JP6957466B2 - Water-based anticorrosion paint composition and anticorrosion coating method - Google Patents

Description

The present invention relates to a water-based anticorrosion coating composition and an anticorrosion coating method.

Steel materials are widely used in various fields such as marine structures, port facilities, ships, buildings, civil engineering structures, and automobiles, but there is a problem that they corrode when exposed to the natural environment. Anticorrosion coating is used as a method of preventing or suppressing corrosion.

In recent years, steel structures such as railway bridges, plants, steel towers, and oil facilities have reached a period of aging and need to be repaired and painted.

In general, in order to perform repair painting of a steel structure, it is important to perform a base treatment before painting, and the life of the coating film depends on its accuracy. Specific examples of the base treatment include removing the rusted portion of the rusted portion of the steel structure, roughening the surface of the old coating film, and removing the coating film that has lost the rust preventive effect and becomes brittle. The degree of base treatment is called "Keren", and it is classified from 1st grade to 3rd grade according to the grade, and the base treatment is performed by the treatment method according to the grade. Although the classification of Keren grades is not generally clearly defined, Type 1 Keren is a full-scale surface treatment that completely removes rust and coating film and cleans the steel surface, while Type 3 Keren. Is a simple base treatment that leaves the active film and removes rust and deteriorated coating film, and Type 2 Keren is in the middle.

Then, in order to perform the base treatment up to the first kind Keren grade, which is ideal for repair painting of steel structures, there are blasting methods such as sandblasting and shot blasting in which abrasive particles are blown with compressed air. The blast method has problems with mechanical noise, work noise, labor, required time, and the like.

For example, when the 1st grade is adopted for the base treatment, it is said that 60 to 70% of the total cost of the repair painting work is the blast method and the industrial waste treatment cost. There has been a need for an anticorrosion repainting method that can exhibit long-term anticorrosion properties even with a simple surface treatment.

As such a measure, Patent Document 1 proposes a rust surface anticorrosion coating forming method in which an epoxy resin paint containing a silane coupling agent is applied to a metal surface having a rust layer. According to the description of Patent Document 1, the silane coupling agent contained in the epoxy resin paint can be fixed to the rust layer and the metal surface by the moisture in the rust layer, and even if rust remains on the metal surface, the rust can be fixed. It is described that the anticorrosion coating provided on the base material can protect the base material.

Further, as a document describing a technique for immobilizing the rust layer by utilizing the moisture contained in the rust layer, Patent Document 2 applies an epoxy resin paint containing a ketimine compound as a curing agent on a metal surface having the rust layer. A method for forming a rust-preventive coating has been proposed.

However, according to the methods of Patent Documents 1 and 2, sufficient quality has not yet been obtained in terms of corrosion resistance and adhesiveness because rust remains on the base material, and further improvement is required.

On the other hand, in recent years, due to consideration for the environment, water-based coatings have been promoted in the field of heavy-duty anticorrosion paints.

As a water-based heavy-duty anticorrosive paint, for example, Patent Document 3 describes a two-component water-based anticorrosive paint containing a main agent containing an epoxy resin emulsion and an amine curing agent containing a cyclic polyamine having a specific active hydrogen equivalent. .. Patent Document 4 describes an aqueous coating composition containing an amine-modified epoxy resin obtained by modifying an epoxy resin having a bisphenol skeleton with an amine compound and a plasticizer having a boiling point of 200 ° C. or higher and being water-insoluble. There is.

The paints described in these patent documents can form a coating film having excellent corrosion resistance even if they are water-based, but they are sufficient when applied on a rusted surface or when exposed for a long period of time in a harsh environment such as a beach. Anticorrosion could not be exhibited, and rust spots may occur on the surface of the coating film.

Japanese Patent Application Laid-Open No. 1-25877 Japanese Patent Application Laid-Open No. 60-78672 Japanese Patent Application Laid-Open No. 2009-149791 International Publication WO2011-118790 Pamphlet International Publication WO2012-150312 Pamphlet

An object of the present invention is to provide a water-based anticorrosion coating composition and an anticorrosion coating method capable of forming a coating film having good corrosion resistance even when applied onto a substrate on which rust remains.

As a result of diligent studies on the above-mentioned problems, the present inventors have made a two-component type in which a component containing a specific polyamine resin and a specific rust preventive pigment is used as a main component and a component containing an epoxy group-containing resin is used as a curing agent component. We have found that the water-based anticorrosion coating composition exhibits excellent anticorrosion properties even on a substrate surface in which rust remains even though it is an water-based composition, and arrived at the present invention.

That is, the present invention includes the following aspects.

Item 1. Contains a first component (I) containing a water-dilutable polyamine resin (A) and a rust preventive pigment component (B), and a second component (II) containing a water-dilutable epoxy group-containing resin (C). ,
The water-dilutable polyamine resin (A) is a resin made from an epoxy resin (a1) and a polyamine compound (a2) and having a total amine value in the range of 20 to 120 mgKOH / g.
The rust preventive pigment component (B) is at least one ion selected from magnesium ion, aluminum ion, calcium ion, zinc ion, silicate ion, phosphate ion, vanadate ion and molybdate ion as a part of the component. The amount of the rust preventive pigment component (B) containing the rust preventive pigment (b) capable of eluting is from 1 to 100 parts by mass based on 100 parts by mass of the water-dilutable polyamine resin (A).
A two-component water-based anticorrosive coating composition in which the weight average molecular weight of the water-dilutable epoxy group-containing resin (C) is lower than that of the water-dilutable polyamine resin (A).

Item 2. The two-component aqueous anticorrosion according to Item 1, wherein the polyamine compound (a2) is a polyamine (a2-1) having a primary amino group at both ends of the molecule and having at least one secondary amino group. Paint composition.

Item 3. The two-component water-based anticorrosion according to Item 1, wherein the water-dilutable polyamine resin (A) is a resin using a ketone compound (a3) as a production raw material in addition to the epoxy resin (a1) and the polyamine compound (a2). Paint composition.

Item 4. The two-component water-based anticorrosive coating composition according to any one of Items 1 to 3, wherein the water-dilutable polyamine resin (A) has a primary amino group at the resin terminal.

Item 5. The two liquids according to any one of Items 1 to 4, wherein the water-dilutable polyamine resin (A) is a resin using a long-chain alkyl compound (a4) having a functional group capable of reacting with an amino group as a production raw material. Mold water-based anticorrosion paint composition.

Item 6, The item that the rust preventive pigment (b) is a component capable of eluting at least one metal ion selected from silicate ion and / or phosphate ion and magnesium ion, aluminum ion, calcium ion and zinc ion. The two-component water-based anticorrosive coating composition according to any one of 1 to 5.

Item 7. Any of Items 1 to 6, wherein the average particle size of the aqueous dispersion of the water-dilutable polyamine resin (A) is smaller than the average particle size of the aqueous dispersion of the water-dilutable epoxy group-containing resin (C). The two-component water-based anticorrosive coating composition according to item 1.

Item 8. The two-component water-based anticorrosive coating composition according to any one of Items 1 to 7, wherein the water-dilutable epoxy group-containing resin (C) contains a novolak type epoxy resin as a part of the components thereof.

Item 2. The two-component water-based anticorrosive coating composition according to any one of Items 1 to 8, wherein the first component and / or the second component (II) further contains a fibrous inorganic compound (D).

Item 2. The two-component water-based anticorrosive coating composition according to any one of Items 1 to 9, wherein the first component and / or the second component (II) further contains a polycarbodiimide compound (E).

An aqueous anticorrosive coating composition obtained by mixing the first component (I) and the second component (II) according to any one of Items 11 and 1 to 10.

Item 12. The anticorrosion coating method, which comprises coating the object to be coated with the water-based anticorrosion coating composition according to Item 11.

Item 13. The anticorrosion coating method according to Item 12, wherein the object to be coated is a substrate surface on which rust remains.

Item 14. The anticorrosion coating method according to Item 13, which comprises a step of simply removing rust before coating the water-based anticorrosion coating composition.

According to the two-component water-based anticorrosive coating composition of the present invention, the storage stability of the coating state before coating is good, and by mixing and coating the two, a coating film having excellent anticorrosion properties can be dried at room temperature. It can be obtained even under conditions, and the aesthetic appearance of the object to be coated can be maintained for a long period of time even if it is exposed to a harsh environment such as a beach for a long period of time.

Further, the water-based anticorrosion coating composition of the present invention can exhibit sufficient anticorrosion properties even when directly coated on a newly installed base material as well as a base material on which rust remains. For this reason, it can be applied to repainting of steel structures that have deteriorated and rust remains, and it is possible to significantly reduce the total labor required for painting as well as being environmentally friendly as a water-based composition. ..

The two-component water-based anticorrosive coating composition of the present invention contains a first component (I) containing a water-dilutable polyamine resin (A) and a rust-preventive pigment component (B), and a water-dilutable epoxy group-containing resin (C). It is composed of the second component (II).

<Water-dilutable polyamine resin (A)>
In the present invention, the water-dilutable polyamine resin (A) that can be a coating film-forming component is a resin using an epoxy resin (a1) and an amine compound (a2) as production raw materials, and has a total amine value of 20 to 120 mgKOH / g. It is a resin within the range.

The epoxy resin (a1) used as a raw material for producing the water-dilutable polyamine resin (A) is a resin having at least one, preferably two or more epoxy groups in the molecule, and is at least 160, preferably 180 to 2500. Those having an epoxy equivalent within the range of are suitable.

Specifically, the epoxy resin (a1) is a bisphenol type epoxy resin such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a bisphenol AD type epoxy resin; an epoxy ester obtained by modifying the above bisphenol type epoxy resin with a dibasic acid or the like. Resin; Novolak type epoxy resin such as cresol novolac type epoxy resin, phenol novolac type epoxy resin; alicyclic epoxy resin; polyglycol type epoxy resin; hydrogenated bisphenol A type epoxy resin; ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether , Polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane polyglycidyl ether, hexahydrophthalate diglycidyl ester , Glycerin polyglycidyl ether, diglycerin polyglycidyl ether, polyglycerin polyglycidyl ether and other aliphatic epoxy resins, glycidyl (meth) acrylate and other epoxy group-containing acrylic monomers as constituents, and the like. Be done. As the epoxy resin, an unmodified epoxy resin is preferable. These can be used alone or in combination of two or more.

Examples of commercially available products of the epoxy resin (a1) include "jER827", "jER828", "jER828EL", "jER828XA", "jER834" (all manufactured by Mitsubishi Chemical Corporation), "EPICLON840", and "EPICLON840-S". , "EPICLON850", "EPICLON850-S", "EPICLON850-CRP", "EPICLON850-LC" (above, manufactured by DIC), "Epototo YD-127", "Epototo YD-128" (above, Toto Kaseisha) (Manufactured by), "Rikaresin BPO-20E", "Rikaresin BEO-60E" (above, manufactured by Shin Nihon Rika Co., Ltd.), etc. Bisphenol A type epoxy resin; Bisphenol F type epoxy resin such as "EPICLON 830", "EPICLON 830-S", "EPICLON 835" (manufactured by DIC), "Epototo YDF-170" (manufactured by Toto Kasei); "jER4250" (manufactured by Mitsubishi Chemical), etc. Bisphenol A type bisphenol F type phenoxy resin, novolak type epoxy resin such as "jER152" (manufactured by Mitsubishi Chemical Co., Ltd.); Water such as "Rika Resin HBE-100" (manufactured by Shin Nihon Rika Co., Ltd.) "Denacol EX-252" (manufactured by Nagase ChemteX), "SR-HBA" (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) Additive bisphenol A type epoxy resin; "YED205", "YED216M", "YED216D" (all manufactured by Mitsubishi Chemical Co., Ltd.), "Epototo YH-300", "Epototo YH-301", "Epototo YH-315", "Epototo" YH-324 ”,“ Epototo YH-325 ”(above, manufactured by Toto Kasei Co., Ltd.),“ Denacol EX-221 ”,“ Denacol EX-212 ”,“ Denacol EX-212L ”,“ Denacol EX-214L ”,“ Denacol EX-216L ”,“ Denacol EX-313 ”,“ Denacol EX-314 ”,“ Denacol EX-321 ”,“ Denacol EX-321L ”,“ Denacol EX-411 ”,“ Denacol EX-421 ”,“ Denacol EX ” -512 ”,“ Denacol EX-521 ”,“ Denacol EX-611 ”,“ Denacol EX-612 ”,“ Denacol EX-614 ”,“ Denacol EX-614 ” B ”,“ Denacol EX-622 ”,“ Denacol EX-810 ”,“ Denacol EX-811 ”,“ Denacol EX-850 ”,“ Denacol EX-850L ”,“ Denacol EX-851 ”,“ Denacol EX-821 ” , "Denacol EX-830", "Denacol EX-832", "Denacol EX-841", "Denacol EX-861", "Denacol EX-911", "Denacol EX-941", "Denacol EX-920", "Denacol EX-931" (all manufactured by Nagase ChemteX Corporation), "SR-NPG", "SR-16H", "SR-16HL", "SR-TMP", "SR-PG", "SR-TPG" , "SR-4PG", "SR-2EG", "SR-8EG", "SR-8EGS", "SR-GLG", "SR-DGE", "SR-DGE", "SR-4GL", Examples thereof include aliphatic epoxy resins such as "SR-4GLS" and "SR-SEP" (all manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.).

The epoxy resin (a1) reacts the above-exemplified epoxy resin with bifunctional polyester polyols, bifunctional polyether polyols, bisphenols, dibasic carboxylic acids and the like so that the epoxy group becomes excessive. The epoxy resin thus obtained is also included.

The polyamine compound (a2) constituting the water-dilutable polyamine resin (A) is a polyamine compound (a2-1) having a primary amino group at both ends of the molecule and having at least one secondary amino group. It is desirable to have.

Examples of such a polyamine compound (a2-1) include dialkylene triamines such as dimethylenetriamine, diethylenetriamine, dipropylenetriamine, dibutylenetriamine and bis (hexamethylene) triamine; triethylenetetramine, tripropylenetetramine and the like. Examples thereof include trialkylene tetramine; tetraalkylene pentamine such as tetraethylene pentamine and tetrapropyl pentamine; pentaalkylene hexamine; hexaalkylene heptamine and the like. These can be used alone or in combination of two or more.

In particular, in the present invention, the polyamine compound (a2-1) is preferably dialkylenetriamine from the viewpoint of production and storage stability of the first component (I) and corrosion resistance on the rust surface, and has 2 to 2 carbon atoms. A dialkylene triamine having 8, preferably 3 to 6 alkylene groups is particularly suitable.

Examples of polyamines applicable other than the polyamine compound (a2-1) include monomethylamine, dimethylamine, monoethylamine, diethylamine, dipropylamine, dibutylamine, dihexylamine, dioctylamine, monoisopropylamine and diisopropylamine. Mono-alkylamines or di-alkylamines such as monobutylamine, monooctylamine, methylbutylamine, dibutylamine; monoethanolamine, N-methylethanolamine, N-ethylethanolamine, diethanolamine, mono (2-hydroxypropyl) Amine, di (2-hydroxypropyl) amine, N-butylethanolamine, dipropanolamine, monomethylaminoethanol, N- (2-hydroxypropyl) ethylenediamine, 3-methylamine-1,2-propanediol, 3-tert Alkanol amines such as −butylamino-1,2-propanediol, N-methylglucamine, N-octylglucamine; polymethylenediamine, polyetherdiamine, ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, trimethylhexamethylene Alkylene polyamines such as diamine, dimethylaminopropylamine, diethylaminopropylamine, bis (4-aminobutyl) amine; mensendiamine, isophoronediamine, bis (4-amino-3-methylcyclohexyl) methane, metaxylylene diamine, meta Aromatic or alicyclic polyamines such as phenylenediamine, naphthylenediamine, dimethylaminomethylbenzene; polyamines having a heterocycle such as piperazine, 1-methylpiperazin, 3-pyrrolidinol, 3-piperidinol, 4-pyrrolidinol; Epoxy-added polyamine obtained by adding 1 to 30 mol of an epoxy group-containing compound to 1 mol of polyamine; the above polyamine and aromatic acid anhydride, cyclic aliphatic acid anhydride, aliphatic acid anhydride, halogenated acid anhydride Polyamide polyamines containing one or more primary or secondary amines in the molecules of a polyamide resin produced by condensation with a substance and / or dimer acid; one or more primary or secondary amines and ketones in the polyamines. Ketiminated amines that have reacted with compounds; and the like. These can be used alone or in combination of two or more.

The ratio of the epoxy resin (a1) and the polyamine compound (a2) to the epoxy resin (a1) is 0.2 to 3.0 mol, preferably 0.5 to 2.5 mol, with respect to 1 mol of the epoxy resin (a1). It is suitable that the ratio is such that.

Further, the water-dilutable polyamine resin (A) is preferably a resin using a ketone compound (a3) as a production raw material in addition to the epoxy resin (a1) and the polyamine compound (a2).

Examples of the ketone compound (a3) include methyl isopropyl ketone, diisobutyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl butyl ketone, ethyl propyl ketone, dipropyl ketone, and methyl ethyl ketone. These can be used alone or in combination of two or more. Of these, methyl isobutyl ketone is preferable.

When the ketone compound (a3) is used, the ratio of use in that case is 0.2 to 3.0 mol, preferably 0.5 to 2. Mol, per 1 mol of the primary amino group in the amine compound (a2). It is suitable that the ratio is 5 mol.

Further, the water-dilutable polyamine resin (A) may be a resin containing a long-chain alkyl compound (a4) (also referred to as an aliphatic monoepoxy compound) having a functional group capable of reacting with an amino group as a production raw material. Are suitable. The compound (a4) is effective in improving the corrosion resistance of the coating film formed by the composition of the present invention.

The long-chain alkyl compound (a4) having a functional group capable of reacting with the amino group can be a compound having an alkyl group having 4 or more carbon atoms and a functional group such as a carboxyl group and / or a glycidyl group. Specific examples include 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxyoctane, 1,2-epoxydecane, 1,2-epoxydodecane, 1,2-epoxytetradecane, 1,2. -Epoxyhexadecane, 1,2-epoxyoctadecane, 1,2-epoxyeikosan, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, benzyl glycidyl ether, cresyl glycidyl ether, tert-butyl phenyl glycidyl ether, etc. Long-chain alkyl glycidyl ether compound; Long-chain alkyl glycidyl ester compound such as butyric acid glycidyl ruester, stearic acid glycidyl ruester, neodecanoic acid glycidyl ester; palm oil fatty acid, cotton seed oil fatty acid, hemp oil fatty acid, rice bran oil fatty acid, fish oil fatty acid, tall oil fatty acid , Soybean oil fatty acid, flaxseed oil fatty acid, tung oil fatty acid, rapeseed oil fatty acid, castor oil fatty acid, dehydrated castor oil fatty acid, long-chain alkyl fatty acid such as safflower oil fatty acid and the like.

When such a long-chain alkyl compound (a4) is used, the usage ratio in that case is that 1 mol of the primary amino group contained in the polyamine compound (a2) reacts with the amino group contained in the compound (a4). It is suitable that the possible functional groups are in the range of 0.1 to 0.8 mol, preferably 0.2 to 0.6 mol.

When the modification ratio by the long-chain alkyl compound (a4) is within the above range, the coating film formed from the aqueous anticorrosive coating composition of the present invention has excellent film-forming properties and can exhibit excellent anticorrosion properties.

In the present invention, the water-dilutable polyamine resin (A) uses the above components (a1) and (a2), and if necessary, (a3) and / or (a4) as raw materials for production, and also has an interface. Other components such as activators can be used as raw materials for production as needed. The production method is not particularly limited, and the primary amine at the end of the polyamine compound (a2) is reacted with the ketone compound (a3) to form ketiminization, and then the secondary amine is reacted with the epoxy group of the epoxy resin (a1). Next, a production method for returning ketimine to a primary amine by hydrolysis when diluted with water can be mentioned.

According to the above production method, the water-dilutable polyamine resin (A) can have a primary amino group which is an aqueous dispersion group at the resin terminal in the presence of water, and is an anticorrosion coating having excellent corrosion resistance on the rust surface. Helps to form a membrane.

The surfactant used as necessary is not particularly limited, and for example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, etc. Polyoxyethylene sorbitan alkyl esters, glycerin esters and derivatives thereof, alkylbenzene sulfonates, alkyl ether sulfates, alkenyl ether sulfates, alkyl sulfates, alkenyl sulfates, α-olefin surfactants, α-sulfo fatty acids or Ester salt, alkane sulfonate, saturated fatty acid salt, unsaturated fatty acid salt, alkyl ether carboxylate, alkenyl ether carboxylate, amino acid type surfactant, N-acyl amino acid type surfactant, alkyl phosphate ester or its Anionic surfactants such as salts, alkenyl phosphate esters or salts thereof; cationic surfactants such as quaternary ammonium salts; amphoteric surfactants such as carboxyl-type amphoteric surfactants and sulfobetaine-type amphoteric surfactants. And so on.

When the above-mentioned surfactant is blended, it may be blended at any stage of the paint manufacturing process, not limited to the resin manufacturing stage. The blending amount is 1 to 15 parts by mass based on the total mass of the non-volatile components of the water-dilutable polyamine (A) and the water-dilutable epoxy group-containing resin from the viewpoint of storage stability in the paint state and corrosion resistance of the formed coating film. In particular, the range of 3 to 8 parts by mass is suitable.

When the compound (a4) is used as a production raw material, it can be used at any stage in the production of the water-dilutable polyamine resin (A), but the primary amine at the terminal of the polyamine compound (a2) is used as a ketone. After reacting with compound (a3) to ketiminize, the secondary amine is reacted with the epoxy group of the epoxy resin (a1), and then ketimine is converted back to primary amine by hydrolysis when diluted with water, and then compound (a4). Is preferred.

The water-dilutable polyamine resin (A) is well dispersed or dissolved in an aqueous medium due to the presence of an amino group which may be neutralized. In the case of an aqueous dispersion, it is generally suitable that the average particle size is in the range of 50 to 500 nm, particularly 100 to 300 nm, from the viewpoint of film forming property and curability at room temperature drying.

Examples of the neutralizing agent used for neutralization include formic acid, acetic acid, oxalic acid, malonic acid, succinic acid, malic acid, citric acid, glutaric acid, adipic acid, maleic acid, lactic acid, propionic acid, and hydroxyethanediphosphonic acid. , Organic acids such as methanesulphonic acid; inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid, zircophylated hydrogen acid, silicofluorinated acid, nitric acid; and the like acid compounds.

The water-dilutable polyamine resin (A) has a total amine value in the range of 20 to 120 mgKOH / g, and preferably in the range of 40 to 100 mgKOH / g.

Further, the water-dilutable polyamine resin (A) has a weight average molecular weight in the range of 1000 to 20000, preferably 2000 to 8000, from the viewpoint of coating film physical properties such as room temperature drying property, corrosion resistance and moisture resistance. Are suitable.

In the present specification, the average particle size is a value of the volume average particle size measured by the Coulter counter method at a measurement temperature of 20 ° C. The measurement by the Coulter counter method can be performed using, for example, "COOLTER N4 type" (manufactured by Beckman Coulter, trade name).

The amine value is measured according to JIS K 7237-1995. All are amine values (mgKOH / g) per resin non-volatile component.

The weight average molecular weight is obtained by converting the retention time (retention capacity) measured using a gel permeation chromatograph (GPC) into the molecular weight of polystyrene by the retention time (retention capacity) of standard polystyrene having a known molecular weight measured under the same conditions. It is a value obtained by The columns are "TSKgel G-4000H x L", "TSKgel G-3000H x L", "TSKgel G-2500H x L", "TSKgel G-2000H x L" (all manufactured by Tosoh Corporation, trade name). ), Mobile phase; tetrahydrofuran, measurement temperature; 40 ° C., flow rate; 1 ml / min, detector; RI conditions.

<Rust preventive pigment component (B)>
In the present invention, the rust preventive pigment component (B) is at least one selected from magnesium ion, aluminum ion, calcium ion, zinc ion, silicate ion, phosphate ion, vanadate ion and molybdate ion in a corrosive environment. It is characterized by containing a rust preventive pigment (b) capable of eluting the ions of. When the rust preventive pigment component (B) contains the specific rust preventive pigment (b), the ions are eluted when the coating film coated on the rust surface or the metal substrate is lost, and the defective portion is formed. It is possible to exert the anticorrosive property more effectively by acting on.

In the present invention, the presence or absence of ion elution of the rust preventive pigment (b) can be examined, for example, by eluting the rust preventive pigment (b) in an aqueous sodium chloride solution and measuring the elution amount by ICP emission spectroscopic analysis. .. More specifically, the supernatant liquid to which 10% by mass of the rust preventive pigment (b) was added to a 5% by mass sodium chloride aqueous solution, stirred at 25 ° C. for 6 hours, allowed to stand for 24 hours, and then the precipitate was removed. Is detected by the presence or absence of the amount of dissolved elements measured by ICP emission spectroscopic analysis.

In the present invention, the first component (I) contains the rust preventive pigment component (B) together with the water-dilutable polyamine resin (A), so that the rust preventive pigment component (B) is contained in a sufficient amount. The production and storage stability of component (I) is good, and the coating film formed from the anticorrosive coating composition of the present invention can exhibit stable anticorrosive properties.

Specific examples of the rust preventive pigment (b) that can be contained in the rust preventive pigment component (B) include a single compound, a composite compound, and a composition in which a plurality of these compounds are used in combination as long as the component can elute the ions. There is no limitation on the form, and specifically, zinc phosphate, magnesium phosphate, magnesium / ammonium phosphate copolymer, magnesium monohydrogen phosphate, magnesium dihydrogen phosphate, magnesium phosphate / calcium phosphate, phosphorus. Magnesium / Cobalt Cooxide Elysate, Magnesium / Nickel Phosphate Elysate, Calcium Phosphate, Calcium Ammonium Phosphate, Calcium Monohydrogen Phosphate, Calcium Dihydrogen Phosphate, Calcium Phosphate Phosphate, Aluminum Phosphate, Aluminum Hydrogen Phosphate, etc. Phosphate metal compounds;
Phosphate-based metal compounds such as magnesium phosphite, calcium phosphite, magnesium phosphite-calcium copolymer, basic zinc phosphite, barium phosphite, manganese phosphite, calcium hypophosphite;
Calcium silicate, zinc silicate, aluminum silicate, aluminum orthosilicate, hydrated aluminum silicate, aluminosilicate, borosilicate, berylosilicate, calcium aluminum silicate, sodium aluminum silicate, aluminum berylium silicate, silicate. Metal silicates such as sodium silicate, calcium orthosilicate, calcium metasilicate, sodium calcium silicate, zirconium silicate, magnesium orthosilicate, magnesium metasilicate, magnesium silicate, manganese silicate, barium silicate; magnesium ion exchange Metal ion exchange silica-based compounds such as silica and calcium ion exchange silica;
Condensed phosphate metal compounds such as aluminum dihydrogen tripolyphosphate, magnesium tripolyphosphate, aluminum tripolyphosphate, zinc dihydrogen tripolyphosphate;
Vanadium-based metal compounds such as vanadium pentoxide, calcium vanadate, magnesium vanadate and ammonium metavanadate, calcined product of manganese oxide and vanadium oxide, and calcined product of calcium phosphate and vanadium oxide;
Molybdic acid-based metal compounds such as aluminum molybdate, calcium molybdate, and aluminum phosphomolybdate;
Zinc compounds such as zinc and zinc oxide;
Silica-based compounds such as silica and colloidal silica;
Composite metal oxides such as composite oxides of iron oxide and magnesium oxide, composite oxides of iron oxide and calcium oxide, composite oxides of iron oxide and zinc oxide;
And so on. As described above, these may be used alone or in combination of two or more kinds, or may be a composite of two or more kinds. Further, the rust preventive pigment (b) also includes a silicic acid compound such as silica and calcium silicate, and a modified product or a treated product of magnesium oxide or the like.

In particular, in the present invention, the rust preventive pigment (b) is a component capable of eluting at least one metal ion selected from silicate ion and / or phosphate ion and magnesium ion, aluminum ion, calcium ion and zinc ion. This is suitable because it is excellent in rust spot suppression property and corrosion resistance against rusted surface and exposed metal surface. That is, in the present invention, the rust preventive pigment (b) is a component capable of eluting [1] silicate ion, and at least one metal ion selected from magnesium ion, aluminum ion, calcium ion and zinc ion is eluted. Possible components, [2] components capable of eluting phosphate ions, and components capable of eluting at least one metal ion selected from magnesium ion, aluminum ion, calcium ion and zinc ion, or [3] It is one of the components capable of eluting silicate ions and phosphate ions and at least one metal ion selected from magnesium ion, aluminum ion, calcium ion and zinc ion. Are suitable.

In particular, the rust preventive pigment (b) is particularly suitable in an embodiment in which it is a component capable of eluting at least one metal ion selected from silicate ion and phosphate ion and magnesium ion, aluminum ion, calcium ion and zinc ion. There is. That is, it is particularly a component capable of eluting silicate ion and phosphate ion, and a component capable of eluting at least one metal ion selected from magnesium ion, aluminum ion, calcium ion and zinc ion. Are suitable.

The form of such a rust preventive pigment (b) is not limited as long as it can elute both silicate ion and / or phosphate ion and the above-mentioned metal ion, and is a single compound or a composite compound. It may be a composition which combined a plurality of the said compounds. For example, the combination of a magnesium oxide-treated product of aluminum dihydrogen tripolyphosphate and magnesium ion exchange silica is a metal selected from silicate ions and phosphate ions, and magnesium ions, aluminum ions, calcium ions and zinc ions. This is an example of the rust preventive pigment (b) capable of eluting ions.

Among the rust preventive pigments (b), the rust preventive pigment capable of eluting silicate ions may contain a silicate-based compound capable of eluting silicate ions in a corrosive environment. For example, silica, colloidal silica, modified compounds of the compounds listed in the description of the rust preventive pigment (b) above with silicic acid compounds, metal ion exchange silica compounds such as magnesium ion exchange silica and calcium ion exchange silica, and the like can be mentioned. can. These can be used alone or in combination of two or more.

The rust-preventive pigment capable of eluting phosphate ions may contain a phosphate-based compound capable of eluting phosphate ions in a corrosive environment. For example, magnesium phosphate, magnesium-ammonium phosphate eutectoid, magnesium monohydrogen phosphate, magnesium dihydrogen phosphate, magnesium phosphate-calcium copolymer, magnesium phosphate-cobalt copolymer, magnesium phosphate-nickel Examples thereof include an eutectoid, magnesium phosphite, magnesium phosphite / calcium eutectoid, magnesium tripolyphosphate, magnesium oxide-treated aluminum dihydrogen tripolyphosphate, magnesium oxide-treated zinc dihydrogen tripolyphosphate, and the like. .. These can be used alone or in combination of two or more.

The rust preventive pigment capable of eluting magnesium ions may contain a magnesium compound capable of eluting magnesium ions in a corrosive environment. Specifically, for example, compounds obtained by treating the compounds listed in the description of the rust preventive pigment (b) with magnesium oxide, magnesium phosphate, magnesium-ammonium phosphate copolymer, magnesium monohydrogen phosphate, dinitrous acid. Magnesium hydrogen hydrogen, magnesium phosphate-calcium eutectoid, magnesium phosphate-cobalt eutectoid, magnesium phosphate-nickel eutectoid, magnesium phosphite, magnesium phosphite-calcium eutectoid, magnesium ion exchange silica, Examples thereof include magnesium tripolypolyphosphate, magnesium vanadate, magnesium metasilicate, magnesium calcium silicate, and a composite oxide of iron oxide and magnesium oxide. These can be used alone or in combination of two or more.

The rust preventive pigment capable of eluting aluminum ions may contain an aluminum compound capable of eluting aluminum ions in a corrosive environment. For example, aluminum phosphate, aluminum hydrogen phosphate, aluminum dihydrogen tripolyphosphate, aluminum tripolyphosphate, aluminum molybdenate, aluminum silicate, aluminum orthosilicate, hydrated aluminum silicate, aluminosilicate, calcium aluminum silicate, silicic acid. Examples thereof include sodium aluminum, beryllium aluminum silicate, and aluminum phosphomolybdate. These can be used alone or in combination of two or more.

The rust preventive pigment capable of eluting calcium ions may contain a calcium compound capable of eluting calcium ions in a corrosive environment. For example, magnesium phosphate-calcium eutectoid, calcium phosphate, calcium ammonium phosphate, calcium monohydrogen phosphate, calcium dihydrogen phosphate, calcium phosphate fluoride, calcium phosphite, magnesium phosphite-calcium copolymer, hypoa Calcium phosphate, calcium ion exchange silica, calcium vanadate, calcined product of calcium phosphate and vanadium oxide, calcium molybdenate, iron oxide and calcium oxide composite oxide, calcium silicate, aluminum calcium silicate, calcium orthosilicate, calcium metasilicate, Calcium calcium silicate, calcium magnesium silicate, etc. can be mentioned. These can be used alone or in combination of two or more.

The rust preventive pigment capable of eluting zinc ions may contain a zinc compound capable of eluting zinc ions in a corrosive environment. For example, zinc, zinc oxide, zinc phosphate, basic zinc phosphite, zinc dihydrogen tripolyphosphate, zinc silicate, composite metal oxide such as a composite oxide of iron oxide and zinc oxide can be mentioned. .. These can be used alone or in combination of two or more.

The rust-preventive pigment component (B) used in the present invention may contain other rust-preventive pigments other than the rust-preventive pigment (b), if necessary. Specific examples of such other rust preventive pigments include cobalt-based compounds such as cobalt hydroxide; borate-based compounds such as barium metaborate; iron phosphate, manganese phosphate, nickel phosphate, cobalt phosphate, and copper phosphate. Phosphate and the like can be mentioned.

When other rust preventive pigments are used, the amount used in that case can be 30% by mass or less in the rust preventive pigment component (B).

As the rust preventive pigment component (B), a commercially available product alone or in combination of two or more can be used. Examples of such commercially available products include "EXPERT NP-1000", "EXPERT NP-1020C", "EXPERT NP-1100", "EXPERT NP-1102" (all manufactured by Toho Pigment Industry Co., Ltd., trade name), and "LF Bowsei". CP-Z ”,“ LF Bowsei MZP-500 ”,“ LF Bowsei CRFC-1 ”,“ LF Bowsei M-PSN ”,“ LF Bowsei MC-400WR ”,“ LF Bowsei PM-300 ”,“ LF Bowsei PM- 308 ”(above, Kikuchi Color Co., Ltd., trade name),“ K-WHITE 140 ”,“ K-WHITE Ca650 ”,“ K-WHITE 450H ”,“ K-WHITE G-105 ”,“ K-WHITE # 105 ”,“ K-WHITE # 82 "(above, trade name manufactured by TAYCA)," SHIELDEX C303 "," SHIELDEX AC-3 "," SHIELDEX C-5 "(all manufactured by WR Race & Co.)," Examples thereof include the silo mask 52, the silo mask 52M, the silo mask 22MR-H (manufactured by Fuji Silicia), and the Novinox ACE-110 (manufactured by SNCZ, France).

The blending amount of the rust preventive pigment component (B) is 1 to 100 parts by mass based on 100 parts by mass of the non-volatile content of the water-dilutable polyamine resin (A). It is preferably in the range of 5 to 90 parts by mass, more preferably 10 to 80 parts by mass. If the blending amount of the rust preventive pigment component (B) exceeds 100 parts by mass, the corrosion resistance of the formed coating film is conversely insufficient on the rust surface, so that an excellent coating composition cannot be obtained.

<Water-dilutable epoxy group-containing resin (C)>
In the present invention, the water-dilutable epoxy group-containing resin (C) is a resin having at least one, preferably at least two epoxy groups in the molecule, which can be dispersed or dissolved in an aqueous medium such as water. As the production raw material, the epoxy group-containing compounds listed in the description of the epoxy resin (a1) can be exemplified.

Among them, the water-dilutable epoxy group-containing resin (C) is a part of its components from the viewpoint of obtaining a coating film having a large number of epoxy groups capable of reacting with the amino groups contained in the resin (A) and having excellent curability. It is preferable to contain a novolak type epoxy resin.

The epoxy equivalent of the water-dilutable epoxy group-containing resin (C) is the epoxy resin in the water-dilutable polyamine resin (A) from the viewpoint of compatibility between the first component (I) and the second component (II). It is suitable that it is lower than (a1), and specifically, it is suitable that it is in the range of at least 50, preferably 100 to 500.

Further, the weight average molecular weight of the resin of the water-dilutable epoxy group-containing resin (C) is lower than that of the water-dilutable polyamine resin (A). It is considered that this further improves the compatibility between the first component (I) and the second component (II) of the composition of the present invention. The weight average molecular weight of the water-dilutable epoxy resin (C) is not particularly limited, and specifically, it is suitable to be in the range of 500 to 10000, preferably 1000 to 5000.

The water-dilutable epoxy group-containing resin (C) is dispersed by a dispersion stabilizer or surfactant having an anionic, nonionic or cationic hydrophilic group, or the resin (C) itself is hydrophilic. It is suitable to have groups, and the presence of these allows the water-dilutable epoxy group-containing resin (C) to be well dispersed or dissolved in an aqueous medium.

In the present specification, "water-dilutability" is used to mean that it is freely miscible with an aqueous medium such as water. The term "water dispersibility" is used to mean that the average particle size of the dispersed resin in which the resin is dispersed in an aqueous medium such as water is 10 nm or more. The term "water-soluble" is used to mean that the dispersed resin in which the resin is dispersed in an aqueous medium such as water has an average particle size of less than 10 nm or is completely dissolved in an aqueous medium such as water.

Examples of the anionic hydrophilic group include an acidic group. Examples of the acidic group include a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phenolic hydroxyl group and the like.

Examples of the nonionic hydrophilic group include a polyoxyalkylene group and a polyglycerin group.

Examples of the cationic hydrophilic group include a 1st to 3rd class amino group, an ammonium group, a pyridinium group, a sulfonium group, a phosphonium group and the like.

When the water-dilutable epoxy group-containing resin (C) is dispersed in an aqueous medium, the average particle size of the water-dilutable epoxy group-containing resin (C) aqueous dispersion is 50 to 1500 nm, preferably 200 to 200. It can be in the range of 1000 nm. When the average particle size is within this range, there is an effect that the film-forming property of the composition after mixing the first component (I) and the second component (II) is excellent. In particular, in the present invention, the average particle size of the water-dilutable epoxy group-containing resin (C) aqueous dispersion is larger than the average particle size of the water-dilutable polyamine (A) aqueous dispersion from the viewpoint of film-forming property of the aqueous anticorrosion coating composition. A large diameter is suitable.

As the water-dilutable epoxy group-containing resin (C), a commercially available product can also be used. Specific examples thereof include Watersol series (manufactured by DIC, trade name), Modepix series (manufactured by Arakawa Chemical Co., Ltd., trade name), and ADEKA RESIN (manufactured by ADEKA, trade name).

<Aqueous anticorrosion paint composition>
The water-based anticorrosion coating composition of the present invention contains a water-dilutable epoxy group-containing resin (C), with the component containing the water-dilutable polyamine resin (A) and the rust-preventive pigment component (B) as the first component (I). This is a two-component coating composition containing the second component (II) as a component.

In the water-based anticorrosion coating composition of the present invention, it is preferable that the first component (I) and / or the second component (II), preferably the first component (I), further contains the fibrous inorganic compound (D).

Although the reason is not clear, the fibrous inorganic compound (D) can suppress the shrinkage of the coating film during film formation, and is particularly effective in improving the adhesion to the rust residual surface and the corrosion resistance.

The material, manufacturing method, production area, etc. of the fibrous inorganic compound (D) are not particularly limited, and specific examples thereof include glass fiber, silicon carbide, silicon nitride, wolastonite, sepiolite, chrysotile, amosite, and tremolite. , Zeolite, Calcium Metasilicate, Zonolite, Potassium Titanium, Rockwool, Aluminum Silicate, Carbon Fiber, Aramid Fiber, Aluminum Borate, Calcium Needle Carbonate, Needle Basic Magnesium Sulfate, Glass Flake, Needle Zinc Oxide, Aragonite Examples include type light calcium carbonate, spindle type light calcium carbonate, and satin white. These can be used alone or in combination of two or more.

In the present invention, the fibrous inorganic compound (D) preferably has an aspect ratio of 3.5 or more, preferably in the range of 4 to 25.

The aspect ratio is the value of the major axis diameter / minor axis diameter of the inorganic needle-like pigment, and the minor axis diameter and the major axis diameter here are each of 100 primary particles existing in a certain area by electron microscope observation. The minor axis diameter and the major axis diameter of are measured and averaged.

The average fiber length of the fibrous inorganic compound (D) is preferably in the range of 5 to 300 μm, particularly 10 to 200 μm. In the present specification, the average fiber length is the average value of the major axis diameters obtained in the measurement of the aspect ratio.

In the present invention, the blending amount of the fibrous inorganic compound (D) is in the range of 0.1 to 30 parts by mass, preferably 5 to 25 parts by mass, based on 100 parts by mass of the total non-volatile content of the resin contained in the coating material. It is suitable to be inside.

Further, it is preferable that the first component (I) and / or the second component (II), preferably the second component (II), further contains the polycarbodiimide compound (E).

The inclusion of the polycarbodiimide compound (E) in the water-based anticorrosion coating composition has the effect of lowering the water absorption rate of the formed coating film.

The polycarbodiimide compound (E) is a polymer having a −N = C = N− group in the molecule, and can be produced, for example, by a decarboxylation condensation reaction of diisocyanate in the presence of a carbodiimideization catalyst. Examples of the carbodiimidization catalyst include tin, magnesium oxide, potassium ion, 18-crown-6, 3-methyl-1-phenyl-2-phospholene oxide and the like, and combinations thereof. These can be used alone or in combination of two or more.

Examples of the diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, isophorone diisocyanate, methylcyclohexyldiisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1, 3-Bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, norbornene diisocyanate, 2,4,6-triisopropylphenyldiisocyanate, 1,12-diisocyanate Decarbonate condensation of one or more polyfunctional isocyanates such as dodecane, 2,4-bis- (8-isocyanate octyl) -1,3-dioctylcyclobutane, n-pentane-1,4-diisocyanate By reacting, it is carbodiimidated, and the residual isocyanate group at the terminal is sealed with a hydrophilic group in order to impart water dilatability.

Examples of the hydrophilic group to be sealed include a residue of an alkyl sulfonate, a quaternary salt of a residue of a dialkylamino alcohol, and a residue of a polyoxyalkylene having an alkoxy group terminal blocked.

Examples of the polycarbodiimide compound include "carbodilite V-02", "carbodilite V-04", "carbodilite V-02-L2", "carbodilite E-02", "carbodilite E-03A", and "Elastostab H01" ( As described above, commercially available products such as product names (manufactured by Nisshinbo Chemical Co., Ltd.) can be used.

The blending amount of the polycarbodiimide compound (E) is within the range of 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the resin non-volatile content contained in the aqueous anticorrosive coating composition. Is suitable from the viewpoint of water absorption rate and corrosion resistance of the coating film.

In the aqueous anticorrosive coating composition of the present invention, a coloring pigment, an extender pigment, a pigment dispersant, an organic solvent, a surface conditioner, a defoaming agent, a thickener, a curing catalyst, a surfactant, a precipitation inhibitor, a softening agent, etc. Additions for ordinary paints such as plasticizers, reactive diluents, antifreezes, antiskinning agents, pH adjusters, preservatives, etc. are added to the first component (I) and / or the second component (II). be able to.

Among these, the coloring pigments include, for example, titanium oxide, carbon black, chrome yellow, ocher, yellow iron oxide, Hansa yellow, pigment yellow, chrome orange, chrome vermillion, permanent orange, amber, permanent red, brilliant carmine, and fast violet. , Methyl violet lake, ultramarine blue, prussian blue, cobalt blue, phthalocyanine blue, pigment green, naphthol green, aluminum paste and the like. These can be used alone or in combination of two or more.

The amount of the coloring pigment to be blended is preferably in the range of 5 to 90 parts by mass, preferably 10 to 50 parts by mass, based on 100 parts by mass of the resin non-volatile content contained in the aqueous anticorrosion coating composition.

Examples of extender pigments include talc, silica, calcium carbonate, mica, kaolin, barium sulfate, and zinc oxide (zinc oxide). These can be used alone or in combination of two or more.

The blending amount of the extender pigment is in the range of 10 to 100 parts by mass, preferably 20 to 70 parts by mass based on 100 parts by mass of the resin non-volatile content contained in the water-based anticorrosion coating composition from the viewpoint of water resistance. Are suitable.

The water-based anticorrosive coating composition of the present invention comprises the water-dilutable polyamine resin (A) of the first component (I), the rust preventive pigment component (B) and other components contained as necessary, and the second component (II). ), The water-dilutable epoxy group-containing resin (C) and other components including, if necessary, are dissolved or dispersed in the aqueous medium. The water-based medium contains water as a main component, and may be water or a mixture of water and an organic solvent.

As the organic solvent, conventionally known ones can be used without limitation, but it is particularly preferable to use an organic solvent having a boiling point of 300 ° C. or lower. Specific examples thereof include ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate and the like. Above all, from the viewpoint of long-term corrosion resistance of the coating film, it is suitable to use the organic solvent having a boiling point of less than 200 ° C.

The content of the organic solvent can be in the range of 0.1 to 30 parts by mass, preferably 3 to 25 parts by mass, based on 100 parts by mass of the non-volatile content of the water-dilutable polyamine resin (A).

Further, in the present invention, even if the first component (I) and / or the second component (II) contains a softening agent from the viewpoint of impact resistance of the formed coating film, film forming property in a low temperature environment, and the like. good. As such a softener, one that is liquid at room temperature is preferably used.

Such softeners are not particularly limited, and are, for example, phthalic acid softeners, fatty acid softeners, aromatic polycarboxylic acid softeners, phosphoric acid softeners, polyol softeners, and epoxys. Examples thereof include a softening agent based on a polyester, a softening agent based on a polyester, and a polymerizable softening agent such as an acrylic monomer or an oligomer thereof.

Among these, epoxy softeners are suitable from the viewpoint of corrosion resistance of the formed coating film. As the epoxy softening agent, for example, it can react with the compounds listed in the description of the epoxy resin (A), the compounds listed in the description of the water-dilutable polyamine resin (A), the epoxy resin (a1), and the amino group. In addition to the compounds listed in the description of the long-chain alkyl compound (a4) having a functional group, epoxidized soybean oil, epoxybutyl stearate, di2-ethylhexyl epoxyhexahydrophthalate, diisodecyl epoxyhexahydrophthalate, Epoxy triglyceride, octyl epoxidized oleate, decyl epoxidized oleate and the like can be mentioned. The blending amount of the softener is 0.5 to 10 parts by mass, particularly 2 by mass, based on 100 parts by mass of the total non-volatile content of the water-dilutable polyamine resin (A) and the water-dilutable epoxy group-containing resin (C). The range of ~ 8 parts by mass is appropriate.

The water-based anticorrosion coating composition of the present invention is stored in a two-component type of the first component (I) and the second component (II) at the time of storage. This is because the active hydrogen group contained in the first component (I) and the epoxy group contained in the second component (II) easily react at room temperature. By mixing the first component (I) and the second component (II) at the time of use by a known method, a water-based anticorrosion coating composition used for coating can be prepared.

As for the blending ratio of the first component (I) and the second component (II), the epoxy group contained in the second component is 0.3 to 1 equivalent to 1 equivalent of the active hydrogen group contained in the first component (I). It is suitable to be in the range of 1.5 equivalents, preferably 0.5 to 1.2 equivalents.

Further, at the time of painting, it can be diluted with deionized water and used if necessary. The viscosity at that time is, for example, in the case of spray painting, the Ford Cup Viscometer No. The measurement according to 4 (20 ° C.) is preferably adjusted to 20 to 60 seconds, and more preferably 30 to 50 seconds. In this case, the solid content is preferably about 35 to 65% by mass, more preferably about 40 to 60% by mass.

The object to be coated to which the method of the present invention is applied is not particularly limited. It is usually steel, but it can also be applied to non-ferrous metals, specifically, building structures such as houses and buildings; civil engineering structures such as towers, bridges and tanks; various plant large structures such as oil drilling plants; Outdoor appliances such as guard fences and industrial machines; and those coated with undercoat paint, intermediate coat paint, and top coat paint as required, and the like can be mentioned.

In particular, as the object to be coated, the effect can be exerted not only on the newly installed object to be coated but also on the existing object to be coated by the base material on which rust remains.

When the anticorrosion coating with the water-based anticorrosion coating composition of the present invention is applied to the surface of the base material on which the rust remains, the rust generated on the surface may be removed in advance.

The method for removing rust is not limited, and examples thereof include hand tools such as blasts, scrapers, and wire brushes, and electric tools such as disc sanders, wire cups, and electric chisel. These can be performed alone or in combination of two or more, and may be washed with water if necessary.

In particular, in the present invention, from the viewpoint of total labor and corrosion resistance, it is suitable to use a tool having abrasive particles or a brush on a rotatable disk-shaped pedestal as a base treatment method.

Examples of such a tool include a disc sander and a wire cup.

When the rust is simply removed by the method of the present invention, it is not necessary to completely remove the rust and the old coating film from the surface of the base material to be coated with anticorrosive coating so that the metal is exposed on the entire surface. The surface portion may also have a state in which a rust residual portion and an active film (an old coating film that does not easily peel off) are mixed.

The degree of rust generation after the base treatment is not particularly limited, and the effect of the present invention is exhibited even if the rust generation area ratio is 3% or more, particularly 10% or more. Can be done.

The rust-generated area ratio is a percentage of the area of the rust-generated area with respect to the area of the object to be coated. Five photographs after the base treatment are taken at random, the area of the rust-generated area in each photograph is calculated, and the average Can be obtained by doing.

In the anticorrosion coating method of the present invention, the theoretical drying thickness of the anticorrosion coating film by the water-based anticorrosion coating composition can be in the range of 10 to 200 μm, preferably 30 to 150 μm.

In the present invention, the theoretical drying film thickness is calculated by the following formula.
A = (B x NV) / (C x 100)
A: Theoretical dry film thickness (μm)
B: Coating amount (g / m ² )
NV: Non-volatile content concentration (%) of paint
C: Specific gravity of paint (g / cm ³ )
The specific gravity of the coating material for determining the theoretical drying thickness shall be measured according to the K 7232-1986 4.2 specific gravity cup method.

As the water-based anticorrosion coating composition, conventionally known methods such as air spray, airless spray, brush coating, and rollers can be adopted. The drying method is preferably room temperature drying for 1 to 48 hours, preferably 2 to 16 hours, and forced drying or heat drying is also possible if necessary.

In the anticorrosion coating method of the present invention, a topcoat coating material different from the anticorrosion coating composition can be applied in a single layer or in multiple layers on the anticorrosion coating film formed by using the anticorrosion coating composition.

Hereinafter, the present invention will be further described with reference to examples. Here, "part" and "%" mean "parts by mass" and "% by mass", respectively.

<Manufacturing of water-dilutable polyamine resin (A)>
Manufacturing example 1
In a flask equipped with a stirrer, thermometer, nitrogen introduction tube and reflux cooler, "jER828" trade name, Mitsubishi Chemical Co., Ltd., bisphenol A type resin, epoxy equivalent 190, number average molecular weight 375) 3200 parts, bisphenol A (molecular weight) 228) was charged with 1700 parts, 900 parts of methylisobutylketone and 5.0 parts of benzyldimethylamine, and reacted at 120 ° C. until the epoxy equivalent per non-volatile component reached 2500 g / equivalent.

Next, 590 parts of a ketiminated product of 3,3'-diaminodipropylamine with methyl isobutyl ketone was added, and the mixture was reacted at 120 ° C. for 1 hour.

Then, 54 parts of deionized water and 380 parts of neodecanoic acid glycidyl ester were charged and reacted at 100 ° C. for 2 hours.

Then, 90 parts of acetic acid and 70 parts of deionized water are added to stir and mix the internal liquid, 6500 parts of deionized water is added to disperse the water, and the pressure is reduced to remove methyl isobutyl ketone, and the solid is solidified with deionized water. The amount was adjusted to obtain an amino group-containing resin emulsion (A-1) having a milky white color and a non-volatile content of 45% and having a primary amino group at the resin terminal.

The emulsion (A-1) had a weight average molecular weight of 7,000, an average particle size of 250 nm, and an amine value per non-volatile component of 60 mgKOH / g.

Production Examples 2-8
Water-dilutable polyamine resins (A-2) to (A8) were produced in the same manner except that the compounding composition was shown in Table 1 below.

Manufacturing example 9
In a flask equipped with a stirrer, thermometer, nitrogen introduction tube and reflux cooler, "jER828" trade name, Mitsubishi Chemical Co., Ltd., bisphenol A type resin, epoxy equivalent 190, number average molecular weight 375) 2438 parts, bisphenol A (molecular weight) 228) was charged with 1254 parts, 678 parts of methylisobutylketone and 3.8 parts of benzyldimethylamine, and reacted at 120 ° C. until the epoxy equivalent per solid content reached 1800 g / equivalent.

Next, 296 parts of a ketiminated product of 3,3'-diaminodipropylamine methyl isobutyl ketone and 78 parts of the amine compound (a) were added, and the mixture was reacted at 120 ° C. for 1 hour.

Then, 27 parts of deionized water and 188 parts of neodecanoic acid glycidyl ester were charged and reacted at 100 ° C. for 2 hours.

Then, 43 parts of acetic acid and 45 parts of deionized water were added to stir and mix the internal liquid, and 4918 parts of deionized water was added to disperse the water. %, An amino group-containing resin emulsion (A-9) having a primary amino group inside the resin was obtained.

The emulsion (A-9) had a weight average molecular weight of 9000, an average particle size of 300 nm, and an amine value per solid content of 55 mgKOH / g.

(*) Ketimine compound (a)
74 parts of 1,3-diaminopropane and 100 parts of methyl isobutyl ketone are charged in a flask equipped with a stirrer, a thermometer, a nitrogen introduction tube and a reflux cooler, and the ketone is refluxed while removing the generated water by co-boiling. After 12 hours at the temperature, the ketimine compound (a) was obtained by removing the solvent by distillation under reduced pressure.

<Manufacturing of water-based anticorrosion paint composition>
Example 1
222 parts of amino group-containing resin emulsion (A-1) (100 parts of non-volatile content), 50 parts of rust preventive pigment (B-4), 20 parts of rust preventive pigment (B-5), 20 parts of glass fiber (*) in a container. 40 parts of titanium oxide, 60 parts of rust, and 20 parts of ethylene glycol monobutyl ether were blended and mixed by stirring to obtain a main component. To another container, add 35.2 parts (17.6 parts of non-volatile content) and 7.5 parts of polycarbodiimide emulsion (3 parts of non-volatile content) of epoxy resin emulsion (C-1), stir and mix, and water-based anticorrosive paint. The composition (I-1) was obtained.

Examples 2-37 and Comparative Examples 1-5
Water-based anticorrosion coating compositions (I-2) to (I-42) were obtained in the same manner as in Example 1 except that the compounding composition was shown in Table 2 below. An evaluation test was conducted on each of the obtained paints according to the following methods and criteria. The results are also shown in Table 2.
The blending amount in Table 2 is a non-volatile content display.

<Creation of a test plate painted on the remaining rust surface>
A shot blast of a mild steel plate with a width of 70 mm, a length of 150 mm, and a plate thickness of 3 mm was shot-blasted on the Pacific coast of Chikura-cho, Chiba Prefecture (offshore distance of 30 m) for 4 months, and an open exposure test was conducted at an angle of 30 ° to the south. A rusted steel sheet having a rust generation area of 100% was prepared, and the surface of the rusted steel sheet was scraped with a wire cup to obtain a simple base material adjusting plate. The rust-generated area of the simple substrate adjusting plate was 85%.

Next, each of the water-based anticorrosion coating compositions (I-1) to (I-42) was air-spray coated on the entire surface of the substrate adjusting plate so that the theoretical dry film thickness was 100 μm, and dried at 23 ° C. for 24 hours. I let you. Next, a weak solvent-soluble epoxy resin-based intermediate coating "Ceratect Mild Intermediate Coating (E)" (trade name, manufactured by Kansai Paint Co., Ltd., base agent / curing agent mass ratio 17/1) was applied so that the dry film thickness was 30 μm. Was spray coated and dried at 23 ° C. for 24 hours. Next, a low-contamination weak solvent-soluble isocyanate-curable polyurethane resin topcoat "Ceratect U Mild Topcoat" (trade name, manufactured by Kansai Paint Co., Ltd., main agent / curing agent mass ratio 6/1) was applied so that the dry film thickness was 25 μm. It was spray-painted and cured in a constant temperature room at 23 ° C. and 50% humidity for 7 days to obtain a test coating plate coated on the residual rust surface.

<Creation of a test plate painted on the mild steel plate surface>
A mild steel plate having a width of 70 mm, a length of 150 mm, and a plate thickness of 3 mm is shot-blasted and rust-free is used as a base material surface. I-42) was air-spray coated so that the theoretical dry film thickness was 100 μm, and cured in a constant temperature room at 23 ° C. and 50% humidity for 7 days to obtain a test coated plate coated on the mild steel plate surface.

(*) Rust preventive pigment (B-1): "LF Bowsei MZP-500", trade name, manufactured by Kikuchi Color Co., Ltd., magnesium phosphate,
(*) Anti-corrosion pigment (B-2): Zinc phosphate tetrahydrate, manufactured by Yoneyama Yakuhin Co., Ltd., reagent, zinc phosphate,
(*) Rust preventive pigment (B-3): "EXPERT NP-1000" manufactured by Toho Pigment Industry Co., Ltd., trade name, calcium phosphate,
(*) Rust-preventive pigment (B-4): "K-WHITE G-105" manufactured by TAYCA Corporation, trade name, magnesium oxide-treated aluminum dihydrogen tripolyphosphate, magnesium oxide-treated amount 15%,
(*) Rust preventive pigment (B-5): "Silomask 22MR-H" manufactured by Fuji Silysia Chemical Ltd., trade name, magnesium ion exchange silica,
(*) Rust preventive pigment (B-6): "SHIELDEX C303" W. R. Grace & Co. Made by the company, product name, calcium ion exchange silica,
(*) Anti-corrosion pigment (B-7): Calcium vanadate,
(*) Fibrous inorganic compound: glass fiber, aspect ratio 20, average fiber length 80 μm
(*) Epoxy resin emulsion (C-1): Nonionic phenol novolac type epoxy resin emulsion, non-volatile content 50%, epoxy equivalent per non-volatile content 200, weight average molecular weight 1200, average particle size 550 nm,
(*) Epoxy resin emulsion (C-2): Nonionic bisphenol A type epoxy resin emulsion, non-volatile content 50%, epoxy equivalent per non-volatile content 200, weight average molecular weight 1200, average particle size 550 nm,
(*) Epoxy resin emulsion (C-3): Epoxy resin emulsion (C-3): Nonionic novolak type epoxy resin emulsion, non-volatile content 50%, epoxy equivalent per non-volatile content 200, weight average molecular weight 21000, average particle size 550 nm,
(*) Polypropylene glycol diglycidyl ether: Epoxy equivalent 300, water-soluble (*) Polycarbodiimide emulsion: Non-volatile content 40%, Carbodiimide equivalent 365.

(*) Storage stability In each of the water-based paints obtained in Examples and Comparative Examples, the first component and the second component were each sealedly stored in a constant temperature room at 40 ° C., and the state after storage for 60 days was used as the following standard. Evaluated by.
S: No change,
A: Very slight agglutination is observed, but when the sample is manually stirred, it immediately returns to the state before storage, and there is no problem.
B: Aggregation is observed, and even if the sample is manually stirred, it does not return to the state before storage.
C: Aggregation lumps are remarkably observed.
(*) Rust-suppressing property Each of the water-based anticorrosion paints obtained in Examples and Comparative Examples was applied to a simple substrate adjustment plate with residual rust so that the dry film thickness was 100 μm, and the coating film was dried at room temperature. Was visually judged and evaluated according to the following criteria.
S: Rust cannot be confirmed,
A: Slight spot rust occurs, and the degree is less than 5 on average per ^{10 cm 2.}
B: Occurrence of spot rust was observed, and the degree was 5 to 20 per ^{10 cm 2 on average.}
C: Significant spot-like or flow trace-like rust is observed.

(*) Corrosion resistance Composite cycle corrosion test using 5% saline solution specified in JIS K 5621 for each test coating plate on which each water-based anticorrosion coating composition is coated on the rust residual surface and the mild steel plate surface. Was carried out for 900 hours and evaluated according to the following criteria by observing the surfaces of the general part and the cut part of the test coating plate.
(General part)
S: No rust is observed,
A: Rust with a diameter of less than 5 mm is observed at 1 to 5 points on the test piece.
B: 1 to 5 points of rust are observed on the test piece and its size exceeds 5 mm, or 6 to 15 points of rust are observed regardless of the size of the rust.
C: Rust of 15 points or more is observed on the test piece.
(Cut part)
S: Rust that progresses from the cut part, the maximum width of the blisters is 10 mm or less across the cut,
A: The maximum value of rust and blisters that progresses from the cut part exceeds 10 mm and 20 mm or less across the cut.
B: Rust that progresses from the cut part, the maximum value of blisters exceeds 20 mm and 30 mm or less across the cut,
C: The maximum value of rust and blisters advancing from the cut portion exceeds 30 mm across the cut.
(*) The sample was uniformly coated on a polypropylene plate (300 × 100 × 5 mm) having a water absorption rate so that the dry film thickness was 40 μm, and dried under the conditions of a temperature of 23 ° C. and a relative humidity of 60% for 7 days. Obtain a coating film. Then, a free coating film is arbitrarily cut out from the coating film in a 3 cm square, submerged in deionized water at 20 ° C. for 24 hours, wiped off water droplets on the surface, and immediately weighed, and the water absorption rate is determined according to the following formula. To measure.
Water absorption rate (%) = [(ba) / a] × 100
However, a: mass (g) of the free coating film before submersion.
b: Mass (g) of the free coating film after submersion.

Claims (11)

It contains a first component (I) containing a water-dilutable polyamine resin (A) and a rust-preventive pigment component (B) and a second component (II) containing a water-dilutable epoxy group-containing resin (C), and is water-diluted. The sex polyamine resin (A) is a resin made from an epoxy resin (a1) and a polyamine compound (a2) and having a total amine value in the range of 20 to 120 mgKOH / g.
The rust preventive pigment component (B) is at least one ion selected from magnesium ion, aluminum ion, calcium ion, zinc ion, silicate ion, phosphate ion, vanadate ion and molybdate ion as a part of the component. The amount of the rust preventive pigment component (B) containing the rust preventive pigment (b) capable of eluting is from 1 to 100 parts by mass based on 100 parts by mass of the water-dilutable polyamine resin (A).
The weight average molecular weight of the resin of water-dilutable epoxy group-containing resin (C) is rather low than water dilutable polyamine resin (A), the meet at least one of the following requirements (1) to (3), two-aqueous anticorrosive Paint composition :
(1) The average particle size of the aqueous dispersion of the water-dilutable polyamine resin (A) is smaller than the average particle size of the aqueous dispersion of the water-dilutable epoxy group-containing resin (C).
(2) The first component and / or the second component (II) further contains the fibrous inorganic compound (D).
(3) The first component and / or the second component (II) further contains the polycarbodiimide compound (E) . The two-component water-based anticorrosive coating composition according to claim 1, wherein the polyamine compound (a2) is a polyamine (a2-1) having a primary amino group at both ends of the molecule and having at least one secondary amino group. thing. The two-component water-based anticorrosive coating composition according to claim 1, wherein the water-dilutable polyamine resin (A) is a resin using a ketone compound (a3) as a production raw material in addition to the epoxy resin (a1) and the polyamine compound (a2). thing. The two-component water-based anticorrosive coating composition according to any one of claims 1 to 3, wherein the water-dilutable polyamine resin (A) has a primary amino group at the resin terminal. The two-component aqueous solution according to any one of claims 1 to 4, wherein the water-dilutable polyamine resin (A) is a resin using a long-chain alkyl compound (a4) having a functional group capable of reacting with an amino group as a production raw material. Anticorrosive paint composition. Claim 1 to claim 1, wherein the rust preventive pigment (b) is a component capable of eluting silicate ion and / or phosphate ion and at least one metal ion selected from magnesium ion, aluminum ion, calcium ion and zinc ion. The two-component water-based anticorrosive coating composition according to any one of 5. The two-component water-based anticorrosive coating composition according to any one of claims 1 to 6 , wherein the water-dilutable epoxy group-containing resin (C) contains a novolak type epoxy resin as a part of the component thereof. A water-based anticorrosion coating composition obtained by mixing the first component (I) and the second component (II) according to any one of claims 1 to 7. An anticorrosion coating method, which comprises applying the water-based anticorrosion coating composition according to claim 8 to an object to be coated. The anticorrosion coating method according to claim 9 , wherein the object to be coated is a substrate surface on which rust remains. The anticorrosion coating method according to claim 10 , further comprising a step of simply removing rust before coating the water-based anticorrosion coating composition.