阅读说明：本技术 防腐蚀涂料组合物 (Anticorrosive coating composition ) 是由 西泽政武 住田友久 于 2020-04-07 设计创作，主要内容包括：本发明的一个实施方式涉及防腐蚀涂料组合物、防腐蚀涂膜、带有防腐蚀涂膜的基材或带有防腐蚀涂膜的基材的制造方法,该防腐蚀涂料组合物含有环氧树脂(A)、胺固化剂(B)、硅烷偶联剂(C)和体质颜料(D),颜料体积浓度(PVC)为30～45％,上述胺固化剂(B)含有乙二胺或其改性物,满足下述(i)或(ii)。(i)上述环氧树脂(A)含有环氧当量为270以下的环氧树脂,(ii)挥发性有机化合物(VOC)的含量为340g/L以下。(One embodiment of the present invention relates to an anticorrosive coating composition containing an epoxy resin (a), an amine curing agent (B), a silane coupling agent (C), and an extender pigment (D), the Pigment Volume Concentration (PVC) being 30 to 45%, the amine curing agent (B) containing ethylenediamine or a modified product thereof, and satisfying the following (i) or (ii), an anticorrosive coating film, a substrate with an anticorrosive coating film, or a method for producing a substrate with an anticorrosive coating film. (i) The epoxy resin (A) contains an epoxy resin having an epoxy equivalent of 270 or less, and the content of (ii) a Volatile Organic Compound (VOC) is 340g/L or less.)

1. An anticorrosion coating composition characterized by:

contains epoxy resin (A), amine curing agent (B), silane coupling agent (C) and extender pigment (D),

the pigment volume concentration is 30-45%,

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.

2. An anticorrosion coating composition characterized by:

contains epoxy resin (A), amine curing agent (B), silane coupling agent (C) and extender pigment (D),

the pigment volume concentration is 30-45%,

the amine curing agent (B) contains ethylenediamine or a modified product thereof,

the content of volatile organic compounds is below 340 g/L.

3. The anticorrosion coating composition of claim 1 or 2, wherein:

the amine curing agent (B) contains a polyamidate of ethylenediamine, an epoxy adduct of the polyamidate, a Mannich modification of ethylenediamine or an epoxy adduct of the Mannich modification.

4. The anticorrosive coating composition according to any one of claims 1 to 3, wherein: further contains a liquid compound (E) having a phenol skeleton.

5. The anticorrosive coating composition according to any one of claims 1 to 4, wherein: also contains (meth) acrylic ester (F).

6. An anticorrosive coating film characterized by:

formed from the anticorrosion coating composition as claimed in any one of claims 1 to 5.

7. A substrate with an anti-corrosion coating film, characterized in that:

comprising the corrosion-resistant coating film according to claim 6 and a substrate.

8. A method for producing a substrate having an anticorrosive coating film, characterized by comprising:

comprising the following steps [1] and [2 ]:

[1] a step of applying the anticorrosive coating composition according to any one of claims 1 to 5 on a substrate;

[2] and drying the coated anticorrosive coating composition to form an anticorrosive coating film.

Technical Field

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

Background

Conventionally, as an anticorrosive coating composition to be applied to a ship or a steel structure, particularly to a ballast water tank which is a severe corrosive environment, an epoxy resin-based coating composition having excellent anticorrosive properties, water resistance, chemical resistance and the like is used, and particularly, since a coating film having excellent anticorrosive properties can be formed, an epoxy resin-based coating composition in which an epoxy resin is reacted with an amine curing agent is widely used.

In order to cope with the environment, it is desirable to use a coating composition having a small content of Volatile Organic Compounds (VOC), that is, a large content of nonvolatile components and a small content of volatile organic components.

As such an epoxy resin-based anticorrosive coating composition having a low VOC content, for example, patent document 1 discloses a high-solid anticorrosive coating composition containing: a main agent component containing a specific epoxy resin; and a curing agent component comprising an epoxy adduct of xylylenediamine and an epoxy adduct of polyamide.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2007/102587

Disclosure of Invention

Technical problem to be solved by the invention

When a coating composition is applied to a substrate, for example, a ballast tank to form a coating film, volatile components of a solvent contained in the coating composition tend to remain near a floor surface due to the structure of the ballast tank, and therefore, drying tends to be performed in a solvent atmosphere.

Since the ballast water tank is filled with a large amount of water, seawater or industrial water containing various bacteria is generally used without using water whose quality is controlled.

To make a low VOC content coating composition, a low viscosity resin is used. Such a resin generally has a small average molecular weight and is likely to bleed out on the surface of the coating film. In particular, it is considered that an anticorrosive coating film formed from an anticorrosive coating composition containing an amine curing agent and having a low VOC content as described in the above patent document is likely to bleed out of the amine curing agent on the surface thereof.

It has been confirmed that a biofilm is formed on the surface of such an anticorrosive coating film, particularly on the surface of a coating film dried in a solvent atmosphere or at a low temperature, by contact with seawater or industrial water in which various bacteria are present. This is presumably because the amine curing agent bleeds out on the surface of the anticorrosive coating film to promote adhesion of bacteria to the coating film surface, and bacteria and metabolites thereof proliferate on the coating film surface.

Further, since a biofilm was formed on the coating film as described above, discoloration of the coating film was observed, which is presumably caused by a structural change due to contact of the amine curing agent with the biofilm, formation of a complex with the metabolite and the like, and fixation of the metabolite and the like to the surface of the coating film.

One embodiment of the present invention provides an anticorrosive coating composition which can form an anticorrosive coating film having excellent anticorrosive properties by suppressing discoloration due to contact with bacteria even when dried in a solvent atmosphere at low temperatures.

Technical solution for solving technical problem

The present inventors have made extensive studies on a method capable of solving the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by a predetermined coating composition. The constitution of the present invention is as follows.

< 1 > an anticorrosive coating composition comprising an epoxy resin (A), an amine curing agent (B), a silane coupling agent (C) and an extender pigment (D),

the Pigment Volume Concentration (PVC) is 30-45%,

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.

< 2 > an anticorrosive coating composition comprising an epoxy resin (A), an amine curing agent (B), a silane coupling agent (C) and an extender pigment (D),

the Pigment Volume Concentration (PVC) is 30-45%,

the amine curing agent (B) contains ethylenediamine or a modified product thereof,

the content of Volatile Organic Compounds (VOC) is below 340 g/L.

< 3 > the anticorrosive coating composition according to < 1 > or < 2 >, wherein the amine curing agent (B) comprises a polyamidate of ethylenediamine, an epoxy adduct of the polyamidate, a Mannich modification of ethylenediamine, or an epoxy adduct of the Mannich modification.

The anticorrosive coating composition of any one of < 4 > to < 1 > to < 3 >, which further contains a liquid compound (E) having a phenol skeleton.

The anticorrosive coating composition of any one of < 5 > to < 1 > < 4 >, which further contains a (meth) acrylate (F).

< 6 > an anticorrosive coating film formed from the anticorrosive coating composition of any one of < 1 > to < 5 >.

< 7 > A substrate having an anticorrosive coating film, which comprises < 6 > said anticorrosive coating film and a substrate.

< 8 > a method for producing a substrate having an anticorrosive coating film, which comprises the following steps [1] and [2 ]:

[1] coating the anticorrosive coating composition of any one of the items < 1 > -5 > on a substrate;

[2] and drying the coated anticorrosive coating composition to form an anticorrosive coating film.

ADVANTAGEOUS EFFECTS OF INVENTION

According to one embodiment of the present invention, an anticorrosive coating film can be formed which is excellent in salt water resistance, high temperature and high humidity resistance, corrosion resistance, and adhesion to a substrate, and which can suppress discoloration due to contact with bacteria even when dried in a solvent atmosphere or at low temperatures.

Drawings

Fig. 1 is a schematic view of a test board scribed with a cut used in the test of the examples.

Detailed Description

Anticorrosive coating composition

An anticorrosive coating composition according to an embodiment of the present invention (hereinafter, also referred to as "the present composition") contains an epoxy resin (a), an amine curing agent (B), a silane coupling agent (C), and an extender pigment (D), the Pigment Volume Concentration (PVC) is 30 to 45%, and 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 below 340 g/L.

The present composition can form an anticorrosive coating film exhibiting the above-described effects. In particular, when a conventional anticorrosive coating material is dried in a solvent atmosphere or at a low temperature to form an anticorrosive coating film, the obtained anticorrosive coating film is discolored when it comes into contact with bacteria, but even when the anticorrosive coating film is formed by drying in a solvent atmosphere or at a low temperature, the obtained anticorrosive coating film can be inhibited from discoloring due to contact with bacteria. Therefore, the present composition can be said to be a coating composition capable of suppressing discoloration caused by bacteria.

Further, since the present composition can easily form an anticorrosive coating film exhibiting the above-described effects, the present composition is suitably used for coating of a part which is in contact with bacteria for a long period of time, specifically, a part which is in contact with seawater or industrial water for a long period of time (storage seawater or industrial water), a part which is dried in a solvent atmosphere, and a part in which it is difficult to control a drying temperature, and is particularly suitably used for coating of an inside surface of a ballast tank or the inside of a ship other than the tank.

The present composition may be a 1-component type composition, but is usually a 2-component type composition comprising a main component containing an epoxy resin (a) and a curing agent component containing an amine curing agent (B). Further, if necessary, a 3-component or higher composition may be prepared.

These main component and curing agent component and the like are generally stored, transported, and the like in separate containers, and are mixed and used immediately before use.

As described above, in the conventional anticorrosive coating composition, when a coating composition having a low VOC content is prepared, discoloration of the anticorrosive coating film is likely to occur due to contact with bacteria, and on the other hand, when it is desired to suppress discoloration of the anticorrosive coating film due to contact with bacteria, it is difficult to prepare a coating composition having a low VOC content. In other words, at present, there is no anticorrosive coating composition capable of simultaneously satisfying a low VOC content and suppressing discoloration of an anticorrosive coating film caused by contact with bacteria.

However, in one embodiment of the present invention, the anticorrosive coating film has a low VOC content and is less likely to be discolored by contact with seawater or industrial water in which bacteria are present even when dried in a solvent atmosphere or at a low temperature.

Therefore, the composition is preferably a coating composition having a low VOC content, and more specifically, the VOC content in the composition is preferably 340g/L or less, more preferably 300g/L or less, and particularly preferably 270g/L or less, from the viewpoints of environmental protection, work environment safety, and the like.

The VOC content can be calculated from the following formula (1) by using the specific gravity of the composition and the value of the heating residue ratio (mass ratio of nonvolatile components). The specific gravity of the composition and the ratio of the residual heat after heating may be values calculated from the raw materials used or measured values measured in the following manner.

VOC content (g/L) ═ composition specific gravity x 1000 (100-heating residue ratio)/100 … (1)

The specific gravity (g/ml) of the composition can be calculated in the following manner.

The composition (in the case of the 2-component type composition, the composition immediately after mixing the main component and the curing agent component) was poured into a specific gravity cup having an internal volume of 100ml under a temperature condition of 23 ℃ and the mass of the composition was calculated.

The residual heat (nonvolatile content) of the present composition can be calculated in the following manner.

According to JIS K5601-1-2: 2008, 1 ± 0.1g of the present composition (in the case of the 2-component type composition, the composition immediately after mixing the main component and the curing agent component) was weighed in a pan, uniformly spread using a wire having a known mass, left at 23 ℃ for 24 hours, dried at 110 ℃ for 1 hour under normal pressure, and the mass of the heated residue and the wire was measured to calculate the composition.

The heating residual ratio (% by mass) is a value of the mass percentage of the above-mentioned heating residual portion (nonvolatile component) in the present composition.

In the present specification, components other than the solvents of the raw materials (for example, the epoxy resin (a)) constituting the main agent component or the curing agent component, the main agent component, and the curing agent component are referred to as "solid components".

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 PVC is in the above range, a composition having excellent drying properties can be obtained, and an anticorrosive coating film having excellent high-temperature and high-humidity resistance and adhesion to a substrate and further suppressed discoloration due to contact with bacteria can be easily obtained.

When the PVC content is less than 30%, the composition is poor in resistance to high temperature and high humidity, and not only does the composition have a reduced drying property, but also the composition has a reduced discoloration resistance to contact with bacteria. When the PVC content exceeds 45%, the film forming property of the formed anticorrosive coating film is lowered, and the adhesion to the substrate and the anticorrosive property are lowered.

The PVC is a volume concentration of the total of all pigments including the extender pigment (D) and a colored pigment described later, and can be specifically determined by the following formula.

PVC [% ] -the sum of the volumes of all pigments in the composition X100/the volume of the nonvolatile component in the composition

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

The volume of the above 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 the raw materials used. The measured value can be calculated, for example, by separating the pigment and other components from the nonvolatile components 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 having 2 or more epoxy groups in the molecule, and polymers or oligomers produced by a ring-opening reaction of the epoxy groups.

The epoxy resin (A) may be used alone in 1 kind, or may be used in 2 or more kinds.

The epoxy resin (a) is preferably an epoxy resin having an epoxy equivalent of 270 or less, more preferably 100 to 270, particularly preferably 100 to 200, and still more preferably an epoxy resin having an epoxy equivalent of the above range, from the viewpoint of easily obtaining a coating composition having a low VOC content. The epoxy resin having an epoxy equivalent in such a range includes liquid or semisolid 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 can be more effectively exhibited, which is preferable. When the epoxy equivalent exceeds 270, a coating composition having a low VOC content tends not to be easily obtained.

The above epoxy equivalent is based on JIS K7236: 2001 was calculated for the solid content of the resin.

In the present composition, an epoxy resin having an epoxy equivalent of more than 270 can be used together within a range not to impair the effects of the present invention, and from the viewpoint of easily obtaining a coating composition having a low VOC content, the proportion of the epoxy resin having an epoxy equivalent of more than 270 to the epoxy resin (a) is preferably 50% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less.

Examples of the epoxy resin (a) include bisphenol epoxy resins, glycidyl ester epoxy resins, glycidyl amine epoxy resins, novolak epoxy resins, cresol epoxy resins, dimer acid-modified epoxy resins, aliphatic epoxy resins, alicyclic epoxy resins, and epoxidized oil epoxy resins.

Among these, bisphenol type epoxy resins and novolac type epoxy resins are preferable, bisphenol a type or bisphenol F type epoxy resins are more preferable, and bisphenol a type epoxy resins are particularly preferable, from the viewpoint of easily forming an anticorrosive coating film having excellent adhesion to a substrate.

Examples of the epoxy resin (a) include epichlorohydrin-bisphenol a epoxy resins (bisphenol a diglycidyl ether type); epichlorohydrin-bisphenol AD epoxy resin; epichlorohydrin-bisphenol F epoxy resin; an epoxy novolac resin; alicyclic epoxy resins obtained from 3, 4-epoxyphenoxy-3 ',4' -epoxyphenylcarboxylmethane and the like; brominated epoxy resins in which at least 1 of the hydrogen atoms bonded to the benzene ring in the epichlorohydrin-bisphenol a epoxy resin is substituted with a bromine atom; an aliphatic epoxy resin obtained from epichlorohydrin and an aliphatic 2-membered alcohol; a polyfunctional epoxy resin obtained from epichlorohydrin and tris (hydroxyphenyl) methane.

Examples of the bisphenol a-type epoxy resin include condensation polymers of bisphenol a-type diglycidyl ethers such as 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 (poly) propylene oxide diglycidyl ether.

As the epoxy resin (a), a compound synthesized by a conventionally known method can be used, and a commercially available product can be used.

As the commercially available product, as a substance which is liquid at ordinary temperature (a temperature of 15 to 25 ℃ C., the same applies hereinafter), there are mentioned "E-028" (manufactured by Diazammonikoku K.K., bisphenol A diglycidyl ether, solid content 100%, epoxy equivalent 180 to 190, viscosity 12,000 to 15,000 mPa.s/25 ℃), "JeR-807" (manufactured by Mitsubishi chemical Co., Ltd., bisphenol F diglycidyl ether, epoxy equivalent 160 to 175, viscosity 3,000 to 4,500 mPa.s/25 ℃), "E-028-90X" (manufactured by Diazamikimnikoku K.K., xylene solution of bisphenol A diglycidyl ether (828 type epoxy resin solution, solid content 90%), epoxy equivalent of solid content about 190), and the like. Examples of the substance which is semisolid at room temperature include "jER-834" (manufactured by mitsubishi chemical corporation, bisphenol a type epoxy resin, epoxy equivalent 230 to 270, and solid content 100%), "E-834-85X" (manufactured by mazamliki seiki chemical corporation, xylene solution of bisphenol a type semisolid epoxy resin (834 type epoxy resin solution, solid content 85%), and epoxy equivalent of solid content about 255), and "d.e.n.431" (manufactured by dow chemical corporation, epoxy equivalent 172 to 179, and solid content 100%), "d.e.n.431" (manufactured by dow chemical corporation, epoxy equivalent 176 to 181, and solid content 100%) and "d.e.n.438" (manufactured by dow chemical corporation, epoxy equivalent 176 to 181, and solid content 100%) which are novolak type epoxy resins.

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, and more preferably 30% by mass or less, relative to 100% by mass of nonvolatile components in the present composition.

In addition, in the case where the present composition is a 2-component type composition composed of a main agent component and a curing agent component, the epoxy resin (a) is contained in the main agent component. The content of the epoxy resin (a) in the main component is preferably 5 to 80% by mass, more preferably 5 to 50% by mass.

When the content of the epoxy resin (a) is within the above range, an anticorrosive coating film having further excellent anticorrosive properties and adhesion to a substrate can be easily obtained.

< amine curing agent (B) >)

The amine curing agent (B) contains ethylenediamine or a modified product thereof.

By using such an amine curing agent (B) together with the above (a), (C) and (D), an anticorrosive coating film capable of suppressing discoloration due to contact with bacteria can be formed even when a coating composition using an epoxy resin having an epoxy equivalent of 270 or less or a liquid or semisolid epoxy resin is dried in a solvent atmosphere or at a low temperature.

The amine curing agent (B) may be used alone in 1 kind, or may be used in 2 or more kinds.

Examples of the modified product of ethylenediamine include polyamidoamide of ethylenediamine (polyamide amine) such as fatty acid modified product of ethylenediamine, epoxy adduct of the polyamidoamide, amine adduct of ethylenediamine and epoxy compound, Mannich modified product of ethylenediamine (e.g., phenol-aldehyde amine, phenol-aldehyde amide), epoxy adduct of the Mannich modified product, Michael adduct of ethylenediamine, ketimine compound of ethylenediamine, and aldimine compound of ethylenediamine. Among these, from the viewpoint of easily obtaining an anticorrosive coating film having more excellent dryability, the polyamidoamine, the epoxy adduct of polyamidoamine, the mannich-modified product, and the epoxy adduct of the mannich-modified product are preferable, the epoxy adduct of polyamidoamine and the epoxy adduct of the mannich-modified product are more preferable, and from the viewpoint of easily obtaining an anticorrosive coating film having more excellent discoloration resistance, the epoxy adduct of polyamidoamine is particularly preferable.

Specific examples of the polyamidoamide (polyamidoamine) include dehydration condensates of ethylenediamine and 1 or 2 or more kinds of carboxylic acids such as dimer acid.

In the case of polyamidation, it is preferable to use a carboxylic acid containing 10 mass% or more of a monomer acid (a compound containing 1 carboxylic acid in 1 molecule) as the carboxylic acid.

The amount of the carboxylic acid used is preferably 50 to 300 parts by mass per 100 parts by mass of ethylenediamine.

The dimer acids described above are dimers of unsaturated fatty acids, and usually contain a small amount of monomers or trimers. The unsaturated fatty acid is preferably a carboxylic acid having 12 or more, more preferably 16 or more, preferably 24 or less, and more preferably 18 or less carbon atoms including the carbon atom of the carboxyl group, and having 1 or 2 or more unsaturated bonds in 1 molecule. Examples of such unsaturated fatty acids include fatty acids having 1 unsaturated bond such as oleic acid and elaidic acid; fatty acids having 2 unsaturated bonds such as linoleic acid; fatty acids having 3 or more unsaturated bonds such as linolenic acid and arachidic acid. Further, fatty acids obtained from animals and plants can be used, and examples of the fatty acids include soybean oil fatty acid, tall oil fatty acid, and linseed oil fatty acid.

Specific examples of the mannich-modified product include mannich-modified amines obtained by mannich condensation of 1 or 2 or more kinds of phenols, 1 or 2 or more kinds of aldehydes, and ethylenediamine.

The phenol may be a 1-membered phenol or a polyhydric phenol, and may be a mononuclear phenol or a polynuclear phenol, and is preferably a 1-membered mononuclear phenol.

Specific examples of the phenols include phenol as a 1-membered mononuclear phenol; resorcinol, hydroquinone, and the like as 2-membered mononuclear phenols; examples of the 2-membered polynuclear phenol include 1, 5-dihydroxynaphthalene, 2, 7-dihydroxynaphthalene, and 2, 6-dihydroxynaphthalene, and further include alkylphenol (alkyl group having 1 to 10, preferably 1 to 5 carbon atoms), halophenol, alkoxyphenol (alkoxy group having 1 to 10, preferably 1 to 5 carbon atoms), bisphenol A, and bisphenol F.

More specifically, the alkylphenol includes 1-membered phenol such as methylphenol (o-, m-, or p-cresol), ethylphenol, butylphenol, t-butylphenol, octylphenol, nonylphenol, dodecylphenol, and dinonylphenol, the halogenated phenol includes 1-membered phenol such as chlorophenol, and the alkoxyphenol includes methoxyphenol.

The phenol may be an unsaturated substituent-containing phenol, and examples of the unsaturated substituent-containing phenol include compounds containing at least 1 monohydroxyphenyl group in the molecule and having 1 to 5 unsaturated hydrocarbon groups substituted for part of the hydrogen atoms in the phenyl group.

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, isobutylphenol, cyclohexenylphenol, and monostyrenated phenol (C)₆H₅－CH＝CH－C₆H₄-OH), distyrenated phenol ((C)₆H₅－CH＝CH)₂－C₆H₃－OH)。

Cardanol is preferred as the phenol.

Examples of the aldehydes include formaldehyde, paraformaldehyde (paraformaldehyde), and acetaldehyde, and among these, formaldehyde is preferable.

In the mannich condensation, for example, although it is theoretically sufficient to use the phenol, the aldehyde and the ethylenediamine in equimolar amounts, the aldehyde is usually used in an amount of 0.5 to 2.5 moles and the ethylenediamine is usually used in an amount of 0.5 to 2.5 moles with respect to 1 mole of the phenol, and the resulting mixture is heated at a temperature of about 50 to 180 ℃ for about 3 to 12 hours.

After the reaction is completed, the reaction product may be heated under reduced pressure to remove water and unreacted materials.

Specific examples of the epoxy adduct include compounds obtained by reacting 1 or 2 or more kinds of amines such as ethylenediamine, the polyamidated compound, and the mannich-modified compound with 1 or 2 or more kinds of epoxy resins such as bisphenol a type epoxy resin.

The amount of the epoxy resin used is preferably 5 to 50 parts by mass based on 100 parts by mass of the amine.

Examples of the epoxy resin include: bisphenol a diglycidyl ether; bisphenol F diglycidyl ether; styrene oxide; oxidizing cyclohexene; glycidyl ethers such as (alkyl) phenols such as phenol, cresol and tert-butylphenol, butanol, 2-ethylhexanol and alcohols having 8 to 14 carbon atoms; alkyl glycidyl ethers (e.g., Epodil 759 (manufactured by Evonik corporation)).

The amine curing agent (B) may contain other amine curing agents besides ethylenediamine and modified products thereof.

The other amine curing agent is not particularly limited, and conventionally known amine curing agents can be used, and specifically aliphatic, alicyclic, aromatic, heterocyclic amines, and modified products thereof can be used.

Examples of the aliphatic amine include alkylene polyamine, polyalkylene polyamine, and alkylaminoalkylamine.

Examples of the alkylenepolyamines 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, and trimethylhexamethylenediamine.

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

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

Examples of the aliphatic amine other than these include tetrakis (aminomethyl) methane, tetrakis (2-aminoethylaminomethyl) methane, 1, 3-bis (2' -aminoethylamino) propane, tris (2-aminoethyl) amine, bis (cyanoethyl) diethylenetriamine, polyoxyalkylene polyamine (particularly diethylene glycol bis (3-aminopropyl) ether), bis (aminomethyl) cyclohexane, Menthanediamine (MDA), o-xylylenediamine, m-xylylenediamine (MXDA), p-xylylenediamine, bis (aminomethyl) naphthalene, bis (aminoethyl) naphthalene, 1, 4-bis (3-aminopropyl) piperazine, 1- (2' -aminoethylpiperazine), and 1- [2' - (2 "-aminoethylamino) ethyl ] piperazine.

Examples of the alicyclic amine include cyclohexanediamine, Isophoronediamine (IPDA), diaminodicyclohexylmethane (particularly 4,4 '-methylenedicyclohexylamine), 4' -isopropylidenebicyclohexylamine, norbornanediamine, and 2, 4-bis (4-aminocyclohexylmethyl) aniline.

Examples of the aromatic amine include aromatic polyamine compounds having 2 or more primary amino groups bonded to a benzene ring.

More specifically, the aromatic amine includes phenylenediamine, naphthalenediamine, diaminodiphenylmethane, 2-bis (4-aminophenyl) propane, 4 '-diaminodiphenyl ether, 4' -diaminobenzophenone, 4 '-diaminodiphenylsulfone, 3' -dimethyl-4, 4 '-diaminodiphenylmethane, diaminodiethylphenylmethane, 2,4' -diaminobiphenyl, 2,3 '-dimethyl-4, 4' -diaminobiphenyl, and 3,3 '-dimethoxy-4, 4' -diaminobiphenyl.

Examples of the heterocyclic amines include 1, 4-diazepane, 1, 11-diazacycloeicosane and 1, 15-diazacyclooctacosane.

Examples of the modified amine of aliphatic, alicyclic, aromatic or heterocyclic system include a polyamide (polyamidoamine) such as a fatty acid modified product, an epoxy adduct of the polyamide, an amine adduct with an epoxy compound, a mannich modified product (e.g., phenol-aldehyde amine, phenol-aldehyde amide), an epoxy adduct of the mannich modified product, a michael adduct, a ketone imide and an aldehyde imide.

When the other amine curing agent is used, an aliphatic amine such as triethylenetetramine or an alicyclic amine such as isophoronediamine is preferable, and particularly, a polyamidate of an aliphatic amine such as triethylenetetramine or a mannich-modified product of an alicyclic amine such as isophoronediamine is preferable.

When the other amine curing agent is used, the content of ethylenediamine or a modified product thereof in the amine curing agent (B) is preferably 50 mass% or more, from the viewpoint that an anticorrosive coating film having more excellent discoloration resistance can be easily obtained.

The amine curing agent (B) may be a compound synthesized by a conventionally known method or a commercially available product.

Examples of the commercially available products include "PA-205" (manufactured by Diazamine New chemical Co., Ltd.) as a polyamide adduct of ethylenediamine (epoxy adduct of a polyamide of ethylenediamine) and "Cardolite NC-556X 80" (manufactured by Kadela corporation) as a phenol-aldehyde amine adduct of ethylenediamine (phenol-aldehyde amine epoxy adduct of ethylenediamine).

From the viewpoint of easily obtaining an anticorrosive coating film having more excellent anticorrosive properties, the active hydrogen equivalent of the amine curing agent (B) is preferably 50 or more, more preferably 80 or more, preferably 1000 or less, more preferably 400 or less.

From the viewpoint of easily obtaining an anticorrosive coating film excellent in anticorrosive property, coating film strength and drying property, it is desirable to use the amine curing agent (B) in an amount such that the reaction ratio calculated by the following formula (1) is preferably 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, an anticorrosive coating film having excellent discoloration resistance, corrosion resistance and adhesion to a substrate can be easily obtained.

Reaction ratio { (amount of amine curing agent (B) blended/active hydrogen equivalent of amine curing agent (B)) + (amount of component reactive with epoxy resin (a)/functional group equivalent of component reactive with epoxy resin (a) }/{ (amount of epoxy resin (a) blended/epoxy equivalent of epoxy resin (a) }/((amount of component reactive with amine curing agent (B)/functional group equivalent of component reactive with amine curing agent (B) } … (1)

Among them, examples of the "component reactive with the amine curing agent (B)" in the formula (1) include a silane coupling agent (C) and a (meth) acrylate (F) described later, and examples of the "component reactive 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 mole of the functional group obtained by dividing the mass of 1 mole of the component by the number of moles of the functional group contained therein.

Since a silane coupling agent having an amino group and an epoxy group as reactive groups can be used as the silane coupling agent (C) described later, it is necessary to judge whether the silane coupling agent is reactive with the epoxy resin (a) or reactive with the amine curing agent (B) depending on the kind of the reactive group, and calculate the reaction ratio.

In the case where the present composition is a 2-component type composition comprising a main component and a curing agent component, the amine curing agent (B) is contained in the curing agent component. The curing agent component is preferably prepared so that the solid content is 50 to 100 mass%, and the viscosity measured by an E-type viscometer in this case is preferably 100,000mPa · s/25 ℃ or less, more preferably 50 to 10,000mPa · s/25 ℃ from the viewpoint of excellent workability and coatability.

< silane coupling agent (C) >

The present composition contains a silane coupling agent (C). By using the silane coupling agent (C), not only the adhesion of the obtained anticorrosive coating film to the substrate but also the corrosion resistance and high temperature and high humidity resistance of the obtained anticorrosive coating film can be improved.

The silane coupling agent (C) may be used alone in 1 kind, or may be used in 2 or more kinds.

The silane coupling agent (C) is not particularly limited, and a conventionally known compound can be used, and preferably a compound having at least 2 functional groups in the same molecule and contributing to improvement of adhesion to a base material, reduction of viscosity of the present composition, and the like, and more preferably represented by the formula: "X-SiMe_nY_3-n"[ n represents 0 or 1," [ X ] represents a reactive group capable of reacting with an organic substance (for example, an amino group, a vinyl group, an epoxy group, a mercapto group, a halogen group, a group in which a part of a hydrocarbon group is substituted with such a group, or a group in which a part of a hydrocarbon group is substituted with an ether bond or the like; and a part of such a group), Me is a methyl group, and Y represents a hydrolyzable group (for example, an alkoxy group such as a methoxy group or an ethoxy group).]The compounds shown.

The silane coupling agent (C) is preferably a compound having an epoxy group or an amino group as a reactive group, more preferably a compound having an epoxy group, and specific examples thereof include "KBM-403" (gamma-glycidoxypropyltrimethoxysilane, available from shin-Etsu chemical Co., Ltd.), "Sila-Ace S-510" (available from JNC Co., Ltd.).

The content of the silane coupling agent (C) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, preferably 10% by mass or less, and more preferably 5% by mass or less, relative to 100% by mass of nonvolatile components in the present composition.

When the content of the silane coupling agent (C) is within the above range, the coating workability is improved because the performance of the anticorrosive coating film such as adhesion to the substrate can be improved and the viscosity of the present composition can be reduced.

Extender pigment (D) >

The composition contains an extender pigment (D). By using the extender pigment (D), an anticorrosive coating film excellent in corrosion resistance, salt water resistance, high temperature and high humidity resistance can be formed, in addition to being advantageous in terms of the cost of the obtained composition.

The extender pigment (D) may be used alone in 1 kind or in 2 or more kinds.

Examples of the extender pigment (D) include fibrous fillers such as zinc oxide, talc, silica, mica, clay, potash feldspar, glass flake, calcium carbonate, kaolin, alumina white, white carbon, aluminum hydroxide, magnesium carbonate, barium sulfate (for example, barite powder), gypsum, rock wool, and glass fiber. Among these, talc, silica, mica, clay, calcium carbonate, kaolin, barium sulfate, potassium feldspar, gypsum, and glass flake are preferable.

In particular, from the viewpoint of easily forming an anticorrosive coating film having excellent corrosion resistance, salt water resistance, high temperature and high humidity resistance, and the like, mica and glass flakes are preferably contained as the flake pigment, and a flake pigment having an average aspect ratio (aspect ratio) of 30 to 90 is more preferably contained.

The average aspect ratio is calculated from "median particle diameter (D50)/average thickness".

This D50 can be measured using a laser scattering diffraction particle size distribution measuring apparatus, for example, "SALD 2200" (manufactured by Shimadzu corporation). The average thickness can be calculated by observing the main surface (the surface having the largest area) of the flake pigment from the horizontal direction using a Scanning Electron Microscope (SEM) such as "XL-30" (manufactured by Philips), measuring the thickness of several tens to several hundreds of pigment particles, and calculating the average value.

Among these scaly pigments, mica is more preferable from the viewpoint of being inexpensive, having excellent acquisition easiness, and being capable of forming an anticorrosive coating film having more excellent effects. Examples of the MICA include "MICA 200-HK" (manufactured by Western Japan trade company, width/thickness ratio: 40-60).

The content of the extender pigment (D) is preferably 5% by mass or more, more preferably 10% by mass or more, preferably 80% by mass or less, and still more preferably 70% by mass or less, based on 100% by mass of the nonvolatile components of the present composition, from the viewpoint of easily forming an anticorrosive coating film having excellent corrosion resistance, salt water resistance, high temperature and high humidity resistance, and the like.

From the viewpoint of improving the performance of the anticorrosive coating film such as water-resistant anticorrosive properties and bending resistance, the content of the flaky pigment is preferably 1% by mass or more, more preferably 3% by mass or more, preferably 40% by mass or less, and more preferably 20% by mass or less, relative to 100% by mass of the nonvolatile component of the present composition.

< liquid Compound (E) having phenol skeleton >

The present composition preferably contains the liquid compound (E) having a phenol skeleton from the viewpoint of being able to improve the flexibility of an anticorrosive coating film obtained from a coating composition having a low VOC content.

The liquid compound (E) may be used alone in 1 kind, or may be used in 2 or more kinds.

In the present specification, the term "liquid compound" means a compound that is liquid at 25 ℃, and specifically means a compound having a viscosity of 10,000mPa · s or less as measured at 25 ℃ with an E-type viscometer.

The liquid compound (E) is not particularly limited as long as it is a compound having a basic skeleton in which a hydroxyl group is bonded to a benzene ring, and examples thereof include alkylphenols such as phenol, cresol and cardanol, and phenol-modified hydrocarbon resins. Among these, phenol-modified hydrocarbon resins are preferred from the viewpoint of good compatibility with the epoxy resin (a).

Examples of the phenol-modified hydrocarbon resin include resins obtained by copolymerizing a phenol (phenol compound) with a diene, a monoolefin or α -methylstyrene contained in a petroleum or coal-decomposed oil fraction as described in, for example, Japanese patent application laid-open Nos. 9-268209 and 7-196793.

More specifically, the phenol-modified hydrocarbon resin may be a phenol-modified hydrocarbon resin obtained by reacting a C5-based (aliphatic) petroleum resin using a C5 fraction as a raw material; a C9-based (aromatic-based) petroleum resin produced from a C9 fraction; c5. C9 copolymerized petroleum resin; dicyclopentadiene resin using dicyclopentadiene obtained by thermal dimerization of cyclopentadiene contained in the C5 fraction as a raw material; resins obtained by reacting phenols with alpha-methylstyrene, etc. Among these, preferred are resins obtained by addition polymerization of phenols and styrene, vinyl toluene, coumarone, indene, α -methylstyrene, or the like contained in the petroleum or coal-decomposed oil fraction.

The phenol-modified hydrocarbon resin has an average molecular weight of usually 200 to 1000 and a viscosity of usually 30 to 10,000 mPas/25 ℃.

As the phenol-modified hydrocarbon resin, commercially available products can be used, and examples thereof include "NEVOXY EPX-L" and "NEVOXY EPX-L2" (manufactured by Neville Chemical Co., Ltd.) "HIRENOL PL-1000S" (manufactured by KOLON Co., Ltd.) ".

When the present composition contains the liquid compound (E), the content of the liquid compound (E) is preferably 1% by mass or more, more preferably 3% by mass or more, preferably 50% by mass or less, and still more preferably 30% by mass or less, per 100% by mass of nonvolatile components in the present composition, from the viewpoint of obtaining an anticorrosive coating film excellent in crack resistance and the like.

< (meth) acrylate (F) >

The present composition preferably contains the (meth) acrylate (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 alone in 1 kind, or may be used in 2 or more kinds.

The (meth) acrylate (F) is not particularly limited, but is preferably a polyfunctional acrylate, more preferably a compound having 3 or more (meth) acryloyloxy groups in 1 molecule, and further preferably a compound having 3 or more acryloyloxy groups in 1 molecule from the viewpoint of reactivity.

The number of (meth) acryloyloxy groups contained in 1 molecule of the (meth) acrylate (F) is preferably 3 or more, more preferably 4 or more, preferably 40 or less, and more preferably 20 or less.

The (meth) acrylate (F) is preferably a compound having a functional group equivalent of (meth) acryloyloxy group of less than 200, more preferably less than 100, from the viewpoint of easily obtaining a coating composition having a low viscosity and excellent curability.

As the (meth) acrylate (F), a commercially available product can be used, and as the commercially available product, for example, "M-Cure 400" (manufactured by SARTOMER, functional group equivalent 85) can be mentioned.

When the present composition contains the (meth) acrylate (F), the content of the (meth) acrylate (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, and particularly preferably 5% by mass or less, relative to 100% by mass of nonvolatile components of the present composition, from the viewpoint of obtaining a coating composition having more excellent curing speed, low-temperature curability, and the like.

< other ingredients >

The present composition may contain, in addition to the above (a) to (F), an organic solvent, a coloring pigment, a resin other than the above (a) and (E), a sagging/settling inhibitor, a curing accelerator, a plasticizer other than the above (E), an inorganic dehydrating agent (stabilizer), a dispersing agent, an antifoaming agent, an antifouling agent, and the like, as necessary, in a range not to impair the object of the present invention.

Examples of such other components include conventionally known components used in anticorrosive coating compositions.

The other components can be used alone in 1 kind, also can use more than 2 kinds.

[ organic solvent ]

The organic solvent is not particularly limited, and examples thereof 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, alcohol solvents such as isopropyl alcohol, n-butyl alcohol, 1-methoxy-2-propanol and benzyl alcohol, and aliphatic hydrocarbon solvents such as mineral spirits, n-hexane, n-octane, 2,2, 2-trimethylpentane, isooctane, n-nonane, cyclohexane and methylcyclohexane.

When the present composition contains the organic solvent, the content of the organic solvent is not particularly limited, and may be adjusted as appropriate according to the coating method used when the present composition is coated, and it is preferable that the VOC content in the present composition is within the above range.

[ coloring pigment ]

The coloring pigment is not particularly limited as long as it is a pigment other than the pigment (D), and examples thereof include titanium white, iron oxide red, yellow iron oxide red, and carbon black.

When the present composition contains the above-mentioned color pigment, the content of the color pigment is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, preferably 15% by mass or less, and more preferably 10% by mass or less, based on 100% by mass of the nonvolatile content of the present composition.

[ other resins ]

Examples of the resin other than the resins (a) and (E) include polyester resins, fluorine resins, polybutene resins, silicone rubbers, polyurethane resins (rubbers), polyamide resins, vinyl chloride resins, chlorinated rubbers (resins), chlorinated olefin resins, styrene-butadiene copolymers, ethylene-vinyl acetate copolymers, coumarone resins, silane-based resins, petroleum resins, ketone resins, formaldehyde resins, polyvinyl alkyl ether resins, and rosins (e.g., gum rosin, wood rosin, and tall oil rosin).

As the other resin, a commercially available product can be used, and as the commercially available product, for example, "Neoplastomer E-100" available from JXTG energy Co., Ltd., which is a hydroxyl group-containing petroleum resin, can be mentioned.

When the present composition contains the other resin, the content of the other resin is, for example, 20% by mass or less with respect to 100% by mass of the nonvolatile component of the present composition.

[ anti-sagging agent and anti-settling agent ]

As the anti-sagging/anti-settling agent, conventionally known organic clay-based waxes such as stearates, lecithin salts, and alkylsulfonates of Al, Ca, and Zn, polyethylene wax, amide wax, hydrogenated castor oil wax, synthetic fine powder silica, polyethylene oxide-based waxes, and the like can be used, and among them, amide wax, synthetic fine powder silica, polyethylene oxide-based waxes, and organic clay-based waxes are preferable.

Examples of such anti-sagging/anti-settling agents include "DISPARLON 305", "DISPARLON 4200-20" and "DISPARLON 6650" manufactured by NAKAYONY CHENJIAO; "ASAT-250F" manufactured by Ito oil-making corporation; "FLOWNON RCM-300" manufactured by Kyoeisha chemical Co., Ltd.; products such as "BENTONE SD-2" manufactured by Elementis Specialties, Inc.

When the present composition contains the anti-sagging/anti-settling agent, the content of the anti-sagging/anti-settling agent is preferably 0.3 to 3% by mass based on 100% by mass of the nonvolatile component of the present composition.

[ curing accelerators ]

The present composition preferably contains a curing accelerator capable of contributing to the adjustment, particularly the acceleration, of the curing speed.

The curing accelerator includes conventionally known curing accelerators used in anticorrosion coating compositions, and tertiary amines and the like are preferred from the viewpoint of obtaining coating compositions having better curing speed and low-temperature curability.

The tertiary amine is not particularly limited, and examples thereof include triethanolamine, dialkylaminoethanol, triethylenediamine [1, 4-diazabicyclo (2,2,2) octane ], and 2,4, 6-tris (dimethylaminomethyl) phenol (for example, a product name "Versamine EH 30" (manufactured by BASF JAPAN Co., Ltd.), and a product name "Ancamine K-54" (manufactured by EVONIK JAPAN Co., Ltd.).

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

[ defoaming agent ]

The present composition preferably contains an antifoaming agent from the viewpoints of suppressing the generation of bubbles, improving the appearance of the obtained anticorrosive coating film, and the like.

As the defoaming agent, for example, various conventionally known defoaming agents such as polymer-based, acrylic-based, silicone-based, mineral oil-based, and olefin-based ones can be used, and among them, polymer-based and olefin-based ones are preferable.

Examples of such defoaming agents include "BYK-1788", "BYK-1790" and "BYK-1794" manufactured by BYK-CHEMIE JAPAN; "AFCONA-2290" manufactured by AFCONA ADDITIVE, Inc.; products such as "SpectraSyn 40", "SpectraSyn Elite 150" and "SpectraSyn Elite 65" manufactured by ExxonMobil Chemical Company.

When the present composition contains the above-mentioned defoaming agent, the content of the defoaming agent is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, preferably 4% by mass or less, and more preferably 2% by mass or less, relative to 100% by mass of nonvolatile components in the present composition.

Anticorrosive coating film and substrate with anticorrosive coating film

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 anticorrosive coating film according to one embodiment of the present invention is not particularly limited as long as it contains the anticorrosive coating film and the substrate, and is preferably obtained by applying the present composition to a substrate, and then drying the applied present composition, and preferably drying and curing the applied present composition. This method can also be said to be a method of preventing corrosion of a substrate.

The substrate is not particularly limited, and is preferably a substrate that requires corrosion resistance from the viewpoint of better exhibiting the effects of the present invention.

As such a base material, a base material made of steel, nonferrous metal (zinc, aluminum, etc.), stainless steel, etc. is preferable, structures such as ships, land structures, bridges, etc. made of these are more preferable, and a ship structure is particularly preferable.

From the viewpoint of further exhibiting the effects of the present invention, the base material is preferably a part that is dried in a solvent atmosphere, a part where it is difficult to control the drying temperature, and a part that comes into contact with bacteria, and particularly a part that comes into contact with water containing bacteria such as seawater and industrial water for a long period of time.

Among these, the ballast water tank is more preferable as the base material.

The ballast tank may be one in which an anode made of zinc, zinc-aluminum, or the like is provided to perform galvanic corrosion prevention. The current density during the electric corrosion prevention is preferably 1-10 mA/m²Left and right.

The base material may be one having a surface treated as necessary (for example, sandblasted (ISO 8501-1 Sa21/2), treated by a rubbing method or degreased to remove oil and dust) for the purpose of removing rust, grease, moisture, dust, slime (slime), salt, etc. and improving the adhesion of the obtained anticorrosive coating film, and may be one having a surface coated with a conventionally known primary anticorrosive paint (shop primer) or other primer as necessary and dried from the viewpoint of the anticorrosive property, weldability, shearing property, etc. of the base material.

The method for applying the present composition to a substrate is not particularly limited, and conventionally known methods can be used without limitation, and spraying is preferred from the viewpoints of excellent workability, productivity, and the like, easiness of coating a large-area substrate, and further more preferable exertion of the effects of the present invention.

The conditions for the above-mentioned spraying can be appropriately adjusted according to the thickness of the anticorrosive coating film to be formed, and when the airless spraying is performed, for example, the coating conditions can be set to the primary (air) pressure: about 0.4-0.8 MPa, secondary (coating) pressure: about 10 to 26MPa, and a moving speed of the spray gun is about 50 to 120 cm/sec.

The film thickness of the anticorrosive coating film may be appropriately selected depending on the intended use, and is preferably 100 μm or more, more preferably 250 μm or more, preferably 450 μm or less, and more preferably 400 μm or less, from the viewpoint of forming an anticorrosive coating film having excellent anticorrosive properties.

When forming an anticorrosive coating film having such a thickness, an anticorrosive coating film having a desired thickness may be formed by 1-time coating (1-time coating), or an anticorrosive coating film having a desired thickness may be formed by 2-time (if necessary, 2 or more) coating depending on the anticorrosive property and the like. From the viewpoint of forming an anticorrosive coating film excellent in anticorrosive property with good workability, it is preferable to form an anticorrosive coating film having a thickness in the above range by 2 coating.

The method of drying and curing the present composition is not particularly limited, and the present composition may be dried and cured by heating at about 5 to 60 ℃ in order to shorten the drying and curing time, but the present composition is usually dried and cured by leaving it at room temperature and under the air for about 1 to 14 days.

Further, the effect of the present invention, particularly discoloration resistance, can be exhibited when the present composition is dried and cured by leaving the composition at a low temperature of about 8 ℃ or lower for about 1 to 14 days.

The present invention can further exhibit the effects of the present invention, particularly discoloration resistance, when the composition is dried and cured by leaving the composition in a solvent atmosphere having a VOC content of about 5mg/L or more in the air for about 1 to 14 days.

Examples

The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples.

[ example 1]

A container was charged with 19 parts by mass of epoxy resin 1 (note 1), 10 parts by mass of petroleum resin (note 3), 4 parts by mass of liquid hydrocarbon resin (note 4), 10.4 parts by mass of xylene, 2 parts by mass of butanol, 1 part by mass of 1-methoxy-2-propanol, 1 part by mass of silane coupling agent (note 5), 24 parts by mass of talc (note 7), 6 parts by mass of mica (note 8), 15 parts by mass of potassium feldspar (note 9), 6 parts by mass of titanium 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 these components were mixed at 56 to 60 ℃ by a high-speed disperser and then cooled to 30 ℃ or lower, thereby preparing a main component.

Further, 14 parts by mass of a polyamide adduct of Ethylenediamine (EDA) (note 15), 0.2 parts by mass of a tertiary amine (note 21), and 0.8 parts by mass of 1-methoxy-2-propanol were mixed by a high-speed disperser to prepare a curing agent component.

The obtained main agent component and curing agent component were mixed before coating to prepare a coating composition.

Examples 2 to 11 and comparative examples 1 to 5

Coating compositions were prepared in the same manner as in example 1, except that the raw materials and the amounts thereof to be blended in the main agent component and the curing agent component were changed as shown in table 1.

In table 1, the numerical values in the columns of the main agent component and the curing agent component represent parts by mass. The details of the raw materials in table 1 are shown in table 2.

The following tests (1) to (5) were carried out on the coating films formed from the coating compositions obtained in the above examples and comparative examples. The results are shown in Table 1.

(1) Test for salt Water resistance

According to JIS K5600-6-1: 2016, and the salt water resistance of the coating film. Specifically, the following procedure was carried out.

The coating compositions obtained in the above examples and comparative examples were sprayed on sand-blown steel sheets (hereinafter, also referred to as "test sheets") having dimensions of 150mm × 70mm × 1.6mm (thickness) so that the dry film thickness thereof became about 320 μm, and the resulting test sheets with a coating film were dried at 23 ℃ and 50% RH for 7 days.

In the position shown in fig. 1 of each test plate, a cut 2 reaching the steel plate was made from the coating film side. The test board 1 with the cut 2 was immersed in 3% saline at 40 ℃ for 180 days with the cut 2 side facing downward (in the direction shown in fig. 1). After the immersion, the cuts 2 were equally divided at 5mm intervals, 11 cuts 3 were formed in the upper part in this order from the left end of the cut 2, and the length of separation between the steel sheet and the coating film (the length from the cut 2) was measured at 10 measuring portions 4 between the cuts 3. The 10-point average value of the measured peel length was evaluated according to the following criteria.

Evaluation criteria

O: has no swelling, cracking, rusting and peeling, and the peeling length is less than 5mm

Δ ≈ Δ: has no swelling, cracking, rusting and peeling, and the peeling length is more than 5mm and less than 10mm

And (delta): some defects caused by any one of swelling, cracking, rusting and peeling occur, or the peeling length is more than 10mm and less than 20mm

X: has obvious defects caused by any one of swelling, cracking, rusting and peeling, or has a peeling length of more than 20mm

(2) Test for electric Corrosion resistance

Test panels with coatings prepared in the same manner as in the salt water resistance test were set to have a current density of 5mA/m²Evaluation was performed in the same manner as in the salt water resistance test described above except that the zinc anode was connected as described below.

(3) High temperature and humidity resistance test

The high temperature and high humidity resistance of the test plate with a coating film prepared in the same manner as in the salt water resistance test was measured in accordance with JIS K5600-7-2: 1999 for evaluation. Specifically, the following procedure was carried out.

After a test plate 1 with cuts 2 prepared in the same manner as in the salt water resistance test was kept in a tester at a temperature of 50 ℃ and a humidity of 95% for 90 days, the same cuts 3 as in the salt water resistance test were cut, and the length of separation between the steel plate and the coating film (the length from the cut 2) was measured at 10 measurement portions 4 between the cuts 3. The average value of 10 points of the measured peel length was evaluated in the same manner as in the salt water resistance test.

(4) Resistance to discoloration (Low temperature drying)

The coating compositions obtained in the above examples and comparative examples were coated on test boards at ambient temperature of 5 ℃ so that the dry film thickness thereof became about 320 μm, and then dried at 5 ℃ for 1 day. Thereafter, the test plate was dried in an atmosphere of 23 ℃ and 50% RH for 7 days to prepare a test plate with a coating film, and the test plate was immersed in an immersion liquid containing a biofilm at 23 ℃ for 1 month so that half of the area of the test plate surface with the coating film was obtained, and the color difference Δ E between the immersed portion and the non-immersed portion in the immersion liquid was evaluated according to the following criteria.

Wherein the color difference is measured in accordance with JIS K5600-4-5: 1999, it was measured using a spectrocolorimeter (model SD 5000, manufactured by Nippon Denshoku industries Co., Ltd.), and measured in accordance with JIS K5600-4-6: 1999, the above color difference Δ E was calculated.

And, biofilms were harvested from surfaces of tanks immersed in the sea for more than half a year. The biofilm was diluted 40-fold with seawater immediately after collection to prepare a submerged solution. In addition, the sea location of the immersion tank, the period of immersion of the tank and the type of tank do not make a significant difference in the results.

(5) Resistance to discoloration (solvent atmosphere)

The coating compositions obtained in the above examples and comparative examples were applied to test boards at an ambient temperature of 5 ℃ so that the dry film thickness thereof became about 320 μm, and then immediately left to stand at a height of 8cm from the bottom of a box made of plastic, which had a bottom portion sprayed with 200g of xylene and an open top portion of 60X 40X 30 cm, in the box, and were dried at 5 ℃ for 1 day. Thereafter, the plate was taken out of the plastic box and dried at 23 ℃ and 50% RH for 7 days to prepare a test plate with a coating film. The color difference Δ E was evaluated in the same manner as in the above-described discoloration resistance (low-temperature drying), except that the obtained test plate with a coating film was used.

[ Table 1]

[ Table 2]

Description of the symbols

1: a test plate; 2: cutting marks; 3: cutting; 4: a measurement unit.