JPS6223473A - Method and apparatus for forming paint film - Google Patents

Abstract

PURPOSE:To make it possible to form both of a smooth paint film and a rough surface paint film to the surface of an article to be painted by one painting line, in forming a paint film by thermosetting resin paint, by controlling the contact/non-contact of acidic gas with the surface of an uncured paint film. CONSTITUTION:A painting line is equipped with a pretreatment apparatus 1, an anodic oxidation treatment apparatus 2, a steeping apparatus 3, a drain and drying oven 4, an immersion painting treatment apparatus 5 having a resin bath, an acidic gaseous atmosphere furnace 6 and a baking/drying oven 7 and a furnace having an acidic gaseous atmosphere is independently arranged as the acidic gaseous atmosphere furnace 6. When a rough surface paint film such as a crepe pattern is formed to an article to be painted after coated with thermosetting resin paint, said article is contacted with the acidic gas in the acidic gaseous atmosphere furnace 6 and, when a smooth pattern having gloss is formed, the treatment in the acidic gaseous atmosphere furnace 6 is omitted.

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Industrial Application Field) This invention provides coating films with different appearances, namely a smooth coating film and a rough coating film, on the surface of a workpiece in one coating line. The present invention relates to a coating film forming method and a coating device used for forming the coating film.

(Conventional technology) Conventionally, methods for forming a coating film on the surface of an object to be coated include:
For example, there is a method in which a thermosetting resin paint using a halogenated hydrocarbon as a solvent is applied to the surface of the object to be coated and then dried and cured. There is a method of forming a certain smooth coating film on the surface of the object to be coated.

In addition, as a coating film formation method developed by the applicant, a thermosetting resin paint is applied to the surface of the object to be coated, and then the uncured coating film on the surface of the object is dried in a heated acidic gas atmosphere. A desired color can be obtained by curing, or by drying and curing the uncured coating film after contacting it with heated acidic gas, and by pre-containing an appropriate pigment in the thermosetting resin coating. There is a method of forming a rough coating film, such as a chilimen pattern, on the surface of an object to be coated.

(Problems to be solved by the invention) However, in such conventional coating film forming methods,
Separate painting lines were used for forming a smooth, glossy coating on the surface of the object to be coated, and for forming a rough coating with a chilimen pattern.
There were problems in that the efficiency of the equipment was quite low and it also caused an increase in painting costs.

This invention was made by focusing on these conventional problems, and it is possible to create a smooth, glossy coating film on the surface of the object to be coated, and a rough surface with a chilimen pattern, etc., on the surface of the object to be coated in one coating line. It is an object of the present invention to provide a coating film forming method and a coating device that can form both coating films.

"Structure of the Invention" (Means for Solving the Problems) A method for forming a coating film according to the present invention is a method for forming a coating film in which a thermosetting resin coating is applied to an object to be coated and then dried and cured. The method is characterized in that the non-contact of the contact table with the surface of the uncured coating film of an acidic gas which contacts the uncured coating film applied to the coating object and promotes surface curing of the uncured coating film is controlled. There is.

Furthermore, the m-film forming apparatus directly used in carrying out the method for forming a coating film according to the present invention includes a coating treatment apparatus for coating a thermosetting resin coating onto an object to be coated, and an uncured coating applied to the object to be coated. The coating line is equipped with a baking drying furnace for drying and curing the coating film, and is characterized by being equipped with a furnace having a heated acidic gas atmosphere.

The paint used in this invention is a thermosetting resin paint, and for example, general thermosetting resin paints such as acrylic resin paint, polyester resin paint, acrylic-melamine resin paint, and epoxy resin paint can be used. It is.

Furthermore, the color of the coating film can be arbitrarily selected by adding an appropriate pigment to the above-mentioned thermosetting resin coating. For example, inorganic pigments such as carbon black, lithopone, lead white, yellow iron oxide, Zinc white, yellow lead, titanium oxide, red bean oxide, etc. can be used alone or in combination. It is also possible to use organic pigments. In addition, by adding an a-free pigment to the paint, it is possible to reliably form a rough coating film such as a chilimen pattern, and it is also possible to express a beautiful and uniform pattern.

Water-soluble or solvent-based dip coating methods, electrodeposition coating methods, electrostatic coating methods, etc. are adopted as means for applying such thermosetting resin paints containing appropriate pigments. Halogenated hydrocarbon-based substances such as trichlorethylene, perchlorethylene, and other conventionally known solvents of this type are used.

Therefore, in the method for forming a coating film according to the present invention, after the above-mentioned thermosetting resin coating is applied to an object to be coated, the uncured coating is brought into contact with the uncured coating film coated on the surface of the object to be coated. The contact/non-contact of the acidic gas (including #-forming gas) that promotes surface hardening of the film to the surface of the uncured coating film is controlled.

That is, when a smooth, glossy coating film is to be formed, the acidic residue is dried and cured as it is without contacting the surface of the uncured coating film. On the other hand, when it is desired to form a rough coating film with a chilimen pattern, etc., the acidic gas is brought into contact with the surface of the uncured coating film, and the coating is dried and cured after this contact or in a contact atmosphere. In this way, acid gas (for example, sulfur dioxide gas, carbon dioxide gas, hydrogen chloride gas, halogenated hydrocarbon gas (trichlorethylene gas, etc.), hydrogen peroxide gas, nitrogen peroxide gas, etc.) is applied to the surface of the uncured coating film, or When an oxidizing gas (e.g., oxygen gas, osone) is brought into contact with the coating, the gas component acts in contact with the surface of the uncured coating film, giving priority to curing of one surface area over the inside, causing distortion in the top and bottom of the coating film. As a result, chilimen patterns (crystalline, stringy,
A rough coating film containing patterns such as shallow cracks and wrinkles is formed. The chili-like pattern varies depending on the components of the uncured coating film (hardness, viscosity), heating conditions, etc. As described above, in the coating film forming method according to the present invention, by controlling the contact and non-contact of acidic gas and oxidizing gas to the surface of the uncured coating film, a smooth, glossy and smooth coating can be achieved in one coating line. It is possible to form a rough coating film such as a film or a chilimen pattern with different degrees.

The frequency of contact and non-contact control of the acidic gas mentioned above differs depending on the difference in demand for smooth coatings and rough coatings, and the demand for one coating may be higher than the demand for the other coating. When the number of acid gases increases considerably, switching between contact and non-contact acid gas in the same coating line becomes less frequent. It is also possible to select a process in which the other coating film is formed for 1 to 2 days.

Figure i1 shows a simple embodiment of the coating film forming apparatus used to carry out the method of the present invention, and the coating line shown in Figure 1 includes a pretreatment apparatus 1 and an anodizing apparatus 2.
It is equipped with a hot water washing device 3, a draining drying oven 4, an immersion coating processing device 5 having a resin bath, a # gas atmosphere oven 6, and a baking drying oven 7. This shows a case where the furnace having an acidic gas atmosphere is installed independently as an acidic gas atmosphere furnace 6.

This acidic gas atmosphere furnace 6, as illustrated in FIG.
When the thermosetting resin coating uses a halogenated hydrocarbon as a solvent, for example, a direct heating drying oven having a heat source 61 of 700° C. or higher is used, in which the halogenated hydrocarbon is thermally decomposed into hydrogen chloride gas. In this case, a recirculation tube 62 is used that allows the halogenated hydrocarbon to reach the heat source 61 together with the circulating air flow. In addition, if the solvent described in 2 is not used in the coating method, an acid gas atmosphere furnace 6 equipped with a means for supplying a halogenated hydrocarbon, for example, and a heat source 61 for thermally decomposing the halogenated hydrocarbon is used. be done.

When forming a rough coating film such as a chilimen pattern, contact with acid gas in the acid gas atmosphere furnace 6 described above, and when forming a smooth and glossy pattern, use acid gas. Avoid generation or contact with acid gases.

In this case, a direct type AA drying furnace is used as the draining drying furnace 4, and an indirect heating drying furnace is used as the baking drying furnace 7 to form a smooth, glossy pattern. 6, and when forming a rough coating film with a chilimen pattern, etc., a process of treating in the acid gas atmosphere furnace 6, or using an indirect heating drying furnace as the draining drying furnace 4, and baking drying. When a direct heating drying oven is used as the oven 7 and a smooth, glossy pattern is to be formed, after painting, the material is reheated to a temperature higher than the curing start temperature in the drain drying oven 4 and then treated directly in the drain drying oven 4 or baked and dried. When processing in the furnace 7 and forming a rough coating film such as a chilimen pattern, there is a process in which the process is performed in the order of the draining drying furnace 4 → painting processing device 5 → acid gas atmosphere furnace 6 → baking drying furnace 7, or 4 and the baking drying oven 7 are both used to form a smooth, glossy, smooth pattern, the process in the acidic scum atmosphere oven 6 is omitted, and the rough surface coating of the chilimen pattern is omitted. When forming a film, treatment is performed in an acidic gas atmosphere furnace 6.

In addition, when a halogenated hydrocarbon is not used as a solvent and a smooth, glossy coating film is to be formed, the treatment in the acid gas atmosphere furnace 6 is omitted and a rough coating film with a chilimen pattern is formed. In this case, treatment is performed in an acidic scum atmosphere furnace 6.

FIG. 3 shows a coating film forming apparatus according to another embodiment of the present invention, and the coating line shown in FIG. , a draining drying oven 4, and an f* dipping coating treatment device 5 having a resin bath,
A baking drying furnace 7 is provided, and the draining drying furnace 4 is also used as a furnace having a heated acidic gas atmosphere. Therefore, hot water washing→draining→drying→
After painting, it is charged again into the draining drying oven 4, brought into contact with acidic scum as necessary, and then baked and dried in the baking drying oven 7 to be hardened.

The draining and drying furnace 4 used in this case doubles as an acid gas atmosphere furnace, so it may be a draining and drying furnace with a direct heating drying structure similar to that shown in FIG. When forming a surface coating film, drain drying oven 4
so that the circulating airflow inside passes through the circulation pipe (62),
Acidic gas such as hydrogen chloride gas thermally decomposed by the heat source (61) is supplied into the furnace, and when forming a smooth and glossy pattern, the reflux pipe (62) is shut off and hydrogen chloride gas is supplied to the furnace. Either prevent acidic gas such as gas from being generated, or omit reprocessing in the waterside drying oven 4.

FIG. 4 shows a coating film forming apparatus according to still another embodiment of the present invention, and the coating line shown in FIG. 3
, a draining drying oven 4, and an immersion coating treatment device 5 having a resin bath.
and a baking drying furnace 7, and shows a case where the baking drying furnace 7 is also used as a furnace having a heated acidic gas atmosphere. Therefore, after finishing the coating process, it is loaded into the baking drying oven 7 and baked and dried in an acidic gas atmosphere or a non-acidic gas atmosphere to harden it.

The baking drying oven 7 used in this case is also used as an acid gas atmosphere oven, and is, for example, a baking drying oven with a direct heating drying structure similar to that shown in FIG. When forming a rough coating film, a baking drying oven 7 is used.
so that the circulating airflow inside passes through the circulation pipe (62),
Acidic gas such as hydrogen chloride gas thermally decomposed by the heat source (61) is supplied into the furnace, and when forming a smooth and glossy pattern, the reflux pipe (62) is shut off and hydrogen chloride gas is supplied to the furnace. Prevent acid gases such as gas from being generated. In addition, even when the circulating air stream is directly heated by the heat source (61) or when the solvent is removed by heating in the drain drying oven 4, it is possible to form a smooth and glossy pattern. can.

FIG. 755 shows a coating film forming apparatus according to still another embodiment of the present invention, and the coating line shown in FIG.
A coating processing device 15 that performs coating and an acid gas atmosphere furnace 16
and a baking drying oven 17, so that a smooth coating film with a smooth gloss and a rough coating film with a chilimen pattern can be formed in one coating line in the same manner as described above. This is what I did. In this case as well, in addition to providing the acidic gas atmosphere furnace 16 exclusively as described above, it is also possible to use a coating line in which the baking drying furnace 17 also serves as the acidic gas atmosphere furnace.

The object to be coated to which this invention is applied is not particularly limited as long as it is a material that can withstand the heating temperature used for baking dry hardening of an uncured coating film. Needless to say, it is not limited to

(Example 1) In this Example 1, the draining drying furnace 4 is a direct type front-type drying furnace that directly heats the circulating airflow in the furnace with a flame, and the baking drying furnace 7 heats the circulating airflow in the furnace. A coating line was used, which was an indirect heating drying oven that heated using a heat exchanger with a primary side heat medium inlet temperature of 450°C. Aluminum alloy A6063 was pretreated in pretreatment device 1 and then anodized film was formed in anodization treatment device 2 by a conventional method.
After transferring the S-T5 material to the hot water washing device 3 and performing a hot water washing process at 70°C for 20 minutes,
℃ for 5 minutes, and then a black acrylic-melamine resin bath (solid content concentration 30
%, pigment concentration 15%) 70. '
immersed in O for 3 minutes, then pulled up at a speed of 1.2 m/
Next, the aluminum alloy A6063S-T5 material after dip coating was transferred to the baking drying oven 7 mentioned above and baked at 190°C for 30 minutes, resulting in a smooth coating with a thickness of 25jLm. A glossy black coating was formed.

Using the same painting line, aluminum alloy A6063S-T5 material was pretreated in pretreatment device 1 and then anodized film was formed in the anodization treatment device 2 by a conventional method, and then washed in hot water and drained and dried under the same conditions as above. After performing the dip coating treatment, this aluminum alloy A6063S-T5 material was again transported to the above-mentioned drain drying oven 4 and heated at 150'C for 15 minutes.
Heat treatment was performed for 1 minute to start curing the surface of the coating film, and then transferred to the above-mentioned baking drying oven 7 and baking drying was performed at 190°C for 30 minutes. A black coating film with a uniform chilimen pattern was formed.

(Example 2) In this Example 2, the drain drying furnace 4 is a direct heating drying furnace that directly heats the circulating air flow in the furnace with a flame, and the baking drying furnace 7 heats the circulating air flow in the furnace as a primary heating drying furnace. A coating line was used, which was an indirect heating drying oven that heated using a heat exchanger with a side heat medium inlet temperature of 480°C. Aluminum alloy A6063S was pretreated in the pretreatment device 1 and then anodized film was formed in the anodization treatment device 2 by a conventional method.
- After transferring the T5 material to hot water washing device 3 and performing hot water washing treatment at 90°C for 5 minutes, it was heated to 160°C in the above-mentioned drain drying oven 4.
After that, a white acrylic-melamine resin bath containing perchlorethylene as a solvent and titanium oxide as a pigment (solid content concentration 40%,
3 at 70°C in the coating treatment device 5 with a pigment concentration of 40%).
The aluminum base A6 after dipping was soaked for 1 minute and then pulled up at a pulling speed of 1.8 m/min.
Transfer the 063S-T5 material to the baking drying oven 7 mentioned above and dry it at 190
After baking and drying at ℃ for 30 minutes, the coating thickness was 25.
A smooth and glossy white coating film of Bm was formed.

Using the same painting line, the aluminum base A6063S-T5 material was pretreated in pretreatment device 1 and then anodized film was formed in anodization device 2 by a conventional method, and then washed in hot water under the same conditions as above and dried on the waterside. After performing the dip coating treatment, this aluminum alloy A6063S-T5 material is again transported to the above-mentioned draining drying oven 4 and heat treated at 160°C for 5 minutes to start hardening the coating film surface, and then, When it was transferred to the above-mentioned baking drying oven 7 and baked and dried at 190° C. for 30 minutes, a white coating film having a coating thickness of 20 gm and having a uniform faded chilimen pattern was formed on the entire surface.

(Example 3) In this Example 3, both the drain drying furnace 4 and the baking drying furnace 7 heat the circulating air flow in the furnace using a heat exchanger whose primary side heat medium inlet temperature is 450°C. In addition to being an indirect heating and drying furnace, it is also equipped with an acid gas atmosphere furnace 6, which is a direct heating and drying furnace that directly heats the circulating air in the furnace with a flame, in addition to the draining drying furnace 4 and the baking drying furnace 7. I used the line. The aluminum alloy A6063S-T5 material, which has been pretreated in the pretreatment device 1 and then anodized by a conventional method in the anodization treatment device 2, is transferred to the hot water washing device 3 and subjected to hot water washing at 70°C for 20 minutes. After that, draining and drying was carried out for 5 minutes at 150'0 in the above-mentioned draining drying oven 4. Next, a black acrylic-melamine resin bath (solid content Concentration 26%, pigment ei degree 2
0%) for 3 minutes at 60°C, and then pulled up at a pulling speed of 1.5 m/min. Next, the dip-coated aluminum alloy A6063S-T5 material was placed in the baking drying oven 7 described above. When the film was transferred to a vacuum cleaner and baked at 190° C. for 30 minutes, a smooth and glossy black coating film with a coating thickness of 15 gm was formed.

Using the same painting line, aluminum alloy A6063S-T5 material was pretreated in pretreatment device 1 and then anodized film was formed in the anodization treatment device 2 by a conventional method. The material was washed in hot water, drained and dried under the same conditions as above. After performing the dip coating treatment, this aluminum alloy A6063S-T5 material was transported into the above-mentioned acidic scum atmosphere furnace 6 and heat treated at 150° C. for 10 minutes to start hardening of the coating film surface. Then, it was transferred to the above-mentioned baking drying oven 7 and baked and dried at 190° C. for 30 minutes, and a black coating film having a coating thickness of 154 m and having a uniform matte chilimen pattern was formed on the entire surface.

(Example 4) In this Example 4, a coating line was used in which the drain drying oven 4 was an indirect heating drying oven and the baking drying oven 7 was a direct heating drying oven. The aluminum alloy A6063S-T5 material, which has been pretreated in the pretreatment device 1 and then formed with an anodic 8i oxide film in the anodization treatment device 2 by a conventional method, is then washed in the hot water washing device 3.
After washing with hot water at 70°C for 20 minutes, it was drained and dried for 5 minutes at 160°C in the drain drying oven 4, and then trichlorethylene was used as a solvent and a small amount of titanium oxide was added as a pigment. Acrylic colored beige by using wood and ocher.
Melamine resin bath (solid content 35%: pigment concentration 35%)
) at 50℃ for 3 minutes, then pulled up at a speed of 1.5m.
/min. Next, the aluminum alloy A6063S-T5 material after dip coating is again transported to the above-mentioned draining drying oven 4 and subjected to heat treatment at 160°C for 3 minutes to start hardening of the coating film, and then the above-mentioned baking drying oven 7 Move to 19
After baking and drying at 0℃ for 30 minutes, the coating thickness was 2.
2 pm of smooth, shiny, beige mIQ was formed.

Aluminum alloy A6063S-T was pretreated and anodized in the same way as above using the same painting line.
This aluminum alloy A6063 was washed with hot water, drained and dried, and dipped in paint under the same conditions as above.
The S-T5 material was transferred to the baking drying oven 7 and heated at 190°C for 30 minutes.
After baking and drying for a few minutes, a beige coating film with a coating thickness of 22 gm and having a uniform matte chilimen pattern was formed over the entire surface.

(Example 5) In this Example 5, the acid gas atmosphere furnace 16 and the baking drying furnace 17 both use a heat exchanger with a heat medium inlet temperature of 450°C on the primary side for circulating air flow in the furnace. A painting line, which is an indirect heating and drying oven, was used. and,
After being pretreated in the pretreatment device 11, the aluminum plate material Al200F on which a chemical conversion film was formed using a phosphoric acid-chromic acid-based chemical conversion treatment agent in the chemical conversion treatment device 12 in a conventional manner is transferred to the coating treatment device 15, where it is coated with titanium oxide. A cream-colored acrylic paint containing yellow lead was electrostatically applied after adjusting its viscosity with thinner, and then applied in the baking drying oven 17.
After baking and drying at 80° C. for 40 minutes, a smooth and glossy coating film with a coating thickness of 30 μm was formed.

Using the same painting line, aluminum plate material Al200F, which has been pretreated with pretreatment embedding 2i11 and then a chemical conversion film formed by a conventional method in chemical conversion treatment equipment 12, is transferred to painting treatment equipment 15.
After static TL coating under the same conditions as in Section L, the aluminum plate was transferred to an acid gas atmosphere furnace 16 containing 15 ppm of hydrogen chloride gas and maintained at a temperature of 160° C. After heating for a minute to start curing the coating film surface,
80'C! When baking was carried out for 40 minutes, a cream-colored coating film with a coating film Jγ of 30 lumen and a uniform matte chilimen pattern was formed over the entire surface.

Effects of the invention As explained above, the FF IIQ due to this invention
In the formation method, a thermosetting resin paint is applied to an object to be coated, and then dried and cured to form a coating film. Contact/non-contact of the acidic gas that promotes surface curing of the cured coating film to the surface of the uncured coating film is controlled;
The coating film forming apparatus according to the present invention, which is used directly to carry out the above method, includes a coating treatment apparatus for coating a thermosetting resin paint on an object to be coated, and a coating treatment apparatus for drying an uncured coating film applied to the object to be coated. In a painting line equipped with a baking drying oven for curing,
Since it is equipped with a furnace that has a heated acidic scum atmosphere, one painting line can produce both a smooth, glossy coating film and a rough coating film with a chili-men pattern on the surface of the object to be coated. It is possible to form and also. It is also possible to easily adjust the degree of roughness of the surface such as chilimen pattern, and a very excellent effect is brought about in that the coating film forming operation can be performed extremely efficiently.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of a coating film forming apparatus according to a one-page embodiment of the present invention, FIG. 2 is a plan explanatory diagram showing the configuration of an acid gas atmosphere furnace, FIGS. 3, 4, and 755 FIG. 2 is an explanatory diagram showing the configuration of a coating film forming apparatus according to another embodiment of the present invention. 4... Draining drying oven, 5.15... Paint processing equipment, 6.16... Acid gas atmosphere oven, 7.17... Baking drying oven.

Claims (5)

[Claims] (1) In a coating film forming method in which a thermosetting resin paint is applied to an object and then dried and cured, the surface of the uncured coating is cured by contacting the uncured coating applied to the object. A method for forming a coating film, which comprises controlling contact/non-contact of an acidic gas that promotes the uncured coating surface to the surface of the uncured coating film. (2) In a coating line equipped with a coating treatment device that applies thermosetting resin paint to the object to be coated, and a baking drying oven that dries and hardens the uncured coating film applied to the object, heated A coating film forming apparatus characterized by comprising a furnace having an acidic gas atmosphere. (3) The coating film forming apparatus according to claim (2), wherein the furnace having the heated acidic gas atmosphere is an independent furnace. (4) The coating film forming apparatus according to claim (2), wherein the furnace having a heated acidic gas atmosphere is also used as a draining and drying furnace. (5) The coating film forming apparatus according to claim (2), wherein the oven having a heated acidic gas atmosphere is also used as a baking drying oven.