Anti-corrosion coating composition, anti-corrosion coating film, and method for producing anti-corrosion coating film

Abstract

One embodiment of the present invention relates to an anti-corrosion coating composition, an anti-corrosion coating film, or a method for producing an anti-corrosion coating film. The anti-corrosion coating composition contains an epoxy compound (A), an amine curing agent (B), and an alkylamine (C).

Description

Technical Field

[0001] One embodiment of the present invention relates to an anti-corrosion coating composition, an anti-corrosion coating film, or a method for manufacturing an anti-corrosion coating film. Background Art

[0002] It is known that an epoxy resin-based anti-corrosion coating composition is applied to the inner surfaces of tanks such as the WBT (ballast tank), COT (cargo oil tank), and chemical storage tanks of ships for the purpose of obtaining a tank body with oil resistance, solvent resistance, chemical resistance, and corrosion resistance.

[0003] In recent years, especially overseas, restrictions on VOCs (volatile organic compounds) have become increasingly strict for such anti-corrosion coating compositions, and a higher solid-type anti-corrosion coating composition is required.

[0004] In addition, not only properties such as oil resistance, solvent resistance, chemical resistance, and corrosion resistance, but also considering the nature of coating on the inner surface of the tank, an anti-corrosion coating composition with good film-forming properties at low temperatures (hereinafter also referred to as "low-temperature film-forming properties") is excellent in coating workability. Therefore, such an anti-corrosion coating composition with excellent low-temperature film-forming properties is also expected.

[0005] As such an anti-corrosion coating composition, for example, the anti-corrosion coating compositions described in Patent Documents 1 and 2 are known.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: International Publication No. 2019 / 022218

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2022-40066 Summary of the Invention

[0010] Technical Problem to be Solved by the Invention

[0011] According to the existing anti-corrosion coating compositions described in Patent Documents 1 and 2 above, although the balance between properties such as oil resistance, solvent resistance, chemical resistance, and corrosion resistance and low-temperature film-forming properties is relatively excellent, when it is necessary to form an anti-corrosion coating film at a lower temperature (for example, below 10°C) and high oil resistance, solvent resistance, chemical resistance, and corrosion resistance are required, when using the existing anti-corrosion coating composition to form an anti-corrosion coating film, the formed coating film is likely to produce wrinkles, and there is still room for improvement in terms of low-temperature film-forming properties. That is, it is difficult for the existing anti-corrosion coating compositions to balance high oil resistance, solvent resistance, chemical resistance, and corrosion resistance with excellent low-temperature film-forming properties.

[0012] One embodiment of the present invention can provide an anticorrosive coating composition capable of forming an anticorrosive coating film with excellent low-temperature film-forming properties and high oil resistance, solvent resistance, chemical resistance, and anticorrosive properties.

[0013] Technical solutions for solving technical problems

[0014] The constitutional examples of the present invention are as follows.

[0015] [1] An anticorrosive coating composition containing an epoxy compound (A), an amine curing agent (B), and an alkylamine (C).

[0016] [2] The anticorrosive coating composition according to [1], wherein the above-mentioned alkylamine (C) is liquid at normal temperature.

[0017] [3] The anticorrosive coating composition according to [1] or [2], wherein the above-mentioned alkylamine (C) is a primary amine represented by R-NH2 [R is an alkyl group having 1 to 20 carbon atoms].

[0018] [4] The anticorrosive coating composition according to any one of [1] to [3], wherein the above-mentioned amine curing agent (B) contains an amine curing agent having a cyclic structure.

[0019] [5] The anticorrosive coating composition according to any one of [1] to [4], wherein the epoxy equivalent of the above-mentioned epoxy compound (A) is 200 or less, and the above-mentioned epoxy compound (A) is liquid at normal temperature.

[0020] [6] The anticorrosive coating composition according to any one of [1] to [5], wherein the above-mentioned amine curing agent (B) is liquid at normal temperature.

[0021] [7] The anticorrosive coating composition according to any one of [1] to [6], wherein the content of the non-volatile component is 90% by mass or more.

[0022] [8] An anticorrosive coating film formed from the anticorrosive coating composition according to any one of [1] to [7].

[0023] [9] A method for manufacturing an anticorrosive coating film, which includes a step of drying the anticorrosive coating composition according to any one of [1] to [7] at a temperature of 10°C or lower to form an anticorrosive coating film.

[0024] Advantages of the invention

[0025] According to one embodiment of the present invention, an anticorrosive coating composition can be provided, which can form an anticorrosive coating film with excellent low-temperature film-forming properties and high oil resistance, solvent resistance, chemical resistance, and anticorrosive properties.

[0026] According to one embodiment of the present invention, an anticorrosion coating film having the above-mentioned excellent various properties can be formed, and therefore it is preferably suitable for coating various substrates, especially the inside of tanks used for transporting or storing chemical substances.

[0027] Furthermore, according to one embodiment of the present invention, a coating composition can be obtained that is high in solids yet exhibits excellent coating workability, particularly spraying workability. Therefore, even on large substrates, an anti-corrosion coating can be easily formed with minimal impact on the environment and human body.

[0028] Here, excellent oil resistance, solvent resistance, and chemical resistance specifically refer to excellent resistance to oils such as heavy oil, gasoline, naphtha, and palm oil, solvents such as methanol, ethanol, xylene, benzene, methyl isobutyl ketone, 1,2-dichloroethane, and ethyl acetate, and chemicals such as sodium hydroxide and sulfuric acid.

[0029] Since these oils, solvents and chemicals have a significant impact on the coating film, a coating film that is resistant to these oils, solvents and chemicals is also considered to be resistant to conventional oils, solvents and chemicals. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of a test plate with cuts used in the corrosion resistance test of the examples. DETAILED DESCRIPTION

[0031] Anti-corrosion coating composition

[0032] An anticorrosive coating composition according to one embodiment of the present invention (hereinafter also referred to as "the present composition") contains an epoxy compound (A), an amine curing agent (B), and an alkylamine (C).

[0033] The content of the nonvolatile component in the present composition is preferably 90% by mass or more, more preferably 92% by mass or more, and even more preferably 95% by mass or more.

[0034] The present composition having a non-volatile component content within the above range can be said to be an anticorrosive coating composition having a higher solid ratio than conventional compositions.

[0035] The content of non-volatile components in the present composition is a value calculated as a mass percentage in the following manner: 1 g of the present composition (for example, a composition immediately after mixing the main agent component and the curing agent component) is collected in a flat-bottomed dish, spread evenly using a metal needle of known mass, left at 23°C for 24 hours, dried at 110°C for 1 hour, and the mass of the heated residue (also called "non-volatile components") and the metal needle is measured to calculate the value.

[0036] It should be noted that in this specification, for the raw materials (e.g., epoxy compound (A)) constituting the main component or the curing agent component, the main component, and the curing agent component, the components other than the organic solvents and the dispersion medium contained in these respective components are referred to as "solid components".

[0037] In this composition, it is preferably substantially free of organic solvents such as VOCs. Specifically, the VOC content in this composition when adjusted to a viscosity suitable for coating is preferably 200 g / L or less, more preferably 150 g / L or less, and even more preferably 100 g / L or less.

[0038] It should be noted that in the present invention, "organic solvent" refers to an organic compound having a boiling point lower than 200 °C under 1 atmospheric pressure.

[0039] Regarding the VOC content of this composition, it can be calculated by the following formula (1) using the values of the specific gravity of the coating (g / cm 3 ) and the content (% by mass) of the non-volatile components in the above-mentioned composition.

[0040] VOC content (g / L) = specific gravity of the coating × 1000 × (100 - content of non-volatile components in the composition) / 100 ··· (1)

[0041] Specific gravity of the coating (g / cm 3 ) : The value calculated by filling a specific gravity cup with an internal volume of 100 ml with this composition (e.g., the composition just after mixing the main component and the curing agent component) under the temperature condition of 23 °C and measuring the mass of this composition.

[0042] This composition can be a one-component composition, but is usually a two-component composition composed of a main component containing an epoxy compound (A) and a curing agent component containing an amine curing agent (B) and an alkylamine (C). Additionally, according to needs, this composition can also be a composition of three or more components.

[0043] These main component and curing agent component are usually stored, preserved, transported, etc. in their respective containers, and are mixed together and used just before use.

[0044] <Epoxy compound (A)>

[0045] Examples of the epoxy compound (A) include polymers or oligomers containing two or more epoxy groups, and polymers or oligomers formed by the ring-opening reaction of their epoxy groups.

[0046] The epoxy compound (A) can be used singly or in combination of two or more.

[0047] Regarding the epoxy equivalent of the above-mentioned epoxy compound (A), since it can form an anticorrosive coating film with excellent properties such as oil resistance, solvent resistance, chemical resistance, and corrosion resistance, it is preferably 200 or less, more preferably 100 - 200, and even more preferably 100 - 190. It should be noted that the epoxy equivalent is calculated based on JIS K 7236:2001.

[0048] For an epoxy compound with an epoxy equivalent exceeding 200, due to its excessively large molecular weight, when using such an epoxy compound, there is often a situation where an organic solvent is required to adjust the viscosity to a suitable level for coating. Therefore, it is sometimes difficult to obtain a high-solid anticorrosive coating composition.

[0049] As the epoxy compound (A), an epoxy compound that is liquid at normal temperature is preferred. As specific examples, bisphenol A epoxy resin, bisphenol F epoxy resin, and bisphenol AD epoxy resin can be cited.

[0050] It should be noted that "normal temperature" in this specification refers to 25°C.

[0051] The epoxy compound (A) can be a commercially available product. As such commercially available products, for example, "E-028" (manufactured by Ohtake Meishin Chemical Co., Ltd., epoxy equivalent 180 - 190, solid content 100%) as bisphenol A epoxy resin, and "jER 807" (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 160 - 175, solid content 100%) as bisphenol F epoxy resin can be cited.

[0052] The viscosity of the epoxy compound (A) measured by an E-type viscometer (manufactured by TOKIMEC Inc., FMD type) at 25°C is preferably 1500 mPa·s or more, more preferably 3000 mPa·s or more, preferably 120000 mPa·s or less, and more preferably 30000 mPa·s or less.

[0053] Regarding the content of the epoxy compound (A) in this composition, from the viewpoints of easily forming an anticorrosive coating film with excellent adhesion to the substrate, oil resistance, solvent resistance, chemical resistance, and corrosion resistance, etc., based on 100% by mass of the non-volatile components of this composition, it is preferably 10% by mass or more, more preferably 15% by mass or more, preferably 50% by mass or less, and more preferably 45% by mass or less.

[0054] <Amine curing agent (B)>

[0055] The amine curing agent (B) is not particularly limited, but from the viewpoints of easily obtaining a high-solid type of this composition, etc., it is preferably liquid at normal temperature. The amine curing agent (B) is a compound different from the alkylamine (C), and is preferably a polyamine having two or more primary amine groups or secondary amine groups in one molecule.

[0056] As the amine curing agent (B), specifically, aliphatic, alicyclic, aromatic, heterocyclic and other amine compounds are preferably used. It should be noted that these amine compounds are classified according to the type of carbon to which the amino group is bonded. For example, an aliphatic amine curing agent refers to a compound having at least one amino group bonded to an aliphatic carbon.

[0057] One type of the amine curing agent (B) can be used, or two or more types can be used.

[0058] It should be noted that the amine curing agent (B) being "liquid at room temperature" means that the viscosity measured using an E-type viscometer at 25 °C is 1000 Pa·s or less.

[0059] By using such an amine curing agent (B), the organic solvent used for adjusting the viscosity suitable for coating can be reduced, and this composition which is a high solid type but has excellent coating workability can be easily obtained.

[0060] Examples of the above-mentioned aliphatic amine curing agent include alkylene polyamines, polyalkylene polyamines, and alkylaminoalkylamines.

[0061] Examples of the above-mentioned alkylene polyamines include compounds represented by the formula: "H2N-R 1 -NH2" (R 1 is a divalent hydrocarbon group having 1 to 12 carbon atoms.). As specific examples, methylene diamine, ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,5-diaminopentane, 1,6-diaminohexane, and trimethylhexamethylenediamine can be mentioned.

[0062] Examples of the above-mentioned polyalkylene polyamines include compounds represented by the formula: "H2N-(C m H 2m NH) n H" (m is an integer from 1 to 10. n is an integer from 2 to 10, preferably an integer from 2 to 6.). As specific examples, diethylenetriamine (DETA), dipropylenetriamine, triethylenetetramine (TETA), tripropylenetetramine, tetraethylenepentamine (TEPA), tetrapropylenepentamine, pentaethylenehexamine, nonaethylene decamine, and triethylene-bis(trimethylene)hexamine can be mentioned.

[0063] Examples of the above-mentioned alkylaminoalkylamines include compounds represented by the formula: "R 2 2N-(CH2) p -NH2" (R 2 is independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms (wherein at least one R 2is an alkyl group having 1 to 8 carbon atoms.), p is an integer of 1 to 6.). As a specific example of the compound represented by, dimethylaminoethylamine, diethylaminoethylamine, dibutylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, dimethylaminobutylamine can be cited.

[0064] As aliphatic amine curing agents other than these, for example: tetra(aminomethyl)methane, tetra(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, tris(2-aminoethyl)amine, bis(cyanoethyl)diethylenetriamine, polyoxyalkylene polyamine (especially diethylene glycol bis(3-aminopropyl)ether), bis(aminomethyl)cyclohexane, isophorone diamine (IPDA), menthane diamine (MDA), o-phenylenediamine, m-phenylenediamine (MXDA), p-phenylenediamine, bis(aminomethyl)naphthalene, bis(aminoethyl)naphthalene, 1,4-bis(3-aminopropyl)piperazine, 1-(2'-aminoethylpiperazine), 1-[2'-(2”-aminoethylamino)ethyl]piperazine can be cited.

[0065] It should be noted that from the viewpoint of being able to easily form a corrosion-resistant coating film with more excellent film-forming properties, etc., it is preferable not to use bis(aminomethyl)cyclohexane and its modified products.

[0066] As specific examples of the above alicyclic amine curing agents, cyclohexanediamine, diaminodicyclohexylmethane (especially 4,4'-methylenebis(cyclohexylamine) [PACM]), 4,4'-isopropylidenebis(cyclohexylamine), norbornanediamine (NBDA), 2,4-bis(4-aminocyclohexylmethyl)aniline can be cited.

[0067] As the above aromatic amine curing agent, for example, an aromatic polyamine compound having two or more primary amino groups bonded to an aromatic ring such as a benzene ring or a naphthalene ring can be cited.

[0068] As specific examples of this aromatic amine curing agent, 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, diaminodiethylphenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl can be cited.

[0069] As specific examples of the above heterocyclic amine curing agents, 1,4-diazepane, 1,11-diazacycloeicosane, 1,15-diazacyclooctacosane can be cited.

[0070] As the amine curing agent (B), modified products of the above-mentioned amine curing agents can also be cited. For example, fatty acid modified products such as polyamide amines, amine adducts with epoxy compounds, Mannich modified products (e.g., phenolic amines, phenolic amides), Michael adducts, ketimines, and aldimines.

[0071] As the amine curing agent (B), from the viewpoint of being able to easily form a corrosion-resistant coating film with more excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance, etc., an amine curing agent having a cyclic structure is preferably contained, and it is more preferably to contain at least one selected from Mannich modified products of methylene-crosslinked poly(cyclohexyl-aromatic) amine (MPCA), 4,4'-methylenebis(cyclohexylamine) (PACM), and m-xylenediamine (MXDA). From the viewpoint of easily forming a corrosion-resistant coating film with higher oil resistance, etc., it is particularly preferred to contain MPCA.

[0072] Thus, from the viewpoint of being able to easily form a corrosion-resistant coating film with more excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance, etc., it is preferred to use at least one selected from Mannich modified products of MPCA, PACM, and MXDA. It is known that when forming a corrosion-resistant coating film at a low temperature (e.g., 10°C or lower) with an existing high-solid (solvent-free) corrosion-resistant coating composition using these amine curing agents, the formed corrosion-resistant coating film is particularly likely to generate wrinkles, so there is room for improvement in terms of low-temperature film-forming properties. This is presumably because in the applied corrosion-resistant coating composition, low-molecular amine compounds contained in amine curing agents such as Mannich modified products of MPCA, PACM, and MXDA precipitate onto the film surface, resulting in uneven presence of the low-molecular amine compounds on the film surface, and then wrinkles (poor film-forming properties) are caused by subsequent drying and curing (curing shrinkage) at low temperature.

[0073] In addition, it is known that wrinkles (poor film-forming properties) are likely to occur when using MPCA and PACM without benzyl alcohol. It is considered that this is because the content of the above-mentioned low-molecular amine compounds in MPCA and PACM without benzyl alcohol is relatively high.

[0074] On the other hand, according to the present composition, for the purpose of being able to easily form a corrosion-resistant coating film with more excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance, even when using at least one selected from Mannich modified products of MPCA, PACM, and MXDA, and further when using these amine curing agents without benzyl alcohol, wrinkles (poor film-forming properties) caused by drying and curing (curing shrinkage) at low temperature are not likely to occur.

[0075] In addition, as the amine curing agent (B), from the viewpoints of being able to easily form a corrosion-resistant coating film with more excellent flexibility and corrosion resistance and more excellent surface coating suitability (e.g., excellent adhesion to the topcoat film that can be formed on the corrosion-resistant coating film formed from this composition), and the tendency to extend the pot life of this composition, etc., it is preferable to use an aliphatic amine curing agent (however, it does not have a cyclic structure. For example: "Ancamine 2738", "Ancamide 506", both manufactured by Evonik Japan Co., Ltd.). From the viewpoints of being able to easily form a corrosion-resistant coating film with a more excellent balance of flexibility, oil resistance, solvent resistance, chemical resistance, corrosion resistance, and surface coating suitability, and being able to extend the pot life of this composition, etc., it is more preferable to use this aliphatic amine curing agent (however, it does not have a cyclic structure) in combination with at least one selected from the Mannich-modified products of MPCA, PACM, and MXDA.

[0076] The above-mentioned methylene-crosslinked poly(cyclohexyl-aromatic)amine (MPCA) is described, for example, in U.S. Patent No. 5,280,091. As a specific example, a polyfunctional polyamine manufactured by hydrogenating an oligomer obtained by condensing aniline and formaldehyde can be cited.

[0077] As the Mannich-modified product of the above-mentioned MXDA, specifically, a Mannich-modified amine obtained by subjecting one or more phenols and one or more aldehydes and m-xylenediamine to Mannich condensation can be cited.

[0078] The amine curing agent (B) can be obtained by known methods in the art, and commercially available products can also be used. When using commercially available products, from the viewpoints of further exerting the effects of the present invention, etc., it is preferable to use a liquid amine curing agent without benzyl alcohol.

[0079] As commercially available products of the above-mentioned liquid amine curing agent without benzyl alcohol, for example, "Ancamine 2738", "Ancamine 2264", "Ancamine 2167", "Ancamine2422", "Ancamine 2089K", "Ancamide506" (the above are manufactured by EVONIK JAPAN Co., Ltd.), "NX-5567" (manufactured by CARDOLITE JAPAN Co., Ltd.) can be cited.

[0080] When the present composition is a two-component composition composed of a main agent component and a curing agent component, the amine curing agent (B) is included in the curing agent component. Regarding the viscosity of the curing agent component measured at 25°C using an E-type viscometer, from the viewpoints of achieving a composition that is more excellent in workability and painting workability, etc., it is preferably 100,000 mPa·s or less, more preferably 10,000 mPa·s or less, and more preferably 50 mPa·s or more.

[0081] Regarding the active hydrogen equivalent of the amine curing agent (B), from the viewpoints of being able to easily form a corrosion protection film with more excellent corrosion resistance, etc., it is preferably 20 or more, more preferably 40 or more, preferably 1000 or less, and more preferably 500 or less.

[0082] Regarding the content of the amine curing agent (B) in the present composition, from the viewpoints of being able to easily form a corrosion protection film with excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance, etc., relative to 100% by mass of the non-volatile components of the present composition, it is preferably 5% by mass or more, more preferably 7% by mass or more, preferably 20% by mass or less, and more preferably 15% by mass or less.

[0083] When the present composition contains at least one of the Mannich modifiers selected from MPCA, PACM, and MXDA, regarding the content of the Mannich modifiers of MPCA, PACM, and MXDA, from the viewpoints of being able to easily form a corrosion protection film with excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance, etc., relative to 100% by mass of the non-volatile components of the present composition, it is preferably 0.5% by mass or more, more preferably 1% by mass or more, preferably 15% by mass or less, and more preferably 10% by mass or less.

[0084] When the present composition contains an aliphatic amine curing agent (but without a cyclic structure), regarding the content of the aliphatic amine curing agent (but without a cyclic structure), from the viewpoints of being able to easily form a corrosion protection film with excellent flexibility, corrosion resistance, and suitability for surface coating, and being able to extend the pot life of the present composition, etc., relative to 100% by mass of the non-volatile components of the present composition, it is preferably 1% by mass or more, more preferably 2% by mass or more, preferably 15% by mass or less, and more preferably 12% by mass or less.

[0085] From the viewpoints of being able to easily form a corrosion protection film with excellent corrosion resistance, film strength, and drying properties, etc., the amount of the amine curing agent (B) used is preferably an amount such that the reaction ratio calculated by the following formula (2) reaches preferably 0.3 or more, more preferably 0.4 or more, preferably 1.2 or less, and more preferably 1.1 or less.

[0086] Reaction ratio = { (Amount of amine curing agent (B) / Active hydrogen equivalent of amine curing agent (B)) + (Amount of component reactive with epoxy compound (A) / Functional group equivalent of component reactive with epoxy compound (A))} / { (Amount of epoxy compound (A) / Epoxy equivalent of epoxy compound (A)) + (Amount of component reactive with amine curing agent (B) / Functional group equivalent of component reactive with amine curing agent (B))} ··· (2)

[0087] Here, as the "component reactive with amine curing agent (B)" in the above formula (2), components reactive with amine curing agent (B) in the following other components can be exemplified. Additionally, as the "component reactive with epoxy compound (A)", alkylamine (C) and components reactive with epoxy compound (A) in the following other components can be exemplified. The "functional group equivalent" of each of the above components refers to the mass per 1 mol of functional group obtained by dividing the mass of 1 mol of these components by the number of moles of functional groups contained therein (g).

[0088] <Alkylamine (C)>

[0089] Regarding alkylamine (C), from the viewpoint of easily obtaining the present composition having excellent low-temperature film-forming properties even when at least one of the Mannich modifiers selected from MPCA, PACM, and MXDA is used, primary alkylamine is preferred, and primary alkyl monoamine is more preferred.

[0090] Regarding alkylamine (C), from the viewpoint of easily obtaining the present composition of high solid type, etc., it is preferably liquid at normal temperature.

[0091] One type of alkylamine (C) can be used, or two or more types can be used.

[0092] Specific examples of alkylamine (C) include primary alkylamines such as butylamine, octylamine, dodecylamine, hexadecylamine, octadecylamine, coconut oil amine, tallow amine, hydrogenated tallow amine, oleylamine, laurylamine, stearylamine; secondary alkylamines such as dicoconut oil amine, dihydrogenated tallow amine, distearylamine; and tertiary alkylamines such as dodecyl dimethylamine, didodecyl monomethylamine, tetradecyl dimethylamine, octadecyl dimethylamine, coconut oil dimethylamine, dodecyltetradecyl dimethylamine, trioctylamine.

[0093] Regarding alkylamine (C), from the viewpoint of being able to form an anticorrosive coating film having high oil resistance, solvent resistance, chemical resistance, and anticorrosion properties, and easily obtaining the present composition of high solid type with excellent low-temperature film-forming properties, a primary amine represented by R-NH2 [R is an alkyl group having 1 to 20 carbon atoms] is preferred.

[0094] Regarding the number of carbon atoms of R above, from the viewpoints of easily realizing an alkylamine that is liquid at room temperature and being able to obtain the present composition with more excellent low-temperature film-forming properties, etc., it is preferably 8 or more, preferably 18 or less, more preferably 12 or less, and particularly preferably 10 or less.

[0095] The alkyl group in R above may have a branched chain or may be cyclic such as a cycloalkyl group, but is preferably a chain-like alkyl group, and more preferably a straight-chain alkyl group.

[0096] From the viewpoints of easily obtaining the present composition with excellent low-temperature film-forming properties, etc., the alkylamine (C) is preferably a compound other than the compound represented by the following formula (3).

[0097]

[0098] [In formula (3), R 1 is an alkyl group having 1 to 6 carbon atoms that may have a hydroxyl group, R 2 NHCH2-(R <( 2 represents an alkyl group having 1 to 6 carbon atoms) or a group represented by the following formula (3A), and p is a number from 0 to 2).]

[0099]

[0100] [In formula (3A), R 3 represents a hydrogen atom or NH2-.]

[0101] When the present composition is a two-component composition composed of a main component and a curing agent component, the alkylamine (C) is contained in the curing agent component.

[0102] The alkylamine (C) can be obtained by existing publicly known methods or commercially available products can be used.

[0103] Examples of such commercially available products include: "FARMIN 08D" (manufactured by Kao Corporation, main component: 98% of primary alkylamine having 8 carbon atoms), "FARMIN CS" (manufactured by Kao Corporation, main component: 51% of primary alkylamine having 12 carbon atoms, sub-components: a total of 14% of primary alkylamine having 8 or 10 carbon atoms, a total of 35% of primary alkylamine having 14 to 18 carbon atoms), "FARMIN 20D" (manufactured by Kao Corporation, main component: primary alkylamine having 12 carbon atoms), "FARMINO-V" (manufactured by Kao Corporation, main component: primary alkylamine having 18 carbon atoms), "FARMIN DM0898" (manufactured by Kao Corporation, main component: tertiary alkylamine having 8 carbon atoms), "FARMIN DM1098" (manufactured by Kao Corporation, main component: tertiary alkylamine having 10 carbon atoms), "FARMIN DM2098" (manufactured by Kao Corporation, main component: tertiary alkylamine having 12 carbon atoms), "FARMIN DM2463" (manufactured by Kao Corporation, main component: tertiary alkylamines having 12 and 14 carbon atoms), "FARMINDM4098" (manufactured by Kao Corporation, main component: tertiary alkylamine having 14 carbon atoms), "FARMIN DM6098" (manufactured by Kao Corporation, main component: tertiary alkylamine having 16 carbon atoms).

[0104] Regarding the content of the alkylamine (C) in the present composition, from the viewpoints of being able to easily obtain the present composition with excellent low-temperature film-forming properties and having a more excellent balance in easily forming a corrosion-resistant coating film with excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance, etc., it is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, preferably 10% by mass or less, more preferably 6% by mass or less, and particularly preferably 4% by mass or less based on 100% by mass of the non-volatile components of the present composition.

[0105] In addition, regarding the content of the alkylamine (C), from the viewpoints of being able to easily obtain the present composition with excellent low-temperature film-forming properties and having a more excellent balance in easily forming a corrosion-resistant coating film with excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance, etc., it is preferably 0.001 part by mass or more, more preferably 0.005 part by mass or more, still more preferably 0.01 part by mass or more, particularly preferably 0.02 part by mass or more, preferably 0.4 part by mass or less, more preferably 0.3 part by mass or less, and particularly preferably 0.2 part by mass or less based on 1 part by mass of the amine curing agent (B).

[0106] <Other Components>

[0107] In this composition, in addition to the above (A) to (C), within the scope of not impairing the effects of the present invention, reactive diluents, silane coupling agents, pigments, anti-sagging agents (sedimentation inhibitors), plasticizers, dispersants, leveling agents, surface modifiers, dioxolane derivatives, organic solvents, epoxy compounds other than epoxy compound (A), curing agents other than amine curing agent (B), and other currently known and publicly available components used in coating compositions may also be contained.

[0108] For each of these other components, one type can be used, or two or more types can be used. They can be incorporated into the main component or the curing agent component.

[0109] This composition may or may not contain benzyl alcohol, and this composition preferably substantially does not contain benzyl alcohol.

[0110] Benzyl alcohol can be mixed with reactive components such as the above (A) to (C). From the viewpoints of dilution effect, viscosity reduction effect, etc., it can be incorporated into the main component or pre-incorporated into a commercially available amine curing agent.

[0111] On the other hand, although benzyl alcohol is considered a chemical substance with low volatility and generally lower harmfulness compared to other organic solvents, according to GHS classification, it is classified as acute toxicity (oral): Category 4, acute toxicity (dermal): Category 4, acute toxicity (inhalation: vapor): Category 3, and it is pointed out that it is harmful to health.

[0112] In addition, since benzyl alcohol is a high-boiling solvent, when the usage amount is relatively large (for example, more than 3% by mass in the composition), it may remain in the dried coating film, and as a result, the coating film performance may sometimes be reduced, especially the corrosion resistance and oil resistance may be reduced.

[0113] Therefore, from the viewpoints of the impact on the environment and human body and good coating film performance, etc., a benzyl alcohol-free composition of the present invention is required. However, as described above, especially when aiming to form a corrosion-resistant coating film with high oil resistance, solvent resistance, chemical resistance, and corrosion resistance, it is preferable to use an amine curing agent with a cyclic structure. However, it is found that in existing corrosion-resistant coating compositions using such an amine curing agent with a cyclic structure, when using a benzyl alcohol-free amine curing agent, there are problems especially in terms of low-temperature film-forming properties.

[0114] On the other hand, it is found that according to this composition, even when using a benzyl alcohol-free amine curing agent with a cyclic structure, its low-temperature film-forming property is excellent. That is to say, according to this composition, although it substantially does not contain benzyl alcohol, it is also possible to easily obtain a corrosion-resistant coating composition with excellent low-temperature film-forming property while forming a corrosion-resistant coating film with excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance.

[0115] In the present invention, "substantially free of benzyl alcohol" means a case where benzyl alcohol is not specifically added to the present composition and a case where a composition containing benzyl alcohol is not specifically used. Specifically, it means that the content of benzyl alcohol in the present composition is 0.5% by mass or less.

[0116] [Reactive diluent]

[0117] The present composition may contain a reactive diluent, and preferably contains a reactive diluent. As the reactive diluent, a reactive diluent containing an epoxy group is preferred.

[0118] One type of reactive diluent may be used, or two or more types may be used.

[0119] As the above-mentioned reactive diluent containing an epoxy group, there is no particular limitation as long as it is an epoxy compound having a viscosity of 500 mPa·s or less at 25°C measured using an E-type viscometer (manufactured by TOKIMEC, FMD type), and it may be a monofunctional type or a polyfunctional type.

[0120] Examples of the reactive diluent containing a monofunctional epoxy group include alkyl glycidyl ethers (alkyl having 1 to 13 carbon atoms), phenyl glycidyl ether, o-cresol glycidyl ether, alkyl phenyl glycidyl ethers (alkyl having 1 to 20 carbon atoms, preferably 1 to 5, e.g., methyl phenyl glycidyl ether, ethyl phenyl glycidyl ether, propyl phenyl glycidyl ether, p-tert-butyl phenyl glycidyl ether), phenol glycidyl ether, alkyl phenol glycidyl ether, phenol(EO) n glycidyl ether (repetition number n = 3 to 20, EO: -C2H4O-).

[0121] Examples of the reactive diluent containing a polyfunctional epoxy group include: 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, resorcinol diglycidyl ether, monoalkylene glycol diglycidyl ether or polyalkylene glycol diglycidyl ether (alkylene having 1 to 5 carbon atoms, e.g., ethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether), trimethylolpropane triglycidyl ether.

[0122] When the composition contains a reactive diluent, regarding the content of the reactive diluent, from the viewpoints of being able to easily form an anti-corrosion coating film excellent in oil resistance, solvent resistance, chemical resistance, corrosion resistance, etc., and contributing to reducing the viscosity of the composition, extending the pot life, etc., it is preferably 10% by mass or less, more preferably 8% by mass or less, particularly preferably 6% by mass or less, preferably 0.1% by mass or more, and more preferably 0.5% by mass or more based on 100% by mass of the non-volatile components of the composition.

[0123] [Silane coupling agent]

[0124] The composition may contain a silane coupling agent and preferably contains a silane coupling agent.

[0125] There is no particular limitation on the silane coupling agent, and known compounds can be used, but compounds having at least 2 functional groups in the same molecule, which contribute to improving the adhesion to the substrate and reducing the viscosity of the composition, etc., are preferred. More preferably, for example, a compound represented by the formula: "X-SiMe n Y 3-n " [n is 0 or 1, X is a reactive group capable of reacting with an organic substance (e.g., amino group, vinyl group, epoxy group, mercapto group, halogen group, a group in which a part of a hydrocarbon group is substituted by the above group, or a part of a group in which a part of a hydrocarbon group is substituted by an ether bond or the like is substituted by the above group), Me is a methyl group, and Y is a hydrolyzable group (e.g., alkoxy groups such as methoxy group and ethoxy group).].

[0126] One kind of silane coupling agent can be used, or two or more kinds can be used.

[0127] As the silane coupling agent, from the viewpoints of being able to easily form an anti-corrosion coating film with excellent adhesion to the substrate and more excellent oil resistance, solvent resistance, chemical resistance, corrosion resistance, etc., a compound having an epoxy group and an alkoxy group is preferred, and a silane coupling agent containing an alkoxy group having 1 epoxy group in 1 molecule is more preferred.

[0128] As the silane coupling agent, commercially available products can be used. Specific examples of the commercially available products include (3,4-epoxycyclohexyl)ethyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM 303", etc.), 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM 403", etc.), γ-glycidoxypropylmethyldimethoxysilane (manufactured by Toray-Dow Corning Co., Ltd., "AY43-026", etc.), γ-glycidoxypropylmethyldiethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., "KBE 402", etc.).

[0129] When the composition contains a silane coupling agent, regarding the content of the silane coupling agent, from the viewpoints of more excellent adhesion to the substrate, easier formation of a corrosion - resistant coating film with more excellent solvent resistance, chemical resistance, and corrosion resistance, contribution to reducing the viscosity of the composition, contribution to extending the pot life, etc., it is preferably 1% by mass or more, more preferably 3% by mass or more, preferably 25% by mass or less, and more preferably 15% by mass or less based on 100% by mass of the non - volatile components of the composition.

[0130] [Pigment]

[0131] The composition may contain a pigment, and preferably contains a pigment.

[0132] Examples of the pigment include extender pigments, coloring pigments, and rust - preventive pigments, and it can be either organic or inorganic.

[0133] One kind of pigment can be used, or two or more kinds can be used.

[0134] Examples of the extender pigments include talc, mica, (precipitated) barium sulfate, (potassium) feldspar, kaolin, alumina white, bentonite, wollastonite, clay, glass flakes, aluminum flakes, flaky iron oxide, magnesium carbonate, barium carbonate, calcium carbonate, dolomite, and silica. Particularly preferred are talc, mica, silica, (precipitated) barium sulfate, and (potassium) feldspar.

[0135] Among these, from the viewpoints of relaxing the internal stress of the cured coating film and improving the adhesion to the substrate, etc., mica is preferably used.

[0136] When the composition contains an extender pigment, regarding the content of the extender pigment, it is preferably 10% by mass or more, more preferably 20% by mass or more, preferably 70% by mass or less, and more preferably 60% by mass or less based on 100% by mass of the non - volatile components of the composition.

[0137] Examples of the coloring pigments include inorganic pigments such as carbon black, titanium dioxide (titanium white), iron oxide (iron red), yellow iron oxide, and ultramarine blue, and organic pigments such as cyanine blue and cyanine green. Particularly preferred are titanium white, carbon black, and iron red.

[0138] When the composition contains a coloring pigment, regarding the content of the coloring pigment, it is preferably 1 - 30% by mass, more preferably 1 - 15% by mass based on 100% by mass of the non - volatile components of the composition.

[0139] Examples of the above rust-inhibitive pigments include zinc powder, zinc alloy powder, zinc phosphate-based compounds, calcium phosphate-based compounds, aluminum phosphate-based compounds, magnesium phosphate-based compounds, zinc phosphite-based compounds, calcium phosphite-based compounds, aluminum phosphite-based compounds, strontium phosphite-based compounds, aluminum tripolyphosphate-based compounds, molybdate-based compounds, zinc cyanamide-based compounds, borate compounds, nitro compounds, and composite oxides.

[0140] When the composition contains a pigment, regarding the pigment volume concentration (PVC) in the composition, from the viewpoints of being able to easily obtain a composition with excellent coating workability and being able to easily form a corrosion-resistant coating film with excellent adhesion to the substrate and water resistance through stress relaxation, it is preferably 10 to 70%, more preferably 10 to 50%.

[0141] The above PVC is the volume concentration of the total amount of the pigment relative to the volume of the non-volatile components in the composition. Specifically, PVC can be obtained by the following formula.

[0142] PVC [%] = (Total volume of all pigments in the composition) × 100 / (Volume of non-volatile components in the composition)

[0143] The volume of the non-volatile components in the above composition can be calculated from the mass and true density of the non-volatile components in the composition. The mass and true density of the non-volatile components can be the measured values or the values calculated from the raw materials used.

[0144] The volume of the above pigment can be calculated from the mass and true density of the pigment used. The mass and true density of the pigment can be the measured values or the values calculated from the raw materials used. For example, it can be calculated by separating the pigment and other components from the non-volatile components of the composition and measuring the mass and true density of the separated pigment.

[0145] [Anti-sagging agent (settling inhibitor)]

[0146] Examples of the above anti-sagging agent (settling inhibitor) include stearate salts of Al, Ca, and Zn, lecithin salts, organic clay-based waxes such as alkyl sulfonates, polyethylene wax, amide wax, hydrogenated castor oil wax, a mixture of hydrogenated castor oil wax and amide wax, synthetic fine silica powder, polyethylene oxide-based wax, etc. Among them, amide wax, synthetic fine silica powder, polyethylene oxide-based wax, and organic clay-based wax are preferably used.

[0147] The anti-sagging agent (settling inhibitor) can be used singly or in combination of two or more.

[0148] Examples of such anti-sagging agents (anti-settling agents) include "Disparlon 305", "Disparlon 4200-20", "Disparlon 6650" manufactured by Nambon Kasei Co., Ltd.; "A-S-A T-250F" manufactured by Ito Seiyu Co., Ltd.; "FLOWNON RCM-300" manufactured by Kyoeisha Chemical Co., Ltd.; "BENTONES D-2" manufactured by Elementis Specialties, Inc., and other products.

[0149] When the composition contains an anti-sagging agent (anti-settling agent), the content of the anti-sagging agent (anti-settling agent) is preferably 0.5 to 4% by mass relative to 100% by mass of the non-volatile components of the composition.

[0150] [Plasticizer]

[0151] Examples of the above plasticizer include, for example, petroleum resin, xylene resin, terpene phenolic resin, and acrylic resin. By containing a plasticizer in the composition, the corrosion resistance, flexibility, surface coating suitability, etc. of the obtained anti-corrosion coating film can be improved.

[0152] One type of plasticizer can be used, or two or more types can be used. [[ID=1"]]

[0153] The above petroleum resin is preferably a hydroxyl-containing polymer using a fraction by-produced in petroleum refining as the main raw material, and preferably a hydroxyl-containing petroleum resin having a softening point of 150°C or lower, preferably 100°C or lower. When the softening point of the petroleum resin exceeds 150°C, the viscosity of the obtained composition may become high, resulting in a decrease in workability, or a decrease in the physical properties of the coating film.

[0154] Specific examples of such petroleum resins include "NECIRES EPX-L" (manufactured by Nevcin Polymersco., indene-styrene type), "HILENOL PL-1000S" (manufactured by Kolon Industries, Inc., C9 fraction petroleum resin), and the like.

[0155] The above xylene resin is preferably a resin synthesized from m-xylene and formaldehyde by a known method. In addition, as the above xylene resin, a xylene resin modified with a phenolic compound (e.g., bifunctional phenols such as phenol and p-tert-butylphenol) can also be used.

[0156] Specific examples of such xylene resins include "NIKANOL Y-51", "NIKANOL Y-100" (both manufactured by Fudow Co., Ltd., xylene formaldehyde resin), and the like

[0157] When the composition contains a plasticizer, the content of the plasticizer is preferably 0.5 to 5% by mass relative to 100% by mass of the non-volatile components of the composition.

[0158] <Manufacturing Method of the Composition>

[0159] The composition is preferably manufactured by mixing the previously prepared main agent component and curing agent component at the time of use.

[0160] The main agent component can be prepared by mixing the components constituting the main agent component and then stirring and mixing. At this time, it is preferable to use, for example, an SG mill or a high-speed disperser, set the temperature of the mill base to 55 to 60 °C and maintain it for about 30 minutes to make the mixed components as uniformly dispersed as possible.

[0161] On the other hand, the curing agent component varies depending on the components to be mixed, but the components constituting the curing agent component can be uniformly mixed using a mixer or the like.

[0162] <Uses of the Composition>

[0163] According to this composition, a corrosion-resistant coating film (layer) having various properties such as oil resistance, solvent resistance, chemical resistance, and corrosion resistance can be formed. This corrosion protection also includes preventing crevice corrosion, dissimilar metal contact corrosion, stress corrosion, etc.

[0164] Since this composition can form a corrosion-resistant coating film having these excellent properties, it is preferably used for the inner surface of cargo tanks (e.g., product tankers or chemical tankers) for transporting or storing chemicals, etc., and also for the inner surface of onshore tanks for storing chemicals, and is also preferably used for the inner surface of tanks such as WBT, COT, FWT (Fresh Water Tank), DWT (Drinking Water Tank), etc., and the inner and outer surfaces of ships, etc. In addition, outside these uses, it is also applicable to seawater desalination plants, maintenance-difficult places such as marine structures, the periphery of the gates of reservoirs or water gates, pipes, water storage tanks, water storage tanks, spent nuclear fuel storage water pools, etc. for large equipment using seawater, river water, or industrial water as cooling water.

[0165] In particular, this composition is preferably used as a general primer for the inner surface of tanks (e.g., product tankers, chemical tankers) for transporting or storing chemicals, etc., WBT, COT, pipes, etc., and for ships.

[0166] In addition, this composition can also be used to repair the surface of a substrate with a corrosion-resistant coating film where corrosion has occurred.

[0167] In addition, this composition can also be applied to the welded part of a substrate such as stainless steel or a location with a gap to prevent local corrosion of the substrate, and can also function as an adhesive for bonding a stainless steel plate to the surface of its coating film, thereby suppressing local corrosion for a long time.

[0168] When repairing such a substrate, methods such as applying this composition to the surface of a substrate having a welded part (welding line) or a gap and bonding other substrates to the surface of the uncured coating film can be carried out, and this composition can also be applied to the other substrates.

[0169] "Anti-corrosion Coating Film and Method for Manufacturing Anti-corrosion Coating Film"

[0170] The anti-corrosion coating film (hereinafter also referred to as "this coating film") according to one embodiment of the present invention can be formed using the above-mentioned composition. Specifically, it can be formed by drying (curing) the composition, and is usually formed on a substrate and used as a substrate with an anti-corrosion coating film.

[0171] There is no particular limitation on the material of the above-mentioned substrate, and examples can include ferrous metals (e.g., iron, steel, alloy iron, carbon steel, low-carbon steel, alloy steel), non-ferrous metals (e.g., zinc, aluminum), stainless steel, etc. The surface of the substrate can also be coated with a primer, etc.

[0172] In addition, when using low-carbon steel (such as SS400) as the above-mentioned substrate, it is preferably subjected to surface grinding, etc. by sandblasting, etc. as needed to perform substrate adjustment in advance (e.g., adjusting the arithmetic mean roughness (Ra) to about 30 to 75 μm).

[0173] The dry film thickness of this coating film is not particularly limited, but from the viewpoint of obtaining an anti-corrosion coating film with sufficient anti-corrosion properties, etc., it is usually 50 μm or more, preferably 200 μm or more, usually 500 μm or less, and preferably 400 μm or less.

[0174] As a method for forming this coating film, an anti-corrosion coating film with a desired film thickness can be formed by one-time coating (single coating) or by coating two or more times (multiple coatings). From the viewpoint of film thickness management and considering the residual organic solvents in the anti-corrosion coating film, it is preferable to form the anti-corrosion coating film by coating two or more times to achieve the desired dry film thickness.

[0175] The method for manufacturing an anti-corrosion coating film according to one embodiment of the present invention includes a step of drying the composition to form an anti-corrosion coating film. Specifically, it includes the following steps [1] and [2]. The method for manufacturing an anti-corrosion coating film including the following steps [1] and [2] can also be said to be a method for manufacturing a substrate with an anti-corrosion coating film.

[0176] Step [1]: A step of coating the present composition on a substrate

[0177] Step [2]: A step of drying the coated present composition to form an anti-corrosion coating film <Step [1]>

[0178] There is no particular limitation on the coating method in the above Step [1]. For example, it can be coated on the surface of the substrate by conventional methods such as airless spraying, air spraying, brush coating, roll coating, etc. However, in the case of coating large structures such as tanks, from the viewpoint of being able to easily coat a large area of the substrate, spraying is preferred.

[0179] It should be noted that during the coating operation, the present composition can be appropriately diluted with a diluent (organic solvent), etc. and then used. However, in such a case of dilution, it is also preferred that the VOC content in the diluted composition is 200 g / L or less.

[0180] The above spraying conditions can be appropriately adjusted according to the dry film thickness to be formed. For example, in the case of airless spraying, it is preferably the primary (air) pressure: about 0.4 - 0.8 MPa, the secondary (paint) pressure: about 15 - 36 MPa, and the spray gun moving speed: about 50 - 120 cm / second.

[0181] In addition, the coating can be carried out in such a way that the dry film thickness of the obtained anti-corrosion coating film reaches the above range.

[0182] Regarding the viscosity of the present composition suitable for spraying, using an E-type viscometer (manufactured by TOKIMEC INC., FMD type), the viscosity under the measurement conditions of 23°C is preferably 1500 - 7000 mPa·s, and more preferably 1500 - 4000 mPa·s.

[0183] <Step [2]>

[0184] There is no particular limitation on the drying conditions in the above Step [2], and they can be appropriately set according to the anti-corrosion coating film formation method, the type of substrate, the use, the coating environment, etc. However, for example, the conditions of 12 - 250 hours at 0 - 35°C can be cited. In addition, forced drying and curing can be carried out by heating and air supply as needed, but usually drying and curing are carried out under natural conditions.

[0185] Since the present composition has excellent low-temperature film-forming properties, it can be dried at a temperature of 10°C or lower, and further at a temperature lower than 10°C, especially at a temperature of 5°C or lower. From the viewpoint of being able to exert the effects of the present invention more compared with the existing compositions, it is preferred to carry out drying at these temperatures.

[0186] Since this composition can also be dried at such a temperature, it is applicable when coating substrates that cannot be heated or are not easily heated. For such substrates, even when coating is carried out at low temperatures such as in winter, a desired anti-corrosion coating film can be formed.

[0187] It should be noted that in the case of forming an anti-corrosion coating film by the above-mentioned coating two or more times, especially by two coatings, after performing steps [1] and [2], a series of steps of repeating steps [1] and [2] in sequence are carried out on the obtained coating film to form an anti-corrosion coating film. In addition, in the case of forming an anti-corrosion coating film by three coatings, for the coating film after two coatings, a series of steps of repeating steps [1] and [2] in sequence are carried out to form an anti-corrosion coating film.

[0188] Examples

[0189] Hereinafter, suitable embodiments of the present invention will be described in more detail based on the examples, but the present invention is not limited to these examples.

[0190] [Examples 1 to 20 and Comparative Examples 1 to 6]

[0191] In a container, the respective materials described in the main agent component columns of Tables 1 to 2 were mixed at the values (parts by mass) described in each column, and stirred with a high-speed disperser at room temperature (23°C) until uniform, and then dispersed at 56 to 60°C for about 30 minutes. Then, it was cooled to below 30°C to prepare the main agent component of the anti-corrosion coating composition.

[0192] In addition, in a container, the respective materials described in the curing agent component columns of Tables 1 to 2 were mixed at the values (parts by mass) described in each column, and these components were mixed using a high-speed disperser at normal temperature and normal pressure to prepare the curing agent component.

[0193] These main agent components and curing agent components were mixed before coating to prepare an anti-corrosion coating composition.

[0194] It should be noted that the descriptions of the respective components described in Tables 1 to 2 are shown in Table 3.

[0195] <Non-volatile component>

[0196] 1 g of the prepared anti-corrosion coating composition (the composition just after mixing the main agent component and the curing agent component) was collected in a flat dish, evenly spread with a metal needle of known mass (xg), left at 23°C for 24 hours, and then dried at 110°C for 1 hour. Then, the mass (yg) of the heated residue and the metal needle was measured.

[0197] The non-volatile component (mass%) of the anti-corrosion coating composition was calculated by the following formula.

[0198] Non-volatile content of anti-corrosion coating composition = (y-x) x 100

[0199] <Low-temperature film-forming properties>

[0200] Prepared SS400 sandblasted steel plates (arithmetic mean roughness (Ra): 30-75 μm) with a size of 150 mm × 70 mm × 2.3 mm (thickness). On the surface of the steel plate, each anticorrosive coating composition prepared as described above was applied by airless spraying to a dry film thickness of 300 μm. Afterwards, the state of the anticorrosive coating film after drying for one day at 5°C and 50% RH was evaluated based on the following criteria. A low-temperature film-forming property evaluation of 2 or higher is considered to be practically problem-free.

[0201] (Evaluation Criteria)

[0202] 5: No wrinkles are generated on the anti-corrosion coating

[0203] 4: The wrinkle area is less than 1% of the entire surface of the anti-corrosion coating

[0204] 3: The wrinkle area of the entire surface of the anti-corrosion coating is 1% or more and less than 5%

[0205] 2: The wrinkle area of the entire anti-corrosion coating is 5% or more and less than 10%

[0206] 1: The area of wrinkles on the entire surface of the anti-corrosion coating is more than 10%

[0207] [Test board preparation]

[0208] Each coating composition was applied in the same manner as described above for low-temperature film-forming properties and then dried at 23°C and 50% RH for 10 days to produce steel plates (test plates) with anticorrosion coatings. Each test plate was subjected to the following tests. The results are shown in Tables 1 and 2.

[0209] Corrosion resistance

[0210] The corrosion resistance of the obtained anticorrosive coating film was tested with reference to JIS K 5600-6-1:2016 (Test method for liquid resistance).

[0211] On each test board Figure 1 Cut the cut 2 from the anti-corrosion coating side to the steel plate at the position shown. Place the test plate 1 with the cut 2 side facing down (with the cut 2 side facing down). Figure 1The (indicated orientation) was immersed in 3% saline solution at 40 °C for 90 days. After immersion, 11 incisions 3 were made upward from the left end of the notch 2 at 5-mm intervals to equally divide the notch 2. In the 10 measurement parts 4 between the incisions 3, the peeling length (length from the notch 2) of the steel plate and the anticorrosive coating film was measured. The average value of the measured peeling lengths at 10 places was evaluated based on the following criteria. When the evaluation of anticorrosion is 2 or more, it can be said that there is no problem in practical use.

[0212] (Evaluation criteria)

[0213] 4: The peeling length is less than 5 mm

[0214] 3: The peeling length is 5 mm or more and less than 10 mm

[0215] 2: The peeling length is 10 mm or more and less than 15 mm

[0216] 1: The peeling length is 15 mm or more <Oil resistance>

[0217] The oil resistance of the obtained anticorrosive coating film was tested with reference to JIS K 5600-6-1:2016 (Test method for liquid resistance).

[0218] Each test plate prepared was immersed in naphtha at room temperature for 180 days. The immersed test plates were evaluated based on the following criteria. Note that the pencil hardness was measured based on JIS K5600-5-4:1999. When the evaluation of oil resistance is 3 or more, it can be said that there is no problem in practical use.

[0219] (Evaluation criteria)

[0220] 6: The steel plate did not rust, the coating film did not bulge, and the pencil hardness of the coating film was H or more (H, 2H, 3H...).

[0221] 5: The steel plate did not rust, the coating film did not bulge, and the pencil hardness of the coating film was HB to F.

[0222] 4: The steel plate did not rust, the coating film did not bulge, and the pencil hardness of the coating film was B to 4B.

[0223] 3: The steel plate did not rust, the coating film did not bulge, and the pencil hardness of the coating film was 5B or less (5B, 6B, 7B...).

[0224] 2: The steel plate rusted slightly and the coating film bulged.

[0225] 1: The steel plate rusted and the coating film bulged [Table 1]

[0226]

[0227] [Table 2]

[0228]

[0229] [Table 3]

[0230]

[0231] The anti-corrosion coating composition obtained in the above embodiments is a high-solids anti-corrosion coating composition, which can not only form an anti-corrosion coating film with excellent oil resistance and corrosion resistance, but also has excellent low-temperature film-forming properties. In addition, the anti-corrosion coating film obtained from the anti-corrosion coating composition of the above embodiments is considered to have excellent solvent resistance and chemical resistance.

[0232] Symbol Explanation

[0233] 1: test plate; 2: notch; 3: incision; 4: measurement part.

Claims

1. An anti-corrosion coating composition, characterized in that, contain: Epoxy compound (A), Amine curing agent (B), and Alkylamine (C).

2. The anticorrosion coating composition according to claim 1, wherein: The alkylamine (C) is liquid at room temperature.

3. The anticorrosion coating composition according to claim 1, wherein: The alkylamine (C) is a primary amine represented by R—NH 2 , wherein R is an alkyl group having 1 to 20 carbon atoms.

4. The anticorrosion coating composition according to claim 1, wherein: The amine curing agent (B) contains an amine curing agent having a cyclic structure.

5. The anti-corrosion coating composition according to claim 1, wherein: The epoxy compound (A) has an epoxy equivalent of 200 or less, and is liquid at room temperature.

6. The anticorrosion coating composition according to claim 1, wherein: The amine curing agent (B) is liquid at room temperature.

7. The anticorrosion coating composition according to claim 1, wherein: The content of the non-volatile component is 90% by mass or more.

8. An anti-corrosion coating, characterized in that: The anticorrosion coating composition is formed from the anticorrosion coating composition according to any one of claims 1 to 7.

9. A method for manufacturing an anti-corrosion coating film, characterized in that, include: A step of drying the anticorrosion coating composition according to any one of claims 1 to 7 at a temperature of 10°C or lower to form an anticorrosion coating film.

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