KR100956081B1 - Surface Treating Composition of Metal and Method of Manufacturing the Same - Google Patents

Abstract

A surface treating agent of a metal that does not contain chromium and exhibits high corrosion resistance is disclosed. The metal surface treatment agent includes 60 to 90 parts by weight of an organic-inorganic composite resin, in which an organic resin and an inorganic binder are coupled at a ratio of 90:10 to 55:45, and 2 to 10 parts by weight of an anticorrosive corrosion agent and sodium hydride. 0.5 to 10 parts by weight of at least one inorganic resin gelling accelerator selected from the group consisting of hydroxide, potassium hydroxide and lithium hydroxide, 2 to 10 parts by weight of a metal chelating agent, and 3 to 12 parts by weight of an additive including a curing agent and a lubricant It has a composition containing a part. The surface treatment agent of the metal is excellent in corrosion resistance, alkali resistance, processed part corrosion resistance, corrosion resistance after coating, and does not contain a chromium component, which is very effective to provide an environmentally friendly steel sheet.

Galvanized Steel Sheet, Surface Treatment, Alkali Resistance, Adhesiveness

Description

Surface Treating Composition of Metal and Method of Manufacturing the Same

The present invention relates to a surface treating agent of a metal that does not contain a chromium component and a method for manufacturing the same, and more particularly, to a surface treating agent of a metal that does not contain chromium, which can ensure corrosion resistance before coating of a metal steel sheet, and a method for manufacturing the same. It is about.

Recently, with increasing interest in environmental issues around the world, regulations on the use of environmental pollutants such as chromium (Cr), lead (Pb), cadmium (Cd), mercury (Hg), PBB, and PBDE have been tightened. . In particular, the Restriction of Hazardous Substances (RoHS) implemented by the EU (Restricted of Hazardous Substances, June 06, 2004), Waste from Electrical and Electronic Equipment (WEEE) (2006.7.1), and the disposal of waste vehicles (ELV). End-of-Life Vehicles (enacted on January 1, 2007) and the Registration, Evaluation and Authorization of Chemicals (REACH) are examples of products that enable companies around the world to develop environmentally friendly products, It is required to actively respond to new environmental management policies such as waste reduction and green procurement in factories.

Conventionally, galvanized steel sheet and zinc-based alloy plated steel sheet, aluminum plated steel sheet, aluminum alloy plated steel sheet, cold rolled steel sheet, hot rolled steel sheet, etc., which are used for automotive materials, home appliances, building materials, etc., are provided with corrosion resistance and paint adhesion. In order to do this, a surface treatment method of coating a chromate coating mainly composed of chromium on the surface is generally performed. The main chromate treatments are electrolytic chromate and coated chromate. Among them, electrolytic chromate treatment consists of hexavalent chromium as a main component and a metal plate using a treatment solution containing various anions such as sulfuric acid, phosphoric acid, boric acid, and halogen. Cathode electrolysis is generally practiced. On the other hand, in the coating type chromate treatment, a method in which an inorganic colloid and an inorganic ion are added to a solution in which a part of hexavalent chromium is reduced to trivalent beforehand is used to deposit a metal plate therein or spray the treatment solution onto the metal plate. It is carried out by.

When using these methods, due to the toxicity of hexavalent chromium contained in the chromate treatment solution, various measures are required in the working environment and drainage treatment, and the recycling and disposal of automobiles, home appliances, building materials, etc. using the surface treatment metals. In addition, it causes human health and environmental pollution.

Therefore, each steel company is focusing on developing a surface-treated steel sheet that does not contain hexavalent chromium and does not contain chromium that can satisfy various requirements such as corrosion resistance, alkali resistance and conductivity. Conventionally, a method of manufacturing a metal salt film mainly composed of phosphate as a main component on the surface of a steel sheet, and then coating a resin-based film mainly composed of acryl and urethane resin as a main component thereon, or the primary film and the second A surface-treated metal steel sheet containing no chromium was produced through the method of forming the primary coating into a resin coating.

However, these products often lower the electrical conductivity and weldability of the metal sheet according to the metal salt or the film thickness, so that the electromagnetic wave suppression, internal noise suppression and processability of LCD, PDP, copier, printer, VCR, and computer are secured. There is a problem that is not suitable for use. In addition, in recent years, since most home appliances require surface-treated steel sheets that do not contain chromium having excellent conductivity, they have developed coated steel sheets that do not contain chromium by a method of primary coating the resin-based coating. However, unless the composition of the resin-based surface treatment composition is particularly excellent, there is a problem in that quality characteristics such as corrosion resistance are significantly lower than those of conventional chromium-treated or phosphate coated steel sheets.

In addition, a method of coating polyaniline on a metal plate as a coating method considering conductivity without including any conventional hexavalent chromium is disclosed in Japanese Patent Application Laid-Open Nos. 8-92479 and 8-500770. have. However, since the polyaniline having high rigidity and low adhesion exists between the metal and the resin film, the film can be easily peeled off from the polyaniline and the metal interface and the polyaniline and the resin interface. Because of this, there is a problem when painting the upper portion in order to give the design, more corrosion resistance and other functions to the steel sheet. Low adhesion films are generally known to have low corrosion resistance. In addition, the solution stability is low, there is a lot of sediment, a bad smell occurs there is also a problem in the workability, such as inhibition of the overall working environment.

Galvanized steel is widely used in building materials, automobiles, home appliances, etc. and is made of finished products through many processes. The surface treatment agent containing chromium could sufficiently secure the corrosion resistance of the processed part by sacrificial corrosion of chromium. However, the surface treatment agent containing no chromium can secure the corrosion resistance of the flat plate part before processing, but it has the disadvantage that the corrosion resistance of the processed part is weak. . In addition, alkali degreasing is performed to coat the exterior after processing, but there is a disadvantage in that corrosion resistance and paintability are vulnerable due to damage to the surface treatment film of the processing part in the alkali degreasing process.

In order to solve the above problems, it is an object of the present invention to provide a surface treatment agent of a metal that does not contain chromium and imparts excellent corrosion resistance, alkali resistance, processed part corrosion resistance, corrosion resistance after coating to the metal steel sheet.

It is another object of the present invention to provide a method for producing the surface treatment agent of the metal.

The present invention for achieving the above object is to provide a surface treatment agent of a metal. The metal surface treatment agent includes 60 to 90 parts by weight of an organic-inorganic composite resin, in which an organic resin and an inorganic binder are coupled at a ratio of 90:10 to 55:45, and 2 to 10 parts by weight of an anticorrosive corrosion agent and sodium hydride. 0.5 to 10 parts by weight of at least one inorganic resin gelling accelerator selected from the group consisting of hydroxide, potassium hydroxide and lithium hydroxide, 2 to 10 parts by weight of a metal chelating agent, and 3 to 12 parts by weight of an additive including a curing agent and a lubricant It has a composition containing a part.

In order to achieve the above-mentioned other object, the present invention provides a method for producing a surface treatment agent of a metal. In order to prepare the surface treatment agent of the metal, the organic resin and the inorganic binder are coupled to each other at a ratio of 90:10 to 55:45 in the presence of a coupling agent of 2 to 10% by weight based on 100% by weight of the reactant. Manufacture inorganic composite resins Subsequently, at least one inorganic resin gelling selected from the group consisting of 60 to 90 parts by weight of the obtained organic-inorganic composite resin, 2 to 10 parts by weight of rust preventive corrosion inhibitor, sodium hydroxide, potassium hydroxide, and lithium hydroxide. 0.5 to 10 parts by weight of accelerator, 2 to 10 parts by weight of a metal chelating agent, and 3 to 12 parts by weight of an additive including a curing agent and a lubricant are mixed. Thereby, the surface treating agent of the metal of this invention is manufactured.

Herein, the water-soluble epoxy resin, epoxy-phosphate resin, acrylic- or vinyl-based monomer-modified epoxy-phosphate resin, acrylic resin, vinyl-based resin, water-dispersible urethane resin and acrylic or vinyl Acrylic-urethane resin etc. modified with the system monomer can be used. In particular, the epoxy-phosphate resin may be obtained by reaction of an epoxy resin with a phosphonic acid compound of Formula 1 or a phosphonic acid compound of Formula 2 below.

(R) _m1 [PO (OH ₂ )] _n1 -------- (Formula 1)

(R) _{m 2} (R 1) _q [PO (OH ₂ )] _n 2 ----- (Formula 2)

In Formulas 1 and 2, R and R1 are each independently hydrogen or a saturated or unsaturated aliphatic or aromatic hydrocarbon having 1 to 20 carbon atoms, unsubstituted or substituted with a hetero atom, and _m1 and _m2 are each independently 1 to 2 Is an integer, _n1 and _n2 are each independently an integer of 1 to 3, and q is an integer of 0 to 2.

As mentioned, the surface treatment agent of the metal produced by the method according to the present invention promotes gelation of inorganic resins, including organic resin-inorganic binder composite resins, thereby improving alkali degreasing, corrosion resistance, processability, and post-processing corrosion resistance of galvanized steel sheets. After coating, the steel sheet has excellent characteristics of corrosion resistance and adhesion. In addition, the surface treatment composition of the metal does not contain a chromium component can prevent environmental pollution.

Hereinafter, a metal surface treatment agent and a method of manufacturing the same according to various aspects of the present invention will be described in detail. However, the present invention is not limited to the following embodiments and may be implemented in other forms. The embodiments introduced herein are provided to make the disclosure more complete and to fully convey the spirit and features of the invention to those skilled in the art.

Surface treatment agent of metal

The surface treatment agent of the metal according to the present invention has a composition comprising the water-soluble organic resin-inorganic binder composite resin obtained and an additive comprising an antirust corrosion agent, an inorganic binder gelling accelerator, a metal chelating agent, a curing agent and a lubricant.

The organic-inorganic composite resin is formed by coupling the organic resin and the inorganic binder in a solid ratio of 90:10 to 55:45. Specifically, in the organic-inorganic composite resin, the organic resin and the inorganic binder are preferably mixed or coupled in a weight ratio of 70:30 to 60:40. This is because if the content of the organic resin is less than 20 weight ratio, the surface treatment composition of the metal cannot be stably attached to the galvanized steel sheet, and if it exceeds 80 weight ratio, the corrosion resistance is lowered.

In particular, the coupling agent applied to obtain the organic-inorganic composite resin is used 2 to 10% by weight, preferably 3 to 8% by weight based on 100 parts by weight of the total of the organic resin and inorganic binder based on solids Use%. Examples of the coupling agent include vinyl silane, epoxy silane, amino silane, alkoxy titanium, and the like. These can be used individually or in mixture of 2 or more.

Hereinafter, the organic resin and the composite resin will be described in detail. The organic resin is preferably a water-soluble or water-dispersible resin having a carboxyl group or a hydroxyl group. This is because if the organic resin does not have a carboxyl group and a hydroxyl group, the water dispersion stability is lowered, and since there is no position of a functional group that can react with the coupling agent, a stable complexation reaction cannot occur. Specifically, examples of the organic resin include a water-soluble epoxy resin having a carboxyl group or a hydroxyl group, an epoxy-phosphate resin, an epoxy-phosphate resin modified with an acrylic or vinyl monomer, an acrylic resin, a vinyl resin, a water-dispersible urethane resin, and And acrylic urethane resins modified with acrylic or vinyl monomers.

As the epoxy resin that can be used in the present invention, a bisphenol A-type resin, a bisphenol F-type resin, a novolak resin, and the like can be used. It is preferable that the molecular weight of the said epoxy resin is 900-7000. This is because when the molecular weight of the epoxy resin is less than 900, the modification reaction is difficult, the water resistance of the dry coating film is poor, and when it exceeds 7000, it is difficult to receive water by the modification reaction. Moreover, it is preferable that the epoxy equivalent of an epoxy resin uses 450-3500. In order to control the molecular weight and the equivalent of the epoxy resin, bisphenol may be added and reacted from the low molecular weight liquid epoxy resin to adjust the molecular weight. The epoxy resin is excellent in adhesion, heat resistance, corrosion resistance, top coat coating properties, etc., widely used in metal coating materials. However, when only epoxy resin is used, the coating material coated with a thin film may lack coating film forming ability and corrosion resistance.

In addition, in the present embodiment, when the phosphonic acid of the formula (1) and the phosphonic acid compound of the formula (2) and / or the acrylic monomer are modified by the epoxy resin, the coating film forming ability and adhesion to the metal material are excellent. Machining part corrosion resistance is improved. Therefore, it is preferable to use an epoxy resin prepared by reacting an epoxy resin with a phosphonic acid compound of Formula 1 or a phosphonic acid compound of Formula 2 as the organic resin of the present invention.

(R) _m1 [PO (OH ₂ )] _n1 -------- (Formula 1)

(R) _{m 2} (R 1) _q [PO (OH ₂ )] _n 2 ----- (Formula 2)

In Formulas 1 and 2, R and R1 are each independently hydrogen or a saturated or unsaturated aliphatic or aromatic hydrocarbon having 1 to 20 carbon atoms, unsubstituted or substituted with a hetero atom, and _m1 and _m2 are each independently 1 to 2 Is an integer, _n1 and _n2 are each independently an integer of 1 to 3, and q is an integer of 0 to 2.

In particular, the phosphonic acid of the formula (1) and the phosphonic acid compound of the formula (2) is very advantageous in improving workability because there is an effect of increasing the curing rate when using a curing agent using a water-soluble and an amino resin of the modified resin.

Examples of the phosphonic acid compound of Chemical Formula 1 include aminotrimethylphosphonic acid, amino-2-benzylphosphonic acid, 3-aminopropylphosphonic acid, o-aminophenylphosphonic acid, 4-methoxyphenylphosphonic acid, Aminophenylphosphonic acid, aminopropylphosphonic acid, benzylphosphonic acid, butylphosphonic acid, 2-carboxyethylphosphonic acid, dodecylphosphonic acid, ethylphosphonic acid, hydrogenphosphonic acid, methylbenzyl Phosphonic acid, methyl phosphonic acid, octadecyl phosphonic acid, phenyl phosphonic acid, diphenyl phosphonic acid, phenyl phosphonic acid, etc. are mentioned.

Examples of the phosphonic acid compound represented by Formula 2 include aminotrimethylphosphonic acid, amino-2-benzylphosphonic acid, 3-aminopropylphosphonic acid, o-aminophenylphosphonic acid, 4-methoxyphenylphosphoic acid, Aminophenylphosphonic acid, aminopropylphosphonic acid, benzylphosphonic acid, butylphosphonic acid, 2-carboxyethylphosphonic acid, dodecylphosphonic acid, ethylphosphonic acid, hydrogenphosphonic acid, methylbenzyl Phosphonic acid, methylphosphonic acid, octadecylphosphonic acid, phenylphosphonic acid, diphenylphosphonic acid, phenylphosphonic acid, and the like.

In addition, it is more preferable that the compounds of Formulas 1 and 2 have a vinyl group or an acryl group. For example, vinyl phosphonic acid, 2-ethyl methacrylate phosphonic acid, 2-ethyl acrylate phosphonic acid, which are condensates of an acryl monomer having a hydroxy group and a compound selected from the group consisting of Chemical Formulas 1 and 2, Propyl methacrylate phosphonic acid, propyl acrylate phosphonic acid, etc. are mentioned.

In particular, when the amount of the compound of Formula 1 or Formula 2 is less than 1% with respect to the epoxy resin equivalent number, it is not preferable due to deterioration of physical properties such as adhesion, corrosion resistance, and solubility, and when the amount of the compound of Formula 1 or Formula 2 exceeds 100%, It is not preferable because of a decrease in water resistance. Therefore, it is preferable to use the number-of-moles in 5 to 80% with respect to the epoxy resin equivalent number. In addition, the present invention may use a tertiary amine, an inorganic compound, and the like as a reaction catalyst to promote the reaction of the epoxy resin with the phosphonic acid of the formula (1) or the phosphonic acid compound of the formula (2). The amount of the reaction catalyst is preferably used in an amount of 0.5 to 1 parts by weight based on 100 parts by weight of the reactant of the epoxy resin and the phosphonic or phosphonic acid compound. Examples of the reaction catalysts include benzyldimethylamine, tributylamine, N, N-dimethylaniline, trimethylphosphine, lithium stearate, stenith octoate, zirconium octoate, triethylbenzyl ammonium chloride, benzyltrimethyl Ammonium hydroxide, etc. are mentioned. These can be used individually or in mixture of 2 or more.

In addition, the epoxy-phosphate resin may be modified with an acrylic or vinyl monomer. Examples of the modification method include radical polymerization by grafting an acrylic or vinyl monomer to an epoxy-phosphate resin or a polymerization method using an unsaturated acid such as maleic acid or fumaric acid.

Examples of the acrylic or vinyl monomers include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, normal butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, acrylic acid metaacrylic acid, maleic acid, fumaric acid as carboxyl functional monomers, Itaconic acid etc. are mentioned. Examples of the hydroxyl group monomers include beta-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, di- (ethylene glycol) mono (meth) acrylate, and the like. have. In addition, as examples of the aromatic vinyl monomer, styrene, alpha-methylstyrene, trans-beta-methylstyrene, beta-methylstyrene, 4-methylstyrene, vinyltoluene vinyl acetate, and the like can be used.

The acrylic or vinyl monomer may be used in an amount of 10 to 100 parts by weight based on 100 parts by weight of the epoxy-phosphate resin. At this time, when the content of the acrylic or vinyl monomer is less than 10 parts by weight, it is difficult to sufficiently exhibit the modification effect, and when it exceeds 100 parts by weight, the corrosion resistance and the water-adhesive resistance rapidly decrease. In addition, a reaction catalyst may be used in the modification of the epoxy-phosphate resin, and as the reaction catalyst, a peroxide-based catalyst generally known in general is preferable.

The epoxy-phosphate resin modified with the acrylic or vinyl monomer is preferably solubilized and converted into a water-soluble epoxy-phosphate resin. In the present invention, a method for converting the water-soluble epoxy-phosphate resin may include a method of saltifying a part of the polymer by using a neutralizing agent that ionizes and charges the resin. Representative ion exchange resins include cationic ion exchange resins, nonionic ion exchange resins, and anionic ion exchange resins. Cationic ion exchange resins can easily corrode containers or equipment due to their acidic properties. It is better to use anionic ion exchange resin which is alkaline and can be used without restriction on equipment.

The water-soluble acrylic or vinyl-based resin may be a polymer synthesized in the composition of various conventional addition-polymerizable monomers containing a carboxyl group of an acceptable level, and a water-soluble polyolefin resin. That is, the acrylic or vinyl monomer may be the same as the acrylic or vinyl monomer used to prepare the epoxy-phosphate resin, except that the acid value of the water-soluble acrylic resin at this time is 50 or more to stably hydrate and complex with an inorganic sol. can do.

Examples of the inorganic binder include silica sol, alumina sol, titania sol, zirconia sol and the like. These may be used alone or in combination of two or more thereof. In particular, the inorganic binder is a product having a strong alkalinity when the particle size is less than 4nm in general has a problem in that the water resistance is weakened accordingly, the corrosion resistance is also weakened, when the particle size is larger in the range of very low adhesion amount of the chromium pre-treatment agent exceeds 20 nm There is a problem in that corrosion is reduced by forming pores. Thus, the inorganic binder has a size of about 4 to 20 nm, preferably about 8 to 15 nm.

The water-soluble organic resin-inorganic binder composite resin is weak in the ability to form a stable film when the content is less than 60 parts by weight with respect to 100 parts by weight of the metal surface treatment agent alkali resistance, corrosion resistance, processability, processed part corrosion resistance, coating coating adhesion There is a problem that is difficult to secure, and if it exceeds 90 parts by weight, the coating adhesion is good, but there is a problem that the corrosion resistance is weak. Accordingly, the surface treatment agent of the metal includes about 60 to 90 parts by weight of the water-soluble organic resin-inorganic binder composite resin, and preferably about 70 to 85 parts by weight.

The inorganic binder hardening accelerator according to the present invention may use a material including an electrolyte component. This is because the organic resin-inorganic binder composite resin can be gelated by reacting with a material containing a large amount of electrolyte. This is because the material containing the electrolyte breaks down the electric double layer stabilized with the colloidal particles and lowers the charge, thereby promoting the curing of the inorganic binder in the composite resin. The gelation rate of the inorganic binder depends on the concentration of the electrolyte, and the electrolyte materials such as Ca2 +, Al3 +, Zn2 +, Mg2 +, Na +, K +, Li +, F +, Cl-, NO3-, CH3COO-, SO42-, PO43-, etc. Can be used. Among these, in the cation, the larger the valence and the larger the atomic weight, the faster the gelation. In anions, the smaller the number of atoms, the smaller the number of atoms tends to cause gelation. The type and concentration of these electrolyte materials also affect the shelf life of the solution. It is possible to use NaOH, KOH, LiOH and the like.

If the amount of the inorganic binder hardening accelerator is less than 0.5 parts by weight, the gelling of the inorganic binder is not affected, and there is no effect of improving alkali resistance and corrosion resistance, and when it exceeds 5 parts by weight, problems of water resistance and corrosion resistance occur. Accordingly, the surface treatment agent of the metal includes about 0.5 to 5 parts by weight of the inorganic binder curing accelerator, and preferably about 1 to 3.5 parts by weight.

Metal ions can be used as an anticorrosive agent applied to the surface treatment agent of the metal of the present invention. The metal ions may be selected according to the pH of the composite resin. Specifically, in an acidic solution, a stable treatment agent having excellent compatibility can be obtained by using a phosphate solution prepared by adding phosphoric acid as a stabilizer to an aqueous solution of phosphate such as aluminum, manganese, zinc, molybdenum, or fluorine phosphate soda. In addition, in the basic solution, the pH is 7 to 7 with an amine added for stabilization to a solution such as hexa ammonium hepta molybdate, diammonium phosphate, ammonium vanadate, sodium vanadate, ammonium zirconium carbonate, and ammonium fluorozirconate. When used after adjusting to 8, a stable treatment agent can be obtained.

If the amount of the anti-corrosive corrosion agent applied to the surface treatment agent of the metal is less than 2 parts by weight, the corrosion resistance as much as the addition of the corrosion inhibitor is not improved, and if it exceeds 10 parts by weight, the corrosion resistance as much as the addition is not improved. There is a problem of low economic efficiency. Accordingly, the surface treatment agent of the metal includes about 2 to 10 parts by weight of the antirust agent, and preferably about 2 to 5 parts by weight.

The metal chelating agent applied to the surface treatment agent of the metal of this invention is used in order to improve the adhesiveness and long-term corrosion resistance after coating. The metal chelating agent is easy to bond with the zinc metal of the galvanized steel sheet due to the metal component contained in itself, and in particular, it may impart stability of the bond due to the phosphoric acid component contained in the epoxy phosphate resin. And the metal chelate can be given more densities of the organic resin itself, and also when the top coating as needed after the treatment on the steel sheet can improve the bonding strength with the paint coming on.

As the metal chelating agent, organic titanate, organic zirconate, and organic silane agent may be used. Examples of the organic titanate and organic zirconate include amino alcohol zirconate, tetra normal butyl titanate, titanium acetyl acetonate, amino alcohol titanate, tetra ethyl titanate and the like. Examples of the organic silane include vinyl silane, epoxy silane, alkoxy silane, and the like, and specific examples thereof include glycidoxy silane and vinyl trimethoxy silane. The metal chelating agent may be used alone or in combination of two or more. Preferably, a mixture of aminoalcohol zirconate and tetranormal butyl titanate, a mixture of aminoalcohol titanate and glycidoxy silane, a mixture of tetranormal butyl titanate and vinyl trimethoxy silane, etc. may be used as the metal chelating agent. Can be.

If the amount of the metal chelating agent applied to the surface treatment agent of the metal is less than 3 parts by weight, the ability to improve corrosion resistance is weak, and the effect of forming an internal mesh structure to strengthen the coating is weakened. On the other hand, if it exceeds 10 parts by weight, the chelate component that remains unreacted is rather weakened in corrosion resistance, resulting in a problem that the cost is very expensive economically. Accordingly, the surface treatment agent of the metal includes about 3 to 10 parts by weight of the metal chelating agent, and preferably about 3 to 7 parts by weight.

Moreover, 3-12 weight part of additives containing a hardening | curing agent and a lubricant are used for the surface treatment of the metal of this invention.

The additive may include a wetting agent, a crosslinking agent, a curing agent, a lubricant, an antifoaming agent, and the like. The wetting agent is effective in streaking and adhesion, the crosslinking agent and the curing agent in corrosion resistance and alkali resistance, the lubricant in friction coefficient and processability, and the antifoaming agent in improving workability. Examples of the wetting agent include a deagglomerated wet dispersant and a polymer wet dispersant, and preferred examples thereof include a wet dispersant commercially available from EFKA, Tego, etc., EFCA 3580 (EFCA), BW-W500 (Bumwoo Chemical). ) Or WET 500 (EFCA). Examples of the crosslinking agent include vinyl silane, acrylic silane, epoxy silane, chloro silane, alkoxy silane, silazane or silylating agent. Examples of the lubricant include silicone wax, polyethylene wax, polypropylene wax, amide wax, polyterafluoroethylene (PTFE) wax, paraffin wax and the like. Examples of the curing agent include polyamine-based, water-dispersed polyamide-based, carbodiimide-based, or acid anhydride-based, oxazoline, water-dispersible oxazolidone, and the like. Examples of the antifoaming agent include oil type, modified type, solution type, powder type, emulsion type silicone antifoaming agent and the like.

The additives are used to impart an optimal coating state and coating performance according to the type thereof, and the additives are mixed in an appropriate ratio because their types and amounts are different, and the amount of each additive is not a limiting factor of the present invention.

The surface treatment agent of the metal of the present invention including the respective constituent parts having such characteristics can secure both long-term corrosion resistance, paint adhesion, and the like with respect to the metal steel sheet.

Preparation of Surface Treatment Agents of Metals

The surface treatment agent of the metal according to the present invention is prepared to have an additive comprising a water-soluble organic resin-inorganic binder composite resin and an anticorrosive corrosion inhibitor, an inorganic binder gelling accelerator, a metal chelating agent, a curing agent and a lubricant. The manufacturing method of the surface treatment agent of the said metal is as follows.

First, the organic-inorganic composite resin is prepared by coupling the organic resin and the inorganic binder in a ratio of 90:10 to 55:45 in the presence of 2 to 10% by weight of a coupling agent based on 100% by weight of the reactant.

Examples of the organic resin applied in the preparation of the organic-inorganic composite resin include an epoxy-phosphate resin, an acrylic resin, and a vinyl resin modified with a water-soluble epoxy resin, an epoxy-phosphate resin, an acrylic or vinyl monomer having a carboxyl group or a hydroxyl group. And water-dispersible urethane resins and acrylic-urethane resins modified with acrylic or vinyl monomers. In particular, the epoxy-phosphate resin is preferably obtained by the reaction of an epoxy resin with a phosphonic acid compound of formula (1) or a phosphonic acid compound of formula (2).

(R) _m1 [PO (OH ₂ )] _n1 -------- (Formula 1)

(R) _{m 2} (R 1) _q [PO (OH ₂ )] _n 2 ----- (Formula 2)

In Formulas 1 and 2, R and R1 are each independently hydrogen or a saturated or unsaturated aliphatic or aromatic hydrocarbon having 1 to 20 carbon atoms, unsubstituted or substituted with a hetero atom, and _m1 and _m2 are each independently 1 to 2 Is an integer, _n1 and _n2 are each independently an integer of 1 to 3, and q is an integer of 0 to 2. Detailed descriptions of the organic-inorganic composite resin, organic resin and inorganic binder are omitted as described above.

Subsequently, at least one inorganic resin gelling accelerator selected from the group consisting of 60 to 90 parts by weight of the obtained organic-inorganic composite resin, 2 to 10 parts by weight of rust-proof corrosion inhibitor, sodium hydroxide, potassium hydroxide, and lithium hydroxide. 0.5 to 2 parts by weight, 3 to 10 parts by weight of a metal chelating agent and 3 to 12 parts by weight of a curing agent to a lubricant are mixed. Thereby, the surface treatment agent of the metal which has storage property, long-term corrosion resistance, and coating adhesiveness is formed.

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are provided only to more easily understand the present invention, and the present invention is not limited to the following examples.

Preparation of Acrylic-Epoxy Resin

A four-necked glass flask was attached with a thermometer, a condenser, a stirrer, and a temperature raising device. Then, 360 g of epoxy resin of bisphenol A type epoxy resin having a epoxy equivalent of 900 to 1000 and 150 g of propylene glycol monomethyl ether were added thereto, and the temperature was raised to 100 ° C. to uniformly dissolve it. Then, 150 g of phosphoric acid was added uniformly over 20 minutes to 1 at 120 ° C. The reaction was maintained for a time. Subsequently, 35 g of styrene, 26 g of methyl methacrylate, 21 g of butyl acrylate, 30 g of propylene glycol monomethyl ether, and 5.4 g of benzoyl peroxide were uniformly mixed in a separate container to form a mixed radish. The reaction was dropwise added at 120 ° C. for about 3 hours to graft polymerize acrylics into epoxy resins. Subsequently, when the dropping was completed, the mixture was reacted at the same temperature for 4 hours to remove unreacted material, cooled to 70 ° C, and neutralized with 87 g of triethylamine. Thereafter, 1,166 g of ion-exchanged water was added dropwise over 30 minutes with strong stirring at about 2000 rpm or more to obtain an acryl-epoxy resin having a nonvolatile content of 25%.

Examples 1-7

After attaching a thermometer, a condenser, a stirrer, and a temperature raising device to a four-necked glass flask, the organic resin (acryl-epoxy resin, acryl-urethane resin), an inorganic binder (inorganic silica sol), and a coupling agent (epoxy) were prepared according to the composition ratio shown in Table 1 below. System silane) and a water-soluble organic polymer resin and an inorganic sol were combined to prepare an organic resin-inorganic binder composite resin. Subsequently, in the obtained composite resin, gelling accelerators (KOH, NaOH, LiOH), anti-corrosive corrosion inhibitors (amide salt phosphate derivatives), metal chelating agents, and curing agents (water dispersion carbodiimide) were used in the content (solid content basis) of Table 1 below. , Lubricant (polyethylene-based lubricant) was added to prepare a surface treatment composition.

[Table 1] (Unit: parts by weight)

Surface of metal Treatment  evaluation

On the surface of the hot-dip galvanized steel sheet having a zinc adhesion of 40 g / m 2 on one side, the surface treatment agent obtained in Examples 1 to 7 and Comparative Examples 1 to 2, respectively, was used on the metal sheet using a continuous roll coating simulator. It was applied to one side of (Pick metal temperature) and dried at 110 ℃ to form a surface treatment coating film. The adhesion amount of the said surface treatment coating film was 1,000 mg / m <2>. Then, the performance of the surface treating agents of Examples 1 to 7 and Comparative Examples 1 and 2 was evaluated under the following conditions, and the results are shown in Table 2.

1) Plate corrosion resistance before painting: Based on the method specified in ASTM B117, the occurrence rate of white rust over time of the coated steel sheet was checked, and the corrosion resistance of the plate was measured and evaluated by the following criteria. Occurs above, Good: White rust occurs more than 120 hours ~ less than 240 hours, Poor: White rust occurs less than 120 hours)

2) Alkali resistance: A specimen prepared in 20 g / l of strong alkaline degreasing agent (FC-L4460, manufactured by Daehan Parkaizing Co., Ltd.) adjusted at a liquid temperature of 45 ° C. is immersed for 2 minutes, washed with running water, dried, and saline spray test according to ASTM B117. The time period up to 5% or less of white rust generating area was evaluated. (Excellence: 96 hours or more, Good: 72 hours or more, less than 96 hours, Poor: less than 72 hours)

3) Constant temperature and humidity before coating: The constant temperature and humidity was measured for the percentage change in whiteness in a constant temperature and humidity tester (98% RH 50 ° C, 120 hours) and evaluated by the following criteria. % Or less, Good: 2 ~ 5% change in whiteness, Bad: 5% or more change in whiteness)

4) Workability: Using an Ericsson cup tester, the holder pressure was 1 ton and the drawing speed was 3 mm / min. The maximum molding pressure (MFD) was measured during processing and evaluated according to the following criteria. 30 KN or less, Good: Maximum molding pressure 30 KN or more 35 KN or less, Poor: Maximum molding pressure 35 KN or more)

5) Corrosion resistance after processing: After performing the square cup molding under the above conditions, the lower end was sealed and the occurrence of white rust over time was checked according to the method defined in ASTM B117, and the corrosion resistance was measured and evaluated by the following criteria. (Excellent: White rust occurs after 72 hours, Good: White rust occurs less than 72 hours and less than 48 hours, Poor: White rust occurs less than 24 hours)

6) Adhesion after coating: According to the method specified in ASTM D3359, the coating film was drawn 11 lines in width and length at 1mm intervals to make 100 columns, and then the adhesion was measured using cellopana tape and evaluated by the following criteria. Coating film remaining rate 100%, Good: Coating film remaining rate 95% or more, Poor: Coating film remaining rate 95% or less)

7) Corrosion resistance after coating: Corrosion resistance was measured according to the method specified in ASTM B117. After cutting the central part of the specimen by X letter, it was maintained for 480 hours. According to the generation area, the following criteria were evaluated. , Poor: more than 10% of white rust area, more than 10mm of blister width)

TABLE 2

Referring to the results of Table 2, as can be seen in Examples 2 to 8 according to the present invention, it can be seen that the corrosion resistance, alkali resistance, corrosion resistance after processing, excellent adhesion after coating, compared to the comparative example. In particular, in the case of Example 1, it was confirmed that the physical properties of the surface treatment agent were excellent when the amount of the organic resin was larger than that of the inorganic binder.

As mentioned above, the surface treatment agent of the metal includes organic resin-inorganic binder composite resins to promote gelation of inorganic resins, thereby improving alkali degreasing, corrosion resistance, processability, corrosion resistance after processing, corrosion resistance of steel sheets after coating, and adhesion. This has excellent characteristics. In addition, the surface treatment composition of the metal does not contain a chromium component can prevent environmental pollution.

Claims (9)

60 to 90 parts by weight of an organic-inorganic composite resin in which an organic resin and an inorganic binder are coupled at a ratio of 90:10 to 55:45 by solid content; 2 to 10 parts by weight of the antirust corrosion agent; 0.5 to 10 parts by weight of at least one inorganic resin gelling accelerator selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide; 3 to 10 parts by weight of the metal chelating agent; And A surface treating agent for metals comprising from 3 to 12 parts by weight of an additive comprising a curing agent and a lubricant. The organic resin of claim 1, wherein the organic resin is a water-soluble epoxy resin, an epoxy-phosphate resin, an epoxy-phosphate resin modified with an acrylic or vinyl monomer, an acrylic resin, a vinyl resin, a water-dispersible urethane resin having a carboxyl group or a hydroxyl group, And an acrylic-urethane resin modified with an acrylic or vinyl monomer. The metal surface treatment agent according to claim 2, wherein the epoxy-phosphate resin is obtained by reaction of an epoxy resin with a phosphonic acid compound of formula (1) or a phosphonic acid compound of formula (2). (R) _m1 [PO (OH ₂ )] _n1 -------- (Formula 1) (R) _{m 2} (R 1) _q [PO (OH ₂ )] _n 2 ----- (Formula 2) (In Formulas 1 and 2, R and R1 are each independently hydrogen or a saturated or unsaturated aliphatic or aromatic hydrocarbon having 1 to 20 carbon atoms, unsubstituted or substituted with a hetero atom, _m1 and _m2 are each independently 1 to 2 _N1 and _n2 are each independently an integer of 1 to 3 and q is an integer of 0 to 2). The surface treating agent of metal of claim 1, wherein the inorganic binder comprises at least one selected from the group consisting of silica sol, alumina sol, titania sol, and zirconia sol having a particle size of 5 to 20 nm. The method of claim 1, wherein the coupling agent is used at least 2 to 10% by weight based on the total of the organic resin and the inorganic binder, at least selected from the group consisting of vinyl silane, epoxy silane, alkoxy silane and alkoxy titanium. It is one, The surface treatment agent of the metal characterized by the above-mentioned. The method of claim 1, wherein the metal chelating agent is at least one selected from the group consisting of organic titanate, organic zirconate and organic silane, and the curing agent is a water-dispersed carbodiimide, water-dispersed polyoxazolidone and water-soluble melamine. At least one selected from the group consisting of metal surface treatment agent. Preparing an organic-inorganic composite resin by coupling the organic resin and the inorganic binder in a ratio of 90:10 to 55:45 in the presence of a coupling agent of 2 to 10% by weight based on 100% by weight of the reactant; And 60 to 90 parts by weight of the obtained organic-inorganic composite resin, 2 to 10 parts by weight of the rust-proof corrosion inhibitor, sodium hydroxide, potassium hydroxide, at least one inorganic resin gelling accelerator selected from the group consisting of lithium hydroxide 2 parts by weight, 3 to 10 parts by weight of a metal chelating agent and 3 to 12 parts by weight of an additive comprising a curing agent and a lubricant. The method of claim 7, wherein the organic resin is a water-soluble epoxy resin, an epoxy-phosphate resin, an epoxy-phosphate resin modified with an acrylic or vinyl monomer having a carboxyl group or a hydroxyl group, an acrylic resin, a vinyl resin, a water-dispersible urethane resin, And an acrylic urethane resin modified with an acrylic or vinyl monomer. The method according to claim 8, wherein the epoxy-phosphate resin is obtained by reaction of an epoxy resin with a phosphonic acid compound of formula (1) or a phosphonic acid compound of formula (2). (R) _m1 [PO (OH ₂ )] _n1 -------- (Formula 1) (R) _{m 2} (R 1) _q [PO (OH ₂ )] _n 2 ----- (Formula 2) (In Formulas 1 and 2, R and R1 are each independently hydrogen or a saturated or unsaturated aliphatic or aromatic hydrocarbon having 1 to 20 carbon atoms, unsubstituted or substituted with a hetero atom, _m1 and _m2 are each independently 1 to 2 _N1 and _n2 are each independently an integer of 1 to 3 and q is an integer of 0 to 2).