KR20220157749A - Eco-friendly painting method of steel - Google Patents

Abstract

The present invention relates to an eco-friendly painting method for steel or steel structures, comprising: a process of surface treatment of steel or steel structure surfaces; a process of painting a water-based epoxy zinc anti-rust paint on the surface of a steel or steel structure treated by the above process; and a process of painting a water-based organic top coat after the water-based epoxy zinc heavy-duty anti-rust paint painted in the above process is dried and cured. According to the eco-friendly painting method for steel of the present invention, paints which do not contain heavy metals and volatile organic compounds (VOCs) are used, and water, not mixed organic solvent thinner, is used as a diluent. For this reason, there is no concern about inhalation of heavy metals, poisoning by organic solvents, fire occurrence, etc. during painting work, providing an anticorrosive painting method for steel and steel structures with excellent work safety and environmentally friendly characteristics. In addition, since strong adhesion and anti-rust function are exhibited on the main body of steel and steel structures by the internal painting film formed of water-based epoxy zinc heavy-duty anti-rust paint, and the outer painting film formed of the water-based organic top coat exhibits excellent chemical resistance such as acid resistance, alkali resistance, and salt water resistance, and physical performance such as impact resistance, abrasion resistance, and freeze-thaw resistance, so that durability is excellent and maintenance costs are minimized.

Description

Eco-friendly painting method of steel

The present invention relates to an eco-friendly painting method capable of minimizing environmental pollution in painting a steel material or steel structure.

Since most steel materials and steel structures containing iron are exposed to corrosive environments, it is common to apply anti-corrosion treatment to the surface of steel structures in order to improve weather resistance. Corrosion of steel structures refers to the occurrence of rust or red rust [Fe(OH) ₃ , Fe ₂ O ₃ ], and the causes of their formation can be seen as oxygen (O ₂ ) and moisture (H ₂ O) in the air. have. This corrosion tends to be accelerated by polluted air, soot, salt in seawater, acid rain, and chemicals (acids, alkalis, salts). As a method for suppressing the corrosion of iron structures as described above, passivating agents such as chromic acid and nitrous acid are used, phosphate coating is performed using phosphate, etc., or Cu, Zn, A sacrificial anode method using metal pigments such as Cr and Ni is used.

Korean Patent Registration No. 0503561 discloses a paint composition for corrosion prevention and durability enhancement of steel structures and an aluminum oxide film adhesion method using the same, which is applied to paints using zinc, chrome, nickel, aluminum oxide, etc. to form a metal film on steel structures. The forming method is disclosed. However, when heavy metals such as chromium and lead are contained in order to improve the anti-rust function of the paint, they can be absorbed into the human body through the respiratory tract or skin, which can cause serious problems, and is also undesirable from an environmental point of view. In particular, the paint used in the existing steel structure corrosion prevention method is an oil-based paint that uses organic solvents containing volatile organic compounds (VOCs), and there is always a risk of poisoning and fire caused by organic solvents that are volatilized during painting work. Therefore, work safety is not secured, and there is a problem that adversely affects the natural environment.

The present invention is to solve the above problems of the prior art,

First, by using water as a water-based paint and diluent that does not contain heavy metals and volatile organic compounds (VOCs), work safety is excellent, and an object is to provide an environmentally friendly anticorrosive coating method for steel and steel structures.

Second, strong adhesion and anti-rust function are exhibited on the main body of steel and steel structures by the inner coating film formed of water-based epoxy zinc heavy-duty anti-corrosive paint, and excellent acid resistance, alkali resistance, salt water resistance, etc. by the outer coating film formed of water-based organic top coating material Physical properties such as chemical resistance, impact resistance, abrasion resistance, and freeze-thaw resistance are exhibited, and the outer coating film formed of the water-based organic top coat forms a strong bond with the inner coating film formed of the water-based epoxy zinc heavy anticorrosive paint. , It is an object of the present invention to provide an eco-friendly coating method for steel and steel structures, which has excellent durability and minimizes maintenance costs.

The present invention,

A process of surface treatment of steel or steel structure surfaces;

A step of painting a water-based epoxy zinc heavy-duty rust-preventive paint on the surface of the steel or steel structure treated by the above process, and

As an eco-friendly coating method for steel materials including a step of painting a water-based organic top coat after the water-based epoxy zinc heavy-duty anti-rust paint applied in the above process is dried and cured,

The water-based epoxy zinc heavy-duty rust-preventive paint contains 10-20% by weight of epoxy resin, 3-9% by weight of Cellusolve acetate, and 30-70% by weight of zinc powder, based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition. , 2.5 to 7.5% by weight of active ceramic powder, 1.8 to 5.5% by weight of an antisettling agent, and 0.2 to 0.5% by weight of an additive; and

Based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition, 2 to 6% by weight of polyamide resin, 2.5 to 7.5% by weight of polyamine resin, 0.5 to 2.5% by weight of aromatic amine resin, 2.5 to 6.5% by weight of Butyl Cellusolve and water It is a two-component paint composed of a hardener part containing 2.5 to 7.5% by weight,

The aqueous organic topcoat contains 70 to 85% by weight of aminoacrylic emulsion resin (solid content: 35%), 10 to 20% by weight of titanium dioxide (TiO2) and 0.6 to 1.9% by weight of additives based on the total weight of the aqueous organic topcoat composition. Subject part containing; and

Based on the total weight of the aqueous organic topcoat composition, steel material characterized in that it is a two-component paint composed of a curing agent part containing 0.7 to 4.9% by weight of epoxysilane resin (solid content: 98%) and 1.1 to 5.8% by weight of Butchil Cellusolve. Provides an eco-friendly coating method of

According to the eco-friendly coating method for steel and steel structures of the present invention, paints that do not contain heavy metals and volatile organic compounds (VOCs) are used, and water is used as a diluent, so heavy metal inhalation, poisoning by organic solvents, and fire occur during painting work. There is no concern about etc., so the work safety is excellent, and an environmentally friendly anticorrosive coating method for steel and steel structures is provided.

In addition, the inner coating formed of water-based epoxy zinc heavy-duty rust-preventive paint exhibits strong adhesion and anti-corrosive function to steel materials and steel structures, and the outer coating formed of water-based organic top coating provides excellent acid resistance, alkali resistance, salt water resistance, etc. Physical properties such as chemical resistance, impact resistance, abrasion resistance, and freeze-thaw resistance are exhibited, and the outer coating film formed of the water-based organic top coat forms a strong bond with the inner coating film formed of the water-based epoxy zinc heavy-duty rust-preventive paint. , Provided is an eco-friendly coating method for steel and steel structures that has excellent durability and minimizes maintenance costs.

The present invention,

A process of surface treatment of steel or steel structure surfaces;

A step of painting a water-based epoxy zinc heavy-duty rust-preventive paint on the surface of the steel or steel structure treated by the above process, and

As an eco-friendly coating method for steel materials including a step of painting a water-based organic top coat after the water-based epoxy zinc heavy-duty anti-rust paint applied in the above process is dried and cured,

The water-based epoxy zinc heavy-duty rust-preventive paint contains 10-20% by weight of epoxy resin, 3-9% by weight of Cellusolve acetate, and 30-70% by weight of zinc powder, based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition. , 2.5 to 7.5% by weight of active ceramic powder, 1.8 to 5.5% by weight of an antisettling agent, and 0.2 to 0.5% by weight of an additive; and

Based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition, 2 to 6% by weight of polyamide resin, 2.5 to 7.5% by weight of polyamine resin, 0.5 to 2.5% by weight of aromatic amine resin, 2.5 to 6.5% by weight of Butyl Cellusolve and water It is a two-component paint composed of a hardener part containing 2.5 to 7.5% by weight,

The aqueous organic topcoat contains 70 to 85% by weight of aminoacrylic emulsion resin (solid content: 35%), 10 to 20% by weight of titanium dioxide (TiO2) and 0.6 to 1.9% by weight of additives based on the total weight of the aqueous organic topcoat composition. Subject part containing; and

Based on the total weight of the aqueous organic topcoat composition, steel material characterized in that it is a two-component paint composed of a curing agent part containing 0.7 to 4.9% by weight of epoxysilane resin (solid content: 98%) and 1.1 to 5.8% by weight of Butchil Cellusolve. It relates to an eco-friendly coating method of

Hereinafter, the present invention is described in detail.

Surface treatment process

In the present invention, the surface treatment process refers to a process of blasting the surface of a steel material or steel structure with sand, wire brush, grit, or shot ball. Specifically, it is preferable to treat the surface of the steel or steel structure so that the pretreatment grade is SIS Sa 21/2 grade or higher.

Water-based epoxy zinc heavy duty anti-rust paint

The water-based epoxy zinc heavy-duty rust-preventive paint of the present invention is a two-component paint comprising a main part and a hardener part.

[Subject]

An epoxy resin having an epoxy equivalent of 184 to 190 may be used as the epoxy resin included as a binder in the main part of the water-based epoxy zinc heavy-duty rust-preventive paint. Epoxy resins as described above include SHELL's Epikote #828 and Kukdo Chemical Co., Ltd. YD-128.

The epoxy resin is preferably included in an amount of 10 to 20% by weight based on the total weight of the water-based epoxy zinc heavy-duty anticorrosive coating composition. When the epoxy resin is included in less than 10% by weight, there is a disadvantage in that the adhesion between the surface of the metal material and the paint is lowered, and when it is included in more than 20% by weight, the content of zinc powder is relatively reduced and the rust prevention effect is lowered. may occur. In the main part, Cellusolve acetate can be used as the solvent, and it is preferably included in an amount of 3 to 9% by weight based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition for dissolving binders and dispersing pigments. do.

In addition, in the main part, zinc powder and active ceramic powder are used as pigments. Since the zinc powder has a higher ionization tendency than iron, it emits electrons more quickly to prevent iron from being oxidized. The particle size of the zinc powder may be about 1.0 to 10.0 μm, and it is preferably included in an amount of 30 to 70% by weight based on the total weight of the water-based epoxy zinc heavy-duty anticorrosive coating composition. If the zinc powder is included in less than 30% by weight, the rust prevention effect is reduced, and if it exceeds 70% by weight, the adhesion of the paint may be reduced. The active ceramic powder is an extender pigment that reacts with water included in the water-based epoxy zinc anticorrosive paint and serves to increase the hardness of the coating film. As the active ceramic powder, Misem 8000 of Ssangyong Cement Co., etc. may be used, and it is preferably included in an amount of 2.5 to 7.5% by weight based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition to enhance the hardness of the coating film.

In addition, the anti-settling agent included in the subject part allows the zinc powder and the active ceramic powder to maintain a dispersed state without settling, and is included in an amount of 1.8 to 5.5% by weight based on the total weight of the water-based epoxy zinc heavy anticorrosive coating composition. desirable. In addition, the additives included in the subject part are common in this field, such as a wetting disper sion agent, a defoamer, an anti-sagging agent, a leveling agent, and a plasticizer. It means a component used as, and it is possible to select and use one or more of the above components. The additive may be included in an amount of 0.2 to 0.5% by weight based on the total weight of the aqueous epoxy zinc heavy-duty rust-preventive paint composition.

[curing agent part]

In the water-based epoxy zinc heavy-duty rust-preventive paint curing agent, polyamide resin, polyamine resin, and aromatic amine resin are included as curing agents. Considering the viscosity, curing temperature, and curing time when mixed with the main part, 2 to 6% by weight of polyamide resin, 2.5 to 7.5% by weight of polyamine resin, and aromatic amine based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition It is preferably included in 0.5 to 2.5% by weight of the resin. Butyl Cellusolve and water may be used as the solvent in the curing agent part, and it is preferably included in 2.5 to 6.5% by weight and 2.5 to 7.5% by weight based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition, respectively.

In the water-based epoxy zinc heavy-duty rust-preventive paint, the mixing weight ratio of the main part and the curing agent part is preferably 80:20 to 87.5:12.5. When the mixing weight ratio satisfies the above range, a strong bond is formed with the steel structure, and excellent anti-rust function is exhibited.

The water-based epoxy zinc heavy-duty anti-rust paint of the present invention has excellent adhesion to steel and steel structures and excellent anti-rust function because the strong adhesion of epoxy resin, excellent anti-rust function by zinc powder, and hydration curing reaction of inorganic active ceramics exhibit mutual synergistic effects. This forms a heavy-duty rust-preventive coating film.

organic topcoat

The water-based organic top coat of the present invention is a two-component paint comprising a main part and a curing agent part.

[Subject]

An aminoacrylic emulsion resin (solid content: 35%) is used as a binder resin included in the main part of the aqueous organic topcoat material. As the amino acryl emulsion resin (solid content: 35%), an amino acryl emulsion resin having an amino value of 5 to 15 may be used. Such an amino acryl emulsion resin may be used, such as WATERSOL WSA-910 from DIC, Japan.

The binder resin is included in 70 to 85% by weight of aminoacrylic resin (35%) based on the total weight of the aqueous organic topcoat composition in consideration of chemical resistance such as acid resistance, alkali resistance, and salt water resistance required for topcoat desirable.

In the main part, titanium dioxide is used as a coloring pigment. Considering the function of the titanium dioxide as a white color pigment, it is preferably included in an amount of 10 to 20% by weight based on the total weight of the aqueous organic topcoat composition. When titanium dioxide is included in less than 10% by weight, the white coloring effect is reduced, and when it exceeds 20% by weight, the strength of the coating film may be weakened, and the dispersion effect of the paint may also be reduced.

In addition, in the main part, additives such as an anti-settling agent, a wetting dispersion agent, a defoamer, an anti-sagging agent, a leveling agent, a plasticizer, etc. It means a component commonly used in the field, and it is possible to select and use one or more of the above components. The additive may be included in an amount of 0.6 to 1.9% by weight based on the total weight of the aqueous organic topcoat composition.

[curing agent part]

In the curing agent part of the aqueous organic topcoat material, an epoxysilane resin (solid content: 98%) is used as the curing agent, and considering the viscosity, curing temperature, curing time, etc. when mixed with the main agent, the total weight of the aqueous organic topcoat composition It is preferably included in 0.7 to 4.9% by weight based on

do. As the epoxysilane resin, Japan DIC's WATERSOL WSA-950 and the like may be used.

Butyl Cellusolve may be used as the solvent of the curing agent part, and it is preferably included in an amount of 1.1 to 5.8% by weight.

In the water-based organic topcoat, it is preferable that the mixed weight ratio of the main part and the curing agent part is 90:10 to 93.75:6.25. When the mixing weight ratio satisfies the above range, chemical resistance such as acid resistance, alkali resistance, salt water resistance, and physical performance such as impact resistance, abrasion resistance, and freeze-thaw resistance are exhibited.

The organic top coat material forms a coating film having excellent physical properties by a chemical reaction between an acrylic emulsion resin having an amino functional group and an epoxy resin containing inorganic silane.

In addition, it has the feature of forming an organic bond with the previously painted heavy-duty rust-preventive coating film. That is, the aminoacrylic resin and epoxy resin included in the organic topcoat film are friendly to the epoxy resin included in the heavy-duty rust-preventive film, and the inorganic silane included in the organic topcoat film is included in the heavy-duty rust-preventive film. Since the zinc powder and the inorganic active ceramic are intimately combined to form a strong interlayer adhesion between the two coatings, the organic topcoat coating has a very excellent function of protecting the heavy-duty rust-preventive coating.

In addition, the upper surface of the organic top coat has excellent chemical resistance and physical performance to block external corrosion factors (CO2, SO2, acid rain, salt, soot, etc.) to prevent corrosion of steel and steel structures to increase durability.

In the eco-friendly coating method for iron materials of the present invention, the water-based epoxy zinc heavy-duty rust-preventive paint is preferably applied to have a film thickness of 150 μm to 300 μm, and the water-based organic topcoat is preferably applied to have a film thickness of 100 μm to 200 μm.

Hereinafter, the present invention will be described in more detail using examples. However, the following examples are intended to illustrate the present invention, and the present invention is not limited by the following examples and can be variously modified and changed.

Example 1: Preparation of water-based epoxy zinc heavy-duty rust-preventive paint

In a container that can be used for general purposes, 6.0% by weight of cellusolve acetate and 15.0% by weight of an epoxy resin having an epoxy equivalent of 184 to 190 were added and mixed, based on the total weight of the aqueous epoxy zinc heavy-duty anticorrosive coating composition. The main part was prepared by adding 50% by weight of zinc powder, 5% by weight of active ceramic powder, 3.7% by weight of an anti-settling agent and 0.3% by weight of a wetting and dispersing agent to the mixture.

In a container that can be used for general purpose, based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition, 4.5% by weight of Butyl Cellusolve, 4% by weight of polyamide resin with an amine value of 350 to 420, and polyamine with an amine value of 190 to 240 5.0% by weight of the resin and 1.5% by weight of the aromatic tertiary amine resin were added and mixed. A curing agent part was prepared by adding 5.0% by weight of clean water to the mixture and mixing.

A water-based epoxy zinc heavy anticorrosive paint was prepared by mixing the main part and the curing agent part.

Example 2: Preparation of an aqueous organic topcoat

In a container that can be used for general purpose, 78% by weight of an amino acrylic emulsion resin (solid content: 35%) with an amino value of 5 to 15 based on the total weight of the aqueous organic topcoat composition, 0.25% by weight of an antifoaming agent, and 0.5% by weight of a wetting and dispersing agent % was added and mixed. The main part was prepared by adding 15% by weight of titanium dioxide (TiO 2 ) to the mixture and mixing.

A curing agent part was prepared by mixing 3.45% by weight of Butyl Cellusolve and 2.8% by weight of an epoxysilane resin (solid content: 98%) based on the total weight of the aqueous organic topcoat in a container that could be used for general purpose.

A water-based organic top coat was prepared by mixing the main part and the curing agent part.

Example 3: Formation of double coating film of water-based epoxy zinc heavy-duty rust-preventive paint and water-based organic top coat

An iron plate with a width of 75 mm, a length of 150 mm, and a thickness of 1.0 mm was blasted with a wire brush and surface treated with SIS Sa 21/2 or higher.

The surface-treated steel plate was spray-coated with the water-based epoxy zinc heavy-duty rust-preventive paint prepared in Example 1 using an airless method to have a dry film thickness of 150-300 μm.

After completely drying and curing the coating film of the water-based epoxy zinc heavy-duty rust-preventive paint, the water-based organic top coat prepared in Example 2 was applied on top of the dry coating film using an airless method to obtain a dry film thickness of 100 to 200 μm. It was spray-painted and dried and cured to complete the painting of the steel plate.

Claims (1)

A process of surface treatment of steel or steel structure surfaces;
A step of painting a water-based epoxy zinc heavy-duty rust-preventive paint on the surface of the steel or steel structure treated by the above process, and
As an eco-friendly painting method for steel materials, which includes a step of painting a water-based organic top coat after the water-based epoxy zinc heavy-duty anti-rust paint applied in the above process is dried and cured,
The water-based epoxy zinc heavy-duty rust-preventive paint contains 10-20% by weight of epoxy resin, 3-9% by weight of Cellusolve acetate, and 30-70% by weight of zinc powder, based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition. , 2.5 to 7.5% by weight of active ceramic powder, 1.8 to 5.5% by weight of an antisettling agent, and 0.2 to 0.5% by weight of an additive; and
Based on the total weight of the water-based epoxy zinc heavy-duty rust-preventive paint composition, 2 to 6% by weight of polyamide resin, 2.5 to 7.5% by weight of polyamine resin, 0.5 to 2.5% by weight of aromatic amine resin, 2.5 to 6.5% by weight of Butyl Cellusolve and water It is a two-component paint composed of a hardener part containing 2.5 to 7.5% by weight,
The aqueous organic topcoat contains 70 to 85% by weight of aminoacrylic emulsion resin (solid content: 35%), 10 to 20% by weight of titanium dioxide (TiO2) and 0.6 to 1.9% by weight of additives based on the total weight of the aqueous organic topcoat composition. Subject part containing; and
Based on the total weight of the aqueous organic topcoat composition, epoxysilane resin solid content; 98%) 0.7 to 4.9% by weight and a curing agent portion containing 1.1 to 5.8% by weight of Butchil Cellusolve. Eco-friendly painting method.