JPWO2013179457A1 - COATING COMPOSITION, PROCESS FOR PRODUCING THE SAME, WATER-REPELLENT MEMBER AND VENT - Google Patents

Abstract

The present invention is a coating composition characterized by being an oil-in-water emulsion containing a fluororesin, hydrophobic silica particles, a water-insoluble solvent, a volatile alcohol, and water. The present invention also includes a step of preparing the first agent by mixing fluororesin, hydrophobic silica particles and a water-insoluble solvent, and a step of dispersing the first agent by mixing volatile alcohol and water. It is a manufacturing method of the coating composition characterized by including. ADVANTAGE OF THE INVENTION According to this invention, the coating composition which is easy to handle and gives the coating film excellent in water repellency, and its manufacturing method can be provided.

Description

  The present invention relates to a coating composition capable of forming a water-repellent surface on the surface of an article, a method for producing the same, a water-repellent member and a ventilation fan.

Currently, water repellent surfaces are required in various articles. For example, when a water drop adheres to the power transmission line, the water drop is likely to be discharged due to a conical drop, which may lead to a power transmission loss. In particular, in winter, water droplets hang down like a wig, and the tip of the water drops sharply, increasing the amount of discharge. Moreover, the roof of a snowfall area may be deformed due to a heavy weight due to snowfall. Similarly, with respect to antennas in snowfall areas, icing snow may cause communication failures such as a decrease in electric field strength. Therefore, in order to prevent deterioration of various performances of these articles, it is necessary to prevent adhesion of water drops, frost, snow, ice and the like by forming a water-repellent surface on the surface of the article.
In addition to water droplets, frost, snow, and ice, the water-repellent surface can prevent the adhesion of various types of dirt such as dust, oil smoke, and cigarette dust, so that home appliances such as air conditioners, vacuum cleaners, and refrigerators can be used. There is a need to form a water-repellent surface even in equipment.

  The water repellent surface can generally be formed by treating the surface with a silicon-based or fluorine-based coating composition. For example, in clothing, automobile glass, painted surfaces, etc., those having a water-repellent surface with a contact angle with water of about 100 to 110 ° have already been put into practical use. Recently, it is also known that an extremely high water-repellent (super water-repellent) surface having a contact angle with water of 150 ° or more can be obtained by a combination of a water-repellent surface and a specific structure formed on the surface. Yes.

  As an example of a coating composition that gives a surface excellent in water repellency, a coating composition containing a hydrophobic treated inorganic fine particle having a primary particle diameter of 100 nm or less, an organic silicon compound, and an organic solvent (see Patent Document 1) In addition, an oil-in-water emulsion coating composition (see Patent Document 2) containing fluorocarbon silane or a partial hydrolyzate thereof, a surfactant, a pH adjuster, and metal oxide particles has been proposed.

JP 2003-206477 A JP 2005-179402 A

However, since the coating composition of Patent Document 1 needs to use a large amount of an organic solvent as a solvent, explosion-proof equipment is required for mass production. As a result, a large capital investment is required, and various restrictions arise from the viewpoint of work safety.
On the other hand, since the coating composition of Patent Document 2 uses a surfactant as a dispersion stabilizer, the surfactant remains in the formed coating film. Since this surfactant has a hydrophilic group, it causes a decrease in water repellency of the coating film.

The present invention has been made to solve the above-described problems, and has an object to provide a coating composition that provides a coating film that is easy to handle and excellent in water repellency, and a method for producing the same. To do.
Moreover, an object of this invention is to provide the water-repellent member and ventilation fan excellent in water repellency.

As a result of diligent research to solve the above problems, the present inventors have found that oil-in-water excellent in stability by combining volatile alcohol with fluororesin, hydrophobic silica particles, water-insoluble solvent and water. It was found that this type of oil-in-water emulsion provides a coating film with excellent water repellency.
That is, the present invention is an oil-in-water emulsion containing a fluororesin, hydrophobic silica particles, a water-insoluble solvent, a volatile alcohol, and water.

The present invention also includes a step of preparing a first agent by mixing fluororesin, hydrophobic silica particles, and a water-insoluble solvent, and a step of dispersing the volatile alcohol and water in the first agent. It is a manufacturing method of the coating composition characterized by including.
Moreover, this invention is a water-repellent member characterized by having a coating film obtained by apply | coating and drying said coating composition.
Furthermore, the present invention provides an intake port, a blade body disposed in a passage of gas taken from the intake port, a motor that rotates the blade body, and a gas formed by the blade body that is rotated by the motor. An exhaust fan that includes an exhaust port that exhausts the gas by a flow, and a housing that is connected to the exhaust port and the intake port and that houses the blade body, the intake port, the blade body, the motor, A ventilating fan having a coating film obtained by applying and drying the coating composition on at least one surface of an exhaust port and the casing.

  ADVANTAGE OF THE INVENTION According to this invention, the coating composition which is easy to handle and gives the coating film excellent in water repellency, and its manufacturing method can be provided. Moreover, according to this invention, the water-repellent member and ventilation fan excellent in water repellency can be provided.

2 is a schematic cross-sectional view of the coating composition of Embodiment 1. FIG. 6 is a schematic cross-sectional view of a water-repellent member according to Embodiment 2. FIG. It is a cross-sectional schematic diagram of the water-repellent member which has a coating film formed from the coating composition using surfactant. 6 is a schematic cross-sectional view of a ventilation fan according to Embodiment 3. FIG.

Embodiment 1 FIG.
The coating composition of the present invention is an oil-in-water emulsion containing a fluororesin, hydrophobic silica particles, a water-insoluble solvent, a volatile alcohol, and water.
Hereinafter, preferred embodiments of a coating composition and a method for producing the same according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of the coating composition of the present embodiment. In FIG. 1, the coating composition is an oil-in-water emulsion, and includes an aqueous phase containing water 1 and an oil phase in which hydrophobic silica particles 3 are dispersed in a fluororesin 2 dissolved in a water-insoluble solvent. The volatile alcohol 4 exists between the water phase and the oil phase. The volatile alcohol 4 is an oil phase dispersion stabilizer and provides an effect of maintaining a stable emulsion state for a long period of time.

Since the coating composition of this embodiment is an oil-in-water emulsion based on water 1, explosion-proof equipment for mass production is provided as in the case of a coating composition using a large amount of an organic solvent as a solvent. Not required. As a result, capital investment is reduced and work safety is improved.
In addition, since the coating composition of the present embodiment uses volatile alcohol 4 that volatilizes during the formation of the coating film as a dispersion stabilizer, as shown in FIG. 2 (see Embodiment 2 for details), the coating composition The volatile alcohol 4 does not remain in the film or on the surface thereof, and a decrease in water repellency of the coating film can be suppressed.
On the other hand, as shown in FIG. 3 (refer to Embodiment 2 for details), the coating film formed from the coating composition using a surfactant instead of the volatile alcohol 4 is present in the coating film or its surface. Surfactant 7 remains, and the water repellency of the coating film decreases due to the hydrophilic group of surfactant 7. Therefore, it is preferable not to contain the surfactant 7 from the viewpoint of improving the water repellency of the coating film. However, the surfactant 7 may be added to the coating composition as long as the water repellency of the coating film is not significantly affected.

  The fluororesin 5 used in the coating composition of the present embodiment is a component having a function effect as a binder that imparts water repellency to the coating film and enhances the adhesion between the substrate 6 and the coating film. The fluororesin 5 that can be used is not particularly limited as long as it can be dissolved in a water-insoluble solvent, and those that are known in the technical field can be used. Examples of the fluororesin 5 include fluoroethylene vinyl ether alternating copolymer (FEVE), fluoroethylene vinyl ester (FEVES), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetra Fluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), ethylene / tetrafluoroethylene copolymer (ETFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoro Examples thereof include ethylene (PCTFE), polyvinyl fluoride (PVF), copolymers and mixtures thereof, or those obtained by mixing other resins with these resins. These fluororesins 5 can be used alone or in combination of two or more.

  Although content of the fluororesin 5 in an oil phase is not specifically limited, Preferably it is 0.5 to 10 mass%, More preferably, it is 2 to 8 mass%. When the content of the fluororesin 5 is less than 0.5% by mass, the adhesion between the substrate 6 and the coating film and the water repellency due to the fluororesin 5 may not be sufficiently obtained. On the other hand, when the content of the fluororesin 5 exceeds 10% by mass, the film thickness of the coating film becomes too large, and the adhesion between the substrate 6 and the coating film may be lowered.

  The hydrophobic silica particles 3 used in the coating composition of the present embodiment are components that improve the water repellency by imparting a fine uneven structure to the surface of the coating film and reducing the contact area with water droplets. The hydrophobic silica particles 3 that can be used are not particularly limited, and those known in the technical field can be used. Specifically, silica particles that have been subjected to a hydrophobic treatment may be used.

The silica particles subjected to the hydrophobic treatment are not particularly limited, and various silica particles produced by a dry method (for example, a combustion method), a wet method (for example, a sol-gel method or a precipitation method) can be used. The silica particles may be silica particles partially or wholly melted.
Here, the dry process silica is also called fumed silica, and can generally be produced by burning a silicon compound such as silicon tetrachloride in an oxyhydrogen flame. The dry process silica can obtain particles having a specific surface area in the range of about 50 to 500 m ² / g by changing production conditions. The average particle diameter of the silica particles calculated from the specific surface area is in the range of about 5 to 200 nm, but usually exists as an aggregate of 1 μm or more.
The wet process silica is also called white carbon, and can generally be produced by precipitating silica in a solution by neutralizing sodium silicate with a mineral acid. Moreover, it can also manufacture using the sol gel method which neutralizes sodium silicate with an acid instead of a mineral acid. Wet process silica can also yield particles having a specific surface area in the range of about 50-1000 m ² / g by varying the production conditions. The wet method silica particles are considered to be aggregated particles in which particles having an average particle diameter of about 3 to 50 nm are aggregated during synthesis. The wet method silica particles can be usually obtained by performing filtration or washing after the neutralization reaction, and drying and then pulverizing if necessary. Generally, the average particle diameter of available wet process silica particles is 1 μm to several hundred μm.
As the silica particles to be subjected to the hydrophobic treatment, those having an appropriate average particle diameter may be selected from the above-mentioned various silica particles according to the use. From the viewpoint of availability, it is preferable to use dry method silica particles.

  Hydrophobic treatment of silica particles is not particularly limited and can be performed according to a method known in the art, but it is preferable to perform the hydrophobic treatment using a trimethylsilylating agent. The trimethylsilylating agent is not particularly limited, and those known in the technical field can be used. Examples of the trimethylsilylating agent include trimethylsilanol, trimethylmethoxysilane, trimethylchlorosilane, aminomethyltrimethylsilane, hexamethyldisilazane, dimethylaminotrimethylsilane, and diethylaminotrimethylsilane. Among these, it is preferable to use hexamethyldisilazane. These trimethylsilylating agents can be used alone or in combination of two or more.

  The average particle size of the hydrophobic silica particles 3 is not particularly limited, but is preferably 5 nm or more and 30 nm or less. Here, the “average particle size of the hydrophobic silica particles” in the present specification means the average particle size of the primary particles of the hydrophobic silica particles 3 measured with a laser light scattering type or dynamic light scattering type particle size distribution meter. It means the value of diameter. If the average particle diameter of the hydrophobic silica particles 3 is less than 5 nm, a fine uneven structure cannot be sufficiently formed on the surface of the coating film, and desired water repellency may not be obtained. On the other hand, when the average particle diameter of the hydrophobic silica particles 3 exceeds 30 nm, the uneven structure on the surface becomes too large, and the durability of the coating film may be lowered. Moreover, the light scattering of a coating film may become large and the designability of the base material 6 may fall.

  Although content of the hydrophobic silica particle 3 in an oil phase is not specifically limited, Preferably it is 0.5 to 30 mass%, More preferably, it is 1 to 25 mass%. If the content of the hydrophobic silica particles 3 is less than 0.5% by mass, a fine uneven structure cannot be sufficiently formed on the surface of the coating film, and desired water repellency may not be obtained. On the other hand, when the content of the hydrophobic silica particles 3 exceeds 30% by mass, the durability of the coating film is lowered, and the light scattering of the coating film is increased, so that the design property of the substrate may be lowered. .

  The mass ratio between the fluororesin 5 and the hydrophobic silica particles 3 in the oil phase is not particularly limited, but is preferably 10:90 to 50:50, more preferably 25:75. With such a mass ratio, a fine uneven structure by the hydrophobic silica particles 3 and a binder effect by the fluororesin 5 can be obtained with a good balance.

The water-insoluble solvent used in the coating composition of the present embodiment is a component that becomes an oil phase solvent. The water-insoluble solvent is not particularly limited as long as it does not dissolve in water, and those known in the technical field can be used.
The dielectric constant of the water-insoluble solvent is not particularly limited, but is preferably 3 or less from the viewpoint of obtaining a stable emulsion state. When the dielectric constant of the water-insoluble solvent is larger than 3, the stability of the emulsion may be lowered.
Examples of water-insoluble solvents include benzene, octane, 2,2,3-trimethylpentane, isooctane, nonane, 2,2,5-trimethylhexane, decane, dodecane, toluene, xylene, styrene, isohexane, butylbenzene, Examples include cyclohexylbenzene, diethylbenzene, cyclohexane, methylcyclohexane, ethylcyclohexane, normal pentane, hexadecane, pentadecane, tetradecane, mineral spirit, naphtha, and the like. These can be used alone or in combination of two or more.

The volatile alcohol 4 used in the coating composition of the present embodiment is a component that becomes an oil phase dispersion stabilizer. Here, “volatile alcohol 4” in this specification means an alcohol that volatilizes when a coating film is formed.
Although carbon number of the volatile alcohol 4 is not specifically limited, Preferably it is 6 or less, More preferably, it is 3 or less. The specific gravity of the volatile alcohol 4 is not particularly limited, but is preferably less than 1 and more preferably 0.9 or less. When the carbon number is larger than 6 or the specific gravity is larger than 1, the hydrophobicity becomes strong and the compatibility with water becomes worse. As a result, the phase inversion phenomenon hardly occurs and it may be difficult to produce an oil-in-water emulsion. Furthermore, when the coating film is used, the water repellency of the coating film may be reduced as a result of being less volatile.

  The dielectric constant of the volatile alcohol 4 is not particularly limited, but is preferably 10 or more and 35 or less, more preferably 12 or more and 30 or less, and most preferably 14 or more and 25 or less. When the dielectric constant is less than 10, the compatibility with water is deteriorated. As a result, the phase inversion phenomenon hardly occurs, and it may be difficult to produce an oil-in-water emulsion. On the other hand, when the dielectric constant exceeds 35, the stability of the emulsion may decrease.

  The boiling point of the volatile alcohol 4 is not particularly limited, but is preferably 140 ° C. or lower, more preferably 50 ° C. or higher and 95 ° C. or lower. When the boiling point of the volatile alcohol 4 exceeds 140 ° C., when the coating film is formed, the volatile alcohol 4 tends to remain in the coating film, and a desired water repellency may not be obtained.

  Examples of the volatile alcohol 4 include ethanol, n-propanol, 2-propanol, isobutyl alcohol, n-butyl alcohol, n-pentanol, 2-pentanol, isoamyl alcohol, n-amyl alcohol, hexyl alcohol, 4- Examples include methyl-2-pentanol, 2-methyl-1-pentanol, 1-hexanol, neopentyl alcohol, 3-methyl-2-butanol, t-pentyl alcohol, 2-ethylbutyl alcohol, methyl amyl alcohol, and acetylene alcohol. . These can be used alone or in combination of two or more.

  Although content of the volatile alcohol 4 in a coating composition is not specifically limited, Preferably it is 0.5 mass% or more and 10.0 mass% or less, More preferably, it is 1.0 mass% or more and 5.0 mass% or less. . When the content of the volatile alcohol 4 is less than 0.5%, the effect as a dispersion stabilizer may not be sufficiently obtained. On the other hand, when the content of the volatile alcohol 4 exceeds 10.0% by mass, when the coating film is formed, the volatile alcohol 4 remains without being completely removed, and the water repellency of the coating film is lowered. There is.

  The water 1 used in the coating composition is not particularly limited, and RO water, deionized water, distilled water, and the like can be used. The water 1 preferably has a lower content of divalent or higher ionic impurities such as calcium ions and magnesium ions. Specifically, the concentration of divalent or higher ionic impurities in water 1 is preferably 200 ppm or less, more preferably 50 ppm or less. A preferred water 1 for use in the coating composition of the present embodiment is deionized water.

  Although content of the water 1 in a coating composition is not specifically limited, Preferably it is 60 to 98 mass%. If content of water 1 is the said range, as a result of the flash point of a coating composition becoming high, handling property becomes easy and use of explosion-proof equipment can be avoided. When the content of water 1 is less than 60% by mass, the ratio of the oil phase increases. As a result, an oil-in-water emulsion may not be formed, and the flash point may be lowered, which may correspond to a fourth class hazardous material and handleability may be reduced. On the other hand, when the content of water 1 exceeds 98% by mass, the solid content concentration in the coating composition is lowered, so that a coating film having a thickness sufficient to impart water repellency may not be obtained.

  In addition to the above-described components, the coating composition may contain components known in the art as long as the effects of the present invention are not impaired. Examples of the component include a dispersant, a leveling agent, an evaporation inhibitor, and an adhesion improver. The blending amounts of these components need to be adjusted as appropriate according to the type of components used.

The coating composition containing the above components is prepared by mixing a fluororesin, hydrophobic silica particles and a water-insoluble solvent to prepare the first agent, and dispersing the volatile alcohol and water in the first agent. And a step including
Here, the blending ratio of the fluororesin, the hydrophobic silica particles and the water-insoluble solvent in the first agent is the same as the blending ratio of the component in the oil phase. Further, the blending ratio of the first agent, the volatile alcohol, and water is the same as the blending ratio of the component in the coating composition.

When mixing a fluororesin, hydrophobic silica particles, and a water-insoluble solvent, it is preferable to carry out a dispersion treatment from the viewpoint of uniformly mixing these components.
The dispersion process is not particularly limited, and a method known in the technical field can be used. Examples of the dispersion treatment include high-pressure dispersion treatment using a commercially available high-pressure disperser. Examples of commercially available high-pressure dispersers include Nanomizer (Yoshida Kikai Kogyo Co., Ltd.), Microfluidizer (MFIC Corporation), Ultimateizer System (Sugino Machine Co., Ltd.), Soundless High-Pressure Emulsifier Disperser (Migrain Co., Ltd.) Use it. These high-pressure dispersers have high shearing force generated in the flow path when the sucked processing object is passed through the fine flow path at high pressure, the collision between the fluid and the wall generated by the device of the flow path, and the fluid The miniaturization process can be performed by an impact force caused by a collision between each other, cavitation generated when discharged from a fine flow path, or the like.

When performing the high pressure dispersion treatment, the pressure is not particularly limited, but is preferably 10 MPa or more and 400 MPa or less, more preferably 20 MPa or more and 350 MPa or less, and most preferably 30 MPa or more and 300 MPa or less.
Moreover, the high pressure dispersion treatment can be repeated 1 to 100 times. Here, in this specification, repeating n times is referred to as n-pass. From the viewpoint of productivity, the number of passes is preferably 1 pass or more and 20 passes or less, more preferably 1 pass or more and 10 passes or less. As a high-pressure dispersion treatment method, the dispersion liquid treated and discharged by the high-pressure disperser may be directly returned to the raw material tank to perform the circulation treatment.

  Further, as a dispersion processing method, dispersion processing using a commercially available high-speed rotary disperser may be performed. Examples of commercially available high-speed rotary dispersers include TK Robotics (Primics Co., Ltd.). Conditions such as the rotational speed, blade peripheral speed, and gap between the rotating body and the fixed part when using this commercially available high-speed rotary disperser may be set as appropriate according to the apparatus to be used.

When blending volatile alcohol and water with the first agent, from the viewpoint of obtaining a uniform mixed state, it is preferable to mix the volatile alcohol with water in advance, and then blend and disperse in the first agent.
The method for the dispersion treatment is not particularly limited, and can be performed in the same manner as the dispersion treatment for the first agent.
When performing a high pressure dispersion process, it is preferable to repeat a high pressure dispersion process 1 to 10 times. From the viewpoint of productivity, the number of passes is more preferably from 1 pass to 5 passes, and most preferably from 1 pass to 3 passes.

  In the oil-in-water emulsion produced as described above, the average particle size of the oil phase is not particularly limited, but is preferably 200 nm to 800 nm, more preferably 300 nm to 500 nm. Here, the “average particle diameter of the oil phase” in the present specification means an average particle diameter measured by a dynamic light scattering particle size distribution meter. When the average particle size of the oil phase is less than 200 nm, the oil phase tends to aggregate and a stable oil-in-water emulsion cannot be obtained. On the other hand, when the average particle diameter of the oil phase exceeds 800 nm, the oil phase is easily precipitated, and a stable oil-in-water emulsion cannot be obtained.

Embodiment 2. FIG.
The water repellent member of the present invention has a coating film obtained by applying and drying the above coating composition.
Hereinafter, preferred embodiments of the water-repellent member of the present invention will be described with reference to the drawings.
FIG. 2 is a schematic cross-sectional view of the water repellent member of the present embodiment. In FIG. 2, the water repellent member includes a base material 6 and a coating film formed on the base material 6. The coating film includes hydrophobic silica particles 3 and a fluororesin 5 as a binder that bonds the hydrophobic silica particles 3 to each other. The coating film can be formed by applying the above coating composition to the substrate 6 and drying it. Of the components of the coating composition, water 1, water-insoluble solvent, and volatile alcohol 4 volatilize when the coating film is formed.

Since the volatile alcohol 4 does not remain in this coating film, the water repellency of the coating film does not decrease. In fact, when FT-IR analysis is performed on the coating film to be formed, since the peak of OH group is hardly detected, it is considered that the coating film has no water repellency inhibiting component and has good water repellency. . Moreover, since this coating film has favorable water repellency, it is excellent also in antifouling performance. Here, the “antifouling performance” in the present specification means a performance in which dirt such as dust, oil smoke and cigarette dust is difficult to adhere, and a performance in which the adhered dirt is easily removed.
In contrast, when a surfactant is used instead of the volatile alcohol 4, the surfactant 7 remains on the surface of the coating film formed on the substrate 6 as shown in FIG. Due to the hydrophilic group of 7, the water repellency of the coating film is lowered.

  The thickness of the coating film formed on the substrate 6 is not particularly limited, but is preferably 0.5 μm or more and 3 μm or less. When the thickness of the coating film is less than 0.5 μm, sufficient adhesion with the substrate 6 may not be obtained. On the other hand, when the thickness of the coating film exceeds 3 μm, defects such as cracks are generated in the coating film, and desired water repellency may not be obtained. Further, the coating film may be peeled off starting from the defect.

  The substrate 6 on which the coating film is formed is not particularly limited, and various parts of articles that require water repellency and antifouling performance can be used. Examples of such parts include a heat exchanger for an air conditioner and a ventilation fan. Specific materials for such components are not particularly limited, and examples thereof include resins such as polypropylene, polystyrene, ABS resin, and ASG resin, metals such as stainless steel and aluminum, and glass.

  The method for applying the coating composition to the substrate 6 is not particularly limited, and methods known in the art can be used. Examples of the coating method include brush coating, spray coating, and immersion. In particular, in order to form a coating film without unevenness, it is preferable to remove the excess coating composition using an air flow after coating the substrate 6 by immersing it in the coating composition. Moreover, you may remove an excess coating composition by rotating the base material 6 instead of airflow. By using such a method, uneven coating can be suppressed.

  It does not specifically limit as a drying method of the coating composition apply | coated to the base material 6, You may dry at room temperature or may be dried by heating. When drying at room temperature, drying time can be shortened by drying under airflow. When heating and drying, warm air may be blown or heated in a heating furnace.

Embodiment 3 FIG.
The ventilation fan of this invention is equipped with the member which has the coating film obtained by apply | coating and drying said coating composition on the surface.
Hereinafter, preferred embodiments of the ventilation fan of the present invention will be described with reference to the drawings.
FIG. 4 is a schematic cross-sectional view of the ventilation fan of the present embodiment. In FIG. 4, the ventilation fan 10 includes an intake port 14, a blade body 12 disposed in a passage of a gas taken in from the intake port 14, a motor 11 that rotates the blade body 12, and a blade body 12 that is rotated by the motor 11. An exhaust port 15 that exhausts gas by the formed gas flow, and a housing 13 that is connected to the exhaust port 15 and the intake port 14 and incorporates the blade body 12 are provided. And it has the coating film obtained by apply | coating and drying said coating composition on the at least 1 surface of the inlet port 14, the blade body 12, the motor 11, the exhaust port 15, and the housing | casing 13. FIG. The method for forming the coating film is the same as that in the second embodiment.

  The formed coating film exhibits excellent water repellency and antifouling performance even in a high-humidity environment, and is optimal for use in various members of a ventilation fan. Therefore, the ventilating fan of the present invention having various members on which the coating film is formed can effectively prevent the performance of the ventilating fan from being deteriorated and adhesion of dirt and water to the ventilating fan.

Hereinafter, although an Example and a comparative example demonstrate the detail of this invention, this invention is not limited by these.
Example 1
Hydrophobic silica particles (average particle size of 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are added to xylene (dielectric constant 2.3). Then, the first agent was prepared by performing high-pressure dispersion treatment for 2 passes under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In the first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively.
Next, after adding the first agent to a mixed solution of deionized water and 1-pentanol (manufactured by Nacalai Tesque, Inc., dielectric constant 14, boiling point 138 ° C., specific gravity 0.8), the same high-pressure dispersion as above A coating composition was prepared by performing one pass of high-pressure dispersion treatment under a pressure of 150 MPa using a machine. In this coating composition, the contents of deionized water, 1-octanol and the first agent were 93.0% by mass, 2.0% by mass and 5.0% by mass, respectively.

(Example 2)
Hydrophobic silica particles (average particle size of 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are added to xylene (dielectric constant 2.3). Then, the first agent was prepared by performing high-pressure dispersion treatment for 2 passes under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In the first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively.
Next, after adding the first agent to a mixed solution of deionized water and ethylene glycol (manufactured by Nacalai Tesque, Inc., dielectric constant 38.7, boiling point 197 ° C., specific gravity 1.1), the same high-pressure dispersion as above A coating composition was prepared by performing one pass of high-pressure dispersion treatment under a pressure of 150 MPa using a machine. In this coating composition, the contents of deionized water, ethylene glycol and the first agent were 93.0% by mass, 2.0% by mass and 5.0% by mass, respectively.

(Example 3)
Hydrophobic silica particles (average particle size of 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are n-hexane (dielectric constant 2.0). In addition to the above, the first agent was prepared by performing two passes of high-pressure dispersion treatment under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In the first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively.
Next, after adding the first agent to a mixed solution of deionized water and ethanol (manufactured by Nacalai Tesque, Inc., dielectric constant 24, boiling point 78 ° C., specific gravity 0.8), the same high-pressure disperser as above was used. A coating composition was prepared by performing one pass of high-pressure dispersion treatment under a pressure of 150 MPa. In this coating composition, the contents of deionized water, ethanol and the first agent were 93.0% by mass, 2.0% by mass and 5.0% by mass, respectively.

Example 4
Hydrophobic silica particles (average particle size of 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are added to xylene (dielectric constant 2.3). Then, the first agent was prepared by performing high-pressure dispersion treatment for 2 passes under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In the first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively.
Next, after adding the first agent to a mixed solution of deionized water and cyclohexanol (manufactured by Nacalai Tesque, Inc., dielectric constant 15, boiling point 161 ° C., specific gravity 0.93), the same high-pressure disperser as above is used. A coating composition was prepared by performing one pass of high-pressure dispersion treatment under a pressure of 150 MPa. In this coating composition, the contents of deionized water, cyclohexanol and the first agent were 93.0% by mass, 2.0% by mass and 5.0% by mass, respectively.

(Example 5)
Hydrophobic silica particles (average particle size of 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are added to xylene (dielectric constant 2.3). Then, the first agent was prepared by performing high-pressure dispersion treatment for 2 passes under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In the first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively.
Next, after adding the first agent to a mixed solution of deionized water and 2-propanol (manufactured by Nacalai Tesque, Inc., dielectric constant 18, boiling point 82 ° C., specific gravity 0.79), the same high-pressure disperser as above The coating composition was prepared by performing one pass of high-pressure dispersion treatment under a pressure of 150 MPa. In this coating composition, the contents of deionized water, 2-propanol and the first agent were 93.0% by mass, 2.0% by mass and 5.0% by mass, respectively.

(Example 6)
Hydrophobic silica particles (average particle size of 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are added to xylene (dielectric constant 2.3). Then, the first agent was prepared by performing high-pressure dispersion treatment for 2 passes under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In the first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively.
Next, after adding the first agent to a mixed solution of deionized water and ethanol (manufactured by Nacalai Tesque, Inc., dielectric constant 24, boiling point 78 ° C., specific gravity 0.8), the same high-pressure disperser as above was used. A coating composition was prepared by performing one pass of high-pressure dispersion treatment under a pressure of 150 MPa. In this coating composition, the contents of deionized water, ethanol and the first agent were 99.0% by mass, 0.5% by mass and 0.5% by mass, respectively.

(Comparative Example 1)
After adding fluoroethylene / vinyl ester-based fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) to xylene (dielectric constant 2.3), a high-pressure disperser (Nanomizer manufactured by Yoshida Kikai Co., Ltd.) The first agent was prepared by performing two passes of high-pressure dispersion treatment under a pressure of 150 MPa using SYNM-1500AR). In this first agent, the blending amount of the fluororesin was 6.0% by mass.
Next, after mixing the first agent with a mixed solution of deionized water and ethanol (manufactured by Nacalai Tesque, Inc., dielectric constant 24, boiling point 78 ° C., specific gravity 0.8), the same high-pressure disperser as above was used. A coating composition was prepared by performing one pass of high-pressure dispersion treatment under a pressure of 150 MPa. In this coating composition, the contents of deionized water, ethanol and the first agent were 94.5% by mass, 1.5% by mass and 4.0% by mass, respectively.

(Comparative Example 2)
Hydrophobic silica particles (average particle size of 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are added to xylene (dielectric constant 2.3). Then, the first agent was prepared by performing high-pressure dispersion treatment for 2 passes under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In the first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively.
Next, after mixing a 1st agent with deionized water, the coating composition was prepared by performing the high-pressure dispersion | distribution process 1 pass under the pressure of 150 MPa using the same high pressure type disperser as the above. In this coating composition, the contents of deionized water and the first agent were 95.0% by mass and 5.0% by mass, respectively.

(Comparative Example 3)
Hydrophobic silica particles (average particle size of 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are added to xylene (dielectric constant 2.3). Then, the first agent was prepared by performing high-pressure dispersion treatment for 2 passes under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In the first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively.
Next, after mixing the first agent with a solution obtained by adding a polyoxyethylene lauryl ether surfactant (Emulgen 109P manufactured by Kao Corporation) to deionized water, a pressure of 150 MPa is used using the same high-pressure disperser as described above. A coating composition was prepared by performing one pass of high pressure dispersion treatment under. In this coating composition, the contents of deionized water, polyoxyethylene lauryl ether surfactant and first agent were 95.0 mass%, 0.5 mass% and 4.5 mass%, respectively.

(Comparative Example 4)
Hydrophobic silica particles (average particle size of 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are added to xylene (dielectric constant 2.3). Then, the first agent was prepared by performing high-pressure dispersion treatment for 2 passes under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In the first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively.
Next, after mixing the first agent with a solution obtained by adding a polyoxyethylene lauryl ether sodium sulfate surfactant (Latemul E-150 manufactured by Kao Corporation) to deionized water, the same high-pressure disperser as above was used. A coating composition was prepared by performing one pass of high-pressure dispersion treatment under a pressure of 150 MPa. In this coating composition, the contents of deionized water, polyoxyethylene lauryl ether sodium sulfate-based surfactant and the first agent were 95.0 mass%, 0.5 mass% and 4.5 mass%, respectively. .

(Comparative Example 5)
Hydrophobic silica particles (average particle size 12 nm, R974 manufactured by Nippon Aerosil Co., Ltd.) and fluoroethylene / vinyl ester-based fluororesin (Fluonate FEM-600 manufactured by Dainippon Ink Industries, Ltd.) are added to 1-propanol (dielectric constant 20). Then, the first agent was prepared by performing high-pressure dispersion treatment for 2 passes under a pressure of 150 MPa using a high-pressure disperser (Nanomizer, YSNM-1500AR manufactured by Yoshida Kikai Kogyo Co., Ltd.). In this first agent, the blending amounts of the hydrophobic silica particles and the fluororesin were 7.0% by mass and 3.0% by mass, respectively. Deionized water and ethanol (Nacalai Tesque, Inc., dielectric constant 24) After adding the first agent to the mixed solution with a boiling point of 78 ° C. and a specific gravity of 0.8), the coating composition is formed by performing one pass of the high-pressure dispersion treatment at a pressure of 150 MPa using the same high-pressure disperser as described above. Was prepared. In this coating composition, the contents of deionized water, ethanol and the first agent were 94.5% by mass, 1.5% by mass and 4.0% by mass, respectively.

  The compositions of the first agent and the coating composition prepared in the above Examples and Comparative Examples are summarized in Tables 1 and 2 below.

  About the coating composition obtained by said Example and comparative example, the average particle diameter of the oil phase was measured using the particle size distribution meter (made by Otsuka Electronics Co., Ltd.) by a dynamic light scattering method. The average particle size of the oil phase of the coating composition was measured immediately after preparation of the coating composition and after standing for 6 hours after preparation.

Next, after immersing the substrate in the coating compositions obtained in the above examples and comparative examples, the excess coating composition is removed using an air stream, and dried at room temperature, thereby the surface of the substrate. A coating film was formed. Here, a plastic substrate (ABS) of 100 mm, 30 mm, and 1 mm was used as the substrate. Moreover, the conditions of immersion and drying are the same in all Examples and Comparative Examples.
About the formed coating film, thickness, a contact angle, and antifouling performance were evaluated.

The thickness of the coating film was measured by taking an electron micrograph of a cross section of the coating film and performing image processing.
The contact angle is a PTFE (polytetrafluoroethylene) coat with an inner diameter of 0.1 mm, using a contact angle meter (CX-150 type, manufactured by Kyowa Interface Science Co., Ltd.) for the coating film left at room temperature (25 ° C.) for 1 hour. About 5 μL of water droplets were dropped on the surface of the coating film from the tip of the needle, and the contact angle was measured. The results of this evaluation are shown in Table 3.

For antifouling performance, the adhesion of sand dust, which is a hydrophilic substance, to the coating film was evaluated under conditions of a temperature of 25 ° C./humidity of 50% and a temperature of 25 ° C./humidity of 90%. Specifically, under the above conditions, JIS Kanto loam dust having a center particle diameter of 1 to 3 μm is sprayed onto the coating film with air, and then the dust adhering to a predetermined portion of the coating film is removed from the mending tape (Sumitomo 3M), and the absorbance (wavelength 550 nm) was measured using a spectrophotometer (Shimadzu Corporation; UV-3100PC). In this evaluation, the following criteria were used.
1: Absorbance is less than 0.1 2: Absorbance is 0.1 or more and less than 0.2 3: Absorbance is 0.2 or more and less than 0.3 4: Absorbance is 0.3 or more and less than 0.4 5: Absorbance is 0.00. 4 or more The results of the above evaluation are shown in Table 3.

  As shown in Table 3, the coating compositions of Examples 1 to 6 using volatile alcohol as a dispersion stabilizer have little change in the average particle size of the oil phase and have good stability. A coating film excellent in water repellency and antifouling performance was given. Further, as in Example 2, when ethylene glycol having a specific gravity of more than 1 is used as a dispersion stabilizer, the stability of the coating liquid tends to be reduced, and the antifouling performance of the coating film is slightly lowered. It was. Further, as in Example 6, when the water content in the coating composition increased, the contact angle and antifouling performance tended to decrease. This is presumably because defects were easily generated in the formed coating film because there were few components of the first agent that gave water repellency.

On the other hand, since the coating composition of Comparative Example 1 did not contain hydrophobic silica particles, a coating film having insufficient water repellency and antifouling performance was obtained. This is considered to be because the fine uneven structure due to the hydrophobic silica particles was not formed on the surface of the coating film, and only the water-repellent effect by the fluororesin was obtained.
Since the coating composition of Comparative Example 2 did not use volatile alcohol as a dispersion stabilizer, the change in the average particle size of the oil phase increased. This is considered due to the fact that the oil phase aggregated with time. Further, the water repellency and antifouling performance of the coating film formed from this coating composition was not sufficient.
Although the coating compositions of Comparative Examples 3 and 4 had good stability, the water repellency and antifouling performance of the formed coating film was not sufficient because the surfactant was used as the dispersion stabilizer.
Since the coating composition of Comparative Example 5 used 1-propanol as a water-soluble solvent, a desired oil-in-water emulsion could not be obtained, and the water repellency and antifouling performance of the formed coating film was not sufficient. .

  As can be seen from the above results, according to the present invention, it is possible to provide a coating composition that is easy to handle and provides a coating film excellent in water repellency and a method for producing the same. Moreover, by using this coating composition, it is possible to provide a water-repellent member and a ventilation fan excellent in water repellency.

As a result of diligent research to solve the above problems, the present inventors have achieved stability by combining a predetermined volatile alcohol with a fluororesin, hydrophobic silica particles, a predetermined water-insoluble solvent and water. It has been found that an excellent oil-in-water emulsion can be obtained, and that this oil-in-water emulsion provides a coating film having excellent water repellency.
That is, the present invention is an oil-in-water type containing a fluororesin, hydrophobic silica particles, a water-insoluble solvent having a dielectric constant of 3 or less, a volatile alcohol having a boiling point of 140 ° C. or lower and a dielectric constant of 10 to 35 and water. It is a coating composition characterized by being an emulsion.

The present invention also includes a step of preparing a first agent by mixing a fluororesin, hydrophobic silica particles, and a non-aqueous solvent having a dielectric constant of 3 or less, and the first agent has a boiling point of 140 ° C. or less and a dielectric. And a step of mixing and dispersing a volatile alcohol having a rate of 10 or more and 35 or less and water, and a method for producing a coating composition.
Moreover, this invention is a water-repellent member characterized by having a coating film obtained by apply | coating and drying said coating composition.
Furthermore, the present invention provides an intake port, a blade body disposed in a passage of gas taken from the intake port, a motor that rotates the blade body, and a gas formed by the blade body that is rotated by the motor. An exhaust fan that includes an exhaust port that exhausts the gas by a flow, and a housing that is connected to the exhaust port and the intake port and that houses the blade body, the intake port, the blade body, the motor, A ventilating fan having a coating film obtained by applying and drying the coating composition on at least one surface of an exhaust port and the casing.

Claims (13)

  A coating composition comprising an oil-in-water emulsion containing a fluororesin, hydrophobic silica particles, a water-insoluble solvent, a volatile alcohol, and water.   The coating composition according to claim 1, wherein the volatile alcohol has 6 or less carbon atoms.   The coating composition according to claim 1 or 2, wherein the volatile alcohol has a specific gravity of less than 1.   The coating composition according to claim 1, wherein the volatile alcohol has a boiling point of 140 ° C. or less.   The oil phase of the oil-in-water emulsion has the hydrophobic silica particles dispersed in the fluororesin dissolved in the water-insoluble solvent. Coating composition.   6. The coating composition according to claim 1, wherein the volatile alcohol has a dielectric constant of 10 or more and 35 or less, and the water-insoluble solvent has a dielectric constant of 3 or less. .   Content of the said water is 60 mass% or more and 98 mass% or less, The coating composition as described in any one of Claims 1-6 characterized by the above-mentioned.   The coating composition according to claim 1, which does not contain a surfactant. A step of preparing a first agent by mixing a fluororesin, hydrophobic silica particles and a water-insoluble solvent;
A method for producing a coating composition comprising: a step of dispersing a volatile alcohol and water in the first agent.   The method for producing a coating composition according to claim 9, wherein the dispersion treatment is a high-pressure dispersion treatment under a pressure of 10 MPa or more and 400 MPa or less.   A water repellent member comprising a coating film obtained by applying and drying the coating composition according to claim 1.   The water repellent member according to claim 11, wherein the coating film has a thickness of 0.5 μm to 3 μm. The air is exhausted by a gas flow formed by an air inlet, a blade disposed in a passage of gas taken in from the air inlet, a motor that rotates the blade, and the blade rotated by the motor. A ventilating fan comprising: an exhaust port that is connected to the exhaust port and the intake port, and a housing that houses the blade body;
It was obtained by applying and drying the coating composition according to any one of claims 1 to 8 on at least one surface of the intake port, the blade body, the motor, the exhaust port, and the housing. A ventilation fan characterized by having a coating film.

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