JP2008184690A - Pre-painting method - Google Patents

Abstract

An object of the present invention is to provide a pre-coating method that does not limit the coating method, has a low environmental impact, and can perform good chemical conversion treatment on all metals such as iron, zinc, and aluminum.
A coating pretreatment method for treating an object to be treated with a chemical conversion treatment agent to form a chemical conversion film, wherein the chemical conversion treatment agent is at least one selected from the group consisting of zirconium, titanium and hafnium, fluorine, And a coating pretreatment method comprising at least one selected from the group consisting of an amino group-containing silane coupling agent, a hydrolyzate thereof, and a polymer thereof.
[Selection figure] None

Description

  The present invention relates to a coating pretreatment method.

  When cationic electrodeposition coating, powder coating or the like is applied to the surface of a metal material, chemical conversion treatment is usually performed for the purpose of improving properties such as corrosion resistance and coating film adhesion. The chromate treatment that has been used in the chemical conversion treatment from the viewpoint of further improving the adhesion and corrosion resistance of the coating film has recently been pointed out as harmful to chromium, and it does not contain chromium. Development has been needed. As such chemical conversion treatment, treatment with zinc phosphate is widely performed (see, for example, Patent Document 1).

  However, since the zinc phosphate-based treatment agent is a highly reactive treatment agent having a high concentration of metal ions and acid, the economical efficiency and workability in wastewater treatment are not good. Further, accompanying the metal surface treatment with the zinc phosphate-based treatment agent, water-insoluble salts are generated and precipitated as precipitates. Such precipitates are generally called sludge, and there is a problem of cost generation due to removal and disposal of such sludge. Moreover, since phosphate ions may cause a load on the environment due to eutrophication, labor is required in the treatment of waste liquid, and it is preferable not to use them. Furthermore, in the metal surface treatment with a zinc phosphate-based treatment agent, it is necessary to adjust the surface, and there is a problem that the process becomes long.

  A metal surface treatment agent composed of a zirconium compound is known as a metal surface treatment agent other than such zinc phosphate-based treatment agent or chromate chemical conversion treatment agent (see, for example, Patent Document 2). The metal surface treatment agent comprising such a zirconium compound has properties superior to the zinc phosphate chemical conversion treatment agent described above in that the generation of sludge is suppressed.

  However, the chemical conversion film obtained with a metal surface treatment agent comprising a zirconium compound has poor adhesion particularly with a coating film obtained by cationic electrodeposition coating, and is usually used as a pretreatment step for cationic electrodeposition coating. There were few. In such a metal surface treatment agent composed of a zirconium compound, improvement of adhesion and corrosion resistance are performed by using a component such as phosphate ion in combination. However, when phosphate ions are used in combination, the problem of eutrophication as described above occurs. In addition, no study has been made on the use of such a treatment with a metal surface treatment agent as a pretreatment method for various coatings such as cationic electrodeposition coating. Moreover, when processing an iron-type base material with such a metal surface treating agent, there existed a problem that sufficient adhesiveness of a coating film and corrosion resistance after coating were not obtained.

  A non-chromate metal surface treatment agent comprising a zirconium compound and an amino group-containing silane coupling agent is also known (for example, see Patent Document 3). However, such a non-chromate metal surface treatment agent is a so-called coating type treatment agent for use in the coil coating field, and the surface treatment using the non-chromate metal surface treatment agent cannot be washed with water after treatment and has a complicated shape. It was not supposed to be processed.

  In addition, it may be necessary to perform surface treatment of all metals in a single treatment on articles made of various metal materials such as automobile bodies and parts such as iron, zinc, and aluminum. There is a demand for the development of a coating pretreatment method that can perform chemical conversion treatment without any problem. On the other hand, it is also desired to develop a pretreatment method capable of performing chemical conversion treatment without causing the above-mentioned problems even in coatings other than cationic electrodeposition coating using powder coating, solvent coating, aqueous coating, and the like.

Japanese Patent Laid-Open No. 10-204649 JP-A-7-310189 JP 2001-316845 A

  In view of the above, the present invention is not limited to a coating method, has a low environmental load, and can perform a good chemical conversion treatment on all metals such as iron, zinc, and aluminum. Is intended to provide.

  The present invention is a coating pretreatment method for treating a treatment object with a chemical conversion treatment agent to form a chemical conversion film, wherein the chemical conversion treatment agent is at least one selected from the group consisting of zirconium, titanium and hafnium, fluorine, And a coating pretreatment method comprising at least one selected from the group consisting of an amino group-containing silane coupling agent, a hydrolyzate thereof, and a polymer thereof.

The content of at least one selected from the group consisting of the amino group-containing silane coupling agent, its hydrolyzate and its polymer is preferably 5 to 5000 ppm in terms of solid content.
It is preferable that the said chemical conversion treatment agent contains at least 1 type chosen from the group which consists of 20-10000 ppm zirconium, titanium, and hafnium in metal conversion, and pH is 1.5-6.5.
The chemical conversion treatment agent preferably further contains at least one adhesion and corrosion resistance imparting agent selected from the group consisting of magnesium ions, zinc ions, calcium ions, aluminum ions, gallium ions, indium ions and copper ions.
Hereinafter, the present invention will be described in detail.

  The present invention performs chemical conversion treatment using a chemical conversion treatment agent containing at least one selected from the group consisting of zirconium, titanium, and hafnium, and fluorine, and substantially not containing phosphate ions or harmful heavy metal ions. This is a pre-painting method. In place of the zinc phosphate treatment that is widely used as a chemical conversion treatment method, if the object to be treated is treated with a chemical conversion treatment agent made of conventional zirconium or the like, sufficient coating adhesion cannot be obtained particularly on an iron-based substrate. Such problems arise. The present invention solves the above-described problems, and at least one selected from the group consisting of zirconium, titanium, and hafnium, and a chemical conversion treatment agent composed of fluorine, enables sufficient coating even on iron-based substrates. This is a coating pretreatment method for forming a chemical conversion film having film adhesion.

  At least one selected from the group consisting of zirconium, titanium, and hafnium contained in the chemical conversion treatment agent is a chemical conversion film forming component, and the chemical conversion film containing at least one selected from the group consisting of zirconium, titanium, and hafnium is used as a base material. By being formed, the corrosion resistance and wear resistance of the substrate can be improved, and the adhesion to the coating film can be further improved.

For example, when the surface treatment of a metal substrate is performed using a chemical conversion treatment agent containing zirconium, metal ions eluted into the chemical conversion treatment agent by the metal dissolution reaction extract the fluorine of ZrF ₆ ²⁻ , It is considered that the zirconium hydroxide or oxide is generated by the increase in the interface pH, and this zirconium hydroxide or oxide is precipitated on the surface of the substrate. As described above, since the chemical conversion treatment agent in the present invention is a reactive chemical conversion treatment agent, it can also be used for immersion treatment of an object to be processed having a complicated shape. In addition, when the surface treatment is performed using the chemical conversion treatment agent, a chemical conversion film firmly attached to the object to be processed is obtained by a chemical reaction, and thus, water washing after the treatment can be performed.

The zirconium source is not particularly limited, and examples thereof include alkali metal fluorozirconates such as K ₂ ZrF ₆ ; fluorozirconates such as (NH ₄ ) ₂ ZrF ₆ ; fluorozirconate acids such as H ₂ ZrF _6, etc. And soluble fluorozirconate, etc .; zirconium fluoride; zirconium oxide and the like.

The titanium source is not particularly limited. For example, alkali metal fluorotitanate, fluorotitanate such as (NH ₄ ) ₂ TiF ₆ ; soluble fluorotitanate such as fluorotitanate such as H ₂ TiF _6, etc .; titanium fluoride A titanium oxide can be mentioned.

The source of hafnium is not particularly limited, and examples thereof include fluorohafnate acids such as H ₂ HfF ₆ ; hafnium fluoride.
The at least one source selected from the group consisting of zirconium, titanium and hafnium is at least one selected from the group consisting of ZrF ₆ ²⁻ , TiF ₆ ²⁻ , and HfF ₆ ²⁻ due to high film forming ability. The compound which has is preferable.

  The content of at least one selected from the group consisting of zirconium, titanium and hafnium contained in the chemical conversion treatment agent is preferably in the range of a lower limit of 20 ppm and an upper limit of 10,000 ppm in terms of metal. If it is less than the lower limit, the resulting chemical conversion film has insufficient performance. If the upper limit is exceeded, no further effect can be expected, which is economically disadvantageous. The lower limit is more preferably 50 ppm, and the upper limit is more preferably 2000 ppm.

  The fluorine contained in the chemical conversion treatment agent serves as an etching agent for the substrate. The fluorine supply source is not particularly limited, and examples thereof include fluorides such as hydrofluoric acid, ammonium fluoride, borofluoric acid, ammonium hydrogen fluoride, sodium fluoride, and sodium hydrogen fluoride. . Examples of the complex fluoride include hexafluorosilicate, and specific examples thereof include hydrofluoric acid, zinc silicofluoride, manganese silicofluoride, magnesium silicofluoride, and hydrosilicofluoride. Examples thereof include nickel, iron silicohydrofluorate, and calcium silicohydrofluoride.

  The chemical conversion treatment agent contains at least one selected from the group consisting of an amino group-containing silane coupling agent, a hydrolyzate thereof, and a polymer thereof. The amino group-containing silane coupling agent is a compound having at least one amino group in the molecule and having a siloxane bond. When at least one selected from the group consisting of the amino group-containing silane coupling agent, the hydrolyzate thereof, and the polymer thereof acts on both the chemical conversion film and the coating film, the adhesion between them is improved.

  Such an effect is that the group that hydrolyzes to produce silanol is hydrolyzed and adsorbed on the surface of the metal substrate in a hydrogen bond manner, and the adhesion between the chemical conversion film and the metal substrate is caused by the action of the amino group. Presumed to be due to increase. As described above, at least one selected from the group consisting of the amino group-containing silane coupling agent, the hydrolyzate and the polymer thereof contained in the chemical conversion film acts on both the metal substrate and the coating film, It is thought that it has the effect | action which improves adhesiveness.

  The amino group-containing silane coupling agent is not particularly limited. For example, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (Aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- Well-known silane coupling agents such as phenyl-3-aminopropyltrimethoxysilane and N, N-bis [3- (trimethoxysilyl) propyl] ethylenediamine can be exemplified. Commercially available amino group-containing silane coupling agents such as KBM-602, KBM-603, KBE-603, KBM-903, KBE-9103, KBM-573 (manufactured by Shin-Etsu Chemical Co., Ltd.), XS1003 (Chisso Corporation) Etc.) can also be used.

  The hydrolyzate of the amino group-containing silane coupling agent is produced by a conventionally known method, for example, a method of dissolving the amino group-containing silane coupling agent in ion-exchanged water and adjusting the acidity with an arbitrary acid. be able to. Commercially available products such as KBP-90 (manufactured by Shin-Etsu Chemical Co., Ltd .: active ingredient 32%) can also be used as the hydrolyzate of the amino group-containing silane coupling agent.

  The polymer of the amino group-containing silane coupling agent is not particularly limited. For example, Silaace S-330 (γ-aminopropyltriethoxysilane; manufactured by Chisso Corporation), Silaace S-320 (N- (2-amino) Ethyl) -3-aminopropyltrimethoxysilane; manufactured by Chisso Corporation).

  The amino group-containing silane coupling agent and its hydrolyzate are suitably used particularly when pretreatment for coating with a cationic electrodeposition paint is performed. Moreover, the polymer of the amino group-containing silane coupling agent should be suitably used for pretreatment of coating using not only the cationic electrodeposition paint but also solvent paint, water paint, powder paint, etc. Can do.

  At least one compounding amount selected from the group consisting of the amino group-containing silane coupling agent, the hydrolyzate and the polymer thereof in the chemical conversion treatment agent is within the range of the lower limit of 5 ppm and the upper limit of 5000 ppm in terms of solid content concentration. Is preferred. If it is less than 5 ppm, sufficient coating film adhesion cannot be obtained. If it exceeds 5000 ppm, no further effect can be expected, which is economically disadvantageous. The lower limit is more preferably 10 ppm and even more preferably 50 ppm. The upper limit is more preferably 1000 ppm and even more preferably 500 ppm.

  It is preferable that the said chemical conversion treatment agent is a thing which does not contain a phosphate ion substantially. The phrase “substantially free of phosphate ions” means that the phosphate ions are not contained so much as to act as a component in the chemical conversion treatment agent, and the chemical conversion treatment agent used in the present invention is substantially free of phosphate ions. Because it does not contain ions, it does not substantially use phosphorus, which causes environmental burdens, and it does not contain sludge such as iron phosphate and zinc phosphate that are generated when zinc phosphate treatment agents are used. Occurrence can be suppressed.

  The chemical conversion treatment agent preferably has a pH in the range of a lower limit of 1.5 and an upper limit of 6.5. If it is less than 1.5, the etching becomes excessive and a sufficient film cannot be formed. If it exceeds 6.5, etching becomes insufficient and a good film cannot be obtained. The lower limit is more preferably 2.0, and the upper limit is more preferably 5.5. The lower limit is more preferably 2.5, and the upper limit is more preferably 5.0. In order to adjust the pH of the chemical conversion treatment agent, acidic compounds such as nitric acid and sulfuric acid and basic compounds such as sodium hydroxide, potassium hydroxide and ammonia can be used.

  The chemical conversion treatment agent preferably further contains at least one selected from the group consisting of magnesium ions, zinc ions, calcium ions, aluminum ions, gallium ions, indium ions and copper ions as an adhesion and corrosion resistance imparting agent. By containing the adhesion and corrosion resistance imparting agent, a chemical conversion film having better adhesion and corrosion resistance can be obtained.

  The content of at least one selected from the group consisting of magnesium ion, zinc ion, calcium ion, aluminum ion, gallium ion, indium ion and copper ion in the chemical conversion treatment agent is in the range of a lower limit of 1 ppm and an upper limit of 5000 ppm. Is preferred. If the content is less than the lower limit, a sufficient effect cannot be obtained, which is not preferable. When the content exceeds the above upper limit, no further improvement in the effect is observed, which is economically disadvantageous, and the adhesion after coating may be reduced. The lower limit is more preferably 25 ppm, and the upper limit is more preferably 3000 ppm.

  The said chemical conversion treatment agent may use arbitrary components together as needed other than the said component. Examples of components that can be used include silica. By adding such components, it is possible to improve post-coating corrosion resistance.

  The chemical conversion treatment in the coating pretreatment method of the present invention is not particularly limited, and can be performed by bringing the chemical conversion treatment agent into contact with the metal surface under normal processing conditions. The treatment temperature in the chemical conversion treatment is preferably in the range of a lower limit of 20 ° C. and an upper limit of 70 ° C. The lower limit is more preferably 30 ° C, and the upper limit is more preferably 50 ° C. The chemical conversion time in the chemical conversion treatment is preferably in the range of a lower limit of 5 seconds and an upper limit of 1200 seconds. The lower limit is more preferably 30 seconds, and the upper limit is more preferably 120 seconds. The chemical conversion treatment method is not particularly limited, and examples thereof include a dipping method, a spray method, and a roll coating method.

In the pre-coating treatment method of the present invention, before the chemical conversion treatment, it is preferable to perform a degreasing treatment and a post-degreasing water washing treatment on the surface of the metal substrate, and a post-chemical conversion water washing treatment after the chemical conversion treatment.
The degreasing treatment is performed to remove oil and dirt adhering to the surface of the base material, and usually with a degreasing agent such as phosphorus-free and nitrogen-free degreasing cleaning liquid at about 30 to 55 ° C. for about several minutes. Immersion treatment is performed. If desired, a preliminary degreasing process can be performed before the degreasing process.

The post-degreasing rinsing treatment is performed by spraying once or more with a large amount of rinsing water in order to wash the degreasing agent after the degreasing treatment.
The post-chemical conversion water-washing treatment is performed once or more so as not to adversely affect the adhesion, corrosion resistance, and the like after the subsequent various coatings. In this case, it is appropriate that the final water washing is performed with pure water. In this post-chemical conversion water washing treatment, either spray water washing or immersion water washing may be used, and these methods may be combined for water washing.
After the post-chemical conversion water-washing treatment, it can be dried as necessary according to a known method, and thereafter various coatings can be performed.

  The coating pretreatment method of the present invention does not have to perform the necessary surface conditioning treatment in the method of treatment using a zinc phosphate-based chemical conversion treatment agent that has been put into practical use, and therefore requires fewer steps. It is possible to carry out the chemical conversion treatment of the metal substrate.

  Examples of the metal substrate to be treated in the present invention include an iron-based substrate, an aluminum-based substrate, and a zinc-based substrate. Iron, aluminum, and zinc-based substrate are iron-based substrates in which the substrate is made of iron and / or an alloy thereof, aluminum substrates in which the substrate is made of aluminum and / or an alloy thereof, and the substrate is made of zinc and / or Or the zinc-type base material consisting of the alloy is meant. The pre-painting treatment method of the present invention can also be applied to an object to be processed consisting of a plurality of metal substrates among an iron-based substrate, an aluminum-based substrate, and a zinc-based substrate.

  The pre-coating treatment method of the present invention is sufficient for adhesion to an iron-based substrate that has been difficult to obtain sufficient coating adhesion by treatment with a chemical conversion treatment agent composed of ordinary zirconium or the like. Therefore, it has excellent properties in that it can be applied to the treatment of an object to be treated containing an iron-based substrate at least in part.

  It does not specifically limit as said iron-type base material, For example, a cold-rolled steel plate, a hot-rolled steel plate, etc. can be mentioned. It does not specifically limit as said aluminum-type base material, For example, 5000 series aluminum alloy, 6000 series aluminum alloy, etc. can be mentioned. The zinc-based substrate is not particularly limited. For example, galvanized steel sheet, zinc-nickel plated steel sheet, zinc-iron plated steel sheet, zinc-chromium plated steel sheet, zinc-aluminum plated steel sheet, zinc-titanium plated steel sheet, zinc- Examples thereof include zinc-based electroplating such as magnesium-plated steel sheet and zinc-manganese-plated steel sheet, zinc such as hot-dip plating and vapor-deposited steel sheet, or zinc-based alloy-plated steel sheet. In the present invention, iron, aluminum, and a zinc-based substrate can be subjected to chemical conversion treatment simultaneously.

Conversion coating obtained by painting pretreatment method of the present invention, the lower limit 0.1 mg / m 2 in a total amount of metal coating weight is comprised chemical conversion treatment agent ^is preferably in the range of the upper limit 500 mg / m ^2. If it is less than 0.1 mg / m ² , a uniform chemical conversion film cannot be obtained, which is not preferable. If it exceeds 500 mg / m ² , no further effect is obtained, which is economically disadvantageous. The lower limit is more preferably 5 mg / m ² , and the upper limit is more preferably 200 mg / m ² .

  The coating that can be performed on the metal substrate treated by the coating pretreatment method of the present invention is not particularly limited, and conventionally known paints such as cationic electrodeposition paints, solvent paints, aqueous paints, and powder paints can be used. The coating used can be performed. For example, the cationic electrodeposition coating is not particularly limited, and a conventionally known cationic electrodeposition coating made of an aminated epoxy resin, an aminated acrylic resin, a sulfoniumated epoxy resin, or the like can be applied. Among them, the chemical conversion treatment agent is blended with at least one selected from the group consisting of an amino group-containing silane coupling agent, a hydrolyzate thereof, and a polymer thereof, thereby further improving the adhesion between the electrodeposition coating film and the conversion coating film. Therefore, a cationic electrodeposition paint made of a resin having a functional group showing reactivity or compatibility with an amino group is preferable.

The coating pretreatment method of the present invention includes at least one selected from the group consisting of zirconium, titanium and hafnium as a chemical film forming component, and further a group comprising an amino group-containing silane coupling agent, a hydrolyzate thereof and a polymer thereof. By using the chemical conversion treatment agent containing at least one kind selected from the above, it is possible to suitably perform the pre-coating treatment that has conventionally been commonly performed with a zinc phosphate-based treatment agent. Furthermore, it is possible to form a chemical conversion film excellent in coating film adhesion even on an iron-based substrate, which has been conventionally unsuitable for pretreatment with a chemical conversion treatment agent composed of zirconium or the like.
Moreover, since the chemical conversion treatment agent used by this invention does not contain a phosphate ion substantially, there is little load with respect to an environment and sludge does not generate | occur | produce. Furthermore, since the coating pretreatment method of the present invention does not require a surface adjustment step, it is possible to carry out the chemical conversion treatment of the metal substrate with fewer steps.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited only to these examples.

Example 1
Using a commercially available cold-rolled steel plate (SPCC-SD, manufactured by Nippon Test Panel Co., Ltd., 70 mm × 150 mm × 0.8 mm), a coating pretreatment was performed under the following conditions.
(1) Pre-coating degreasing treatment: 2% by mass “Surf Cleaner 53” (Nippon Paint Co., Ltd. degreasing agent) was immersed at 40 ° C. for 2 minutes.
Washing with water after degreasing: spraying with tap water for 30 seconds.
Chemical conversion treatment: KBM-603 (N-2 (aminoethyl) 3-aminopropyltrimethoxysilane: effective concentration 100%: manufactured by Shin-Etsu Chemical Co., Ltd.) is used as a silane coupling agent containing zircon hydrofluoric acid and amino group. A chemical conversion treatment agent having a zirconium concentration of 100 ppm and an amino group-containing silane coupling agent concentration of 100 ppm as a solid content was prepared. The pH was adjusted to 4 using sodium hydroxide. The temperature of the chemical conversion treatment agent was adjusted to 40 ° C., and the base material was immersed for 60 seconds. The coating amount in the initial stage of the treatment was 10 mg / m ² .

Water treatment after chemical conversion: Sprayed with tap water for 30 seconds. Furthermore, it spray-processed for 10 second with ion-exchange water. Then, electrodeposition coating was performed in a wet state.
The coating amount is included in the chemical conversion treatment agent using “XRF1700” (Shimadzu X-ray fluorescence analyzer) after the cold-rolled steel sheet after the water washing treatment is dried at 80 ° C. for 5 minutes in an electric drying furnace. The total amount of metals analyzed.

(2) Coating After processing 1 m ² of cold-rolled steel sheet per liter of chemical conversion treatment agent, electrodeposition coating using “Powernics 110” (Cation Electrodeposition Paint manufactured by Nippon Paint Co., Ltd.) to a dry film thickness of 20 μm. After washing with water, baking was performed by heating at 170 ° C. for 20 minutes to prepare a test plate.

Evaluation test <sludge observation>
After processing 1 m ² metal base material per liter of chemical conversion treatment agent, the turbidity in the chemical conversion treatment agent was visually observed.
○: No turbidity ×: Turbidity

<Secondary adhesion test (SDT)>
Two vertical and parallel cuts reaching the substrate were put in the obtained test plate, and then immersed in a 5% NaCl aqueous solution at 50 ° C. for 480 hours. Thereafter, the cut part was peeled off with tape, and the peeling of the paint was observed.
A: No peeling ○: Slight peeling ×: Peeling width 3 mm or more

<SST>
The obtained test plate was cross-cut reaching the substrate, and then sprayed with a 5% NaCl aqueous solution continuously for 240 hours in a salt spray tester maintained at 35 ° C. Then, the swelling width from the cut part was measured.

<Moisture resistance test>
The obtained test plate was left in a constant temperature and humidity tester (humidity 95%, temperature 50 ° C.) for 240 hours. Next, after leaving the test plate in the atmosphere for 1 hour, a crosscut (1 mm square × 100 pieces) was put in, the tape was peeled off, and the number of remaining coating films was measured as an index of coating film adhesion.

Example 2
A test plate was prepared in the same manner as in Example 1 except that KBM-903 (3-aminopropyltrimethoxysilane: effective concentration 100%: manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the amino group-containing silane coupling agent. Produced.

Example 3
A test plate was prepared in the same manner as in Example 1 except that KBE-903 (3-aminopropyltriethoxysilane: effective concentration 100%: manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the amino group-containing silane coupling agent. Produced.

Example 4
Example 1 except that KBP-90 (3-aminopropyltrimethoxysilane hydrolyzate: effective concentration 32%: manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the hydrolyzate of the amino group-containing silane coupling agent. A test plate was prepared in the same manner as described above.

Example 5
As a hydrolyzate of the amino group-containing silane coupling agent, XS-1003 (a methanol solution of N, N-bis [3- (trimethoxysilyl) propyl] ethylenediamine: effective concentration 50%: manufactured by Chisso Corporation) was used. A test plate was prepared in the same manner as in Example 1 except that.

Example 6
A test plate was produced in the same manner as in Example 2 except that the concentration of the amino group-containing silane coupling agent was changed to 5 ppm.

Example 7
A test plate was produced in the same manner as in Example 2 except that the concentration of the amino group-containing silane coupling agent was changed to 5000 ppm.

Example 8
A test plate was produced in the same manner as in Example 2 except that the metal base material was changed to a zinc-based plated steel plate (GA steel plate, Nippon Test Panel, 70 mm × 150 mm × 0.8 mm).

Example 9
A test plate was produced in the same manner as in Example 2 except that the metal base material was changed to 5000 series aluminum (manufactured by Nippon Test Panel Co., Ltd., 70 mm × 150 mm × 0.8 mm).

Examples 10-35
Table 1 using magnesium nitrate and zinc nitrate as adhesion and corrosion resistance imparting agents, and using Silaace S-330 or Silaace S-320 (both manufactured by Chisso Corporation) as a polymer of amino group-containing silane coupling agent. And a chemical conversion treating agent having the composition shown in Fig. 2 and a hot dip galvanized steel sheet (GI, manufactured by Nippon Test Panel Co., Ltd., 70 mm x 150 mm x 0.8 mm), an electroplated galvanized steel sheet (EG, Japanese test panel). 70 mm × 150 mm × 0.8 mm), black steel plate (SS400, manufactured by Nippon Test Panel, 70 mm × 150 mm × 0.8 mm) or 6000 series aluminum (manufactured by Nippon Test Panel, 70 mm × 150 mm × 0.8 mm) ) Was used in the same manner as in Example 1 except that a test plate was prepared.

Comparative Example 1
A test plate was produced in the same manner as in Example 1 except that the amino group-containing silane coupling agent was not blended.

Comparative Example 2
A test plate was produced in the same manner as in Example 1 except that zircon hydrofluoric acid was not blended.

Comparative Example 3
A test plate was prepared in the same manner as in Example 1 except that zircon hydrofluoric acid was not blended and Silaace S-330 was used as the amino group-containing silane coupling agent.

Comparative Examples 4-8
Using the base materials shown in Table 2, the surface was adjusted for 30 seconds at room temperature using Surffine 5N-8M (manufactured by Nippon Paint Co., Ltd.) after degreasing and washing with water, and Surfdyne SD-6350 (Nippon Paint Co., Ltd.). A test plate was obtained in the same manner as in Example 1 except that the chemical conversion treatment was performed by performing immersion treatment at 35 ° C. for 2 minutes using a zinc phosphate-based chemical conversion treatment agent).

Examples 36-40
Using a chemical conversion treatment agent and a base material having the composition shown in Table 3, instead of “Powernics 110” (cationic electrodeposition paint manufactured by Nippon Paint Co., Ltd.), “Orga Select OTS900 White” (solvent paint manufactured by Nippon Paint Co., Ltd.) Was coated to a dry film thickness of 35 ± 2 μm, and a test plate was obtained in the same manner as in Example 1 except that it was baked by heating at 140 ° C. for 30 minutes.

Comparative Examples 9-13
Using the base materials shown in Table 3, “Olga Select OTS900 White” (Nippon Paint Co., Ltd. solvent paint) is used instead of “Powernics 110” (Nippon Paint Co., Ltd. Cationic electrodeposition paint). Dry film thickness 35 ± 2 μm A test plate was obtained in the same manner as in Comparative Example 4 except that the coating was applied and heated at 140 ° C. for 30 minutes and baked.

Examples 41-45
Using a chemical conversion treatment agent and a base material having the composition shown in Table 3, instead of “Powernics 110” (cationic electrodeposition paint manufactured by Nippon Paint Co., Ltd.), “Ode Eco Line OEL100” (water paint manufactured by Nippon Paint Co., Ltd.) Was coated to a dry film thickness of 35 ± 2 μm, and a test plate was obtained in the same manner as in Example 1 except that it was baked by heating at 140 ° C. for 30 minutes.

Comparative Examples 14-18
Using the base materials shown in Table 3, instead of “Powernics 110” (Cation Electrodeposition Paint made by Nippon Paint Co., Ltd.), “Ode Eco Line OEL100” (Water Paint made by Nippon Paint Co., Ltd.) was dried film thickness 35 ± 2 μm A test plate was obtained in the same manner as in Comparative Example 4 except that the coating was applied and heated at 140 ° C. for 30 minutes and baked.

Examples 46-50
Using a chemical conversion treatment agent and a substrate having the composition shown in Table 3, instead of “Powernics 110” (Cation Electrodeposition Paint manufactured by Nippon Paint Co., Ltd.), “Powax P100” (Powder Paint manufactured by Nippon Paint Co., Ltd.) is used. A test plate was obtained in the same manner as in Example 1 except that coating was performed so that the dry film thickness was 100 ± 5 μm, and heating was performed at 180 ° C. for 20 minutes for baking.

Comparative Examples 19-23
Using the base materials shown in Table 3, instead of “Powernics 110” (Cation Electrodeposition Paint made by Nippon Paint Co., Ltd.), “Paudax P100” (Powder Paint made by Nippon Paint Co., Ltd.) was dried to a thickness of 100 ± 5 μm. A test plate was obtained in the same manner as in Comparative Example 4 except that the coating was applied and heated at 180 ° C. for 20 minutes and baked.

  Tables 1 to 3 show that no sludge is generated in the chemical conversion treatment agent used in the examples. Furthermore, it was shown that the chemical conversion film obtained by the coating pretreatment method of the present invention has good adhesion to a coating film formed by various coatings. On the other hand, in the comparative example, it was not possible to obtain a chemical conversion film that suppresses the generation of sludge in the chemical conversion treatment agent and has excellent adhesion to the coating film.

  According to the present invention, it has been possible to obtain a pre-coating method that can reduce the burden on the environment and can perform good chemical conversion treatment on all metals such as iron, zinc, and aluminum. Moreover, since the coating pretreatment method of the present invention can form a good chemical conversion film without adjusting the surface, it is excellent in terms of workability and cost.

Claims (9)

Cationic electrodeposition coating in which a metal base material is surface-treated with a chemical conversion treatment agent to form a chemical conversion film, the surface-treated metal base material is washed with water without drying, and then subjected to electrodeposition coating in a wet state. A method,
The chemical conversion treatment agent comprises at least one selected from the group consisting of zirconium, titanium and hafnium, fluorine, and at least one selected from the group consisting of an amino group-containing silane coupling agent, a hydrolyzate thereof and a polymer thereof. A cationic electrodeposition coating method characterized by using a chemical conversion treatment agent substantially free of phosphoric acid.   2. The cationic electrodeposition coating method according to claim 1, wherein the content of at least one selected from the group consisting of an amino group-containing silane coupling agent, a hydrolyzate thereof and a polymer thereof is 5 to 5000 ppm in terms of solid concentration.   The cationic electrodeposition coating method according to claim 1 or 2, comprising a polymer of an amino group-containing silane coupling agent.   The cationic conversion coating method according to any one of claims 1 to 3, wherein the chemical conversion treatment agent contains at least one selected from the group consisting of zirconium, titanium, and hafnium in an amount of 20 to 10,000 ppm in terms of metal.   5. The cationic electrodeposition coating method according to claim 1, wherein the chemical conversion treatment agent has a pH of 1.5 to 6.5.   The chemical conversion treatment agent further contains at least one adhesion and corrosion resistance imparting agent selected from the group consisting of magnesium ions, zinc ions, calcium ions, aluminum ions, gallium ions, indium ions and copper ions. The cationic electrodeposition coating method according to any one of the above.   The cationic electrodeposition coating method according to claim 6, wherein the adhesion and corrosion resistance imparting agent is aluminum ion and / or copper ion.   The cationic electrodeposition coating method according to claim 6, wherein the adhesion and corrosion resistance imparting agent is magnesium ion and / or zinc ion.   The cation electrodeposition coating method according to claim 1, wherein the water washing is performed with ion exchange water.