KR100950339B1 - Composition for metal surface treatment, water-based solution composition for metal surface treatment comprising the same, fabrication method of plated steel sheet using the solution composition, plated steel sheet fabricated thereby - Google Patents

Abstract

The present invention is a water-based ethylene-acrylic acid copolymer resin 50 to 80% by weight based on the total weight of the composition converted into solids; 2 to 20% by weight of a water-soluble acrylic emulsion resin containing a phosphoric acid acrylic monomer; Silica sol 10 to 30% by weight; 1 to 10% by weight of the silane coupling agent; 0.3 to 3% by weight of a fluororesin-modified polyolefin wax; 0.1-5% by weight of organometallic complex; And it relates to a metal surface treatment composition, a water-based metal treatment solution composition comprising the composition, a method for producing a plated steel sheet using the composition, and a plated steel sheet produced by the manufacturing method .

Water-based, metal surface treatment composition, water dispersion, plated steel sheet

Description

Composition for metal surface treatment, a solution composition for water-based metal surface treatment comprising the same, a method for producing a plated steel sheet using the aqueous solution composition, and a plated steel sheet prepared by the above method (composition for metal surface treatment, water-based solution composition for metal surface treatment comprising the same, fabrication method of plated steel sheet using the solution composition, plated steel sheet fabricated hence}

The present invention is excellent in corrosion resistance and powder coating, environmentally friendly chromium-free (Cr-Free) metal surface treatment composition, a water-based metal surface treatment solution composition comprising the same, a method for producing a plated steel sheet using the solution composition And to a plated steel sheet produced by the above method.

Conventionally, zinc-based and aluminum-based plated steel sheets are shipped in a coil state by applying a coated chromate treatment to prevent rust generation during distribution and storage for a certain period of time. The consumer has processed such steel sheet as it is or after processing the coated oil and processed and used it for the final purpose.

However, conventional chromate treatment solutions and surface treated steel sheets contain hexavalent chromium (Cr), which is particularly harmful to humans and the environment. On the other hand, in recent years, since the seriousness of the world and the demand for environmental regulation is increasing, the restriction on the use of Cr is increasing. According to these regulations, it is necessary to prepare a treatment solution containing no hexavalent chromium. As a method for producing a treatment solution containing no hexavalent chromium, there are two methods of using trivalent chromium and a method of coating an organic or organic-inorganic complex solution without chromium itself. In this regard, research on products that satisfy the processability, paintability and workability, economical efficiency while having the corrosion resistance function of the existing Cr is in progress.

However, the technologies currently being developed are yet to be developed for a multifunctional surface treatment composition that satisfies corrosion resistance, solvent resistance, chemical resistance, and the like, and also has powder coating properties which are most used in post-processing.

An object of the present invention is to provide a composition for metal surface treatment excellent in solution stability, chemical resistance and lubricity, and a solution composition for aqueous metal treatment comprising the composition. In addition, another object of the present invention is to provide a method for producing an environmentally friendly plated steel sheet which is excellent in corrosion resistance, abrasion resistance, and powder coating, and does not contain a chromium component, and a plated steel sheet manufactured by the above method.

In order to achieve the above object, the present invention is based on the total weight of the composition in terms of solid content, 50 to 80% by weight of water-based ethylene-acrylic acid copolymer resin; 2 to 20% by weight of a water-soluble acrylic emulsion resin containing a phosphoric acid acrylic monomer; Silica sol 10 to 30% by weight; 1 to 10% by weight of the silane coupling agent; 0.3 to 3% by weight of a fluororesin-modified polyolefin wax; 0.1-5% by weight of organometallic complex; And it provides a metal surface treatment composition comprising a residual amount of the additive.

The present invention, in the total weight of the composition, 14 to 15% by weight of the metal surface treatment composition; And it provides a solution composition for water-based metal surface treatment comprising a residual amount of water.

The present invention, the aqueous metal surface treatment solution composition is applied to the plated steel sheet surface with a dry adhesion amount of 0.3 to 2.0g / ㎡, hot air, induction heating so that the temperature of the metal surface to which the composition is applied is 80 to 140 ℃ Or it provides a surface treatment method of a metal steel sheet, characterized in that drying by NIR (Near Infrared) method.

The present invention provides a plated steel sheet, which is manufactured by the surface treatment method of the metal steel sheet.

The metal surface treatment composition of the present invention and a solution composition for an aqueous metal surface treatment containing the composition are excellent in solution stability, chemical resistance, and lubricity. The coated steel sheet coated with the surface treatment composition of the present invention is excellent in corrosion resistance, abrasion resistance, and powder coating properties. In addition, it does not contain a chromium component can provide an environmentally friendly plated steel sheet.

Hereinafter, the present invention will be described in detail.

I. Metal surface treatment composition

The composition for metal surface treatment of the present invention comprises a water-soluble ethylene-acrylic acid copolymer resin, a water-soluble acrylic emulsion resin containing a phosphate acrylic monomer, a silica sol, a silane coupling agent, a fluororesin-modified polyolefin wax, an organometallic complex compound, and an additive. Include. In the present invention, the metal refers to zinc or zinc aluminum-based alloy plated steel sheet.

The water-dispersible ethylene-acrylic acid copolymer resin contained in the composition for metal surface treatment of this invention is contained in 50 to 80 weight% with respect to the total weight of the composition converted into solid content. If the above-mentioned range is satisfied, the solvent resistance, chemical resistance, and corrosion resistance of the composition for metal surface treatment of this invention become excellent.

The water-dispersible ethylene-acrylic acid copolymer resin is prepared by dissolving an ethylene-acrylic acid copolymer and an amine in distilled water. More specifically, the water-dispersible ethylene-acrylic acid copolymer resin is prepared by emulsifying the ethylene-acrylic acid copolymer with an amine. The ethylene-acrylic acid copolymer is a copolymer obtained by radical polymerization of ethylene and acrylic acid, preferably acrylic acid is copolymerized at 10 to 40% by weight, more preferably 15 to 25% by weight. As the amine has a boiling point of 50 ° C. to 100 ° C., the amine is emulsified by neutralizing the ethylene-acrylic acid copolymer.

Specific examples of the amine include tertiary amines, secondary amines, primary amines, and the like. Tertiary amines include triethylamine, N, N-dibutylamine, N, N-dimethylarylamine, N-methylpyrrolidine, tetramethyldiaminomethane, trimethylamine, and the like. . Examples of secondary amines include N-methylamine, diisopropylamine, diethylamine, and the like. As primary amine, propylamine, t-butylamine, sec-butylamine, isobutylamine, 1,2-dibutylpropylamine, 3-pentylamine, etc. are mentioned. Of these, triethylamine is most preferred. Moreover, 1 type, or 2 or more types of amine can be mixed and used.

The said amine is contained in 0.2-1 mol with respect to 1 mol of carboxyl groups which ethylene-acrylic acid copolymer resin has, Preferably it is 0.5-0.8 mol. If the above-mentioned range is satisfied, the resin is completely dissolved in water to facilitate emulsification, and emulsification with an appropriate viscosity can be prevented, thereby preventing gelation.

The water-soluble acrylic emulsion resin containing the phosphate acrylic monomer contained in the composition for metal surface treatment of the present invention is contained in 2 to 20% by weight based on the total weight of the composition converted into solid content. If the above-mentioned range is satisfied, adhesiveness with a metal will improve and corrosion resistance, workability, and arrival adhesiveness will become excellent.

The phosphate-based acrylic monomer is preferably represented by the following formula (1) to enhance the adhesion to the metal, and to include a phosphate group and an acrylic group in the molecule.

<Formula 1>

In Formula 1, R is H or CH ₃ group, n is 0 to 10.

Examples of the phosphoric acid-based acrylic monomer represented by the formula (1) include mono-2-methacryloyloxyethyl acid phosphate, mono-2-acryloyloxyethyl acid phosphate, and the like. Commercially available products include SIPOMER PAM-100, SIPOMER PAM-200, SIPOMER PAM-300, etc. of Rhodia, USA. The phosphoric acid-based acrylic monomer is included in 0.5 to 10 parts by weight in 100 parts by weight of the total monomers contained in the water-soluble acrylic resin. If the above-mentioned range is satisfied, the adhesive force with a metal is excellent. If included below the above range, the adhesion to the metal can not be expected. If it exceeds the above-mentioned range, the physical property improvement by the addition amount cannot be expected.

The water-soluble acrylic emulsion resin is composed of an acrylic or vinyl monomer. The water-soluble acrylic emulsion resin includes an acrylic monomer capable of internal crosslinking and the phosphate-based acrylic monomer so as to have excellent wear resistance and corrosion resistance when processing a metal.

Examples of the acryl or vinyl monomers are as follows. Examples of nonfunctional acrylic monomers include methyl acrylate, ethyl acrylate, isopropyl acrylate, N-butyl acrylate, ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate. Low reel methacrylate etc. are mentioned. Examples of the acrylic monomer containing a carboxyl functional group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, and the like. Examples of the acrylic monomer containing a hydroxyl group include 2-hydroxymethacrylate, hydroxypropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxyamyl (meth) acrylate, and the like. Can be.

Examples of the vinyl monomers include styrene, vinyltoluene, acrylonitrile, vinyl acetate, and other commercially available vinyl esters such as vermicul 9, versatile 10, and versatile 11, such as beobar 9 and beoba 10. , Beoba 11, and the like.

In addition, examples of other internal crosslinkable acrylic monomers include acrylamide, N-methylol acrylamide, butyrol acrylamide, glycidyl methacrylate, and the like.

In the case where the monomers are used in an appropriate ratio, the monomers including amides capable of internal crosslinking are preferably included in an amount of 2 to 10% by weight based on the weight ratio of solids. If the above range is satisfied, it exhibits appropriate reactivity during the reaction to implement the stability of the excellent resin.

The mixed monomer containing at least one of the said acryl or vinylic monomer, 1 or more types of internal crosslinkable monomers, and the said phosphate acryl monomer are mixed, and it is stable using a surfactant, a radical polymerization initiator, and a pH adjuster. A water-dispersible water soluble acrylic emulsion resin can be prepared.

Preferred examples of the surfactant include reactive anionic and nonionic surfactants. Specific examples of the reactive anionic surfactants include PD-104, and reactive nonionic surfactants include PD-420 and PD-430. The surfactant is included in an amount of 0.2 to 5 parts by weight based on 100 parts by weight of the monomer composition used in the water-soluble acrylic emulsion resin. When the above-mentioned range is satisfied, the emulsifying power of the monomer is excellent, so that it is easy to be an emulsion resin, and suitable emulsion particles can be realized, thereby preventing separation of the reactant and the solvent. In addition, foaming during the reaction is suppressed and the water resistance of the coating film is excellent.

As the radical polymerization initiator as the reaction initiator, ammonium persulfate, sodium persulfate, potassium persulfate, or the like may be used. The reaction initiator is included in 0.1 parts by weight to 2 parts by weight based on 100 parts by weight of the monomer composition used in the water-soluble acrylic emulsion resin. When included in the above-mentioned range, the polymerization of the emulsion is easy, and an appropriate amount of salt in the emulsion resin is included, it is possible to implement excellent water resistance and corrosion resistance.

The pH adjusting agent is used to maintain the internal pH in a certain range when synthesizing the water-soluble acrylic emulsion resin. Examples of the pH adjusting agent include compounds such as sodium sulfite, sodium sulfate, sodium bicarbonate, and ammonium bicarbonate. It is preferable that the said pH adjuster is contained 0.1 weight part-1 weight part with respect to 100 weight part of monomer compositions used for the said water-soluble acrylic emulsion resin. When the above-mentioned range is satisfied, the pH control ability is excellent, and an appropriate salt is included to provide excellent water resistance and corrosion resistance of the emulsion resin.

The water-soluble acrylic emulsion resin may be synthesized into an emulsion by amine neutralization. Generally, dimethylethanol amine, triethylamine, aqueous ammonia, etc. may be used as a neutralizing agent to maintain a pH of 7 to 9 to obtain a stable water-soluble acrylic emulsion resin.

Silica sol contained in the composition for metal surface treatment of the present invention is contained in 10 to 30% by weight based on the total weight of the composition converted into solids. If the above range is satisfied, excellent corrosion resistance can be realized, and gelation is prevented to increase the stability of the solution. It is preferable to use the said silica sol as an inorganic component and a particle diameter of 10-50 nm.

The silane coupling agent included in the metal surface treatment composition of the present invention is preferably used in an amount of 1 to 10% by weight based on the total weight of the composition converted into solid content. If the above range is satisfied, excellent corrosion resistance and solution stability can be realized.

The silane coupling agent may be used one selected from the group consisting of amino silane, epoxy silane, acrylic silane, vinyl silane. The silane coupling agent has a hydrolyzable group such as an alkoxy group and an organic functional group such as an acryl, epoxy, vinyl and mecapto group. Thereby, it contributes to the increase of the bonding force and the adhesiveness improvement between organic materials, such as resin, and inorganic materials, such as a silica, glass, and a metal.

The fluororesin-modified polyolefin wax contained in the composition for metal surface treatment of the present invention improves blackening resistance and lubricity. The fluororesin-modified polyolefin wax is contained in 0.3 to 3% by weight based on the total weight of the composition converted into solids. When the above-mentioned range is satisfied, sufficient lubrication is performed to implement blackening resistance, and adhesion of the coating film is increased.

The fluororesin-modified polyolefin wax realizes the same effect in terms of lowering the coefficient of friction of the coating film than the olefin wax used generally, but is much superior to the general olefin wax in terms of blackening after processing.

The organic complex compound included in the composition for metal surface treatment of the present invention increases the adhesion between the plated steel sheet and the film, enhances the bond between the organic resin and the inorganic metal base, and ultimately contributes to the improvement of corrosion resistance. The organometallic complex compound is included in an amount of 0.1 to 5% by weight based on the total weight of the composition converted into solids. When the above-mentioned range is satisfied, adhesion and corrosion resistance can be improved, and excellent solution stability can be realized. Exceeding the above-mentioned range is not only uneconomical but also reduces the stability of the solution.

Examples of the organometallic complex compound include titanate-based or zirconium-based compounds, which may be used alone or in combination of two or more. Examples of the titanium compound include titanium stearate complex, titanium organophosphate complex, titanium acetylacetonate, isobutoxy titanium ethylacetoacetate, diisopropoxy titanium bisethylacetoacetate, tetraisopropyl titanate, tetranormal butyl Titanate, tetraethyl titanate, a reactant of lactic acid and titanium alkoxide, titanyl sulfate, and fluoro titanic acid. Examples of the zirconium-based compound include amine group-containing zircon aluminates such as tetranormal propyl zirconate, tetranormal butyl zirconate, triethanolamine zirconate, and carboxy zirco aluminate; Zirconyl nitrate; Zirconyl sulfate; Zirconyl acetate; Zirconyl carbonate; Fluoro zirconium acid; And ammonium hexafluoro zirconate.

As the additive included in the composition for metal surface treatment of the present invention, a wetting agent, a leveling agent, an antifoaming agent, and the like may be used in order to improve coating and workability.

II. Aqueous metal surface treatment solution composition

Aqueous metal surface treatment solution composition of the present invention, the total weight of the composition, 14 to 15% by weight of the metal surface treatment composition of the present invention; And the remaining amount of water. If the above range is satisfied, pick-up is easy during roll coating, and thus uniform coating may be performed. In addition, the solution is stable and easy to store.

III. Manufacturing method of plated steel sheet and plated steel sheet manufactured by the above method

The composition for a water-based metal surface treatment of the present invention is coated on a plated steel sheet and baked in a dry manner such that the metal surface temperature is 80 ° C to 140 ° C. When the baking is dried in the above-described range, the baking-drying state is good, and surface defects and discoloration can be prevented.

This completes the plated steel sheet using the composition for water-based metal surface treatment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited thereto.

Preparation Example 1 : Water dispersion  Preparation of Ethylene-Acrylic Copolymer Resin

A 1 liter four-necked flask was equipped with a thermometer, a condenser and a stirrer. 225 g of distilled water, 60 g of ethylene-acrylic acid copolymer (20% by weight of acrylic acid) and 15 g of triethylamine were added thereto to dissolve to prepare Example 1 of an aqueous dispersion of ethylene-acrylic copolymer resin solution having a solid content of 20%.

Preparation Example 2 : Water dispersion  Preparation of Ethylene-Acrylic Copolymer Resin

A 1 liter four-necked flask was equipped with a thermometer, a condenser and a stirrer. 225 g of distilled water, 60 g of ethylene-acrylic acid copolymer (25% by weight of acrylic acid) and 15 g of triethylamine were added thereto to dissolve to prepare Example 2 of an aqueous dispersion of ethylene-acrylic copolymer resin solution having a solid content of 20%.

Synthesis Example 1 Water Soluble Acrylic emulsion  Synthesis of Resin

A 2-liter four-necked flask was equipped with a thermometer, a condenser and a stirrer, and 510 g of distilled water, 1.9 g of sodium bicarbonate, and 1.1 g of potassium persulfate were added thereto, and the temperature was increased to 85 ° C. 170 g of distilled water, 44.9 g of BC10, 11.2 g of RN20, 2.2 g of potassium persulfate, 32 g of phosphate methacrylate, 195 g of methyl methacrylate, 100 g of butyl acrylate, 12 g of N- (hydroxymethyl) acrylamide, 115 g of Veova-10, 3 g of 2-hydroxyethyl methacrylate, 3 g of glycidyl methacrylate, 4 g of acrylic acid, and 4 g of methacrylic acid were added thereto, followed by stirring for about 30 minutes to prepare a preemulsion. About 5% by weight of the total preemulsion was added to the reactor for 10 minutes and stirred for 15 minutes to form an emulsion nucleus. After nucleation was formed, the remaining preemulsion was added dropwise and uniformly for 5 hours to perform emulsion polymerization. After the dropping was completed, the mixture was maintained for 1 hour and 30 minutes, cooled to 40 ° C. or less, neutralized to pH 8 to 9 with ammonia water, and stirred for 30 minutes to prepare a water-soluble acrylic emulsion resin.

Synthesis Example 2 Water Soluble Acrylic emulsion  Synthesis of Resin

A 2-liter four-necked flask was equipped with a thermometer, a condenser, and a stirrer, and 700 g of distilled water, 2 g of sodium bicarbonate, and 15 g of N-07 were added thereto, and the temperature was increased to 85 ° C. In a separate container, 150g of distilled water, 25g of N-07, 2g of potassium persulfate, 300g of methyl methacrylate, 70g of N- (hydroxymethyl) acrylamide, 100g of Veova-10, and 15g of 2-hydroxyethylmethacrylate Stir for about 30 minutes to prepare a preemulsion. About 5% by weight of the total preemulsion was added to the reactor for 10 minutes and stirred for 15 minutes to form an emulsion nucleus. After nucleation was formed, the remaining preemulsion was added dropwise and uniformly for 5 hours to perform emulsion polymerization. After the dropping was completed, the mixture was maintained for 1 hour 30 minutes, cooled to 40 ° C. or less, neutralized to pH 8 to 9 with ammonia water, and stirred for 30 minutes to prepare a water-soluble acrylic emulsion resin.

Example 1  To 5, Comparative Example 1  To 5: metal surface treatment of steel sheet

Each component was added in the amount (solid weight%) shown in Table 1, water was added to prepare a surface treatment composition having a solid content of 18%, which was coated on a hot dip galvanized steel sheet at 1.2 g / m 2, and then 110 ° C. After the baking was passed through an oven to prepare a plated steel plate was post-treated.

Examples 1 to 5 and Comparative Examples 1 to 5 were prepared by the above method, and the physical properties of the coating film were evaluated based on the following criteria, and are shown in Table 1 below.

(1) corrosion resistance

72 hours of 5% brine spraying at 35 ^° C and 95% humidity (according to ASTM B117 method)

(2) acid resistance

 20 min observation after 5% HCl solution drop

(3) alkali resistance

 2 min observation after 5% NaOH solution drop

(4) solvent resistance

 Rub with methanol gauze 10 times and observe changes

(5) blackening resistance

240 hours at 50 ° C and 95% humidity

(6) Paint adhesion after powder coating

After coating the powder coating of polyester type and immersing the specimen in boiling water for 1 hour, the coating film is drawn 11 lines horizontally and vertically at 1mm intervals according to the method specified in ASTM D3359 to make 100 columns, and then taped peel test with adhesive tape.

Silica sol: ST-30 (trade name, manufacturer: Snowtex)

Silane Coupling Agent: Epoxy Silane

Wax: Fluoropolymer Modified Polyolefin Wax

Organometallic Compounds: Tetraisopropyl Titanate

Comparative Example 4 and Comparative Example 5: Post-treatment Agent for Acrylic Urethane Corrosion and Coating

Referring to Table 1, it can be seen that the corrosion resistance and powder coating properties of the surface-treated steel sheet coated with the surface treatment composition of the present invention is superior to the surface-treated steel sheet coated with the conventional surface treatment composition shown in the comparative example.

Claims (11)

With respect to the total weight of the composition in terms of solids, 50 to 80% by weight of an aqueous ethylene-acrylic acid copolymer resin; 2 to 20% by weight of a water-soluble acrylic emulsion resin containing a phosphoric acid acrylic monomer; Silica sol 10 to 30% by weight; 1 to 10% by weight of the silane coupling agent; 0.3 to 2% by weight of a fluororesin-modified polyolefin wax; 0.1-5% by weight of organometallic complex; And A metal surface treatment composition comprising a residual amount of additives. The method according to claim 1, The ethylene-acrylic acid copolymer resin In the ethylene-acrylic acid copolymer copolymerized acrylic acid at 10 to 40% by weight, A composition for metal surface treatment, characterized in that it is emulsified by neutralization with an amine having a boiling point of 50 ° C to 100 ° C. The method according to claim 2, The amine is triethylamine, N, N-dibutylamine, N, N-dimethylarylamine, N-methylpyrrolidine, tetramethyldiaminomethane, trimethylamine, N-methylamine , Diisopropylamine, diethylamine, propylamine, t-butylamine, sec-butylamine, isobutylamine, 1,2-dibutylpropylamine, and 3-pentylamine 1 or 2 or more types of composition for metal surface treatment. The method according to claim 1, The phosphoric acid-based acrylic monomer is a compound for metal surface treatment, characterized in that the compound represented by the formula (1) comprising a phosphate group and an acrylic group in the molecule: <Formula 1>

In formula 1, R is H or CH ₃ group, n is 0 to 10. The method according to claim 1, The organometallic complex compound is a metal surface treatment composition, characterized in that one or two or more selected from the group consisting of titanium compounds and zirconium compounds. The method according to claim 5, The titanium compound may be a titanium stearate complex, a titanium organophosphate complex, titanium acetylacetonate, isobutoxy titanium ethyl acetoacetate, diisopropoxy titanium bisethylacetoacetate, tetraisopropyl titanate, tetranormalbutyl titanate, An aqueous metal surface treatment composition comprising at least one selected from the group consisting of tetraethyl titanate, a reactant of lactic acid and titanium alkoxide, titanyl sulfate, and fluoro titanic acid. The method according to claim 5, The zirconium-based compound is tetranormal propyl zirconate, tetranormal butyl zirconate, triethanolamine zirconate, carboxy zirco aluminate, zirconyl nitrate, zirconyl sulfate, zirconyl acetate, zirconyl carbonate, fluoro zirconate Water-based metal surface treatment composition, characterized in that one or two or more selected from the group consisting of ammonium hexafluoro zirconate. The method according to claim 1, The metal surface treatment composition, characterized in that the zinc or zinc aluminum-based alloy plated steel sheet. In terms of the total weight of the composition, 14 to 15% by weight of the composition according to any one of claims 1 to 8; And A water-based metal surface treatment solution composition comprising a residual amount of water. The solution composition for aqueous metal surface treatment according to claim 9 is applied to the surface of the plated steel sheet at a dry deposition amount of 0.3 to 2.0 g / m 2, The surface treatment method of the metal sheet, characterized in that the drying by hot air, induction heating or NIR (Near Infrared) method so that the temperature of the metal surface coated with the composition is 80 to 140 ℃. It is manufactured by the surface treatment method of the metal steel sheet of Claim 10, The plated steel sheet characterized by the above-mentioned.