WO2020213270A1 - Coating composition and coated article - Google Patents

Abstract

The present invention provides a coating composition for providing a paint film having excellent corrosion resistance. The coating composition includes a polyethersulfone resin, at least one polyimide-based resin selected from the group consisting of a polyamide-imide resin and a polyimide resin, a non-melt-processible fluorine-containing polymer, and a melt-processible fluorine-containing polymer.

Description

Coating composition and coating article

The present disclosure relates to coating compositions and coating articles.

Fluororesin such as polytetrafluoroethylene, tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer, and tetrafluoroethylene / hexafluoropropylene copolymer have a low friction coefficient, and have non-adhesiveness, heat resistance, etc. Due to its excellent properties, it is widely used for surface processing of food industry products, cooking utensils such as frying pans and pots, kitchen products, household products such as irons, electrical industry products, machinery industry products, and the like.

Patent Document 1 describes a dispersion containing a predetermined ratio of polyether sulfone, polyamide-imide and polytetrafluoroethylene.

Patent Document 2 describes a composition containing a polyether sulfone, a polyamide-imide, and a tetrafluoroethylene / hexafluoropropylene copolymer in a predetermined ratio.

Japanese Unexamined Patent Publication No. 11-349878 Japanese Unexamined Patent Publication No. 6-264000

An object of the present disclosure is to provide a coating composition that provides a coating film having excellent corrosion resistance. It is also an object of the present disclosure to provide a coated article having excellent corrosion resistance.

The present disclosure includes a polyether sulfone resin, at least one polyimide resin selected from the group consisting of a polyamide-imide resin and a polyimide resin, a non-melt processable fluorine-containing polymer, and a melt processable fluorine-containing polymer. With respect to a coating composition comprising.

The mass ratio of the polyether sulfone resin to the polyimide resin is preferably 85/15 to 65/35.

The mass ratio of the total amount of the polyether sulfone resin and the polyimide resin to the total amount of the non-melt processable fluorine-containing polymer and the melt processable fluorine-containing polymer is 15/85 to 35/65. Is preferable.

The mass ratio of the non-melt processable fluorine-containing polymer to the melt processable fluorine-containing polymer is preferably 5/95 to 95/5.

The coating composition preferably further contains water.

The average particle size of the polyether sulfone resin and the polyimide resin is preferably 0.1 to 10 μm.

The non-melt processable fluorine-containing polymer is preferably at least one selected from the group consisting of tetrafluoroethylene homopolymers and modified polytetrafluoroethylene.

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

The coating composition is preferably applied directly onto a substrate made of a metal or non-metal inorganic material or on a layer made of a heat resistant resin.

The coating composition preferably further contains an organic solvent.

The organic solvent is N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, 3-alkoxy-N, N-dimethylpropanamide, γ-butyrolactone, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidi. Non, 3-methyl-2-oxazolidinone, dimethylacetamide, dimethylformamide, N-formylmorpholine, N-acetylmorpholine, dimethylpropyleneurea, anisole, diethyl ether, ethylene glycol, acetophenone, methylethylketone, methylisobutylketone, cyclohexanone, cyclopenta It is preferably at least one selected from the group consisting of non, xylene, toluene, ethanol and 2-propanol.

The present disclosure also relates to a coated article having a substrate, a primer layer (A1) formed from the coating composition, and a fluorine-containing layer (C1) containing a fluorine-containing polymer (a).

The present disclosure discloses a base material, a primer layer (A2) containing a heat-resistant resin (a), an intermediate layer (B1) formed from the coating composition, and a fluorine-containing layer containing a fluorine-containing polymer (a). It also relates to a coated article having (C2).

According to the present disclosure, it is possible to provide a coating composition that gives a coating film having excellent corrosion resistance. According to the present disclosure, it is also possible to provide a coated article having excellent corrosion resistance.

Hereinafter, the present disclosure will be specifically described.
The present disclosure includes a polyether sulfone resin, at least one polyimide resin selected from the group consisting of a polyamide-imide resin and a polyimide resin, a non-melt processable fluorine-containing polymer, and a melt processable fluorine-containing polymer. With respect to a coating composition comprising.
The coating composition of the present disclosure can provide a coating film having excellent corrosion resistance.

The coating composition of the present disclosure comprises a polyether sulfone resin (PES). PES is the following general formula:

It is a resin made of a polymer having a repeating unit represented by. The PES is not particularly limited, and examples thereof include a resin made of a polymer obtained by polycondensation of dichlorodiphenyl sulfone and bisphenol.

The coating composition of the present disclosure further contains at least one polyimide-based resin selected from the group consisting of a polyamide-imide resin (PAI) and a polyimide resin (PI). PAI is preferable as the polyimide resin.

PAI is a resin composed of a polymer having an amide bond and an imide bond in its molecular structure. The PAI is not particularly limited, and for example, a reaction between an aromatic diamine having an amide bond in the molecule and an aromatic tetravalent carboxylic acid such as pyromellitic acid; and an aromatic trivalent carboxylic acid such as trimellitic anhydride. Reaction with diisocyanate such as 4,4-diaminophenyl ether or diisocyanate such as diphenylmethane diisocyanate; Consists of high molecular weight polymer obtained by each reaction such as reaction between dibasic acid having an aromatic imide ring in the molecule and diisium. Examples include resin. From the viewpoint of excellent heat resistance, the PAI is preferably a polymer having an aromatic ring in the main chain.

PI is a resin composed of a polymer having an imide bond in its molecular structure. The PI is not particularly limited, and examples thereof include a resin made of a high molecular weight polymer obtained by a reaction of an aromatic tetravalent carboxylic acid anhydride such as pyromellitic anhydride. From the viewpoint of excellent heat resistance, the PI is preferably composed of a polymer having an aromatic ring in the main chain.

The mass ratio of the PES to the polyimide resin is preferably 85/15 to 65/35 in that a coating film having further excellent corrosion resistance can be obtained. The mass ratio is more preferably 80/20 or less, and more preferably 70/30 or more.

From the viewpoint of dispersion stability in the coating composition and surface smoothness of the obtained coating film, the PES and the polyimide resin preferably have an average particle size of 0.1 to 10 μm. The average particle size is more preferably 0.2 μm or more, more preferably 8 μm or less, and further preferably 5 μm or less.
The average particle size can be measured by a laser light scattering method.

The coating composition of the present disclosure further comprises a non-melt processable fluorinated polymer. "Non-melt processability" means a property that the melt flow rate cannot be measured at a temperature higher than the crystallization melting point in accordance with ASTM D-1238 and D-2116.

The non-melt processable fluorine-containing polymer is preferably non-melt processable polytetrafluoroethylene (PTFE).

The non-meltable PTFE is preferably one having fibrillation property. The fibrillation property refers to a property of easily fibring to form fibrils. The presence or absence of fibrillation can be determined by "paste extrusion", which is a typical method for molding "high molecular weight PTFE powder" which is a powder made from a polymer of TFE. Generally, paste extrusion is possible because high molecular weight PTFE has fibrillation properties. If the unbaked molded product obtained by paste extrusion does not have substantial strength or elongation, for example, if the elongation is 0% and it breaks when pulled, it can be considered that there is no fibrillation property.

The non-melt processable PTFE preferably has a standard specific gravity (SSG) of 2.130 to 2.230. The SSG is more preferably 2.130 to 2.190, and even more preferably 2.140 to 2.170. When the SSG of the non-melt processable PTFE is within the above range, a coating film having further excellent corrosion resistance can be formed. SSG is a value measured in accordance with ASTM D 4895.

The non-meltable PTFE has no history of heating to a temperature of 300 ° C. or higher. The non-meltable PTFE has a heat of fusion curve obtained by a differential scanning calorimeter at a heating rate of 10 ° C./min. It preferably has a peak top (DSC melting point) at 347 ° C. More preferably, it has a peak top at 333 to 345 ° C, and even more preferably, it has a peak top at 340 to 345 ° C. When the peak top (DSC melting point) is within the above range, a coating film having more excellent corrosion resistance can be formed.

More specifically, for example, in the differential scanning calorimetry (DSC), RDC220 (manufactured by SII Nanotechnology), which has been temperature-calibrated using indium and lead as a standard sample in advance, is used as a PTFE powder. 3 mg is placed in an aluminum pan (crimp container), and the temperature range of 250 to 380 ° C. is raised at 10 ° C./min under an air flow of 200 ml / min. The calorific value is calibrated using indium, lead, and tin as standard samples, and the empty aluminum pan is sealed and used as a measurement reference. The obtained heat of fusion curve uses Muse standard analysis software (manufactured by SII Nanotechnology), and the temperature indicating the peak top of the heat of fusion is used as the DSC melting point.

The non-melt processable PTFE is at least one selected from the group consisting of tetrafluoroethylene homopolymer (hereinafter, also referred to as “homo-PTFE”) and modified polytetrafluoroethylene (hereinafter, also referred to as “modified PTFE”). It is preferably a seed.

The modified PTFE is a modified PTFE composed of tetrafluoroethylene (TFE) and a monomer other than TFE (hereinafter, also referred to as “modified monomer”).

The modified monomer is not particularly limited as long as it can be copolymerized with TFE, and is, for example, a perfluoroolefin such as hexafluoropropylene (HFP); a chlorofluoroolefin such as chlorotrifluoroethylene (CTFE); Hydrogen-containing fluoroolefins such as trifluoroethylene and vinylidene fluoride (VDF); perfluorovinyl ethers; perfluoroalkylethylene, ethylene and the like. Further, the modified monomer used may be one kind or a plurality of kinds. There may be.

The perfluorovinyl ether is not particularly limited, and for example, the following general formula (1)
CF ₂ = CF-ORf ¹ (1)
(In the formula, Rf ¹ represents a perfluoroorganic group.) Examples thereof include perfluorounsaturated compounds represented by. In the present specification, the above-mentioned "perfluoroorganic group" means an organic group in which all hydrogen atoms bonded to carbon atoms are replaced with fluorine atoms. The perfluoroorganic group may have ether oxygen.

Examples of the perfluorovinyl ether include perfluoro (alkyl vinyl ether) (PAVE) in which Rf ¹ is a perfluoroalkyl group having 1 to 10 carbon atoms in the above general formula (1). The number of carbon atoms of the perfluoroalkyl group is preferably 1 to 5.

Examples of the perfluoroalkyl group in PAVE include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, and the like. The group is preferably a perfluoropropyl group. That is, the PAVE is preferably perfluoropropyl vinyl ether (PPVE).

Further, as the perfluorovinyl ether, in the above general formula (1), Rf ¹ is a perfluoro (alkoxyalkyl) group having 4 to 9 carbon atoms, and Rf ¹ is the following formula:

(In the formula, m represents 0 or an integer of 1 to 4), and Rf ¹ is the following formula:

(In the formula, n represents an integer of 1 to 4), and the like is a group represented by.

The perfluoroalkylethylene (PFAE) is not particularly limited, and examples thereof include perfluorobutylethylene (PFBE) and perfluorohexylethylene.

The modified monomer in the modified PTFE is preferably at least one selected from the group consisting of HFP, CTFE, VDF, PAVE, PFAE and ethylene. More preferably, it is PAVE, and even more preferably, it is PPVE.

The homo-PTFE is substantially composed of only TFE units, and is preferably obtained without using, for example, a modified monomer.

The modified PTFE has a modified monomer unit of 0.001 to 2 mol%, more preferably 0.001 to 1 mol%.

The content of each monomer unit of the non-melt processable fluorine-containing polymer can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescent X-ray analysis depending on the type of monomer.

The coating composition of the present disclosure further comprises a melt processable fluorinated polymer. The above-mentioned "melt processability" means that it is possible to melt and process a polymer by using conventional processing equipment such as an extruder and an injection molding machine. Therefore, the melt-processable fluorine-containing polymer usually has a melt flow rate (MFR) of 0.01 to 100 g / 10 minutes.

In the present specification, the above MFR uses a melt indexer (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) in accordance with ASTM D 1238, and the measurement temperature determined by the type of fluoropolymer (for example, 372 in the case of PFA or FEP). As the mass (g / 10 minutes) of the polymer flowing out from a nozzle having an inner diameter of 2 mm and a length of 8 mm under a load (for example, 5 kg for PFA, FEP and ETFE) at ° C. (297 ° C. for ETFE). This is the value obtained.

The melt-processable fluorine-containing polymer preferably has a melting point of 100 to 333 ° C., more preferably 140 ° C. or higher, further preferably 160 ° C. or higher, and particularly preferably 180 ° C. or higher. preferable. Further, it is more preferably 332 ° C or lower, further preferably less than 322 ° C, and particularly preferably 320 ° C or lower.

In the present specification, the melting point of the melt-processable fluorine-containing polymer is a temperature corresponding to the maximum value in the heat of fusion curve when the temperature is raised at a rate of 10 ° C./min using a differential scanning calorimeter [DSC]. is there.

Examples of the melt-processable fluoropolymer include low molecular weight PTFE, TFE / PAVE copolymer (PFA), TFE / HFP copolymer (FEP), ethylene (Et) / TFE copolymer (ETFE), Et /. At least one selected from the group consisting of TFE / HFP copolymers, polychlorotrifluoroethylene (PCTFE), CTFE / TFE copolymers, Et / CTFE copolymers and polyvinylidene fluoride (PVDF) can be mentioned.
The melt-processable fluorine-containing polymer is preferably at least one selected from the group consisting of FEP and PFA, and more preferably FEP, in that a coating film having further excellent corrosion resistance can be obtained.

The FEP is not particularly limited, but a copolymer having a molar ratio of TFE units to HFP units (TFE unit / HFP unit) of 70/30 or more and less than 99/1 is preferable. A more preferable molar ratio is 70/30 or more and 98.9 / 1.1 or less, and a more preferable molar ratio is 80/20 or more and 98.9 / 1.1 or less. If the TFE unit is too small, the mechanical properties tend to deteriorate, and if it is too large, the melting point tends to be too high and the moldability tends to decrease. In the above FEP, the monomer unit derived from the monomer copolymerizable with TFE and HFP is 0.1 to 10 mol%, and the total amount of TFE unit and HFP unit is 90 to 99.9 mol%. It is also preferable that it is a copolymer. The TFE and HFP monomers copolymerizable _with, PAVE, (wherein, Rf ² represents. A perfluoroalkyl group having 1 to 5 carbon _{atoms) CF 2 = CF-OCH 2} -Rf 2 is represented by Alkyl perfluorovinyl ether derivatives and the like can be mentioned.

The FEP preferably has a melting point of less than 150 to 322 ° C, more preferably 200 to 320 ° C, and even more preferably 240 to 320 ° C.

The FEP preferably has an MFR of 1 to 100 g / 10 minutes.

The FEP preferably has a thermal decomposition start temperature of 360 ° C. or higher. The thermal decomposition start temperature is more preferably 380 ° C. or higher, further preferably 390 ° C. or higher.

In the present specification, the thermal decomposition start temperature is set by using a differential thermal / thermogravimetric measuring device [TG-DTA] (trade name: TG / DTA6200, manufactured by Seiko Electronics Co., Ltd.) at a temperature rise rate of 10 ° C./min for 10 mg of a sample. It is a temperature at which the temperature is raised from room temperature and the sample is reduced by 1% by mass.

The PFA is not particularly limited, but a copolymer having a molar ratio of TFE units to PAVE units (TFE units / PAVE units) of 70/30 or more and less than 99/1 is preferable. A more preferable molar ratio is 70/30 or more and 98.9 / 1.1 or less, and a more preferable molar ratio is 80/20 or more and 98.9 / 1.1 or less. If the TFE unit is too small, the mechanical properties tend to deteriorate, and if it is too large, the melting point tends to be too high and the moldability tends to decrease. The PFA contains 0.1 to 10 mol% of monomer units derived from a monomer copolymerizable with TFE and PAVE, and 90 to 99.9 mol% of TFE units and PAVE units in total. It is also preferable that it is a copolymer. Examples of monomers copolymerizable with TFE and PAVE include HFP, CZ ¹ Z ² = CZ ³ (CF ₂ ) _n Z ⁴ (in the formula, Z ¹ , Z ² and Z ³ are the same or different, and hydrogen. Represents an atom or a fluorine atom, Z ⁴ represents a hydrogen atom, a fluorine atom or a chlorine atom, and n represents an integer of 2 to 10), and CF ₂ = CF-OCH. (wherein, Rf ² represents. a perfluoroalkyl group having 1 to 5 carbon atoms) ₂ -Rf ² include alkyl perfluorovinyl ether derivatives represented by.

The PFA has a melting point of preferably less than 180 to 322 ° C, more preferably 230 to 320 ° C, and even more preferably 280 to 320 ° C.

The PFA preferably has a melt flow rate (MFR) of 1 to 100 g / 10 minutes.

The PFA preferably has a thermal decomposition start temperature of 380 ° C. or higher. The thermal decomposition start temperature is more preferably 400 ° C. or higher, and further preferably 410 ° C. or higher.

The content of each monomer unit of the melt-processable fluorine-containing polymer can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescent X-ray analysis depending on the type of monomer.

From the viewpoint of dispersion stability in the coating composition and surface smoothness of the obtained coating film, the non-melt processable fluorinated polymer and the melt processable fluorinated polymer have an average particle size of 0. It is preferably 01 to 40 μm. The average particle size is more preferably 0.05 μm or more, more preferably 20 μm or less, further preferably 10 μm or less, and particularly preferably 5 μm or less.
The average particle size can be measured by a laser light scattering method.

The mass ratio of the total amount of the PES and the polyimide resin to the total amount of the non-melt processable fluorine-containing polymer and the melt processable fluorine-containing polymer is 15 in that a coating film having more excellent corrosion resistance can be obtained. It is preferably / 85 to 35/65. The mass ratio is more preferably 20/80 or more, and more preferably 30/70 or less.

Further, the mass ratio of the non-melt processable fluorine-containing polymer to the melt processable fluorine-containing polymer is preferably 5/95 to 95/5 in that a coating film having further excellent corrosion resistance can be obtained. The mass ratio is more preferably 20/80 or more, further preferably 30/70 or more, further preferably 40/60 or more, and particularly preferably 50/50 or more. Further, it is more preferably 90/10 or less, further preferably 80/20 or less, and particularly preferably 70/30 or less.

The coating composition of the present disclosure may be liquid or powdery, but is preferably liquid.

The coating composition of the present disclosure preferably contains water. The coating composition is preferably an aqueous coating composition. It is also preferable that the PES, the polyimide resin, the non-melt processable fluorine-containing polymer and the melt processable fluorine-containing polymer are dispersed in water.

The coating composition of the present disclosure may contain an organic solvent. The organic solvent is an organic compound and is preferably a liquid at room temperature of about 20 ° C.

Examples of the organic solvent include N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, 3-alkoxy-N, N-dimethylpropanamide, γ-butyrolactone, and dimethyl. Sulfoxide, 1,3-dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, dimethylacetamide, dimethylformamide, N-formylmorpholine, N-acetylmorpholine, dimethylpropyleneurea, anisole, diethyl ether, ethylene glycol, Acetphenone, methylethylketone, methylisobutylketone, cyclohexanone, cyclopentanone, xylene, toluene, ethanol, 2-propanol and the like can be mentioned, and one or more of them can be used.

The organic solvent is N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, 3-alkoxy-N, N-dimethylpropanamide, γ-butyrolactone, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidi. Non, 3-methyl-2-oxazolidinone, dimethylacetamide, dimethylformamide, N-formylmorpholin, N-acetylmorpholin, dimethylpropyleneurea, anisole, diethyl ether, ethylene glycol, acetophenone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopenta It is preferably at least one selected from the group consisting of non, xylene, toluene, ethanol and 2-propanol, preferably N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, 3-alkoxy-N, N. -Dimethylpropanamide, γ-butyrolactone, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, dimethylacetamide, dimethylformamide, N-formylmorpholin, N-acetylmorpholin and dimethylpropylene More preferably, it is at least one selected from the group consisting of urea, N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, 3-alkoxy-N, N-dimethylpropanamide, 1,3-. It is more preferably at least one selected from the group consisting of dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, N-formylmorpholin, N-acetylmorpholin and dimethylpropylene urea.

The above 3-alkoxy-N, N-dimethylpropanamide is represented by N (CH ₃ ) ₂ COCH ₂ CH ₂ OR ¹¹ (R ¹¹ is an alkyl group). Alkoxy group (R ^{11 O} group) is not particularly limited, it is an alkoxy group containing a lower alkyl group having about 1 to 6 carbon atoms and is preferably a methoxy group, an ethoxy group, a propoxy group, or butoxy group Is more preferable. As the 3-alkoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide (N (CH ₃ ) ₂ COCH ₂ CH ₂ OCH ₃ ) is particularly preferable.

The organic solvent also preferably has a boiling point of 150 ° C. or higher, more preferably 170 ° C. or higher, and even more preferably 210 ° C. or higher. As a result, the drying rate at the time of coating can be delayed and the surface smoothness of the coating film can be improved.
The boiling point is a value measured at 1 atm (atm).

The coating composition preferably contains water and optionally an organic solvent.
When the coating composition contains water and an organic solvent, the content of the organic solvent is preferably 1 to 50% by mass with respect to the total amount of water and the organic solvent. The content is more preferably 5% by mass or more, further preferably 10% by mass or more, further preferably 40% by mass or less, and further preferably 30% by mass or less. ..

It is preferable that the coating composition is substantially free of N-methyl-2-pyrrolidone (NMP). The fact that NMP is substantially not contained means that the content of NMP is 1.0% by mass or less with respect to the coating composition. The content of NMP is more preferably 0.01% by mass or less, and further preferably 0.001% by mass or less, based on the above coating composition.
It is particularly preferable that the coating composition does not contain NMP.

The solid content concentration of the coating composition is preferably 5 to 70% by mass, more preferably 10% by mass or more, more preferably 60% by mass or less, and preferably 50% by mass or less. It is more preferably 40% by mass or less, and particularly preferably 40% by mass or less.

The coating composition of the present disclosure may further contain various additives. The additive is not particularly limited, and for example, a filler, a leveling agent, a solid lubricant, an anti-settling agent, a water absorbent, a surfactant, a surface conditioner, a thixotropy-imparting agent, a viscosity modifier, and an anti-gelling agent. Agents, UV absorbers, light stabilizers, plasticizers, color-coding inhibitors, anti-skin agents, anti-scratch agents, anti-mold agents, antibacterial agents, antioxidants, antistatic agents, silane coupling agents, colorants (Iron oxide, titanium dioxide, etc.) and the like.

The coating composition of the present disclosure may contain a filler as the additive for the purpose of imparting properties to the obtained coated article, improving physical properties, increasing the amount, and the like. Examples of the above-mentioned characteristics and physical properties include strength, durability, weather resistance, flame retardancy, and designability.

The filler is not particularly limited, and for example, wood powder, quartz sand, carbon black, clay, talc, diamond, fluorinated diamond, corundum, silicate, boron nitride, boron carbide, silicon carbide, molten alumina, tourmaline, etc. Jade, germanium, zirconium oxide, zirconium carbide, chrysoberyl, topaz, beryl, garnet, extender pigments, bright flat pigments, scaly pigments, glass, glass powder, mica powder, metal powder (gold, silver, copper, platinum, stainless steel) , Aluminum, etc.), various reinforcing materials, various bulking materials, conductive fillers, etc.

The coating composition also preferably contains a surfactant. As the above-mentioned surfactant, conventionally known ones can be used, but nonionic surfactants and anionic surfactants are preferable, and polyether nonionic surfactants are more preferable.

The content of the additive is preferably 0.01 to 10.0% by mass, more preferably 0.1 to 5.0% by mass, based on the coating composition.

The coating composition of the present disclosure may be applied directly on a base material made of a metal or non-metal inorganic material, or may be applied on a layer made of a heat-resistant resin (hereinafter, also referred to as a heat-resistant layer). Preferably, it is more preferably applied directly onto a substrate made of a metallic or non-metallic inorganic material.

Examples of the metal include elemental metals such as iron, aluminum and copper, and alloys thereof. Examples of the alloys include stainless steel and the like.
Examples of the non-metallic inorganic material include enamel, glass, ceramic and the like.
The base material may contain other materials as well as metallic or non-metallic inorganic materials.

As the base material, those made of metal are preferable, and those made of aluminum or stainless steel are more preferable.

The base material may be subjected to surface treatment such as degreasing treatment and roughening treatment, if necessary. The roughening treatment method is not particularly limited, and examples thereof include chemical etching with an acid or alkali, anodizing (anodizing), and sandblasting. The surface treatment may be appropriately selected depending on the type of the base material, the coating composition, and the like, but for example, sandblasting is preferable.

The base material may be subjected to a degreasing treatment by pyrolyzing at 380 ° C. to remove impurities such as oil by thermal decomposition. Further, an aluminum base material which has been surface-treated and then roughened with an alumina sweeping material may be used.

The heat-resistant resin in the heat-resistant layer is not particularly limited as long as it is a resin generally recognized as having heat resistance, but a fluorine-containing polymer is excluded. As used herein, the term "heat resistance" means a property that allows continuous use at a temperature of 150 ° C. or higher.

Examples of the heat-resistant resin include polyamideimide resin (PAI), polyimide resin (PI), polyethersulfone resin (PES), polyetherimide resin, aromatic polyetherketone resin, aromatic polyester resin and polyarylene sulfide resin. Can be used alone or in combination of two or more.

Examples of PAI, PI and PES include those described above.

The aromatic polyetherketone resin is a resin containing a repeating unit composed of an arylene group, an ether group [−O−], and a carbonyl group [−C (= O) −]. Examples of the aromatic polyetherketone resin include polyetherketone resin (PEK), polyetheretherketone resin (PEEK), polyetheretherketoneketone resin (PEEKK), and polyetherketone ester resin. The above aromatic polyetherketone resin may be used alone or in combination of two or more.
As the aromatic polyetherketone resin, at least one selected from the group consisting of PEK, PEEK, PEEKK and polyetherketone ester resins is preferable, and PEEK is more preferable.

The heat-resistant resin in the heat-resistant layer may be the same as or different from the PES or polyimide resin contained in the coating composition of the present disclosure.
The heat-resistant layer may further contain components other than the heat-resistant resin, but preferably does not contain a fluorine-containing polymer.

The method of applying the coating composition on the base material or the heat-resistant layer is not particularly limited, and when the coating composition is liquid, spray coating, roll coating, coating with a doctor blade, dipping (immersion) Examples thereof include painting, impregnation painting, spin flow painting, curtain flow painting and the like, and among them, spray painting is preferable. When the coating composition is in the form of powder, electrostatic coating, a flow dipping method, a lotining method and the like can be mentioned, and electrostatic coating is preferable.

After the coating composition is applied, it may or may not be fired. When the coating composition is in a liquid state, it may or may not be further dried after the coating.

The drying is preferably carried out at a temperature of 70 to 300 ° C. for 5 to 60 minutes. The firing is preferably carried out at a temperature of 260 to 410 ° C. for 10 to 30 minutes.

When the coating composition is in a liquid state, it is preferable to apply the coating composition onto the base material and then dry the coating composition. Moreover, it is preferable not to perform firing.

When the coating composition is in the form of powder, it is preferable to apply the coating composition on the base material and then perform firing.

The coating composition of the present disclosure is preferably applied under a layer containing a fluorine-containing polymer. It is one of the preferred embodiments that the coating composition of the present disclosure is used as an undercoat (primer) for a layer containing a fluorine-containing polymer.

The coating composition of the present disclosure can be used to form a primer layer (A1) or an intermediate layer (B1) constituting the first and second coating articles described later.

The present disclosure is a coating article having a base material, a primer layer (A1) formed from the coating composition of the present disclosure described above, and a fluorine-containing layer (C1) containing a fluorine-containing polymer (a) (hereinafter, Also referred to as the first coated article).
The first coated article has excellent corrosion resistance.

Examples of the material of the base material constituting the first coated article include simple metals such as iron, aluminum and copper, metals such as alloys thereof; and non-metallic inorganic materials such as enamel, glass and ceramics. Examples of the alloys include stainless steel and the like.
The base material may contain other materials as well as metallic or non-metallic inorganic materials.

As the base material, those made of metal are preferable, and those made of aluminum or stainless steel are more preferable.

The primer layer (A1) constituting the first coating article is formed from the coating composition of the present disclosure.
The coating composition of the present disclosure is as described above.

The primer layer (A1) preferably has a film thickness of 5 to 90 μm. If the film thickness is too thin, pinholes are likely to occur, and the corrosion resistance of the coated article may decrease. If the film thickness is too thick, cracks are likely to occur, and the water vapor resistance of the coated article may decrease. When the primer layer (A1) is formed from a liquid composition, a more preferable upper limit of the film thickness is 60 μm, and a further preferable upper limit is 50 μm. When the primer layer (A1) is formed from a powdery composition, the more preferable upper limit of the film thickness is 80 μm, and the more preferable upper limit is 70 μm.

The fluorine-containing layer (C1) constituting the first coated article contains the fluorine-containing polymer (a).

The fluorine-containing polymer (a) constituting the fluorine-containing layer (C1) is a polymer having a fluorine atom directly bonded to a carbon atom constituting a main chain or a side chain. The fluorine-containing polymer (a) may be non-melt processable or melt processable.

The fluorine-containing polymer (a) is preferably obtained by polymerizing a fluorine-containing monoethylene-based unsaturated hydrocarbon (I).

The above-mentioned "fluorinated monoethylene-based unsaturated hydrocarbon (I) (hereinafter, also referred to as" unsaturated hydrocarbon (I) ")" is a vinyl in which a part or all of hydrogen atoms are replaced by fluorine atoms. It means an unsaturated hydrocarbon having one group in the molecule.

In the unsaturated hydrocarbon (I), a part or all of hydrogen atoms not substituted with fluorine atoms are composed of halogen atoms other than fluorine atoms such as chlorine atoms and fluoroalkyl groups such as trifluoromethyl groups. It may be substituted by at least one selected from the group. However, the unsaturated hydrocarbon (I) excludes trifluoroethylene, which will be described later.

The unsaturated hydrocarbon (I) is not particularly limited, and for example, tetrafluoroethylene [TFE], hexafluoropropylene [HFP], chlorotrifluoroethylene [CTFE], vinylidene fluoride [VdF], vinyl fluoride [ VF] and the like, and one kind or two or more kinds can be used for these.

The fluorine-containing polymer (a) may be a homopolymer of the unsaturated hydrocarbon (I). Examples of the homopolymer of the unsaturated hydrocarbon (I) include tetrafluoroethylene homopolymer [TFE homopolymer], polychlorotrifluoroethylene [PCTFE], polyvinylidene fluoride [PVdF], and polyvinyl fluoride [PVF]. ] Etc. can be mentioned.

The fluorine-containing polymer (a) may be a copolymer of the unsaturated hydrocarbon (I). Examples of the copolymer include a copolymer of two or more kinds of the unsaturated hydrocarbon (I), at least one of the unsaturated hydrocarbons (I), and the unsaturated hydrocarbon (I). Examples thereof include a copolymer with an unsaturated compound (II) that can be polymerized.

In the present disclosure, the polymer obtained by polymerizing only one or more of the unsaturated hydrocarbons (I) can be used as the fluorine-containing polymer (a), whereas 1 A polymer obtained by polymerizing only a seed or two or more unsaturated compounds (II) cannot be used as the fluorine-containing polymer (a). In this respect, the unsaturated compound (II) is different from the unsaturated hydrocarbon (I).

The unsaturated compound (II) is not particularly limited, and examples thereof include monoethylene-based unsaturated hydrocarbons such as trifluoroethylene [3FH]; ethylene [Et] and propylene [Pr]. As these, one kind or two or more kinds can be used.

Specific examples of the above-mentioned unsaturated hydrocarbon (I) copolymer are not particularly limited, and TFE / HFP copolymer [FEP], TFE / CTFE copolymer, TFE / VdF copolymer, and TFE / 3FH are used together. TFE-based copolymers such as polymers, Et / TFE copolymers [ETFE], TFE / Pr copolymers; VdF / HFP copolymers; VdF / TFE / HFP copolymers; Et / CTFE copolymers [ ECTFE]; Et / HFP copolymer and the like can be mentioned.
In the present specification, the above-mentioned "TFE-based copolymer" means a product obtained by copolymerizing TFE with one or more of other monomers other than TFE. In the TFE-based copolymer, the proportion of the polymerization unit based on other monomers other than TFE in the TFE-based copolymer is usually the ratio of the polymerization unit based on TFE and the polymerization unit based on the other monomer. It is preferable that it exceeds 1% by mass of the total mass of.

The other monomer other than the TFE in the TFE-based copolymer may be another monomer (III) capable of copolymerizing with the TFE below. The other monomer (III) is represented by the following general formula _{X (CF 2) m O n} CF = CF 2
(In the formula, X represents -H, -Cl or -F, m represents an integer of 1 to 6, and n represents an integer of 0 or 1) (where HFP). ), The following general formula C ₃ F ₇ O [CF (CF ₃ ) CF ₂ O] _p -CF = CF ₂
(In the formula, p represents an integer of 1 or 2.) And the compound represented by the following general formula X (CF ₂ ) _q CY = CH ₂
(In the formula, X is the same as above, Y represents -H or -F, q represents an integer of 1 to 6), at least one selected from the group consisting of the compounds. It is preferably a seed monomer. As these, one kind or two or more kinds can be used.

Examples of the TFE-based copolymer using the other monomer (III) include TFE / perfluoro (alkyl vinyl ether) [PAVE] copolymer [PFA] and the like. As the PFA, PFA fluorinated by the method described in International Publication No. 2002/08827 can also be used.

The fluorine-containing polymer (a) may also be modified polytetrafluoroethylene [modified PTFE]. As the modified PTFE, for example, the same as the modified PTFE as the non-melt processable fluorine-containing polymer in the coating composition of the present disclosure can be exemplified.

The fluorine-containing polymer (a) may be one kind or two or more kinds, and is a copolymer of one kind of homopolymer of unsaturated hydrocarbon (I) and the copolymer of unsaturated hydrocarbon (I). It may be a mixture of one type or two or more types, or a mixture of two or more types of the above-mentioned copolymer of unsaturated hydrocarbon (I).

Examples of the mixture include a mixture of a TFE homopolymer and the TFE-based copolymer, a mixture of two or more types of copolymers belonging to the TFE-based copolymer, and the like. Such a mixture includes. For example, a mixture of TFE homopolymer and PFA, a mixture of TFE homopolymer and FEP, a mixture of TFE homopolymer, PFA and FEP, a mixture of PFA and FEP, and the like can be mentioned.

The fluorine-containing polymer (a) is also a perfluoroalkyl group-containing ethylenically unsaturated monomer (IV) having a perfluoroalkyl group (hereinafter, also referred to as “unsaturated monomer (IV)”). It may be obtained by polymerizing. The unsaturated monomer (IV) has the following general formula.

(In the formula, Rf represents a perfluoroalkyl group having 4 to 20 carbon atoms, R ¹ represents an alkyl group having −H or 1 to 10 carbon atoms, and R ² represents an alkylene group having 1 to 10 carbon atoms. R ³ represents an −H or 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. It is represented by.).
The fluorine-containing polymer (a) may be a copolymer of the unsaturated monomer (IV), or the unsaturated monomer (IV) and the unsaturated monomer (IV). ) And a copolymer of a monomer (V) capable of copolymerizing with the above.

The monomer (V) is not particularly limited, and cyclohexyl (meth) acrylic acid, benzyl (meth) acrylic acid, polyethylene glycol di (meth) acrylic acid, N-methylolpropaneacrylamide, and (meth) acrylic acid amide. , (Meta) acrylic acid derivatives such as alkyl esters of (meth) acrylic acid having an alkyl group having 1 to 20 carbon atoms; ethylene, vinyl chloride, vinyl fluoride, styrene, α-methylstyrene, p-methylstyrene and the like. Substituent or unsubstituted ethylene; vinyl ethers such as alkyl vinyl ethers having an alkyl group having 1 to 20 carbon atoms and halogenated alkyl vinyl ethers having an alkyl group having 1 to 20 carbon atoms; alkyl groups having 1 to 20 carbon atoms. Vinyl ketones such as vinyl alkyl ketones; aliphatic unsaturated polycarboxylic acids such as maleic anhydride and derivatives thereof; polyenes such as butadiene, isoprene, and chloroprene can be mentioned.

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

The fluorine-containing polymer (a) is at least one selected from the group consisting of TFE homopolymers, modified PTFE and the TFE-based copolymers because the obtained coating film is excellent in corrosion resistance and water vapor resistance. Polymers are preferred. As the TFE-based copolymer, at least one copolymer selected from the group consisting of PFA and FEP is preferable.

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

The fluorine-containing layer (C1) may contain an additive in addition to the fluorine-containing polymer (a). The additive is not particularly limited, and for example, the additive exemplified in the coating composition of the present disclosure can be used.
The content of the additive is preferably 0.01 to 30% by mass, more preferably 0.1 to 20% by mass, based on the total mass of the fluorine-containing layer (C1).

The fluorine-containing layer (C1) may contain a filler as the additive for the purpose of imparting properties to the obtained coated article, improving physical properties, increasing the amount, and the like. Examples of the above-mentioned characteristics and physical properties include strength, durability, weather resistance, flame retardancy, and designability. When a filler having a brilliant feeling is used, the coated article of the present disclosure has a good shining feeling.

The filler is not particularly limited, and for example, wood powder, quartz sand, carbon black, clay, talc, diamond, fluorinated diamond, corundum, silicate, boron nitride, boron carbide, silicon carbide, molten alumina, tourmaline, etc. Jade, germanium, zirconium oxide, zirconium carbide, chrysoberyl, topaz, beryl, garnet, extender pigments, bright flat pigments, scaly pigments, glass, glass powder, mica powder, metal powder (gold, silver, copper, platinum, stainless steel) Etc.), various reinforcing materials, various bulking materials, conductive fillers, etc. As the filler, a brilliant filler is preferable when the fluorine-containing laminate of the present invention is required to have a brilliant feeling. The above-mentioned "brilliant filler" is a filler capable of imparting a brilliant feeling to the obtained fluorine-containing laminate.

The filler is preferably 0.01 to 40% by mass, more preferably 0.05 to 30% by mass, and 0.1 to 10% by mass with respect to the total mass of the fluorine-containing layer (C1). It is more preferably%.

The fluorine-containing layer (C1) preferably has a film thickness of 5 to 90 μm. If the film thickness is too thin, the corrosion resistance of the coated article may decrease. If the film thickness is too thick, when the coated article is in the presence of water vapor, the water vapor tends to remain in the coated article, and the water vapor resistance may be inferior. When the fluorine-containing layer (C1) is formed from a liquid composition, a more preferable upper limit of the film thickness is 60 μm, a further preferable upper limit is 50 μm, and a particularly preferable upper limit is 40 μm. When the fluorine-containing layer (C1) is formed from the powdery composition, the more preferable upper limit of the film thickness is 80 μm, the more preferable upper limit is 75 μm, and the particularly preferable upper limit is 70 μm.

In the first coated article, the thickness of the primer layer (A1) is 5 to 90 μm, and the film thickness of the fluorine-containing layer (C1) is 5 to 90 μm, which is one of the preferred embodiments.

In the first coated article, it is preferable that the base material, the primer layer (A1) and the fluorine-containing layer (C1) are laminated in this order.
In other words, it is preferable that the primer layer (A1) is provided on the base material and the fluorine layer (C1) is provided on the primer layer (A1).

The primer layer (A1) is preferably in direct contact with the base material.
The fluorine-containing layer (C1) may be in direct contact with the primer layer (A1) or may be in contact with another layer, but is preferably in direct contact with the primer layer (A1).

A further layer may be provided on the fluorine-containing layer (C1), but it is preferable that the fluorine-containing layer (C1) is the outermost layer.

Characters, drawings, etc. may be printed on the upper surface of the primer layer (A1).

The present disclosure comprises a base material, a primer layer (A2) containing a heat-resistant resin (a), an intermediate layer (B1) formed from the above-described coating composition of the present disclosure, and a fluorine-containing polymer (a). It also relates to a coated article having a fluorine-containing layer (C2) (hereinafter, also referred to as a second coated article).
The second coated article has excellent corrosion resistance.

As the base material constituting the second coated article, the same base material as the base material that can be used for the first coated article described above can be exemplified, and the preferred example is also the same.

The primer layer (A2) constituting the second coated article contains a heat-resistant resin (a).

Examples of the heat-resistant resin (a) constituting the primer layer (A2) include polyamideimide resin (PAI), polyimide resin (PI), polyethersulfone resin (PES), polyetherimide resin, and aromatic polyetherketone resin. Examples thereof include aromatic polyester resin and polyarylene sulfide resin, and one type can be used alone or two or more types can be used in combination. The heat-resistant resin (a) excludes the fluorine-containing polymer.

Examples of the PAI, PI, PES, and aromatic polyetherketone resin include those described above.

The heat-resistant resin (a) is preferably at least one selected from the group consisting of PAI, PI and PES. As a result, it has excellent adhesion to the base material, has sufficient heat resistance even under the temperature at the time of firing performed when forming the coating film, and the obtained coating film has excellent corrosion resistance and water vapor resistance.
PAI, PI and PES may be composed of one kind or two or more kinds respectively.

The heat-resistant resin (a) preferably contains PES and at least one selected from the group consisting of PAI and PI because the coating film is particularly excellent in corrosion resistance. It is particularly preferable that the heat-resistant resin (a) contains PES and PAI.

When the heat-resistant resin (a) contains PES and at least one selected from the group consisting of PAI and PI, PES is a PES and at least one selected from the group consisting of PAI and PI. It is preferably 65 to 85% by mass of the total amount. More preferably, it is 70 to 80% by mass.

The primer layer (A2) preferably does not contain a fluorine-containing polymer.

The primer layer (A2) may further contain an additive in addition to the heat-resistant resin (a). As the additive, examples of additives that can be used in the coating composition of the present disclosure described above can be exemplified.
The content of the additive is preferably 0.01 to 10.0% by mass, more preferably 0.1 to 5.0% by mass, based on the total mass of the primer layer (A2).

The primer layer (A2) preferably has a film thickness of 5 to 90 μm. If the film thickness is too thin, pinholes are likely to occur, and the corrosion resistance of the coated article may decrease. If the film thickness is too thick, cracks are likely to occur, and the water vapor resistance of the coated article may decrease. When the primer layer (A2) is formed from a liquid composition, a more preferable upper limit of the film thickness is 60 μm, and a further preferable upper limit is 50 μm. When the primer layer (A2) is formed from a powdery composition, the more preferable upper limit of the film thickness is 80 μm, and the more preferable upper limit is 70 μm.

The intermediate layer (B1) constituting the second coated article is formed from the coated composition of the present disclosure.
The coating composition of the present disclosure is as described above.

The film thickness of the intermediate layer (B1) is preferably 5 to 90 μm. If the film thickness is too thin, the wear resistance of the obtained coated article may not be sufficient. If the film thickness is too thick, it becomes difficult for the water permeated from the intermediate layer (B1) to escape, and the water vapor resistance of the coated article may decrease. A more preferable upper limit of the film thickness of the intermediate layer (B1) is 60 μm, and a more preferable upper limit is 50 μm.

The fluorine-containing layer (C2) constituting the second coated article contains the fluorine-containing polymer (a).

Examples of the fluorinated polymer (a) constituting the fluorinated layer (C2) include the same fluorinated polymer (a) that can be used for the fluorinated layer (C1) of the first coated article described above. The same applies to the preferred examples.

The fluorine-containing layer (C2) may contain an additive in addition to the fluorine-containing polymer (a). The additive is not particularly limited, and for example, the additive exemplified in the coating composition of the present disclosure can be used.
The content of the additive is preferably 0.01 to 30% by mass, more preferably 0.1 to 20% by mass, based on the total mass of the fluorine-containing layer (C2).

The fluorine-containing layer (C2) may contain the same filler as exemplified in the fluorine-containing layer (C1) of the first coated article.
The filler is preferably 0.01 to 40% by mass, more preferably 0.05 to 30% by mass, and 0.1 to 10% by mass with respect to the total mass of the fluorine-containing layer (C2). It is more preferably%.

The fluorine-containing layer (C2) preferably has a film thickness of 5 to 90 μm. If the film thickness is too thin, the corrosion resistance of the coated article may decrease. If the film thickness is too thick, when the coated article is in the presence of water vapor, the water vapor tends to remain in the coated article, and the water vapor resistance may be inferior. When the fluorine-containing layer (C2) is formed from a liquid composition, a more preferable upper limit of the film thickness is 60 μm, a further preferable upper limit is 50 μm, and a particularly preferable upper limit is 40 μm. When the fluorine-containing layer (C2) is formed from the powdery composition, the more preferable upper limit of the film thickness is 80 μm, the more preferable upper limit is 75 μm, and the particularly preferable upper limit is 70 μm.

In the second coated article, the primer layer (A2) has a film thickness of 5 to 90 μm, the intermediate layer (B1) has a film thickness of 5 to 90 μm, and the fluorine-containing layer (C2) has a film thickness of 5 to 90 μm. Is one of the preferred embodiments.

In the second coated article, it is preferable that the base material, the primer layer (A2), the intermediate layer (B1) and the fluorine-containing layer (C2) are laminated in this order.
In other words, a primer layer (A2) is provided on the base material, an intermediate layer (B1) is provided on the primer layer (A2), and a fluorine layer (C2) is provided on the intermediate layer (B1). It is preferable that the primer is used.

The primer layer (A2) is preferably in direct contact with the base material.
The intermediate layer (B1) may be in direct contact with the primer layer (A2) or may be in contact with another layer, but it is preferable that the intermediate layer (B1) is in direct contact with the primer layer (A2).
The fluorine-containing layer (C2) may be in direct contact with the intermediate layer (B1) or may be in contact with another layer, but is preferably in direct contact with the intermediate layer (B1).

A further layer may be provided on the fluorine-containing layer (C2), but it is preferable that the fluorine-containing layer (C2) is the outermost layer.

Characters, drawings, etc. may be printed on the upper surface of the primer layer (A2), the upper surface of the intermediate layer (B1), or both.

The first coated article is, for example, a step (A1) of forming a primer coating film (A1p) by applying a primer coating composition (A1) on a substrate.
A step (C1) of forming a coating film (C1p) by applying a fluorine-containing paint (C1) on a primer coating film (A1p), and
By firing the coating film laminate having the primer coating film (A1p) and the coating film (C1p), the first coated article having the base material, the primer layer (A1) and the fluorine-containing layer (C1) is formed. Process (D1)
It can be produced by a method including (hereinafter, also referred to as a first production method).

In the step (A1), the coating composition for a primer (A1) may be the coating composition of the present disclosure described above.

The method of applying the primer coating composition (A1) on the substrate is not particularly limited, and when the primer coating composition (A1) is liquid, spray coating, roll coating, coating with a doctor blade, and dipping Examples thereof include (immersion) coating, impregnation coating, spin flow coating, curtain flow coating, etc. Among them, spray coating is preferable. When the coating composition for a primer (A1) is in the form of powder, electrostatic coating, a flow dipping method, a lotining method and the like can be mentioned, and electrostatic coating is particularly preferable.

After the application of the primer coating composition (A1) in the step (A1) and before the step (C1), the firing may or may not be performed. When the primer coating composition (A1) is in a liquid state, it may or may not be further dried after the above coating.

In the step (A1), the drying is preferably performed at a temperature of 70 to 300 ° C. for 5 to 60 minutes. The firing is preferably carried out at a temperature of 260 to 410 ° C. for 10 to 30 minutes.

When the primer coating composition (A1) is in a liquid state, it is preferable that the primer coating composition (A1) is applied on the substrate and then dried in the step (A1). Further, since the coating film laminate is fired in the step (D1) described later, it is preferable not to fire the coating film laminate.

When the primer coating composition (A1) is in the form of powder, in the step (A1), it is preferable to apply it on the substrate and then perform firing.

The primer coating film (A1p) is formed by coating the primer coating composition (A1) on the substrate and then drying or firing it as necessary. The primer coating film (A1p) becomes a primer layer (A1) in the obtained coated article.

The step (C1) is a step of forming a coating film (C1p) by applying a fluorine-containing paint (C1) on the primer coating film (A1p).

The fluorinated coating material (C1) in the step (C1) preferably contains the fluorinated polymer (a).
The fluorine-containing paint (C1) may further optionally contain an additive.
The fluorine-containing polymer (a) and the above-mentioned additives are as described above.

The fluorine-containing paint (C1) may be a powder paint or a liquid paint such as a water-based paint. A powder coating is preferable in that a drying step is not required and a thick coating film can be easily obtained with a small number of coatings. When the fluorine-containing paint (C1) is a liquid paint, it is preferable that the particles of the fluorine-containing polymer (a) are dispersed in a liquid medium, and the particles of the fluorine-containing polymer (a) are mainly used. More preferably, it is a water-based paint dispersed in a water-based medium composed of water.

The average particle size of the particles of the fluorine-containing polymer (a) in the fluorine-containing coating material (C1) is preferably 0.01 to 40 μm in the case of a liquid coating material and 1 to 50 μm in the case of a powder coating material.

When the fluorine-containing polymer (a) is melt-processable, the fluorine-containing coating material (C1) may contain a small amount of PTFE (at least one of a TFE homopolymer and a modified PTFE) for the purpose of refining spherulites. .. In this case, the content of PTFE is preferably 0.01 to 10.0% by mass with respect to the fluorine-containing polymer (a).

Further, the fluorine-containing paint (C1) preferably does not contain a coloring pigment. Since the coloring pigment can cause deterioration of the corrosion resistance, if the fluorine-containing paint (C1) does not contain the coloring pigment, the obtained coated article will have more excellent corrosion resistance and water vapor resistance.

The method of applying the fluorine-containing coating material (C1) on the primer coating film (Ap) is not particularly limited, and examples thereof include the same method as the method of applying the above-mentioned primer coating composition (A1). When the fluorine-containing coating material (C1) is a powder coating material, electrostatic coating is preferable.

The coating film (C1p) may be formed by drying or firing as necessary after the above coating. The drying or firing in the step (C1) is preferably performed under the same conditions as the drying or firing in the step (A1). The coating film (C1p) becomes a fluorine-containing layer (C1) in the obtained coated article.

In the step (D1), the first coating film laminate having the primer coating film (A1p) and the coating film (C1p) is fired to have the above-mentioned base material, the primer layer (A1) and the fluorine-containing layer (C). It is a step of forming a covering article of.

The firing in the step (D1) is preferably performed under the same conditions as the firing in the steps (A1) and (C1).

The first manufacturing method may include a step of printing characters, drawings, etc. after the step (A1) of forming the primer coating film (A1p). The characters, drawings, etc. are, for example, characters and lines indicating the amount of water when the covering article is a rice cooker.

The printing method is not particularly limited, and examples thereof include pad transfer printing. The printing ink used for the above printing is not particularly limited, and examples thereof include a composition composed of PES, TFE homopolymer, and titanium oxide.

The second coated article is, for example, a step (A2) of forming a primer coating film (A2p) by applying a primer coating composition (A2) on a substrate.
A step (B1) of forming a coating film (B1p) by applying a fluorine-containing paint (B1) on a primer coating film (A2p).
The step (C2) of forming the coating film (C2p) by applying the fluorine-containing paint (C2) on the coating film (B1p), and
By firing the coating film laminate having the primer coating film (A2p), the coating film (B1p) and the coating film (C2p), the above-mentioned base material, the primer layer (A2), the intermediate layer (B1) and the fluorine-containing layer (B1) Step of forming a second coated article having C2) (D2)
It can be manufactured by a method including.

The step (A2) is a step of forming a primer coating film (A2p) by applying the primer coating composition (A2) on the substrate.

In the step (A2), the primer coating composition (A2) preferably contains a heat-resistant resin (a).
The coating composition for a primer (A2) can further optionally contain an additive.
The heat-resistant resin (a) and the above additives are as described above.
The primer coating composition (A2) preferably does not contain a fluorine-containing polymer.

The method of applying the primer coating composition (A2) on the substrate is not particularly limited, and when the primer coating composition (A2) is liquid, spray coating, roll coating, coating with a doctor blade, and dipping Examples thereof include (immersion) coating, impregnation coating, spin flow coating, curtain flow coating, etc. Among them, spray coating is preferable. When the coating composition for a primer (A2) is in the form of powder, electrostatic coating, a flow dipping method, a lotining method and the like can be mentioned, and electrostatic coating is particularly preferable.

After the application of the primer coating composition (A2) in the step (A2) and before the step (B1), the firing may or may not be performed. When the primer coating composition (A2) is in a liquid state, it may or may not be further dried after the above coating.

In the step (A2), the drying is preferably performed at a temperature of 70 to 300 ° C. for 5 to 60 minutes. The firing is preferably carried out at a temperature of 260 to 410 ° C. for 10 to 30 minutes.

When the primer coating composition (A2) is in a liquid state, it is preferable that the primer coating composition (A2) is applied on the substrate and then dried in the step (A2). Further, since the coating film laminate is fired in the step (D2) described later, it is preferable not to fire the coating film laminate.

When the primer coating composition (A2) is in the form of powder, in the step (A2), it is preferable to apply the primer coating composition (A2) onto the substrate and then perform firing.

The primer coating film (A2p) is formed by applying the primer coating composition (A2) on the substrate and then drying or firing as necessary. The primer coating film (A2p) becomes a primer layer (A2) in the obtained coated article.

The step (B1) is a step of forming a coating film (B1p) by applying a fluorine-containing paint (B1) on the primer coating film (A2p).

The fluorine-containing coating material (B1) in the step (B1) may be the coating composition of the present disclosure described above.

The method of applying the fluorine-containing paint (B1) on the primer coating film (A2p) is not particularly limited, and examples thereof include the same method as the method of applying the primer coating composition (A2). When the fluorine-containing coating material (B1) is a powder coating material, electrostatic coating is preferable.

In the step (B1), the fluorine-containing paint (B1) may be applied onto the primer coating film (A2p) and then dried or fired. The drying or firing in the step (B1) is preferably performed under the same conditions as the drying or firing in the step (A2).

It is preferable that the fluorine-containing paint (B1) is applied onto the primer coating film (A2p) and then not fired. This is because all the coating films can be fired at the same time when the coating film laminate is fired in the step (D2) described later.

The coating film (B1p) is formed by applying a fluorine-containing coating film (B1) on a primer coating film (A2p) and then drying or firing as necessary. The coating film (B1p) becomes an intermediate layer (B1) in the obtained coated article.

The step (C2) is a step of forming a coating film (C2p) by applying a fluorine-containing paint (C2) on the coating film (B1p).

The fluorinated coating material (C2) in the step (C2) preferably contains the fluorinated polymer (a).
The fluorine-containing coating material (C2) can further optionally contain an additive.
The fluorine-containing polymer (a) and the above-mentioned additives are as described above.

The fluorine-containing paint (C2) may be a powder paint or a liquid paint such as a water-based paint. A powder coating is preferable in that a drying step is not required and a thick coating film can be easily obtained with a small number of coatings. When the fluorine-containing paint (C2) is a liquid paint, it is preferable that the particles of the fluorine-containing polymer (a) are dispersed in a liquid medium, and the particles of the fluorine-containing polymer (a) are mainly used. More preferably, it is a water-based paint dispersed in a water-based medium composed of water.

The average particle size of the particles of the fluorine-containing polymer (a) in the fluorine-containing coating material (C2) is preferably 0.01 to 40 μm in the case of a liquid coating material and 1 to 50 μm in the case of a powder coating material.

When the fluorine-containing polymer (a) is melt-processable, the fluorine-containing coating material (C2) may contain a small amount of PTFE (at least one of TFE homopolymer and modified PTFE) for the purpose of refining spherulites. .. In this case, the content of PTFE is preferably 0.01 to 10.0% by mass with respect to the fluorine-containing polymer (a).

Further, the fluorine-containing paint (C2) preferably does not contain a coloring pigment. Since the coloring pigment can cause deterioration of the corrosion resistance, if the fluorine-containing coating material (C2) does not contain the coloring pigment, the obtained coated article will have more excellent corrosion resistance and water vapor resistance.

The method of applying the fluorine-containing paint (C2) on the coating film (B1p) is not particularly limited, and examples thereof include the same method as the method of applying the above-mentioned primer coating composition (A2). When the fluorine-containing coating material (C2) is a powder coating material, electrostatic coating is preferable.

The coating film (C2p) may be formed by drying or firing as necessary after the above coating. The drying or firing in the step (C2) is preferably performed under the same conditions as the drying or firing in the step (A2). The coating film (C2p) becomes a fluorine-containing layer (C2) in the obtained coated article.

In the step (D2), the substrate, the primer layer (A2), and the intermediate layer (B1) are formed by firing the coating film laminate having the primer coating film (A2p), the coating film (B1p), and the coating film (C2p). ) And a second coated article having a fluorine-containing layer (C2).

The firing in the step (D2) is preferably performed under the same conditions as the firing in the steps (A2), (B1) and (C2).

In the second manufacturing method, after the step (A2) of forming the primer coating film (A2p), after the step (B1) of forming the coating film (B1p), or both, characters, drawings, etc. are added. It may have a step of printing. The characters, drawings, etc. are, for example, characters and lines indicating the amount of water when the covering article is a rice cooker.

The printing method is not particularly limited, and examples thereof include the method exemplified in the first manufacturing method.

The coating composition of the present disclosure can provide a coating film having excellent corrosion resistance, and the first and second coating articles have excellent corrosion resistance. Therefore, the coating composition of the present disclosure and the first and second coating articles can be suitably used in all fields where corrosion resistance is required. The applicable applications are not particularly limited, and examples thereof include applications utilizing the non-adhesiveness, heat resistance, slipperiness, etc. of the fluorine-containing polymer. For example, cooking utensils such as frying pans, pressure pans, pots, grill pans, rice cookers, ovens, hot plates, pan baking molds, kitchenettes, gas tables, etc .; electric pots, ice trays, molds, etc. Kitchen utensils such as range hoods; food industry parts such as kneading rolls, rolling rolls, conveyors, hoppers; rolls for office automation (OA), belts for OA, separation claws for OA, paper making rolls, calendar rolls for film manufacturing, etc. Industrial supplies; Molds and molds for foam styrol molding, etc .; Molds for molding molds for plywood / decorative board manufacturing molds, etc .; Industrial containers (especially for the semiconductor industry), etc., which utilize slipperiness Tools such as saws and shavings; household items such as irons, shears and kitchenware; metal foils; electric wires; sliding bearings for food processing machines, packaging machines, textile machines, etc .; sliding parts for cameras and watches; pipes, valves, Automotive parts such as bearings; snow scraping shovels; plows; chutes and the like.

The coating composition of the present disclosure and the first and second coating articles are preferably used for cooking utensils or kitchen utensils, more preferably for cooking utensils, and even more preferably for rice cookers. ..
The first and second coated articles are preferably cooking utensils, kitchen utensils or their constituent members, more preferably cooking utensils or their constituent members, and even more preferably rice cookers or their constituent members. ..

Hereinafter, the present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited to these examples. “%” And “part” represent mass% and mass part, respectively.

Production Example 1 Preparation of Polyamide-imide Resin Aqueous Dispersion (1) Polyamide-imide Resin [PAI] varnish with a solid content of 29% (containing 71% of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) (boiling point 202 ° C.)) Was put into water to precipitate PAI. This was pulverized in a ball mill for 48 hours to obtain a PAI aqueous dispersion (average particle size 2 μm). The solid content of the obtained PAI aqueous dispersion was 20%.

Production Example 2 Preparation of Polyether Sulfone Resin Aqueous Dispersion (1) 60 parts of polyether sulfone resin [PES] and 60 parts of deionized water having an average molecular weight of about 24,000 are completely pulverized by particles made of PES in a ceramic ball mill. The mixture was stirred for about 10 minutes. Then, 180 parts of NMP was added, and the mixture was further pulverized for 48 hours to obtain a dispersion. The obtained dispersion was further pulverized with a sand mill for 1 hour to obtain a PES aqueous dispersion (average particle size 2 μm) having a PES concentration of about 20%.

Production Example 3 Preparation of Polyamide-imide Resin Aqueous Dispersion (2) Polyamide-imide Resin [PAI] varnish with a solid content of 29% (containing 71% of N-ethyl-2-pyrrolidone (hereinafter referred to as NEP) (boiling point 218 ° C.)) Was put into water to precipitate PAI. This was pulverized in a ball mill for 48 hours to obtain a PAI aqueous dispersion (average particle size 2 μm). The solid content of the obtained PAI aqueous dispersion was 20%.

Production Example 4 Preparation of Polyether Sulfone Resin Aqueous Dispersion (2) 60 parts of polyether sulfone resin [PES] and 60 parts of deionized water having an average molecular weight of about 24,000 are completely pulverized by particles made of PES in a ceramic ball mill. The mixture was stirred for about 10 minutes. Then, 180 parts of NEP was added, and the mixture was further pulverized for 48 hours to obtain a dispersion. The obtained dispersion was further pulverized with a sand mill for 1 hour to obtain a PES aqueous dispersion (average particle size 2 μm) having a PES concentration of about 20%.

Production Example 5 Preparation of Polyamide-imide Resin Aqueous Dispersion (3) Polyamide-imide resin [PAI] varnish with a solid content of 29% (3-methoxy-N, N-dimethylpropanamide (hereinafter referred to as NDPA)) (boiling point 215 ° C.) (Containing 71%) was put into water to precipitate PAI. This was pulverized in a ball mill for 48 hours to obtain a PAI aqueous dispersion (average particle size 2 μm). The solid content of the obtained PAI aqueous dispersion was 20%.

Production Example 6 Preparation of Polyether Sulfone Resin Aqueous Dispersion (3) 60 parts of polyether sulfone resin [PES] and 60 parts of deionized water having an average molecular weight of about 24,000 are completely pulverized by particles made of PES in a ceramic ball mill. The mixture was stirred for about 10 minutes. Then, 180 parts of NDPA was added and further pulverized for 48 hours to obtain a dispersion. The obtained dispersion was further pulverized with a sand mill for 1 hour to obtain a PES aqueous dispersion (average particle size 2 μm) having a PES concentration of about 20%.

Example 1
The PES aqueous dispersion obtained in Production Example 2 and the PAI aqueous dispersion obtained in Production Example 1 were mixed so that the PES was 75% of the total solid content of PES and PAI. Tetrafluoroethylene homopolymer [TFE homopolymer, hereinafter referred to as PTFE] Aqueous dispersion (average particle size 0.28 μm, solid content 60%, polyether nonionic surfactant as dispersant 6% with respect to PTFE (Contains) and tetrafluoroethylene-hexafluoropropylene copolymer (hereinafter referred to as FEP) aqueous dispersion (average particle size 0.20 μm, solid content 60%, polyether-based nonionic surface activity as a dispersant The agent is contained in 5% of FEP), FEP is 50% of PTFE by mass ratio of solid content, and PES and PAI are 25% of the total solid content of PES, PAI, PTFE and FEP. In addition, 0.7% of methyl cellulose was added to the solid content of the TFE homopolymer as a thickener, and a polyether nonionic surfactant was added to the solid content of the TFE homopolymer as a dispersion stabilizer. 6% was added to obtain an aqueous dispersion (coating composition for undercoating (1)) having a solid content of the polymer of 34%.

Example 2
Except that the blending amount was changed so that PES was 65% of the total solid content of PES and PAI, and PES and PAI were 20% of the total solid content of PES, PAI and PTFE and FEP. A coating composition (2) for undercoating was obtained in the same manner as in Example 1.

Example 3
An undercoat coating composition (3) was obtained in the same manner as in Example 1 except that the amount of FEP added was 100% by mass ratio of the solid content to PTFE.

Example 4
Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (hereinafter referred to as PFA) instead of FEP aqueous dispersion Aqueous dispersion (average particle size 0.26 μm, solid content 68%, polyether nonionic surfactant as dispersant) The undercoat coating composition (4) was obtained in the same manner as in Example 1 except that the activator (containing 3% of the PFA) was added.

Example 5
Instead of the PES aqueous dispersion obtained in Production Example 2, the PES aqueous dispersion obtained in Production Example 4 was replaced with the PAI aqueous dispersion obtained in Production Example 1 and the PAI aqueous dispersion obtained in Production Example 3 was replaced. An undercoat coating composition (5) was obtained in the same manner as in Example 1 except that the dispersion was used.

Example 6
Instead of the PES aqueous dispersion obtained in Production Example 2, the PES aqueous dispersion obtained in Production Example 6 was replaced with the PAI aqueous dispersion obtained in Production Example 1 and the PAI aqueous dispersion obtained in Production Example 5 was substituted. An undercoat coating composition (6) was obtained in the same manner as in Example 1 except that the dispersion was used.

Comparative Example 1
An undercoat coating composition (7) was obtained in the same manner as in Example 1 except that the FEP aqueous dispersion was not added.

Comparative Example 2
An undercoat coating composition (8) was obtained in the same manner as in Example 2 except that the FEP aqueous dispersion was not added.

<Preparation of test plate>
After degreasing the surface of the aluminum plate (A-1050P) with acetone, sandblasting is performed so that the surface roughness Ra value measured in accordance with JIS B 1982 is 2.5 to 4.0 μm, and the surface is roughened. It became. After removing the dust on the surface by air blowing, the coating composition for undercoating obtained in Examples and Comparative Examples was subjected to an RG-2 type gravity spray gun (trade name, trade name) so that the dry film thickness was about 10 μm. Using Anest Iwata Co., Ltd., nozzle diameter 1.0 mm), spray coating was performed at a spray pressure of 0.2 MPa. The coating film on the obtained aluminum plate was dried at 80 to 100 ° C. for 15 minutes and cooled to room temperature. PFA powder coating is electrostatically coated on the obtained coating film under the conditions of an applied voltage of 40 KV and a pressure of 0.08 MPa, fired at 380 ° C. for 20 minutes, cooled, and the top coat is coated with PFA having a film thickness of about 40 μm. By forming a layer, a test coated plate was obtained. In the obtained test coating plate, an undercoat layer and a topcoat layer made of PFA were formed on the aluminum plate.
The film thickness was measured using a high-frequency film thickness meter (trade name: LZ-300C, manufactured by Kett Science Institute Headquarters).

<Evaluation method>
The coating film of the obtained test coating plate was evaluated as follows.
(Corrosion resistance test)
A cross cut was made on the surface of the coating film of the obtained test coating plate with a cutter knife, and scratches reaching the base material were made. This test plate is immersed in a solution of 20 g of oden (manufactured by S & B Foods Co., Ltd.) in 1 liter of water, kept at 70 ° C, and checked every 100 hours for abnormalities such as blisters. confirmed. Table 1 shows the time for maintaining the coating film without any abnormality such as swelling.

Claims (13)

1. Coating composition containing a polyether sulfone resin, at least one polyimide resin selected from the group consisting of a polyamide-imide resin and a polyimide resin, a non-melt processable fluorine-containing polymer, and a melt processable fluorine-containing polymer. object.
2. The coating composition according to claim 1, wherein the mass ratio of the polyether sulfone resin to the polyimide resin is 85/15 to 65/35.
3. A claim that the mass ratio of the total amount of the polyether sulfone resin and the polyimide resin to the total amount of the non-melt processable fluorine-containing polymer and the melt processable fluorine-containing polymer is 15/85 to 35/65. Item 2. The coating composition according to Item 1 or 2.
4. The coating composition according to any one of claims 1 to 3, wherein the mass ratio of the non-melt processable fluorine-containing polymer to the melt processable fluorine-containing polymer is 5/95 to 95/5.
5. The coating composition according to any one of claims 1 to 4, further comprising water.
6. The coating composition according to any one of claims 1 to 5, wherein the polyether sulfone resin and the polyimide resin have an average particle size of 0.1 to 10 μm.
7. The coating composition according to any one of claims 1 to 6, wherein the non-melt processable fluorine-containing polymer is at least one selected from the group consisting of a tetrafluoroethylene homopolymer and a modified polytetrafluoroethylene.
8. The melt-processable fluorine-containing polymer is at least one selected from the group consisting of a tetrafluoroethylene / hexafluoropropylene copolymer and a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer. 7. The coating composition according to any one of 7.
9. The coating composition according to any one of claims 1 to 8, which is applied directly onto a base material made of a metal or non-metallic inorganic material, or applied onto a layer made of a heat-resistant resin.
10. The coating composition according to any one of claims 1 to 9, further comprising an organic solvent.
11. The organic solvent is N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, 3-alkoxy-N, N-dimethylpropanamide, γ-butyrolactone, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidi. Non, 3-methyl-2-oxazolidinone, dimethylacetamide, dimethylformamide, N-formylmorpholine, N-acetylmorpholine, dimethylpropyleneurea, anisole, diethyl ether, ethylene glycol, acetophenone, methylethylketone, methylisobutylketone, cyclohexanone, cyclopenta The coating composition according to claim 10, which is at least one selected from the group consisting of non, xylene, toluene, ethanol and 2-propanol.
12. With the base material
    A primer layer (A1) formed from the coating composition according to any one of claims 1 to 11.
    A coated article having a fluorine-containing layer (C1) containing a fluorine-containing polymer (a).
13. With the base material
    A primer layer (A2) containing a heat-resistant resin (a) and
    An intermediate layer (B1) formed from the coating composition according to any one of claims 1 to 11.
    A coated article having a fluorine-containing layer (C2) containing a fluorine-containing polymer (a).