KR101716737B1 - Ecofriendly Zinc Flake Surface Treatment Solution for corrosion protection of metal products - Google Patents

Abstract

The present invention relates to an eco-friendly zinc flake surface treatment solution for corrosion protection of metal parts, and a surface treatment method using the surface treatment solution. Specifically, the eco-friendly zinc flake surface treatment solution for corrosion protection of metal parts comprises: 1-11 wt% of zinc flake; 0-12 wt% of aluminum flake; 25-50 wt% of zinc-aluminum flake; 5-13 wt% of triethoxysilane; 0-10 wt% of tetraethoxysilane; 0-6 wt% of stearic acid; 2-10 wt% of vinyltriethoxysilane; 1.5-11 wt% of methyltriethoxysilane; 1-4 wt% of tetrabutyl titanate; 15-37 wt% of dipropylene glycol; and 0-20 wt% of ethanol.

Description

TECHNICAL FIELD [0001] The present invention relates to a zinc flake surface treatment solution for preventing corrosion of metal parts,

The present invention relates to an environmentally friendly zinc flake surface treatment solution for preventing corrosion of metal parts and a surface treatment method using the surface treatment solution.

Efforts to inhibit metal corrosion have been studied continuously since the Iron Age, and since the 1900s, efforts have been made to prevent corrosion through alloys and many developments have been made in plating and coating techniques since the Second World War. The most widely used iron (Fe) is low in price and strong in heat resistance. Further, there is an advantage that it is easy to form a desired shape by applying pressure. It is a metal that is widely used in the first half of modern industry which is alloyed with another metal element. Iron offers convenience to modern people in various aspects such as offshore plant, ship, marine bridge, wind turbine, automobile, and railway engine.

However, this iron reacts with oxygen in the atmosphere and causes corrosion. This corrosion reduces the durability and life of parts and threatens the safety of modern people who use them. Therefore, many techniques have been developed so far to prevent corrosion of iron used throughout the industry.

Although most of the people do not know the seriousness of this corrosion because it is not confirmed by numerical values, the total loss of groundwater leakage, building corrosion, automobile corrosion and corrosion of marine buildings is about 3% of GDP in Korea About 27 trillion won), which is equivalent to defense or education expenses.

Surface treatment technology not only improves the durability and functionality of materials and parts by physically, chemically or electrochemically treating surface physical properties of materials, but also improves the beauty and enhances the value of goods. And the surface properties of materials other than the main characteristics of the materials.

Corrosion refers to the destruction of metal and the shortening of the useful life of a metal caused by chemical reaction or electrochemical reaction with various substances in its environment.

In other words, most of the metal is an unstable material refined by applying a lot of energy to the ore in its natural state, and has instinct to return to a stable natural state again by the corrosion of the metal, and this property is called a property to react.

Most metals are stable as ions (+ ions or - ions) rather than as metal agglomerates themselves. Thus, like the nature of returning to the mixture, the metal tends to ionize if conditions are met. Therefore, another scientific expression of corrosion is the tendency of metals to ionize.

Corrosion in the atmosphere is affected by temperature, humidity, rain, sea salt particles, and sulfur dioxide, but it also depends on the shape, direction, and size of the member. The extent of these corrosion is mainly investigated worldwide for test specimens, and the environmental dependence of the aging of corrosion is large.

Corrosion rates are determined according to these trends by the influence of humidity, temperature, rainfall, sunshine, pollutants (sea salt particles, dioxide gas), sulfur dioxide and the like as the aforementioned corrosion factors. Since molten water is generated by water and oxygen, humidity is a direct cause of corrosion and has a great influence. Generally, when the humidity exceeds 60%, rust starts to appear on the exposed surface of the iron. As for the temperature, the rate of progress of the rust tends to be higher as the temperature is higher. This is due to the rise in the chemical reaction rate with the rise in temperature. In other words, since the generation and progress of rust are caused by chemical reactions, the higher the temperature, the faster the corrosion rate.

Particularly, airborne contaminants are especially influenced by sea salt particles and dioxide gas. Sea salt particles, which are carried by the wind, attach to the metal surface to destroy the passive film and promote the generation of rust and corrosion. Sulfur dioxide gas reacts with oxygen and water in the air to become sulfuric acid. Sulfur dioxide gas is a very strong promoter against corrosion. The sunshine and pollutants are a major factor in the deterioration progression of the coating film. And, as mentioned above, in the environment where the influence of the corrosion factor is great, if the countermeasure which is not suitable for the influence is selected, the corrosion proceeds early.

Corrosion does not only result in rust, but can lead to personal injury due to collapse of bridges due to corrosion, automobile accidents caused by car corrosion, and metal that is corroded by spontaneous process loses its original structure and properties It also brings about economic losses, which are used to replace about 25% of the iron and steel produced each year, which is rusty. However, the surface treatment industry, which is one of the root industries, relies on foreign products in the current harsh environment and domestic development is urgent.

Compared with a decade ago, the big frame of surface treatment technology has not changed. In the case of wet surface treatment using a liquid containing a chemical compound such as plating, the processing cost is low and mass production is easy, but the problem of plating wastewater still has limitations of conventional methods. Dry surface treatment using a vacuum device also did not significantly improve the treatment method.

Because dry surface treatment is a clean production technology, there is no local restriction on the operation. However, due to the use of vacuum equipment, the unit price is high, the size of the workpiece is limited, and the initial investment cost for mass production is high. Therefore, there is a pollution problem in which plating wastewater or toxic gas is generated. It must be produced only in the plating complex that handles toxic substances.

Because of these disadvantages, wet surface treatment should be improved to make it easy, cheap, and clean. In other words, there is no need for wastewater treatment and pretreatment, volatile organic compounds (VOC) are not generated, and there is no odor, so that it can be processed in a machining plant. High hardness, high corrosion resistance, and high functionality. It is necessary to develop and introduce new technologies that complement the limitations of conventional wet surface treatment.

Dacro treatment has contributed greatly to many surface treatment industries for about 30 years now.

Dark surface treatment is a surface treatment of 6 ~ 8 micron thickness of zinc particle layer coated with chromium polymer on the surface of base metal by immersing it in dark solution mixed with chromic acid, zinc particles, aluminum particles, reducing agent and deionized water and heating. to be.

The corrosion protection mechanism is composed of zinc sacrificial corrosion, passivation that chromic acid polymer forms an anti-corrosive oxide film to suppress corrosion of zinc, and chromium acid prevents movement of ions to prevent corrosion, thereby protecting the base metal. Recently, it is in the limelight.

This dark surface treatment is characterized by excellent corrosion resistance and especially corrosion resistance in heat-resistant corrosion resistance and damaged film areas. It has strong hydrogen embrittlement, can form a coating film of complex shape, has no waste water process, .

Darkcoat is the most used in the surface treatment of automobile parts because it can cover various parts in addition to excellent heat resistance and corrosion resistance as mentioned above. Recently, Regulation of hexavalent chromium (Cr ⁶⁺ ), which is a harmful substance, is one of the most urgent and significant influences in the domestic market.

Geomet coating is a high-performance corrosion inhibitor developed for environmentally friendly surface treatment and does not contain heavy metal chromium at all. As environmental problems have become global issues, the legal restrictions on harmful substances have become more strict, and the use of hexavalent chromium, which has excellent effects on rust inhibition performance, has been limited. It was developed to meet the needs of these markets.

These geometric coatings have a double layer structure of zinc flakes and aluminum flakes, providing excellent corrosion barriers between other corrosive media (barrier protection). Also, on the same principle as the sacrificial method, Zn is first corroded to protect the steel (galvanic protection). And, as a passivation action, the metal oxide slows the corrosion reaction of Zn and steel and provides three times greater corrosion protection than other pure Zn.

As a feature of the geomat coating, it is environmentally friendly and it is possible to treat the coating with no heavy metal material at all. Though it is thin film coating about 8μm thick, it shows high corrosion resistance and can be applied to fasteners such as bolts and nuts. , The corrosion resistance is doubled and the torque stability required for screw tightening is excellent. As a water-soluble metallic paint, it is not regarded as dangerous material handling and its working environment is very safe compared to other types. In addition, unlike ordinary electroplating, there is no washing process, so there is no waste water discharge.

Magni coating is a coating for high performance fasteners that is somewhat more corrosion resistant than a geomat coating. It is composed of Zinc-rich base coating and Al-pigmented organic top coating which does not contain chromium at all. It is composed of cathodic method by sacrificial zinc of iron (Fe) and anti corrosion of aluminum by external corrosion environment Is an environmentally friendly surface treatment.

The double coating technique of base coating and top coating provides sacrificial protection and barrier protection, and provides bimetalic corrosion resistance which also reduces whitening. Since the top coating contains a friction modifier, there is no need to perform a lubricant coating such as a geometh and a dark coating after coating.

This Magnet Coating does not contain heavy metals such as chromium, lead, mercury and cadmium and is an eco-friendly coating method that fully complies with the regulations of RoHS, ELV, etc., and has strong corrosion resistance over 1,000 hours, Lt; / RTI > Typical plating / water-based coatings suffer corrosion resistance degradation after thermal shock, but the magneic coating maintains excellent corrosion resistance even after thermal shock.

In addition, since the coating material itself contains a lubricant, there is no need for a separate lubricant addition step and the coating thickness is reduced, thereby ensuring excellent economical efficiency compared to other surface treatments. In the case of hardened steel for fasteners, the susceptibility of hydrogen embrittlement is high, so it is necessary to heat treatment for removal of hydrogen embrittlement in automobile parts, but in case of magnesium coating, there is no case of exposure to hydrogen, and the coating process itself includes a heat treatment process A heat treatment step for eliminating hydrogen embrittlement only is not necessary. It is possible to sufficiently satisfy the fastening without requiring a separate torque stabilization treatment and to have excellent fastening properties.

In the conventionally disclosed patents, Korean Patent No. 0687278 discloses a coating composition for a system using a zinc-aluminum alloy powder, glycidoxypropylmethoxysilane and deionized water, which is excellent in coating power, It is manufactured in non-chrome type that can cope with the enhancement of safety hazard standard. However, since it reacts methoxysilane with deionized water to produce methanol which is a by-product, it can pose a threat to safety of workers.

Korean Patent Laid-Open Publication No. 2008-0047573 has also developed a corrosion-resistant coating composition composed of ultrafine solid particles free from other undesirable substances such as heavy metals such as lead, nickel, chromium, etc. However, Methanol is contained in a large amount, and expensive high-temperature plasma is used, so there is a problem of safety and uneconomical worker's safety.

Korean Patent No. 0918615 discloses a corrosion-resistant coating method using hybrid crystals having an environmentally-soluble water-soluble high polymer acrylic bonded thereto which can secure workers' safety and prevent environmental pollution. Although the abrasion resistance, corrosion resistance and scratch resistance of the metal are enhanced, the polyvinyl butyral (PVB) used in the process is produced in the presence of strong acid, and the production of the raw material is industrially expensive. In this patent, However, the problem of environmental pollution has been solved, but the problem is uneconomical.

Korea Patent No. 0687278 Korean Patent Publication No. 2008-0047573 Korean Patent No. 0918615

DISCLOSURE Technical Problem Accordingly, the present invention has been made in order to solve the above problems, and it is an object of the present invention to provide an alternative coating solution for domestic 6-chrome chromium which can actively respond to environmental regulations We have established eco-friendly manufacturing technology using Zn-Al Flake, and have developed a resin technology that can control the viscosity to improve adhesion, an additive manufacturing technique added to the surface part of the coating agent to improve the corrosion resistance, And the process technology for blending the solution into the solution.

Further, according to one embodiment of the present invention, there is a need for a substitute material for hazardous substances and environmental load substances, as the guidelines for specific harmful substances (RoHS) and volatile organic compounds (VOCs) In order to meet the requirements, the environmentally friendly zinc flake coating applied to the present invention is not only beautiful in appearance, but also suitable for the RoHS Directive, does not contain volatile organic compounds (VOCs) It is intended to provide excellent corrosion resistance, uniform thickness coating, and environment-friendly working environment.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. It can be understood.

A first object of the present invention is to provide a surface treatment solution for surface treatment of an iron-based base material, which comprises zinc flake in the form of flake powder, . ≪ / RTI >

It may further comprise at least one of the zinc flakes, the aluminum flakes and the zinc-aluminum alloy flakes.

Further, it may further comprise triethoxysilane.

Further, it may further comprise tetraethoxysilane.

Further, it may further comprise at least one of stearic acid, vinyltriethoxysilane, methyltriethoxysilane, and tetrabutyl titanate.

Further, it may further comprise at least one of dipropylene glycol and ethanol.

A second object of the present invention is to provide a surface treatment solution for surface treatment of an iron base material, which comprises 1 to 11% by weight of zinc flakes, 0 to 12% by weight of aluminum flakes, 25 to 50% 5 to 13 wt% of ethoxysilane, 0 to 10 wt% of tetraethoxysilane, 0 to 6 wt% of stearic acid, 2 to 10 wt% of vinyltriethoxysilane, 1.5 to 11 wt% of methyltriethoxysilane, A zinc flake surface treatment solution for preventing corrosion of metal parts, which comprises 1 to 4% by weight of butyl titanate, 15 to 37% by weight of dipropylene glycol and 0 to 20% by weight of ethanol.

More preferably in the second aspect of the present invention there is provided a composition comprising 3 to 5% by weight of zinc flakes, 8 to 10% by weight of aluminum flakes, 25 to 30% by weight of zinc-aluminum flakes, 7 to 10% by weight of triethoxysilane, By weight of stearic acid, 3 to 6% by weight of vinyltriethoxysilane, 2.5 to 5% by weight of methyltriethoxysilane, 1 to 1.5% by weight of tetrabutyl titanate, 2 to 5% by weight of dipropylene 22 to 25% by weight of glycol, and 15 to 20% by weight of ethanol.

A third object of the present invention is to provide a method for surface treatment of an iron base material, comprising the steps of: preparing a surface treatment solution according to the first or second object; A pretreatment step of removing foreign matters from the iron-based preform to be surface treated; Immersing the base material in the surface treatment solution in a dipping manner; Removing the base material from the surface treatment solution, dewatering the same, and uniformly applying the base material; And preheating and drying, followed by drying and curing at a high temperature to form a coating layer. The surface treatment method using the environmentally friendly zinc flake surface treatment solution can be achieved.

The step of forming the coating layer may be preheated at 100 to 130 ° C for 15 to 25 minutes and then dried and cured at 200 to 350 ° C for 15 to 25 minutes.

According to one embodiment of the present invention, as a guide to specific RoHS (RoHS), volatile organic compounds (VOCs) and the like is strengthened in Europe, the necessity of materials for replacing harmful substances and environmental load substances becomes very high. The Zinc flake coating applied to the present invention so as to be in conformity with the present invention is not only beautiful in appearance but also suitable for the RoHS directive and contains no volatile organic compounds (VOCs) Coating with a uniform thickness, and an environment-friendly working environment.

It should be understood, however, that the effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those skilled in the art to which the present invention belongs It will be possible.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description, serve to further the understanding of the technical idea of the invention, It should not be construed as limited.
1 is a photograph of a bolt coated with a surface treatment solution according to an embodiment of the present invention,
FIG. 2 shows comparison experimental data showing the cross-section and performance analysis of the coating layer of Example 2 and Comparative Example of the present invention,
Fig. 3 is a graph showing a cutting axial force graph measured 9 times for Example 2 of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages of the present invention will become more readily apparent from the following description of preferred embodiments with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

In this specification, when an element is referred to as being on another element, it may be directly formed on another element, or a third element may be interposed therebetween. Also in the figures, the thickness of the components is exaggerated for an effective description of the technical content.

Embodiments described herein will be described with reference to cross-sectional views and / or plan views that are ideal illustrations of the present invention. In the drawings, the thicknesses of the films and regions are exaggerated for an effective description of the technical content. Thus, the shape of the illustrations may be modified by manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention are not limited to the specific forms shown, but also include changes in the shapes that are produced according to the manufacturing process. For example, the area shown at right angles may be rounded or may have a shape with a certain curvature. Thus, the regions illustrated in the figures have attributes, and the shapes of the regions illustrated in the figures are intended to illustrate specific forms of regions of the elements and are not intended to limit the scope of the invention. Although the terms first, second, etc. have been used in various embodiments of the present disclosure to describe various components, these components should not be limited by these terms. These terms have only been used to distinguish one component from another. The embodiments described and exemplified herein also include their complementary embodiments.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms "comprises" and / or "comprising" used in the specification do not exclude the presence or addition of one or more other elements.

In describing the specific embodiments below, various specific details have been set forth in order to explain the invention in greater detail and to assist in understanding it. However, it will be appreciated by those skilled in the art that the present invention may be understood by those skilled in the art without departing from such specific details. In some instances, it should be noted that portions of the invention that are not commonly known in the description of the invention and are not significantly related to the invention do not describe confusing reasons to explain the present invention.

≪ Configuration of Surface Treatment Solution >

According to one embodiment of the present invention described below, guidance for a specific harmful substance (RoHS), volatile organic compounds (VOCs), etc. is strengthened mainly in Europe, In order to meet the growing demand, the environmentally friendly zinc flake coating applied to the present invention is not only beautiful in appearance but also suitable for the RoHS directive and does not contain volatile organic compounds (VOCs) In addition, it has an effect of providing a coating with excellent corrosion resistance, a uniform thickness, and an environment-friendly working environment.

Hereinafter, the composition and composition ratio of the environmentally-friendly zinc flake surface treatment solution for preventing corrosion of metal parts according to one embodiment of the present invention will be described in more detail.

The surface treatment solution for surface treatment of the iron base material according to an embodiment of the present invention includes zinc flake in the form of flake powder.

More specifically, in one embodiment of the present invention, it may comprise at least one of zinc flake, aluminum flake and zinc-aluminum alloy flake. Therefore, zinc and aluminum as a sacrificial effect of zinc and the effect of oxidation of aluminum provides high corrosion resistance performance.

In an embodiment of the present invention, the metal powder should be added with a proper amount so as to exhibit a sufficient anticorrosive effect, and a material for providing strong adhesion between the surface treatment solution (coating solution) and the metal base material should be added. In one embodiment of the present invention, triethoxysilane is included as a material for providing adhesion with the metal base material.

In an embodiment of the present invention, tetraethoxysilane is included as a material for forming a stable film.

In one embodiment of the present invention, the additive for increasing the corrosion resistance may further comprise at least one of stearic acid, vinyltriethoxysilane, methyltriethoxysilane, and tetrabutyl titanate.

In one embodiment of the present invention, at least one of dipropylene glycol and ethanol is contained as a solvent. The high corrosion resistant surface treatment solution according to one embodiment of the present invention is a chromium free solution, which is an environmentally friendly solution manufactured in conformity with RoHS.

Hereinafter, the specific composition ratio of the environmentally-friendly zinc flake surface treatment solution for preventing corrosion of metal parts according to one embodiment of the present invention will be described. The environmentally friendly zinc flake surface treatment solution for preventing corrosion of a metal part according to an embodiment of the present invention comprises 1 to 11% by weight of zinc flakes, 0 to 12% by weight of aluminum flakes, 25 to 50% by weight of zinc flakes of aluminum, 5 to 13 wt% of ethoxysilane, 0 to 10 wt% of tetraethoxysilane, 0 to 6 wt% of stearic acid, 2 to 10 wt% of vinyltriethoxysilane, 1.5 to 11 wt% of methyltriethoxysilane, 1 to 4% by weight of butyl titanate, 15 to 37% by weight of dipropylene glycol and 0 to 20% by weight of ethanol.

More preferably, it is more preferable to add 3 to 5 wt% of zinc flake, 8 to 10 wt% of aluminum flake, 25 to 30 wt% of zinc-aluminum flake, 7 to 10 wt% of triethoxysilane, By weight of stearic acid, 0 to 2% by weight of stearic acid, 3 to 6% by weight of vinyltriethoxysilane, 2.5 to 5% by weight of methyltriethoxysilane, 1 to 1.5% by weight of tetrabutyl titanate, 22 to 25% by weight of dipropylene glycol % And ethanol in an amount of 15 to 20% by weight.

Hereinafter, a method for surface-treating an iron-based base material according to an embodiment of the present invention will be described. First, an environmentally-friendly zinc flake surface treatment solution for preventing corrosion of metal parts according to an embodiment of the present invention is prepared.

Then, a pretreatment step for removing foreign matters from the iron-based preform to be subjected to the surface treatment is performed. This pretreatment process is a process of removing rust and surface oxides existing on the foreign materials and surface of the iron-based base material and is removed by shot blast or sand blast. In addition, it is preferable that this process is performed so that an effective coating layer can be formed by imparting roughness to the surface.

Then, the base material is immersed in the surface treatment solution in a dipping manner. Then, the base material is taken out of the surface treatment solution, dewatered, and uniformly applied. That is, in order to apply the surface treatment solution to the iron base material to be coated first in this process, it is dipped in the dipping method for 3 to 5 seconds, then taken out, dehydrated at a suitable rpm for 200-1000 rpm, Respectively.

Then, after preheating and drying, the coating layer is formed by drying and curing at a high temperature. More specifically, after the surface treatment solution is applied, it is pre-dried at 100 to 130 ° C for 15 to 25 minutes for 15 to 25 minutes and then dried and cured at 200 to 350 ° C for 15 to 25 minutes to form a coating layer.

The coating process of the surface treatment solution according to an embodiment of the present invention is easy to apply to mass production and is eco-friendly.

It does not require any special after-treatment, and it is only necessary to cool the finished product which has been hot-dried and cured at 300 to 350 ° C to room temperature.

<Experimental data>

Hereinafter, the above-mentioned surface treatment solution of the present invention is coated on a base material, a brine fraction test for a product subjected to a surface treatment, a cross-section and component analysis of a coating layer, adhesion performance, and friction coefficient analysis experimental data will be described.

As the mixed powder material used in this experiment, Zinc flake was used in ESB Co., Aluminum flake in Metal player, zinc-aluminum alloy flake in ECKART, Stearic acid (3-aminopropyl) triethoxysilane, tetraethoxysilane, vinyltriethoxysilane and methyltriethoxysilane are used in the case of heterogeneous materials, and dipropylene glycol ) In SKC, tetrabutyl titanate was purchased from Sigma-Aldrich and the experiment was conducted.

The surface treatment solutions of Examples 1 to 5 applied to the experiment were prepared by mixing at the composition ratios shown in Table 1 below.

Components (% by weight) Example 1 Example 2 Example 3 Example 4 Example 5 zinc
flake 1-3 3 to 5 5 ~ 7 7 ~ 9 9-11 aluminum
flake 0 to 1 8-10 10-12 5 to 6 0 Zinc - Aluminum
flake 35 ~ 39 25 to 30 32 to 36 35 ~ 39 45 to 50 Stearic acid 0 0 2 to 4 3 to 5 4 to 6 Dipropylene glycol 34 to 37 22-25 15 ~ 18 25-28 28 ~ 31 (3-aminopropyl)
Triethoxysilane 5 ~ 7 7 to 10 5 ~ 8 8 ~ 11 10 to 13 Vinyltriethoxysilane 2 to 5 3 to 6 4 to 7 5 ~ 8 6 to 10 Methyltriethoxysilane 1.5 to 3 2.5 to 5 3.5 to 7 4.5 to 9 5.5 to 11 Tetraethoxysilane 8-10 8-10 4 to 6 0 0 Tetrabutyl titanate 1 to 1.5 1 to 1.5 3 to 4 1.5 to 2 1.5 to 2 ethanol 10 to 15 15-20 7-12 6 to 11 0

Then, the surface treatment solutions of Examples 1 to 5 were surface-treated with each of the bolts of the iron series by the above-mentioned surface treatment method to prepare samples.

The salt spray test is the most basic method for evaluating the corrosion resistance of highly corrosion-resistant coated samples. It is carried out by spraying salt water and keeping it at the proper temperature to accelerate the corrosion. This standardization procedure was carried out in accordance with KS D 9502, which was conducted by spraying 5% NaCl solution at 35 ° C and keeping the chamber temperature at 35 ° C. After 1000 hours of salt spray test, the corrosion resistance performance was measured according to the area where the red rust was generated. FIG. 11 is a photograph of a bolt coated with a surface treatment solution according to an embodiment of the present invention after 1,000 hours of salt spray test. FIG.

Measurement contents
Example 1 Example 2 Example 3 Example 4 Example 5 Corrosion resistance
○ ◎ △ ○ △

⊚: Reddish area generated - 0% or less of area

○: Red area of the red area - 5% or less of the area

?: Red area generated - 15% or less of area

X: Red-green area - 15% or more of area

As shown in Fig. 11 and Table 2, in all the examples in Experimental Example, it was found that no red shade generation area of 15% or more was generated, and Example 2 had no red shade generation area.

EDX (Energy Dispersive X-ray Spectroscopy) was used to analyze the composition of the coating layer. The surface state and cross section of the coating layer were examined using an environment-friendly scanning electron microscope (E-SEM, Quanta 400) Respectively.

In order to analyze the thickness of the formed coating layer, the sample was cut and mounted, the surface scratch was removed through various grinding processes, and the thickness of the coating layer formed on the metal base material was measured through an environmental scanning electron microscope. 12 shows comparative experimental data showing the cross-section and performance analysis of the coating layer of Example 2 and Comparative Example of the present invention.

As shown in FIG. 12, it can be seen that Example 2 is an eco-friendly surface treatment solution containing no heavy metal such as chromium in comparison with the comparative example.

Adhesion is a very important part of the coating process because the coating after the surface treatment solution has good adhesion with the substrate, which can protect the substrate for a long period of time. Experiments were conducted according to ASTM D3002 and D3359 in order to test the coating layer adhesion of the samples coated with the surface treatment solutions of Examples 1 to 5 of the present invention, and the adhesion performance grades thereof were evaluated as ASTM class 5B to 0B. The smaller the area is, the better the adhesion.

Measurement contents
Example 1 Example 2 Example 3 Example 4 Example 5 Adhesion
△ ◎ ○ △ ◎

◎: ASTM class 5B

○: ASTM class 4B

△: ASTM class 3B

X: ASTM class 0,1,2B

As shown in Table 3, it can be seen that the adhesiveness is best in Examples 2 and 5.

In the friction coefficient analysis, the coefficient of friction (k) is obtained by the equation of T = kDN (T = torque, D = nominal diameter, N = axial force) and the friction coefficient is stably maintained by the surface treatment solution according to the embodiment of the present invention It was confirmed that the deviation was small.

FIG. 13 shows a cut axial force graph measured 9 times for Example 2 of the present invention. FIG. Table 4 below shows the torque coefficient value and the cutting axial force measured for the ninth time in the second embodiment of the present invention. Table 5 shows the relationship between the maximum value and the minimum value of the torque coefficient value measured 9 times for the second embodiment of the present invention And Table 6 shows the maximum and minimum cutting angles and deviation of the cutting axial force measured nine times for Example 2 of the present invention.

No. One 2 3 4 5 6 7 8 9 Average talk
Count value 0.1419 0.1505 0.1488 0.1620 0.1423 0.1386 0.1472 0.1482 0.1455 0.1472 cut
Axial force 18878.7 18348.0 18796.5 17642.1 18975.0 19070.6 18181.9 17956.3 18347.7 18466.3

Torque coefficient value Min 0.1386 Max 0.1620 σ 0.0067

Cutting axial force Min 17642.1 Max 19070.6 σ 493.9

As shown in FIG. 13 and Tables 4 to 6, the second embodiment of the present invention shows a low friction coefficient deviation and has a good friction coefficient stability.

It should be noted that the above-described apparatus and method are not limited to the configurations and methods of the embodiments described above, but the embodiments may be modified so that all or some of the embodiments are selectively combined .

Claims (10)

A surface treatment solution for surface treatment of an iron base material,
3-5 wt% zinc flakes;
8-10 wt% aluminum flake;
25-30 wt% zinc-aluminum flake;
7 to 10% by weight of triethoxysilane;
7-10% by weight of tetraethoxysilane;
More than 0 to 2% by weight stearic acid;
3 to 6% by weight of vinyltriethoxysilane;
2.5 to 5% by weight of methyltriethoxysilane;
1 to 1.5% by weight of tetrabutyl titanate;
22-25% by weight of dipropylene glycol; And
And 15 to 20% by weight of ethanol. Description: FIELD OF THE INVENTION The present invention relates to an eco-friendly zinc flake surface treatment solution for corrosion prevention of metal parts.
delete delete delete delete delete delete delete A method for surface treatment of a base material of iron series,
Preparing a surface treatment solution according to claim 1;
A pretreatment step of removing foreign matters from the iron-based preform to be surface treated;
Immersing the base material in the surface treatment solution in a dipping manner;
Removing the base material from the surface treatment solution, dewatering the same, and uniformly applying the base material; And
And drying and curing at a high temperature to form a coating layer on the surface of the zinc flake surface.
10. The method of claim 9,
Wherein forming the coating layer comprises:
Drying at 100 to 130 ° C for 15 to 25 minutes, and then drying and curing at 200 to 350 ° C for 15 to 25 minutes. The surface treating method using the environmentally friendly zinc flake surface treatment solution.

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