JPS5916569A - Method for forming striped pattern in corner part of metallic member - Google Patents

Abstract

PURPOSE:To form easily a sharp striped pattern in the corner part of a metallic member, by painting an org. soln. type paint consisting of a specific compsn. on the metallic member having the corner part with an atomizing type coater. CONSTITUTION:An org. solvent such as butyl carbitol, acetophenone, or the like having >=32 dyne/cm surface tension at 25 deg.C and >=200 deg.C b. p. is used as a specific solvent at 20-70wt%. Such org. solvent and a vehicle component as well as 1-6wt% coloring pigment are used as essential components of this paint, and the viscosity of the paint is regulated to 8-15sec/Iwata cup at 20 deg.C in order to improve the suitability to painting and the smoothness of the paint coated film. The nonvolatile solid content of the paint is regulated to 10-30wt% and the surface tension to 20-40dyne/cm at 25 deg.C respectively in order to obtain sharp stripes. The paint having such compsn. is applied in the corner part of a metallic member with an electrostatic atomizing type coater or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables coating a metal member having a corner part with a paint having a specific composition using an atomizing coating machine, thereby making the color tone of the corner part different from that of other parts. This invention relates to a method for forming a clear striped pattern on a part of the corner.

In the present invention, the metal member having a corner portion is made of, for example, iron, aluminum, copper, stainless steel, or an alloy containing these.

However, a part of a corner is a convex part, a concave part, or a corner part formed in a linear or dotted manner on the surface of a metal member. For example, if the inner angle (or outer angle) is 150 degrees or less, The present invention includes a convex portion, a concave portion, or a corner portion having a radius of curvature of 5 or less, or a convex portion, a concave portion, or a corner having a radius of curvature of 5 or less at the tip. The present invention is not limited to the above examples, and any part of a corner where a striped pattern can be formed by applying a paint having a specific composition described later using an atomizing coating machine may be used. Examples of metal members having such corners include fittings (sashes, shoji screens,
(sliding doors, sliding doors), architectural structures, household goods, home appliances, appliances,
Examples include items that require design and decoration, such as crafts and ornaments.

In addition, the striped pattern in the present invention is a pattern formed by making the color tone of the coating film on some corners of the coating film on the surface of a metal member different from that on other parts (mainly flat parts). It is. In other words, the coating film on some corners is thin and almost transparent, allowing the surface to be coated (base surface) to be seen through, but the coating film on other parts (mainly flat areas) is colored and opaque. In addition, the color tones of these image areas are different, and a zero-stripe pattern is formed in which the surface to be coated can be seen through only a portion of the corner. This striped pattern includes not only linear patterns but also dotted patterns in irregularities other than linear shapes, which are determined by the shape of a part of the corner, and the width or diameter thereof is about 1 to 10 mm.

Conventionally, aluminum extruded shapes are coated with a chlorinated hydrocarbon solvent-based or water-based thermosetting paint using the dip coating method, making the color tone of some corners different from other parts. Colored surface treatment methods are already known. Moreover, this thermosetting paint for dip coating was not newly developed for patterned applications, but ordinary thermosetting paints or paints to which dimethylpolysiloxane was added were used.

The inventors of the present invention conducted a detailed study on the coloring surface treatment method for patterning aluminum materials by the above coating method, and as a result, it was found that there were various defects caused by the dip coating itself, as shown below. That's what I did. In other words, ■Regardless of the size of the object to be coated (aluminum extrusion), it is necessary to always fill the dip coating bath with a certain amount of paint. It is not possible to immediately meet the demands for a wide variety of striped pattern finishes, and in order to meet these demands, it is necessary to renew the paint bath, and the nine operations of removing the paint and cleaning the bathtub become extremely complicated and require a large amount of work. It is extremely disadvantageous economically as it requires a lot of effort. ■In order to achieve a uniform coating thickness, the conditions for the speed at which the object to be coated is lifted from the dip coating bath are important, but it is extremely difficult to set these conditions. In order to prevent the pigments contained in the paint in the bathtub from settling, it is necessary to constantly stir the paint even when not painting, and even if stirring is done, it may not get into the corners of the bathtub. Since the accumulation of pigment is unavoidable, it is economically disadvantageous, and the coating color stability and finished appearance deteriorate, and it is necessary to improve the equipment by not curving the corners to prevent pigment accumulation. ■When lifting the object from the bathtub, if the object twists, twists, vibrates, or the surface of the paint is rippled, an unnecessary wavy pattern will appear on the painted surface, resulting in a uniform coating. It has the disadvantage that it cannot be obtained.

Therefore, the inventors of the present invention applied the thermosetting paint using an atomizing coating machine, which has almost no such defects, and found that the color tones of some corners and other parts were clearly different. This was difficult, and it was not possible to obtain colored aluminum with a clear striped pattern and excellent design and decorative properties.

In view of this situation, the present inventors formed a clear striped pattern on a part of the corner of a metal member using an atomizing coating machine that does not have the above-mentioned defects 1 to 2 caused by the dip coating method. He conducted intensive research on the method. As a result, by using an organic solution type paint having a specific color pigment content, solvent component, viscosity, non-volatile solid content, surface tension, etc., the objective was achieved and the present invention was completed.

That is, in the present invention, a metal part having a part of the corner is coated with an organic solution type paint 1 to make the color tone of the part of the corner different from that of the other parts. According to the metal department, (1) the coloring pigment content is J to 6%, and (2) the surface tension at 25°C is 32 dyne/ctn or more. And the boiling point is 20
Contains 20-70% by weight of an organic solvent having a temperature of 0°C or higher, (3) Has a viscosity of 8-15 seconds at 20°C (Iwata Cup)
(4) The nonvolatile solid content is 10 to 30% by weight,
and (5) the surface tension at 25°C is 20 to 40 dyneA.
A method for forming a stripe pattern on a part of a corner of a metal member, the method comprising forming a stripe pattern on a part of the corner by applying a 1N organic solution paint using an atomizing coating machine. The organic solution type paint (hereinafter abbreviated as "this paint") used in the present invention will be explained.

This paint contains a vehicle component, a colored pigment, and an organic solvent as essential components9.Moreover, in order to form a clear striped pattern and finish the coated surface with excellent smoothness using an atomizing coating machine, In the present invention, it is extremely important to adjust the content of color pigments and nonvolatile solids to a specific range, to use an organic solvent with specific properties, and to adjust the viscosity and surface tension of the paint to a specific range. be.

That is, it is necessary that the content of color pigments in this paint is in the range of 1 to 6% by weight, including the paint at the time of painting. Within this range, 3 to 6 weight q'L% when a light colored pigment is blended, and 1% when a dark colored pigment is blended.
~: The 3rd grade clerk is in good shape. When adjusted within this range, the coating film applied to some corners becomes thinner, allowing the surface to be coated (underlying surface) to be seen through, and - the brim and other areas (mainly flat areas) are sufficiently colored and hidden by this paint. Because it is possible to
As a result, a clear striped pattern can be formed in some corners. Therefore, if the coloring pigment content is less than 1 weight factor, the hiding power of the paint film applied to the coating surface in some corners will decrease, while if it exceeds 6 weight factors, the coating will be applied to some corners. The transparency of the painted film decreases,
Both have clear stripes in some corners.

In this paint, a specific organic solvent with a surface tension of 3 2 dyne/z or more at 25°C and a boiling point of 200°C or more (hereinafter referred to as "specific solvent") is used as one or all of the organic solvent components. It is necessary to use

This is because, by using the specific solvent, the coating performance with an atomizing type coating machine is improved, and the width of the Strife 0 pattern in a part of the corner can be increased to more than 1 stage, which prevents sagging of the paint film. This prevents the occurrence of yuzu skin, and as a result, a clear striped pattern can be formed.

The specific solvent has excellent compatibility with the vehicle component and other organic solvents, evaporates after the cured coating film is formed, and has little or no remaining in the coating film, and has a surface tension of 32 dyneAm or more at 25°C. , preferably 3
3-5 Q dyne A7n, and the boiling point is 20
It is an organic solvent with a temperature of 0.0C or more, preferably 200 to 250C. Specifically, acetophenone, calpitol,
Examples include butylcarpitol, noethylene glycol, and benzyl alcohol, and these may be used alone or in combination of two or more, but butylcarpitol is particularly preferred.

When the above-mentioned surface tension of the specific solvent is lower than 3 2 dyne/z, the striped pattern at some corners becomes narrower, resulting in poor design and decorative properties.In fact, when the boiling point is lower than 200°C, the coating film deteriorates. This is undesirable as the striped pattern in some corners becomes unclear.

In addition, the content of specific solvent in this paint at the time of painting is 2
0 to 70% by weight (preferably d, 20 to 50% by weight), and if the weight is less than 20% by weight, the leveling properties of the coating will deteriorate, and yuzu skin and sagging will occur on the coating surface, as well as the formation of a striped pattern. On the other hand, if the amount is insufficient and the amount exceeds 70 parts by weight, poor coating will occur with the atomizing paint machine, sagging will occur easily, and the concealability of the paint film will decrease in areas other than some corners. It is difficult to obtain a clear striped pattern. becomes.

Furthermore, in order to improve the paintability and smoothness of the paint film, and to form a clear striped pattern, the viscosity of this paint during painting must be adjusted to 8 to 15 seconds/Iwata cup at 20°C. . The viscosity can be easily adjusted by adjusting the composition and content of vehicle components and specific solvents (including other organic agents). When the viscosity becomes lower than 8 seconds, the hiding power decreases, and the sulfur color of the @ film formed on the parts other than the corners becomes insufficient, resulting in a stripe of 0.
The pattern becomes unclear. On the other hand, when the viscosity is higher than 15 seconds, the transparency of a part of the corner decreases, the striped pattern becomes unclear, and moreover, there is a risk that skin spots and secondary sag may occur in the coating film.

In addition, in order to form a clear striped pattern, it is necessary to adjust the nonvolatile solid content of the paint at the time of coating to 10 to 30% by weight. The nonvolatile solid content is mainly composed of a vehicle component and a coloring pigment, and may also contain a small amount of other pigments and additives. When the non-volatile solids content decreases by 10% by weight,
The coating thickness in areas other than the corners becomes thinner and the hiding power decreases, and conversely, if the amount increases by more than 30% by weight, the coating thickness in the corners becomes thicker and the transparency decreases.
In either case, a clear striped pattern cannot be formed.

Furthermore, the surface tension of the paint during coating is also important, and must be adjusted to 20 to 40 dyneAjn (preferably 25 to 35 dyneA-In) at 25°C. This is because when the size is smaller than 20dy11e/Cm, it becomes difficult to form a striped pattern in some corners, while when the size is larger than 40dyne/z, marks, scratches, etc. occur on the coating film, and the finished state is affected. It is inferior. The surface tension can be easily adjusted mainly by using a specific solvent, and if necessary, additives can also be used in combination.

The requirements specified above for this paint are essential for achieving the purpose of the present invention, and the absence of any of these requirements is not preferable.

The vehicle component of this paint is preferably a thermosetting resin, such as amino-acrylic resin, in order to maintain the physical and chemical properties of the paint film, weather resistance, etc. Preferred are resins based on polyamides, amide/alkyd resins, and combinations of these with epoxy resins, but the present invention is not limited thereto. Also, known coloring pigments can be used, such as inorganic and organic coloring pigments such as titanium oxide, yellow lead, zinc oxide, chromate, red iron oxide, cadmium yellow, phthalocyanine blue, cobalt flue, and carbon black. can be given. Furthermore, the organic solvent is mainly composed of the above-mentioned specific solvent, and if necessary, other organic solvents may be used in combination. Hydrogen solvents, propyl alcohol, butyl alcohol, hexyl alcohol, cyclohexanol natono alcohol solvents, ketone solvents such as methyl ethyl ketone, methyl isobutyl keto/, cyclohexanone, inpropyl ether, 2-ethylhexyl ether, ethylene glycol monomethyl ether, Examples include volatile solvents having a boiling point lower than 200° C. or a surface tension lower than 32 dyne/cm, such as ether solvents such as ethylene glycol monobutyl ether, ethylene glycol monobutyl ether, and isoethylene glycol monomethyl ether.

In terms of composition, this paint has the above-mentioned vehicle component, color pigment, and organic solvent (including specific solvent) as essential components, but if necessary, extender pigment, metallic pigment, plasticizer, There is no problem even if a compound containing a polypropylene compound, other additives, and the like may be added as appropriate.

Examples of extender pigments include alumina, clay, kaolin, talc, barium carbonate, pallite, and flexure, and examples of metallic pigments include aluminum powder, gold powder, copper powder, and stainless steel powder.

Examples of plasticizers include dimethyl phthalate, butyl phthalate, butyl phthalate, diisobutyl phthalate, nooctyl fucre-1, butylbennorfucrate, tricresyl phosphate, and butyl sepacate. Benzyl phthalate is particularly preferred. Examples of the siloxane compounds include nomethylzoloxane, methylphenylsiloxane, methylalkylsiloxane, methylhalokened alkylsiloxane, and derivatives thereof. In this paint, the amounts of the above plasticizer and siloxane compound added are each 0.0 based on the paint at the time of painting.
Particularly preferred is a weight ratio of 1 to 0.5.

Next, a method of forming a striped pattern on a part of the corner of a metal member by applying the above-described paint using an atomizing type coating machine will be described.

This paint can be applied directly to metal parts, but
It is preferable to pre-treat the surface of the member in advance. This pretreatment is a known method and can be easily performed.

For example, when looking at metal parts made of aluminum (including its alloys), after degreasing, etching, etc.
An anodic oxide film or a chemical film is formed.

An anodic oxide film is formed by electrolyzing a metal member in a bath of sulfuric acid, oxalic acid, or a mixture of these acids, and then the film can be dyed with a dye, electrolytically colored, electrolytically colored, etc. to any desired color tone. Can be colored. Further, the chemical film is formed by chromate treatment, phosphoric acid treatment, boehmite treatment, etc., and the film can also be colored. In the present invention, a colored film is preferable compared to a colorless film because it allows the striped pattern of a part of the corner to have a wide variety of colors.

Furthermore, it is preferable to form a colored base film on metal members other than aluminum in advance in order to improve adhesion with the present paint and to diversify the colors of the striped pattern.

In the present invention, an atomizing type coating machine is a coating machine that atomizes paint into fine particles and applies it to the object to be coated, and simply refers to an air spray coating machine, an airless spray coating machine, and an electrostatic atomization coating machine. For example, a type coating machine can be used, and any known ones can be used.

In the present invention, among these, an electrostatic atomizing coating machine is particularly preferable because it has excellent spreading properties (coating efficiency) of atomized paint and excellent ability to form a striped pattern.

First, an air spray paint machine atomizes paint using the power of compressed air and applies the paint onto an object. When forming a striped pattern on a part of the corner of a metal member,
Coating with this paint using the coating machine can be carried out by a known method, but in particular, during coating, the paint temperature is 10 to 40°C, the coating atmosphere temperature is 10 to 40°C, the coating atmosphere humidity is 25 to 85%, and the compressed air pressure is 2 to 85%. 5kVCTn2, air consumption 40~5
5017 minutes, paint discharge rate 10-600cc/min/gun,
It is preferable to conduct the coating under conditions such as a distance of 20 to 50 crn to the surface to be coated.

Airless spray paint machines are paint machines that apply high pressure to the paint, blow it out at high speed through small holes in the spray nozzle, and atomize it due to air resistance as it travels into the air. The temperature and humidity of the painting atmosphere were set to the same range as the previous air spray paint machine, the paint pressure was set to 50 to 200 cm (97 cm), and the paint discharge amount was set to 10 cm.
~700 (IC/min/gun, distance to coated surface 20
It is preferable to adjust it to ~50α.

However, electrostatic atomizers use the object to be coated as an anode and the paint spraying device as a cathode, and apply a high negative voltage to this to create an electrostatic field. This is a paint machine that sticks to objects. The coating machines can be roughly divided into two types: electrostatic atomization, which uses electrostatic force to atomize the paint and adsorbs it to the object to be coated using electrostatic attraction, and electrostatic atomization, which uses mechanical force to apply an electric charge to the atomized paint particles.
It is classified into a gun-type method in which the coating material is attracted to the object by electrostatic attraction, and both can be used in the present invention, but the former method is particularly preferred.

The electrostatic atomization method described above includes a disk type and a bell type. The disc shape supplies paint to the disc under high voltage,
As the disc rotates, the paint spreads into a thin film and becomes electrically charged, and a strong electric field is formed between the disc edge and the object to be coated.When the charged paint flies out from this edge, it becomes fine particles due to a repulsion phenomenon. This is a coating machine that absorbs the paint onto the object being coated. There are fixed type and V shift 0 locate type, both of which can be used in the present invention.

In the present invention, when applying the present paint in the disc shape, the paint temperature, coating atmosphere temperature and humidity may be the same as those of the air spray paint machine, the diameter of the disc is 5 to 30 inches, and the rotation of the disc is as follows. The number is 500 to 5000 rpm, the voltage is -50 to -15
0kV, supply amount (discharge amount) of this paint is 10 to 700cc
It is preferable to adjust the speed to /min/disc.

In a bell-shaped paint sprayer, when paint is supplied to the center of a bell-shaped atomizing head discharge electrode that rotates at high speed, it spreads into a thin film on the inner surface of the bell due to the action of centrifugal force9, and from the edges it forms a thread. As it is shaken out, it is atomized by high voltage and charged,
This is a coating machine that attracts the object to be coated according to the electric field formed between the edge and the object. There are stand type and V diglocate type, both of which can be used in the present invention. Further, although the bell-shaped atomizer includes a standard type and a mini-bell type in which the bell is miniaturized, it is preferable to use the latter in the present invention. In the present invention, when applying this paint with a mini-bell type atomizer, the paint temperature, coating atmosphere temperature and humidity may be the same as those of the air spray atomizer, but the atomizing head discharge electrode (rotating head) diameter 1~1
5 inches, its rotation speed is approximately 5,000 to 30,000 rpm,
It is preferable that the paint supply amount (discharge amount) is 10 to 1500 CC/min/bell and the voltage is -50 to -150 kV. In addition, in the mini-bell type, in order to rotate the bell at high speed, the centrifugal force effect increases and the direction of paint scattering is perpendicular to the paint sprayer, so a near ring is installed on the back of the bell to eject air called shaving air. Blow out and make the paint scattering direction the same direction as the paint sprayer (towards the surface to be coated),
It is necessary to adjust the turn diameter.

On the other hand, gun-type electrostatic atomizers improve the coating efficiency by providing an electrode for applying a negative high voltage to the gun tip of the air spray atomizer and airless atomizer. The discharged atomized paint particles are negatively charged by the high voltage of the electrode, fly in the direction of the electric field formed between the electrode and the object to be coated, and are applied to the object to be coated.

By applying this paint to a metal part having a part of the corner using an atomizer using the method described above and curing it by heating, the striped pattern with excellent design and decorative properties as the object of the present invention can be obtained. A metal part 4.4 having the following values is obtained.

In other words, for objects to be coated that have a part of a linear corner, the part of the corner is suspended in an almost vertical direction, and for an object to be coated that has a part of a corner other than a line, it is suspended in an arbitrary direction. Then, the present paint is applied to the object to be coated. After painting, it may be heated and cured (fired) directly, but it is necessary to prevent the applied paint from dripping, to make the film thickness uniform, and to prevent the paint from flowing down at the upper end of the metal part. Therefore, it is preferable to heat at 50 to 140°C for 1 to 10 minutes, and then heat cure (baking) at 150 to 180°C for 10 to 30 minutes. In order to make the striped pattern clear, the thickness of the flat part of the cured film of this paint should be 7 to 7.
25 noi is preferred.

With the completion of the present invention, it has become possible to form a clear striped pattern on a part of the corner of a metal member using an atomizing type coating machine, which has never been done before. This is due to the use of this paint having the specific composition and properties described above. The reason for this is unknown, but it is thought that the mechanism for forming a coating film using this paint and the atomizing type coating machine matched the mechanism for forming a striped pattern on a part of the corner. As a result, all the above-mentioned deficiencies in the conventional method of forming a striped pattern using the spy coating method can be eliminated.

The present invention will be explained in more detail below by giving Examples and Comparative Examples.

■Paint composition and properties As shown in Table 1, all amounts of each component are shown in parts by weight.

The surface tensions and boiling points of the organic solvents used in paint plates 1 to 9 are as shown in Table 2.

Table 2 Among the above paints, paints A1 to A3 correspond to the main coatings that can be used in the present invention, and paints A to A 9 are for comparison.

II Examples and Comparative Examples (1) Object to be coated (a) After forming an anodized film, an extruded aluminum profile was electrolytically colored. Length: 67n1 Corner angle: 90°, radius of curvature of one corner: 1 To and Sanho aluminum alloy (A606
3S-T5) Two types of extruded shapes were degreased, etched, and smut removed by conventional methods, and then 18w/
Anodic oxidation treatment was performed at 1.2 A/dm for 2.35 minutes in an electrolytic solution containing v% sulfuric acid, 15,9/A aluminum, and a liquid temperature of 20° C. to form an oxide film of 12 μm. After washing with water, AC electrolysis was carried out at 15 V for 6 minutes using the following coloring solution to obtain a bronze-colored product 1T-1.

Ni50・6H030g/1 2 H3BO225Vt MgSO4・7H2015gμ (↑籟.)2so43og/1- pH5,5 Liquid temperature 25℃ Counter electrode Carbon However, the extruded phase with the above radius of curvature of 1 mm is Example 1
The extruded shape used in Comparative Examples 1 and 2 and having three radius curvatures was used in Example 2.

(b) Aluminum alloy extruded shape with chemical conversion treatment, length 6m, corner angle 90°, radius of curvature of one corner of 2mm (A6063-T5)
) An extruded shape was chemically treated with Bonderite-#-713 (chromate treatment, manufactured by Nippon Barker Reishi Co., Ltd., trade name) (the surface was colored pale yellow).

(2) Atomization type paint machine A disc type electrostatic coating machine was used.

Disc diameter: 20 inch disc rotation speed: 1700 rpm Paint discharge rate: 400 cc/min/disk painting atmosphere temperature = 25°C Painting atmosphere humidity = 50 cm Paint temperature = 25°C Distance to object to be coated: 50 crn (3) Painting Then, apply the above coatings 1 to 9 electrostatically to the object to be coated hanging vertically so that the film thickness of the heat-cured flat part is about 20 μm (cured coating film).
After pre-drying at 00°C for 5 minutes, it was heat-cured at 170°C for 30 minutes.

■Performance test results The results regarding the coating film performance and finish and appearance of the metal parts coated as described above are shown in Table 3.

In Table 3, (*1) Stickiness: According to JIS H8602 467.

(*2) Hardness: According to JIS H8602 4.8.

(*3) Coating film thickness: According to JISH8602 4.6. The measurement points are a position 10 to 15> from the upper end (upper part), a central part (middle part), and a position 10 to 15> from the lower end (lower part).

(*4) Striped pattern: Erosion of a striped pattern formed at a part of the corner where the base surface can be seen through was measured.

"Unclear" means that the striped pattern could not be clearly recognized.

(*5) Uniformity of strike 0 pattern: This is the result of observing whether the width of the striped pattern formed in a part of the corner is uniform from the top edge to the bottom edge of the object to be coated.

◎ indicates that a uniform pattern is formed, △ indicates that the pattern itself is unclear and the width is uneven, and × indicates that the pattern is hardly visible and the width is extremely uneven.

(*6) Gloss: This is the result of visual judgment of the painted surface of the flat part (parts other than some corners). ◎ indicates good, ○ indicates slightly glossy, and × indicates poor gloss.

(*7) Painted surface condition: According to JISH8602 4.4.

(*8) Concealability: ``◎'' indicates that the colored coating film formed on the flat area completely covers the base surface.
Those where the base surface was clearly visible through the paint film were marked as "×". Toe 9: On the flat part, a coating film is formed that completely hides the base surface so that it cannot be seen through, while on the other hand, at some corners, a part where the color tone of the base surface can be clearly seen is formed by the width of the base. (striped pattern) is the most suitable.

patent applicant Yoshida Industries Co., Ltd. Kansai Paint Co., Ltd.

Claims (1)

[Claims] To form a striped pattern on a part of the corner by applying an organic solution type paint to a metal member having a part of the corner and making the color tone of the part of the corner different from that of the other part. At the time, the metal member has (1) a coloring pigment content of 1 to 6;
(2) surface tension at 25°CK is 32
dyne/m or more and contains 20 to 70% by weight of an organic solvent with a boiling point of 200°C or more, (3) a viscosity of 8 to 15 seconds at 20°C (Iwata cup)
(4) The nonvolatile solid content is 10 to 30% by weight,
and (5) the surface tension at 25°C is 20 to 40 dyne.
A method for forming a striped pattern on a part of a corner of a metal member, characterized in that a striped pattern is formed on a part of the corner by applying an organic solution type paint of /z using an atomizing coating machine.