Tie coat composition or anticorrosive coating composition and coating film

Abstract

One embodiment of the present invention relates to a tie coat composition or an anticorrosive coating composition, or a coating film. The tie coat composition or the anticorrosive coating composition contains: a first agent containing a phenoxy resin (A) that is a resin containing a structure represented by formula (1) and a structure represented by formula (2); and a second agent containing an amine-based curing agent (B). R represents a hydrocarbon group having 10-18 carbon atoms, l represents an integer of 1-10, X represents a divalent linking group having 1-10 carbon atoms, R represents a hydrocarbon group having 10-18 carbon atoms, and m represents an integer of 1-10.

Description

Tycoat composition or anticorrosive paint composition and coating film

[0001] One embodiment of the present invention relates to a tiecoat composition or a corrosion-resistant coating composition, or a coating film.

[0002] Conventionally, large steel structures such as ships, bridges, tanks, plants, buoys, and underwater pipelines have been coated with a coating film obtained from epoxy resin-based coating compositions to prevent corrosion. On top of such coatings, various resin-based topcoat coating compositions are applied to provide functions such as aesthetic appeal, weather resistance, corrosion resistance, and antifouling properties, depending on the use and purpose of the steel structure, thereby forming a topcoat coating film. For example, an antifouling coating composition is applied as a topcoat coating composition to the bottom of a ship to prevent the attachment of aquatic organisms such as barnacles and seaweed.

[0003] Generally, primer films formed from epoxy resin-based paint compositions have poor weather resistance, which can easily lead to a decrease in interlayer adhesion with the topcoat film and a reduction in the physical properties of the laminate with the topcoat film (reduced suitability for topcoat application). In particular, if the interval between the application of the epoxy resin-based paint composition primer and the application of the topcoat is long, there is a problem in that the interlayer adhesion (interval adhesion) between the formed primer and topcoat films becomes insufficient.

[0004] To address these previous problems, various epoxy resin coating compositions have been proposed. Patent Document 1 discloses an epoxy resin coating composition containing a vinyl chloride copolymer, and Patent Document 2 discloses an epoxy resin coating composition containing an ethylene vinyl acetate copolymer.

[0005] Japanese Patent Publication No. 10-259351 Japanese Patent Publication No. 2009-197106

[0006] Conventional epoxy resin coating compositions described in Patent Documents 1 and 2, among others, had room for improvement in terms of interval adhesion. Furthermore, in order to improve the adhesion between the substrate or undercoat and the topcoat, a tie coat (also called a bonding coating) is sometimes formed between the substrate or undercoat and the topcoat, and interval adhesion was also required for such a tie coat.

[0007] One embodiment of the present invention provides a tie-coat composition or anticorrosive coating composition that can form a coating film with excellent interval adhesion properties.

[0008] An example of the configuration of the present invention is as follows. In this specification, "A to B" indicating a numerical range means A or greater and B or less.

[0009] [1] A tiecoat composition or anticorrosion coating composition comprising a first agent containing a phenoxy resin (A) and a second agent containing an amine-based curing agent (B), wherein the phenoxy resin (A) is a resin comprising a structure represented by the following formula (1) and a structure represented by the following formula (2).

[0010] In formula (1), R is independently a hydrocarbon group having 10 to 18 carbon atoms, and l is an integer from 1 to 10.

[0011] In formula (2), X is independently a divalent linking group having 1 to 10 carbon atoms, R is independently a hydrocarbon group having 10 to 18 carbon atoms, and m is an integer from 1 to 10.

[0012] [2] The composition according to [1], wherein R in formulas (1) and (2) is a hydrocarbon group having 12 to 16 carbon atoms. [3] The composition according to [1] or [2], wherein the structure represented by formula (1) is a structure derived from cardanol.

[0013] [4] A composition according to any one of [1] to [3], which contains a pigment. [5] A composition according to [4], which contains particulate solids, wherein the volume concentration (PVC) of the particulate solids is 20 to 50%.

[0014] [6] The composition according to any one of [1] to [5], wherein the first agent contains an epoxy resin other than the phenoxy resin (A). [7] The composition according to [6], wherein the solid content of the phenoxy resin (A) is 15 to 95% by mass with respect to 100% by mass of the total solid content of the phenoxy resin (A) and the epoxy resin.

[0015] [8] A coating film formed from any of the compositions described in [1] to [7].

[0016] According to one embodiment of the present invention, a coating film with excellent interval adhesion can be formed. Furthermore, according to one embodiment of the present invention, a coating film that is less prone to stickiness and has a good balance of excellent drying and curing properties, water resistance to whitening, discoloration resistance, corrosion resistance, damage resistance, flexibility resistance, and interval adhesion can be formed.

[0017] Figure 1 is a schematic diagram showing the evaluation criteria for damage resistance testing in the examples.

[0018] <<Tie Coat Composition or Anticorrosion Paint Composition>> A tie coat composition or anticorrosion paint composition according to one embodiment of the present invention (hereinafter also referred to as "this composition") contains a first agent containing a phenoxy resin (A) and a second agent containing an amine-based curing agent (B), wherein the phenoxy resin (A) is a resin containing a structure represented by the following formula (1) and a structure represented by the following formula (2). The tie coat composition is a composition that forms tie coat, and can also be called a tie coat composition. The anticorrosion paint composition is a composition that forms an anticorrosion coating film, and can also be called an anticorrosion paint composition.

[0019] This composition can be obtained by mixing the first agent and the second agent, and can also be described as a kit for a tiecoat composition or anticorrosive coating composition containing the first agent and the second agent. This composition may optionally contain an nth agent (n is 3 or more) other than the first agent and the second agent, but it is preferable that it does not contain such nth agent. In other words, this composition may be a two-component or more composition, but it is preferable that it is a two-component composition.

[0020] The components of this composition, namely the first, second, and nth components, are usually stored, transported, etc., in separate containers and mixed immediately before use.

[0021] The solid content in this composition is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and there is no particular upper limit, but for example it is 90% by mass. The solid content in this composition corresponds to the heating residue rate shown below. The solid content of this composition can also be calculated as the total amount of components other than the solvent and dispersion medium (e.g., water) in the first and second agents, which are raw materials constituting the first agent, the second agent, etc. (e.g., phenoxy resin (A)), and which have a boiling point of less than 180°C at normal pressure. When the solid content in this composition is within the above range, it is possible to easily obtain a composition that has excellent drying properties, is less prone to dripping during painting, can form a thick film in a single coat, and has excellent paintability.

[0022] The composition is preferably an organic solvent-based agent containing an organic solvent, and more preferably a composition that is substantially water-free (no water is added when preparing the composition). The VOC (volatile organic compound) content in the composition is preferably 10 to 600 g / L, more preferably 20 to 500 g / L.

[0023] The VOC content in this composition can be calculated using the following formula (II), based on the composition's specific gravity and the heat residue ratio (mass ratio of solids). The composition's specific gravity and heat residue ratio may be measured values ​​or values ​​calculated from the raw materials used. VOC content (g / L) = Composition's specific gravity × 1000 × (100 - heat residue ratio) / 100 ... (II)

[0024] Composition specific gravity (g / cm ３ ): A value calculated by filling a 100 mL specific gravity cup with the composition (the composition immediately after mixing the first agent, the second agent, and (if the nth agent is included, the nth agent) under a temperature of 23°C, and weighing the mass of the composition.

[0025] Heating residue ratio (mass %): Weigh 1 ± 0.1 g of the composition (the composition immediately after mixing the first agent, the second agent, and (if the nth agent is included, the nth agent)) into a flat-bottom dish, spread it evenly using a wire of known mass, dry it at 23°C for 24 hours, and then measure the mass of the heating residue (solid content [non-volatile content]) and the mass of the wire when heated at a heating temperature of 125°C for 1 hour (under normal pressure). The value of the mass percentage calculated in this way is what is referred to as the "solid content of the composition" in this specification. In this specification, among the components (e.g., phenoxy resin (A)) that are raw materials constituting the first agent, the second agent, etc., components other than solvents and dispersion media (e.g., water) with a boiling point of less than 180°C under normal pressure in the first agent, and in the second agent are referred to as "solid content".

[0026] <First agent>The first agent contains phenoxy resin (A). The first agent is preferably prepared in the following step 1.

[0027] [Phenoxy resin (A)] Phenoxy resin (A) contains a structure represented by the following formula (1) and a structure represented by the following formula (2). The phenoxy resin (A) used in the composition may be one kind or two or more kinds.

[0028]

[0029] In formula (1), R is independently a hydrocarbon group having 10 to 18 carbon atoms, and l is an integer of 1 to 10. If R is a hydrocarbon group having 10 to 18 carbon atoms, a coating film having flexibility and followability to the topcoat film can be easily formed, and a coating film excellent in interval adhesion can be formed.

[0030] The hydrocarbon group having 10 to 18 carbon atoms in R in the formula (1) may be linear or branched, and may be saturated or unsaturated. R in the formula (1) is preferably independently a hydrocarbon group having 11 to 17 carbon atoms, and more preferably a hydrocarbon group having 12 to 16 carbon atoms from the viewpoint of easily forming a coating film excellent in interval adhesion, etc. When l is an integer of 2 or more, the plurality of Rs may be the same or different, but from the viewpoint of easy synthesis of the phenoxy resin (A), etc., the plurality of Rs are preferably the same.

[0031] The structure represented by formula (1) is preferably a structure derived from cardanol, from the viewpoint of imparting interval adhesion to the formed coating film and from the viewpoint of the availability of the corresponding raw materials. An example of the cardanol-derived structure is a structure in which R in formula (1) is a hydrocarbon group having 15 carbon atoms and 25 to 31 hydrogen atoms.

[0032] In formula (1), l represents the number of constituent units expressed in parentheses in formula (1) in the phenoxy resin (A). The constituent units expressed in parentheses in formula (1) may exist in continuous blocks in the phenoxy resin (A) or may exist randomly.

[0033]

[0034] In formula (2), X is independently a divalent linking group having 1 to 10 carbon atoms, R is independently a hydrocarbon group having 10 to 18 carbon atoms, and m is an integer from 1 to 10. If X is independently a divalent linking group having 1 to 10 carbon atoms, the spatial distance and relative arrangement of the aromatic ring skeleton bonded to X do not change significantly, and it is considered that the rigidity and steric hindrance derived from the aromatic skeleton can be largely maintained, thus producing equivalent effects on the free volume, chemical resistance, and heat resistance of the phenoxy resin (A) as a whole. Furthermore, if m is an integer from 1 to 10, the chemical properties unique to the skeleton enclosed in [ ] are expressed, so it is considered that equivalent effects are produced when m is 1 and when m is 10. Note that if m becomes excessively large beyond 10, the molecular weight of the phenoxy resin (A) becomes excessively large, leading to an increase in resin viscosity, which may make it difficult to handle the composition when preparing it or when coating it.

[0035] When m is an integer of 2 or more, the multiple Rs may be the same or different, but it is preferable that they be the same, for example, because it facilitates the synthesis of the phenoxy resin (A). When m is an integer of 2 or more, the multiple Xs may be the same or different, but it is preferable that the multiple Xs are the same, for example, because it facilitates the synthesis of the phenoxy resin (A).

[0036] In formula (2), the hydrocarbon group having 10 to 18 carbon atoms in R may be linear or branched, and may be saturated or unsaturated. In formula (2), R is preferably a hydrocarbon group having 11 to 17 carbon atoms, and a hydrocarbon group having 12 to 16 carbon atoms is more preferred because it allows for the easy formation of a coating film with excellent interval adhesion.

[0037] The structure represented by formula (2) is preferably a structure derived from cardanol, from the viewpoint of imparting interval adhesion to the formed coating film and from the viewpoint of the availability of the corresponding raw materials. An example of the cardanol-derived structure is a structure in which R in formula (2) is a hydrocarbon group having 15 carbon atoms and 25 to 31 hydrogen atoms.

[0038] The divalent linking group having 1 to 10 carbon atoms in X in formula (2) above may be linear or branched, saturated or unsaturated, and may have a cyclic structure. The divalent linking group having 1 to 10 carbon atoms may have substituents, such as alkyl groups, alkoxy groups, hydroxyl groups, alkoxy-substituted alkyl groups, and carboxyl groups.

[0039] In formula (2), the divalent linking group having 1 to 10 carbon atoms in X specifically includes hydrocarbon groups having 1 to 10 carbon atoms, such as alkylene groups, alkenylene groups, alkylylene groups, cycloalkylidene groups, and aryl groups, and groups in which a portion of the hydrocarbon group is substituted with atoms other than carbon, such as oxygen atoms, nitrogen atoms, and halogen atoms. Among the hydrocarbon groups, alkylene groups having 3 to 7 carbon atoms are preferred from the viewpoint of the availability of the corresponding raw materials.

[0040] -O in formula (2) above ２ -ph-X-ph-O １ Structures represented by -(ph:phenylene group) include, for example, structures derived from bisphenols (e.g., bisphenol A, AP, AF, B, BP, E, F).

[0041] In the above formula (2), O １This may be in the ortho, meta, or para position relative to X, O ２ The position of X may be ortho, meta, or para, but from the standpoint of the availability of the corresponding raw materials, it is preferable that it be in the para position relative to X.

[0042] In formula (2), m represents the number of constituent units expressed in parentheses in formula (2) in the phenoxy resin (A). The constituent units expressed in parentheses in formula (2) may be present in continuous blocks in the phenoxy resin (A) or may be present randomly.

[0043] The weight-average molecular weight (Mw) of the phenoxy resin (A) is preferably 1,000 to 20,000, more preferably 2,000 to 10,000. This Mw is measured, for example, as a polystyrene equivalent value by gel permeation chromatography (GPC).

[0044] The solid content of phenoxy resin (A) is preferably 3 to 40% by mass, more preferably 5 to 35% by mass, based on 100% by mass of the solid content of the composition. Furthermore, the solid content of phenoxy resin (A) is preferably 4 to 40% by mass, more preferably 6 to 35% by mass, based on 100% by mass of the solid content of the first agent. When the phenoxy resin (A) content is within the above range, a coating film with excellent interval adhesion can be easily formed.

[0045] • Method for synthesizing phenoxy resin (A) Phenoxy resin (A) can be synthesized, for example, by a method including step a in which at least one compound represented by the following formula (3) and at least one compound represented by the following formula (4) are reacted in the presence of a base. In step a, the hydroxyl group of the compound represented by the following formula (3) and the epoxy group of the compound represented by the following formula (4) react to synthesize phenoxy resin (A). After performing step a, the resin may be purified by a known method or not, but the former is more preferred.

[0046]

[0047] In formula (3), R is independently synonymous with R in the above formula (1), and n is an integer from 2 to 20.

[0048] As the compound represented by the above formula (3), a commercially available product may be used, or it may be synthesized by, for example, the following method.

[0049] As a method for synthesizing the compound represented by the above formula (3), for example, a method including step b of reacting at least one compound represented by the following formula (5) in the presence of an acid catalyst can be mentioned. After performing the above step b, it may be purified by a known method or may not be purified, but the former is more preferable.

[0050]

[0051] In formula (5), R １ is an unsaturated hydrocarbon group having 10 to 18 carbon atoms.

[0052] The R in the above formula (5) １ The unsaturated hydrocarbon group having 10 to 18 carbon atoms may be linear or branched-chain. The R in the above formula (5) １ is preferably an unsaturated hydrocarbon group having 11 to 17 carbon atoms, and more preferably an unsaturated hydrocarbon group having 12 to 16 carbon atoms in terms of easily forming a coating film with excellent interval adhesion.

[0053] The R in the above formula (5) １ is preferably a hydrocarbon group having 15 carbon atoms and 25 to 29 hydrogen atoms from the viewpoints of imparting interval adhesion to the formed coating film and easy availability of the corresponding raw materials. That is, the compound represented by the above formula (5) is preferably cardanol (a compound having a cardanol structure).

[0054] As the acid catalyst, known catalysts can be used, such as inorganic acids like sulfuric acid, hydrochloric acid, and nitric acid, or organic acids like acetic acid, citric acid, propionic acid, oxalic acid, and p-toluenesulfonic acid. Among these, p-toluenesulfonic acid is preferred in terms of catalytic activity and solubility in solution. One type of acid catalyst may be used, or two or more types may be used. The amount of acid catalyst used is, for example, about 0.1 to 4 parts by mass per 100 parts by mass of the compound represented by formula (5).

[0055] The reaction temperature in step b is, for example, about 120 to 180°C. The reaction time is, for example, about 1 to 10 hours.

[0056] Furthermore, the acquisition of the target compound represented by formula (3) can be confirmed, for example, by using GPC to observe a decrease in the peak derived from formula (5) and the appearance of a new peak.

[0057]

[0058] In equation (4), X is the same as X in equation (2).

[0059] In the above formula (4), O １ This may be in the ortho, meta, or para position relative to X, O ２ The position of X may be ortho, meta, or para, but from the standpoint of the availability of the corresponding raw materials, it is preferable that it be in the para position relative to X.

[0060] In step a, the mass ratio of the compound represented by formula (3) to the compound represented by formula (4) (compound represented by formula (3):compound represented by formula (4)) is preferably 1:0.7 to 1.5, from the viewpoint that a coating film with excellent coating film properties can be easily formed.

[0061] The base is not particularly limited, but examples include alkali metal hydrides, alkaline earth metal hydrides, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates, alkaline earth metal carbonates, alkali metal bicarbonates, alkali metal alkoxides, alkaline earth metal alkoxides, alkali metal fluorides, amines, and organophosphorus compounds. One base may be used, or two or more may be used. The amount of base used varies depending on the type of base, but is, for example, about 0.1 to 2.0 parts by mass per 100 parts by mass of the compound represented by formula (3).

[0062] In step a, a solvent may be used. The solvent is not particularly limited, but preferred examples include water, alcohols such as methanol, ethanol, and 2-propanol, aprotic polar solvents such as dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran, dioxane, methyl ethyl ketone, methyl isobutyl ketone, acetonitrile, methylene chloride, and dimethylformamide, aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, chloroform, and carbon tetrachloride. One solvent may be used, or two or more may be used. The amount of solvent used is, for example, about 30 parts by mass or less per 100 parts by mass of the compound represented by formula (3).

[0063] The reaction temperature in step a is, for example, about 60 to 120°C. The reaction time is, for example, about 1 to 10 hours. The fact that the target phenoxy resin (A) has been obtained can be confirmed, for example, by using GPC to observe the decrease in the peak originating from the raw material (e.g., the compound represented by formula (4)) and the appearance of a new peak.

[0064] [Other Components] The first agent may optionally contain other components besides the phenoxy resin (A), to the extent that it does not impair the effects of the present invention, such as pigments, epoxy resins, reactive diluents, vinyl (co)polymers, silane coupling agents, defoaming agents, viscosity modifiers (anti-sagging agents, anti-settling agents, thixotropes), curing accelerators, dehydrating agents, plasticizers, (pigment) dispersants, film-forming aids, organic solvents, and other components. Each of these other components may be used individually or in combination of two or more.

[0065] Pigments Examples of pigments include extender pigments, coloring pigments, and rust-preventive pigments, and may be organic or inorganic. One type of pigment may be used, or two or more types may be used.

[0066] Examples of the aforementioned extender pigments include talc, mica, (precipitating) barium sulfate, (potassium) feldspar, kaolin, alumina white, bentonite, wollastonite, clay, glass flakes, aluminum flakes, magnesium carbonate, barium carbonate, calcium carbonate, dolomite, and silica. Talc, mica, silica, (precipitating) barium sulfate, and (potassium) feldspar are particularly preferred.

[0067] If the composition contains an extender pigment, the amount of the extender pigment is preferably 30 to 90% by mass, more preferably 50 to 70% by mass, based on 100% by mass of the solid content of the composition.

[0068] Examples of the coloring pigments include inorganic pigments such as carbon black, titanium dioxide (titanium white), iron oxide (red iron oxide), yellow iron oxide, flaky iron oxide, and ultramarine, as well as organic pigments such as cyanine blue and cyanine green. Titanium white, carbon black, and red iron oxide are particularly preferred.

[0069] If the composition contains a coloring pigment, the amount of the coloring pigment is preferably 1 to 30% by mass, more preferably 1 to 15% by mass, based on 100% by mass of the solids content of the composition.

[0070] Examples of the rust-preventive pigments include zinc powder, zinc alloy powder, zinc phosphate compounds, calcium phosphate compounds, aluminum phosphate compounds, magnesium phosphate compounds, zinc phosphite compounds, calcium phosphite compounds, aluminum phosphite compounds, strontium phosphite compounds, aluminum tripolyphosphate compounds, molybdate compounds, zinc cyanamide compounds, borate compounds, nitro compounds, and complex oxides.

[0071] If the composition contains a rust-preventive pigment, the amount of the rust-preventive pigment is preferably 0.5 to 20% by mass, more preferably 1 to 10% by mass, based on 100% by mass of the solid content of the composition.

[0072] When this composition contains particulate solids, the volume concentration of particulate solids (PVC) in this composition is preferably 20 to 50%, more preferably 30 to 50%. When the PVC is within this range, this composition with excellent paintability can be easily obtained, and a coating film with excellent adhesion to the substrate and undercoat film, as well as corrosion resistance, can be easily formed due to stress relaxation.

[0073] The PVC in the composition refers to the volume concentration of the total particulate solids in the composition relative to the volume of the solids in the composition. Particulate solids refer to solid particles containing the pigment and the following dehydrating agents (e.g., synthetic zeolite, anhydrous gypsum, hemihydrate gypsum), thixotropes, etc. The PVC can be specifically calculated using the following formula: PVC in the composition [%] = Total volume of all particulate solids in the composition × 100 / Volume of solids in the composition

[0074] The volume of the solid content of the composition can be calculated from the mass and true density of the solid content of the composition. The mass and true density of the solid content may be measured values ​​or values ​​calculated from the raw materials used. The volume of the particulate solid can be calculated from the mass and true density of the particulate solid used. The mass and true density of the particulate solid may be measured values ​​or values ​​calculated from the raw materials used. For example, it can be calculated by separating the particulate solid from other components from the solid content of the composition and measuring the mass and true density of the separated particulate solid.

[0075] Epoxy resin The epoxy resin is a compound other than the phenoxy resin (A). The epoxy resin is not particularly limited, but examples include polymers or oligomers containing two or more epoxy groups in the molecule, and polymers or oligomers produced by the ring-opening reaction of the epoxy groups. One type of epoxy resin may be used, or two or more types may be used.

[0076] Examples of epoxy resins include glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, glycidylamine type epoxy resins, bisphenol type epoxy resins, phenol novolac type epoxy resins, cresol type epoxy resins, dicyclopentadiene type epoxy resins, aliphatic epoxy resins, alicyclic epoxy resins, and fatty acid modified epoxy resins.

[0077] In one embodiment of the present composition, it is preferable that it contains the compound represented by formula (4). In this case, when preparing the present composition, a phenoxy resin (A) containing the unreacted compound represented by formula (4) synthesized by the method including step a may be used.

[0078] Among these, bisphenol-type epoxy resins are preferred because they can easily form coatings with excellent adhesion to substrates and undercoat films, and one or more selected from bisphenol A-type and bisphenol F-type epoxy resins are more preferred, with bisphenol A-type epoxy resins being particularly preferred.

[0079] Examples of the bisphenol A type epoxy resin include polycondensates of bisphenol A type diglycidyl ethers. Examples of the bisphenol A type diglycidyl ethers include bisphenol A diglycidyl ether, bisphenol A (poly)ethylene oxide diglycidyl ether, and bisphenol A (poly)propylene oxide diglycidyl ether.

[0080] Bisphenol A type epoxy resins are graded according to their structure and physical properties. In one embodiment of the epoxy resin, it is preferable to use epoxy resin of grade 1001 or higher, as it tends to easily form a coating film with excellent damage resistance, and it is preferable to use epoxy resin of grade 834 or lower, as it allows for easy acquisition of a composition with excellent paintability, and it is preferable to use epoxy resin of grade 1001 or higher and epoxy resin of grade 834 or lower in combination, as it allows for both of these effects to be achieved. Examples of epoxy resins of grade 1001 or higher include epoxy resins of grades 1001, 1002, 1003, 1004, 1007, 1009, and 1010, and examples of epoxy resins of grade 834 or lower include epoxy resins of grades 834, 828, and 827.

[0081] When using epoxy resin of grade 834 or lower and epoxy resin of grade 1001 or higher, the solid content of the epoxy resin of grade 834 or lower relative to 100% by mass of the total solid content of these resins is preferably 10 to 99% by mass, more preferably 30 to 90% by mass. When the content of epoxy resin of grade 834 or lower is within this range, it tends to be possible to easily form a coating film with excellent adhesion to the substrate and undercoat film.

[0082] At room temperature (15 to 25°C, the same applies hereinafter), the epoxy resin may be in either a liquid or solid state, but a semi-solid or solid epoxy resin is preferred.

[0083] Furthermore, the epoxy equivalent of the epoxy resin is preferably 150 to 1,000, more preferably 150 to 600, and particularly preferably 180 to 500. In this specification, the epoxy equivalent is calculated in accordance with JIS K 7236:2001 (perchloric acid titration method).

[0084] When using commercially available raw materials (e.g., epoxy resin or amine-based curing agent (B)) in each composition described herein, the equivalent values ​​of each raw material (e.g., epoxy equivalent or active hydrogen equivalent) may be those listed in the catalog of the commercially available product. Note that the equivalent values ​​may be listed as a numerical range in the catalog of the commercially available product. When using a commercially available product in which the equivalent value is listed as a numerical range, this specification uses the median value of that numerical range as the equivalent value of the commercially available product.

[0085] The viscosity of epoxy resin measured at 25°C using an E-type viscometer (TOKIMEC Corporation, FMD type, rotation speed: 60 rpm) is preferably 1,500 mPa·s or more, more preferably 3,000 mPa·s or more, preferably 120,000 mPa·s or less, and more preferably 30,000 mPa·s or less.

[0086] The epoxy resin may be a resin synthesized by a conventionally known method, or it may be a commercially available product. Examples of commercially available resins that are liquid at room temperature include "E-028" (manufactured by Ohtake Meishin Chemical Co., Ltd., bisphenol A type epoxy resin, epoxy equivalent 185, viscosity 12,000-15,000 mPa·s / 25℃), "jER807" (manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin, epoxy equivalent 170, viscosity 2,000-5,000 mPa·s / 25℃), and "Frep 60" (manufactured by Toray Fine Chemical Co., Ltd., bisphenol S type epoxy resin, epoxy equivalent 280, viscosity approximately 17,000 mPa·s / 25℃). An example of a commercially available resin that is semi-solid at room temperature is "jER834" (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent 250). Examples of commercially available resins that are solid at room temperature include "jER1001" (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent 475). In addition, solutions obtained by diluting the aforementioned semi-solid or solid epoxy resins with a solvent, such as "E-834-85X" (manufactured by Otake Meishin Chemical Co., Ltd., xylene solution of bisphenol A type epoxy resin (834 type epoxy resin solution), epoxy equivalent of the product 300) and "E-001-75X" (manufactured by Otake Meishin Chemical Co., Ltd., xylene solution of bisphenol A type epoxy resin (1001 type epoxy resin solution), epoxy equivalent of the product 630), can also be used.

[0087] When this composition contains an epoxy resin, the solid content of the epoxy resin is preferably 0.1 to 50% by mass, more preferably 1 to 30% by mass, based on 100% by mass of the solid content of this composition. When the epoxy resin content is within the above range, a coating film with excellent adhesion to the substrate and undercoat can be easily formed.

[0088] When the composition contains epoxy resin, the solid content of phenoxy resin (A) is preferably 15 to 95% by mass, more preferably 20 to 90% by mass, based on 100% by mass of the total solid content of phenoxy resin (A) and epoxy resin. When the composition is a tie-coat composition containing epoxy resin, the solid content of phenoxy resin (A) is preferably 15 to 95% by mass, more preferably 30 to 90% by mass, based on 100% by mass of the total solid content of phenoxy resin (A) and epoxy resin. Furthermore, when the composition is a corrosion-resistant coating composition containing epoxy resin, the solid content of phenoxy resin (A) is preferably 15 to 95% by mass, more preferably 20 to 90% by mass, based on 100% by mass of the total solid content of phenoxy resin (A) and epoxy resin. When the content of phenoxy resin (A) is within the above range, a coating film with excellent interval adhesion and flexibility can be easily formed.

[0089] • Reactive Diluent This composition may contain a reactive diluent. It is preferable to include a reactive diluent, for example, because it allows for easy acquisition of a low-viscosity composition. An epoxy group-containing reactive diluent is preferred as the reactive diluent. When using a reactive diluent that is reactive with the amine-based curing agent (B), such as an epoxy group-containing reactive diluent, it is preferable to incorporate the reactive diluent into the first agent. One type of reactive diluent may be used, or two or more types may be used.

[0090] The epoxy group-containing reactive diluent is a compound other than the phenoxy resin (A) and the epoxy resin. The epoxy group-containing reactive diluent is not particularly limited as long as it is an epoxy compound whose viscosity at 25°C, as measured by an E-type viscometer (TOKIMEC, FMD type, rotation speed: 60 rpm), is 500 mPa·s or less, and may be monofunctional or polyfunctional.

[0091] Examples of monofunctional epoxy group-containing reactive diluents include alkyl glycidyl ethers (preferred examples of alkyl groups: 1 to 13 carbon atoms), phenyl glycidyl ethers, o-cresyl glycidyl ethers, alkylphenyl glycidyl ethers (preferred examples of alkyl groups: 1 to 20 carbon atoms, preferably 1 to 5 carbon atoms, e.g., methylphenyl glycidyl ether, ethylphenyl glycidyl ether, propylphenyl glycidyl ether, p-tert-butylphenyl glycidyl ether), phenol glycidyl ethers, alkylphenol glycidyl ethers, and phenol (EO). ｎ Glycidyl ether (number of repetitions n = 3 to 20, EO: -C) ２ H ４ Examples include O-), alkylglycidyl esters (preferred examples of alkyl groups: 3 to 10 carbon atoms), and polyglycol glycidyl ethers.

[0092] Examples of polyfunctional epoxy group-containing reactive diluents include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, resorcinol diglycidyl ether, polyglycol diglycidyl ether, mono- or polyalkylene glycol diglycidyl ether (preferred examples of alkylene groups: 1 to 5 carbon atoms, e.g., ethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether), trimethylolpropane triglycidyl ether, alkyl diglycidyl ether, and alkyl diglycidyl ester. Preferred examples of the alkyl group include alkyl groups having 3 to 10 carbon atoms, specifically alkyl groups such as neopentyl group and 2-ethylhexyl group.

[0093] If the composition contains a reactive diluent, the solid content of the reactive diluent is preferably 0.1 to 15% by mass, more preferably 1 to 10% by mass, based on 100% by mass of the solid content of the composition. When the reactive diluent content is within the above range, a coating film with excellent oil resistance, solvent resistance, chemical resistance, and corrosion resistance can be easily formed, contributing to a reduction in the viscosity of the composition and an extension of its pot life.

[0094] The vinyl-based (co)polymer is not particularly limited, but examples include polyvinyl alkyl ether (co)polymers, vinyl chloride (co)polymers, and vinyl acetate (co)polymers. One vinyl-based (co)polymer may be used, or two or more may be used.

[0095] Examples of vinyl-based (co)polymers include polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl isopropyl ether, polyvinyl isobutyl ether, polyvinyl alcohol, polyvinyl acetal, vinyl chloride homopolymer, vinyl acetate homopolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl propionate copolymer, vinyl chloride-alkyl vinyl ether copolymer, vinyl chloride-acrylonitrile copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-maleic anhydride copolymer, vinyl chloride-(meth)acrylate alkyl copolymer (alkyl group: approximately 1 to 5 carbon atoms), vinyl chloride-styrene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-vinyl stearate copolymer, vinyl chloride-maleic acid (or maleic acid ester) copolymer, vinyl chloride-aliphatic vinyl copolymer, ethylene-vinyl acetate copolymer, and vinyl chloride-vinyl acetate-vinyl alcohol copolymer.

[0096] As the vinyl (co)polymer, compounds synthesized by conventionally known methods may be used, or commercially available products may be used. Examples of such commercially available products include "Lutanal M-40" (BASF, polyvinyl methyl ether), "Lutanal A-25" (BASF, polyvinyl ethyl ether), "Lutanal I-60" (BASF, polyvinyl isobutyl ether), "Esrec B BL-1", "Esrec B BL-2", "Esrec B BM-1", "Esrec B BM-2" (all manufactured by Sekisui Chemical Co., Ltd., polyvinyl acetal resin), and "UCAR Examples include "VAGH" (manufactured by Dow Chemical Japan Ltd., vinyl chloride-vinyl acetate-vinyl alcohol copolymer), "Laloflex MP-25" (manufactured by BASF, vinyl chloride-isobutyl vinyl ether copolymer [isobutyl vinyl ether content is less than 50% by mass]), "Evaflex EV-45X" (manufactured by Mitsui DuPont Polychemical Co., Ltd., ethylene-vinyl acetate copolymer), and "UltraCen 760" (manufactured by Tosoh Corporation, ethylene-vinyl acetate copolymer).

[0097] When the composition contains a vinyl-based (co)polymer, the solid content of the vinyl-based (co)polymer is preferably 0.1 to 10% by mass, more preferably 1 to 7% by mass, based on 100% by mass of the solid content of the composition. When the content of the vinyl-based (co)polymer is within the above range, a composition with superior paintability can be obtained, and a coating film with superior interval adhesion can be easily formed.

[0098] Furthermore, it is preferable not to include vinyl chloride-based (co)polymers in this composition, as this improves the yellowing resistance of the coating film under heating conditions and allows for the easy formation of a coating film with excellent weather resistance and appearance. Also, when vinyl chloride-based (co)polymers are included in this composition, a large amount of solvent is generally required, so it is preferable not to include vinyl chloride-based (co)polymers when aiming for a high-solids composition.

[0099] • Silane coupling agent: By using a silane coupling agent, not only can the adhesion of the resulting coating film to the substrate and undercoat film be further improved, but the corrosion resistance, saltwater resistance, and heat resistance of the resulting coating film can also be improved. One type of silane coupling agent may be used, or two or more types may be used.

[0100] The silane coupling agent is not particularly limited, and conventionally known compounds can be used. However, it is preferable that the compound has at least two functional groups within the same molecule and can contribute to improving adhesion to the substrate and reducing the viscosity of the composition.

[0101] Silane coupling agents include, for example, formula: "X-SiMe ｎ Y ３－ｎ It is preferable that the compound is represented by "[n is 0 or 1, X represents a functional group that can react with organic matter (e.g., amino group, vinyl group, epoxy group, mercapto group, halogeno group, a group in which part of a hydrocarbon group is substituted with these groups, or a group in which part of a hydrocarbon group is substituted with an ether bond, etc., and part of that group is substituted with these groups), Me is a methyl group, and Y represents a hydrolyzable group (e.g., alkoxy groups such as methoxy group and ethoxy group)].

[0102] When using a silane coupling agent that is reactive with an amine-based curing agent (B), such as an epoxy group-containing silane coupling agent, it is preferable to incorporate the silane coupling agent into the first agent. Furthermore, when using a silane coupling agent that is reactive with a phenoxy resin (A), such as an amino group-containing silane coupling agent, it is preferable to incorporate the silane coupling agent into the second agent.

[0103] Among the silane coupling agents, it is preferable that the X is an epoxy group-containing silane coupling agent in which X is an epoxy group, a group in which part of a hydrocarbon group is substituted with an epoxy group, or a group in which part of a hydrocarbon group is substituted with an ether bond or the like and part of it is substituted with an epoxy group.

[0104] Commercially available silane coupling agents may be used, and examples of such commercially available products include "KBM-403" (manufactured by Shin-Etsu Chemical Co., Ltd.), which is 3-glycidoxypropyltrimethoxysilane, and "Sylace S-510" (manufactured by JNC Corporation).

[0105] When the composition contains a silane coupling agent, the solid content of the silane coupling agent is preferably 0.1 to 10% by mass, more preferably 0.1 to 5% by mass, based on 100% by mass of the solid content of the composition. When the silane coupling agent content is within the above range, the viscosity of the composition can be reduced, which not only improves the paintability but also improves the adhesion, corrosion resistance, and heat resistance of the resulting coating film to the substrate and undercoat film.

[0106] - Defoaming agent: It is preferable that the composition contains a defoaming agent, as it can suppress the generation of foam during the manufacture or application of the composition, or can break the foam that has been generated in the composition, thereby easily forming a corrosion-resistant coating with desired physical properties. One type of defoaming agent may be used, or two or more types may be used.

[0107] Commercially available products may be used as the antifoaming agent, and examples of such products include "BYK-392", "BYK-066N", "BYK-1770", "BYK-1790" (all manufactured by Bic Chemie Japan Co., Ltd.), "TEGO Airex 902W" (manufactured by Evonik), and "Spectrasyn 40" (manufactured by Exxonmobil Chemical Company).

[0108] If the composition contains an antifoaming agent, the solid content of the antifoaming agent is preferably 0.005 to 3% by mass, more preferably 0.01 to 1% by mass, based on 100% by mass of the solid content of the composition. When the antifoaming agent content is within the above range, foam generation can be sufficiently suppressed, and a coating film with the desired physical properties can be easily formed.

[0109] • Viscosity modifier The viscosity modifier is not particularly limited, but it is preferable that it is a material that can suppress the settling of pigments, etc., in the composition and improve its storage stability, or a material that can improve the anti-sagging properties of the composition during and after painting. One type of viscosity modifier may be used, or two or more types may be used.

[0110] Examples of viscosity modifiers include conventionally known viscosity modifiers such as organic clay waxes like stearate salts, lecithin salts, and alkyl sulfonates of Al, Ca, and Zn; polyethylene wax; amide viscosity modifiers; amide neutralized salt viscosity modifiers; mixtures of amide viscosity modifiers; hydrogenated castor oil wax; mixtures of hydrogenated castor oil wax and amide wax; synthetic fine silica powder; oxidized polyethylene wax; and urea viscosity modifiers. Among these, amide viscosity modifiers, amide neutralized salt viscosity modifiers, and mixtures of amide viscosity modifiers are preferred because they can further improve the anti-sagging properties of the composition during and after painting.

[0111] Commercially available viscosity modifiers may be used, such as "Disparlon 305," "Disparlon 4200-20," "Disparlon 6650," and "Disparlon AQ600" from Kusumoto Chemical Co., Ltd., "A-S-A T-250F," "A-S-A T-950F," "A-S-A T-75F," "A-S-A TW-121," "A-S-A TW-123," and "A-S-A TW-124" from Ito Oil Co., Ltd., "Flonon RCM-300" from Kyoeisha Chemical Co., Ltd., "RHEOBYK-420" from Big Chemie Japan Co., Ltd., and "Benton" from Elementis Specialties, Inc. Examples include "SD-2", "Aerosil R972" from Nippon Aerosil Co., Ltd., and "Crayvallac Optima" and "Crayvallac REV" from Arkema Coating Resins Co., Ltd.

[0112] If the composition contains a viscosity modifier, the solid content of the viscosity modifier is preferably 0.01 to 10% by mass, more preferably 0.05 to 8% by mass, based on 100% by mass of the solid content of the composition. When the viscosity modifier content is within the above range, the composition with excellent storage stability can be easily obtained, and the composition with excellent (spray) coating workability and anti-sagging properties can be easily obtained.

[0113] Curing accelerators: Curing accelerators may be added to this composition as needed for purposes such as accelerating the drying and curing process when forming a coating film from this composition. Examples of such curing accelerators include polymerizable (meth)acrylate monomers (however, the monomer is a compound other than a polycarboxylic acid) and tertiary amines. When polymerizable (meth)acrylate monomers are used, they are added to the first agent, and when tertiary amines are used, they are added to the second agent, which will be described later. One type of curing accelerator may be used, or two or more types may be used.

[0114] Examples of commercially available polymerizable (meth)acrylate monomers include "M-CURE 100" (monofunctional aromatic acrylate, functional group equivalent 262), "M-CURE 200" (difunctional aromatic acrylate, functional group equivalent 135), "M-CURE 201" (difunctional aliphatic acrylate, functional group equivalent 100), "M-CURE 300" (trifunctional aliphatic acrylate, functional group equivalent 117), "M-CURE 400" (tetrafunctional aliphatic acrylate, functional group equivalent 85), and "M-CURE 400NS" (tetrafunctional aliphatic acrylate, functional group equivalent 85) (all manufactured by SARTOMER COMPANY, INC.).

[0115] Specific examples of the tertiary amines include triethanolamine, dialkylaminoethanol, triethylenediamine (1,4-diazabicyclo[2.2.2]octane), and 2,4,6-tris(dimethylaminomethyl)phenol. Commercially available products include, for example, "Ancamine K-54" (manufactured by Evonik, 2,4,6-tri(dimethylaminomethyl)phenol) and Hiescat HI-54K (manufactured by Keum Jung, tris-2,4,6-dimethylaminomethylphenol).

[0116] If the composition contains a curing accelerator, the solid content of the curing accelerator is preferably 0.05 to 5.0% by mass, more preferably 0.1 to 3.0% by mass, based on 100% by mass of the solid content of the composition.

[0117] - Dehydrating agent: Conventionally known dehydrating agents such as synthetic zeolite, anhydrous gypsum, hemihydrate gypsum (also known as calcined gypsum), alkyl orthoformate esters, and tetraethoxysilane can be used. One dehydrating agent may be used, or two or more may be used.

[0118] If the composition contains a dehydrating agent, the solid content of the dehydrating agent is preferably 0.1 to 30% by mass, more preferably 1 to 15% by mass, based on 100% by mass of the solid content of the composition. When the dehydrating agent content is within the above range, the increase in viscosity of the composition during storage can be easily suppressed.

[0119] • Plasticizers: This composition may contain plasticizers. It is preferable to include plasticizers, for example, to improve the flexibility of the resulting coating film. One type of plasticizer may be used, or two or more types may be used.

[0120] As the plasticizer, a wide range of conventionally known plasticizers can be used, such as liquid hydrocarbon resins such as low-boiling fractions obtained by thermal decomposition of naphtha, solid petroleum resins at room temperature, xylene resins, and coumarone indene resins. Specifically, examples include the liquid hydrocarbon resin and flexibility-imparting resin described in Japanese Patent Application Publication No. 2006-342360.

[0121] Among these, liquid hydrocarbon resins are preferred, and phenol-modified hydrocarbon resins are more preferred. Examples of the phenol-modified hydrocarbon resins include resins obtained using diolefins, monoolefins, or α-methylstyrene contained in the cracked oil fractions of petroleum and coal, and phenols (phenol compounds), as described in Japanese Patent Publication No. 9-268209, Japanese Patent Publication No. 7-196793, etc.

[0122] More specifically, the phenol-modified hydrocarbon resins include C5-based (aliphatic) petroleum resins made from C5 fractions; C9-based (aromatic) petroleum resins made from C9 fractions; C5-C9 copolymer petroleum resins; dicyclopentadiene resins made from dicyclopentadiene obtained by thermal dimerization of cyclopentadiene contained in the C5 fraction; α-methylstyrene; and resins obtained by reacting these with phenols. Among these, resins obtained by addition polymerization of styrene, vinyltoluene, coumarone, indene, and α-methylstyrene, which are contained in the cracked oil fractions of petroleum and coal, with phenols are preferred.

[0123] The average molecular weight of the phenol-modified hydrocarbon resin is typically 200 to 1,000, and its viscosity is typically 30 to 10,000 mPa·s / 25°C.

[0124] Commercially available products may be used as the liquid hydrocarbon resin. Examples of such commercial products include "Nesiles EPX-L" and "Nesiles EPX-L2" (both manufactured by NEVCIN Corporation / phenol-modified hydrocarbon resin), and "Hirenol PL-1000S" (manufactured by Kolon Industries, Inc. / phenol-modified hydrocarbon resin).

[0125] If the composition contains a plasticizer, the solid content of the plasticizer is preferably 0.1 to 15% by mass, more preferably 1 to 10% by mass, based on 100% by mass of the solid content of the composition. When the plasticizer content is within the above range, a coating film with superior crack resistance and other properties can be easily formed.

[0126] - (Pigment) Dispersant The (pigment) dispersant is preferably a dispersant that can uniformly (wet) disperse the pigments in the composition and prepare a stable dispersion. Examples of such (pigment) dispersants include polymer dispersants. One type of (pigment) dispersant may be used, or two or more types may be used.

[0127] If the composition contains a (pigment) dispersant, the solid content of the (pigment) dispersant is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on 100% by mass of the solid content of the composition.

[0128] The organic solvent is preferably an organic solvent with a boiling point of less than 180°C at normal pressure. Examples include aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK), ether solvents such as butyl cellosolve, ester solvents such as butyl acetate, alcohol solvents such as isopropanol, isobutyl alcohol, n-butanol, and methoxypropanol, and aliphatic hydrocarbon solvents such as n-hexane, n-octane, 2,2,2-trimethylpentane, isooctane, n-nonane, cyclohexane, and methylcyclohexane. One organic solvent may be used, or two or more may be used.

[0129] When preparing the composition containing an organic solvent, it is preferable to use an organic solvent such that the VOC content in the composition falls within the aforementioned range. The first agent is preferably a solvent-based agent containing an organic solvent. When preparing the first agent containing an organic solvent, it is preferable to use an organic solvent such that the content of the organic solvent is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, based on 100% by mass of the first agent.

[0130] <Second Agent> The second agent contains an amine-based curing agent (B). The second agent is preferably prepared in step 2 below.

[0131] [Amine-based curing agent (B)] The amine-based curing agent (B) is not particularly limited as long as it is an amine compound other than a tertiary amine (an amine compound having only a tertiary amino group as the amino group), and examples include amine compounds containing two or more primary or secondary amino groups in one molecule. Specific examples of the amine-based curing agent (B) include aliphatic amine curing agents, alicyclic amine curing agents, aromatic amine curing agents, aromatic aliphatic amine curing agents, and heterocyclic amine curing agents. One type of amine-based curing agent (B) may be used, or two or more types may be used.

[0132] Examples of the aliphatic amine-based curing agents include alkyl monoamines, alkylene polyamines, polyalkylene polyamines, and alkylaminoalkylamines.

[0133] The alkylene polyamine is, for example, a polyamine of formula: ２ N-R １ -NH ２ (R １ A is a divalent hydrocarbon group having 1 to 12 carbon atoms. Examples of compounds represented by ( ) include methylenediamine, ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, and trimethylhexamethylenediamine.

[0134] Examples of the polyalkylene polyamine include those with the formula: ２ N-(C) ｍ H ２ｍ NH) ｎ Compounds represented by (H) (where m is an integer from 1 to 10, and n is an integer from 2 to 10, preferably from 2 to 6) are examples. Specific examples include diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, bis(hexamethylene)triamine, and triethylene-bis(trimethylene)hexamine.

[0135] Examples of the alkylaminoalkylamine include formula: ２ ２ N-(CH ２ ) ｐ -NH ２ (R ２ These are independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms (wherein at least one R ２ Compounds represented by (a) are alkyl groups having 1 to 8 carbon atoms, and p is an integer from 1 to 6. Specific examples include dimethylaminoethylamine, diethylaminoethylamine, dibutylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, and dimethylaminobutylamine.

[0136] Other aliphatic amine-based curing agents include, for example, tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, 2,2'-[ethylenebis(iminotrimethyleneimino)]bis(ethaneamine), tris(2-aminoethyl)amine, bis(cyanoethyl)diethylenetriamine, and polyoxyalkylene polyamines (especially diethylene glycol bis(3-aminopropyl) ether).

[0137] Examples of the alicyclic amine-based curing agents include cyclohexanediamine, diaminodicyclohexylmethane (especially 4,4'-methylenebiscyclohexylamine), 4,4'-isopropylidenebiscyclohexylamine, norbornanediamine, 2,4-di(4-aminocyclohexylmethyl)aniline, bis(aminomethyl)cyclohexane, isophoronediamine, and mensendiamine (MDA).

[0138] Examples of aromatic amine-based curing agents include aromatic polyamine compounds having two or more primary amino groups bonded to aromatic rings such as benzene rings or naphthalene rings. Specific examples of aromatic amine-based curing agents include phenylenediamine, naphthalenediamine, diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylsulfone, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, and 3,3'-dimethoxy-4,4'-diaminobiphenyl.

[0139] Examples of aromatic aliphatic amine curing agents include bis(aminoalkyl)benzene and bis(aminoalkyl)naphthalene. Specific examples of aromatic aliphatic amine curing agents include o-xylylenediamine, m-xylylenediamine (MXDA), p-xylylenediamine, bis(aminomethyl)naphthalene, and bis(aminoethyl)naphthalene.

[0140] Examples of heterocyclic amine-based curing agents include N-methylpiperazine, morpholine, 1,4-bis-(3-aminopropyl)piperazine, 1,4-diazacycloheptane, 1-(2'-aminoethylpiperazine), 1,4-bis(3-aminopropyl)piperazine, 1-[2'-(2''-aminoethylamino)ethyl]piperazine, 1,11-diazacycloeicosane, and 1,15-diazacyclooctacosane.

[0141] Examples of amine-based curing agents (B) include amines (amine compounds) described in Japanese Patent Publication No. 49-48480, polyetherdiamines, modified products of the aforementioned amine compounds, such as fatty acid modified products such as polyamidoamines, amine adducts with epoxy compounds, Mannich-modified amines (e.g., Mannich-modified amines having a phenol-derived skeleton (phenalkamine, phenalkamide, etc.)), Michael adducts, ketimines, aldimines, urethane-modified products, and the like.

[0142] As the amine-based curing agent (B), one or more selected from polyamidoamine, amine adducts with epoxy compounds of polyamidoamine, and Mannich-modified products are preferred, with polyamidoamine being more preferred, in order to easily form a coating film with excellent interval adhesion.

[0143] The active hydrogen equivalent of the amine-based curing agent (B) is preferably 50 to 1,000, more preferably 80 to 500, from the viewpoint that it is possible to easily form a coating film with excellent corrosion resistance.

[0144] As the amine-based curing agent (B), a compound obtained by conventionally known synthesis methods may be used, or a commercially available product may be used. Examples of such commercially available products include the aliphatic polyamine "AD-71" (manufactured by Otake Meishin Chemical Co., Ltd., active hydrogen equivalent 290); the polyamidoamines "PA-66S" (manufactured by Otake Meishin Chemical Co., Ltd., active hydrogen equivalent 377) and "Ancamide 910" (manufactured by Evonik, active hydrogen equivalent 230); the epoxy adducts of polyamidoamines "PA-23" (manufactured by Otake Meishin Chemical Co., Ltd., active hydrogen equivalent 375) and "PA-290(A)" (manufactured by Otake Meishin Chemical Co., Ltd., active hydrogen equivalent 277); the Mannich-modified aromatic aliphatic polyamine "MAD-204(A)" (manufactured by Otake Meishin Chemical Co., Ltd., active hydrogen equivalent 202); and the Mannich-modified Examples include the polyamidoamine "ADEKA Hardener EH-342W3" (manufactured by ADEKA Corporation, active hydrogen equivalent 110); the Mannich-modified aliphatic polyamine "SANMIDE CX-1154" (manufactured by Sanwa Chemical Co., Ltd., active hydrogen equivalent 255); the phenalkamine adduct "Cardwright NX-5459" (manufactured by Cardwright, active hydrogen equivalent 164); and the phenalkamine "ANCAMINE 2724" (manufactured by Evonik, active hydrogen equivalent 255).

[0145] The amount of amine-based curing agent (B) in this composition is preferably such that the reaction ratio calculated from the following formula (I) is 0.3 to 1.2, more preferably 0.35 to 1.15, and even more preferably 0.4 to 1.1.

[0146] Reaction ratio = {(Amount of solids of amine-based curing agent (B) / Active hydrogen equivalent of the solids of amine-based curing agent (B)) + (Amount of solids of the component reactive with phenoxy resin (A) / Functional group equivalent of the solids of the component reactive with phenoxy resin (A))} / {(Amount of solids of phenoxy resin (A) / Epoxy equivalent of the solids of phenoxy resin (A)) + (Amount of solids of the component reactive with amine-based curing agent (B) / Functional group equivalent of the solids of the component reactive with amine-based curing agent (B))} ... (I)

[0147] Here, the "component that is reactive to the amine-based curing agent (B)" in formula (I) can be a compound having an epoxy group or a (meth)acryloyl group, and specific examples include the epoxy resin, the epoxy group-containing reactive diluent, the silane coupling agent, and the polymerizable (meth)acrylate monomer. The "component that is reactive to the phenoxy resin (A)" in formula (I) can be a compound having a primary or secondary amino group, and a specific example is the silane coupling agent. As the silane coupling agent, a silane coupling agent having an amino group or an epoxy group as a reactive group can be used, so it is necessary to determine whether the silane coupling agent is reactive to the amine-based curing agent (B) or to the phenoxy resin (A) depending on the type of reactive group, and calculate the reaction ratio.

[0148] The "functional group equivalent" of each component refers to the mass (g) per 1 mol of functional group obtained by dividing the mass of 1 mol of these components by the number of mol of functional groups contained within them.

[0149] The solid content of the amine-based curing agent (B) is preferably such that the reaction ratio falls within the above range, but is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, relative to 100% by mass of the solid content of the composition. Furthermore, the solid content of the amine-based curing agent (B) is preferably such that the reaction ratio falls within the above range, but is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, relative to 100% by mass of the solid content of the second agent. When the content of the amine-based curing agent (B) is within the above range, a coating film with excellent corrosion resistance, coating film strength, and drying properties can be easily formed.

[0150] [Other Components] The second agent may optionally contain components other than the amine-based curing agent (B), to the extent that it does not impair the effects of the present invention, such as pigments, (pigment) dispersants, divalent or higher polycarboxylic acids, vinyl (co)polymers, viscosity modifiers (anti-sagging agents, anti-settling agents, thixotropes), plasticizers, silane coupling agents, defoaming agents, curing accelerators, curing catalysts, film-forming aids, dehydrating agents, organic solvents, and other components. Each of these other components may be used individually or in combination of two or more.

[0151] The aforementioned other components can be conventionally known components, and examples of pigments, (pigment) dispersants, vinyl (co)polymers, viscosity modifiers, plasticizers, silane coupling agents, defoamers, curing accelerators, dehydrating agents, and organic solvents include components similar to those listed in the section for the first agent.

[0152] The second agent is preferably a solvent-based agent containing an organic solvent. When preparing the second agent containing an organic solvent, it is preferable to use an organic solvent such that the content of the organic solvent is preferably 1 to 80% by mass, more preferably 10 to 70% by mass, based on 100% by mass of the second agent.

[0153] <Method for producing this composition> The method for producing this composition includes: step 1 of preparing a first agent using a phenoxy resin (A); step 2 of preparing a second agent using an amine-based curing agent (B); and step 3 of mixing the first agent and the second agent.

[0154] Furthermore, the method for producing this composition may include a step of preparing an nth agent (where n is 3 or more), in which case step 3 may be a step of mixing the first agent, the second agent, and the nth agent.

[0155] <Step 1> Step 1 is a step of preparing the first agent using phenoxy resin (A). In Step 1, phenoxy resin (A) itself may be used as the first agent (in this case, Step 1 can also be said to be a step of using phenoxy resin (A)), or the first agent may be prepared by mixing phenoxy resin (A) with the other components, but the latter is preferred.

[0156] Step 1, which involves mixing the phenoxy resin (A) with the other components to prepare the first agent, is specifically a step of mixing (or kneading) each component to be incorporated into the first agent. During this mixing (or kneading), each component may be added and mixed all at once, or added and mixed in multiple steps.

[0157] <Step 2> Step 2 is a step of preparing the second agent using an amine-based curing agent (B). In Step 2, the amine-based curing agent (B) itself may be used as the second agent (in this case, Step 2 can also be said to be a step of using the amine-based curing agent (B)), or the amine-based curing agent (B) may be mixed with the other components to prepare the second agent, but the latter is preferred.

[0158] Step 2, which involves mixing the amine-based curing agent (B) with the other components to prepare the second agent, specifically involves mixing (or kneading) each component to be incorporated into the second agent. During this mixing (or kneading), each component may be added and mixed all at once, or added and mixed in multiple stages.

[0159] <Step 3> Step 3 is a step of mixing the first agent and the second agent prepared in Steps 1 and 2, respectively, and the nth agent is used as needed. The composition can be manufactured by mixing (or kneading) these first agent, second agent and the nth agent used as needed.

[0160] During the mixing (or kneading) in steps 1 to 3 described above, conventionally known devices such as mixers, dispersers, and agitators can be used. Examples of such devices include dispersers, mixing / dispersing mills, mortar mixers, rolls, paint shakers, and homogenizers. Furthermore, the mixing (or kneading) may be carried out while heating or cooling, depending on the season, environment, etc.

[0161] ≪Coating Film≫ A coating film according to one embodiment of the present invention (hereinafter also referred to as "the coating film") is formed from the composition described above. The coating film is a so-called tie coat or anticorrosion coating film. The coating film is usually used as a laminate including the coating film and a substrate.

[0162] The aforementioned tie coat refers to a coating film for which corrosion resistance is not required, and is a coating film provided between a substrate such as a steel plate or an undercoat coating and a topcoat coating, and is also called a bonding coating film. The undercoat coating film referred to here simply refers to a coating film that exists below the main coating film (on the substrate side), and examples include a primer coating film, a corrosion-resistant coating film, and an intermediate coating film. The topcoat coating film referred to here simply refers to a coating film that exists on top of the main coating film (on the opposite side from the substrate), and examples include a corrosion-resistant coating film, an intermediate coating film, and a topcoat coating film. If the main coating film is a corrosion-resistant coating film, the corrosion-resistant coating film is not particularly limited as long as corrosion resistance is required, and is usually formed on a substrate such as a steel plate or an undercoat coating film (specifically, a primer coating film), and an intermediate coating film and / or a topcoat coating film may be formed on top of the corrosion-resistant coating film (on the opposite side from the substrate). In other words, although the tie coat and the corrosion-resistant coating film in this invention differ in whether or not corrosion resistance is required, they may be formed in substantially the same locations and may be substantially indistinguishable.

[0163] The dry film thickness of this coating is not particularly limited and can be appropriately selected depending on the application. When this coating is a tie coat, the dry film thickness is usually 10 to 250 μm, preferably 15 to 200 μm. When this coating is a corrosion-resistant coating, the dry film thickness is usually 50 to 500 μm, preferably 100 to 400 μm, in order to obtain a coating with sufficient corrosion resistance.

[0164] The material of the base material is not particularly limited and examples include iron (iron, steel, ferroalloy, carbon steel, mild steel, alloy steel, etc.), non-ferrous metals (zinc, aluminum, copper, brass, galvanized, zinc sprayed, etc.), and stainless steel (SUS304, SUS410, etc.). Furthermore, when using mild steel (SS400, etc.) as the base material, it is desirable to prepare the surface by polishing the base material surface with grit blasting or the like as necessary (e.g., adjusting so that the arithmetic mean roughness (Ra) is about 30 to 75 μm). The base material may also be a base material that has undergone pretreatment such as cleaning or blasting to remove rust, dirt, paint (old paint film), etc. adhering to the base material.

[0165] Examples of the aforementioned substrates include ships; land structures such as bridges, tanks, containers, plants, and steel towers; and marine structures such as port facilities, buoys, underwater pipelines, FPSOs (Floating Production, Storage and Offloading Units), FLNGs (Floating Offshore Natural Gas Liquefaction Units), oil drilling rigs, oil storage bases, mega-floats, offshore wind power generation facilities, and tidal power generation facilities.

[0166] Examples of the aforementioned undercoat include coatings formed from various primer compositions such as known epoxy resin-based coatings. Examples of the aforementioned intermediate coating include coatings formed from various known intermediate coating compositions such as (meth)acrylic resin-based, epoxy resin-based, and urethane resin-based coatings. Examples of the aforementioned topcoat include coatings formed from various known topcoat compositions such as (meth)acrylic resin-based, (meth)acrylic silicone resin-based, urethane resin-based, silicone resin-based, and fluororesin-based coatings. Because this coating has excellent adhesion to such undercoat coatings, intermediate coatings, topcoat coatings, and the substrate, it can be suitably used as a tie coat and / or anticorrosion coating.

[0167] The coating film can be manufactured, for example, by a method comprising step A of applying the composition onto a substrate or an undercoat, and step B of drying the applied composition to form the coating film.

[0168] The painting method in step A is not particularly limited, and examples include conventionally known methods such as spray painting including airless spray painting, air spray painting, and electrostatic spray painting, as well as brush painting, roller painting, and dipping. Among these, spray painting is preferred because it better demonstrates the effects of the present invention and allows for easy painting of large surface areas of substrates such as structures.

[0169] The aforementioned electrostatic spray coating, also simply called electrostatic painting, generally involves applying a high voltage (usually around tens of thousands of volts) to atomize the paint using a spray gun or other spraying device, thereby imparting a positive or negative charge to the paint particles. Here, the object to be painted (workpiece) is grounded, and the charged paint particles are attracted to the workpiece surface by electrostatic force and adhere to it. Electrostatic spray coating can provide benefits such as improved coating efficiency, reduced paint loss, suppression of paint dust scattering, and adaptation to complex shapes of the object to be painted (substrate or primer film) (paint can easily penetrate uneven surfaces and the back surface). When applying electrostatic spray coating, the conductivity of this composition, humidity control, safety measures (handling high voltage), and the grounding design of the object to be painted are important. This anticorrosive paint composition is also suitable for electrostatic spray coating.

[0170] The conditions for the spray coating described above can be adjusted as appropriate depending on the desired dry film thickness. For example, in the case of airless spray coating, a primary (air) pressure of approximately 0.3 to 0.6 MPa, a secondary (paint) pressure of approximately 10 to 30 MPa, and a gun travel speed of approximately 50 to 120 cm / second are preferred.

[0171] The aforementioned coating is preferably applied in such a way that the dry film thickness of the main coating formed in step B falls within the aforementioned range. In this case, the main coating of the desired thickness may be formed in a single coat (one coat), or it may be formed in two or more coats (two or more coats). Note that two coats refer to performing steps A and B, and then performing step A, etc., on the coating obtained in step B.

[0172] When applying this composition to a substrate, it is preferable to treat the surface of the substrate as necessary (for example, blasting (ISO 8501-1 Sa2 1 / 2), degreasing to remove oil and dust) in order to remove rust, oil, moisture, dust, salt, etc. from the substrate or the undercoat, and to improve the adhesion of the resulting coating to the substrate. In addition, the substrate may be coated with a shop primer or the like for primary rust prevention.

[0173] The drying conditions in step B are not particularly limited and can be set appropriately according to the method of forming the coating film, the type of substrate, the application, the painting environment, etc. However, the drying temperature is usually 5 to 35°C when drying at room temperature, and usually 30°C or more and less than 100°C, more preferably 40 to 80°C, when forced drying is performed using a hot air dryer or the like. With this composition, the composition can be dried and cured even with such room temperature drying. The drying time varies depending on the method of drying the coating film, for example, it is about 1 to 7 days when drying at room temperature, and for example, it is about 5 to 60 minutes when forced drying is performed.

[0174] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0175] <Synthesis Example 1> Synthesis of Phenoxy Resin A-1 100 parts by mass of purified cardanol were weighed into a flask equipped with a reflux condenser and a stirrer while purging with nitrogen, and 0.8 parts by mass of p-toluenesulfonic acid monohydrate were added to prepare a reaction solution. The prepared reaction solution was then heated to 150°C and stirred for 3 hours. After that, the reaction temperature was returned to room temperature and neutralized with an aqueous sodium hydroxide solution. Next, the aqueous layer was extracted three times with ethyl acetate, and the organic layer was dehydrated with sodium sulfate. After that, the sodium sulfate was removed by filtration, and the solvent was removed by distillation using an evaporator to obtain the crude product. The obtained crude product was heated to 300°C and stirred under reduced pressure for 3 hours to remove the distillate components and obtain the compound represented by formula (3) (wherein formula (3) is a hydrocarbon group having 15 carbon atoms). Gel permeation chromatography (GPC) was used to confirm the decrease in the peak derived from cardanol and the appearance of a new high molecular weight component, confirming that the compound represented by formula (3) was obtained.

[0176] In a flask equipped with a reflux condenser and a stirring device, 100 parts by mass of the compound represented by formula (3) obtained were weighed out while purging with nitrogen, and a reaction solution was prepared by adding 100 parts by mass of bisphenol A type epoxy resin jER828 (manufactured by Mitsubishi Chemical Corporation), 0.6 parts by mass of sodium hydroxide, 18 parts by mass of methanol, and 5 parts by mass of water. Next, the prepared reaction solution was heated to 75°C and stirred under reflux for 3 hours. After that, the reaction temperature was returned to room temperature, the aqueous layer was extracted three times with toluene, and the organic layer was dehydrated with sodium sulfate. After that, the sodium sulfate was removed by filtration, and the solvent was removed by distillation using an evaporator to obtain phenoxy resin A-1 containing the structure represented by formula (1) (wherein formula (1) is a hydrocarbon group having 15 carbon atoms) and the structure represented by formula (2) (wherein formula (2) is a linking group having 3 carbon atoms and R is a hydrocarbon group having 15 carbon atoms). GPC analysis confirmed a decrease in the peak originating from bisphenol A epoxy resin and the appearance of a new high-molecular-weight component, thus confirming that the target phenoxy resin A-1 was obtained.

[0177] [Example 1] In a container, 16.0 parts by mass of phenoxy resin A-1, 0.9 parts by mass of silane coupling agent, 4.0 parts by mass of reactive diluent, 0.2 parts by mass of defoaming agent, 4.4 parts by mass of barium sulfate, 32.7 parts by mass of talc, 8.8 parts by mass of potassium feldspar, 3.5 parts by mass of titanium white, 0.03 parts by mass of carbon black, 0.7 parts by mass of viscosity modifier, 13.9 parts by mass of xylene, 1.3 parts by mass of butyl cellosolve, and 2.6 parts by mass of n-butanol were placed and dispersed uniformly at room temperature (23°C) using a high-speed disperser. After heating to 56-60°C, the mixture was cooled to 30°C or below to prepare the first agent. Furthermore, a second agent was prepared by mixing 7.2 parts by mass of amine-based curing agent B-1, 0.12 parts by mass of curing accelerator 1, 1.4 parts by mass of xylene, and 0.5 parts by mass of n-butanol using a high-speed disperser (at room temperature and atmospheric pressure). The obtained first agent and second agent were mixed before painting to prepare a composition (Tiecoat composition or anticorrosive paint composition).

[0178] [Examples 2-17, Comparative Example 1, and Reference Examples 1-7] Compositions (for tie coat or anticorrosive coating) were prepared in the same manner as in Example 1, except that each component listed in Tables 1-3 was used in the amounts (numerical values, parts by mass) listed in Tables 1-3. A description of each component listed in Tables 1-3 is shown in Table 4.

[0179]

[0180]

[0181]

[0182]

[0183] <Drying and Curing Properties> Each composition prepared in the Examples, Comparative Examples, and Reference Examples was applied to a glass plate measuring 25 mm wide x 348 mm long x 2 mm thick using a film applicator to achieve a dry film thickness of approximately 100 μm. The time required for the coating to partially harden (T2) and fully harden (T3) was measured using an RC-type drying time recorder (manufactured by Coating Tester Co., Ltd.) under temperature conditions of 5°C or 23°C. The results are shown in Tables 5 to 7. In this drying and curing properties test, the state of the coating was determined from the trace left by the test needle of the RC-type drying time recorder, which was moved slowly at a constant speed over the unhardened coating, and the time required for the coating to partially harden (T2) or fully harden (T3) was determined. The time from the application of each composition until the glass plate is no longer visible in the path of the test needle was defined as the semi-curing time (T2), and the time from the application of each composition until the test needle slides across the surface of the coating and no longer leaves any marks was defined as the full curing time (T3).

[0184] <Tackiness of the coating film> Each composition prepared in the examples, comparative examples, and reference examples was applied to a sandblasted steel plate measuring 70 mm wide x 150 mm long x 1.6 mm thick to a dry film thickness of approximately 200 μm. Then, in accordance with JIS K 5600-1-6:1999, the coating was dried for 7 days under conditions of 23°C and 50% RH to prepare coated test specimens. The presence or absence of tackiness was checked by touching the coated test specimens, and they were evaluated according to the evaluation criteria below. The results are shown in Tables 5 to 7.

[0185] [Evaluation Criteria] ○: No pleats ×: With pleats

[0186] <Preparation of test plates (coated substrates) for evaluating corrosion resistance> A steel plate measuring 70 mm wide x 150 mm long x 1.6 mm thick, which had been sandblasted, was coated with each of the compositions prepared in the examples, comparative examples, and reference examples using an air spray to achieve a dry film thickness of 200 μm. The coated plates were then dried at 23°C for 7 days to prepare test plates (coated substrates) for evaluating corrosion resistance.

[0187] <Corrosion Resistance> The aforementioned test plate for evaluating corrosion resistance has an electrical current density of 5 mA / m². ２The zinc anode was connected as shown below, and a scribe reaching the depth of the steel plate was inserted in the width direction of the test plate. After immersion in 3% salt water at 40°C for 90 days, the length of the peeling coating from the scribe was measured. The results are shown in Tables 5 to 7. If the peeling length is less than 20 mm, it can be said that there is no practical problem.

[0188] Furthermore, the appearance of the coating after immersion for 90 days was visually inspected, and blistering of the coating was evaluated according to the evaluation criteria below. The results are shown in Tables 5 to 7. In this evaluation of blistering, the coating within 3 mm of the scribe was excluded from the evaluation.

[0189] [Evaluation Criteria] ○: No blistering is observed on the coating film △: Blistering is observed on part of the coating film ×: Blistering is observed on the entire coating film

[0190] <Damage Resistance (Resistance to Solid Wood)> A test plate for damage resistance evaluation (coated substrate) was prepared by applying each composition prepared in the examples and comparative examples to a sandblasted steel plate measuring 70 mm wide x 150 mm long x 1.6 mm thick using an air spray to achieve a dry film thickness of 200 μm, and drying it at 5°C for 48 hours. A wooden piece measuring 30 mm wide x 30 mm long x 10 mm thick was placed in the center of the coated surface of the prepared test plate, and a load of 40 kgf / cm² was applied vertically (in the direction of the coating) from above the wooden piece. ２ After applying a pressure of 3.9 MPa for 20 minutes, the condition of the coating surface was observed (the degree of coating damage was measured). The evaluation criteria are shown in Figure 1. In Figure 1, 10 is the wood chip and 20 is the coating. Evaluation criterion 5 indicates no deformation of the coating 20, representing the best condition. Evaluation criterion 4 indicates slight deformation of the coating 20, but no marks from the wood chip 10 are visible on the coating 20, representing a good condition. Evaluation criteria 3, 2, and 1 indicate deformation of the coating 20 and visible marks from the wood chip 10, with the degree of damage (deformation) in the order of 3 < 2 < 1. The results are shown in Table 5 or 6. If the damage resistance evaluation result is 5 or 4, it can be said that there are no practical problems.

[0191] <Flexural Resistance> Each composition prepared in the examples and comparative examples was applied to a tinplate sheet measuring 150 mm in length, 50 mm in width, and 0.3 mm in thickness using an air spray to achieve a dry film thickness of approximately 200 μm. The coated specimens were then dried at 23°C or 40°C for one week to prepare the coated specimens. In accordance with JIS K 5600-5-1:1999 "Flexural Resistance (Cylindrical Mandrel Method)," the prepared specimens and a cylindrical mandrel bending tester manufactured by Taiyu Kikai Co., Ltd. were used to visually inspect for cracking or peeling of the coating from the tinplate sheet. The results were evaluated according to the following evaluation criteria. The results are shown in Table 5 or 6. A mandrel with a diameter of 10 mm was used in this test.

[0192] [Evaluation Criteria] ○: No cracks or peeling from the tin plate are observed in the paint film. △: Cracks are observed in the paint film, but no peeling from the tin plate is observed. ×: Cracks and peeling from the tin plate are observed in the paint film.

[0193]

[0194]

[0195]

[0196] <Topcoat Paints> The following paints were used as topcoat paints for each.

[0197] - Silyl resin-based antifouling coating: Coating composition described in Example 1 of International Publication No. 2017 / 094767

[0198] - Zinc acrylic resin-based antifouling coating: Coating composition described in Example 1 of International Publication No. 2021 / 182454

[0199] - In an epoxy resin topcoat paint container, 30 parts by mass of epoxy resin "E-001-75X", 10 parts by mass of epoxy resin "E834-85X(T)" (both manufactured by Otake Meishin Chemical Co., Ltd.), 20 parts by mass of talc "F-2 Talc" (manufactured by Fuji Talc Industry Co., Ltd.), 10 parts by mass of heavy calcium carbonate "Calcium Carbonate Super SS" (manufactured by Maruo Calcium Co., Ltd.), 3 parts by mass of carbon black "MA-100" (manufactured by Mitsubishi Chemical Corporation), 5 parts by mass of anti-sagging agent "Disparon A-630-20X" (manufactured by Kusumoto Kasei Co., Ltd., solid content 20% by mass), 6 parts by mass of propylene glycol monomethyl ether, 7 parts by mass of butyl cellosolve, and 9 parts by mass of methyl isobutyl ketone were placed. Glass beads were then added and these components were mixed in a paint shaker, and then the glass beads were removed to prepare the main components constituting the epoxy resin topcoat paint. In addition, 80 parts by mass of polyamide adduct-type curing agent "PA-23" (manufactured by Ohtake Meishin Chemical Co., Ltd.), 3 parts by mass of tertiary amine "Ancamine K-54" (manufactured by EVONIK Corporation), 14 parts by mass of xylene, and 3 parts by mass of n-butanol were mixed in a separate container using a high-speed disperser (at room temperature and atmospheric pressure) to prepare the curing agent component for the epoxy resin topcoat. The obtained main component and curing agent component were mixed in a predetermined mixing ratio (mass of main component:mass of curing agent = 9:1) before painting to prepare the epoxy resin topcoat.

[0200] • Urethane resin-based topcoat paint: "Unimarine" (manufactured by Chugoku Marine Paints Ltd.)

[0201] - An acrylic resin-based topcoat paint was prepared by placing 20 parts by mass of acrylic resin "Paraloid B-66" (manufactured by Rohm & Haas Japan Co., Ltd.), 16 parts by mass of precipitated barium sulfate "Precipitated Barium Sulfate FTB" (manufactured by Fukuoka Talc Industry Co., Ltd.), 20 parts by mass of titanium white "Titanium White R-930" (manufactured by Sakai Chemical Industry Co., Ltd.), 3 parts by mass of anti-sagging agent "Disparon A-630-20X", 27 parts by mass of xylene, 2 parts by mass of butyl cellosolve, 9 parts by mass of aromatic hydrocarbon "Ipsol 100" (manufactured by Idemitsu Kosan Co., Ltd.), and 3 parts by mass of n-butanol into an acrylic resin-based topcoat paint container, mixing these components with a paint shaker, and then removing the glass beads.

[0202] <Preparation of test panels for interval adhesion evaluation (substrates with laminated coatings)> Each composition prepared in the examples, comparative examples, and reference examples was applied to a sandblasted steel plate measuring 70 mm wide x 150 mm long x 1.6 mm thick using an air spray to achieve a dry film thickness of approximately 200 μm. The plates were then forced-dried at 40°C for 1, 2, or 3 days to prepare test specimens with coatings for each coating interval. A topcoat was applied to the coatings of the prepared test specimens, and then dried for 7 days at 23°C and 50% RH in accordance with JIS K 5600-1-6:1999 to prepare test panels for interval adhesion evaluation. When epoxy resin-based topcoat paint, urethane resin-based topcoat paint, or acrylic resin-based topcoat paint was applied to the test specimens, a film applicator was used to apply the paint to achieve a dry film thickness of 50 μm. Furthermore, when applying silyl resin-based antifouling paint or zinc acrylic resin-based antifouling paint as a topcoat to the aforementioned test specimen, the paint was applied using a film applicator to achieve a dry film thickness of 150 μm.

[0203] <Interval Adhesion> The prepared interval adhesion evaluation test plates were immersed in salt water (3% salinity) at 23°C for 30 days, and then their adhesion was evaluated according to the cross-cut method specified in JIS K 5600-5-6:1999. The results are shown in Table 8 or 9.

[0204]

[0205]

[0206] 10: Wood chips 20: Paint film

Claims

1. A tiecoat composition or anticorrosive coating composition comprising a first agent containing a phenoxy resin (A) and a second agent containing an amine-based curing agent (B), wherein the phenoxy resin (A) is a resin comprising a structure represented by the following formula (1) and a structure represented by the following formula (2): In formula (1), R is independently a hydrocarbon group having 10 to 18 carbon atoms, and l is an integer from 1 to 10; In formula (2), X is independently a divalent linking group having 1 to 10 carbon atoms, R is independently a hydrocarbon group having 10 to 18 carbon atoms, and m is an integer from 1 to 10.

2. The composition according to claim 1, wherein R in formulas (1) and (2) is a hydrocarbon group having 12 to 16 carbon atoms.

3. The composition according to claim 1, wherein the structure represented by formula (1) is a structure derived from cardanol.

4. The composition according to claim 1, comprising a pigment.

5. The composition according to claim 4, wherein the particulate solid contains particulate solid, and the volume concentration of the particulate solid is 20 to 50%.

6. The composition according to claim 1, wherein the first agent contains an epoxy resin other than the phenoxy resin (A).

7. The composition according to claim 6, wherein the solid content of the phenoxy resin (A) is 15 to 95% by mass with respect to 100% by mass of the total solid content of the phenoxy resin (A) and the epoxy resin.

8. A coating film formed from the composition according to any one of claims 1 to 7.

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