KR102567190B1 - Coating composition, coating film, substrate with coating film and producing method for substrate with coating film - Google Patents

Abstract

The present invention can form a coating film with excellent oil resistance, solvent resistance, chemical resistance and anticorrosive properties, and also, even if the coating interval is short (within 1 day) when forming a coating film by coating two or more times, a short period after coating ( It is an object to provide a coating composition having excellent curability, in which good coating performance is maintained even when immersed in hot water after drying within a few days).
The present invention relates to a coating composition, a coating film, a substrate with a coating film, and a method for producing the substrate with a coating film, the coating composition comprising an epoxy compound (A), an amine-based curing agent having a cyclic structure (B), and an imidazole-based compound (C) and a pigment (D), wherein the content of the resorcinol diglycidyl ether compound (A1) in the epoxy compound (A) is 50% by mass or less with respect to 100% by mass of the epoxy compound (A).

Description

Coating composition, coating film, substrate with coating film, and manufacturing method of substrate with coating film {Coating composition, coating film, substrate with coating film and producing method for substrate with coating film}

The present invention relates to a paint composition that can form a coating film having excellent oil resistance, solvent resistance, chemical resistance and corrosion resistance, and is suitable for painting the inner surface of a cargo tank for transporting or storing chemicals, for example, and its use. .

Worldwide, more than 5,000 liquid chemicals are transported by cargo tanks. These chemicals range from having no effect at all on the material constituting the cargo tank, such as steel, to being very corrosive.

The inner surface of the cargo tank is usually coated with a composition including paint or a metal spray. By coating the inner surface of the tank in this way, it is possible to protect the tank from chemical substances as cargo, and at the same time, to prevent contamination of the cargo due to corrosion of the tank.

In addition, by selecting an appropriate material for coating the inner surface of the cargo tank, the number of chemical substances that can be transported into the tank is increased, and the time required for tank maintenance or cleaning, for example, is reduced, which is beneficial in tank operation. effect can be enjoyed.

Coating of the inner surface of cargo tanks with non-metals is mainly performed with epoxy resin compositions. For example, Patent Document 1 discloses a coating composition containing a resorcinol diglycidyl ether epoxy resin as a main component of the resin component.

Patent Document 2 discloses an anticorrosive coating composition including an epoxy resin including a novolac type epoxy resin, a Mannich type curing agent, a silane coupling agent, a petroleum resin containing a hydroxyl group, and a trifunctional or higher functional acrylate compound.

Patent Document 3 contains a main component containing a bisphenol-type epoxy resin having an epoxy equivalent of 250 to 300, and a curing agent component containing an epoxy adduct of xylylenediamine and an epoxy adduct of polyamide, oil resistance and solvent resistance. An anticorrosive coating composition capable of forming a coating film having excellent chemical resistance and anticorrosive properties is disclosed.

Japanese Patent Publication No. 2014-511424 Japanese Patent Laid-Open No. 2010-24408 International Publication No. 2007/102587

However, since the composition described in Patent Document 1 has a high content of a resorcinol diglycidyl ether (hereinafter also referred to as "RDGE") compound, it is known that the skin irritation is strong and adversely affects the health of paint workers. could

In addition, the composition described in Patent Document 1 required heating at 50° C. or higher to form a coating film having performance suitable for the cargo tank use. For example, when the composition described in Patent Document 1 is applied to a large-capacity tank such as a cargo tank of a ship, a method of immersing the obtained coating film in hot water of 50 ° C. or higher for several hours or more is suitable, but after coating, it is suitable for soaking in hot water for a short period of time (within a few days). When immersed, it turned out that the solvent resistance of the formed coating film becomes insufficient.

In addition, in order for a coating film formed of the composition to exhibit original coating performance such as oil resistance, solvent resistance, chemical resistance, corrosion resistance, and water resistance at an early stage after coating, the organic solvent contained in the coating film needs to be volatilized. Therefore, when the coating film is a thick film, it is preferable to apply the coating so that the dry film thickness is 70 to 180 μm, since the organic solvent tends to remain inside the coating film.

On the other hand, in order to maintain the coating film performance over a long period of time, a film thickness of 200 μm or more is required as a dry film thickness. A coating film with a film thickness of 200 μm or more is normally applied with two or more coats (coating two or more times). At this time, in the case of coating a cargo tank or the like, it is required to perform the coating interval for a short period of time (within 1 day), but the composition of Patent Document 1 has a high content of the RDGE compound, so the drying of the coating film is slow.

In addition, it was found that the coating film formed from the anticorrosive coating composition described in Patent Document 2 had insufficient oil resistance, solvent resistance and chemical resistance to be applied to the above application.

In addition, it was found that there is room for improvement in terms of solvent resistance in order to apply the coating film formed from the anticorrosive coating composition described in Patent Document 3 to the above application.

The present invention is an invention to solve the problems associated with the prior art, and it is possible to form a coating film having excellent curability and excellent oil resistance, solvent resistance, chemical resistance and corrosion resistance, and in particular, by applying two or more times. A coating composition capable of forming a coating film with excellent oil resistance, solvent resistance, chemical resistance and anticorrosion even if the coating interval is short-term (within 1 day) during formation or even if it is immersed in hot water by drying for a short period of time (within several days) after coating is intended to provide

This inventor, as a result of repeating earnest examination about the method of solving the said subject, discovered that the said subject could be solved according to the coating composition of a specific composition, and came to complete this invention.

An example of the configuration of the present invention is as follows.

<1> contains an epoxy compound (A), an amine-based curing agent (B) having a cyclic structure, an imidazole-based compound (C), and a pigment (D);

A coating composition wherein the content of the resorcinol diglycidyl ether compound (A1) in the epoxy compound (A) is 50% by mass or less with respect to 100% by mass of the epoxy compound (A).

<2> The coating composition according to <1>, wherein the amine-based curing agent (B) having a cyclic structure is at least one selected from alicyclic amines and modified products thereof.

<3> The coating composition according to <1> or <2>, in which the pigment (D) contains a flat pigment (D1).

<4> The coating composition according to any one of <1> to <3>, further containing a silane coupling agent (E).

<5> The coating composition according to any one of <1> to <4>, wherein the coating composition has a pigment volume concentration (PVC) of 10 to 40%.

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

<7> A substrate with a coating film comprising the coating film and substrate according to <6>.

<8> The substrate with a coating film according to <7>, wherein the substrate is an inner surface of a cargo tank.

<9> The manufacturing method of the base material with a coating film containing the following process [1] and [2].

[1] Step of coating the coating composition according to any one of <1> to <5> on a substrate

[2] Step of drying the coated coating composition to form a coating film

The coating composition of the present invention is a composition having excellent curability with a low content of RDGE, which is highly irritating to the skin. It is possible to form a coating film with excellent oil resistance, solvent resistance, chemical resistance and anticorrosion even if the coating interval is short-term (within 1 day) or immersed in hot water by drying for a short period (within several days) after coating.

The paint composition of the present invention is coated on the inner surface of a cargo tank for transportation or storage in land transportation, sea transportation, etc., especially on the inner surface of a cargo tank such as a product carrier or chemical tanker that requires high oil resistance, solvent resistance, and chemical resistance in addition to anticorrosive properties It can also be suitably used as an anticorrosive coating composition to be coated on the inner surface of a pipeline or the like.

1 is a schematic diagram of a test plate with incisions used in the anticorrosion test of Examples.

<<paint composition>>

A coating composition (hereinafter also referred to as "the present composition"), which is an embodiment of the present invention, comprises an epoxy compound (A), an amine-based curing agent (B) having a cyclic structure, an imidazole-based compound (C), and a pigment (D). contains,

The content of the RDGE compound (A1) in the epoxy compound (A) is 50% by mass or less with respect to 100% by mass of the epoxy compound (A).

This composition contains the above (A) to (D), particularly specific (A) to (C), and since the content of the compound (A1) is within a specific range, the above effects are exhibited.

Here, excellent oil resistance, solvent resistance, and chemical resistance specifically mean oils such as heavy oil, gasoline, naphtha, and palm oil, methanol, ethanol, xylene, benzene, methyl isobutyl ketone, 1,2-dichloroethane, and ethyl acetate. It has excellent resistance to chemicals such as solvents such as sodium hydroxide and sulfuric acid.

Since these oils, solvents and chemicals have a great influence on the coating film, it is thought that the coating film resistant to these oils, solvents and chemicals is also resistant to general oils, solvents and chemicals.

This composition may be a one-component composition, but is usually a two-component composition comprising a main component containing an epoxy compound (A) and a curing agent component containing an amine-based curing agent (B). In addition, if necessary, the present composition may be a three-component or higher composition.

These main components and curing agent components are usually preserved, stored, transported, etc. in separate containers, and mixed together immediately before use.

<Epoxy compound (A)>

The epoxy compound (A) is not particularly limited as long as the content of the RDGE compound (A1) in 100 mass% of the compound (A) is 50 mass% or less, but 0 to 50 mass% of the RDGE compound (A1) and 50 to 100 It is preferable to include an epoxy compound (A2) other than the RDGE compound (A1) in mass %.

Since this composition contains such a specific epoxy compound (A), adverse effects on the human body and the environment are suppressed, and the composition has excellent curing properties, and also has excellent oil resistance, solvent resistance, chemical resistance and anticorrosion properties, especially twice When forming a coating film by over-coating, even if the coating interval is short (within 1 day), even if it is immersed in hot water by drying for a short period (within several days) after coating, a coating film with excellent oil resistance, solvent resistance, chemical resistance and corrosion resistance is formed. can do.

The content of the RDGE compound (A1) in 100% by mass of the epoxy compound (A) is preferably greater than 0% by mass, from the viewpoint of easily obtaining a coating film having more excellent oil resistance, solvent resistance, chemical resistance and corrosion resistance. 50% by mass or less, the lower limit of the content of the compound (A1) is preferably 10% by mass, particularly preferably 15% by mass, the upper limit is preferably 45% by mass, and the content of the epoxy compound (A2) is It is preferably 50% by mass or more and less than 100% by mass, the lower limit of the content of the compound (A2) is preferably 55% by mass, and the upper limit is preferably 90% by mass, particularly preferably 85% by mass.

From the standpoint of easily obtaining a composition capable of suppressing adverse effects on the human body and the environment, it is preferable that the RDGE compound (A1) is not substantially contained, and the RDGE compound in 100% by mass of the epoxy compound (A) The content of (A1) is more preferably 0% by mass, and the content of the epoxy compound (A2) is preferably 100% by mass.

The content of the epoxy compound (A) in the present composition is 100 mass of the non-volatile matter of the present composition in terms of obtaining a coating film having better adhesion to the substrate, coating strength, oil resistance, solvent resistance, chemical resistance and corrosion resistance, etc. With respect to %, it is preferably 10 to 60% by mass, more preferably 20 to 55% by mass.

<RDGE compound (A1)>

The RDGE compound (A1) is a low-viscosity epoxy compound represented by the following formula (2), and the epoxy equivalent is usually about 111.

As a commercial item of RDGE compound (A1), "ERISYS RDGE" (CVC Thermoset Specialties make, epoxy equivalent 115-135, non-volatile matter 100%) is mentioned, for example.

RDGE compound (A1) has a short molecular length among bifunctional epoxy compounds having an aromatic ring, and can form a coating film with a high crosslinking density by reacting with an amine-based curing agent (B), and is also suitable for imidazole-based compounds (C). A coating film having good oil resistance, solvent resistance, chemical resistance, etc. can be easily obtained by polymerization alone.

<Epoxy compounds (A2) other than RDGE compound (A1)>

Examples of the epoxy compound (A2) include polymers or oligomers containing two or more epoxy groups in the molecule, and epoxy compounds such as reactive diluents. In terms of formation, etc., an epoxy compound having an epoxy equivalent of preferably 200 or less, more preferably 100 to 200 is preferred. In addition, epoxy equivalent is calculated based on JIS K 7236.

Epoxy compound (A2) contained in epoxy compound (A) may use 1 type, and may use 2 or more types.

Examples of the epoxy compound (A2) include novolac type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, hydrogenated novolac type epoxy resins, hydrogenated bisphenol A type epoxy resins, and hydrogenated bisphenol F type epoxy resins. A resin, an aliphatic type epoxy resin, and an aromatic type epoxy resin are mentioned. When the present composition does not substantially contain the RDGE compound (A1), the epoxy compound (A2) preferably contains at least one of a novolak-type epoxy resin and a bisphenol F-type epoxy resin.

As the epoxy compound (A2), an epoxy compound such as a reactive diluent may be used in consideration of coating workability depending on the method for forming a coating film from the present composition, the type of substrate, use, and coating environment. Examples of epoxy compounds such as the reactive diluent include aliphatic, alicyclic and/or aromatic epoxy compounds containing 1 to 5 epoxy groups in a molecule.

As the epoxy compound (A2), a commercial item may be used, and examples of the commercial item include “D.E.N. 425” (manufactured by The Dow Chemical Company, epoxy equivalent 169 to 175, average functional group number 2.5, non-volatile content 100%), “D.E.N. 431” (manufactured by The Dow Chemical Company, epoxy equivalent 172 to 179, average functional group number 2.8, non-volatile content 100%) and “D.E.N. 438" (manufactured by The Dow Chemical Company, epoxy equivalent 176 to 181, average functional group number 3.6, non-volatile content 100%), bisphenol A type epoxy resin "E-028" (manufactured by Otake Meishin Chemical Co., Ltd., epoxy equivalent 180 ~ 190, non-volatile content 100%), and "jER 807" which is a bisphenol F-type epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent 160-175, non-volatile content 100%). From the viewpoint of easily obtaining a better coating film, it is preferable to use a novolac-type epoxy resin having an average number of functional groups of 2.5 or more, and it is more preferable to use a novolac-type epoxy resin having an average number of functional groups of 2.5 to 5.0, , It is more preferable to use a novolak-type epoxy resin having an average number of functional groups of 2.5 to 4.0.

In addition, as a commercial item of the epoxy compound, such as the said reactive diluent, for example, "ERISYS GE-22" which is cyclohexane dimethanol diglycidyl ether (made by CVC Thermoset Specialties, epoxy equivalent 155, non-volatile content 100%) is mentioned. there is.

<Amine curing agent (B) having a cyclic structure>

The amine-based curing agent (B) having a cyclic structure is not particularly limited as long as it is a polyamine having a cyclic structure, except for an imidazole-based compound (C) and a tertiary amine (an amine compound having only a tertiary amino group) described later, and an alicyclic , aromatic and heterocyclic polyamines, modified products of these polyamines, Mannich compounds using aliphatic polyamines and phenolic compounds (e.g., phenalkamine), or aliphatic polyamines and epoxy compounds having a phenolic structure (e.g., bisphenol A-type epoxy compound), etc. are mentioned.

One type of amine-based curing agent (B) may be used, or two or more types may be used.

Specifically, as the alicyclic polyamine, 1,4-cyclohexanediamine, diaminodicyclohexylmethane (especially 4,4'-methylenebiscyclohexylamine), and 4,4'-isopropylidenebiscyclohexylamine , norbornanediamine, bis(aminomethyl)cyclohexane, isophoronediamine, mensendiamine (MDA), 2,4-di(4-aminocyclohexylmethyl)aniline, and the like.

Examples of the aromatic polyamine include bis(aminoalkyl)benzene, bis(aminoalkyl)naphthalene, and compounds having two or more primary amino groups bonded to a benzene ring.

Specifically as this aromatic polyamine, 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'-diaminodiphenylsulfone, 3,3'-dimethyl-4, 4'-diaminodiphenylmethane, diaminodiethylphenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy -4,4'-diaminobiphenyl, bis(aminomethyl)naphthalene, bis(aminoethyl)naphthalene, etc. are mentioned.

The heterocyclic polyamine is not particularly limited as long as it is other than the imidazole-based compound (C) described later, and 1,4-bis(3-aminopropyl)piperazine, 1,4-diazacycloheptane, 1-(2 '-aminoethylpiperazine), 1-[2'-(2"-aminoethylamino)ethyl]piperazine, 1,11-diazacycloeicosan, 1,15-diazacyclooctacosan, and the like. there is.

Examples of the alicyclic, aromatic, and heterocyclic modified polyamines include Mannich-modified polyamines, epoxy adducts, and fatty acid-modified products.

Examples of the aliphatic polyamines include alkylene polyamines, polyalkylene polyamines, and alkylaminoalkylamines.

Examples of the alkylene polyamine include compounds represented by the formula: "H ₂ NR ¹ -NH ₂ " (R ¹ is a divalent hydrocarbon group having 1 to 12 carbon atoms). Specifically, methylenediamine , ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diamino heptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, trimethylhexamethylenediamine and the like.

As the polyalkylene polyamine, for example, the formula: "H ₂ N-(C _m H _2m NH) _n H" (m is an integer of 1 to 10. n is 2 to 10, preferably 2 to 6 It is an integer of), and specifically includes diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripropylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, and pentaethylenehexane. Min, nonaethylenedecamine, bis(hexamethylene)triamine, etc. are mentioned.

Examples of aliphatic polyamines other than these include tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, 2,2'-[ethylenebis (already Notrimethyleneimino)] bis(ethaneamine), tris(2-aminoethyl)amine, bis(cyanoethyl)diethylenetriamine, polyoxyalkylene polyamine (especially diethylene glycol bis(3-aminopropyl) ) ether) and the like.

Among these polyamines, alicyclic polyamines and modified products thereof are preferred, and polyamines having a cyclohexane ring are more preferred, and 4,4' -Methylenebiscyclohexylamine, 2,4-di(4-aminocyclohexylmethyl)aniline and modified products thereof are particularly preferred.

As said alicyclic polyamine, you may use a commercial item, and "Ancamine 2264" and "Ancamine 2143" (above Air Products Co., Ltd. product) etc. are mentioned as the commercial item.

In the present composition, the total content of the epoxy compound (A) and the amine-based curing agent (B) has a high crosslinking density, and from the viewpoint of obtaining a coating film with better oil resistance, solvent resistance, chemical resistance and corrosion resistance, etc. It is preferably 30 to 80% by mass, more preferably 40 to 70% by mass with respect to 100% by mass of the non-volatile matter of the composition.

The content of the amine-based curing agent (B) in the present composition is an amount such that the reaction ratio calculated by the following formula (1) is preferably 0.2 to 0.5, more preferably 0.25 to 0.45.

When the reaction ratio is within the above range, it is easily cured at an extremely general environmental temperature (for example, 0 to 50 ° C.), and can be cured to the extent that no adverse effect occurs on the surface of the coating film due to contact with water.

In addition, when the reaction ratio exceeds the above range, the solvent resistance of the obtained coating film tends to decrease.

Reaction ratio = (blending amount of curing agent (B)/active hydrogen equivalent of curing agent (B) + blending amount of component reactive with compound (A)/functional group equivalent of component reactive with compound (A)/(compound Compounding amount of (A) / Epoxy equivalent of compound (A) + Compounding amount of component reactive with curing agent (B) / Functional group equivalent of component reactive with curing agent (B) ... (1)

Here, as the "component having reactivity to the curing agent (B)" in the above formula (1), for example, a silane coupling agent (E) described later can be cited, and furthermore, "reactivity to the compound (A) Examples of the component having " include an amine-based curing agent other than the curing agent (B) described later, an imidazole-based compound (C) and a silane coupling agent (E) described later. In addition, the "functional group equivalent" of each component above means the mass (g) per 1 mol functional group obtained by subtracting the number of moles of functional groups contained therein from the mass of 1 mol of these components.

In the present invention, since the silane coupling agent (E) can use a silane coupling agent having an amino group or an epoxy group as a reactive group, whether the silane coupling agent has reactivity to the compound (A) according to the type of the reactive group, It is necessary to calculate the reaction ratio by determining whether the curing agent (B) has reactivity.

<Imidazole-based compound (C)>

The imidazole-based compound (C) is not particularly limited as long as it has an imidazole group. When the present composition is a two-component type, the imidazole-based compound (C) is preferably blended with the curing agent component.

By using such a compound (C), polymerization of the epoxy groups of the epoxy compound (A) can be efficiently and quickly promoted. And, by using the compound (C), even if the coating interval is short (within 1 day) when forming a coating film by coating twice or more, even if immersed in hot water by drying for a short period (within several days) after coating, oil resistance, A coating film excellent in solvent resistance, chemical resistance and corrosion resistance can be obtained.

1 type of imidazole type compound (C) may be used, and 2 or more types may be used.

Examples of the imidazole-based compound (C) include 1-methylimidazole, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-ethyl-4-methylimidazole. and 2-heptadecylimidazole, etc. are preferable. Among these, 1-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4- Methylimidazole is preferred.

The content of the imidazole-based compound (C) in the present composition is preferably used in an amount such that the reaction ratio falls within the above range, but the polymerization between the epoxy groups of the epoxy compound (A) can be efficiently and quickly progressed, and two or more times When forming a coating film by application, even if the coating interval is short (within 1 day), even if it is immersed in hot water by drying for a short period (within several days) after coating, a coating film with better oil resistance, solvent resistance, chemical resistance and corrosion resistance can be obtained. In terms of availability, etc., it is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on 100% by mass of the non-volatile matter of the present composition.

In addition, the content of the imidazole-based compound (C) in the present composition is preferably based on 100 parts by mass of the epoxy compound (A) from the viewpoint of obtaining a coating film excellent in oil resistance, solvent resistance, chemical resistance, and corrosion resistance. It is 0.2-20 mass parts, More preferably, it is 1-10 mass parts.

<Pigment (D)>

The present composition contains pigments (D) such as one or two or more kinds of extender pigments, color pigments, flat pigments, and rust-preventive pigments.

The pigment (D) may be blended with either or both of the main component and the curing agent component, but it is preferably blended with the main component.

The content of the pigment (D) in the present composition is usually 5 to 80% by mass, preferably 10 to 70% by mass, and more preferably 20 to 60% by mass, based on 100% by mass of the non-volatile matter of the main component. Further, it is preferably 10 to 60% by mass, more preferably 20 to 50% by mass, based on 100% by mass of the non-volatile matter of the present composition.

The pigment volume concentration (PVC) of the present composition, preferably the pigment volume concentration of the pigment (D) of the present composition, can easily obtain a composition with better painting workability, adhesion to the substrate by stress relaxation and water resistance. From the standpoint of being able to easily obtain a coating film superior to this, it is preferably 10 to 40%, more preferably 15 to 35%.

If the PVC content is less than the above range, the resulting coating film tends to deteriorate in its anticorrosive properties and the stress relieving effect due to the blending of the pigment tends to be insufficient. tend to become

The above-mentioned PVC refers to the volume concentration of the sum of the pigments with respect to the volume of the non-volatile matter in the present composition. PVC can be specifically obtained from the formula below.

PVC [%] = total volume of all pigments in this composition × 100 / volume of non-volatile matter in this composition

The non-volatile content (solid content) of the present composition means the mass percentage of the coating film (heating residue) after the present composition is sufficiently cured (heating), or the coating film (heating residue) itself. According to JIS K 5601-1-2, 1 ± 0.1 g of the present composition (for example, the composition immediately after mixing the main component and the curing agent component) is weighed for the non-volatile content in a flat-bottomed dish, and the wire of the mass is known. It can be calculated by measuring the heating residue and the mass of the wire when it is spread uniformly using , dried at 23 ° C for 24 hours, and then heated at a heating temperature of 110 ° C for 1 hour (at normal pressure). In addition, this non-volatile matter is a value equal to the total amount of solid content (components other than a solvent) of the raw material components used for this composition.

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

The volume of the pigment can be calculated from the mass and true density of the pigment used. The mass and true density of the pigment may be measured values or values calculated from raw materials to be used. For example, it can calculate by separating a pigment and other components from the non-volatile matter of this composition, and measuring the mass and true density of the separated pigment.

〈Constitutive Pigment〉

The extender pigments are pigments other than colored pigments and flat pigments, and examples of the extender pigments include conventionally known talc, (precipitated) barium sulfate, (potassium) feldspar, kaolin, alumina white, clay, magnesium carbonate, barium carbonate, and calcium carbonate. , dolomite, silica and the like can be used. Among these, silica, talc, (precipitated) barium sulfate, and (potassium) feldspar are preferable.

1 type may be used for an extender pigment, and 2 or more types may be used.

When the extender pigment is blended into the present composition, the blending amount is usually 5 to 80% by mass, preferably 10 to 70% by mass, more preferably 20 to 60% by mass, based on 100% by mass of the non-volatile matter of the main component, It is preferably 10 to 60% by mass, more preferably 20 to 50% by mass with respect to 100% by mass of the non-volatile matter of the present composition.

<coloring pigment>

The color pigments are pigments other than flat pigments, and examples of the color pigments include conventionally known inorganic pigments such as carbon black, titanium dioxide (titanium white), iron oxide (Bengala), yellow iron oxide, ultramarine blue, cyanine blue, and cyanine green. Organic pigments and the like can be used. Among these, titanium bag, carbon black, and bengala are preferable.

One type of color pigment may be used, and two or more types may be used.

When the color pigment is incorporated into the present composition, the blending amount is usually 1 to 50% by mass, preferably 1 to 20% by mass, and more preferably 2 to 10% by mass, based on 100% by mass of the non-volatile matter of the main component, It is preferably 1 to 20% by mass with respect to 100% by mass of the non-volatile matter of the present composition.

<flat pigment (D1)>

The present composition preferably contains a flat pigment (D1) as the above-mentioned pigment (D) from the viewpoint of being able to easily obtain a coating film having more excellent anticorrosive properties and reducing internal stress.

As for the flat pigment (D1), 1 type may be used and 2 or more types may be used.

As the flat pigment (D1), the median diameter (D50) is preferably 30 to 200 µm, and the average aspect ratio A pigment having a (median diameter/average thickness) of preferably 10 to 150, more preferably 20 to 100 is preferred.

D50 can be measured using a laser scattering diffraction type particle size distribution measuring device, for example, "SALD 2200" (manufactured by Shimadzu Corporation).

The average thickness is observed in the horizontal direction with respect to the main surface of the flat pigment D1 using a scanning electron microscope (SEM), for example, "XL-30" (manufactured by Philips), and the thickness of several tens to several hundred pigment particles. can be calculated as the average value of

Examples of the flat pigment (D1) include mica, glass flakes, aluminum flakes, flaky iron oxides, stainless steel flakes, plastic flakes, etc., which are inexpensive, have excellent availability, and can form a coating film with more excellent effects. In terms of, mica is preferred.

As said mica, "mica powder 100 mesh" (made by Fukuoka Talc Industrial Co., Ltd., D50:41 micrometer, average aspect ratio: 35) etc. are mentioned.

The content of the flat pigment (D1) in the present composition is preferably 1 to 40% by mass, based on 100% by mass of the non-volatile matter of the present composition, from the viewpoint of easily obtaining a coating film having more excellent effects. Preferably it is 3-20 mass %.

<Silane coupling agent (E)>

The present composition preferably contains a silane coupling agent (E) from the standpoint of easily obtaining a coating film having more excellent adhesion to a substrate.

Silane coupling agent (E) may use 1 type, and may use 2 or more types.

The silane coupling agent (E) is not particularly limited, and conventionally known compounds can be used. Compounds that have at least two hydrolysable groups in the same molecule and can contribute to improving adhesion to substrates and reducing the viscosity of the present composition. It is preferable, and it is more preferable that it is a compound represented by the following formula.

X-SiMe _n Y _{3 -n}

[n is 0 or 1, X is a functional group capable of reacting with organic matter (eg, amino group, vinyl group, epoxy group, mercapto group, halogeno group, a group in which a part of a hydrocarbon group is substituted with these groups, or a hydrocarbon group A group in which a part of a group partially substituted with an ether bond or the like is substituted with these groups.), Me is a methyl group, and Y represents a hydrolysable group (e.g., an alkoxy group such as a methoxy group or an ethoxy group).]

Among these, the adhesion to the base material of the coating film obtained can further be improved by using the alkoxysilane compound containing an epoxy group in which the said X is an epoxy group.

As a preferable silane coupling agent (E), specifically, "KBM403" which is γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), "Syla Ace S-510" (manufactured by JNC Corporation) etc. can be mentioned.

When the present composition contains the silane coupling agent (E), its content (non-volatile content) is determined from the viewpoint of easily obtaining a coating film having better adhesion to substrates, corrosion resistance, etc., and the non-volatile content of the present composition. With respect to 100 mass%, it is preferably 0.05 to 15 mass%, more preferably 0.3 to 5 mass%.

In addition, when the present composition contains a silane coupling agent (E), its content (non-volatile content) can easily obtain a coating film having better solvent resistance, chemical resistance, corrosion resistance, etc. With respect to mass%, it is preferably 0.1 to 15 mass%, more preferably 0.1 to 10 mass%, and particularly preferably 0.1 to 5 mass%.

＜Other ingredients＞

In this composition, as other components, an amine-based curing agent other than the curing agent (B), an anti-sagging agent (anti-settling agent), a fiber material, a surfactant (eg, a surfactant described in Japanese Unexamined Patent Publication No. 2-298563), a dispersant, Various additives such as a leveling agent, a surface conditioner, a curing accelerator (eg: tertiary amine), and an organic solvent can be blended appropriately.

These may use 1 type, respectively, and may use 2 or more types.

The above other components may be blended with the main component or may be blended with the curing agent component.

In addition, as the curing agent component, within a range that does not impair the effect of the present invention, you may use an amine curing agent that does not have one type or two or more types of cyclic structures.

This composition may also contain an amine type hardening|curing agent other than the said hardening|curing agent (B). Examples of such an amine-based curing agent include the aliphatic polyamines described above, and polyoxyalkylene polyamines are preferred.

A commercial item may be used as an amine-type hardener other than the said hardening|curing agent (B), As the commercial item, "Jeffamine D-230" (made by Huntsman Japan Co., Ltd.) etc. which are polyoxypropylene diamine are mentioned.

As the anti-sagging agent (anti-settling agent), stearate salts of Al, Ca, and Zn, lecithin salts, organic clay waxes such as alkyl sulfonates, polyethylene waxes, amide waxes, hydrogenated castor oil waxes, hydrogenated castor oil waxes, and amides Conventionally known waxes such as mixtures of waxes, synthetic fine powder silica and polyethylene oxide wax can be used, and among them, amide wax, synthetic fine powder silica, polyethylene oxide wax and organoclay wax are preferable.

As such an anti-sagging agent (antisettling agent), "Disparon 305", "Disparon 4200-20", and "Disparon 6650" manufactured by Kusumoto Chemicals Co., Ltd.; ASAT-250F"; products, such as Kyoeisha Chemical Co., Ltd. product "Flownon RCM-300", are mentioned.

When blending an anti-sagging agent (anti-settling agent) into the present composition, it may be blended in an amount of, for example, 0.1 to 10% by mass in the main component.

Examples of the organic solvent include, but are not particularly limited to, 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, Alcoholic solvents such as 1-methoxy-2-propanol, mineral spirits, aliphatic hydrocarbons such as n-hexane, n-octane, 2,2,2-trimethylpentane, isooctane, n-nonane, cyclohexane, and methylcyclohexane A system solvent etc. are mentioned.

When the organic solvent is blended into the present composition, the blending amount is not particularly limited and may be appropriately adjusted according to the coating method when coating the present composition. Considering the paintability of the present composition, etc. It is preferable to blend in an amount such that the concentration is preferably 55 to 98% by mass, more preferably 65 to 95% by mass.

In addition, when the organic solvent is spray-coated with the present composition, the concentration of the non-volatile content of the present composition is preferably 55 to 95% by mass, more preferably 65 to 95% by mass, from the viewpoint of paintability and the like. It is preferable to blend in an amount.

[Manufacture of coating composition]

The present composition is preferably prepared by mixing and kneading the main component and the curing agent component prepared separately in advance at the time of use.

The main component can be prepared by blending, stirring, and kneading each component constituting it. At this time, it is preferable to use, for example, an SG mill or a high-speed disper to disperse the blended ingredients as uniformly as possible while maintaining the temperature of the mill base at 55 to 60 ° C. for about 30 minutes.

On the other hand, the curing agent component is also different depending on the components to be blended, but it is only necessary to mix each component constituting it and uniformly disperse it with a stirrer.

[Use of coating composition]

According to this composition, it is possible to form a coating film (layer) having various properties such as oil resistance, solvent resistance, chemical resistance, water resistance and anticorrosive properties. The methods include interstitial corrosion, dissimilar metal contact corrosion, and stress corrosion.

Since this composition can form a coating film having these excellent properties, it is recommended to use it on the inner surface of a cargo tank (e.g., product carrier or chemical tanker) for transporting or storing chemicals by land or sea transport. It is preferable, and it is also preferable to use it for structures in contact with chemicals, such as the inner surface of a pipeline. In addition to this application, it is difficult to maintain seawater desalination equipment, offshore structures, etc., around dams and gates of sluice gates, piping such as plants using seawater, river water or industrial water as cooling water, water storage tanks, water storage tanks, etc. It is suitable for use as a pool for storing finished nuclear fuel.

<< coating film, substrate with a coating film, manufacturing method of a substrate with a coating film >>

A coating film (hereinafter also referred to as “this coating film”) of one embodiment of the present invention is formed using the present composition, and a base material with a coating film of one embodiment of the present composition includes this coating film and an object (substrate) to be coated. It is a layered body.

The material of the substrate is not particularly limited, and examples thereof include steel (iron, steel, alloy iron, carbon steel, mild steel, alloy steel, stainless steel, etc.) and non-ferrous metal (zinc, aluminum, etc.). etc. may be covered.

In addition, when using, for example, mild steel (SS400, etc.) as the base material, surface preparation (eg, arithmetic mean roughness (Ra) of 30 to Adjusted to be about 75 μm) is preferable.

The dry film thickness of this coating film is not particularly limited, but is usually 50 to 500 µm, preferably 200 to 400 µm, from the viewpoint of obtaining a coating film having sufficient anticorrosive properties and the like.

As the method for forming the coating film, a desired film thickness may be formed by one coating (one application), or a coating film having a desired film thickness may be formed by two or more coatings (two or more coatings). From the viewpoint of facilitating film thickness management and easily reducing the residual organic solvent in the coating film, it is preferable to form a coating film so as to achieve a desired dry film thickness by painting twice or more.

The method for manufacturing a substrate with a coating film of the present invention (hereinafter also referred to as "this method") includes the following steps [1] and [2].

Step [1]: Step of coating the composition on a substrate

Step [2]: Step of drying the coated coating composition to form a coating film

In addition, this method can form a coating film more excellent in oil resistance, solvent resistance, chemical resistance, etc. by including the following process [3].

Process [3]: The process of heating the coating film obtained in the said process [2] at 60-150 degreeC

When manufacturing a base material with a coating film by the method including the said process [1] - [3], this composition is (1) reaction of the epoxy group of an epoxy compound (A) and the functional group which has an active hydrogen in a hardening|curing agent (B), and (2) It is estimated that curing occurs through two mechanisms of the reaction between the epoxy groups of the epoxy compound (A) (epoxy homopolymerization).

(1) In the reaction between the epoxy group of the epoxy compound (A) and the functional group having an active hydrogen in the curing agent (B), for example, in step [2], the epoxy group in the epoxy compound contained in the main component is ring-opened. The epoxy oxygen (O) becomes a hydroxyl group (-OH), and the carbon at the end of the molecule forming the epoxy group reacts with the amino group (-NH ₂ ) in the curing agent to form a "-NH-" bond, etc. It is presumed to be associated with

(2) The reaction between the epoxy groups of the epoxy compound (A) (epoxy homopolymerization) occurs, for example, in step [3].

For this reason, it is thought that the coating film with a higher crosslinking density than the coating film obtained by process [2] is obtained by performing process [3]. It is thought that this increase in crosslinking density is useful for improving the oil resistance, solvent resistance and chemical resistance of the coating film.

Since this composition is used in the above method, a coating film can be formed through such a double curing process, and in particular, the first stage curing (drying in step [2]) can be performed at a time suitable for a general coating process, and , It is possible to obtain a coating film with a high crosslinking density that exhibits the above effect by the second stage curing process.

<Process [1]>

The coating method in the step [1] is not particularly limited, and may be coated on the surface of the base material by a conventional method such as airless spray coating, air spray coating, brush coating, roller coating, etc. In the case of coating a structure, spray coating is preferable from the standpoint of being able to easily coat a substrate having a large area.

The conditions of the spray coating may be appropriately adjusted according to the dry film thickness to be formed. For example, in the case of airless spray, the primary (air) pressure: about 0.4 to 0.8 MPa, the secondary (paint) pressure: 10 to About 26 MPa and a key moving speed of about 50 to 120 cm/sec are preferable.

In addition, what is necessary is just to coat so that the dry film thickness of the obtained coating film may become the said range.

The viscosity of this composition suitable for spray coating is preferably 1,500 to 6,000 mPa s, more preferably 1,500 to 3,500 under measurement conditions at 23°C using an E-type viscometer (FMD type manufactured by TOKIMEC) as a measuring instrument. mPa·s.

<Process [2]>

The drying conditions in the step [2] are not particularly limited, and may be appropriately set according to the method of forming the coating film, the type of substrate, use, coating environment, etc., but the drying temperature is preferably 0 to 60 ° C., more preferably is 5 to 40 ° C. On the other hand, the drying time varies depending on the method of forming the coating film, and in the case of one-time application, it is preferably 1 hour to 3 days, more preferably about 2 days. In addition, in the case of application twice or more, the drying time of the coating film (first layer) formed by the first coating is preferably 1 hour to 2 days, more preferably 1 hour to 18 hours, and 2 hours other than the final coating The same applies to the coating film (second layer or higher) formed by the first and subsequent coatings. However, the drying time of the coating film formed by the final coating is preferably 1 hour to 3 days, more preferably 1 hour to 2 days.

This drying condition can be said to be a time suitable for a general painting process, and can be said to be a short period. By using this composition, it is possible to form a coating film having the desired physical properties under such dry conditions.

<Process [3]>

The heating conditions in the step [3] are not particularly limited, but the heating temperature is preferably 60 to 150°C, and the heating time is preferably 5 to 24 hours, more preferably 6 to 20 hours.

As such a heating method, for example, (a) a method of bringing the surface of the coating film obtained in the step [2] into contact with warmed seawater or water, (b) a method of heating the surface of the coating film obtained in the step [2] with hot air, or (c) Several methods, such as the method of spraying hot water on the surface of the coating film obtained in the said process [2], are mentioned.

Further, as a method of performing step [3], in the case of forming a coating film by the above two or more coatings, particularly two coatings, after performing steps [1] and [2], steps [1] and [2] on the obtained coating film ] and [3]. In addition, when forming a coating film by application|coating 3 times or more, after repeating a series of processes of process [1] and [2] 3 times or more, process [3] is performed.

Example

Preferable aspects of the present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[Examples 1 to 14 and Comparative Examples 1 to 3]

Each component constituting the main component listed in Table 1 was added to a plastic container according to the amount (numerical value) shown in Table 1, an appropriate amount of glass beads were added, and dispersed in a paint shaker for 1 to 2 hours. Then, after removing the glass beads, it was stirred using a high-speed disper and dispersed at 56 to 60°C for about 30 minutes. After that, the main ingredient was prepared by cooling to 30°C or lower.

In addition, each component constituting the curing agent component shown in Table 1 was added to a container according to the amount (numerical value) shown in Table 1, and a curing agent was obtained by dispersing with a table top stirrer.

A paint composition was prepared by mixing the obtained base material and a curing agent.

In addition, the description of each component described in Table 1 is shown in Table 2. In Table 1, the numerical values of the components of the main agent and the curing agent respectively represent parts by mass.

[Production of trial version]

SS400 sandblasted steel sheets having dimensions of 150 mm x 70 mm x 2.3 mm (thickness) (arithmetic mean roughness (Ra): 30 to 75 µm) were prepared. Each of the coating compositions prepared as described above was applied to the surface of the steel sheet using an airless spray to a dry film thickness of 125 μm, and dried at 23° C. for 16 hours. Next, the same coating composition as the first layer was applied on the obtained dry film to a dry film thickness of 125 μm, and dried at 23° C. for 2 days. That is, a coating film of 250 μm was formed on the steel sheet by coating twice. Then, it was immersed in 80 degreeC hot water for 8 hours, and the obtained steel plate (test board) with a coating film was used for each test mentioned later. The results are shown in Table 3.

Moreover, all the pencil hardness of the coating film in the obtained test plate was "H" or more. In the present invention, pencil hardness was measured based on JIS K 5600-5-4.

＜Corrosion resistance test＞

In accordance with JIS K 5600-6-1 (test method for liquid resistance), the obtained coating film was tested for corrosion resistance.

An incision 2 reaching the steel sheet from the coating film side was placed at the position shown in Fig. 1 of each obtained test panel. The test plate 1 into which the incision 2 was placed was immersed in 3% saline at 40°C for 90 days with the incision 2 side facing down (in the direction shown in Fig. 1). After immersion, 11 cuts (3) are placed upwards in order from the left end of the incision (2) as if dividing the incision (2) equally at intervals of 5 mm, and the 10 locations between the cuts (3) are measured In part (4), the peel length (length from incision (2)) between the steel sheet and the coating film was measured. The average value of 10 measured peeling lengths was evaluated based on the following criteria.

(Evaluation standard)

4: Peeling length less than 5 mm

3: Peeling length of 5 mm or more and less than 10 mm

2: Peeling length of 10 mm or more and less than 15 mm

1: Peeling length of 15 mm or more

<Oil resistance test>

In accordance with JIS K 5600-6-1 (test method for liquid resistance), the obtained coating film was tested for oil resistance.

Each obtained test plate was immersed in naphtha at room temperature for 180 days. The test plates after immersion were evaluated according to the following criteria.

(Evaluation standard)

5: There was no occurrence of rust on the steel sheet, no generation of blisters on the coating film, and the pencil hardness of the coating film was H or higher.

4: There was no occurrence of rust on the steel sheet, no generation of blisters on the coating film, and the pencil hardness of the coating film was F to 4B.

3: There was no occurrence of rust on the steel sheet, no generation of blisters on the coating film, and the pencil hardness of the coating film was 5B or less.

2: Slight rust occurred on the steel sheet, and blisters occurred on the coating film.

1: Rust occurred on the steel sheet and blisters occurred on the coating film.

<Solvent resistance test>

In accordance with JIS K 5600-6-1 (test method for liquid resistance), the obtained coating film was tested for solvent resistance.

Each obtained test plate was immersed in various solvents such as methanol, benzene, methyl isobutyl ketone, ethyl acetate and 1,2-dichloroethane at room temperature for 180 days. The test plates after immersion were evaluated according to the same criteria as in the above oil resistance test.

<Chemical resistance test>

In accordance with JIS K 5600-6-1 (test method for liquid resistance), the obtained coating film was tested for chemical resistance.

Each obtained test plate was immersed in various chemicals of 10% sulfuric acid and 30% sodium hydroxide solution at room temperature for 180 days. The test plates after immersion were evaluated according to the same criteria as in the above oil resistance test.

1: Trial
2: Incision
3: cut
4: Measuring part

Claims (9)

containing an epoxy compound (A), an amine-based curing agent (B) having a cyclic structure, an imidazole-based compound (C), and a pigment (D);
The content of the resorcinol diglycidyl ether compound (A1) in the epoxy compound (A) is 50% by mass or less with respect to 100% by mass of the epoxy compound (A),
The amine-based curing agent (B) includes 2,4-di (4-aminocyclohexylmethyl) aniline and modified products thereof,
paint composition. According to claim 1,
A coating composition wherein the amine-based curing agent (B) having a cyclic structure is at least one selected from alicyclic amines and modified products thereof. According to claim 1,
A coating composition in which the pigment (D) contains a flat pigment (D1). According to claim 1,
A coating composition further containing a silane coupling agent (E). According to claim 1,
A paint composition wherein the pigment volume concentration of the paint composition is 10 to 40%. A coating film formed from the coating composition according to any one of claims 1 to 5. A substrate with a coating film comprising the coating film according to claim 6 and the substrate. According to claim 7,
A substrate with a coating film in which the substrate is an inner surface of a cargo tank. The manufacturing method of the base material with a coating film including the following process [1] and [2].
[1] A step of coating the substrate with the coating composition according to any one of claims 1 to 5
[2] Step of drying the coated coating composition to form a coating film