KR20130043339A - Electro-deposition coating method - Google Patents

Abstract

PURPOSE: An electro-deposition coating method is provided to evenly generate a coating thickness due to excellent even adhesive property. CONSTITUTION: Contaminants buried in a surface of a coating object are removed with spray processing(S10). Pre-degreasing and main degreasing are performed to prevent passivating caused by iron oxide and iron hydroxide(S20). A rinse process is performed(S60). Cation type electro-deposition coating is performed at the coating object(S70). A spray process is performed with a spray gun to remove a residual chemical(S80). A dry process is performed at a drying furnace(S90), and a sealed shrink film is packed(S110) after a coating state is inspected(S100). [Reference numerals] (AA) First pre-degreasing; (BB) Second pre-degreasing; (CC) Fourth washing; (DD) Main degreasing; (EE) First washing; (FF) Second washing; (GG) Third washing; (HH) Hand washing; (II) UF first washing; (JJ) UF second washing; (KK) UF third washing; (S10) Hot-water washing process; (S100) Inspection process; (S110) Packing process; (S20) Alkaline degreasing process; (S30) First washing process; (S40) Pre-treatment process; (S50) Coating process; (S60) Second washing process; (S70) Electroplating process; (S80) UF washing process; (S90) Drying process;

Description

Electrodeposition coating method

The present invention relates to an electrodeposition coating method.

Specifically, by providing an improved electrodeposition coating method, it is suitable for an automated line, so that the process is shortened and the loss of the paint is minimized, and as the coating thickness is uniform, the electrodeposition coating is maximized. It's about how

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In general, electrodeposition coating is a coating method for depositing the coating film on the surface of the coating object through the direct current between the coating object and its counter electrode by using the coating material as an anode or a cathode in an aqueous coating solution for electrodeposition. Also known as a dojo.

In Korea, since the first electrodeposition coating has been introduced to the automotive industry since 1978, it has continued to grow steadily in each industry.In addition, the electrodeposition coating has to be mass-produced by automation and has the advantage of no fire hazard, while it should be a conductive coating. It is impossible to repaint and not suitable for small quantity production, and it is difficult to replace colors.

On the other hand, the coating method can be divided into anionic electrodeposition coating and cationic electrodeposition coating. Anion electrodeposition coating is also called anion electrodeposition coating, and is a method of electrodeposition coating by passing the anode through the coating, whereas cation electrodeposition coating is cation. Also known as electrodeposition coating, it is a method of electrodeposition coating by passing a cathode to a workpiece.

Unlike the anion electrodeposition coating, the cationic electrodeposition coating precipitated at the cathode is spotlighted due to its high rust resistance, which has not been developed for a long time, but has been used worldwide because of its excellent rust resistance and excellent chip resistance. Coating lines that are applying paints are also being replaced by cationic types. These cationic electrodeposition coatings have a thin coating film and excellent anti-rusting properties, contribute to corrosion resistance because there is no elution of chemically treated coatings, and can be pale-colored finish because there is no elution of metals, and uniform adhesion is superior to anions. In comparison with the anion type, there are problems such as a characteristic of obtaining a uniform and smooth appearance, high temperature heating, acid resistance, and equipment cost being excessive compared to the anion type.

In addition, in the anion electrodeposition coating, the electrodeposition coating used for the anion electrodeposition coating is one in which a maleated adduct or an acrylic acid introduction product is introduced into the resin. However, in order to improve the anti-rusting properties of automobile bodies, the substitution of oils with liquid polybutadiene is mostly applied to vehicle body coatings. Such anion electrodeposition coating has stable quality of workability, high degree of freedom in terms of equipment cost, easy synthesis of resins in manufacturing, and can be diversified. There is a limiting problem in finishing.

The present invention is to solve the problem to implement the electrodeposition coating method suitable for the automation line to maximize the overall work efficiency.

In constructing the electrodeposition coating method of the present invention in order to achieve the above problems,

The electrodeposition coating method, the hot water step (S10) to remove the contaminants buried in the coating with a spray gun to remove at a temperature of 40 ~ 50 ℃; An alkali degreasing step (S20) in which the first and second preliminary degreasing and the main degreasing are sequentially performed using an alkali degreasing agent and sodium hydroxide in order to remove oils on the workpiece and prevent passivation due to iron oxide and iron hydroxide; 180 ~ 240 seconds of spray cleaning to remove residual chemicals of alkaline components, 1st, 2nd water washing and spray cleaning of 180 ~ 240 seconds under the conditions of temperature 20 ~ 30 ℃, ph 5 ~ 8, pressure 0.6 ~ 1.6atm Washing step I (S30), which is divided into third washings carried out under the conditions of a temperature of 20 to 30 ° C, a ph of 5 to 8 and a pressure of 0.8 to 1.6 atm; Activated with DI water and titanium oxide surface modifier, spray surface 180 ~ 240 seconds, temperature 20 ~ 30 ℃, ph 7 ~ 10, pressure 0.8 ~ 1.6atm, alkali contamination 2.5 ~ 3.5 Pretreatment step (S40) to adjust the surface in order to; Insoluble chemical coating on the surface of the coating under conditions of immersion 180 ~ 240 sec, temperature 65 ~ 75 ℃, acidity 22 ~ 23.5, free acidity 0.6 ~ 0.8, acceleration 2.5 ~ 3.5, ph 3 ~ 4 A film forming process (S50) for forming a film; Fourth flush and DI water electrical conductivity conducted to remove residual chemical film solution under conditions of immersion 180 ~ 240 seconds, temperature 20 ~ 30 ℃, ph 5 ~ 7, pressure 1.0 ~ 1.5atm Washing process II including pure water to remove coating ions and to protect paint components under conditions of 180 to 240 seconds of immersion, pH 5.5 to 6.5, circulation pressure of 0.4 to 1.0 kgf / cm ² and at the same time (S60). ); Electrodeposition coating process (S70) which performs a cationic electrodeposition coating under the conditions of a to-be-coated object and a potential difference of 250V, a temperature of 29-30 degreeC, and a pH of 7.5-8.5; UF washing process (S80) for spraying with a spray gun to remove residual chemicals; Drying step (S90) for drying for 50 minutes at a temperature of 150 ~ 175 ℃ in a drying furnace; An inspection step (S100) of inspecting a coating state of the workpiece; Characterized in that consisting of; packaging process (S110) for packaging with a closed shrink film.

And, the first preliminary degreasing of the alkali degreasing step (S20) under the conditions of immersion 180 ~ 240 seconds, temperature 50 ~ 60 ℃, ph 12.5 ~ 13.5, the second preliminary degreasing spray spray 180 ~ 240 seconds, temperature 50 ~ Under the conditions of 60 ° C. and ph 12.5 to 13.5, the main stripping paper is characterized by being carried out under the conditions of spray washing 180 to 240 seconds, temperature 30 to 40 ° C., ph 12.5 to 13.5, and pressure 0.6 to 1.6 atm.

In the film forming process (S50), a zinc phosphate coating agent and an accelerator are used.

And, the UF washing step (S80) is carried out sequentially divided into UF1 washing, UF2 washing, UF3 washing, UF1 washing under the conditions of spray cleaning 80 ~ 90 seconds, spray pressure 0.7 ~ 1.1, UF2 washing spray spray 180 Under the conditions of ˜240 seconds, the spray pressure of 0.7 to 1.1, the UF3 water washing is characterized by being carried out under the conditions of spray cleaning 100 seconds or less, spray pressure of 0.7 to 1.1, respectively.

In the electrodeposition coating process (S70), the cationic epoxy or the cationic acrylic is selected and used.

According to the present invention made of the above-described configuration, the film thickness is uniform, such as suitable for the automation line, shortening the process and minimizing the loss of paint, as well as perfect coating even complex coatings due to excellent uniform adhesion. As a result, the arrival efficiency of the paint is maximized.

1 is a floor chart of the electrodeposition coating method constituted by a preferred embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings, and the configuration and operation and effects thereof according to various embodiments will be described in detail below with reference to various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims. And, throughout the specification, like reference numerals refer to like elements.

1 is a floor chart of the electrodeposition coating method constituted by a preferred embodiment of the present invention.

As shown in Figure 1, the electrodeposition coating method of the present invention is largely hot-drinking step (S10); Alkali process (S20); Water washing I step (S30); Pretreatment step (S40); Film forming process (S50); Washing II process (S60); Electrodeposition coating process (S70); UF washing step (S80); Drying process (S90); Inspection process (S100); Packaging process (S110); can be made, including.

Specifically, the hot water treatment step (S10) to remove the contaminants in the coating object by spraying the spray gun to remove at a temperature of 40 ~ 50 ℃, and to remove the oil on the coating and to prevent passivation due to iron oxide, iron hydroxide Alkaline degreasing process (S20), in which the first and second preliminary degreasing and the main degreasing are sequentially performed using an alkali degreasing agent and sodium hydroxide, and spray cleaning 180-240 seconds to remove the residual chemicals of the alkaline component. First and second flushing and spray washing 180 to 240 seconds at 20 to 30 ° C, pH 5 to 8, pressure 0.6 to 1.6 atm, temperature 20 to 30 ° C, ph 5 to 8, pressure 0.8 to 1.6 atm Water washing I step (S30) divided into the third water washing performed under the conditions; and using a water (DI water) and titanium oxide surface conditioner as the material, spray cleaning 180 ~ 240 seconds, temperature 20 ~ 30 ℃, ph 7 ~ 10 Activates the surface of workpiece under pressure of 0.8 ~ 1.6atm and alkali pollution of 2.5 ~ 3.5 Pretreatment step (S40) to adjust the surface in order to; and, immersion 180 ~ 240 seconds, temperature 65 ~ 75 ℃, acidity 22 ~ 23.5, free acidity 0.6 ~ 0.8, acceleration 2.5 ~ 3.5, ph to improve the corrosion resistance A film forming step (S50) for forming an insoluble chemical film on the surface of the workpiece under the conditions of 3 to 4; and immersion 180 to 240 seconds, temperature 20 to 30 ° C., ph 5 to 7, and pressure 1.0 to 1.5 atm. Fourth washing and DI water electric conductivity conducted to remove residual chemical film solution under 500,000Ω or more, immersion 180 ~ 240 seconds, ph 5.5 ~ 6.5, circulation pressure 0.4 ~ 1.0kgf / cm ² Water washing II process (S60) including pure water which is carried out to remove the ions and to protect the paint components under the conditions; and under the conditions of the potential of 250 V, temperature of 29 to 30 DEG C, pH 7.5 to 8.5 of the workpiece being a cathode Electrodeposition coating step (S70) for carrying out the cationic electrodeposition coating; and spray treatment with a spray gun to remove residual chemicals The UF washing step (S80); And, drying step (S90) for drying 50 minutes at a temperature of 150 ~ 175 ℃ in a drying furnace; And Inspection step (S100) for checking the coating state of the coating; And, Hermetic shrink film Packaging process (S110) for packaging with; may be made.

In particular, the first preliminary degreasing of the alkali degreasing step (S20) under the conditions of immersion 180 ~ 240 seconds, temperature 50 ~ 60 ℃, ph 12.5 ~ 13.5, the second preliminary degreasing spray 180 ~ 240 seconds, temperature 50 ~ Under the conditions of 60 ℃, ph 12.5 ~ 13.5, main degreasing can be carried out under the conditions of spray cleaning 180 ~ 240 seconds, temperature 30 ~ 40 ℃, ph 12.5 ~ 13.5, pressure 0.6 ~ 1.6 atm, the film forming process ( In S50), a zinc phosphate coating agent and an accelerator are preferably used.

In addition, the UF washing step (S80) is sequentially performed by UF1 washing, UF2 washing, UF3 washing, UF1 washing under the conditions of spray cleaning 80 ~ 90 seconds, spray pressure 0.7 ~ 1.1, UF2 washing spray spray 180 Under conditions of ˜240 seconds, spray pressure of 0.7 to 1.1, UF3 washing is performed under the conditions of spray cleaning of 100 seconds or less and spray pressure of 0.7 to 1.1, respectively, and in the electrodeposition coating process (S70), cationic epoxy or cationic acrylic can be selected and used. Can be.

Example 1-Wiping process (S10)

The process involves spraying the workpiece to remove contaminants on the surface of the workpiece.

In the present invention, the spray treatment using a spray gun using water, the conditions were carried out in the temperature range of 40 ~ 50 ℃.

Example 2-Alkaline Process (S20)

The process is carried out to remove the process oil and rust preventive oil, etc. of the press product on the iron surface, and dipping the oil on the coating as an alkaline degreasing agent to add a surface active agent.

In the present invention, the first preliminary degreasing, the second preliminary degreasing and the main degreasing were carried out, and the first preliminary degreasing was performed in an bathtub (tank) using an alkali degreasing agent and sodium hydroxide, but the conditions were 180 to 240 seconds. Immersion time was given during, and carried out under the conditions of temperature 50 ~ 60 ℃ and ph 12.5 ~ 13.5. The second preliminary degreasing was given a spray cleaning time for 180 to 240 seconds, and was carried out under the conditions of a temperature of 50 to 60 ° C and a ph of 12.5 to 13.5. On the other hand, the main degreasing is a process for washing the oil or dust adhered to the coating material that has not been treated by the preliminary degreasing step, and given the same spray cleaning time as the second preliminary degreasing, the temperature 30 ~ 40 ℃, ph The conditions were 12.5-13.5 and 0.6-1.6 atm of pressure.

Example 3-Washing-I Process (S30)

The above process is to prevent the surface adjustment process (pre-treatment process) from causing an obstacle by removing the alkali component remaining in the workpiece after the alkali process.

In the present invention, the first washing, the second washing, and the third washing are carried out.

The first and second washes were carried out under the conditions of spray washing 180 to 240 seconds, temperature 20 to 30 ° C., ph 5 to 8, and pressure 0.6 to 1.6 atm. It carried out under the conditions of 20-30 degreeC, ph 5-8, and pressure 0.8-1.6 atm.

Example 4 Pretreatment Process (S40)

The process is a step for surface adjustment, which involves increasing the number of active points on the surface to give fine and uniform crystals.

In the present invention, pure water (DI water) and titanium oxide surface modifier were used as materials, and the conditions were spray washing 180 to 240 seconds, temperature 20 to 30 ° C., ph 7 to 10, pressure 0.8 to 1.6 atm, and alkali pollution degree 2.5 to 3.5. Was carried out.

Example 5-Film Forming Step (S50)

The process is to induce the formation of a fine and uniform zinc phosphate coating by chemically treating the coating material several active points formed on the metal surface through the surface adjustment, to increase the rust resistance, corrosion resistance, high temperature, oxidation resistance, hardness, wear resistance It is effective.

In the present invention, while using zinc phosphate coating agent and accelerator, the conditions of immersion 180 ~ 240 seconds, temperature 65 ~ 75 ℃, acidity 22 ~ 23.5, free acidity 0.6 ~ 0.8, acceleration 2.5 ~ 3.5, ph 3 ~ 4 by providing An insoluble chemical film was formed on the surface of the workpiece.

Example 6-washing with water II (S60)

In the above process, as the chemical film solution is weakly acidic, the fourth liquid and the pure water are separated in order to solve the problems that remain on the metal surface, so that the coating film can be removed cleanly.

The fourth washing was carried out under the conditions of immersion 180 ~ 240 seconds, temperature 20 ~ 30 ℃, ph 5 ~ 7, pressure 1.0 ~ 1.5atm using water to remove residual chemical film solution. Pure water (DI water) of 500,000 Ω or more was used under conditions of immersion 180 to 240 seconds, ph 5.5 to 6.5, and circulation pressure of 0.4 to 1.0 kgf / cm ² to remove the ions and to protect the paint components. In particular, in pure water, the RO filter is used to completely prevent aging of the electrodeposition liquid as residual impurities are completely removed.

Example 7-Electrodeposition process (S70)

In the above process, for the purpose of electrolysis, electrophoresis, electroprecipitation, and electroprecipitation, the object to be coated was carried out using a cationic epoxy or a cationic acryl under conditions of a potential difference of 250 V, a temperature of 29 to 30 ° C., and a pH of 7.5 to 8.5.

Example 8-UF washing process (S80)

In the present invention, the process was performed by dividing the process into UF1, UF2, and UF3, respectively, and sprayed with a spray gun to remove residual chemicals.

Specifically, UF1 washing was performed under the spray cleaning time of 80 to 90 seconds and the spray pressure of 0.7 to 1.1, and UF2 washing was performed under the spray cleaning time of 180 to 240 seconds and the spray pressure of 0.7 to 1.1. UF3 water washing was performed under the spray pressure conditions of 100 second or less and 0.7-1.1.

S10. Hot Washing Process
S20. Alkali process
S30. Suse I process
S40. Pretreatment process
S50. Film Forming Process
S60. Suse II process
S70. Electrodeposition coating process
S80. UF washing process
S90. Drying process
S100. Inspection process
S110. Packaging process

Claims (5)

In the electrodeposition coating method,
Hot water treatment step (S10) of spraying a contaminant on the object to be sprayed with a spray gun to remove at a temperature of 40 ~ 50 ℃; An alkali degreasing step (S20) in which the first and second preliminary degreasing and the main degreasing are sequentially performed using an alkali degreasing agent and sodium hydroxide in order to remove oils on the workpiece and prevent passivation due to iron oxide and iron hydroxide; 180 ~ 240 seconds of spray cleaning to remove residual chemicals of alkaline components, 1st, 2nd water washing and spray cleaning of 180 ~ 240 seconds under the conditions of temperature 20 ~ 30 ℃, ph 5 ~ 8, pressure 0.6 ~ 1.6atm Washing step I (S30), which is divided into third washings carried out under the conditions of a temperature of 20 to 30 ° C, a ph of 5 to 8 and a pressure of 0.8 to 1.6 atm; Activated with DI water and titanium oxide surface modifier, spray surface 180 ~ 240 seconds, temperature 20 ~ 30 ℃, ph 7 ~ 10, pressure 0.8 ~ 1.6atm, alkali contamination 2.5 ~ 3.5 Pretreatment step (S40) to adjust the surface in order to; Insoluble chemical coating on the surface of the coating under conditions of immersion 180 ~ 240 sec, temperature 65 ~ 75 ℃, acidity 22 ~ 23.5, free acidity 0.6 ~ 0.8, acceleration 2.5 ~ 3.5, ph 3 ~ 4 A film forming process (S50) for forming a film; Fourth flush and DI water electrical conductivity conducted to remove residual chemical film solution under conditions of immersion 180 ~ 240 seconds, temperature 20 ~ 30 ℃, ph 5 ~ 7, pressure 1.0 ~ 1.5atm Washing process II including pure water to remove coating ions and to protect paint components under conditions of 180 to 240 seconds of immersion, pH 5.5 to 6.5, circulation pressure of 0.4 to 1.0 kgf / cm ² and at the same time (S60). ); Electrodeposition coating process (S70) which performs a cationic electrodeposition coating under the conditions of a to-be-coated object and a potential difference of 250V, a temperature of 29-30 degreeC, and a pH of 7.5-8.5; UF washing process (S80) for spraying with a spray gun to remove residual chemicals; Drying step (S90) for drying for 50 minutes at a temperature of 150 ~ 175 ℃ in a drying furnace; An inspection step (S100) of inspecting a coating state of the workpiece; Electrodeposition coating method comprising a; packaging step (S110) for packaging with a closed shrink film.
The method of claim 1,
The first preliminary degreasing of the alkaline degreasing step (S20) is immersed 180 ~ 240 seconds, temperature 50 ~ 60 ℃, pH 12.5 ~ 13.5 under the conditions, the second preliminary degreasing spray spray 180 ~ 240 seconds, temperature 50 ~ 60 ℃ , under a condition of pH 12.5-13.5, the main stripping paper is carried out under the conditions of spray cleaning 180 ~ 240 seconds, temperature 30 ~ 40 ℃, ph 12.5 ~ 13.5, pressure 0.6 ~ 1.6atm.
The method of claim 1,
In the film forming process (S50), a zinc phosphate coating agent and an accelerator are used. The method of claim 1,
The UF washing process (S80) is divided into UF1 washing, UF2 washing, UF3 washing in sequence, but
UF1 flush under spray conditions of 80-90 seconds, spray pressure 0.7-1.1, UF2 flush under spray conditions of 180-240 seconds, spray pressure 0.7-1.1, UF3 flush under 100 seconds spray wash, spray pressure 0.7 Electrodeposition coating method characterized in that each carried out under the conditions of ~ 1.1.
The method of claim 1,
In the electrodeposition coating step (S70), the electrodeposition coating method characterized in that the use of cationic epoxy or cationic acrylic.

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