KR20240056180A - Coating agent containing zirconium and metal surface pretreatment method using the same - Google Patents

Abstract

The present invention relates to a coating agent containing zirconium and a metal surface pretreatment method using the same, wherein the coating agent containing zirconium contains zirconium that can be simultaneously treated on a metal surface or a metal surface including a composite material in the coating step of the painting process. As a coating degree, 10 ppm to 500 ppm of ferric ion; 75ppm to 300ppm of zirconium (Zr) ions that can be used as industrial water; and 500 ppm to 55,000 ppm of nitric acid (NO ₃ ) ions, and is characterized in that a metal oxide film with a thickness of 0.01 ㎛ to 0.05 ㎛ is formed on the metal surface at a pH of 1.5 to 5.0.

Description

Coating agent containing zirconium (Zr) and metal surface pretreatment method using the same {COATING AGENT CONTAINING ZIRCONIUM AND METAL SURFACE PRETREATMENT METHOD USING THE SAME}

The present invention relates to a coating agent containing zirconium and a metal surface pretreatment method using the same. More specifically, an eco-friendly ultra-thin zirconium (Zr) coating agent that can be used as industrial water and is capable of processing composite metal materials. It forms a metal oxide film and is harmful to the environment. It relates to a coating agent containing zirconium that does not contain ions, that is, zinc (Zn), manganese (Mn), nickel (Ni), and phosphorus (P), and a metal surface pretreatment method using the same.

In general, painting a metal surface directly can give the metal some degree of corrosion resistance, but various contaminants (rust, dust, oil, etc.) remaining on the metal surface deteriorate the quality of the paint and reduce the adhesion of the paint film.

Therefore, in the case of metal painting where painting quality must be guaranteed, such as in automobiles, prior work such as electrodeposition painting is performed before painting. First, oils and unnecessary oxide films on the target metal surface are thoroughly cleaned, and metal oxide film formation work, that is, film formation work, is performed to improve the painting properties on the cleaned metal surface.

Until now, phosphate coating was used for steel and zinc-based materials, and for steel materials containing 58-1 aluminum, phosphate coating was performed by adding fluorine (F).

However, zinc phosphate-based coating treatments have the disadvantage of having high concentrations of phosphoric acid, zinc, manganese, nickel, and hydrofluoric acid (10 to 2000 ppm), making it difficult to treat wastewater from washing water or waste liquid after coating. In the end, even if emissions are below environmental pollution regulations, it is inevitable that unenvironmentally friendly discharge water will be released.

Therefore, attempts and developments are being made to ensure that ingredients harmful to the environment are not included or minimized in coating products that ensure excellent paint adhesion to the metal surface to be painted, and the patent documents in the [Prior Art Document] section below are examples. It applies.

The patent documents presented as examples of the following prior art documents are clearly more environmentally friendly than conventional phosphate coating agents, but still contain zinc (Zn) and manganese (Mn), metals regulated for environmental pollution, and amine-based polymer compounds and silane, which are not environmentally friendly. Most of them include couple systems, etc.

Amine-based polymer compounds and silane couplers are substances that may be subject to regulation of C.O.D. (Chemical Oxygen Demand), i.e., chemical oxygen demand, and B.O.D. (Biochemical Oxygen Demand), i.e., biochemical oxygen demand, among environmental regulations.

In addition, using one or more types of oxidizing agents, such as nitrous acid, sulfurous acid, bromous acid, hydrogen chloride, hydrogen peroxide, HMnO ₄ , KMnO ₄ , H ₂ WO ₄ , etc., can threaten the safety of workers. admit.

Patent documents in the prior art literature section show that when surface treatment of a metal substrate is performed, metal ions eluted from the chemical treatment agent due to a dissolution reaction of the metal cut off fluorine and increase the interfacial pH (hydrogen ion concentration index) to form hydroxide or zirconium. It is thought that oxides are generated and the hydroxides or oxides of zirconium are precipitated on the surface of the substrate, and as a means to help this, zinc (Zn), manganese (Mn), fluorine (F), many types of oxidizing agents, amine-based polymer compounds, and silane are used. It appears that a coupling agent, etc. is being used.

Meanwhile, with the development of the automobile industry and in line with the demand for lighter products (increasing fuel efficiency and ensuring safety), steel-based materials, zinc-based materials such as galvanizers (GA), aluminum-based materials, and sometimes magnesium-based materials are being filmed at the same time. A situation in which something must be done has arrived, and it is necessary to meet it.

In addition, in order to meet the demand for eco-friendly cars, in the United States and Europe, cars running on combustible fuels such as gasoline and diesel are expected to be replaced with cars running on electricity or hydrogen, and the manufacturing of eco-friendly products is in full swing in all related fields. It is becoming. This demand for environmental friendliness has become no exception in the metal surface treatment industry, and the need for manufacturing better, more environmentally friendly metal surface treatment agents is increasing.

Therefore, the purpose of the present invention is to provide a coating agent containing zirconium and a metal surface pretreatment method using the same. More specifically, it relates to an eco-friendly ultra-thin zirconium (Zr) coating agent metal oxide film that can be used as industrial water and is capable of processing composite metal materials. It relates to a coating agent containing zirconium that forms but does not contain metal ions harmful to the environment, such as zinc (Zn), manganese (Mn), nickel (Ni), and phosphorus (P), and a metal surface pretreatment method using the same.

Another object of the present invention is to be able to simultaneously process single or two or more types of composite materials such as iron-based materials, zinc-based materials, aluminum-based materials, magnesium-based materials, etc., and to provide high paint adhesion to the metal surface to be painted. The aim is to provide an eco-friendly chemical composition and a method of using the same, which can form a metal oxide film with excellent paint adhesion on any metal surface to be painted by allowing the chemical composition to penetrate even the fine gaps in complex joints or overlaps.

A coating agent containing zirconium that can be simultaneously treated on a metal surface or a metal surface including a composite material in the coating step of the painting process, comprising 10 ppm to 500 ppm of ferric ion; 75ppm to 300ppm of zirconium (Zr) ions that can be used as industrial water; and 500 ppm to 55,000 ppm of nitric acid (NO ₃ ) ions, and is characterized in that a metal oxide film with a thickness of 0.01 ㎛ to 0.05 ㎛ is formed on the metal surface at a pH of 1.5 to 5.0.

The coating agent containing zirconium is one selected from 500ppm to 55,000ppm of sulfuric acid (SO ₄ ) ions, 500ppm to 55,000ppm of hydrochloric acid (Cl) ions, 2ppm to 10ppm copper (Cu) ions, and 20ppm to 90ppm fluorine (F) ions. Includes more species.

The coating agent containing zirconium is characterized in that the concentration ratio of the ferric ion to the zirconium ion is 0.1 to 10 based on mass.

The coating agent containing zirconium further includes 50 ppm to 500 ppm of a non-amine-based wetting and dispersing agent that can be used in the industrial water.

The ferric ions include ferric citrate, ferric ammonium citrate, ferric sulfate, ferric ammonium sulfate, and ferric hydrochloride. Chloride, Ferric nitrate, Ammonium Oxalate, Ferric Oxalate, Ferric Sodium Oxalate, Ferric bromide ) is characterized by being formed by one type or a combination of at least two types.

The ferric ions are formed by ferricizing a compound containing ferrous ions with a 60% nitric acid (HN03) solution to form the metal oxide film.

Zirconium (Zr) compounds having the zirconium (Zr) ion include Hexafluoro Zirconic Acid (H2ZrF6), Zirconium Tetrafluoride (ZrF4), Zirconium Sulfate (ZrSO4), Zirconium Nitrate (Zr(No3)2)·nH2O), Potassium Hexafluoro zirconate (K2ZrF6), Ammonium Hexafluoro zirconate (NH4)2ZrF6) It is characterized by including.

In order for the chemical composition to penetrate even into complex joints and fine gaps in overlapping areas, it is characterized by forming a metal oxide film containing at least one type of alcohol of 20 to 300 ppm from ethyl alcohol and isopropyl alcohol. .

A metal surface pretreatment method using a coating agent containing zirconium exposes the metal or the metal containing the composite material to the coating agent containing zirconium at a temperature of 15°C to 50°C for 15 to 120 seconds, thereby forming the metal surface or It is characterized by forming a metal oxide film on the surface of a metal containing a composite material.

The present invention is an eco-friendly zirconium (Zr) ultra-thin film coating agent that can use industrial water and process composite metal materials, unlike the existing process using DI Water. By enabling the use of industrial water in addition to the performance of existing eco-friendly zirconium (Zr) products, Not only is it easy to apply to existing processes because there is no replacement of process equipment and the process costs (DI water cost, cleaning cost, etc.) are reduced, but it can also provide high paint adhesion to metal surfaces to be painted, as well as fine gaps in complex joints or overlapping areas. It has the advantage of allowing the chemical composition to penetrate well and forming a metal oxide film with excellent paint adhesion on any metal surface to be painted.

In addition, the eco-friendly chemical composition of the present invention forms a metal oxide film with excellent paint adhesion on the metal surface to be painted, while eliminating environmentally harmful metal ions such as zinc (Zn), manganese (Mn), nickel (Ni), and phosphorus (P). There is an advantage in that it can greatly contribute to preventing environmental pollution by not including it.

Figure 1 is a mechanism for forming a metal oxide film on a metal surface by applying ferric ions according to an embodiment of the present invention;
Figure 2 shows the shape of the metal surface according to the use of ferric ions according to an embodiment of the present invention.
Results of EDX analysis of the formed metal oxide film, analysis spectrum graph and composition table,
Figure 3 shows the shape of the metal surface according to the use of ferric ions according to an embodiment of the present invention.
Spectrum graph and composition table of the results of analyzing the formed metal oxide film using XRF,
Figure 4 shows a metal cleaning process before the process of forming a metal oxide film according to the present invention.
degree,
Figures 5 and 6 are process and post-process diagrams for forming a metal oxide film of the present invention.

In describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

The terms described below are terms set in consideration of the functions in the present invention, and since they may vary depending on the intention or custom of operators such as experimenters and measurers, their definitions should be made based on the content throughout the specification.

The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in this specification, should not be interpreted in an idealized or overly formal sense. No.

Additionally, when a part "includes" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

In the description of the present invention, the “metal oxide film” is sometimes called a “film,” and the “chemical composition” that forms the metal oxide film is sometimes abbreviated as “metal oxide film chemical composition” or called a “film agent.”

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

In the present invention, single or two or more types of composite materials such as iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials can be processed simultaneously, and high paint adhesion can be provided to the metal surface to be painted, as well as complex joints or overlaps. In implementing a chemical composition (hereinafter abbreviated as 'metal oxide film chemical composition') that can form a metal oxide film with excellent paint adhesion on any metal surface to be painted by allowing the chemical composition to penetrate even into negative microscopic gaps, environmental pollution regulation metal It does not contain zinc (Zn) and manganese (Mn), nor does it contain environmentally friendly amine-based polymer compounds or silane coupling agents.

The reason for using a silane coupling agent, which is not environmentally friendly as existing pre-treatment coating agents, is to increase the adhesion between metal materials and the paint used in electrodeposition coating.

As can be seen in the mechanism of Chemical Formula 1, the silane coupling agent has two types of functional groups with different reactivity in one molecule, so one side acts on the metal material and the other side acts on the paint, thereby forming a bond between the paint and the metal material. It serves as a bridge between metal materials and paint, which have different properties, so that they can be combined. In other words, the purpose of the existence of the silane coupling agent is to improve the coating properties after electrodeposition coating on the metal material.

However, the metal oxide film chemical composition of the present invention does not use a silane coupling agent to improve the adhesion of the paint.

The oxide film chemical composition for painting pretreatment of the present invention introduces ferric ions along with zirconium to enhance the environmental friendliness of the coating agent.

The ferric ion introduced according to the present invention does not serve as a bridge between heterogeneous substances (metal-paint), but participates in the oxidation of ferric ions and the composition of the paint-friendly metal oxide film, thereby forming a film and thereby performing electrodeposition. Improves paint properties after painting.

< Action of ferric ion >

Compounds with ferric iron (Fe ⁺³ ) ions that are necessary for the formation of metal oxides and are highly soluble in water include ferric chloride (FeCl ₃ ) and ferric citrate (C ₆ H ₅ FeO). ₇ 3H ₂ O), Ferric ammonium citrate (Fe(NH ₄ )2H(C ₆ H ₅ O ₇ ) ₂ ), Ferric sulfate (Fe ₂ (S0 ₄ ) ₃ ), Ferric ammonium sulfate (FeNH ₄ (S0 ₄ ) ₂ ·12H ₂ 0), ferric nitrate (Fe(N0 ₃ ) ₃ ·6H ₂ O), ferric ammonium oxalate (Ammonium oxalate, (NH ₄ )3Fe(C ₂ 0 ₄ ) ₃ )3H ₂ O), Ferric oxalate (Fe ₂ (C ₂ 0 ₄ ) ₃ ), Ferric sodium oxalate , Na ₂ Fe(C ₂ O ₄ ) ₃ )·5H ₂ O), ferric bromide (FeBr ₃ ), etc.

Among these, ferric ion-containing substances composed of inorganic compounds (e.g. ferric chloride, ferric nitrate, ferric sulfate, etc.) are oxidizing agents and have a strong corrosive or metal-eroding effect on metals, so they are used for etching of molds and metal plates. It is widely used as a caustic solution, for photolithography, as a dyeing aid, as an analysis reagent, and as an adsorbent for radioactive substances.

On the other hand, in an environmentally friendly way, ferric ions are well used in wastewater treatment. In other words, ferric ion iron compounds are used in the bioelectrochemical anaerobic digestion tank of a wastewater treatment plant to increase the activity of planktonic anaerobic bacteria, thereby increasing wastewater treatment efficiency.

It is also used as a blue or black dye for iron materials.

On the other hand, ferric ions containing organic substances, such as ferric citrate, ammonium ferric citrate, ferric oxalate, ammonium ferric oxalate, ferric soda, ferric bromine, etc., are used as dyes, dyeing aids, etc. It is used as a raw material for ink color, as a health supplement, and as an iron enhancer in the blood.

The present inventor is particularly interested in the two functions of oxidation and chemical film in ferric compounds that perform various functions, and considering the reality that environmentally friendly drug development continues to be required, if ferric ions are used, metal oxide film formation reaction occurs. The motivation was that the formed metal oxide film could satisfy rust prevention and painting properties.

In this way, research was conducted with the hope that there would be a method of securing rust prevention and painting compatibility without using zinc (Zn) and manganese (Mn), which are environmentally hazardous substances used in zirconium coating agents in the prior art, in the present invention. Development continued.

As another motivating opportunity, the present inventor recognized that significant quality improvement in the plating industry was achieved due to the use of iron ions in plating processing. For example, in the past galvanizing, the salt spray test (SST) corrosion resistance was only 300 hours, but by using iron ions in galvanizing, plating smoothness and corrosion resistance were further secured. In particular, in the case of zinc, iron, and nickel alloy plating, salt spray corrosion resistance of 1,000 hours can be secured. In this way, it was found that iron ions play a significant role in improving quality in the plating industry.

Accordingly, the inventor of the present application became convinced that iron ions could be used in painting pretreatment chemicals, and continued to conduct research, eventually developing zinc (Zn), manganese (Mn), phosphorus (P) compounds, amine-based polymer compounds, silane coupling agents, It was possible to manufacture a chemical composition that can form a metal oxide film with excellent paint adhesion to a metal surface without using various oxidizing agents.

The inventor of the present application was able to achieve the effect shown in Figure 1 by utilizing the oxidizing power and film properties of ferric iron (Fe ⁺³ ).

Referring to the mechanism shown in Figure 1, ferric ions of ferric iron (Fe ⁺³ ) act on various metal surfaces to oxidize metals and combine with other metal ions. It was designed to have a reactor (radical). This is possible if the temperature is maintained at 1.5 pH to 5.0 pH, preferably 2.0 pH to 4.5 pH, the temperature is maintained at 15°C to 35°C during coating agent treatment, and chemical compositions of appropriate concentrations are present.

If this is expressed chemically, it is as shown in Chemical Formula 2 below.

According to an embodiment of the present invention, an eco-friendly chemical composition for forming a metal oxide film with excellent paint adhesion to a metal surface contains 10 to 500 ppm of ferric ion (Fe ⁺³ ) ion and 10 to 500 ppm of zirconium (Zr) ion. It contains 300 ppm, 500 to 55,000 ppm of nitrate radical (N0 ₃ ) ion, and is composed at pH 1.5 to 5.0.

In the present invention, a chemical composition for forming a metal oxide film containing zirconium (Zr) is used to remove environmental pollutants such as zinc (Zn), manganese (Mn), nickel (Ni), and phosphorus (P), polymers, and oxidants, as in the prior art. , it can be seen that no silane coupling agent was used, and that the metal oxide film chemical composition of the present invention forms a metal oxide film with excellent paint adhesion to the metal surface, as shown in Figures 2 and 3 using spectra using analysis equipment. This could be confirmed through graphs and ingredient lists.

Figure 2 is a spectrum graph analyzed by EDX (Energy Dispersive This is the result analysis spectrum graph and ingredient table for (cold rolled iron sheet), GA (galvanized iron sheet) after film, AL (aluminum sheet for automobiles) after film, and Mg (magnesium sheet) after film.

And, Figure 3 is a spectrum graph analyzed with an This is the result analysis spectrum graph and ingredient table for SPC (cold rolled steel sheet), GA (galvanized steel sheet) after film, AL (automotive aluminum sheet) after film, and Mg (magnesium sheet) after film.

According to the present invention, the result of analysis ^using EDX (Energy Dispersive As shown in the graph and ingredient table, it was confirmed that the film was composed of zirconium (Zr), oxygen (O), and iron (Fe).

Additionally, as a result of taking pictures with an Here, as in Figure 2, it can be seen that Fe ions played a leading role in the film.

The eco-friendly chemical composition of the present invention, which forms a metal oxide film with excellent paint adhesion on a metal surface, contains zirconium ions as well as ferric ions. In order for the metal oxide film chemical composition of the present invention to contain ferric ions, a compound that has ferric iron (Fe ⁺³ ) ions and is soluble in water is used.

According to the present invention, compounds having ferric iron (Fe ⁺³ ) ions and soluble in water include ferric citrate, ferric ammonium citrate, ferric sulfate, and sulfuric acid. Ferric Ammonium Sulfate, Ferric Chloride, Ferric Nitrate, Ferric Ammonium Oxalate, Ferric Oxalate, Oxalate It contains ferric sodium oxalate and ferric bromide, and one type or a combination of two or more types is used.

In the present invention, the eco-friendly chemical composition for forming a metal oxide film with excellent paint adhesion on a metal surface contains 10 to 300 ppm of ferric ion and zirconium (Zr) ion and 500 to 55,000 ppm of nitrate ion (NO3). Including, a compound having the ferric ion and soluble in water is used so that the concentration ratio of the ferric ion to the zirconium (Zr) ion is in the range of 0.1 to 10 based on mass, and pH 1.5 to 5. It is created with O.

Also, when expressed specifically in terms of the amount of ferric ion used, ferric ion is one of the components of the eco-friendly metal oxide film chemical composition (coating agent) of the present invention for forming a metal oxide film with excellent paint adhesion to a metal surface. ) has a content of 10 to 500 ppm, and more preferably, the content of ferric ion is 15 to 200 ppm.

In the present invention, the range of ferric ion usage is set to 10 to 500 ppm. If the ferric ion content is less than 10 ppm, the formation of metal oxide that acts as a film is insufficient, and the ferric ion content is less than 500 ppm. In the above cases, the formation of metal oxides becomes excessive and has a critical significance in that it has a negative effect on the physical properties of the coating film.

Meanwhile, as another method of securing ferric ions in the present invention, a compound containing ferrous ions can be prepared by ferricizing it with a 60% nitric acid (HNO ₃ ) solution.

For example, in the case of ferrous sulfate, a 60% nitric acid (HN0 ₃ ) solution is used to form ferric sulfate through a reaction as shown in Chemical Formula 3 below.

Compounds that can be used by ionizing ferric iron with a 60% nitric acid (HN0 ₃ ) solution include ferrous chloride (FeCl ₂ 4H ₂ O), ferrous sulfate (FeSO ₄ ), and ferrous fluoroborate. (Ferrous fluoroborate, Fe(BF ₄₎₂ ), etc.

Most of them are blue-green in color, but during the reaction with nitric acid (HN0 ₃ ), they change from an initial black-green color to a final ferric ion, turning light pink to yellow. Therefore, when it turns light pink or yellow, it means that ferric iron has been ionized.

However, it should be noted that ferrous ions with organic compounds, such as ferrous gluconate (C1 ₂ H ₂ FeO ₁₄ ·2H ₂ 0), are decomposed by nitric acid (HN0 ₃ ) into CO _2, H ₂ , Since it emits NO ₂ gas, it is not suitable for use in the present invention.

Meanwhile, in the present invention, zirconium (Zr) ions are included as another component of the environmentally friendly metal oxide film chemical composition.

Zirconium (Zr) compounds having zirconium (Zr) ions according to the present invention include Hexafluoro Zirconic Acid (H ₂ ZrF ₆ ), Zirconium Tetrafluoride (ZrF ₄ ), and zirconium sulfate ( Zirconium Sulfate, ZrSO ₄ ), Zirconium Nitrate (Zr(NO ₃ ) ₂ )·nH ₂ O), Potassium Hexafluoro zirconate (K ₂ ZrF ₆ ), Ammonium Hexafluoro Zirconate Conate (Ammonium Hexafluoro zirconate, (NH ₄ )2ZrF ₆ ), etc.

In the present invention, the content contained in the chemical composition of the present invention, which forms a metal oxide as zirconium (Zr) ion by selecting one or two of these zirconium compounds, is in the range of 10 to 300 ppm, preferably 50 to 200 ppm. have

If the content of zirconium (Zr) ions is less than 10ppm, the film formation is unstable and there are many unfilmed areas, and if it exceeds 300ppm, the film formation is excessive and there is a problem with the paint adhesion, which is a critical significance. There is.

Additionally, as another component of the eco-friendly metal oxide film chemical composition of the present invention, it contains nitrate radical (NO ₃ ) ions.

In addition, nitrate radical (NO3) ion, one of the components of the metal oxide film chemical composition of the present invention, is a means to help oxidation of each metal ion, and for this purpose, the content of nitrate radical (NO3) ion contained in the metal oxide film chemical composition is It is 500 to 55,000 ppm.

In the present invention, 60% nitric acid, sodium nitrate (NaNO ₃ ), or potassium nitrate (KNO ₃ ) is used to obtain nitrate radical (NO ₃ ) ions. In addition, the present inventor tried using sulfuric acid (H ₂ SO ₄ ) and hydrochloric acid (HCl) instead of the nitric acid radical (NO ₃ ) ion, but the electrodeposition coating properties were satisfactory as shown in Examples 12 and 13 and the summary table described later. It was confirmed that it was not possible.

However, Examples 12 and 13 use ferric ion and nitrate (NO ₃ ) ion as essential components among the components of the present invention, and have general coating properties [ [The standard is lower than the physical properties of electrodeposition coating] is meaningful in that it can be sufficiently satisfied. In Examples 12 and 13, an example of using 1,000 ± 10 ppm was given as an experimental example, but a sulfuric acid (H ₂ SO ₄ ) or hydrochloric acid (HCl) content of 500 to 55,000 ppm of nitrate radical (NO ₃ ) ions can be used. You can.

Therefore, the metal oxide film chemical composition of the present invention used for electrodeposition coating does not use a separate oxidizing agent other than ferric ion and nitrate ion (NO ₃ ).

Meanwhile, among the prior art documents, Registered Patent No. 10-1539042 and others require deionized water as water for use in zirconium coating agents. However, deionized water used as water is very cumbersome at production sites such as automobiles, and production of deionized water, including management and replacement of ion exchange resins, requires a lot of cost, installation location, and time.

The reason why deionized water is required is because of the side effects of calcium (Ca ²⁺ ) ions dissolved in industrial water. This calcium (Ca ²⁺ ) ion causes the following reaction with the fluorine (F ^- ) ion or sulfuric acid (S04 ^2- ) ion contained in the chemical composition to form a precipitate.

These deposits may cause poor appearance (microscopic irregularities) after painting.

To solve this problem, the metal oxide film chemical composition of the present invention can be implemented so that industrial water or tap water, rather than deionized water, can be used as the chemical composition for forming metal oxide and all water used between processes. In other words, the metal oxide film chemical composition of the present invention can be implemented so that industrial water or tap water with a calcium ion concentration of up to 100 ppm and an electrical conductivity of 100 to 300 ㎲/cm can be used.

The present invention makes it possible to use industrial water or tap water by introducing a non-amine-based wetting and dispersing agent, especially a carboxyl-based wetting and dispersing agent, which is easily naturally decomposed, into the metal oxide film chemical composition.

This means that the carboxyl-based wetting and dispersing agent included in the metal oxide film chemical composition of the present invention has greater binding and dispersing power than the existing sediment reaction that generates sediment, and Ca ²⁺ , Mg ²⁺ , Si ⁴⁺ , This is because it fundamentally blocks SO ^4- ions from being dissolved or from forming into precipitates of calcium fluoride (CaF ₂ ) or calcium sulfate (CaSO ₄ ).

This appears to be due to the hydrogen (H) of the carboxyl group (-COOH) and its characteristic dispersion force, and the mechanism is as shown in Chemical Formula 4 below.

As shown in Formula 4, the oxidation reaction of the metal oxide film chemical composition of the present invention with metal achieves a metal oxide film without being affected by various ions contained in industrial water.

As described above, since the metal oxide film chemical composition of the present invention contains an environmentally friendly carboxyl-based wetting and dispersing agent that is easily naturally decomposed, it can be used in industrial water or tap water.

Moreover, since the metal oxide film chemical composition of the present invention contains a non-amine-based wetting and dispersing agent (particularly a carboxyl group wetting and dispersing agent) that is easily decomposed naturally, not only can industrial water be used, but the chemical composition can also be used in microgaps created by complex joint structures or overlaps. This helps in penetration.

The non-amine-based wetting and dispersing agent (especially carboxyl group wetting and dispersing agent), which is easily naturally decomposed in the metal oxide film chemical composition according to the present invention, has a content of 50 to 500 ppm, and is preferably used at 200 ± 50 ppm. Examples of the non-amine-based wetting and dispersing agents (especially carboxyl group wetting and dispersing agents) include San Nopco's product names HS-Diperant 5803, Dispexel DS-1040, 58-21COEXEL-1520, HS-Dispersant 2026S, and SN-Dispersant 44S. , SN-Dipersant-5034, or BASF's Dispexultra PA-4503, TEGO's TEG-60, etc., and it is preferable to select 1 or 2 types from among 3 different manufacturers' products.

In addition, the metal oxide film chemical composition of the present invention is preferably formulated to further include 20 to 300 ppm of alcohol for more effective diffusion of the metal oxide film chemical composition.

The alcohol used is one of ethyl alcohol and isopropyl alcohol.

The metal oxide film chemical composition of the present invention can simultaneously treat single or two or more types of composite materials such as iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials.

When treating iron-based materials, zinc-based materials, aluminum-based materials, magnesium-based materials, etc. with the chemical composition of the present invention to form a metal oxide film with excellent paint adhesion on a metal surface, the treatment conditions are a treatment temperature of 15 to 50°C, preferably 30°C. It is used at ±5°C, the treatment time is 15 to 120 seconds, preferably 90±30 seconds, and the treatment method is immersion or spray.

In addition, if 100 to 500 ppm of surfactant is added to the metal oxide film chemical composition of the present invention, it can be used as a coating agent for degreasing general paint products that do not meet automobile quality standards.

It is preferable to supply the metal oxide film chemical composition of the present invention to companies that use it as a concentrated undiluted solution. The user company prepares the composition of the metal oxide film chemical composition of the present invention by diluting the concentrated stock solution of the metal oxide film chemical composition with a solvent (mainly industrial water) (called 'make up' in the chemical field). It is added as a separate additive accordingly.

It is advisable to use a pH adjuster, that is, 45% KOH solution, 45% NaOH solution, or 30% HNO ₃ if necessary, so that the pH falls within the pH range of 2.0 to 5.0 according to the present invention.

The concentrated stock solution is manufactured and supplied to reduce the burden of transportation, and is preferably used after being prepared with the chemical composition of the present invention by dry bathing in the chemical treatment process to form a metal oxide film according to the present invention.

The chemical composition according to the present invention was treated with each material according to the chemical composition and treatment conditions mentioned in specific Examples 1 to 13 to be described later, and as a result, the paint adhesion to the metal surface of each material was as shown in Table 1 to be described later. This excellent metal oxide film was obtained.

[Specific Example]

<Preparation of the Psalms>

SPC (KSD 3512 cold rolled steel sheet) - 70 x 150mm thickness 0.8t

GA (Zn + Fe alloy galvanized steel sheet) - 70 x 150mm thickness 0.8t

Al (6000 series automotive aluminum plate) - 70 x 150mm thickness 0.8t

Prepare a Mg material plate (magnesium plate) - 70 Used in Examples 10 and 11.

<Metal Cleaning Process>

Before the process of forming a metal oxide film according to the present invention, a metal cleaning process is first performed to clean the metal surface of the target material.

The same process as in Figure 4 was performed to ensure a clean surface of the metal. That is, “S1. Bath tax → S2. Skim → S3. Suse → S4. It goes through the “wash” process.

S1. The water for industrial washing process is heated to 45 ± 5℃, and when the material is input, the temperature of the material is raised in advance to the degreasing temperature. Soak for 2±1 minutes.

S2. Using the degreasing process chemical Suji clean 106 (Sungjin Chemical brand name) [a chemical based on Korean Patent No. 0250385], perform a 5% dry bath and remove oil, grease, grease, etc. at 45°C for 2 minutes.

S3~S4. Washing process: Wash by soaking or spraying with industrial water for at least 30 seconds.

<Process and post-process for forming metal oxide film>

With the chemical composition according to the present invention, a metal oxide film is formed on the metal surface of the material, as shown in Figure 5a or 5b, and then painting is performed.

The specific process is as shown in FIG. 5A, “S5. Film treatment (metal oxide film formation) → S6. Suse → S7. Net tax → S8. Electrodeposition coating” or “S5. Chemical treatment (metal oxide film formation) → S6” as shown in Figure 5b. Suse → S9. Dry → S10. Perform “powder coating and other painting.”

S5. Film treatment (metal oxide film formation process)

See Examples 1 to 13 described below.

S6. defensive

It is the same as the washing process in S2.

S7. Pure tax (process for electrodeposition coating)

Treatment by dipping or spraying for at least 30 seconds

S8. Electrodeposition coating

Follows electrodeposition coating specifications (Spec).

S9. dry

S10. Powder coating and other painting

<Method for measuring and controlling the content of each ion>

Cationic compounds such as metal ions, such as Fe, Zr, Cu, Zn, Mn, and Ca, are measured using ICP (inductively coupled plasma, manufacturer: Agilent), and the amount of ions is adjusted as necessary.

Nitrate ions (NO ₃ ^- ) were measured and controlled using an ion meter (manufacturer: Metrohm) NO ₃ measuring electrode.

F ^- Measure and control ions using an ion meter (manufacturer: Metrohm).

F ^- Measured and controlled using an ion measuring electrode.

Details of specific examples of forming a metal oxide film with the chemical composition of the present invention are as follows.

[Example 1]

As a chemical composition for forming a metal oxide film, a ferric compound such as ferric citrate, ferric ammonium citrate, ferric tartrate, ferric hydrochloride, ferric sulfate, or ferric nitrate is used. Using two or more types, add them to a chemical composition so that the concentration of iron ions is 130 ± 15 ppm and add zirconium compounds, such as HZr ₂ F ₆ (zirconium fluoride acid), K ₂ ZrF ₆ (potassium zirconium fluoride), ZrCl ₄ (zirconium chloride). ), ZrOCl ₂ (zirconium chlorate), Zr(NO ₃ ) ₄ (zirconium nitrate), and Zr(SO ₄ ) ₂ (zirconium sulfate) so that the zirconium ion in the chemical composition is 130±15ppm (Fe Add the ion and mass ratio (1:1) using 60% HNO ₃ so that the nitrate ion is 1500 ± 50 ppm, and add 300 ± 30 ppm of a carboxyl-based wetting and dispersing agent with good natural degradability, then diffusion of the wetting and dispersing agent and a smooth metal oxide film are added. To aid in the formation, 30 ± 10 ppm of ethyl alcohol was added and the pH was adjusted to 3.5 ± 0.5 with 45% KOH or 45% NaOH solution to create a metal oxide film chemical composition.

After the previously prepared SPC, GA, AL, and Mg specimens went through a metal cleaning process, a metal oxide film formation process was performed at a temperature of 35±5°C for 120±5 seconds using the prepared metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, and only the washing water immediately before electrodeposition coating was used as ion exchange water (deionized water).

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to achieve a film thickness of 25 ± 5㎛.

[Example 2]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 15 ± 5 ppm, and the ferric ion compounds mentioned in [Example 1] are selected. Use one or two or more types of zirconium compounds to make zirconium ions 150±15ppm (10 times the mass of Fe ions), and add 60% nitric acid to make nitrate radical ions 1000±10ppm, and it is also naturally degradable. After adding this good carboxylic wetting and dispersing agent at 300±30ppm, adding isopropyl alcohol at 30±10ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then adding 45% KOH or 45% KOH to bring the pH to 3.5±0.5. A metal oxide film chemical composition was prepared by adjusting it with NaOH solution.

After the previously prepared SPC, GA, AL, and Mg specimens were subjected to a metal cleaning process, a process for forming a metal oxide film was performed at a temperature of 35 ± 5°C for 120 ± 5 seconds using the prepared metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

[Example 3]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 200 ± 20 ppm, as mentioned in [Example 1]. One or two or more types of zirconium compounds are used to make zirconium ions at 20 ± 5 ppm (1/10 the mass compared to Fe ions), and NaNO ₃ is used to make nitrate radical ions at 50,000 ± 50 ppm. It is also naturally degradable. Add a good carboxylic wetting and dispersing agent at 200±20ppm, then add isopropyl alcohol at 30±10ppm to help spread the wetting and dispersing agent and form a smooth metal oxide film, and then adjust the pH to 4.0±0.5 with 30% HNO ₃ solution. Thus, a metal oxide film chemical composition was created.

The previously prepared SPC, GA, AL, and Mg specimens were subjected to a metal cleaning process, and then a process for forming a metal oxide film was performed at a temperature of 20±5°C for 60±5 seconds using the prepared metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

[Example 4]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 300 ± 30 ppm as mentioned in [Example 1]. One or two or more types of zirconium compounds are used to make zirconium ions 50±5ppm (1/6 the mass compared to Fe ions), and 60% nitric acid is used to make nitrate radical ions 2000±20ppm, and it is also naturally degradable. After adding this good carboxylic wetting and dispersing agent at 200±20ppm, adding ethyl alcohol at 100±10ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then adding 45% KOH or 45% NaOH to bring the pH to 2.0±0.5. A metal oxide film chemical composition was prepared by adjusting the solution.

After the previously prepared SPC, GA, AL, and Mg specimens went through a metal cleaning process, a process for forming a metal oxide film was performed at a temperature of 15±5°C for 20±5 seconds using the prepared metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

[Example 5]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 130 ± 15 ppm, as mentioned in [Example 1]. Using one or two or more types of zirconium compounds, add zirconium ions to 130 ± 15 ppm (mass compared to Fe ions 1:1), and add nitrate radical ions to 5000 ± 50 ppm using 60% nitric acid.

After adding a carboxyl-based wetting and dispersing agent with good decomposability at 300±30ppm, adding isopropyl alcohol at 30±10ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then adding 45% KOH or A metal oxide film chemical composition was prepared by adjusting it to a 45% NaOH solution.

After the previously prepared SPC, GA, AL, and Mg specimens were subjected to a metal cleaning process, a process for forming a metal oxide film was performed at a temperature of 30 ± 5°C for 120 ± 5 seconds using the prepared metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray color paint with the product name KCC-ED-2100 to achieve a film thickness of 25 ± 5㎛.

[Example 6]

As a chemical composition for forming a metal oxide film, select one or two or more types of ferric ion compounds mentioned in [Example 1] and add them so that the iron ion content in the chemical composition is 50 ± 5 ppm, as mentioned in [Example 1]. One or two or more types of zirconium compounds are used to make zirconium ions at 250 ± 30 ppm (5 times the mass of Fe ions), and KNO ₃ is used to make nitrate radical ions at 10,000 ± 50 ppm. It is also highly biodegradable. After adding a carboxylic wetting and dispersing agent at 100±10ppm, adding ethyl alcohol at 50±10ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then adjusting the pH to 2.0±0.5 with a 30% HNO ₃ solution to remove the metal. An oxide film chemical composition was prepared.

The previously prepared SPC, GA, AL, and Mg specimens were subjected to a metal cleaning process, and then a metal oxide film formation process was performed at a temperature of 20±5°C for 60±5 seconds using a metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

[Example 7]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 30 ± 5 ppm, as mentioned in [Example 1]. One or two or more types of zirconium compounds are used to make zirconium ions at 90 ± 5 ppm (3 times the mass of Fe ions), NaNO ₃ is used to make nitrate radical ions at 50,000 ± 50 ppm, and it is naturally degradable. After adding a good carboxylic wetting and dispersing agent at 200±20ppm, adding ethyl alcohol at 50±5ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then adding 45% KOH or 45% NaOH solution to pH 4.5±0.5. was adjusted to create a metal oxide film chemical composition.

The previously prepared SPC, GA, AL, and Mg specimens were subjected to a metal cleaning process, and then a metal oxide film formation process was performed at a temperature of 30±5°C for 60±5 seconds using a metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed with a gray color paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

[Example 8]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 150 ± 15 ppm, as mentioned in [Example 1]. Using one or two or more types of zirconium compounds, add zirconium ions to 150 ± 15 ppm (mass compared to Fe ions 1:1), add nitrate radical ions to 500 ± 50 ppm using 60% nitric acid, and add natural After adding a carboxyl-based wetting and dispersing agent with good decomposability at 50±5ppm, adding ethyl alcohol at 100±10ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then using a 2.5% Cu(NO ₃ ) ₂ solution. A metal oxide film chemical composition was prepared by adding 10 ± 2 ppm of Cu ions and adjusting the pH to 4.5 ± 0.5 with 45% KOH or 45% NaOH solution.

The previously prepared SPC, GA, AL, and Mg specimens were subjected to a metal cleaning process, and then a process for forming a metal oxide film was performed at a temperature of 25±5°C for 30±5 seconds using the prepared metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

[Example 9]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 130 ± 15 ppm, as mentioned in [Example 1]. Using one or more types of zirconium compounds, add zirconium ions to 130 ± 15 ppm (mass compared to Fe ions 1:1), add nitrate radical ions to 1600 ± 20 ppm using 60% nitric acid, and add natural After adding a carboxyl-based wet dispersant with good decomposability at 300 ± 30 ppm, add isopropyl alcohol at 30 ± 10 ppm to help spread the wet dispersant and form a smooth metal oxide film, and then use a 2.5% Cu(NO ₃ ) ₂ solution. Cu ions were added to 10 ± 2 ppm, F ions were added to 60 ppm using a 30% solution of NaF or KF, and the pH was adjusted to 3.5 ± 0.5 with 45% KOH or 45% NaOH solution to prepare a metal oxide film chemical composition.

The previously prepared SPC, GA, AL, and Mg specimens were subjected to a metal cleaning process, and then a metal oxide film formation process was performed at a temperature of 35±5°C for 120±5 seconds using a metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to achieve a film thickness of 58-3325 ± 5㎛.

[Example 10]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 100 ± 10 ppm, as mentioned in [Example 1]. One or two or more types of zirconium compounds are used to make zirconium ions at 130 ± 15 ppm (1.3 times the mass compared to Fe ions), and 60% nitric acid is used to make nitrate radical ions at 3000 ± 30 ppm, and it is also naturally degradable. After adding this good carboxylic wetting and dispersing agent at 300±30ppm, adding ethyl alcohol at 30±10ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then adding Cu using a 2.5% CU(NO ₃ ) ₂ solution. It was added to 10±2ppm and the pH was adjusted to 3.5±0.5 with 45% KOH or 45% NaOH solution to prepare a metal oxide film chemical composition.

The previously prepared black specimen (hot forged product) was subjected to a metal cleaning process, and then a process for forming a metal oxide film was performed at a temperature of 20 ± 5°C for 120 ± 5 seconds using a metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

[Example 11]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 100 ± 10 ppm, as mentioned in [Example 1]. Use one or two or more types of zirconium compounds to make zirconium ions at 130 ± 15 ppm (1.3 times the mass compared to Fe ions), add nitrate radical ions at 1500 ± 50 ppm using 60% nitric acid, and make it naturally degradable. After adding this good carboxylic wetting and dispersing agent at 300±30ppm, adding isopropyl alcohol at 30±10ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then using a 2.5% Cu(NO ₃ ) ₂ solution. Cu ions were added to 10 ± 2 ppm, F ions were added at 60 ± 5 ppm using NaF or KF, and the pH was adjusted to 3.5 ± 0.5 with 45% KOH or 45% NaOH solution to prepare a metal oxide film chemical composition.

The previously prepared black specimen (hot forged product) was subjected to a metal cleaning process, and then a process for forming a metal oxide film was performed at a temperature of 25 ± 5°C for 120 ± 5 seconds using the prepared metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

[Example 12]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 130 ± 15 ppm, as mentioned in [Example 1]. Using one or more types of zirconium compounds, add zirconium ions to 130 ± 15 ppm (mass compared to Fe ions 1: 1), add SO4 ions to 1000 ± 10 ppm using 1: 1 sulfuric acid, and add natural After adding a highly decomposable carboxylic wetting and dispersing agent at 300±30ppm, adding ethyl alcohol at 100±10ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then adjusting the pH to 3.5±0.5 with 45% KOH or 45% A metal oxide film chemical composition was prepared by adjusting it with NaOH solution.

After the previously prepared SPC, GA, AL, and Mg specimens were subjected to a metal cleaning process, a process for forming a metal oxide film was performed at a temperature of 35 ± 5°C for 120 ± 5 seconds using the prepared metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

[Example 13]

As a chemical composition for forming a metal oxide film, one or two or more types of ferric ion compounds mentioned in [Example 1] are selected and added so that the iron ion content in the chemical composition is 130 ± 15 ppm, as mentioned in [Example 1]. Using one or more types of zirconium compounds, add zirconium ions to 130 ± 15 ppm (mass compared to Fe ions 1:1), add Cl ions to 1000 ± 10 ppm using 36% hydrochloric acid, and add naturally degradable After adding this good carboxylic wetting and dispersing agent at 300±30ppm, adding ethyl alcohol at 100±10ppm to help spread the wetting and dispersing agent and forming a smooth metal oxide film, and then adding 45% KOH or 45% NaOH to adjust the pH to 3.5±0.5. A metal oxide film chemical composition was prepared by adjusting the solution.

After the previously prepared SPC, GA, AL, and Mg specimens were subjected to a metal cleaning process, a process for forming a metal oxide film was performed at a temperature of 35 ± 5°C for 120 ± 5 seconds using the prepared metal oxide film chemical composition. At this time, all water used in the pre-process was industrial water, not deionized water. Deionized water was used only for washing water immediately before electrodeposition coating, as in the previous technique.

Then, electrodeposition coating was performed using a gray-colored paint with the product name KCC-ED-2100 to a film thickness of 25 ± 5㎛.

The above-described Examples 1 to 12 are summarized in Table 1 below.

The method for evaluating the paint (painting) properties of the metal oxide film formed on the surface of a metal material according to an embodiment of the present invention is as follows.

[Method for evaluating paint properties of metal oxide film]

1. Adhesion test

According to KSM 6711, use a razor blade on one side of the painted surface of the test specimen.

① Create 100 checkerboard marks by drawing 11 horizontal and vertical lines at 1mm intervals so that they touch the metal surface. ② Attach a tape with a width of 12 mm as specified in KSA 1528 on the eyes of the checkerboard while pressing it strongly with your fingers and immediately peel it off strongly upward to check for peeling with the naked eye. There should be no peeling.

2. Flexibility test

According to JIS-K-5600-5-1, a round bar with a diameter of 10 mm must be bent 180° using a bending test device and there must be no peeling.

3. Impact resistance test

When a weight of 500 g is dropped from a height of 30 cm using a JIS-K5600-5-3 Dupont-type falling ball tester, there must be no peeling of the coating film.

4. Salt spray test

Cross cut the specimen according to KSD 9502, maintain the chamber temperature of 35 ± 2℃ with 5% salt water, and spray for 1000 hours. Wash the specimen with clean water, dry it, and then use your fingers to tape a tape with a width of 12 mm as specified in KSA 1528. Apply while pressing strongly and immediately peel off in an upward direction to visually inspect the peeling phenomenon. It must be within 3 mm on one side. However, for the black skin specimens, a salt spray test was conducted for 800 hours according to current standards and the results were examined.

5. Salt water immersion test

Cross cut the specimen, soak it in 5% salt water for 240 hours, wash it with clean water, dry it, and attach a tape with a width of 12mm as specified in KSA 1528 while pressing it strongly with your fingers. Immediately remove it strongly in the upward direction and inspect the peeling phenomenon with the naked eye. . It must be within 3mm on one side.

Table 2 below is a physical property evaluation table that evaluates the physical properties of the paint applied to the metal oxide film formed according to the present invention based on [Method for evaluating paint (painting) physical properties of metal oxide film].

Table 3 below shows the measured values of the metal oxide film formed on the surface of the metal material according to the present invention, showing the measured value of Fe ions, the amount of Zr (zirconium) attached (mg/m2), and the XRF measured value for each metal material. is giving

The Fe measurement values in Table 3 show that in the case of SPC and GA specimens, the Fe of the iron material and GA alloy was measured together with Fe in the metal oxide film, and in the case of the AL specimens and Mg specimens, iron, which is classified as an impurity in the alloy, was measured. It is reasonable to assume that it was measured together with on.

Also, what should be noted here is that since it is measured in XRF along with Zr ions, which are the main component of the film, it can be inferred that a certain portion of the measured iron film formed on the metal material was mobilized to form a metal oxide film, as shown in Table 2.

In addition, referring to the appearance of the specimen shown in Table 3 in terms of color, the metal oxide film formed on the metal material is bluish red to golden or light blue in the case of SPC (cold rolled) steel sheet, and in the case of GA (galvanized steel sheet) material. has a dark gray to gray color, and Al-based materials and Mg-based materials have pink wish to gray wish colors.

The inventor of the present application found that the more ferric ions added to a chemical composition containing zirconium, the more the exterior of the film took on a blue color and the film gradually became thicker. However, the less the ferric ion content was added, the more the film appeared golden or golden in color. It was confirmed that the color became yellowish and the film gradually became thinner. This is evidence that iron ions in the metal oxide film chemical composition were mobilized for film formation.

Meanwhile, the content of ferric iron (Fe ⁺³ ) ions included as a component in the metal oxide film chemical composition of the present invention can be measured more accurately using the following measurement method, which was developed by the present inventor.

Since the ferric iron (Fe ⁺³ ) ion mobilized in the metal oxide film chemical composition of the present invention is an oxidizing agent, its amount can be measured using a 0.1N-Na ₂ S ₂ O ₃ (sodium thiosulfate) reducing agent solution.

Ferric iron (Fe ⁺³ ) ions liberate potassium iodide (KI) into iodine (I ₂ ) in the presence of excess hydrochloric acid, and this liberated iodine (I ₂ ) is measured with a 0.1N-Na ₂ S ₂ O ₃ solution. So, you can know the content of ferric iron (Fe ⁺³ ) ions from that value. That is, the free iodine (I ₂ ) is titrated with 0.1N-Na ₂ S ₂ O ₃ solution to find the content of ferric iron (Fe ⁺³ ) ions.

If this is expressed in formula, it is as Chemical Formula 5 and Chemical Formula 6 below.

The free iodine (I2) in Formula 5 reacts as in Formula 6 below.

Referring to Formula 5 and Formula 6 together, ultimately, sodium thiosulfate (Na ₂ S ₂ O ₃ ·5H ₂ O) with a molecular weight (MV) of 404 g and ferric iron (Fe ⁺³ ) ion with a molecular weight (MW) of 56 g reacted. The theory is that in 1 ml of 0.1N-Na ₂ S ₂ O ₃ ·5H ₂ O, 0.404 g (made by dissolving 40.4 g in 1 liter) and 0.0056 g of ferric ion (5.6 g/1000 ml) are oxidized 1:1. The conclusion is that it is mobilized in a reduction reaction.

Here, since we know the amount of 0.1N-Na ₂ S ₂ O ₃ ·5H ₂ O as a standard solution (40.4 g/1000 mL), we can determine the unknown ferric iron (Fe ⁺³ ) ion in the sample. You will also be able to find the amount of .

However, since the sample contains not only ferric ions but also various chemical substances, the measurement results in I.C.P (Inductively Coupled Plasma) were measured about 10 times, as well as the known substances directly added by the inventor to the chemical composition of the metal oxide film of the present invention. 2

As a result of repeated experiments based on the content of iron (Fe ⁺³ ) ions, the content of ferric iron (Fe ⁺³ ) ions corresponding to 1 ml of 0.1N-Na ₂ S ₂ O ₃ ·5H ₂ O solution was " The data “0.558mg” was obtained.

The data "0.558mg" is reflected in the following measurement formula [Formula 7] for calculating the content of ferric ions, and a test to measure the content of ferric iron (Fe ⁺³ ) ions in the sample is performed as follows.

<Measurement of ferric iron (Fe+3) ion content in sample>

Accurately take 10 ml of the in-process sample with a mass hole pipette, place it in a 300 ml stoppered Erlenmeyer flask, add 50 ml of distilled water, then add 3 ml of hydrochloric acid (HCl) and 3 g of potassium iodide (KI) and shake well. Next, leave it in a cool, dark place for 30 minutes, add 50 ml of distilled water to make 100 ml, and titrate with 0.1N-Na ₂ S ₂ O ₃ ·5H ₂ O solution. At the point when the yellow color of the free iodine (I ₂ ) begins to fade, add 5% starch solution (Starch soln.) and titrate from blue to colorless. Substitute the consumption mL into [Chemical Formula 7] below to obtain sample. Calculate the content (concentration) of ferric iron (Fe+3) ions contained in it.

here,

0.558: Content of ferric iron (Fe+3) ion equivalent to 1 ml of 0.1N-Na2S2O3·5H2O [mg]

: 10 is the number of ml of sampling, 1000 is the number of ml, and 1 liter is converted to ml.

f: The commonly measured titer (factor) of 0.1N-Na ₂ S ₂ O ₃ ·5H ₂ O. If exactly 40.4 g of 0.1N-Na ₂ S ₂ O ₃ ·5H ₂ O is dissolved in 1 liter, f is 1.0. It is within ±0.1.

As described above, the present invention provides high paint adhesion to the metal surface to be painted by using a chemical composition that can simultaneously treat single or two or more composite materials such as iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials. In addition, the chemical composition penetrates well into the fine gaps in complex joints and overlaps, forming an excellent metal oxide film on any metal surface to be painted.

In addition, the chemical composition of the present invention for forming a metal oxide film does not initially use zinc (Zn) and manganese (Mn) ions, which were used as rust inhibitors or auxiliaries in existing zirconium-based metal oxide films, and will greatly contribute to preventing environmental pollution. Since copper ions and fluorine ions are not used to form the oxide film, it can be said to be an environmentally friendly coating agent. In the case of the frame (substructure) of hot forged products used only as vehicle underbody, 2~10ppm of copper (Cu) ions and 20~90ppm of fluorine (F) ions were used in an extremely limited amount.

In addition, the metal oxide film chemical composition of the present invention does not contain additional metal ions, such as tin (Sn) ions, indium ions, aluminum ions, nynabium ions, tantalum ions, yttrium ions, and cerium ions, and also does not contain polyamines that are difficult to biodegrade. Sufficient coating properties were maintained even without the use of compounds, chelate compounds, or silane coupling agents.

Moreover, the present invention is very good economically and conveniently because it can use industrial water, whereas the water used in the zirconium coating agent of the prior art required the use of pure water such as deionized water.

In the above description of the present invention, specific embodiments have been described, but various modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be determined by the described embodiments, but by the claims and equivalents to the claims.

Claims (10)

A coating agent containing zirconium that can be simultaneously treated on a metal surface or a metal surface including a composite material in the coating step of the painting process,
10 ppm to 500 ppm of ferric ion;
75ppm to 300ppm of zirconium (Zr) ions that can be used as industrial water; and
Contains 500 ppm to 55,000 ppm of nitric acid (NO ₃ ) ions,
At a pH of 1.5 to 5.0, a metal oxide film with a thickness of 0.01 ㎛ to 0.05 ㎛ is formed on the metal surface.
A coating agent containing zirconium.
According to paragraph 1,
Further comprising one selected from the group consisting of 500ppm to 55,000ppm sulfuric acid (SO ₄ ) ions, 500ppm to 55,000ppm hydrochloric acid (Cl) ions, 2ppm to 10ppm copper (Cu) ions, and 20ppm to 90ppm fluorine (F) ions,
A coating agent containing zirconium.
According to paragraph 1,
The concentration ratio of the ferric ion to the zirconium ion is,
Characterized in that the mass basis is 0.1 to 10,
A coating agent containing zirconium.
According to paragraph 1,
Further comprising 50 ppm to 500 ppm of a non-amine-based wetting and dispersing agent that can be used in the industrial water,
A coating agent containing zirconium.
According to paragraph 1,
The ferric ion is,
Ferricitrate, Ferric Ammonium, Ferric Sulfate, Ferric Ammonium Sulfate, Ferric Chloride, Ferric Nitrate One or at least one of Ferric nitrate, Ammonium Oxalate, Ferric Oxalate, Ferric Sodium Oxalate, and Ferric bromide Characterized by being formed by combining two types,
A coating agent containing zirconium.
According to paragraph 1,
The ferric ion is,
Characterized in that a compound containing ferrous ions is ironized with a 60% nitric acid (HN0 ₃ ) solution.
A coating agent containing zirconium.
According to paragraph 1,
Zirconium (Zr) compounds having zirconium (Zr) ions include Hexafluoro Zirconic Acid (H ₂ ZrF ₆ ), Zirconium Tetrafluoride (ZrF ₄ ), and Zirconium Sulfate (Zirconium Sulfate). ZrSO ₄ ), Zirconium Nitrate (Zr(No ₃ ) ₂ )·nH ₂ O), Potassium Hexafluoro zirconate (K ₂ ZrF ₆ ), Ammonium Hexafluoro Zirconate ( Characterized in that it contains Ammonium Hexafluoro zirconate, (NH ₄ ) ₂ ZrF ₆ ),
A coating agent containing zirconium.
According to paragraph 1,
Characterized by forming a metal oxide film containing 20 to 300 ppm of any one of ethyl alcohol and isopropyl alcohol in order for the chemical composition to penetrate even into complex joints and fine gaps in overlaps.
A coating agent containing zirconium.
Using a coating agent containing zirconium according to any one of claims 1 to 8,
Metal surface pretreatment method.
According to clause 9,
Forming a metal oxide film on the metal surface or the metal surface containing the composite material by exposing the metal or the metal containing the composite material to a coating agent containing the zirconium at a temperature of 15 ° C. to 50 ° C. for 15 seconds to 120 seconds. ,
Metal surface pretreatment method.