Aqueous fluororesin coating material, aqueous fluororesin coating film, and method for forming aqueous fluororesin coating film

Abstract

Provided are a water-based fluororesin coating material having excellent water repellency and weather resistance as a water-based coating material, a water-based fluororesin coating film, and a method for forming the water-based fluororesin coating film. The present invention is characterized by comprising a solute containing a fluororesin powder, a binder, a fluorine-based oil or fat, titanium oxide, and a film-forming aid, and an aqueous solvent containing water and / or a water-soluble organic solvent.

Description

Technical Field

[0001] The present invention relates to a water-based fluororesin coating, a water-based fluororesin coating film, and a method for forming a water-based fluororesin coating film.

[0002] This application claims priority based on Japanese Patent Application No. 2022-083968 filed in Japan on May 23, 2022, and the contents are cited herein. Background Art

[0003] Fluororesin coatings have excellent weather resistance and are used in a wide range of fields such as architecture and automobiles. Conventional fluororesin coatings used to form such fluororesin coatings are mostly single-component coatings using copolymers of fluoroolefins and various hydrocarbons. In addition, two-component fluororesin coatings are also known, which are mainly composed of tetrafluoroethylene or vinylidene fluoride mixed with a special acrylic resin.

[0004] However, these fluororesin coatings all have low water repellency, and the contact angle of the formed coating film to water is about 80 degrees. Therefore, fluororesin coatings with improved water repellency are also known (see, for example, Patent Document 1).

[0005] On the other hand, in recent years, it has also been known that a fluororesin coating film can maintain functions such as anti-fouling properties over a long period of time by decomposing dirt such as organic substances attached to the surface due to ultraviolet irradiation into carbon dioxide and water by containing titanium oxide powder having a photocatalytic effect (for example, see Patent Document 2).

[0006] However, paints used for such coatings have been increasingly water-based in recent years. Paints using non-aqueous organic solvents as solvents have concerns about ignition when the organic solvents evaporate, and there are also concerns about the effects of the volatile gases of the organic solvents on the environment and human bodies.

[0007] In addition, there are many restrictions on the air transportation of paints, and paints using non-aqueous organic solvents are classified as dangerous goods, so special transportation procedures are required. Therefore, non-aqueous paints using organic solvents have the problem of high transportation costs.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 06-122838,

[0011] Patent document 2: Japanese Patent Application Laid-Open No. 10-088061. Summary of the invention

[0012] Problems to be solved by the invention

[0013] Among fluororesin coatings, it is desired to use an aqueous solvent as a solvent, not to be classified as a hazardous substance, and to have an aqueous fluororesin coating that does not decrease in contamination resistance even through changes over time.

[0014] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a water-based fluororesin coating having excellent water repellency and weather resistance as a water-based coating, a water-based fluororesin coating film, and a method for forming a water-based fluororesin coating film.

[0015] Means of solving problems

[0016] Based on the above background, the present inventors have studied water-based fluororesin coatings that are excellent in water repellency and use an aqueous solvent as a solvent, and have newly discovered a water-based fluororesin coating that has high water repellency with a water contact angle of 140 degrees or more and excellent weather resistance even after long-term water immersion in a four-component system coating film in which fluororesin powder is dispersed in a binder.

[0017] (1) The water-based fluororesin coating material according to the first aspect of the present invention is characterized by comprising a solute containing fluororesin powder, a binder, a fluorinated oil, titanium oxide, and a film-forming aid, and a solvent containing at least one of water and a water-soluble organic solvent.

[0018] (2) Aspect 2 of the present invention is the water-based fluororesin coating material of aspect 1, wherein the film-forming aid may contain 2,2,4-trimethyl-1,3-pentanediol 1-isobutyrate.

[0019] (3) Aspect 3 of the present invention is the water-based fluororesin coating material of aspect 1 or 2, wherein the titanium oxide may have a photocatalytic anatase type or rutile type crystal form.

[0020] (4) A fourth aspect of the present invention is the water-based fluororesin coating material according to any one of aspects 1 to 3, wherein the fluorine-based oil may contain at least one of perfluoropolyether, perfluoroalkyl polyether and trifluoroethylene polymer.

[0021] (5) A fifth aspect of the present invention is the water-based fluororesin coating material according to any one of aspects 1 to 4, wherein terminal groups of the fluororesin powder may be partially or fully fluorinated.

[0022] (6) Aspect 6 of the present invention is the water-based fluororesin coating material according to any one of aspects 1 to 5, wherein the fluororesin powder may include one or more powders selected from tetrafluoroethylene resin powder, tetrafluoroethylene-hexafluoropropylene copolymer resin powder, and fluoroethylene-based resin powder.

[0023] (7) Aspect 7 of the present invention is the water-based fluororesin coating material according to any one of aspects 1 to 6, wherein the binder may contain at least one of an emulsion-based fluoroethylene or a vinyl ether resin.

[0024] (8) Aspect 8 of the present invention is the water-based fluororesin coating material according to any one of aspects 1 to 7, wherein the fluororesin oil may be a material having a larger surface free energy than the fluororesin powder.

[0025] (9) The water-based fluororesin coating film of aspect 9 of the present invention is characterized in that it is a coating film comprising fluororesin powder, a binder, fluorinated oil, titanium oxide and a film-forming aid.

[0026] (10) Aspect 10 of the present invention is the water-based fluororesin coating film of aspect 9, wherein the film-forming aid may contain 2,2,4-trimethyl-1,3-pentanediol 1-isobutyrate.

[0027] (11) Aspect 11 of the present invention is the water-based fluororesin coating film of aspect 9 or 10, wherein the titanium oxide may have a photocatalytic anatase type or rutile type crystal.

[0028] (12) Aspect 12 of the present invention is the water-based fluororesin coating film according to any one of aspects 9 to 11, wherein the fluorine-based oil may contain at least one of perfluoropolyether, perfluoroalkyl polyether and trifluoroethylene polymer.

[0029] (13) A thirteenth aspect of the present invention is the water-based fluororesin coating film according to any one of aspects 9 to 12, wherein terminal groups of the fluororesin powder may be partially or completely fluorinated.

[0030] (14) Aspect 14 of the present invention is a water-based fluororesin coating according to any one of aspects 9 to 13, wherein the fluororesin powder may include one or more powders selected from tetrafluoroethylene resin powder, tetrafluoroethylene-hexafluoropropylene copolymer resin powder, and fluoroethylene-based resin powder.

[0031] (15) A fifteenth aspect of the present invention is the water-based fluororesin coating film according to any one of aspects 9 to 14, wherein the binder may contain at least one of an emulsion-based fluoroethylene or a vinyl resin.

[0032] (16) Aspect 16 of the present invention is the water-based fluororesin coating film according to any one of aspects 9 to 14, wherein the fluororesin oil may be a material having a larger surface free energy than that of the fluororesin powder.

[0033] (17) The method for forming a water-based fluororesin coating film according to embodiment 17 of the present invention is the method for forming a water-based fluororesin coating film as described in (9) to (16), characterized in that it comprises: a coating step of applying the water-based fluororesin coating to a coating object, a pre-drying step of evaporating the solvent contained in the applied water-based fluororesin coating to form a dry coating film, a wetting step of forming a wet coating film by containing water in the dry coating film, and a re-drying step of evaporating the water contained in the wet coating film to obtain a water-based fluororesin coating film.

[0034] Effects of the Invention

[0035] According to the present invention, there can be provided a water-based fluororesin coating material having excellent water repellency and weather resistance as a water-based coating material, a water-based fluororesin coating film, and a method for forming a water-based fluororesin coating film. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] [ Figure 1 ] is a flow chart showing in stages the method for forming a water-based fluororesin coating film according to the present embodiment.

[0037] [ Figure 2 ]A diagram showing the results of Verification Example 2.

[0038] [ Figure 3 ]A diagram showing the results of Verification Example 3.

[0039] [ Figure 4 ]A diagram showing the loop conditions of Verification Example 4. DETAILED DESCRIPTION

[0040] Hereinafter, with reference to the accompanying drawings, a water-based fluororesin coating, a water-based fluororesin coating film, a method for manufacturing a water-based fluororesin coating, and a method for forming a water-based fluororesin coating according to an embodiment of the present invention will be described. It should be noted that the embodiments shown below are specifically described in order to better understand the main purpose of the invention, and unless otherwise specified, the present invention is not limited. In addition, in order to facilitate the understanding of the features of the present invention, the drawings used in the following description will sometimes be enlarged portions of the main parts for convenience, and the dimensional ratios of the various components may not be the same as the actual ones.

[0041] (Water-based fluororesin coating)

[0042] A water-based fluororesin coating material according to one embodiment of the present invention will be described.

[0043] The water-based fluororesin coating of the present embodiment is a water-based coating, which is composed of a coating having a solute and an aqueous solvent and dispersing (dissolving) the solute in the solvent, wherein the solute includes fluororesin powder, a binder, fluorine-based oil, titanium oxide and a film-forming aid, and the aqueous solvent includes at least one of water or a water-soluble organic solvent.

[0044] The fluororesin powder constituting the solute of the water-based fluororesin coating can be a resin whose terminal groups are partially or completely substituted with fluorine atoms. Specific examples of the fluororesin powder include tetrafluoroethylene resin powder, tetrafluoroethylene-hexafluoropropylene copolymer resin powder, and fluoroethylene-based resin powder. These fluororesin powders can be used alone or in combination with a plurality of fluororesin powders.

[0045] The binder constituting the solute of the water-based fluororesin coating may be, for example, at least one of an emulsion-based fluoroethylene or a vinyl ether resin, or a binder obtained by mixing the two.

[0046] The fluorine-based grease constituting the solute of the water-based fluorine resin coating preferably uses a material having a surface free energy greater than that of the fluorine resin powder. As specific examples of fluorine-based grease, there can be cited fluorine-based greases containing at least one of perfluoropolyether, perfluoroalkyl polyether, and trifluoroethylene polymer, or fluorine-based greases mixed with multiple thereof. Among them, examples of surface free energy (mN / m) corresponding to the molecular weight of perfluoropolyether are shown in Table 1.

[0047] [Table 1]

[0048]

[0049]

[0050] The titanium oxide constituting the solute of the water-based fluororesin coating material may be any titanium oxide powder having a crystal form of anatase type or rutile type having a photocatalytic effect.

[0051] As the film-forming aid constituting the solute of the water-based fluororesin coating material, for example, 2,2,4-trimethyl-1,3-pentanediol 1-isobutyrate (Texanol) can be used.

[0052] The solvent of the water-based fluororesin coating can be an aqueous solvent, such as water or a solvent obtained by adding a water-soluble organic solvent to water. As the water-soluble organic solvent, lower alcohols such as methanol, ethanol, and propanol can be used. As the aqueous solvent, water is particularly preferably used from the viewpoint of reducing flammability. As water, low-cost tap water or distilled water can be used.

[0053] The water-based fluororesin coating material of the present embodiment is composed of a coating material in which the solute having the above-mentioned structure is dispersed (dissolved) in an aqueous solvent.

[0054] As described above, the water-based fluororesin coating of the present embodiment uses a water-based solvent as a solvent, and even if it is a fluororesin coating, there is no concern about fire caused by volatilization of the organic solvent or the concern about the volatile gas of the organic solvent affecting the environment or the human body, and a fluororesin coating with excellent safety can be provided. In addition, by using a water-based solvent as a solvent, for example, regarding the transportation of the coating by aircraft, it is not classified as a dangerous substance, but is handled as ordinary cargo, so the cost involved in transportation is low, and it can be provided at a low cost.

[0055] (Water-based fluororesin coating)

[0056] The water-based fluororesin coating of the present embodiment is a coating formed by applying the water-based fluororesin coating of the above-mentioned structure to the coating object and drying it to volatilize the solvent. That is, the water-based fluororesin coating of the present embodiment is a coating containing fluororesin powder, a binder, fluorinated oil, titanium oxide and a film-forming aid.

[0057] The surface of the conventional fluororesin coating film, when used outdoors, has excellent water repellency at the beginning, but exhaust gas, sand, dust, etc. adhere to the coating film surface, and in the long term, the water repellency decreases due to time changes. On the other hand, the water-based fluororesin coating film of the present embodiment described above can decompose the dirt on the fluororesin coating film.

[0058] Furthermore, in conventional coatings in which titanium oxide powder is added, the coating itself decomposes and powders due to the strong reaction of titanium oxide. However, in the water-based fluororesin coating of the present embodiment, the fluororesin powder, adhesive, and fluorogrease serving as constituent materials are all made of fluororesin materials. Due to the strong bonding force between fluorine and other elements (CF bond energy: 116 kcal / mol), their combination will not be decomposed by titanium oxide, and only the dirt attached to the surface will be decomposed.

[0059] That is, by dispersing titanium oxide in the binder, the surface of the coating film receives ultraviolet rays contained in sunlight, and the binder itself is decomposed (powdered) by the photocatalytic effect of titanium oxide. Dirt attached to the surface of the coating film and the coating film itself are washed away by wind and rain, and a new surface is always exposed during the remaining period of the coating film. This makes it possible to achieve a water-based fluororesin coating film that maintains antifouling properties over a long period of time.

[0060] In addition, since the fluorine-based grease uses a material with a larger surface free energy than the fluorine resin powder, the gaps between the individual fluorine resin powders are filled with the fluorine-based grease, which can suppress the generation of gaps that cause the water resistance to change (deteriorate) over time, and can achieve a water-based fluorine resin coating that can prevent the water resistance from decreasing over a long period of time.

[0061] (Method for producing water-based fluororesin coating)

[0062] The method for producing the water-based fluororesin coating of the present embodiment is produced through a dispersing step of diluting a solute containing fluororesin powder, a binder, fluorinated oil, titanium oxide and a film-forming aid with a solvent and then uniformly dispersing the solute in the solvent.

[0063] Specifically, a solute consisting of fluororesin powder, a binder, fluorine-based oil, titanium oxide and a film-forming aid is diluted with tap water and a small amount of ethanol as an aqueous solvent, these solutes are slowly added while premixing, and then the solute is dispersed in the solvent by any stirring means, thereby producing a water-based fluororesin coating.

[0064] Thus, according to the method for manufacturing a water-based fluororesin coating of the present embodiment, by uniformly dispersing the solute in the solvent, the solutes of the five components, namely, fluororesin powder, binder, fluorinated oil, titanium oxide and film-forming aid, can be uniformly dispersed in the water-based solvent, thereby manufacturing a water-based fluororesin coating of uniform composition with no deviation in properties.

[0065] (Method for forming a water-based fluororesin coating film)

[0066] Figure 1 The flowchart shows the method for forming a water-based fluororesin coating film according to the present embodiment in stages. The method for forming a water-based fluororesin coating film according to the present embodiment comprises a coating step S1, a preliminary drying step S2, a wetting step S3, and a re-drying step S4.

[0067] The coating step S1 is implemented as follows: after the water-based fluororesin coating of the above-mentioned present embodiment is fully stirred, the water-based fluororesin coating is applied to the coating object with a thickness of several microns to about 1 mm by various coating methods such as coating with a sprayer, coating with a brush or roller, or spin coating.

[0068] The pre-drying step S2 dries the water-based fluororesin coating applied in the coating step S1 to evaporate the water-based solvent such as water, thereby forming a dry coating film on the coating object. The pre-drying step S2 can be dried by various drying methods such as natural drying, hot air drying, infrared drying, etc.

[0069] In the wetting step S3, water is sprayed on the dry coating obtained in the pre-drying step S2 by a sprayer, etc., so that the dry coating contains water to form a wet coating. It should be noted that in order to promote re-drying in the subsequent step, a water-soluble organic solvent such as a lower alcohol may be mixed with water and sprayed.

[0070] In the re-drying step S4, water contained in the wet coating film obtained in the wetting step S3 is evaporated to obtain a water-based fluororesin coating film. The re-drying step S4 can be carried out by various drying methods such as natural drying, hot air drying, infrared drying, etc.

[0071] As described above, in the method for forming a water-based fluororesin coating film of the present embodiment, by making the once dried coating film contain water to form a wet coating film and then drying it again, the water repellency of the water-based fluororesin coating film can be further improved compared with the coating film which is dried once after coating.

[0072] Example

[0073] The effects of the present invention are verified below as examples.

[0074] (Verification Example 1)

[0075] The fluororesin powder is a tetrafluoroethylene resin powder with an average molecular weight of 8500 and an average particle size of 1 μm, which is 75% by weight. The binder is a vinylidene fluoride resin. The fluorine-based oil is a perfluoropolyether with a molecular weight of 2700, which is 2% by weight. The titanium oxide is an anastase powder with an average particle size of 50 nm. The film-forming aid is a Texanol with a weight percentage of 10% of the total solute.

[0076] The solutes of these five components were diluted with tap water and a small amount of ethanol as an aqueous solvent, and the raw materials (solutes) were slowly mixed while being pre-mixed, and then dispersed using a bead mill to prepare the water-based fluororesin coating of the present invention. It should be noted that the amount of ethanol added to the tap water as a solvent was 1.6% by mass of the entire coating.

[0077] In Example 1 of the present invention, the titanium oxide was added at 0.2% by weight relative to the total solute. In Example 2 of the present invention, the titanium oxide was added at 0.5% by weight. In Comparative Example 1, no titanium oxide was added.

[0078] The surface free energies of the raw materials are about 15 to 20 mN / m for fluororesin powder, 30 to 45 mN / m for binder, and 15 to 20 mN / m for fluorinated oil.

[0079] For evaluation, primer paint (urethane resin paint) was applied in advance or sprayed, brushed or roller-coated on a clean FRP plate, aluminum plate or glass plate to prepare respective coating films (specimens).

[0080] Then, these various samples were exposed outdoors at a south-facing setting angle of 45° for 450 days.

[0081] As a result, regarding the appearance of the coating film, the sample of Comparative Example 1 which does not contain titanium oxide powder has dirt on the surface, and vertical rain streaks or dirt remaining after the water droplets have dried are observed. On the other hand, the sample of Example 1 of the present invention which contains 0.2% titanium oxide has no dirt at all, and the white color of the initial sample is maintained. The sample of Example 2 of the present invention which contains 0.5% titanium oxide has the color of the primer coating film (gray) visible through the self-cleaning of titanium oxide due to the photocatalytic effect. The reduction in the coating film of these samples after exposure for 9 months, 15 months, and 20 months is shown in Table 2.

[0082] [Table 2]

[0083]

[0084]

[0085] In addition, water repellency is described below. The contact angle of water is the most well-known standard for water repellency. The larger the angle, the higher the water repellency. Water repellency was evaluated using a contact angle meter manufactured by Kyowa Interface Chemical Co., Ltd. About 4 μl (4×10 -9 m 3 ) water droplet and measure the water contact angle.

[0086] The measurement was performed at room temperature 23°C, and the average value of 5 measurements was used. The initial water contact angles of Inventive Examples 1 and 2 and Comparative Example 1 were all 150° or more. Therefore, it is considered that there is no difference in the initial water repellency between Inventive Examples 1 and 2 and Comparative Example 1.

[0087] The water contact angles of the samples after 15 months and 20 months are as follows.

[0088] [After 15 months]

[0089] Comparative Example 1: Contact angle 108°

[0090] Inventive Example 1: Contact angle 154°

[0091] Inventive Example 2: Contact angle 154°

[0092] [After 20 months]

[0093] Comparative Example 1: Contact angle 110°

[0094] Inventive Example 1: Contact angle 152°

[0095] Inventive Example 2: Contact angle 151°

[0096] From the above results, it was confirmed that the water-based fluororesin coating film of the present invention has an effect of preventing the antifouling property and water repellency from deteriorating with time.

[0097] (Verification Example 2)

[0098] The coating films of various samples used in Verification Example 1 were immersed in pure water, taken out at different test times, and the water contact angle was measured. This operation was repeated to evaluate the effect of long-term water immersion. The results are shown in Figure 2 .Right now, Figure 2 This is a graph showing the results of the deterioration of water resistance over time due to water immersion. Figure 2 The horizontal axis indicates the number of days of water immersion (days), and the vertical axis indicates the contact angle of water (degrees).

[0099] like Figure 2 As shown, it was confirmed that the coating films of Examples 1 and 2 of the present invention, although containing hydrophilic titanium oxide powder, had little decrease in water repellency over time, similar to the coating film of Comparative Example 1, and had long-term durability against water.

[0100] (Verification Example 3)

[0101] The coating film of the sample of Example 1 of the present invention used in Verification Example 1 was continuously irradiated with ultraviolet rays, and the film was taken out at each test time to measure the contact angle of water. This operation was repeated to evaluate the effect of long-term ultraviolet exposure. The test conditions are shown in Table 3 and the results are shown in Figure 3 .

[0102] [Table 3]

[0103]

[0104] according to Figure 3 The results shown show that even after irradiation with ultraviolet rays for 2500 hours (about 3 years), the water contact angle is maintained at 140° or more. This confirms the effect of preventing ultraviolet degradation (waterproofness) of the water-based fluororesin coating of the present invention.

[0105] (Verification Example 4)

[0106] The coating film of the sample of Example 1 of the present invention used in Verification Example 1 was subjected to 0 to 100 cycles of Figure 4 The water contact angle was measured at 0, 12, 24, 64, and 100 cycles of the above-mentioned heating and cooling cycles. The results are shown in Table 4.

[0107] [Table 4]

[0108]

[0109]

[0110] The results shown in Table 4 show that the water contact angle of the coating film of the sample of Example 1 of the present invention hardly decreases even after the -30°C to 70°C cooling and heating cycle is repeated 100 times. The weather resistance of the water-based fluororesin coating film of the present invention was confirmed.

[0111] Industrial Applicability

[0112] The water-based fluororesin coating of the present invention disperses fluororesin powder in a binder and further contains titanium oxide with a photocatalytic effect. The water-based fluororesin coating formed by using such a water-based fluororesin coating has water-repellency, so it can be applied to a variety of items that require water-repellency or difficulty in snow accumulation and ice accumulation. As items that require water-repellency, for example, umbrellas and other rain gear can be listed, and as items that require difficulty in snow accumulation and ice accumulation, for example, roofs of buildings in heavy snow areas, wireless communication antennas, etc. can be listed. In addition, since the present invention contains titanium oxide with a photocatalytic effect, it is not limited to the use of water-repellency, difficulty in snow accumulation, and difficulty in ice accumulation, and can also be applied to fields that require pollution resistance, atmospheric cleanliness, antibacterial properties, and deodorization properties for exhaust gases containing nitrogen oxides, dust, sand, smoke tar, etc. These coatings have a photodecomposition effect not only under sunlight, but also under indoor fluorescent lamps, so they can be applied not only to outdoor, but also to all indoor items. Therefore, it has industrial applicability.

Claims

1. A water-based fluororesin coating, characterized in that: The invention comprises a solute containing fluororesin powder, a binder, a fluorine-based oil, titanium oxide and a film-forming aid, and an aqueous solvent containing at least one of water and a water-soluble organic solvent.

2. The water-based fluororesin coating according to claim 1, characterized in that: The film-forming aid comprises 2,2,4-trimethyl-1,3-pentanediol 1-isobutyrate.

3. The water-based fluororesin coating according to claim 1 or 2, characterized in that: The titanium oxide has the following crystal forms: anatase type or rutile type having a photocatalytic effect.

4. The water-based fluororesin coating according to claim 1 or 2, characterized in that: The fluorine-based oil comprises at least one of perfluoropolyether, perfluoroalkyl polyether and trifluoroethylene polymer.

5. The water-based fluororesin coating according to claim 1 or 2, characterized in that: The terminal groups of the fluororesin powder are partially or fully fluorinated.

6. The water-based fluororesin coating according to claim 1 or 2, characterized in that: The fluororesin powder includes one or more powders selected from tetrafluoroethylene resin powder, tetrafluoroethylene-hexafluoropropylene copolymer resin powder, and fluoroethylene-based resin powder.

7. The water-based fluororesin coating according to claim 1 or 2, characterized in that: The binder includes at least one of an emulsion-based fluoroethylene resin and a vinyl ether resin.

8. The water-based fluororesin coating according to claim 1 or 2, characterized in that: The fluorine-based grease is a material having a larger surface free energy than that of the fluorine resin powder.

9. A water-based fluororesin coating, characterized in that: It is a coating film containing fluororesin powder, a binder, fluorine-based oil, titanium oxide and a film-forming aid.

10. The water-based fluororesin coating according to claim 9, characterized in that: The film-forming aid comprises 2,2,4-trimethyl-1,3-pentanediol 1-isobutyrate.

11. The water-based fluororesin coating according to claim 9 or 10, characterized in that: The titanium oxide has the following crystal forms: anatase type or rutile type having a photocatalytic effect.

12. The water-based fluororesin coating according to claim 9 or 10, characterized in that: The fluorine-based oil comprises at least one of perfluoropolyether, perfluoroalkyl polyether and trifluoroethylene polymer.

13. The water-based fluororesin coating according to claim 9 or 10, characterized in that: The terminal groups of the fluororesin powder are partially or fully fluorinated.

14. The water-based fluororesin coating according to claim 9 or 10, characterized in that: The fluororesin powder includes one or more powders selected from tetrafluoroethylene resin powder, tetrafluoroethylene-hexafluoropropylene copolymer resin powder, and fluoroethylene-based resin powder.

15. The water-based fluororesin coating according to claim 9 or 10, characterized in that: The binder includes at least one of an emulsion-based fluoroethylene resin and a vinyl ether resin.

16. The water-based fluororesin coating according to claim 9 or 10, characterized in that: The fluorine-based grease is a material having a larger surface free energy than that of the fluorine resin powder.

17. A method for forming a water-based fluororesin coating film, which is a method for forming a water-based fluororesin coating film using the water-based fluororesin coating material according to claim 1 or 2, characterized in that: have: a coating step of applying the water-based fluororesin coating to a coating object, a pre-drying step of evaporating the solvent contained in the applied water-based fluororesin coating to form a dry coating film, a wetting step of making the dry coating film contain water to form a wet coating film, and A re-drying step of evaporating the water contained in the wet coating film to obtain a water-based fluororesin coating film.

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