KR20100079436A - Anti-corrosion coating composition and method of manufacturing the same - Google Patents

Abstract

PURPOSE: An anti-corrosion coating composition and a manufacturing method thereof are provided to use the composition for coating a galvanized steel pipe, and to secure the alkali resistance and the water resistance. CONSTITUTION: A manufacturing method of an anti-corrosion coating composition comprises the following steps: preparing a silane-modified water-soluble acrylic resin with the acid value of 35~60 mgKOH/g, and the weight average molecular weight of 15,000~30,000; producing an organic-inorganic silica composite resin by an organic-inorganic complexation reaction, of a water-soluble acrylic resin, water-dispersible colloidal silica, and a silane coupling agent; and mixing 20~50wt% of silane-modified water-soluble acrylic resin, 5~25wt% of organic-inorganic silica composite resin, 10~30wt% of water-soluble organic solvent, and 30~60wt% of water.

Description

Water-soluble rust-preventive coating composition and manufacturing method thereof {ANTI-CORROSION COATING COMPOSITION AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to a water-soluble rust-preventive coating composition and a method for producing the same, and more particularly, to a water-soluble rust-preventive coating composition having improved corrosion resistance, adhesion, alkali resistance, water resistance, moisture resistance and a method for producing the same.

Steel pipes (pipes) are mainly produced from black pipes using hot rolled steel sheets and white pipes using galvanized steel sheets, and their manufacturing processes consist of cutting, processing (pipe forming), painting, packaging and transportation. The products are mainly stored outdoors. Compared with the past, today's surrounding environment is intensifying. Therefore, in order to maintain product quality, there is an urgent need for a resin-based anti-corrosive coating that can protect steel pipes from the external environment.

In addition, conventional anti-corrosive coatings are mostly oily alkyd resins, acrylic resins, epoxy resins, and the like. Since the solvents are organic solvents, contamination of the working environment and worker's Due to health problems and fire risks, it is gradually being converted to a water-soluble antirust coating. Water-soluble rust preventive coatings are less resistant to rust than organic solvent type rust preventive coatings. However, chromium is a heavy metal that has been known to cause gastroenteritis and skin diseases as well as cancer, and is known to cause fatal environmental pollution when introduced into rivers.

Therefore, there is a need for a water-soluble rustproof coating composition that does not contain chromium and has excellent adhesion, rust resistance, alkali resistance, water resistance, and moisture resistance.

It is an object of the present invention to provide a water-soluble antirust coating having improved corrosion resistance, adhesion, alkali resistance, water resistance, moisture resistance, and a method for producing the same.

Water-soluble rust-preventive coating composition according to an embodiment for achieving the above object of the present invention has a weight average molecular weight of about 15,000 to 30,000, the acid value of about 35 to 60 mgKOH / g silane-modified water-soluble acrylic resin about 20 to 50% by weight , About 5 to 25 wt% of the organic-inorganic silica composite resin, about 10 to 30 wt% of the water-soluble organic solvent, and about 30 to 60 wt% of water.

According to one embodiment, the silane-modified water-soluble acrylic resin has a glass transition temperature of about 15 to 40 ℃, non-volatile content may be about 40 to 70%.

According to one embodiment, the silane-modified water-soluble acrylic resin is methyl methacrylate, methyl acrylate, ethyl acrylate, styrene, 2-ethylhexyl acrylate, butyl acrylate, 2-hydroxyethyl methacrylate, 2- Vinyltrimethoxy silane, vinyltriethoxy silane, vinyltris (2-methoxyethoxy) based on 100 parts by weight of an acrylic monomer comprising hydroxyethyl acrylate, methacrylic acid, acrylic acid, itaconic acid or a mixture thereof It may be formed by modifying 0.5 to 10 parts by weight of a vinyl silane including a silane or a mixture thereof.

According to one embodiment, the organic-inorganic silica composite resin may be obtained by an organic-inorganic complexation reaction of a hydrolyzate of a water-soluble acrylic resin, a water-dispersible colloidal silica and a silane coupling agent.

According to one embodiment, the water-soluble acrylic resin has a hydroxyl value of about 30 to 100mgKOH / g, the water-dispersible colloidal silica has a SiO ₂ content of about 10 to 50% by weight, the hydrolyzate of the silane coupling agent is γ- Aminopropyltrimethoxy silane, γ-aminopropyltriethoxy silane, γ-glycidoxy propyltrimethoxy silane, γ-methacryloxypropyltriethoxy silane, N- [2- (vinylbenzylamino) ethyl] Hydrolyzate of a silane coupling agent comprising 3-aminopropyltrimethoxy silane or mixtures thereof.

According to one embodiment, the organic-inorganic silica composite resin is hydrolyzed about 100 parts by weight of the silane coupling agent, the hydrolyzate of the silane coupling agent and about 150 to 400 parts by weight of the water-soluble acrylic resin, the water-dispersible colo It can be obtained by reacting 80 to 160 parts by weight of silica this month.

According to an embodiment, the water-soluble organic solvent is methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol mono methyl ether, ethylene glycol Monoethyl ether, butyl cellosolve, and mixtures thereof.

According to one embodiment, about 100 parts by weight of the water-soluble antirust coating agent composition may further include about 0.2 to 4 parts by weight of an additive including an antifoaming agent, a surface conditioner or a mixture thereof.

Method for producing a water-soluble rust-preventive coating composition according to an embodiment for achieving the object of the present invention has a weight average molecular weight of about 15,000 to 30,000, an acid value of about 35 to 60 mgKOH / g, glass transition temperature of about 15 to 40 ℃ Silane-modified water-soluble acrylic resin having a nonvolatile content of about 40 to 70%, and the organic-inorganic silica composite resin is prepared by an organic-inorganic complex reaction of a hydrolyzate of a water-soluble acrylic resin, a water-dispersible colloidal silica, and a silane coupling agent. After preparing, about 20 to 50% by weight of the silane-modified water-soluble acrylic resin, about 5 to 25% by weight of the organic-inorganic silica composite resin, about 10 to 30% by weight of the water-soluble organic solvent and about 30 to 60% by weight of water are mixed. And stir.

According to one embodiment, the organic-inorganic silica composite resin may be obtained at a process temperature of about 30 to 130 ℃.

The water-soluble antirust coating agent according to the present invention may be coated on a galvanized steel pipe (white pipe) or the like, and the coated coating film has excellent corrosion resistance, adhesion, alkali resistance, water resistance, and moisture resistance. In addition, unlike conventional organic rust-preventive coatings containing chromium, it is environmentally friendly because it does not contain chromium ions harmful to the human body.

Hereinafter, a water-soluble rust-preventive coating according to embodiments of the present invention and a manufacturing method thereof will be described in detail. However, the present invention is not limited to the following embodiments, and those skilled in the art may implement the present invention in various other forms without departing from the technical spirit of the present invention.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. The singular forms “a,” “an” and “the” include “the” and “the” unless the context clearly indicates otherwise. It is to be understood that the present invention is intended to designate that there is a part or a combination thereof, and does not exclude in advance the possibility of the presence or addition of one or more other features or numbers, steps, actions, components, parts or combinations thereof. . Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Water Soluble Antirust Coating Composition

Hereinafter, the present invention will be described in detail.

First, about 20 to 50% by weight of the silane-modified water-soluble acrylic resin having a weight average molecular weight of about 15,000 to 30,000 and an acid value of about 35 to 60 mgKOH / g, about 5 to 25% by weight of the organic-inorganic silica composite resin, and a water-soluble organic solvent. A water soluble rust preventive coating having a composition comprising about 10 to 30 weight percent and about 30 to 60 weight percent water is described.

The silane-modified water-soluble acrylic resin used in the present invention has a weight average molecular weight of about 15,000 to 30,000, and an acid value of about 35 to 60 mgKOH / g. The silane-modified water-soluble acrylic resin has an acrylic backbone structure containing a carboxyl group and a silane.

Generally using acrylic resin monomer and silane which are widely used, the acid value is about 35 to 60 mgKOH / g, the weight average molecular weight is about 15,000 to 30,000, the glass transition temperature is about 20 to 40 ℃, and the non-volatile content is about 40 to 70% of the silane-modified water-soluble acrylic resin can be synthesized.

When the weight average molecular weight of the silane-modified water-soluble acrylic resin is about 15,000 or less, the molecular weight decreases, and there is a limitation of the general physical properties of the coating film and the viscosity control when applied to the anti-corrosive coating composition, and the weight average molecular weight exceeds about 30,000. The limitation of the viscosity control and workability of the anticorrosive coating composition become weak. Therefore, the weight average molecular weight of the silane-modified water-soluble acrylic resin is preferably about 15,000 to 30,000.

If the acid value of the silane-modified water-soluble acrylic resin is less than about 35mgKOH / g, it is difficult to be water-soluble, and if the acid value exceeds about 60mgKOH / g, the water resistance may be weak. Therefore, it is preferable that the acid value of the said silane-modified water-soluble acrylic resin is about 35-60 mgKOH / g.

When the glass transition temperature of the silane-modified water-soluble acrylic resin is about 20 ° C. or less, the coating film hardness is weak, scratch resistance is weak, and the blocking property occurs. When the glass transition temperature exceeds about 40 ° C., the coating film is cracked due to excessive hardness. The phenomenon appears. Therefore, the glass transition temperature of the silane-modified water-soluble acrylic resin is preferably about 20 ℃ to 40 ℃.

When the non-volatile content of the silane-modified water-soluble acrylic resin is about 40% or less, the thickness of the coating film formed during coating may be thinner. When the non-volatile content is more than about 70%, the content of the non-volatile content may be high and the drying time may be slightly longer. Therefore, the nonvolatile content of the silane-modified water-soluble acrylic resin is preferably about 40 to 70%.

When the content of the silane-modified water-soluble acrylic resin applied to the water-soluble rust-preventing coating composition is less than about 20% by weight, there is a limit in the solid content control and the rust-preventing ability of the water-soluble rust-preventing coating composition. It is not preferable because viscosity control of the coating composition is difficult and water resistance is weak. Therefore, the amount of the silane-modified acrylic resin is preferably about 20 to 50% by weight of the water-soluble rust-preventive coating composition. More preferably, the amount of the silane-modified acrylic resin is about 25 to 40% by weight, and most preferably about 25 to 35% by weight of the water-soluble rustproof coating composition.

The silane-modified water-soluble acrylic resin can be obtained by adding a silane-modified water-soluble acrylic resin, a silane and a radical initiator to an organic solvent, reacting the same, and neutralizing it with a neutralizing agent.

Examples of the acrylic monomer monomer that can be used for synthesizing the silane-modified water-soluble acrylic resin include methyl methacrylate, methyl acrylate, ethyl acrylate, styrene, 2-ethyl Hexyl acrylate (2-ethylhexyl acrylate), butyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, methacrylic acid (methacrylic acid), acrylic acid (acrylic acid), itaconic acid (itaconic acid) and the like, each of these may be used alone or in combination.

Examples of the silane which can be used for the synthesis of the silane-modified water-soluble acrylic resin include vinyl silane, and specific examples of the vinyl silane include vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris ( 2-methoxyethoxy) silane (vinyltris (2-methoxyethoxy) silane) and the like, and the like, each can be used alone or in combination.

The use of the silane for modification is preferably about 0.5 to 10 parts by weight based on 100 parts by weight of the acrylic resin monomer. If the amount of the silane is less than about 0.5 parts by weight of 100 parts by weight of the acrylic resin monomer, the lack of chemical bonding causes corrosion resistance. If the amount of the silane exceeds about 10 parts by weight, the gelation phenomenon and the deterioration of storage properties are observed. Therefore, the amount of the silane is preferably about 0.5 to 10 parts by weight based on 100 parts by weight of the acrylic resin monomer. More preferably, the amount of silane used is about 0.5 to 8 parts by weight, and most preferably about 1 to 6 parts by weight based on 100 parts by weight of the acrylic resin monomer.

When preparing the silane-modified water-soluble acrylic resin, a water-soluble organic solvent may be added as a reaction solvent. As examples of the water-soluble organic solvent, alcohols are preferable, and methyl alcohol (methylalcohol), ethyl alcohol (ethylalcohol), n-propyl alcohol (n-propylalcohol), isopropyl alcohol (isopropylalcohol), n-butylalcohol ), sec-butylalcohol, tert-butylalcohol, ethylene glycol monomethyl ether, ethylene glycol monotheyl ether, butyl cellosolve (butyl cellosolve).

As the neutralizing agent of the silane-modified water-soluble acrylic resin, volatile amines are preferable. Examples of the volatile amines include ammonia water, trimethylamine, triethylamine, diethanolamine, triethanolamine, and diethanol. Ethyl ethanolamine, dimethylethanolamine, dimethylpropanolamine, dimethylpropanolamine, phenyldiethanolamine, triisoproylamine, tribytylamine, and the like. Each may be used alone or in combination.

The organic-inorganic silica composite resin used in the present invention is used to supplement the rust resistance of the water soluble rust preventive coating composition. The organic-inorganic silica composite resin is obtained by an organic-inorganic complexation reaction of a hydrolyzate of a water-soluble acrylic resin, a water dispersible colloidal silica, and a silane coupling agent.

The water-soluble acrylic resin is synthesized by polymerizing an acrylic resin monomer. Examples of the water-soluble acrylic resin monomers include methyl methacrylate, methyl acrylate, ethyl acrylate, styrene, 2-ethylhexyl acrylate, butyl acrylate, 2-hydroxyethyl methacrylate and 2-hydroxyethyl acrylate. , Methacrylic acid, acrylic acid, itaconic acid, and the like, and these may be used alone or in combination. In preparing the water-soluble acrylic resin, a water-soluble organic solvent may be added as a reaction solvent. Alcohols are preferable as examples of the water-soluble organic solvent, and methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol mono methyl ether, ethylene glycol Monoethyl ether, butyl cellosolve, etc. can be mentioned, These can be used individually or in mixture, respectively.

The water-soluble acrylic resin must have a hydroxyl group (-OH) in the main chain in order to react with the hydrolyzed silane coupling agent and the water dispersible silica colloidal silica. When the hydroxyl value of the water-soluble acrylic resin is about 30 mgKOH / g or less, the organic-inorganic complex reaction of the hydrolyzate of the water-soluble acrylic resin, the water-dispersible colloidal silica, and the silane coupling agent does not proceed well, so the transparency of the resin is insufficient. When the dry coating appears cloudy, the hydroxyl value exceeds about 100mgKOH / g may be weak water resistance, chemical resistance. Therefore, it is preferable that the hydroxyl value of the said water-soluble acrylic resin is about 30-100 mgKOH / g.

When the water-dispersible colloidal silica has an SiO ₂ content of about 10% by weight or less, due to the absolute shortage of inorganic components in the preparation of the organic-inorganic silica composite resin, the water-soluble colloidal silica cannot utilize the hardness, adhesion, and corrosion resistance of the composite in the final coating. If the SiO ₂ content is about 50% by weight or more, the dispersibility of the solid content SiO ₂ may be unstable, and thus SiO ₂ may be precipitated, which is difficult to apply to manufacturing an organic-inorganic silica composite resin. Therefore, the water dispersible colloidal silica preferably has a SiO ₂ content of 10 to 50% by weight.

The water dispersible colloidal silica has a pH of about 2 to 4, a particle diameter of about 5 to 50 nm, and a Si0 ₂ content of about 10 to 50 wt%, trade name Ludox SK, TMA, CL, CL-P, HSA (above Grace Corporation). The same company's products have pH of about 7 to 11, particle size of about 5 to 50nm, and Si0 ₂ content of about 10 to 50% by weight, and HS-40, TM, SM, AM, AS, LS, Can be used.

Examples of the silane coupling agent include γ-aminopropyltrimethoxy silane, γ-aminopropyltriethoxysilane, γ-glycidxoxypropyltimethoxysilane, γ-methacryloxypropyltriethoxysilane, N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxy silane (N- [2- (vinylbenzylamino) ethyl] -3 -aminopropyltrimethoxysilane) and the like, each of which can be used alone or in combination.

The silane coupling agent must be hydrolyzed in order to perform the organic-inorganic complex reaction with the water-soluble acrylic resin and the water-dispersible colloidal silica, and the water required for hydrolysis can be used directly or water contained in the water-dispersible colloidal silica can be used. have. In order to increase the hydrolysis reaction rate, a hydrolysis catalyst may be used, and as the hydrolysis catalyst, an organic acid or an inorganic acid may be used alone or in combination. Examples of the inorganic acid include hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like. Examples of the organic acid may include acetic acid, acrylic acid, lactic acid, succinic acid, phthalic acid, citric acid, salicylic acid, and the like. About 0.01 to 5 parts by weight may be used based on 100 parts by weight of the silane coupling agent.

The reaction mechanism of the organic-inorganic complexation reaction of the hydrolyzate of the water-soluble acrylic resin, the water-dispersible colloidal silica and the silane coupling agent is a hydrolysis reaction of the silane coupling agent in the first step, and the general formula is as follows.

              H +

R ₁ -Si- (OR ₂ ) ₃ ---- → R ₁ -Si (OH) ₃

3H ₂ O

The second step of the reaction mechanism of the organic-inorganic complexation reaction is an intermolecular coupling reaction of a hydrolyzate of the silane coupling agent, a water dispersible colloidal silica, and a water-soluble acrylic resin.

In the formation of the organic-inorganic silica composite resin, the coupling action between the hydrolyzate of the silane coupling agent, the water dispersible colloidal silica, and the three components of the water-soluble acrylic resin is as described above. Condensation reaction occurs between the alcoholic hydroxyl group (silanol group) present on the surface and the hydroxyl group or carboxyl group of the water-soluble acrylic resin, and the hydroxyl group and the water dispersible colloidal produced by the hydrolysis of the alkoxy moiety of the silane coupling agent. The organic-inorganic silica composite resin is completed by the crosslinking reaction of the silane coupling agent by the reaction between the silanol group of silica, the hydroxyl group of the water-soluble acrylic resin and the carboxyl group, and the interaction between the organic portion of the silane coupling agent and the water-soluble acrylic resin. do.

As an example, after hydrolyzing about 100 parts by weight of the silane coupling agent, the hydrolyzate of the silane coupling agent and about 150 to 400 parts by weight of the water-soluble acrylic resin and about 80 to 160 parts by weight of the water-dispersible colloidal silica are reacted to form an organic-inorganic compound. The silica composite resin can be formed.

If the content of the organic-inorganic silica composite resin applied to the water-soluble rust-preventing coating composition is less than about 5% by weight, there is a limit in improving the rust-preventing property of the water-soluble rust-preventing coating composition. It is not preferable because the viscosity control becomes difficult. Therefore, the amount of the organic-inorganic silica composite resin is preferably about 5 to 25% by weight of the water-soluble rust-preventive coating composition. More preferably, the amount of the organic-inorganic silica composite resin is about 10 to 20% by weight, and most preferably about 10 to 15% by weight of the water-soluble antirust coating composition.

The water-soluble organic solvent applied to the water-soluble rust-preventive coating composition is added to the water-soluble organic solvent in consideration of the viscosity of the silane-modified water-soluble acrylic resin, fluidity and stability of the organic-inorganic silica composite resin. Examples of the organic solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol mono methyl ether, ethylene glycol monoethyl ether, butyl cell Rosolve, etc. can be mentioned. When the amount of the water-soluble organic solvent is less than about 10% by weight of the water-soluble rust-preventive coating composition, there is a limit in controlling the viscosity and fluidity of the water-soluble rust-preventive coating composition, and when it exceeds about 30% by weight, the limit of proper viscosity control and workability are weak. Become. Therefore, the amount of the water-soluble organic solvent is preferably used to have about 10 to 30% by weight of the water-soluble antirust coating composition. More preferably, the amount of the water-soluble organic solvent is 10 to 25% by weight of the water-soluble rust-preventive coating composition, most preferably 15 to 20% by weight.

If the amount of water applied to the water-soluble rust-preventive coating composition is less than about 30% by weight of the water-soluble rust-preventive coating composition, there is a limit in controlling the viscosity and fluidity of the water-soluble rust-preventive coating composition. There is a limit to improving the rust prevention ability. Therefore, the amount of water used is preferably about 30 to 60% by weight of the water-soluble antirust coating composition. More preferably, the amount of water used is about 35 to 50% by weight of the water-soluble rustproof coating composition, and most preferably about 35 to 45% by weight.

The composition of the present invention may comprise various additives. The additives include antifoaming agents and surface conditioners for inhibiting or removing the generation of bubbles, and may be used alone or in combination. The additive is preferably used in an amount of about 0.2 to 4 parts by weight, and more preferably about 0.4 to 2 parts by weight, based on 100 parts by weight of the water-soluble rustproof coating composition. When the amount of the additives used is out of the range, the workability is poor or the appearance of the dry coating is not preferable.

Process for preparing water-soluble antirust coating composition

Hereinafter, the manufacturing method of a water-soluble rustproof coating composition is demonstrated.

In the composition, a weight average molecular weight of about 15,000 to 30,000, an acid value of about 35 to 60 mgKOH / g, a glass transition temperature of about 15 to 40 ° C., and a non-volatile content of about 40 to 70 wt% of a silane-modified water-soluble acrylic resin are prepared. do. The silane-modified water-soluble acrylic resin is formed to have an acrylic backbone structure containing a carboxyl group and a silane.

The silane-modified water-soluble acrylic resin can be obtained by adding a silane-modified water-soluble acrylic resin, a silane and a radical initiator to an organic solvent, reacting the same, and neutralizing it with a neutralizing agent.

Examples of the acrylic monomer monomer which can be used for synthesizing the silane-modified water-soluble acrylic resin include methyl methacrylate, methyl acrylate, ethyl acrylate, styrene, 2-ethylhexyl acrylate, butyl acrylate and 2-hydroxyethyl methacrylate. , 2-hydroxyethyl acrylate, methacrylic acid, acrylic acid, itaconic acid, and the like, and these may be used alone or in combination.

Examples of the silane which can be used for synthesizing the silane-modified water-soluble acrylic resin include vinyl silane. Specific examples of the vinyl silane include vinyl trimethoxy silane, vinyl triethoxy silane, and vinyl tris (2-methoxyethoxy. Silane, etc., and these may be used alone or in combination.

The use of the silane for modification is preferably about 0.5 to 10 parts by weight based on 100 parts by weight of the acrylic resin monomer. If the amount of the silane is less than about 0.5 parts by weight of 100 parts by weight of the acrylic resin monomer, the lack of chemical bonding causes corrosion resistance. If the amount of the silane exceeds about 10 parts by weight, the gelation phenomenon and the deterioration of storage properties are observed. Therefore, the amount of the silane is preferably about 0.5 to 10 parts by weight based on 100 parts by weight of the acrylic resin monomer. More preferably, the amount of silane used is about 0.5 to 8 parts by weight, and most preferably about 1 to 6 parts by weight based on 100 parts by weight of the acrylic resin monomer.

When preparing the silane-modified water-soluble acrylic resin, a water-soluble organic solvent may be added as a reaction solvent. Alcohols are preferable as examples of the water-soluble organic solvent, and methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol mono methyl ether, ethylene glycol Monoethyl ether, butyl cellosolve, and the like.

Volatile amines are preferable as the neutralizer of the silane-modified water-soluble acrylic resin. Examples of the volatile amines include ammonia water, trimethylamine, triethylamine, diethanolamine, triethanolamine, diethylethanolamine, dimethylethanolamine, and dimethylpropanol. Amine, phenyldiethanolamine, triisopropylamine, tributylamine, and the like, and the like, each of which may be used alone or in combination.

An organic-inorganic silica composite resin is prepared by an organic-inorganic complex reaction of a hydrolyzate of a water-soluble acrylic resin, a water dispersible colloidal silica, and a silane coupling agent.

The water-soluble acrylic resin is synthesized by polymerizing an acrylic resin monomer. Examples of the water-soluble acrylic resin monomers include methyl methacrylate, methyl acrylate, ethyl acrylate, styrene, 2-ethylhexyl acrylate, butyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, Methacrylic acid, acrylic acid, itaconic acid, etc. are mentioned, These can respectively be used individually or in mixture. In preparing the water-soluble acrylic resin, a water-soluble organic solvent may be added as a reaction solvent. Alcohols are preferable as examples of the water-soluble organic solvent, and methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol mono methyl ether, ethylene glycol Monoethyl ether, butyl cellosolve, etc. can be mentioned, These can be used individually or in mixture, respectively.

The water-soluble acrylic resin must have a hydroxyl group (-OH) in the main chain in order to react with the hydrolyzed silane coupling agent and the water dispersible silica colloidal silica. When the hydroxyl value of the water-soluble acrylic resin is about 30 mgKOH / g or less, the organic-inorganic complex reaction of the hydrolyzate of the water-soluble acrylic resin, the water-dispersible colloidal silica, and the silane coupling agent does not proceed well, resulting in a lack of transparency of the resin, resulting in a blurred coating film. If the hydroxyl value exceeds about 100 mgKOH / g, water resistance and chemical resistance may become weak. Therefore, it is preferable that the hydroxyl value of the said water-soluble acrylic resin is about 30-100 mgKOH / g.

When the water-dispersible colloidal silica has an SiO ₂ content of about 10% by weight or less, due to the absolute lack of inorganic components in the preparation of the organic-inorganic silica composite resin, the water-soluble colloidal silica cannot utilize the advantages of hardness, adhesion, and corrosion resistance of the composite in the final coating film. If the SiO ₂ content is about 50% by weight or more, the dispersibility of the solid content SiO ₂ may be unstable, and thus SiO ₂ may be precipitated, which is difficult to apply to manufacturing an organic-inorganic silica composite resin. Therefore, the water dispersible colloidal silica preferably has a SiO ₂ content of about 10 to 50% by weight.

The water-dispersible colloidal silica has a pH of about 2 to 4, a particle diameter of about 5 to 50 nm, and a Si0 ₂ content of 10 to 50 wt%, trade name Ludox SK, TMA, CL, CL-P, HSA (above Grace Corporation). Also, the same company products have pH of about 7 to 11, particle size of about 5 to 50nm, and Si0 ₂ content of about 10 to 50% by weight, and are used by HS-40, TM, SM, AM, AS, LS, etc. do.

Examples of the silane coupling agent include γ-aminopropyltrimethoxy silane, γ-aminopropyltriethoxy silane, γ-glycidoxypropyltrimethoxy silane, γ-methacryloxypropyltriethoxy silane, N- [2 -(Vinylbenzylamino) ethyl] -3-aminopropyltrimethoxy silane, and the like, which can be used alone or in combination.

The silane coupling agent must be hydrolyzed in order to perform the organic-inorganic complex reaction with the water-soluble acrylic resin and the water-dispersible colloidal silica, and the water required for hydrolysis can be used directly or water contained in the water-dispersible colloidal silica can be used. have. In order to increase the hydrolysis reaction rate, a hydrolysis catalyst may be used, and as the hydrolysis catalyst, an organic acid or an inorganic acid may be used alone or in combination. Examples of the inorganic acid include hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like. Examples of the organic acid may include acetic acid, acrylic acid, lactic acid, succinic acid, phthalic acid, citric acid, salicylic acid, and the like. About 0.01 to 5 parts by weight may be used based on 100 parts by weight of the silane coupling agent.

As an example, after hydrolyzing about 100 parts by weight of the silane coupling agent, the hydrolyzate of the silane coupling agent and about 150 to 400 parts by weight of the water-soluble acrylic resin and about 80 to 160 parts by weight of the water-dispersible colloidal silica are reacted to form an organic-inorganic compound. The silica composite resin can be formed.

The organic-inorganic silica composite resin manufacturing process is reacted at a reaction temperature of about 30 to 130 ° C. for about 30 minutes to 6 hours. When the reaction temperature of the organic-inorganic silica composite resin manufacturing process is about 30 ° C. or less, hydrolysis of the alkoxy group of the silane coupling agent, which is the first step reaction of the organic-inorganic hybridization reaction mechanism, is difficult to occur. If the reaction is difficult and the reaction temperature is about 130 ° C. or more, the organic-inorganic hybridization reaction mechanism in the first step of the reaction, the hydrolysis of the silane coupling agent is accelerated to increase the amount of the silane coupling agent, so that the excess valence of the silane coupling agent Rather than reacting with water-dispersible colloidal silica or water-soluble acrylic resins, the decomposed products tend to gel because they undergo many self-condensation reactions between hydrolyzates of silane coupling agents. Therefore, the reaction temperature of the organic-inorganic silica composite resin manufacturing process is preferably about 30 to 130 ℃. More preferably, the reaction temperature of the organic-inorganic silica composite resin manufacturing process is about 40 to 100 ° C.

In addition, when the reaction time of the organic-inorganic silica composite resin manufacturing process is about 30 minutes or less, the organic-inorganic complexation reaction of the hydrolyzate of the silane coupling agent, the water-dispersible colloidal silica, and the water-soluble acrylic resin is insufficient for the metal. When applied to the substrate, film formation is impossible, and if the reaction time of the process is about 6 hours or more, the organic-inorganic silica composite is formed due to the overreaction between the three components of the hydrolyzate of the silane coupling agent, the water dispersible colloidal silica, and the water-soluble acrylic resin. Since the molecular weight of the resin is very large and the final composition is highly viscous, there is a disadvantage that the painting workability is not easy. Therefore, the reaction time of the organic-inorganic silica composite resin production process is preferably about 30 minutes to 6 hours, more preferably the reaction time is about 1 to 4 hours.

20 to 50% by weight of the silane-modified water-soluble acrylic resin, 5 to 25% by weight of the organic-inorganic silica composite resin, 10 to 30% by weight of water-soluble organic solvent, and 30 to 60% by weight of water are mixed and stirred to form a water-soluble rustproof coating composition To obtain.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, it is to be understood that the following examples are intended to illustrate the invention and are not intended to limit the invention.

Silane Modified Water Soluble Acrylic Resin Synthesis

Synthesis Example 1

About 18 parts by weight of butyl cellosolve was added to the synthetic flask, and the temperature was raised to about 120 ° C. Thereafter, about 19 parts by weight of styrene, about 14.9 parts by weight of methyl methacrylate, about 13 parts by weight of butyl acrylate, about 2.6 parts by weight of acrylic acid, about 0.5 parts by weight of vinyltrimethoxy silane and benzoyl peroxide as an organic peroxide radical initiator (benzoyl peroxide, 75%) About 0.7 parts by weight of the mixture was added dropwise into the synthetic flask at a uniform rate over about 3.5 hours. After dropping, the reaction was carried out for about 45 minutes, and then 0.2 parts by weight of benzoyl peroxide (75%) and 2.0 parts by weight of butyl cellosolve were added thereto, and the reaction was carried out for about 2.5 hours. The mixture was cooled to about 80 ° C., about 4.0 parts by weight of triethylamine as a neutralizing agent was added, and the mixture was maintained for about 20 minutes. Thereafter, about 10 parts by weight of butyl cellosolve and about 16 parts by weight of distilled water were added to the resultant, followed by cooling to obtain a water-soluble acrylic resin of Table 1 below.

Synthesis Example 2

About 18 parts by weight of butyl cellosolve was added to the synthetic flask, and the temperature was increased to about 120 ° C. Thereafter, about 18 parts by weight of styrene, about 14.9 parts by weight of methyl methacrylate, about 13 parts by weight of butyl acrylate, about 2.6 parts by weight of acrylic acid, about 1.5 parts by weight of vinyltrimethoxy silane and benzoyl peroxide as an organic peroxide radical initiator (75%) About 0.7 parts by weight of the mixture was added dropwise into the synthetic flask at a uniform rate over about 3.5 hours. After the dropwise addition, the reaction was carried out for 45 minutes, and then 0.2 parts by weight of benzoyl peroxide (75%) and 2.0 parts by weight of butyl cellosolve were added thereto, and the reaction was carried out for about 2.5 hours. The mixture was cooled to about 80 ° C., about 4.0 parts by weight of triethylamine as a neutralizing agent was added, and the reaction was maintained for about 20 minutes. Thereafter, about 10 parts by weight of butyl cellosolve and about 16 parts by weight of distilled water were added to the resultant, followed by cooling to obtain a water-soluble acrylic resin of Table 1 below.

Synthesis Example 3

About 18 parts by weight of butyl cellosolve was added to the synthetic flask, and the temperature was increased to about 120 ° C. Then, about 17 parts by weight of styrene, about 14.9 parts by weight of methyl methacrylate, about 13 parts by weight of butyl acrylate, about 2.6 parts by weight of acrylic acid, about 2.5 parts by weight of vinyltrimethoxy silane and benzoyl peroxide as an organic peroxide radical initiator (75%) About 0.7 parts by weight of the mixture was added dropwise into the synthetic flask at a uniform rate over about 3.5 hours. After dropping, the reaction was carried out for about 45 minutes, and then 0.2 parts by weight of benzoyl peroxide (75%) and 2.0 parts by weight of butyl cellosolve were added thereto, and the reaction was carried out for about 2.5 hours. The mixture was cooled to 80 ° C., about 4.0 parts by weight of triethylamine as a neutralizing agent was added, and the mixture was maintained for about 20 minutes. Then, butyl cellosolve in the result About 10 parts by weight and about 16 parts by weight of distilled water were added, followed by cooling to obtain a water-soluble acrylic resin of Table 1 below.

Synthesis Example 4

About 18 parts by weight of butyl cellosolve was added to the synthetic flask, and the temperature was increased to about 120 ° C. Then, a mixture of about 19.5 parts by weight of styrene, about 14.9 parts by weight of methyl methacrylate, about 13 parts by weight of butyl acrylate, about 2.6 parts by weight of acrylic acid, and about 0.7 parts by weight of benzoyl peroxide (75%) which is an organic peroxide-based radical initiator The flask was added dropwise at a uniform rate over about 3.5 hours. After dropping, the reaction was carried out for about 45 minutes, and then 0.2 parts by weight of benzoyl peroxide (75%) and about 2.0 parts by weight of butyl cellosolve were added and held for 2.5 hours. The mixture was cooled to about 80 ° C., and about 4.0 parts by weight of triethylamine, a neutralizing agent, was reacted for about 20 minutes. Thereafter, about 10 parts by weight of butyl cellosolve and about 16 parts by weight of distilled water were added to the resultant, followed by cooling to obtain a water-soluble acrylic resin of Table 1 below.

Synthesis Example 5

About 18 parts by weight of butyl cellosolve was added to the synthetic flask, and the temperature was increased to about 120 ° C. Thereafter, about 15 parts by weight of styrene, about 13.4 parts by weight of methyl methacrylate, about 10.5 parts by weight of butyl acrylate, about 2.6 parts by weight of acrylic acid, about 8.5 parts by weight of 2-hydroxyethyl acrylate and benzoyl which is an organic peroxide radical initiator 0.7 parts by weight of a mixture of peroxide (75%) was added dropwise into the synthetic flask at a uniform rate over about 3.5 hours. After dropping, the reaction was carried out for about 45 minutes, and then 0.2 parts by weight of benzoyl peroxide (75%) and about 2.0 parts by weight of butyl cellosolve were added and held for 2.5 hours. The mixture was cooled to about 80 ° C., about 4.0 parts by weight of triethylamine as a neutralizing agent was added, and the mixture was maintained for about 20 minutes. Thereafter, about 10 parts by weight of butyl cellosolve and about 16 parts by weight of distilled water were added to the resultant, followed by cooling to obtain a water-soluble acrylic resin of Table 1 below.

Synthesis Examples 1 to 5 of the water-soluble acrylic resin prepared by the above method are shown in Table 1 below.

[Table 1] Acrylic resin synthesis

Synthesis of Organic-Inorganic Silica Composite Resin

After adding about 80 g of γ- glycidoxy propyl trimethoxy silane and 0.02 g of acetic acid to the synthetic flask installed in Preparation Example 1, 20 g of distilled water was added and the reaction was maintained at about 50 ° C. for 1 hour to confirm that the solution became transparent. Thereafter, about 200 g of a water-soluble acrylic resin was added to the reactant in Synthesis Example 5, about 100 g of rudox HSA was added thereto, maintained at about 70 ° C. for about 2 hours, and then about 100 g of distilled water was added to the organic-inorganic material having a solid content of 40%. Silica composite resin was synthesized.

Soluble anticorrosive coating

The water-soluble rust-preventive coating composition is a blend of parts by weight as shown in Table 2 below, using an organic-inorganic silica composite resin and a water-soluble organic solvent, an antifoaming agent, a surface conditioner, and water to the water-soluble acrylic resins obtained in Synthesis Examples 1 to 4. It is obtained by mixing to have a mixture. The water-soluble rustproof coating composition of Examples 1 to 3 and Comparative Examples 1 to 3 are as shown in Table 2.

TABLE 2

(Typical examples used in the above paint formulations are as follows. The water-soluble organic solvents are butyl cellosolve and isopropyl alcohol, the antifoaming agent is Byk-020, the surface control agent is Byk-346, and the chromium solution is about 10 % Aqueous solution of ammonium dichromate.)

According to the compounding ratio of Examples 1 to 3 and Comparative Examples 1 to 3 of Table 2, the acrylic resin, organic-inorganic silica composite resin, water-soluble organic solvent, water, antifoaming agent, surface control agent of Synthesis Examples 1 to 4 in order The water-soluble rustproof coating composition was obtained by stirring, putting.

Water Soluble Antirust Coating

In order to evaluate the water-soluble rust-preventive coating composition obtained in Examples 1 to 3 and Comparative Examples 1 to 3 by spray coating to a galvanized steel pipe (white pipe) with a thickness of 5 to 10㎛, and after naturally drying for 24 hours to evaluate the physical properties of Table 3 It evaluated by the experimental method. Evaluation of the results for the physical properties of the coating composition for water-soluble steel pipes is shown in Table 3.

As can be seen from the evaluation of the test item, the water-soluble rust-preventive coating composition of the present invention exhibited excellent physical properties in corrosion resistance, adhesion, alkali resistance, water resistance, and moisture resistance in galvanized steel pipes (white pipes). Compared with the water-soluble rust-preventive coating composition included, the corrosion resistance showed comparable physical properties.

The water-soluble anti-corrosive coating agent of the present invention described above can be used as a non-chromic water-soluble anti-corrosive coating agent can replace the conventional organic solvent type steel pipe anti-corrosive coating agent, coated on a galvanized steel pipe (white pipe), adhesion, rust resistance, alkali resistance, water resistance, It has excellent physical properties such as moisture resistance.

As described above with reference to the embodiments of the present invention, those skilled in the art may variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. I can understand that you can.

Claims (10)

20 to 50% by weight of a silane-modified water-soluble acrylic resin having a weight average molecular weight of 15,000 to 30,000 and an acid value of 35 mgKOH / g to 60 mgKOH / g; 5-25 wt% of organic-inorganic silica composite resin; 10 to 30% by weight of a water-soluble organic solvent; And Water-soluble antirust coating composition comprising 30 to 60% by weight of water. The water-soluble antirust coating composition according to claim 1, wherein the silane-modified water-soluble acrylic resin has a glass transition temperature of 15 to 40 ° C and a nonvolatile content of 40 to 70%. The method of claim 1, wherein the silane-modified water-soluble acrylic resin is methyl methacrylate (methyl methacrylate), methyl acrylate (methyl acrylate), ethyl acrylate (ethyl acrylate), styrene (styrene), 2-ethylhexyl acrylate ( 2-ethylhexyl acrylate, butyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, methacrylic acid , Vinyltrimethoxysilane, vinyltriethoxysilane and vinyltris based on 100 parts by weight of at least one acrylic resin monomer selected from the group consisting of acrylic acid and itaconic acid. 0.5 to 10 parts by weight of at least one vinyl silane selected from the group consisting of (2-methoxyethoxy) silane (vinyltris (2-methoxyethoxy) silane) Water-soluble anti-corrosive coating composition characterized in that the sex. The water-soluble rust-preventing coating composition according to claim 1, wherein the organic-inorganic silica composite resin is obtained by an organic-inorganic complexation reaction of a hydrolyzate of a water-soluble acrylic resin, a water dispersible colloidal silica, and a silane coupling agent. According to claim 4, wherein the water-soluble acrylic resin has a hydroxyl value of 30 to 100mgKOH / g, the water-dispersible colloidal silica has a SiO ₂ content of 10 to 50% by weight, the hydrolyzate of the silane coupling agent is γ-amino Γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidxoxypropyltimethoxysilane, γ-methacryloxypropyltriethoxy At least one selected from the group consisting of silane (γ-methacryloxypropyltriethoxysilane) and N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxy silane (N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane) It is a hydrolyzate of any one silane coupling agent, The water-soluble antirust coating composition characterized by the above-mentioned. The method of claim 4, wherein the organic-inorganic silica composite resin is hydrolyzed 100 parts by weight of the silane coupling agent, the hydrolyzate of the silane coupling agent and 150 to 400 parts by weight of the water-soluble acrylic resin, the water-dispersible colloidal silica Water-soluble rust-preventive coating composition characterized in that it is prepared by reacting 80 to 160 parts by weight. According to claim 1, wherein the water-soluble organic solvent is methyl alcohol (methylalcohol), ethyl alcohol (ethylalcohol), n-propylalcohol (n-propylalcohol), isopropyl alcohol (isopropylalcohol), n-butylalcohol (n-butylalcohol) sec-butylalcohol, tert-butylalcohol, ethylene glycol monomethyl ether, ethylene glycol monotheyl ether and butyl cellosolve water-soluble anti-corrosive coating composition, characterized in that at least one selected from the group consisting of. The water-soluble rustproof coating composition according to claim 1, further comprising 0.2 to 4 parts by weight of an additive including an antifoaming agent, a surface conditioner or a mixture thereof, based on 100 parts by weight of the water-soluble rustproof coating composition. Preparing a silane-modified water-soluble acrylic resin having a weight average molecular weight of 15,000 to 30,000, an acid value of 35 mgKOH / g to 60 mgKOH / g, a glass transition temperature of 15 to 40 ° C., and a nonvolatile content of 40 to 70%; Preparing an organic-inorganic silica composite resin by an organic-inorganic complex reaction of a hydrolyzate of a water-soluble acrylic resin, a water dispersible colloidal silica, and a silane coupling agent; 20 to 50% by weight of the silane-modified water-soluble acrylic resin, 5 to 25% by weight of the organic-inorganic silica composite resin, 10 to 30% by weight of a water-soluble organic solvent and 30 to 60% by weight of water, comprising the steps of mixing and stirring Method for producing a water-soluble antirust coating composition. The method of claim 9, wherein the preparing of the organic-inorganic silica composite resin is performed at a process temperature of 30 to 130 ° C. 11.