JP7146071B2 - Anticorrosive paint composition - Google Patents

Description

One embodiment of the present invention relates to an anticorrosion coating composition, an anticorrosion coating, a substrate with an anticorrosion coating, or a method for producing a substrate with an anticorrosion coating.

Conventionally, epoxy resin-based coating compositions, which are excellent in corrosion resistance, water resistance, chemical resistance, etc., have been used as anti-corrosion coating compositions for ships and steel structures, especially in ballast tanks, which are in a severely corrosive environment. Epoxy resin-based coating compositions, in which an epoxy resin and an amine curing agent are reacted, are widely used because they can form a coating film having particularly excellent corrosion resistance.

As the coating composition, there is a demand for a coating composition with a low content of volatile organic compounds (VOC), that is, a coating composition with a high content of non-volatile components and a low content of volatile organic components, in order to be environmentally friendly. there is

As such an epoxy resin-based anticorrosive coating composition with a low VOC content, for example, Patent Document 1 discloses a main ingredient component containing a specific epoxy resin and a curing agent containing an epoxy adduct of xylylenediamine and an epoxy adduct of polyamide. A high-solids type anti-corrosion coating composition is disclosed comprising:

WO2007/102587

When the coating composition is applied to a base material such as a ballast tank to form a coating film, the volatile matter of the solvent contained in the coating composition tends to stay near the floor surface due to the structure of the ballast tank. Drying tends to proceed in a solvent atmosphere, and since the coating area is large, it is difficult to control the drying temperature.

Water is injected into these ballast tanks, but since the amount of water injected is enormous, the quality-controlled water is not used. and industrial water are commonly used.

Resins with low viscosity are used to provide coating compositions with low VOC content. Such resins usually have a small average molecular weight and tend to bleed to the coating film surface. In particular, anticorrosion coating films formed from anticorrosion coating compositions with a low VOC content containing an amine curing agent, such as those described in the above-mentioned patent documents, are believed to be susceptible to bleeding of the amine curing agent onto the surface.

Biofilms are formed on the surface of such anticorrosive coatings, especially on the surfaces of coatings dried in a solvent atmosphere or at low temperatures, where various types of bacteria are present due to contact with seawater and industrial water. It was confirmed. This is probably because the amine curing agent bleeds onto the surface of the anticorrosive coating, promoting adhesion of bacteria to the surface of the coating, and proliferating bacteria and their metabolites on the surface of the coating.

Then, due to the formation of a biofilm on the coating film in this way, the amine curing agent undergoes structural changes due to contact with the biofilm, complex formation with the metabolites, etc., and the metabolites Discoloration of the coating film, which is presumed to be caused by adhesion to the coating film surface, etc., was confirmed.

One embodiment of the present invention provides an anticorrosion coating composition that can form an anticorrosion coating film with excellent anticorrosion properties by suppressing discoloration caused by contact with bacteria even when dried in a solvent atmosphere or at a low temperature.

The present inventors have made intensive studies on methods for solving the above problems, and as a result, have found that the above problems can be solved by using a predetermined coating composition. A configuration example of the present invention is as follows.

<1> Contains an epoxy resin (A), an amine curing agent (B), a silane coupling agent (C) and an extender pigment (D),
Pigment volume concentration (PVC) is 30 to 45%,
The amine curing agent (B) contains ethylenediamine or a modified product thereof,
The epoxy resin (A) contains an epoxy resin having an epoxy equivalent of 270 or less,
Anticorrosive paint composition.

<2> Contains an epoxy resin (A), an amine curing agent (B), a silane coupling agent (C) and an extender pigment (D),
Pigment volume concentration (PVC) is 30 to 45%,
The amine curing agent (B) contains ethylenediamine or a modified product thereof,
The content of volatile organic compounds (VOC) is 340 g / L or less,
Anticorrosive paint composition.

<3> <1> or <2>, wherein the amine curing agent (B) comprises a polyamide of ethylenediamine, an epoxy adduct of the polyamide, a Mannich-modified ethylenediamine, or an epoxy adduct of the Mannich-modified The anticorrosion coating composition described.

<4> The anticorrosion paint composition according to any one of <1> to <3>, further comprising a liquid compound (E) having a phenol skeleton.
<5> The anticorrosive coating composition according to any one of <1> to <4>, further comprising a (meth)acrylic acid ester (F).

<6> An anticorrosion coating film formed from the anticorrosion coating composition according to any one of <1> to <5>.
<7> A substrate with an anticorrosive coating comprising the anticorrosive coating according to <6> and a substrate.

<8> A method for producing a substrate with an anticorrosive coating, comprising the following steps [1] and [2].
[1] A step of coating the substrate with the anticorrosion coating composition according to any one of <1> to <5> [2] A step of drying the coated anticorrosion coating composition to form an anticorrosion coating film

According to one embodiment of the present invention, it has excellent salt water resistance, high temperature and high humidity resistance, corrosion resistance, and adhesion to the substrate, and even when dried in a solvent atmosphere or at a low temperature, it does not discolor due to contact with bacteria. A controllable anticorrosion coating can be formed.

FIG. 1 is a schematic diagram of a notched test plate used in the tests of the examples.

≪Anticorrosion paint composition≫
An anticorrosive coating composition according to one embodiment of the present invention (hereinafter also referred to as "this composition") comprises an epoxy resin (A), an amine curing agent (B), a silane coupling agent (C) and an extender (D). ), the pigment volume concentration (PVC) is 30 to 45%, the amine curing agent (B) contains ethylenediamine or a modified product thereof, and satisfies the following (i) or (ii).
(i) the epoxy resin (A) contains an epoxy resin having an epoxy equivalent of 270 or less (ii) the content of volatile organic compounds (VOC) is 340 g/L or less

According to such a present composition, it is possible to form an anti-corrosion coating film exhibiting the above effects. In particular, when a conventional anticorrosion paint is dried in a solvent atmosphere or at low temperature to form an anticorrosion coating film, the resulting anticorrosion coating film discolors when it comes into contact with bacteria. Even if the anticorrosion coating film is formed by drying at , the resulting anticorrosion coating film can suppress discoloration caused by contact with bacteria. Therefore, it can be said that the present composition is a paint composition for inhibiting discoloration caused by bacteria.
In addition, according to the present composition, since it is possible to easily form an anticorrosion coating film that exhibits the above effects, the present composition can be used in places where bacteria can be indirect for a long period of time, specifically, where it is in contact with seawater or industrial water for a long period of time. Locations (where seawater and industrial water are stored), locations where drying progresses in a solvent atmosphere, locations where it is difficult to control the drying temperature, especially the inside of tanks such as ballast tanks and the inside of ships other than tanks Suitable for painting.

Although the present composition may be a one-component composition, it is usually a two-component type consisting of a main component containing the epoxy resin (A) and a curing agent component containing the amine curing agent (B). is the composition of Moreover, it is good also as a composition of a 3-component type or more if needed.
These main component and curing agent component are usually stored, stored, transported, etc. in separate containers, and mixed just before use.

As described above, in the conventional anticorrosion coating composition, if the coating composition has a low VOC content, the anticorrosion coating film is likely to discolor due to contact with bacteria, while the anticorrosion coating film discolors due to contact with bacteria. It has not been easy to achieve a coating composition with a low VOC content when trying to suppress the In other words, there has been no anticorrosive coating composition that satisfies both a low VOC content and suppression of discoloration of the anticorrosive coating film due to contact with bacteria.

On the other hand, in one embodiment of the present invention, even though it has a low VOC content, even if it is dried in a solvent atmosphere or at a low temperature, the anticorrosion coating film discolors due to contact with seawater, industrial water, etc. in which bacteria are present. is unlikely to occur.
Therefore, from the viewpoint of environmental conservation and safety of working environment, the present composition is preferably a coating composition having a low VOC content. Specifically, the VOC content in the present composition is preferably It is 340 g/L or less, more preferably 300 g/L or less, and particularly preferably 270 g/L or less.

The VOC content can be calculated from the following formula (1) using the specific gravity of the composition and the percentage of residual content after heating (mass ratio of non-volatile matter). The specific gravity of the composition and the residual fraction after heating may be values calculated from the raw materials used, or may be values measured as follows.
VOC content (g/L) = specific gravity of composition x 1000 x (100 - residual fraction after heating)/100 (1)

The composition specific gravity (g/ml) can be calculated as follows.
Under a temperature condition of 23° C., the present composition (in the case of the two-component composition, the composition immediately after mixing the main component and the curing agent component) is filled in a specific gravity cup having an internal volume of 100 ml, and the composition is It is calculated by calculating the mass of the object.

The heating residue (non-volatile content) of the present composition can be calculated as follows.
According to JIS K 5601-1-2: 2008, 1 ± 0.1 g of this composition (in the case of the two-component composition, the composition immediately after mixing the main component and the curing agent component) was weighed into a flat-bottom dish. Take it out, spread it evenly with a wire of known mass, leave it at 23°C for 24 hours, dry it at 110°C for 1 hour under normal pressure, and measure the mass of the heating residue and the wire.
The heating residue ratio (mass %) is the mass percentage value of the heating residue (non-volatile matter) in the present composition.

In this specification, in the raw materials (eg, epoxy resin (A)) constituting the main agent component or the curing agent component, components other than the solvent in the main agent component and the curing agent component are referred to as "solid content".

The pigment volume concentration (PVC) in the present composition is 30% or more, preferably 32% or more, more preferably 34% or more, and 45% or less, preferably 43% or less, more preferably 42% or less. When the PVC is in the above range, a composition having excellent drying property can be obtained, and the anticorrosion coating film can be easily formed with excellent resistance to high temperature and high humidity and adhesion to the substrate, and further suppressing discoloration caused by contact with bacteria. Obtainable.
If the PVC content is less than 30%, the resistance to high temperature and high humidity is poor, the drying property of the composition is lowered, and the discoloration resistance to contact with bacteria is lowered. On the other hand, when the PVC content exceeds 45%, the anticorrosive coating film formed has poor film-forming properties, resulting in poor adhesion to substrates and anticorrosive properties.

The PVC refers to the total volume concentration of all pigments, including the extender pigment (D) and the following color pigments, and can be specifically determined from the following formula.
PVC [%] = total volume of all pigments in this composition x 100/volume of non-volatile matter in this composition

The volume of nonvolatile matter in the present composition can be calculated from the mass and true density of the nonvolatile matter of the present composition. The mass and true density of the non-volatile matter may be measured values or values calculated from raw materials used.

The volume of the pigment can be calculated from the mass and true density of the pigment used. The mass and true density of the pigment may be measured values or values calculated from raw materials used. The measured value can be calculated, for example, by separating the pigment and other components from the non-volatile matter of the present composition and measuring the mass and true density of the separated pigment.

<Epoxy resin (A)>
Examples of the epoxy resin (A) include polymers or oligomers containing two or more epoxy groups in the molecule, and polymers or oligomers produced by ring-opening reaction of the epoxy groups.
Epoxy resin (A) may be used individually by 1 type, and may be used 2 or more types.

The epoxy resin (A) preferably has an epoxy equivalent weight of 270 or less, more preferably 100 to 270, and particularly preferably 100 to 200, in order to easily obtain a coating composition having a low VOC content. It is preferable that the epoxy resin contains an epoxy resin having an epoxy equivalent weight within the above range. Epoxy resins having an epoxy equivalent within this range include liquid or semi-solid epoxy resins.
When the epoxy equivalent is in the above range, a coating composition having a low VOC content can be easily obtained, and the effects of the present invention are more exhibited, which is preferable. If the epoxy equivalent exceeds 270, it tends to be difficult to obtain a coating composition with a low VOC content.
The epoxy equivalent is calculated from the solid content of the resin based on JIS K 7236:2001.

In addition, an epoxy resin having an epoxy equivalent of more than 270 can be used in combination with the present composition as long as the effect of the present invention is not impaired. is preferably 50% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less, from the viewpoint of easily obtaining a coating composition with a low VOC content.

Examples of the epoxy resin (A) include bisphenol-type epoxy resins, glycidyl ester-type epoxy resins, glycidylamine-type epoxy resins, novolak-type epoxy resins, cresol-type epoxy resins, dimer acid-modified epoxy resins, aliphatic epoxy resins, and alicyclic epoxy resins. group epoxy resins and epoxidized oil-based epoxy resins.

Among these, bisphenol-type epoxy resins and novolac-type epoxy resins are preferable, and bisphenol-A or bisphenol-F type epoxy resins are preferable, since they can easily form anticorrosive coatings with excellent adhesion to substrates. A bisphenol A type epoxy resin is more preferable, and a bisphenol A type epoxy resin is particularly preferable.

Examples of the epoxy resin (A) include epichlorohydrin-bisphenol A epoxy resin (bisphenol A diglycidyl ether type); epichlorohydrin-bisphenol AD epoxy resin; epichlorohydrin-bisphenol F epoxy resin; epoxy novolac resin; Alicyclic epoxy resin obtained from 3',4'-epoxyphenylcarboxymethane, etc.; brominated epoxy in which at least one hydrogen atom bonded to the benzene ring in epichlorohydrin-bisphenol A epoxy resin is substituted with a bromine atom resins; aliphatic epoxy resins obtained from epichlorohydrin and aliphatic dihydric alcohols; and polyfunctional epoxy resins obtained from epichlorohydrin and tri(hydroxyphenyl)methane.

Examples of the bisphenol A epoxy resin include bisphenol A diglycidyl ether, bisphenol A (poly)propylene oxide diglycidyl ether, bisphenol A (poly)ethylene oxide diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, and hydrogenated bisphenol A. Condensation products such as bisphenol A diglycidyl ether such as (poly)propylene oxide diglycidyl ether can be mentioned.

As the epoxy resin (A), a compound synthesized by a conventionally known method may be used, or a commercially available product may be used.
As the commercially available product, "E-028" (Bisphenol A diglycidyl ether, manufactured by Ohtake Meishin Kagaku Co., Ltd., solid content 100%) is a liquid at normal temperature (15 to 25 ° C., hereinafter the same). , epoxy equivalent 180 to 190, viscosity 12,000 to 15,000 mPa s / 25 ° C.), "jER-807" (manufactured by Mitsubishi Chemical Corporation, bisphenol F diglycidyl ether, epoxy equivalent 160 to 175, viscosity 3, 000 to 4,500 mPa s / 25 ° C.), "E-028-90X" (manufactured by Ohtake Meishin Chemical Co., Ltd., xylene solution of bisphenol A diglycidyl ether (828 type epoxy resin solution, solid content 90%), The epoxy equivalent of the solid content is about 190) and the like. As semi-solid at room temperature, "jER-834" (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent 230-270, solid content 100%), "E-834-85X" (Akira Otake Xylene solution of bisphenol A type semi-solid epoxy resin (834 type epoxy resin solution, solid content 85%), epoxy equivalent of solid content about 255), etc., manufactured by Shinkagaku Co., Ltd., which is a novolak type epoxy resin. "DEN 425" (manufactured by DOW Chemical, epoxy equivalent 169 to 175, solid content 100%), "DEN 431" (manufactured by DOW Chemical, epoxy equivalent 172 to 179, solid content 100%) and "D.E.N. 438" (manufactured by DOW Chemical, epoxy equivalent 176-181, solid content 100%).

The content of the epoxy resin (A) is preferably 5% by mass or more, more preferably 10% by mass or more, preferably 40% by mass or less, more preferably 30% by mass, based on 100% by mass of the nonvolatile matter of the present composition. % or less.
In addition, the epoxy resin (A) is included in the main agent component when the present composition is a two-component composition consisting of the main agent component and the curing agent component. The content of the epoxy resin (A) in the main component is preferably 5-80% by mass, more preferably 5-50% by mass.
When the content of the epoxy resin (A) is within the above range, it is possible to easily obtain an anticorrosion coating film with superior anticorrosion properties and adhesion to substrates.

<Amine curing agent (B)>
The amine curing agent (B) includes ethylenediamine or a modified product thereof.
By using such an amine curing agent (B) together with the above (A), (C) and (D), an epoxy resin having an epoxy equivalent of 270 or less or a liquid or semi-solid epoxy resin can be obtained. Even if the coating composition is dried in a solvent atmosphere or at a low temperature, it is possible to form an anticorrosion coating film that can suppress discoloration caused by contact with bacteria.
The amine curing agent (B) may be used alone or in combination of two or more.

Examples of the modified ethylenediamine include polyamidoamides of ethylenediamine such as fatty acid modified ethylenediamine (polyamideamine), epoxy adducts of the polyamides, amine adducts of ethylenediamine and epoxy compounds, and Mannich-modified ethylenediamines (e.g., phenalkamine, phenalkamide), epoxy adducts of the Mannich-modified products, Michael adducts of ethylenediamine, ketimines of ethylenediamine, and aldimines of ethylenediamine. Among these, polyamidoamine, polyamidoamine epoxy adducts, Mannich-modified products, and Mannich-modified epoxy adducts are preferable in that an anticorrosion coating film having excellent drying property can be easily obtained, and epoxy adducts of polyamidoamine. , and Mannich-modified epoxy adducts are more preferred, and polyamidoamine epoxy adducts are particularly preferred from the viewpoint that an anticorrosive coating film having excellent discoloration resistance can be easily obtained.

Specific examples of the polyamide compound (polyamideamine) include dehydration condensation products of ethylenediamine and one or more carboxylic acids such as dimer acid.
When polyamidating, it is preferable to use a carboxylic acid containing 10% by mass or more of a monomeric acid (compound having one carboxylic acid in one molecule) as the carboxylic acid.
The amount of carboxylic acid to be used is preferably 50 to 300 parts by mass based on 100 parts by mass of ethylenediamine.

The dimer acids are dimers of unsaturated fatty acids, usually containing minor amounts of monomers or trimers. The unsaturated fatty acid preferably has 12 or more, more preferably 16 or more, preferably 24 or less, more preferably 18 or less carbon atoms, including the carbon atoms of the carboxyl group, and , a carboxylic acid having one or more unsaturated bonds in one molecule is desirable. Examples of such unsaturated fatty acids include fatty acids having one unsaturated bond such as oleic acid and elaidic acid; fatty acids having two unsaturated bonds such as linoleic acid; unsaturated bonds such as linolenic acid and arachidonic acid. and fatty acids having 3 or more. Furthermore, fatty acids obtained from animals and plants can also be used, and examples of such fatty acids include soybean oil fatty acids, tall oil fatty acids, and linseed oil fatty acids.

Specific examples of the Mannich-modified products include Mannich-modified amines obtained by Mannich condensation of one or more phenols, one or more aldehydes, and ethylenediamine.

The phenols may be monovalent or polyvalent, and may be mononuclear or polynuclear, but monovalent mononuclear phenols are preferred.
Specific examples of the phenols include, for example, phenol which is a monovalent mononuclear phenol; resorcinol and hydroquinone which are divalent mononuclear phenols; 1,5-dihydroxynaphthalene which is a divalent polynuclear phenol, 2, In addition to 7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, etc., alkylphenols (the number of carbon atoms in the alkyl group: 1 to 10, preferably 1 to 5), halogenated phenols, alkoxyphenols (the number of carbon atoms in the alkoxy group: 1 to 10, preferably 1 to 5), bisphenol A and bisphenol F.

More specifically, the alkylphenols include monohydric phenols such as methylphenol (o, m or p-cresol), ethylphenol, butylphenol, t-butylphenol, octylphenol, nonylphenol, dodecylphenol and dinonylphenol. Halogenated phenols include monohydric phenols such as chlorophenol, and alkoxyphenols include methoxyphenol and the like.

Further, the phenols may be unsaturated substituent-containing phenol, and the unsaturated substituent-containing phenol contains at least one monohydroxyphenyl group in the molecule, and hydrogen in the phenyl group Some of the atoms, ie, compounds in which 1 to 5 of the hydrogen atoms are substituted with unsaturated hydrocarbon groups are included.
Examples of the unsaturated hydrocarbon group include an alkylene group having 1 to 30 carbon atoms and a phenyl group containing an alkylene group having 1 to 30 carbon atoms.
Specific examples of such unsaturated substituent-containing phenols include cardanol, isopropenylphenol, diisopropenylphenol, butenylphenol, isobutenylphenol, cyclohexenylphenol, _{monostyrenated} phenol (C6 H ₅ -CH=CH-C ₆ H ₄ -OH), distyrenated phenol ((C ₆ H ₅ -CH=CH) ₂ -C ₆ H ₃ -OH).

Cardanol is preferable as the phenols.

Examples of the aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, etc. Among these, formaldehyde is preferable.

In the Mannich condensation, for example, phenols, aldehydes, and ethylenediamine may be theoretically used in equimolar amounts. An amount of up to 2.5 mol and 0.5 to 2.5 mol of ethylenediamine may be used and heated at a temperature of about 50 to 180° C. for about 3 to 12 hours.
After completion of the reaction, the reaction product may be heated under reduced pressure to remove moisture and unreacted substances.

Specific examples of the epoxy adduct include reaction of one or more amines such as ethylenediamine, polyamides, and Mannich-modified products with one or more epoxy resins such as bisphenol A epoxy resins. A compound obtained by
The amount of the epoxy resin to be used is preferably 5 to 50 parts by mass with respect to 100 parts by mass of the amines.

Examples of the epoxy resin include bisphenol A diglycidyl ether; bisphenol F diglycidyl ether; styrene oxide; cyclohexene oxide; Glycidyl ethers such as alcohols of 8 to 14; alkyl glycidyl ethers (eg, Epodil 759 [manufactured by Evonik]).

The amine curing agent (B) may contain amine curing agents other than ethylenediamine and modified products thereof.
The other amine curing agent is not particularly limited, and conventionally known amine curing agents can be used. Specifically, aliphatic, alicyclic, aromatic, and heterocyclic amines, and , modifications of these can be used.

Examples of the aliphatic amines include alkylenepolyamines, polyalkylenepolyamines, and alkylaminoalkylamines.

Examples of the alkylenepolyamine include 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, trimethylhexamethylenediamine.

Examples of the polyalkylenepolyamine include diethylenetriamine, dipropylenetriamine, triethylenetetramine (TETA), tripropylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, and bis(hexamethylene). triamines, triethylene-bis(trimethylene)hexamine;

Examples of the alkylaminoalkylamines include dimethylaminoethylamine, diethylaminoethylamine, dibutylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine and dimethylaminobutylamine.

Aliphatic amines other than these include, for example, tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2′-aminoethylamino)propane, tris(2-amino ethyl)amine, bis(cyanoethyl)diethylenetriamine, polyoxyalkylenepolyamine (especially diethylene glycol bis(3-aminopropyl)ether), bis(aminomethyl)cyclohexane, menzenediamine (MDA), o-xylylenediamine, m- Xylylenediamine (MXDA), p-xylylenediamine, bis(aminomethyl)naphthalene, bis(aminoethyl)naphthalene, 1,4-bis(3-aminopropyl)piperazine, 1-(2'-aminoethylpiperazine) , 1-[2′-(2″-aminoethylamino)ethyl]piperazine.

Examples of the alicyclic amine include cyclohexanediamine, isophoronediamine (IPDA), diaminodicyclohexylmethane (especially 4,4'-methylenebiscyclohexylamine), 4,4'-isopropylidenebiscyclohexylamine, and norbornanediamine. , 2,4-di(4-aminocyclohexylmethyl)aniline.

Examples of the aromatic amine include aromatic polyamine compounds having two or more primary amino groups bonded to a benzene ring.
More specifically, the aromatic amines include phenylenediamine, naphthalenediamine, diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4′-diaminodiphenyl ether, and 4,4′-diaminobenzophenone. , 4,4′-diaminodiphenyl sulfone, 3,3′-dimethyl-4,4′-diaminodiphenylmethane, diaminodiethylphenylmethane, 2,4′-diaminobiphenyl, 2,3′-dimethyl-4,4′- diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl.

Examples of the heterocyclic amine include 1,4-diazacycloheptane, 1,11-diazacycloeicosane, and 1,15-diazacyclooctacosane.

Modified products of aliphatic, alicyclic, aromatic, and heterocyclic amines include, for example, polyamide compounds (polyamide amines) such as fatty acid-modified products, epoxy adducts of the polyamide compounds, and amines with epoxy compounds. adducts, Mannich-modified products (eg, phenalkamine, phenalkamide), epoxy adducts, Michael adducts, ketiminated products, and aldimine-modified products of the Mannich-modified products.

When other amine curing agents are used, aliphatic amines such as triethylenetetramine and alicyclic amines such as isophoronediamine are preferable, and in particular, polyamides of aliphatic amines such as triethylenetetramine and isophoronediamine. Mannich-modified alicyclic amines are preferred.

When the other amine curing agent is used, the content of ethylenediamine and its modified products in the amine curing agent (B) is 50% by mass, because it is possible to easily obtain an anticorrosion coating film with excellent discoloration resistance. It is preferable to use in an amount equal to or above.

As the amine curing agent (B), a compound synthesized by a conventionally known method may be used, or a commercially available product may be used.
Examples of the commercially available products include "PA-205" (manufactured by Ohtake Meishin Chemical Co., Ltd.), which is a polyamide adduct of ethylenediamine (epoxy adduct of polyamide of ethylenediamine), phenalkamine adduct of ethylenediamine (phenalkamine of ethylenediamine). "Cardolite NC-556X80" (manufactured by Cardlite Co., Ltd.), which is an epoxy adduct).

The active hydrogen equivalent of the amine curing agent (B) is preferably 50 or more, more preferably 80 or more, and preferably 1000 or less, from the viewpoint of easily obtaining an anticorrosion coating film having excellent anticorrosion properties. Preferably it is 400 or less.

From the viewpoint of easily obtaining an anticorrosion coating film having excellent anticorrosion properties, coating strength and drying property, the amine curing agent (B) preferably has a reaction ratio calculated by the following formula (1). It is desirable to use an amount of 0.3 or more, more preferably 0.5 or more, preferably 1.5 or less, more preferably 1.0 or less.
When the reaction ratio is within the above range, it is possible to easily obtain an anti-corrosion coating film having excellent discoloration resistance, anti-corrosion properties, and adhesion to substrates.
Reaction ratio = {(mixed amount of amine curing agent (B)/active hydrogen equivalent of amine curing agent (B)) + (mixed amount of component having reactivity with epoxy resin (A)/epoxy resin (A) functional group equivalent of component reactive to)}/{(mixture amount of epoxy resin (A)/epoxy equivalent of epoxy resin (A)) + (reactive to amine curing agent (B) Compounding amount of component/functional group equivalent of component having reactivity with amine curing agent (B))} (1)

Here, the "component reactive with the amine curing agent (B)" in the formula (1) includes, for example, a silane coupling agent (C) and a (meth)acrylic acid ester (F), which will be described later. In addition, examples of the "component having reactivity with the epoxy resin (A)" include a silane coupling agent (C) described later. The "functional group equivalent" of each component means the mass (g) per 1 mol functional group obtained by subtracting the number of moles of functional groups contained therein from the mass of 1 mol of these components.
As the silane coupling agent (C) described later, a silane coupling agent having an amino group or an epoxy group as a reactive group can be used. It is necessary to determine whether there is reactivity with A) or with reactivity with the amine curing agent (B), and calculate the reaction ratio.

When the present composition is a two-component composition consisting of a main agent component and a curing agent component, the amine curing agent (B) is included in the curing agent component. The curing agent component is preferably a component prepared so that the solid content is 50 to 100% by mass, and the viscosity measured with an E-type viscometer at that time is excellent in handleability, coatability, etc. From the point of view, it is preferably 100,000 mPa·s/25°C or less, more preferably 50 to 10,000 mPa·s/25°C.

<Silane coupling agent (C)>
The composition contains a silane coupling agent (C). By using the silane coupling agent (C), it is possible to further improve the adhesion of the obtained anticorrosion coating film to the substrate, and also improve the corrosion resistance and high temperature and high humidity resistance of the obtained anticorrosion coating film. can be made
The silane coupling agent (C) may be used alone or in combination of two or more.

The silane coupling agent (C) is not particularly limited, and conventionally known compounds can be used. It is preferably a compound that can contribute to a decrease in viscosity, etc. For example, the formula: Formula: "X-SiMen Y _{3-n "} [n is 0 or 1, X is a reactive group capable of reacting with an organic substance ( Examples: amino groups, vinyl groups, epoxy groups, mercapto groups, halogen groups, groups in which a portion of the hydrocarbon group is substituted with these groups, or groups in which a portion of the hydrocarbon group is substituted with an ether bond, etc. A group partially substituted with these groups), Me is a methyl group, and Y is a hydrolyzable group (eg, an alkoxy group such as a methoxy group or an ethoxy group). ] is more preferable.

As the silane coupling agent (C), a compound having an epoxy group or an amino group as a reactive group is preferable, and a compound having an epoxy group is more preferable. Propyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.), "Sila Ace S-510" (manufactured by JNC Co., Ltd.), and the like.

The content of the silane coupling agent (C) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and preferably 10% by mass or less with respect to 100% by mass of the nonvolatile content of the present composition. , more preferably 5% by mass or less.
When the content of the silane coupling agent (C) is within the above range, the performance of the anticorrosion coating film, such as adhesion to the substrate, is improved, and the viscosity of the present composition can be reduced, thereby improving coating workability. do.

<Extender Pigment (D)>
The composition contains an extender (D). By using the extender pigment (D), it is possible to form an anticorrosive coating film that is excellent not only in terms of the cost of the resulting composition, but also in corrosion resistance, salt water resistance, high temperature and high humidity resistance, and the like.
The extender pigment (D) may be used alone or in combination of two or more.

Extender pigments (D) include zinc oxide, talc, silica, mica, clay, potassium feldspar, glass flakes, calcium carbonate, kaolin, alumina white, white carbon, aluminum hydroxide, magnesium carbonate, barium sulfate (e.g. barite powder ), gypsum, rock wool, and fibrous fillers such as glass fibers. Among these, talc, silica, mica, clay, calcium carbonate, kaolin, barium sulfate, potassium feldspar, gypsum, and glass flakes are preferred.

In particular, it is preferable to contain mica and glass flakes, which are scale-like pigments, from the viewpoint that it is possible to easily form an anticorrosion coating film that is excellent in corrosion resistance, salt water resistance, high temperature and high humidity resistance, etc., and the average aspect ratio is It is more preferable to contain scale-like pigments of 30 to 90.
The average aspect ratio is calculated by "median diameter (D50)/average thickness".
The D50 can be measured using a laser scattering diffraction particle size distribution analyzer such as "SALD 2200" (manufactured by Shimadzu Corporation). The average thickness is observed from the horizontal direction with respect to the main surface (surface with the largest area) of the scale-like pigment using a scanning electron microscope (SEM) such as "XL-30" (manufactured by Philips). By measuring the thickness of ten to several hundred pigment particles, the average value can be calculated.

Among these scaly pigments, mica is more preferable because it is inexpensive, readily available, and can form an anticorrosive coating film having the above effects. Examples of the mica include "Suzolite Mica 200-HK" (manufactured by Nishinihon Boeki Co., Ltd., aspect ratio: 40 to 60).

The content of the extender (D) with respect to 100% by mass of the non-volatile content of the present composition is such that it is possible to easily form an anti-corrosion coating film that is excellent in corrosion resistance, salt water resistance, high temperature and high humidity resistance, etc. It is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less.

In addition, the content of the scale-like pigment with respect to 100% by mass of the non-volatile content of the present composition is preferably 1% by mass or more from the viewpoint of improving the performance of the anticorrosion coating film such as waterproof corrosion resistance and flex resistance. It is more preferably 3% by mass or more, preferably 40% by mass or less, and more preferably 20% by mass or less.

<Liquid compound (E) having a phenol skeleton>
The present composition preferably contains a liquid compound (E) having a phenol skeleton from the viewpoint that the flexibility of the anticorrosive coating film obtained from the coating composition having a low VOC content can be improved.
The liquid compound (E) may be used singly or in combination of two or more.

In the present specification, the term "liquid compound" refers to a compound that is liquid at 25°C. It refers to a compound that is

The liquid compound (E) is not particularly limited as long as it is a compound having a basic skeleton in which a hydroxy group is bonded to a benzene ring. mentioned. Among these, phenol-modified hydrocarbon resins are preferred because of their good compatibility with the epoxy resin (A).

Examples of the phenol-modified hydrocarbon resin include diolefins contained in cracked oil fractions of petroleum and coal, as described in JP-A-9-268209 and JP-A-7-196793. Examples thereof include resins obtained by copolymerizing monoolefins or α-methylstyrene with phenols (phenolic compounds).

More specifically, the phenol-modified hydrocarbon resin includes a C5 (aliphatic) petroleum resin made from a C5 fraction; a C9 (aromatic) petroleum resin made from a C9 fraction; Copolymerized petroleum resin; dicyclopentadiene resin made from dicyclopentadiene obtained by thermally dimerizing cyclopentadiene contained in C5 fraction; α-methylstyrene; mentioned. Among these, resins obtained by addition polymerization of styrene, vinyltoluene, coumarone, indene, α-methylstyrene, and the like contained in cracked oil fractions of petroleum and coal with phenols are preferable.

The average molecular weight of the phenol-modified hydrocarbon resin is usually 200-1000, and the viscosity is usually 30-10,000 mPa·s/25°C.

As the phenol-modified hydrocarbon resin, a commercial product may be used, and examples of the commercial product include "NEVOXY EPX-L" and "NEVOXY EPX-L2" (manufactured by Neville Chemical / phenol-modified hydrocarbon resin), and "HIRENOL PL-1000S" (manufactured by KOLON / phenol-modified hydrocarbon resin).

When the present composition contains the liquid compound (E), from the viewpoint of obtaining an anticorrosive coating film having excellent crack resistance etc., The content is preferably 1% by mass or more, more preferably 3% by mass or more, and preferably 50% by mass or less, more preferably 30% by mass or less.

<(Meth) acrylic acid ester (F)>
The present composition preferably contains a (meth)acrylic acid ester (F) from the viewpoint of further improving the curing speed and low-temperature curability of the composition.
The (meth)acrylic acid ester (F) may be used singly or in combination of two or more.

The (meth)acrylic acid ester (F) is not particularly limited, but is preferably a polyfunctional acrylic acid ester, more preferably a compound having three or more (meth)acryloyloxy groups in one molecule, from the viewpoint of reactivity. Compounds having three or more acryloyloxy groups in one molecule from are more preferable.
The number of (meth)acryloyloxy groups that the (meth)acrylic acid ester (F) has in one molecule is preferably 3 or more, more preferably 4 or more, and preferably 40 or less, more preferably 20 or less. be.

The (meth)acrylic acid ester (F) has a low viscosity and can easily obtain a coating composition having excellent curability. Compounds are preferred, and compounds that are less than 100 are more preferred.

As the (meth)acrylic acid ester (F), a commercial product may be used, and examples of the commercial product include "M-Cure 400" (manufactured by SARTOMER, functional group equivalent weight 85).

When the present composition contains a (meth) acrylic acid ester (F), from the viewpoint of obtaining a coating composition having excellent curing speed and low-temperature curability, etc., the non-volatile content of 100% by mass of the composition The content of (meth)acrylic acid ester (F) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, preferably 15% by mass or less, more preferably 10% by mass or less, Particularly preferably, it is 5% by mass or less.

<Other ingredients>
In addition to the above (A) to (F), the present composition may optionally include an organic solvent, a coloring pigment, other resins other than the above (A) and (E), an anti-sagging/anti-settling agent, and a curing agent. Accelerators, plasticizers other than the above (E), inorganic dehydrating agents (stabilizers), dispersants, antifoaming agents, antifouling agents and the like may be contained within a range that does not impair the object of the present invention.
These other components include those conventionally known for use in anticorrosive coating compositions.
Each of the other components may be used singly or in combination of two or more.

[Organic solvent]
The organic solvent is not particularly limited, but examples include aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as butyl acetate, isopropanol, n-butanol, 1 -Alcoholic solvents such as methoxy-2-propanol and benzyl alcohol, mineral spirits, n-hexane, n-octane, 2,2,2-trimethylpentane, isooctane, n-nonane, cyclohexane, methylcyclohexane and other aliphatic carbonization Hydrogen-based solvents are mentioned.

When the present composition contains the above organic solvent, the content of the organic solvent is not particularly limited and may be appropriately adjusted according to the coating method when applying the present composition. It is preferable that the content is within the above range.

[Color pigment]
The coloring pigment is not particularly limited as long as it is a pigment other than (D), and examples thereof include titanium white, rouge, yellow rouge, and carbon black.

When the composition contains the coloring pigment, the content of the coloring pigment is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, relative to 100% by mass of the non-volatile content of the composition. , preferably 15% by mass or less, more preferably 10% by mass or less.

[Other resins]
Examples of resins other than the above (A) and (E) include polyester resins, fluororesins, polybutene resins, silicone rubbers, urethane resins (rubbers), polyamide resins, vinyl chloride resins, chlorinated rubbers (resins), Chlorinated olefin resin, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, coumarone resin, silyl resin, petroleum resin, ketone resin, formaldehyde resin, polyvinyl alkyl ether resin, rosin (e.g. gum rosin, wood rosin, tall oil rosin).

As the other resin, a commercial product may be used, and examples of the commercial product include "Neopolymer E-100" manufactured by JXTG Energy Co., Ltd., which is a hydroxyl group-containing petroleum resin.

When the composition contains the other resins, the content of the other resins is, for example, 20% by mass or less with respect to 100% by mass of the non-volatile matter of the composition.

[Anti-sagging and anti-settling agents]
Examples of anti-sagging agents and anti-settling agents include organoclay waxes such as Al, Ca, and Zn stearates, lecithin salts, and alkylsulfonates, polyethylene waxes, amide waxes, hydrogenated castor oil waxes, and synthetic finely divided silica. , oxidized polyethylene waxes and the like can be used. Among them, amide waxes, synthetic finely divided silica, oxidized polyethylene waxes and organoclay waxes are preferred.

Such anti-sagging agents/anti-settling agents include "Disparlon 305", "Disparlon 4200-20" and "Disparlon 6650" manufactured by Kusumoto Kasei Co., Ltd.; Commercial products such as "FLOWON RCM-300" manufactured by Kyoeisha Chemical Co., Ltd.;

When the present composition contains the anti-sagging agent/anti-settling agent, the content of the anti-sagging agent/anti-settling agent is preferably 0.3 to 3 mass with respect to 100% by mass of the non-volatile content of the composition. %.

[Curing accelerator]
The composition preferably contains a curing accelerator that can contribute to adjusting, particularly accelerating, the curing speed.
Examples of the curing accelerator include conventionally known curing accelerators used in anticorrosive coating compositions. is preferred.

Although the tertiary amine is not particularly limited, examples include triethanolamine, dialkylaminoethanol, triethylenediamine [1,4-diazabicyclo(2,2,2) octane], 2,4,6-tri(dimethylaminomethyl ) Phenol (eg, trade name “Versamin EH30” (manufactured by BASF Japan Ltd.), trade name “Ancamine K-54” (manufactured by Evonik Japan Ltd.)).

When the present composition contains the curing accelerator, the content of the curing accelerator is preferably 0.01% by mass or more, more preferably 0.05% by mass, relative to 100% by mass of the nonvolatile matter of the composition. % or more, preferably 5% by mass or less, more preferably 3% by mass or less.

[Antifoaming agent]
The present composition preferably contains an antifoaming agent from the viewpoint of suppressing the generation of air bubbles and improving the appearance of the obtained anticorrosion coating film.
As the defoaming agent, for example, various conventionally known defoaming agents such as polymer-based, acrylic, silicone-based, mineral oil-based, and olefin-based defoaming agents can be used. Foaming agents are preferred.

Examples of such defoaming agents include "BYK-1788", "BYK-1790", and "BYK-1794" manufactured by BYK-Chemie Japan; "AFCONA-2290" manufactured by AFCONA ADDITIVE; and manufactured by ExxonMobil Chemical Company. "SpectraSyn 40", "SpectraSyn Elite 150", "SpectraSyn Elite 65" and the like.

When the present composition contains the antifoaming agent, the content of the antifoaming agent is preferably 0.01% by mass or more, more preferably 0.05%, based on 100% by mass of nonvolatile matter in the composition. % by mass or more, preferably 4% by mass or less, more preferably 2% by mass or less.

≪Anti-corrosion coating, base material with anti-corrosion coating≫
The anticorrosive coating film according to one embodiment of the present invention is not particularly limited as long as it is formed from the present composition. The substrate with an anticorrosion coating film according to one embodiment of the present invention is not particularly limited as long as it includes the anticorrosion coating film and the substrate, but after coating the composition on the substrate, the coated composition It is preferably obtained by a method of drying, preferably drying and curing the coated composition. This method can also be said to be a method for preventing corrosion of the base material.

The base material is not particularly limited, but is preferably a base material that requires anti-corrosion properties so that the effects of the present invention can be exhibited more effectively.
As such a substrate, substrates made of steel, non-ferrous metals (zinc, aluminum, etc.), stainless steel, etc. are preferable. preferable.
In addition, from the viewpoint that the effect of the present invention is more exhibited, the base material is a place where drying progresses in a solvent atmosphere or a place where it is difficult to control the drying temperature, and may come into contact with bacteria. Locations, particularly locations that can be in direct contact with water containing bacteria such as seawater and industrial water for a long period of time, are preferred.

Among these, a ballast tank is more preferable as the substrate.
The ballast tank may be provided with an anode of zinc, zinc-aluminum, or the like to provide anti-corrosion protection. The current density for the cathodic protection is preferably about 1 to 10 mA/m ² .

In addition, the substrate surface may be treated ( For example, blasting (ISO8501-1 Sa2 1/2), friction method, treatment to remove oil and dust by degreasing) may be used. If necessary, the base material surface may be coated with a conventionally known primary rust preventive paint (shop primer) or other primers and dried.

The method of applying the present composition to a substrate is not particularly limited, and conventionally known methods can be used without limitation, but it is excellent in workability and productivity, and can be easily applied to a large-area substrate. Spray coating is preferable because it can be coated and the effects of the present invention can be exhibited more effectively.

The conditions for the spray coating may be appropriately adjusted according to the thickness of the anticorrosion coating film to be formed. ) Pressure: about 10 to 26 MPa, gun moving speed about 50 to 120 cm/sec.

The film thickness of the anticorrosion coating film may be appropriately selected according to the desired application, but it is preferably 100 μm or more, more preferably 250 μm or more, from the viewpoint of providing an anticorrosion coating film with excellent anticorrosion properties. is 450 μm or less, more preferably 400 μm or less.
When forming an anti-corrosion coating film with such a thickness, the anti-corrosion coating film with a desired thickness may be formed with one coating (one coating), or two coatings ( (or more if necessary) may be applied to form an anticorrosion coating film of a desired thickness. It is preferable to form an anticorrosive coating film having a thickness within the above range by two coats, because it is possible to form an anticorrosive coating film having excellent anticorrosive properties with good workability.

The method for drying and curing the composition is not particularly limited, and the composition may be dried and cured by heating at about 5 to 60 ° C. in order to shorten the drying and curing time, but usually, The composition is dried and cured by leaving it at room temperature in the air for about 1 to 14 days.
Further, when the present composition is dried and cured by leaving it at a low temperature of about 8° C. or lower for about 1 to 14 days, the effects of the present invention, particularly discoloration resistance, are more exhibited.
In addition, when the present composition is dried and cured by leaving it for about 1 to 14 days in a solvent atmosphere with a VOC content in the air of about 5 mg/L or more, the effects of the present invention, particularly discoloration resistance, are enhanced. demonstrated.

EXAMPLES The present invention will be further described below with reference to Examples, but the present invention is not limited to these.

[Example 1]
In a container, epoxy resin 1 (Note 1) 19 parts by mass, petroleum resin (Note 3) 10 parts by mass, liquid hydrocarbon resin (Note 4) 4 parts by mass, xylene 10.4 parts by mass, butanol 2 parts by mass, 1- Methoxy-2-propanol 1 part by mass, silane coupling agent (Note 5) 1 part by mass, talc (Note 7) 24 parts by mass, mica (Note 8) 6 parts by mass, potassium feldspar (Note 9) 15 parts by mass, titanium Add 6 parts by mass of white (Note 10), 0.1 part by mass of carbon black (Note 11), and 1.5 parts by mass of anti-sagging agent (Note 13), and use a high-speed disper to disperse these at 56 to 60 ° C. After mixing the components, cooling to 30° C. or less prepared a main ingredient component.

Also, 14 parts by mass of polyamide adduct (Note 15) of ethylenediamine (EDA), 0.2 parts by mass of tertiary amine (Note 21), and 0.8 parts by mass of 1-methoxy-2-propanol, a high speed disper A hardener component was prepared by mixing using
A coating composition was prepared by mixing the obtained main agent component and curing agent component before coating.

[Examples 2 to 11 and Comparative Examples 1 to 5]
A coating composition was prepared in the same manner as in Example 1, except that the raw materials to be blended in the main agent component and the curing agent component and the blending amounts thereof were changed as shown in Table 1.
In Table 1, the numerical values in the main agent component and curing agent component columns indicate parts by mass. Further, Table 2 shows the details of the raw materials in Table 1.

The following tests (1) to (5) were performed on coating films formed from the coating compositions obtained in the above Examples and Comparative Examples. Table 1 shows the results.

(1) Salt water resistance test The salt water resistance of the coating film was measured according to JIS K 5600-6-1:2016. Specifically, it was carried out as follows.
Each of the coating compositions obtained in the above Examples and Comparative Examples was coated on a blasted steel plate (hereinafter also referred to as “test plate”) having dimensions of 150 mm × 70 mm × 1.6 mm (thickness) to form a dry film. Spray coating was applied to a thickness of about 320 μm, and the resulting coated test panel was dried in an atmosphere of 23° C. and 50% RH for 7 days.

An incision 2 reaching the steel plate from the coating film side was made at the position shown in FIG. 1 of each test plate. The test panel 1 with the incision 2 was immersed in 3% salt water at 40° C. for 180 days with the incision 2 side down (orientation shown in FIG. 1). After immersion, 11 cuts 3 are made in order from the left end of the cut 2 upward so that the cut 2 is equally divided at intervals of 5 mm, and the steel plate and the coating film are measured at 10 measurement portions 4 between each cut 3. The peel length (the length from the cut 2) was measured. The average value of 10 measured peel lengths was evaluated according to the following criteria.

Evaluation criteria ○: No blisters, cracks, rust, or peeling, peel length less than 5 mm ○△: No blisters, cracks, rust, or peeling, peel length 5 mm or more and less than 10 mm △: Blisters, cracks, rust, Slight defects due to any of peeling, or peeling length of 10 mm or more and less than 20 mm ×: Blisters, cracks, rust, peeling, or obvious defects due to peeling, or peeling length of 20 mm or more

(2) Cathodic resistance test The test was conducted in the same manner as in the salt water resistance test, except that a zinc anode was connected to a coated test plate prepared in the same manner as in the salt water resistance test so that the electric current density was 5 mA/m ² or less. evaluated.

(3) High-temperature and high-humidity resistance test The high-temperature and high-humidity resistance of the coated test plate prepared in the same manner as the salt water resistance test was evaluated according to JIS K 5600-7-2:1999. Specifically, it was carried out as follows.
After holding the test plate 1 with the incision 2 made in the same manner as in the salt water resistance test in a tester at a temperature of 50 ° C. and a humidity of 95% for 90 days, a cut 3 was made in the same manner as in the salt water resistance test. At 10 measurement points 4 between 3, the peeling length (the length from the cut 2) between the steel plate and the coating film was measured. An average value of 10 measured peel lengths was evaluated in the same manner as the salt water resistance test.

(4) Discoloration resistance (low temperature drying)
Each of the coating compositions obtained in the above examples and comparative examples was coated on a test panel at an environmental temperature of 5°C so that the dry film thickness was about 320 µm, and then dried at 5°C for one day. After that, a test plate with a coating film was prepared by drying in an atmosphere of 23 ° C. and 50% RH for 7 days, and half of the surface area of the test plate with the coating film was immersed in the immersion liquid containing the biofilm. The color difference ΔE between the portion immersed in the immersion liquid and the portion not immersed in the immersion liquid was evaluated according to the following criteria.

The color difference was measured using a spectral colorimeter (model SD 5000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 5600-4-5: 1999, and JIS K 5600-4-6. : 1999, the color difference ΔE was calculated.

In addition, biofilms were collected from the surface of tanks immersed in the sea for more than half a year. The collected biofilm was immediately diluted 40-fold with seawater to prepare an immersion liquid. There was no significant difference in the results depending on the location of the sea where the tank was immersed, the time of immersion of the tank, and the type of tank.

(5) Discoloration resistance (solvent atmosphere)
Each of the coating compositions obtained in the above examples and comparative examples was applied to a test plate at an ambient temperature of 5 ° C. so that the dry film thickness was about 320 μm, and immediately, 200 g of xylene was sprinkled on the bottom. It was allowed to stand at a height of 8 cm from the bottom of an open plastic box of 60×40×30 (height) cm and dried at 5° C. for one day. After that, it was taken out of the plastic box and dried in an atmosphere of 23° C. and 50% RH for 7 days to prepare a coated test plate. The color difference ΔE was evaluated in the same manner as for the discoloration resistance (drying at a low temperature) except that the obtained test plate with a coating film was used.

1: test plate 2: notch 3: cut 4: measurement part

Claims (8)

Contains epoxy resin (A), amine curing agent (B), silane coupling agent (C) and extender pigment (D),
Pigment volume concentration is 30 to 45%,
The amine curing agent (B) contains ethylenediamine or a modified product thereof,
The epoxy resin (A) contains an epoxy resin having an epoxy equivalent of 270 or less,
Anticorrosive paint composition. Contains epoxy resin (A), amine curing agent (B), silane coupling agent (C) and extender pigment (D),
Pigment volume concentration is 30 to 45%,
The amine curing agent (B) contains ethylenediamine or a modified product thereof,
The content of volatile organic compounds is 340 g / L or less,
Anticorrosive paint composition. The anticorrosive coating composition according to claim 1 or 2, wherein the amine curing agent (B) comprises a polyamide of ethylenediamine, an epoxy adduct of the polyamide, a Mannich-modified ethylenediamine, or an epoxy adduct of the Mannich-modified. thing. The anticorrosion paint composition according to any one of claims 1 to 3, further comprising a liquid compound (E) having a phenol skeleton. The anticorrosive coating composition according to any one of claims 1 to 4, further comprising a (meth)acrylic acid ester (F). An anticorrosion coating film formed from the anticorrosion coating composition according to any one of claims 1 to 5. A substrate with an anticorrosive coating comprising the anticorrosive coating according to claim 6 and a substrate. A method for producing a substrate with an anticorrosive coating, comprising the following steps [1] and [2].
[1] A step of coating a substrate with the anticorrosive coating composition according to any one of claims 1 to 5. [2] A step of drying the coated anticorrosive coating composition to form an anticorrosive coating film.

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