KR101900167B1 - Coated article, and anticorrosive coating forming method - Google Patents

Abstract

An object of the present invention is to provide a coated article excellent in wear resistance and excellent in corrosion resistance. A fluorine-containing layer (C) formed from a primer layer (A) comprising a fluorine-containing polymer (a) and a heat-resistant resin, a fluorine-containing layer (B) formed from a powdery coating material (I) Wherein the powder coating composition (I) comprises particles of the melt-processible fluoropolymer (b) and particles of the filler (i), and the 100 parts of the particles of the melt processible fluoropolymer (b) (ii) comprises particles of the melt-processible fluorine-containing polymer (c) and the particles of the filler (ii), and the number of particles of the melt-processible fluorine-containing polymer (c) is from 0.0001 to 30.0, And the number of particles of the filler (ii) is 0.0001 to 30.0 per 100 particles.

Description

TECHNICAL FIELD [0001] The present invention relates to a coated article and a method for forming a corrosion-

The present invention relates to a coated article and a method of forming a corrosion-resistant coating film. More particularly, the present invention relates to a coated article having a layer containing a fluorine-containing polymer and a method of forming a corrosion-resistant coating film.

The fluorine-containing polymer such as tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer [PFA] has a low coefficient of friction and is excellent in properties such as non-tackiness, chemical resistance and heat resistance, Kitchen utensils such as fans and pots, domestic appliances such as irons, electrical appliances, and mechanical industrial appliances.

The surface treatment is carried out by forming a layer containing a fluorine-containing polymer on a substrate. However, if the fluorine-containing polymer to be used is melt-processable such as PFA, it is easy to obtain a thick layer by a general industrial production method, The surface can easily exhibit various properties of the fluorine-containing polymer.

A filler may be added at the time of layer formation for the purpose of improving abrasion resistance and strength of a layer containing a fluorine-containing polymer.

For example, there has been disclosed a mixing machine having a pot in which a fluororesin coating is formed on the inner surface of a substrate and at least one of silicon carbide and diamond is distributed as additive particles on the surface layer side of the top coating of the fluororesin coating For example, see Patent Document 1).

Further, a fluorine resin coating film having a primer layer, an intermediate coating layer containing PFA, a filler such as diamond powder or glass flake, and a top coating layer containing PFA is disclosed on a substrate (see, for example, Patent Document 2) .

It is also preferable that at least three layers of a primer layer formed on the base material, an intermediate layer formed on the primer layer, and a top coating layer formed on the intermediate layer are provided, and the intermediate layer and the top coating layer each contain at least one hard filler having a Shinmos hardness of 10 or more And all of the hard fillers contained in the top coating layer have an average particle diameter smaller than the average particle diameter of any of the hard fillers contained in the intermediate layer (see, for example, Patent Document 3).

Japanese Patent Laid-Open No. 2006-15114 Japanese Patent Application Laid-Open No. 2006-297685 Japanese Patent Laid-Open No. 11116075

As a method of forming a coating film excellent in abrasion resistance, there is known a method of electrostatic coating a powder coating material of a fluorine-containing polymer containing a filler. However, the compatibility between the fluorine-containing polymer and the filler is not necessarily high. In addition, a voltage is applied to the powder coating at the time of electrostatic painting. Since the filler and the fluorine-containing polymer are different in degree of charging, it is not easy to form a homogeneous coating film. For these reasons, if a coating film is scratched, the coating film may peel off from the base material or the primer layer due to moisture entering from the scratches or the like. Therefore, there is a demand for a coated article excellent in wear resistance and excellent in corrosion resistance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a coated article excellent in wear resistance and excellent in corrosion resistance in view of the above situation.

As a method of forming a coating film excellent in wear resistance as described above, there is known a method of electrostatically coating a powder coating material of a fluorine-containing polymer including a filler. However, the powder coating material of a fluorine- In addition, since electrostatic coating is not easy, there has been a demand for a method of easily forming a coating film by electrostatic coating.

It is also an object of the present invention to provide a method of forming a corrosion-resistant coating film which is excellent in wear resistance and which is capable of forming a coating film excellent in corrosion resistance and capable of easily forming a coating film by electrostatic painting.

The present inventors have found that when a powder coating material of a fluorine-containing polymer containing a filler is used to coat the surface of a substrate with a plurality of layers and the number of particles of the fluorine-containing polymer and the number of particles of the filler are set to a specific ratio, And at the same time, a coated article excellent in corrosion resistance is obtained, thereby completing the present invention.

That is, the present invention relates to a substrate,

A primer layer (A) comprising a fluorine-containing polymer (a) and a heat-resistant resin,

A fluorine-containing layer (B) formed from the powder coating (I)

Containing layer (C) formed from the powder coating (II), wherein the fluorinated layer

The powder coating material (I) contains the particles of the melt-processible fluoropolymer (b) and the particles of the filler (i), and the particle number of the filler (i) 0.0001 to 30.0,

The powder coating material (II) contains the particles of the melt-processible fluoropolymer (c) and the particles of the filler (ii), and the particle number of the filler (ii) 0.0001 to 30.0.

The filler (i) is preferably at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond, mica and glass flake.

The filler (ii) is preferably at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond, mica and glass flake.

The filler (i) and the filler (ii) are preferably of different kinds.

The melt processible fluorine-containing polymer (b) is preferably at least one selected from the group consisting of tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer and tetrafluoroethylene / hexafluoropropylene copolymer .

The particles of the melt-processible fluorine-containing polymer (b) preferably have an average particle diameter of 1 to 50 μm.

The melt-processible fluorine-containing polymer (c) is preferably at least one selected from the group consisting of tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer and tetrafluoroethylene / hexafluoropropylene copolymer .

The particles of the melt-processible fluorine-containing polymer (c) preferably have an average particle diameter of 1 to 50 μm.

The fluorine-containing polymer (a) may be at least one selected from the group consisting of a tetrafluoroethylene homopolymer, a modified polytetrafluoroethylene, a tetrafluoroethylene / hexafluoropropylene copolymer, and a tetrafluoroethylene / perfluoro (alkyl vinyl ether) At least one kind selected from the group consisting of

The heat resistant resin is at least one selected from the group consisting of a polyamideimide resin, a polyimide resin, a polyether sulfone resin, a polyether imide resin, a polyether ether ketone resin, an aromatic polyester resin and a polyarylene sulfide resin desirable.

Wherein the heat resistant resin is at least one of a polyether sulfone resin, a polyamideimide resin and a polyimide resin, and the polyether sulfone resin is a polyether sulfone resin, a polyamideimide resin and a polyimide resin Is preferably 65 to 85% by mass.

The heat-resistant resin is preferably 15 to 50% by mass of the sum of the solid content of the heat-resistant resin and the fluorine-containing polymer (a).

It is preferable that the primer layer (A) has a thickness of 5 to 30 탆, the fluorine-containing layer (B) has a thickness of 1 to 90 탆, and the fluorine-containing layer (C) .

Further, the inventors of the present invention found that, when a coating film is electrostatically coated on a primer layer formed on the surface of a base material, a powder coating material mixed with a filler at a predetermined number ratio is used to obtain a corrosion-resistant coating film which is surprisingly superior in wear resistance, The present invention has been accomplished on the basis of these findings.

That is, the present invention relates to a process for preparing a powder coating material by mixing particles of a melt-processible fluorine-containing polymer and particles of a filler such that the number of particles of the filler is from 0.0001 to 30.0 to 100 particles of the melt-

And a step of coating the powder coating material on the primer layer formed on the substrate by electrostatic coating to form a corrosion-resistant coating film (R1).

It is preferable that the forming method further includes a step of coating the powder coating material on the corrosion-resistant coating film R1 by electrostatic coating to form the corrosion-resistant coating film R2.

The coated article of the present invention has the above-described structure, and thus has excellent abrasion resistance and corrosion resistance. Such coated articles can be suitably used particularly in cooking utensils and kitchen utensils. Further, according to the method for forming a corrosion-resistant coating film of the present invention, it is possible to form a coating film having excellent abrasion resistance and excellent corrosion resistance by the above-described constitution, and also to easily form a coating film by electrostatic painting. Such a method of forming a corrosion-resistant coating film can be suitably used particularly in the production of cooking utensils, kitchen utensils and the like.

Hereinafter, the present invention will be described in detail.

≪ Cloth article &

The coated article of the present invention comprises a substrate, a primer layer (A), a fluorine-containing layer (B) and a fluorine-containing layer (C) wherein the fluorine-containing layer (C) is formed from the powder coating material (I) containing particles of the melt-processible fluorine-containing polymer (c) and the powder coating material (II) will be.

The number of particles of the filler (i) in the powder coating (I) is 0.0001 to 30.0 per 100 particles of the melt-processible fluoropolymer (b), and the content of the filler ii) is 0.0001 to 30.0 parts per 100 particles of the melt-processible fluorine-containing polymer (c).

As described above, the coated article of the present invention is a coated article comprising a substrate, a primer layer (A), a fluorine-containing layer (B), and a fluorine-containing layer (C) The number of particles of the filler contained in the resin composition is adjusted, thereby providing excellent abrasion resistance and corrosion resistance.

The coated article of the present invention comprises a substrate, a primer layer (A) formed on the substrate, a fluorine-containing layer (B) formed on the primer layer (A) and a fluorine-containing layer (C) formed on the fluorine- .

Hereinafter, the coated article of the present invention will be described in more detail with specific examples.

The base material constituting the coated article of the present invention is not particularly limited, and examples thereof include metals such as metals such as iron, aluminum and copper and alloys thereof; Non-metallic inorganic materials such as ceramics, glass, and ceramics. Examples of the alloy flow include stainless steel and the like. As the base material, a metal is preferable, and aluminum or stainless steel is more preferable.

The substrate may be subjected to a surface treatment such as a degreasing treatment or a roughening treatment, if necessary. The roughening treatment method is not particularly limited, and examples thereof include chemical etching with an acid or an alkali, anodic oxidation (anodic treatment), and sandblasting. The above-mentioned surface treatment is preferably carried out from the viewpoint that the coating composition for forming a primer for forming the primer layer (A) can be uniformly applied without causing cratering and the adhesion between the base material and the primer layer is improved, The coating composition for the primer, and the like, but it is preferably, for example, sandblast.

The primer layer (A) constituting the coated article of the present invention comprises the fluorine-containing polymer (a) and the heat-resistant resin.

The fluorine-containing polymer (a) is a polymer having a fluorine atom directly bonded to a carbon atom constituting the main chain or side chain. The fluorine-containing polymer (a) may be nonfossilable or melt-processable.

The fluorine-containing polymer (a) is preferably obtained by polymerizing the fluorine-containing monoethylenically unsaturated hydrocarbon (a1).

The term "fluorine-containing monoethylenically unsaturated hydrocarbon (a1)" (hereinafter also referred to as "unsaturated hydrocarbon (a1)") refers to an unsaturated hydrocarbon having one vinyl group in which a part or all of hydrogen atoms are substituted by fluorine atoms Hydrocarbons.

In the unsaturated hydrocarbon (a1), a part or all of the hydrogen atoms not substituted by a fluorine atom may be replaced by a halogen atom other than a fluorine atom such as a chlorine atom and / or a fluoroalkyl group such as a trifluoromethyl group And may be substituted. However, the unsaturated hydrocarbon (a1) excludes trifluoroethylene which will be described later.

The unsaturated hydrocarbon (a1) is not particularly restricted but includes, for example, tetrafluoroethylene [TFE], hexafluoropropylene [HFP], chlorotrifluoroethylene [CTFE], vinylidene fluoride [VdF] Vinyl [VF], and the like. These may be used alone or in combination of two or more.

The fluorine-containing polymer (a) may be a homopolymer of the unsaturated hydrocarbon (a1). Examples of the homopolymer of the unsaturated hydrocarbon (a1) include tetrafluoroethylene homopolymer [TFE homopolymer], polychlorotrifluoroethylene [PCTFE], polyvinylidene fluoride [PVdF], polyvinyl fluoride [PVF ] And the like. The TFE homopolymer is finely flowable.

The fluorine-containing polymer (a) may also be a copolymer of at least one unsaturated hydrocarbon (a1) and an unsaturated compound (a2) copolymerizable with the unsaturated hydrocarbon (a1). That is, the unsaturated compound (a2) is different from the unsaturated hydrocarbon (a1).

The unsaturated compound (a2) is not particularly limited and includes, for example, trifluoroethylene [3FH]; And monoethylenically unsaturated hydrocarbons such as ethylene [Et] and propylene [Pr]. These may be used alone or in combination of two or more.

The fluorine-containing polymer (a) may also be a copolymer of two or more of the unsaturated hydrocarbons (a1). The copolymer of the at least one unsaturated hydrocarbon (a1) and the at least one unsaturated hydrocarbon (a1) and the unsaturated compound (a2) is not particularly limited and includes, for example, a binary copolymer, Ternary copolymers and the like.

The binary copolymer is not particularly limited, and examples thereof include VdF / HFP copolymer, Et / CTFE copolymer [ECTFE], Et / HFP copolymer and the like.

The terpolymer may also be a TFE / HFP copolymer [FEP], a TFE / CTFE copolymer, a TFE / VdF copolymer, a TFE / 3FH copolymer, an Et / TFE copolymer [ETFE] Of a TFE-based copolymer. In the present specification, the "TFE-based copolymer" means a copolymer obtained by copolymerizing TFE with one or more of other monomers other than TFE. It is preferable that the TFE-based copolymer generally has a proportion of other monomers other than TFE added in the TFE-based copolymer exceeding 1% by mass of the total mass of the TFE and the other monomers.

Examples of the terpolymer include VdF / TFE / HFP copolymers and the like.

The other monomer other than the TFE in the TFE-based copolymer may be other monomer (a3) copolymerizable with TFE described below. The other monomer (a3) is represented by the following general formula

_{X (CF 2) m O n} CF = CF 2

(Wherein, X represents -H, -Cl or -F, m represents an integer of 1 to 6, and n represents an integer of 0 or 1), except for HFP, A compound represented by formula

C ₃ F ₇ O [CF (CF ₃ ) CF ₂ O] _p -CF = CF ₂

(Wherein p represents an integer of 1 or 2), and a compound represented by the following general formula

_{X (CF 2) q CY =} CH 2

(Wherein X is as defined above, Y represents -H or -F, and q represents an integer of 1 to 6), preferably at least one kind of monomer selected from the group consisting of . These may be used alone or in combination of two or more. Examples of such TFE-based copolymers include TFE / perfluoro (alkyl vinyl ether) [PAVE] copolymer [PFA]. As the PFA, PFA fluorinated by the method described in WO 2002/088227 may be used.

The fluorine-containing polymer (a) may also be modified polytetrafluoroethylene [modified PTFE]. In the present specification, the above-mentioned "modified PTFE" means that a small amount of a comonomer is copolymerized with TFE so as not to impart melt processability to the resulting copolymer. The small amount of the comonomer is not particularly limited and examples thereof include HFP and CTFE among the unsaturated hydrocarbons (a1), and 3FH among the unsaturated compounds (a2), and the other monomers (a3 ) Among PAVE, perfluoro (alkoxyvinyl ether), (perfluoroalkyl) ethylene and the like. These small amounts of comonomers may be used alone or in combination of two or more.

The ratio of the small amount of the comonomer added to the modified PTFE differs depending on the type thereof. When PAVE, perfluoro (alkoxyvinyl ether) or the like is used, the proportion of the TFE and the small amount It is preferably 0.001 to 1% by mass of the total mass of the comonomer.

The fluorine-containing polymer (a) may be at least one kind or two or more kinds of the fluorine-containing polymers (a), and one kind or two or more kinds of the copolymers of the unsaturated hydrocarbons (a1) Or a mixture of two or more kinds of the copolymer of the unsaturated hydrocarbon (a1).

Examples of the mixture include a mixture of a TFE homopolymer and a TFE copolymer, and a mixture of two or more copolymers belonging to the TFE copolymer. Examples of the mixture include a TFE homopolymer and a PFA A mixture of TFE homopolymer and FEP, a mixture of TFE homopolymer and PFA and FEP, a mixture of PFA and FEP, and the like.

The fluorine-containing polymer (a) may also be obtained by polymerizing a perfluoroalkyl group-containing ethylenically unsaturated monomer (a4) having a perfluoroalkyl group (hereinafter also referred to as "unsaturated monomer (a4)"). The unsaturated monomer (a4) is represented by the following general formula

(Wherein Rf represents a perfluoroalkyl group having 4 to 20 carbon atoms, R ¹ represents -H or an alkyl group having 1 to 10 carbon atoms, R ² represents an alkylene group having 1 to 10 carbon atoms, R ³ represents - H or a methyl group, R ⁴ represents an alkyl group having 1 to 17 carbon atoms, r represents an integer of 1 to 10, and s represents an integer of 0 to 10).

The fluorine-containing polymer (a) may be a homopolymer of the unsaturated monomer (a4), or may be a copolymer of the unsaturated monomer (a4) and the monomer (a5) capable of copolymerizing with the unsaturated monomer (a4) .

The monomer (a5) is not particularly limited and includes, for example, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, polyethylene glycol di (meth) acrylate, N-methylolpropane acrylamide, (Meth) acrylic acid derivatives such as alkyl esters of (meth) acrylic acid having 1 to 20 carbon atoms in the alkyl group; Substituted or unsubstituted ethylene such as ethylene, vinyl chloride, vinyl fluoride, styrene,? -Methylstyrene and p-methylstyrene; Vinyl ethers such as alkyl vinyl ethers having 1 to 20 carbon atoms in the alkyl group and alkyl vinyl vinyl ethers having 1 to 20 carbon atoms in the alkyl group; Vinyl ketones such as vinyl alkyl ketone in which the alkyl group has 1 to 20 carbon atoms; Aliphatic unsaturated polycarboxylic acids such as maleic anhydride and derivatives thereof; And polyenes such as butadiene, isoprene and chloroprene.

The fluorine-containing polymer (a) can be obtained, for example, by a conventionally known polymerization method such as emulsion polymerization.

As the fluorine-containing polymer (a), at least one kind of polymer selected from the group consisting of TFE homopolymer, modified PTFE and the TFE-based copolymer is preferable because the obtained coated article is excellent in corrosion resistance and water vapor resistance. As the TFE-based copolymer, at least one kind of copolymer selected from the group consisting of FEP and PFA is preferable.

From the above description, the fluorine-containing polymer (a) is preferably at least one polymer selected from the group consisting of TFE homopolymer, modified PTFE, FEP and PFA.

As the fluorine-containing polymer (a), it is preferable that the fluorine-containing polymer (a) contains a TFE-based copolymer in view of excellent adhesion between the primer layer (A) and the fluorine-containing layer (B). The coated article having excellent adhesion between the primer layer (A) and the fluorine-containing layer (B) is excellent in water vapor resistance, so that occurrence of coating film defects such as blisters can be suppressed even in the presence of water vapor. Examples of the fluorine-containing polymer (a) containing a TFE copolymer include a TFE homopolymer alone, PFA alone, a mixture of a TFE homopolymer and a FEP, a mixture of a TFE homopolymer and a PFA, a mixture of a modified PTFE and a FEP, , A mixture of modified PTFE and PFA is preferred. The fluorine-containing polymer (a) in the primer layer (A) is preferably at least one selected from the group consisting of TFE (A), fluorine- It is preferred that the homopolymer alone, PFA alone, a mixture of TFE homopolymer and PFA, or a mixture of TFE homopolymer and FEP is used, more preferably the TFE homopolymer alone or a mixture of TFE homopolymer and FEP.

The heat-resistant resin that can form the primer layer (A) is usually a resin recognized to have heat resistance, and a resin having a continuous usable temperature of 150 ° C or higher is preferable. However, the above-mentioned fluorine-containing polymer (a) is excluded as the heat resistant resin.

The heat resistant resin is not particularly limited, and examples of the heat resistant resin include a group consisting of a polyamideimide resin, a polyimide resin, a polyether sulfone resin, a polyether imide resin, a polyether ether ketone resin, an aromatic polyester resin and a polyarylene sulfide resin Is preferably at least one kind of resin selected from the group consisting of

The polyamideimide resin [PAI] is a resin containing a polymer having an amide bond and an imide bond in a molecular structure. The PAI is not particularly limited and includes, for example, a reaction between an aromatic diamine having an amide bond in its molecule and an aromatic tetracarboxylic acid such as pyromellitic acid; The reaction of an aromatic trivalent carboxylic acid such as trimellitic anhydride with a diisocyanate such as a diamine such as 4,4-diaminophenyl ether or diphenylmethane diisocyanate; A resin containing a high molecular weight polymer obtained by various reactions such as a reaction between a dibasic acid having an aromatic imide ring in its molecule and a diamine, and the like. As the PAI, it is preferable to include a polymer having an aromatic ring in the main chain from the viewpoint of excellent heat resistance.

The polyimide resin [PI] is a resin containing a polymer having an imide bond in a molecular structure. The PI is not particularly limited, and for example, a resin containing a high molecular weight polymer obtained by, for example, reaction of an aromatic tetravalent carboxylic acid anhydride such as pyromellitic anhydride. As the PI, it is preferable to include a polymer having an aromatic ring in the main chain from the viewpoint of excellent heat resistance.

The polyethersulfone resin [PES] is represented by the following general formula

Is a resin comprising a polymer having a repeating unit represented by the following formula The PES is not particularly limited, and examples thereof include resins containing a polymer obtained by polycondensation of dichlorodiphenyl sulfone and bisphenol.

The heat-resistant resin is excellent in adhesion to a substrate, has sufficient heat resistance even under the temperature at the time of baking when forming the coated article, and is excellent in corrosion resistance and water vapor resistance. At least one kind of resin selected from the group consisting of PAI, PI, and PES may be one or two or more species, respectively.

It is more preferable that the heat resistant resin is at least one resin selected from the group consisting of PAI and PI in view of excellent adhesion with the substrate and heat resistance.

As the heat resistant resin, it is preferable to include at least one resin selected from the group consisting of PES and PAI and PI in view of excellent resistance to corrosion and water vapor. That is, the heat resistant resin may be a mixture of PES and PAI, a mixture of PES and PI, or a mixture of PES and PAI and PI. It is particularly preferable that the heat resistant resin is a mixture of PES and PAI.

When the heat-resistant resin contains PES and either or both of PAI and PI, the PES is preferably 65 to 85% by mass of the total amount of the PES and PAI and PI. And more preferably 70 to 80 mass%.

The content of the heat resistant resin is preferably 10 to 50% by mass, more preferably 10 to 40% by mass, and more preferably 15 to 30% by mass, based on the total amount of solids of the heat resistant resin and the fluoropolymer (a) More preferable. In the present specification, the term "solid content" means a solid at 20 ° C. In the present specification, the "total amount of solids of the heat-resistant resin and the fluorine-containing polymer (a)" refers to the total amount of the heat-resistant resin and the fluorine-containing polymer (a), which is applied on a substrate, dried at a temperature of 80 to 100 ° C, Means the total mass of the heat-resistant resin and the fluorine-containing polymer (a) in the residue after the minute firing.

The primer layer (A) is usually formed on a substrate. The primer layer (A) is obtained, for example, by coating a coating composition for a primer, which contains a fluorine-containing polymer (a) and a heat-resistant resin, on a substrate, drying it if necessary and then firing it. The primer layer (A) obtained in this manner is a fluorine-containing polymer having a fluorine-containing polymer (a) which is different from the heat-resistant resin in that the fluorine-containing polymer The above-mentioned fluorine-containing polymer (a) is mainly disposed on the surface side of the substrate, and the heat-resistant resin is mainly disposed on the substrate side.

The primer layer (A) contains the above-mentioned fluorine-containing polymer (a) and the heat-resistant resin, and the heat-resistant resin has adhesiveness with the base material, and therefore the adhesion to the base material is excellent. The primer layer (A) is also excellent in adhesion with the fluorine-containing layer (B) because the fluorine-containing polymer (a) has affinity with the melt-processible fluorine-containing polymer (b). Thus, the primer layer (A) has excellent adhesion to both the substrate and the fluorine-containing layer (B) because the primer layer (A) contains the fluorine-containing polymer (a) and the heat-resistant resin.

The primer layer (A) preferably contains a polymer component and an additive to be described later. In the primer layer (A), it is preferable that the polymer component is a fluorine-containing polymer (a) and a heat-resistant resin. In the present specification, the term "the primer layer (A) is a fluorine-containing polymer (a) and a heat-resistant resin" means that the polymer in the primer layer (A) But it means. The primer layer (A) has excellent adhesion to both the substrate and a fluorine-containing layer (B) described later, because the polymer component is a fluorine-containing polymer (a) and a heat-resistant resin.

The polymer component is preferably a fluorine-containing polymer (a) and a heat-resistant resin in that the primer layer (A) effectively exerts excellent adhesion to both the substrate and the fluorine-containing layer (B) Containing polymer (a) and the heat-resistant resin may further contain other resins in that they can further improve the heat resistance and water vapor resistance. Other resins may be mentioned later.

The primer layer (A) preferably has a film thickness of 5 to 30 mu m. If the film thickness is too thin, pinholes are likely to be generated, and corrosion resistance of the coated article may be deteriorated. If the film thickness is too large, cracks tend to occur, and there is a fear that the water vapor resistance of the coated article is lowered. A more preferable lower limit of the film thickness of the primer layer (A) is 7 mu m, and an upper limit is 25 mu m.

As the melt-processible fluorine-containing polymer (b) constituting the fluorine-containing layer (B), among the fluorine-containing polymers (a) described above, those having melt processability can be used. The melt-processible fluorine-containing polymer (b) is preferably such that the fluorine-containing layer (B) obtained is excellent in adhesion between the primer layer (A) and the fluorine-containing layer (C), and the resulting coated article is excellent in corrosion resistance and water vapor resistance , And has a melting point of 150 to 350 캜 and a melt viscosity at a temperature higher by 50 캜 than the melting point of 10 ⁶ (pascal-second) or less, and is preferably the TFE-based copolymer described above. The melt-processible fluorine-containing polymer (b) may be used alone or in combination of two or more. It is more preferable that the melt processible fluorine-containing polymer (b) is at least one fluoropolymer selected from the group consisting of PFA and FEP. The melt-processible fluorine-containing polymer (b) may be either PFA or FEP alone, or a mixture thereof. From the viewpoint of excellent heat resistance, it is more preferable that the melt processible fluorine-containing polymer (b) is PFA.

The fluorine-containing layer (B) is preferably laminated on the primer layer (A). It is preferable that a fluorine-containing layer (C) described later is laminated on the fluorine-containing layer (B).

The fluorine-containing layer (B) is formed from the powdery coating material (I) containing particles of the melt-processible fluorine-containing polymer (b) and particles of the filler (i). Unlike liquid coating materials such as water-based paints, a powder coating material does not require a drying step, and it is easy to obtain a thick coating film with a small number of coatings, and excellent abrasion resistance is also excellent.

The number of particles of the filler (i) in the powder coating (I) is 0.0001 to 30.0 per 100 particles of the melt-processible fluoropolymer (b).

The lower limit is preferably 0.0005, more preferably lower limit is 0.001, still more preferably lower limit is 0.005, still more preferably lower limit is 0.01, particularly preferably lower limit is 0.1, and the most preferable lower limit is one. The preferred upper limit is 28, the more preferable upper limit is 25, the more preferable upper limit is 20, and the particularly preferable upper limit is 15.

The filler (i) is preferably at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluoride diamond, mica, glass flake, zirconium oxide, aluminum nitride and boron nitride, More preferably at least one member selected from the group consisting of silicon, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond, mica and glass flake, and more preferably at least one member selected from the group consisting of silicon carbide, alumina and diamond desirable. When the powder coating material (I) contains such a filler, the abrasion resistance and corrosion resistance of the coated article are further improved.

Fluorinated diamonds can be obtained by fluorinating diamonds. The fluorination of the diamond can be carried out, for example, by a known method disclosed in the 26th Annual Meeting of the Fluorochemical Society, published on Nov. 14, 2002, pages 24-25. That is, diamond may be enclosed in a reactor containing a material having a corrosion resistance to fluorine, such as an alloy containing nickel or nickel, and fluorine gas may be introduced to fluorinate it.

The melt-processible fluorine-containing polymer (b) preferably has an average particle diameter of 1 to 50 탆, more preferably 3 to 40 탆, and further preferably 5 to 30 탆, from the viewpoint of electrostatic coating property.

The filler (i) preferably has an average particle diameter of 0.01 to 100 mu m, more preferably 0.05 to 50 mu m, and further preferably 0.1 to 40 mu m, from the viewpoint of electrostatic paintability.

The filler (i) is preferably 0.01 to 40% by mass relative to the total amount of the melt-processible fluorine-containing polymer (b) and the filler (i). More preferably from 0.05 to 30% by mass, and still more preferably from 0.1 to 10% by mass. When the amount of the filler (i) is too large, the corrosion resistance is deteriorated. When the amount of the filler (i) is too small, sufficient wear resistance is not obtained.

The powder coating material (I) for forming the fluorine-containing layer (B) may be at least one selected from the group consisting of wood powder, quartz, carbon black, clay, talc, corundum, silica, tourmaline, jade, germanium, silica powder, , Zirconium carbide, tantalum carbide, titanium carbide, tungsten carbide, extender pigments, bright colored flat pigments, scaly pigments, glass, various reinforcements, various extenders, conductive fillers and the like.

The fluorine-containing layer (B) preferably has a film thickness of 1 to 90 mu m. If the film thickness is too thin, wear resistance of the resultant coated article may not be sufficient. If the film thickness is too thick, moisture permeated from the fluorine-containing layer (B) is hardly released, and there is a fear that the water vapor resistance of the coated article is lowered. A more preferable lower limit of the film thickness of the fluorine-containing layer (B) is 5 mu m, and a more preferable upper limit is 80 mu m.

As the melt-processible fluorine-containing polymer (c) constituting the fluorine-containing layer (C), among the fluorine-containing polymers (a) described above, those having melt processability can be used.

As the melt-processible fluorine-containing polymer (c), it is preferable that the fluorine-containing polymer (c) is excellent in film formability, the fluorine-containing layer (C) obtained is excellent in adhesion to the fluorine-containing layer (B) and the abrasion- It is preferable that they are the same kind as the above-mentioned melt-processible fluorine-containing polymer (b). It is also preferable that the polyester resin has a melting point of 150 to 350 ° C and a melt viscosity of 10 ⁶ (Pascal-second) or less at a temperature higher than the melting point by 50 ° C. Examples of such a melt-processible fluorine-containing polymer (c) include a TFE-based copolymer. As the melt-processible fluorine-containing polymer (c), at least one kind of polymer selected from the group consisting of PFA and FEP is preferable from the viewpoint of excellent heat resistance, non-tackiness and film formability. The melt processible fluorine-containing polymer (c) may be PFA alone, FEP alone, or a mixture of PFA and FEP. As the melt-processible fluorine-containing polymer (c), PFA is more preferable because of its superior heat resistance.

In the coated article of the present invention, it is preferable that the fluorine-containing layer (C) is formed on the fluorine-containing layer (B), and it is preferable that the fluorine-containing layer (C) is fired at a temperature equal to or higher than the melting point of the melt processible fluoropolymer (c).

The fluorine-containing layer (C) is formed from the powdery coating material (II) containing particles of the melt-processable fluorine-containing polymer (c) and particles of the filler (ii). Unlike liquid coating materials such as water-based paints, a powder coating material does not require a drying step, so that it is easy to obtain a thick coating film with a small number of coatings and excellent abrasion resistance.

The number of particles of the filler (ii) in the powder coating (II) is 0.0001 to 30.0 per 100 particles of the melt-processible fluoropolymer (c).

The lower limit is preferably 0.0005, more preferably lower limit is 0.001, and still more preferably 0.005. In addition, the preferred upper limit is 28, the more preferable upper limit is 25, the more preferable upper limit is 20, and the more preferable upper limit is 15.

The filler (ii) is preferably at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluoride diamond, mica and glass flake, zirconium oxide, aluminum nitride and boron nitride, , Alumina, and diamond are more preferable. When the powder coating material (II) contains such a filler, the abrasion resistance and corrosion resistance of the coated article are further improved.

The filler (i) and filler (ii) may be the same or different, but from the viewpoint of designing the coating film, it is preferable that the filler (i) and filler (ii) are different in kind.

The powder coating material (II) may contain a filler (iii) separately from the filler (ii) for the purpose of imparting properties, improving physical properties, and increasing the properties of the resulting coated article. Examples of the properties and physical properties include strength, durability, weather resistance, flame retardancy, designability and the like. When a filler having a luminous feel is used, the coated article of the present invention has a good luminous feeling.

The filler (iii) is not particularly limited and may be, for example, wood powder, quartz, carbon black, clay, talc, corundum, silica, boron nitride, fused alumina, tourmaline, jade, germanium, silica powder, , Garnet, garnet, zirconium carbide, tantalum carbide, titanium carbide, tungsten carbide, extender pigments, bright white flat pigments, scaly pigments, glass, metal powders, various reinforcements, various fillers and conductive fillers. As the filler, when the coated article of the present invention is required to have a luminous feeling, a light-weight filler is preferable. The " light-permeable filler " is a filler capable of imparting luminosity to the resulting coated article.

The melt-processible fluorine-containing polymer (c) preferably has an average particle diameter of 1 to 50 mu m, more preferably 3 to 40 mu m, and still more preferably 5 to 30 mu m, from the viewpoint of electrostatic coating property.

The filler (ii) preferably has an average particle diameter of 0.01 to 100 탆, more preferably 0.05 to 50 탆, and further preferably 0.1 to 40 탆, from the viewpoint of electrostatic paintability.

The filler (ii) is 0.01 to 40% by mass based on the total amount of the melt-processible fluorine-containing polymer (c) and the filler (ii). , Preferably 0.05 to 30 mass%, and more preferably 0.1 to 10 mass%. When the amount of the filler (ii) is too large, the corrosion resistance is deteriorated. When the amount of the filler (ii) is too small, sufficient wear resistance is not obtained.

The fluorine-containing layer (C) preferably has a thickness of 1 to 90 mu m. If the film thickness is too thin, the corrosion resistance of the coated article may be deteriorated. If the film thickness is too large, if the coated article is in the presence of water vapor, the water vapor tends to remain in the coated article, and the steam resistance may be lowered. A more preferable lower limit of the film thickness of the fluorine-containing layer (C) is 5 mu m, and a more preferable upper limit is 80 mu m.

In the coated article of the present invention, both of the fluorine-containing layer (B) and the fluorine-containing layer (C) contain a filler and the number of particles thereof is appropriately adjusted, thereby providing excellent abrasion resistance and excellent corrosion resistance.

It is preferable that the film thickness of the primer layer (A) is 5 to 30 占 퐉, the film thickness of the fluorine-containing layer (B) is 1 to 90 占 퐉 and the film thickness of the fluorine- Which is one of the preferred embodiments of the present invention.

The order of lamination of the layers constituting the coated article of the present invention is not particularly limited, but it is preferable that the base material, the primer layer (A), the fluorine-containing layer (B), and the fluorine- desirable. This makes it possible to more effectively combine wear resistance and corrosion resistance.

Usually, the coated article of the present invention does not include another layer between the respective layers of the substrate, the primer layer (A), the fluorine-containing layer (B), and the fluorine-containing layer (C) Another layer may be interposed between the layers of the layer (A) and the fluorine-containing layer (B) or between the layers of the fluorine-containing layer (B) and the fluorine-containing layer (C).

When the substrate, the primer layer (A), the fluorine-containing layer (B), and the fluorine-containing layer (C) are laminated in this order, the coated article of the present invention has the upper surface of the primer layer (A) Alternatively, the upper surface of the fluorine-containing layer (B) may be printed with characters, drawings, and the like.

The coated article of the present invention may also be as long as it has the primer layer (A), the fluorine-containing layer (B) and the fluorine-containing layer (C) , It is preferable that the fluorine-containing layer (C) is the outermost layer. By providing the fluorine-containing layer (C) which greatly contributes to improvement of the abrasion resistance to the outermost layer, which is particularly required to be abrasion-resistant under the use environment, the effect on the abrasion resistance of the present invention can be more remarkably exhibited.

The coated article of the present invention can be obtained by, for example, a step (1) of forming a primer coating film (Ap) by applying a primer coating composition (i) on a substrate, a step (1) of forming a primer coating film A step (2) of forming a coating film (Bp) by applying a powder coating material (I) containing particles of the filler (i) and the particles of the polymer (b) a step (3) of forming a coating film (Cp) by applying a powder coating material (II) comprising particles of the coating material (c) and the particles of the filling material (ii) (A), a fluorine-containing layer (B) and a fluorine-containing layer (C) by firing a coating film laminate including a fluorine-containing layer (C) And the like.

The number of particles of the filler (i) in the powder coating (I) is 0.0001 to 30.0 per 100 particles of the melt-processible fluoropolymer (b), and the amount of the filler (ii) in the powder coating (II) Is 0.0001 to 30.0 with respect to 100 particles of the melt-processible fluorine-containing polymer (c).

The above step (1) is a step of forming a primer coating film (Ap) by applying a coating composition (i) for a primer onto a substrate.

In the step (1), the coating composition (i) for a primer preferably contains a fluorine-containing polymer (a) and a heat-resistant resin. The fluorine-containing polymer (a) and the heat-resistant resin are as described above. The coating composition (i) for a primer may be a liquid or a powder. The coating composition (i) for a primer includes a liquid medium together with the fluorine-containing polymer (a) and the heat-resistant resin when it is a liquid. The liquid medium usually includes water and / or an organic liquid. In the present specification, the term "organic liquid" means an organic compound, which means liquid at room temperature of about 20 ° C.

When the liquid medium of the coating composition (i) for primer mainly comprises an organic liquid, the heat-resistant resin and the fluorine-containing polymer (a) are dispersed as particles in the liquid medium and / It is dissolved in the medium. As the organic liquid, conventionally known organic solvents and the like may be used, or they may be used alone, or two or more kinds may be used in combination.

When the liquid medium of the coating composition (i) for primer mainly comprises water, the heat-resistant resin is dispersed as particles in the liquid medium, and the fluorine-containing polymer (a) Distributed.

When the liquid medium mainly contains water, the coating composition (i) for primer usually contains a surfactant for the purpose of dispersing and stabilizing particles containing the fluorine-containing polymer (a) will be. As the surfactant, conventionally known surfactants may be used. In the coating composition (i) for primer, the organic liquid may be used in combination with the surfactant for the purpose of dispersing and stabilizing particles containing the fluorine-containing polymer (a).

The primer coating composition (i) may also be an organosol obtained by the method described in Japanese Patent Publication No. 49-17017.

The coating composition (i) for a primer is preferably liquid in that it is excellent in adhesion with a base material, and in view of environmental problems, it is more preferable that the liquid medium mainly consists of water.

The above-mentioned coating composition (i) for a primer, together with the above-mentioned fluorine-containing polymer (a) and a heat-resistant resin, is further added with the aim of further improving the coating workability and the corrosion resistance and water vapor resistance of the obtained coated article May be included.

The primer coating composition (i) may further contain the above-mentioned other resin together with the fluorine-containing polymer (a) and the heat-resistant resin from the viewpoint of further improving the corrosion resistance and water vapor resistance of the coated article do.

The method for applying the coating composition (i) for a primer to the substrate is not particularly limited, and the coating composition (i) for a primer may be applied by spray coating, roll coating, doctor blade coating, Immersion coating), impregnation coating, spin flow coating, curtain flow coating and the like, among which spray painting is preferable. When the coating composition (i) for a primer is a powder, electrostatic coating, flow-dipping, lot lining and the like can be mentioned. Among them, electrostatic coating is preferable.

After the application of the coating composition (i) for primer in the above step (1), firing may be performed before or after the step (2), and firing may not be performed. When the coating composition (i) for a primer is in the form of a liquid, it may be dried after the application, or may not be dried.

In the step (1), the drying is preferably performed at a temperature of 70 to 300 캜 for 5 to 60 minutes. The firing is preferably performed at a temperature of 260 to 410 DEG C for 10 to 30 minutes.

When the coating composition (i) for a primer is in the form of a liquid, it is preferable that the primer coating composition (i) is applied on a substrate and then dried in the step (1). Further, in order to carry out the firing of the coating film laminate in the step (4) to be described later, it is preferable that firing is not performed.

In the case where the coating composition (i) for a primer is a powder, it is preferable that the primer coating composition (i) is applied on a substrate and then fired in the step (1).

The primer coating film is formed by applying the coating composition (i) for a primer onto a substrate, and then drying or baking if necessary. The primer coating film becomes a primer layer in the obtained coated article.

The step (2) is a step of coating the coating film (Bp) on the primer coating film (Ap) by applying the powder of the melt-processible fluoropolymer (b) and the powder coating material (I) .

The powder coating (I) includes particles of the melt-processible fluoropolymer (b) and particles of the filler (i). Unlike liquid coating materials such as water-based paints, a powder coating material does not require a drying step, and it is easy to obtain a thick coating film with a small number of coatings, and excellent abrasion resistance is also excellent.

The number of particles of the filler (i) is 0.0001 to 30.0 per 100 particles of the melt-processible fluorine-containing polymer (b).

The lower limit is preferably 0.0005, more preferably lower limit is 0.001, still more preferably lower limit is 0.005, still more preferably lower limit is 0.01, particularly preferably lower limit is 0.1, and the most preferable lower limit is one. The preferred upper limit is 28, the more preferable upper limit is 25, the more preferable upper limit is 20, and the particularly preferable upper limit is 15.

The average particle diameter of the particles of the melt-processible fluorine-containing polymer (b) is preferably from 1 to 50 μm, more preferably from 3 to 40 μm, still more preferably from 5 to 30 μm from the viewpoint of electrostatic coating Do.

The average particle diameter of the filler (i) is preferably 0.01 to 100 占 퐉, more preferably 0.05 to 50 占 퐉, and still more preferably 0.1 to 40 占 퐉, from the viewpoint of electrostatic paintability.

The filler (i) is preferably at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluoride diamond, mica, glass flake, zirconium oxide, aluminum nitride and boron nitride, More preferably at least one member selected from the group consisting of silicon, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond, mica and glass flake, and more preferably at least one member selected from the group consisting of silicon carbide, alumina and diamond desirable. When the powder coating material (I) contains such a filler, the abrasion resistance and corrosion resistance of the coated article are further improved. The powder coating material (I) may be at least one selected from the group consisting of wood powder, quartz, carbon black, clay, talc, corundum, zircon, tourmaline, jade, germanium, silica, chrysopheryl, beryl, garnet, garnet zirconium, Tungsten carbide, extender pigments, light bright flat pigments, scaly pigments, glass, various reinforcements, various extenders, conductive fillers, and the like.

The powder coating material (I) may further contain a small amount of PTFE (TFE homopolymer, modified PTFE) together with the melt-processible fluorine-containing polymer (b) for the purpose of refining spherical crystals. In this case, the content of PTFE is preferably 0.01 to 10.0 mass% with respect to PFA.

The method of applying the powder coating material (I) on the primer coating film is not particularly limited, and examples thereof include electrostatic coating, flow-dipping, lot lining and the like, among which electrostatic painting is preferable.

In the step (2), the powder coating material (I) may be coated on the substrate and then fired. The firing in the step (2) is preferably carried out under the same conditions as the firing in the step (1).

Generally, it is preferable that the powder coating material (I) is not applied to the primer coating film and then fired. This is because all the coating films can be simultaneously fired when the coating film laminate is fired in the step (4) to be described later.

The coating film (Bp) is formed by applying the powder coating material (I) on the primer coating film, and then baking if necessary. The coating film (Bp) is a fluorine-containing layer (B) in the obtained coated article.

In the step (3), the coating film (Cp) is formed by applying the powdery coating material (II) containing particles of the melt-processable fluorine-containing polymer (c) and particles of the filler (ii) onto the coating film Process.

The powder coating material (II) in the step (3) includes particles of the melt-processable fluoropolymer (c) and particles of the filler (ii). Unlike liquid coating materials such as water-based paints, a powder coating material does not require a drying step, and it is easy to obtain a thick coating film with a small number of coatings, and excellent abrasion resistance is also excellent.

The number of particles of the filler (ii) is 0.0001 to 30.0 per 100 particles of the melt-processible fluorine-containing polymer (c).

The lower limit is preferably 0.0005, more preferably lower limit is 0.001, and still more preferably 0.005. In addition, the preferred upper limit is 28, the more preferable upper limit is 25, the more preferable upper limit is 20, and the more preferable upper limit is 15.

The average particle diameter of the particles of the melt-processible fluorine-containing polymer (c) is preferably from 1 to 50 μm, more preferably from 3 to 40 μm, still more preferably from 5 to 30 μm from the viewpoint of electrostatic coating Do.

The filler (ii) preferably has an average particle diameter of 0.01 to 100 탆, more preferably 0.05 to 50 탆, further preferably 0.1 to 40 탆.

The filler (ii) is preferably at least one member selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluoride diamond, mica and glass flake, and is preferably selected from the group consisting of silicon carbide, alumina and diamond More preferably at least one selected. When the powder coating material (II) contains such a filler, the abrasion resistance and corrosion resistance of the coated article are further improved.

The filler (i) and the filler (ii) may be the same or different, but the filler (i) and the filler (ii) are preferably of different kinds from the standpoint of designing the coating film.

The powder coating material (II) may contain other fillers for the purpose of imparting properties, improving physical properties, and increasing the properties of the resulting coated article. Examples of the properties and physical properties include strength, durability, weather resistance, flame retardancy, designability and the like. Examples of the filler include those described above.

The powder coating material (II) may further contain a small amount of PTFE (TFE homopolymer, modified PTFE) together with the melt-processible fluorine-containing polymer (c) for the purpose of miniaturizing the glass. In this case, the content of PTFE is preferably 0.01 to 10.0 mass% with respect to PFA.

It is preferable that the powder coating material (II) does not contain a coloring pigment. The colored pigment is generally considered to cause deterioration of the corrosion resistance. Therefore, if the powder coating material (II) does not contain a coloring pigment, the resulting coated article has better corrosion resistance and water vapor resistance.

The method of applying the powder coating material (II) on the coating film (Bp) is not particularly limited and, for example, electrostatic painting is preferable.

The coating film (Cp) may be formed by baking as required after the application. The firing in the step (3) is preferably performed under the same conditions as the firing in the step (1). The coating film (Cp) becomes the fluorine-containing layer (C) in the obtained coated article.

The step (4) is a step of firing the coating film laminate including the primer coating film Ap, the coating film Bp and the coating film Cp to form a base material, a primer layer A, a fluorine- And a fluorine-containing layer (C).

The firing in the step (4) is preferably performed under the same conditions as the firing in the above-mentioned steps (1) to (3).

The manufacturing method has a step of printing characters, drawings, and the like after the step (1) of forming the primer coating film (Ap) or after the step (2) of forming the coating film (Bp) . The characters, drawings, and the like are, for example, letters and lines indicating the amount of water when the coated article is a cooking pot.

The printing method is not particularly limited, and for example, pad transfer printing may be used. The printing ink used for the printing is not particularly limited, and for example, a composition containing a PES and a TFE homopolymer and titanium oxide can be mentioned.

≪ Method of Forming Corrosion-resistant Coating Film &

The method for forming a corrosion-resistant coating film of the present invention comprises mixing particles of a melt-processible fluorine-containing polymer and particles of a filler so that the number of particles of the filler is from 0.0001 to 30.0 to 100 particles of the melt-processible fluorine-containing polymer to prepare a powder coating material The process,

And a step of coating the powder coating material on the primer layer formed on the substrate by electrostatic coating to form the corrosion-resistant coating film R1.

By this method, a coating film excellent in wear resistance and excellent in corrosion resistance can be formed, and furthermore, a corrosion-resistant coating film can be easily formed by electrostatic coating. Further, the method for forming a corrosion-resistant coating film of the present invention is suitably used for manufacturing the coated article of the present invention described above.

The primer layer is obtained, for example, by applying a coating composition for a primer onto a substrate (film forming step (1)). The coating composition for a primer preferably contains a fluorine-containing polymer (a) and a heat-resistant resin. The fluorine-containing polymer (a) and the heat-resistant resin are as described above. The coating composition for a primer may be a liquid or a powder. The coating composition for a primer includes a liquid medium together with the fluorine-containing polymer (a) and the heat-resistant resin when it is in a liquid state. The liquid medium usually includes water and / or an organic liquid. In the present specification, the term "organic liquid" means an organic compound, which means liquid at room temperature of about 20 ° C.

When the liquid medium of the coating composition for primer mainly contains an organic liquid, the heat-resistant resin and the fluorine-containing polymer (a) are preferably dispersed as particles in the liquid medium and / or dissolved in the liquid medium . As the organic liquid, conventionally known organic solvents and the like may be used, or they may be used alone, or two or more kinds may be used in combination.

When the liquid medium of the coating composition for primer is mainly composed of water, the heat-resistant resin is dispersed as particles in the liquid medium, and the fluorine-containing polymer (a) is dispersed as particles in the liquid medium.

When the liquid medium is mainly composed of water, the coating composition for a primer usually comprises a surfactant added for the purpose of dispersing and stabilizing particles containing the fluorine-containing polymer (a). As the surfactant, conventionally known surfactants may be used. In the coating composition for a primer, the organic liquid may be used in combination with the surfactant for the purpose of dispersing and stabilizing particles containing the fluorine-containing polymer (a).

The coating composition for a primer may also be an organosol obtained by the method described in Japanese Patent Publication No. 49-17017.

The coating composition for a primer is preferably in a liquid state because of its excellent adhesion with a substrate, and in view of environmental problems, it is more preferable that the liquid medium is mainly composed of water.

The above-mentioned coating composition for a primer further includes the above-mentioned additives for the purpose of further improving the coating workability and the corrosion resistance and the water vapor resistance of the obtained corrosion-resistant coating film together with the fluoropolymer (a) and the heat- It is acceptable.

The coating composition for a primer may further comprise the above-mentioned other resin together with the fluorine-containing polymer (a) and the heat-resistant resin from the viewpoint of further improving the corrosion resistance and water vapor resistance of the corrosion-resistant coating film.

The method for applying the coating composition for primer to the substrate is not particularly limited and, for example, spray coating, roll coating, doctor blade coating, dip (immersion) coating, , Spin flow coating, curtain flow coating, and the like. Of these, spray coating is preferable. When the coating composition for a primer is a powder, electrostatic coating, flow-dipping, lot lining and the like can be mentioned. Among them, electrostatic painting is preferable.

After the application of the coating composition for a primer in the film forming step (1), firing may be performed before the film forming step (2) described later, and firing may not be performed. Further, when the coating composition for a primer is in a liquid form, it may be subjected to further drying after the application, or may not be dried.

In the film forming step (1), the drying is preferably carried out at a temperature of 70 to 300 캜 for 5 to 60 minutes. The firing is preferably performed at a temperature of 260 to 410 DEG C for 10 to 30 minutes.

When the coating composition for a primer is in the form of a liquid, it is preferable that the coating is carried out after the coating is carried out on the substrate in the film forming step (1).

When the coating composition for a primer is a powder, it is preferable that in the film forming step (1), it is applied to a substrate and then fired. However, as will be described later, in the case where the entire coating film is fired, the firing at this point is not necessary.

The primer layer is formed by applying the coating composition for a primer onto a substrate and then drying or baking if necessary. The primer coating film becomes a primer layer in the obtained corrosion-resistant coating film.

The method for forming a corrosion-resistant coating film of the present invention is a process for preparing a powder coating material suitable for forming a coating film on a primer layer formed on such a substrate by electrostatic coating, wherein particles of the melt- , And mixing the fluorine-containing polymer with 100 parts of the melt-processible fluorine-containing polymer so that the number of particles of the filler is 0.0001 to 30.0. Then, the powder coating material is applied to the primer layer formed on the base material by electrostatic painting as described above to form the corrosion-resistant coating film R1 (film forming step (2)). Further, if necessary, the powder coating material is applied on the corrosion-resistant coating R1 by electrostatic painting to form a corrosion-resistant coating R2 (film-forming step (3)).

By using a powder coating material, a drying process is unnecessary differently from a liquid coating material such as a water-based coating material, and it is easy to obtain a thick coating film with a small number of coatings and excellent abrasion resistance. However, when the powder coating material is electrostatically coated, the powder coating material of the fluorine-containing polymer including the filler is not necessarily high in fluidity, and electrostatic coating is not easy. However, according to the study by the present inventors, when the number of particles of the filler with respect to the number of particles of the melt-processible fluorine-containing polymer satisfies a specific range as described above, it becomes possible to form a homogeneous coating film, It is possible to obtain an excellent corrosion-resistant film.

In the step of preparing the powder coating material, the particles of the melt-processible fluoropolymer and the particles of the filler are mixed so that the number of particles of the filler is 0.0001 to 30.0 with respect to 100 particles of the melt-processible fluoropolymer.

The lower limit is preferably 0.0005, more preferably lower limit is 0.001, and still more preferably 0.005. The preferred upper limit is 28, the more preferable upper limit is 25, and the more preferable upper limit is 20.

As the powder coating material for forming the corrosion-resistant coating film (R1), a powder coating material (I) containing the filler (i) is suitably used. As the powder coating material for forming the corrosion-resistant coating film (R2), a powder coating material (II) containing the filler (ii) is suitably used.

The process (film forming process (2)) for forming the corrosion-resistant film R1 and the process (film forming process (3)) for forming the corrosion-resistant film R2 will be described in detail below.

In the film forming step (2), the powder coating material is applied to the primer layer by electrostatic coating to form a corrosion-resistant coating film (R1).

The average particle diameter of the melt-processible fluorine-containing polymer particles contained in the powder coating material used in the film forming step (2) is preferably 1 to 50 占 퐉, more preferably 3 to 40 占 퐉, More preferably 5 to 30 mu m.

The filler contained in the powder coating material used in the film forming step (2) preferably has an average particle diameter of 0.01 to 100 mu m, more preferably 0.05 to 50 mu m, and more preferably 0.1 to 40 mu m Is more preferable.

The filler contained in the powder coating material used in the film forming step (2) is at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond, mica and glass flake, zirconium oxide, aluminum nitride and boron nitride And at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond, mica and glass flake is more preferable, and silicon carbide, alumina and diamond More preferably at least one kind selected from the group consisting of When the powder coating material contains the filler, the wear resistance and corrosion resistance of the corrosion-resistant coating film are further improved.

The powder coating material to be used in the film forming step (2) may be at least one selected from the group consisting of wood powder, quartz, carbon black, clay, talc, corundum, silica, tourmaline, jade, germanium, silica powder, chrysoberyl, beryl, garnet, Tantalum carbide, titanium carbide, tungsten carbide, extender pigments, bright colored flat pigments, scaly pigments, glass, various reinforcements, various extenders, conductive fillers, and the like.

The powder coating material used in the film forming step (2) may also contain a small amount of PTFE (TFE homopolymer, modified PTFE) together with the melt-processible fluorine-containing polymer for the purpose of miniaturizing the glass. In this case, the content of PTFE is preferably 0.01 to 10.0 mass% with respect to PFA.

In the film forming step (2), the powder coating material may be coated on the primer layer, followed by firing. The firing in the film forming step (2) is preferably performed under the same conditions as the firing in the film forming step (1).

However, as will be described later, when the entire coating film is fired, all the coating films can be fired at the same time, so that firing is not required at the time of coating the powder coating material on the primer layer. The obtained coating film becomes the corrosion-resistant coating film R1.

In the method of forming a corrosion-resistant coating film of the present invention, it is preferable to further include a film-forming step (3) after the film-forming step (2). The film forming step (3) is a step of applying the powder coating material to the corrosion-resistant coating film R1 by electrostatic coating to form the corrosion-resistant coating film R2.

The average particle diameter of the particles of the melt-processible fluorine-containing polymer contained in the powder coating material used in the film forming step (3) is preferably 1 to 50 탆, more preferably 3 to 40 탆, , And more preferably from 5 to 30 mu m.

The filler contained in the powder coating material used in the film forming step (3) preferably has an average particle diameter of 0.01 to 100 mu m, more preferably 0.05 to 50 mu m, and more preferably 0.1 to 40 mu m Is more preferable.

The filler contained in the powder coating material used in the film forming step (3) is at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond, mica and glass flake, zirconium oxide, aluminum nitride and boron nitride And at least one selected from the group consisting of silicon carbide, alumina and diamond is more preferable. When the powder coating material contains the filler, the wear resistance and corrosion resistance of the corrosion-resistant coating film are further improved.

The powder coating material to be used in the film forming step (3) may contain other fillers for the purpose of imparting properties to the resulting corrosion-resistant coating film, improving physical properties, increasing the amount, and the like. Examples of the properties and physical properties include strength, durability, weather resistance, flame retardancy, designability and the like.

Examples of the filler include fillers such as wood powder, quartz, carbon black, clay, talc, corundum, zirconium, boron nitride, fused alumina, tourmaline, jade, germanium, silica, chrysoveryl, beryl, garnet, garnet, zirconium, Titanium carbide, tungsten carbide, extender pigments, light-colored flat pigments, scaly pigments, glass, metal powders, various reinforcements, various extenders, and conductive fillers. When the formed corrosion-resistant coating film is required to have a brightness feeling, a light-weight filler is preferable. The " light-permeable filler " is a filler capable of imparting luminosity to the obtained corrosion-resistant coating film.

The powder coating material used in the film forming step (3) may also contain a small amount of PTFE (TFE homopolymer, modified PTFE) together with the melt-processible fluorine-containing polymer for the purpose of miniaturizing the glass. In this case, the content of PTFE is preferably 0.01 to 10.0 mass% with respect to PFA.

It is preferable that the powder coating material used in the film forming step (3) does not contain a coloring pigment. Since the color pigment may cause deterioration of the corrosion resistance, the above-mentioned powder coating material does not contain the color pigment, so that the obtained corrosion-resistant coating film has better corrosion resistance and water vapor resistance.

In the film forming step (3), the powder coating material may be coated on the corrosion-resistant coating film (R1), followed by firing. The firing in the film forming step (3) is preferably performed under the same conditions as the firing in the film forming step (1) or (2). The obtained coating film becomes a corrosion-resistant coating film R2.

After the film forming steps (1) to (3), the entire coating film may be baked. That is, the method for forming a corrosion-resistant coating film of the present invention is characterized in that after the film forming step (1) for forming the corrosion-resistant coating film (R1) or after the step (2) for forming the corrosion- May be further included. The firing step is preferably performed under the same conditions as the firing in the film forming steps (1) to (3).

The forming method may be such that after the film forming step (1) for forming the corrosion-resistant coating film (R1), the film forming step (2) for forming the corrosion-resistant coating film (R2) May be used. The letters, drawings and the like are, for example, letters and lines indicating the amount of water when the corrosion-resistant coating is applied to the cooking kiln.

The printing method is not particularly limited, and for example, pad transfer printing may be used. The printing ink used for the printing is not particularly limited, and for example, a composition containing a PES and a TFE homopolymer and titanium oxide can be mentioned.

The coated article of the present invention or the corrosion-resistant film formed by the method of forming the corrosion-resistant film of the present invention can be used for the purpose of using the non-tackiness, heat resistance, slipperiness, etc. of the fluorine- A cooking pot such as a frying pan, a pressure pot, a pot, a grill pan, a cooking oven, an oven, a hot plate, a baking frame, a kitchen knife, and a gas range; Kitchen utensils such as electric pots, ice-making trays, molds, and range hoods; Parts for the food industry such as mill rolls, rolling rolls, conveyors and hoppers; Industrial goods such as office automation (OA) rolls, OA belts, OA separation claws, papermaking rolls, and calender rolls for film production; Molds such as molds for molding foamed plastic, molds for forming molds such as molds for producing plywoods and lacquers, industrial containers (especially for semiconductor industries), and the like. Household appliances such as irons, scissors, kitchen knives; Sliding parts such as metal foil, electric wire, food processing machine, packing machine, textile machine, slide parts of cameras and watches, automobile parts such as pipes, valves and bearings, snow shovels, plows and chutes.

Among them, it can be suitably used for cooking utensils and kitchen utensils, and can be suitably used particularly in a cooking oven.

[Example]

Hereinafter, 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. % &Quot; and " part " represent mass% and mass part, respectively.

Production Example 1 Preparation of aqueous dispersion of polyethersulfone resin

60 parts of a polyethersulfone resin [PES] having a number average molecular weight of about 24,000 and 60 parts of deionized water were stirred in a ceramic ball mill until particles containing PES were completely pulverized. Subsequently, 180 parts of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) was added to obtain a PES aqueous dispersion having a PES concentration of about 20%. The average particle diameter of the PES-containing particles in the PES aqueous dispersion was 2 탆.

Preparation Example 2 Preparation of aqueous dispersion of polyamideimide resin

A polyamide-imide resin [PAI] varnish (containing 71% of NMP) having a solid content of 29% was added to water and pulverized in a ball mill to obtain a PAI aqueous dispersion. The solid content of the obtained PAI aqueous dispersion was 20%, and the average particle diameter of PAI in the PAI aqueous dispersion was 2 占 퐉.

Preparation Example 3 Preparation of coating composition (i) for primer

The PES aqueous dispersion obtained in Production Example 1 and the PAI aqueous dispersion obtained in Production Example 2 were mixed so that the PES was 75% of the total amount of solids of PES and PAI, and tetrafluoroethylene homopolymer [TFE homopolymer] Aqueous dispersion (having an average particle diameter of 0.28 탆, a solid content of 60% and a polyether-based nonionic surfactant (polyoxyethylene tridecyl ether) as a dispersing agent in an amount of 6% based on the TFE homopolymer) , PAI and TFE homopolymer, and methyl cellulose as a thickening agent was added in an amount of 0.7% based on the solid content of the TFE homopolymer to prepare a nonionic surfactant (polyoxyethylene nonylphenyl ether) as a dispersion stabilizer. 6% of the solid content of the TFE homopolymer was added to obtain an aqueous dispersion having a solid content of 34% of the TFE homopolymer.

Example 1

After the surface of the aluminum plate (A-1050P) was degreased with acetone, the surface was roughened by sandblasting so that the surface roughness Ra value measured in accordance with JIS B 1982 was 2.0 to 3.0 占 퐉. After the dust on the surface was removed by air blow, the coating composition (i) for primer obtained in Production Example 3 was spray-coated at a spraying pressure of 0.2 MPa using a gravity type spray gun so as to have a dry film thickness of 10 mu m. The obtained coating film on the aluminum plate was dried at 80 to 100 캜 for 15 minutes and cooled to room temperature. Powder coating material containing PFA (trade name: ACX-21, manufactured by Daikin Industries, Ltd., average particle diameter 23 μm) and silicon carbide (average particle diameter 15 μm, 2% of the total amount of PFA and silicon carbide) as a filler was coated on the obtained primer coating film Was subjected to electrostatic painting under the conditions of an applied voltage of 50 KV and a pressure of 0.08 MPa so that the film thickness after firing was 40 m. The PFA and the diamond (average particle size of 18 mu m, 1% of the total amount of PFA and diamond) as the filler were electrostatically coated and applied with a thickness of 5 mu m after firing under the conditions of an applied voltage of 50 KV and a pressure of 0.08 MPa. The obtained coated plate was fired at 380 占 폚 for 20 minutes to obtain a test plate for testing. The resultant coating film for test was formed with a primer layer, a middle layer and an upper layer on an aluminum plate.

(Assessment Methods)

The coating film of the obtained coating film for test was subjected to the following evaluation.

(Calculation of ratio of number of particles (number ratio)) [

The number of particles was calculated by the following equation.

w = d x 4/3 x (circle diameter) x ((average particle diameter) / 2) ³

w: weight of particle 1

d: Specific gravity of fluorine-containing resin or filler

The ratio (number ratio) X of the number of particles was calculated by the following equation, where w1 is the weight of one particle of the fluorine-containing resin, w2 is the weight of one particle of the filler, and F is weight% .

X = (F / w2) / ((100-F) / w1) x100

(Measurement of angle of repose and evaluation of paintability)

In order to examine the fluidity of the powder coating, the angle of repose was measured by the following method. 100 g of the powder coating material was dropped from the funnel (the upper portion was 8 cm in diameter and the lower outlet was 1 cm in diameter), and the angle of repose of the powder coating material deposited at the lower portion was measured by a separator. The better the fluidity of the powder coating material, the smaller the angle of repose of the deposited powder coating material and the better the paintability.

When the angle of repose was 43 ° or less, the paintability was good (O).

When the angle of repose was 44 ° or more, the paintability was evaluated as poor (X). This indicates that the flow rate of the powder coating material is unstable.

(Amount of wear)

The abrasion resistance of the obtained test coat was measured by using a rotary abrasion tester manufactured by Toyo Seiki Seisakusho Co., Ltd. under the conditions of a load of 1 kg and a load of 500 revolutions of the abrasive wheel CS-10.

(Corrosion resistance)

Two test pieces (50 mm x 100 mm, thickness 2.5 mm) were coated on the surface of the coating film so that scratches reaching the base material having a length of 50 mm were crossed with a cutter knife (cross cut). This test plate was immersed in a solution prepared by dissolving 20 g of Odenumoto (manufactured by S & B Shocquihin Co., Ltd.) in 1 liter of water, kept at 70 DEG C, and after 500 hours, abnormalities such as occurrence of blister .

○: No blistering at all

?: Blisters of less than 3 mm were generated in the crosscut portion (no abnormality other than the crosscut portion)

X: Blister occurred on the entire surface

Examples 2 to 7

As a powder coating material in the intermediate process, test plates for Examples 2 to 7 were obtained in the same manner as in Example 1 except that a powder coating material containing the filler shown in Table 1 in the amount shown in Table 1 was used instead of silicon carbide. Evaluation of the physical properties of the coating film was carried out in the same manner as in Example 1, with respect to the obtained test coating plate.

Comparative Examples 1 to 3

Powder coating materials containing the fillers shown in Table 2 in the amounts shown in Table 2 were used as the powder coating materials in the intermediate process and powders containing the fillers shown in Table 2 as the powder coating materials in the topcoating step in the amounts shown in Table 2 The coating plates for test of Comparative Examples 1 to 3 were obtained in the same manner as in Example 1 except that the paints were used. Evaluation of the physical properties of the coating film was carried out in the same manner as in Example 1, with respect to the obtained test coating plate.

Comparative Example 4

Except that the filler was not added as the powder coating material in the intermediate step and the powder coating material containing the filler shown in Table 2 in the amount shown in Table 2 was used as the powder coating material in the top coat step, ≪ / RTI > Evaluation of the physical properties of the coating film was carried out in the same manner as in Example 1, with respect to the obtained test coating plate.

The evaluation results of the test plates for use in Examples 1 to 7 are shown in Table 1, and the test results for the test plates for use in Comparative Examples 1 to 4 are shown in Table 2.

Since the coated article of the present invention has the above-described constitution, it is excellent in both abrasion resistance and corrosion resistance and can be suitably used particularly for coated articles such as cooking utensils and kitchen utensils.

Claims (15)

materials,
A primer layer (A) comprising a fluorine-containing polymer (a) and a heat-resistant resin,
A fluorine-containing layer (B) formed from the powder coating (I)
Containing layer (C) formed from the powder coating (II), wherein the fluorinated layer
The powder coating material (I) contains particles of the melt-processible fluoropolymer (b) and particles of the filler (i), and the particles of the melt-processible fluoropolymer (b) have an average particle diameter of 5 to 30 탆, The particles of the filler (i) have an average particle diameter of 0.1 to 40 탆, the number of particles of the filler (i) is 1 to 15 for 100 particles of the melt-processible fluorine-containing polymer (b) At least one member selected from the group consisting of silicon, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond and glass flake,
The powder coating material (II) comprises particles of the melt-processable fluoropolymer (c) and particles of the filler (ii), wherein the particles of the melt-processible fluoropolymer (c) have an average particle diameter of 5 to 30 탆, The particles of the filler (ii) have an average particle diameter of 0.1 to 40 탆, the number of particles of the filler (ii) is 0.005 to 15 per 100 particles of the melt-processible fluorine-containing polymer (c)
The filler (i) and the filler (ii)
≪ / RTI > delete The method according to claim 1,
Wherein the filler (ii) is at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond, mica and glass flake. delete The method according to claim 1,
The melt-processable fluorine-containing polymer (b) is at least one selected from the group consisting of a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer and a tetrafluoroethylene / hexafluoropropylene copolymer. delete The method according to claim 1,
The melt-processable fluorine-containing polymer (c) is at least one selected from the group consisting of a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer and a tetrafluoroethylene / hexafluoropropylene copolymer. delete The method according to claim 1,
The fluorine-containing polymer (a) may be at least one selected from the group consisting of a tetrafluoroethylene homopolymer, a modified polytetrafluoroethylene, a tetrafluoroethylene / hexafluoropropylene copolymer, and a tetrafluoroethylene / perfluoro (alkyl vinyl ether) And at least one member selected from the group consisting of The method according to claim 1,
The heat resistant resin is at least one selected from the group consisting of a polyamideimide resin, a polyimide resin, a polyether sulfone resin, a polyether imide resin, a polyether ether ketone resin, an aromatic polyester resin and a polyarylene sulfide resin. article. The method according to claim 1,
The heat-resistant resin may be one or both of a polyethersulfone resin, a polyamideimide resin and a polyimide resin, and the polyethersulfone resin may be a polyether sulfone resin, a polyamideimide resin and a polyimide resin in a total amount of 65 to 85% by mass. The method according to claim 1,
Wherein the heat resistant resin is 15 to 50% by mass of the sum of the solid content of the heat resistant resin and the fluorine-containing polymer (a). The method according to claim 1,
The primer layer (A) has a film thickness of 5 to 30 mu m,
The fluorine-containing layer (B) has a film thickness of 1 to 90 탆,
The fluorine-containing layer (C) has a thickness of 1 to 90 탆. The particles of the melt-processible fluorine-containing polymer (b) and the particles of the filler (i) were mixed so that the number of particles of the filler (i) was 1 to 15 per 100 particles of the melt-processible fluorine-containing polymer (b) I)
A step of coating the powder coating material (I) on the primer layer formed on the substrate by electrostatic coating to form the corrosion-resistant coating film (R1)
The particles of the melt-processible fluorine-containing polymer (c) and the particles of the filler (ii) were mixed so that the number of particles of the filler (ii) was 0.005 to 15 per 100 particles of the melt-processible fluorine- II), and
The step of applying the powder coating material (II) on the corrosion-resistant coating film (R1) by electrostatic coating and forming the corrosion-resistant coating film (R2)
/ RTI >
The particles of the melt-processible fluorine-containing polymer (b) have an average particle diameter of 5 to 30 占 퐉, the particles of the filler (i) have an average particle diameter of 0.1 to 40 占 퐉,
The particles of the melt-processible fluorine-containing polymer (c) have an average particle diameter of 5 to 30 占 퐉, the particles of the filler (ii) have an average particle diameter of 0.1 to 40 占 퐉,
The filler (i) is at least one selected from the group consisting of silicon carbide, boron carbide, silicon nitride, alumina, diamond, fluorinated diamond and glass flake,
The filler (i) and the filler (ii)
≪ / RTI > delete