JPS61249567A - Method and apparatus for coating coating liquid such as sizing agent - Google Patents

Abstract

PURPOSE:To form a uniform and stable extremely thin film on the surface of a material to be treated by placing the material in a hermetic treating chamber, bringing a coating liq. into aerosol, atomizing the aerosol into the treating chamber and making the pressure of the aerosol higher than the atmospheric pressure. CONSTITUTION:When a coating liq. such as a sizing agent and a colorant is coated on the surface of a plastic molding, paper, etc., a material 16 to be treated is placed in a treating chamber 2 and the chamber is hermetically closed. Then a compressor is operated and a soln. in a tank 6 is introduced into an aerosol atomizer 5 and spouted from a nozzle 5a in the form of many fine particles having <=100mu diameter into an aerosol atomization chamber 4. The formed aerosol is injected into the treating chamber 2. The pressure in the treating chamber 2 is made higher than the atmospheric pressure, the chamber is supersaturated with aerosol and a coated film consisting of the aerosol component is formed on the surface of the material to be treated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method and apparatus for applying a coating liquid used for surface treatment of metals, etc., and application of food additives.

[Conventional technology]

To apply and form a film made of a surface modifier such as an antistatic agent on the surface of a synthetic resin molded product, the object to be treated is immersed in a solution or aqueous dispersion of the surface modifier, or with a brush, etc. In addition, surface modifiers are kneaded into raw materials during synthetic resin molding, and this is allowed to bleed onto the surface to form a film of surface modifiers on the surface of synthetic resin molded products.
In these methods, the coating of the surface modifier becomes too thick and easily peels off due to friction or the like, uneven coating occurs, the coating is easily moved, and it is difficult to obtain a stable and uniform coating.

Therefore, the surface modifying agent is made into a mist or aerosol consisting of fine particles, and this mist or aerosol is sprayed onto the object to be treated, thereby forming a uniform and stable ultra-thin film on the surface of the object to be treated, resulting in a long-term surface modification effect. A method has been developed by the Applicant that allows for retention over an extended period of time.

[Problem to be solved by this invention] In this application using mist or aerosol, the particle size of these particles is i.
Although the particle size is preferably less than ooμ, such fine particles repel each other and stably float in the air to form an aerosol. Therefore, this aerosol has very weak adhesion to the object to be treated, so-called poor wettability. Particularly in the case of complex synthetic resin products, or when the surface of paper, cloth, or fiber has complex irregularities, the permeability of particles to every corner of the surface is affected by the influence of these surface shapes.

[Means for solving problems]

This invention was made in view of this point, and can be used not only for modifiers but also for all coating liquids.

That is, in the first invention, the object to be treated is placed in a sealed processing chamber, a coating solution such as a surface modifier is made into an aerosol consisting of a large number of fine particles, and the aerosol is sprayed into the processing chamber, and the pressure of the aerosol is increased within the processing chamber. This is a coating method in which the aerosol is stabilized at a pressure higher than atmospheric pressure, speeds up diffusion, and supersaturation, and the aerosol is quickly attached or adsorbed to the object to be treated, forming a film made of the components of the aerosol on the surface of the object to be treated. .

In addition, the second invention provides a processing chamber that can be sealed freely in which the object to be processed can be stored, and sprays a coating liquid such as a surface modifier into the processing chamber in the form of an aerosol consisting of a large number of fine particles at a pressure higher than atmospheric pressure. The coating device is equipped with a sprayer, the processing chamber has a structure capable of withstanding pressurization, and an adjustable exhaust port is provided on the inner wall of the processing chamber or in the air passage leading to the processing chamber.

[For production]

As a result, the aerosol is stably diffused within the processing chamber and becomes supersaturated, and the aerosol quickly penetrates into the finely uneven surface and elongated tube shape of the object to be processed, and is adsorbed or attached to the surface of the object to be processed. A film made of aerosol components is formed on the surface of the object to be treated.

〔Example〕

An embodiment of this invention will be described below with reference to the drawings.

1 is a substantially box-shaped device main body; 2 is a processing chamber provided at the front of the device main body 1 and having a space for storing objects to be processed;
Reference numeral 3 denotes an opening/closing door provided at the front of the processing chamber 2, which can freely open and close an opening. By closing the opening/closing door 3, the processing chamber 2 is sealed, and the processing chamber 2 has a pressure-resistant structure. Reference numeral 4 denotes an aerosol spray chamber provided at the rear of the processing chamber 2; 5 an aerosol sprayer provided at the bottom of the aerosol spray chamber 4; The solution is introduced from a tank 6 containing the solution, and a compressor (not shown) sends compressed air to it through an air pipe 7 to spray a large number of fine particles (preferably 10,071 particles or less). The upper surface of this aerosol spray chamber 4 has an inclined reflecting plate 4a, and the distance l between this reflecting plate 4a and the nozzle 5a of the aerosol sprayer 5 is 300-taO.
O attack. 8 is an aerosol spout provided on the top surface of the aerosol spray chamber 4 that continues to the top of this reflector 4;
This aerosol jet port 8 faces the upper part of the processing chamber 2 . 9 is a gutter provided at the upper part of the processing chamber 2 on the opposite side from this aerosol jet port 8; 10 is a mesh-like upper bottom plate of the processing chamber 2;
Reference numeral 11 denotes a lower mesh-like bottom plate with a narrower mesh, which is provided below the mesh-like upper bottom plate 10. Below the mesh-like lower bottom plate 11, the tank 6 whose top surface is open is located. The exhaust ducts 12 are provided on both the left and right sides of the processing chamber 2, and the lower part of the exhaust duct 12 is connected to the processing chamber 2 through the mesh upper bottom plate 10.
I understand. 13 is a liquefied material that closes the middle of each of these exhaust ducts 12; 14 is an exhaust slit provided at the top of each of these exhaust ducts 12;
are exposed on both outer surfaces of the device main body 1, and can be freely adjusted in the gap between the slits. 15 is the aerosol spray chamber 4
This is a pipe that hangs down from the bottom of the tank 6 into the tank 6.

Next, an example of the method of the present invention will be described based on this example. First, the opening/closing door 3 is opened, the workpiece 16 is put into the processing chamber 2, and the opening/closing door 3 is closed again. At this time, as shown in the figure, a large number of objects 16 to be processed can be placed on a shelf or the like placed inside the processing chamber 2. As a result, the processing chamber 2 is sealed. When a compressor (not shown) is activated, the solution in the tank 6 is guided to the aerosol sprayer 5, and the compressed air that passes through the air pipe from the compressor converts it into a large number of fine particles of about iooμ or less and is sprayed from the nozzle 5m into the aerosol spray chamber 4. gushes out. The ejected particles hit the reflection plate 4a, and only the small particles are carried by the air and injected into the processing chamber 2 from the jet nozzle 8 as an aerosol.The larger particles hit the reflection plate 4a and are liquefied there, and are sent to the lower part of the aerosol spray chamber 4. It starts to droop.

The particles sprayed by the aerosol sprayer 5 in this manner are selected for their particle sizes, and only stable aerosols with small particle sizes are injected into the processing chamber 2. The inside of the processing chamber 2 is gradually filled with aerosol having a pressure higher than atmospheric pressure, and the number of aerosol particles is concentrated, diffusion is accelerated, and the aerosol is stabilized in a supersaturated state. Then, the air pressure in the processing chamber 2 becomes ai~3/-. As a result, the aerosol penetrates to every corner of the surface of the object to be treated 16, and upon contact with the object to be treated, it immediately adheres or adsorbs. The components of the aerosol adhering to the surface of the object J6 form a film proportional to its particle size and density. This is formed as a film formed by evaporating the solvent such as water that forms the components of the aerosol and drying it up.

Also, depending on the amount of aerosol attached, aggregates of micro particles are formed. Further, the aerosol that did not adhere to the object to be processed passes through the mesh upper bottom plate 10 of the processing chamber 2 and is passed through the exhaust duct 1.
2 and passes through the liquefied material 13. Here, the aerosol air or other gas is exhausted from the exhaust slit 14 to the outside of the apparatus main body 1 through the liquefied material 13, and its pressure is adjusted. Further, the components of the aerosol are liquefied by the liquefier 13 and are appropriately exhausted to the outside of the device body 1 or returned to the tank 6. On the other hand, the solution stored in the lower part of the aerosol spray chamber 4 returns to the tank 6 through the pipe 15. In this way, the processing chamber 2 is filled with aerosol and the air in the processing chamber 2 is increased, and after a certain period of time, the operation of the aerosol sprayer 5 is stopped, the opening/closing door 3 is opened, and the object to be processed 16 is taken out.

FIG. 3 shows another embodiment of the apparatus of the present invention, in which a fan 2 is provided on the inner wall of the exhaust duct 12 in front of the liquefied material 13, and the air sucked by the fan 25 is sucked into the hole 17. Further, behind this fan λ5 and close to the fan 25, a regulating valve 18 that can freely adjust the opening and closing of the exhaust duct 12 is provided, and the liquefied material 13 is positioned behind this regulating valve 18. It was forced upon me.

In this embodiment, the aerosol filling the processing chamber 2 passes through the coarse mesh top plate 10, enters the exhaust duct 12, is further sucked by the fan 25, and returns to the upper part of the processing chamber 2 through the hole 17. Then, a part of the aerosol in the exhaust duct 12 passes through 18 adjustment valves, passes through the liquefier 13, and is liquefied, and only air is exhausted to the outside through the exhaust slit 14. In this way, a part of the air filled with aerosol is circulated, and by speeding up the air flow using the fan U, the aerosol is spread faster and the aerosol in the processing chamber 2 is prevented from penetrating and adhering to the object to be processed 16. In both of the above two embodiments, the pressure inside the processing chamber 2 is adjusted by adjusting the slit width of the exhaust sleeve 14 or adjusting the resistance of the liquefied material 13 and adjusting the spraying pressure.

Further, in each of the above embodiments, when the object to be treated is put into the processing chamber 2 and subjected to coating treatment, the object to be processed 16 is supported in the processing chamber 2 on a suitable rotating support 19 as shown in FIG. When the aerosol is rotated, moved up and down, or vibrated, the aerosol quickly penetrates the surface of the object.

Furthermore, in each of the above embodiments, the operation of the aerosol sprayer 5 can be stopped by a timer or the like, and warm air can be automatically sent into the processing chamber 2 to dry the object to be processed.
It is also possible to take out the material to be treated and put it in a separate dryer for drying.

Furthermore, as shown in FIG. 5, a turret type system can be used for automatic processing. That is, in Fig. J, the empty rotation axis is the rotation axis, 21 is the four movable tables protruding horizontally from this rotation axis, n is the processing chamber, and ri is the drying chamber. Objects are placed thereon, the rotating shaft I is rotated, the objects are sequentially placed in the processing chamber n1 drying chamber for a certain period of time, and the objects are taken out. In this way, automatic processing can be performed.

〔Effect of the invention〕

In general, aerosols with a particle size of 100 μm or less can be transported stably, but they also have the property of being difficult to adhere to objects to be treated. In order to obtain a small amount of uniform coating film by utilizing the characteristics of aerosol with this property, it is necessary to create a stable supersaturated state. Therefore, in this invention, by filling the processing chamber with aerosol at high pressure, The concentration of aerosol per unit volume increases, leading to a state of supersaturation.
As a result, the aerosol penetrates to every corner of the surface of the object to be processed, which has complex irregularities in the processing chamber, and when it comes into contact with the surface, it is quickly adsorbed or attached. Therefore, even if a workpiece has a complicated surface, the aerosol can evenly penetrate and be adsorbed or adhered to every corner of the workpiece, and compared to conventional methods, the aerosol can be adjusted to a very small amount and processed at extremely high speed.

This invention also applies surface modifiers such as antistatic agents, coloring agents, and adhesives to materials ranging from smooth surfaces such as synthetic resin molded products to porous surfaces such as paper, cloth, wood, and ceramics. It is a coating method and equipment that can be used for a variety of coating solutions, such as coating agents, surface treatment of metals, and coating additives to foods, and can control the application of these coating solutions in minute amounts.◇

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a vertical cross-sectional side view of a first embodiment of the device of the present invention;
FIG. 2 is a longitudinal sectional front view of the same, FIG. 3 is a longitudinal sectional front view of the first embodiment of the apparatus of the present invention, and FIG. The figure is a configuration diagram showing a turret type apparatus of the present invention. In the figure, 1 is the main body of the device, 2 is the processing chamber, 3 is the opening/closing door, 5 is the aerosol sprayer, 6 is the tank, 12 is the exhaust duct, 1
4 is an exhaust slit.

Claims (2)

[Claims] (1) Place the object to be treated in a sealed processing chamber, turn a coating liquid such as a surface modifier into an aerosol consisting of many fine particles, and spray it into the processing chamber, and lower the pressure of the aerosol in the processing chamber to below atmospheric pressure. A surface modifier that stabilizes the aerosol and accelerates its diffusion to bring it into a supersaturated state, adsorbs or adheres the aerosol to the object to be treated, and forms a film made of the components of the aerosol on the surface of the object to be treated. How to apply a coating liquid such as. (2) Provide a sealable processing chamber that can store the objects to be processed;
A sprayer is installed that sprays a coating liquid such as a surface modifier into an aerosol consisting of a large number of fine particles at a pressure higher than atmospheric pressure into the processing chamber, and the processing chamber has a structure that can withstand pressurization. An apparatus for applying a coating liquid such as a surface modifier, characterized in that an adjustable exhaust port is provided on an indoor wall or an air passageway leading thereto.