JP3080089B1 - Fluororesin coating and production method thereof - Google Patents

Abstract

An object of the present invention is to provide a fluororesin coating excellent in abrasion resistance, scratch resistance, corrosion resistance, blister resistance and the like, and a method for producing the same. SOLUTION: In a fluororesin coating on which one or two or more fluororesin layers are coated on a substrate, the outermost layer has a melt flow rate defined by ASTM-D-3307 of 0.2 to less. PFA containing 10 g / 10 min of tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) at a ratio of 20 to 100% by weight based on the total amount of PFA and having a thickness of 10 to 90 μm.
A fluororesin coating, which is a layer, and a method for producing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluororesin coating and a method for producing the same, and more particularly to a fluororesin coating excellent in wear resistance, scratch resistance, corrosion resistance, blister resistance and the like, and a method for producing the same. . Further, the present invention relates to a fluororesin paint suitable for producing a fluororesin coating excellent in the above-mentioned various properties.

[0002]

2. Description of the Related Art Conventionally, a fluororesin coating obtained by coating a fluororesin on a base material such as a metal base material has a non-adhesive surface. Cooking utensils; household appliances such as hot plates, grill pans, auto-bakers, rice cakes; oil pots, etc .;
-234618, JP-B-7-55182). As the fluororesin, polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkylvinyl ether copolymer (PFA), and the like, which are excellent in heat resistance, are generally used.

[0003] The fluororesin coating is usually produced by applying a fluororesin paint on a substrate and baking to form a fluororesin coating. When molding the fluororesin coating into a container shape such as a pot, a pot, a frying pan, or a jar rice cooker, a fluororesin coating is produced using a metal substrate as a base material, and if necessary, a circle is formed. After punching into a predetermined shape such as a plate shape, it is formed into a desired shape by press working or the like. The fluorocarbon coating may be produced using a metal base material that has been punched into a predetermined shape such as a disk shape in advance. The fluororesin layer is formed as one layer or two or more layers. Fluororesin coating is non-adhesive,
Since it has a heat-resistant and corrosion-resistant surface and does not stick to cooked food, it is particularly suitable for the field of cookware.

However, the conventional fluororesin coating has a problem that the abrasion resistance and the scratch resistance are not always sufficient, and it is liable to be worn or damaged during repeated use. It is presumed that the cause is that the mechanical strength and stress crack resistance of the fluororesin film are not sufficient. Conventionally, as a fluororesin, from the viewpoint of processability into a coating film, PTFE having a relatively high molecular weight is used by coating as a fine particle dispersion, or PFA having a relatively low molecular weight is used in a relatively large particle size. Was used as a dry electrostatic powder coating. In order to improve mechanical strength and stress crack resistance, it is conceivable to further increase the molecular weight of the fluororesin used. However, ultra-high molecular weight PTFE and high molecular weight PFA can be applied to a uniform and smooth coating film. Is extremely difficult to form.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluororesin coating excellent in abrasion resistance, scratch resistance, corrosion resistance, blister resistance and the like, and a method for producing the same.
Another object of the present invention is to provide a fluororesin paint capable of forming such a fluororesin coating film having excellent properties.

The present inventors have conducted intensive studies to overcome the above-mentioned problems of the prior art, and as a result, have found that a high molecular weight tetrafluoroethylene / polymer having a low melt flow rate (MFR) is used.
Perfluoroalkyl vinyl ether copolymer (PF
Even if A) is used, practical use can be achieved by combining PFA particles having an average particle size of 5 to 40 μm (large particle size) and PFA particles having an average particle size of 0.1 to 0.5 μm (small particle size). It has been found that an excellent coating film can be easily formed, thereby forming a coating film having excellent mechanical strength and stress crack resistance. Both high molecular weight PFA particles can be used as the large particle size PFA particles and the small particle size PFA particles, but conventional low molecular weight PFA particles having a large MFR may be used as the small particle size PFA particles .

[0007] Fluororesin The fluororesin coating material for coating film formation, large particle size of the PFA particles and small particle diameter PFA
Excellent in stability and the coating film formability of the particles as the fluorine resin coating is paint disc over bread John form dispersed in a liquid medium, smoothing effect there Ru alone this time. By forming such a PFA coating film directly or on the outermost layer through at least one fluororesin layer, wear resistance and scratch resistance are remarkably improved, and corrosion resistance and blister resistance are also improved. A good fluororesin coating can be obtained. The present invention has been completed based on these findings.

[0008]

According to the present invention, in a fluororesin coating having one or more fluororesin layers coated on a substrate, the outermost layer has an average particle size of 5 to 4%.
0 μm tetrafluoroethylene / perfluoroalkyl
Vinyl ether copolymer (PFA) particles and average particle size
0.1: 0.5 μm PFA particles in a weight ratio of 20:80
~ 80: 20 fluororesin paint dispersed in liquid medium
Formed using, ASTM-D-3307 melt flow rate specified in the 0.2 to 10 g / 10 min P
A fluororesin coating is provided, which is a PFA layer having a thickness of 10 to 90 μm and made of PFA containing FA at a ratio of 20 to 100% by weight in the total amount of PFA.

According to the present invention, there is further provided a method for producing a fluororesin coating wherein one or more fluororesin layers are coated on a substrate, wherein the fluororesin is directly or at least one layer on the substrate. Through the resin layer, average particle size 5 to 40 μm
PFA particles and PFA particles having an average particle size of 0.1 to 0.5 μm
ASTM-D-330 , wherein the particles are dispersed in a liquid medium.
7, the melt flow rate is 0.2 to 10 g /
It is characterized in that a fluororesin paint composed of PFA containing PFA containing 10 to 10% by weight of the total amount of PFA in the total amount of PFA is applied and baked to form an outermost layer composed of a PFA layer having a thickness of 10 to 90 μm. A method for producing a fluororesin coating is provided.

Further, according to the present invention, the average particle size is 5 to 4
PFA particles having a melt flow rate of 0.2 to 10 g / 10 min specified by ASTM-D-3307 at 0 μm and a melt flow rate 0 specified by ASTM-D-3307 having an average particle size of 0.1 to 0.5 μm The present invention provides a fluororesin coating material in which 0.2 to 40 g / 10 minutes of PFA particles are dispersed in a liquid medium in a weight ratio of 20:80 to 80:20.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The fluororesin coating of the present invention is a fluororesin coating in which one or more fluororesin layers are coated on a substrate. As the base material, aluminum base material such as aluminum or aluminum alloy, magnetic or non-magnetic stainless steel base material, or aluminum-S
Various metal base materials such as composite base materials such as US can be used. In addition, a ceramic substrate, a glass substrate, or the like can be used as the substrate. Among these base materials, an aluminum base material is preferable for use in cooking utensils because of its good thermal conductivity and moldability.

In the fluororesin coating of the present invention, the outermost layer has an MFR defined by ASTM-D-3307 of 0.
In the case of forming a PFA layer composed of PFA containing 20 to 100% by weight of PFA in 2 to 10 g / 10 minutes,
Although a pigment or a filler may be added to PFA, it is preferable to use only PFA from the viewpoints of abrasion resistance, scratch resistance, and film formability. The MFR used in the present invention is 0.2 to 1
0 g / 10 min PFA is high molecular weight PFA. If the MFR is less than 0.2 g / 10 minutes, the coating processability becomes poor, and it becomes difficult to form a uniform and smooth coating film. If the MFR exceeds 10 g / 10 minutes, the effect of improving abrasion resistance and scratch resistance is small, there is no great difference from conventional products, and sufficient durability cannot be obtained. The MFR is preferably 0.5 to 5 g / 10 min, more preferably 1 to 4 g / min.
g / 10 minutes.

By the way, PFA conventionally used in the technical field of fluororesin coating has an MFR of 10 g / 10
It has a relatively low molecular weight of less than about 40 g / 10 minutes. For example, PFA (trade name MP102) manufactured by Mitsui DuPont Fluorochemicals Co., Ltd. has an MFR of 13 g / 10
In minutes, the melt viscosity is 4 × 10 ⁴ Poise at 380 ° C. and the molecular weight is estimated to be about 500,000. Also, PFA (trade name MP10) manufactured by Mitsui DuPont Fluorochemicals Co., Ltd.
MFR of 16 and melt viscosity of 380 equivalent to MP102
It is 4 × 10 ⁴ Poise at ° C., and the molecular weight is estimated to be about 500,000. PFAs of comparable molecular weight are also commercially available from Daikin Industries and Asahi Glass and are in practical use in this technical field. These PFAs are supplied as spherical or pulverized irregular shaped powders or dispersions. In the dispersion, PFA whose molecular weight is estimated to be about 200,000 is commercially available from Daikin Industries.
FR is 16-35 and melt viscosity is 1.5 × 1 at 380 ° C.
0 ⁴ It is said that Poise. However, when these PFAs are used, the coating processability is good, but the abrasion resistance of the obtained fluororesin coating becomes insufficient.

On the other hand, in the present invention, the MFR is 0.1.
A high molecular weight PFA of 2 to 10 g / 10 min is used in a specific ratio. As such a high molecular weight PFA, a commercially available product can be suitably used. Examples of commercially available products include PFA (product name MP103) manufactured and sold by DuPont. This MP103 is MFR
Is about 2 and the melt viscosity is 3 × 10 ⁵ at 380 ° C.
Processing is difficult because of the high Poise and extremely high.
Therefore, it has been difficult to use such a high molecular weight PFA for coating on kitchen utensils such as pots, pots, pots, and frying pans in jar rice cookers. On the other hand, this PF
A has a molecular weight of about 900,000 or more and is excellent in mechanical strength and stress crack resistance. Therefore, if it can be applied to the technical field of fluororesin coatings, it will have an effect on abrasion durability and scratch resistance. It is expected that an excellent coating film will be obtained. The present inventors manufactured a test piece by compression molding using such a high molecular weight PFA.
It was confirmed that abrasion durability more than twice that of the FA molded product was obtained.

However, such a high molecular weight PFA having a small MFR can be applied as a dispersion paint in which the particles are dispersed in a liquid medium, or as a powder coating, to obtain a dense and defective coating. It is difficult to form a coating film having a uniform thickness. As a method of solving this problem, for example, a method of increasing the average particle size of the high molecular weight PFA and performing powder coating is considered. The present inventors have further studied and found that the average particle size is 5 to 40 μm.
PFA particles having an MFR of 0.2 to 10 g / 10 min.
MFR 0.2-40 g with average particle size 0.1-0.5 μm
/ 10 min PFA particles at a weight ratio of 20:80 to 80: 2.
By using a fluororesin coating containing 0, it was found that a coating film having good workability and no coating film defects could be formed, and that the coating film was easily smoothed. As the PFA particles having a small average particle size of 0.1 to 0.5 μm, high molecular weight PFA particles having an MFR of 0.2 to 10 g / 10 min may be used, but an MFR of 10 g / 10
It is preferable to use low molecular weight PFA particles having a molecular weight exceeding 40 g / 10 minutes. Here, if the compounding ratio of the large PFA particles having an average particle diameter of 5 to 40 μm is too small, the film-forming property is inferior, and if too large, the wet paint (dispersion) is used.
, The stability decreases. The mixing ratio of the large PFA particles and the small PFA particles is preferably 50: 5.
0 to 80:20.

The fluororesin paint containing PFA particles used in the present invention, prior to SL 2 kinds of PFA particles be used as a dispersion dispersed in a liquid medium (wet paint), particle gap of the coating Is easy to pack,
It is preferable because smoothing is easy. In addition, large particle size PF
Either A particles or small PFA particles with high molecular weight PFA
Particles may be used, but as PFA particles having a large particle diameter, MFA
It is preferable to use high molecular weight PFA particles having a small FR since the processability is further improved and the occurrence of coating film defects is easily suppressed. The ratio of the high molecular weight PFA particles having a small MFR to the total PFA particles is 20 to 100% by weight. It is desirably about 80% by weight. By setting this ratio to 20% by weight or more, the abrasion resistance of the coating film can be remarkably improved.

The fluororesin paint containing the PFA particles, for example, can be painted spray coating of de Isupajon, transfer, flow coating, screen coating other printing techniques, spin-coating, by a roll coating or the like. Among these coating methods, dispersion spray coating is preferable because a coating film having no coating defects and easily smoothing is easily obtained.

When the outermost layer is formed of a PFA coating film (PFA layer), it is necessary that the film thickness be in the range of 10 to 90 μm. The fluororesin coating is required to have corrosion resistance and blister resistance (blister durability) as practically necessary characteristics in addition to wear resistance (wear durability). The corrosion resistance is a durability that when the food or the like is cooked, the metal of the base material is corroded by a salt or an organic substance penetrating from minute defects or the like of the coating film. The blister durability is a performance that resists the occurrence of peeling or blistering called blister between coats or between coats and a substrate during actual use in which cooking is repeated. It is presumed that blisters are generated because water accumulated inside the coating, between coatings, or between the coating and the base material escapes as gas during rapid heating such as cooking and pushes up the coating exceeding the adhesive strength. You. As a result of the experiment, it was found that when the average thickness of the outermost PFA layer exceeds 90 μm, the frequency of blister generation increases. The thickness of the PFA layer is preferably as large as possible in order to enhance the wear durability, but is preferably small from the viewpoint of blister durability. If the thickness of the PFA layer is too small, coating defects such as pinholes penetrating the coating film are likely to occur, and the corrosion resistance is reduced. Therefore, in order to balance the blister durability and the corrosion resistance, the outermost layer has a thickness of 10 to 90 μm, preferably 15 to 60 μm.

The fluororesin coating of the present invention comprises PFA particles having an average particle size of 5 to 40 μm and an MFR of 0.2 to 10 g / 10 min directly or via at least one fluororesin layer. And MFR with average particle size of 0.1-0.5μm
Is 0.2 to 40 g / 10 min of PFA particles at a weight ratio of 2
It can be manufactured by applying and baking a fluororesin paint contained at 0:80 to 80:20. According to this production method, the MFR is 0.2 to 10 g / 10 min.
A coating film (PFA layer) composed of PFA containing FA at a ratio of 20 to 100% by weight in the total amount of PFA is formed. The thickness of the outermost PFA layer is in the range of 10 to 90 μm. The baking conditions and the like can be appropriately determined according to a usual method for forming a PFA coating film.

The fluororesin coating of the present invention can be subjected to a smoothing treatment, if necessary. Smoothing can also be achieved by coating with a wet paint containing PFA particles having a large particle size and PFA particles having a small particle size, and can also be performed by heating and pressing described below, or these may be performed alone. However, it is better to combine them. Since the outermost layer of the fluororesin coating of the present invention is formed of the above-mentioned specific PFA layer, the surface can be easily smoothed. In this smoothing process, after forming the outermost layer composed of the PFA layer, while heating to a temperature lower than the crystal melting point of PFA,
This is performed by pressing the surface of the outermost layer in a direction perpendicular to the surface. The pressing method is a method of passing between press-bonded rolls such as a pinch roll and a leveler while heating to room temperature or higher,
By hot pressing method used for joining dissimilar metals, etc.
A method in which heating and pressing at the same time in a direction perpendicular to the painted surface can be mentioned. When performing a smoothing process by a hot press method, usually 150 ° C. to 300 ° C., preferably 220 to 28 ° C.
Under heating at 0 ° C., in an atmosphere of an inert gas such as nitrogen gas or argon gas, under normal pressure or under reduced pressure of 1.5 atm or less in the atmosphere, it is usually 200 to 1,000 kgf / cm ² , preferably 300 to 1,000 kgf / cm ² . The pressing is generally performed at a pressing pressure of 800 kgf / cm ² for 5 to 60 minutes, preferably 10 to 30 minutes.

The surface smoothness of the fluororesin coating of the present invention depends on the coating conditions and the smoothing treatment conditions, but can be finished to a surface roughness Ra of about 0.1 μm to about 5 μm. is there. By selecting various conditions, it is possible to make the surface roughness in the range of 0.2 to 3 μm suitable for applications such as a cooker in a jar rice cooker and a cooking utensil.

A base material such as a metal base material can be coated with a primer in advance to enhance the adhesion between the base material and the fluororesin coating film. In the case of a metal substrate, it is preferable to form fine irregularities on the surface of the metal substrate by a chemical or electrochemical etching treatment to enhance the adhesion between the metal substrate and the fluororesin coating film. Using a metal substrate that has been subjected to etching treatment, after forming a fluororesin coating film on the plate material, it is possible to mold it into any shape, and also to perform smoothing treatment by painting with wet paint or pressing Cheap. A mixed system of an adhesive system and a physical bonding system by etching or the like, in which a primer containing a relatively low-concentration adhesive is coated on the etched surface, is also preferably used. The primer treatment, the etching treatment, and the like can be performed according to a conventional method.

The fluororesin coating of the present invention may have, if desired, one or more fluororesin layers formed between the substrate and the outermost layer. Such a fluororesin layer is made of polytetrafluoroethylene (PTFE), PF
A, can be formed by painting a fluororesin such as tetrafluoroethylene / hexafluoropropylene (FEP) alone or in combination of two or more. The type of fluororesin paint used for the lower layer and various conditions such as application and baking can be appropriately selected according to a conventional method. As PFA used for the lower layer,
The same type as the outermost layer may be used, or a conventional low molecular weight PFA having a large MFR may be used. By using two or more fluororesin layers, coating film defects such as pinholes can be eliminated, and the abrasion resistance can be further improved. Further, by coloring the lower fluororesin layer or forming a pattern or the like, a function such as a design property can be added. When placing a fluororesin layer in the lower layer,
The number of layers is not particularly limited, but is usually about 1 to 3 layers,
The total thickness is usually 5 to 100 μm, preferably 1
The thickness is about 0 to 60 μm.

[0024] Thus, the fluorine resin coating of the present invention, abrasion resistance, scratch resistance, corrosion resistance, <br/> are excellent in such as blister resistance. The fluororesin coating of the present invention can be applied to a wide range of fields, including the field of cooking utensils, by forming a fluororesin layer on a substrate or by molding into various shapes by pressing or the like. can do.

[0025]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, the measuring method of a physical property is as follows. (1) Surface Roughness The surface roughness was measured according to the method of measuring the center line average roughness (Ra) specified in JIS-B-0601. The unit is μm. (2) Pinhole Degree The fluororesin coating was immersed in a 2.5% by weight aqueous sodium chloride solution, and the metal substrate of the fluororesin coating was used as a cathode. Current (mA) flowing from the pinhole when energized for 2 seconds
Was calculated per unit area. The unit is mA / c
m ² . (3) Scotch bright abrasion test Rotate the scotch bright in contact with the surface of the fluororesin coating layer and rotate the scotch bright at a thickness of 1 μm.
The number of rotations required to remove the PFA layer is shown. Units are 10 ³ rotation / [mu] m. (4) Corrosion resistance A test piece was immersed in a test solution prepared by dissolving 25 g of oden element (manufactured by House Foods Industry) in 1 liter of water,
The temperature is kept at １００100 ° C., and the time until corrosion occurs on the coating film surface is measured.

Example 1 An aluminum disk (MG-110, manufactured by Sumitomo Light Metal Industries, Ltd.) having a thickness of 1.2 mm was used as an aluminum substrate.
First, using this aluminum disk as an anode, electrochemical etching was performed in an aqueous solution of ammonium chloride with an amount of electricity of 25 coulombs / cm ² to form fine irregularities on the surface of the aluminum disk. This fine uneven surface is spin-coated with a PTFE dispersion (D-1F, manufactured by Daikin Industries, Ltd.) containing no filler, then, after drying the moisture, baked at 400 ° C. for 10 minutes to obtain a thickness of 2
A coating film (first layer) of 5 μm was formed.

Next, a PFA powder having an average particle size of 15 μm and a melt flow rate of 1.6 g / 10 min (Mupont, manufactured by DuPont)
33.3% by weight of P-103), 34.8% by weight of water, a fluorine-based surfactant (Unidyne, DS-
401) Dispersed in a liquid medium obtained by mixing 1.0% by weight and 0.5% by weight of a hydrocarbon surfactant (Nonion K-204 manufactured by NOF CORPORATION), and the resulting mixture is mixed with an average particle diameter of 0.4%.
μm, 47% by weight of PFA spherical particles having a melt flow rate of about 25 g / 10 minutes, 6% by weight of a surfactant, 47% by weight of water
PFA dispersion (AD-2C, manufactured by Daikin Industries, Ltd.)
R) 30.4% by weight was added and mixed well to prepare a fluororesin paint. The weight ratio between the PFA particles having an average particle size of 15 μm and the PFA particles having an average particle size of 0.4 μm was 70:30. After spin-coating the fluororesin paint on the first layer, and then drying the water, 390
Baking at 30 ° C for 30 minutes, 15 µm thick coating film (second layer)
Was formed. Table 1 shows the results.

Comparative Example 1 In Example 1, a fluororesin paint for forming the second layer was obtained by replacing two kinds of PFA particles with PFA particles having an average particle diameter of 13 μm and a melt flow rate of 13 g / 10 min. Except having used, it carried out similarly to Example 1, and produced the fluororesin coating. Table 1 shows the results.

[0029]

[Table 1]

As shown in Table 1, MF was used as PFA particles.
It can be seen that the wear resistance of the sample using MP-103 having a small MFR (Example 1) is about twice that of the sample using MP-102 having a large R (Comparative Example 1). .

Example 2 The outermost layer (the second layer) of the fluororesin coating obtained in Example 1
The layer (La) had a surface roughness Ra of 2.3 to 2.5 µm.
The surface roughness Ra is 1.0 on the upper surface of the fluororesin coating.
A SUS plate having a thickness of 0.2 μm is stacked and heated at 270 ° C. in the atmosphere.
Pressing at 500 kgf / cm ² under reduced pressure of 5 atm
When hot pressing was performed for 0 minutes, a surface with a surface roughness Ra of 1.2 to 1.5 μm and improved smoothness was obtained.

Example 3 A 1.2 mm-thick aluminum disk (MG-110, manufactured by Sumitomo Light Metal Industries, Ltd.) was used as an aluminum substrate. First, using this aluminum disk as an anode, electrochemical etching was performed in an aqueous solution of ammonium chloride with an amount of electricity of 25 coulombs / cm ² to form fine irregularities on the surface of the aluminum disk. 33.3% by weight of PFA powder (MP-103, manufactured by DuPont) having an average particle diameter of 15 μm and a melt flow rate of 1.6 g / 10 minutes was mixed with 34.8% by weight of water, and a fluorine-based surfactant (Daikin Industries, Ltd.) Unidyne
DS-401) and 0.5% by weight of a hydrocarbon-based surfactant (Nonion K-204, manufactured by NOF CORPORATION), and dispersed in a liquid medium. 0.4 µm, melt flow rate about 25 g / 10 min
FA spherical particles 47% by weight, surfactant 6% by weight, water 47
% By weight of a PFA dispersion (ADIN, manufactured by Daikin Industries, Ltd.)
-2CR) was added and mixed well to prepare a fluororesin coating. The weight ratio of the PFA particles having an average particle size of 15 μm to the PFA particles having an average particle size of 0.4 μm is 70:
30.

This fluororesin paint is spin-coated on the fine irregular surface of the aluminum disk, and after drying the water, it is baked at 390 ° C. for 30 minutes to have a thickness of 25%.
A μm coating was formed. The sample on which the coating film was formed was press-molded into a pot shape, and the corrosion resistance was evaluated. As a result, in a 90-hour corrosion resistance test, almost no corrosion was observed, and a practically usable one was obtained.

[Comparative Example 2] In Example 3, two kinds of PFA particles were prepared with an average particle size of 13%.
A fluororesin coating was prepared and evaluated in the same manner as in Example 3 except that the particles were replaced with PFA particles (MP102) having a melt flow rate of 13 g / 10 min with a μm of 13 μm. As a result, in a 90-hour corrosion resistance test, almost no corrosion was observed, and a practically usable one was obtained. That is, in comparison with Comparative Example 2, it can be understood that the fluorine tree covering of Example 3 achieved corrosion resistance comparable to the conventional product.

[0035]

According to the present invention, there is provided a fluororesin coating excellent in abrasion resistance, scratch resistance, corrosion resistance, blister resistance and the like, and a method for producing the same. Further, according to the present invention, there is provided a fluororesin paint capable of forming a fluororesin coating film having such excellent properties. The fluororesin coating of the present invention can be used in a wide range of fields such as cooking utensils such as pots, pots, frying pans, pots in jar rice cookers; home appliance cooking utensils such as hot plates, grill pans, autobakers, rice cake stickers; and oil pots. Can be applied to

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI B32B 33/00 B32B 33/00 (56) References JP-A-8-118561 (JP, A) JP-A-10-298316 (JP) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 129/10 B05C 9/14 B05D 7/24 B32B 15/08 B32B 27/20 B32B 33/00 CA (STN) CAOLD (STN ) REGISTRY (STN) WPIDS (STN)

Claims (7)

(57) [Claims] 1. A fluororesin coating comprising one or more fluororesin layers coated on a substrate, wherein the outermost layer is tetrafluoroethylene having an average particle size of 5 to 40 μm.
/ Perfluoroalkyl vinyl ether copolymer (PF
A) Particles and PFA particles having an average particle diameter of 0.1 to 0.5 μm
Are dispersed in a liquid medium at a weight ratio of 20:80 to 80:20.
ASTM-D formed using the prepared fluororesin paint
The melt flow rate defined by −3307 is 0.2 to
10 g / 10 minutes of PFA is added in a total amount of 20 to 100 in the total amount of PFA.
Thickness of 10 to 90 made of PFA contained at a ratio of weight%
A fluororesin coating comprising a PFA layer having a thickness of μm. 2. A of PFA particles having an average particle size of 5 to 40 μm.
The melt flow rate specified in STM-D-3307 is 0.2 to 10 g / 10 min, and the average particle size is 0.
ASTM-D-3307 of 1-0.5 μm PFA particles
Is 0.2 to 40 g / 1.
0 min claim 1 fluororesin coating according. 3. A method for producing a fluororesin coating in which one or more fluororesin layers are coated on a substrate, wherein the substrate is directly or via at least one fluororesin layer. PFA particles having an average particle size of 5 to 40 μm and the average
PFA particles with a particle size of 0.1 to 0.5 μm
Dispersed PFA having a melt flow rate defined by ASTM-D-3307 of 0.2 to 10 g / 10 min.
PF contained at a ratio of 20 to 100% by weight in the total amount of FA
A method for producing a fluororesin coating, comprising applying a fluororesin paint composed of A and baking to form an outermost layer composed of a PFA layer having a thickness of 10 to 90 μm. 4. A PFA-containing fluororesin paint having an average particle size of 5 to 40 μm and a melt flow rate defined by ASTM-D-3307 of 0.2 to 10 g / 10 min.
ASTM-D-3 with particles and average particle size of 0.1 to 0.5 μm
Melt flow rate specified in 307: 0.2 to 40 g
/ 10 min PFA particles at a weight ratio of 20:80 to 80: 2.
The method for producing a fluororesin coating according to claim 3, which is a fluororesin paint containing 0. 5. After forming an outermost layer comprising a PFA layer,
While heating to a temperature below the crystalline melting point of PFA, claim 3 or performing a smoothing process pressurized in a direction perpendicular to the surface of the outermost layer
Or the method for producing a fluororesin coating according to item 4 . 6. A plate-shaped metal substrate having fine irregularities formed on its surface by a chemical or electrochemical etching treatment as a substrate, forming an outermost layer composed of a PFA layer, and then forming a desired shape. The method for producing a fluororesin coating according to any one of claims 3 to 5 , wherein the fluororesin coating is formed. 7. An ASTM-D- having an average particle size of 5 to 40 μm.
Melt flow rate 0.2 to 10 defined in 3307
g / 10 min PFA particles and average particle size 0.1-0.5 μm
And PFA particles having a melt flow rate of 0.2 to 40 g / 10 min specified in ASTM-D-3307 and a weight ratio of 2
A fluororesin paint dispersed in a liquid medium at a ratio of 0:80 to 80:20.