JP7074414B2 - Room temperature one-component cross-linking paint composition - Google Patents

Description

The present invention relates to a room temperature one-component cross-linking coating composition.

Building structures constructed and painted during the high-growth period have become obsolete in recent years, and the time for repainting is approaching. In recent years, water-based coating has been progressing in the field of paints as well, but when repainting such an object to be coated is performed, a coating film having excellent permeability to the old coating film and having excellent finished appearance and physical properties is obtained. From the point of view, organic solvent-based paints are often applied.

However, paints containing a large amount of organic solvents with high dissolving power such as toluene and xylene, so-called strong solvents, are not preferable from the viewpoints of safety to painters and the surrounding environment, work hygiene, and the like. In addition, if a strong solvent-based paint is applied directly to the surface of the old paint film, the old paint film may swell and float (lifting), so the content of the strong solvent is suppressed as much as possible and the dissolving power is low. There is a need to develop paints that use organic solvents as the main medium.

By the way, in the painting of building structures, etc., it is necessary to crosslink the paint film at room temperature. Therefore, by dividing the paint into a main component and a cross-linking agent component and designing it as a two-component cross-linking type paint, the storage stability of the paint is stable. It is generally practiced to achieve both properties and physical properties of the coating film. However, the two-component cross-linked paint requires a painter to mix accurately at a predetermined ratio at the painting site and stir sufficiently, and the usable time is limited. The current situation is that there are some obstacles.

For this reason, there is an increasing need for paints using an organic solvent system that is a one-component type that can be crosslinked even under normal temperature drying conditions and has a low dissolving power.

Examples of the paint capable of one-component room temperature crosslinking include paints containing an oxidation-curable resin.

Patent Document 1 describes a coating material containing an oxidative curing resin, a metal dryer, and a solvent containing an aliphatic hydrocarbon as essential components, and Patent Document 2 describes a non-aqueous resin dispersion containing a urethane bond and an unsaturated fatty acid group. A room temperature curable coating composition containing a liquid and a non-aqueous resin solution containing a urethane bond and an unsaturated fatty acid group as a coating film forming component is disclosed. According to the coating composition, the initial drying property is good even under normal temperature drying conditions, a coating film having excellent gloss and crack followability can be formed, and even if it is applied to an iron part such as a handrail, it is a hand. It is possible to maintain a good appearance for a long period of time without the coating film being softened or peeled off due to oil, handrails, or the like.

However, in the coating composition utilizing oxidative curing as described in these patent documents, there is a problem that the inside of the coating film becomes uncured when it is coated on a thick film, resulting in poor appearance.

On the other hand, as a coating material capable of one-component room temperature crosslinking, there is a composition containing an epoxy resin, a ketimine compound and a dehydrating agent. According to such a composition, ketimine is stably present in the paint state due to the action of the dehydrating agent, and when the coating film is exposed to the moisture in the air after coating, the deketimization reaction proceeds and the amine is regenerated. As a result, it reacts with the epoxy groups contained in the coating film to obtain an epoxy / amine crosslinked coating film.

Patent Document 3 discloses a coating composition containing a specific epoxy resin, pigment, ketimines compound, polyfunctional acrylate and dehydrating agent. According to the coating composition, the coating form can be one-component type, and the coating film formed by this can rapidly undergo a crosslinking reaction even under low temperature conditions.

However, the composition described in Patent Document 3 lacks pigment dispersibility because it contains a large amount of an organic solvent having a low dissolving power, and a paint is produced in a high temperature and high humidity environment, and the paint is stored for a long period of time. The paint viscosity may increase over time.

Japanese Unexamined Patent Publication No. 2013-40331 Japanese Unexamined Patent Publication No. 2001-329212 Japanese Unexamined Patent Publication No. 2002-88299

An object of the present invention is to provide a room temperature one-component crosslinkable coating composition which is excellent in long-term storage stability even when manufactured and stored in a high temperature and high humidity environment and can be sufficiently crosslinked even under normal temperature drying conditions. There is something in it.

As a result of diligent studies on the above-mentioned problems, the present inventors have made a coating composition containing a coloring pigment and ketimines into a coating composition containing a specific polyvalent metal compound and an inorganic filler to form a coating material during storage. We have found that the thickening phenomenon is suppressed, and have reached the present invention.

That is, the present invention relates to a resin component (A), a compound (B) having a plurality of ketimines, a coloring pigment (C) (excluding the inorganic filler (D) and the polyvalent metal compound (E)), calcium carbonate, barium sulfate, and the like. Tark, magnesium carbonate, calcium sulfate, diatomaceous soil, mica, clay, kaolin, silica, alumina, aluminum, barite powder, bentonite, lithopon, glass flakes, glass fiber, carbon fiber, mineral fiber, molybdenum disulfide, wallacenite, montmorillonite, At least one inorganic filler (D), a polyvalent metal compound (E), and an aliphatic hydrocarbon-based organic solvent (F) selected from the group consisting of biderite, hectrite, saponite, stibunsite, sericite, illite and vermucrite. ), And the resin component (A) contains a resin (a1) having at least two epoxy groups and a resin (a2) different from the resin (a1) as a part of the component, and is a polyvalent metal compound (a). E) is a compound of phosphoric acid or a condensate thereof of at least one metal selected from the group consisting of magnesium, calcium, aluminum and zinc, and the resin (a2) is an epoxy group-containing resin, a fatty acid and a polyisocyanate. One liquid at room temperature, which is at least one selected from a resin containing a urethane bond as a constituent and an acrylic resin, which does not have an epoxy group and has a hydroxyl value in the range of 10 to 100 mgKOH / g. A coating method for coating a cross-linking paint composition or a surface to be coated with the room temperature one-component cross-linking paint composition, a coating finishing method for forming a coating film with the coating composition and then applying a top coat on the coating composition. Regarding.

According to the coating composition of the present invention, it can be stably produced even if it contains a large amount of an organic solvent having a low dissolving power, and it is produced under high temperature and high humidity conditions, and the paint thickens even when stored for a long period of time. Can be suppressed and stable quality can be obtained.

In addition, the present coating composition dries well to the inside even when it is applied to a thick film under low temperature and low humidity conditions, and forms a crosslinked coating film having excellent physical properties such as water resistance and substrate adhesion. Can be done.

Since the coating composition of the present invention mainly uses an organic solvent having a low dissolving power, a coating film having less non-landing can be obtained without damaging the surface of the object to be coated by coating, and the base material and the topcoat coating can be obtained. Both have excellent adhesion to the film. Therefore, even if another topcoat paint is applied on the paint film using the paint composition of the present invention, the durability of the multi-layer paint film as a whole is extremely excellent.

The room temperature one-component cross-linking coating composition of the present invention comprises a resin component (A), a compound (B) having a plurality of ketimines, a coloring pigment (C), an inorganic filler (D), a polyvalent metal compound (E) and an aliphatic material. Contains a group hydrocarbon-based organic solvent (F). Hereinafter, each component contained in the coating composition of the present invention will be described.

<Resin component (A)>
<< Resin (a1) having at least two functional groups capable of reacting with amino groups >>
In the coating composition of the present invention, the resin component (A) that can be a coating film-forming component contains a resin (a1) having at least two functional groups that can react with an amino group as a part of the component.

The functional group is not particularly limited, and specifically, an epoxy group, an isocyanate group, a (meth) acryloyl group, an aldehyde group, a ketone group, a carboxyl group, a carboxylated product group, and a carboxylic acid anhydride group. Among them, the epoxy group is suitable.

The resin (a1) preferably has a weight average molecular weight in the range of 2000 to 40,000, preferably 3000 to 30,000, and a functional group equivalent in the range of 80 to 2400, preferably 200 to 1500.

In the present specification, the weight average molecular weight is a value obtained by converting the weight average molecular weight measured by gel permeation chromatography based on the weight average molecular weight of polystyrene.

Specifically, a value obtained by converting the weight average molecular weight measured by a gel permeation chromatograph (manufactured by Tosoh Corporation, “HLC8120GPC”) based on the weight average molecular weight of polystyrene can be mentioned. 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). It was carried out under the conditions of mobile phase; tetrahydrofuran, measurement temperature; 40 ° C., flow rate; 1 cc / min, detector; RI.

When the resin (a1) has an epoxy group, specific examples thereof include glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, alicyclic epoxy resin, dimer acid diglycidyl ester, novolak type epoxy resin and the like. Epoxy resin; Epoxy group-introduced alkylphenol or alkylphenol novolak type resin obtained by reacting an alkylphenol or an alkylphenol novolak type resin with another epoxy resin such as a glycidyl ether type epoxy resin can be mentioned.

Examples of the glycidyl ether type epoxy resin include an epoxy resin having a glycidyl ether group formed by reacting a polyhydric alcohol, a polyhydric phenol, or the like with epihalohydrin or an alkylene oxide.

Examples of the polyhydric alcohol include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, neopentyl glycol, butylene glycol, hexanediol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, diglycerin, and sorbitol. Can be mentioned.

Examples of the above polyhydric phenols include 2,2-bis (4-hydroxyphenyl) propane [bisphenol A], 2,2-bis (2-hydroxyphenyl) propane, and 2- (2-hydroxyphenyl) 2- ( 4-Hydroxyphenyl) propane, halogenated bisphenol A, bis (4-hydroxyphenyl) methane [bisphenol F], tris (4-hydroxyphenyl) propane, resorcin, tetrahydroxyphenylethane, 1,2,3-tris (2) , 3-Epoxypropoxy) Propane, novolak-type polyhydric phenol, cresol-type polyhydric phenol, etc. can be mentioned.

Examples of the other glycidyl type epoxy resin include tetraglycidylaminodiphenylmethane and triglycidyl isocyanurate.

Examples of the alicyclic epoxy resin include (3,4-epoxy-6-methylcyclohexyl) methyl-3,4-epoxy-6-methylcyclohexanecarboxylate and (3,4-epoxycyclohexyl) methyl-3,4-. Epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, "Epolide GT300" (manufactured by Daicel Chemical Industry Co., Ltd., trade name, 3) Functional alicyclic epoxy resin), "Epolide GT400" (manufactured by Daicel Chemical Industry Co., Ltd., trade name, 4-functional alicyclic epoxy resin), "EHPE" (manufactured by Daicel Chemical Industry Co., Ltd., trade name, polyfunctional) (Ali ring type epoxy resin) and the like can be mentioned.

It is preferable that the resin (a1) has a bisphenol skeleton in the molecule from the viewpoint of corrosion resistance of the coating film formed from the coating composition of the present invention.

Further, in the present invention, it is suitable that the resin (a1) is a resin containing an alkylphenol as a constituent component from the viewpoint of storage stability of the coating material.

As the alkylphenol, a phenol having an alkyl group having about 2 to 18 carbon atoms is preferable, and specific examples thereof include parat-butylphenol, paraoctylphenol, nonylphenol, and a novolak resin obtained by condensing these with an aldehyde.

In particular, as the resin (a1), a resin containing the above-mentioned alkylphenol and / or fatty acid and an epoxy resin containing a bisphenol skeleton as a constituent is suitable.

The fatty acid includes an aliphatic monocarboxylic acid having 6 to 24 carbon atoms, particularly 12 to 20 carbon atoms, and unsaturated fatty acids and saturated fatty acids known per se can be used without particular limitation. For example, fish oil fatty acid, etc. Dehydrated castor oil fatty acid, safflower oil fatty acid, flaxseed oil fatty acid, soybean oil fatty acid, sesame oil fatty acid, poppy oil fatty acid, eno oil fatty acid, hemp oil fatty acid, grape kernel oil fatty acid, corn oil fatty acid, tall oil fatty acid, sunflower oil fatty acid, Dry oil fatty acids such as cottonseed oil fatty acid, walnut oil fatty acid, rubber seed oil fatty acid; non-drying oil fatty acid such as palm oil fatty acid, hydrogenated palm oil fatty acid, palm oil fatty acid; caproic acid, capric acid, lauric acid, myristic acid, palmitin Saturated fatty acids such as acid and stearic acid can be mentioned. Among these, drying oil fatty acids and semi-drying oil fatty acids are suitable from the viewpoint of normal temperature crosslinkability.

In the present invention, the resin (a1) may be a commercially available product or may be synthesized and prepared.

≪Resin (a2) ≫
In the present invention, it is suitable that the resin component (A) contains a resin (a2) different from the resin (a1) in addition to the resin (a1) from the viewpoint of storage stability and impact resistance.

The resin (a2) is preferably a non-reactive resin that does not react with the resin (a1) or the compound (B) described later.

As used herein, non-reactivity means that even if each component is mixed, a chemical reaction occurs at all or only to a negligible degree.

For example, if 800 g of a 1-liter round can in which each component is mixed at a solid content ratio of 1: 1 is collected, covered, and left for 3 months, if no gel-like substance is visually observed, both are not. It can be determined to be reactive.

Further, the resin (a2) is preferably a resin having compatibility with the resin (a1).

As used herein, compatibility means that even if each component is mixed, a uniform mixed film is formed without separation.

For example, each component is mixed at a solid content ratio of 1: 1 and applied to a glass plate using an applicator so that the dry film thickness is 30 μm, dried at room temperature for 1 week, and then visually free of turbidity. When a transparent coating film is obtained, it can be determined that the two are compatible with each other.

The resin (a2) is preferably a resin having dilutability in the aliphatic hydrocarbon-based organic solvent (F) described later.

In the present specification, having dilutability means that even if each component is mixed, it does not separate and is in a homogenized mixed state.

For example, when the resin is diluted with a solvent so that the solid content concentration becomes 10% and allowed to stand, it is judged that the resin has dilutability in the solvent when it is kept stable without separation or the like. be able to.

The resin (a2) preferably has a weight average molecular weight in the range of 200 to 80,000, particularly 300 to 60,000 from the viewpoints of storage stability, adhesion to the substrate and the topcoat film, and impact resistance.

Further, the resin (a2) is preferably a resin having a hydroxyl group from the viewpoint of adhesion to the base material or the topcoat coating film.

The hydroxyl value of the resin (a2) is preferably in the range of 10 to 100 mgKOH / g, particularly 15 to 90 mgKOH / g. When the hydroxyl value is within this range, the resin (a1) and the resin (a2) can be stably coexisted even in the presence of the aliphatic hydrocarbon-based organic solvent (F) described later. It is possible to obtain a coating film having excellent long-term storage stability and excellent adhesion.

Examples of the resin (a2) used in combination with the resin (a1) include at least one resin selected from the group consisting of a resin containing a urethane bond, an acrylic resin, a petroleum resin, and a xylene resin.

Among the resins (a2) described above, the resin containing a urethane bond is not particularly limited as long as it has at least one urethane bond in the molecule, and conventionally known resins can be used. The coating film formed from the coating composition of the present invention due to the urethane bond contained in the molecule of the resin (a2) has an appropriate internal stress and is particularly excellent in adhesion to various substrates and topcoat coating films. effective.

Examples of the urethane bond-containing resin include resins containing various polyisocyanates and various polyols as constituents.

Examples of the polyisocyanate include aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimerate diisocyanate, and lysine diisocyanate; burette type adducts and isocyanurate ring adducts of these diisocyanate compounds; isophorone diisocyanate, 4, 4'-methylenebis (cyclohexylisocyanate), methylcyclohexane-2,4- (or -2,6-) diisocyanate, 1,3- (or 1,4-) di (isocyanatomethyl) cyclohexane, 1,4-cyclohexane Alicyclic diisocyanate compounds such as diisocyanate, 1,3-cyclopentane diisocyanate, 1,2-cyclohexanediisocyanate; burette type adducts and isocyanurate ring adducts of these diisocyanates; xylylene diisocyanate, metaxylylene diisocyanate, tetra Methylxylylene diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalenedi isocyanate, 1,4-naphthalenedi isocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether isocyanate, (m- Alternatively, p-) phenylenediisocyanate, 4,4'-biphenylenediocyanate, 3,3'-dimethyl-4,4'-biphenylenediisocyanate, bis (4-isocyanatophenyl) sulfate, isopropyridenebis (4-phenylisocyanate), etc. Aromatic diisocyanate compounds; burette-type adducts of these diisocyanate compounds, isocyanurate ring adducts; triphenylmethane-4,4', 4'-triisocyanate, 1,3,5-triisocyanato Polyisocyanate compounds having 3 or more isocyanate groups in one molecule such as benzene, 2,4,6-triisocyanatotoluene, 4,4'-dimethyldiphenylmethane-2,2', 5,5'-tetraisocyanate Burette-type adducts, isocyanurate ring adducts of these polyisocyanate compounds; polyols such as ethylene glycol, propylene glycol, 1,4-butylene glycol, dimethylol propionic acid, polyalkylene glycol, trimethyl propane, hexanetriol, etc. Ratio of excess isocyanate groups to the hydroxyl groups of Urethane adducts formed by reacting polyisocyanate compounds at a rate; bullet-type adducts of these urethanization adducts, isocyanurate ring adducts, etc. can be mentioned, and these may be used alone or in combination of two or more. Can be used.

Examples of the polyol include polyether polyols such as polyethylene glycol, polypropylene glycol, polyethylene-propylene (block or random) glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, and polyoctamethylene ether glycol; dicarboxylic acids (adipic acid, adipic acid, Succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, etc.) and glycols (ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5- Diol-polymerized polyols with pentanediol, neopentyl glycol, bishydroxymethylcyclohexane, etc.), such as polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyneopentyl adipate, poly-3-methylpentyl adipate, polyethylene / butylene Polyester polyols such as adipate, polyneopentyl / hexyl adipate; polycaprolactone polyol, poly-3-methylvalerolactone polyol; polycarbonate polyol; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butane Diol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, octanediol, tricyclodecanedimethylol, hydrogenated bisphenol A, cyclohexanedimethanol, low molecular weight glycols such as 1,6 hexanediol; etc. It can be used in combination with or in combination of two or more.

The urethane bond-containing resin preferably has a bisphenol skeleton, and is particularly suitable as a resin containing an epoxy group-containing resin, a fatty acid, and a polyisocyanate as constituents. Since the resin (a2) has such a structure, it has an effect that the compatibility with the resin (a1) is good and the adhesion to various base materials and the topcoat coating film is excellent.

Examples of the epoxy group-containing resin that can be a constituent component of the resin (a2) include the same resin as the exemplified resin as the resin (a1) having an epoxy group. In particular, it is preferable to use an epoxy group-containing resin having a bisphenol skeleton as the epoxy group-containing resin.

Examples of the fatty acid include fatty acids similar to those exemplified as the denaturing agent for the resin (a1) having an epoxy group.

Examples of the polyisocyanate include compounds similar to the compounds exemplified above.

The resin containing the epoxy group-containing resin, fatty acid, and polyisocyanate as constituents can be produced, for example, by reacting the epoxy group-containing resin with the fatty acid and reacting the generated hydroxyl group with the polyisocyanate compound. ..

If necessary, rosins may be used in combination with fatty acids in this reaction. Rosins are resin oils obtained from pine plants, which are residual resins containing resin acid as a main component after distilling off volatile substances such as essential oils. For example, natural rosins such as gum rosin, tall rosin, and wood rosin. Rosin; Polymerized rosin derived from the natural rosin; Stabilized rosin obtained by disproportionating or hydrogenating the natural rosin or polymerized rosin; Maleic acid-modified rosin, Anhydrous maleate rosin, Fumaric acid-modified rosin, Itaconic acid Examples thereof include unsaturated acid-modified rosins such as modified rosins, crotonic acid-modified rosins, silicic acid-modified rosins, acrylic acid-modified rosins, and methacrylate-modified rosins, which can be used alone or in combination of two or more. can.

The acrylic resin as the resin (a2) can be a resin having 50% by mass or more of monomer units derived from (meth) acrylic acid and (meth) acrylate compound, and the glass transition temperature of the resin is −65 to 100. It is suitable that the temperature is in the range of −65 to 80 ° C. from the viewpoint of adhesion to the base material and the topcoat.

In the present invention, the glass transition temperature of the acrylic resin is a value calculated by the following formula.
Tg (K) = W ₁ / T ₁ + W ₂ / T ₂ + ... W _n / T _n
Tg (° C) = Tg (K) -273
In the formula, W ₁ , W ₂ , ... W _n is the mass fraction of each monomer, and T ₁ , T ₂ ... T _n is the glass transition temperature Tg (K) of the homopolymer of each monomer. ..
The glass transition temperature of the homopolymer of each monomer is determined by POLYMER HANDBOOK Fourth Edition, J. Mol. Brandrup, E.I. h. Immunogut, E.I. A. The value according to Grulke ed. (1999), and the glass transition temperature of the monomer not described in the document is static when the homopolymer of the monomer is synthesized so as to have a weight average molecular weight of about 50,000. Let it be the glass transition temperature.

The petroleum resin as the resin (a2) is specifically an aromatic petroleum resin obtained by polymerizing a C9 fraction such as a styrene derivative, inden, or vinyl toluene from heavy oil produced by decomposition of petroleum naphtha. , 1,3-Pentadien, an aliphatic petroleum resin obtained by polymerizing a C5 fraction such as isoprene, a copolymerized petroleum resin obtained by polymerizing the above C9 fraction and a C5 fraction, cyclopentadiene, 1,3- Examples include an aliphatic petroleum resin in which the conjugated diene of the C5 fraction such as pentadiene is partially cyclized and polymerized, a resin obtained by hydrogenating the above aromatic petroleum resin, and an alicyclic petroleum resin obtained by polymerizing dicyclopentadiene. be able to.

Commercially available petroleum resins can be appropriately used, and specific examples thereof include Quinton 100 series, Quinton 1000 series (above, trade name, manufactured by Nippon Zeon Co., Ltd.), "Marcarets T-100AS", and the like. "Marcarets R-100AS", "Marcarets M-890A", "Marcarets M-845A" (trade name, manufactured by Maruzen Petrochemical Co., Ltd.), "Neopolymer L-90", "Neopolymer 120", "Neopolymer" 130 ”,“ Neopolymer 140 ”,“ Neopolymer 150 ”,“ Neopolymer 170S ”,“ Neopolymer 160 ”,“ Neopolymer E-100 ”,“ Neopolymer E-130 ”,“ Neopolymer 130S ”,“ Neopolymer S ”(trade name, manufactured by JX Nikko Nisseki Energy Co., Ltd.),“ Petroleum LX ”,“ Petroleum LX-HS ”,“ Petroleum 100T ”,“ Petroleum 120 ”,“ Petroleum 120HS ”,“ Petroleum 130 ” , "Petroleum 140", "Petroleum 140HM", "Petroleum 140HM5", "Petroleum 150", "Petroleum 150AS", "Petrotack 60", "Petrotack 70", "Petrotack 90", "Petrotack 100", Examples thereof include "petroleum 100V", "petroleum 90HM", (above, trade name, manufactured by Toso Co., Ltd.), and the like.

Examples of the xylene resin as the resin (a2) include a reaction product of xylene and formaldehyde; a reaction product of mecitylene and formaldehyde; a reaction product of xylene, phenol and formaldehyde, and the like. If necessary, resins modified with phenols such as phenols and bifunctional phenols such as parat-butylphenol can also be used.

Commercially available xylene resins can be appropriately used, and specific examples thereof include "Nicanol LL", "Nicanol LL", "Nicanol L", "Nicanol H", "Nicanol G", and "Nicanol Y-50". "Niknol Y-100", (above, trade name, manufactured by Fudo Co., Ltd.) and the like can be mentioned.

In the present invention, when the resin component (A) contains the resin (a2), the blending ratio thereof is as follows.
Resin (a1) The solid content of the resin (a1) should be in the range of 5 to 150 parts by mass, particularly 7.5 to 100 parts by mass based on 100 parts by mass, so that the coating film can be dried at room temperature and adheres to various substrates and topcoat coating films. Suitable from the point of view of sex.

<Compound (B) having a plurality of ketimines>
In the present invention, as the compound (B) having a plurality of ketimines, for example, any ketimine, that is, any compound having at least two structures represented by the following formulas can be used.

In the formula, R ₁ and R ₂ represent a monovalent hydrocarbon group such as a hydrogen atom or an alkyl group or a cycloalkyl group, which are the same or different.

Compound (B) can be, for example, a reaction product of a polyamine and a carbonyl compound.

The polyamine may be any of an aliphatic type, an alicyclic group type and an aromatic type, and a polyamine having two or more primary amino groups in one molecule is suitable. Specific examples include, for example, ethylenediamine, propylenediamine, butylenediamine, trimethylenedimine, tetramethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethylenediamine, trimethylhexamethylenediamine, and N-amino. Ethylpiperazine, 1,2-diaminopropane, iminobispropylamine, methyliminobispropylamine, polyetherdiamine (eg, "Jeffamine EDR148" trade name, manufactured by San Techno Chemical Co., Ltd.); isophoronediamine, 1,3-bisaminomethyl Cyclohexane, 1-cyclohexylamino-3-aminopropane, 3-aminomethyl-3,3,5-trimethyl-cyclohexylamine, norbornandiamine, p-phenylenediamine, metaxylylene diamine; having an amino group at the molecular end of polyamide. Polyamidoamine; etc. can be mentioned.

Examples of the carbonyl compound include aldehydes such as acetaldehyde, propionaldehyde, n-butylaldehyde, isobutylaldehyde, diethylacetaldehyde, glyoxal and benzaldehyde; cyclic ketones such as cyclopentanone, trimethylcyclopentanone, cyclohexanone and trimethylcyclohexanone; acetone. , Methyl ethyl ketone, Methyl propyl ketone, Methyl isopropyl ketone, Methyl isobutyl ketone, diethyl ketone, dipropyl ketone, diisopropyl ketone, dibutyl ketone, diisobutyl ketone and other aliphatic ketones; acetylacetone, methyl acetoacetate, ethyl acetoacetate, dimethyl malonate , Β-dicarbonyl compounds such as diethyl malonate, methyl ethyl malonate, dibenzoylmethane; and the like.

The compounding ratio of the compound (B) is the polyamine compound in which the carbonyl compound of the compound (B) is eliminated to form a primary amino group with respect to 1 equivalent of the amine-reactive functional group in the resin (a1). The storage stability and coating film of the coating composition of the present invention should be used in a ratio such that the total amount of active hydrogen bonded to the amino group is 0.5 to 5.0 equivalents, preferably 0.6 to 3.0 equivalents. It is suitable from the viewpoint of internal cross-linking reactivity and corrosion resistance.

<Coloring pigment (C)>
The coating composition of the present invention contains a coloring pigment (C). As such a coloring pigment (C), a known coloring pigment used for the purpose of coloring a coating film in the coating field can be used without limitation.

Specific examples include white pigments such as titanium dioxide; black pigments such as carbon black, acetylene black, lamp black, carbon black, graphite, iron black, and aniline black; yellow iron oxide, titanium yellow, monoazo yellow, and condensation. Yellow pigments such as azo yellow, azomethin yellow, bismus vanadate, benzimidazolone, isoindolinone, isoindrin, quinophthalone, benzidine yellow, permanent yellow; orange pigments such as permanent orange; red iron oxide, naphthol AS azored, ansan Red pigments such as throne, anthracinoyl red, perylene maroon, quinacridone red pigment, diketopyrrolopyrrole, watching red, permanent red; purple pigments such as cobalt purple, quinacridone violet, dioxazine violet; cobalt blue, phthalocyanine blue, Blue pigments such as slene blue; green pigments such as phthalocyanine green can be mentioned, and these can be used alone or in combination of two or more.

The content of the coloring pigment (C) can be adjusted depending on the type of coloring pigment used, but is generally 10 to 100 parts by mass, preferably 30 to 60 parts by mass based on 100 parts by mass of the solid content of the resin (a1). Within range is suitable.

In the present specification, the solid content means a residue excluding volatile components, and the residue may be solid or liquid at room temperature. The solid content mass can be calculated by multiplying the solid content ratio by the sample mass before drying, with the ratio of the residual substance amount after drying to the pre-drying mass as the solid content ratio. The conditions for determining the solid content are that the mass of the sample is about 1 gram and the drying condition is 110 ° C. for 3 hours.

<Inorganic filler (D)>
In the present invention, examples of the inorganic filler (D) include calcium carbonate, barium sulfate, talc, magnesium carbonate, calcium sulfate, diatomaceous soil, mica, clay, kaolin, silica, alumina, aluminum, barite powder, bentonite, lithopon, and glass. Examples include flakes, glass fibers, carbon fibers, mineral fibers, molybdenum disulfide, wollasite, montmorillonite, byderite, hectrite, saponite, stibnsite, sericite, illite, vermucrite and the like. These can be used alone or in combination of two or more.

The content of the inorganic filler (D) is in the range of 30 to 500 parts by mass, preferably 60 to 300 parts by mass, and more preferably 90 to 200 parts by mass, based on 100 parts by mass of the solid content of the resin (a1). It is suitable to be inside.

In the present invention, it is suitable to use the flaky inorganic filler (d1) as the inorganic filler (D) from the viewpoint of adhesion to various substrates and topcoat coating films. In the present specification, the flaky shape includes a shape such as a plate shape or a scale shape, and refers to a shape obtained by crushing a three-dimensional shape such as a spherical shape or a lump shape in one direction.

Examples of such flaky inorganic filler (d1) include talc, mica, scaly alumina, scaly silica, foliate silica, scaly molybdenum disulfide, glass flakes, scaly aluminum, montmorillonite, biderite, and hectrite. Examples thereof include saponite, stibunsite, sericite, illite, kaolin, montmorillonite, clay, etc., which can be used alone or in combination of two or more.

In the present invention, the average particle size of the flaky inorganic filler (d1) is in the range of 0.2 to 40 μm, particularly 1.0 to 25 μm, which is suitable from the viewpoint of corrosion resistance of the coating film.

In the present specification, the average particle diameter of the flaky inorganic filler (d1) is a median diameter derived from the volume distribution measured by the laser diffraction / scattering method.

Further, it is suitable to use the fibrous inorganic filler (d2) as the inorganic filler (D) from the viewpoint of impact resistance of the coating film.

In the present specification, the fibrous shape includes a shape such as a thread shape, a needle shape, a rod shape, a cone shape, and a tubular shape, and refers to a shape obtained by stretching a three-dimensional shape such as a spherical shape or a lump shape in one direction.

Examples of such fibrous inorganic filler (d2) include carbon fiber, mineral fiber, glass fiber, wallacenite, zonolite, potassium titanate, rock wool, aluminum silicate, aramid fiber, aluminum borate, acicular calcium carbonate, and needle. Examples thereof include basic magnesium sulfate, acicular zinc oxide, aragonite-type light calcium carbonate, spindle-type light calcium carbonate, satin white and the like, and these can be used alone or in combination of two or more.

The average length of the fibrous inorganic filler (d2) is preferably in the range of 5 to 300 μm, particularly 10 to 200 μm, and the average major axis is preferably in the range of 0.1 to 100 μm, particularly 1 to 50 μm.

In the present specification, the average length and the average major axis are measured by measuring the length and major axis of each of the 100 primary particles existing in a certain area by electron microscope observation, and the number average value is obtained for each. ..

As the inorganic filler (D), it is preferable to use a flaky inorganic filler (d1) and a fibrous inorganic filler (d2) in combination. In this case, the fibrous inorganic filler (d2) is 0.5 to 50 parts by mass based on the total mass of 100 parts by mass of the flaky inorganic filler (d1) and the fibrous inorganic filler (d2). In particular, a ratio of 5 to 30 parts by mass is appropriate.

<Multivalent metal compound (E)>
In the present invention, the polyvalent metal compound (E) is a compound of at least one metal selected from the group consisting of magnesium, calcium, aluminum and zinc.

The form of the polyvalent metal compound (E) is not limited as long as it is a compound containing the above-exemplified metal, such as a single compound, a composite compound with other metal compounds, and a composition in which a plurality of these compounds are used in combination. In the present invention, from the viewpoint of storage stability and corrosion resistance of the coating composition, it is preferable that the polyvalent metal compound (E) is a compound of phosphoric acid or a condensate thereof and the above-exemplified polyvalent metal. Examples of the polyvalent metal compound (E) include phosphoric acid such as phosphoric acid, phosphoric acid, orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, and metaphosphoric acid of the above metals, or a condensate-based compound thereof.

Specific examples of the polyvalent metal compound (E) include magnesium phosphate, calcium phosphate, aluminum phosphate, zinc phosphate, calcium ammonium phosphate, calcium monohydrogen phosphate, calcium dihydrogen phosphate, calcium phosphate phosphate, and the like. Metal phosphates such as magnesium diphosphate, zinc hydrogen phosphate, aluminum phosphate, aluminum hydrogen phosphate, magnesium hydrogen phosphate, magnesium ammonium phosphate; magnesium phosphite, calcium phosphite, zinc phosphite, sub Metal phosphite salts such as aluminum phosphate, calcium zinc phosphite, potassium zinc phosphite; metal orthophosphate salts such as zinc orthophosphate, calcium orthophosphate, aluminum orthophosphate, magnesium orthophosphate; aluminum pyrophosphate, calcium pyrophosphate. , Pyrophosphate metal salt such as magnesium pyrophosphate; polyphosphate metal salt such as aluminum tripolyphosphate, zinc tripolyphosphate, aluminum dihydrogen tripolyphosphate; metal phosphate metal salt such as aluminum metaphosphate, calcium metaphosphate; etc. , These can be used alone or in combination of two or more.

The content of the multivalent metal compound (E) should be in the range of 10 to 50 parts by mass, preferably 15 to 25 parts by mass, based on 100 parts by mass of the solid content of the resin (a1). It is suitable from the viewpoint of property, substrate adhesion and corrosion resistance.

In the present invention, the presence of the inorganic filler (D) and the polyvalent metal compound (E) in the coating composition has an effect of suppressing thickening in the storage stage of the coating composition.

The combined ratio of the inorganic filler (D) and the polyvalent metal compound (E) is 3/1 to 30/1 in terms of the mass ratio of the inorganic filler (D) / polyvalent metal compound (E), particularly 5/1 to 15 /. It is suitable that it is within the range of 1 from the viewpoint of adhesion to various substrates.

<Alphatic hydrocarbon-based organic solvent (F)>
The coating composition of the present invention contains an aliphatic hydrocarbon-based organic solvent (F) as an organic solvent.

The aliphatic hydrocarbon-based organic solvent (F) has a high flash point, a high boiling point, and a low toxicity as typified by tarpen and mineral spirit. Specific examples thereof include aliphatic hydrocarbons such as n-butane, n-hexane, n-heptane, n-octane, isononane, n-decane, n-dodecane, cyclopentane, cyclohexane and cyclobutane, but minerals. Also included are mixed solvents such as spirit, white spirit, mineral tarpen, isoparaffin, solvent kerosene, aromatic naphtha, VM & P naphtha, solvent naphtha and the like. Commercially available products include "Solbesso 100", "Solbesso 150", "Solbesso 200" (trade name, manufactured by Esso Oil Co., Ltd.), "Swazole 310", "Swazole 1000", "Swazole 1500" (above, product name). , Cosmo Oil Co., Ltd.) and the like.

The content of the aliphatic hydrocarbon-based organic solvent (F) is not particularly limited as long as it can maintain the paint state and the paint viscosity within an appropriate range, and is usually 20 to 80 mass in the paint composition. It is an amount that becomes%.

When the coating composition of the present invention contains an organic solvent other than the aliphatic hydrocarbon-based organic solvent (F), its mass is 30% by mass or less in the total organic solvent, preferably 10% by mass in the total organic solvent. % Or less is preferable.

<Paint composition>
The coating composition of the present invention comprises a resin component (A), a compound (B) having a plurality of ketimines, a coloring pigment (C), an inorganic filler (D), a polyvalent metal compound (E), and an aliphatic hydrocarbon-based organic material. A resin for modification other than the resin (a2) such as a toluene resin, a kumaron resin, a phenol resin, a dicyclopentadiene resin, and a terpene phenol resin, which contains a solvent (F) as an essential component, if necessary. It can contain a pigment component other than the coloring pigment (C) such as a corrosion-preventing pigment and a brilliant pigment, a precipitation inhibitor, a dispersant, a plasticizer, a wetting agent, a paint additive such as a dehydrating agent, and the like.

The coating composition of the present invention described above can have a water content in the range of 3000 ppm or less, particularly 2000 ppm or less, due to the above-mentioned constitution.

In the present specification, the water content of the coating composition is a value based on the Karl Fischer titration method (simply also referred to as a potentiometric titration method) measured by the following method.

0.5 g of a sample is collected and measured by the Karl Fischer titration method. As a measuring device, a Karl Fischer Moisture Meter (potentiometric titration method) and "MKC-610-DT" (trade name, manufactured by Kyoto Electronics Co., Ltd.) were used.

<Painting method>
The surface to be coated with the coating composition of the present invention is not particularly limited, and if desired, a base-treated metal material (iron plate, zinc plating, stainless steel, aluminum, etc.) and an alkaline base material (an alkaline base material (iron plate, zinc plating, stainless steel, aluminum, etc.)) Concrete, stone, mortar, slate, slate roof tiles), ceramic building materials, plastics, wood, etc., and the old paint surface on the base material surface can be mentioned.

The coating composition can be coated by a known means such as spray coating, roller coating, brush coating, and sink coating.

The coating amount of the coating composition of the present invention can be appropriately adjusted depending on the intended use, and is not particularly limited, but generally, the dry film thickness is preferably in the range of 30 to 150 μm, particularly 40 to 120 μm.

The coating composition of the present invention can be easily crosslinked even under normal temperature drying conditions, and a coating film having excellent corrosion resistance and adhesion to various substrates and a topcoat coating film provided on the substrate can be obtained. If necessary, forced drying or heat drying may be performed.

Further, the topcoat paint can be applied on the coating film obtained by painting the coating composition of the present invention and drying it if necessary. The topcoat paint is not particularly limited, and for example, organic solvent-based paints such as alkyd resin-based, rubber chloride-based, epoxy resin-based, silicon alkyd resin-based, urethane resin-based, acrylic resin-based, silicon acrylic resin-based, and fluororesin-based. Alternatively, a water-based topcoat paint can be used.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to these examples. In addition, "part" and "%" in the following example mean "part by mass" and "% by mass", respectively.

<Manufacturing of paint>
Examples 1 to 22 and Comparative Examples 1 to 8
Each component is sequentially charged in a container under an atmosphere of 80% RH so as to have the compounding composition shown in Table 1, and the mixture is stirred and mixed to produce each coating composition (X-1) to (X-30), and the following test is performed. It was offered to.

The components (A), (C), (D) and (E) in Table 1 are indicated by solid content, and the components (B) and (F) are indicated by actual composition. In Table 1, the water content (water content) (ppm) of the coating composition is measured according to the method described in the specification.

(* Note) Resin (a1-1): Mineral spirit solution of modified epoxy resin made by reacting nonylphenol novolak resin and bisphenol A type epoxy resin, solid content 60%, weight average molecular weight 8300, epoxy equivalent per solid content 700 ,
(* Note) Resin (a1-2): Alkylphenol novolak type epoxy resin, weight average molecular weight 10,000, solid content: 60%, epoxy equivalent per solid content 1200,
(* Note) Resin (a1-3): Alkylphenol novolak type epoxy resin, solid content 60%, weight average molecular weight 10,000, epoxy equivalent per solid content 1200,
(* Note) Resin (a1-4): A fatty acid-modified epoxy resin (100% solid content) formed by reacting 60 parts of a bisphenol skeleton-containing epoxy resin with 40 parts of a tall oil fatty acid, a weight average molecular weight of 15,000, and an epoxy per solid content. Epoxy 1200,
(* Note) Resin (a2-1): Propylene glycol blocked product of tolylene diisocyanate, weight average molecular weight 3000,
(* Note) Resin (a2-2): A product obtained by reacting bisphenol A type epoxy resin / safflower oil fatty acid / rosin / tolylene diisocyanate until no epoxy group is detected, solid content 60%, weight average molecular weight 11000, Hydroxyl value 40 mgKOH / g,
(* Note) Resin (a2-3): xylene formaldehyde resin, weight average molecular weight 433, hydroxyl value 40 mgKOH / g,
(* Note) Resin (a2-4): Petroleum resin, weight average molecular weight 708,
(* Note) Resin (a2-5): Acrylic resin having a glass transition temperature of 30 ° C. and a weight average molecular weight of 30,000, a hydroxyl value of 40 mgKOH / g,
(* Note) Resin (a2-6): Acrylic resin, glass transition temperature, -61 ° C, weight average molecular weight 6000,
(* Note) Compound (B-1): Methyl isobutyl ketone adduct of norbornane diamine,
(* Note) Compound (B-2): "Versamine K-13", trade name, manufactured by Henkel Japan Ltd.,
Ketimine, a chain aliphatic polyamine having a secondary amino group inside the molecule and a primary amino group at the end of the molecule, adduct to which an epoxy compound is added to the secondary amino group,
(* Note) Compound (B-3): Methyl isobutyl ketone adduct of m-xylylenediamine,
(* Note) Inorganic filler (d1-1): talc average particle diameter 17 μm,
(* Note) Inorganic filler (d1-2): Talc average particle diameter 0.6 μm,
(* Note) Inorganic filler (d1-3): Kaolin average particle size 4 μm,
(* Note) Inorganic filler (d1-4): Mica average particle diameter 20 μm,
(* Note) Inorganic filler (d2-1): glass fiber number average major axis 5 μm, number average length 40 μm, columnar shape,
(* Note) Metal compound (E-1): Aluminum dihydrogen dihydrogen tripolyphosphate,
(* Note) Metal compound (E-2): Zinc phosphate,
(* Note) Metal compound (E-3): Magnesium phosphate,
(* Note) Metal compound (E-4): barium borate,
(* Note) Metal compound (E-5): lead sulfate,
(* Note) Metal compound (E-6): Strontium silicate,
(* Note) Metal compound (E-7): Zirconium silicate,
(* Note) Metal compound (E-8): Sodium hydrogen phosphate,
(* Note) Metal compound (E-9): Barium sulfate.

<Evaluation test>
(*) Storage stability:
800 g of each coating composition was collected in a 1-liter round can under an atmosphere of 40 ° C. and 80% RH, covered, and the state of the coating material after being left for 3 months was observed and evaluated according to the following criteria.
◎: No thickening,
○: Slightly thickened,
△: Clearly thickened,
×: Gelling.

(*) Adhesion to various materials and topcoat coatings For each material shown in Table 1, each coating composition was spray-coated so that the dry film thickness was 60 μm, and dried at 20 ° C. and 65% RH for 16 hours. After that, a commercially available weak solvent-based epoxy resin polyamine-based two-component intermediate coating paint was spray-coated so that the dry film thickness was 35 μm, dried at 20 ° C. and 65% RH for 16 hours, and then a commercially available low-contamination type. The isocyanate-cured polyurethane resin topcoat was spray-coated so that the dry film thickness was 25 μm, and dried at 20 ° C. and 65% RH for 16 hours to obtain a test coating plate.

The multi-layer coating film of each test coating plate was cut in a grid pattern with a cutter so as to reach the substrate, and 100 Goban meshes having a size of 2 mm × 2 mm were formed. Subsequently, an adhesive cellophane tape was attached to the surface thereof, and the residual state of the Goban-mesh coating film after the tape was rapidly peeled off at 20 ° C. was examined and evaluated according to the following criteria.
⊚: 100 Goban-grained coating films remained, and the edges of the coating film were not chipped at the cut edge of the cutter.
◯: 100 Goban-grained coating films remained, but the edge of the coating film was missing from the substrate at the edge of the notch of the cutter.
Δ: The number of Goban-mesh coatings missing from the substrate is 1 to 10,
X: The number of Goban-mesh coatings missing from the substrate is 11 or more.

(*) Each coating composition is coated on a dry glass plate with a film applicator so that the dry film thickness is 80 μm, dried in an atmosphere of 5 ° C. and a relative humidity of 30% RH, and then the coating film is applied. The evaluation was made based on the time required for the coating film surface to reach a semi-cured state by pressing with a finger.
◎: Less than 8 hours,
◯: 8 hours or more and less than 16 hours,
Δ: 16 hours or more and less than 24 hours,
X: 24 hours or more.
(*) The smoothness of the coated surface of the test coating plate prepared for the coating film appearance dryness test was visually evaluated.
◎: Very good,
○: Good,
△: Slightly defective,
×: Defective.
(*) Corrosion resistance 70 mm × 150 mm × 0.8 mm SPCC-SB steel sheet is polished with P280 water-resistant abrasive paper, and each coating composition is air-spray coated so that the dry film thickness is 60 μm, and the temperature is 20 ° C., 65% relative. It was dried for 7 days under humidity conditions to obtain a test coating plate. The degree of red rust and blisters generated on the test coat plate (general part, cut part) after exposing this test coat plate to salt spray for 1500 hours was evaluated according to the following criteria.
◎: No rust on the general part, blisters and rust width on the cut part is 2 mm or less,
◯: No rust on the general part, blister and rust width on the cut part is 4 mm or less,
Δ: No rust on the general part, the width of the blisters and rust on the cut part is 4 mm or more,
X: Rust is observed in both the general part and the cut part.

(*) Impact resistance Using a DuPont impact tester, at room temperature of 20 ° C, the weight of the drop weight is 300 g, the height of the drop weight is 50 cm, and the tip diameter of the striking core is 1 with respect to the coated surface on the surface side of each test coating plate. A drop weight test was performed under the condition of / 2 inch, and a cellophane adhesive tape was adhered to the surface of the coating film, and the degree of cracking and peeling of the coating film after being rapidly peeled off was evaluated.
⊚: No peeling of the coating film was observed.
◯: Cracks were observed in the coating film, but peeling was slight.
Δ: Cracks were observed on the coating film, and peeling that could be easily visually confirmed occurred.
X: Many cracks and peeling are observed in the coating film.

Claims (7)

Resin component (A), compound (B) having a plurality of ketimines, coloring pigment (C) (excluding inorganic filler (D) and polyvalent metal compound (E)), calcium carbonate, barium sulfate, talc, magnesium carbonate, Calcium sulfate, diatomaceous soil, mica, clay, kaolin, silica, alumina, aluminum, barite powder, bentonite, lithopon, glass flakes, glass fiber, carbon fiber, mineral fiber, molybdenum disulfide, wallacenite, montmorillonite, biderite, epoxide, A resin containing at least one inorganic filler (D), a polyvalent metal compound (E) and an aliphatic hydrocarbon-based organic solvent (F) selected from the group consisting of saponite, stibunsite, sericite, eliite and vermucrite. The component (A) contains a resin (a1) having at least two epoxy groups and a resin (a2) different from the resin (a1) as a part of the component, and the polyvalent metal compound (E) is magnesium. A compound of phosphoric acid or a condensate thereof of at least one metal selected from the group consisting of calcium, aluminum and zinc, wherein the resin (a2) is a urethane containing an epoxy group-containing resin, a fatty acid and a polyisocyanate as constituents. A normal temperature one-component cross-linking coating composition which is at least one selected from a resin containing a bond and an acrylic resin, which does not have an epoxy group and has a hydroxyl value in the range of 10 to 100 mgKOH / g. .. The normal temperature one-component cross-linking coating composition according to claim 1, wherein the resin (a1) is a resin containing an alkylphenol as a constituent. The room temperature one-component crosslinked coating composition according to any one of claims 1 or 2 , wherein a flaky inorganic filler (d1) and a fibrous inorganic filler (d2) are used in combination as the inorganic filler (D). Claim 1 in which the ratio of the inorganic filler (D) and the polyvalent metal compound (E) used is in the range of 3/1 to 30/1 in terms of the mass ratio of the inorganic filler (D) / polyvalent metal compound (E). The room temperature one-component cross-linking coating composition according to any one of 3 to 3 . The room temperature one-component crosslinked coating composition according to any one of claims 1 to 4 , wherein the coating composition has a water content of 3000 ppm or less. A coating method for coating a surface to be coated with the room temperature one-component crosslinked coating composition according to any one of claims 1 to 5 . The surface to be coated is coated with the room temperature one-component crosslinked coating composition according to any one of claims 1 to 5 , dried to form a coating film, and then top-coated on the coated surface. Method.