JP2015224330A - Corrosion protection method for mechanical facility and anti-corrosive mechanical facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the anti-corrosive property of a mechanical facility such as an air conditioner for a long term and extend the life of the mechanical facility.SOLUTION: The portion of a mechanical facility that is in contact with air is coated with an anti-corrosive paint composition that comprises a basis comprising vinyl ester resin and an organic peroxide curing agent with a coating thickness of 5-500 μm.

Description

  The present invention relates to an anticorrosion method for mechanical equipment such as air conditioners, heat exchangers, refrigerators, water heaters, exhaust ducts, pipes and the like provided in hotels, inns, hot springs, houses, stores, etc. and a machine obtained by the method. Regarding equipment.

Some air-conditioning equipment and other mechanical equipment (hereinafter referred to as “mechanical equipment”) installed in a building is placed outside the room, such as an outdoor unit, and requires resistance to corrosion caused by external factors such as sea breeze and rainfall. In addition, anticorrosion treatment such as application of anticorrosion paint is performed.
Conventionally, anticorrosion treatment for mechanical equipment has been performed in accordance with standards established by the Japan Refrigeration and Air Conditioning Industry Association. This standard is intended to prevent the occurrence of rust caused by sea salt particles, etc., and mainly stipulates the parts that make up the exterior of mechanical equipment installed outdoors. The parts constituting the outline of the mechanical equipment have been subjected to anticorrosion treatment by applying urethane paint or the like on the surface thereof.

  On the other hand, parts (for example, heat exchangers and pipes) constituting the inside of mechanical equipment are generally subjected to anticorrosion treatment by cationic electrodeposition coating based on epoxy resin as shown in Patent Document 1. For other parts, there was no salt damage test standard for corrosion protection, and measures such as making with stainless steel were taken.

Japanese Patent No. 2879186

  However, the standard established by the Japan Refrigeration and Air Conditioning Industry Association has a short test period to confirm its durability, and is placed in a corrosive environment such as along the coast, on a remote island, or in a hot spring area or chemical factory with sulfur. Even if the outer shell of the machine equipment is subjected to anticorrosion treatment according to the standard, there is a problem that a sufficient anticorrosion effect cannot be obtained.

In addition, for example, when the anti-corrosion treatment using the epoxy resin-based cationic electrodeposition paint described in Patent Document 1 is performed on the heat exchanger that is a component constituting the inside of the mechanical equipment, the entire coating is applied in order to further improve the anti-corrosion property. The film had to be thickened, resulting in a problem that the heat exchange rate was significantly reduced. In addition, in order to perform the treatment, it is necessary to put the object to be treated in a cation tank, which cannot be used for a heat exchanger having a surface area of more than 100 m ² , and further, discoloration due to ultraviolet rays, surface chalking (choking), etc. Since it tends to occur, there is a problem that it is difficult to maintain the anticorrosion property of the epoxy resin-based cationic electrodeposition coating, particularly when it is excessively directly exposed to corrosive substances such as seawater splashes, sea breeze, sulfur and vinegar.

  On the other hand, vinyl ester resin-based paints used for buildings such as bridges in the sea are known as paints with excellent acid resistance and high anti-corrosion properties. It could not be used for coating parts where the distance between parts is narrow (1 to 7 mm, 1 to 2.5 mm for frequently used types), such as aluminum fins constituting the heat exchanger of the equipment.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an anticorrosion method capable of maintaining anticorrosion properties for mechanical equipment such as air conditioners over a long period of time, and mechanical equipment excellent in anticorrosion properties. And

  In order to solve the above-described problems, the first anti-corrosion method and anti-corrosion machine equipment of the present invention includes a main agent containing a vinyl ester resin, an organic peroxide curing agent, An anticorrosive coating composition containing a coating of 5 to 500 μm is applied.

  In order to solve the above-mentioned problems, the corrosion prevention method and the corrosion prevention machine equipment of the second machine equipment according to the present invention perform primer treatment on the portion of the machine equipment that comes into contact with air with a base adhesive paint, and vinyl ester An anticorrosive coating composition containing a main component containing a resin and an organic peroxide curing agent is applied with a coating thickness of 5 to 500 μm.

  ADVANTAGE OF THE INVENTION According to this invention, favorable anticorrosion property can be maintained over a long period with respect to mechanical equipment, such as an air-conditioning apparatus, and the lifetime of mechanical equipment can be extended.

It is a schematic diagram of the aluminum fin of a heat exchanger, (a) is a front view of the aluminum fin of a heat exchanger, (b) is a top view of the aluminum fin of a heat exchanger, (c) is a heat exchanger It is a side view of the aluminum fin. It is a figure which shows the state which has applied the coating material using the spray gun which can be sprayed linearly from the front side of the aluminum fin of a heat exchanger.

  The present invention provides an anticorrosion treatment by applying a vinyl ester resin-based paint that is not generally used for an anticorrosion treatment of an air conditioner or the like to a machine facility such as an outdoor unit of an air conditioner or the like. It has been found to be effective, and can be applied with a spray gun by adjusting the viscosity of the vinyl ester resin-based paint, enabling anti-corrosion treatment with an optimum coating thickness for the heat exchanger.

  The “location in contact with air” of the mechanical equipment in the present invention does not refer only to a portion that is directly exposed to the outside air, such as an outline of the mechanical equipment such as an air conditioner, but for example, a mechanical equipment such as a heat exchanger or various steel pipes. The part which comprises the inside is also included.

(Composition of vinyl ester resin paint)
The vinyl ester resin-based paint used for the anticorrosion treatment of the present invention is diluted with respect to the anticorrosive paint composition containing the main agent and the organic peroxide curing agent, which are mainly composed of vinyl ester resin and containing various additives. It can be obtained by mixing the agent.

  The vinyl ester resin that is the main component of the vinyl ester resin-based paint is a reaction product resin of various epoxy resins and methacrylic acid or acrylic acid, and bisphenol type glycidyl ether or novolac type glycidyl as an epoxy compound as a raw material of the epoxy resin. Examples include ether.

  The concentration of the vinyl ester resin in the main agent may be set as appropriate depending on the component of the additive to be added and the purpose of coating. However, as a coating used for anticorrosion treatment of an air conditioner or the like, it is 50 to 70% by mass, particularly 55 to 65% by mass. % Is preferred. If the concentration is less than 50% by mass, there is a possibility of separation due to a decrease in the standing stability of the paint, and if the concentration exceeds 70% by mass, the thickening of the main agent is remarkably difficult to manufacture and paint. This is because there is a possibility of becoming.

Examples of the additive added to the vinyl ester resin-based paint include flaky substances such as glass flakes, coloring / extreme pigments, and other various additives.
By adding flaky substances such as glass flakes, flakes are dispersed and arranged almost in parallel in the coating film to form a layered structure, and corrosive substances (water, oxygen, harmful ions, etc.) that pass through the coating film. Since the time to reach the base metal can be lengthened, the acid resistance and corrosion resistance of the coating film can be improved. Further, by adding a coloring / extreme pigment, it is possible to color the paint or to save the amount of vinyl ester resin used.

  Furthermore, as various additives, for example, an antioxidant, an ultraviolet absorber, an antifoaming agent, a thickener, a coloring agent, and the like can be added to further improve light resistance, acid resistance, water resistance, and the like.

  The organic peroxide curing agent used in vinyl ester resin coatings is obtained by substituting one or two hydrogen atoms of hydrogen peroxide with other substituents, and has an peroxide structure in the molecule. If it is a thing, there will be no restriction | limiting in particular, For example, methyl ethyl ketone peroxide, cyclohexanone peroxide, acetylacetone peroxide, cumene hydroperoxide, dibenzoyl peroxide, t-butylperoxybenzoate etc. are mentioned. These may be used alone or in combination of two or more.

  Further, for the purpose of accelerating curing, a tertiary amine may be added to the organic peroxide curing agent. The tertiary amine is not particularly limited, and examples thereof include trialkylamine, N, N-dialkyltoluidine, and N-dialkylaniline whose alkyl group has 1 to 4 carbon atoms.

  The diluent used in the vinyl ester resin-based paint is not particularly limited as long as it is an organic solvent that dissolves the vinyl ester resin-based paint, and examples thereof include styrene. By blending a diluent with the paint, the viscosity of the paint is reduced, and spray coating with a paint spraying device is possible.

  The concentration of the organic solvent such as styrene with respect to the vinyl ester resin-based paint should be within the viscosity range (15 ± 5 dPa · s: 23 ° C., measured by a Rion viscometer) that the vinyl ester resin-based paint can be applied with a spray gun. There is no particular limitation. In this invention, about 5 mass% or less is preferable from the component of the anticorrosion coating composition containing a main ingredient and an organic peroxide hardening | curing agent.

(Method of applying vinyl ester resin paint)
The vinyl ester resin-based paint is applied to the outline of the mechanical equipment and the parts constituting the inside by spraying using a paint spraying device. As a paint spraying device, a spray gun generally used for painting may be used. For example, as shown in FIG. 1, when painting a heat exchanger A or the like, it is sufficient between the fins of the aluminum fins 1. It is preferable to use a spray gun capable of spraying the paint coating in a straight line so that the paint spreads over the surface.

The viscosity of the vinyl ester resin-based paint applied by the spray gun is adjusted to about 15 dPa · s (23 ° C: measured by a viscometer manufactured by Rion Co., Ltd.). The coating can be applied with a coating thickness of 5 to 500 μm on the surface of the outer shell and the surface of the portion constituting the inner shell. The coating thickness can be adjusted by the spraying pressure and the number of spraying, and can be appropriately selected depending on the object to be coated and the application. It is possible to coat with a coating thickness of preferably 100 to 250 μm on a part where the interval between parts is not dense or on a part arranged substantially perpendicular to the spraying direction. Moreover, it can coat with the coating-film thickness of preferably 10-50 micrometers to the part with a narrow space | interval between components like the aluminum fin of a heat exchanger. Thereby, sufficient anti-corrosion processing can be performed without reducing heat exchange efficiency with respect to the part where the space | interval of a fin is very narrow like the aluminum fin 1 of a heat exchanger.
As above

(Ground bonding process)
In the anticorrosion treatment of the present invention, depending on the condition of the surface of the object to be subjected to the anticorrosion treatment by spray coating with a spray gun, it is preferable to perform the primer treatment with the base adhesive paint prior to the application of the vinyl ester resin paint. Specifically, when the metal substrate is exposed, such as when the surface of the object to be subjected to the anticorrosion treatment is not coated, the base adhesive paint is applied prior to the application of the vinyl ester resin-based paint.

  The primer coating used for primer treatment is, for example, thermoplastic acrylic resin, fluororesin, polyolefin resin as the main component, and solvents such as toluene, xylene, ethyl acetate, butyl acetate, methanol, mineral split alone or two kinds It is formed by blending the above together.

  Examples of the thermoplastic acrylic resin that is a main component of the base adhesive coating include acrylic acid ester or methacrylic acid ester polymers, such as polymethyl methacrylate or polyethyl acrylate.

  Examples of the fluororesin that is a main component of the base adhesive coating include fluorine-containing olefin polymers such as polytetrafluoroethylene, polyvinylidene fluoride, and polychlorotrifluoroethylene.

  The polyolefin resin that is the main component of the base adhesive coating is an α-olefin polymer having a double bond at the 1-position, such as polyethylene, polypropylene, ethylene / propylene copolymer, and ethylene / vinyl acetate copolymer. Can be mentioned.

  The concentration of the solvent used for the base adhesive coating is not particularly limited as long as it is a viscosity that can be applied by a spray gun, and is appropriately set depending on other components to be blended. In the present invention, for example, 60 to 95% by mass, particularly 70 to 90% by mass with respect to the base adhesive coating is preferable from the viewpoint of adhesion of the coating.

  Then, the base adhesive coating is sprayed on the portion to be subjected to the anticorrosion treatment by a paint spraying instrument such as a spray gun used for applying the vinyl ester resin-based paint, and the primer treatment is performed.

  Examples of the anticorrosion method of the present invention will be specifically described below with reference to the drawings.

  The heat exchanger shown in FIG. 1 includes an aluminum fin 1 and a pipe 2. The aluminum fin 1 is formed by subjecting an aluminum plate to a predetermined number of holes, and a copper tube is formed in the hole of the aluminum fin 1. Or the piping 2 which consists of aluminum pipes is press-fit, and the aluminum fin 1 is integrated in the state arrange | positioned by predetermined spacing (2.1 mm), and the heat exchanger is formed. The surfaces of the aluminum fins 1 and the pipes 2 are not painted, and the material aluminum is exposed. Therefore, the primer treatment was performed using the base adhesive coating prior to the anticorrosion treatment by applying the vinyl ester resin-based paint.

(paint)
The composition of the vinyl ester resin paint used for the anticorrosion treatment is shown below.

Vinyl ester resin paint [main agent]
Vinyl ester resin varnish 56.6% by mass
Glass flakes 18.9% by mass
Coloring and extender 9.5% by mass
Other additives 9.5% by mass
[Curing agent]
Organic peroxide curing agent 0.9% by mass
[Diluted solvent]
Styrene 4.6% by mass

The vinyl ester resin-based paint with the above composition had a viscosity of 15 dPa · s (23 ° C .: measured with a viscometer manufactured by Rion).
In addition, although the said Example is mix | blended on the assumption that it processes in the summer, for example, when it takes comparatively long time for drying of paints, such as winter, the amount of hardening agents is increased, etc. It can be changed as appropriate according to the local climate.

The composition of the base adhesive paint used for the primer treatment is shown below.

Base adhesive coating [main component] 84.0% by mass
(Including thermoplastic acrylic, silicon, and polyvinylidene fluoride)
[Solvent] 16.0% by mass
(Including xylene, butyl acetate, ethyl acetate, mineral split, toluene)

(Processing process)
Anticorrosion treatment consists of the following steps.
Process 1. The surface of the heat exchanger A shown in FIG. 1 is washed, oil components such as grease, salt and dirt are removed and dried well.

Step 2. As shown in FIG. 2, a spray gun B that can be sprayed in a straight line is applied to the heat exchanger A that has been thoroughly dried. It was sprayed and applied in the shape. The air pressure of the spray gun B was set to a low pressure (0.4 to 0.7 MPa), and coating was performed twice.
The spray gun B capable of spraying in a straight line is composed of a paint spraying port 4 for spraying paint and a high-pressure air nozzle 5 arranged on the side thereof for ejecting high-pressure air, and spraying from the paint spraying port 4 The coating material a was sprayed linearly by the high-pressure air curtain b from the high-pressure air nozzle 5, and the coating material could be applied to the depth between the aluminum fins 1 of the heat exchanger A.

  Step 3. After drying the base adhesive coating, the vinyl ester resin-based coating having the above composition was sprayed and applied linearly from the side surface of the heat exchanger A using a spray gun B that can be sprayed linearly.

(Results of anticorrosion treatment)
In the heat exchanger A of the air conditioner that was subjected to the anticorrosion treatment in the above treatment process, a coating film made of a vinyl ester resin was formed on the aluminum fin 1. The coating film had no wrinkles, cracks or peeling, and the thickness of the coating film was 10 to 25 μm.

  The anticorrosion coating film formed on the aluminum fin 1 of the heat exchanger A can withstand a 200-hour salt spray test, and can be immersed in tap water at 50 ° C. for 7 days, or in a 50 ° C. saline solution for 7 days. No abnormalities occurred on the surface even after immersion.

In this example, the non-corrosion-treated surface is not subjected to coating or the like, and the metal is exposed, so the primer treatment is performed. However, the non-corrosion-treated surface is subjected to protective treatment such as painting. If so, primer treatment can be omitted.
Further, the number of times of application of the base adhesive coating in the primer treatment can be appropriately selected according to the state of salt damage. Furthermore, when pulling the yarn from the spray gun, such as when the humidity is high, it is preferable to further dilute the base adhesive paint to adjust the viscosity of the base adhesive paint.

  As described above, according to the embodiment of the present invention, the anti-corrosion treatment can be performed by applying the vinyl ester resin-based paint with the spray gun to the mechanical equipment arranged along the coastline where the environment is severe. Therefore, it is possible to easily adjust the thickness of the coating film, and for the parts that make up the outline of the mechanical equipment, a coating film that can provide a sufficient anti-corrosion effect even if it is placed in a highly corrosive environment. It can be formed, and the components that make up the inside of the machine equipment such as the aluminum fins of the heat exchanger can be subjected to necessary and sufficient anticorrosion treatment without lowering the heat exchange efficiency. As such, the corrosion resistance can be improved and the service life can be extended.

1 Aluminum Fin 2 Piping 4 Paint Spray Port 5 High Pressure Air Nozzle A Heat Exchanger B Spray Gun a Spray Paint b High Pressure Air Curtain

Claims (4)

  Anticorrosion of machinery and equipment by applying an anticorrosion coating composition containing a vinyl ester resin-containing main agent and an organic peroxide curing agent to a portion exposed to air outside the machinery and equipment with a coating thickness of 5 to 500 μm. Method.   The anticorrosion method according to claim 1, wherein a primer treatment is performed with a base adhesive paint before applying the anticorrosion paint composition.   An anti-corrosion machine facility comprising an anti-corrosion coating composition containing a main component containing a vinyl ester resin and an organic peroxide curing agent with a coating thickness of 5 to 500 μm, to a portion that is exposed to outside air.   The anticorrosion machine equipment according to claim 3, wherein a primer treatment is performed with a base adhesive paint before applying the anticorrosion paint composition.

Images