JP2006045490A - Water base paint composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water base paint composition that contains a fluorine-containing polymer and is capable of forming a primer coating film excellent in brightness. <P>SOLUTION: The water base paint composition comprises an aqueous dispersion containing a heat resistance resin (A) and a fluorine-containing polymer (B), and further contains a metal powder (C) and an alcohol (D) whose boiling point is at least 100°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a composition for water-based paints, and more particularly to a composition for fluorine-containing water-based paints.

Fluoropolymers such as polytetrafluoroethylene [PTFE] are excellent in properties such as heat resistance, chemical resistance and electrical insulation, so household items such as irons, kitchen appliances such as frying pans and hot plates, food industry, It has a wide range of applications in fields such as electrical industry and machine industry.

The fluoropolymer also has a low coefficient of friction and excellent non-adhesiveness. Since this surface property is linked to water / oil repellency, releasability, slidability, etc., the fluorine-containing polymer is, for example, a composition for a water-based paint, and is applied to the surface of an article so that a frying pan can be obtained. In addition to kitchen appliances such as the above, the application has been expanded to mold release materials, rolls for OA equipment, and the like.

Surface treatment is performed by providing a layer made of a fluororesin on the object to be coated, but the adhesion between this layer and the object to be coated is poor due to the non-adhesiveness of the fluororesin. For the purpose of improving the adhesion, a primer has been previously applied as an undercoat on an object to be coated.
As this primer, there is a primer in which a fluororesin is blended in order to have adhesion with a layer made of a fluororesin and a binder resin is blended in order to have adhesion with an object to be coated.

When the above fluororesin is obtained by polymerization using a conventionally known polymerization method such as emulsion polymerization, for example, water is used as a medium, and thus the primer containing it is often aqueous.

On the other hand, metal powders such as aluminum have been added for the purpose of imparting glitter to the primer coating (see, for example, Patent Document 1 and Patent Document 2).

It has also been reported that when metal flakes are included in the primer coating, the scratch resistance of the layer made of fluororesin formed thereon is improved (see, for example, Patent Document 3). However, even when metal powder is added to the water-based paint, there is a problem that the glittering property is not sufficiently developed in the coating film after drying and baking.
JP-A-6-264000 International Publication No. 2004/041537 Pamphlet JP-A-52-18741

An object of the present invention is to provide an aqueous coating composition that includes a fluoropolymer and is capable of forming a primer coating film excellent in glitter.

The present invention comprises an aqueous dispersion containing a heat-resistant resin (A) and a fluoropolymer (B), and further comprises a metal powder (C) and an alcohol (D) having a water-soluble boiling point of 100 ° C. or higher. It is a composition for water-based paints characterized by including.
The present invention is a method for producing a glittering coating film comprising coating an aqueous coating composition on an object to be coated, wherein the aqueous coating composition is the aqueous coating composition of the present invention. Is a method for producing a glitter coating film.
The present invention is described in detail below.

The aqueous coating composition of the present invention is capable of forming a coating film on the object to be coated by coating the object to be coated. In the present specification, “coating” for the water-based paint composition means a process comprising applying the water-based paint composition, drying it if necessary, and then baking it.
As a result of conducting various studies to solve the above-mentioned problems, the water-based paint composition has been found to be able to improve the glitter of the resulting coating film by blending with a specific alcohol (D). Is.

The aqueous coating composition of the present invention comprises an aqueous dispersion containing a heat resistant resin (A) and a fluoropolymer (B), and further comprises a metal powder (C) and the specific alcohol (D). It is characterized by including.

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

The fluorine-containing polymer (B) is obtained by polymerizing the fluorine-containing monoethylenically unsaturated hydrocarbon (a).
The fluorine-containing monoethylenically unsaturated hydrocarbon (a) (hereinafter referred to as “unsaturated hydrocarbon (a)”) is a molecule in which a vinyl group in which some or all of the hydrogen atoms are substituted by fluorine atoms It is an unsaturated hydrocarbon having one in it.
The unsaturated hydrocarbon (a) may be substituted with a halogen atom other than a fluorine atom such as a chlorine atom and / or a fluorinated methyl group such as a trifluoromethyl group. However, the unsaturated hydrocarbon (a) excludes trifluoroethylene described later.

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

The fluoropolymer (B) is also a copolymer of at least one unsaturated hydrocarbon (a) and an unsaturated compound (b) that can be copolymerized with the unsaturated hydrocarbon (a). It may be.
The unsaturated compound (b) does not use a polymer obtained by polymerizing only one or two or more unsaturated compounds (b) as the fluoropolymer (B). The point that the unsaturated hydrocarbon (a) can be used as the fluoropolymer (B) is a polymer obtained by polymerizing only one or more of the unsaturated hydrocarbons (a). Is different from the unsaturated hydrocarbon (a).
The unsaturated compound (b) is not particularly limited, and examples thereof include trifluoroethylene [3FH]; monoethylenically unsaturated hydrocarbons having no halogen atom such as ethylene [Et] and propylene [Pr]. . These can use 1 type (s) or 2 or more types.

The fluoropolymer (B) may be a homopolymer, a copolymer, or a mixture of a homopolymer and at least one copolymer. A mixture of at least two or more types of copolymers may be used.
The homopolymer is not particularly limited, and examples thereof include polytetrafluoroethylene [PTFE], polychlorotrifluoroethylene [PCTFE], polyvinylidene fluoride [PVdF], and polyvinyl fluoride [PVF].
It does not specifically limit as said copolymer, For example, a binary copolymer, a ternary copolymer, etc. are mentioned. Examples of the binary copolymer include TFE / HFP copolymer [FEP], TFE / CTFE copolymer, TFE / VdF copolymer, TFE / 3FH copolymer, Et / TFE copolymer [ETFE]. ], TFE copolymers such as TFE / Pr copolymer; VdF / HFP copolymer; Et / CTFE copolymer [ECTFE]; Et / HFP copolymer. In the present specification, the “TFE copolymer” means a copolymer obtained by copolymerizing TFE and one or more monomers other than TFE. In the TFE copolymer, the proportion of other monomers other than TFE added to the TFE copolymer is usually 1 mass of the total mass of the TFE and the other monomers. % Is preferably exceeded.
Examples of the ternary copolymer include VdF / TFE / HFP copolymer.

The other monomer other than the TFE in the TFE copolymer may be another monomer (c) that can be copolymerized with the following TFE. The other monomer (c) has the following general formula:
_{X (CF 2) m O n} CF = CF 2
(Wherein X represents a hydrogen atom, a chlorine atom or a fluorine atom, m represents an integer of 1 to 6, and n represents an integer of 0 or 1) (however, HFP The following general 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), or the following general formula:
X (CF ₂ ) _q CY═CH ₂
(Wherein X is the same as above, Y represents a hydrogen atom or a fluorine atom, and q represents an integer of 1 to 6). These can use 1 type (s) or 2 or more types.

The other monomer (c) is not particularly limited as long as it is represented by the above general formula. For example, perfluoroolefin having 4 or more carbon atoms such as perfluorobutylene; perfluoro (methyl vinyl ether) , Perfluoro (ethyl vinyl ether), perfluoro (alkyl vinyl ether) such as perfluoro (flopyr vinyl ether) [PAVE] and the like.

Examples of the TFE copolymer obtained by copolymerizing TFE and the other monomer (c) include TFE / PAVE copolymer [PFA].
The above-mentioned “mixture comprising a homopolymer and at least one copolymer” is not particularly limited. For example, a mixture of PTFE and PFA, a mixture of PTFE and FEP, a mixture of PTFE, PFA and FEP, etc. Is mentioned. The “mixture comprising at least two types of copolymers” is not particularly limited, and examples thereof include a mixture of PFA and FEP.

The fluoropolymer (B) is also obtained by polymerizing a perfluoroalkyl group-containing ethylenically unsaturated monomer (d) having a perfluoroalkyl group (hereinafter referred to as “PAE (d)”). It may be obtained. The PAE (d) is represented by the following general formula:

(In the formula, Rf represents a perfluoroalkyl group having 4 to 20 carbon atoms, R ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ² represents an alkylene group having 1 to 10 carbon atoms. R ³ represents a hydrogen atom 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 It is expressed by.)

The fluoropolymer (B) may be a homopolymer of the PAE (d), or a monomer (e) that can be copolymerized with the PAE (d) and the PAE (d). And a copolymer thereof. The monomer (e) is not particularly limited, and examples thereof include cyclohexyl (meth) acrylate, benzyl (meth) acrylate, polyethylene glycol di (meth) acrylate, N-methylolpropane acrylamide, (meth) acrylic. (Meth) acrylic acid derivatives such as acid amides and 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-methyl Substituted or unsubstituted ethylene such as styrene; alkyl vinyl ethers having 1 to 20 carbon atoms in the alkyl group; vinyl ethers such as halogenated alkyl vinyl ethers having 1 to 20 carbon atoms in the alkyl group; Vinyl ketones such as vinyl alkyl ketones of ˜20; Aliphatic unsaturated polycarboxylic acids and derivatives thereof such as phosphate; butadiene, isoprene, polyenes such as chloroprene.

The fluoropolymer (B) is preferably PTFE, FEP and / or PFA from the viewpoint of excellent non-adhesiveness, slipperiness, heat resistance and the like. As the “PTFE, FEP and / or PFA”, Examples thereof include PTFE, FEP, PFA, a mixture of PTFE and FEP, a mixture of PTFE and PFA, and the like.

The PTFE is TFE, FEP is TFE and HFP, and PFA is TFE and PAVE, respectively. However, other trace monomers other than these essential monomers are added. Good.

The trace monomer is not particularly limited. For example, the unsaturated hydrocarbon (a) such as CTFE; the unsaturated compound (b) such as 3FH; perfluoro (alkyl vinyl ether), (perfluoroalkyl) ethylene. And other monomers (c) and the like. When the fluoropolymer (B) is the PTFE, examples of the trace monomer include HFP and PAVE. When the fluoropolymer (B) is the FEP, further examples include PAVE and the PFA. Furthermore, HFP is mentioned. The said trace amount monomer can use 1 type (s) or 2 or more types.
Although the said trace amount monomer changes with the kinds, it is preferable normally that it is 1 mass% or less of the mass of a fluoropolymer (B). A more preferred upper limit is 0.5% by mass, and a still more preferred upper limit is 0.3% by mass.

The fluoropolymer (B) is more preferably PTFE and / or FEP. The above “PTFE and / or FEP” means PTFE, FEP, and a mixture of PTFE and FEP.

The said fluoropolymer (B) can be obtained by superposing | polymerizing using conventionally well-known polymerization methods, such as emulsion polymerization and suspension polymerization, for example. The fluoropolymer (B) obtained by the polymerization method is pulverized so as to have an average particle diameter within the range described later, if desired. The pulverization method is not particularly limited, and examples thereof include a method in which the fluoropolymer (B) is compressed into a sheet with a roll, and pulverized and classified by a pulverizer.

When the fluoropolymer (B) is obtained by using emulsion polymerization or suspension polymerization, it may be used for the preparation of an aqueous coating composition as a dispersion without isolating only the resulting polymer component. The dispersion is obtained by concentrating the dispersion by adding the surfactant (S1) to the dispersion comprising the polymer component obtained, and further adding the surfactant (S2) as necessary. What was prepared as a composition for water-based paints may be used. In the present specification, a dispersion composed of a fluoropolymer (B) obtained by polymerization and having no surfactant (S2) added thereto is referred to as “product polymer concentrate”. There is. Nonionic surfactants are preferably used as the surfactant (S1) and the surfactant (S2).

In the aqueous coating composition of the present invention, the fluoropolymer (B) is dispersed as particles in an aqueous medium. The fluoropolymer (B) is preferably composed of particles having an average particle diameter of 0.01 to 50 μm. If it is less than 0.01 μm, the dispersibility of the particles comprising the fluoropolymer (B) is poor, and the resulting aqueous coating composition may be inferior in mechanical stability and storage stability. If it exceeds 50 μm, the particles of the fluoropolymer (B) lack uniform dispersibility, and when coating with the resulting aqueous coating composition, a coating film with a smooth surface cannot be obtained, and the coating film properties May be inferior. A more preferred upper limit is 5 μm, a still more preferred upper limit is 0.5 μm, and a more preferred lower limit is 0.05 μm. The mechanical stability is a property that hardly produces aggregates that cannot be redispersed even when strong stirring or shearing force is applied by a homogenizer or the like during liquid feeding and redispersion.

The heat-resistant resin (A) is usually a resin that is recognized as having heat resistance, and is preferably a resin having a continuous usable temperature of 150 ° C. or higher.
The heat-resistant resin (A) is not particularly limited, and examples thereof include polyamideimide resin, polyimide resin, polyethersulfone resin, polyetherimide resin, polyetheretherketone resin, aromatic polyester resin, and polyarylene sulfide resin. Can be mentioned. As said heat resistant resin (A), 1 type (s) or 2 or more types can be used.

The polyamide-imide resin [PAI] is a resin composed of a polymer having an amide bond and an imide bond in the molecular structure. The PAI is not particularly limited. 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; an aromatic trivalent carboxylic acid such as trimellitic anhydride; It consists of a high molecular weight polymer obtained by a reaction with a diamine such as 4,4-diaminophenyl ether or a diisocyanate such as diphenylmethane diisocyanate; a reaction between a dibasic acid having an aromatic imide ring in the molecule and a diamine. Examples thereof include resins. As said PAI, what consists of a polymer which has an aromatic ring in a principal chain from the point which is excellent in heat resistance is preferable.

The polyimide resin [PI] is a resin made of a polymer having an imide bond in the 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 anhydride such as pyromellitic anhydride. As said PI, what consists of a polymer which has an aromatic ring in a principal chain from the point which is excellent in heat resistance is preferable.

The polyethersulfone resin [PES] has the following general formula:

It is resin which consists of a polymer which has a repeating unit represented by these. The PES is not particularly limited, and examples thereof include a resin made of a polymer obtained by polycondensation of dichlorodiphenyl sulfone and bisphenol.
Each of PAI, PI, and PES may be composed of one type or two or more types.

The heat-resistant resin (A) can improve the adhesion between the object to be coated and the coating film obtained by coating the aqueous coating composition, and this adhesion can be maintained even at high temperatures. PAI and / or PI are more preferable because they can be used. The “PAI and / or PI” means PAI, PI, or a mixture of PAI and PI.

The heat-resistant resin (A) is excellent in adhesion to an object to be coated, has sufficient heat resistance even at the firing temperature when forming the coating film, and the resulting coating film has corrosion resistance and water vapor resistance. PAI, PI, and / or PES are preferable from the viewpoint of superiority. The above “PAI, PI and / or PES” means any one of PAI, PI and PES, a mixture of PAI and PI, a mixture of PES and PAI, a mixture of PES and PI, PES, PAI and PI. Means a mixture.

The heat-resistant resin (A) is excellent in heat resistance and adhesion to an object to be coated, and in particular, PES and PAI and / or PI are more preferable because the coating film has particularly excellent corrosion resistance and water vapor resistance. . The “PES and PAI and / or PI” means a mixture of PES and PAI, a mixture of PES and PI, or a mixture of PES, PAI and PI. The heat resistant resin (A) is more preferably a mixture of the PES and PAI.

In the aqueous coating composition of the present invention, the PES is preferably 65 to 85% by mass of the total mass of PES and PAI and / or PI. If it is less than 65% by mass, the water vapor resistance of the coating film obtained from the aqueous coating composition may be reduced, and if it exceeds 85% by mass, the corrosion resistance of the coating film may be reduced.

In the aqueous coating composition of the present invention, the heat-resistant resin (A) is dispersed as particles in an aqueous medium described later or dissolved in an aqueous medium. When the heat resistant resin (A) is dispersed as particles in the aqueous medium, the particles made of the heat resistant resin (A) are particles having an average particle diameter of 0.1 to 10 μm dispersed as particles in the aqueous medium. Preferably there is. When the average particle size of the heat resistant resin (A) is within the above range, the corrosion resistance of the coating film obtained from the aqueous coating composition is good.

Examples of the metal powder (C) include powders of simple metals such as aluminum, iron, tin, zinc and copper; powders of alloys such as aluminum alloys and stainless steels, but aluminum powders and / or stainless steel powders are preferred. Aluminum powder is more preferably used.
In the present specification, the metal powder (C) is distinguished from the pigment described later in that the pigment described later is mainly intended for coloring, but can give glitter. Is done.
The shape of the metal powder (C) is not particularly limited, and examples thereof include particles, flakes, and the like, but flakes are preferable from the viewpoint of excellent glitter. The average particle size of the metal powder (C) is usually 1 to 100 μm, preferably 5 to 50 μm, more preferably 10 to 40 μm. The amount of the metal powder (C) added is usually 0.01 to 50 parts by weight, preferably 0.05 to 20 parts by weight, based on 100 parts by weight of the total solid content of the fluoropolymer (B) and the heat resistant resin (A). Parts, more preferably 0.1 to 10 parts by mass. If it is less than the lower limit, the glitter may be insufficient, and if it exceeds the upper limit, the adhesion to the article to be coated may be reduced.

In the aqueous coating composition of the present invention, it is possible to improve the glitter of the coating film by containing an alcohol (D) that is water-soluble and has a boiling point of 100 ° C. or higher.
150 degreeC or more is preferable and, as for the boiling point of the said specific alcohol (D), 170 degreeC or more is more preferable.

The specific alcohol (D) preferably has a boiling point within the above range and a surface tension of 40 dyn / cm or less. When the specific alcohol (D) has a surface tension within the above range, the wettability with the metal powder (C) can be improved, and the aqueous coating composition of the present invention is applied to an object to be coated. At the time, as a result of transferring the metal powder (C) to the coating film surface at the time of evaporation, it is considered that the glitter can be improved.
The upper limit of the surface tension of the specific alcohol (D) is more preferably 35 dyn / cm.
As the specific alcohol (D), those having a boiling point of 170 ° C. or more and a surface tension of 40 dyn / cm or less are more preferable.

Examples of the specific alcohol (D) include alkylene glycols and monoalcohols.
Examples of the alkylene glycols include ethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol.
Examples of the alkylene glycols include the following general formula (I)
_{R- (OCH 2 CH 2) n} - (OCH 2 CH 2 CH 2) m -OH (I)
(In the formula, R represents H or an alkyl group having 1 to 4 carbon atoms, n represents an integer of 0 to 3, and m represents an integer of 0 to 2. However, (n + m) = 1 to 3 is satisfied.)
The oxyalkylene unit containing alcohol represented by these may be sufficient.
In the said general formula (I), it is preferable that R is a C1-C4 alkyl group. Moreover, it is preferable that either one of n and m is 0 and the other is 1 or 2. That is, when two oxyalkylene units in the general formula (I) are contained in one molecule, the oxyalkylene units are more preferably of the same type in terms of easy preparation.
As said monoalcohol, furfuryl alcohol, diacetone alcohol, etc. are preferable.

As said specific alcohol (D), 1 type (s) or 2 or more types can be used, and 1 type selected from the group which consists of alkylene glycols, furfuryl alcohol, and diacetone alcohol from the point of the improvement of glitter. Two or more are preferable, more preferably any of ethylene glycol, propylene glycol, and furfuryl alcohol, and still more preferably including furfuryl alcohol. As the specific alcohol (D), furfuryl alcohol can sufficiently improve the glitter without using an alkylene glycol and / or diacetone alcohol in combination, and may be used alone.
The specific alcohol (D) is preferably an oxyalkylene unit-containing alcohol represented by the general formula (I) from the viewpoint of improving not only glitter but also stirring stability. Ether is more preferable, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, Propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol mono Butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether is more preferable. Further, it may contain a dialkyl ether such as diethylene glycol dimethyl ether.

The amount of the specific alcohol (D) added is usually 0.1 to 50 parts by mass, preferably 1 to 40 parts by mass with respect to 100 parts by mass of the total solid content of the fluoropolymer (B) and the heat resistant resin (A). Part, more preferably 3 to 30 parts by mass. If it is less than the lower limit, the improvement of the glitter of the coating film may be insufficient, and if it exceeds the upper limit, the mechanical stability of the aqueous coating composition may be lowered.

The aqueous coating composition of the present invention may contain other known organic liquid (E) as necessary. Examples of such an organic liquid (E) include aromatic hydrocarbon solvents such as toluene, xylene, trimethylbenzene, methylethylbenzene, propylbenzene, and butylbenzene; saturated hydrocarbon solvents having 6 to 12 carbon atoms; Nitrogen-containing solvents such as N-methyl-2-pyrrolidone, 2-pyrrolidone and N, N-dimethylacetamide; Lactones such as γ-butyrolactone; Acyclic esters such as butyl acetate; Ketones such as methyl isobutyl ketone and methyl ethyl ketone And glycol ethers such as butyl cellosolve.

As the aromatic hydrocarbon solvent, commercially available products such as Solvesso 100, Solvesso 150, Solvesso 200 (all trade names, manufactured by Exxon Chemical) may be used. As the saturated hydrocarbon solvent, a commercially available mineral spirit (Japanese Industrial Standard, Industrial Gasoline No. 4) or the like may be used. The said organic liquid (E) may be used independently and may use 2 or more types together.

As the organic liquid (E), a nitrogen-containing solvent is preferably used, and N-methyl-2-pyrrolidone and N, N-dimethylacetamide are more preferably used.

The aqueous medium may be, for example, one in which various additives described below are dissolved or dispersed. The aqueous medium may be the aqueous medium used for the polymerization of the fluoropolymer (B) or may be prepared separately from the aqueous medium used for the polymerization. When (B) is obtained by emulsion polymerization or suspension polymerization, the aqueous medium used for the polymerization of the fluoropolymer (B) can be used as it is.

The composition for water-based paints of the present invention may contain a known resin, if necessary, in addition to the fluoropolymer (B) and the heat-resistant resin (A). By blending other known resins, it may be possible to improve the film forming property, corrosion resistance, etc. of the coating film obtained from the aqueous coating composition.
The other resin is not particularly limited, and examples thereof include phenol resin, urea resin, epoxy resin, urethane resin, melamine resin, polyester resin, polyether resin, acrylic resin, acrylic silicone resin, silicone resin, and silicone polyester resin. Can be mentioned.

The composition for water-based paints of this invention may contain the pigment as needed. By including the pigment, the coating film obtained from the aqueous coating composition can be colored. Although it does not specifically limit as a pigment, Carbon black, titanium oxide, iron oxide etc. can be illustrated.

The aqueous coating composition of the present invention further contains various additives usually used in general coating compositions for the purpose of improving the properties of the coating film obtained from the coating property and the aqueous coating composition. May be. The various additives are not particularly limited, and are selected according to the use of a coated article described later obtained by using the aqueous coating composition of the present invention. For example, a leveling agent, a solid lubricant, mica filling, etc. Materials, pigment dispersants, anti-settling agents, moisture absorbers, surface modifiers, thixotropic agents, viscosity modifiers, anti-gelling agents, UV absorbers, light stabilizers, plasticizers, anti-coloring agents, skinning Examples thereof include an inhibitor, an anti-scratch agent, an antifungal agent, an antibacterial agent, an antioxidant, an antistatic agent and a silane coupling agent.

The aqueous coating composition of the present invention preferably has a viscosity at 25 ° C. of 0.1 to 50000 mPa · s. If the viscosity is less than 0.1 mPa · s, sagging or the like is likely to occur during application on the object to be coated, and it may be difficult to obtain the desired film thickness. The workability may be deteriorated, the film thickness of the obtained coating film may not be uniform, and the surface smoothness and the like may be inferior. A more preferred lower limit is 1 mPa · s, and a more preferred upper limit is 30000 mPa · s. The said viscosity is a value obtained by measuring using a BM type single cylinder type rotational viscometer (made by Tokyo Keiki Co., Ltd.).

The aqueous coating composition of the present invention may be a coating composition used for a one-coat described later or a primer composition used for a two-coat described later, but is suitable for a primer composition.

When using the composition for water-based paints of this invention as a primer composition, the said heat resistant resin (A) is 10-50 mass% of the total solid content mass of the said heat resistant resin (A) and a fluoropolymer (B). It is preferable that
In the present specification, the above-mentioned “total solid mass of the heat-resistant resin (A) and the fluoropolymer (B)” refers to 80 to 100 after the aqueous coating composition of the present invention is applied on an object to be coated. It means the total mass of the heat-resistant resin (A) and the fluoropolymer (B) in the residue after drying at a temperature not higher than ° C. and baking at 380 to 400 ° C. for 45 minutes.
When the heat resistant resin (A) is less than 10% by mass of the total solid content of the heat resistant resin (A) and the fluoropolymer (B), the heat resistant resin is small, and thus the heat resistant resin (A) is obtained from the aqueous coating composition. In some cases, the adhesion between the coating film and the object to be coated is insufficient. When it exceeds 50 mass%, since there are few fluoropolymers (B), there exists a possibility that the adhesiveness of the said coating film and top coat film may be inadequate. A more preferred lower limit is 15% by mass, and a more preferred upper limit is 40% by mass.

The aqueous coating composition of the present invention can be prepared by a conventionally known method. For example, the heat-resistant resin (A), the fluoropolymer (B), the metal powder (C) and the specific alcohol ( D), and an organic liquid (E) blended as necessary and other resins are mixed as appropriate and dispersed in the aqueous medium to obtain an aqueous dispersion. If necessary, a viscosity modifier or the like is used. Examples include a method of adjusting the viscosity to be easily applied and blending various additives other than the viscosity modifier as desired. The composition for water-based paints of the present invention is prepared by preparing in advance respective dispersions such as the heat-resistant resin (A), the fluoropolymer (B), the metal powder (C), and a pigment to be blended as necessary. The dispersion may be prepared by mixing the obtained dispersion and the specific alcohol (D). For the preparation of each of the above dispersions, a nonionic surfactant or the like may be used as necessary.

The aqueous coating composition of the present invention also contains the fluoropolymer (B), so that when the aqueous coating composition is a coating composition used for one-coat described later, Lubricity etc. can be provided, and when it is a primer composition used for the below-mentioned two coat, the adhesiveness of the coating film obtained by coating and the below-mentioned top coat film can be improved.
Since the composition for water-based paint of the present invention contains the heat-resistant resin (A), the heat-resistant resin has adhesiveness to the object to be coated, so that the coating film obtained by coating is applied to the object to be coated. It has excellent adhesion.
By including the specific alcohol (D), the aqueous coating composition of the present invention is excellent in stirring stability and can provide a coating film excellent in glitter when coated.

Since the composition for water-based paints of this invention contains the said specific alcohol (D), when it coats as a paint composition, it can form the coating film excellent in the glitter.
A method for producing a glitter coating film comprising coating the composition for water-based paint of the present invention on an object to be coated is also one aspect of the present invention.
The object to be coated will be described later.

Since the composition for water-based coatings of this invention consists of the above-mentioned structure, it can be used suitably for preparation of a coated article as a coating composition.
Preparation of the said coated article consists of apply | coating the composition for water-based coatings of this invention on a to-be-coated article, and obtaining a coating film by drying as needed.
The aqueous coating composition of the present invention contains a liquid composition (A01) comprising the specific alcohol (D), an aqueous solution containing a heat resistant resin (A), a fluoropolymer (B), and a metal powder (C). An aqueous composition (A02) composed of a dispersion may be mixed before coating. Specifically, the liquid composition (A01) and the aqueous composition (A02) are stored separately, and the liquid composition (A01) and the aqueous composition (A02) are mixed and stirred immediately before coating. Therefore, it is also possible to paint, and by this method, the glitter of the coating film is further improved.

The material to be coated is not particularly limited, and examples thereof include simple metals such as iron, aluminum, and copper and metals such as alloys thereof; nonmetallic inorganic materials such as enamel, glass, and ceramics. Examples of the alloys include stainless steel.
The object to be coated may be subjected to a surface treatment such as a degreasing treatment or a roughening treatment in advance according to the type. The surface roughening treatment method is not particularly limited, and examples thereof include chemical etching with acid or alkali, anodization (alumite treatment), and sandblasting. The surface treatment is preferably performed from the viewpoint that the water-based coating composition can be uniformly applied without causing repellency and the adhesion between the object to be coated and the coating film is improved.

The application method is not particularly limited, and examples thereof include spray coating, roll coating, doctor blade coating, dip (immersion) coating, impregnation coating, spin flow coating, and curtain flow coating.
It does not specifically limit as said drying, For example, a conventionally well-known method etc. are used, and it is preferable to carry out for 5 to 60 minutes at the temperature of 60-300 degreeC.
In the case of one coat in which a top coat film is not laminated on the coating film, the coated article is produced by obtaining the coating film and then baking the coating film. The firing is not particularly limited. For example, a conventionally known method is used, and depending on the type of the fluoropolymer (B), the heat-resistant resin (A), etc., Perform for 30 minutes.

In the case of two coats in which a top coat film is laminated on the coating film, the coated article is prepared by obtaining the coating film, applying a top coating material on the coating film, and drying if necessary. By baking, a coating film composed of the composition for water-based coatings and a top coating film composed of a top coating composition are obtained.

In the present specification, the “top coating material” is a coating material applied on the coating film, and is made of a fluoropolymer for top coating. The topcoat fluoropolymer is a polymer having a fluorine atom directly bonded to a carbon atom constituting the main chain or side chain. The above-mentioned fluoropolymer for topcoat is common with the above-mentioned fluoropolymer (B) in that it is a polymer having a fluorine atom directly bonded to a carbon atom constituting the main chain or side chain. It is conceptually different from the fluoropolymer (B) blended in the aqueous coating composition of the present invention in that it is blended in the coating composition. When the above-mentioned fluoropolymer for topcoat is present in the above-mentioned topcoat film, it can impart non-adhesiveness, lubricity, etc. to the object to be coated, and has an affinity for the above-mentioned fluoropolymer (B). Since it has, adhesiveness with the said coating film can also be improved.

The topcoat fluorine-containing polymer is not particularly limited, and examples thereof include PTFE, PFA, FEP, and the like. From the viewpoint of improving the interlayer adhesion between the above coating film and the topcoat film, the water-based paint of the present invention. The same as the above-mentioned fluoropolymer (B) in the composition for use, or those having similar properties such as the presence or absence of melt processability are preferred. Examples of the top coating include a PTFE paint whose main component is PTFE, a PFA paint whose main component is PFA, an FEP paint whose main component is FEP, and the like.

In addition to the above-mentioned fluoropolymer for topcoat, the above topcoat paint further contains additives similar to the various additives that can be used in the above-mentioned aqueous paint composition for the purpose of improving paintability and properties of the resulting coating film. You may mix | blend.

For example, when the main component is PTFE, PFA or FEP, examples of the top coat include liquid coatings such as aqueous dispersion-based paints and solvent-based paints. When the main component is PFA or FEP, Can be mentioned.

In the case where a liquid paint is used as the top coat, the coating film is not usually fired before the top coat is applied, but may be fired as necessary. It is preferable not to perform the baking before applying the top coating because it can simplify the process and reduce energy, labor, time, and the like.
When the powder coating is used as the top coating, the coating film is usually fired before the top coating is applied.

The method for applying the top coating is not particularly limited. For example, when the top coating is a liquid coating, the same method as the method for applying the aqueous coating composition of the present invention can be used. When is a powder paint, electrostatic spray coating, fluidized dip coating, and a rotational training method can be used.
Drying and baking after applying the above-mentioned top coating material can be performed under the same conditions as drying and baking after applying the above-mentioned aqueous coating composition.

In the case of the above-described two-coat, the coated article may be obtained by using the film instead of the top coat.
In the present specification, the film is mainly composed of the above-mentioned fluoropolymer for topcoat, and is formed into a film shape. When the film is used for forming the top coat film, a conventionally known method such as placing the film on the coating film and bringing the coating film and the film into close contact by thermocompression bonding is used. Can do.

The film thickness of the coating film after baking and the film thickness of the top coating film are not particularly limited, and depending on the use of the coated article, the film thickness of the coating film is 1 to 100 μm, and the film of the top coating film The thickness is preferably 10 to 200 μm.

When the coating film is formed on the object to be coated by the above-mentioned one-coat, the non-adhesiveness, lubricity, etc. of the fluoropolymer (B) can be imparted to the object to be coated. When the top coat film is laminated on the above-mentioned coating film by the above-mentioned two coat, both the adhesiveness to the object to be coated and the adhesiveness to the above-mentioned top coat film are excellent.

The said coated article consists of a to-be-coated article and the said coating film, Comprising: The said coating film was obtained by coating the above-mentioned composition for water-based paints of this invention on the said to-be-coated article. Is. As long as the said covering article consists of the said to-be-coated article and the said coating film at least, it may have the said top coat film further.

Since the coating film is obtained from the above-described aqueous coating composition of the present invention, it is excellent in glitter.
Since the fluoropolymer (B) and the heat-resistant resin (A) have a difference in surface tension, the fluoropolymer (B) floats during firing, and the coating film has a surface side. The above-mentioned fluoropolymer (B) is mainly disposed, and the above heat-resistant resin (A) is mainly disposed on the object to be coated.
Since the heat-resistant resin (A) has adhesiveness to the object to be coated, the coating film can have excellent adhesion to the object to be coated. Moreover, since the said fluoropolymer (B) has affinity with the said fluoropolymer for topcoats, when adhering a topcoat film on a coating film, the said coating film has adhesiveness with a topcoat film. Also excellent.

The said coated article can be used for the use using the characteristic which the fluoropolymer (B) used for the above-mentioned one coat, or the fluoropolymer for topcoats used for the above-mentioned two coats has.

The coated article is not particularly limited. For example, when non-adhesiveness is used as the above characteristic, a frying pan, a grill pan, a pressure cooker, other various pans, a rice cooker, a mochi cooker, an oven, a hot plate, a baking pan Cooking utensils such as kitchen knives and gas tables; Food and beverage containers such as electric pots and ice trays; Food industry parts such as kneading rolls, rolling rolls and conveyor hoppers; Rolls for office automation equipment [OA], belts for OA, and papermaking Industrial goods such as rolls and calendar rolls for film production; molds for foamed polystyrene molding, mold release such as release plates for plywood and decorative board production; kitchen supplies such as range hoods; frozen foods such as conveyor belts A manufacturing apparatus etc. are mentioned.
As the above-mentioned coated article, when sliding is used as the above-mentioned property, tools such as saws and files; household items such as irons; metal foils; sliding bearings for food processing machines, packaging machines, textile machines, etc .; cameras・ Sliding parts for watches; automobile parts.

Since the composition for water-based paints of the present invention has the above-described configuration, it is excellent in stirring stability, excellent in glitter of the coating film after drying and baking, and excellent in adhesion to an object to be coated. It can be obtained. Since the method for producing a glittering coating film of the present invention is obtained by coating the above-mentioned composition for water-based paint, a coating film having excellent glitter can be obtained.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. Hereinafter, “%” and “part” represent mass% and mass part, respectively.
Production Example 1 Preparation of Polyethersulfone Resin Aqueous Dispersion 60 parts of polyethersulfone resin [PES] having a number average molecular weight of about 24,000 and 60 parts of deionized water are completely pulverized in a ceramic ball mill. Stir for about 10 minutes. Next, 180 parts of N-methyl-2-pyrrolidone [NMP] 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 having a PES concentration of about 20%. The particle diameter of the particles composed of PES in the PES aqueous dispersion was 2 to 3 μm.

Production Example 2 Preparation of Polyamideimide Resin Aqueous Dispersion Polyamideimide resin [PAI] varnish (containing 71% NMP) having a solid content of 29% was poured into water to precipitate PAI. This was pulverized for 48 hours in a ball mill to obtain an aqueous PAI dispersion. In the obtained PAI aqueous dispersion, the solid content was 20%, and the average particle diameter of the particles composed of PAI was 2 μm.

Production Example 3 Preparation of Aqueous Dispersion of Pigment A mixture of 90.2 parts of deionized water, 6.24 parts of nonionic surfactant and 31.1 parts of carbon was mixed using a ball mill to prepare an aqueous dispersion of pigment. Prepared.

Example 1
The PAI aqueous dispersion obtained in Production Example 2 was added to a polytetrafluoroethylene [PTFE] aqueous dispersion (average particle size 0.28 μm, solid content 60%, polyether nonionic surfactant (HLB value = HLB = 14) is added so that the PAI is 20% of the total solid mass of PAI and PTFE, and the pigment obtained in Production Example 3 is added. An aqueous dispersion was added so as to be 12.3% of the total solid content mass of PAI and PTFE, and an aqueous dispersion containing aluminum powder (average particle size 25 μm, dispersed in water of the same mass) was added to the aluminum powder. The content is added so as to be 3 parts with respect to 100 parts of the total solid content of PAI and PTFE, and 0.7 parts of methyl cellulose as a thickener is added with respect to 100 parts of the solid content of PTFE. As a dispersion stabilizer, 6 parts of polyoxyethylene tridecyl ether (HLB value = 10) was added to 100 parts of the solid content of PTFE to obtain a coating composition having a solid content of PTFE of 34%. 18 parts of furfuryl alcohol is added to 100 parts of PAI and PTFE solids in this coating composition and stirred to prepare an aqueous coating composition, which is immediately applied, and an evaluation coating plate according to the procedure shown below. Was made.
The following evaluation was performed about the said composition for water-based paints, and the coating plate for evaluation.

(Preparation of evaluation paint plate)
After degreasing the surface of an aluminum plate (A-1050F) having a thickness of 2.0 mm with acetone, sand blasting was performed so that the surface roughness Ra value measured according to JIS B 1982 was 2.5 to 3.5 μm. And roughened. After removing dust on the surface by air blowing, the resulting aqueous coating composition was dried using a gravity spray gun RG-2 (trade name, manufactured by Anest Iwata Co., Ltd., nozzle diameter: 1.0 mm). Was applied by spray coating at a spraying pressure of 0.2 MPa so that the thickness was 10-15 μm. The obtained coating film was dried at 80 to 100 ° C. for 15 minutes and cooled to room temperature. On the obtained coating film, an aqueous paint polyflon PTFE EK-3700C-201 (trade name, manufactured by Daikin Industries) containing PTFE as a top coat is applied by spray coating under the same conditions, and at 80 to 100 ° C. Dry for 15 minutes. Thereafter, it was baked at 380 ° C. for 20 minutes to produce an overcoat film having a film thickness of about 20 μm, and an evaluation coated plate was obtained.

(Appearance of coating film)
In the process of producing the above-mentioned evaluation coated plate, the appearance (brightness) of the coated plate after applying the top coating, then drying and firing was visually observed, and evaluated based on the following criteria.
Judgment criteria A : Remarkably good.
○: Good.
Δ: Slightly inferior
X: Inferior.
(Stirring stability)
100 g of the aqueous coating composition was placed in a 100 ml capacity Stirens beaker and stirred continuously at 40 rpm at 300 rpm. Evaluation was made based on the following criteria, using as a guide the time from the start of stirring to the gelation of the aqueous coating composition.
Criteria A : Does not gel for 3 hours or more.
○: Gelation occurs in 1 to 3 hours.
Δ: Gelled within 1 hour.

Example 2
The PES aqueous dispersion obtained in Production Example 1 and the PAI aqueous dispersion obtained in Production Example 2 were mixed so that PES was 80% of the total solid mass of PES and PAI. PTFE aqueous dispersion (average particle size 0.28 μm, solid content 60%, polyether nonionic surfactant (HLB value = 14) as a dispersant, 6 parts per 100 parts of PTFE solid content) ) So that PES and PAI are 20% of the total solid mass of PES, PAI and PTFE, and the aqueous dispersion of the pigment obtained in Production Example 3 is added to the total solid mass of PES, PAI and PTFE. The aqueous powder containing aluminum powder (dispersed in water having an average particle size of 25 μm and the same mass) was added to PSA, PAI and PTFE. Addition of 3 parts to 100 parts of solid content, 0.7 part of methylcellulose as a thickener to 100 parts of solid content of PTFE, polyoxyethylene tridecyl ether (HLB value) as dispersion stabilizer = 10) was added in an amount of 6 parts to 100 parts of the solid content of PTFE to obtain a coating composition having a solid content of PTFE of 34%. To this coating composition, 18 parts of furfuryl alcohol was added to 100 parts of PES, PAI, and PTFE solids, stirred, and immediately coated.
Using the resulting aqueous coating composition, an evaluation coated plate was prepared and evaluated in the same manner as in Example 1.

Examples 3-7
A coating composition and an aqueous coating composition were prepared and evaluated in the same manner as in Example 1 except that the type of alcohol (D) added to the coating composition was changed to that shown in Table 1, respectively.

Comparative Example 1
A coating composition was obtained in the same manner as in Example 1 except that no furfuryl alcohol was added.
Using the resulting aqueous coating composition, an evaluation coated plate was prepared and evaluated in the same manner as in Example 1.

Comparative Example 2
A coating composition was obtained in the same manner as in Example 2 except that no furfuryl alcohol was added.
Using the obtained aqueous coating composition, an evaluation coated plate was prepared and evaluated in the same manner as in Example 2.
The results of each example and each comparative example are shown in Table 1.

As shown in Table 1, in Examples 1 to 7 to which alcohol (D) was added, the glitter was remarkably good, but in Comparative Examples 1 to 2 in which alcohol (D) was not added, the glitter was inferior. . Further, the aqueous coating composition of Example 4 to which 3-methoxy-3-methyl-1-butanol was added as the alcohol (D) had excellent stirring stability, and each of the above-mentioned alkylenes was used as the alcohol (D). The aqueous coating compositions of Examples 3 and 5-7 to which glycols were added were very excellent in stirring stability.

The composition for water-based paints of the present invention is excellent in stirring stability, has good glossiness of the coating film after drying and baking, and can obtain a coating film having excellent adhesion to the object to be coated. Therefore, it can be widely used for manufacturing various coated articles.
Since the method for producing a glittering coating film of the present invention is obtained by coating the above-mentioned composition for water-based coatings, it is possible to obtain a coating film having excellent glittering properties, and is suitable for coating various electrical appliances. Can be used.

Claims (8)

It comprises an aqueous dispersion containing a heat-resistant resin (A) and a fluoropolymer (B), and further comprises a metal powder (C) and a water-soluble alcohol (D) having a boiling point of 100 ° C. or higher. A water-based paint composition characterized by the above. The composition for water-based paint according to claim 1, wherein the alcohol (D) has a boiling point of 170 ° C or higher and a surface tension of 40 dyn / cm or lower. The alcohol (D) is represented by the following general formula (I)
_{R- (OCH 2 CH 2) n} - (OCH 2 CH 2 CH 2) m -OH (I)
(In the formula, R represents H or an alkyl group having 1 to 4 carbon atoms, n represents an integer of 0 to 3, and m represents an integer of 0 to 2. However, (n + m) = 1 to The composition for water-based paints according to claim 1 or 2, which is an oxyalkylene unit-containing alcohol represented by formula (3). The composition for water-based paints of Claim 1 or 2 containing furfuryl alcohol as alcohol (D). The composition for water-based paint according to claim 1, wherein the heat-resistant resin (A) is a polyamide-imide resin and / or a polyimide resin. The heat resistant resin (A) is a polyethersulfone resin, a polyamideimide resin and / or a polyimide resin,
The water-based paint according to claim 1, 2, 3, 4 or 5, wherein the polyethersulfone resin is 65 to 85 mass% of a total mass of the polyethersulfone resin and the polyamideimide resin and / or the polyimide resin. Composition. The fluoropolymer (B) is polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, and / or tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer, The composition for water-based paints according to 3, 4, 5 or 6. A method for producing a glittering coating film comprising coating an aqueous coating composition on an object to be coated,
The method for producing a glittering coating film, characterized in that the composition for water-based paint is the composition for water-based paint according to claim 1, 2, 3, 4, 5, 6 or 7.