JPH1147685A - Coated article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a rust preventing property of a coating specification on a surface of a metal such as iron by forming a multilayer coating film having a lower layer coating film consisting of a coating film incorporated with a specified amount of zinc powder per binder and an uppermost layer coating film consisting of the coating film having a water contact angle of a specified value on the surface of the metal. SOLUTION: In the case that a rust preventive coating film having a high water repellency and also an excellent rust preventing property is provided, the multilayer coating film having the lower layer coating film consisting of the coating film containing 150-2000 pts.wt. zinc powder per 100 pts.wt. binder and the uppermost layer coating film consisting of the coating film having >=120 deg. contact angle is formed on the surface of the metal. The uppermost layer coating film is obtained by a method in which the surface of the coating film is roughened by fixing a blast or particulate powder or the method in which a thin film protective layer having the coating film having a thickness not more than 1/2 of a surface roughness of the coating film is formed on the roughened surface of the coating film having the surface having a fine rugged structure obtained by fixing the blast or particulate powder and the roughened part is coated with the thin film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated article having a rust-preventive coating film having a high water repellency and an excellent rust-preventive property formed on a metal surface.

[0002]

2. Description of the Related Art In order to prevent corrosion of a metal surface, a coating is generally formed by applying a paint. In particular, since the iron surface is easily corroded, rust-preventive treatment of an article having iron on the surface has conventionally been performed by applying a paint containing zinc powder or a paint containing an epoxy resin to the iron surface.

[0003]

However, the rust prevention treatment of the prior art described above has a problem that rust prevention is insufficient for applications requiring a higher degree of rust prevention. An object of the present invention is to provide a coated article that has high water repellency on a metal surface such as iron and at the same time has excellent rust prevention.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, the uppermost layer having high water repellency, which has been considered to have no influence on the rust-preventing effect up to now. By forming a coating film on a rust-preventive coating film on a metal surface such as conventional iron, it has been found that the rust-prevention property of a conventional metal surface such as iron can be further improved in a coating specification, and the present invention It was completed. That is, the present invention
150 to 20 zinc powder per 100 parts by weight of binder
A multilayer coating having a lower coating consisting of a coating containing 00 parts by weight and an uppermost coating consisting of a coating having a contact angle of water of 120 ° or more is formed on a metal surface. It is intended to provide a painted article to be made.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The rust preventive coating of the present invention has a multilayer coating having an uppermost coating and a lower coating on the surface of a corrosive metal such as iron. The coating film used as the uppermost coating film is a coating film having a water contact angle of 120 ° or more, and preferably a coating film having a water contact angle of 135 to 175 °. Such an uppermost layer coating film is formed by, for example, (1) a method of roughening the coating film surface by blasting or fixing of fine particle powder, and (2) a fine uneven structure obtained by blasting or fixing of fine particle powder. A method of forming a thin film protective layer having a thickness equal to or less than half of the surface roughness of the coating film on the roughened surface of the coating film having the surface, and coating the rough surface portion with a thin film; In the above method, the protective layer is obtained by a method in which the protective layer is formed of a thin film of a resin having a side chain terminal represented by the general formula (1).

[0006]

Embedded image CF ₃ CF (X) (CF ₂ ) _2- (1)

(Where X is F, CF ₃ or CF ₂ Cl
The surface roughness (center plane average roughness) of the fine uneven structure is 0.1.
It is preferably from 50 to 50 m, and particularly preferably from 1 to 15 m.

As a specific example of the surface of the fine uneven structure,
For example, a surface obtained by means of roughening the surface of the coating film by blasting or the like, a method of fixing fine particle powder on the surface of the coating film, a foamed resin surface, or a fine surface formed by a finely processed resist. An uneven surface or the like can be exemplified, but is not particularly limited as long as the surface of the fine uneven structure shows water repellency. As means for roughening the surface of the coating film by blasting or the like, for example, a method of dispersing fine particle powder such as PTFE in a curable resin coating material to form a coating film and then blasting to roughen the surface. , A method of blasting the surface of the fluororesin coating to roughen the surface, a method of roughening the surface of the fluororesin coating by contacting fluorine gas after blasting the surface,
And a method of blasting after heat-treating a resin coating film obtained by mixing a fluororesin powder into a thermoplastic resin as necessary. As means for roughening by fixing the fine particle powder, for example, a curable resin paint is applied to the surface of the base material, and the uncured surface of the paint is collided so as to partially embed the fine powder, and then A method of curing a coating, fixing the fine particle powder to a resin to form a roughened surface, applying a curable resin coating, drying the applied coating surface, and then dispersing the fine particle powder in a dispersion medium. A method of spray-coating a liquid onto the surface of the dried paint, evaporating the dispersion medium to cure the curable resin paint, and embedding and fixing a part of the fine particle powder to form a roughened surface is exemplified. When the curable resin paint is cured by spray coating, it is preferable that after the spray coating, the surface of the dried paint is swelled and softened by a dispersion medium of fine particle powder, and then the dispersion medium is evaporated to cure the curable resin paint.

The thermoplastic resin used in the method for forming the surface of the fine uneven structure is not particularly limited. For example, thermoplastic fluororesin, thermoplastic acrylic resin, polyethersulfone resin, polyphenylenesulfide resin, Examples include a vinyl chloride resin, a polycarbonate resin, a polyamide resin, a polyolefin resin, and a polystyrene resin. Preferred thermoplastic resins are thermoplastic fluororesins, for example, tetrafluoroethylene-perfluoro (propylvinylether) copolymer resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, polychlorotrifluoroethylene resin, tetrafluoroethylene resin. Examples include an ethylene-ethylene copolymer resin, a chlorotrifluoroethylene-ethylene copolymer resin, a polyvinylidene fluoride resin, and a polyvinyl fluoride resin.

The curable resin paint in the present invention means a resin in which the resin in the paint is a thermosetting resin or a resin which is cured by using a curing agent. These resins include thermosetting fluororesin, thermosetting acrylic resin, thermosetting acrylic silicone resin, thermosetting acrylic urethane resin, etc., and are preferably thermosetting fluororesin, thermosetting acrylic silicone resin. It is.

Fine particle powders include, for example, graphite fluoride; pitch fluoride; polytetrafluoroethylene resin;
Fluorinated resins such as the aforementioned thermoplastic fluorine resins; Thermoplastic resins such as polyethylene, polyvinyl chloride, and elastomers; Thermosetting resins such as urea resins, phenolic resins, and silicone resins; Engineering such as polyamide resins, polycarbonates, and polymer alloys Plastics; metals; metal oxides; minerals; glass; sand; ceramics; fluorinated fine silica; and the like. The particle size of the fine particle powder is not particularly limited, but the average particle size is usually preferably 0.1 to 100 μm, more preferably 0.1 to 50 μm, and particularly preferably 2 to 20 μm. The average particle size of the fluororesin powder to be mixed with the thermoplastic resin is preferably 1 to 10 μm, more preferably 2 to 7 μm.

The material for forming the thin film protective layer is preferably a hydrophobic material. As such a hydrophobic material, a material having a water contact angle of 40 ° or more, preferably 80 ° or more, or a water absorption rate of 0.5 % Or less. Such materials include epoxy resin, urethane resin, silicone resin, fluorine resin, fluorosilicone resin, acrylic resin, polycarbonate resin, phenol resin, polyester resin, polyamide resin, polyimide resin, polyether sulfone resin, polyphenylene sulfide resin, Examples thereof include a photopolymerizable resin, a vinyl chloride resin, a polyolefin resin such as polyethylene and polypropylene, and a polystyrene resin, and preferred are a fluororesin, a silicone resin, and a fluorosilicone resin.

As the fluororesin, a resin having a side chain terminal group represented by the general formula (1) (hereinafter abbreviated as _Rf group) is particularly preferred. Resins having _the R _f group refers to at least _the R _f group one having resin in one molecule of the polymer constituting the resin. Specific examples of the resin having _the R _f group may, for example, perfluoroalkyl acrylate homopolymers thereof, homopolymers of monomers containing _the R _f group such as perfluoroalkyl methacrylate homopolymer product, R _f
A copolymer of two or more different comonomers containing a group, one or more comonomers containing an _Rf group and solubility in a solvent, film-forming properties, weatherability, lubricity, etc. A copolymer with one or more comonomers may be used, but is not particularly limited. When using a copolymer of a comonomer containing an R _f group and a comonomer not containing an R _f group, the oil repellency tends to decrease as the composition of the comonomer containing an R _f group decreases, and the R _f group in the polymerization composition is reduced. The composition of the comonomer to be contained is desirably 20% by weight or more, preferably 40% by weight or more.

The monomer containing an R _f group may contain a chlorine atom or a hydrogen atom at the other branched terminal as long as it contains an R _f group, but is preferably a linear or branched one. A monomer having an _Rf group as a terminal of a perfluoroalkyl group or a perfluoroether group of the following is desirable, and the following acrylate or methacrylate in which the side chain terminal of the polymer can have a structure represented by the general formula (1) And unsaturated esters.

[0015]

Embedded image CF ₃ (CF ₂ ) ₄ CH ₂ OCOC (CH ₃ ) = CH ₂ CF ₃ (CF ₂ ) ₆ (CH ₂ ) ₂ OCOC (CH ₃ ) = CH
_{2 CF 3 (CF 2) 6} COOCH = CH 2 CF 3 (CF 2) 7 (CH 2) 2 OCOCH = CH 2 CF 3 (CF 2) 7 (CH 2) 2 OCOC (CH 3) = CH 2 (CF ₃ ) ₂ CF (CF ₂ ) ₅ (CH ₂ ) ₂ OCOCH = CH
_{2 CF 3 (CF 2) 7} SO 2 N (C 3 H 7) (CH 2) 2 OCOC
H = CH ₂ CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₄ OCOCH = CH ₂ CF ₃ (CF ₂ ) ₇ SO ₂ N (CH ₃ ) (CH ₂ ) ₂ OCOC
(CH ₃ ) = CH ₂ CF ₃ (CF ₂ ) ₇ SO ₂ N (C ₂ H ₅ ) (CH ₂ ) ₂ OCOC
_{H = CH 2 CF 3 (CF} 2) 7 CONH (CH 2) 2 OCOCH = CH 2 (CF 3) 2 CF (CF 2) 6 (CH 2) 3 OCOCH = CH
₂ (CF ₃ ) ₂ CF (CF ₂ ) ₆ CH ₂ CH (OCOCH ₃ ) O
_{COC (CH 3) = CH 2} (CF 3) 2 CF (CF 2) 6 CH 2 CH (OH) CH 2 OC
_{OCH = CH 2 CF 3 (CF} 2) 8 (CH 2) 2 OCOCH = CH 2 CF 3 (CF 2) 8 (CH 2) 2 OCOC (CH 3) = CH 2 CF 3 (CF 2) 8 CONH (CH ₂ ) ₂ OCOC (CH ₃ )
ＣＨCH ₂ CF ₃ (CF ₂ Cl) CF (CF ₂ ) ₇ CONHCOOCH
_{= CH 2 CH 2 = CHCOOC 2} H 4 OCOCF (CF 3) (OC 3
F ₆ ) ₂ OC ₄ F ₉ CH ₂ ＣＨCHCONHC ₂ H ₄ OCOCF (CF ₃ ) OC ₃
F ₆ OC ₄ F ₉ CH ₂ ＣC (CH ₃ ) CONHC ₂ H ₄ OCOCF (C
F ₃ ) OC ₄ F ₉

The comonomer which can be copolymerized with the above-mentioned comonomer having an _Rf group can be selected from a wide range as long as the action of the present invention is not impaired. For example, ethylene, vinyl acetate, vinyl chloride, vinyl fluoride, halogenated Vinylidene, styrene, α-methylstyrene, p-methylstyrene, (meth) acrylic acid and its alkyl ester, poly (oxyalkylene) (meth) acrylate, (meth)
Acrylamide, diacetone (meth) acrylamide,
Methylolated diacetone (meth) acrylamide, N-
Methylol (meth) acrylamide, vinyl alkyl ether, halogenated alkyl vinyl ether, vinyl alkyl ketone, butadiene, isoprene, chloroprene, glycidyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate , Maleic anhydride, aziridinyl (meth) acrylate, (meth) acrylate having polysiloxane, N-vinylcarbazole, and the like. Here, (meth) acryl means methacryl and acryl, and (meth) acrylate means methacrylate and acrylate, respectively.

In order to obtain the resin having the R _f group,
A method of dissolving the raw material monomer in an appropriate organic solvent and performing solution polymerization by the action of a polymerization initiation source can be usually employed.
Suitable solvents for solution polymerization include, for example, toluene, ethyl acetate, isopropanol, dichloropentafluoropropane, tetrachlorodifluoroethane, methylchloroform and the like. In the present invention, the resin having an _Rf group can be used alone or in combination of two or more.

As the thermosetting fluororesin, a wide range can be used without any particular limitation, and it is obtained by copolymerizing a fluoroolefin known as a fluororesin for paint and a monomer copolymerizable therewith. Resin (hereinafter, referred to as resin (a)) has solubility in a solvent, weather resistance of a coating film,
It is preferable from the viewpoint of painting workability and the like. Examples of the fluoroolefin include C2 or C3 fluoroolefins such as tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, hexafluoropropylene, and pentafluoropropylene. As monomers copolymerizable with the fluoroolefin, vinyl ether, vinyl carboxylate,
Allyl ether, carboxylic acid allyl ester, isopropenyl ether, carboxylic acid isopropenyl ester,
Methallyl ether, carboxylic acid methallyl ester, α-
At least one monomer selected from olefins, acrylic esters, methacrylic esters, and the like is included.

Here, as the vinyl ether, ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, fluoroalkyl vinyl ether,
Examples thereof include alkyl vinyl ethers such as perfluoro (alkyl vinyl ether). As the vinyl carboxylate, Veova-10 having a branched alkyl group can be used.
(Trade names, manufactured by Shell Chemical Co., Ltd.), fatty acid vinyl esters such as vinyl butyrate, vinyl acetate, vinyl pivalate and vinyl versatate, and vinyl aromatic carboxylate such as vinyl benzoate. Examples of the allyl ether include an alkyl allyl ether such as ethyl allyl ether and cyclohexyl allyl ether. Allyl carboxylate includes allyl propionate,
Fatty acid allyl esters such as allyl acetate are exemplified. Examples of the isopropenyl ether include an alkyl isopropenyl ether such as methyl isopropenyl ether. As the α-olefin, ethylene, propylene,
Isobutylene and the like are exemplified.

If the copolymerization ratio of the fluoroolefin is too small, sufficiently excellent weather resistance as a weather-resistant paint cannot be exhibited. On the other hand, if the copolymerization ratio of the fluoroolefin is too large, the solubility in a solvent and the like are reduced, so that it is not preferably used. Therefore, the resin (a)
It is preferable that the polymerization unit based on the fluoroolefin is contained in the copolymer in a proportion of 30 to 70 mol%, particularly, in a proportion of 40 to 60 mol%. Resin (a)
It is preferable from the viewpoint of solubility in a solvent and the like that a compound as described above is copolymerized in addition to the fluoroolefin. In particular, vinyl ether, vinyl carboxylate, allyl ether and allyl carboxylate are preferred because of their excellent copolymerizability with fluoroolefin. Further, alkyl vinyl ethers having a linear, branched or alicyclic alkyl group having 1 to 10 carbon atoms, fatty acid vinyl esters, alkyl allyl ethers, fatty acid allyl esters, and the like are preferable.

The resin (a) has a functional group capable of undergoing a cross-linking reaction with the curing agent (b) described below, in addition to the above-mentioned copolymer components, so that a tougher coating film can be obtained. Examples of the functional group include an active hydrogen-containing group capable of reacting with an isocyanate-based curing agent and an aminoplast-based curing agent, such as a hydroxyl group, an amino group, an amide group, and a carboxyl group.
In addition to the active hydrogen-containing groups, epoxy groups, halogens,
Functional groups such as double bonds are also exemplified. It is preferably an active hydrogen-containing group, and particularly preferably a hydroxyl group. As a method for introducing such a functional group, monomers having a functional group other than a double bond participating in polymerization, for example, hydroxybutyl vinyl ether, hydroxybutyl allyl ether, ethylene glycol monoallyl ether, cyclohexanediol monovinyl ether, acrylic There is a method of copolymerizing an acid, methacrylic acid, crotonic acid, undecenoic acid, glycidyl vinyl ether, glycidyl allyl ether, and the like.

Also, a method of introducing a functional group by modifying the copolymer, for example, by reacting a polybasic acid anhydride such as succinic anhydride with a copolymer having a hydroxyl group or an epoxy group to form a carboxyl group And a method in which isocyanate alkyl methacrylate or the like is reacted to modify the copolymer into a copolymer having a double bond. The copolymer unit having a functional group is preferably 5 to 20 mol% in the copolymer. As such a resin (a), for example, those commercially available under the trade names Lumiflon (Asahi Glass), Sefral Coat (Central Glass), Zaffron (Toa Gosei), Zeffle (Daikin Industries), Fluonate (Dainippon Ink Industries) and the like are used. it can.

The curing agent (b) is not particularly limited as long as it can crosslink the resin (a). Resin at room temperature (a)
Examples of the compound that undergoes a crosslinking reaction with a polyvalent isocyanate compound. Examples of the curing agent used for baking coating as a one-pack paint include an aminoplast-based curing agent and a blocked isocyanate-based curing agent. By crosslinking this curing agent (b) with the resin (a), a cured coating film having excellent physical properties can be formed. Examples of the aminoplast-based curing agent include methylolmelamines, methylolguanamines, and methylolureas. Examples of the methylol melamines include methylol melamine etherified with a lower alcohol such as butylated methylol melamine and methylated methylol melamine, and epoxy-modified methylol melamine. Examples of the methylol ureas include alkylated methylol ureas such as methylated methylol urea and ethylated methylol urea. When an aminoplast-based curing agent is used, a crosslinking reaction can be promoted by adding an acidic catalyst.

As the blocked isocyanate-based curing agent, there is a blocked product of a polyvalent isocyanate compound.
The polyvalent isocyanate compound is a compound having two or more isocyanate groups, and may be a compound having two or more isocyanate groups, which is a modified or multimeric form thereof. Polyvalent isocyanate compounds, specifically, aliphatic polyvalent isocyanate compounds such as ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, hexamethylene triisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diisocyanate methyl cyclohexane, etc. And a non-yellowing aromatic isocyanate compound such as m-xylene diisocyanate and p-xylene diisocyanate.

Examples of the modified and multimeric polyisocyanate compounds include those referred to as urethane modified products, urea modified products, isocyanurate modified products, buret modified products, allophanate modified products, carbodiimide modified products and the like. is there. In particular, there are a modified isocyanurate which is a trimer, and a modified urethane which is a reaction product with a polyhydric alcohol such as trimethylolpropane. Preferred polyvalent isocyanate compounds include non-yellowing isocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and multimers thereof. When a polyvalent isocyanate compound or a blocked isocyanate compound is used, the crosslinking reaction can be promoted by adding a known catalyst such as dibutyltin dilaurate.

The acrylic resin is not particularly limited as long as it is used as an acrylic resin for paints. For example, (meth) acrylic acid and / or alkyl (meth) acrylate and a monomer copolymerizable therewith And a resin having a functional group such as a hydroxyl group, a carboxyl group, or an epoxy group, which is obtained by copolymerizing the above. Here, (meth) acrylic acid is a general term for methacrylic acid and acrylic acid. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate,
Tertiary butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate and the like can be mentioned. Here, (meth) acrylate is a general term for methacrylate and acrylate.

Examples of the copolymerizable monomer include, for example,
Epoxy group-containing unsaturated monomers such as glycidyl (meth) acrylate; halogen-containing unsaturated monomers such as vinyl chloride and vinylidene chloride; aromatic unsaturated monomers such as styrene, α-methylstyrene and vinyltoluene; Carboxylic acid vinyl esters such as vinyl acetate, alkyl or cycloalkyl vinyl ethers such as ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether; unsaturated cyanide compounds such as (meth) acrylonitrile; (meth) acrylic acid, crotonic acid, itaconic acid, and maleic acid One or a combination of two or more of unsaturated monomers having a carboxyl group such as maleic anhydride and unsaturated monomers having a sulfonic acid group such as vinyl sulfonic acid, styrene sulfonic acid and sulfoethyl (meth) acrylate. Is mentioned. Here, (meth) acrylonitrile is a general term for methacrylonitrile and acrylonitrile. Examples of the curing agent capable of performing a crosslinking reaction with the acrylic resin include the same curing agents as those described above for the curing agent (b).

The acrylic silicone resin is not particularly limited as long as it is used as an acrylic silicone resin for coatings. For example, a homopolymer of a silane-containing acrylic monomer and a monomer copolymerizable therewith are copolymerized. And the polymer obtained by the above method. Preferred specific examples of the silane-containing acrylic monomer include, for example, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and the like. Examples of the copolymerizable monomer include, for example, the (meth) acrylic acid alkyl ester described above in the acrylic resin and a monomer copolymerizable therewith. Examples of the curing agent capable of performing a cross-linking reaction with the acrylic silicone resin include the same curing agents as those described above for the curing agent (b). Further, a curing catalyst such as an aluminum chelate may be used in combination.

The acrylic urethane resin is a combination of an acrylic resin component and a urethane resin component, and is not particularly limited as long as it is used as an acrylic urethane resin for paints. For example, the acrylic resin and the urethane resin are crosslinked. And those crosslinked with an agent. Examples of the acrylic resin include those described above. Examples of urethane resins include reaction products of polyols such as alkyl polyols, polyester polyols, polyether polyols and acrylic polyols with polyisocyanate compounds such as aliphatic diisocyanates and aromatic diisocyanates. Examples of the crosslinking agent include a polyisocyanate compound and aminoplast.

The uppermost coating film may contain other resins such as a pigment, an ultraviolet absorber, a silane coupling agent, and a polyester resin. The coating used for the lower layer coating is a coating containing zinc powder, which is usually composed of a paint called zinc rich paint, and depending on the type of binder, it is called an organic zinc rich paint or an inorganic zinc rich paint, respectively. is there. The coating film used for the lower layer coating film contains zinc powder in an amount of 150 to 2,000 parts by weight, preferably 350 to 70 parts by weight, based on 100 parts by weight of the binder.
0 parts by weight.

Examples of the binder include various resin binders such as epoxy resin, acrylic resin, polyester resin, polyurethane resin, and melamine resin, and inorganic binders such as silicate. Preferred binders include epoxy resins and silicates. Preferred examples of the epoxy resin as the binder include a bisphenol-type epoxy resin and an alkyl-modified epoxy resin. Preferable examples of the silicate as the binder include partial hydrolysis condensates of tetraalkoxysilanes such as tetramethoxysilane and tetraethoxysilane.

The thickness of the uppermost coating film is not particularly limited, but is usually 5 to 50 μm, preferably 10 to 25 μm. The thickness of the lower layer coating film is not particularly limited, but is usually 5 to 10
00 μm, preferably 10 to 200 μm,
More preferably, it is 20 to 100 μm. The multilayer coating film of the present invention may have an intermediate coating film in addition to the uppermost coating film and the lower coating film. The intermediate coating may be present between the uppermost coating and the lower coating and / or between the lower coating and the metal surface. The intermediate layer coating film may be a single layer or a multilayer of two or more layers. Examples of the resin component of the coating film used for the intermediate layer coating film include resins frequently used in anticorrosion coating films such as acrylic urethane resin and epoxy resin.

As the acrylic urethane resin, the same as the above-mentioned acrylic urethane resin can be used. Examples of the epoxy resin include a bisphenol-type epoxy resin obtained by polycondensation of a bisphenol such as bisphenol A and epihalohydrin. As a curing agent for the epoxy resin, a resin containing a methylol group or an etherified methylol group such as a phenol resin and an amino resin can be suitably used.

The thickness of the intermediate layer coating film is not particularly limited, but is usually 15 to 1000 μm, preferably 20 to 200 μm.
μm, and more preferably 30 to 100 μm.
Any method such as spray coating, dipping, a roll coater, and a flow coater can be applied as a method of applying a paint for forming the uppermost layer coating, the intermediate layer coating, and the lowermost layer coating.

In the rust preventive coating film of the present invention, the multilayer coating film is formed on a corrosive metal surface such as iron. Articles having the rust-proof coating film of the present invention include, for example, automobiles, trains,
Transport equipment such as helicopters, ships, bicycles, snowmobiles, ropeways, lifts, hovercraft, motorcycles,
Sashes, shutters, water tanks, doors, balconies, architectural skin panels, roofing materials, stairs, skylights, fences and other architectural components, architectural facades, guardrails, pedestrian bridges, sound barriers, signs, expressway sidewalls, railway viaducts , Bridges and other road components, tanks, pipes, towers, chimneys and other plant equipment,
Agricultural equipment such as greenhouses, greenhouses, silos, agricultural sheets, etc., communication equipment such as electric poles, power transmission towers, and parabolic antennas, electric wiring boxes, lighting equipment, air conditioners, and electric equipment such as washing machines. .

[0036]

Next, the present invention will be specifically described based on examples. Note that these examples do not limit the present invention in any way. The evaluation method of the coating film in the examples was performed by the following method. Evaluation method (1) Salt spray resistance (JIS method): Salt spray method (JIS)
According to the method of Z2371), the test plate was subjected to a cone spray test for 2,000 hours, and the occurrence of rust at the cross-cut portion of the test plate was compared. Was passed. The test plate was 7 cm × 15 cm, and the cross cut was set in the salt spray test apparatus at a 45 ° angle with an X mark in the lower half of the test plate at a depth reaching the substrate with a cutter knife.

Example 1 Step 1: Inorganic zinc-rich paint having a thickness of 75 μm on a surface of an iron plate (binder: a partial hydrolytic condensate of tetraethoxysilane, an amount of 20 parts by weight, an amount of zinc powder: 200)
Parts by weight) and a 2% xylene solution of an epoxy resin, and then the epoxy resin was applied twice to a thickness of 60 μm to form an acrylic urethane resin coating film having a thickness of 30 μm. Step 2: After forming a 10 μm thick coating film from a 5% xylene solution of Lumiflon 200C (fluoroolefin copolymer / polyisocyanate compound) manufactured by Asahi Glass Co., Ltd. as a fluororesin, polytetrafluoroethylene (PTFE) powder Spray again, Lumiflon 2
A 5% xylene solution of 00C was applied, and then AG650 (a polyfluoroalkyl group-containing acrylate polymer solution) manufactured by Asahi Glass Co., Ltd. was applied by spraying.

(Example 2) In step 2 of Example 1, P
TFE powder was converted to CEF-V20 (PT
FE fine powder) and KMP1 manufactured by Shin-Etsu Chemical as an additive.
10 (fluorinated fine silica) was used, and a coating film was formed in the same manner as in Example 1 except that the second coating of Lumiflon 200C was omitted.

(Example 3) In Step 1 of Example 1, an iron plate was sandblasted to form an uneven structure, and then an epoxy resin was applied to a thickness of 5 µm, and in Step 2, only AG650 was applied. A coating film was formed in the same manner as in Example 1.

(Example 4) In place of Lumiflon 200C in the second step in Step 2 of Example 1, an acrylic silicone resin paint (Kanebuchi Chemical Zemrak was used as titanium oxide Ishihara Sangyo CR90)
Was formed in the same manner as in Example 1, except that 43PHR was used.

(Embodiment 5) In the third embodiment, the last AG
A coating film was formed in the same manner as in Example 3 except that instead of 650, an acrylic urethane paint (high urethane manufactured by NOF Corporation) was applied.

(Comparative Example 1)
Except for stopping only by applying the second Lumiflon 200C,
A coating film was formed in the same manner as in Example 1.

[0043]

[Table 1]

[0044]

The coated article of the present invention has high water repellency on a metal surface such as iron and also has excellent rust prevention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (71) Applicant 593107236 Akio Tokukai 1-14-50- 305 Namamugi, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Takashi Takayanagi 3-474-2 Tsukakoshi, Kochi-ku, Kawasaki-shi, Kanagawa Asahi Glass Tamagawa Branch Office Co., Ltd. Within the company (72) Kazuchika Hiromatsu 4-6-14 Shibaura, Minato-ku, Tokyo Inside TEPCO Environmental Engineering Co., Ltd. (72) Akio Tokukai 1-14-50-305 Namamugi, Tsurumi-ku, Yokohama, Kanagawa Prefecture

Claims (1)

[Claims] 1. A multilayer having an undercoat consisting of a paint containing 150 to 2,000 parts by weight of zinc powder per 100 parts by weight of a binder and an uppermost coat consisting of a paint having a contact angle of water of 120 ° or more. A coated article characterized in that a coating film is formed on a metal surface.