Active energy ray-curable composition

Abstract

Provided is an active energy ray-curable composition capable of imparting rust prevention performance to a coating. For this purpose, the active energy ray-curable composition comprises: (component A) one or more compounds including two or more ethylenically unsaturated groups; (component B) one or more compounds including at least one aromatic ring and one ethylenically unsaturated group; and (component C) one or more metal salts including an ethylenically unsaturated group and / or including no ethylenically unsaturated group.

Description

Active energy ray-curable composition

[0001] The present specification relates to an active energy ray-curable composition.

[0002] (Cross-reference to related applications) This application claims the benefit of priority based on Japanese Patent Application No. 2024-105696, filed on June 28, 2024, and the entire contents of that Japanese application are incorporated herein by reference as part of this specification.

[0003] Active energy ray-curable coating compositions that cure with active energy rays such as ultraviolet rays are known (Patent Documents 1 to 5). Such coating compositions complete their curing reaction in a short time. Furthermore, solvent-free compositions do not require solvent drying. Therefore, they have attracted attention for their contribution to high productivity of coated products. Furthermore, due to the high hardness of the coating film, they are considered useful for hard coatings and anti-corrosion coatings for plastic products.

[0004] Anticorrosive coating compositions contain carbodiimide compounds or benzotriazole-based anticorrosive agents as acid scavengers (see, in particular, Patent Documents 4 and 5).

[0005] JP 2019-196461 A JP 2008-049623 A JP 2018-115300 A JP 2019-108426 A JP 2011-012251 A

[0006] In recent years, coatings using such energy ray curable coating compositions have been required to have not only waterproof properties but also special rust prevention properties for metals. For example, in automotive applications, rust prevention properties are required under high temperature and humidity conditions and in environments where strong acidic corrosive substances are present. In particular, LiPF contained in the electrolyte of secondary batteries ６ Hydrogen fluoride, which is both an impurity and a hydrolyzate of lithium salts such as those mentioned above, is highly corrosive. The present inventors have found that it is difficult to suppress rust formation using conventional anticorrosive coating compositions in the presence of hydrogen fluoride.

[0007] The present specification provides an active energy ray-curable composition that can impart high rust prevention performance to a coating.

[0008] The present inventors have conducted extensive research into the properties of a coating that will provide rust prevention even in the presence of highly corrosive substances such as hydrogen fluoride. As a result, they have discovered a composition that can provide both water resistance and acid resistance in a coating. They have also discovered that this composition can provide excellent rust prevention even in highly corrosive environments in which highly corrosive substances such as hydrogen fluoride are present. This specification provides the following means.

[0009] [1] An active energy ray-curable composition comprising: (Component A) one or more compounds having two or more ethylenically unsaturated groups; (Component B) one or more compounds having at least one aromatic ring and one ethylenically unsaturated group; and (Component C) one or more metal salts having and / or not having an ethylenically unsaturated group, wherein Component A comprises a (meth)acrylate (excluding urethane (meth)acrylate) having three or more (meth)acryloyl groups, and the (meth)acrylate accounts for 65% by mass or more and 80% by mass or less of the total mass of curable components in the active energy ray-curable composition; Component B accounts for 15% by mass or more and 30% by mass or less of the total mass of curable components in the active energy ray-curable composition; and Component C accounts for 7.5% by mass or more and 15% by mass or less of the total mass of the active energy ray-curable composition. [2] The active energy ray-curable composition according to [1], wherein the (meth)acrylate comprises a (meth)acrylate having three (meth)acryloyl groups and the compound having 5 to 6 (meth)acryloyl groups. [3] The active energy ray-curable composition according to [2], wherein the (meth)acrylate having three (meth)acryloyl groups and the (meth)acrylate having 5 to 6 (meth)acryloyl groups comprise glycerin triacrylate and the pentaacrylate and hexaacrylate of dipentaerythritol, respectively. [4] The active energy ray-curable composition according to any one of [1] to [3], wherein Component B comprises a (meth)acrylate having one aromatic ring and one (meth)acryloyl group. [5] The active energy ray-curable composition according to [4], wherein the (meth)acrylate having one aromatic ring and a (meth)acryloyl group is benzyl (meth)acrylate. [6] The active energy ray-curable composition according to any one of [1] to [5], wherein Component C includes an alkaline earth metal salt containing a (meth)acryloyl group. [7] The active energy ray-curable composition according to [6], wherein the alkaline earth metal salt containing a (meth)acryloyl group is calcium methacrylate.[8] The active energy ray-curable composition according to any one of [1] to [7], wherein the active energy ray-curable composition has a hot water absorption of less than 1.6 mass% when measured by the following method: a 50 mm x 50 mm x 2 mm cured product of the active energy ray-curable composition is dried at 50°C for 1 hour, allowed to stand at 23±2°C and 50±5% RH for 24 hours, and then immersed in 60°C water for 24 hours, and the amount of cured material before and after immersion is measured. Hot water absorption (%) = (amount of cured material after immersion - amount of cured material before immersion) / amount of cured material before immersion × 100 [9] The active energy ray-curable composition has a hot water absorption of less than 1.6 mass% when measured by the following method: a 50 mm x 50 mm x 2 mm cured product of the active energy ray-curable composition is dried at 50°C for 1 hour, allowed to stand at 23±2°C and 50±5% RH for 24 hours, and then immersed in 60°C water for 24 hours, and the amount of cured material before and after immersion is measured. ６ ) solution") to 1 cm ２ After applying 0.01 g per 1000 μm film, the active energy ray-curable composition was applied on top of the electrolyte solution using a bar coater, and irradiated with 365 nm ultraviolet light using an LED light source (ultraviolet light intensity: 250 mW / cm ２ , the cumulative light amount is 1000 mJ / cm ２ The active energy ray-curable composition according to any one of [1] to [8], wherein a cured product having a film thickness of 10 μm obtained by curing the electrolytic solution is left at 60°C and 90% RH for 72 hours, and the cured product is checked for rust at the area where the electrolytic solution was applied, and the area where rust has formed is less than 10% of the total area where the electrolytic solution has been applied.

[10] An active energy ray-curable composition comprising: (Component A) one or more compounds having two or more ethylenically unsaturated groups, (Component B) one or more compounds having at least one aromatic ring and one ethylenically unsaturated group, and (Component C) one or more metal salts with and / or without an ethylenically unsaturated group, and wherein the active energy ray-curable composition has a crosslink density (mol / kg) of 7.3 or more, as represented by the following formula (1): wherein, in formula (1), wi represents the mass fraction of component i (where component i represents a curable component, 1≦i≦n, and n is an integer of 2 or greater) in the active energy ray-curable composition, and Mci represents the molecular weight between crosslinking points (kg / mol) of component i.

[11] The active energy ray-curable composition according to

[10] , wherein component A contains the compound having three or more ethylenically unsaturated groups.

[12] The active energy ray-curable composition according to

[10] or

[11] , wherein component A accounts for 65% by mass or more and 80% by mass or less of the total mass of the curable components in the active energy ray-curable composition.

[13] The active energy ray-curable composition according to any of

[10] to

[12] , wherein component B accounts for 15% by mass or more and 30% by mass or less of the total mass of the curable components in the active energy ray-curable composition.

[14] The active energy ray-curable composition according to any one of

[10] to

[13] , wherein the active energy ray-curable composition contains Component C in an amount of 7.5% by mass or more and 15% by mass or less of the total mass of the active energy ray-curable composition.

[15] The active energy ray-curable composition according to any one of

[10] to

[14] , further containing (Component D) a photopolymerization initiator, and wherein Component D contains 7.5% by mass or more and 15% by mass or less of the total mass of the active energy ray-curable composition.

[16] The active energy ray-curable composition is prepared by the following method: A 50 mm x 50 mm x 2 mm cured product of the active energy ray-curable composition is dried at 50°C for 1 hour, and then heated at 23±2°C and 50±5% RH. The active energy ray-curable composition according to any one of

[10] to

[15] , wherein the composition is left standing at room temperature for 24 hours, then immersed in water at 60°C for 24 hours, and the amount of cured material is measured before and after immersion, and the hot water absorption calculated by the following formula is less than 1.6 mass%. Hot water absorption (%) = (amount of cured material after immersion - amount of cured material before immersion) / amount of cured material before immersion x 100

[17] The active energy ray-curable composition is prepared by the following method: ６) solution") to 1 cm ２ After applying 0.01 g per 1000 μm film, the active energy ray-curable composition was applied on top of the electrolyte solution using a bar coater, and irradiated with 365 nm ultraviolet light using an LED light source (ultraviolet light intensity: 250 mW / cm ２ , the cumulative light amount is 1000 mJ / cm ２ The active energy ray-curable composition according to any one of

[10] to

[16] , wherein the active energy ray-curable composition is a coating composition for a coating object having a surface made of a metal material, the active energy ray-curable composition according to any one of [1] to

[17] , the active energy ray-curable composition being a coating composition for a coating object having a surface made of a metal material.

[19] A method for preventing rust on a coating object, the method comprising: supplying the active energy ray-curable composition according to any one of [1] to

[18] to the surface of the coating object having a surface made of a metal material, and irradiating the active energy ray-curable composition on the surface of the coating object with active energy rays.

[20] A method for producing a coated object having a coating, the method comprising supplying the active energy ray-curable composition according to any one of [1] to

[18] to the surface of the coating object, the active energy ray-curable composition being a coating composition for a coating object having a surface made of a metal material, and irradiating the active energy ray-curable composition on the surface of the coating object with active energy rays.

[0010] The disclosure of this specification relates to an active energy ray-curable composition (hereinafter also simply referred to as a composition) and use thereof. The composition disclosed herein contains the following Components A to C in the following ratios: Component A includes the compound having three ethylenically unsaturated groups and the compound having five to six ethylenically unsaturated groups, and the content of Component A is 65 to 80 mass% of the total mass of the curable components in the active energy ray-curable composition; Component B is 15 to 30 mass% of the total mass of the curable components in the active energy ray-curable composition; and Component C is 7.5 to 15 mass% of the total mass of the active energy ray-curable composition; and / or the crosslink density (mol / kg) of the composition is 7.3 or more. Component A: one or more compounds having two or more ethylenically unsaturated groups; Component B: one or more compounds having one ethylenically unsaturated group, including a compound having at least one aromatic ring and one ethylenically unsaturated group; and Component C: one or more metal salts having and / or not having an ethylenically unsaturated group.

[0011] As a result of various investigations, the present inventors arrived at a combination and content ratio of Components A to C, and discovered that a coating made from a composition containing these components exhibits excellent rust-preventing performance. That is, it was discovered that by using Components A, B, and C to achieve a crosslink density (mol / kg) of 7.3 or more, water resistance and acid resistance are improved, and excellent rust-preventing performance can be exhibited as a synergistic effect of these components.

[0012] Although not intended to be binding on the disclosure of this specification, it is presumed that the excellent rust-preventing performance is exhibited because Component A contributes to the crosslink density (crosslinked structure) and water resistance, Component B contributes to the water resistance and dispersibility of Component C, and Component C contributes to the acid resistance.

[0013] Furthermore, according to the rust prevention method for a coating object disclosed in this specification, a coating with excellent water resistance and acid resistance is formed on the surface of a coating object having a surface made of, for example, a metal material, and excellent rust prevention performance is exhibited even in a highly corrosive environment.

[0014] Furthermore, according to the method for manufacturing a coated body having a coating disclosed in this specification, by forming a coating on the surface of the object to be coated, it is possible to manufacture a coated body that has excellent water resistance and acid resistance, or a coated body that has excellent rust prevention performance even in a highly corrosive environment.

[0015] The composition, rust prevention method, and method for manufacturing a coated body disclosed in this specification are useful, for example, as a coating agent for current collectors, terminals, packages, etc. of lithium ion secondary batteries mounted on vehicles, etc., as a rust prevention method, and as a method for manufacturing secondary batteries equipped with rust prevention properties.

[0016] (Active Energy Ray-Curable Composition) Components contained in the composition will be described below.

[0017] (Component A) Component A is one or more compounds having two or more ethylenically unsaturated groups. It is a so-called polyfunctional compound. Component A includes multiple compounds having two or more ethylenically unsaturated groups, which may be the same or different. Component A can be used as one or two or more compounds in appropriate combination.

[0018] The ethylenically unsaturated group in Component A is not particularly limited, and examples thereof include a (meth)acryloyl group, a (meth)acrylamide group, a vinyl group, and a (meth)allyl group. The two or more ethylenically unsaturated groups may be two ethylenically unsaturated groups, three ethylenically unsaturated groups, four ethylenically unsaturated groups, five or six ethylenically unsaturated groups, or more ethylenically unsaturated groups.

[0019] Examples of (meth)acrylates having two ethylenically unsaturated groups include aliphatic diol di(meth)acrylates such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, and nonanediol di(meth)acrylate; di(meth)acrylates of trihydric or higher polyols such as glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, and dipentaerythritol di(meth)acrylate; di(meth)acrylates of alkylene oxide adducts of these polyols; di(meth)acrylates having an isocyanuric acid skeleton such as di(meth)acrylate of an ethylene oxide adduct of isocyanuric acid; and Examples of the alkylene oxide adduct include di(meth)acrylates of bisphenol alkylene oxide adducts, such as di(meth)acrylates of alkylene oxide adducts of bisphenol A and di(meth)acrylates of alkylene oxide adducts of bisphenol F. In this case, examples of the alkylene oxide in the alkylene oxide adduct include ethylene oxide, propylene oxide, tetramethylene oxide, and ethylene oxide and propylene oxide.

[0020] Examples of the (meth)acrylate having three or more ethylenically unsaturated groups include poly(meth)acrylates of polyols such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, diglycerin tri- or tetra(meth)acrylate, pentaerythritol tri- or tetra(meth)acrylate, ditrimethylolpropane tri- or tetra(meth)acrylate, and dipentaerythritol tri-, tetra-, penta-, or hexa(meth)acrylate; tri-, tetra-, penta-, or hexa(meth)acrylates of alkylene oxide adducts of these polyols; and tri(meth)acrylates having an isocyanuric acid skeleton, such as tri(meth)acrylates of isocyanuric acid ethylene oxide adducts. In this case, examples of the alkylene oxide in the alkylene oxide adduct include ethylene oxide, propylene oxide, tetramethylene oxide, and a combination of ethylene oxide and propylene oxide.

[0021] Examples of polyfunctional (meth)acrylamides include N,N-bis(2-acrylamidoethyl)acrylamide, N-[tris(3-acrylamidopropoxymethyl)methyl]acrylamide, and N,N-1,2-ethanediyl "N-[2-(acryloylamino)ethyl]acrylamide."

[0022] Examples of polyfunctional vinyl compounds include 1,4-divinylbenzene, 1,3-divinylbenzene, and 2,5-divinylterephthalaldehyde.

[0023] Examples of polyfunctional (meth)allyl monomers include diallyl fumarate, diallyl adipate, triallyl citrate, diallyl hexahydrophthalate, diallyl hexahydrophthalate, trimethylolpropane diallyl ether, 1,3-diallyloxy-2-propanol, and pentaerythritol tetraallyl ether.

[0024] Among these compounds of component A, it is preferable to use at least a compound having three or more ethylenically unsaturated groups, because a high crosslink density is easily obtained.

[0025] The compound of component A is effective when it has two or more ether groups, for example, three or more, four or more, five or more, six or more, etc. Examples include glycerin tri(meth)acrylate, diglycerin tri- or tetra(meth)acrylate, pentaerythritol tri- or tetra(meth)acrylate, dipentaerythritol tri-, tetra-, penta- or hexa(meth)acrylate, and tri-, tetra-, penta- or hexa(meth)acrylates of alkylene oxide adducts of these polyols.

[0026] As component A, it may be preferable to use a combination of a compound having three ethylenically unsaturated groups such as (meth)acryloyl groups and a compound having four, five, or six (especially five or six) ethylenically unsaturated groups such as (meth)acryloyl groups. This is because it is easy to ensure crosslink density and to obtain a crosslinked structure with excellent water resistance. Furthermore, such combinations are not particularly limited, but examples include a combination of glycerin tri(meth)acrylate as the former and tetra-, penta-, or hexa(meth)acrylate of dipentaerythritol as the latter (preferably penta- and hexa(meth)acrylate of dipentaerythritol). Furthermore, preferably, both are acrylates. The mass ratio of the compound having three ethylenically unsaturated groups to the compound having four to six ethylenically unsaturated groups is not particularly limited, but for example, the compound having three ethylenically unsaturated groups accounts for 10% by mass or more and 15% by mass or less, and the compound having four to six ethylenically unsaturated groups accounts for 85% by mass or more and 90% by mass or less, relative to the total mass of these.

[0027] It may be preferable to use the above-mentioned compound of Component A as Component A. Furthermore, examples of compounds having two or more ethylenically unsaturated groups other than the above-mentioned Component A include urethane (meth)acrylate, polyester (meth)acrylate, epoxy (meth)acrylate, and polyether (meth)acrylate. These other compounds having two or more ethylenically unsaturated groups described here are compounds selected after the compound of Component A. Therefore, it may be preferable not to use this type of Component A, such as urethane (meth)acrylate.

[0028] The content of component A in the composition can be appropriately set within a range that satisfies the crosslink density and rust prevention performance described below. The content of component A is not particularly limited, but can be, for example, 65% by mass or more of the total mass of the curable components in the composition. Here, the curable components in the composition are component A, component B, and component C having an ethylenically unsaturated group, which are polymerized by component D. If the content of component A is less than 65% by mass, the crosslinked network tends to be loose, and moisture permeability (water resistance) tends to increase. The content of component A is, for example, 66% by mass or more, 67% by mass or more, 68% by mass or more, 70% by mass or more, 72% by mass or more, or 75% by mass or more.

[0029] The content of component A is, for example, 80% by mass or less. If it exceeds 80% by mass, cure shrinkage increases, the composition tends to separate from the adherend, and the rust prevention performance tends to decrease. Other examples include 78% by mass or less, 75% by mass or less, 73% by mass or less, 72% by mass or less, 70% by mass or less, 68% by mass or less, and 67% by mass or less.

[0030] The range of the content of Component A is not particularly limited, but may be, for example, 65% by mass or more and 80% by mass or less, and may be set by appropriately combining the above-mentioned lower limit and upper limit values.

[0031] (Component B) Component B is one or more compounds having one ethylenically unsaturated group. It is a so-called monofunctional compound. By having one ethylenically unsaturated group, it is possible to form a linear portion in the crosslinked structure formed together with the compound of component A. Component B is a concept that does not include component C, which will be described later, and does not include acids such as (meth)acrylic acid or salts thereof.

[0032] Component B contains a compound having at least one aromatic ring and one ethylenically unsaturated group (hereinafter also referred to as an aromatic compound). An aromatic ring refers to a ring structure having a π-electron count of [4n+2] according to Hückel's rule, where n is an integer. Examples of aromatic rings include hydrocarbon cyclic compounds and heterocyclic compounds. The aromatic ring interacts with component C, described below, allowing component C to be contained in the composition with good dispersibility. As a result, component C can be maintained with good dispersibility in the coating after curing by irradiation with active energy rays, making it easier for the coating to exhibit its fluoride ion capturing ability. Furthermore, the presence of such an aromatic ring also contributes to the water resistance of the coating.

[0033] The aromatic ring as a partial structure of an aromatic compound is one or more selected from a monocyclic component consisting of a single ring, a fused ring component in which at least two such monocyclic components share two atoms, and a ring assembly component in which at least two such monocyclic components are connected via a bond without sharing an atom. An aromatic compound can also have two or more of these components, which may be the same or different. Aromatic rings are generally components derived from hydrocarbon cyclic compounds and heterocyclic compounds. Examples of monocyclic components include a benzene ring. Examples of moieties having two monocyclic components include a diphenylmethane structure. Examples of fused ring components include a naphthalene structure. Examples of ring assembly components include a biphenyl structure.

[0034] In the aromatic ring, one, two, three, etc. hydrogen atoms bonded to carbon atoms on the ring may be substituted with an alkyl group having 1 to 4 carbon atoms such as a methyl group or an ethyl group, an alkoxy group having an alkyl group having 1 to 4 carbon atoms such as a methoxy group or an ethoxy group, a hydroxyl group, or an oxide adduct of an alkylene group having 1 to 4 carbon atoms.

[0035] The ethylenically unsaturated group in the aromatic compound is not particularly limited, but may be a (meth)acryloyl group, a (meth)acrylamide group, a vinyl group, a (meth)allyl group, or the like. A (meth)acryloyl group may be preferred in some cases. Such an ethylenically unsaturated group may be directly bonded to a carbon atom on the aromatic ring, may be bonded to the aforementioned substituent, or may be bonded to another part.

[0036] Examples of aromatic compounds include aromatic monofunctional (meth)acrylates such as phenyl(meth)acrylate, benzyl(meth)acrylate, phenoxyethyl(meth)acrylate, o-phenylphenol(meth)acrylate, (meth)acrylates of alkylene oxide adducts of phenol, (meth)acrylates of alkylene oxide adducts of alkylphenol, (meth)acrylates of alkylene oxide adducts of p-cumylphenol, and (meth)acrylates of alkylene oxide adducts of o-phenylphenol. Of these, the use of benzyl methacrylate and benzyl acrylate may be effective in some cases.

[0037] Examples of compounds having one ethylenically unsaturated group and no aromatic ring include (meth)acrylates having one (meth)acryloyl group and (meth)acrylamides having one (meth)acryloyl group.

[0038] Examples of (meth)acrylates having one ethylenically unsaturated group include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate nonyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate; polyethylene glycol monoalkyl ether (meth)acrylates such as mono-, di-, and triethylene glycol monoethyl (meth)acrylate, and mono-, di-, and triethylene glycol monomethyl (meth)acrylate; Polyol mono(meth)acrylates such as trimethylolpropane mono(meth)acrylate, glycerin mono(meth)acrylate, pentaerythritol mono(meth)acrylate, ditrimethylolpropane mono(meth)acrylate, and dipentaerythritol mono(meth)acrylate; and alkyl carbitol (meth)acrylates such as ethyl carbitol (meth)acrylate, butyl carbitol (meth)acrylate, and 2-ethylhexyl carbitol (meth)acrylate.

[0039] Furthermore, examples of the (meth)acrylate having one ethylenically unsaturated group without an aromatic ring include monofunctional (meth)acrylates having an alicyclic group, such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, tricyclodecanemethylol (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate.

[0040] As this type of component B having no aromatic ring, polyethylene glycol monoalkyl ether (meth)acrylates such as diethylene glycol monoethyl ether acrylate (ethoxyethoxyethyl acrylate) may be effective.

[0041] It may be preferable to use the above-described compound of component B that does not have an aromatic ring. Among them, polyethylene glycol monoalkyl ether (meth)acrylates such as diethylene glycol monoethyl ether acrylate may be effective as component B. Furthermore, it may be preferable to use, for example, benzyl (meth)acrylate in combination as the aromatic compound.

[0042] Examples of compounds of Component B other than the above-mentioned Component B include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, as well as 2-hydroxy-3-phenoxypropyl (meth)acrylate, etc. Furthermore, examples of monofunctional (meth)acrylates having a cyclic ether group include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclohexanespiro-2-(1,3-dioxolan-4-yl)methyl (meth)acrylate, 3-ethyl-3-oxetanylmethyl (meth)acrylate, etc. Furthermore, examples of the monofunctional (meth)acrylate having a heterocycle include (meth)acryloylmorpholine and compounds having a maleimide group, and examples of the monofunctional (meth)acrylate having an imide group include N-(2-(meth)acryloxyethyl)hexahydrophthalimide and N-(2-(meth)acryloxyethyl)tetrahydrophthalimide.

[0043] The content of component B in the composition can be appropriately set within a range that satisfies the crosslink density and rust prevention performance described below. The content of component B is not particularly limited, but can be, for example, 15 mass% or more of the total mass of the curable components in the composition. If the content of component B is less than 15 mass%, the water resistance of the coating tends to decrease, the dispersibility of component C tends to decrease, and the fluorine ion trapping ability tends to decrease. The content of component B is, for example, 17 mass% or more, 18 mass% or more, 20 mass% or more, 22 mass% or more, 23 mass% or more, or 24 mass% or more.

[0044] The content of Component B is, for example, 30% by mass or less. If it exceeds 30% by mass, the crosslinked network becomes large and the rust prevention performance tends to decrease. The content of Component B is, for example, 28% by mass or less, 27% by mass or less, 26% by mass or less, 25% by mass or less, 24% by mass or less, or 23% by mass or less.

[0045] The range of the content of component B is not particularly limited, but may be, for example, from 15% by mass to 30% by mass, or may be set by appropriately combining the above-mentioned lower limit and upper limit values, for example, from 15% by mass to 28% by mass, or from 15% by mass to 25% by mass, etc.

[0046] The aromatic compound in Component B is, for example, 50% by mass or more of the total mass of Component B. If it is less than 50% by mass, it tends to be difficult to impart sufficient water resistance and dispersibility of Component C to the coating. The aromatic compound is, for example, 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass or more of Component B. Furthermore, the aromatic compound in Component B can be 7% by mass or more and 27% by mass or less, 8% by mass or more and 25% by mass or less, or 10% by mass or more and 25% by mass or less of the total mass of the curable components in the composition.

[0047] (Component C) One or more metal salts selected from metal salts containing an ethylenically unsaturated group and metal salts not containing an ethylenically unsaturated group. The metal salt can capture fluorine ions derived from hydrogen fluoride. When an ethylenically unsaturated group is contained, the metal salt contains one such group. The metal salt containing an ethylenically unsaturated group is also a curable component in the composition. As component C, one or more metal salts can be used in appropriate combination.

[0048] The metal salt containing an ethylenically saturated group is not particularly limited, but examples of metal salts containing an ethylenically unsaturated group include metal salts of (meth)acrylic acid, as well as maleic acid, itaconic acid, and crotonic acid. Other examples include metal salts of ethylenically unsaturated compounds having a sulfonic acid group, such as acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, and (meth)allylsulfonic acid. Still other examples include metal salts of ethylenically unsaturated compounds having a phosphoric acid group, such as phosphoric acid-containing (meth)acrylates, such as esters of phosphoric acid and (meth)acrylic acid.

[0049] Examples of metal salts that do not contain an ethylenically unsaturated group include metal salts of carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, and isobutyric acid. Examples of metal salts of inorganic acids that do not contain an ethylenically unsaturated group include metal chlorides and sulfates.

[0050] The metal constituting the metal salt is not particularly limited, but examples thereof include alkaline earth metal salts such as calcium salts, barium salts, and magnesium salts, and zinc salts. Among these salts, examples of salts containing an ethylenically unsaturated group include the aforementioned compounds having a carboxy group and an ethylenically unsaturated group, such as calcium (meth)acrylate (calcium (meth)acrylic acid), magnesium (meth)acrylate (magnesium (meth)acrylic acid), zinc (meth)acrylate (zinc (meth)acrylic acid), and calcium maleate, compounds having a sulfonic acid group and an ethylenically unsaturated group, and compounds having a phosphoric acid group and an ethylenically unsaturated group. Examples of salts not containing an ethylenically unsaturated group include alkaline earth metal and zinc salts of the above-mentioned various carboxylic acids and inorganic acids.

[0051] A calcium salt containing an ethylenically unsaturated group such as a (meth)acryloyl group may be preferred as component C in the composition. A photopolymerization initiator may be able to effectively bond with fluorine ions.

[0052] The content of component C in the composition can be appropriately set within a range that satisfies the crosslink density and rust-preventive performance described below. The content of component C is not particularly limited, but can be, for example, 7.5 mass% or more of the total mass of the composition. If the content of component C is less than 7.5 mass%, fluoride ion capture tends to be insufficient, resulting in reduced rust-preventive performance. The content of component C is, for example, 7.7 mass% or more, 7.8 mass% or more, 8.0 mass% or more, 8.2 mass% or more, 8.4 mass% or more, 8.6 mass% or more, or 8.8 mass% or more.

[0053] The content of component C is, for example, 15% by mass or less. If the content exceeds 15% by mass, component C will disperse in the composition without dissolving, and if the content is too high, there is a risk of blocking active energy rays and inhibiting curing. The content of component C is, for example, 14% by mass or less, 13% by mass or less, 12% by mass or less, 11% by mass or less, or 10% by mass or less.

[0054] The content of component C can be in the range of 7.5% by mass or more and 15% by mass or less of the total mass of the composition, and can also be set by appropriately combining the above-mentioned lower and upper limits.

[0055] (Component D) Component D is one or more photopolymerization initiators. Component D is a component to be blended when ultraviolet light and visible light are used as the active energy rays. When electron beams are used as the active energy rays, it is not necessarily required to blend Component D, but a small amount can be blended as needed to improve curability.

[0056] Examples of the photopolymerization initiator include benzil dimethyl ketal, benzil, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, oligo[2-hydroxy-2-methyl-1-[4-1-(methylvinyl)phenyl]propanone, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-pro aromatic ketone compounds such as 2-methyl-1-[4-(methylthio)]phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)butan-1-one, 3,6-bis(2-methyl-2-morpholinopropionyl)-9-n-octylcarbazole, methyl phenylglyoxylate, ethyl anthraquinone, and phenanthrenequinone; Benzophenone-based compounds such as benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 4-(methylphenylthio)phenylphenylmethane, methyl-2-benzophenone, 1-[4-(4-benzoylphenylsulfanyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)propan-1-one, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, and 4-methoxy-4'-dimethylaminobenzophenone; acylphosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl(2,4,6-trimethylbenzoyl)phenylphosphineate, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide;Thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propylthioxanthone, 3-[3,4-dimethyl-9-oxo-9H-thioxanthone-2-yl-oxy]-2-hydroxypropyl-N,N,N-trimethylammonium chloride, and fluorothioxanthone are included;

[0057] Among these compounds, aromatic ketone compounds such as 2-methyl-1-[4-(methylthio)]phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, and 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)butan-1-one may be preferred because they have good surface curing properties even when used in thin film coatings. Thioxanthone compounds such as 2,4-diethylthioxanthone may also be preferred. These compounds may be used alone or in combination.

[0058] The content of component D in the composition can be appropriately set within a range that satisfies the crosslink density and rust prevention performance described below. The content of component D is not particularly limited, but can be, for example, 7.5 mass% or more of the total mass of the composition. If the content of component D is less than 7.5 mass%, the curing reaction tends to be insufficient, making it difficult to sufficiently block moisture. The content of component D is, for example, 7.7 mass% or more, 7.8 mass% or more, 8.0 mass% or more, 8.2 mass% or more, 8.4 mass% or more, 8.6 mass% or more, or 8.8 mass% or more.

[0059] The content of component D is, for example, 15% by mass or less. If it exceeds 15% by mass, the amount of unreacted component D increases, and the rust-preventing performance tends to be easily reduced due to plasticization of the cured product by the residue. The content of component D is, for example, 14% by mass or less, 13% by mass or less, 12% by mass or less, 11% by mass or less, 10% by mass or less, or 9% by mass or less.

[0060] The content of component D can be in the range of 7.5% by mass or more and 15% by mass or less of the total mass of the composition, and can also be set by appropriately combining the above-mentioned lower and upper limits.

[0061] In addition, the composition may contain organic solvents, antioxidants, UV absorbers, pigments / dyes, leveling agents, silane coupling agents, etc. as needed. Organic solvents, antioxidants, UV absorbers, pigments / dyes, leveling agents, and silane coupling agents are well known to those skilled in the art, as disclosed in JP 2019-108426 A, JP 2019-196461 A, JP 2022-172885 A, etc., and those skilled in the art can appropriately select the type and appropriately set the content. The composition can be used as a solvent-free composition, but can also be used as a solvent-based composition by blending an organic solvent. By including an organic solvent, the viscosity of the composition can be adjusted to improve coatability, and the film thickness can be adjusted according to the purpose.

[0062] When the composition is a solvent-based composition, a solvent having an aromatic ring can be used. This can improve the dispersibility of component C in the composition. Examples of such solvents include, but are not limited to, xylene, toluene, benzene, cresol, etc. When the composition is a solvent-based composition, such a solvent having an aromatic ring can sometimes replace part or all of component B.

[0063] (Crosslink Density) It may be preferable that the composition has a crosslink density (mol / kg) of 7.3 or more, as represented by the following formula (1). The crosslink density can be adjusted by the total amount of Components A, B, and C, and the number of ethylenically unsaturated groups and the molar mass of the compound having two or more ethylenically unsaturated groups in Component A. The crosslink density can be calculated based on the types of Components A, B, and C in the composition and their compositions at the time of charging.

[0064] The crosslink density (mol / kg) represented by the following formula (1) is 7.3 or more.

[0065] In formula (1), wi represents the mass fraction of component i (where component i represents a curable component, and 1≦i≦n, and n is an integer of 2 or more) in the active energy ray-curable composition, and Mci represents the molecular weight between crosslinking points (kg / mol) of component i.

[0066] The crosslink density disclosed herein defines the ratio of the total number of crosslinking points (total number of moles) to the total mass of the curable components in the composition. The curable components include a crosslinking agent in addition to a monomer component having a polymerizable functional group.

[0067] In the numerator and denominator of formula (1), wi represents the mass fraction of component i. Furthermore, Mci in the numerator of formula (1) represents the molecular weight between crosslink points (kg / mol) of component i.

[0068] As a result, the numerator of formula (1) is the total number (mol) of crosslinking points for component i (1≦i≦n, n is an integer of 2 or greater), and the denominator of formula (1) is the total mass (kg) of component i. As a result, as described above, formula (1) defines the ratio of the total amount (mol) of crosslinking points to the total mass (kg) of the curable components.

[0069] The crosslink density is an index of the fineness of the network structure of the crosslinked structure of the coating obtained by curing the composition, and it is believed that the higher the crosslink density, the finer the network structure formed by crosslinking.

[0070] If the crosslink density is 7.3 or more, the network of the crosslinked structure in the coating tends to become loose, moisture tends to permeate more easily, and the rust prevention performance tends to decrease. The crosslink density is, for example, 7.4 or more, 7.5 or more, 7.6 or more, 7.7 or more, 7.8 or more, 7.9 or more, 8.0 or more, 8.1 or more, 8.2 or more, 8.3 or more, 8.4 or more, or 8.5 or more.

[0071] In addition, it may be preferable that the crosslink density is 10.0 or less. Shrinkage due to curing increases, and the coating may become more susceptible to lifting or peeling off from the adherend, which may result in a decrease in rust prevention performance. The crosslink density may be, for example, 9.9 or less, 9.8 or less, 9.7 or less, 9.6 or less, 9.5 or less, 9.4 or less, 9.3 or less, 9.2 or less, 9.1 or less, 9.0 or less, 8.9 or less, 8.8 or less, 8.7 or less, 8.6 or less, 8.5 or less, or 8.4 or less.

[0072] The range of the crosslink density can be from 7.3 to 10.0, or can be set by appropriately combining the above-mentioned lower and upper limits, for example, from 7.4 to 9.5, from 7.5 to 9.5, from 7.6 to 9.5, from 7.8 to 9.2, from 7.8 to 9.0, or from 7.8 to 8.5.

[0073] (Hot Water Absorption Rate) The composition may be cured by the following method: a 50 mm x 50 mm x 2 mm cured product of the composition is dried at 50°C for 1 hour, allowed to stand at 23±2°C and 50±5% RH for 24 hours, and then immersed in 60°C water for 24 hours, and the amount of cured material is measured before and after immersion. The hot water absorption rate calculated by the following formula may preferably be less than 1.6 mass%: Hot Water Absorption Rate (%) = (Amount of cured material after immersion - Amount of cured material before immersion) / Amount of cured material before immersion x 100

[0074] In the above method, the cured product was obtained as follows: A 7 cm square, 2 mm thick rubber sheet with a 5 cm square hole in the center was placed on a 10 cm square polyethylene terephthalate (PET) film, the composition was poured into it, and the liquid surface was laminated with the same PET film as above. The top and bottom of the sheet were then sandwiched and fixed between 10 cm square glass plates, and the sheet was irradiated with ultraviolet light from an 80 W / cm high-pressure mercury lamp. The lamp was set to a height of 30 cm, and both sides were irradiated for 30 seconds each, and then the glass plates and PET film were removed and the front and back were irradiated for 1 minute each.

[0075] The hot water absorption is an index of the water resistance of the coating, which is a cured product obtained by curing the composition. High hot water absorption is thought to facilitate penetration of water or moisture in the air under humid conditions into the coating, i.e., to increase water permeability (moisture permeability). The hot water absorption can be adjusted, for example, by the aromatic compound as component B and the crosslink density.

[0076] If the hot water absorption rate is 1.6% by mass or more, water permeability increases and rust prevention performance tends to decrease. The hot water absorption rate is, for example, 1.5% by mass or less, 1.4% by mass or less, 1.3% by mass or less, 1.2% by mass or less, 1.1% by mass or less, or 1.0% by mass or less.

[0077] The hot water absorption rate is not particularly limited, but is, for example, 0.0% by mass or more, or 0.1% by mass or more.

[0078] (Calcium Salt Dispersibility and Rust Prevention Performance) The composition can exhibit good calcium salt dispersibility as measured by the measurement method described in the Examples below. Furthermore, a coating obtained from the composition can exhibit excellent rust prevention performance (rating A or B) in a rust prevention evaluation as measured by the measurement method described in the Examples below. That is, the rust area ratio obtained for the cured product by the procedure disclosed in the Examples is less than 10%.

[0079] (Use of the composition) The composition can be used, for example, as a coating agent. A coating obtained by supplying and curing the composition can exhibit excellent rust prevention performance by containing a combination of Component A, which contributes to the crosslink density of the coating, Component B, which contributes to the dispersibility of Component C and the water resistance of the coating, and Component C, which contributes to acid resistance, etc.

[0080] Therefore, the composition can be used as a coating composition for forming a coating intended to prevent rust, as well as a coating composition for forming a coating intended to be water resistant or acid scavenging. A method for producing a coating from the composition will be described later.

[0081] The object of the coating obtained by curing the composition (coating target) is not particularly limited, and examples include the surface of inorganic materials such as metal materials, and organic materials such as artificial polymer materials and natural polymer materials. Furthermore, a coated object having a coating is a structure having a coated target on at least a part thereof.

[0082] When the coating is intended to prevent rust, the surface of the object to be coated is made of a metal material such as stainless steel or aluminum. The application of the composition and coating is not particularly limited, but for example, LiPF of a lithium ion secondary battery. ６ Examples of such structures include those having a coating target that may come into contact with an electrolyte solution containing the above-mentioned compound.

[0083] The thickness of the resulting coating is not particularly limited and is set appropriately depending on the application of the coating. For example, the thickness can be about several μm to several tens of μm.

[0084] (Method for preventing rust on an object to be coated) The method for preventing rust on an object to be coated disclosed in this specification comprises supplying a composition to the surface of an object to be coated, the surface of the object having a surface made of a metal material, and irradiating the composition on the surface of the object to be coated with active energy rays. According to this rust prevention method, even when the surface of the object to be coated comes into contact with a highly corrosive acid under humid conditions, the coating has excellent water resistance and acid resistance, and therefore rust formation on the surface of the object to be coated can be effectively prevented.

[0085] The method for obtaining a coating using the composition may be any conventional method used for obtaining a coating from this type of composition. For example, the composition may be supplied to the object to be coated by various methods, and then irradiated with active energy rays. If the composition is not solvent-free but contains an organic solvent, the composition is supplied to the adherend, heated and dried to evaporate the organic solvent, and then irradiated with active energy rays.

[0086] The method for supplying the composition to the coating target is not particularly limited, and any known method used in forming a coating can be used as appropriate. Examples of active energy rays irradiated onto the composition include ultraviolet light, visible light, and electron beams, with ultraviolet light being preferred. Examples of ultraviolet irradiating devices include high-pressure mercury lamps, metal halide lamps, UV electrodeless lamps, and LEDs. The irradiation energy should be appropriately set depending on the type of active energy ray and the formulation. For example, when a high-pressure mercury lamp is used, the irradiation energy in the UV-A region is 100 to 5,000 mJ / cm. 2 is preferred, and 200 to 1,000 mJ / cm 2 is more preferred.

[0087] (Method for manufacturing a coated body) The method for manufacturing a coated body disclosed in this specification includes supplying a composition to the surface of a coating target, which is at least a part of the coated body, and irradiating the composition on the surface of the coating target with active energy rays. This manufacturing method makes it possible to obtain a coated body having a coating that is excellent in water resistance and acid resistance, and as a result, exhibits high rust prevention performance. In addition to the coating target, coated body, and composition used in this manufacturing method, the method for forming the coating can take various forms as described above. Such a coated body can be, for example, LiPF ６ The present invention can be used for components that may come into contact with an electrolyte solution containing a lithium salt, such as the above.

[0088] The method for preventing rust from occurring on an object to be coated and the method for manufacturing an object to be coated have been described above. However, the method for obtaining a coating by supplying a composition and curing it can also be carried out as a method for imparting water resistance and / or acid resistance to the object to be coated.

[0089] Examples will be described below as specific examples to more specifically explain the disclosure of this specification. The following examples are provided to illustrate the disclosure of this specification and are not intended to limit the scope thereof. In the following examples, unless otherwise specified, "parts" and "%" represent parts by mass and % by mass, respectively.

[0090] (Preparation of active energy ray-curable composition) The compounds shown in Table 1 were stirred, mixed, and dissolved in a stainless steel vessel in the proportions shown in Table 1 to prepare active energy ray-curable compositions. As comparative examples, compositions shown in Table 2 were prepared in the same manner. Furthermore, reference examples were also prepared in the same manner.

[0091]

[0092]

[0093] The numbers in Tables 1 and 2 indicate the number of copies, and the abbreviations have the following meanings.・M-402: A reaction product of dipentaerythritol and acrylic acid, mainly composed of dipentaerythritol penta / hexaacrylate, manufactured by Toagosei Co., Ltd., "Aronix M-402" (number of functional groups per molecule: 5.7, molecular weight: 562); ・UN-6200: Urethane acrylate (number of functional groups per molecule: 2.0, molecular weight: 27,000), manufactured by Negami Chemical Industrial Co., Ltd., "Art Resin UN-6200"; ・M-309: Trimethylolpropane triacrylate, manufactured by Toagosei Co., Ltd., "Aronix M-309" (number of functional groups per molecule: 3.0, molecular weight: 296); ・M-930: Glycerin triacrylate, manufactured by Toagosei Co., Ltd., "Aronix M-930" (number of functional groups per molecule: 3.0, molecular weight: 254). OT-1005: urethane acrylate, Toagosei Co., Ltd. "Aronix OT-1005" (number of unsaturated ethylene groups per molecule: 3.0, molecular weight: 312, acryloyl group concentration: 3.201 mol / kg) BzMA: benzyl methacrylate, Kyoeisha Chemical Co., Ltd. "Light Ester Bz" (number of functional groups per molecule: 1.0) BzA: benzyl acrylate, Osaka Organic Chemical Industry Co., Ltd. "Viscoat #160" (number of functional groups per molecule: 1.0) ACMO: acryloylmorpholine, KJ Chemicals Co., Ltd. "ACMO" (number of functional groups per molecule: 1.0) EEEA: ethoxyethoxyethyl acrylate, Osaka Organic Chemical Industry Co., Ltd. "Viscoat #190" (number of functional groups per molecule: 1.0) IBXA: isobornyl acrylate, "IBXA" manufactured by Osaka Organic Chemical Co., Ltd. (number of functional groups per molecule: 1.0) Ca(Me) ２: Calcium methacrylate, manufactured by Tokyo Chemical Industry Co., Ltd. "Calcium Methacrylate" (number of functional groups per molecule: 2.0, molecular weight: 210.24) Om-907: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, manufactured by IGM Resins "Omnirad 907" DETX: Diethylthioxanthone, manufactured by IGM Resins "Omnirad DETX" SH-28: Polyether-modified silicone, manufactured by The Dow Chemical Company "DOWSIL SH-28" OA-386: 1-[N,N-bis(2-ethylhexyl)aminomethyl]-4 or 5-methylbenzotriazole, manufactured by Daiwa Kasei Co., Ltd. "VERZONE" OA-386"

[0094] (Evaluation of Rust Prevention Performance) A cured product was prepared by the following procedure. An electrolyte ("Lithium hexafluorophosphate (LiPF) manufactured by Sigma-Aldrich) was applied to an SS400 steel plate test piece. ６ ) solution") to 1 cm ２ After applying 0.01 g per coating, the prepared composition was applied on top of the electrolyte solution using a bar coater, and then irradiated with ultraviolet light of 365 nm using an LED light source to prepare a cured product. The ultraviolet light intensity was 250 mW / cm ２ , the cumulative light intensity is 1000 mJ / cm ２ The film thickness of the cured product was set to 10 μm.

[0095] Next, the prepared cured product was left for 72 hours under conditions of 60°C and 90% RH, and the area where the electrolyte was applied was visually inspected for rust and evaluated according to the following four levels: A: Rust occurred in less than 5% of the entire area where the electrolyte was applied B: Rust occurred in 5% or more but less than 10% of the entire area where the electrolyte was applied C: Rust occurred in 10% or more but less than 50% of the entire area where the electrolyte was applied D: Rust occurred in 50% or more of the entire area where the electrolyte was applied

[0096] (Evaluation of Hot Water Absorption Rate) A cured product was prepared using the following procedure. A 7 cm square, 2 mm thick rubber sheet with a 5 cm square hole in the center was placed on a 10 cm square polyethylene terephthalate (PET) film, the composition was poured into it, and the liquid surface was laminated with the same PET film as above. After that, the top and bottom surfaces were sandwiched and fixed between 10 cm square glass plates, and ultraviolet light was irradiated from an 80 W / cm high-pressure mercury lamp. The lamp height was 30 cm, and irradiation was carried out for 30 seconds on both sides, and then, with the glass plates and PET film removed, irradiation was carried out for 1 minute on each side to obtain a cured product.

[0097] The cured product was then dried at 50°C for 1 hour, conditioned at 23±0.5°C and 50±2.5% RH for 24 hours, and then immersed in water at 60°C for 24 hours. The amount of the cured product was weighed before and after immersion. The hot water absorption (%) was calculated using the following formula:

[0098] Hot water absorption rate (%) = (change in mass before and after immersion / mass of hardened material before immersion) × 100 (mass%)

[0099] (Calcium salt dispersion test) A stirrer and 10 g of the composition prepared as described above were placed in a 20 mL screw cap bottle and stirred at 80°C for 30 minutes using a hot stirrer. The stirrer was then removed and the composition was left to stand at 23±0.5°C and 50±2.5% RH for 7 days, and the dispersibility of calcium in the composition was evaluated. Evaluation was based on the following criteria: ○: The calcium salt was dispersed, and no precipitate was observed in the supernatant or on the bottom of the container. ×: The calcium salt was precipitated, and at least one of the supernatant and precipitate on the bottom of the container was visible. -: Test not performed (due to the absence of calcium salt)

[0100] (Results) As is clear from the results of Examples 1 to 4, the coatings obtained from these compositions exhibited high anticorrosion performance (A to B). In addition, the coatings obtained from these compositions had a high crosslink density. At the same time, the coatings had a low water absorption rate (1.5% or less).

[0101] Comparing Examples 1 to 4 with Comparative Examples 1 and 2, the comparative coating obtained from a composition that did not contain calcium salt component C had poor rust-preventive performance (rating D), with significantly reduced rust-preventive properties. From the above, it is believed that the calcium salt bonded with the acid fluoride ions that cause rusting, turning into calcium fluoride, which is insoluble in water and inactive, thereby preventing rust.

[0102] Comparing Examples 1 to 4 with Comparative Example 3, the coatings obtained from compositions that did not contain Component B, a curable component having an aromatic ring, had poor rust prevention properties (evaluation D). This is thought to be because in Examples 1 to 4, the calcium salt was stably dispersed in the cured product due to the π-cation interaction acting between the π electrons on the aromatic ring and the calcium salt.

[0103] Comparing the results of the dispersion test of calcium salt in the composition, it was found that the calcium salt was stably dispersed in the resin for one week in Examples 1 to 4, whereas sedimentation was observed in Comparative Example 3. This result supports the above-mentioned observation.

[0104] Furthermore, when Examples 1 to 4 were compared with Comparative Example 3, the coating obtained from Comparative Example 3, in which Component B was ACMO, which has a high affinity for water, rather than Component B, a curable component having an aromatic ring, had a high water absorption rate (3.64%). This suggests that Component B, which has an aromatic ring, also contributes to suppressing water absorption.

[0105] Comparing Examples 1 to 4 with Comparative Examples 4 to 10, coatings obtained from compositions with low crosslink densities exhibited poor rust-preventive performance (evaluations C to D). These results suggest that a low crosslink density does not prevent moisture from passing through from the ambient air (moisture permeability), resulting in insufficient rust prevention. In particular, Comparative Examples 4 and 5 demonstrated that even when a coating contains Component B having an aromatic ring and Component C, which is a calcium salt, if the content of Component A is low (60%, 40%) and the crosslink density is low, the rust-preventive performance decreases depending on the crosslink density, even if the water absorption rate is maintained. Furthermore, Comparative Examples 6 and 7 demonstrated that, even when a coating contains Component B having an aromatic ring and Component C, which is a calcium salt, the crosslink density is reduced, resulting in reduced rust-preventive performance and increased water absorption rate, by using urethane acrylate (OT-1005) as Component A. Furthermore, Comparative Examples 8 and 9 show that by changing M-402, which has 5.7 functional groups per molecule and is one of the components A, to UN-6200 (urethane acrylate (oligomer)), which has 2 functional groups per molecule, the crosslink density also decreases and the water absorption rate increases significantly. Furthermore, Comparative Examples 3 and 10 show that using a non-aromatic ring-containing acrylate, such as acroylmorpholine or isobornyl acrylate, which does not have an aromatic ring, as component B reduces calcium salt dispersibility.

[0106] Comparing Examples 1 to 4 with Comparative Example 11, Comparative Example 11, which used a benzotriazole-based rust inhibitor, showed poor rust prevention (evaluation D). This result shows that by including Component C, sufficient rust prevention performance can be exhibited under harsh conditions where conventional rust inhibitors such as benzotriazole-based rust inhibitors cannot suppress rust formation.

[0107] To confirm the effect of the aromatic ring, a composition containing xylene as a non-polymerizable aromatic ring compound, as in the Reference Example, was investigated. The results of Comparative Example 3 and the Reference Example show that the addition of xylene significantly improved the dispersibility of the Ca salt. It can be inferred that the dispersion stability of the Ca salt can be improved by including an aromatic ring compound, not limited to a monomer.

[0108] From the above, it was found that the crosslink density obtained based on component A, the water resistance obtained based on components A and B, and the acid scavenging ability (acid resistance) based on component C improve the rust prevention performance of the coating obtained from the composition.

Claims

1. An active energy ray-curable composition comprising: (Component A) one or more compounds having two or more ethylenically unsaturated groups; (Component B) one or more compounds having at least one aromatic ring and one ethylenically unsaturated group; and (Component C) one or more metal salts having and / or not having an ethylenically unsaturated group, wherein Component A comprises a (meth)acrylate (excluding urethane (meth)acrylate) having three or more (meth)acryloyl groups, and the (meth)acrylate accounts for 65% by mass or more and 80% by mass or less of the total mass of curable components in the active energy ray-curable composition; Component B accounts for 15% by mass or more and 30% by mass or less of the total mass of curable components in the active energy ray-curable composition; and Component C accounts for 7.5% by mass or more and 15% by mass or less of the total mass of the active energy ray-curable composition.

2. The active energy ray-curable composition according to claim 1, wherein the (meth)acrylate comprises a (meth)acrylate having three (meth)acryloyl groups and a (meth)acrylate having five to six (meth)acryloyl groups.

3. The active energy ray-curable composition according to claim 2, wherein the (meth)acrylate having three (meth)acryloyl groups and the (meth)acrylate having five to six (meth)acryloyl groups include glycerin triacrylate and dipentaerythritol pentaacrylate and hexaacrylate, respectively.

4. The active energy ray-curable composition according to any one of claims 1 to 3, wherein component B comprises a (meth)acrylate having one aromatic ring and one (meth)acryloyl group.

5. The active energy ray-curable composition according to claim 4, wherein the (meth)acrylate having one aromatic ring and a (meth)acryloyl group is benzyl (meth)acrylate.

6. The active energy ray-curable composition according to any one of claims 1 to 5, wherein component C comprises a salt of an alkaline earth metal containing a (meth)acryloyl group.

7. The active energy ray-curable composition according to claim 6, wherein the alkaline earth metal salt containing a (meth)acryloyl group is calcium methacrylate.

8. The active energy ray-curable composition according to any one of claims 1 to 7, wherein the hot water absorption calculated by the following formula is less than 1.6 mass% when a 50 mm x 50 mm x 2 mm cured product of the active energy ray-curable composition is dried at 50°C for 1 hour, allowed to stand at 23±2°C and 50±5% RH for 24 hours, and then immersed in 60°C water for 24 hours, and the amount of cured material is measured before and after immersion: Hot water absorption (%) = (amount of cured material after immersion - amount of cured material before immersion) / amount of cured material before immersion × 100 9. The active energy ray-curable composition was prepared by the following method: An electrolyte (Sigma-Aldrich, "Lithium hexafluorophosphate (LiPF ６ ) solution") to 1 cm ２ After applying 0.01 g per 1000 μm film, the active energy ray-curable composition was applied on top of the electrolyte solution using a bar coater, and irradiated with 365 nm ultraviolet light using an LED light source (ultraviolet light intensity: 250 mW / cm ２ , the cumulative light amount is 1000 mJ / cm ２ 9. The active energy ray-curable composition according to claim 1, wherein the active energy ray-curable composition is cured in a film thickness of 10 μm by the above-mentioned method, and the cured product is left to stand under conditions of 60°C and 90% RH for 72 hours, and the area where rust has occurred is checked.

10. An active energy ray-curable composition comprising: (Component A) one or more compounds having two or more ethylenically unsaturated groups; (Component B) one or more compounds having at least one aromatic ring and one ethylenically unsaturated group; and (Component C) one or more metal salts having and / or not having an ethylenically unsaturated group, wherein the active energy ray-curable composition has a crosslink density (mol / kg) of 7.3 or more, as represented by the following formula (1): In formula (1), wi represents the mass fraction of component i (where component i represents a curable component, 1≦i≦n, and n is an integer of 2 or more) in the active energy ray-curable composition, and Mci represents the molecular weight between crosslinking points (kg / mol) of component i.

11. The active energy ray-curable composition according to claim 10, wherein component A includes the compound having three or more ethylenically unsaturated groups.

12. The active energy ray-curable composition according to claim 10 or 11, wherein the active energy ray-curable composition contains component A in an amount of 65 mass % or more and 80 mass % or less of the total mass of the curable components in the active energy ray-curable composition.

13. ] The active energy ray-curable composition according to any one of claims 10 to 12, wherein the active energy ray-curable composition contains Component B in an amount of 15 mass% or more and 30 mass% or less of the total mass of the curable components in the active energy ray-curable composition.

14. The active energy ray-curable composition according to any one of claims 10 to 13, wherein the active energy ray-curable composition contains Component C in an amount of 7.5 mass% or more and 15 mass% or less of the total mass of the active energy ray-curable composition.

15. The active energy ray-curable composition according to any one of claims 10 to 14, further comprising (component D) a photopolymerization initiator, and comprising 7.5 mass % or more and 15 mass % or less of the total mass of the active energy ray-curable composition.

16. The active energy ray-curable composition according to any one of claims 10 to 15, wherein the hot water absorption of the active energy ray-curable composition is less than 1.6 mass% when measured by the following method: a 50 mm x 50 mm x 2 mm cured product of the active energy ray-curable composition is dried at 50°C for 1 hour, allowed to stand at 23±2°C and 50±5% RH for 24 hours, and then immersed in 60°C water for 24 hours, and the amount of the cured material is measured before and after immersion. Hot water absorption (%) = (amount of cured material after immersion - amount of cured material before immersion) / amount of cured material before immersion × 100 17. The active energy ray-curable composition was prepared by the following method: An electrolyte solution (Sigma-Aldrich, "Lithium hexafluorophosphate (LiPF ６ ) solution") to 1 cm ２ After applying 0.01 g per 1000 μm film, the active energy ray-curable composition was applied on top of the electrolyte solution using a bar coater, and irradiated with 365 nm ultraviolet light using an LED light source (ultraviolet light intensity: 250 mW / cm ２ , the cumulative light amount is 1000 mJ / cm ２ 17. The active energy ray-curable composition according to any one of claims 10 to 16, wherein the active energy ray-curable composition is cured by the above-mentioned method, and the cured product having a film thickness of 10 μm is left under conditions of 60°C and 90% RH for 72 hours, and the area where rust has occurred is checked.

18. The active energy ray-curable composition according to any one of claims 1 to 17, which is a coating composition for a coating object having a surface made of a metal material.

19. A method for preventing rust on an object to be coated, comprising: supplying the active energy ray-curable composition according to any one of claims 1 to 18 to a surface of the object to be coated, the surface being made of a metal material; and irradiating the active energy ray-curable composition on the surface of the object to be coated with active energy rays.

20. A method for producing an object to be coated with a coating, comprising: supplying an active energy ray-curable composition according to any one of claims 1 to 18 to a surface of the object to be coated; and irradiating the active energy ray-curable composition on the surface of the object to be coated with active energy rays.

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