JP2020084003A - Anticorrosive coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anticorrosion coating composition having a low VOC amount and excellent in coating workability, which is capable of forming an anticorrosion coating film having excellent anticorrosion properties and having good adhesion to a substrate even when an electrocorrosion system is used together Providing a composition.
An anticorrosion coating composition containing an epoxy resin (A), an amine curing agent (B), a scaly aluminum powder (C), and an aluminum powder (D) other than the (C).
[Selection diagram] None

Description

The present invention relates to an anticorrosion coating composition, and specifically to an anticorrosion coating composition, an anticorrosion coating film, a substrate with an anticorrosion coating film, and a method for producing a substrate with an anticorrosion coating film.

BACKGROUND ART Conventionally, epoxy resin-based paints have been used as anticorrosion paints applied to steel structures such as ships and marine structures, and especially in a severe corrosive environment, an electrocorrosion system is also used. In particular, by utilizing the anticorrosion system together with the corrosion protection on the coating film, it is possible to suppress the corrosion on the defective portion of the coating film.
For galvanic protection, there are galvanic anode method, external power source method, etc., and the potential of metal is changed by the action of current to prevent corrosion. Due to the low electrical resistivity of seawater, cathodic protection systems are particularly useful for offshore structures.

Further, in recent years, there has been a demand for a coating composition having a low VOC amount with a small amount of volatile organic compounds (hereinafter also referred to as “VOC”) as an environmental measure.

As the anticorrosive paint, Patent Documents 1 and 2 describe the use of an aluminum pigment in an epoxy resin-based paint, and the aluminum pigment includes a leafing type and a non-leafing. These leafing type and non-leafing type aluminum pigments are scale-like pigments, although the surface treatment agents used and the like are different.

JP, 10-259351, A JP, 2016-65118, A

Since the conventional paint using the flaky aluminum powder has a high viscosity due to the shape of the aluminum powder, it is necessary to use a large amount of VOC to adjust the viscosity, and as a result, a coating composition with a low VOC amount is used. I found it difficult to get things.

In addition, the combined use of the anticorrosion coating and the cathodic protection system protects the hull, etc. from these corrosive environments in ships and marine structures that are exposed to severe dry and wet conditions in an atmosphere containing salt and It is useful for maintaining safety and long-term operation and operation. However, when a coating film on a ship, an offshore structure, or the like has a defect, calcium carbonate or magnesium carbonate or hydroxide, which is referred to as electrocoating, is deposited/precipitated at the film coating defect portion due to cathodic protection. Since these substances are alkaline, they suppress the corrosion of the base material such as the steel plate, but promote the deterioration of the coating film around the defective portion of the coating film, and as a result, reduce the adhesion of the coating film to the base material. I found out.

The present invention has been made in view of such circumstances, and the present invention is an anticorrosion coating composition having a low VOC amount and excellent coating workability, which is excellent in anticorrosion property and can be used in combination with an electrocorrosion system. An object of the present invention is to provide a coating composition capable of forming an anticorrosion coating film having good adhesion to a substrate.

As a result of intensive studies on a method for solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a predetermined coating composition, and have completed the present invention. The configuration example of the present invention is as follows.

<1> An anticorrosion coating composition containing an epoxy resin (A), an amine curing agent (B), a scaly aluminum powder (C), and an aluminum powder (D) other than the (C).

<2> In <1>, the aluminum powders (C) and (D) are contained in an amount of 0.1 to 15% by mass (solid content) with respect to 100% by mass of the nonvolatile content in the anticorrosion coating composition. The anticorrosion coating composition described.
<3> The ratio of the mass (solid content) of the aluminum powder (D) to the mass (solid content) of the aluminum powder (C) is in the range of 0.1 to 5, and described in <1> or <2>. Anticorrosion paint composition.
<4> The anticorrosion coating composition according to any one of <1> to <3>, wherein the aluminum powder (D) has an aspect ratio of less than 5.

<5> The anticorrosion coating composition according to any one of <1> to <4>, further containing a silane coupling agent (E).
<6> The anticorrosion coating composition according to any one of <1> to <5>, further containing an extender pigment (F).

<7> An anticorrosion coating film formed from the anticorrosion coating composition according to any one of <1> to <6>.
<8> A substrate with an anticorrosion coating, which comprises the anticorrosion coating according to <7> and a substrate.

<9> A method for producing a substrate with an anticorrosion coating, which comprises the following steps [1] and [2].
[1] A step of applying the anticorrosion coating composition according to any one of <1> to <6> to a substrate [2] A step of drying the applied anticorrosion coating composition to form a coating film

According to the present invention, an anticorrosion coating composition having a low VOC amount and excellent coating workability, which is excellent in anticorrosion properties and has good adhesion to a substrate even when used in combination with an anticorrosion system. A coating composition that can be formed can be provided.

<<Paint composition>>
An anticorrosive coating composition according to an embodiment of the present invention (hereinafter, also referred to as “the present composition”) includes an epoxy resin (A), an amine curing agent (B), a scaly aluminum powder (C), and the ( It is a coating composition containing aluminum powder (D) other than C) (hereinafter also referred to as "non-scaly aluminum powder (D)").

Since the present composition exhibits the above-mentioned effects, it is suitably used for corrosion protection of steel structures such as ships and marine structures. Furthermore, it is preferably used for ships and marine structures used in combination with an anticorrosion system, such as ballast tanks and ship skins.

Although the composition may be a one-component composition, it is usually a two-component composition comprising a main component containing an epoxy resin (A) and a curing agent containing an amine-based curing agent (B). Mold composition. Further, if necessary, the present composition may be a three-component or more composition.
The main ingredient component and the curing agent component are usually stored, stored, transported, etc. in separate containers and mixed together just before use.

The VOC content of the composition is preferably 340 g/L or less, more preferably 300 g/L or less, and particularly preferably 270 g/L or less.

The VOC content of this composition can be calculated from the following formula (1) using the values of the paint specific gravity and the mass NV described below.
VOC content (g/L)=paint specific gravity×1000×(100−mass NV)/100 (1)

Specific gravity of paint (g/cm ³ ): Under a temperature condition of 23° C., a specific gravity cup having an internal volume of 100 ml was filled with the present composition (eg, a composition immediately after mixing a main component and a curing agent component), Value calculated by measuring the mass of the composition

Mass NV (mass %): According to JIS K 5601-1-2, 1±0.1 g of the present composition (eg, a composition immediately after mixing a main component and a curing agent component) is weighed in a flat bottom dish, and mass Spread evenly using a known wire, leave it at 23° C. for 24 hours, then dry at 110° C. for 1 hour under normal pressure, and calculate the mass percentage value calculated by weighing the heating residue and the wire ( Content of heating residue in this composition)

In addition, in the present invention, the heating residue of the present composition measured in the same manner as above is referred to as “nonvolatile content”. In addition, a component other than the solvent in the main agent component and the curing agent component in each component (epoxy resin (A), etc.) as a raw material constituting the present composition, the main agent component or the curing agent component is referred to as “solid content”.

The pigment volume concentration (PVC) of the present composition is preferably from the viewpoint that a composition having excellent coating workability can be easily obtained, and a coating film having excellent corrosion resistance and water resistance can be easily obtained. It is 10% or more, more preferably 25% or more, preferably 75% or less, more preferably 60% or less, particularly preferably 50% or less.
If the PVC is less than the lower limit, the corrosion resistance of the resulting coating film tends to decrease, and if it exceeds the upper limit, the water resistance of the obtained coating film and the coating workability tend to decrease. ..

The PVC means all pigments including the scale-like aluminum powder (C), the non-scale-like aluminum powder (D), the following extender pigment (F), and the following coloring pigment, with respect to the volume of the non-volatile components in the composition. It means the total volume concentration of. The PVC can be specifically calculated from the following formula.
PVC [%]=total volume of all pigments in the composition×100/volume of non-volatile content in the composition

The volume of the non-volatile matter in the present composition can be calculated from the mass and the true density of the non-volatile matter of 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 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. For example, it can be calculated by separating the pigment and other components from the nonvolatile content of the composition and measuring the mass and true density of the separated pigment.

<Epoxy resin (A)>
The epoxy resin (A) is not particularly limited, and conventionally known epoxy resins can be used, and one kind may be used alone, or two or more kinds may be used.
Examples of the epoxy resin (A) include non-tar-based epoxy resins described in JP-A Nos. 11-343454 and 10-259351.

Examples of the epoxy resin (A) include polymers and oligomers containing two or more epoxy groups in the molecule, and polymers and oligomers produced by ring-opening reaction of these epoxy groups. Examples of such epoxy resin include glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, bisphenol type epoxy resin, novolac type epoxy resin, aliphatic epoxy resin, alicyclic epoxy resin, fatty acid modified epoxy resin. Examples thereof include resins and epoxidized oil-based epoxy resins.
Among these, bisphenol type epoxy resins are preferable, and bisphenol A type and bisphenol F type epoxy resins are more preferable, and bisphenol A type, from the viewpoints of easily forming an anticorrosion coating film having excellent adhesion to a substrate. Epoxy resins are particularly preferred.

Examples of the epoxy resin (A) include bisphenol A type epoxy resin (bisphenol A type diglycidyl ethers); bisphenol AD type epoxy resin; bisphenol F type epoxy resin; phenol novolac type epoxy resin; cresol novolac type epoxy resin; Examples thereof include trishydroxyphenylmethane type epoxy resins, hydrogenation reaction products thereof (hereinafter, also referred to as “hydrogenation”), fatty acid modified products, bromides in which at least one hydrogen atom in the resin is substituted with a bromine atom, and the like. May be

Examples of the bisphenol A type 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, hydrogenated bisphenol A. Examples thereof include condensation polymerization products of bisphenol A type diglycidyl ethers such as (poly)propylene oxide diglycidyl ether and hydrogenated bisphenol A (poly)ethylene oxide diglycidyl ether.

The epoxy resin (A) may be obtained by synthesizing by a conventionally known method, or may be a commercially available product. As the commercially available product, "E-028" (manufactured by Otake Meishin Chemical Co., Ltd., bisphenol A type epoxy resin, epoxy equivalent 180-) as a liquid at normal temperature (15 to 25°C, the same applies below). 190, viscosity 12,000-15,000 mPa·s/25° C.), “jER-807” (manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin, epoxy equivalent 160-175, viscosity 3,000-4,500 mPa). -S/25°C), "Flep 60" (manufactured by Toray Fine Chemical Co., Ltd., epoxy equivalent: 280, viscosity: 17,000 mPa-s/25°C) and the like. Examples of the semi-solid substance at room temperature include "jER-834" (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent 230 to 270). Examples of solid substances at room temperature include "jER1001" (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent 450 to 500).
Further, the above-mentioned semi-solid or solid epoxy resin was diluted with a solvent to prepare a solution "E-834-85X" (manufactured by Ohtake Meishin Chemical Co., Ltd., xylene solution of bisphenol A type epoxy resin (834 type). Epoxy resin solution), epoxy equivalent of about 300), "E-001-75" (manufactured by Ohtake Meishin Chemical Co., Ltd., xylene solution of bisphenol A type epoxy resin (1001 type epoxy resin solution), epoxy equivalent of about 630), etc. Can also be used.

The epoxy resin (A) is preferably a liquid or semi-solid epoxy resin at room temperature from the viewpoint of obtaining a composition having excellent adhesion to a substrate.

The epoxy equivalent of the epoxy resin (A) is preferably 150 or more, more preferably 175 or more, preferably 1000 or less, more preferably from the viewpoint that a coating film having excellent anticorrosion property can be easily obtained. It is 600 or less, particularly preferably 500 or less.

Although the weight average molecular weight of the epoxy resin (A) measured by GPC (gel permeation chromatograph) is not unconditionally determined depending on the coating curing conditions (eg, normal dry coating or baking coating) of the obtained composition. , Preferably 350 to 20,000.

The content of the epoxy resin (A) in the composition is preferably 5% by mass or more, more preferably 10% by mass or more, from the viewpoint that a coating film having more excellent corrosion resistance can be obtained. Is 40% by mass or less, more preferably 30% by mass or less. The epoxy resin (A) is contained in the main agent component when the composition is a two-component type composition comprising a main agent component and a curing agent component, and preferably 5 to 80 in the main agent component. It is desirable that the content is in the range of 5% by mass, more preferably 5 to 50% by mass.
The content of the epoxy resin (A) in the composition is preferably 10% by mass or more, more preferably 15% by mass, based on 100% by mass of the nonvolatile content of the composition for the same reason as above. It is above, preferably 50 mass% or less, more preferably 35 mass% or less.

<Amine curing agent (B)>
The amine curing agent (B) is not particularly limited as long as it is an amine compound except for a tertiary amine (an amine compound having only a tertiary amino group) described later, but an aliphatic type, an alicyclic type, an aromatic type, Amine compounds such as heterocyclic amine curing agents are preferred.
The amine curing agent (B) may be used alone or in combination of two or more.

Examples of the aliphatic amine curing agent include alkylene polyamines, polyalkylene polyamines, alkylaminoalkylamines and the like.

Examples of the alkylene polyamines, for example, the formula: "H ₂ N-R ¹ -NH _2" (R ¹ is a divalent hydrocarbon group having 1 to 12 carbon atoms.) Include compounds represented by Specifically, methylenediamine, ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7- Examples thereof include diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane and trimethylhexamethylenediamine.

Examples of the polyalkylene polyamines, for example, the formula: is _{"H 2 N- (C m H 2m} NH) n H " (m is an integer of 1 to 10 .n is an integer from 2 to 10, preferably 2 Is an integer of 6 to 6), and specifically, diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripropylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, Examples thereof include nonaethylenedecamine, bis(hexamethylene)triamine, and triethylene-bis(trimethylene)hexamine.

Other aliphatic amine curing agents include tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, tris(2-amino). Examples thereof include ethyl)amine, bis(cyanoethyl)diethylenetriamine, and polyoxyalkylene polyamine (particularly diethylene glycol bis(3-aminopropyl)ether).

Specific examples of the alicyclic amine curing agent include cyclohexanediamine, diaminodicyclohexylmethane (particularly 4,4′-methylenebiscyclohexylamine), 4,4′-isopropylidenebiscyclohexylamine, norbornanediamine, Examples thereof include bis(aminomethyl)cyclohexane, isophoronediamine, mensendiamine (MDA), and 2,4-di(4-aminocyclohexylmethyl)aniline.

Examples of the aromatic amine curing agent include bis(aminoalkyl)benzene, bis(aminoalkyl)naphthalene, and aromatic polyamine compounds having two or more primary amino groups bonded to the benzene ring.
As the aromatic amine curing agent, more specifically, o-xylylenediamine, m-xylylenediamine (MXDA), p-xylylenediamine, phenylenediamine, naphthalenediamine, diaminodiphenylmethane, 2,2-bis (4-aminophenyl)propane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl sulfone, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, diaminodiethyl Phenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, bis(aminomethyl)naphthalene, bis( Aminoethyl)naphthalene and the like can be mentioned.

As the heterocyclic amine curing agent, 1,4-bis(3-aminopropyl)piperazine, 1,4-diazacycloheptane, 1-(2'-aminoethylpiperazine), 1-[2'-( 2″-aminoethylamino)ethyl]piperazine, 1,11-diazacycloeicosane, 1,15-diazacyclooctacosane and the like can be mentioned.

As the amine curing agent (B), a modified product of the amine curing agent described above, for example, a modified product of a fatty acid such as polyamidoamine, an amine adduct with an epoxy compound, a Mannich modified product (eg, phenalkamine, phenalcamide), Michael Examples include adducts, ketimines and aldimines. Of these, polyamidoamines, amine adducts with epoxy compounds, and Mannich modified products are preferable.

The amine curing agent (B) may be obtained by synthesizing by a conventionally known method, or may be a commercially available product. Examples of commercially available products include "ACI Hardener K-39" (manufactured by PTI Japan Co., Ltd.), which is an aliphatic polyamine, and "Sunmaid CX-1154" (manufactured by Sanwa Chemical Co., Ltd.), which is a Mannich modified aliphatic polyamine. Examples include phenorcamine adduct "Cardlight NC556X80" (manufactured by Cardlight) and amine curing agents used in the following examples.

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 that a coating film excellent in anticorrosion property can be easily obtained. It is preferably 400 or less.

The amine curing agent (B) preferably has a reaction ratio calculated by the following formula (2) of 0 from the viewpoint that a coating film excellent in anticorrosion property, coating film strength and drying property can be easily obtained. 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.

Reaction ratio={(amount of amine curing agent (B)/amount of active hydrogen of amine curing agent (B))+(amount of component having reactivity with epoxy resin (A)/epoxy resin (A)) Functional group equivalent of a component having a reactivity with respect to]/{(blending amount of epoxy resin (A)/epoxy equivalent of epoxy resin (A))+(having reactivity with amine curing agent (B)) Amount of component/functional group equivalent of component reactive with amine curing agent (B)}} (2)

Here, examples of the “component reactive with the amine curing agent (B)” in the above formula (2) include a silane coupling agent, an epoxy group-containing reactive diluent, and an acrylate compound described below. Examples of the “component having reactivity with the epoxy resin (A)” include silane coupling agents described below. The "functional group equivalent" of each component means the mass (g) per 1 mol functional group obtained by dividing the mol number of the functional group contained therein from the mass of 1 mol of these components.
As the silane coupling agent described below, a silane coupling agent having an amino group or an epoxy group as a reactive group can be used. Therefore, depending on the type of the reactive group, the silane coupling agent may be an epoxy resin (A). It is necessary to determine whether the resin has reactivity with the amine curing agent (B) or not, and calculate the reaction ratio.

When the present composition is a two-component composition comprising a main component and a curing agent component, the curing agent (B) is included in the curing agent component. The curing agent component is preferably a component adjusted to have a solid content of 50 to 100% by mass, and the viscosity at 25° C. measured by an E-type viscometer at that time depends on handleability and coating workability. From the viewpoint of providing an excellent composition, etc., it is preferably 100,000 mPa·s or less, and more preferably 50 to 10,000 mPa·s.

<Flake shaped aluminum powder (C)>
The term “scaly” in the scale-like aluminum powder (C) refers to a scale-like shape, and there is no particular specified range, but usually the aspect ratio is preferably 5 or more. , More preferably 10 or more, still more preferably 20 or more, preferably 150 or less, more preferably 120 or less.
In the obtained anticorrosion coating film, the scale-like aluminum powder (C) tends to have powder particles oriented horizontally with respect to the coating film, thereby forming an anticorrosion coating film having excellent salt water resistance and moisture resistance. be able to.

The aspect ratio of the scale-like aluminum powder (C) can be measured using an electron microscope. The scaly aluminum powder (C) was observed using a scanning electron microscope (SEM), for example, “XL-30” (trade name; manufactured by Philips), and the thickness and the main surface of several tens to several hundreds of powder particles were observed. It can be calculated by measuring the maximum length and calculating the average value of these ratios (maximum length/thickness on the main surface).
The thickness of the aluminum powder (C) can be measured by observing from a horizontal direction with respect to the main surface (the surface having the largest area) of the powder, and the thickness of the main surface of the aluminum powder (C) can be measured. The maximum length in the plane means, for example, the length of a diagonal line if the main surface is quadrangular, the diameter if the main surface is circular, and the length of the major axis if the main surface is elliptical. ..

The flaky aluminum powder (C) has a median diameter (D50) of preferably 100 μm or less, more preferably 5 to 70 μm, and particularly preferably, from the viewpoint that a coating film having more excellent anticorrosion property can be obtained. It is 5 to 50 μm.
The D50 is an average value measured three times using a laser scattering diffraction type particle size distribution measuring device, for example, "SALD 2200" (manufactured by Shimadzu Corporation).

The scale-like aluminum powder (C) may be a leafing type or a non-leafing type, but it is possible to further suppress the deterioration of the coating film due to the alkaline substance caused by the electrocorrosion and the deterioration of the adhesion to the substrate. It is preferable to use the leafing type from the viewpoints of being able to do so.
The scale-like aluminum powder (C) may be used in combination with a leafing type and a non-leafing type.

<Non-scaly aluminum powder (D)>
The non-scaly aluminum powder (D) refers to one having a shape other than scaly, such as spherical, teardrop-shaped, and spindle-shaped, and does not have a specified range, but usually has an aspect ratio. Is preferably less than 5, and more preferably the aspect ratio is 1 to 3.
By using the non-scaly aluminum powder (D) together with the scaly aluminum powder (C), the composition has a low VOC amount and excellent coating workability, but also has excellent anticorrosion properties and even when used in combination with an electrocorrosion system. An anticorrosion coating film having good adhesion to a substrate can be formed.

The aspect ratio of the non-scaly aluminum powder (D) can be measured using an electron microscope. The non-scaly aluminum powder (D) is observed using a scanning electron microscope (SEM), for example, "XL-30" (trade name; manufactured by Philips), and the long axis length of several tens to several hundreds of powder particles is observed. And the length of the short axis, and can be calculated by obtaining the average value of these ratios (length of long axis/length of short axis).
The length of the major axis of the aluminum powder (D) is specifically the longest length in the sectional view near the center of the powder, and the length of the minor axis of the aluminum powder (D) is In the cross-sectional view, it is the length of a line orthogonal to the long axis at the center of the cross-sectional view.

The non-scaly aluminum powder (D) is preferably an aluminum powder produced by an atomizing method (spraying method).

The median diameter (D50) of the non-scaly aluminum powder (D) is preferably 50 μm or less, more preferably 5 to 30 μm from the viewpoint that a composition having a low VOC amount and excellent coating workability can be obtained. It is particularly preferably 5 to 15 μm. The D50 can be measured by the same method as the D50 of the scale-like aluminum powder (C).

The eccentricity of the non-scaly aluminum powder (D) is preferably 0.85 or less, more preferably 0.7 or less from the viewpoint that a composition having excellent coating workability can be obtained with a low VOC amount. is there.
The eccentricity can be calculated by measuring the minor axis b and the major axis a and determining the average value of eccentricity=√(a ² −b ² )/a, as in the measurement of the aspect ratio.

The total content of the scaly aluminum powder (C) and the non-scaly aluminum powder (D) in the composition is preferably 0.1% by mass or more, and more preferably 100% by mass of the nonvolatile content of the composition. It is 5% by mass or more, preferably 15% by mass or less, and more preferably 10% by mass or less.
When the total content of the scaly aluminum powder (C) and the non-scaly aluminum powder (D) is in the above range, deterioration of the coating film due to the alkaline substance caused by cathodic protection and deterioration of the adhesion to the base material may occur. In addition to being able to suppress it, it is also excellent in anticorrosion property, and even when used in combination with an electrocorrosion system, it is possible to form an anticorrosion coating film with better adhesion to the substrate, and it is possible to avoid the generation of sparks due to discharge. it can.

The ratio [(D)/(C)] of the mass (solid content) of the aluminum powder (D) to the mass (solid content) of the aluminum powder (C) in the composition is preferably 0.1 or more, and more preferably It is preferably 0.2 or more, more preferably 0.3 or more, preferably 5 or less, more preferably 4 or less, still more preferably 3 or less.
When (D)/(C) is in the above range, a composition having a low VOC amount and excellent coating workability can be more easily prepared, and the anticorrosion property is excellent. An anticorrosion coating film having good adhesion can be formed.

<Silane coupling agent (E)>
By using the silane coupling agent (E), it is possible not only to further improve the adhesion of the obtained anticorrosion coating film to the substrate, but also to improve the anticorrosion properties such as salt water resistance of the obtained anticorrosion coating film. Therefore, the present composition preferably contains a silane coupling agent (E).
The silane coupling agent (E) may be used alone or in combination of two or more.

The silane coupling agent (E) is not particularly limited, and conventionally known compounds can be used. However, the silane coupling agent (E) has at least two functional groups in the same molecule to improve adhesion to a substrate, and a coating composition. It is preferable that the compound is a compound that can contribute to a decrease in the viscosity of, for example, the formula: “X—SiMe _n Y _3−n ” [n is 0 or 1, and X is a reactive group capable of reacting with an organic substance (eg, : One of 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 these groups, or a group in which a part of a hydrocarbon group is substituted with an ether bond or the like. Is a group 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). ] It is more preferable that it is a compound represented by these.

The silane coupling agent (E) is preferably a compound having an epoxy group or an amino group as a reactive group, specifically, "KBM403" (γ-glycidoxypropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd. )), “Cyla Ace S-510” (manufactured by JNC), “KBM603” (3-(2-aminoethylamino)propyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

When the composition contains the silane coupling agent (E), the content of the silane coupling agent (C) is preferably 0.1% by mass or more, and more preferably 100% by mass of the composition. Is 0.3% by mass or more, preferably 10% by mass or less, and more preferably 5% by mass or less.
When the content of the silane coupling agent (E) is within the above range, the performance of the anticorrosion coating film such as the adhesion to the base material is improved and the viscosity of the present composition can be lowered, so that the coating workability is improved. To do.

<Extended pigment (F)>
By using the extender pigment (F), not only the cost advantage of the obtained coating composition but also an anticorrosion coating film excellent in anticorrosion property, particularly salt water resistance, moisture resistance and the like can be easily formed. The composition preferably contains an extender pigment (F).
The extender pigment (F) may be used alone or in combination of two or more.

The extender pigment (F) is not particularly limited as long as it is a pigment other than (C) and (D), and specifically, barium sulfate, potassium feldspar, sodium feldspar, barite powder, silica, calcium carbonate, Examples include talc, mica, glass flakes and the like.

When the present composition contains the extender pigment (F), the content of the extender pigment (F) is preferably 100% by mass of the non-volatile content of the present composition, from the viewpoint that the above effects can be more exerted. Is 5 mass% or more, more preferably 10 mass% or more, preferably 80 mass% or less, more preferably 70 mass% or less.

<Other ingredients>
In the composition, in addition to the above (A) to (F), if necessary, an organic solvent, an epoxy group-containing reactive diluent, a plasticizer, an acrylate compound, a color pigment, an anti-sagging/precipitation inhibitor , A curing accelerator, an inorganic dehydrating agent (stabilizer), a defoaming agent, an antifouling agent and the like may be added within a range that does not impair the object of the present invention.
These other components may be those conventionally known for use in the anticorrosion coating composition.
Each of the other components may be used alone or in combination of two or more.

<Organic solvent>
The organic solvent is not particularly limited, for example, 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, mineral spirits, n-hexane, n-octane, 2,2,2-trimethylpentane, isooctane, n-nonane, cyclohexane, methylcyclohexane and other aliphatic hydrocarbon solvents Is mentioned.

When the organic solvent is used, it is preferable to use it in such an amount that the VOC amount in the present composition falls within the above range.
When the present composition contains the solvent, the content of the solvent is not particularly limited and may be appropriately adjusted according to the coating method at the time of coating the present composition. Considering this, the nonvolatile content of the present composition is preferably 70% by mass or more, more preferably 80% by mass or more, preferably 98% by mass or less, more preferably 95% by mass or less. It is desirable that the amount is included.
In addition, the solvent preferably has a nonvolatile content of 70 to 95% by mass, more preferably from the viewpoint of providing a composition having excellent coatability when the composition is spray-coated. Is preferably contained in an amount such that it is 80 to 95 mass %.

<Epoxy group-containing reactive diluent>
The composition may contain an epoxy group-containing reactive diluent from the viewpoint that a coating composition having a lower VOC amount can be easily obtained.
The epoxy group-containing reactive diluent is not particularly limited as long as it is an epoxy compound having a viscosity at 25° C. of 500 mPa·s or less, and may be a monofunctional type or a polyfunctional type.

Examples of the monofunctional epoxy group-containing reactive diluent include alkyl glycidyl ether (alkyl group having 1 to 13 carbon atoms), phenyl glycidyl ether, o-cresyl glycidyl ether, alkyl phenyl glycidyl ether (alkyl group having carbon number). 1 to 20, preferably 1 to 5, for example: methylphenyl glycidyl ether, ethylphenyl glycidyl ether, propylphenyl glycidyl ether, p-tert-butylphenyl glycidyl ether), phenol glycidyl ether, alkylphenol glycidyl ether, phenol (EO) _n glycidyl ether (number of repetitions _{n = 3~20, EO: -C 2} H 4 O-) and the like.

Examples of the polyfunctional epoxy group-containing reactive diluent include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, and resorcinol. Diglycidyl ether, mono- or polyalkylene glycol diglycidyl ether (alkylene group having 1 to 5 carbon atoms, for example, ethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether), trimethylolpropane triglycidyl ether Is mentioned.

When the present composition contains the epoxy group-containing reactive diluent, the content of the epoxy group-containing reactive diluent is the same as that of the present composition from the viewpoint that an anticorrosive coating film excellent in anticorrosion property and the like can be obtained. It is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, preferably 15% by mass or less, more preferably 10% by mass or less, and further preferably 5 with respect to 100% by mass of the nonvolatile content of the product. It is not more than mass %.
From the viewpoint of the anticorrosion property of the formed coating film, it is better to avoid blending a large amount of the reactive diluent, but in this case, it was not easy to solve the above problems. As a result of diligent studies by the present inventors, the use of the non-scaly aluminum powder (D) was able to obtain the above-mentioned predetermined effects even when the amount of the reactive diluent used was reduced.

<Plasticizer>
The composition preferably contains a plasticizer from the viewpoint of improving the flexibility and weather resistance of the resulting anticorrosion coating film.
As the plasticizer, conventionally known ones can be widely used, and liquid hydrocarbon resins such as low boiling point fraction obtained by thermally decomposing naphtha, petroleum resin solid at normal temperature, xylene resin, coumarone indene resin, etc. Can be mentioned. Specific examples thereof include liquid hydrocarbon resins and flexibility-imparting resins described in JP-A 2006-342360.

Among these, a liquid hydrocarbon resin, a petroleum resin, a xylene resin, and coumarone containing a hydroxyl group and being solid at room temperature, from the viewpoint of good compatibility with the epoxy resin (A). Indene resin is preferred.

Examples of commercially available liquid hydrocarbon resins include "Nesiles EPX-L", "Nesiles EPX-L2" (above, manufactured by NEVCIN/phenol-modified hydrocarbon resin), "HILENOL PL-1000S" (manufactured by KOLON Chemical Co., Ltd./ Liquid hydrocarbon resins) and the like, and commercially available petroleum-based resins that are solid at room temperature include "Neopolymer E-100", "Neopolymer K-2", and "Neopolymer K3" (above, New Japan Petrochemical Co., Ltd./C9 type hydrocarbon resin) and the like, and commercial products of coumarone indene resin include "NOVARES CA 100" (manufactured by Rutgers Chemicals AG) and the like, and commercial products of xylene resin. Examples thereof include "Nicanol Y-51" (manufactured by Mitsubishi Gas Chemical Co., Inc.) and the like.

When the composition contains the plasticizer, the content of the plasticizer is 100% by mass of the nonvolatile content of the composition from the viewpoint that an anticorrosive coating film having excellent weather resistance and crack resistance can be obtained. On the other hand, it is preferably 1% by mass or more, more preferably 3% by mass or more, preferably 50% by mass or less, more preferably 30% by mass or less.

<Acrylate compound>
The composition may contain an acrylate compound from the viewpoint of improving the curing rate of the resulting composition.
As the acrylate compound, for example, a monofunctional or polyfunctional aliphatic (meth)acrylate monomer or a monofunctional or polyfunctional aromatic (meth)acrylate monomer can be used. Such acrylate compounds may be used alone or in combination of two or more.

Examples of commercially available acrylate compounds include "M-CURE 100" (monofunctional aromatic acrylate, functional group equivalent weight of 257 to 267 g/eq), "M-CURE 200" (bifunctional aromatic acrylate, functional group equivalent weight). 130-140 g/eq), "M-CURE 201" (difunctional aliphatic acrylate, functional group equivalent 95-105 g/eq), "M-CURE 300" (trifunctional aliphatic acrylate, functional group equivalent 112-). 122 g/eq), “M-CURE 400” (tetrafunctional aliphatic acrylate, functional group equivalent 80 to 90 g/eq) (all manufactured by SARTOMER COMPANY, INC) and the like.

When the present composition contains the acrylate compound, the content of the acrylate compound is preferably 0. It is 1 mass% or more, more preferably 0.2 mass% or more, preferably 5 mass% or less, more preferably 3 mass% or less.

<Color pigment>
The color pigment is not particularly limited as long as it is a pigment other than (C), (D) and (F), and conventionally known color pigments can be used. Specific examples of the color pigment include titanium white, red iron oxide, yellow iron oxide, and carbon black.

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

In addition, when the present composition contains the extender pigment (F) and/or the coloring pigment, in the anticorrosive coating film formed from the present composition, from the viewpoint that a coating film excellent in anticorrosion property can be obtained. The volume concentration of the extender pigment (F) and the color pigment occupying in the above is preferably 10% or more, more preferably 15% or more, preferably 65% or less, more preferably 40% or less.

<Anti-sagging/anti-settling agent>
As the anti-sagging agent (anti-settling agent), organic clay wax such as Al, Ca, Zn stearate salt, lecithin salt, alkyl sulfonate, polyethylene wax, amide wax, hydrogenated castor oil wax, synthetic fine powder Although conventionally known ones such as silica and polyethylene oxide wax can be used, among them, amide wax, synthetic fine powder silica, polyethylene oxide wax and organic clay wax are preferable.

As such an anti-sagging agent (anti-settling agent), "Disparon 305", "Disparon 4200-20", "Disparon 6650" manufactured by Kusumoto Kasei Co., Ltd.; "ASAT-250F" manufactured by Ito Oil Co., Ltd. "Flowon RCM-300" manufactured by Kyoeisha Chemical Co., Ltd.; products such as "Benton SD-2" manufactured by Elementis Specialties, Inc.;

When the composition contains the anti-sagging agent (anti-settling agent), the content of the anti-sagging agent (anti-settling agent) is preferably 0.3 to 100% by mass of the nonvolatile content of the composition. It is 3% by mass.

<Curing accelerator>
The composition preferably contains a curing accelerator that can contribute to the adjustment of the curing rate, especially the acceleration.
Examples of the curing accelerator include tertiary amines, and specifically, for example, triethanolamine, dialkylaminoethanol, triethylenediamine [1,4-diazabicyclo(2,2,2)octane], 2,4,6-Tri(dimethylaminomethyl)phenol (Example: trade name "Versamine EH30" (manufactured by Henkel Hakusui Co., Ltd.), trade name "Ankamin K-54" (manufactured by Evonik Japan Co., Ltd.)) Be done.

When the composition contains the curing accelerator, the content of the curing accelerator is preferably 0.05 to 2.0 mass% with respect to 100 mass% of the nonvolatile content of the composition.

<< Corrosion-proof coating, base material with anti-corrosion coating >>
The anticorrosion coating film according to one embodiment of the present invention is not particularly limited as long as it is formed from the present composition, and the substrate with an anticorrosion coating film according to one embodiment of the present invention is the anticorrosion coating film. It is not particularly limited as long as it includes a substrate and a substrate, but after coating the present composition on a substrate, drying the coated present composition, preferably drying and curing the coated present composition It is preferably obtained by This method can also be said to be a method of preventing corrosion of the base material.
This anticorrosion coating film is excellent in anticorrosion properties such as salt water resistance and moisture resistance, and is excellent in adhesion to a substrate even when an electrocorrosion system is used together.

The base material is not particularly limited, but a base material that is required to have anticorrosive properties is preferable because the effects of the present invention can be more exerted.
As such a base material, base materials made of steel, non-ferrous metals (zinc, aluminum, etc.), stainless steel, etc. are preferable, and ships, land structures, structures such as bridges made of these, more preferably ship structures. is there.
As the base material, it is particularly preferable to install an anode such as zinc or zinc-aluminum or to be subjected to cathodic protection by an external power supply method because the effects of the present invention can be more exerted. The current density is preferably 1 to 10 mA/m ² .

As the base material, in order to remove rust, oil and fat, water, dust, slime, salt and the like, and in order to improve the adhesion of the resulting anticorrosion coating, the base material surface is treated as necessary (for example, Blast treatment (ISO8501-1 Sa2 1/2), friction method, treatment to remove oil and dust by degreasing) may be applied, and in view of corrosion resistance of the base material, weldability, and shearability, if necessary, A coating for forming a thin film such as a conventionally known primary rust preventive coating (shop primer) or other primer may be applied and dried on the surface of the substrate.

The method for applying the present composition onto a substrate is not particularly limited, and conventionally known methods can be used without limitation, but it is excellent in workability and productivity, etc., and easy for a large-area substrate. Spray coating is preferable from the standpoints that it can be applied to the above and the effects of the present invention can be more exerted.
When the present composition is a two-component composition, the main component and the curing agent component may be mixed immediately before coating and spray coating may be performed.

The conditions of the spray coating may be appropriately adjusted according to the thickness of the anticorrosion coating film to be formed, but during airless spraying, for example, primary (air) pressure: about 0.4 to 0.8 MPa, secondary (paint) ) Pressure: about 10 to 26 MPa, the gun moving speed may be set to about 50 to 120 cm/sec.

The thickness of the anticorrosion coating film may be appropriately selected according to the desired application, but from the viewpoint of a coating film having excellent anticorrosion properties, it is preferably 100 μm or more, more preferably 250 μm or more, and preferably It is 450 μm or less, more preferably 400 μm or less.
When forming an anticorrosion coating having such a film thickness, the anticorrosion coating having a desired thickness may be formed by one coating (one coating), or two times (necessary depending on the anticorrosion property). Therefore, the anticorrosion coating film having a desired thickness may be formed by coating more than that. It is preferable to form the anticorrosion coating having a thickness within the above range by two-time coating from the viewpoint that an anticorrosion coating having excellent anticorrosion properties can be formed with good workability.

The method for drying and curing the coating film is not particularly limited, and the coating film may be dried and cured by heating at about 5 to 60° C. in order to shorten the drying and curing time. The coating film is dried and cured by leaving it in the atmosphere for about 1 to 14 days.

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto.

[Example 1]
As shown in Table 1 below, in a container, 19 parts by mass of a bisphenol A type epoxy resin (Note 1), 14 parts by mass of a liquid hydrocarbon resin (Note 6), 9 parts by mass of xylene, 2 parts by mass of n-butanol, 1- 1 part by mass of methoxy-2-propanol, 1 part by mass of silane coupling agent 1 (Note 5), 15 parts by mass of talc (Note 8), 14 parts by mass of potassium feldspar (Note 9), 6 parts by mass of titanium white (Note 10) , 1.5 parts by mass of yellow stalk (Note 11), 5 parts by mass of mica (Note 12), 7 parts by mass of scale-like aluminum (Note 14), 4 parts by mass of non-scaly aluminum (Note 17), and anti-sagging agent (Note 19) 1.5 parts by mass was put therein, glass beads were added thereto, and these components were mixed using a paint shaker. Then, the glass beads were removed, and the dispersion was dispersed at 56 to 60° C. using a high speed disperser, and then cooled to 30° C. or less to prepare the main ingredient.

In addition, as shown in Table 1 below, 9.4 parts by mass of polyamidoamine (Note 20), 4.7 parts by mass of modified polyamine (Note 21), 0.1 parts by mass of tertiary amine (Note 25), and 1- A curing agent component was prepared by mixing 0.8 parts by mass of methoxy-2-propanol using a high speed disper.

A coating composition was prepared by mixing the obtained main agent component and curing agent component before coating.
The details of each component shown in Table 1 are as shown in Table 2.

[Examples 2 to 8 and Comparative Examples 1 to 3]
A coating composition was prepared in the same manner as in Example 1 except that the types and amounts of the components to be added to the main component and the curing agent component were changed as shown in Table 1 below.

The “theoretical NV” in Table 1 is a value (mass %) obtained by dividing the total sum of the solid contents of the raw materials used (the total sum of components other than the solvent) by the mass of the coating composition. Further, “theoretical VOC amount” in Table 1 is a value calculated based on ASTM D5201, and “reaction ratio” is a value calculated based on the above formula (2).
The numerical value in the column of each component in Table 1 shows mass part, and the numerical value in the column of aluminum content shows mass %.

The following tests (1) to (4) were performed on the anticorrosion coating films formed from the compositions obtained in the above Examples and Comparative Examples. The results are shown in Table 3.
The composition obtained in Comparative Example 3 had a high viscosity, and it was difficult to perform the following tests (1) to (4). In order to perform the following tests (1) to (4) using the composition obtained in Comparative Example 3, it was necessary to increase the VOC amount to about 350 g/L.

(1) Salt water resistance test The salt water resistance of the anticorrosion coating film was measured according to JIS K-5600 6-1. Specifically, it was performed as follows.
Each of the compositions obtained in Examples and Comparative Examples had a dry film thickness of about 150 mm×70 mm×1.6 mm (thickness) on a blasted steel plate (hereinafter also referred to as “test plate”). A test plate with an anticorrosion coating film was prepared by spray-coating to a thickness of 320 μm, and drying the obtained test plate with a coating film in an atmosphere of 23° C. and 50% RH for 7 days. Using this test plate with an anticorrosion coating, the appearance of the anticorrosion coating after immersion in 3% salt water at 40° C. for 180 days was visually evaluated according to the following criteria.

(Evaluation criteria)
◯: No blister, crack, rust, peeling, or hue change.
Δ: Blisters, cracks, rust, peeling, and some defects (changes) in any of the hues.
Poor: blister, crack, rust, peeling, or change in hue is clearly observed.

(2) Cathodic protection test (sacrificial anode method)
After dipping a sample in which a zinc anode was connected to a test plate with an anticorrosion coating film prepared in the same manner as the salt water resistance test so that the current density was 5 mA/m ² or less, in 3% salt water at 40° C. for 180 days The appearance of the anticorrosion coating film was visually evaluated according to the same evaluation criteria as in the salt water resistance test.

(3) Cathodic protection test (external power supply method)
A test plate with an anticorrosion coating film prepared in the same manner as in the salt water resistance test was prepared with a coating film defect (holiday) having a diameter of 10.0 mm according to ASTM G8, and immersed in artificial seawater at 23°C for 180 days. The peeling length of the coating film around the subsequent holidays (length (mm)-10.0 from the center of the holiday of the peeling portion of the coating film) is in 4 directions (holiday 0 o'clock, 3 o'clock, 6 o'clock, 9 o'clock direction) ), and the average value (mm) of these peeled widths was obtained.

(4) Moisture resistance test The moisture resistance of the anticorrosion coating film was measured according to JIS K-5600 7-2. Specifically, it was performed as follows.
The appearance of the anticorrosion coating after holding the test plate with the anticorrosion coating prepared in the same manner as in the saltwater resistance test in a tester at a temperature of 50° C. and a humidity of 95% for 180 days was similar to that in the saltwater resistance test. It was visually evaluated according to the evaluation criteria.

Claims (9)

An anticorrosion coating composition containing an epoxy resin (A), an amine curing agent (B), a scaly aluminum powder (C), and an aluminum powder (D) other than the (C). The anticorrosion according to claim 1, which contains the aluminum powders (C) and (D) in an amount of 0.1 to 15% by mass (solid content) based on 100% by mass of the nonvolatile content in the anticorrosion coating composition. Coating composition. The anticorrosion coating composition according to claim 1 or 2, wherein the ratio of the mass (solid content) of the aluminum powder (D) to the mass (solid content) of the aluminum powder (C) is in the range of 0.1 to 5. .. The anticorrosion coating composition according to any one of claims 1 to 3, wherein the aluminum powder (D) has an aspect ratio of less than 5. Further, the anticorrosion coating composition according to any one of claims 1 to 4, further comprising a silane coupling agent (E). Furthermore, the anticorrosion coating composition according to any one of claims 1 to 5, further comprising an extender pigment (F). An anticorrosion coating film formed from the anticorrosion coating composition according to any one of claims 1 to 6. A substrate with an anticorrosion coating, comprising the anticorrosion coating according to claim 7 and a substrate. A method for producing a substrate with an anticorrosion coating, which comprises the following steps [1] and [2].
[1] A step of applying the anticorrosion coating composition according to any one of claims 1 to 6 on a substrate [2] A step of drying the applied anticorrosion coating composition to form a coating film