JP2003265986A - Coating method and coating apparatus used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating method and a coating apparatus capable of forming a patterned coating film having a rugged surface by using a water based coating material. <P>SOLUTION: A patterned coating film 5 having the projecting and recessed surface is formed by spraying the mist of the water based coating material 2 toward a material 3 to be coated and ejecting and mixing the mist of an additive 4 containing a silicone with the mist-like body of the water based coating material 2. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus and a coating method capable of forming a patterned coating film having an uneven surface using a water-based coating material.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
BACKGROUND ART It is known to form a pattern coating film having fine irregularities on the surface of an object to be coated such as an exterior material and a case of an electronic device inside a building. A typical example of such a pattern coating film is a so-called Hammerton pattern in which small irregularities like a metal hit with a hammer are evenly continuous. Generally, such a patterned coating film is prepared by blending an organic solvent-based resin coating with an additive containing silicon oil, thoroughly stirring and mixing, and then spraying it onto a coating object using a coating tool such as a spray gun. It will be constructed. Then, the silicon repels a part of the coating material to form an uneven portion on the surface.

By the way, in recent years, from the viewpoint of protecting the global environment and improving the coating environment, various building manufacturers, automobile manufacturers, and the like have made efforts to use water-based paints instead of organic solvent-based paints. There is. For this reason, it is desired to form the above-mentioned patterned coating film by using a water-based coating material. However, even if liquid silicone oil is mixed with water-based paint and stirred and mixed, silicon cannot be uniformly dispersed in the paint and agglomerates immediately, resulting in uniform unevenness on the coating surface. Cannot be formed. As described above, it has been conventionally considered difficult to form the patterned coating film by using an aqueous paint.

As a result of intensive studies, the inventors of the present invention sprayed the water-based paint toward the object to be coated in a mist state and
The additive containing silicon is blown and mixed in the form of mist of this water-based paint in a mist state, that is, the water-based paint and the additive containing silicon, which are difficult to mix uniformly in a liquid state, are mixed together in the form of mist and The present invention has been completed by finding that the above-mentioned patterned coating film can be formed even when using a water-based coating material, based on the novel idea of immediately adhering the coating material onto the article to be coated.

As described above, it is an object of the present invention to provide a coating apparatus and a coating method capable of forming a patterned coating film having an uneven surface by using a water-based coating material.

[0006]

According to a first aspect of the present invention, the water-based paint is sprayed toward the object to be coated in a mist state, and the water-based paint atomized body contains silicon. It is a coating method characterized in that a patterned coating film having a surface with irregularities is formed by discharging and mixing the additives in a mist state.

It is desirable that the weight mixing ratio of the water-based paint and the silicon is, for example, 10,000: 1 to 10,000: 100. Further, dimethylpolysiloxane is suitable as the silicon.

Further, in the invention according to claim 4, a first coating tool capable of discharging the water-based paint in a mist state toward the object to be coated,
A coating apparatus comprising: a second coating tool that discharges and mixes an additive containing silicon in a mist state with a mist of a water-based coating material blown out from the first coating tool. To do.

The first coating tool includes a first gun body,
A gravity-type first spray gun having a paint tank connected to one side of the first gun body can be preferably used. The second coating tool is connected to a second gun-shaped body fixed to an upper portion of the first gun body and a side portion of the second gun-shaped body opposite to the paint tank. It is preferable to use a suction-type spray gun-shaped body having an additive tank.

The invention according to claim 6 is a coated article having a coating film formed by the coating method according to any one of claims 1 to 3.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. According to the present invention, as shown in FIG. 1, a water-based paint 2 is blown out toward an object 3 to be coated in a mist state, and an additive 4 containing silicon is atomized in a mist body 2a of the water-based paint. Discharge and mix. As a result, the water-based paint 2 and the additive 4 can be adhered to the article to be coated 3 in a uniformly mixed state, and as a result, the patterned coating film 5 having an uneven surface can be formed.

As described above, even if liquid silicone oil is mixed with water-based paint and stirred and mixed, silicon cannot be uniformly dispersed in the paint and agglomerates. However, it was thought that it was difficult to form irregularities uniformly on the surface of the coating film. However, as a result of earnest studies by the inventors, the water-based paint 2 and the additive containing silicon, which are not mixed uniformly in a liquid state, are atomized into a fine mist and mixed and immediately sprayed onto the article 3 to be coated. As a result, the water-based paint 2 and the additive 4 are formed on the surface of the article 3
It has been found that the silicon contained in the can be attached in a state of being mixed almost uniformly. Since the water-based paint 2 is partially repelled by silicon, the portion is made concave and the periphery thereof is made relatively convex. Since this action occurs randomly in all areas of the coating film, the patterned coating film 5 having an excellent appearance can be formed.

As the water-based paint 2, a liquid paint which is liquid at room temperature is used in this embodiment. The coating film main element of the water-based paint 2 is not particularly limited, but as an example,
Polyvinyl acetate, polyacrylic compounds, polystyrene butadiene, water-soluble synthetic resins, etc. can be used,
These can be appropriately changed depending on the use and physical properties of the article to be coated 3. The coating film forming main element is diluted with water (pure water) as a coating film forming auxiliary element, but if necessary, a coating film forming subelement such as a pigment and / or a binder may be blended.

As the additive 4, a liquid additive which is liquid at room temperature is used in this example. Specifically, a mixed liquid of silicon and a solvent is suitable. Silicon oil is preferably used for the silicon. The silicone oil may include both unmodified silicone oil and modified silicone oil, for example.

Examples of the unmodified silicone oil include dimethyl silicone oil, methylhydrogenpolysiloxane, methylphenylsilicon oil, dimethylpolysiloxane and the like. Examples of the modified silicone oil include alkyl-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, fluorine-modified silicone oil, amino-modified silicone oil, mercapto-modified silicone oil, epoxy-modified silicone oil, carboxyl-modified silicone oil, and high-grade silicone oil. Examples thereof include fatty acid-modified silicone oil. In particular, it is desirable to use dimethylpolysiloxane from the viewpoints of pattern reproducibility and design.

Further, according to the results of the experiments conducted by the inventors, when the amount of silicon blended with the water-based paint 2 is too large, the silicon adheres to the surface of the coating film in a solid coating form, so that the surface becomes smooth and a fine uneven pattern is developed. However, if the amount is too small, the water-based paint 2 is not repelled by silicon, and the recesses are discretely formed, which makes it difficult to form a uniform beautiful uneven pattern. is there. From this point of view, the weight mixing ratio of the water-based paint 2 and the silicon is not particularly limited, but is, for example, 100.
00: 1 to 10000: 100, more preferably 100
It is preferably from 00: 1 to 10000: 80. When forming a Hammerton pattern with an organic solvent-based paint, at least about 30 parts of silicon were mixed with 10,000 of the paint in a weight mixing ratio. It can be seen that the amount of silicon compounded is significantly smaller than that in the case of the system.

As a solvent for the additive 4, an ether type solvent such as butyl carbitol is suitable.

Further, if the total thickness of the pattern coating film 5 is too large, the performance of the coating film may be deteriorated due to sagging or cracks and the formation of the pattern may be affected. However, the coating film strength is unfavorably reduced. From such a viewpoint, the total coating film thickness is not particularly limited, but is about 35 to 55 μm, and more preferably 45 to 55.
It is desirable that the thickness is about μm. The coating method of the present invention is preferably carried out after the surface of the article to be coated 3 is preliminarily subjected to a base treatment including a chemical conversion treatment and / or a degreasing treatment, and then an undercoat is applied. In the case of undercoating, it is preferable to use only the water-based paint used for forming the patterned coating film in terms of adhesion.

Next, a coating apparatus 1 suitable for forming such a patterned coating film 5 will be described with reference to FIG. 2 and subsequent figures. FIG. 2 is an overall perspective view of the coating apparatus 1 of this embodiment,
3 is a front view thereof, and FIG. 4 is a sectional view taken along line AA of FIG. In the drawings, the coating device 1 of the present embodiment
Is a first coating tool 6 capable of ejecting the water-based coating material 2 toward the article to be coated 3 in a mist state, and an atomized body 2a of the water-based coating material blown out from the first coating tool 6 (see FIG. 1). 2) is integrally provided with a second coating tool 7 in which the additive 4 containing silicon is discharged and mixed in a mist state.

The first coating tool 6 has a first gun body 9 in the form of a pistol in this embodiment, and a paint tank 10 connected to one side of the first gun body 9. An example using a gravity-type first spray gun 11 is illustrated.

As shown in FIG. 4, the first spray gun 11 has a first air passage 16 in which an air on-off valve 15 that opens and closes by operation and a first on-off valve 17 intervene, and an aqueous paint. 2 through which the paint flow path 18 passes.
Then, the high-pressure air blown through the first air passage 16 can atomize and jet the water-based paint 2 that passes through the paint passage 18. Note that, in FIG. 4, the corner portions are directed upward and downward unlike FIGS. 2 and 3 so that the cross-sectional shape of the air cap 19 can be easily understood.

The air opening / closing valve 15 includes a valve seat portion 20 and a valve body portion 21. The valve seat portion 20 is formed with a through hole 23 formed in the front and rear through the handle 22 of the gun body 9.
Is interpolated to. Further, the valve seat portion 20 has a valve seat 20A having a tapered inner hole whose diameter increases rearward.

A supply path 24 of the first air flow path 16 from the guide hole 25 at the lower end of the handle 22 to the through hole 23 communicates with the through hole 23. This supply path 24 is provided with the adjusting screw 2
The air flow rate can be adjusted by the throttle valve 27 that moves forward and backward at 6. The guide hole 25 is connected to a high pressure air source (not shown) and is, for example, 150 to 500 kPa, and more preferably 25.
High-pressure air of about 0 to 420 kPa is supplied.

An outflow passage 29 communicates with the through hole 23. This outflow passage 29 extends upwards and the gun body 9
The air discharge port 34 or the pattern hole 35 provided in the air cap 19 through the circumferential groove 30 at the tip of the gun and the air hole 32 around the paint nozzle 31 through the joint hole 51 extending through the body portion of
Lead to The air supply amount to the pattern hole 35 is
It can be adjusted by a throttle valve 37 which can be moved back and forth with an adjusting screw 36.

The valve body portion 21 has a tapered base portion 21A capable of communicating or blocking the supply passage 24 and the outflow passage 29 by coming into contact with and separating from the valve seat 20A, and the base portion 21A.
And a valve shaft 21B extending from the front to the front.
The valve shaft 21B projects close to the back surface of the trigger h while being axially sealed by using a sleeve, an O-ring, and the like in addition to the pressing metal fitting 39.

The paint flow path 18 through which the water-based paint 2 flows
Is communicated with the paint tank 10 from a paint discharge port 40 provided at the tip of the center hole of the paint nozzle 31 to an inner hole 41 of the gun head and a lateral hole 42 laterally communicating with the inner hole 41. Is formed as. The water-based paint 2 is stored in the paint tank 10, and the water-based paint 2 is supplied by gravity to the position immediately before the paint nozzle 31.

Further, in this example, the paint tank 10 generates a frictional force with which the gun body 9 is rotatable about the horizontal axis L1 shown in FIG. 2 and can maintain the rotated position. It is connected to the gun body 9 through a joint portion 44 having an O-ring or the like inserted therein. Therefore, even if the gun body 9 is directed upward or downward depending on the coated surface of the object to be coated 3,
As shown in FIG. 2, the axis V1 of the paint tank 10 can be aligned so that it is always in the vertical direction. Therefore, the water-based paint can be reliably fed to the paint nozzle 31.

The first on-off valve 17 is a needle valve that can open and close the paint discharge port 40 in this example, and the rear end side of the seal ring 45 that is juxtaposed with the inner hole 41 is used to move the handle 22. It reaches the hole 46 at the upper end. Then, the rear end side of the first on-off valve 17 is slidably held by a support fitting 47 inserted in the hole 46 via a plunger 49. Further, the plunger 49 is biased forward by the spring 50.

In the present embodiment, the second coating tool 7 is composed of a suction type second spray gun-shaped body 12. The second spray gun-shaped body 12 includes a second gun-shaped main body 13 having no trigger fixed to the upper part of the first gun main body 9 through a connecting pipe portion 53, and the second gun-shaped main body 13. An example is one having an additive tank 14 which is connected to a side portion of the main body 13 opposite to the paint tank 10 and can store the additive 4. In such a coating apparatus 1, the second gun-shaped main body 13 is fixed to the upper part of the first gun main body 9, and the paint tank 10 and the additive tank 1 are provided on both sides thereof.
Since 4 are separately arranged, the weight balance during painting work is excellent and it is useful for improving usability. Further, since the suction type spray gun generally has a smaller feeding force for sending out the paint (additive in this example) than the gravity type, when the mixing ratio of the additive 4 is small as in this example. It is particularly suitable.

The second gun-shaped body 13 is shown in FIGS.
As shown in FIG. 3, the blowing direction B for spraying the additive 4 is set in the same plane (vertical plane in this example) and intersects substantially with the paint blowing direction A of the first spray gun 11 in this example. Shows that the front end is tilted downward.
Although not particularly limited, it is desirable that the angle θ sandwiched by the blowing directions A and B of the guns 11 and 12 is, for example, about 15 to 35 °, more preferably about 20 to 30 °. This is preferable in that the atomized water-based paint 2 and the additive 4 containing silicon can be more efficiently and uniformly mixed and can be attached to the article to be coated 3 in that state.

As shown in FIG. 4 and FIG. 5 which is an enlarged view thereof, the second gun-shaped main body 13 has a base cylinder portion 60 which is open and substantially cylindrical, and a front portion of the base cylinder portion 60. An outer pipe portion 63, which is airtightly screwed through a lock nut 62 and has an air cap 64 attached to the front end portion, is inserted into the outer pipe portion 63 with a gap, and the additive is discharged to the front end portion. And an inner pipe portion 65 having an additive nozzle 57 attached thereto.

The base tubular portion 60 includes a stepped tubular portion 60A having a void therein, and an end cap portion 60B fixed to the rear end thereof. A screw shaft 67 capable of adjusting the pulling margin S of the second opening / closing valve 55 that controls the injection amount of the additive 4 described later is screwed to the end cap portion 60B via a lock nut 69.

The outer pipe portion 63 and the inner pipe portion 65.
A second air passage 54 is formed between and. One end of the second air passage 54 passes through an axial groove 70 that is separated from the outer peripheral surface of the additive nozzle 57, and an air cap 64 is formed.
While being connected to the air hole 71, the other end is connected to the joint hole 51 of the first spray gun 11 through the connecting hole 72 provided in the base tube portion 60 and the inner hole 52 of the connecting pipe portion 53.
Therefore, the high pressure air from the first spray gun 11 is branched and taken into the second air flow path 54.

In the second gun-shaped body 13, the inside of the inner pipe portion 65 and the inner hole 73 formed in the base tube portion 60 are cut off from the second air flow path 54 to communicate with each other. , An additive flow path 56 through which the additive 4 passes. The additive flow path 56 is provided with the second opening / closing valve 55 that is a needle valve that controls the injection amount of the additive 4 from the additive nozzle 57. Further, the additive flow path 56 has an end that communicates with the additive tank 14 at one end of the inner hole 73.
The other end of 6 communicates.

The second opening / closing valve 55 is moved forward so that its tip portion is inserted into the tip hole 57a of the additive nozzle 57 to close the tip hole 57a and retreat to release the tip hole 57a. . The second on-off valve 55
Is guided to move back and forth by a sleeve member 80 installed in the base tube portion 60. The sleeve member 80 is useful for preventing leakage of the additive due to sliding of the second opening / closing valve 55 due to the inserted O-ring. As shown in FIG. 5, the additive flow path 56 has a radial gap t of 0.2 to 0.5 mm between the additive nozzle 70 and the second opening / closing valve 55.
More preferably, the additive squeezing portion 110 having a small thickness of 0.25 to 0.35 mm is provided. This gives resistance to the feed of the additive and helps to set the injection amount to a very small value.

A piston 77 is provided at the rear end of the second on-off valve 55. The piston portion 77 is arranged so as to be slidable back and forth in a cylinder chamber 74 provided between the sleeve member 80 and the end cap portion 60B. The piston portion 77 of the present example has a disc-shaped piston piece 75 fixed by a lock nut 79 and an inner peripheral surface of the cylinder chamber 74 by being inserted into an annular groove provided on the outer peripheral surface of the piston piece 75. And an O-ring 76 that keeps the space airtight. Further, by compressing and interposing a spring 58 between the piston piece 75 and the end cap portion 60B, the piston portion 77 always biases the second opening / closing valve 55 in the forward direction (the additive nozzle 57 It can be urged in the closing direction).

The inner hole 52 of the connecting pipe portion 53 has a second
It communicates with the cylinder chamber 74 through the lateral hole 81. Therefore, the air opening / closing valve 1 of the first spray gun 11 is
By opening 5, the high-pressure air continuously flows into this cylinder chamber 74 as well. As a result, the pressure in the cylinder chamber 74 is raised, and the second opening / closing valve 55 is retracted while the spring 58 is contracted. At this time, the retreat of the needle valve 55 can be restricted by screwing the needle valve 55 to the end cap portion 60B and bringing the piston portion 77 into contact with the screw shaft 67. Therefore, the second
The pulling amount S of the opening / closing valve 55, that is, the injection amount of the additive 4 can be easily controlled by adjusting the protrusion amount of the screw shaft 67 into the base tubular portion 60. After adjusting the pulling margin S, the adjustment amount of the screw shaft 67 can be maintained by the lock nut 69. This is because the force received from the piston portion 77 prevents the screw shaft 67 from being displaced and keeps a constant pulling margin S.
Help to keep.

In particular, when the mixing ratio of the additive 4 to the water-based paint 2 is very small and fine adjustment is required as in the present embodiment, the second adjustment by the screw shaft 67 is performed.
The adjustment of the pulling margin S of the open / close valve 55 and the maintenance of its position are extremely effective. Although not shown, for example, the operation head 67a of the screw shaft 67 may be provided with a scale visible from the outside to improve the usability by improving the efficiency of adjustment work.

As shown in FIG. 6 and FIG. 7 which is an exploded perspective view of the additive tank 14, the additive tank 14 has a cylindrical tank body 14a having an opening O in the upper portion and capable of storing the additive 4.
And an inner plug portion 14b that closes the opening O of the tank body 14a and has a small hole 14d in the center thereof.
An example is shown which is formed on the tank main body 14a and includes an upper lid portion 14e which also covers the inner plug portion 14b.

Although the tank main body 14a is small and made of resin in this example, its shape, material and the like can be appropriately changed. The inner plug portion 14b is closely fitted to the inner peripheral surface of the opening of the tank body 14a, and the flange portion 14b1 prevents the inner plug portion 14b from coming off.

As shown in FIG. 7, a screw hole 101 for mounting and an air hole 102 for taking in air are provided on the upper surface of the upper lid portion 14e (this will be described later).
The upper lid 14e has a pipe-shaped suction pipe 14
An example is shown in which "c" penetrates vertically and is integrally attached by a mounting nut 14f. The suction pipe 14c
Penetrates the upper lid portion 14e and protrudes upward and downward. Further, the suction pipe 1 protruding to the lower side of the upper lid portion 14e
The lower portion 14c2 of 4c passes through the small hole 14d of the inner plug portion 14b and is attached to the tank body 14a.
It communicates with the additive 4 in a. In addition, the small hole 1 of the inner plug portion 14b
A small gap is formed between 4d and the suction pipe 14c so that air can flow back and forth.

The additive tank 14 as described above is connected to the second gun-shaped main body 13 via a connecting member 85 in this embodiment. As shown in FIGS. 6 and 7, the connecting member 85 has an additive take-out flow path 86 having one end communicating with the additive flow path 56 and the other end communicating with the additive 4 in the additive tank 14, and one end. Has an air intake passage 87 (shown in FIG. 9) communicating with the outside air and the other end communicating with the inside of the additive tank 14.

The connecting member 85 includes, for example, an outer cylinder portion 90,
It is configured to include an inner tubular portion 91 that is inserted into the outer tubular portion 90 and is rotatable with respect to the outer tubular portion 90. The outer tubular portion 90 forms a block body having a substantially rectangular parallelepiped outer shape, and has horizontal through-holes 89 that are open on both sides in the longitudinal direction. The through hole 89 has a central hole portion 89A having a small inner diameter at a substantially middle portion of the axial length thereof and a second portion thereof.
An inner hole portion 89B having a large inner diameter and continuously provided on the gun-shaped body 13 side, and an outer hole portion 89C having a large inner diameter and continuously provided on the opposite side of the inner hole portion 89B. It has a dumbbell shape.

The inner shaft portion 91 has a nut portion 91B.
And a screw shaft portion 91A integrally formed on the second gun-shaped body 13 side of the nut portion 91B, and an insertion shaft portion integrally formed on the nut portion 91B on the side opposite to the screw shaft portion 91A. 91C and a shaft-shaped body. The inner shaft portion 91 is inserted into the inner shaft portion 91C side from the hole portion 89B side inside the outer cylindrical portion 90, and the insertion shaft portion 91C protruding from the outer hole portion 89C outside the outer cylindrical portion 90.
To the double nut 94 through the sleeve 93 and washer.
Are screwed on. Accordingly, the inner shaft portion 91 is rotatably held by the outer tubular portion 90 by the double nut 94 and the nut portion 91B.

Further, the insertion shaft portion 91C of this embodiment comprises a large diameter portion 91C1 having a large outer diameter, which is on the side of the nut portion 91B, and an insertion shaft portion 91C2 which is continuous with the large diameter portion 91C1 and has a small outer diameter. The O-ring 97A is interposed between the side end surface of the shaft portion 91C1 and the stepped portion of the central hole portion 89A, and the O-ring 97 is interposed between the sleeve 93 and the stepped portion of the central hole portion 89A.
B is interposed. As a result, an appropriate frictional force is generated between the inner shaft portion 91 and the outer cylinder portion 90 due to the O-rings 97A and 97B, and the frictional force is generated at the rotated position while allowing relative rotation between the two. It can be stopped. This is similar to the case of the first spray gun 11.
Even when the coating device is turned up and down according to the coating surface, the axis V2 of the additive tank 14 can always be freely aligned and held as shown in FIG. 2, and as a result, the additive 4 can be fed. Help to facilitate.

Further, the inner shaft portion 91 has a screw shaft portion 91A as a second screw shaft portion.
Of the gun-shaped main body 13 can be screwed into a mounting screw hole 82 provided on the side surface of the gun-shaped main body 13 to connect the connecting tool 85 to the second gun-shaped main body 13, and the one end of the additive flow path 5 can be connected by this screwing.
6 has an inner hole 91i communicating with 6. The inner hole 91i
Extends in the axial direction, and the O-rings 97A, 97
It ends between B. Further, the inner shaft portion 91 is provided with a circumferential groove 95 having a small depth extending in the circumferential direction between the O-rings 97A and 97B, and connects the circumferential groove 95 and the inner hole 91i. An upper joint hole 92a and a lower joint hole 92b are provided. In addition, the additive tank 14
The upper portion 14c1 of the suction pipe 14c of the
It is airtightly inserted and fixed in the pilot hole 99 of No. 0. Also, the upper lid 1
4e is integrally fixed to the outer cylinder portion 90 in advance in the state of FIG. 6 by means of screws 100 and screw holes 106. In such an embodiment, the additive withdrawal flow path 86 is
i, the upper and lower joint holes 92a and 92b, the circumferential groove 95, and the suction pipe 14c.

The connecting member 85 is provided with an air intake passage 87, one end of which communicates with the outside air and the other end of which communicates with the inside of the additive tank 14, as shown in FIGS. In the present embodiment, an example is provided in which the air intake passage 87 is provided so as to prevent moisture or the like from entering the additive tank 14 during normal application work or cleaning of the coating apparatus 1. ing. In addition, FIG.
It is sectional drawing (only half) of the BB part of FIG.

The air intake passage 87 of this embodiment has a first small hole 103 extending vertically and a second small hole 104 extending obliquely provided in the outer cylinder portion 90, and an outer peripheral surface of the sleeve 93. The structure including the peripheral groove 105 provided is illustrated. One end of the first small hole 103 is provided in the upper lid portion 14e of the additive tank 14 (see FIG. 7).
(Shown in FIG. 3) and communicates with the inside of the additive tank 14, and the other end opens at a hole 89C outside the outer tubular portion 90. As a result, the first small hole 103 and the circumferential groove 105 can communicate with each other inside the outer tubular portion 90. In this example, the first small hole 10
3 is provided at a position closer to one side in the circumferential direction with the screw hole 106 interposed therebetween.

In the present example, one end of the second small hole 104 communicates with the outside (atmosphere) of the outer cylindrical portion 90, and the other end opens with an outer hole portion 89C. The second small hole 104 is the screw hole 1
It is shown that it is provided on the side opposite to the first small hole 103 in the circumferential direction with 06 placed therebetween. In this example, the second small hole 1
04 is formed as an oblique small hole that extends at an angle α with respect to the side end surface 90X of the outer tubular portion 90 and with an angle β with respect to the lower end surface 90Y as shown in FIG. In the present example, both the angles α and β are set to 45 °, but the angle α and β are not limited to this, and it is desirable that the angles α and β are both set to a small angle less than 45 °.

In addition, one end of the second small hole 104 is open at the chamfered surface C including the lower end surface 90Y, the side end surface 90X and the side surface perpendicular to the side end surface in this example. Such an air intake flow path 87 communicates with the inside of the additive tank 14 from the opening 104a of the second small hole 104 provided on the chamfered surface C through the circumferential groove 105 and the first small hole 103. be able to. Such an air intake passage 87
Is opened to the outside (atmosphere) using the second small hole 104 extending downward, so that the cleaning liquid or the like is unlikely to enter into this opening. Therefore, when the coating apparatus 1 is washed, it is possible to prevent water from entering the inside of the additive tank 14 through the opening 104a. Therefore, even if washed, the additive tank 1
It is possible to effectively prevent foreign matter or unnecessary chemicals from entering the interior of the additive 4, and it is possible to always maintain the additive 4 in a pure state. The opening 104a of the second small hole 104
Is preferably a small hole having an outer diameter of about 1.0 to 2.0 mm.

The coating apparatus 1 of this embodiment opens the air opening / closing valve 15 of the first spray gun 11 by pulling the trigger h on the first spray gun 11.
The high pressure air sent from the guide hole 25 is supplied to the air discharge port 34.
And it can blow out from the pattern hole 35 as needed. As a result, a low pressure portion is generated around the paint discharge port 40.
Further, by further pulling the trigger 17, the first opening / closing valve 1
7 opens the paint discharge port 40, the water-based paint 2 is sucked into the low-pressure portion, and atomized by the continuously discharged high-pressure air to be jetted onto the object 3 to be coated.

At the same time, the high pressure air is discharged from the air hole 71 through the inner hole 52 of the connecting pipe portion 53, and
By raising the pressure in the cylinder chamber 74 through the lateral hole 81 and retracting the second opening / closing valve 55, the tip hole 57a of the additive nozzle 57 is opened. As a result, the additive 4 is atomized and can be sprayed onto the atomized body 2 a of the water-based paint 2. At this time, since the inside of the additive tank 14 is depressurized by sucking up the additive 4, air from the outside is sucked into the additive tank 14 through the air intake passage 87.

The pattern coating film 5 of this embodiment can shorten the drying time as compared with the conventional water-based coating film. It is considered that this is because the surface area of the coating film increases due to the uneven surface. For the drying, for example, initial drying at room temperature for 5 to 30 minutes, preferably preheating at 60 to 80 ° C. for about 5 minutes, and baking drying at 150 ° C. for about 20 minutes are sufficient. Therefore, it eliminates the need for large and complicated drying equipment that was required for conventional water-based coating,
The drying process can be realized with the same equipment as solvent-based paints. Further, as a result that the drying time can be shortened, it is possible to suppress a decrease in productivity as compared with the solvent paint.

FIG. 10 shows another embodiment of the present invention. In this form, for example, in an automatic coating line in which the object M to be coated is continuously supplied, it can be adopted as an automatic gun which is automatically operated by a computer or the like and has no trigger or the like. Furthermore, when a spray gun is used, the paint supply system can be modified into various forms such as a gravity system, a suction system, and a pressure system. Further, the coating apparatus 1 is not limited to the configuration shown in FIG. 2, and various arrangements of the tanks and the first and second guns can be changed.

[0055]

EXAMPLES A coating test was conducted under the coating conditions shown in Table 1 using the coating apparatus shown in FIG. 1 in the above embodiment. For the water-based paint, water-soluble melamine alkyd resin paint diluted with pure water (“Saimizu Diaton” manufactured by Taitai Kako Co., Ltd.) is used, and as an additive, an additive containing dimethylpolysiloxane (Asahi Denka Kogyo) is used. The product names “Adecanate B-190, Adecanate B-199” manufactured by Co., Ltd.) were used, and coating was performed on an iron plate having a smooth surface. In each example, after subjecting the object to be coated to chemical conversion treatment and degreasing treatment, the viscosity of the water-soluble melamine alkyd resin paint containing no additives described above was adjusted (paint coating viscosity 50-
The undercoat was applied for 60 seconds (NK-2CUP 20 ° C.).

As the undercoat, a gravity type air spray gun having a nozzle diameter of 1.5 mmφ was used, and the pattern width was 1 at room temperature of 20 ° C.
Reciprocating coating was performed 3 to 4 times at 00 °, air pressure of 350 kPa, gun distance to the object to be coated 25 cm, and gun operating speed 80 cm / sec. Then, it was baked and dried at 150 ° C. for 20 minutes.

Next, after the undercoat was dried, the water-based paint and the additive containing silicon were mixed in a mist form to carry out the overcoat. The topcoat was approximately the same as the bottomcoat in the first spray gun. The second gun-shaped body had a nozzle diameter of 0.5 mm and a pattern width of about 10 mm. For the drying of the topcoat, for example, the initial drying is performed at room temperature for 5 to 30 minutes, and further preheated at 60 to 80 ° C. for about 5 minutes, and further 15
It was baked and dried at 0 ° C. for about 20 minutes. The test results are shown in Table 1.

[0058]

[Table 1]

As a result of the test, it can be confirmed that the examples have good appearance and coating strength. In particular, the weight mixing ratio of the water-based paint and silicon is 10,000: 1 to 10
In the range of 000: 100, the recesses and the projections were well balanced, and the recesses had a diameter of about 0.5 mm and were uniformly recessed, and a very excellent appearance was obtained. Moreover, even if the surface was stroked, it was smooth and very good.

[0060]

As described above, according to the first aspect of the invention, the water-based paint is blown toward the object to be coated in the form of mist, and the additive containing silicon is added to the mist of the water-based paint. By ejecting and mixing in a mist state, a pattern coating film having an uneven surface can be formed using an aqueous paint.

When the weight mixing ratio of the water-based paint and silicon is limited to a certain range as in the second aspect of the invention, fine irregularities are easily formed evenly on the surface of the coating film, and the appearance is more excellent. Helps to form patterned coatings.

Further, as a fourth aspect of the present invention, as a coating apparatus, a first coating tool capable of ejecting the water-based coating in a mist state toward the object to be coated, and the first coating tool is blown out. A water-based uneven coating film can be formed by integrally providing a mist of a water-based coating material with a second coating tool that mixes the additive containing silicon by spraying it in a mist state.

According to a fifth aspect of the present invention, the first coating tool includes a first gun body and a paint tank connected to one side portion of the first gun body. And a second gun-shaped body fixed to an upper portion of the first gun body, and the paint tank of the second gun-shaped body. When it is composed of a suction type spray gun-shaped body having an additive tank connected to the side opposite to the above, it is possible to provide a coating apparatus excellent in weight balance.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a sprayed state of a coating material showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of a coating apparatus of this embodiment.

FIG. 3 is a front view thereof.

FIG. 4 is a sectional view taken along the line AA.

FIG. 5 is a sectional view of a second gun-shaped body.

FIG. 6 is a cross-sectional view showing an additive tank.

FIG. 7 is an exploded perspective view thereof.

FIG. 8 is a partial cross-sectional view of a connector.

FIG. 9 is an exploded perspective view of an outer cylinder portion.

FIG. 10 is a schematic diagram showing another embodiment of the present invention.

[Explanation of symbols]

1 coating equipment 2 Water-based paint 2a Water-based paint mist 3 Objects to be coated 4 additives 4a Additive mist 5 pattern coating 11 First spray gun 12 Second spray gun 13 Second gun-shaped body 14 Additive tank

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeru Baba             Hyogo Prefecture Amagasaki City Higashi Sonoda-cho 7-16-1 2-             507 F-term (reference) 4D075 AA01 AA39 AA40 AA83 AA85                       AE21 AE23 AE25 CB21 CB32                       DA06 DC03 DC18 DC21 EA06                       EA19 EB02 EB32 EB36 EC33                 4F033 QA01 QB02Y QB03X QB12Y                       QB18 QC02 QC07 QD14 QD18                       QD21 QD23 QE01 QE21 QF01X                       QF07Y QF27 QK03X QK16X                       QK20X QK23X

Claims (6)

[Claims] 1. A surface of a water-based paint is sprayed toward an object to be coated in a mist state, and an additive containing silicon is discharged in a mist state and mixed with the mist of the water-based paint. A coating method characterized by forming a patterned coating film having an uneven shape. 2. The coating method according to claim 1, wherein the weight mixing ratio of the water-based paint and the silicon is 10,000: 1 to 10,000: 100. 3. The coating method according to claim 1, wherein the silicon contains dimethylpolysiloxane. 4. A first coating tool capable of ejecting a water-based coating material in a mist state toward an object to be coated, and a water-based coating material atomized from the first coating tool containing silicon. A second coating tool that discharges and mixes the agent in a mist state. 5. The first coating tool comprises a first gun body,
A first gravity type spray gun having a paint tank connected to one side of the first gun body, and the second coating tool is fixed to an upper portion of the first gun body. And a second type gun-shaped main body and an additive tank connected to a side of the second type gun-shaped main body opposite to the paint tank. The coating apparatus according to claim 4, wherein: 6. A coated article having a coating film formed by the coating method according to claim 1.