment processes, for example acrylic polymers and copolymers, polyesters, epoxy polymers and polyurethanes. The organic polymerizable compound (e) is a water-soluble polymer such as polyacrylic acid, maleic acid-methylvinylether copolymer, and polyacrylamide, and a water-insoluble polymer such as acrylic ester polymer and copolymer, styrene- Acrylic ester copolymers, epoxy resins, ethylene-acrylic acid copolymers and polyesters, and may be in an aqueous emulsion state. In particular, an aqueous emulsion of an epoxy resin having a bisphenol structure effectively improves the paint adhesion of the resulting coating film.

The organic component (2), in particular the organic polymerizable compound (e), preferably has a solids content in the aqueous chromate treatment composition of 350 g / liter or less, more preferably 0.5 to 350 g / liter. If the content exceeds 350 g / liter, the resulting aqueous composition may have a too high viscosity and low fluidity and thus have a reduced potlife since the high content of organic components (2) is locally oxidized and aggregated by chromium ions. Because it can be.

The emulsifying component (3) in the aqueous chromate treatment composition of the present invention comprises at least one hydrophobic segment and at least one member selected from the group consisting of polyethylene glycol groups and addition polymerized ethylene oxide groups and anionic portions. (F) at least one nonionic-anionic composite surface active compound consisting of at least one hydrophilic composite segment consisting of:

The organic component 2 is in an aqueous emulsion state in which the organic component 2 is stably emulsified with the aid of the emulsifying component 3 in the aqueous composition.

Nonionic and anionic composite surfactants consist of at least one compound having at least one hydrophobic segment and at least one hydrophilic segment. The hydrophilic segment consists of a nonionic and anionic composite structure composed of anionic moieties and anionic moieties having at least one member selected from the group consisting of polyethylene glycol groups and addition polymerized ethylene oxide groups. Preferably, the hydrophilic segment is bonded to the hydrophobic segment via a bond other than an ester bond.

Nonionic and anionic complex surface-active compounds can be produced by reacting nonionic surface-active compounds with hydrophilic acid compounds such as sulfuric acid, phosphoric acid, carbonic acid and water-soluble salts of the acids.

Nonionic surface active compounds useful as nonionic and anionic complex surface active compounds include: (1) nonionic compounds without aromatic ring structures, such as addition products of higher aliphatic alcohols and ethylene oxide, aliphatic carboxylic acids and ethylene oxide Adducts of aliphatic carboxylic acids and aliphatic polyhydric alcohols and adducts of ethylene oxide, adducts of higher alkylamines and ethylene oxide, adducts of aliphatic carboxylic acid amides and ethylene oxide, and of polypropylene glycol and ethylene oxide Polyethyllan glycol compounds such as adducts; Glycerol-aliphatic carboxylic acid ester compound; Aliphatic carboxylic acid-pentaerythritol and sorbitol ester compounds; Polyhydric alcohol-alkyl ether compounds; And alkanol-amine-aliphatic carboxylic acid amide compounds,

(2) Nonionic compounds having aromatic ring structures, for example, addition products of aromatic monocyclic hydroxyl compounds such as phenol compounds, alkylated phenol compounds and styrenated phenol compounds with ethylene oxide, hydroxynaphthalene compounds and hydroxyanthracenes Addition products of aromatic polycyclic hydroxyl compounds such as compounds and ethylene oxide, and

(3) nonionic aromatic compounds, for example aromatic monocyclic hydroxyl compounds such as styrenated phenol compounds, polyvinylphenol compounds, and phenolic compounds, and aldehyde compounds such as formaldehyde and acetaldehyde or acetone and methylethyl Polycondensation products of ketone compounds such as ketones; The addition, condensation or polymerization product of the aromatic polycyclic compound, wherein the product has a polycyclic aromatic structure; Condensation and polymerization products of aromatic polycyclic hydroxyl compounds such as hydroxylnaphthalene compounds and bisphenol compounds with aldehyde compounds such as formaldehyde and acetaldehyde or ketone compounds such as acetone and methyl ethyl ketone; And other nonionic compounds having two or more of the above structures.

Among the nonionic compounds, higher aliphatic alcohol-ethylene oxide addition products, alkylphenol-ethylene oxide addition products and styrenated phenol-ethylene oxide addition products are readily available and can be advantageously used in the present invention.

Nonionic compounds are reacted with hydrophilic acid compounds such as sulfuric acid, phosphoric acid or carbonic acid to react nonionic hydrophilic and anionic hydrophilic groups such as sulfuric acid ester groups, -OSO ₃ H, sulfonic acid groups, -SO ₃ H, phosphate esters. And nonionic and anionic composite surface active ingredients having a water-soluble salt of a group, -OPO ₃ H, a carboxylic acid group, -COOH and an acid group of an alkali metal and an ammonium group.

Non-ionic moieties consisting of at least one member selected from carbon-carbon double bonds (C = C), polyethyleneglycol groups and addition-polymerized ethylene oxide groups having at least two addition-polymerized ethylene oxide groups, and anionic moieties. Special nonionic and anionic composite surface active ingredients (fa) are advantageously used in the present invention.

The surface active compound (fa) has an improved reactivity due to the carbon-carbon double bond contained therein, so that the organic component (2) can be emulsified with improved stability in the aqueous composition. Therefore, the resulting aqueous chromate composition when the surface active compound (fa) is used to emulsify the organic component (2) has a long port life and can form a coating film having improved corrosion resistance and paint-overcoating properties.

Surface active compounds (fa) can be obtained from reactive surface active compounds useful as emulsion polymerization additives for acrylic acid polymers.

Reactive surface active compounds (fa) useful in the present invention include non-ionic and anionic complex structures prepared by reacting an alkylated phenol-ethylene oxide adduct with sulfuric acid, and represent -CH = CHCH ₃ or -CH ₂ OCH. ₂ CH = CH ₂ was added and the ethylenically unsaturated compound react with a group, sikimeuro optionally neutralized with ammonia to a reaction product can be prepared.

Alternatively, the reactive surface active compound (f2) may be an esterification product of an ethylenically unsaturated compound such as acrylic acid or methacrylic acid with polyethylene glycol or polypropylene glycol, or styrene monomer in an amount of 2 moles per mole of unsaturated compound. Or addition polymerization with ethylene oxide; The nonionic segment of the addition polymerization product can be produced by addition reaction with an anionic acid compound, for example phosphoric acid or sulfuric acid.

The emulsifying component 3 can be mixed with the organic component 2 to emulsify the component 2 when the aqueous composition is prepared. Alternatively, the emulsifying component (3) can be used for the preparation of the organic polymerizable compound (e) by emulsion polymerization and can be fed together with the organic polymerizable compound (e) to the preparation of the aqueous chromate treatment composition of the present invention. .

The nonionic-anionic composite surface active component (f) in the emulsifying component (3) is 0.5 to 20 weight percent per 100 parts by weight of at least one member selected from the group consisting of wax (c) and fluorine-containing organic compounds (d) Parts, more preferably 1 to 15 parts by weight. If the amount of the composite surface-active compound (f) is less than 0.5 part by weight, the wax (c) and / or the fluorine-containing organic compound (d) cannot be sufficiently emulsified, and the resulting treated composition may have a poor pot life. And the resulting coating may exhibit insufficient corrosion resistance and paint coatability.

If the amount of the surface active compound (f) is greater than 20 parts by weight, the emulsifying effect of the resulting emulsifying component 3 may be saturated and the resulting coating may exhibit insufficient corrosion resistance, water resistance and paint coatability.

Further, preferably the emulsified component (3) in the aqueous chromate treatment composition of the present invention has a solids weight ratio of 5/100 to 25/100 to the total amount of the organic component (2) and the emulsified component (3), more preferably Is from 5/100 to 20/100. If the solids weight ratio is less than 5/100, the organic component 2 and the inorganic component 1 cannot be uniformly mixed with each other, so that the resulting composition exhibits poor port life. In addition, if the solids weight ratio exceeds 25/100, the resulting coating film exhibits insufficient water resistance and paint paintability, in particular secondary paint adhesion.

In the aqueous chromate treatment composition of the present invention, the total amount of the organic component (2) and the emulsifying component (3) is present in a weight ratio to hexavalent chromium ions of 2/1 to 800/1. If the weight ratio is less than 2/1, the resulting aqueous chromate treatment composition may exhibit insufficient stability and poor potlife, the resulting coating may contain too much content of chromate components, and hexavalent chromium emulsified components. Due to the low content of (3), the coating film could not be sufficiently reduced so that the coating film may exhibit a solid solution release of chromium. In addition, if the weight ratio exceeds 800/1, the resulting coating film may have an insufficiently low content of chromium and thus may exhibit insufficient corrosion resistance.

The emulsified component (3) in the aqueous chromate treatment composition of the present invention has a hydrophilic nonionic segment (h) having at least one member selected from the group consisting of polyethylene glycol groups having a degree of polymerization of 2 or more and addition-polymerized ethylene oxide groups. Optionally further comprising a warm surfactant.

Preferably the nonionic surface active compound (h) is present in a weight ratio to the nonionic-anionic composite surface active compound (f) of less than 2/1, preferably 1/20 to 2/1. Also preferably, the total emulsifying component (3) containing the nonionic surface active compound (h) is present in a dry weight ratio relative to the organic component (2) of 5/100 to 25/100.

When the organic component (2) consists of at least one wax (c) and at least one organic polymerizable compound (e), the weight ratio (c) / (e) of the wax (c) to the organic polymerizable compound (e) is The range of 2/98 to 30/70 is preferred. If the weight ratio is less than 2/98, the resulting coating film may exhibit insufficient lubricity. In addition, if the weight ratio exceeds 30/70, the resulting coating film may exhibit sufficient adhesion to the metal surface but may have insufficient corrosion resistance, paint paintability and lubricity.

In an embodiment of the aqueous chromate treatment composition of the present invention, the inorganic component (1) consists of hexavalent chromium (a), trivalent chromium (b) and particulate silica (g)-(iii), and the organic component ( 2) an emulsified component consisting of at least one member selected from a wax (c) and a fluorine-containing organic compound (d), wherein the organic component (2) consists of at least one nonionic-anionic complex surface active compound ( It is emulsified uniformly and stably with the help of 3).

In this embodiment, the emulsifying component (3) is preferably used at 0.5 to 20 parts by weight per 100 parts by weight of the organic component (2).

Granular silica (g)-(iii) is preferably selected from silica sol, colloidal silica and fumed silica having a particle size of 5 to 300 nm.

The inorganic component (1) optionally further includes phosphoric acid (g)-(i).

In another embodiment of the aqueous chromate treatment composition of the present invention, the inorganic component (1) comprises hexavalent chromium (a), trivalent chromium (b) and optionally phosphoric acid (g)-(i) and inorganic fluoride compounds ( g)-(ii) and at least one member selected from the group consisting of at least one member selected from waxes (c) and fluorine-containing organic compounds (d) and emulsifying components ( 3) consists of at least one nonionic-anionic composite surface active compound (f).

The organic component 2 is preferably emulsified uniformly and stably with the aid of the emulsifying component 3 used at 0.5 to 20 parts by weight per 100 parts by weight of the organic component 2.

In another embodiment of the aqueous chromate treatment composition of the present invention, the inorganic component (1) is a hexavalent chromium ion (Cr ⁶⁺ ) in a weight ratio (Cr ³⁺ ) / (Cr ⁶⁺ ) of 2/8 to 7/3. And trivalent chromium ions (Cr ³⁺ ), wherein the organic component (2) consists of at least one organic polymerizable compound (e) and optionally at least one wax (e), emulsifying component (3) Consists of at least one nonionic-anionic composite surface active compound (f).

In this embodiment, the emulsifying component (3) is used in solids weight ratio to the total amount of the organic component (2) and the emulsifying component (3) from 5/100 to 25/100, and the organic component (2) and emulsifying The total amount of component (3) is present in a weight ratio of hexavalent chromium ions of 2/1 to 800/1 and the aqueous composition has a pH value of 3 or less.

The inorganic component (1) is at least one selected from the group consisting of phosphoric acid (i), inorganic fluoride component (ii), granular silica (iii), and zinc, iron, nickel, cobalt, aluminum, titanium and zirconium ions (iv) And optionally further comprises an additive component (g) consisting of members.

Also in this embodiment, the emulsifying component (3) comprises (h) a nonionic surface active compound having a hydrophilic nonionic segment consisting of at least one member selected from the group consisting of polyethylene glycol groups and addition polymerized ethylene oxide groups. It includes more. The nonionic surfactant (h) is preferably present in a weight ratio relative to the nonionic-anionic composite surface active compound (f) of less than 2/1, and the total emulsifying component (3) is 5/100 to 25/100 It exists in the dry weight ratio with respect to the organic component (2) of.

In this embodiment, the nonionic and anionic composite surface active compound (f) is optionally selected from reactive nonionic-anionic composite surface active compounds (fa) having at least one carbon-carbon double bond per molecule. When a reactive nonionic-anionic composite surface active compound (fa) is used, the organic polymerizable compound (e) may be one produced by an emulsion polymerization process using a reactive nonionic-anionic composite surface active compound as an emulsifier. have. The resulting aqueous emulsion of organic polymerizable compound (e) containing an emulsifier can be used as the aqueous composition of the present invention.

Also preferably, the wax (c) for the organic component (2) useful in this embodiment has a softening temperature of 50 to 160 ° C., an average particle size of 0.1 to 5 μm and an organic polymerizable of 2/98 to 30/70. It is used by the weight ratio of solids with respect to compound (e).

The aqueous chromate treated composition of the present invention can be gymnastic by conventional methods of preparing liquid compositions. For example, the organic component 2 is uniformly emulsified with the aid of the emulsion component 3 in water, and the resulting aqueous emulsion is mixed with an aqueous solution of the inorganic component 1. In this manufacturing method, the emulsifying component 3 is preferably used in the solid content weight ratio with respect to the total amount of the organic component 2 and the emulsifying component 3 of 5/100 to 25/100 as described above.

The method of the present invention for surface treatment of metallic materials is carried out as follows.

An aqueous treatment liquid is usually prepared from an aqueous chromate treatment composition by diluting the composition with water, and the pH of the treatment liquid is adjusted to 3.0 or less, preferably 0.8 to 3.0. The aqueous treatment solution is then applied to the surface of the metal material to form a liquid layer with a solids weight of 10 to 8000 mg / m ² , preferably 10 to 5000 mg / m ² , and the liquid layer is dried to form a lubricant chromate coating on the surface of the metal material. To form. Preferably, the coating film has a chromium compound of 5 to 150 mg / m ² , more preferably 5 to 100 mg / m ² , 0.05 to 3 g / m ² , and more preferably 0.1 to 2 g / m ² in terms of metal chromium. It consists of the organic component (2).

If the total content of chromium compounds is less than 5 mg / m ² with respect to the metal chromium, the resulting coating film may exhibit insufficient corrosion resistance. If the total content of chromium compounds exceeds 100 mg / m ² with respect to metal chromium, the effect of improving the corrosion resistance of the resulting coating film may be saturated, resulting in economic disadvantages. If the content of the organic component ^{2 is} less than 0.05 g / m ² , the resulting coating film may exhibit insufficient lubricity, corrosion resistance and paint coatability. If the content of the organic component 2 exceeds 3 g / m ² , the effect of improving the corrosion resistance of the coating film may be saturated, resulting in economic disadvantage.

Coating of the aqueous treatment liquid may be carried out by a conventional coating method, and the drying process may be carried out using a conventional dryer, for example, a hot air dryer or a high frequency induction dryer. The drying temperature and time may be set in consideration of the type and temperature of the metal material, productivity and economic efficiency.

The aqueous chromate treatment composition of the present invention consists of an inorganic component (1) consisting of at least hexavalent chromium ions and trivalent chromium ions, an organic component (2) emulsified by a special emulsifying component (3), and having a pH value. 3.0 or less.

Generally speaking, particles of a hydrophilic polymerizable compound having anionic functional groups or hydrophilic groups such as hydroxyl groups or polyethylene glycol groups in the polymerized structure are self-emulsified in water to form an aqueous emulsion of polymerizable compound particles. However, aqueous emulsions of hydrophilic polymerizable compound particles can be prepared by emulsifying the polymerizable compound particles with a surface active emulsifier or by emulsion polymerizing monomers with the aid of a reactive surface active emulsifier.

If the coating film formed from the aqueous polymerizable compound emulsion should have high water resistance, the content of the hydrophilic group in the polymerizable compound and the content of the hydrophilic group in the surfactant should be as small as possible. Thus, polymerizable compounds capable of self emulsifying in water should have anionic functional groups and hydrophilic groups in the required minimum amounts. However, this type of self-emulsifying polymeric compound readily aggregates in aqueous acid solution. In addition, the self-emulsifying polymerizable compound emulsion is mixed with an acid aqueous solution containing a hexavalent chromium ion having a strong oxidative property, and the functional group capable of self-emulsifying the polymerizable compound is oxidized in the presence of the hexavalent chromium ion. Compound emulsions become unstable. Due to this phenomenon, the polymerizable compound should be stably emulsified in the presence of a surface active emulsifier in an aqueous solution containing hexavalent chromium and trivalent chromium and having a pH value of 3.0 or lower.

The organic compound (2) in the aqueous treatment composition of the present invention is stable with the aid of the emulsifying component (3) consisting of the special nonionic and anionic composite surface active compound (f) in the aqueous composition containing the inorganic component (1). Emulsified uniformly. The resulting aqueous composition exhibits excellent potlife. In addition, the resulting coating film formed from the aqueous chromate treatment composition exhibits excellent corrosion resistance, water resistance and paint coatability.

In order to maintain the organic component (2) in a stable aqueous emulsion state in aqueous chromate compositions containing hexavalent and trivalent chromium ions, the emulsifiers are characterized by the molecular weight of the hydrophilic (anionic and / or nonionic) groups versus the emulsifier compound. The proportion of total molecular weight should be high. That is, if the concentration of anionic groups in the surface portion of the organic component (2) particles is high or the surface of the organic component is coated with a nonionic hydrophilic group, the resulting emulsified organic component particles can remain stable in the aqueous chromate treatment composition. have. The high pot life of the aqueous chromate treatment composition is derived from the special nonionic and anionic complexes of the surface active compound (f).

When the organic component 2 is emulsified by conventional nonionic surfactants, the resulting coating film exhibits insufficient paint coatability. In addition, if the organic component 2 is emulsified by a conventional anionic surfactant having a high content of anionic groups, the resulting coating shows good paint paintability, but the corrosion resistance of the resulting coating is poor and elutes from the coating and chromium. This is undesirably high.

In the present invention, at least one hydrophobic segment and at least one consisting of an anionic moiety and a nonionic moiety having at least one member selected from the group consisting of polyethylene glycol groups and addition-polymerized ethylene oxide groups (2 or more degrees of polymerization) Special nonionic and anionic composite surface active compounds (f) with hydrophilic segments allow the resulting aqueous chromate treatment compositions to exhibit very long potlife even at pH values of 3.0 or less, resulting in excellent corrosion resistance and paint coating It has been found that it can exhibit high resistance to chromium elution from the performance coating. That is, the special nonionic segment of the nonionic-anionic composite surface active compound (f) of the present invention effectively improves the dispersion stability of the organic component (2) particles in the acidic aqueous chromate treatment liquid. In addition, while the coating film is formed from the aqueous chromate treatment liquid, the nonionic segment is oxidized to hexavalent chromium ion so that the hexavalent chromium ion is reduced to trivalent chromium ion. Therefore, the resulting coating shows a reduced chromium elution therefrom. When an aqueous emulsion of an organic polymerizable compound (e) is prepared by emulsion polymerization of a monomer compound with the aid of a reactive nonionic-anionic composite surface active compound (fa) having an ethylenic double bond (C = C), The resulting aqueous chromate treatment compositions and treatment solutions exhibit improved potlife and the resulting coatings exhibit significantly improved corrosion and paint coatability.

When the inorganic component 1 contains granular silila (g)-(iii), the corrosion resistance of the resulting coating film is further improved.

If the organic component 2 in an aqueous chromate treatment composition containing granular silica is emulsified with the aid of conventional nonionic surfactants, the granular silica is known to aggregate and precipitate. It is also known that granular silica exhibits weak anionicity in aqueous solutions with a pH value of less than 3.0. Therefore, the special nonionic-anionic composite surface active compound (f) having an anionic moiety prevents the granular silica from agglomerating and precipitation.

When the inorganic component (1) further contains phosphoric acid (g)-(i) and / or inorganic fluoride compound (g)-(ii), the resulting aqueous chromate treatment liquid composition or treatment liquid has an improved port life and is produced. The coated film exhibits excellent corrosion resistance and paint paintability.

Moreover, when the inorganic component 1 further contains at least one kind of additional metal ions selected from zinc, iron, nickel, cobalt, aluminum, titanium and zirconium ions, the resulting coating film exhibits significantly improved corrosion resistance. The additional metal ions, together with the chromate ions, form a water soluble chromate in the resulting coating to improve the corrosion resistance durability of the coating.

Example

The invention is further illustrated by the following examples, which are merely exemplary and in no way limit the scope of the invention.

Examples 1-9 and Comparative Examples 1-7

In each of Examples 1 to 9 and Comparative Examples 1 to 7, the chromate treatment was applied to the metal material by the following method.

(A) Preparation of Aqueous Inorganic Component Solutions (I), (II), (III) and (IV)

The inorganic component aqueous solution (I) having the composition shown in Table 1 was dissolved in 100 g of pure chromic acid in 500 g of pure water, and methyl alcohol was added to the aqueous chromic acid solution in an amount sufficient to reduce the chromic acid portion. Adjust the weight ratio (Cr ⁶⁺ ) / (Cr ³⁺ ) to 7/3, and add the phosphoric acid, H ₂ ZrF ₆ and pure water in the amounts shown in Table 1 to the adjusted aqueous solution of chromic acid to obtain the total amount of the treated solution. Prepared by adjusting to 1 kg.

Each of the other inorganic component aqueous solutions (II), (III) and (IV) was prepared in the same manner as for solution (I) except that the resulting solution had the composition shown in Table 1.

(B) Preparation of Aqueous Emulsions (a) to (f) of Organic Component (2) by Surface Active Emulsifier

The organic component was emulsified to provide the aqueous emulsion shown in Table 2.

(C) Preparation of Aqueous Chromate Treatment Liquid

An aqueous chromate treatment solution having the composition shown in Table 3 was prepared by mixing an inorganic component solution with an aqueous emulsion of an organic component.

(D) surface treatment

(a) metal materials

The following metal materials were applied with an aqueous chromate treatment solution.

(i) galvanized steel sheet (EG)

(ii) galvanized galvanized steel (GI)

(iii) alloy and galvanized galvanized steel (GA)

(iv) 5% aluminum containing zinc alloy plated steel sheet (GF)

(v) Alumium Plated Steel Sheet (AS)

Each specimen of the steel sheet was 300 mm long, 200 mm wide, and 0.6-0.8 mm thick.

(b) surface treatment steel

(i) The specimen of the steel sheet was degreased by the following procedure.

Degreaser: An alkaline degreaser (trade name: Fine Cleaner 4336, manufactured by Nihon Parkarizing Co., Ltd.) was used at a concentration of 20 g / liter.

Degreasing method: spray

Degreasing temperature: 60 ℃

Degreasing time: 10 seconds

Washing: water

Can-remove

(ii) surface coating

In each of Examples 1 to 9 and Comparative Examples 1 to 6, the degreasing specimen was applied with a chromate treatment at 5 ml / m ² of moisture using a roll coder, and the applied liquid layer was applied at a specimen target temperature of 100 ° C. It dried for second and formed the dry coating film in the quantity shown in Table 3.

In Comparative Example 7 an aqueous emulsion (a) having a solids content of 20% by weight was applied to EG using # 3 bar and dried.

Table 1

Composition of inorganic components

TABLE 2

Composition of Aqueous Emulsion of Inorganic Components

TABLE 3

Composition of Aqueous Chromate Treatment Solution

(E) test

The resulting chromate coated specimens were subjected to the following test.

(A) corrosion resistance test

According to Japanese Industrial Standard (JIS) Z 2371, an aqueous NaCl aqueous solution spray test was performed for 100 hours on GA applied for EG and GI for 150 hours, 240 hours on GF applied, and 360 hours on AS applied. .

The total area of the rusty part of the specimen was visually observed and the corrosion resistance of the applied specimen was evaluated in the following grades.

(B) workability test

High speed cylindrical deep drawing with continuous elongation of blank holder pressure in 0.5 ton increments at a draw rate of 2.2 using a blank with a diameter of 88 mm and a punch with a diameter of 40 mm at a drawing speed of 10 m / min. A deep drawing test was made and the blank holder pressure (tons) at which the applied specimens broke was measured.

The workability of the applied specimens was evaluated as follows.

(C) dynamic friction coefficient test

The applied specimens were subjected to a dynamic friction test using a Bauden tester under the following conditions.

The dynamic friction coefficient of the specimen was determined in the tenth sliding motion. If the dynamic friction coefficient of the applied specimen cannot be measured under 100 gf load, apply the applied specimen with press oil (trade name: Nox Rust 550 HN, manufactured by Parker Alpine) in an amount of 1 to 2 g / m ² , and then perform the test. It was done.

(D) weldability test

The coated galvanized steel sheet was subjected to a spot weldability test under the following conditions.

When the welding process is carried out continuously, the weld terminals of the specimens deteriorate and the weldability decays. The weldability of the test piece can be evaluated by the deterioration of the terminal after every 100 welding operations, and a new test piece of 30 mm x 100 mm is welded. The total number of weld operations on the specimen was measured until the welded specimen could exhibit a tensile strength of 400 kgf or more.

The weldability of the coated specimen was evaluated as follows.

(E) Electrical collection resistance (inner layer electrical resistance)

The inner layer electrical resistance of the coated specimens was measured according to Japanese Industrial Standard (JIS) C 2550. The measurement results were evaluated as follows.

(F) paint coatability test

Each applied specimen was painted with a melamine-alkyl resin paint (trade name: Dericon # 700, manufactured by Dainippon Paint) to a thickness of 25 μm and the paint layer baked at a temperature of 140 ° C. for 30 minutes.

The resulting paint coated specimens were subjected to the following paint coatability test.

(3) primary adhesion test

(i) cross-cut test

In each paint coated specimen, the paint layer was cross-cut at intervals of 1 mm with a cutting knife to form 100 squares, the adhesive tape was adhered, and the cross-cut face of the specimen was peeled off. The remaining squares were counted from the face tested.

(ii) Dupont impact test

Each coated specimen was subjected to a DuPont impact test using impact pins 1/2 inch in diameter under a load of 500 gf at a distance of 50 cm and an adhesive tape peel test was applied to the impact surface of the specimen. The removed coating area of the specimen was visually observed.

The test results of the DuPont impact test were evaluated as follows.

(b) secondary adhesion test

Each applied specimen was immersed in boiling water for 4 hours before the next test was made.

(i) cross-cut test

This test was performed in the same manner as described above.

(ii) Dupont impact test

This test was performed in the same manner as described above.

(iii) corrosion resistance test after paint

The applied specimens were painted in the same manner as the paint coatability test.

In each paint coated specimen, the paint layer was cross-cut into a metal substrate. The cross-cut specimen was subjected to a NaCl solution spray test (JIS Z 2371) for 500 hours. The width of the portion of the paint layer removed from the cross-cut surface was measured in mm. The smaller the width of the removed portion, the higher the corrosion resistance of the painted specimen.

(F) Portlife (stability) test

Each aqueous chromate treatment was left at room temperature or at a temperature of 40 ° C. for one month. The appearance of the solution was visually observed and evaluated as follows.

The test results are shown in Table 4.

Table 4

Test result

Table 4 clearly shows that the resulting coating films of Examples 1 to 9 obtained from the aqueous chromate treatment composition of the present invention have a low coefficient of friction, good workability, and excellent weldability, corrosion resistance and paint coatability.

The coating films of Comparative Examples 1 to 4 using the conventional chromate treatment liquid have high friction coefficient and poor workability. In other words, if the press oil is not applied to the specimens of Comparative Examples 1 to 3, it is impossible to measure or mold the friction coefficient thereof. Also in Comparative Examples 5 and 6, the resulting aqueous chromate treatment liquid has very poor stability and thus cannot be used in practice, but the resulting coating film has good workability, corrosion resistance, weldability, grounding property, and paint paintability.

In Comparative Example 7, the resulting coating film has a small coefficient of friction and sufficient workability. However, this coating film has a large insulating property and thus shows poor weldability, electrical grounding resistance, corrosion resistance and paint paintability.

Examples 10 to 12 and Comparative Examples 8 to 10

In each of Examples 10-12 and Comparative Examples 8-10, the chromate treatment was applied to the metal material by the following method.

(A) Preparation of Inorganic Component Aqueous Solutions (I), (II) and (III)

The inorganic component aqueous solution (V) having the composition shown in Table 1 was dissolved in 100 g of chromic anhydride in 250 g of pure water, and methyl alcohol was added to the aqueous solution of chromic acid in an amount sufficient to reduce the chromic acid moiety to give a weight ratio of hexavalent chromium to trivalent chromium. Prepared by adjusting (Cr ⁶⁺ ) / (Cr ³⁺ ) to 7/3 and adding the silica and pure water in the amounts shown in Table 5 to the adjusted aqueous solution of chromic acid to adjust the total amount of the treatment solution to be produced to 1 kg. .

Each of the other inorganic component aqueous solutions (VI) and (VII) was prepared in the same manner as for solution (V) except that the resulting solution had the composition shown in Table 5.

(B) Preparation of Aqueous Emulsions (a) to (f) of Organic Component (2) by Surface Active Emulsifier

The manufacturing method of aqueous emulsion (a)-(f) is the same as that shown in Table 2.

(C) Preparation of Aqueous Chromate Treatment Liquid

An aqueous chromate treatment liquid having the composition shown in Table 6 was prepared by mixing the inorganic component with an aqueous emulsion of the organic component.

(D) surface treatment

(a) metal materials

The same metal materials (EG), (GI), (GA), (GF) and (AS) as described above were used.

(b) surface treatment method

Specimens of the steel sheet were degreased and surface-coated in the same manner as in Example 1 except that the aqueous chromate treatment solution had the composition shown in Table 6.

Table 5

Composition of inorganic components

Table 6

Composition of Aqueous Chromate Treatment Solution

(E) test

The resulting chromate coated specimens were subjected to the same test as in Example 1 except for the following.

(A) corrosion resistance test

A NaCl aqueous solution spray test according to Japanese Industrial Standard (JIS) Z 2371 was carried out for 200 hours on the applied EG and GI, 120 hours on the applied GA, 300 hours on the applied GF, and 400 hours on the applied AS. It was.

(B) operating friction coefficient test

The applied specimens were subjected to an operating friction test using a Bowden tester under the following conditions.

The dynamic coefficient of friction of the specimen was determined at the tenth sliding motion. If the dynamic coefficient of friction of the coated specimen cannot be measured under a load of 1 kgf, the applied specimen is applied in press oil (trade name: Nox Rus 550 HN, manufactured by Parker Alpine) in an amount of 1 to 2 g / m ² and then tested. Was performed.

(C) The electrical grounding test was omitted.

(D) In the cross-cut test in the primary and secondary adhesion tests, the coating layer was cross-cut at intervals of 1 mm using a cutting knife to form 100 squares, and the cross-cut portion of the specimen was Ericsen 5 mm extrusion was carried out by an Erichsen tester, the adhesive tape was adhered, and the cross-cut face of the specimen was peeled off. The number of squares removed from the face tested was counted.

The test results are shown in Table 7.

TABLE 7

Test result

Table 7 clearly shows that the resulting coating films of Examples 10, 11 and 12 obtained from the aqueous chromate treated composition of the present invention have a low coefficient of friction, good workability, and excellent weldability, corrosion resistance and paint coatability.

The coating films of Comparative Examples 8 to 10 using the conventional chromate treatment liquid have high friction coefficient and poor workability. That is, unless press oil is applied, the specimens of Comparative Examples 1 to 3 cannot measure or mold their friction coefficient.

Examples 13-20 and Comparative Example 11

In each of Examples 13 to 20 and Comparative Example 11, the metal material was surface treated by the following method.

(A) Preparation of Inorganic Component Aqueous Solutions (VIII) to (X)

Inorganic component aqueous solution (VIII) was prepared by dissolving 200 g of chromic anhydride in 700 g of water; To the resulting aqueous solution, methyl alcohol was added in an amount sufficient to reduce the chromic acid moiety to adjust the weight ratio (Cr ³⁺ / Cr ⁶⁺ ) of trivalent chromium ions to 3/7; Water was added to the adjusted aqueous solution to adjust the total weight of the aqueous solution to 1 kg. The total content of chromium in the resulting aqueous inorganic component solution was 104 g / liter.

Each of the inorganic component aqueous solutions (IX) and (X) was prepared in the same manner as for the solution (VIII) except that the composition of the resulting solution was adjusted to that shown in Table 8.

Table 8

Composition of inorganic components

(B) aqueous organic component emulsion

(a) an organic polymerizable compound

The emulsified organic polymerizable compounds (i) to (iv) shown in Table 9 were used.

Table 9

Composition of Organic Polymerizable Compounds (i) to (iv)

(b) wax

A polyethylene wax emulsion manufactured by Mitsui Sekiyu Chemical Co., Ltd., having an average wax particle size of 3 μm, a solid content of 40 wt%, and a wax softening temperature of 132 ° C. was used.

(C) the composition of the surfactant

Surfactants (i) to (iv) shown in Table 10 were used.

Table 10

Composition of Surface Active Agents (i)-(iv)

(D) Preparation of an aqueous chromate treatment liquid

In each of Examples 13 to 20 and Comparative Example 11, an aqueous chromate treatment solution having the composition shown in Tables 11 and 12 was prepared using the inorganic component, organic component, and emulsified component.

(E) surface treatment

(a) metal materials

Zinc electroplated steel sheet (EG), galvanic mild plated steel sheet (GI), alloy galvanic mild plated steel sheet (GA) and aluminum plated steel sheet (AS) were used. Each steel plate was 300 mm long, 200 mm wide and 0.8 mm thick.

(b) surface treatment process

(i) degreasing process

This process was the same as in Example 1.

(ii) surface coating

In each of Examples 13 to 20 and Comparative Example 11, the degreasing specimen was applied with an aqueous chromate treatment solution as shown in Tables 11 and 12 in the amounts shown in Tables 11 and 12 using a bar coder, and the applied liquid layer was 180 It was dried with a warm air dryer at a temperature of < RTI ID = 0.0 > C < / RTI > for 5 seconds to form a dry coating film in the amounts shown in Tables 11 and 12. The coating amount was adjusted to a predetermined value using a bar coder of a suitable type. Specimens applied in the drying process reached an optimum temperature of 80 ° C. The amount and composition of the coating film formed on the specimen is shown in Table 13.

(E) test

The resulting chromate coated specimens were subjected to the following test.

(A) corrosion test

(a) Corrosion test on unprocessed specimens

The applied specimens were subjected to an aqueous NaCl-spray test in accordance with Japanese Industrial Standard (JIS) Z 2371. Test times were 168 hours for EG, 240 hours for GI, 120 hours for GA, and 360 hours for AS.

The total area of the rusty part of the specimen was measured and evaluated as follows.

(b) Corrosion test on processed specimens

The specimen was extruded to a length of 5 mm with an Eriksen tester and the extruded portion of the specimen was sprayed with aqueous NaCl solution for 72 hours for EG, 72 hours for GI, 48 hours for GA, and 120 hours for AS. . The corrosion resistance of the extruded part was evaluated in the same manner as the corrosion test (a).

(B) Chromium elution resistance test

The applied specimen was immersed in boiling water for 30 minutes. The specimens before and after the dipping process measured the weight of chromium and the chromium leaching was calculated according to the following equation.

W ₀ represents the weight of chromium applied to the specimen before dipping and W ₁ represents the weight of chromium remaining on the specimen after dipping. W ₀ and W ₁ were measured in mg / m ² .

The test results were evaluated as follows.

(C) workability test

The applied specimens were subjected to a high speed cylindrical deep drawing test using a punch having a diameter of 40 mm at a blank feeder pressure of 2.0 tons at a drawing speed of 30 m / min. In this test the diameter of the blank was varied to break the specimen. At each specimen fracture, the elongation, which is the ratio of blank diameter to punch diameter, was measured. The test results were evaluated as follows.

(D) paint coatability test

Each applied specimen was painted in the same manner as in Example 1.

The following paint adhesion test was carried out with the resulting paint coated specimens.

(a) Primary adhesion test

(Ericsen cross-cut test)

In each painted specimen, the paint layer was cross-cut at intervals of 1 mm using a cutting knife to form 100 squares, and the cross-cut portion of the specimen was extruded 5 mm in length using an Eriksen tester. . The extruded portion was subjected to an adhesive tape-adhesion-peel test. The number of squares remaining in the specimen was measured. The more squares remaining in the specimen, the greater the paint adhesion of the applied specimen.

The test results were evaluated as follows.

(b) secondary adhesion test

Each applied specimen was immersed in boiling water for 2 hours and then subjected to the same Eriksen cross-cut test as the primary adhesion test.

The test results were evaluated in the same manner as in the first adhesion test.

(E) Stability (Port Life) Test on Aqueous Chromium Solution

Each chromate treatment solution was placed in an airtight container and left at a temperature of 50 ° C. for 5 days, and then the appearance of the solution was visually observed.

The observation result was evaluated as follows.

The test results are shown in Table 13.

Table 11

Note of Table 11 ( ^★ ) 1 ... Colloidal silica (SiO ₂ , trade name: SnowtexC, Nissan

Kagaku Corporation)

( ^★ ) 2 ... Phosphoric Acid (Reagent Grade: 1 Grade)

( ^★ ) 3 ... Cobalt Nitrate (Reagent Grade: 1 Grade)

( ^★ ) 4 ... (f) ... nonionic-anionic composite surfactant

(Non-reactive)

(fa) ... reactive nonionic-anionic composite surfactant

(h) ... nonionic surfactant

( ^★ ) 5 .. of the emulsifying component (3) versus the organic component (2) and the emulsifying component

Weight ratio of total amount

( ^★ ) 6 ... nonionic surfactant (h) vs. nonionic-anionic

Weight ratio of the composite surfactant (f)

( ^★ ) 7 ... Emulsifier (3) Total Amount versus Organic Ingredients (2) and Emulsifier

Weight ratio of total amount of component (3)

Table 12

Table 13

Table 13 clearly shows that the aqueous chromate treatment solution produced in Examples 13 to 20 according to the present invention has sufficient potlife and the resulting coating shows sufficient corrosion resistance, chromium elution resistance and paint adhesion test.

Claims (9)

pH is below 3.0, (1) an inorganic component consisting of (a) hexavalent chromium ions and (b) trivalent chromium ions dissolved in water; (2) an organic component consisting of at least one member selected from the group consisting of (c) a wax, (d) a fluorine-containing organic compound and (e) an organic polymerizable compound; And (3) having at least one hydrophobic segment and at least one hydrophilic composite segment consisting of anionic moiety and a nonionic moiety having at least one member selected from the group consisting of polyethylene glycol groups and addition-polymerized ethylene oxide groups (f) ) An emulsifying component consisting of at least one nonionic-anionic composite surface active compound, The emulsifying component (3) is present in a solids weight ratio with respect to the total amount of the organic component (2) and the emulsifying component (3) from 5/100 to 25/100, The total amount of organic component (2) and emulsifying component (3) is present in the weight ratio to hexavalent chromium ions of 2/1 to 800/1, and thereby The organic component (2) is an aqueous chromate treatment composition for a metal material in which the organic component (2) is present in the form of an aqueous emulsion in which the organic component (2) is stably emulsified with the aid of the emulsifying component (3) in the aqueous composition. The aqueous chromate treatment composition according to claim 1, wherein the trivalent chromium ion (b) in the inorganic component (1) is present in a weight ratio to the hexavalent chromium ion (a) of 2/8 to 7/3. The class of claim 1 wherein the inorganic component (1) is a class consisting of (i) phosphoric acid, (ii) inorganic fluoride compounds, (iii) granular silica and (iv) zinc, iron, nickel, cobalt, aluminum, titanium and zirconium ions An aqueous chromate treatment composition further comprising (g) an additive component consisting of at least one member selected from. The aqueous chromate treatment composition of claim 1 wherein the wax (c) is selected from the class consisting of paraffin wax, microcrystalline wax and polyethylene wax. The fluorine-containing organic compound (d) according to claim 1, wherein the fluorine-containing organic compound (d) is polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polytetrafluoroethylene, at least one olefin monomer and vinyl fluoride, vinyl fluoride An aqueous chromate treatment composition, characterized in that it is selected from the group consisting of copolymers with at least one member selected from the group consisting of lidene, trifluoroethylene, tetrafluoroethylene, and modified products of said polymers and copolymers. The method of claim 1, wherein the organic polymerizable compound (e) is polyacrylic acid, maleic acid-methyl vinyl ether copolymer, polyacrylamide, acrylic ester copolymer, styrene-acrylic acid ester copolymer, epoxy resin, ethylene-acrylic acid ester copolymer An aqueous chromate treatment composition, characterized in that it is selected from the class consisting of polymers and polyester resins. The total amount of trivalent and hexavalent chromium ions (a and b) of claim 1, wherein at least one member selected from the group consisting of wax (c) and fluorine-containing organic compounds (d) is 1/50 to 100/1. Aqueous chromate treatment composition, characterized in that it is present in a weight ratio to. The amount of 0.5 to 20 parts by weight per 100 parts by weight of at least one member according to claim 1, wherein the nonionic-anionic composite surface active compound (f) is selected from the group consisting of wax (c) and fluorine-containing organic compound (d) An aqueous chromate treatment composition, characterized in that present. A method for forming an aqueous coating layer comprising the aqueous chromate treatment composition according to any one of claims 1 to 8 and containing chromate in a solid amount of 5 to 150 mg / m ² in terms of metal chromium on the surface of the metal material. And drying the aqueous coating liquid layer to form a lubricant chromate coating on the surface of the metal material.