KR101636023B1

KR101636023B1 - flushing water for prevent rust using metal pre-treatment

Info

Publication number: KR101636023B1
Application number: KR1020150183950A
Authority: KR
Inventors: 오덕진; 오상민; 김봉철
Original assignee: 삼양화학산업 주식회사
Priority date: 2015-12-22
Filing date: 2015-12-22
Publication date: 2016-07-04

Abstract

The present invention provides flushing water for metal pretreatment for corrosion prevention which removes residues of treatment liquid and process byproducts from a surface of an object to be coated in pretreatment processes including an oxide film removal process, a degreasing process, and a film treatment process to minimize corrosion of a metal surface during the pretreatment processes to improve quality of electro-deposition coating. The flushing water for metal pretreatment for corrosion prevention comprises 0.0001-10 wt% of a mixture of one or more selected from a group consisting of acrylamide, sebacic acid, and triethanolamine based on 100 wt% of water, maintains a pH range of 5-14, and further comprises 0.01-10 wt% of a mixture of one or more selected from a group consisting of octylphenol ether, ethoxylated octylphenol, and ethoxyl-oxidized nonylphenol.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flushing water for preventive rust using metal pre-

The present invention relates to a water treatment water for metal pretreatment for preventing corrosion and a pretreatment method to which the metal pretreatment water is applied. More specifically, the present invention relates to a water pretreatment method for metal pretreatment for corrosion prevention which minimizes corrosion of a metal surface during a pretreatment process, And the pretreatment method to which he applies.

Generally, in order to coat a surface of a metal such as iron or zinc material, an oxide film removing process, a degreasing process, a primary washing process, a surface adjusting process, a phosphate coating process process, a secondary washing process, And the coating process is continuously performed after the pretreatment process to improve the corrosion resistance, adhesion and durability of the coating.

Here, the oxide film and the carbonized film formed on the metal surface during the process such as welding or heat treatment through the oxide film removing process can be removed, and the contaminants such as metalwork oil and anti-rust oil can be removed through the degreasing process.

The phosphate coating treatment process is one of widely used methods for pretreating metal, and is a method of chemically treating a metal surface to form a compound coating having high stickiness and stability on its surface. Prior to such a phosphate coating process, most of the surface conditioning process using a surface modifier is performed to activate the metal surface.

At this time, the quality of the coating process or the coating process can be improved by removing the degreasing agent or the oxide film remover used in each process through the washing process between each process.

Conventionally, a strongly acidic solution such as hydrochloric acid or sulfuric acid has been used for the oxide film removing process. However, when a strongly acidic solution is used, the generation of acid vapor and the acid solution remaining on the surface contaminate the front and rear process, There was a problem of exposure to the environment.

Recently, automobile parts are used as separate parts or welded with various kinds of materials such as iron and non-ferrous metals, alloys, and plating materials for the purpose of reducing fuel consumption and improving the strength and durability of the car body. Are simultaneously injected into the pretreatment and painting process. At this time, when the strongly acidic solution as in the past is used, there is a problem that plating is removed or issued by excessive corrosion depending on the material of each part.

Here, in the process using the oxide film remover, the deposition and spraying time are 2 minutes in short, 5 minutes or longer depending on the conveyor speed of the coating line and the tank deposition capacity. As a result, there is a problem that the waiting time between processes is increased and rust is formed on the surface of the washed metal after the treatment through each process.

In detail, in cold rolled steel sheet (CR) washed after each pretreatment process such as removal of oxide film, degreasing, coating, etc., white rust was generated in red rust and galvannealed steel sheet (GA), and coarse fine powder / A large amount of wrinkles or unevenness that can be visually recognized when the metal is painted is formed, and the productivity is lowered due to the loss of the material.

Korean Patent No. 10-1295679

In order to solve the above problems, it is an object of the present invention to provide a water treatment water for metal pretreatment for preventing corrosion which minimizes corrosion of metal surfaces during a pretreatment process and a quality of electrodeposition coating is improved, and a pretreatment method applied thereto.

In order to solve the above-mentioned problems, the present invention provides a process for removing corrosion of a surface of an object to be coated, comprising removing an oxide film removing process, a degreasing process, and a coating process, In the water for washing metal, 0.0001 to 10 parts by weight of one or more selected from the group consisting of acrylamide, sebacic acid and triethanolamine is contained in 100 parts by weight of water, , Octyl phenol ether, ethoxylated octyl phenol, and ethoxyl nonyl phenol, and at least one member selected from the group consisting of ammonium molybdate, sodium molybdate, borax, isopropyl amine, methylene Amines, ethanolamines, propylamines, butylamines, and compounds thereof. And 0.01 to 10 parts by weight of at least one member selected from the group consisting of sodium diphosphate, sodium dibasic, sodium dibasic, potassium dibasic, potassium dibasic and mixtures thereof. To provide a water treatment water for metal pretreatment for corrosion prevention.

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A first step in which the coated object is subjected to an oxide film removing process using an oxide film remover having a pH of 1 to 10; A second step of degreasing the coated object by a degreasing agent; Wherein the treated object to be treated to remove the oxide film remover and the remnants of the degreasing agent and the process by-products is at least one selected from the group consisting of tolithriazole, benzotriazole, triazole, acrylamide, sebacic acid and triethanolamine A third step of treating the water with water containing water in an amount of 0.0001 to 10 parts by weight, A fourth step in which the coating material is treated with a chemical conversion coating solution at a free acid pH of 0.7 to 1.1, a degree of acidity of 19 to 21, and an acceleration of 2.5 to 3.5 so that an insoluble chemical conversion coating is formed on the surface of the coating object activated by the surface conditioner; And a fifth step of washing the coated object with the wash water so as to remove residues and process by-products of the chemical conversion coating liquid.

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A first step of degreasing the coated object with a degreasing agent; Wherein the treated object to be treated to remove the remnants of the degreasing agent and the process by-products is selected from the group consisting of toluic acid, Or a mixture of two or more of the above components in an amount of 0.0001 to 10 parts by weight; A third step in which the coated object is subjected to an oxide film removing process using an oxide film remover having a pH of 1 to 10; A fourth step in which the coated object is washed with the wash water so that the residue of the oxide film remover and the process by-products are removed; A fifth step in which the coating material is treated with a chemical conversion coating solution so that an insoluble chemical conversion coating is formed on the surface of the coating object activated by the surface conditioner at a free acid pH of 0.7 to 1.1, a computer numerical value of 19 to 21, and an acceleration degree of 2.5 to 3.5; And a sixth step of washing the coated object with the wash water so as to remove residues of the chemical conversion coating liquid and process byproducts. The pretreatment method is applied to a pretreatment method for metal pretreatment for corrosion prevention.

Through the above solution, the water treatment water for metal pretreatment for prevention of corrosion of the present invention and the pretreatment method to which it is applied provide the following effects.

First, water is added to the water washing process between the pretreatment steps such as oxide film removal, degreasing, and coating treatment, in which rust preventive substances such as tolytriazole, benzotriazole, triazole, acrylamide, sebacic acid and triethanolamine are added The occurrence of corrosion of the object to be coated due to contact with moisture / atmosphere can be reduced and the quality of the coating and electrodeposition coating can be improved.

Secondly, as the occurrence of corrosion of the coating object due to contact with moisture is reduced, a more precise washing process can be performed after the removal of the oxide film and the degreasing process, so that the deterioration of the purity of the chemical conversion coating liquid due to the process residue during the coating process of the coating target is minimized So that the processing cost can be reduced along with improvement of the coating film quality.

Third, since the penetrating substance such as monoethylene glycol added to the washing water improves permeability to rust preventive substance such as triethanolamine, even a coated object having a complicated shape can be treated with uniform corrosion prevention even to a fine portion including fine grooves on the surface It is possible to provide a synergy effect that remarkably improves the quality of coating treatment and electrodeposition coating.

Fourth, addition of a reducing material such as sodium molybdate in addition to a rust inhibitive substance such as triethanolamine in the washing water can significantly increase the corrosion resistance of the coating target, and it is possible to improve the corrosion resistance of the coating target with high quality electrodeposition Painting is possible.

FIG. 1 is a flow chart illustrating a pretreatment method applied with water wash water for metal pretreatment to prevent corrosion according to an embodiment of the present invention. FIG.
FIG. 2 is a photograph showing a state of a film and an electrodeposition state formed by a pretreatment process to which water for washing a metal for pretreatment for corrosion prevention according to an embodiment of the present invention is compared with a conventional example. FIG.
3 is a flow chart illustrating a pretreatment method to which water for washing metal pretreatment is applied to prevent corrosion according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the present invention are shown.

FIG. 1 is a flowchart illustrating a pretreatment method applied with water wash water for metal pretreatment to prevent corrosion according to an embodiment of the present invention.

As shown in FIG. 1, the pretreatment method to which the pretreatment water for metal pretreatment for corrosion prevention according to an embodiment of the present invention is applied includes an oxide film removing step (s10), a degreasing step (s20), a primary washing step (s30) A treatment step (s50), and a secondary water washing step (s60).

At this time, the water for washing the metal pretreatment is used in the first washing step (s20) after the degreasing step and the second washing step (s30) after the coating processing step. After the last washing step, pure water The process (s70), the drying process, the electrodeposition coating process (s80), and the like can be performed.

First, the coated object is subjected to an oxide film removing process at 40 to 60 ° C for 2 to 5 minutes by an oxide film remover having a pH of 1 to 10 (s10). At this time, the oxide film removing agent may be a neutral type or an acid type formed by compounding a phosphate compound, a chelating agent, a reducing agent, etc., and may be used in a hot bath. That is, the object to be coated may be immersed in the oxidized film removing liquid in which the oxide film removing agent has been dried for 2 to 5 minutes to remove the oxide film.

Here, the object to be coated means a part provided with a cold-rolled steel sheet CR, a galvanized steel sheet GA, an electro-galvanized steel sheet GI, a hot-dip galvanized steel sheet GI, It is also possible that a part is formed, or a plurality of materials are combined through welding or the like.

At this time, an oxide film or a carbonized film formed by mixing and bonding iron (Fe) oxide, zinc (Zn) oxide, P (phosphorus) oxide, manganese (Mn) .

Since the oxide film or the carbonized film is not coated, the oxide film or the carbonized film may be removed to uniformly form a coating on the surface of the coated object to improve the paint properties.

Then, the coated object subjected to removal of the oxide film is degreased at 40 to 50 DEG C for 3 to 5 minutes by a degreasing agent (s20).

At this time, foreign substances such as various kinds of processing oil and dust are present on the surface of the painting target object, and the foreign matter attached due to the oils and fats and oils can be removed through the degreasing treatment. Here, the degreasing agent may be an alkaline degreasing agent or an alkali emulsion degreasing agent obtained by mixing a surfactant degreasing agent, an alkaline degreasing agent, and a surfactant degreasing agent.

On the other hand, the degreased coated object is washed with the water for washing metal pretreatment at room temperature for 2 to 6 minutes (s30).

At this time, the process by-products such as the oxide film remover and the remnants of the degreasing agent, the oxide film and the oil separated in the oxide film removing process and the degreasing process can be removed through the water washing process.

In addition, the water washing treatment may be performed by immersion or spraying, and in the case of spraying, the spraying pressure on the surface of the coating body is preferably set to 0.5 to 2 atm.

Herein, the water washing water is preferably added to 100 parts by weight of water in the presence of at least one selected from the group consisting of Tolytriazole, Benzotriazole, Triazole, Acrylamide, Sebacic acid, Triethanolamine), and 0.0001 to 10 parts by weight of a mixture of two or more thereof.

That is, the washing water may be a rust preventive substance such as Tolytriazole, Benzotriazole, Triazole, Acrylamide, Sebacic acid, Triethanolamine, Means that the water is added to water, and the water is preferably provided as industrial water.

For example, the wash water may be formed by adding 0.001 to 100 kg of the rust preventive substance to 1000 kg of industrial water.

At this time, the use of the rinse water containing the rust preventive material can reduce the occurrence of corrosion of the paint object due to contact with moisture during the water washing process, and the occurrence of corrosion of the paint object due to contact with the atmosphere during the process wait time after the water rinse process .

Also, in the case where various process-by-products, such as an oxide film remover and a remover of a degreasing agent, remain on the surface of the coating target, the quality of the coating process may deteriorate due to the lowered purity of the chemical coating liquid used for the coating process. And thus the process cost can be increased.

At this time, as the rust preventive material contained in the wash water reduces the occurrence of corrosion of the object to be coated due to contact with moisture at the time of flushing, a more precise flushing process can be performed without causing corrosion.

Accordingly, it is possible to minimize the deterioration of the purity of the chemical film due to the process residue generated during the oxide film removing process and the degreasing process in the chemical film forming process, thereby improving the quality of the chemical film coating process. It is possible to provide an effect of reducing the process cost.

In addition, the pretreatment process is performed in a large quantity by an automated line in which individual processes are sequentially applied in accordance with movement of a coating object through a conveyor belt or the like. Due to the difference in time required for each process, the coating object is inevitably exposed to the atmosphere .

The corrosive part of the coating object generated by the atmospheric exposure appears as red rust in the cold rolled steel sheet (CR) and white rust in the galvanized steel sheet (GA), which interferes with the uniform formation of the coating with a substrate similar to the oxide film, It causes wrinkles and stains.

At this time, the water-repellent water can protect the surface of the object to be coated from corrosion, thereby preventing the occurrence of corrosion parts such as red rust and white rust, and it is possible to provide a uniform coating treatment and to improve the quality of electrodeposition painting.

On the other hand, the washed coated object is subjected to coating treatment (s50) through a surface adjusting step (s40) in which the surface is treated with a surface adjusting agent at a pH of 8 to 11 and at a room temperature for 2 to 6 minutes.

Here, the number of active points can be increased on the surface of the coating object through the surface adjustment process, and coarsening of the coating film formed on the surface can be prevented, and a dense chemical film can be formed. At this time, the facial expression control agent may be formed of titanium oxide, a nano-sized zinc phosphate salt solution or the like, and is sprayed onto the surface of the coating object by using a DI water or the like.

In addition, the chemical conversion coating liquid is provided in a slightly acidic state, in which the zinc phosphate coating agent and the accelerator are dry-baked, and the chemical conversion coating liquid has a glass transition point of 0.7 to 1.1, a degree of computerization of 19 to 21, a degree of acceleration of 2.5 to 3.5, It is immersed in the coating liquid for 2 to 4 minutes to form an insoluble chemical conversion coating, that is, a zinc phosphate coating on the surface.

Then, the coated object is washed with water containing rust preventive material such as triethanolamine at room temperature for 2 to 4 minutes so as to remove the remnants of the chemical conversion coating liquid and process by-products from the surface (s60) (S70) and a drying step (s80).

FIG. 2 is a photograph showing a state of a coating film and an electrodeposition state formed by a pretreatment process to which water for washing a metal for pretreatment is applied to prevent corrosion according to an embodiment of the present invention.

Here, when water containing water containing a rust inhibitive substance is used in the water washing step, the surface state after coating and the electrodeposition coating can be visually identified and the corrosion inhibiting ability can be grasped.

That is, when the water wash of the present invention is applied to the water washing process, the surface of all coated objects provided with the cold-rolled steel sheet CR, the galvanized steel sheet GA, the galvanized steel sheet EGI and the hot-dip galvanized steel sheet GI It can be seen that the generation amount of red rust, white rust and the like and the resulting wrinkles and stain generation on the electrodeposited coating surface are remarkably reduced.

Test Items Required quality Test Methods stamp Coat
condition Pinhole, crawling, crater without smoothing Visual inspection Attachment Should be M-2.5 or higher Go Scale Test Bug
Gigantic There should be no film crack and peeling injury 1/2 inch 500g Falling 50cm of the collapse Water resistance There should be no abnormalities such as softening of the film, bulging, peeling, etc., and the secondary adhesion property should be M-2.5 or higher. 40 ± 1 ° C, 240 hours immersion Coating treatment Salt water silent Specified time No more than 1mm (one side) from the cross cut part after salt spray, no rusting, swelling, etc. Within 1 hour Peel off from the cross cut part during tape test should be within 3mm (one side) Continuous spray of 5% brine for 800 hours on the sample

Table 1 shows test items, evaluation methods, and test methods for confirming the quality of the outer appearance of the coating and electrodeposition coating. The test items, evaluation methods and test methods are described in "KS D ISO 3520, Coated Hot- KS M ISO 2409 paint test method, salt spray test of KS D 9502D ".

Item Material Surface treatment method Existing water use products Comparison 1 Comparison 2 Comparison 3 Comparison 4 Visual inspection CR Rustic Rustic Good Good GA White Chung White Chung White Chung White Chung GI White Chung White Chung White Chung White Chung EGI White Chung White Chung White Chung White Chung Impact resistance CR Bad Bad Bad Bad GA Good Bad Bad Bad GI Bad Bad Bad Bad EGI Bad Bad Bad Bad Attachment CR Good Good Good Good GA Good Bad Bad Bad GI Good Good Good Good EGI Good Good Good Good Water resistance CR Good Good Good Good GA Good Bad Bad Bad GI Good Good Good Good EGI Good Good Good Good Brine
Split CR Bad Bad Good Good

Table 2 summarizes the results of Table 2 for the specimens prepared by cold-rolled steel (CR), galvanized galvanized steel (GA), electrogalvanized steel sheet (EGI) and hot-dip galvanized steel sheet (GI) The results are shown in Fig.

Here, the visual inspection was performed on the coated sample after the completion of the pretreatment process, and the impact resistance test, the adhesion test, the water resistance test, and the salt water abstraction test were performed on the electrodeposited sample.

At this time, each of the samples used in Comparative Examples 1 to 4 was provided in the same shape and area, and was subjected to an oxide film removal, degreasing, first washing, surface conditioning, coating, second washing, .

In Comparative Examples 1 and 2, the oxide film remover was set at a temperature of 50 ° C., and the oxide film remover was performed for 3 minutes each at a rate of 5% and 10%, respectively. In the first and second washing processes, As shown in Fig.

Comparative Example 3 shows the results of using industrial water of pH 10 in which caustic soda was added to the primary and secondary water washing steps under the same conditions as Comparative Example 1, And the ratio of the humidification to 10%.

As shown in Table 2, the bath ratio of the oxide remover did not affect the appearance of the sample coating. In the case where the alkaline industrial water was used in the first and second water washing processes, (CR), but it is difficult to apply it to the pretreatment process of the composite product because it shows no improvement in the samples of other materials.

That is, red rust or white rust was found in the coatings of all the samples except for CR materials using alkali industrial water, and the occurrence of stains after electrodeposition coating can be confirmed in all samples in which red rust or white rust was generated.

In addition, most of the samples showed poor quality in terms of impact resistance, although the adhesion of the electrodeposition coating and the water resistance were found to be mostly good.

Item Material Surface treatment method The water-washable product of the present invention Practice 1 Practice 2 Practice 3 Practice 4 Conduct 5 Conduct 6 Visual inspection CR Good Good Good Good Good Good GA Fine White Chung Fine White Chung Fine White Chung Fine White Chung White Chung Fine White Chung GI Fine White Chung Good Good Fine White Chung White Chung Good EGI Good Good Good Fine White Chung Good Good Impact resistance CR Good Good Good Good Good Good GA Good Good Good Good Good Good GI Good Good Good Good Good Good EGI Good Good Good Good Good Good Attachment CR Good Good Good Good Good Good GA Good Good Good Good Good Good GI Good Good Good Good Good Good EGI Good Good Good Good Good Good Water resistance CR Good Good Good Good Good Good GA Good Good Good Good Good Good GI Good Good Good Good Good Good EGI Good Good Good Good Good Good Brine
Split CR Good Good Good Good Good Good

Table 3 shows the results of the evaluation of the coating film appearance and the electrodeposition coating of the samples prepared by using cold-rolled steel (CR), galvannealed steel sheet (GA), electrogalvanized steel sheet (EGI) and hot-dip galvanized steel sheet (GI) The results are shown in Fig.

Each of the samples used in Examples 1 to 6 was provided in the same shape and area and was subjected to electrodeposition coating through removal of oxide film, degreasing, first water washing, surface conditioning, coating, second water washing, However, the water washing water of the present invention is applied to primary water washing and secondary water washing.

In Examples 1, 2, and 3, the samples were immersed for 3 minutes in a state where the temperature of the bath for drying the oxide film remover was 40 ° C and the bath ratio was 5%, and water for industrial use 0.1 part by weight, 0.2 part by weight, and 0.3 part by weight of rust preventive substance were added to the weight parts, respectively.

The fourth embodiment shows the result of changing the ratio of the bath ratio of the oxide film remover to 10% under the same conditions as those of the first embodiment. The fifth embodiment is a result of changing the bath temperature of the oxide film remover to 50 캜 And the sixth embodiment shows the results obtained by changing the treatment time to 5 minutes under the same conditions as in the first embodiment.

As shown in Table 3, irrespective of the bath temperature, the ratio, and the immersion time of the oxide film remover, the improvement effect of the appearance test results on samples of all the raw materials with the rust-preventive material added with the rust-preventive substance can be confirmed.

That is, most of the red rust and white rust were removed from the samples of the cold rolled steel sheet (CR), the electro galvanized steel sheet (EGI) and the hot dip galvanized steel sheet (GI) after the coating treatment, and in the case of the galvannealed steel sheet It can be seen that the amount of white rust was reduced.

Furthermore, it can be confirmed that the measurement results of impact resistance, adhesion, water resistance, and salt water repellency except for the appearance inspection all show a satisfactory state.

As described above, it is possible to improve the quality of coating and electrodeposition coating only by putting a rust preventive material such as toluic acid, benzotriazole, triazole, acrylamide, sebacic acid, and triethanolamine in the washing water used in general pre- It can be easily applied to various automation lines, so that compatibility of products can be improved.

Furthermore, since it is possible to improve the quality of coating and electrodeposition coating on all kinds of materials such as cold rolled steel (CR), galvannealed steel sheet (GA), electro galvanized steel sheet (EGI) and hot dip galvanized steel sheet (GI) It is possible to provide a base technology capable of simultaneously pretreating a composite component.

Meanwhile, in the pretreatment process including the oxide film removing process, the degreasing process, and the coating process, the water for the pretreatment of metal is removed from the surface of the object to be coated and the process by- To an appropriate temperature for the subsequent process.

Here, the term treatment liquid for each process is preferably understood to mean that the oxide film remover includes a dried oxide film remover, a degreasing solution in which a degreasing agent is dry-etched, and a chemical film film used for film treatment, and the process by- The oxide film constituent material removed through the degreasing process, and the fuels foreign matter separated through the degreasing process.

At this time, the wash water contains 0.0001 to 10 parts by weight of one or more than one selected from the group consisting of toluitriazole, benzotriazole, triazole, acrylamide, sebacic acid and triethanolamine per 100 parts by weight of water do.

That is, the wash water refers to water to which a rust preventive substance such as tolyltriazole, benzotriazole, triazole, acrylamide, sebacic acid, triethanolamine is added, and the water is fresh water and salt water, , Processed water, distilled water, deionized water, softened water, ground water, rainwater, and drinking water, and is preferably provided with industrial water. For example, the wash water may be provided by adding 0.001 to 100 kg of rust preventive material to 1000 kg of industrial water.

If the amount of the rust preventive material is less than 0.0001 part by weight, there is a possibility that the anticorrosion function is degraded. If the rust preventive substance is more than 10 parts by weight, the rust preventive material may be deposited on the surface of the paint target.

It is more preferable that the wash water includes 0.1 to 4 parts by weight of the rust preventive material. That is, the washing water contains 0.1 to 4 parts by weight of at least one selected from the group consisting of toluitriazole, benzotriazole, triazole, acrylamide, sebacic acid and triethanolamine per 100 parts by weight of water To maintain the pH in the range of 5 to 14. [

At this time, if the amount of the rust preventive substance such as tolylthiazole, benzotriazole, triazole, acrylamide, sebacic acid, triethanolamine and the like added to the washing water is less than 0.1 part by weight, there is a possibility that the surface of the paint target object is not uniformly treated If the amount of the anticorrosive material is more than 4 parts by weight, excessive cost for purification and discharge of washing water may be economized, and there is a fear of environmental pollution.

Here, the rust preventive material provides an effect of preventing the corrosion of the object to be coated due to contact with water during the water washing process, and the corrosion of the object to be coated due to contact with the atmosphere in the process waiting time after the water washing process.

In detail, the pretreatment process is performed in a large quantity by an automated line in which individual processes are sequentially applied in accordance with movement of a coating object through a conveyor belt or the like, and the coating target is inevitably exposed to the atmosphere due to a difference in time required for each process .

Further, as the rust prevention material contained in the wash water minimizes the occurrence of corrosion of the coating target due to contact with water during washing, more precise washing process can be performed, and deterioration of the purity of the chemical conversion coating liquid due to the process residue is minimized It is possible to provide the effect of improving the quality of the coating treatment and reducing the process cost.

On the other hand, the wash water may contain disodium phosphate, trisodium phosphate, dipotassium phosphate, tripotassium phosphate, and the like, together with the rust preventive material. And a hardness-adjusting material, which is a mixture of two or more selected from the group consisting of the above-mentioned compounds.

Here, the compound may be selected from the group consisting of sodium hexametaphosphate, sodium pyrophosphate, potassium pyrophosphate, potassium potassium pyrophosphate, sodium polyphosphate, polyphosphoric acid, It is desirable to understand the concept as including Potassium Polyphosphate, Sodium Metaphosphate, and Potassium Metaphosphate.

That is, the wash water may be comprised of 100 parts by weight of water, 0.0001 to 10 parts by weight of a rust preventive material, and 0.01 to 15 parts by weight of the hardness adjusting material, more preferably 100 parts by weight of water, 0.1 To 4 parts by weight and a hardness adjusting material in an amount of 0.01 to 15 parts by weight.

At this time, the hardness adjusting material can soften water by precipitating minerals such as calcium (Ca) and magnesium (Mg) present in the water, and lowers the acidity of water to alkalize the water.

If the hardness adjusting material added to the water washing water is less than 0.01 part by weight, the water softening performance may be deteriorated. If the hardness adjusting material is more than 15 parts by weight, the washing ability may be lowered due to the increase of the water washing water viscosity .

Specifically, the mineral substances contained in the water can form a silica gel, a scale, or the like on the surface of the object to be coated at the time of water washing, and may cause a coating failure and a coating film adhesion deterioration.

In this case, when the water hardness adjusting material is added to the water washing water, water used as the base of the water washing water is used not only as soft water having a small mineral content but also as general industrial water having a high mineral content, Quality can be improved.

Item Material Surface treatment method The water-washable product of the present invention Conduct 13 Practice 14 Conduct 15 Implementation 16 Conduct 17 Conduct 18 Coat state CR Good Good Good Good Good Good GA Bad Bad Good Good Good Good GI Bad Bad Good Good Good Good EGI Good Good Good Good Good Good Attachment CR Good Good Good Good Good Good GA Good Good Good Good Good Good GI Bad Bad Good Good Good Good EGI Good Good Good Good Good Good

Table 4 shows the results of the electrodeposition painting of various samples prepared for cold-rolled steel (CR), galvannealed steel sheet (GA), electrogalvanized steel sheet (EGI), and hot-dip galvanized steel sheet (GI) The results are as follows.

Each of the samples used in Examples 13 to 18 was provided in the same shape and area and was subjected to electrodeposition coating through removal of oxide film, degreasing, first washing, surface conditioning, coating, second washing, And the water washing water of the present invention is applied to the first water washing and the second water washing.

Specifically, in Example 13, the sample was immersed for 3 minutes in a state where the temperature of the bath for drying the oxide film remover was 50 캜 and the bath ratio was 5%, 0.3 parts by weight of rust inhibitor was added to 100 parts by weight of the hard water in the first and second washing steps And Example 14 shows the result of changing the bath ratio of the oxide film remover to 10% under the same conditions as in Example 13. [

In Example 15, the same procedure as in Example 13 was repeated, except that 0.3 part by weight of rust preventive material and 0.1 part by weight of hardness adjusting material were added to 100 parts by weight of hard water in the first and second washing steps. Example 16 shows the result of changing the ratio of the bath ratio of the oxide film remover to 10% under the same conditions as in Example 15, and Example 17 shows the result of changing the bath temperature of the oxide film remover to 40 ° C under the same conditions as in Example 15 , And Example 18 shows the result of changing the immersion time for the oxide film remover to 5 minutes under the same conditions as in Example 15.

As shown in Table 4, when hard water is used as the base of the wash water irrespective of the bath temperature, the ratio and the immersion time of the oxide film remover, the hardness of the galvannealed steel sheet (GA) and the hot dip galvanized steel sheet In the test, spots and wrinkles were found and the state of the poor coating film was confirmed. In the case of the hot-dip galvanized steel sheet (GI), the deterioration of the coating adhesion can be confirmed.

At this time, hard water is used as the base of the wash water, and in addition to the rust preventing substance, disodium phosphate, trisodium phosphate, dipotassium phosphate, tripotassium Phosphate) and a compound thereof were added in an amount of 0.1 part by weight, it was possible to confirm a good coating film state in which no stains and wrinkles were hardly observed in a visual inspection, and a good quality satisfying the reference value was confirmed in terms of adhesion .

As described above, even when the base of the wash water used in the washing process is not a soft water but a light water added with a large amount of mineral matter, the coating quality and the coating quality after the pretreatment process can be improved. Therefore, a separate ionization treatment process The process cost can be reduced and the economical efficiency of the product can be improved.

On the other hand, the wash water may be at least one selected from the group consisting of ammonium molybdate, sodium molybdate, sodium borate, isopropylamine, methyleneamine, ethanolamine, It is preferable to further include 0.01 to 10 parts by weight of a reducing material, which is one or a mixture of two or more selected from the group consisting of propylamine, butylamine and compounds thereof.

That is, the washing water may include 100 parts by weight of water, 0.0001 to 10 parts by weight of a rust preventive material, and 0.01 to 10 parts by weight of the reducing material, more preferably 100 parts by weight of water, 4 parts by weight, and 0.01 to 10 parts by weight of a reducing material.

At this time, the reducing material improves the corrosion resistance of the coating target, thereby preventing corrosion at the time of exposure to air and water. Accordingly, the occurrence of stains and wrinkles due to corrosion at coating and electrodeposition coating can be significantly reduced.

If the amount of the reducing material added to the water washing water is less than 0.01 part by weight, corrosion blocking performance may not be imparted to the whole water washing water. If the reducing material is more than 10 parts by weight, There is a fear that the surface is damaged.

Item Material Surface treatment method The water-washable product of the present invention Conduct 19 Practice 20 Conduct 21 Implementation 22 Coat state
(Per 100 cm <
Average number of stains) CR 0 0 0 0 GA 0.1 0.2 0 0 GI 0.1 0.1 0 0 EGI 0 0.1 0 0

Table 5 shows the results of the electrodeposition painting of each sample provided with cold rolled steel (CR), galvannealed steel sheet (GA), electrogalvanized steel sheet (EGI) and hot-dip galvanized steel sheet (GI) And the state of the coating film after the visual inspection.

Each of the samples used in Examples 19 to 22 was provided in the same shape and area and was subjected to electrodeposition coating after removal of oxide film, degreasing, first washing, surface conditioning, coating, second washing, And the water wash water of the present invention was applied to primary water washing and secondary water washing.

Here, each of the samples is formed of a square plate having a size of 30 cm x 30 cm, and the state of the coating film is calculated by averaging the number of stains generated in the entire area of the sample to 100 cm < 2 >.

Specifically, in Example 19, the sample was immersed for 3 minutes in a state where the bath temperature of the oxide film remover was 40 ° C and the humidification ratio was 5%, and 0.3 parts by weight of a rust inhibitive substance was added to 100 parts by weight of industrial water And Example 20 shows the result of changing the bath ratio of the oxide film remover to 10% under the same conditions as in Example 19. [

In Example 21, the results of using 0.3 parts by weight of rust preventive material and 100% by weight of water reducing agent added to 100 parts by weight of industrial water in the first and second washing steps under the same conditions as in Example 19, Example 22 shows the result of changing the ratio of the dry condition of the oxide film remover to 10% under the same conditions as in Example 21.

As shown in Table 5, when the rust inhibitor was added only to the washing water, the number of stains after electrodeposition coating due to the white rust / red rust portion generated in the sample after the coating treatment increased to the total area (900 cm 2) of the sample And it was confirmed that there existed inside and outside.

On the other hand, when a reducing material is further added to the wash water, the stain can not be confirmed after electrodeposition coating in all the samples, and the decrease is remarkably reduced as compared with the case where only the anticorrosive material is added.

As described above, the corrosion resistance of the coating object can be remarkably increased according to the addition of the reducing material, and high quality electrodeposition coating with minimal occurrence of stains and wrinkles due to corrosion is possible.

In addition, the washing water may be selected from the group consisting of monoethylene glycol, octyl phenyl ether, ethoxylated octylphenol, ethoxylated nonylphenol, ethoxylated fluorochemical surfactant Ethoxylated fluorosurfactant), preferably 0.01 to 10 parts by weight, per 100 parts by weight of the penetrant.

That is, the washing water may include 100 parts by weight of water, 0.0001 to 10 parts by weight of a rust preventive material, and 0.01 to 10 parts by weight of the penetrant, more preferably 100 parts by weight of water, 4 parts by weight, and 0.01 to 10 parts by weight of a penetrant.

At this time, the penetrating material such as monoethylene glycol can induce smooth penetration of the rust preventive material and the reducing material contained in the wash water to the gap formed in the surface depressed portion and the bent portion of the painting object.

Accordingly, since corrosion-preventive treatment through a rust-preventive substance and a reducing substance can be performed to a fine portion such as a fine groove on the surface of a three-dimensional coated object having a complicated shape upon cleaning, quality of coating treatment and electrodeposition coating can be remarkably improved.

If the amount of the penetrant added to the water washing water is less than 0.01 part by weight, the improvement amount of the penetration performance may be insufficient, and the penetrating material may be deposited in the gap formed in the recessed portion and the bent portion of the coated object exceeding 10 parts by weight There is a possibility that the quality of the coating treatment and the electrodeposition coating after the pretreatment is lowered.

Item Material Surface treatment method The water-washable product of the present invention Conduct 23 Practice 24 Conduct 25 Conduct 26 Coat state
(stain) CR Good Good Good Good GA Bad Bad Good Good GI Good Good Good Good EGI Good Good Good Good

Table 6 shows the results of the electrodeposition painting of each sample provided with cold rolled steel (CR), galvannealed steel sheet (GA), electrogalvanized steel sheet (EGI) and hot-dip galvanized steel sheet (GI) And the state of the back coating film.

At this time, each of the samples used in Examples 23 to 26 was provided with the same shape and area, and was provided so as to form depressions and bent portions on one side of the surface, and the state of the coating was formed in the gap of the formed depressed portion and the adjacent portion It is desirable to understand it as a result of the test.

The respective samples were subjected to electrodeposition coating through oxidation film removal, degreasing, primary washing, surface conditioning, coating, secondary washing, pure washing and drying, and the washing water of the present invention was subjected to primary washing and secondary washing .

Specifically, in Example 23, the sample was immersed for 3 minutes in a state where the bath temperature of the oxidizing agent remover was 40 ° C and the humidification ratio was 5%, and 0.3 parts by weight of rust inhibitive substance was added to 100 parts by weight of industrial water And Example 24 shows the results of changing the bath ratio of the oxide film remover to 10% under the same conditions as in Example 23. [

The above Example 25 is a result of using 0.3 parts by weight of rust preventive material and 0.1 part by weight of water permeation water added to 100 parts by weight of industrial water under the same conditions as in Example 23, Under the condition that the ratio of the bath ratio of the oxide film remover was changed to 10%.

As shown in Table 6, after the pre-treatment and the electrodeposition applied with the washing process using the industrial water and the rinsing water provided with the rust preventive material, irrespective of the drying ratio of the oxide film remover, the bending portion of the sample of the galvannealed steel sheet (GA) And the occurrence of stains in the gap between the depressed portion and its adjacent portion.

In the case where the above-mentioned water-washing water is provided with 100 parts by weight of industrial water, 0.3 parts by weight of rust inhibitive substance and 0.1 part by weight of penetrating substance, a good coating film state in which there is no stain in the gap between the bending portion and the depressed portion, I could confirm.

Meanwhile, FIG. 3 is a flowchart illustrating a pretreatment method applied with water wash water for metal pretreatment to prevent corrosion according to another embodiment of the present invention. In this embodiment, a washing process is added in the order of the degreasing process, the primary washing process, the oxide film removing process, the secondary washing process, the coating process, and the tertiary washing process, and the order of the degreasing process and the oxide film removing process is changed The basic configuration is the same as that of the above-described embodiment, so that a detailed description of the same configuration will be omitted.

As shown in FIG. 3, the pretreatment method to which the metal pretreated water is applied includes a degreasing step (s110), a first water washing step (s120), an oxide film removing step (s130), a second water washing step (s140) s160), and a third water washing process (s150).

At this time, the water for washing the metal pretreatment is subjected to the first water washing process (s120) after the degreasing process (s110), the second water washing process (s140) after the oxide film removing process (s130) After the last washing step, pure water (s180), drying, electrodeposition coating (s190), and the like can be performed in the process (s160).

First, the coating object is degreased at 40 to 50 DEG C for 3 to 5 minutes by a degreasing agent (S110).

Then, the treated object to be treated to remove the remnants of the degreasing agent and the process by-products may be added to 100 parts by weight of water in such a manner that the amount of the water-soluble organic solvent in the group consisting of toluylenol, benzotriazole, triazole, acrylamide, sebacic acid and triethanolamine (S120) with water containing water selected from the group consisting of 0.0001 to 10 parts by weight of one or more selected mixtures at room temperature for 2 to 6 minutes.

At this time, the use of the rinse water containing the rust preventive material can minimize the occurrence of corrosion of the paint object due to contact with water during the water washing process, and the corrosion of the paint object due to contact with the atmosphere during the process wait time after the water rinse process .

Then, the coated object is subjected to an oxide film removing treatment (s130) at 40 to 60 DEG C for 2 to 5 minutes by an oxide film removing agent having a pH of 1 to 10, and the coating object And then washed with the wash water at room temperature for 2 to 6 minutes (s140).

On the other hand, the washed coated object is subjected to coating treatment (s160) through a surface adjusting step (s150) in which the surface is treated with a surface adjusting agent at a pH of 8 to 11 and at a room temperature for 2 to 6 minutes.

Then, the coated object is washed with water containing the rust-preventive material at room temperature for 2 to 4 minutes so as to remove the remnants of the chemical conversion coating liquid and the process by-products from the surface (S170) (S180) and a drying process, and then electrodeposited (s190).

Item Material Surface treatment method Existing water use products Compare 5 Compare 6 Compare 7 Compare 8 Visual inspection CR Rustic Rustic Good Good GA Good Good White Chung White Chung GI Good White Chung White Chung White Chung EGI Good White Chung White Chung White Chung Impact resistance CR Bad Bad Good Good GA Good Good Bad Bad GI Good Bad Bad Bad EGI Good Bad Bad Bad Attachment CR Good Good Good Good GA Good Good Good Good GI Good Good Good Good EGI Good Good Good Good Water resistance CR Good Good Good Good GA Good Good Good Good GI Good Good Good Good EGI Good Good Good Good Brine
Split CR Bad Bad Good Good

Table 7 shows the results of Table 7 for each sample prepared from cold rolled steel (CR), galvanized steel sheet (GA), electrogalvanized steel sheet (EGI) and hot-dip galvanized steel sheet (GI) The results are shown in Fig.

At this time, each of the samples used in the above Comparative Examples 5 to 8 is provided in the same shape and area, and is manufactured in the same manner as that of Comparative Examples 5 to 8 except for the steps of degreasing, primary rinsing, oxide removing, secondary rinsing, surface conditioning, coating, And then electrodeposited.

In Comparative Examples 5 and 6, oxide film remover was set at 50 ° C., and the oxide film remover was performed for 3 minutes at a rate of 5% and 10%, respectively. In the first, second and third cases, The results of using industrial water are shown.

Comparative Example 7 shows the results of using industrial water of pH 10 to which caustic soda was added in the primary, secondary and tertiary washings under the same conditions as in Comparative Example 5, The results of using industrial water of pH 10 with caustic soda added in the primary, secondary and tertiary washings are shown.

As shown in Table 7, it was confirmed that the drying ratio of the oxide remover was improved in the appearance inspection results in the electro galvanized steel sheet (EGI) and the hot-dip galvanized steel sheet (GI), that is, It is unlikely that it can be applied to the pretreatment process of composite materials since no special improvement can be identified in the samples of other materials.

Further, it has been confirmed that the use of alkaline industrial water at the time of flushing improves the appearance test result slightly in the sample of the CR material compared with that in the case of using the general industrial water, that is, it reduces the amount of red rust generation of the sample after the coating treatment. (GA) material, the appearance test results were deteriorated and the amount of white rust was increased.

Furthermore, most of the samples showed poor quality in impact resistance of electrodeposition coating.

Item Material Surface treatment method The water-washable product of the present invention Practice 7 Practice 8 Conduct 9 Conduct 10 Conduct 11 Conduct 12 Visual inspection CR Good Good Good Good Good Good GA Good Good Good Good Good Good GI Good Good Good Good Good Good EGI Good Good Good Good Good Good Impact resistance CR Good Good Good Good Good Good GA Good Good Good Good Good Good GI Good Good Good Good Good Good EGI Good Good Good Good Good Good Attachment CR Good Good Good Good Good Good GA Good Good Good Good Good Good GI Good Good Good Good Good Good EGI Good Good Good Good Good Good Water resistance CR Good Good Good Good Good Good GA Good Good Good Good Good Good GI Good Good Good Good Good Good EGI Good Good Good Good Good Good Brine
Split CR Good Good Good Good Good Good

Table 8 shows the results of the evaluation of the properties of each of the samples provided with the cold-rolled steel sheet (CR), the galvanized steel sheet (GA), the electro galvanized steel sheet (EGI), and the hot-dip galvanized steel sheet (GI) The results are shown in Fig.

At this time, each sample used in the above Examples 7 to 12 is provided in the same shape and area, and is subjected to degreasing, primary washing, oxide film removal, secondary washing, surface conditioning, coating, And the water wash water of the present invention was applied to the first water washing, the second water washing and the third water washing.

Specifically, in Examples 7, 8, and 9, the samples were immersed for 3 minutes in a state where the bath temperature of the oxide film remover was 40 ° C and the bath ratio was 5%, and in the first, second and third washing steps, And 0.1% by weight, 0.2% by weight and 0.3% by weight of rust-preventive substances, respectively.

The above Example 10 is a result of changing the bath ratio of the oxide film remover to 10% under the same conditions as in Example 7, and Example 11 is a result of changing the bath temperature of the oxide film remover to 50 캜 under the same conditions as in Example 7 And Example 12 shows the result of changing the immersion time to 5 minutes under the same conditions as in Example 7. [

As shown in Table 8, regardless of the bath temperature, the ratio, and the immersion time of the oxide film remover, it was confirmed that the visual inspection results of all the samples of the raw materials of the present invention improved when the rust-preventive material was added.

That is, after the coating treatment, the amount of red rust / white rust of the sample was improved, so that the state of the coating film after the electrodeposition coating was in a good state in which the stain could not be confirmed, and the measurement results of impact resistance, adhesion property, water resistance, It can be confirmed that it is in a good state.

As described above, it is possible to improve the quality of coating and electrodeposition coating only by putting a rust preventive material such as toluic acid, benzotriazole, triazole, acrylamide, sebacic acid, and triethanolamine in the washing water used in general pre- It is possible.

Further, even when the order of the oxide film removing process and the degreasing process is changed during the pretreatment process and the water washing process is added between the oxide film removing process and the degreasing process, the quality of coating and electrodeposition coating can be improved, And the compatibility of the product can be improved.

Furthermore, since the quality of coating and electrodeposition coating can be improved in samples of all materials such as cold rolled steel (CR), galvanized galvanized steel (GA), electro galvanized steel (EGI) and hot dip galvanized steel (GI) It is possible to provide a base technology capable of simultaneously pretreating a composite component.

Item Material Surface treatment method Existing water use products The water-washable product of the present invention Compare 9 Compare 10 Conduct 27 Conduct 28 Visual inspection CR Rustic Rustic Good Good GA White Chung White Chung Good Good GI White Chung White Chung Good Good EGI White Chung White Chung Good Good

Table 9 shows the quality of the outer appearance of the coated steel sheets by different pretreatment methods for each of the samples provided with cold rolled steel sheets (CR), galvanized steel sheets (GA), electro galvanized steel sheets (EGI) and hot-dip galvanized steel sheets (GI) This is the result of the test. Here, the visual inspection is performed on a film-coated sample after completion of the pretreatment process.

In this case, each of the samples used in the comparative examples 9, 10 and 27, 28 is provided in the same shape and area, and is subjected to degreasing, primary washing, oxide film removal, secondary washing, surface conditioning, Was carried out by bathing the pH of the oxidative membrane remover of pH 1-10 with the pH of 3 used.

Specifically, Comparative Example 9 shows the result of using a general industrial water for the first and second washing steps while immersing the sample for 3 minutes in a state where the oxide film remover was washed at pH 3, 40 ° C, and 5%.

Comparative Example 10 shows the result of changing the bath ratio of the oxide film remover to 10% under the same conditions as in Example 9. In Example 27, the rust-inhibitive material was added in an amount of 0.3 wt% Shows the results of using the added industrial water as wash water, and Example 28 shows the result of changing the ratio of the drying rate of the oxide film remover to 10% under the same conditions as in Example 27. [

As shown in Table 9, regardless of the drying rate of the oxide film remover, it was confirmed that the appearance of the samples of all materials was improved when the washing water of the present invention containing the rust preventive material was added.

As described above, even in the case of using an acid type oxide film remover as well as a neutral type oxide film remover, it is possible to improve the quality of the coating process and improve the quality of the electrodeposition coating through the water containing the rust inhibitor, .

As described above, the present invention is not limited to the above-described embodiments, and variations and modifications may be made by those skilled in the art without departing from the scope of the present invention. And such modifications are within the scope of the present invention.

s10, s130: oxide film removal process s20, s110: degreasing process
s30, s120: primary water washing step s40, s150: surface adjusting step
s50, s160: coating treatment process s60, s140: secondary water washing process
s70, s180: pure water process s80, s190: electrodeposition process
s170: Third water washing process

Claims

A water treatment water for metal pretreatment for corrosion prevention, which removes residues of process solutions and process byproducts from the surface of a coating target in a pretreatment process including an oxide film removing process, a degreasing process, and a coating process,
Wherein the aqueous solution contains 0.0001 to 10 parts by weight of one or more selected from the group consisting of acrylamide, sebacic acid and triethanolamine per 100 parts by weight of water,
0.01 to 10 parts by weight of a mixture of one or more selected from the group consisting of octylphenol ether, ethoxylated octylphenol and ethoxylated nonylphenol,
0.01 to 10 parts by weight of a mixture of one or more selected from the group consisting of ammonium molybdate, sodium molybdate, borax, isopropylamine, methyleneamine, ethanolamine, propylamine, butylamine,
Further comprising 0.01 to 15 parts by weight of a mixture of one or more selected from the group consisting of dibasic sodium phosphate, tribasic sodium phosphate, dibasic potassium phosphate, tribasic potassium phosphate and compounds thereof. Wash water for pretreatment.

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