KR100385158B1 - Surface Treating Composition of Metal and Method of Manufacturing the Same - Google Patents

Abstract

Disclosed are compositions for metal surface treatments that do not contain chromium and methods for their preparation. Such a composition comprises 95 to 60% by weight of solid content of resin and 1 to 10% by weight of anticorrosive rust inhibitor in solid content of organic resin and inorganic metal sol in a ratio of 80:20 to 30:70 in solid content. It comprises 0.5 to 10% by weight of the metal complex. Since it does not contain chromium, the problem of damaging the human body is solved and low temperature curing, which is a treatment condition of the surface treatment agent of a general coated steel sheet, is possible without causing a problem of environmental pollution.

Description

Surface Treating Composition of Metal and Method of Manufacturing the Same

The present invention relates to a composition for metal surface treatment and a method for producing the same, and in detail, the surface treatment of an environmentally friendly galvanized steel sheet having corrosion resistance to the galvanized steel sheet and having a practical level of economics and containing no chromium. It relates to a composition for and a method for producing the same.

Galvanized steel sheet and various plated steel sheets are plated with metals of various components in order to add corrosion resistance and special functions to cold rolled steel sheets, and rust such as white blue occurs as metal components such as zinc are exposed to corrosive environment for a long time.

Therefore, in order to protect the surface of a plated steel plate, steel companies have provided the corrosion resistance of the steel plate surface using pretreatment agents, such as an inorganic phosphate type and a chromate type. Among them, chromate pretreatment has the most excellent results until now in terms of corrosion resistance and economical efficiency.

Therefore, in order to improve the corrosion resistance of the zinc alloy plated steel sheet or the aluminum alloy steel sheet, the coating resistance, etc., chromium is treated to the extent of showing appropriate physical properties. The coated chromate exhibits corrosion resistance due to barrier properties of the chromium film itself and self repairability by hexavalent chromium in the film. In addition, chromate treatment technology has been widely used as a post-treatment coating agent of zinc-based galvanized steel sheet by exhibiting excellent corrosion resistance and coating film adhesion at low cost.

As the chromate treatment method, there are treatment methods such as reaction type, coating type and electrolytic type. Reaction type is the most common method of reacting a zinc surface with a treatment liquid to form a film, followed by washing with water and drying. The application type is a method in which a treatment liquid is applied to the surface of a plated steel sheet to contain hexavalent chromium in the coating. The electrolytic type is a method of forming a film by cathodic electrolytic treatment in a treatment liquid. Among them, the coated chromate treatment is advantageous in terms of corrosion resistance and economical efficiency, and has been commercialized mainly in Japan.

Recently, however, environmental problems caused by various production activities have been seriously considered both at home and abroad. Chromic acid is harmful to workers in the production process such as the pretreatment process of steel sheet, causing disease, and during the cleaning process after the pretreatment work process. If the generated wastewater is released, it causes severe water pollution, so its wastewater treatment cost is excessively generated. In addition, the strong oxidation of chromium causes serious invasion of the human body and the natural environment, and inhalation of these substances can also be a cause of lung cancer. As a result, it is almost impossible to use it by industry. Increasing demands on environmental regulations around the world have increased the use of harmful ingredients. In 2003, Europe will regulate the use of steel sheets containing hexavalent chromium in automotive vehicles.

To solve this problem, many studies have been conducted for many years.

Step 1: As an alternative, water-soluble resin and corrosion inhibitors such as sodium benzoate and potassium triphosphate were used. However, they were problematic in terms of adhesion and stability.

Step 2: Alkali-lithium silicate solution was discussed, consisting only of inorganic materials without organic resins. Physical properties approached similarly to chromate, but the processing time was long and economical efficiency was lowered due to high temperature.

Step 3: A solution in the form of titanium oxide (titanium ion, (TiO) 2+) or titanium peroxide ion (peroxytitanic ion) in which titanium or titanium metal is oxidized has been developed, but also economics have been deteriorated.

In addition, although a treatment agent was prepared using a mixture of corrosion resistant organic resin, organic silane, and inorganic acid, physical properties such as corrosion resistance were inferior to those of conventional chromate.

In addition, the effect of corrosion resistance as much as chromate treatment is not technically great, and the effect of coating base property etc. is also weak. In addition, since the drying conditions are not suitable to be applied directly to the pre-processing line of the existing chromate system is difficult to work, and the economic increase is very large, there is a large economic burden to be put to practical use.

Many years ago, many studies on chromium substitutes for plated steel have been conducted, and some of them are known to have started mass production.

On the other hand, chromium-free after-treatment coatings to solve the environmental problems may be prepared by mixing with other acidic substances by applying trivalent chromium, which is relatively less harmful to the environment and human body, and has some effect, This is far from pure chromium-free surface treatment agents.

In addition, a coating using molybdate or the like that forms an oxide on the surface, a rare earth metal salt (formation of hydrated cerium oxide on the surface using CeCl _3, etc.), a zirconium oxide coating silane, titanate (R'OTi ( OR) is used to form MOTi (OR) ₃ ), thioglycollate, alkoxide coating, and various other techniques have been studied.

However, these products have a very different physical properties depending on the drying conditions, so the drying temperature must be very high PMT 150 ~ 200 ℃, the treatment time of the treatment agent also has a disadvantage that must be deposited in a few minutes to a few minutes.

Recently, in addition to pure inorganic acid-based treatment agent, there is also a technology of applying organic, inorganic and organic + inorganic coatings. The organic component is a resin coating, a special organic coating, a method of mixing special additives with an organic resin, an organic resin and an inorganic It is based on the mechanism by which the components are used in combination.

These products are also in a condition where drying conditions are better than acid treatment systems, but drying temperatures are required at about 120 to 180 ° C.

Therefore, an object of the present invention is to solve the environmental and energy problems as an aqueous solution containing no chromium at all, and to dry quickly at a low temperature of PMT 70 ~ 150 ℃ which is a treatment condition of a general surface treatment agent for plated steel sheet, giving a corrosion resistance while giving chromium treatment It is to provide a composition for metal surface treatment which is enhanced in blackening resistance due to the weak physical properties of the steel sheet and excellent properties such as coating film adhesion.

Another object of the present invention is to provide an easy method for preparing the above composition.

Another object of the present invention is to provide a method for treating the surface of a metal using the composition described above.

In order to achieve the above object, in the present invention, a resin in which the organic resin and the inorganic metal sol are coupled to each other in a ratio of 80:20 to 30:70 in a solid ratio of 95 to 60% by weight as a solid content, and the corrosion resistance rust preventive agent is used as a solid content. It provides the composition for metal surface treatment containing-10 weight% and 0.5-10 weight% of an organometallic complex.

Particularly, the aqueous organic resin includes any one of hydroxyl group and carboxyl group, and at least one selected from the group consisting of a water-soluble acryl polymer resin, a water-soluble alkyd resin, a water dispersible urethane resin, and a water dispersible epoxy resin is preferably used. do.

In addition, the solid content may be preferably used in the range of 5 to 20% by weight in the composition.

Another object of the present invention

Preparing an aqueous organic resin;

Based on the total amount of the reactants, the organic-inorganic composite is formed by coupling the aqueous organic resin and the inorganic metal sol at a ratio of 80:20 to 30:70 in a solid ratio in the presence of a coupling agent in the range of 0.05 to 5% by weight. Preparing a resin; And

60 to 95% by weight of the resulting organic-inorganic composite resin in solid content, 1 to 10% by weight of the metal anticorrosive rust preventive agent and 0.5 to 10% by weight of the organometallic compound. Is achieved by.

In particular, as the coupling agent, a compound capable of chemically bonding an organic material and an inorganic material including two or more different functional groups in a molecule is preferably used.

Another object of the present invention is achieved by a method of surface treatment of the composition by any one of spray coating and roll coating on the substrate.

In particular, the drying temperature after the surface treatment is in the range of 70 to 150 ° C., and it is preferable that the solid content after drying is deposited on the surface of the substrate with an adhesion amount of 200 to 2000 mg / m ² .

According to the present invention, the surface protection ability of the anti-corrosion on the plated galvanized steel sheet and the coating film adhesion performance of varnish, powder coating, etc. than the pure chromate-treated steel sheet is also significantly improved, especially the drying temperature is very low, even with a small adhesion amount The composition of the coating material of the metal surface which can exhibit the outstanding performance can be manufactured.

The surface treating agent according to the present invention uses an aqueous organic resin and an aqueous inorganic metal sol in a solid content ratio of 80:20 to 30:70 wt%, and introduces an organic metal coupling agent to introduce an organic resin and an inorganic metal. Molecular weight is improved by intermolecular crosslinking with sol to compensate for physical properties of film.

The aqueous organic resin used in the present invention may be a water-soluble acrylic resin, a water-soluble alkyd resin, a water-dispersible epoxy resin, a water-dispersible urethane resin, or a modified resin of each resin.

There are many methods for the solubilization of organic polymers, typically emulsion polymerization using an emulsifier, and water-soluble type for dissolving in water using a neutralizing agent such as amine after imparting a polar group to the polymer. ), The water dispersion type (physical dispersion type), which is dispersed in water as physically fine particles, is most commonly used.

The liquid prepared by each method has advantages and disadvantages such as chemical, physical properties and storage stability, and the physical properties are very different depending on the monomers to be reacted. What is important is that the organic resin contains functional groups such as hydroxyl groups and carboxyl groups to participate in the reaction with the inorganic metal sol.

The hydroxyl groups contained in the resin are typically hydroxy ethyl (meth) acrylates, hydroxy propyl (meth) acrylates and aryl alcohols, and N-methylol acrylamide in the case of aric ), Alcohol amides such as N-butoxy methyol acrylamide are widely used, and in other polyester and alkyd resins, trimethylol propane, neopentyl glycol, glycerin, pentaerythritol, etc. Hydroxyl group-containing monomers are used.

In epoxy and urethane resins, the hydroxyl groups contained in the epoxy resins themselves can be used or the residual polyol groups of the urethane-based can be used for the reaction.

As the carboxyl group-containing monomer, (meth) acrylic acid is used in the acryl resin and benzic acid, phthalic anhydride, trimellitic acid and the like are used in the polyester and alkyd resin to be used for the solubilization and internal crosslinking reaction.

However, when the amount of the organic solvent contained in the water-soluble resin is within 20% of the total solvent content, the complex reaction with the inorganic sol easily occurs. If the solvent content exceeds 20%, the complex reaction with the inorganic sol may be rather hindered. On the other hand, if the content of the organic solvent is too small, the stability of the water-soluble resin may be lowered, so that the layer separation phenomenon such as sedimentation during storage of the resin and the treatment agent may occur, this should be in the appropriate range according to the type of resin.

In addition, the inorganic metal sol used by this invention used what has the following characteristics.

Properties of Used Inorganic Metal Sols Alumina sol Silica sol Titania sol Zirconia Sol Exterior White translucent solution Translucent liquid White opaque solution Translucent liquid PH of the sol 3.2 7-9 8.7 4.0 to 5.5 Concentration (%) 42 20-30 1 to 3 10 to 20 Particle size (nm) 50-800 3 to 700 50 to 150 60 to 80

These inorganic sols have a great influence on the physical properties such as reactivity with water-soluble resins, corrosion resistance of iron and coating film adhesion, depending on the size and pH of the solution, respectively.

In the present invention, the pH after the solubilization of the organic resin and the pH of the inorganic sol were used. The pH of the resin after the solubilization and the pH of the inorganic sol are preferably acidic if they are acidic and basic if they are basic. Otherwise, it may be due to aggregation immediately without compatibility when mixing and reacting.

In addition, the reaction amount of an organic resin and an inorganic sol is used in 80: 20-30: 70 by solid content ratio. If the ratio of the inorganic sol is not more than 20% in terms of solid content, it is difficult to obtain the durability and corrosion resistance of the inorganic sol. If the amount of the inorganic sol exceeds 70%, the internal crosslinking reaction with the organic resin does not proceed well. The storage stability of the coating is greatly reduced, making it difficult to use as a treatment agent, and the coating film is too hard, so that the physical properties of the coating base may be weak. Therefore, these addition amount ratio is made into the said range.

In the inorganic sol used, the particle size greatly influences the corrosion resistance of the treatment agent, and the range of the particles is adjusted according to the adhesion amount of the treatment agent. The smaller the adhesion amount of the treatment agent, the smaller the particle size should be used. If the adhesion amount is 2,000 mg / m ² or more, the particle size may show good physical properties even if it is about 100 nm.

If an inorganic sol having a large particle size is used at a small adhesion amount, the uniform coating effect is reduced, and thus there is little effect of increasing the corrosion resistance. In addition, when an inorganic sol of too small particle size is used at a high adhesion amount, the effect of increasing corrosion resistance against an increase in adhesion amount is inferior. Therefore, the inorganic sol needs to be selected to have an appropriate particle size as needed.

The coupling agent for coupling-reacting the aqueous organic resin and the inorganic sol has two or more different reactors in the molecule to act to chemically bond the organic material and the inorganic material. For example, silane coupling agents can be used to bond even poorly compatible materials due to chemical intermediation. By applying this property, it can be used for improving mechanical strength, water resistance, adhesion of composite materials, modifying resins, surface modification of fillers, etc. to improve performance and quality.

With the development of composite materials and the progress of hybridization, silane coupling agents and titanium-based coupling agents have wide application ranges and are widely used. Their mechanism is as follows.

First, the alkoxy group contained in the coupling agent is hydrolyzed by water or moisture to become a hydroxyl group. This hydroxyl group and an inorganic surface form a coupling bond by condensation reaction. In addition, other reactors can be commercially bound to organics and consequently chemically combine inorganics with organics.

As such a coupling agent, a silane compound and a titanium compound are generally used, but the types thereof are as follows.

As the silane coupling agent, vinyl trichloro silane, vinyl triethoxy silane, vinyl trimethoxy silane, 3-methacryloxypropyl trimethoxy silane, 2-glycidoxy propyl trimethoxy silane, 3-glycidoxypropyl Methyl dimethoxy silane, 3-glycidoxypropyl methyldiethoxy silane, N-2- (amino ethyl) -3-aminopropyl triethoxy silane, 4-amino propyl triethoxy silane, N-phenol-3-amino Propyl trimethoxy silane, 3-ureido alkyl triethoxy silane, and the like.

Titanium crab coupling agents include titanium stearate complex, titanium organo phosphate complex, titanium acetyl acetonate, iso-butoxy titanium ethyl aceto acetate, di-iso-propoxy titanium bis ethyl aceto acetate, tetra isopropyl titanate, tetra normal Butyl titanate, tetra ethyl nitanate and the like.

At this time, the amount of the coupling agent is to be 0.05 to 5% by weight based on the total amount of the reactants. If the addition amount thereof is less than 0.05% by weight, it is difficult to obtain a coupling effect, and when the amount is more than 5% by weight, the stability of the solution may be reduced, resulting in a gel during storage, and the price is also high, thereby reducing economic efficiency.

Importantly, in the method of introducing these coupling agents, it is not simply mixing to obtain a composite through an organic-inorganic internal coupling reaction. Even if these are simply mixed in the preparation of the treatment agent, an increase in physical properties is observed, but the organic-inorganic reactant obtained through the internal crosslinking reaction is remarkably excellent in viscosity and physical properties.

When the organic-inorganic composite resin obtained through such a coupling reaction is based on the total amount of the composition, a metal ion solution is added as a corrosion-resistant antirust additive to a solid content of 60 to 95% by weight, and the amount used is 1 to 10% by solid content. Add.

If the addition amount of the organic-inorganic composite resin exceeds 95% by weight, the resin occupies most of the composition, so the addition amount of the corrosion inhibitor and the organic metal complex used as the additive component decreases, so that the effect of their addition is reduced and excellent corrosion resistance is achieved. It is difficult to obtain, and if the addition amount thereof is less than 60% by weight, it is difficult to obtain a uniform and continuous film on the polymer, so that physical properties such as corrosion resistance and paintability may be weakened, and it is difficult to obtain a completely dried film at low temperature. Therefore, the addition amount thereof is in the above range.

Metal ions used as corrosion-resistant anti-rust additives can be selected according to the pH of the inorganic metal sol reacted with the water-soluble polymer. In acidic solutions, phosphate solutions such as aluminum, manganese, zinc, molybdenum, fluoride phosphate and soda can be selected. By adding a solution prepared by adding phosphoric acid as a stabilizer, a stable treatment agent having excellent compatibility can be obtained.

In the basic solution, amines are added to stabilize solutions such as hexaammonium hepta molybdate, diammonium dihydroxy phosphate, ammonium vanadate, sodium vanadate, ammonium zirconium carbonate, and ammonium fluorozirconate. When it adjusts to 7-8, and adds, a stable processing agent can be obtained.

The amount of these corrosion-resistant rust inhibitors is added in the range of 1 to 10% by weight as a solid content, which is very small if the added amount is less than 1% by weight, and when the amount is more than 10% by weight, the price is expensive and the economical efficiency is lowered. It is because the case where the storage stability of falls will arise.

In addition, the organometallic complex compound may be used to increase the adhesion of the plated steel sheet and to improve the adhesion through the intermolecular coupling between the polymer and the inorganic metal sol. In general, an organic metal compound in which an organic material is bonded to a metal complex having a complex shape is used. In addition, the organometallic complex is used in the range of 0.5 to 10% by weight based on the total amount of the composition, thereby strengthening the bond between the organic resin and the inorganic metal substrate, thereby improving adhesion of the treatment agent to the substrate, thereby providing excellent corrosion resistance and coating film adhesion. The treatment agent having physical properties superior to that of the conventional treatment agent containing chromium is obtained.

Examples of the organometallic complex compound include organic titanates, organic zirconates, other organic silanes, and the like, including the above-mentioned coupling agents. Specifically, for example, titanium stearate complex, titanium organo phosphate complex, titanium acetyl acetonate, iso-butoxy titanium ethyl aceto acetate, di-iso-propoxy titanium bistetyl aceto acetate, tetraiso as an organic titanate compound Propyl titanate, tetra normal butyl titanate, tetra ethyl titanate and the like.

Examples of the zirconium compounds include pure zirconate-based tetra normal-propyl zirconate, tetra-normal-butyl zirconate, triethanamine amine zirconate and zirco aluminate carboxy zirco aluminate, and amine group-containing zircon alumina. Nate and the like. In addition, hydroxy and -SH groups are contained. These zirconium aluminates are used in polymers such as water-soluble acryl, alkyd, polyester polymers, epoxy, urethane, etc. It improves the bonding force with and serves to strengthen the coating film.

As the silanes, vinyl trimethoxy silane, metha acryloxy propyl trimethoxy silane, 3-glycidoxy trimethoxy silane, N- (2-amino ethyl) amino propyl triethoxy silane, amino alkyl group silane, gamma- Glydyl propyl trimethoxy silane and the like can be used.

In the finally applied metal surface treatment agent composition for a coated steel sheet, an anti-foaming agent for adjusting the bubbles of the solution, a surface tension regulator for the surface and workability may be used together. The prepared composition is coated on a substrate such as a galvanized steel sheet by spray coating, roll coating, or the like. The drying temperature after the surface treatment is in the range of 70 to 150 ° C., and the solid content after drying is 200 to 2000 mg / m ² . It is preferably attached on the surface of the body.

Hereinafter, the present invention will be described in more detail with reference to specific examples.

<Example 1>

Organic-Inorganic Coupling Reaction: An acid value of about 70 parts by weight of an aqueous amine resin solution neutralized with amine and 70 parts by weight of an inorganic silica sol were added to a 2 L flask, followed by 2 parts by weight of a vinyl trimethoxy silane coupling agent. After all the raw materials were added, the flask temperature was raised to 75 ° C. and maintained for about 2 hours. An organic-inorganic-coupled composite resin was obtained when the coupling reaction occurred during the holding to increase the viscosity and no change in viscosity.

200 parts by weight of the composite resin thus obtained, 15 parts by weight of an aqueous solution of ammonium fluoro zirconate, and 7.8 parts by weight of triethanol amine zirconate were mixed to prepare an alkaline metal surface treatment agent having a pH of 8.4 and a total solid content of 14% by weight. This was coated on a galvanized steel sheet and dried at 100 ° C. to produce a galvanized steel sheet having an adhesion amount of 0.8 g / m ² .

<Example 2>

The resin solution obtained by neutralizing the epoxy water-dispersible resin having a hydroxyl value of 50 in the molecule with phosphoric acid and the inorganic alumina sol were carried out according to the method of Example 1 in a solid ratio of 70:30, except that N- instead of the vinyl trimethoxy silane coupling agent. 1.2 parts by weight of 2- (amino ethyl) -3-aminopropyl triethoxy silane coupling agent was added at a solid content ratio of 300 parts by weight of a composite resin prepared by coupling reaction, 8.9 parts by weight of an aqueous solution of hexaammonium hepta molybdate and organic 9.6 parts by weight of the titanium phosphate complex was mixed to prepare an acidic metal surfacing agent having a pH of 3.5 and a total solids of 10% by weight. This was coated on a galvanized steel sheet and dried at 100 ° C. to produce a galvanized steel sheet having an adhesion amount of 0.6 g / m ² .

<Example 3>

An acid value of about 80, 300 parts by weight of a composite resin obtained by coupling an aqueous amine resin solution neutralized with an amine with an inorganic silica sol at a solid content of 50:50, 21 parts by weight of an ammonium vanadate solution, and 13.5 parts by weight of diisopropoxy titanium Mixing produced an alkaline metal surface treatment agent having a pH of 8.6. A galvanized steel sheet having an adhesion amount of 0.6 g / m ² after coating on a galvanized steel sheet and drying at 100 ° C. was produced.

Comparative Example 1

200 parts by weight of a resin obtained by simply mixing an aqueous amine resin solution neutralized with an amine with an acid value of about 70 and an inorganic silica sol at a solid content of 30:70, 15 parts by weight of an aqueous solution of ammonium fluoro zirconate, and 7.8 parts by weight of triethanol amine zirconate The parts were mixed to prepare an alkaline metal surface treatment agent having a pH of 8.4 and a total solid content of 14% by weight. A galvanized steel sheet having an adhesion amount of 0.8 g / m ² after coating on a galvanized steel sheet and drying at 100 ° C. was produced.

Comparative Example 2

300 parts by weight of a composite resin obtained by coupling an epoxy water-dispersible resin having a hydroxyl value of 50 in the molecule with phosphoric acid and an inorganic alumina sol at a solid ratio of 20:80, 25 parts by weight of an aqueous solution of hexaammonium hepta molybdate, and 9.6 parts by weight of the organic titanium phosphate complex was mixed to prepare an acidic metal surfacing agent having a pH of 3.5 and a total solids of 10% by weight. A galvanized steel sheet having an adhesion amount of 0.6 g / m ² after coating on a galvanized steel sheet and drying at 100 ° C. was produced.

Comparative Example 3

An acid value of about 80, 300 parts by weight of a composite resin obtained by coupling an aqueous amine resin solution neutralized with an amine and an inorganic silica sol at a solid content of 90:10, 15 parts by weight of an ammonium vanadate solution, and 13.5 parts by weight of diisopropoxy titanium. Mixing produced an alkaline metal surface treatment agent having a pH of 8.6. This was coated on a galvanized steel sheet and dried at 100 ° C. to produce a galvanized steel sheet having an adhesion amount of 0.6 g / m ² .

Coating film experiment result Experimental Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Appearance ^{Note 1)} Adhesiveness ^{Note 2)} Plate corrosion resistance ^{Note 3)} Machining part corrosion resistance ^{Note 4)} Blackening resistance ^{Note 5)} Top coat after coating ^{Note 6)} Top coat finish after process ^{Note 7)} Storage stability ^{Note 8)} Powdering ^{note 9)} ◎◎◎ ○○ ◎◎◎ ○ ◎◎◎ ○○ ◎◎◎ ○ ◎◎◎ ○ ◎◎◎◎ ○ ◎ △△ X ○ XX ○ X △ X △ XXXX △ X ◎ ○ XX △△ X ○○

Evaluation: ◎; Best, ○; Excellent, △; Usually, X; Bad

Note 1) Appearance: Observe the staining and peeling phenomenon by visual observation

Note 2) Adhesiveness: Taping test with cellophane tape after 100/100 cross cut

Note 3) Corrosion resistance test of plate: Observed red blue after spraying 5% saline solution at 35 ℃ for 120 hours

Note 4) Corrosion resistance test of processed part: Observation of red blue after 72 hours of salt spraying after Erichsen processing with 6mm

Note 5) Resistance to blackening: within 5% of the decrease in whiteness after 120 hours at 85% relative humidity and 60 ℃

Note 6) Adhesiveness after top coat: Tapping test with cellophane tape after 100/100 cross cut after powder coating

Note 7) Processability after top coat: Observation of coating after 1T processing after powder coating

Note 8) Storage stability: Viscosity change after 10 days storage at 40 ℃ should be within 5% range.

Note 9) Powdering property: Observe the degree of powdering phenomenon on the surface after processing with square cup tester

From the results obtained, it can be confirmed that the composition obtained according to the examples forms a coating film having excellent properties without containing chromium.

The composition for metal surface treatment according to the present invention as described above significantly improves the coating film adhesion performance of varnish, powder coating and the like than pure chromate treated steel sheet while having the surface protection ability of corrosion prevention of the plated galvanized steel sheet. In addition, the drying temperature is particularly low, and uniform and excellent performance can be exhibited even with a small deposition amount.

In addition, the composition of the present invention does not contain chromium, which is a heavy metal harmful to the human body, is excellent in corrosion resistance, coating film adhesion, and the like, and is a surface treatment agent for metal for plated steel sheet without environmental pollution by VOC. In addition, it compensates for blackening resistance due to high temperature wetting, which is one of the weak physical properties of chromium-treated steel sheets, and is excellent in various properties such as paintability.

In addition, it is possible to quickly dry at a low temperature of PMT 70 ~ 150 ℃ which is a treatment condition of the surface treatment agent of a general coated steel sheet, it is possible to save energy and easy to apply to the product. Not only is it possible to cure at low temperatures, but it is also possible to apply spraying and roll coating to the current operating conditions.

Although the present invention has been described above according to an embodiment of the present invention, it will be apparent to those skilled in the art that various modifications may be made without departing from the spirit of the present invention.

Claims (14)

95 to 60% by weight of solids, 1 to 10% by weight of anticorrosive rust preventives, and organometallic complexes 0.5% by weight of a resin in which an aqueous organic resin and an inorganic metal sol are coupled and bonded at a ratio of 80:20 to 30:70 in a solid content. Metal surface treatment composition containing -10 weight%. The water-based organic resin of claim 1, wherein the aqueous organic resin includes any one of a hydroxyl group and a carboxyl group, and at least one selected from the group consisting of a water-soluble acryl polymer resin, a water-soluble alkyd resin, a water dispersible urethane resin, and a water dispersible epoxy resin. The composition characterized in that the. The composition of claim 1, wherein the inorganic metal sol is at least one selected from the group consisting of alumina sol, silica sol, titania sol and zirconia sol. The anticorrosive rust inhibitor according to claim 1, wherein the corrosion resistant rust inhibitor is an aqueous solution of acidic phosphate including aluminum, manganese, zinc, molybdenum and fluorine phosphate, and hexa ammonium hepta molybdate, diammonium dihydro phosphate, ammonium vanadate, sodium vanadate , A solution of any one of basic solutions comprising ammonium zirconium carbonate and ammonium fluorozirconate. The method of claim 1, wherein the organometallic complex comprises i) titanium stearate complex, titanium organo phosphate complex, titanium acetyl acetonate, iso-butoxy titanium ethyl aceto acetate, di-iso-propoxy titanium bis ethyl aceto acetate, Organic titanate compounds including tetra isopropyl titanate, tetra normal butyl titanate and tetra ethyl nitanate, ii) tetra normal-propyl zirconate, tetra normal-butyl zirconate, tri ethanolamine zirconate, carboxy Organic zirconates comprising zirco aluminate and amine group containing zirco aluminate and iii) vinyl trimethoxy silane, methacryloxy propyl trimethoxy silane, 3-glycidoxy trimethoxy silane, N-2 -(Amino ethyl) amino propyl triethoxy silane, amino alkyl Silane and gamma-glycidyl trimethoxy composition, wherein any one of an organosilane containing a silane. The composition of claim 1, further comprising an antifoaming agent and a surface tension modifier. The composition according to claim 1, wherein the content of solids is in the range of 5-20% by weight. Preparing an aqueous organic resin; Based on the total amount of the reactants, the organic-inorganic composite is formed by coupling the aqueous organic resin and the inorganic metal sol at a ratio of 80:20 to 30:70 in a solid ratio in the presence of a coupling agent in the range of 0.05 to 5% by weight. Preparing a resin; And 95 to 60% by weight of the resulting organic-inorganic composite resin in solid content, 1 to 10% by weight of the metal corrosion-resistant rust inhibitor and 0.5 to 10% by weight of the organometallic compound, a method for producing a composition for metal surface treatment . The method of claim 8, wherein the coupling agent is a compound capable of chemically bonding an organic material and an inorganic material including two or more different functional groups in a molecule. The method of claim 9, wherein the coupling agent is vinyl trichloro silane, vinyl triethoxy silane, vinyl trimethoxy silane, 3-methacryloxypropyl trimethoxy silane, 2-glycidoxy propyl trimethoxy silane, 3 -Glycidoxypropyl methyl dimethoxy silane, 3-glycidoxypropyl methyldiethoxy silane, N-2- (amino ethyl) -3-aminopropyl triethoxy silane, 4-amino propyl triethoxy silane, N- Silane based compounds including phenol-3-aminopropyl trimethoxy silane and 3-ureido alkyl triethoxy silane, and titanium stearate complex, titanium organo phosphate complex, titanium acetyl acetonate, iso-butoxy titanium ethyl Aceto acetate, di-iso-propoxy titanium bis ethyl aceto acetate, tetra isopropyl titanate, tetra normal butyl titanate and tetra ethyl nitane It is any one of a titanium compound containing a nitrate. The method of claim 8, wherein the aqueous organic resin is prepared by emulsion polymerizing a polymer using an emulsifier, a method of preparing a water-soluble polymer using a neutralizing agent including an amine after imparting a polar group to the polymer, and water. A method for producing a water-dispersible polymer dispersed in the form of any one of the manufacturing method characterized by the manufacturing method. The production method according to claim 8, wherein the pH of the aqueous organic resin and the pH of the inorganic sol are adjusted to the same acidity or the same basicity. The method of treating a metal surface according to claim 1, wherein the composition according to claim 1 is surface-treated by any one of spray coating and roll coating. The method according to claim 13, wherein the drying temperature after the surface treatment is in the range of 70 to 150 ° C., and after drying, the solid content is deposited on the surface of the body with an adhesion amount of 200 to 2000 mg / m ² .