JP2015171687A - Particle coating device and particle coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that sprays and applies multiple particles to a target surface and allows the multiple particles to be applied to the target surface dispersing in a uniform manner.SOLUTION: A spray gun 12 which sprays a volatile spray liquid into a spray space SS is disclosed. The spray gun includes: a spray liquid injection port 20a which injects the spray liquid to the spray space; compression gas injection ports 22, 23 which inject a compression gas into the spray space; and a hot air injection port 210 which is disposed at a position offset to the lateral side from the spray liquid injection port and the compression gas injection ports when the spray gun is viewed from the front surface side, injects hot air, which has a temperature higher than that of a periphery space AS enclosing the spray space from the lateral side, to the front side, and thereby forms a hot air shield HSD having an annular cross section enclosing the spray space from the lateral side.

Description

  The present invention relates to a technique for spraying a volatile spray liquid into a spray space, and a technique for spraying and applying a plurality of particles to a target surface.

In recent years, the use of particles having unique properties in various applications has attracted attention. An example of such particles is photocatalytic particles. The photocatalyst particles are particles that exhibit a catalytic action when receiving light, and titanium oxide TiO ₂ is widely used as a typical example.

  The important features of the photocatalyst particles are high decomposing power (strong oxidation action) and high hydrophilicity. Thanks to its high decomposing power, the photocatalytic particles decompose organic substances to remove dirt and odors and perform antibacterial action. Moreover, thanks to the high hydrophilicity, the surface on which the photocatalyst particles are applied is easily wetted with water, and the effects of self-cleaning and anti-fogging can be obtained.

  Patent Document 1 discloses a conventional example of a photocatalyst particle coating method in which a plurality of photocatalyst particles are sprayed onto a target surface for coating. In this conventional method, a heating step of heating a volatile spray liquid in which a plurality of photocatalyst particles are mixed in a volatile medium in a dispersed state, and a compressed gas are combined with the heated spray liquid. And a spraying step of atomizing the spray liquid using the compressed gas and spraying the spray liquid from the spray gun.

JP 2007-229587 A

  The inventor conducted research on the conventional method. As a result, the following knowledge was obtained.

  In this conventional method, the heated spray liquid is discharged from the spray gun until it reaches the target surface, that is, during the flight (floating) period, the volatile medium in the spray liquid is Ideally it is completely vaporized. When the volatile medium is vaporized, the particles mixed in the spray liquid are released from the constraint of the volatile medium (liquid), so that the particles are dispersed with each other, and each particle is almost independent. Float in the air.

  The plurality of particles tend to agglomerate with each other when mixed in the volatile medium, whereas the particles tend to disperse with each other when the particles float in the air almost alone.

  In addition, the more the particles tend to disperse with each other, the stronger the tendency for the particles to uniformly disperse on the target surface when they reach the target surface and adhere to the target surface.

  When a plurality of particles are uniformly dispersed and coated on the target surface in this way, the area of the continuous region where no particles are attached on the target surface, that is, the particle-free region is reduced. .

  In order to maximize the photocatalytic effect, it is important that the photocatalyst particles come into contact with an object that undergoes a chemical reaction promoted by photocatalysis. Therefore, the larger the area of the particle absence region on the target surface, the lower the photocatalytic effect.

  Therefore, it is ideal that the spray solution sprayed completely evaporate before reaching the target surface. However, the ease of vaporization of the spray liquid depends on the temperature of the spray liquid. Specifically, the lower the temperature is, the more difficult it is to vaporize. On the other hand, the temperature of the spray liquid depends on the outside air temperature. Specifically, the temperature of the spray liquid becomes lower as the outside air temperature is lower.

  Therefore, when the conventional method is performed in a situation where the outside air temperature is low (for example, 0 ° C.), vaporization of the sprayed spray liquid becomes incomplete, and as a result, a plurality of particles are placed on the target surface. It was unevenly distributed. On the target surface, while a plurality of particles locally overlap and overlap each other, there is a continuous region where none of the particles exist.

  Based on the knowledge described above, the present invention is a technique for spraying a volatile spray liquid into a spray space using a compressed gas, and the volatile medium in the spray liquid during the flight of the sprayed spray liquid. And the volatile spray liquid includes a plurality of particles (for example, including but not limited to the above-described photocatalytic particles, other types of particles, For example, in the case of containing metal particles), it has been made as an object to provide what enables the particles to be sprayed and applied so as to be uniformly dispersed on the target surface. Is.

In order to solve the problem, according to the first aspect of the present invention, there is provided a spray gun for spraying a volatile spray liquid into a spray space,
A spray liquid injection port for injecting the spray liquid into the spray space;
A compressed gas injection port for injecting compressed gas into the spray space;
When the spray gun is viewed from the front, the hot air is disposed at a position laterally away from the spray liquid injection port and the compressed gas injection port and is hotter than the surrounding space surrounding the spray space from the side. And a hot air injection port forming a warm air shield having an annular cross section surrounding the spray space from the side.

  Before spraying by this spray gun, a plurality of particles are mixed in the spray liquid in a dispersed state. The spray liquid is made into a mist (mist) by spraying of the spray gun, and in that state, it is allowed to fly in the air toward the target surface. That is, the spray liquid is allowed to fly in the air in the form of a collection of a plurality of fine particles (droplets) in the mist.

  After the spray gun sprays, the volatile medium among the fine particles in each mist is vaporized by taking heat from the surroundings while the fine particles in the mist are flying in the air toward the target surface. When the volatile medium among the fine particles in each mist is vaporized, a plurality of particles mixed in the fine particles in each mist fly by themselves in the air. On the other hand, when the plurality of particles are mixed in the fine particles in each mist, they tend to aggregate with each other. However, when the fine particles in each mist themselves float in the air individually, they tend to disperse with each other.

  The temperature of the fine particles in each mist flying in the air is affected by the outside air temperature. Specifically, when the outside air temperature is lower than the temperature of the spray liquid, the spray liquid is cooled by the outside air.

  In this spray gun, if the peripheral space surrounding the spray space from which the sprayed spray liquid flies is cooler, the air in the spray space may be cooled by the air in the ambient air. There is sex. In order to vaporize the spray liquid in the spray space, the heat of vaporization is taken away from the air. Therefore, there is a possibility that the spray space becomes cooler than the surrounding space.

  On the other hand, in this spray gun, when the said spray gun is seen from the front, a warm air injection port is arrange | positioned in the position which remove | deviated from the spray liquid injection port and the compressed gas injection port. This spray gun ejects warm air, which is higher in temperature than the surrounding space, from its warm air ejection port, thereby forming a warm air shield having an annular cross section surrounding the spray space from the side. Since the hot air shield is hotter than the surrounding space, the temperature of the spray space is less affected by the cooling effect of the surrounding air than when the hot air shield is not present.

  On the other hand, the sprayed liquid sprayed by this spray gun is more easily vaporized as its own temperature is higher. The easier the spray solution is vaporized, the greater the tendency for all of the spray solution to evaporate before it reaches the target surface after being sprayed from the spray gun.

  Further, the fine particles (droplets) in each mist sprayed by this spray gun take away heat necessary for vaporization from the surroundings as vaporization heat. Therefore, the higher the temperature around each fine mist particle, that is, the temperature of the compressed gas surrounding each fine mist particle, the more easily the spray liquid is vaporized.

  As a result, according to this spray gun, the spray liquid tends to float in the air by itself, as compared with the case where the hot air shield is not formed, and thus all the particles are Furthermore, the tendency to fly in a state of being largely dispersed from each other and reach the target surface is increased.

  Therefore, according to this spray gun, substantially all of the spray liquid is vaporized by the spray gun before reaching the target surface without being affected by the outside air temperature. It is easy to realize.

  If it is realized that substantially all of the spray liquid vaporized by the spray gun reaches the target surface, the plurality of particles are each individually, that is, in the spray liquid. It flies in a state where it is not mixed (a state where it is released from the constraint of the spray liquid) and reaches the target surface.

  Therefore, according to this spray gun, the tendency for a plurality of particles to be uniformly dispersed on the target surface increases. That is, according to this spray gun, a plurality of particles are dispersed with respect to each other over the entire target surface, and the degree of dispersion is made uniform over the entire target surface.

  If the tendency of a plurality of particles to disperse with each other on the target surface becomes strong, the concentration of the plurality of particles that can be contained in the spray liquid before spraying of the spray gun is reduced while preventing the uneven distribution of particles on the target surface, It can be increased. As a result, it is easy to increase the density of particles on the target surface.

  That is, according to this spray gun, it becomes easy to apply a plurality of particles so as to be uniformly dispersed at a high density on the target surface.

  Because the plurality of particles are uniformly dispersed on the target surface, the area of the continuous region where no particles are attached on the target surface is reduced. Also, the area of the continuous region where no particles are present on the target surface also decreases because the density of the particles on the target surface increases.

  As a result, according to this spray gun, when the plurality of particles include a plurality of photocatalyst particles, the photocatalytic effect of the plurality of photocatalyst particles adhering to the target surface is maximized (that is, the number of photocatalyst particles). It is easy to achieve a relatively large photocatalytic effect).

  In this spray gun, the “spray liquid” includes, for example, a plurality of particles that do not completely volatilize and have components that remain finally, or a plurality of solid particles. It can be prepared to contain volatile liquids or non-volatile liquids instead of containing those that can be charged and containing those particles.

  In a desirable mode of the spray gun, a diffuser that diffuses the spray liquid sprayed from the spray liquid outlet is further used.

  In another desirable mode of the spray gun, a passage common to both the compressed gas injection port and the hot air injection port for the compressed gas that has been heated is used.

Further, according to the second aspect of the present invention, there is provided a particle coating apparatus for spraying and coating a plurality of particles on a target surface,
A first heater for heating the spray liquid in which the plurality of particles are mixed in a volatile solvent in a dispersed state;
A second heater for heating the compressed gas;
A spray gun for spraying the spray liquid into a spray space using the compressed gas when the warmed spray liquid is supplied together with the warmed compressed gas;
The spray gun
A spray liquid injection port for injecting the spray liquid into the spray space;
A compressed gas injection port for injecting the compressed gas into the spray space;
When the spray gun is viewed from the front, the hot air is disposed at a position laterally away from the spray liquid injection port and the compressed gas injection port and is hotter than the surrounding space surrounding the spray space from the side. And a hot air spray port forming a warm air shield having an annular cross section surrounding the spray space from the side.

  In one desirable mode of this particle application device, furthermore, before each part of the above-mentioned spray liquid injects from the above-mentioned spray liquid injection mouth, a plurality of microbubble generation which generates a plurality of microbubbles in each part of the above-mentioned spray liquid A device is used.

  In a desirable mode of some of the above-described particle coating apparatuses, the plurality of particles carry metal silver particles in a state of being exposed on the respective surfaces.

According to the third aspect of the present invention, there is provided a spray method for spraying a volatile spray liquid into the spray space,
A spray liquid injection step of heating the spray liquid and spraying the spray liquid into the spray space;
A compressed gas injection step for heating and injecting the compressed gas into the spray space, thereby promoting atomization of the spray liquid;
Hot air that is hotter than the surrounding space that surrounds the spray space from the side is sprayed so as to form a warm air shield having an annular cross-section that surrounds the spray space from the side, whereby the spray space And a hot air shield forming step for promoting heat insulation in the inside.

  In this spraying method, the “spraying liquid” includes, for example, a plurality of particles that do not completely volatilize and have components that remain finally, or are a plurality of solid particles. It can be prepared to contain volatile liquids or non-volatile liquids instead of containing those that can be charged and containing those particles.

  The following aspects are obtained by the present invention. Each aspect is divided into sections, each section is given a number, and is described in a form that cites other section numbers as necessary. This is to facilitate understanding of some of the technical features that the present invention can employ and combinations thereof, and the technical features that can be employed by the present invention and combinations thereof are limited to the following embodiments. Should not be interpreted. That is, it should be construed that it is not impeded to appropriately extract and employ the technical features described in the present specification as technical features of the present invention although they are not described in the following embodiments.

  Further, describing each section in the form of quoting the numbers of the other sections does not necessarily prevent the technical features described in each section from being separated from the technical features described in the other sections. It should not be construed as meaning, but it should be construed that the technical features described in each section can be appropriately made independent depending on the nature.

(1) A particle coating method for spraying and coating a plurality of particles on a target surface,
A solution heating step of heating a volatile spray liquid in which the plurality of particles are mixed in a dispersed state;
A gas heating step for heating the compressed gas;
A spraying step of supplying the warmed compressed gas together with the warmed spray liquid to a spray gun, thereby atomizing the spray liquid using the compressed gas and spraying from the spray gun; Including
The solution warming step and the gas warming step include the solution warming step in which the spray solution is vaporized substantially as a whole before the spray solution sprayed from the spray gun reaches the target surface. And a method of applying particles in which the spray liquid and the compressed gas are heated to a temperature at which the gas heating step is realized in cooperation with each other.

  In this method, before spraying with a spray gun, a plurality of particles are mixed in the spray liquid in a dispersed state. The spray liquid is made into a mist (mist) by spraying with a spray gun, and in that state, it is allowed to fly in the air toward the target surface. That is, the spray liquid is allowed to fly in the air in the form of a collection of a plurality of fine particles (droplets) in the mist.

  After the spray gun sprays, the volatile medium among the fine particles in each mist is vaporized by taking heat from the surroundings while the fine particles in the mist are flying in the air toward the target surface. When the volatile medium among the fine particles in each mist is vaporized, a plurality of particles mixed in the fine particles in each mist fly by themselves in the air. On the other hand, when the plurality of particles are mixed in the fine particles in each mist, they tend to aggregate with each other. However, when the fine particles in each mist themselves float in the air individually, they tend to disperse with each other.

  The temperature of the fine particles in each mist flying in the air is affected by the outside air temperature. Specifically, when the outside air temperature is lower than the temperature of the spray liquid, the spray liquid is cooled by the outside air.

  After spraying with the spray gun, the mist-like spray liquid flying in the air is a mixture of the fine particles in each mist and the compressed gas used to atomize the spray liquid. The fine particles in each mist are surrounded by compressed gas ejected from the same spray gun. That is, each fine particle in mist is made to fly in the air surrounded by the compressed gas.

  In the method according to this section, not only the spray liquid but also the compressed gas is heated prior to spraying with the spray gun. As a result, according to this method, in addition to the spray liquid being directly heated before spraying with the spray gun, the spray liquid is a compressed gas that has been heated in the spraying process with the spray gun. It is also heated by what is sprayed from the spray gun.

  Therefore, according to this method, as long as the temperature of the compressed gas is higher than the outside air temperature after the spray gun is sprayed, the amount of decrease in the temperature of the atomized spray liquid due to the outside air is less than when the compressed gas is not heated. I'll do it.

  On the other hand, the sprayed liquid sprayed by the spray gun is more easily vaporized as the temperature of itself is higher. The easier the spray solution is vaporized, the greater the tendency for all of the spray solution to evaporate before it reaches the target surface after being sprayed from the spray gun.

  Moreover, each fine particle (droplet) in the mist sprayed by the spray gun takes away heat necessary for vaporization from the surroundings as vaporization heat. Therefore, the higher the temperature around each fine mist particle, that is, the temperature of the compressed gas surrounding each fine mist particle, the more easily the spray liquid is vaporized.

  As a result, according to the method according to this section, compared to the case where the spray solution only warms the spray solution, all the particles themselves have a tendency to float in the air independently, and all The particles are more likely to fly in a state of being dispersed with respect to each other and reach the target surface.

  Further, in the method according to this section, after spraying with a spray gun, the spray liquid is heated and the compressed gas is heated substantially before the spray liquid reaches the target surface. And the spray liquid and the compressed gas are heated to a temperature that can be realized in cooperation with each other.

  Therefore, according to this method, not only the spray liquid but also the compressed gas is heated, so that the spray liquid sprayed by the spray gun reaches the target surface without being strongly influenced by the outside air temperature. It becomes easy to realize that substantially all of the spray liquid is vaporized.

  If it is realized that substantially all of the spray liquid vaporized by the spray gun reaches the target surface, the plurality of particles are mixed individually, that is, in the spray liquid. It will fly to the target surface in a state where it is not released (a state where it is released from the constraint of the spray liquid).

  Therefore, according to this method, a plurality of particles are placed on the target surface compared to the case where substantially all of the spray liquid is not vaporized before the spray liquid sprayed by the spray gun reaches the target surface. Disperse uniformly.

  That is, according to this method, a plurality of particles are dispersed with each other over the entire area on the target surface, and the degree of dispersion is made uniform over the entire area of the target surface.

  If the tendency of a plurality of particles to disperse with each other on the target surface becomes strong, the concentration of the plurality of particles that can be contained in the spray liquid before spraying of the spray gun is reduced while preventing the uneven distribution of particles on the target surface, It can be increased. As a result, it is easy to increase the density of particles on the target surface.

  That is, according to the method according to this section, it becomes easy to apply a plurality of particles so as to be uniformly dispersed at a high density on the target surface.

  Because the plurality of particles are uniformly dispersed on the target surface, the area of the continuous region where no particles are attached on the target surface is reduced. Also, the area of the continuous region where no particles are present on the target surface also decreases because the density of the particles on the target surface increases.

  As a result, according to this method, it is easy to maximize the photocatalytic effect of a plurality of particles adhering to the target surface (that is, to realize a large photocatalytic effect for the number of particles).

(2) The particle coating method according to (1), wherein a temperature at which the gas heating step heats the compressed gas is equal to or higher than a temperature at which the solution heating step heats the spray liquid. .

  According to this method, the temperature at which the compressed gas is heated (the target temperature of the compressed gas or the temperature of the compressed gas immediately after spray gun ejection) is the temperature at which the spray liquid is heated (the target temperature of the spray liquid or the spray gun). It is not lower than the temperature of the spray liquid immediately after ejection.

  On the other hand, when the temperature of the compressed gas is not lower than the temperature of the spray liquid after being sprayed by the spray gun, the temperature drop of the spray liquid is effectively suppressed by the compressed gas.

  That is, according to this method, in addition to the spray liquid being heated before spraying with the spray gun (the spray liquid is heated to a temperature higher than the outside air temperature), during the spraying process with the spray gun, The temperature drop of the spray liquid is suppressed by the compressed gas.

  Therefore, according to this method, the easiness of vaporization of the spray liquid is such that the temperature at which the compressed gas is heated (target temperature of the compressed gas) is higher than the temperature at which the spray liquid is heated (target temperature of the spray liquid). Lower than the case, it improves.

  Therefore, according to this method, it is more reliably realized that substantially all of the spray liquid is vaporized by the spray gun before reaching the target surface regardless of whether the outside air temperature is high or low. The

(3) The temperature at which the gas heating step heats the compressed gas is in the range of about 50 to about 70 ° C.,
The particle coating method according to (2), wherein the temperature at which the solution heating step heats the spray liquid is in the range of about 30 to about 50 ° C.

(4) In the gas heating step, the compressed gas is heated to a height at which the temperature of the spray liquid after spraying the spray gun does not rise above the temperature before spraying of the spray gun by the compressed gas. The particle coating method according to any one of (1) to (3).

  The spray liquid may be flammable. In this case, the higher the temperature of the spray liquid, the more easily the vaporized liquid is vaporized. However, when the temperature of the spray liquid is increased, the flammability and the ignitability of the spray liquid are increased. Therefore, there is a limit to increasing the temperature of the spray liquid.

  On the other hand, according to the method according to this section, the compressed gas before spraying the spray gun is such that the temperature of the spray liquid during the spraying process of the spray gun is the temperature of the spray liquid before spraying the spray gun due to the compressed gas. It is heated to a height that does not rise further. Therefore, the flammability and the ignitability of the spray liquid do not increase because the spray liquid is heated by the compressed gas during the spraying process of the spray gun.

  Therefore, according to this method, the temperature drop of the spray liquid can be suppressed while preventing the flammability / ignitability of the spray liquid from increasing during the spraying process of the spray gun. As a result, according to this method, the easiness of vaporization of the spray liquid is maintained without increasing the flammability and the ignitability.

(5) The gas warming step warms the compressed gas using a heater,
The spray gun is selectively switched between an inflow permission state for permitting inflow of the compressed gas and an inflow inhibition state for blocking,
The particle coating method further includes:
Regardless of whether the inflow permission state or the inflow prevention state, a gas supply step of supplying the compressed gas to the heater;
A gas release step of releasing the compressed gas that has passed through the heater into the atmosphere in at least the inflow prevention state of the inflow permission state and the inflow prevention state, according to any one of (1) to (4) Particle coating method.

  In this method, the compressed gas to be sprayed by the spray gun is heated by the heater.

  By the way, while the compressed gas is flowing from the heater to the spray gun, the controller controls the heater on / off state so that the temperature of the compressed gas does not deviate from the allowable range in order to manage the temperature of the compressed gas. Is normal.

  The controller normally turns off the heater when the flow of compressed gas from the heater to the spray gun is blocked, thereby stopping the use of the heater. Thereafter, the heater dissipates heat to the atmosphere while the flow of gas surrounding it is substantially stationary, thereby naturally cooling the heater.

  However, when the heater is naturally cooled in this way, the temperature of the heater may temporarily rise immediately after the start of the air cooling. There is a possibility that the temperature of the heater may rise after the use of the heater is stopped than during the use. This is because immediately after the heater is turned off, if the gas flow around the heater stops, the heat in the heater is not released but is accumulated in the heater.

  On the other hand, the heater is usually configured using a heating element (for example, nichrome wire), and it is undesirable for the heating element that the heating element is maintained at a high temperature for a long time. This is because the life of the heating element is reduced. Therefore, after the flow of compressed gas from the heater to the spray gun is prevented, it is desirable to devise so that the heater temperature is quickly lowered after the heater is turned off.

  On the other hand, according to the method according to this section, regardless of whether the spray gun is in the inflow permitted state or the inflow blocked state, the compressed gas is supplied to the heater, and the inflow permitted state and the inflow of the spray gun are supplied. The compressed gas that has passed through the heater is released to the atmosphere in at least the inflow prevention state of the prevention state.

  As a result, according to this method, in the spray gun inflow prevention state (heater stoppage state), the compressed gas having a temperature substantially equal to the outside air temperature is allowed to pass through the heater because it is not heated by the heater. It is done. Thereby, the heater is forcibly cooled by the compressed gas.

  Therefore, according to this method, when the inflow of compressed gas from the heater to the spray gun is blocked, the heater is forcibly cooled by air, whereby the temperature of the heater is quickly lowered. As a result, an increase in the temperature of the heater is suppressed after the use of the heater is stopped, thereby suppressing a decrease in the life of the heater due to overheating.

(6) In the gas discharge step, in the inflow permitted state, a portion of the compressed gas that has passed through the heater that does not flow into the spray gun is discharged to the atmosphere, while in the inflow prevention state, the heater The particle coating method according to item (5), wherein all of the compressed gas that has passed through is discharged to the atmosphere.

  In order to carry out this method, for example, in addition to an outlet port for supplying the compressed gas supplied to the heater to the spray gun, an outlet port for releasing the compressed gas to the atmosphere is installed in the heater, and The latter outlet port may be kept open at all times.

  Therefore, according to this method, it becomes easy to simplify the structure of the apparatus necessary for carrying out the method according to the item (5).

(7) In the gas discharge step, the compressed gas that has passed through the heater is not released to the atmosphere in the inflow permission state, but in the inflow prevention state, all of the compressed gas that has passed through the heater is discharged to the atmosphere. The particle coating method according to item (5), wherein

  According to this method, unlike the method according to the item (6), part of the heated compressed gas does not needlessly be released to the atmosphere in the spray gun inflow permitted state.

  Therefore, according to this method, since the heated compressed gas does not leak into the atmosphere during the inflow permission state of the spray gun, that is, during use of the heater, the heat generated from the heater is effectively transferred to the spray gun. It can be used for heating the compressed gas to be supplied.

(8) The particle application method according to any one of (1) to (7), wherein the spraying step includes a charging step of charging the plurality of particles so as to have the same polarity in the spray gun.

  According to this method, since the plurality of particles sprayed by the spray gun are charged with the same polarity, the particles repel each other electrostatically. As a result, the particles have a greater tendency to disperse with each other during flight than if none of the particles were positively or negatively charged.

  Therefore, according to this method, it is easy to increase the density of a plurality of particles attached to the target surface.

(9) The plurality of particles include a plurality of photocatalyst particles, and the photocatalyst particles carry a plurality of metal silver particles on each surface, according to any one of (1) to (8). Particle application method.

  The photocatalytic particles have an antibacterial effect and the same effect also has silver ions. On the other hand, the metallic silver particles continuously release silver ions.

  Based on the above knowledge, according to the method according to this item, each photocatalyst particle applied by the method according to any one of (1) to (8) above has a plurality of metallic silver particles on the surface thereof. It is assumed that particles are supported.

  Therefore, according to this method, in addition to the antibacterial effect of the photocatalyst particles, the antibacterial effect of the metal silver particles can be obtained, so that the antibacterial effect is improved as a whole.

(10) A photocatalytic coating method for coating a coating film formed on the surface of an object with a plurality of particles,
A solution heating step of heating a volatile spray liquid in which the plurality of particles are mixed in a dispersed state;
A gas heating step for heating the compressed gas;
In the spraying step of supplying the warmed compressed gas to the spray gun together with the warmed spray liquid, thereby atomizing the spray liquid using the compressed gas and spraying from the spray gun Then, with the coating film being semi-dry, the spray liquid is sprayed toward the object to be coated, whereby the plurality of particles are applied to the surface of the coating film, and each particle is locally applied to the coating film. Which is applied so as to bite into the surface of the film,
In the solution heating step and the gas heating step, the solution heating means that the spray solution vaporized from the spray gun vaporizes substantially as a whole before reaching the surface of the coating film. The photocatalyst coating method which heats the said spray liquid and the said compressed gas to the temperature of the height which a temperature process and the said gas heating process mutually implement | achieve jointly, respectively.

  According to this method, in order to coat a coating film with a plurality of particles, a coating process for forming a coating film and a coating process for coating the coating film with a plurality of particles are performed separated from each other in time. Rather, the coating process is started consecutively with each other, i.e. before the painting process is completed, i.e. before the coating formed by the painting process is completely dried, so that the semi-dried A plurality of particles are applied to the coating film and engulfed.

  Therefore, according to this method, the time and labor required for the entire operation can be reduced as compared with the case where the painting process and the coating process are performed separately from each other in time.

  Furthermore, according to this method, since each particle is applied in a state of partially biting into the coating film, each particle is applied more than when each particle previously surrounded by a binder is applied to a completely dry coating film. The film adheres firmly. Therefore, according to this method, it is possible to easily improve the durability and durability in which each particle continues to adhere to the coating film.

(11) A particle coating apparatus for spraying and coating a plurality of particles on a target surface,
A first heater for heating a volatile spray liquid in which the plurality of particles are mixed in a dispersed state;
A second heater for heating a compressed gas for atomizing the spray liquid;
The warmed spray liquid is a spray gun that is supplied together with the warmed compressed gas, and includes the spray gun atomized and sprayed with the compressed gas;
The first and second heaters are configured so that the sprayed liquid ejected from the spray gun substantially vaporizes the sprayed liquid before reaching the target surface. A particle coating apparatus that heats the spray liquid and the compressed gas to a temperature that is realized jointly with each other.

(12) Furthermore, it includes first and second outlet ports that allow the compressed gas heated by the second heater to flow out of the second heater,
From the first outlet port, the compressed gas from the second heater flows out toward the spray gun, while from the second outlet port, the compressed gas from the second heater. The particle coating apparatus according to item (11), wherein is released into the atmosphere.

  According to this apparatus, the method according to the item (5) or (6) is preferably performed.

(13) The particle application device according to (12), further including a valve that operates to close the second outlet port in the inflow permission state, and open in the inflow prevention state.

  In this section, the “valve” can be configured as, for example, a manually operated valve, an electromagnetically operated valve, or a pilot operated switching valve.

(14) A particle coating method of spraying and coating a plurality of particles on a target surface,
A solution heating step of heating a volatile spray liquid in which the plurality of particles are mixed in a dispersed state;
A gas heating step of heating the compressed gas using a heater;
A spraying step of supplying the warmed compressed gas together with the warmed spray liquid to a spray gun, thereby atomizing the spray liquid using the compressed gas and spraying from the spray gun; A particle coating method comprising:

(15) A particle coating method for spraying and coating a plurality of particles on a target surface,
A solution heating step of heating a volatile spray liquid in which the plurality of particles are mixed in a dispersed state;
A gas heating step of heating the compressed gas using a heater;
In the spraying step of supplying the warmed compressed gas to the spray gun together with the warmed spray liquid, thereby atomizing the spray liquid using the compressed gas and spraying from the spray gun The spray gun is selectively switched between an inflow permission state for permitting the inflow of the compressed gas and an inflow prevention state for blocking,
Regardless of whether the spray gun is in the inflow permission state or the inflow prevention state, a gas supply step of supplying the compressed gas to the heater;
And a gas discharge step of releasing the compressed gas that has passed through the heater to the atmosphere when the spray gun is in at least the inflow prevention state of the inflow permission state and the inflow prevention state.

  According to this method, basically the same effect is obtained in accordance with basically the same principle as the method according to the above item (5).

It is a systematic diagram which represents notionally the structure of the photocatalyst particle coating apparatus according to 1st Embodiment of this invention. It is side surface sectional drawing which expands and shows the head of the spray gun shown in FIG. FIG. 3 is a front view showing the head shown in FIG. 2. 4 (a) is a side view for schematically explaining the operation of the spray gun shown in FIG. 1, and FIG. 4 (b) is a front view showing the spray gun shown in FIG. 4 (a). . It is a side view which expands and shows the spray gun shown in FIG. It is a functional block diagram which represents notionally the structure of the solution heating apparatus shown in FIG. It is side surface sectional drawing which expands and shows the heater safety device shown in FIG. FIG. 3 is a side cross-sectional view showing an enlarged main part of the head shown in FIG. 2. It is process drawing showing the application start process of the photocatalyst particle coating apparatus shown in FIG. It is process drawing showing the application completion | finish process of the said photocatalyst particle coating apparatus shown in FIG. It is process drawing showing the said photocatalyst particle application | coating method. It is a front view which expands and shows the antimicrobial fine particle apply | coated by the said photocatalyst particle application | coating method. It is a conceptual diagram for demonstrating the principle by which antimicrobial microparticles | fine-particles are apply | coated to the target surface by the said photocatalyst particle application | coating method. It is another conceptual diagram for demonstrating the principle by which antimicrobial microparticles | fine-particles are apply | coated to the target surface by the said photocatalyst particle application | coating method. It is a conceptual diagram for demonstrating the principle by which antibacterial microparticles adhere to the target surface by the conventional method. It is a conceptual diagram for demonstrating the principle by which antibacterial microparticles adhere to the target surface by the said photocatalyst particle application method. It is a conceptual diagram for demonstrating a mode that several antibacterial microparticles adhere uniformly on a target surface with high density by the said photocatalyst particle application | coating method. It is a conceptual diagram for demonstrating a mode that several antibacterial microparticles adhere uniformly on a target surface with high density by the said photocatalyst particle application | coating method.

  Hereinafter, some of the more specific embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a system diagram conceptually showing the structure of a photocatalyst particle coating apparatus (hereinafter simply referred to as “coating apparatus”) 10 according to an embodiment of the present invention. The coating device 10 is used for carrying out a method of spraying and coating a plurality of antibacterial fine particles on a target surface.

  In the present embodiment, “antimicrobial fine particles” are an example of the photocatalyst particles and an example of the particles. Antibacterial fine particles are used to actively utilize antibacterial properties among some properties of photocatalyst particles. In the present embodiment, each antibacterial fine particle carries metallic silver particles on the surface thereof. The metallic silver particles improve the antibacterial action in cooperation with the antibacterial fine particles.

  In this embodiment, antibacterial fine particles carrying metal silver particles, that is, silver-carrying titanium dioxide, are used. A method for producing this type of antibacterial agent is disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-81409. And that publication is incorporated herein by reference. Moreover, this type of antibacterial agent is, for example, an antibacterial agent (trade name: “Hikari Gintech”) developed by Daido Steel Co., Ltd. In addition, this type of antibacterial agent is not particularly limited as long as it can be charged.

  The coating apparatus 10 can be used for applications in which a semi-dry coating film formed on the surface of an object to be coated is coated with a plurality of antibacterial fine particles (hereinafter simply referred to as “particles”). The coating apparatus 10 can also be used for applications in which a binder is applied to a completely dry target surface and then a plurality of particles are applied to the surface of the binder.

  First, the configuration of the coating apparatus 10 will be described with reference to FIGS. 1 to 8.

  As shown in FIG. 1, the coating apparatus 10 is used to apply a plurality of particles to a target surface by wet and spraying.

  Specifically, the coating apparatus 10 is a spray liquid (hereinafter, referred to as “alcohol solution”) in which compressed air is mixed in a dispersed state in ethyl alcohol, which is an example of a volatile medium. Together, it is used to feed the spray gun 12 and thereby atomize the alcohol solution using compressed air and spray it from the spray gun 12 into the spray space. The spray space is a space located in front of the spray gun 12.

  In the present embodiment, “alcohol solution” is an example of the volatile spray solution, and “compressed air” is an example of the compressed gas.

  As shown in an enlarged view in FIG. 2, the spray gun 12 is a hand-held type that is used by being held by an operator's hand, and hangs down from a horizontally extending main body portion 14 and a rear end portion of the main body portion 14. And a grip 16.

  This spray gun 12 is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-267960, which is incorporated herein by reference.

  As shown in FIG. 2, the spray gun 12 has a nozzle 20 for injecting an alcohol solution into an injection space in a head 18 which is a front end portion of the main body portion 14. The nozzle 20 has a center line. The nozzle 20 has a spray liquid outlet 20a (which constitutes an example of the spray liquid injection port). The diameter of the outlet 20a is, for example, in the range of about 0.8 to about 1.6 mm.

The pressure when the spray gun 12 sprays the alcohol solution from the nozzle 20 is, for example, in the range of about 0.5 to about 1.5 kg / cm ² .

As shown in FIGS. 2 and 4B, the spray gun 12 includes a plurality of air injection holes 22 for injecting compressed air into the injection space in the head 18, and the center line of the nozzle 20. Are arranged at substantially equal intervals along one circumference that is coaxial with each other (each of which constitutes an example of the compressed gas injection port). The pressure at which the spray gun 12 injects compressed air from each air injection hole 22 is, for example, in the range of about 1.5 to about 3.0 kg / cm ² .

As shown in FIGS. 2 and 4B, the spray gun 12 includes a plurality of air injection holes 23 for injecting compressed air into the injection space in the head 18, and the center line of the nozzle 20. Are arranged in a point-symmetrical manner with respect to the center line of the nozzle 20 at a plurality of positions deviating from the position of the air injection hole 22 in the radially outward direction (each of the compressed gas injection ports is another example). Comprising). The pressure at which the spray gun 12 injects compressed air from each air injection hole 23 is, for example, in the range of about 1.5 to about 3.0 kg / cm ² .

  The plurality of air injection holes 22 and 23 have a function of promoting atomization of the spray liquid injected from the nozzle 20, but the plurality of air injection holes 22 are generally parallel to the direction of the spray liquid injected from the nozzle 20. The plurality of air injection holes 23 are oriented to inject the compressed air so as to intersect the spray liquid injected from the nozzle 20 at generally the same angle. ing. The compressed air jetted from the air jet holes 23 and the spray liquid jetted from the nozzle 20 are generally joined to each other at the same one position.

  As shown in FIGS. 1 to 3, the spray gun 12 further includes a hot air shield forming device 24 in the head 18. The hot air shield forming device 24 has a function of forming a hot air shield by injecting hot air. The hot air shield forming device 24 executes the above-described hot air shield forming step. Details of the hot air shield forming device 24 will be described later.

  As shown in FIGS. 2 and 8, the spray gun 12 further includes a diffuser 25 in the head 18. The diffuser 25 has a function of diffusing the spray liquid sprayed from the nozzle 20. Details of the diffuser 25 will also be described later.

  The spray gun 12 further includes an adjustment valve (not shown) for adjusting the amount of the alcohol solution injected from the nozzle 20 and an air passage (not shown) for supplying compressed air to the air injection holes 22 and 23. ) And an air valve (not shown) for opening and closing the air passage.

  As shown in FIG. 5, the spray gun 12 further includes a trigger 25 operated by an operator and a trigger guard 26 guarded by the trigger 25. Each of the regulating valve and the air valve is mechanically interlocked with the operation of the trigger 25 via a link mechanism (not shown).

  The spray gun 12 is selectively switched between an inflow permitting state in which the alcohol solution is allowed to flow into the nozzle 20 and compressed air is allowed to flow into the air injection holes 22 and 23 and an inflow blocking state in which the alcohol is blocked. When the trigger 25 is pulled by the operator, the spray gun 12 is switched from the inflow prevention state, which is the initial state, to the inflow permission state, and then when the operation of the trigger 25 is released, the inflow prevention state is changed from the inflow permission state. Restore to.

  The spray gun 12 further has a mist-like alcohol solution sprayed from the nozzle 20, that is, a plurality of particles (droplets) of the alcohol solution, each having the same polarity (in this embodiment, positive). A charging device (not shown) having an electrode (not shown) to be charged is provided. The voltage used by the charging device is, for example, in the range of about 25 to about 60 kV.

  Therefore, as shown in FIG. 5, the spray gun 12 takes in the compressed air from the hose connection port 30 for taking in the alcohol solution from the outside, and finally the compressed air into the air injection holes 22 and 23. Air connection port 32 for supplying, air connection port 33 for taking in compressed air from the outside, and finally supplying the compressed air to the hot air shield forming device 24, and cable connection for taking in electricity from the outside And a mouth 34.

  As shown in FIG. 1, the spray gun 12 is connected to one end of a flexible hose 36 through which an alcohol solution flows at a hose connection port 30. The other end of the hose 36 is connected in series with a solution heating device 40 for heating the alcohol solution, a pressure pump 42 and a material tank 44 in that order.

  The material tank 44 stores under pressure the alcohol solution in which a plurality of particles are mixed in a dispersed state. The alcohol solution contained in the material tank 44 is, for example, 100 weights of alcohol so that the particles are too dilute to obtain a practical antibacterial action and the particles are too thick to aggregate and settle together. To about 0.1 to about 3.0 parts by weight of particles per part. In order to achieve both the practical antibacterial action and appropriate dispersibility of the particles, the alcohol solution contained in the material tank 44 is, for example, about 0.2 to about 0.6 with respect to 100 parts by weight of alcohol. It is desirable to adjust so as to contain particles by weight.

  The pumping pump 42 is a so-called circulation type, and is operated by electric power supplied from the main power supply 50, thereby pressurizing the material tank 44 (for example, the upper space in the material tank 44), and thereby the material tank. The alcohol solution is extruded from 44 (for example, the bottom of the material tank 44) and supplied to the solution warming device 40. As a result, the alcohol solution is supplied to the hose 36 connection port 30 of the spray gun 12 under pressure. The solution warming device 40 is also operated by electric power supplied from the main power supply 50.

  As shown in FIG. 1, a microbubble generator 48 is attached to the material tank 44. The microbubble generator 48 is also operated by electric power supplied from the main power supply 50. The microbubble generator 48 takes in air from the outside, mixes the air and the alcohol solution taken in from the material tank 44 by a pump, and thereby, air is introduced into the alcohol solution with a diameter of 0.1 to 0. A plurality of bubbles of 01 mm are mixed in an ultrafine state. The alcohol solution stored in the material tank 44 is desirably adjusted to contain, for example, about 5 to about 10 volume parts of microbubbles with respect to 100 volume parts of alcohol.

  As conceptually shown in the block diagram of FIG. 6, the solution heating device 40 includes a solution heater 52 for heating the alcohol solution supplied from the pressure pump 42, and the alcohol heated by the solution heater 52. A solution temperature controller 54 for controlling the temperature of the solution (hereinafter referred to as “solution temperature”) and a solution temperature sensor 56 for detecting the solution temperature are provided.

  It is desirable that the solution temperature sensor 56 is disposed at the most downstream position in the solution passage through which the alcohol solution flows in the solution heater 52 or at a position near the position in order to detect the solution temperature with high accuracy.

  The solution temperature controller 54 monitors the solution temperature detected by the solution temperature sensor 56 so that the current value between the solution heater 52 and the main power supply 50 is adjusted so that the actual value of the solution temperature is within an allowable range. Control the flow. The solution temperature controller 54 controls the on / off state of the solution heater 52 so that the solution temperature is within a range of about 30 to about 50 ° C., for example.

  As shown in FIG. 1, the spray gun 12 is connected to a heater safety device 60 and an air heater 62 that heats compressed air in that order at the air connection port 32. The spray gun 12 is connected to the hose 63, the heater safety device 60, and the air heater 62 in that order at the air connection port 33. The compressed air heated by the air heater 62 is supplied to both the air connection ports 32 and 33, and eventually supplied to both the air injection holes 22 and 23 and the hot air shield forming device 24.

  In the present embodiment, the heater safety device 60 and the air heater 62 are integrally attached to the spray gun 12. Therefore, the operator moves the spray gun 12 by hand together with the heater safety device 60 and the air heater 62. That is, the air heater 62 is not an installation type installed at a work place, but a portable type (moving type) that moves with the worker.

  Thus, in this embodiment, since the air heater 62 is attached to the spray gun 12 without using a long hose, the air heater 62 is heated more than when attached to the spray gun 12 via a hose. While the compressed air moves from the air heater 62 to the spray gun 12, the amount by which the temperature of the compressed air decreases due to heat transfer or the like decreases.

  Furthermore, in this embodiment, since the air heater 62 is not built in the spray gun 12 but is externally attached, the temperature of the spray gun 12 itself grasped by the operator is higher than the case where it is built in. The rise is suppressed. This also improves worker safety.

  The structure of the air heater 62 alone is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-277040, which is incorporated herein by reference.

  As shown in an enlarged view in FIG. 7, the air heater 62 has a hollow heat generating portion 64. Although not shown in the drawing, the heat generating portion 64 is configured by connecting a coaxial inner cylinder and an outer cylinder by a pair of annular side plates facing each other in the axial direction. A coiled nichrome wire as a heating element that converts electrical energy into thermal energy is coaxially disposed in a cylindrical space in the heat generating portion 64.

  The air heater 62 further has an air passage 66 coaxially passing through the center of the heat generating portion 64 with a circular cross section. The compressed air flows in the air passage 66 while being heated by the heat generating portion 64 in one direction from the upstream side to the downstream side. Both ends of the heater safety device 60 are connected to the heater outlet 68 of the air passage 66 and the air connection port 32 of the spray gun 12.

  The heater safety device 60 includes a main body portion 72 that forms the main passage 70 and a branch portion 74 that branches off from the main body portion 72 and that forms a branch passage 76 that branches off from the main passage 70. . Both ends of the main passage 70 are connected to the air connection port 32 and the heater outlet 68, respectively. The tip of the branch passage 76 is open to the atmosphere.

  Although not shown in FIG. 7, as is clear from FIG. 1, the central portion of the main passage 70 (or any other portion) is connected to one end portion of the hose 63, and the other end portion of the hose 63 is As shown in FIG. 1, the air connection port 33 is connected. As a result, the compressed air heated by the air heater 62 is supplied not only to the air connection port 32 but also to the air connection port 33.

  Accordingly, when the compressed air passes through the air heater 62 because the spray gun 12 is in the inflow permitted state, the compressed air is supplied to the spray gun 12 through the main passage 70. At this time, a part of the compressed air that has passed through the air heater 62 is released to the atmosphere via the branch passage 76.

  On the other hand, when the spray gun 12 shifts to the inflow prevention state (accordingly, the air heater 62 is turned off), the compressed air continues to be supplied to the air heater 62 as described later. Thus, this time, all of the compressed air that has passed through the air heater 62 is released to the atmosphere via the branch passage 76. Thereby, the air heater 62 is forcibly cooled by air.

  As shown in FIG. 1, the air heater 62 is connected to a compressor 82 via a flexible hose 80 at an inlet 78 of the air passage 66. The compressor 82 is operated by electric power supplied from the main power supply 50, thereby sucking ambient air and supplying it to the air heater 62 as compressed air.

  The compressor 82 is not linked to the trigger 25 of the spray gun 12, and the compressor 82 supplies compressed air to the air heater 62 as long as the compressor 82 is turned on even if the operation of the trigger 25 is released. Continue to supply.

  As shown in FIG. 1, the air heater 62 includes an air temperature sensor (for example, a thermocouple) 84 that detects the temperature of the compressed air heated by the air heater 62 (hereinafter referred to as “air temperature”). It is installed.

  It is desirable that the air temperature sensor 84 is disposed at the most downstream position in the air passage 66 in the air heater 62 or at a position in the vicinity thereof in order to detect the air temperature with high accuracy.

  As shown in FIG. 1, an air temperature controller 90 is electrically connected to the air heater 62 and the air temperature sensor 84. The air temperature controller 90 monitors the air temperature detected by the air temperature sensor 84 so that the current between the air heater 62 and the main power supply 50 is such that the actual value of the air temperature is within an allowable range. To control the flow. The air temperature controller 90 controls the air heater 62 so that the air temperature is within a range of about 50 to about 70 ° C., for example.

  As shown in FIG. 1, the spray gun 12 is connected to the electrostatic generator 94 via the electric cable 90 at the cable connection port 34. The electrostatic generator 94 is operated by electric power supplied from the main power supply 50, thereby generating a positive charge (or a negative charge) and supplying the generated charge to the electrode of the charging device. To do.

  Here, an example of the warm air shield forming device 24 will be specifically described with reference to FIGS. 2 to 4.

  First, in order to explain the function, the hot air shield forming device 24 uses hot air that is higher in temperature than the surrounding space AS surrounding the spray space SS set in front of the head 18 from the side, and the hot air shield forming device 24 side the spray space SS. It sprays so that the warm air shield HSD which has the annular cross section surrounding from the direction may be formed, and thereby, the heat retention in the spray space SS is promoted.

  Next, to describe a configuration for realizing the function, the warm air shield forming device 24 includes a main body 200 that is attached to the head 18. The main body 200 has an annular shape and is attached to the outer housing 202 so as to surround the outer housing 202 of the head 18 from the side.

  The main body 200 has a plurality of nozzles 210 arranged along a circumference that is coaxial with the nozzle 20. The main body 200 is shown in FIGS. 4A and 4B by injecting warm air from the outlet 212 of each nozzle 210 (which constitutes an example of the warm air injection port) to the front of the head 18. Thus, the warm air shield HSD is formed.

  As shown in FIG. 3, the main body 200 has a communication path 214 that allows a plurality of nozzles 210 to communicate with each other, and the communication path 214 communicates with the air connection port 33. The communication path 214 extends along a circumference that is concentric with the outer housing 202 so as to surround the outer housing 202 of the head 18 from the side.

  As shown in FIG. 4, the plurality of nozzles 210 are arranged at equiangular intervals along one circumference. The center line of each nozzle 210 may be oriented to extend in a direction parallel to the center line of the nozzle 20, but instead, in a direction non-parallel to the center line of the nozzle 20. It can be oriented to extend. For example, the center lines of the plurality of nozzles 210 can be aligned so as to form a divergent shape together with each other, or can be aligned so as to form a tapered shape together with each other.

The diameter of the outlet of each nozzle 210 is, for example, in the range of about 1.0 to about 2.0 mm. Moreover, the pressure when this spray gun 12 injects compressed air from each nozzle 210 is in the range of about 1.5 to about 3.0 kg / cm ² , for example.

  In an example in which each nozzle 210 is oriented so as to extend in a direction parallel to the nozzle 20, a cylindrical hot air shield HSD is formed. On the other hand, in an example in which each nozzle 210 is oriented so that the distance from the center line of the nozzle 20 increases as the nozzle 210 moves in a direction parallel to the nozzle 20 and away from the nozzle 20, FIG. As shown in a), a diverging hot air shield HSD is formed.

  Next, the thermodynamic effect of the warm air shield HSD will be described.

  First, in comparison with the temperature of the surrounding space AS, the temperature of the warm air shield HSD is higher than that of the surrounding space AS.

  Next, prior to the comparison with the temperature of the spray space SS, a phenomenon that occurs in the spray space SS will be described. In the spray space SS, a plurality of compressed air that is the same as the warm air forming the warm air shield HSD is provided. Since the air is injected from the air injection holes 22 and 23, there is a possibility that the temperature is higher than that of the ambient air AS. However, since the spray liquid (alcohol solution) ejected from the nozzle 20 is a volatile alcohol solution, the spray liquid is atomized and vaporized during the flight. Therefore, the heat of vaporization is taken away from the air in the spray space SS, and as a result, the temperature of the spray space SS may not be as high as that of the warm air shield HSD.

  Then, as a result of the spray space SS being surrounded by the hot air shield HSD from the side, the temperature of the spray space SS rises more than when the hot air shield HSD is not present. The higher the temperature of the spray space SS, the more heat of vaporization can be given to the spray liquid. As a result, the distance required to fly before the spray liquid vaporizes is shortened.

  Then, the volatile components in the spray solution are substantially completely vaporized before reaching the target surface on which the plurality of particulates contained in the spray solution are to be applied, and only the plurality of particulates are mutually connected. It is facilitated to reach the target surface in a state of being dispersed and floating in the air without agglomeration.

  Next, an example of the diffuser 25 will be specifically described with reference to FIGS. 2 and 8.

  First, in order to explain the function, the diffuser 25 diffuses the spray sprayed from the nozzle 20 by mechanical parts.

  Next, to describe a configuration for realizing the function, the diffuser 25 has a cone 300 installed coaxially with the nozzle 20 in front of the outlet 20 a of the nozzle 20. The cone 300 has, as a mechanical diffusion surface, a metal inverted conical surface 302 whose diameter increases in cross section as it moves away from the outlet 20a of the nozzle 20 in the traveling direction of the spray liquid. The cone 300 is oriented so as to extend coaxially with the nozzle 20 and is disposed at a position having a certain relative position with respect to the outlet 20 a of the nozzle 20.

  In order to realize such an arrangement, the cone 300 is attached to the head 18 by a positioning member 310. An example of the positioning member 310 is a metal rod that extends coaxially within the nozzle 20. The rod is fixedly connected to the head 18.

  Next, the function and effect will be described with reference to FIG. 8. This diffuser 25, when biting into the central part of the flow of the spray liquid sprayed from the nozzle 20 in the reverse direction of the flow of the spray liquid, The spray liquid is advanced along the reverse conical surface 302 of the diffuser 25 so as to form a taper shape whose diameter increases along the forward direction of the flow. As a result, when the spray liquid is cut at a plurality of virtual planes passing through a plurality of virtual points arranged along the center line of the diffuser 25, each cross section of the spray liquid has an inner circle and an outer circle that are concentric with each other. An annular shape defined by.

  The plurality of annular cross sections generated for the spray liquid expand in diameter along the forward direction of the flow. On the other hand, since the flow rate of the spray liquid is constant at any virtual point, the area of each annular cross section is also constant. On the other hand, the circumferences of the inner circle and outer circle of each annular cross section increase with the forward direction of the flow. As a result, the thickness of each annular cross section, that is, the thickness of the spray liquid layer covering the surface of the diffuser 25 decreases along the forward direction of the flow. That is, the spray liquid layer is thinned in the forward direction of the flow.

  Thus, when the spray liquid layer is thinned, after the spray liquid exits from the diffuser 25 or in the middle of passing through the diffuser 25, the spray liquid has a larger number of smaller particles in the spray space. The tendency to disperse and mist is increased. On the other hand, the finer the fine particles in the mist of the spray liquid (fine particles in the mist), the easier the fine particles in the mist are vaporized.

  As shown in FIG. 8, a plurality of microbubbles are mixed in the spray liquid layer. As a result, the spray liquid is more likely to be divided into a plurality of segments (the tendency that the liquid is divided into a plurality of liquid portions by the plurality of bubbles) as compared to the case where such microbubbles are not mixed. Furthermore, as the spray liquid advances downstream, the tendency of the spray liquid constituting the spray liquid layer to be divided into a plurality of segments is further strengthened as the thickness of the spray liquid layer approaches the diameter of one microbubble. Is done.

  Thus, when a plurality of microbubbles are mixed in the spray liquid, the tendency of the spray liquid to be divided increases, and the microbubbles burst after the spray liquid exits the diffuser 25 or while passing through the diffuser 25, There is an increased tendency that the spray liquid is dispersed into a larger number of finer particles having a smaller diameter in the spray space and becomes mist. On the other hand, as described above, the fine particles in the mist become easier to vaporize as the fine particles (fine particles in the mist) of the mist of the spray liquid (hereinafter referred to as “spray mist”) become finer.

  As is clear from the above description, in the present embodiment, the diffusion effect of the spray liquid by the diffuser 25, the effect of dividing the spray liquid by mixing a plurality of microbubbles into the spray liquid, and the spray space by the hot air shield By coordinating with the heat retaining effect, the miniaturization of each of the plurality of fine particles in the mist constituting the spray mist is promoted. This facilitates shortening the complete vaporization time of each particle, that is, shortening the flight distance that the spray solution must fly in the spray space in order for the spray solution to completely vaporize.

  Next, the operation of the coating apparatus 10 will be described with reference to FIGS. 9 to 11.

  As shown in FIG. 9, in order to start the coating operation, the operator first turns on the main power supply 50 in step S1, then turns on the compressor 82 in step S2, and then continues in step S3. , The air temperature controller 90 is turned on. Thereafter, the operator turns on the pumping pump 42 in step S4, and then turns on the solution warming device 40 in step S5. As described above, the coating apparatus 10 shifts to a standby state.

  If the operator has not yet pulled the trigger 25 of the spray gun 12, the determination in step S6 is NO, and the spray gun 12 is maintained in the inflow blocking state in step S7. On the other hand, when the operator pulls the trigger 25 of the spray gun 12, the determination in step S6 is YES, and in step S8, the spray gun 12 shifts to the inflow permission state.

  As a result, in step S9, the compressed air heated by the air heater 62 is supplied to the spray gun 12 together with the alcohol solution heated by the solution heater 52. Thereby, the alcohol solution is atomized using the compressed air and sprayed from the spray gun 12 toward a target surface (not shown).

  Thereafter, when the operator releases his / her hand from the trigger 25 of the spray gun 12, the spray gun 12 is restored to the inflow blocking state, whereby the spraying of the alcohol solution is completed.

  As shown in FIG. 10, the operator first turns off the air temperature controller 90 in step S11 in order to end the application work. Thereby, the power supply from the main power supply 50 to the air heater 62 is interrupted. However, residual heat exists in the air heater 62. Next, the operator turns off the pumping pump 42 in step S12, and then turns off the solution warming device 40 in step S13.

  At the present time, the compressor 82 continues to operate, and all of the compressed air that has passed through the air heater 62 is discharged from the branch passage 76 to the atmosphere as shown in FIG. Thereby, compressed air is used for the use of the air cooling which is not an original use, and the air heater 62 is forcedly air-cooled. As a result, the temperature of the air heater 62 quickly returns to room temperature, and the air heater 62 is not heated unnecessarily.

  When the worker determines that the cooling of the air heater 62 has been completed as described above, the determination in step S14 is YES, and the worker turns off the compressor 82 in step S15. Thereby, the supply of compressed air to the air heater 62 is stopped. Subsequently, the worker turns off the main power supply 50 in step S16. Thus, the coating operation is completed, and thereby the coating apparatus 10 is restored to the initial state.

  FIG. 11 shows a plurality of steps over time when the coating operation is performed using the coating apparatus 10.

  First, there is a solution heating step S101 for heating an alcohol solution in which a plurality of particles are mixed in a dispersed state. Further, there is a gas supply step S102 for supplying compressed air to the air heater 62 regardless of whether the spray gun 12 is in an inflow permitting state or an inflow blocking state. Further, there is a gas heating step S103 in which the supplied compressed air is heated using the air heater 62.

  Further, there is a gas release step S104 in which the compressed air that has passed through the air heater 62 is released to the atmosphere in at least the inflow prevention state of the inflow permission state and the inflow prevention state of the spray gun 12.

  Further, the spraying step S105 for supplying the warmed compressed air together with the warmed alcohol solution to the spray gun 12 and atomizing the alcohol solution using the compressed air and spraying from the spray gun 12 is performed. Exists. This spraying step S105 has a charging step S106 for charging a plurality of particles in the spray gun 12 so as to have the same polarity.

  Next, by referring to FIG. 12 to FIG. 18, the application method implemented using the coating apparatus 10 and the antibacterial effect of the applied antibacterial fine particles will be described by focusing on the behavior of the antibacterial fine particles. To do.

  FIG. 12 conceptually shows an enlarged outline of one antibacterial agent fine particle (also referred to as “antibacterial fine particle”). The diameter of the antimicrobial fine particles is about 80 nm (for example, about 80 to about 100 nm). Since the diameter of the antibacterial agent fine particles is nano-sized in this manner, the total surface area of the plurality of antibacterial agent fine particles having the same total weight is increased as compared with the case where the diameter is smaller than that. This contributes to the improvement of the antibacterial effect.

  As described above, the antibacterial fine particles carry a plurality of metallic silver particles on the surface thereof. Antibacterial fine particles cannot perform a catalytic action unless they receive light, whereas metallic silver exhibits an antibacterial action without requiring light. Thus, metallic silver enhances the catalytic action of the antimicrobial fine particles.

  As conceptually shown in FIG. 13, the alcohol solution sprayed from the spray gun 12 is vaporized during flight, and after the vaporization is completed, a plurality of antibacterial agent fine particles (in this embodiment, positively charged) ) Reaches the target surface. In the present embodiment, the target surface is the surface of the coating film baked and applied on the surface of the object to be coated, and the antibacterial agent fine particles are adhered to the coating film when the coating film is semi-dry. It is done.

  In the present embodiment, prior to supplying the alcohol solution and compressed air to the spray gun 12, the alcohol solution sprayed from the spray gun 12 is substantially completely evaporated before reaching the target surface. The alcohol solution and the compressed air are heated to a temperature at which the heating of the alcohol solution and the heating of the compressed air are realized in cooperation with each other.

  Specifically, as described above, in this embodiment, the compressed air is equal to or higher than the temperature (about 30 to about 50 ° C.) at which the alcohol solution is heated (about 50 to about 70 ° C.). ° C).

  As a result, according to the present embodiment, after the alcohol solution is sprayed by the spray gun 12, it completely evaporates before reaching the target surface, and as a result, a plurality of alcohol solutions contained in the original alcohol solution All of the antibacterial microparticles are individually allowed to fly in the air and reach the target surface in that state. The minimum value of the flight distance (spray distance) that the alcohol solution must fly for the volatile medium to substantially completely vaporize before the antimicrobial fine particles reach the target surface is, for example, about 50 to It is about 60 cm.

  As conceptually shown in FIG. 14, the form of the alcohol solution sprayed from the spray gun 12 changes with time in the process of reaching the target surface.

  Immediately after being sprayed from the spray gun 12, the alcohol solution is in the form of a mist and exists as a collection of a plurality of particles (droplets). In each grain, a plurality of positively charged (or negative) charged particles are present in an aggregated state.

  As described above, in this embodiment, prior to the supply to the spray gun 12, not only the alcohol solution but also the compressed air is heated. Accordingly, the alcohol evaporates from each particle, and the plurality of antibacterial agent fine particles are released from the constraint by the particles. As a result, the plurality of antibacterial agent fine particles are dispersed with each other.

  And in this embodiment, since all the antibacterial agent fine particles are charged to the same polarity, they repel each other electrostatically. As a result, the antibacterial fine particles have a tendency to disperse with each other. These antibacterial agent fine particles adhere to the surface of the semi-dry coating film in a densely and uniformly dispersed state.

  In one conventional example, as shown in FIG. 15, the surface of each antibacterial agent fine particle is coated with a liquid binder prior to attachment to the surface of the object to be coated. If the antimicrobial agent particles adhere to the target surface and are dried, the antibacterial agent fine particles adhere to the target surface, but the binder remains on the surface of the antibacterial agent fine particles. As a result, the effective surface area (effective exposed area) of each antibacterial agent fine particle decreases. The remaining binder interferes with the contact between the antibacterial fine particles and the object to be antibacterial, and reduces the antibacterial action of the antibacterial fine particles.

  In contrast, in the present embodiment, as conceptually shown in FIG. 16, each antibacterial agent fine particle locally adheres to the surface of a semi-dry coating film (undercoating film) without coating with a binder. . The coating film may be positively charged or negatively charged regardless of the polarity of the electric charge of each antibacterial agent fine particle to be attached as long as the whole is at the same potential.

  Due to the joint action of the pressure when sprayed on the coating surface and the surface tension of the coating, the coating swells in the vicinity of the contact with each antimicrobial fine particle, and each antimicrobial fine particle bites into the coating locally. . It is avoided that each antibacterial agent fine particle is completely buried in the coating film.

  Thereafter, the process proceeds to the baking effect / drying process of the coating film, and in the process, the antibacterial fine particles are drawn into the coating film. Thereby, an integrated coating film in which a plurality of antibacterial agent fine particles are integrated with the coating film is formed.

  As conceptually shown in the enlarged sectional view in FIG. 17, a plurality of antibacterial agent fine particles are applied to the target surface, that is, the surface of the coating film on which the surface of the object is baked. It is allowed to adhere in a dry state. Eventually, the coating film dries. As a result, the plurality of antibacterial agent fine particles are fixed in a state where they are bitten into the coating film. The plurality of antibacterial agent fine particles fixed to the surface of the coating film are adjacent to each other with an interval w of several μ.

  As conceptually shown in a plan view enlarged in FIG. 18, the plurality of antibacterial agent fine particles fixed to the surface of the coating film are substantially uniformly dispersed at intervals w.

  As shown in FIG. 18, according to the present embodiment, since a plurality of antibacterial agent fine particles are uniformly dispersed and fixed on the coating film surface, any antibacterial agent fine particles are coated on the coating film surface. The area of the continuous region which does not exist is reduced as compared with the conventional case where a plurality of antibacterial agent fine particles are aggregated with each other and exist on the surface of the coating film.

  As a result, the probability that each bacterium to be killed will come into contact with any of the coating film surfaces to which a plurality of antibacterial agent particles adhere according to the present embodiment is that the plurality of antibacterial agent particles aggregate to each other on the coating film surface. Increases if present.

  According to the present embodiment, a plurality of silver-based antibacterial agent fine particles that have been confirmed to have an effect on fungi, molds, and viruses are sprayed so that they adhere to the surface of the coating film in a state of being dispersed with high density. Applied. Furthermore, the silver antibacterial agent fine particles are applied so that they do not overlap each other by utilizing the spray pressure of the spray liquid, the surface tension of the coating film, and the static electricity of a plurality of fine particles (charged to the same polarity) of the spray liquid. The silver antibacterial agent fine particles are fixed to the coating film while partially biting into the film (while leaving the exposed surface).

  Therefore, these silver antibacterial agent fine particles ensure long-lasting durability and long-lasting effects, and these silver antibacterial agent fine particles are dispersed and adhered on the coating film at a high density, so that these silver antibacterial particles The probability that the agent fine particles come into contact with fungi and the like increases dramatically. As a result, the antibacterial effect, the deodorizing effect, and the antifungal effect are all demonstrated over a long period of time.

  In the embodiment described above, the silver-based antibacterial agent fine particles are employed as an example of a plurality of particles contained in the spray liquid for the purpose of an antibacterial effect, a deodorizing effect, and an antifungal effect. Instead of this, for example, metal particles can be employed as another example of a plurality of particles contained in the spray solution for the purpose of electrostatic shielding, for example.

  As described above, some of the embodiments of the present invention have been described in detail with reference to the drawings. However, these are exemplifications, and are based on the knowledge of those skilled in the art including the aspects described in the section of [Summary of the Invention]. The present invention can be implemented in other forms with various modifications and improvements.

In order to solve the problem , according to one aspect of the present invention, a plurality of particles are sprayed on a target surface, which is a surface of a semi-dry coating film formed on the surface of an object to be coated, or completely applied. A particle coating apparatus that sprays and coats a plurality of particles on the surface of the binder after the binder is applied to the target surface that has been dried;
A microbubble generator for generating a plurality of microbubbles in a volatile spray liquid in which the plurality of particles are mixed in a volatile solvent in a dispersed state;
A first heater for heating the spray liquid in which the plurality of microbubbles are mixed;
A spray liquid injection port for injecting the heated spray liquid;
A diffuser having, as a diffusion surface, a conical surface that expands in diameter in the traveling direction of the spray liquid injected from the spray liquid injection port, and the spray liquid injected from the spray liquid injection port passes through the diffusion surface. The spray layer formed on the diffusion surface is thinned by the diffusion surface, and the thin spray layer is injected into the spray space;
A second heater for heating the compressed gas;
A compressed gas injection port for injecting the heated compressed gas into the spray space;
Hot air that is hotter than the surrounding space that surrounds the spray space from the side is sprayed so as to form a warm air shield having an annular cross-section that surrounds the spray space from the side, whereby the spray space Promotes heat retention in the interior, whereby the volatile components in the spray liquid are vaporized before reaching the target surface, and the plurality of particles are dispersed in each other and suspended in the air without agglomerating with each other. A hot air shield forming device that facilitates reaching the target surface in a state;
A particle coating apparatus is provided.
According to another aspect of the present invention, a plurality of particles are sprayed on a target surface, which is a surface of a semi-dry coating film formed on the surface of an object to be coated, or completely dried. A particle coating method in which a plurality of particles are sprayed and applied to the surface of the binder after the binder is applied to the target surface,
A microbubble generating step of generating a plurality of microbubbles in a volatile spray liquid in which the plurality of particles are mixed in a volatile solvent in a dispersed state;
A conical surface that heats the spray liquid in which the plurality of microbubbles are mixed, injects the warmed spray liquid, and expands the diameter of the sprayed spray liquid as it proceeds in the traveling direction of the spray liquid A spray liquid spraying step of thinning a spray liquid layer formed on the diffusion surface by allowing the diffuser to pass through the diffusion surface of the diffuser and spraying the thinned spray liquid layer into the spray space When,
A compressed gas injection step for heating and injecting the compressed gas into the spray space, thereby promoting atomization of the spray liquid;
Hot air that is hotter than the surrounding space that surrounds the spray space from the side is sprayed so as to form a warm air shield having an annular cross-section that surrounds the spray space from the side, whereby the spray space Promotes heat retention in the interior, whereby the volatile components in the spray liquid are vaporized before reaching the target surface, and the plurality of particles are dispersed in each other and suspended in the air without agglomerating with each other. A hot air shield forming step that promotes reaching the target surface in a state;
A particle coating method is provided.
Furthermore, according to the first aspect of the present invention, there is provided a spray gun for spraying a volatile spray liquid into a spray space,
A spray liquid injection port for injecting the spray liquid into the spray space;
A compressed gas injection port for injecting compressed gas into the spray space;
When the spray gun is viewed from the front, the hot air is disposed at a position laterally away from the spray liquid injection port and the compressed gas injection port and is hotter than the surrounding space surrounding the spray space from the side. And a hot air injection port forming a warm air shield having an annular cross section surrounding the spray space from the side.

In order to solve the problem, according to one aspect of the present invention, a particle coating apparatus for spraying and coating a plurality of particles on a target surface of an object to be coated,
A tank containing a volatile solution in which the plurality of particles are mixed in a volatile solvent in a dispersed state ;
A microbubble generator for generating a plurality of microbubbles in the solution contained in the tank ;
A solution heating apparatus for heating the solution in which the plurality of microbubbles are mixed,
When the warmed solution is supplied, a spray gun that sprays the solution
Including
The spray gun
A spray liquid injection port for injecting the heated solution in which the plurality of microbubbles are mixed as a spray liquid;
The conical surface whose diameter increases as one proceeds in the traveling direction of the spray liquid sprayed liquid that has been ejected from the ejection nozzle possess as a diffusion surface, the spray liquid ejected from the spray injection port is passed through the diffusion surface, A diffuser that thins the spray liquid layer formed on the diffusion surface by the diffusion surface, thereby rupturing the plurality of microbubbles in the spray liquid while the spray liquid passes through the diffusion surface ;
A compressed gas heater for heating the compressed gas ;
The heated compressed gas is injected into the spray space, and the injected compressed gas and the spray liquid injected from the spray liquid injection port are merged, thereby injecting from the spray liquid injection port A compressed gas injection port for promoting atomization of the sprayed liquid ,
Hot air that is hotter than the surrounding space that surrounds the spray space from the side is sprayed so as to form a warm air shield having an annular cross-section that surrounds the spray space from the side, whereby the spray space Promotes heat retention in the interior, whereby the volatile components in the spray liquid are vaporized before reaching the target surface, and the plurality of particles are dispersed in each other and suspended in the air without agglomerating with each other. And a hot air shield forming device that facilitates reaching the target surface in a state.
According to another aspect of the present invention, there is provided a particle coating method for spraying and coating a plurality of particles on a target surface of an object to be coated,
A microbubble generating step of generating a plurality of microbubbles in a volatile solution in which the plurality of particles are mixed in a volatile solvent in a dispersed state and contained in a tank ;
A solution heating step of heating said solution to said plurality of microbubbles are mixed,
Supplying a heated solution to the spray gun;
Including
The spray gun has a spray liquid injection port, a diffuser, a compressed gas injection port, and a hot air shield forming device,
The method further includes:
The warmed solution supplied to the spray gun, which is mixed with the plurality of microbubbles, is sprayed as a spray liquid from the spray liquid spray port, and the sprayed spray liquid is sprayed. by passing the diffusing surface of the diffuser with a conical surface whose diameter increases as one proceeds in the traveling direction of the liquid as a diffuse surface, a spray liquid layer thinned formed on the diffusing surface, whereby said spray Spray liquid injection step of rupturing the plurality of microbubbles in the spray liquid in the middle of passing through the diffusion surface ,
The compressed gas heated City, injecting the warmed compressed gas from said compressed gas injection port into the spray space, whereby its injected compressed gas, injected from the spray injection port spray A compressed gas injection step for merging the liquid and thereby promoting atomization of the spray liquid;
The hot air shield forming device injects hot air that is hotter than the surrounding space surrounding the spray space from the side so as to form a hot air shield having an annular cross section that surrounds the spray space from the side. Thus, the heat retention in the spray space is promoted, whereby the volatile components in the spray liquid are vaporized before reaching the target surface, and the plurality of particles do not aggregate with each other. And a hot air shield forming step for promoting reaching the target surface in a state of being dispersed and floating in the air.
Furthermore, according to the first aspect of the present invention, there is provided a spray gun for spraying a volatile spray liquid into a spray space,
A spray liquid injection port for injecting the spray liquid into the spray space;
A compressed gas injection port for injecting compressed gas into the spray space;
When the spray gun is viewed from the front, the hot air is disposed at a position laterally away from the spray liquid injection port and the compressed gas injection port and is hotter than the surrounding space surrounding the spray space from the side. And a hot air injection port forming a warm air shield having an annular cross section surrounding the spray space from the side.

Claims (5)

A spray gun for spraying volatile spray liquid into the spray space,
A spray liquid injection port for injecting the spray liquid into the spray space;
A compressed gas injection port for injecting compressed gas into the spray space;
When the spray gun is viewed from the front, the hot air is disposed at a position laterally away from the spray liquid injection port and the compressed gas injection port and is hotter than the surrounding space surrounding the spray space from the side. A hot air spray port that forms a warm air shield having an annular cross-section surrounding the spray space from the side. A particle coating apparatus for spraying and coating a plurality of particles on a target surface,
A first heater for heating the spray liquid in which the plurality of particles are mixed in a volatile solvent in a dispersed state;
A second heater for heating the compressed gas;
A spray gun for spraying the spray liquid into a spray space using the compressed gas when the warmed spray liquid is supplied together with the warmed compressed gas;
The spray gun
A spray liquid injection port for injecting the spray liquid into the spray space;
A compressed gas injection port for injecting the compressed gas into the spray space;
When the spray gun is viewed from the front, the hot air is disposed at a position laterally away from the spray liquid injection port and the compressed gas injection port and is hotter than the surrounding space surrounding the spray space from the side. And a hot air spraying port that forms a hot air shield having an annular cross section that surrounds the spray space from the side.   The particle application according to claim 2, further comprising a microbubble generator that generates a plurality of microbubbles in each part of the spray liquid before each part of the spray liquid is sprayed from the spray liquid injection port. apparatus.   The particle coating apparatus according to claim 2 or 3, wherein the plurality of particles carry metallic silver particles in a state of being exposed on each surface. A spraying method of spraying a volatile spray liquid into a spray space,
A spray liquid injection step of heating the spray liquid and spraying the spray liquid into the spray space;
A compressed gas injection step for heating and injecting the compressed gas into the spray space, thereby promoting atomization of the spray liquid;
Hot air that is hotter than the surrounding space that surrounds the spray space from the side is sprayed so as to form a warm air shield having an annular cross-section that surrounds the spray space from the side, whereby the spray space And a hot air shield forming step for promoting heat insulation in the inside.

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