KR102050288B1 - Rust-converting Composition Having Metal Surface Repairing Effect - Google Patents

Abstract

A rust convertor composition for removing rust on a metal surface and forming a coating layer to prevent corrosion, comprising: an acrylic copolymer, tannic acid, n-butyl acrylate, polyoxyethylene lauryl ether, polyamide-based microparticles, and water Provide a conversion composition.

Description

Rust-converting Composition Having Metal Surface Repairing Effect

The present invention is a rust conversion composition for forming a coating layer to remove rust and prevent corrosion of the metal surface, the acrylic copolymer, tannic acid, n-butyl acrylate, polyoxyethylene lauryl ether, polyamide-based microparticles and water It relates to a rust conversion composition having an effect of converting the rust generated on the metal surface and the crack surface by applying to the surface of the metal surface crack in the thickness direction from the metal surface, and repairing the crack.

Metal corrosion refers to the modification of metals by reacting them chemically or electrochemically with materials contained in the environment. In order for corrosion to occur, four elements must be provided: an anode, a cathode, an electrolyte, and a return circuit.

In nature, metals are highly oxidatively reactive, causing corrosion of metals in the presence of moisture and oxygen. Metals are oxidized to exist as metal oxides, which are more stable compounds than metals. However, metal oxides generally have lower physical properties such as stiffness and metal-specific toughness and conductivity compared to metals.

As such, the corrosion of metal is accepted as a natural phenomenon. However, as metal is widely used in various fields such as buildings and industrial facilities in modern society, the corrosion of metal in terms of protecting social infrastructure and public capital of society Various techniques are used to prevent corrosion.

Corroded metal is weaker than before corrosion is easily destroyed and deformed even from the external impact, the corrosion generated on the surface of the metal proceeds to the corrosion in the depth direction of the metal there is a problem that the metal is eventually cut or easily deformed. The rust conversion agent is applied to the surface of the corroded metal, and at the same time to remove the corroded metal to form a corrosion prevention layer at the applied site to effectively prevent the corrosion of the metal.

On the other hand, cracks formed in the depth direction of the metal improves the surface area where the metal is corroded, which causes the metal to corrode more quickly, and the rigidity of the metal is very weak in the direction perpendicular to the depth direction. It is necessary to form a coating layer that removes rust and prevents corrosion while repairing the scratches formed.

Since cracks formed in the depth direction from the metal surface have a great influence on the physical properties of the metal material, repairing cracks formed on the metal is very important to increase the life of the metal material.

Republic of Korea Patent No. 10-1107795 relates to a corrosion inhibitor for preventing metal corrosion, and a mixture of a rust conversion solution comprising an emulsion resin binder containing water and isopropyl alcohol and acetic acid solution added with tannic acid or gallic acid as a rust inhibitor By using it, it is disclosed that there is no need for a pretreatment process for use on a corroded metal surface and that it can be used as an undercoat for heavy coatings. When cracks are generated in the depth direction on the surface, there is no disclosure regarding a technique for repairing them.

Japanese Patent Laid-Open Publication No. 199-320936 relates to an antirust treatment agent by rust conversion of a steel surface, and is made by combining a fluorine compound, a carboxyl group-containing compound, and a humectant with an aqueous solution of tannic acid, thereby effectively dissolving rust and forming an antirust coating. Has only disclosed a rust preventive treatment agent and has not disclosed a technique for repairing metal surface cracks.

Therefore, as a rust converting agent, not only the formation of a coating layer having a rust-preventing effect at the same time as removing the rust of the metal surface, but also has the effect of repairing cracks formed in the depth direction from the metal surface to improve the life of the metal material The demand continues.

Republic of Korea Patent No. 10-1107795 Japanese Patent Laid-Open No. 1993-320936

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

The inventors of the present invention, after recognizing the above problems and repeating a number of experiments and studies to solve them, acrylic copolymer, tannic acid, n-butyl acrylate, polyoxyethylene lauryl ether, polyamide-based microparticles and Water-based rust conversion composition containing water is excellent in the rust conversion effect and rust prevention effect of the metal surface, and at the same time penetrates the crack formed on the metal surface, the two surfaces of the metal with cracks are firmly connected to each other to repair the crack It confirmed that it had an effect, and came to complete this invention.

Therefore, the rust conversion composition according to the present invention for achieving the above object includes an acrylic copolymer, tannic acid, n-butyl acrylate, polyoxyethylene lauryl ether, polyamide-based microparticles and water.

Rust conversion agent composition according to the present invention, based on the total weight of the composition, the acrylic copolymer is 5 to 30% by weight, the tannic acid is 0.1 to 10% by weight, the n-butyl acrylate is 1 to 20% by weight, The polyoxyethylene lauryl ether may include 0.1 to 10% by weight, the polyamide-based microparticles may include 0.1 to 10% by weight and water to 50 to 80% by weight.

The rust conversion agent composition according to the present invention may further comprise a silane coupling agent, the silane coupling agent may be included in 0.1 to 10% by weight.

Meanwhile, the polyamide-based microparticles may be polyamide 6 (nylon 6) and / or polyamide 66 (nylon 6, 6).

The polyamide-based microparticles may have an average diameter of 1 to 20 ㎛ (micrometer).

As described above, the rust conversion composition according to the present invention is excellent in the rust conversion effect formed on the metal surface, the anti-rust coating layer formed after the rust conversion has a semi-permanent rust prevention effect.

In addition, when a crack is formed on the metal surface, it penetrates between the metal cracks and has a repair effect that is firmly bonded to the metal layers on the two surfaces on which the crack is formed.

In addition, the rust conversion composition according to the present invention has an effect that can be directly coated on the surface of the antirust coating layer without any additional pretreatment process on the surface on which the coating layer is formed.

1 is a photograph (left) showing a rusty iron part before use of a rust converter and a photograph of an operation of applying a rust converter to a rusty iron part;
2 is a photograph sequentially showing a rusty iron component before applying a rust converting agent according to the present invention, a process of applying the rust converting agent, and a steel part after application;
3 is a photograph 20 minutes after the rust conversion agent according to the present invention is applied to a rusty iron component according to the present invention;
Figure 4 is a photograph of one day after the rust conversion agent according to the invention is applied to the rust conversion agent according to the invention rusty metal parts.

In the following, each configuration will be described in more detail, but this is only one example, the scope of the present invention is not limited by the following.

The present invention relates to a rust conversion agent that forms a rust-preventive coating layer on the metal surface while removing rust formed on the metal surface. In particular, the rust conversion composition according to the present invention is to solve the problem that the stiffness of the metal material is significantly reduced by the corrosion of the metal when cracks are formed in the depth direction from the metal surface to further improve the life of the metal material, It provides a rust conversion composition having an effect of repairing cracks.

Since cracks formed in the depth direction from the surface of the metal significantly improve the possibility of cutting of the metal material, there is an effect that can effectively prevent the cutting of the metal material by preventing and preventing corrosion of the metal and repairing the crack of the metal. .

Metal materials are used as supporting materials such as H beams, rebars, steel pipes, etc. that support heavy weights, such as buildings and large structures, and they are used as drainage pipes and exhaust pipes of power plants. It is a very important factor in the lifespan.

In the case where the rust-prevented metal material has formed some rust over time, the rust conversion agent according to the present invention is used to clean and rust-proof the surface where some rust has been formed, further extending the life of the metal material. However, the chemical damage caused by the corrosion progresses more rapidly when there is a physical damage such as crack formation in the metal material, and the chemical damage also progresses the physical damage more rapidly, thereby significantly reducing the physical properties of the metal material. Therefore, preventing physical damage simultaneously with chemical damage can further prolong the life of the metal material.

The rust conversion composition according to the present invention comprises an acrylic copolymer, tannic acid, n-butyl acrylate, polyoxyethylene lauryl ether, polyamide-based microparticles and water.

The acrylic copolymer is not particularly limited as long as it is copolymerized with at least one selected from the group consisting of acrylic acid, methacrylic acid and derivatives thereof as a monomer. Specifically, it may be a copolymer copolymerized with one or more selected from the group consisting of acrylic acid, methacrylic acid and derivatives thereof as a monomer and copolymerizing one or more olefinic monomers containing an unsaturated bond.

More preferably, the monomer selected from the group consisting of acrylic acid, methacrylic acid and derivatives thereof may be at least one selected from n-butyl acrylate, 2-hydroxyethyl acrylate and methacrylic acid, and the olefinic monomer may be It may be at least one selected from the group consisting of ethylene, propylene and styrene.

Most preferably, the acrylic copolymer may be a copolymer of n-butyl acrylate, 2-hydroxyethyl acrylate, methacrylic acid and styrene. The average molecular weight of the copolymer is not particularly limited, but may be an average molecular weight of 1000 to 20000.

In the rust conversion composition according to the present invention, the acrylic copolymer may be included in 5 to 30% by weight, preferably 8 to 25% by weight based on the total weight of the composition, most preferably 10 To 20 wt%.

When added in excess of the above content, the composition has a high viscosity, so that the composition is solidified before penetrating into the cracks, so that the composition does not sufficiently penetrate into the cracks of the metal, resulting in insufficient crack repair effect. . On the other hand, when added in a smaller amount than the content there is a problem that the workability is inferior because the drying time is long after applying the composition to the metal surface.

On the other hand, the tannic acid is a carboxylic acid compound synthesized by plants as a kind of polyphenol, a compound containing a large number of hydroxyl groups. It is included as a component of the rust conversion agent, and reacts with iron oxide formed on the metal surface to form iron tannate (Ferric Tannate) has the effect of removing the rust on the metal surface.

Since most of the metal materials requiring high stiffness are composed of alloy materials including iron, the present invention is preferably suitable for application to metal materials including iron.

The tannic acid may be included in 0.1 to 10% by weight, based on the total weight of the rust conversion composition, preferably 0.5 to 7% by weight, most preferably, 1 to 5% by weight.

The n-butyl acrylate is an ester compound obtained by esterifying n-butanol and acrylic acid, and may be included in an amount of 1 to 20% by weight based on the total weight of the composition, preferably 5 to 18% by weight, most preferably May be included in 7 to 15% by weight.

The polyoxyethylene lauryl ether is also called poly (oxy-1,2-ethanediyl) or alpha-dodecyl-omega-hydroxy-polyoxyethylene, the rust conversion agent according to the present invention It may be included in 0.1 to 10% by weight based on the total weight of the composition. Preferably from 0.5 to 8% by weight, most preferably from 1 to 5% by weight. The polyoxyethylene lauryl ether may have an average molecular weight of 500 to 2000.

On the other hand, the polyamide-based microparticles are microparticles made of a polyamide-based polymer, preferably the polyamide-based polymer may be polyamide 6 (nylon 6) and / or polyamide 66 (nylon 66).

The polyamide-based microparticles are not particularly limited as long as they are within a range capable of achieving the object of the present invention, but may preferably be 5000 to 20000.

The polyamide-based microparticles may be an average diameter of 1 to 20 ㎛ (micrometer), preferably 5 to 15 ㎛ (micrometer), most preferably 8 to 12 ㎛ (micrometer) have.

The polyamide-based microparticles are in close contact with the surface of the crack formed in the depth direction on the metal surface and the metal surface and the microparticles are bonded in a state in which the microparticles are in close contact with the surface of the crack in the process of solidifying the rust conversion composition. Particles are bonded to each other by other components such as an acrylic copolymer has the effect of repairing the metal cracks.

This effect is that the finer the particles are in close contact with the cracked metal surface, the more the contact surface of the rust conversion agent penetrates between the cracks and connects the cracked metal surfaces, and thus the two metal surfaces can be more firmly connected. have.

Therefore, in the rust converter composition of the present invention, the average particle diameter of the polyamide-based microparticles has an important effect on the number of microparticles that are in close contact with the metal surface, that is, the adhesion area with the metal surface of the rust converter composition.

In the case where the average diameter is larger than the above range, the fine particles are not sufficiently adhered to the surface where the crack is formed, so that the force connecting the two metal surfaces where the crack is formed is not large compared with the case where only the antirust coating layer is formed, and the average diameter is larger than the above range. In the small case, as the arrangement of microparticles varies, the surface energy increases greatly, rather than agglomeration of microparticles rather than close contact with the crack surface of the metal, so that the composition does not penetrate the crack so as to adhere to the metal surface. have.

The polyamide-based microparticles may be included in 0.1 to 10% by weight based on the total weight of the rust conversion composition, preferably, 2 to 8% by weight, most preferably, 4 to 7% by weight. have.

When added in excess of the content, it is difficult to use the spray injection method, which is a method of applying a rust converting agent to the metal surface, and when added in a smaller amount than the content, the metal crack is filled. There is a problem in that the bonding force connecting the two metal surfaces is low, so that the effect of extending the life of the metal material due to the repair of the crack does not appear significantly.

In addition, the rust conversion composition according to the invention may further comprise a silane coupling agent in addition to the above components. The type of silane coupling agent is not particularly limited as long as the object of the present invention can be achieved, but preferably, may be selected from the group consisting of alkylalkoxysilane, amino silane and olefin silane, more preferably amino silane Specifically, amino propyl triethoxy silane, amino propyne trimethoxy silane, amino propyl methyl diethoxy silane, m-amino phenyl trimethoxy silane, phenylaminopropyltrimethoxysilane, trimethoxy It may be at least one selected from the group consisting of silylpropyl diethylene triamine.

The silane coupling agent may be added in an amount of 0.1 to 10% by weight, preferably 0.5 to 8% by weight, and most preferably 1 to 5% by weight.

When added in excess of the content there is a problem that the stiffness of the repaired portion of the metal crack is rather falling, even when added in a small amount than the content there is a problem that the bond strength between the fine particles and the metal surface is lowered and the stiffness is lowered.

On the other hand, the rust conversion composition according to the invention is an aqueous composition based on water. Water constituting the rust conversion composition may be composed of the remaining amount, except for the above components, specifically, may be included in 50 to 80% by weight.

If necessary, it is possible to incorporate other additives that may be added to the rust conversion composition, for example, a plasticizer, an antifoaming agent, a curing retardant or a dispersant may be added.

If the rust conversion composition according to the present invention is a method that can be applied to the metal surface, the coating method is not particularly limited, for example, spray spraying, brushing or impregnation may be used. It is comprised so that all of the above methods may have suitable physical properties, and it is possible to apply | coat easily to a metal surface even when using any coating method.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited thereto.

Preparation of Rust Converting Agent Composition

<Example 1>

The rust conversion composition was prepared by mixing the components shown in Table 1 below.

ingredient CAS number Content (% by weight) Styrene, n-butyl acrylate, 2-hydroxyethyl acrylate, methacrylic acid copolymer 34407-02-8 12 Tannic acid 1401-55-4 3.5 N-butyl acrylate 141-32-2 10.5 Polyoxyethylene lauryl ether 9002-92-0 3 Polyamide 6 Fine Particles (Average Particle Size 8 ㎛) 2038-54-4 5 Amino propyl triethoxy silane 919-30-2 2 water 7732-18-5 Remaining amount

<Example 2>

A rust conversion composition was prepared in the same manner as in Example 1 except that the particle diameter of the polyamide 6 microparticles was 10 μm.

Comparative Example 1

A rust conversion composition was prepared in the same manner as in Example 1 except that no amino propyl triethoxy silane was added.

Comparative Example 2

A rust conversion composition was prepared in the same manner as in Example 1, except that 12 wt% of amino propyl triethoxy silane was added.

Comparative Example 3

A rust conversion composition was prepared in the same manner as in Example 1 except that the average particle diameter of the polyamide 6 microparticles was 3 μm.

<Comparative Example 4>

A rust conversion composition was prepared in the same manner as in Example 1 except that the average particle diameter of the polyamide 6 microparticles was 18 μm.

Comparative Example 5

A rust conversion composition was prepared in the same manner as in Example 1 except that no polyamide 6 microparticles were added.

Comparative Example 6

A rust conversion composition was prepared in the same manner as in Example 1, except that 15 wt% of polyamide 6 microparticles were added.

Experimental Example 1-strength measurement experiment

The steel bar SD300 D32 for reinforced concrete used in concrete was used.

Cracks having a gap of about 0.7 cm depth and a distance of about 0.1 to 0.2 cm from the surface of the reinforcing bars were formed and a rust conversion composition according to the Examples and Comparative Examples was applied thereto.

After sufficiently drying for about 5 days, the tensile strength and the yield strength of the repaired rebar were measured using the rust conversion agent compositions of Examples and Comparative Examples (a universal material tester, using a Screw Type Universal Testing Machine DA-272). Table 2 shows a comparison of tensile strength and yield strength of unreinforced steel bars.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 The tensile strength 82% 75% 18% 21% 24% 30% 12% 31% Yield strength 77% 71% 11% 15% 22% 21% 9% 26%

Experimental Example 2-Antirust Effect Confirmation Experiment

Reinforcing bar according to Experimental Example 1 was maintained for 21 days while being impregnated in a 10% NaCl aqueous solution.

Before the impregnation of the reinforcing bar, after 7 days, 14 days, and 21 days after the rust was visually confirmed and shown in Table 3.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 0 days later X X X X X X X X 7 days later X X X X X X X X 14 days later X X X X X X X X 21 days later X X △ △ X X △ X

(O: Rust on the front, △: Some rust, X: No change)

Experimental Example 3-Rust Confirmation Effect Experiment

The bar was impregnated with an aqueous NaCl solution for 21 days as in Experiment 2 without any treatment, and then exposed to air for about 5 days.

It is shown in Table 4 to confirm the rust conversion effect by applying the rust conversion composition of the Example and Comparative Example to the rust formed rebar.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Change O O △ O O O △ O

(O: mostly removed, △: partially removed, X: no change)

Referring to the experimental results, it was confirmed that the difference between the rust conversion effect of the Example and Comparative Example and the antirust effect of the antirust coating layer.

On the other hand, the rust conversion agent of the embodiment was applied to the rust conversion agent as shown in FIG. 3 and immediately the rust conversion effect appeared to the maximum value, it was confirmed that the effect appears very quickly to a level similar to the rust conversion effect after 1 day of application. Comparative examples were confirmed that the rust conversion effect gradually appeared as the drying time after the application, the rust conversion agent according to the present invention was further confirmed that the advantage that the rust conversion effect appears immediately.

In Comparative Example 1, Comparative Example 2 and Comparative Example 5 was confirmed that the rust preventive effect, but this is different from the site where the metal crack is generated, that is, the surface of the rebar with a predetermined anti-rust treatment on the surface, the crack formed rebar This is because the inner surface of the steel is not rust-prevented and is more susceptible to corrosion than the surface of the rebar.

In addition, in Table 4, in the case of Comparative Example 1 and Comparative Example 5, it was confirmed that the rust conversion effect is somewhat inferior, rust conversion agent composition by adding the remaining amount of water by the amount of amino propyl triethoxy silane or fine particles not added It is judged that the result of thinner concentration of.

On the other hand, in the tensile strength and yield strength measurement test of the reinforcing bars, when the rust conversion agent composition of the comparative example was added, the strength of the reinforcing bar was significantly lower than that without any treatment, there was no crack repair effect on the surface of the rebar. On the other hand, in Examples 1 and 2, the tensile strength and the yield strength showed strength values of about 70% of the reinforcing bar before crack formation, and the reinforcing material of the reinforcing material according to the repair of the crack was found to be large.

Claims (6)

A rust convertor composition for forming a coating layer that removes rust on a metal surface and prevents corrosion.
Acrylic copolymers, tannic acid, n-butylacrylate, polyoxyethylene lauryl ether, polyamide based microparticles and water,
Based on the total weight of the composition,
The acrylic copolymer is 5 to 30% by weight,
The tannic acid is 0.1 to 10% by weight,
The n-butyl acrylate is 1 to 20% by weight,
The polyoxyethylene lauryl ether is 0.1 to 10% by weight,
The polyamide-based microparticles are 0.1 to 10% by weight and
The water is rust conversion composition, characterized in that 50 to 80% by weight. delete The method of claim 1,
The rust converter composition further comprises a silane coupling agent. The method of claim 3,
Based on the total weight of the composition,
The silane coupling agent is a rust conversion composition, characterized in that 0.1 to 10% by weight. The method of claim 1,
The polyamide-based microparticles are made of a polyamide-based polymer,
The polyamide-based polymer is polyamide 6 (nylon 6) and / or polyamide 66 (nylon 66) rust conversion composition, characterized in that. The method of claim 1,
The polyamide-based microparticles are rust conversion composition, characterized in that the average diameter of 1 to 20 ㎛ (micrometer).

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