JPWO2019202679A1 - Coating film, article, coating composition and centrifugal blower - Google Patents

Abstract

A fluoroethylene vinyl ether alternating copolymer having a hydroxyl value of 7 mgKOH / g or more and 110 mgKOH / g or less and hydrophilic silica particles having an average particle diameter of 10 nm or more and 300 nm or less are dispersed and arranged in a perfluoroalkyl group-containing fluororesin. A coating film containing the perfluoroalkyl group-containing fluororesin, wherein the fluoroethylene vinyl ether alternating copolymer is contained in an amount of 0.01% by mass or more and 20.0% by mass or less, and the perfluoroalkyl group-containing fluororesin is contained. The hydrophilic silica particles are contained in an amount of 0.001% by mass or more and 3.0% by mass or less based on the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer, and a part of the hydrophilic silica particles is The hydrophilic silica particles exposed on the surface of the coating film and Area of the exposed portion, the coating film, wherein the 50% or less than 1.5% of the total area of the surface of the coating film.

Description

  The present invention relates to coating films, articles, coating compositions and centrifugal blowers.

  As a technique for suppressing the adhesion of oil drops and oil smoke generated in a space, there is a technique in which a coating film is formed on an article surface with an oil repellent paint such as a fluorine paint or a silicone paint. For example, in Patent Document 1, (A) a hydrolyzable group-containing silane modified with a fluorooxyalkylene group-containing polymer and / or a partially hydrolyzed condensate thereof, and an average molecular weight of the (A) component or less are described. There is described a fluorine-containing coating agent containing (B) a fluorooxyalkylene group-containing polymer which is contained, and a mixing mass ratio of the (A) component and the (B) component is 40:60 to 95: 5.

JP, 2005-199915, A

  However, since the cured film formed from the fluorine-containing coating agent of Patent Document 1 has poor adhesion to the substrate, there is a problem that it is peeled off by a physical impact such as cleaning.

  Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a coating film that can suppress the adhesion of oil and dust and that has excellent adhesion to a substrate. .

  The present invention provides a perfluoroalkyl group-containing fluororesin comprising fluoroethylene vinyl ether alternating copolymer having a hydroxyl value of 7 mgKOH / g or more and 110 mgKOH / g or less and hydrophilic silica particles having an average particle diameter of 10 nm or more and 300 nm or less. A coating film dispersedly arranged, wherein the fluoroethylene vinyl ether alternating copolymer is contained in an amount of 0.01% by mass or more and 20.0% by mass or less with respect to the perfluoroalkyl group-containing fluororesin. The hydrophilic silica particles are contained in an amount of 0.001% by mass or more and 3.0% by mass or less with respect to the total of the fluoroalkyl group-containing fluororesin and the fluoroethylene vinyl ether alternating copolymer, Part of it is exposed on the surface of the coating film and is hydrophilic. Area of the exposed portion of the silica particles is a coating film, wherein the coating film is 50% or less than 1.5% of the total area of the surface of the.

  ADVANTAGE OF THE INVENTION According to this invention, adhesion of oil and dust can be suppressed and the coating film which is excellent in adhesiveness with a base material can be provided.

FIG. 3 is a schematic cross-sectional view showing a state in which a coating film according to an embodiment of the present invention is formed on the surface of a base material. FIG. 3 is a schematic view showing a state of components in a coating film according to an embodiment of the present invention. 1 is a schematic cross-sectional view of a centrifugal blower according to an embodiment of the present invention. It is a graph which shows the critical meaning of the hydroxyl value of a fluoroethylene vinyl ether alternating copolymer. 1 is a graph showing the critical significance of the amount of fluoroethylene vinyl ether alternating copolymer with respect to a perfluoroalkyl group-containing fluororesin. 3 is a graph showing the critical significance of the amount of hydrophilic silica particles with respect to the total of a perfluoroalkyl group-containing fluororesin and a fluoroethylene vinyl ether alternating copolymer. It is a graph which shows the critical meaning of the average particle diameter of hydrophilic silica particles. It is a graph which shows the critical significance of the area ratio of the exposed part of hydrophilic silica particles.

Embodiment 1.
In order to carry out the present invention, the coating film according to the first embodiment includes a fluoroethylene vinyl ether alternating copolymer having a hydroxyl value of 7 mgKOH / g or more and 110 mgKOH / g or less and 10 nm or more and 300 nm in a perfluoroalkyl group-containing fluororesin. Hydrophilic silica particles having the following average particle size are dispersed and arranged, and the fluoroethylene vinyl ether alternating copolymer is 0.01% by mass or more and 20.0% by mass or less with respect to the perfluoroalkyl group-containing fluororesin. The hydrophilic silica particles are contained in an amount of 0.001% by mass or more and 3.0% by mass or less with respect to the total of the perfluoroalkyl group-containing fluororesin and the fluoroethylene vinyl ether alternating copolymer. Part of the particles are exposed on the surface of the coating film, and hydrophilic silica Area of the exposed portion of the child, and wherein the 50% or less than 1.5% of the total area of the surface of the coating film.

  FIG. 1 is a schematic cross-sectional view showing a state in which the coating film according to the first embodiment is formed on the surface of a base material. FIG. 2 is a schematic diagram showing states of components in the coating film according to the first embodiment. As shown in FIGS. 1 and 2, in the coating film 4 formed on the surface of the substrate 5, the fluoroethylene vinyl ether alternating copolymer 2 and the hydrophilic silica particles 3 are contained in the perfluoroalkyl group-containing fluororesin 1. It is distributed. Since the perfluoroalkyl group-containing fluororesin 1 is a resin composed only of a fluorine component having the smallest surface energy, it has an excellent effect of suppressing the adhesion of oil droplets and oil smoke, but has poor adhesion to the base material 5. It is enough. Therefore, in the coating film 4, the fluoroethylene vinyl ether alternating copolymer 2 is dispersedly arranged in the perfluoroalkyl group-containing fluororesin 1 to improve the adhesiveness with the substrate 5. Further, in the coating film 4, the hydrophilic silica particles 3 are dispersedly arranged in the perfluoroalkyl group-containing fluororesin 1 to improve the effect of suppressing the adhesion of dust. Further, in the coating film 4, by setting the area ratio of the exposed portion of the hydrophilic silica particles 3 within a predetermined range, the dust adhesion suppressing effect and the oil adhesion suppressing effect are highly compatible.

  The perfluoroalkyl group-containing fluororesin 1 is a fluororesin containing a perfluoro-substituted alkyl group in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms.

  The perfluoroalkyl group-containing fluororesin 1 is not particularly limited, and those known in the technical field can be used. Specifically, as the perfluoroalkyl group-containing fluororesin 1, "GC Co., Ltd.-SFE-DP02", "SC Coat (registered trademark) -SFE-B002", and "SC" manufactured by AGC Seimi Chemical Co., Ltd. Coat (registered trademark) -SCV-B002 "," SF coat (registered trademark) -SFE-X008 "," SF coat (registered trademark) -SCV-X008 "," SF coat (registered trademark) -SDF-X008 ", "SF coat (registered trademark) -MSN-02", "SF coat (registered trademark) -SNF-AF180E", "SF coat (registered trademark) -SNF-DP20", "SF coat (registered trademark) -SNF-B200" "," SF coat (registered trademark) -SR-4000 "," SF coat (registered trademark) " SNF-X800 "," science fiction coat (registered trademark) -YF-X30 ", and the like" science fiction coat (registered trademark) -EC-400 ".

The fluoroethylene vinyl ether alternating copolymer 2 is obtained by alternately polymerizing a fluorine component that exhibits oil repellency and a vinyl ether component that improves the adhesion to the base material 5. Such fluoroethylene vinyl ether alternating copolymer 2 is represented by the following formula (I). In the following formula (I), R represents a C1-C10 alkyl group, R ¹ represents a C1-C16 alkyl group, R ² represents a C1-C16 alkylene group, X represents fluorine, Represents chlorine or bromine. Further, k, l, m and n in the following formula (I) are selected in such a range that the fluoroethylene vinyl ether alternating copolymer 2 has a weight average molecular weight of 1,000 to 2,000,000.

  The fluoroethylene vinyl ether alternating copolymer 2 is a solvent-soluble fluororesin (dissolvable in various solvents). The fluoroethylene vinyl ether alternating copolymer 2 can be dried and cured at room temperature, unlike fluororesins for paints (for example, polyvinylidene fluoride PVDF, polychlorotrifluoroethylene PCTFE, polyvinyl fluoride PVF, etc.). .

  In the coating film 4, the fluoroethylene vinyl ether alternating copolymer 2 is contained in an amount of 0.01% by mass or more and 20.0% by mass or less, preferably 0.5% by mass, with respect to the perfluoroalkyl group-containing fluororesin 1. It is contained in an amount of 15.0 mass% or less. If the content of the fluoroethylene vinyl ether alternating copolymer 2 in the coating film 4 is less than 0.01% by mass, the effect of improving the adhesiveness with the base material 5 cannot be obtained. On the other hand, when the content of the fluoroethylene vinyl ether alternating copolymer 2 in the coating film 4 exceeds 20.0 mass%, the oil adhesion suppressing performance cannot be sufficiently obtained.

  The hydroxyethylene vinyl ether alternating copolymer 2 has a hydroxyl value (mgKOH / g) of 7 mgKOH / g or more and 110 mgKOH / g or less. When the hydroxyl value is less than 7 mgKOH / g, sufficient adhesion with the base material 5 cannot be obtained. On the other hand, when the hydroxyl value exceeds 110 mgKOH / g, sufficient oil adhesion inhibiting performance cannot be obtained. According to JIS K0070, the hydroxyl value of the fluoroethylene vinyl ether alternating copolymer 2 is potassium hydroxide required for neutralizing acetic acid bound to the hydroxyl group when 1 g of the fluoroethylene vinyl ether alternating copolymer 2 is acetylated. It means the number of mg of (KOH).

  The weight average molecular weight of the fluoroethylene vinyl ether alternating copolymer 2 is not particularly limited, but is preferably 1,000 or more and 2,000,000 or less, more preferably 5,000 or more and 1,000,000. The following is most preferably 10,000 or more and 500,000 or less. The weight average molecular weight of the fluoroethylene vinyl ether alternating copolymer 2 can be measured by a gel permeation chromatography (GPC) method. Specifically, the fluoroethylene vinyl ether alternating copolymer 2 is adjusted to 2.0 g / L using a tetrahydrofuran (THF) solution, and then allowed to stand for 12 hours. Then, this THF solution was filtered through a 0.45 μm membrane filter, and “HLC-8120GPC” manufactured by Tosoh Corporation was used as an analyzer, and measurement conditions were: column / TSKgel GMH-H (S) × 2, column size / 7.8 mmI. D. GPC measurement is performed on the filtrate under × 300 mm, eluent / THF, flow rate / 0.5 mL / min, detector / RI, column temperature / 40 ° C., injection volume / 100 μL.

  The fluoroethylene vinyl ether alternating copolymer 2 is not particularly limited, and those known in the technical field can be used. Specifically, as the fluoroethylene vinyl ether alternating copolymer 2, "Lumiflon (registered trademark) -LF100", "Lumiflon (registered trademark) -LF400", "Lumiflon (registered trademark) -LF600" manufactured by Asahi Glass Co., Ltd., "Lumiflon (registered trademark) -LF200F", "Lumiflon (registered trademark) -LF710F", "Lumiflon (registered trademark) -LF916F", "Lumiflon (registered trademark) -LF200", "Lumiflon (registered trademark) -LF800", etc. Is mentioned.

  The hydrophilic silica particles 3 are not particularly limited as long as they have an average particle diameter of 10 nm or more and 300 nm or less. Here, the average particle diameter of the hydrophilic silica particles 3 means the average particle diameter measured by the laser light scattering method. When the average particle diameter of the hydrophilic silica particles 3 exceeds 300 nm, it becomes difficult to form fine irregularities on the surface of the coating film 4, and cracks are likely to occur on the surface of the coating film 4. On the other hand, when the average particle size of the hydrophilic silica particles 12 is less than 10 nm, the hydrophilic silica particles 3 are likely to aggregate with each other.

  In the coating film 4, the hydrophilic silica particles 3 are contained in an amount of 0.001% by mass or more and 3.0% by mass or less with respect to the total of the perfluoroalkyl group-containing fluororesin 1 and the fluoroethylene vinyl ether alternating copolymer 2. It is preferably contained in an amount of 0.1% by mass or more and 2.5% by mass or less. If the content of the hydrophilic silica particles 3 in the coating film 4 is less than 0.001% by mass, the effect of suppressing dust adhesion cannot be sufficiently obtained. On the other hand, when the content of the hydrophilic silica particles 3 in the coating film 4 exceeds 3.0% by mass, sufficient oil adhesion suppressing performance cannot be obtained.

  The hydrophilic silica particles 3 are not particularly limited, and those known in the art can be used. Specifically, as the hydrophilic silica particles 3, "organo silica sol (registered trademark) -MA-ST-M", "organo silica sol (registered trademark) -MA-ST-L", manufactured by Nissan Chemical Industries, Ltd., " "Organo silica sol (registered trademark) -IPA-ST", "organo silica sol (registered trademark) -ST-L", "organo silica sol (registered trademark) -IPA-ST-L", "organo silica sol (registered trademark) -IPA-" "ST-ZL", "organo silica sol (registered trademark) -IPA-UP", "organo silica sol (registered trademark) -EG-ST", "organo silica sol (registered trademark) -NPC-ST-30", "organo silica sol ( (Registered trademark) -PGM-ST "," organosilica sol (registered trademark) -DMAC-ST "," ADELITE AT manufactured by ADEKA Corporation " 30 "," ADELITE AT-40 "and" ADELITE AT-50 ", JGC Catalysts and Chemicals Ltd. of" CATALOID SI-550 "and" CATALOID SI-50 ", and the like.

  A part of the hydrophilic silica particles 3 is exposed on the surface of the coating film 4. The area of the exposed part of the hydrophilic silica particles 3 is 1.5% or more and 50% or less, preferably 5% or more and 45% or less, of the total area of the surface of the coating film 4. If the area ratio of the exposed portion of the hydrophilic silica particles 3 is less than 1.5%, a fine uneven structure is not formed on the surface, and the effect of suppressing dust adhesion cannot be sufficiently obtained. On the other hand, if the area ratio of the exposed part of the hydrophilic silica particles 3 exceeds 50%, the oil adhesion suppressing performance cannot be sufficiently obtained. In particular, by setting the area ratio of the exposed portion of the hydrophilic silica particles 3 to 5% or more and 45% or less, the effect of suppressing the adhesion of edible oil and the effect of suppressing the adhesion of dust generated from the food packaging container are maintained for a long period of time. Therefore, it is suitable as the coating film 4 on the blade of the ventilation fan.

  The reason why the hydrophilic silica particles 3 are exposed on the surface of the coating film 4 is that since the hydrophilic silica particles 3 have hydrophilicity, the perfluoroalkyl group-containing fluororesin 1 having oil repellency and the fluoroethylene vinyl ether alternating copolymer. This is because the compatibility with 2 is low.

  Here, a method of measuring the area ratio of the exposed portion of the hydrophilic silica particles 3 will be described. As for the area ratio (%) of the exposed part of the hydrophilic silica particles 3, the surface of the coating film was photographed with a scanning electron microscope (SEM) manufactured by Hitachi High Technology Co., Ltd. The ratio of the area occupied by the hydrophilic silica particles to the total area is calculated and the arithmetic mean of them is calculated.

  Around the hydrophilic silica particles 3, it is preferable to have a void portion having the same size as the hydrophilic silica particles 3 that are dispersed and arranged. By forming the void portion, the effect of unevenness can be obtained more easily, and a high dust adhesion suppressing effect can be realized. Such a void portion is formed by the repulsion of the hydrophilic group existing on the surface of the hydrophilic silica particle 3 and the oil repellent group existing on the surface of the perfluoroalkyl group-containing fluororesin 1 in the vicinity of the hydrophilic silica particle 3. It is formed.

  Next, the coating composition used to form the coating film 4 described above will be described. The coating composition according to the present embodiment contains perfluoroalkyl group-containing fluororesin 1, fluoroethylene vinyl ether alternating copolymer 2, and hydrophilic silica particles 3 having an average particle diameter of 10 nm or more and 300 nm or less. Is characterized by.

  In the coating composition according to the present embodiment, the fluoroethylene vinyl ether alternating copolymer 2 is contained in an amount of 0.01% by mass or more and 20.0% by mass or less with respect to the perfluoroalkyl group-containing fluororesin 1, and preferably Is contained in an amount of 0.5% by mass or more and 15.0% by mass or less. When the content of the fluoroethylene vinyl ether alternating copolymer 2 in the coating composition is less than 0.01% by mass, the effect of improving the adhesiveness with the substrate 5 cannot be obtained. On the other hand, when the content of the fluoroethylene vinyl ether alternating copolymer 2 in the coating composition exceeds 20.0 mass%, the oil adhesion suppressing performance cannot be sufficiently obtained.

  In the coating composition according to the present embodiment, the hydrophilic silica particles 3 are 0.001 mass% or more based on the total amount of the perfluoroalkyl group-containing fluororesin 1 and the fluoroethylene vinyl ether alternating copolymer 2. It is contained in an amount of 0 mass% or less, preferably 0.1 mass% or more and 2.5 mass% or less. If the content of the hydrophilic silica particles 3 in the coating composition is less than 0.001% by mass, the effect of suppressing dust adhesion cannot be sufficiently obtained. On the other hand, when the content of the hydrophilic silica particles 3 in the coating composition exceeds 3.0% by mass, sufficient oil adhesion suppressing performance cannot be obtained.

  The coating composition according to the present embodiment is prepared by dissolving a fluoroethylene vinyl ether alternating copolymer in alcohol to obtain a first agent, and then using hydrophilic silica particles, a perfluoroalkyl group-containing fluororesin and a fluorine as the first agent. It can be produced by further adding a system solvent. The coating composition produced in this way has excellent stability without aggregation or the like.

  The alcohol that dissolves the fluoroethylene vinyl ether alternating copolymer 2 is not particularly limited, and ethanol, n-propanol, 2-propanol, isobutyl alcohol, n-butyl alcohol, isoamyl alcohol, n-amyl alcohol, hexyl alcohol, 2 -Ethyl butyl alcohol, methyl amyl alcohol, cyclohexanol, 2-ethylhexyl alcohol, octyl alcohol, benzyl alcohol and the like can be mentioned. These alcohols may be used alone or in combination of two or more.

  The fluorine-based solvent that dissolves the perfluoroalkyl group-containing fluororesin 1 is not particularly limited, and examples thereof include hydrofluoroether, hydrofluorocarbon, and hydrochlorofluorocarbon. These fluorine-based solvents may be used alone or in combination of two or more.

  The solvent in which the hydrophilic silica particles 3 are dispersed is preferably a solvent compatible with water. Specifically, as a solvent, ethanol, n-propanol, 2-propanol, isobutyl alcohol, n-butyl alcohol, isoamyl alcohol, n-amyl alcohol, hexyl alcohol, 2-ethylbutyl alcohol, methylamyl alcohol, cyclohexanol, 2-ethylhexyl alcohol, octyl alcohol, benzyl alcohol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethyl lactate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol isopropyl Methyle Tell, dipropylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, ethylene glycol monophenyl ether, triethylene glycol monomethyl ether, diethylene glycol dibutyl ether , Triethylene glycol butyl methyl ether, polyethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol monomethyl ether, N-methyl-2-pyrrolidone and the like. These solvents may be used alone or in combination of two or more.

  As a method of forming the coating film 4 using the coating composition of the present embodiment, the coating composition described above may be applied to the substrate 5 and then dried. The thickness of the coating film 4 is preferably 0.02 μm or more and 1.0 μm or less. When the thickness of the coating film is less than 0.02 μm, sufficient adhesion with the base material 5 may not be obtained. On the other hand, when the film thickness of the coating film 4 exceeds 1.0 μm, defects such as cracks are likely to occur in the coating film 4 and the desired oil adhesion suppressing performance may not be obtained, and the coating may start from the defect. The film 4 may peel off.

  The base material 5 on which the coating film 4 is formed is not particularly limited, and examples thereof include parts constituting various articles that require oil repellency. Examples of such components include air conditioner heat exchangers, ventilation fan blades, and the like. Examples of the material of the base material 5 include plastics such as polypropylene, polystyrene, acrylonitrile-butadiene-styrene (ABS) and glass fiber reinforced styrene-acrylonitrile (ASG), metals such as stainless steel and aluminum, and glass. .

  The method for applying the coating composition is not particularly limited, and a method known in the art can be used. Specifically, examples of the application method include brush application, spray application, and dipping. In particular, in order to form the coating film 4 having no unevenness, it is preferable to remove the excess coating composition by using an air stream after applying the base material 5 by immersing it in the coating composition. Further, the excess coating composition may be removed by rotating the substrate 5 instead of the air flow. By using such a method, coating unevenness can be suppressed.

  The drying method is not particularly limited, and it may be dried at room temperature or heated to be dried. When drying at room temperature, the drying time can be shortened by drying under airflow. When heating and drying, hot air may be blown or heating may be performed in a heating furnace.

Embodiment 2.
In the second embodiment, an article to which the coating film described in the first embodiment is applied will be described.
FIG. 3 is a schematic cross-sectional view of the centrifugal blower according to the second embodiment of the present invention. In FIG. 3, the centrifugal blower 16 includes a multi-blade impeller 13, an electric motor that rotationally drives the multi-blade impeller 13, and a fan casing 14. The fan casing 14 has a suction port 21 through which the airflow is sucked by the rotation of the multiblade impeller 13, and a blowout port 22 through which the airflow is blown out. The suction port 21 is a circular opening. The center of the opening of the suction port 21 is located coaxially with the rotation axis. The space between the multi-blade impeller 13 and the inner surface 15 of the fan casing 14 is a spiral blower passage through which the air flow blown out from the multi-blade impeller 13 flows. The air outlet 22 is an opening that serves as an outlet of a spiral air passage.

  The multi-blade impeller 13 includes a plurality of blades 11 and a main plate 12 having a boss 10. The plurality of wings 11 are arranged in a ring shape around the boss 10 on the main plate 12. The main plate 12 is a circular plate member having the boss 10 as its center, and is formed such that the central portion thereof is convex toward the suction port 21 side rather than the peripheral edge portion. The boss 10 is connected to the shaft 20 of the electric motor. A coating film 4 obtained by applying and drying the coating composition described in the first embodiment on at least one surface of the multiblade impeller 13, the electric motor, the suction port 21, the air outlet 22 and the fan casing 14. It is a thing. The method of forming coating film 4 is the same as that described in the first embodiment.

  Since the coating film 4 described in the first embodiment can suppress the adhesion of oil and dust and has excellent adhesion to the base material, the electric motor that constitutes the centrifugal blower 16, the suction port 21, the air outlet port 22, and the It is most suitable for use in the fan casing 14. Therefore, by forming the coating film 4 on at least one surface of the multiblade impeller 13, the electric motor, the suction port 21, the air outlet 22 and the fan casing 14, it is possible to prevent the performance of the centrifugal blower 16 from being deteriorated, and It is possible to effectively prevent oil and dust from adhering to.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

<Example 1>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Example 2>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 19.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing fluororesin. It was 0.0018 mass% with respect to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Example 3>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF810 manufactured by Asahi Glass Co., Ltd., hydroxyl value 9 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Example 4>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF916N manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 100 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFGC-SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Example 5>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 0.013% by mass with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Example 6>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 19.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing fluororesin. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Example 7>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 0.0012 mass% with respect to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Example 8>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorine-based solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 2.9 mass% with respect to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Example 9>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ST manufactured by Nissan Chemical Industries, Ltd., average particle diameter 12 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Example 10>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (particles having an organosilica sol IPA-ST manufactured by Nissan Chemical Industry Co., Ltd., average particle diameter 295 nm) and a fluorine-based solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) are further added to the coating composition. I got a thing. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative Example 1>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF916F manufactured by Asahi Glass Co., Ltd., hydroxyl value 100 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 6.0% by mass based on the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing fluororesin. It was 3.1% by mass based on the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative example 2>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 0.009% by mass with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing fluororesin. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative example 3>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 20.3% by mass with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative example 4>
Fluoroethylene vinyl ether alternating copolymer (Lumiflon manufactured by Asahi Glass Co., Ltd., hydroxyl value 6 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFGC SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) , Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative Example 5>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF9010 manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 114 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative example 6>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 0.0008 mass% with respect to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative Example 7>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (particles having an organosilica sol IPA-ZL manufactured by Nissan Chemical Industry Co., Ltd., an average particle diameter of 316 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) are further added to the coating composition. I got a thing. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative Example 8>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ST manufactured by Nissan Chemical Industries, Ltd., average particle diameter 8 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 1.5% by mass relative to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative Example 9>
Fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., hydroxyl value 46 mgKOH / g) was dissolved in 1-propanol, and then hydrophilic silica particles (organic silica sol IPA-ST manufactured by Nissan Chemical Industries, Ltd., average particle diameter). 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of hydrophilic silica particles was 1.5% by mass based on the fluoroethylene vinyl ether alternating copolymer.

<Comparative Example 10>
After mixing a perfluoroalkyl group-containing fluororesin (AGC Seimi Chemical Co., Ltd. SFC coat SFE-DP02) and hydrophilic silica particles (Nissan Chemical Co., Ltd. organosilica sol IPA-ZL, average particle size 80 nm), a fluorocarbon solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) was further added to obtain a coating composition. In this coating composition, the content of hydrophilic silica particles was 1.5% by mass with respect to the perfluoroalkyl group-containing fluororesin.

<Comparative Example 11>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ) And a fluorine-based solvent (Asahi Klin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin.

<Comparative Example 12>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (organic silica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle diameter 80 nm) and a fluorinated solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) were further added to obtain a coating composition. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 4.9 mass% with respect to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

<Comparative Example 13>
A fluoroethylene vinyl ether alternating copolymer (Lumiflon LF710F manufactured by Asahi Glass Co., Ltd., a hydroxyl value of 46 mgKOH / g) was dissolved in 1-propanol, and then a perfluoroalkyl group-containing fluororesin (SFC Coat SFE-DP02 manufactured by AGC Seimi Chemical Co., Ltd.) was used. ), Hydrophilic silica particles (particles having an organosilica sol IPA-ZL manufactured by Nissan Chemical Industries, Ltd., average particle size 80 nm) and a fluorine-based solvent (Asahi Kulin AC-6000 manufactured by Asahi Glass Co., Ltd.) are further added to obtain a coating composition. I got a thing. In this coating composition, the content of the fluoroethylene vinyl ether alternating copolymer was 18.0 mass% with respect to the perfluoroalkyl group-containing fluororesin, and the content of the hydrophilic silica particles was perfluoroalkyl group-containing. It was 0.0005 mass% with respect to the total of the fluororesin and the fluoroethylene vinyl ether alternating copolymer.

  Details of the coating compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 13 are shown in Table 1. Each of the coating compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 13 was applied by dipping a 100 mm x 30 mm x 1 mm plastic substrate (ABS resin), and then excess coating was performed using an air stream. A coating film was formed by removing the composition.

The coating film was evaluated for falling angle, dust adhesion suppressing performance and adhesion according to the following methods.
<Fall angle>
The sliding angle was measured by using a contact angle meter (CX-150 type manufactured by Kyowa Interface Science Co., Ltd.) for a coating film left at room temperature (25 ° C.) for 1 hour and coated with PTFE (polytetrafluoroethylene) having an inner diameter of 0.1 mm. A 7 μL oil droplet (salad oil manufactured by Nisshin Oillio Co., Ltd.) was dropped on the surface of the coating film from the tip of the needle. Then, the tilt angle at the start of sliding was measured by a tilting device and evaluated according to the following criteria. It is judged that the smaller the falling angle, the higher the oil adhesion suppressing effect. The results are shown in Table 2.

1: A sliding angle of less than 10 °.
2: A sliding angle of 10 ° or more and less than 30 °.
3: A falling angle of 30 ° or more and less than 60 °.
4: A falling angle of 60 ° or more and less than 90 °.
5: Falling angle of 90 ° or more.

<Dust adhesion control performance>
For the dust adhesion suppression performance, the sticking property of sand dust, which is a hydrophilic fouling substance, was evaluated. A JIS Kanto loam dust with a center particle size of 1 to 3 μm is blown onto the coating film with air at a temperature of 25 ° C. and a humidity of 50%, and then collected with a mending tape (Sumitomo 3M Co., Ltd.) for spectrophotometry. The absorbance (wavelength 550 nm) by (Shimadzu Corporation UV-3100PC) was measured and evaluated according to the following criteria. The results are shown in Table 2.

1: Absorbance less than 0.1.
2: Absorbance of 0.1 or more and less than 0.2.
3: Absorbance of 0.2 or more and less than 0.3.
4: Absorbance of 0.3 or more and less than 0.4.
5: Absorbance of 0.4 or more.

<Adhesion>
The adhesion was measured by using a wear tester Crockmeter (produced by Yasuda Machinery Co., Ltd.) and reciprocating the surface of the coating film 20 times with a load of 90 gf / cm ² . The peeled state of the coating film after the abrasion test was evaluated by image-processing the residual state of the coating film using an electron microscope and calculating the residual area. The peeled state after the abrasion test was evaluated according to the following criteria. The results are shown in Table 2.

1: No peeling of the coating film.
2: The residual area of the coating film is 1% or more and less than 20%.
3: The residual area of the coating film is 20% or more and less than 60%.
4: The residual area of the coating film is 60% or more and less than 90%.
5: The residual area of the coating film is 90% or more.

  As shown in Table 2, the coating films formed from the coating compositions of Examples 1 to 10 have high oil adhesion suppressing performance and dust adhesion suppressing performance, and also have high adhesion to the base material. I understand.

  Among them, the coating film formed from the coating composition of Example 1 had high oil adhesion suppressing performance and dust adhesion suppressing performance, and had the best adhesion to the substrate. It is considered that this is because fine irregularities were formed by the perfluoroalkyl group-containing fluororesin, the fluoroethylene vinyl ether alternating copolymer, and the hydrophilic silica particles.

  FIG. 4 is a graph showing the critical significance of the hydroxyl value of the fluoroethylene vinyl ether alternating copolymer. When the hydroxyl value of the fluoroethylene vinyl ether alternating copolymer is less than 7 mgKOH / g, the adhesion of the coating film to the base material deteriorates (Comparative Example 4). On the other hand, when the hydroxyl value of the fluoroethylene vinyl ether alternating copolymer exceeds 110 mgKOH / g, the sliding angle becomes large and the oil adhesion suppressing performance deteriorates (Comparative Example 5).

  FIG. 5 is a graph showing the critical significance of the amount of fluoroethylene vinyl ether alternating copolymer with respect to the perfluoroalkyl group-containing fluororesin. When the amount of the fluoroethylene vinyl ether alternating copolymer is less than 0.01% by mass, the adhesiveness of the coating film to the substrate cannot be sufficiently obtained (Comparative Example 2). On the other hand, when the amount of the fluoroethylene vinyl ether alternating copolymer exceeds 20.0 mass%, the dust adhesion suppressing performance deteriorates (Comparative Example 3).

  FIG. 6 is a graph showing the critical significance of the amount of hydrophilic silica particles with respect to the total of a perfluoroalkyl group-containing fluororesin and a fluoroethylene vinyl ether alternating copolymer. When the amount of hydrophilic silica particles is less than 0.001% by mass, the adhesion of the coating film to the substrate cannot be sufficiently obtained (Comparative Example 6). On the other hand, when the amount of the hydrophilic silica particles exceeds 3.0% by mass, the falling angle becomes large and the oil adhesion suppressing performance deteriorates (Comparative Example 1).

  FIG. 7 is a graph showing the critical significance of the average particle size of hydrophilic silica particles. If the average particle size of the hydrophilic silica particles is less than 10 nm, the dust adhesion suppressing performance deteriorates (Comparative Example 8). On the other hand, when the average particle diameter of the hydrophilic silica particles exceeds 300 nm, the falling angle becomes large, the oil adhesion suppressing performance deteriorates, and the dust adhesion suppressing performance also deteriorates (Comparative Example 7).

  FIG. 8 is a graph showing the critical significance of the area ratio of the exposed part of the hydrophilic silica particles. When the area ratio of the exposed portion of the hydrophilic silica particles exceeds 50%, the falling angle becomes large and the oil adhesion suppressing performance deteriorates (Comparative Example 12). On the other hand, if the area ratio of the exposed portion of the hydrophilic silica particles is less than 1.5%, the dust adhesion suppressing performance deteriorates (Comparative Examples 6, 11 and 13).

  In addition, the coating film of Comparative Example 9 which did not contain the perfluoroalkyl group-containing fluororesin resulted in a marked deterioration in the oil adhesion suppressing performance. Further, the coating film of Comparative Example 10 containing no fluoroethylene vinyl ether alternating copolymer resulted in poor adhesion. The coating film of Comparative Example 11 containing no hydrophilic silica particles resulted in deterioration of the dust adhesion suppressing performance.

  As can be seen from the above results, the coating film according to the present invention can simultaneously realize excellent oil adhesion suppressing performance, dust adhesion suppressing performance, and adhesiveness. Further, the coating film according to the present invention does not deposit or accumulate oil, dust or the like even after repeated use, and can keep the adhesion of oil smoke and oil droplets suppressed.

  1 Perfluoroalkyl group-containing fluororesin, 2 Fluoroethylene vinyl ether alternating copolymer, 3 Hydrophilic silica particles, 4 Coating film, 5 Base material, 10 Boss, 11 Blades, 12 Main plate, 13 Multi-blade impeller, 14 Fans Casing, 15 inner surface, 16 centrifugal blower, 20 shaft, 21 inlet, 22 outlet.

Claims (4)

A fluoroethylene vinyl ether alternating copolymer having a hydroxyl value of 7 mgKOH / g or more and 110 mgKOH / g or less and hydrophilic silica particles having an average particle diameter of 10 nm or more and 300 nm or less are dispersed and arranged in a perfluoroalkyl group-containing fluororesin. A coating film that
The fluoroethylene vinyl ether alternating copolymer is contained in an amount of 0.01% by mass or more and 20.0% by mass or less based on the perfluoroalkyl group-containing fluororesin, and the perfluoroalkyl group-containing fluororesin and the fluoroethylene vinyl ether are contained. The hydrophilic silica particles are contained in an amount of 0.001% by mass or more and 3.0% by mass or less based on the total of the alternating copolymer, and a part of the hydrophilic silica particles is exposed on the surface of the coating film. And the area of the exposed portion of the hydrophilic silica particles is 1.5% or more and 50% or less of the total area of the surface of the coating film.   An article, wherein the coating film according to claim 1 is formed on the surface of a substrate. Coating composition comprising perfluoroalkyl group-containing fluororesin, fluoroethylene vinyl ether alternating copolymer having a hydroxyl value of 7 mgKOH / g or more and 110 mgKOH / g or less, and hydrophilic silica particles having an average particle diameter of 10 nm or more and 300 nm or less A thing,
The fluoroethylene vinyl ether alternating copolymer is contained in an amount of 0.01% by mass or more and 20.0% by mass or less with respect to the perfluoroalkyl group-containing fluororesin, and the perfluoroalkyl group-containing fluororesin and the fluoroethylene. A coating composition comprising the hydrophilic silica particles in an amount of 0.001% by mass or more and 3.0% by mass or less based on the total amount of the vinyl ether alternating copolymer. A multi-blade impeller,
An electric motor for rotationally driving the multi-blade impeller,
A centrifugal blower comprising: a fan casing having the multi-blade impeller housed therein; and a fan casing having a suction port through which an air flow is sucked by the rotation of the multi-blade impeller and an outlet through which the air flow is blown out.
A centrifugal fan having the coating film according to claim 1 on at least one surface of the multiblade impeller, the electric motor, the suction port, the air outlet, and the fan casing.

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