KR20130118414A - White type electrodeposition coating method - Google Patents

Abstract

PURPOSE: A white electro-deposition coating method is provided to form a coating film using paint and a preprocessing agent in an acryl group 1 component type without phosphate, thereby preventing the environmental contamination by the phosphate and offering excellent chemical and mechanical properties. CONSTITUTION: A white electro-deposition coating method comprises the following steps: removing foreign materials and oil from the surface of a coating object for preventing the generation of an uneven surface processing film (12); washing the surface of the coating object to remove a remaining degreasing solution and an alkali component (14); forming a coating layer on the coating object using a zirconium type reactive preprocessing agent for improving durability, corrosion resistance, and adhesion power (16); washing the surface of the coating object to remove the foreign materials and a conversion coating liquid (18); drying the surface of the coating object with air (20); forming a coating film on the surface of the coating object using acrylic deposition paint (22); collecting the remaining paint from the surface of the coating object (24); and drying the coating object (26). [Reference numerals] (10) Lot test and raking; (12) Fat removing process; (121) First preliminary fat removal; (122) Second preliminary fat removal; (123) Main fat removal; (14) First washing process; (141) First washing; (142) Second washing; (143) Fisrt pure washing; (16) Chemical conversion coating process; (18) Second washing process; (181) Second pure washing; (182) Third pure washing; (20) Drying process; (22) Electroplating process; (24) Third washing process; (241) First UF washing; (242) Second UF washing; (243) Third UF washing; (244) Fourth UF washing; (26) Baking process; (28) Un-raking and test

Description

White type Electrodeposition Coating Method

The present invention relates to a white electrodeposition coating method, and in particular, by forming a coating film using an acrylic pretreatment agent and a coating material free of phosphate, mechanical properties such as acid resistance, hot water resistance, corrosion resistance, etc. It relates to an environmentally friendly white electrodeposition coating method with excellent physical properties.

In general, it gives aesthetics (color) and corrosion resistance to the surface of the metal material, and is a painting process that surface-treats the surface of the metal material for use as a means of transportation such as automobiles and aircrafts and electronic products such as home appliances, mobile phones and mobile devices. Electrodeposition coating and electrostatic powder coating is used, but in recent years, the electrodeposition coating with good coating adhesion has been used a lot.

However, in the conventional electrodeposition coating, after removing impurities and oils on the coated objects such as iron and zinc, an anticorrosive phosphate film is formed on the surface of the coated object, such as epoxy type 2 mixed paint, to provide excellent corrosion resistance. Because of providing adhesion, there was a problem that the environmental pollution problem caused by phosphate.

The present invention is to solve the above problems, by forming a coating film using a phosphate-free acrylic pretreatment and paint, such as acid resistance, hot water resistance, corrosion resistance, such as chemical properties and adhesion, impact resistance, flexibility An object of the present invention is to provide an environmentally friendly white electrodeposition coating method with excellent mechanical properties.

In order to achieve the above object, the present invention provides a degreasing step (12) for removing foreign matter and oil remaining on the surface of the coating material to prevent the non-uniform surface treatment film is formed on the coating material of the metal material; A first washing step (14) of washing the surface of the coating material subjected to the degreasing step (12) to remove residual degreasing solution and alkali components adhering to the surface of the coating material; A chemical conversion coating step (16) of forming a film with a zirconium-type reactive pretreatment agent to improve durability, corrosion resistance, and adhesion of the surface of the coating material subjected to the first washing step (14); A second washing step (18) of washing the surface of the coating material subjected to the chemical conversion coating step (16) to remove impurities and the chemical conversion film remaining on the surface of the coating object; A drying step (20) of drying the surface of the coated object that has passed through the second washing step (18) with air; An electrodeposition process 22 for forming a coating film with an acrylic electrodeposition paint on the surface of the coated object which has been subjected to the drying process 20; A third washing step (24) for recovering the paint remaining on the surface of the coated object which has passed the electrodeposition step (22); And a baking step 26 for drying the coated object passed through the third washing step 24.

In the present invention, the degreasing step (12), 1 to 1.2 kg of a BN cleaner, which is an electrolytic / precipitate degreasing agent for alkali metals and nonmetals, to remove foreign substances and oils on the surface of the coating material. A first preliminary degreasing 121 sprayed onto the surface of the object to be coated by a spray method for 110 to 130 seconds at a pressure / cm 2; A second preliminary degreasing 122 in which the coated material is precipitated in the degreasing solution for 110 to 130 seconds at a temperature of 50 ° C. to 65 ° C. to remove foreign substances and oil remaining in the coated object; And a main degreasing 123 in which the coated material is precipitated in the degreasing solution for 110 to 130 seconds at a temperature of 50 ° C. to 65 ° C. to remove foreign substances and oil on the surface of the workpiece.

In the first washing process 14 in the present invention, the spray method and the precipitation method are sequentially performed for 110 to 130 seconds at room temperature so as to remove impurities and alkali components adhering to the surface of the coated object, and the 5.5 to 7.5 It is characterized in that the coating material is precipitated in the wash liquor for 110 to 130 seconds at room temperature with a pH of 1㏁ ~ 50㏁.

In the present invention, the chemical conversion coating step 16 is to precipitate the coating material in the zirconium-type reactive pretreatment for 110 ~ 130 seconds at a pH of 4.5 ~ 5.5 and a temperature of 20 ℃ ~ 40 ℃ and a concentration of 0.1 ~ 0.45. It features.

In the present invention, the second washing step 18 is characterized in that the spray method and the precipitation method are sequentially performed for 110 to 130 seconds at room temperature with a pH of 5.5 to 7.5 and a conductivity of 1 kPa to 50 kPa, respectively.

In the present invention, the drying step 20 is characterized in that for injecting air in a spray method for 200 to 240 seconds at a pressure of 2 ~ 3㎏ / ㎠ at room temperature.

In the present invention, the electrodeposition step 22 is characterized in that the coating is precipitated in the water-soluble acrylic electrodeposition paint for 110 to 130 seconds at a temperature of 25 ℃ to 30 ℃ to form a coating film on the coating.

In the third washing process 24 in the present invention, the spray method and the sedimentation method are sequentially performed for 110 to 130 seconds at room temperature in order to recover the paint remaining on the surface of the object to be coated, thereby improving the water droplets on the coating surface. For the pH of 5.5 ~ 7.5 and the conductivity of 1㏁ ~ 50㏁, the spray method and the precipitation method are performed sequentially for 110 to 130 seconds at room temperature, respectively.

In the present invention, the baking step 26 is characterized in that for 18 to 22 minutes at 170 ℃ ~ 185 ℃.

According to the present invention, by forming a coating film using an acrylic one-component pretreatment and paint without phosphate, it is possible not only to prevent environmental pollution caused by phosphate, but also to chemical properties such as acid resistance, hot water resistance, corrosion resistance, and adhesion. It is possible to obtain a product having excellent mechanical properties such as impact resistance and flexibility.

1 is a process chart showing a white electrodeposition coating method according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, particular advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings and the preferred embodiments thereof.

Prior to this, the terms or words used in this specification and claims should not be interpreted in a conventional and dictionary sense, and the inventors may appropriately define the concept of terms in order to best explain the invention in the best way. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

It should be noted that, in the present specification, the same reference numerals are used to denote the same elements in the drawings, even if they are shown in different drawings.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an overall process chart showing a white electrodeposition coating method according to an embodiment of the present invention.

Referring to Figure 1, the white electrodeposition coating method according to an embodiment of the present invention is a total inspection and raking (Raking) 10, degreasing step 12, the first washing step 14, the chemical coating process (16) And a second washing process 18, a drying process 20, an electrodeposition process 22, a third washing process 24, a baking process 26 and an un-lacing 28. .

When the product to be subjected to electrodeposition coating (that is, the object to be coated) is received, the electrostatic inspection and the raking 10 perform inspection of unidentified products among the received products, and work of the electrodeposition coating system on the finished products. Rakes on the work bar and puts it in the electrodeposition coating process.

After the total inspection and the raking 10, a degreasing process 12 for removing various foreign matters and oils on the surface of the coated object is performed.

The degreasing step 12 is a process for preventing a non-uniform surface treatment film from being formed on the coated object due to oil stains, oils and other impurities remaining on the surface of the coated object. 2 preliminary degreasing 122 and the main degreasing 123, the first preliminary degreasing 121, the second preliminary degreasing 122 and the main degreasing 123 are performed sequentially.

At this time, the first preliminary degreasing 121 is a BN (BN) cleaner, which is an electrolytic / precipitating degreasing agent for alkali metals and nonmetals, which does not contain phosphate among electrolytic / precipitating degreasing agents for metals and nonmetals, at a temperature of 50 ° C. to 65 ° C. It is a process of removing various foreign matters and oils on the surface of the to-be-painted object by spraying on the surface of a to-be-painted object for 110 to 130 second, preferably 120 second at a pressure of -1.2 kg / cm <2>.

In addition, the second preliminary degreasing 122 precipitates the coating material in a BN cleaner (ie, a degreasing solution) at a temperature of 50 ° C. to 65 ° C. for 110 to 130 seconds, preferably 120 seconds. After the preliminary degreasing 121 is a process of removing the foreign matter and oil remaining in the coating.

In addition, the degreasing 123 is a process of completely removing foreign substances and oil from the coated material by precipitating the coated material in the degreasing solution at a temperature of 50 ° C. to 65 ° C. for 110 to 130 seconds, preferably 120 seconds.

After the degreasing step 12, the surface of the coating object is washed with tap water or pure water (Deiomized Water) to perform a first washing step 14 for removing residual degreasing solution and alkali components adhering to the surface of the coating object.

Such a first water washing step 14 is a first water washing (141). It consists of the 2nd water washing 142 and the 1st pure water washing 143, and the 1st water washing 141 is carried out. The second water washing 142 and the first pure water washing 143 are performed sequentially.

The first water washing 141 is water-washed the coating material in a spray method for 110 ~ 130 seconds, preferably 120 seconds at room temperature after the degreasing 123 to remove impurities and alkali components adhering to the surface of the coating material It is a process to do it.

The second water washing 142 after the first water washing (141) by precipitating the coating material in the wash water (ie, water) for 110 ~ 130 seconds, preferably 120 seconds at room temperature after the first water washing (141) It is a process of removing impurities and alkali components remaining on the surface of the workpiece.

The first pure water 143 is a process for removing impurities adhering to the surface of the coated object after the second water washing 142 and preventing contamination of the chemical conversion film pretreatment agent. , 1㏁ ~ 50㏁) at room temperature to 110 ~ 130 seconds, preferably 120 seconds to precipitate the coating in the wash solution to prevent contamination of the chemical coating agent, and to remove impurities on the surface of the coating It is a process of removal.

After the first washing step 14, the coating is chemically treated to form an insoluble coating crystal on the surface of the coating, to secure the durability and adhesion of the coating, and to block the bond with oxygen in the air to prevent corrosion. A chemical conversion process 16 is performed to improve.

At this time, the chemical conversion process 16 is the surface of the metal, such as steel, zinc, aluminum for 110 ~ 130 seconds, preferably 120 seconds at a pH of 4.5 ~ 5.5, a temperature of 20 ℃ ~ 40 ℃ and a concentration of 0.1 ~ 0.45 It is a process of precipitation on NT-1, a zirconium (Zr) type reactive pretreatment free of phosphate for treatment.

After the chemical conversion process 16, a second washing process 18 for washing impurities and chemical conversion components on the surface of the coating object is performed.

In this case, the second washing process 18 is composed of a second pure water 181 and a third pure water 182, the second pure water 181 and the third pure water 182 is performed sequentially. .

The second pure water 181 is sprayed in the washing method by a spray method for 110 to 130 seconds, preferably 120 seconds at room temperature with a pH of 5.5 ~ 7.5 and a conductivity of 50 kPa or less (that is, 1 kPa to 50 kPa). It is a process of washing impurities and chemical conversion film components on the surface of the workpiece.

The third pure water 182 is a pH of 5.5 ~ 7.5 and the conductivity of less than 50㏁ (ie 1 (~ 50㏁) at room temperature 110 ~ 130 seconds, preferably 120 seconds in the wash liquid It is a process to prevent contamination of the electrodeposition liquid by completely removing impurities on the surface of the workpiece by precipitation.

After the second washing process 18, by spraying the air in a spray method for 200 to 240 seconds, preferably 220 seconds at a pressure of 2 ~ 3㎏ / ㎠ at room temperature may cause problems in the quality of the coating after electrodeposition A drying process 20 is performed to completely remove moisture.

After the drying step 20, an electrodeposition step 22 for forming a coating film on the object to be coated is performed.

At this time, the electrodeposition step 22 is precipitated in the ACED # 2000 white water-soluble acrylic electrodeposition paint 110 to 130 seconds, preferably 120 seconds at a temperature of 25 ℃ ~ 30 ℃ between the coating and the counter electrode It is a process of forming a coating film of a reference value on a to-be-painted object by energizing a direct current.

After the electrodeposition step 22, a third washing step 24 is performed to improve the appearance of the coated object and to recover the paint.

In this case, the third water washing step 24 includes a first UF water washing 241, a second UF water washing 242, a fourth pure water washing 243, and a fifth pure water washing 244, and the first UF washing with water. 241, the second UF washing 242, the fourth pure tax 243, and the fifth pure tax 244 are performed sequentially.

The first UF water washing (241) is a process of improving the appearance of the coating and recovering the paint remaining on the surface of the coating by water washing the coating in a spray method for 110 to 130 seconds, preferably 120 seconds at room temperature to be.

The second UF water washing 242 is a process of precipitating the coating material in the washing solution for 110 to 130 seconds, preferably 120 seconds at room temperature, thereby improving the appearance of the coating material and recovering the paint remaining on the surface of the coating material. .

The fourth pure water (243) is a spray of the coating method for 110 ~ 130 seconds, preferably 120 seconds at room temperature with a pH of 5.5 ~ 7.5 and a conductivity of 50 kPa or less (that is, 1 kPa to 50 kPa). It is a process to improve the appearance of the coated object by washing with water and to improve the water droplet on the surface of the coating.

The fifth pure water 244 is a pH of 5.5 ~ 7.5 and the conductivity of 50 ℃ or less (that is, 1 ~ 50 ~) at room temperature 110 ~ 130 seconds, preferably 120 seconds It is a process to improve the appearance of the coated material by precipitation and to improve the water droplet on the surface of the coating.

After performing the third washing process 24, the coating material is placed in a baking system using electricity as a heat source, and then the coating material is heated at 170 ° C. to 185 ° C. for 18 to 22 minutes, preferably 20 minutes. The baking step 26 is carried out to dry.

Thereafter, the dried coating in the baking system is separated from the work bar and inspected to move a product having no reason for quality defect to the packaging process.

Looking at the coating conditions for proceeding the white electrodeposition coating method according to an embodiment of the present invention, the coating voltage is 70V ~ 350V, the coating time is 110 ~ 130 seconds, preferably 120 seconds, 170 ℃ ~ 185 ℃ When dried for 15 to 25 minutes, preferably 20 minutes at a temperature can be obtained a coating film of 25㎛ 35㎛.

On the other hand, when performing the white electrodeposition coating method according to an embodiment of the present invention under the coating conditions as described above to obtain the properties shown in Table 1 below.

Item Test Methods characteristic Glossy (60 °) 50-70 Hardness 1H ~ 2H Hot water resistance 98 ± 2 ℃, 1 hour Good Acid resistance 20 ± 2 ℃, 10% Acetic Acid 48 hours Adhesion Cross cut (1㎡, 100EA) 100/100 Corrosion resistance 5% NaOH, 35 ° C., 10 times Good Impact resistance 1000g × 40cm × 1/2 Extensibility 5 mm Flexibility φ8.0mm

As described above, the white electrodeposition coating method according to the embodiment of the present invention can not only prevent the environmental pollution caused by phosphate by forming a coating film using an acrylic one-component pretreatment agent and a paint that is free of phosphate, but also acid resistance, hot water resistance, Chemical products such as corrosion resistance and mechanical properties such as adhesion, impact resistance, and bendability can be obtained.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. And changes may be made without departing from the spirit and scope of the invention.

10: all inspection and raking 12: degreasing process
14, 18, 24: washing process 16: chemical conversion process
20: drying step 22: electrodeposition step
26: Baking Process 28: Un-Raking and Inspection
121, 122: preliminary degreasing 123: main degreasing
141, 142: defensive 143, 181, 182, 243, 244: pure tax
241, 242: UF defensive

Claims (9)

Degreasing step (12) of removing foreign matter and oil remaining on the surface of the coating material to prevent the non-uniform surface treatment film is formed on the coating material of the metal material;
A first washing step (14) of washing the surface of the coating material subjected to the degreasing step (12) to remove residual degreasing solution and alkali components adhering to the surface of the coating material;
A chemical conversion coating step (16) of forming a film with a zirconium-type reactive pretreatment agent to improve durability, corrosion resistance, and adhesion of the surface of the coating material subjected to the first washing step (14);
A second washing step (18) of washing the surface of the coating material subjected to the chemical conversion coating step (16) to remove impurities and the chemical conversion film remaining on the surface of the coating object;
A drying step (20) of drying the surface of the coated object that has passed through the second washing step (18) with air;
An electrodeposition process 22 for forming a coating film with an acrylic electrodeposition paint on the surface of the coated object which has been subjected to the drying process 20;
A third washing step (24) for recovering the paint remaining on the surface of the coated object which has passed the electrodeposition step (22); And
And a baking step (26) of drying the coated object which has passed through the third washing step (24). The method according to claim 1,
The degreasing step 12,
The BN cleaner, an electrolytic / precipitating degreasing agent for alkali metals and nonmetals, is removed at 110 to 130 seconds at a temperature of 50 to 65 ° C. at a pressure of 1 to 1.2 kg / cm 2 to remove foreign substances and oil from the surface of the coated object. A first preliminary degreasing 121 sprayed on the surface of the paint by a spray method;
A second preliminary degreasing 122 in which the coated material is precipitated in the degreasing solution for 110 to 130 seconds at a temperature of 50 ° C. to 65 ° C. to remove foreign substances and oil remaining in the coated object; And
White electrodeposition process characterized in that it comprises a main degreasing (123) to be precipitated in the degreasing liquid 110 ~ 130 seconds at a temperature of 50 ℃ ~ 65 ℃ to remove foreign matter and oil on the surface of the workpiece . The method according to claim 1,
In the first washing process 14, the spray method and the precipitation method are sequentially performed for 110 to 130 seconds at room temperature so that impurities and alkali components adhering to the surface of the coated object are removed, respectively, pH of 5.5 to 7.5, 1 White electrodeposition process method characterized in that the coating material is precipitated in the wash liquor for 110 ~ 130 seconds at room temperature with a conductivity of ㏁ ~ 50㏁. The method according to claim 1,
The chemical coating process 16 is characterized in that the coating material is precipitated in the zirconium-type reactive pretreatment for 110 ~ 130 seconds at a pH of 4.5 ~ 5.5, a temperature of 20 ℃ ~ 40 ℃ and a concentration of 0.1 ~ 0.45 White electrodeposition process method. The method according to claim 1,
In the second washing process 18, the spray method and the precipitation method are sequentially performed for 110 to 130 seconds at room temperature with a pH of 5.5 to 7.5 and a conductivity of 1 to 50 Hz, respectively. . The method according to claim 1,
The drying step 20 is a white electrodeposition process method characterized in that for spraying the air in a spray method for 200 ~ 240 seconds at a pressure of 2 ~ 3kg / ㎠ at room temperature. The method according to claim 1,
The electrodeposition step 22 is a white electrodeposition process method characterized in that the coating is precipitated in the water-soluble acrylic electrodeposition paint for 110 to 130 seconds at a temperature of 25 ℃ ~ 30 ℃ to form a coating film on the coating. The method according to claim 1,
In the third washing process 24, the spray method and the sedimentation method are sequentially performed for 110 to 130 seconds at room temperature to recover the paint remaining on the surface of the coated object. White electrodeposition process method characterized in that the spray method and the precipitation method is performed sequentially for 110 ~ 130 seconds at room temperature with a pH of 7.5 and 1㏁ ~ 50㏁. The method according to claim 1,
The baking step 26 is white electrodeposition process method characterized in that for 18 to 22 minutes at 170 ℃ ~ 185 ℃.

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