Blocked polyisocyanate composition, resin composition, cured resin and laminated body

Abstract

To provide a blocked polyisocyanate composition, a resin composition, a cured resin, and a laminated body.SOLUTION: Provided is a blocked polyisocyanate composition of which the isocyanate group of a polyisocyanate compound is blocked with a blocking agent in which the polyisocyanate compound is a polyisocyanate compound derived from one or more diisocyanates selected from a group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate, the blocking agent includes a blocking agent (a) and a blocking agent (b), and a molar ratio of a structure derived from the blocking agent (a) and a structure derived from the blocking agent (b), (the blocking agent (a) / (the blocking agent (b)) is 20 / 80-90 / 10.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a blocked polyisocyanate composition, a resin composition, a cured resin, and a laminate. [Background technology]

[0002] Coating films obtained from two-component polyurethane compositions using a polyisocyanate composition derived from an aliphatic diisocyanate or an alicyclic diisocyanate as a curing agent exhibit excellent performance in terms of weather resistance, chemical resistance, abrasion resistance, etc., and are therefore widely used as paints, inks, adhesives, etc. In recent years, there has been growing awareness of global environmental issues, and two-component polyurethane compositions that do not use organic solvents or that use reduced amounts of organic solvents have been proposed.

[0003] Furthermore, from the viewpoint of ease of handling, one-component paints are desired whose paint properties do not change even when the base resin and curing agent are mixed. These are produced by protecting the isocyanate groups of the curing agent with a blocking agent, and by heating after application on site, the isocyanate groups are regenerated and react with the hydroxyl groups of the base polyol to form a hardened coating film. Such isocyanates are called blocked polyisocyanates. Many blocking agents have been studied, and representative examples include phenol and methyl ethyl ketoxime.

[0004] However, the curing temperature is high, and the high baking temperature not only consumes a lot of energy, but also limits the application to materials that are not heat-resistant. Several methods have been proposed to lower the curing temperature of blocked polyisocyanates. Known blocking agents for blocked polyisocyanates include oximes, phenols, alcohols, and lactams.

[0005] As blocked polyisocyanates capable of forming crosslinked coating films at relatively low temperatures, pyrazole-based blocked polyisocyanate compositions (see, for example, Patent Document 1) and aliphatic secondary amine-based blocked polyisocyanate compositions (see, for example, Patent Document 2) have been disclosed.

[0006] Furthermore, as blocked polyisocyanate compositions that can further lower the baking temperature, blocked polyisocyanate compositions using malonic acid diester as a blocking agent (see, for example, Patent Document 3) and blocked polyisocyanate compositions using diethyl malonate and ethyl acetoacetate as blocking agents (see, for example, Patent Documents 4 and 5) have been proposed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] European Patent Application Publication No. 159117 [Patent Document 2] Japanese Patent Application Publication No. 59-4658 [Patent Document 3] Japanese Patent Application Publication No. 57-121065 [Patent Document 4] Japanese Patent Application Publication No. 8-225630 [Patent Document 5] Japanese Patent Application Publication No. 9-255915 Summary of the Invention [Problem to be solved by the invention]

[0008] The baking conditions for film coating are usually high temperature (150 to 250°C) and short time (several minutes), and the film is characterized by being rolled up immediately after baking. To improve production efficiency, it is preferable to further shorten the baking time. Since the rolled-up film needs to be opened when proceeding to the next process, the surface drying property of the coating film or the curing property of the polyisocyanate composition is required.

[0009] Furthermore, since the coated film is often used outdoors, it is required to have excellent long-term resistance to moist heat. However, it was difficult for the blocked isocyanate compositions described in Patent Documents 1 to 5 to satisfy all of the above requirements.

[0010] Blocked polyisocyanate compositions such as those described in Patent Documents 1 and 2 generally require a baking temperature of about 120°C and a baking time of 30 minutes or more to form a crosslinked coating film, and there has been a problem in that a good crosslinked coating film cannot be formed under high temperature and short time conditions. Furthermore, the blocked polyisocyanate compositions described in Patent Documents 3, 4, and 5 can form crosslinked coating films at temperatures of 100°C or less for 30 minutes or more, or at high temperatures for a short period of time. However, the formed coating films have further issues, such as adhesion to substrates, chemical resistance, and long-term resistance to moist heat.

[0011] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a blocked polyisocyanate composition which retains its curability under high-temperature, short-time baking conditions, and which forms a crosslinked coating film that has excellent adhesion to the substrate, good compatibility with the base resin, and exhibits chemical resistance and long-term moist heat resistance, as well as a resin composition, a cured resin, and a laminate using the same. [Means for solving the problem]

[0012] That is, the present invention includes the following aspects. [1] A blocked polyisocyanate composition in which the isocyanate group of a polyisocyanate compound is blocked with a blocking agent, wherein the polyisocyanate compound is a polyisocyanate compound derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, the blocking agent includes a blocking agent (a) and a blocking agent (b), the blocking agent (a) is an active methylene-based compound, and the active methylene-based compound is a malonic acid diester compound and a β-ketoester compound. a blocked polyisocyanate composition comprising a malonic acid diester compound, the malonic acid diester compound being at least one selected from the group consisting of malonic acid diester compounds represented by the following formula (1), the β-ketoester compound being at least one selected from the group consisting of β-ketoester compounds represented by the following formula (2), the blocking agent (b) being a thermally dissociating blocking agent, and the molar ratio of a structure derived from the blocking agent (a) to a structure derived from the blocking agent (b) (blocking agent (a) / blocking agent (b)) being 20 / 80 to 90 / 10. [ka] [In formula (1), R 1 and R 2 R each independently represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a benzyl group. 1 and R 2 may be the same or different.] [ka] [In formula (2), R 3 and R 4 R each independently represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a benzyl group. 3 and R 4 may be the same or different.] [2] R in the above formula (1) 1 and R 2 are the same and are a methyl group, an ethyl group, or an isopropyl group, and R 3 and R4 is a methyl group or an ethyl group. [3] The blocked polyisocyanate composition according to [1] or [2], wherein the blocking agent (b) is at least one selected from the group consisting of oxime compounds, acid amide compounds, amine compounds, imidazole compounds, and pyrazole compounds. [4] The blocked polyisocyanate composition according to any one of [1] to [3], wherein the blocking agent further contains a blocking agent (c), the blocking agent (c) is a monohydric alcohol-based compound, and the molar ratio of the structure derived from the blocking agent (c) to the total amount of the structure derived from the blocking agent (a), the structure derived from the blocking agent (b), and the structure derived from the blocking agent (c) is 3 mol % or more and less than 10 mol %. [5] The blocked polyisocyanate composition according to any one of [1] to [4], wherein the average number of isocyanate functional groups in the polyisocyanate compound is 2.5 or more and 6.0 or less. [6] The blocked polyisocyanate composition according to any one of [1] to [5], which contains at least one selected from the group consisting of an isocyanurate group and an allophanate group, a uretdione group, a uretoneimino group, a urethane group, a biuret group, a urea group, and an iminooxadiazinedione group, and which contains 30% to 90% of isocyanurate groups relative to 100% of the total number of moles of the isocyanurate groups, allophanate groups, uretdione groups, uretoneimino groups, urethane groups, biuret groups, urea groups, and iminooxadiazinedione groups. [7] The blocked polyisocyanate composition according to any one of [1] to [6], comprising a blocked polyisocyanate composition (A) derived from the blocking agent (a) and a blocked polyisocyanate composition (B) derived from the blocking agent (b). [8] The blocked polyisocyanate composition according to any one of [1] to [7], further comprising the blocking agent (b) that has not reacted with the polyisocyanate compound. [9] A resin composition comprising the blocked polyisocyanate composition according to any one of [1] to [9] and a polyol.

[10] The resin composition according to [9], wherein the molar ratio (NCO / OH) of the isocyanate groups bonded to the blocking agent (b) in the blocked polyisocyanate composition to the hydroxyl groups of the polyol is 0.4 / 1.0 or more and 1.2 / 1.0 or less.

[11] A cured resin obtained by curing the resin composition according to [9] or

[10] .

[12] A laminate obtained by laminating one or more layers of a film made of the cured resin described in

[11] on a substrate. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a blocked polyisocyanate composition which retains its curability under high-temperature, short-time baking conditions, forms a crosslinked coating film which has excellent adhesion to the substrate, has good compatibility with the base resin, and exhibits chemical resistance and long-term moist heat resistance, as well as a resin composition, a cured resin, and a laminate which use the same. DETAILED DESCRIPTION OF THE INVENTION

[0014] <Blocked polyisocyanate composition> The present invention relates to a blocked polyisocyanate composition in which the isocyanate groups of a polyisocyanate compound are blocked with a blocking agent.

[0015] <Polyisocyanate compounds> The polyisocyanate compound is a polyisocyanate compound derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

[0016] The aliphatic diisocyanate is not particularly limited, but examples thereof include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, ethyl (2,6-diisocyanato)hexanoate, 1,6-diisocyanatohexane (hereinafter sometimes referred to as "HDI"), 1,9-diisocyanatononane, 1,12-diisocyanatododecane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, and the like.

[0017] The alicyclic diisocyanate is not particularly limited, but examples thereof include 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane (hereinafter sometimes referred to as "hydrogenated XDI"), 1,3- or 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl-1-isocyanato-3-(isocyanatomethyl)cyclohexane (hereinafter sometimes referred to as "IPDI"), 4-4'-diisocyanato-dicyclohexylmethane (hereinafter sometimes referred to as "hydrogenated MDI"), and 2,5- or 2,6-diisocyanatomethylnorbornane.

[0018] Among these, as the diisocyanate, HDI, IPDI, hydrogenated XDI or hydrogenated MDI is preferred from the viewpoint of weather resistance, and HDI or IPDI is more preferred.

[0019] These diisocyanates can be used alone or in combination of two or more.

[0020] Furthermore, in addition to the diisocyanates, aliphatic triisocyanates may be contained, such as 1,3,6-triisocyanatohexane, 1,8-diisocyanato-4-isocyanatomethyloctane, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

[0021] <Blocking agent> The blocking agent includes a blocking agent (a) and a blocking agent (b), and preferably further includes a blocking agent (c).

[0022] (Blocking agent (a)) The blocking agent (a) is an active methylene compound, and the active methylene compound includes a malonic acid diester compound and a β-ketoester compound. The use of the blocking agent (a) including a malonic acid diester compound and a β-ketoester compound can improve compatibility with the base agent and the like when the coating material is formed. The malonic acid diester compound is at least one selected from the group consisting of malonic acid diester compounds represented by the following formula (1). The β-keto ester compound is at least one selected from the group consisting of β-keto ester compounds represented by the following formula (2). [ka] [In formula (1), R 1 and R 2 R each independently represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a benzyl group. 1 and R 2 may be the same or different.] [ka] [In formula (2), R 3 and R 4 R each independently represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a benzyl group. 3 and R 4 may be the same or different.]

[0023] In the above formula (1), R 1 and R 2 R each independently represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a benzyl group. 1 and R 2 may be the same or different, but it is preferable that they are the same in terms of ease of availability. R 1 and R 2 When represents an alkyl group or a cycloalkyl group having 8 or less carbon atoms, the effective NCO content can be increased, and compatibility with the main agent, etc. when formed into a paint tends to be improved.

[0024] Among these, an alkyl group having 1 to 8 carbon atoms is preferred, and an alkyl group having 1 to 4 carbon atoms is more preferred. More specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or an n-butyl group is preferred, a methyl group or an ethyl group is more preferred, and an ethyl group is particularly preferred. Here, the effective NCO content refers to the content (% by mass) of potentially present isocyanate relative to the total amount (100% by mass) of the blocked isocyanate composition.

[0025] In the above formula (2), R 3 and R 4 R each independently represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a benzyl group. 3 and R 4 may be the same or different, but it is preferable that they are the same in terms of ease of availability. R 3 and R 4 When represents an alkyl group or a cycloalkyl group having 8 or less carbon atoms, the effective NCO content can be increased, and compatibility with the main agent, etc. when formed into a paint tends to be improved.

[0026] Among these, R 3 and R 4 is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. More specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or an n-butyl group is preferred, a methyl group or an ethyl group is more preferred, and an ethyl group is particularly preferred. Here, the effective NCO content refers to the content (mass%) of isocyanate that is potentially present relative to the total amount (100 mass%) of the blocked isocyanate composition.

[0027] Specific examples of β-ketoester compounds include, but are not limited to, methyl acetoacetate, ethyl acetoacetate, methyl isobutanoylacetate, ethyl isobutanoylacetate, and acetylacetone. Among these, methyl acetoacetate, ethyl acetoacetate, methyl isobutanoylacetate, and ethyl isobutanoylacetate are preferred. Methyl acetoacetate and ethyl acetoacetate are more preferred, and ethyl acetoacetate is even more preferred. The above-listed β-ketoester compounds can be used alone or in combination of two or more.

[0028] In one embodiment of the present invention, R in formula (1) 1 and R 2 are the same and are a methyl group, an ethyl group, or an isopropyl group, and R 3 and R 4 is preferably a methyl group or an ethyl group.

[0029] (Blocking agent (b)) The blocking agent (b) is a thermally dissociable blocking agent. A thermally dissociable blocking agent is a compound having one active hydrogen atom in the molecule, and has the property of dissociating from an isocyanate group upon heating. Specific examples of the thermally dissociable blocking agent include alcohol-based compounds, alkylphenol-based compounds, phenol-based compounds, mercaptan-based compounds, acid amide-based compounds, acid imide-based compounds, imidazole-based compounds, urea-based compounds, oxime-based compounds, amine-based compounds, imine-based compounds, and pyrazole-based compounds.

[0030] Among the above, the blocking agent (b) is preferably at least one selected from oxime compounds, acid amide compounds, amine compounds, imidazole compounds, and pyrazole compounds.

[0031] More specifically, examples of the thermally dissociable blocking agent include the compounds shown in the following (1) to (13). These blocking agents may be used alone or in combination of two or more.

[0032] (1) Alcohol compounds: methanol, ethanol, 2-propanol, n-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxyethanol, and 2-butoxyethanol.

[0033] (2) Alkylphenol compounds: mono- or di-alkylphenols having an alkyl group having 4 or more carbon atoms as a substituent, such as mono-alkylphenols such as n-propylphenol, i-propylphenol, n-butylphenol, sec-butylphenol, t-butylphenol, n-hexylphenol, 2-ethylhexylphenol, n-octylphenol, and n-nonylphenol; and di-n-propylphenol, diisopropylphenol, isopropyl cresol, di-n-butylphenol, di-t-butylphenol, di-sec-butylphenol, di-n-octylphenol, di-2-ethylhexylphenol, and di-n-nonylphenol.

[0034] (3) Phenolic compounds: phenol, cresol, ethylphenol, styrenated phenol, hydroxybenzoic acid ester.

[0035] (4) Mercaptan compounds: butyl mercaptan, dodecyl mercaptan. (5) Acid amide compounds: acetanilide, acetic acid amide, ε-caprolactam, δ-valerolactam, γ-butyrolactam. (6) Acid imide compounds: succinimide, maleimide.

[0036] (7) Imidazole compounds: imidazole, 2-methylimidazole. (8) Urea compounds: urea, thiourea, ethyleneurea.

[0037] (9) Oxime compounds: formaldoxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, cyclohexanone oxime. (10) Amine compounds: diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, isopropylethylamine.

[0038] (11) Imine compounds: ethyleneimine, polyethyleneimine. (12) Pyrazole compounds: pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole.

[0039] Among these, the thermally dissociable blocking agent preferably contains at least one selected from the group consisting of oxime compounds, pyrazole compounds, amine compounds, and acid amide compounds. From the viewpoint of storage stability when formed into a coating liquid, oxime compounds or pyrazole compounds are more preferred, and pyrazole compounds are even more preferred.

[0040] In this embodiment, the molar ratio of the structure derived from the blocking agent (a) to the structure derived from the blocking agent (b) (blocking agent (a) / blocking agent (b)) is 20 / 80 to 90 / 10, preferably 30 / 70 to 80 / 20, and more preferably 45 / 55 to 75 / 25.

[0041] The number of structures (number of moles) derived from the blocking agent (a) is the number of bond structures (number of moles) between an isocyanate group and an active methylene compound, and is calculated, for example, as the sum of the number of bond structures (number of moles) between an isocyanate group and a malonic acid diester compound and the number of bond structures (number of moles) between an isocyanate group and an acetoacetic acid ester compound. The number of bond structures between an isocyanate group and a malonic acid diester compound is determined from the number of amino groups adjacent to an amide formed by bonding an isocyanate group with diethyl malonate. The number of bond structures between an isocyanate group and an acetoacetic ester compound is determined from the number of amino groups adjacent to an amide formed by bonding an isocyanate group with ethyl acetoacetate.

[0042] When the blocking agent (b) is an alcohol-based compound, the number of structures (number of moles) derived from the blocking agent (b) is the number of urethane bond structures (number of moles) between the isocyanate group and the alcohol-based compound. The number of urethane bond structures between an isocyanate group and an alcohol-based compound is determined from the number of amino groups resulting from urethane bonds obtained by bonding an isocyanate group with n-butanol, isobutanol, or isopropanol.

[0043] When the blocking agent (b) is an oxime compound, the number of structures (number of moles) derived from the blocking agent (b) is the number of urethane bond structures (number of moles) between the isocyanate group and the oxime compound. The number of urethane bond structures between an isocyanate group and an oxime-based compound is determined from the number of amino groups resulting from urethane bonds obtained by bonding an isocyanate group with formaldoxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, or cyclohexanone oxime.

[0044] When the blocking agent (b) is a pyrazole-based compound, the number of structures (number of moles) derived from the blocking agent (b) is the number of urethane bond structures (number of moles) between the isocyanate group and the pyrazole-based compound. The number of urethane bond structures between an isocyanate group and a pyrazole-based compound is determined from the number of amino groups resulting from urethane bonds obtained by bonding an isocyanate group with pyrazole, 3-methylpyrazole, or 3,5-dimethylpyrazole.

[0045] When the blocking agent (b) is an amine compound, the number of structures (number of moles) derived from the blocking agent (b) is the number of urethane bond structures (number of moles) between the isocyanate group and the amine compound. The number of urethane bond structures between an isocyanate group and an amine compound is calculated from the number of amino groups resulting from urethane bonds obtained by bonding an isocyanate group with diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, or isopropylethylamine.

[0046] When the blocking agent (b) is an acid amide compound, the number of structures (number of moles) derived from the blocking agent (b) is the number of urethane bond structures (number of moles) between the isocyanate group and the acid amide compound. The number of urethane bond structures between an isocyanate group and an acid amide compound is calculated from the number of amino groups resulting from urethane bonds obtained by bonding an isocyanate group with acetanilide, acetic acid amide, ε-caprolactam, δ-valerolactam, or γ-butyrolactam.

[0047] In one embodiment of the present invention, the blocked polyisocyanate composition may contain a blocking agent (b) that has not reacted with the polyisocyanate compound. That is, when the blocking agents are blended in such a ratio that the molar ratio of the structure derived from the blocking agent (a) to the structure derived from the blocking agent (b) falls within the above-mentioned range, excess or unreacted blocking agent may remain in the blocked polyisocyanate composition.

[0048] (Blocking agent (c)) The blocking agent preferably further contains a blocking agent (c). The blocking agent (c) is a monohydric alcohol compound. Examples of the blocking agent (c) include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, pentanol, hexanol, heptanol, octanol, 2-ethyl-1-hexanol, n-butyl cellosolve, propylene glycol monomethyl ether, cyclohexanol, and benzyl alcohol.

[0049] When the blocking agent contains blocking agent (c), the molar ratio of the structure derived from blocking agent (c) to the total amount of the structure derived from blocking agent (a), the structure derived from blocking agent (b), and the structure derived from blocking agent (c) is preferably 3 mol % or more and less than 10 mol %.

[0050] The number of structures (number of moles) derived from the blocking agent (c) is the number of urea bond structures (number of moles) between an isocyanate group and a monohydric alcohol. The number of urea bond structures between an isocyanate group and a monohydric alcohol is determined from the number of amino groups resulting from urea bonds obtained by bonding an isocyanate group with n-butanol, isobutanol, or isopropanol.

[0051] In one embodiment of the present invention, the blocked polyisocyanate composition comprises a blocked polyisocyanate composition (A) derived from a blocking agent (a) and a blocked polyisocyanate composition (B) derived from a blocking agent (b). The blocked polyisocyanate composition (A) is a blocked polyisocyanate composition in which the isocyanate groups of the above polyisocyanate compound are blocked with a blocking agent (a). The blocked polyisocyanate composition (B) is a blocked polyisocyanate composition in which the isocyanate groups of the above polyisocyanate compound are blocked with a blocking agent (b).

[0052] In this case, the mixing ratio (mass ratio) of the blocked polyisocyanate composition (A) to the blocked polyisocyanate composition (B) is, for example, 20 / 80 to 90 / 10.

[0053] <Structure of Blocked Polyisocyanate Composition> The blocked polyisocyanate composition can be obtained by reacting a diisocyanate other than the blocking agent with an isocyanate group contained in a polyisocyanate compound and the blocking agent.

[0054] The polyisocyanate component derived from the above diisocyanate is not particularly limited, but examples thereof include the polyisocyanates shown in the following (a) to (h). (a): Polyisocyanate having uretdione groups obtained by cyclodimerization of two isocyanate groups. (b): Polyisocyanate having an isocyanurate group or an iminooxadiazinedione group obtained by cyclotrimerization of three isocyanate groups. (c): Polyisocyanate having biuret groups obtained by reacting three isocyanate groups with one water molecule. (d): Polyisocyanate having an oxadiazinetrione group obtained by reacting two isocyanate groups with one molecule of carbon dioxide. (e): Polyisocyanate having multiple urethane groups obtained by reacting one isocyanate group with one hydroxyl group. (f): Polyisocyanate having an allophanate group obtained by reacting two isocyanate groups with one hydroxyl group. (g): Polyisocyanate having an acylurea group obtained by reacting one isocyanate group with one carboxy group. (h): Polyisocyanate having a urea group obtained by reacting one isocyanate group with one primary or secondary amine.

[0055] Among these, the polyisocyanate compound preferably has an isocyanurate group and an allophanate group. That is, the polyisocyanate compound may contain a mixture of polyisocyanate compounds having one of these functional groups, or a mixture of polyisocyanate compounds having two or more of these functional groups, or a polyisocyanate compound having a functional group other than the above two types.

[0056] The isocyanurate group is a functional group obtained by cyclotrimerizing three isocyanate groups, and has a structure represented by the following formula (I). The allophanate group is a functional group formed by the reaction of a hydroxyl group of an alcohol with an isocyanate group, and has a structure represented by the following formula (II).

[0057] The uretdione group is a functional group obtained by cyclodimerization of two isocyanate groups, and has a structure represented by the following formula (III). The iminooxadiazinedione group is a functional group obtained by cyclotrimerizing three isocyanate groups, and has a structure represented by the following formula (IV).

[0058] [ka]

[0059] In the polyisocyanate compound used in this embodiment, the molar ratio of isocyanurate groups relative to the total molar amount (100 mol%) of isocyanurate groups, allophanate groups, uretdione groups, and iminooxadiazinedione groups is preferably 20.0 mol% to 90.0 mol%, more preferably 30.0 mol% to 80.0 mol%. When the molar ratio of isocyanurate groups is in the above range, the hardness and water resistance of the resulting coating film are superior.

[0060] The blocked polyisocyanate composition of the present embodiment preferably contains an isocyanurate group and at least one selected from the group consisting of an allophanate group, a uretdione group, a uretoneimino group, a urethane group, a biuret group, a urea group, and an iminooxadiazinedione group. The molar ratio of isocyanurate groups is preferably 30 mol % or more and 90 mol % or less relative to the total molar number of isocyanurate groups, allophanate groups, uretdione groups, uretoneimino groups, urethane groups, biuret groups, urea groups, and iminooxadiazinedione groups (100%).

[0061] These blocked polyisocyanate compositions may be used alone or in combination of two or more.

[0062] (average number of isocyanate groups per molecule) The average number of isocyanate groups per molecule of the polyisocyanate component that is the precursor of the blocked polyisocyanate component used in this embodiment is preferably 2.5 or more and 6.0 or less, more preferably 3.0 or more and 5.9 or less, and even more preferably 4.0 or more and 5.8 or less, from the viewpoint of obtaining a coating film that is excellent in curability, crosslink density, and blocking resistance. The average number of isocyanate groups per molecule is the number of isocyanate functional groups statistically contained in one molecule of a polyisocyanate compound, and can be calculated using the following formula from the number average molecular weight (Mn) and isocyanate group content (NCO%) of the polyisocyanate compound.

[0063] [Average number of isocyanate groups per molecule] = Mn × NCO% / 4,200

[0064] <Method for producing blocked polyisocyanate composition> The blocked polyisocyanate component of the present embodiment can be produced by the following production methods 1 and 2. Production method 1: A method in which a diisocyanate is reacted with a blocking agent (a) and a blocking agent (b) all at once. Production method 2: A method in which a diisocyanate is reacted with a blocking agent (a) to produce a blocked polyisocyanate composition (A), and a diisocyanate is reacted with a blocking agent (b) to produce a blocked polyisocyanate composition (B).

[0065] The method for producing the polyisocyanate component is shown below.

[0066] <Method for producing polyisocyanate compound> (1) Method for producing polyisocyanate compounds containing isocyanurate groups The method for producing a polyisocyanate containing an isocyanurate group is not particularly limited, but examples thereof include a method in which a diisocyanate is subjected to an isocyanuration reaction using a catalyst or the like, the reaction is stopped when a predetermined conversion rate is reached, and unreacted diisocyanate is removed.

[0067] The catalyst used in the isocyanuration reaction is not particularly limited, but is preferably one that exhibits basicity, and specific examples include tetraalkylammonium hydroxides and weak organic acid salts, hydroxyalkylammonium hydroxides and weak organic acid salts, alkali metal salts of alkylcarboxylic acids, metal alcoholates, aminosilyl group-containing compounds, Mannich bases, combined use of tertiary amines and epoxy compounds, and phosphorus-based compounds.

[0068] Examples of tetraalkylammonium include tetramethylammonium and tetraethylammonium.

[0069] Examples of organic weak acids include acetic acid, capric acid, etc. Examples of hydroxyalkylammonium include trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, triethylhydroxyethylammonium, etc.

[0070] Examples of alkylcarboxylic acids include acetic acid, caproic acid, octylic acid, and myristic acid.

[0071] Examples of metals constituting the alkali metal salt include tin, zinc, and lead.

[0072] Examples of metal alcoholates include sodium alcoholate and potassium alcoholate.

[0073] An example of the aminosilyl group-containing compound is hexamethyldisilazane.

[0074] Examples of phosphorus compounds include tributylphosphine.

[0075] The amount of these catalysts used is preferably 10 ppm or more and 1.0% or less based on the total mass of the diisocyanate raw material. To terminate the isocyanurate-forming reaction, the catalyst may be inactivated by adding an acidic substance that neutralizes the catalyst, or by thermal decomposition, chemical decomposition, or the like. Examples of acidic substances that neutralize the catalyst include phosphoric acid and acidic phosphate esters.

[0076] The yield of polyisocyanate generally tends to be 10% by mass or more and 70% by mass or less, and preferably 35% by mass or more and 60% by mass or less. Polyisocyanate obtained with a higher yield tends to have a higher viscosity. The yield can be calculated from the ratio of the mass of the obtained polyisocyanate to the total mass of the raw material components.

[0077] The reaction temperature for the isocyanurate reaction is not particularly limited, but is preferably from 50° C. to 200° C., and more preferably from 50° C. to 150° C. When the reaction temperature is equal to or higher than the lower limit, the reaction tends to proceed more easily, and when the reaction temperature is equal to or lower than the upper limit, side reactions that cause coloration tend to be more effectively suppressed.

[0078] After completion of the isocyanurate reaction, it is preferable to remove unreacted diisocyanate using a thin film evaporator, extraction, or the like. Even if the polyisocyanate contains unreacted diisocyanate, the diisocyanate content is preferably 3.0 mass% or less, more preferably 1.0 mass% or less, and even more preferably 0.5 mass% or less, based on the total mass of the polyisocyanate. When the concentration of residual unreacted diisocyanate is within the above range, curability tends to be better.

[0079] After completion of the isocyanurate reaction, it is preferable to remove unreacted diisocyanate using a thin film evaporator, extraction, or the like. Even if the polyisocyanate contains unreacted diisocyanate, the diisocyanate content is preferably 3.0 mass% or less, more preferably 1.0 mass% or less, and even more preferably 0.5 mass% or less, based on the total mass of the polyisocyanate. When the concentration of residual unreacted diisocyanate is within the above range, curability tends to be better. The concentration of the residual unreacted diisocyanate can be measured by gas chromatography analysis.

[0080] (2) Method for producing polyisocyanate compounds containing allophanate groups The polyisocyanate containing allophanate groups can be produced, for example, by adding an alcohol to a diisocyanate and using an allophanate reaction catalyst.

[0081] The alcohol used to form the allophanate group is preferably an alcohol formed only from carbon, hydrogen and oxygen. Specific examples of the alcohol include, but are not limited to, monoalcohols, dialcohols, etc. These alcohols may be used alone or in combination of two or more.

[0082] Examples of the monoalcohol include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, and nonanol. Examples of the dialcohol include ethylene glycol, 1,3-butanediol, neopentyl glycol, and 2-ethylhexanediol.

[0083] The molar ratio of the isocyanate groups of the diisocyanate to the hydroxyl groups of the alcohol is preferably 10 / 1 or more and 1000 / 1 or less, more preferably 100 / 1 or more and 1000 / 1 or less. When this molar ratio is equal to or greater than the lower limit, the average number of isocyanate groups per molecule can be more sufficiently ensured. When this molar ratio is equal to or less than the upper limit, the effect of excellent surface hardness is achieved.

[0084] The allophanatization reaction catalyst includes, but is not limited to, alkyl carboxylates of tin, lead, zinc, bismuth, zirconium, zirconyl, and the like. Examples of tin alkylcarboxylates (organotin compounds) include tin 2-ethylhexanoate and dibutyltin dilaurate. Examples of lead alkylcarboxylates (organic lead compounds) include lead 2-ethylhexanoate. Examples of zinc alkylcarboxylates (organic zinc compounds) include zinc 2-ethylhexanoate. Examples of bismuth alkylcarboxylates include bismuth 2-ethylhexanoate. Examples of zirconium alkylcarboxylates include zirconium 2-ethylhexanoate. Examples of zirconyl alkylcarboxylates include zirconyl 2-ethylhexanoate, etc. These catalysts can be used alone or in combination of two or more.

[0085] Furthermore, the above-mentioned isocyanurate-forming reaction catalyst can also serve as an allophanate-forming reaction catalyst. When the allophanate-forming reaction is carried out using the above-mentioned isocyanurate-forming reaction catalyst, an isocyanurate-type polyisocyanate is naturally also produced. Among these, it is preferable from the viewpoint of economical production to carry out the allophanate formation reaction and the isocyanurate formation reaction using the above-mentioned isocyanurate formation catalyst as the allophanate formation reaction catalyst.

[0086] The upper limit of the amount of the allophanate formation reaction catalyst used is preferably 10,000 ppm by mass, more preferably 1,000 ppm by mass, and even more preferably 500 ppm by mass, relative to the mass of the charged diisocyanate. On the other hand, the lower limit of the amount of the isocyanurate formation reaction catalyst used is not particularly limited, and may be, for example, 10 ppm by mass.

[0087] The lower limit of the allophanate reaction temperature is preferably 60° C., more preferably 70° C., even more preferably 80° C., and particularly preferably 90° C. On the other hand, the upper limit of the allophanate reaction temperature is preferably 160° C., more preferably 155° C., even more preferably 150° C., and particularly preferably 145° C.

[0088] That is, the allophanatization reaction temperature is preferably 60°C or higher and 160°C or lower, more preferably 70°C or higher and 155°C or lower, even more preferably 80°C or higher and 150°C or lower, and particularly preferably 90°C or higher and 145°C or lower. By setting the allophanate reaction temperature to the above lower limit or higher, the reaction rate can be further improved. By setting the allophanate reaction temperature to the above upper limit or lower, changes in properties such as coloration of the polyisocyanate tend to be more effectively suppressed.

[0089] The lower limit of the allophanate reaction time is preferably 0.2 hours, more preferably 0.4 hours, even more preferably 0.6 hours, particularly preferably 0.8 hours, and most preferably 1 hour, while the upper limit of the allophanate reaction time is preferably 8 hours, more preferably 6 hours, even more preferably 4 hours, particularly preferably 3 hours, and most preferably 2 hours. That is, the allophanatization reaction time is preferably 0.2 hours or more and 8 hours or less, more preferably 0.4 hours or more and 6 hours or less, even more preferably 0.6 hours or more and 4 hours or less, particularly preferably 0.8 hours or more and 3 hours or less, and most preferably 1 hour or more and 2 hours or less. When the allophanate formation reaction time is equal to or greater than the above-mentioned lower limit, the viscosity of the polyisocyanate can be made lower, while when the allophanate formation reaction time is equal to or less than the above-mentioned upper limit, changes in properties such as coloration of the polyisocyanate tend to be more effectively suppressed.

[0090] When the desired yield is reached, the allophanation reaction is stopped by adding a deactivator for the allophanation reaction catalyst such as phosphoric acid or methyl paratoluenesulfonate.

[0091] (3) Method for producing polyisocyanate compounds containing uretdione groups As a method for producing a polyisocyanate containing uretdione groups, there is mentioned a method using a uretdione reaction catalyst.

[0092] Specific examples of the urethodionation reaction catalyst include, but are not limited to, tertiary phosphines, such as trialkylphosphines, e.g., tri-n-butylphosphine and tri-n-octylphosphine; tris(dialkylamino)phosphines, e.g., tris-(dimethylamino)phosphine; and cycloalkylphosphines, e.g., cyclohexyl-di-n-hexylphosphine. Many of these compounds also accelerate the isocyanuration reaction at the same time, producing an isocyanurate group-containing polyisocyanate in addition to an uretdione group-containing polyisocyanate.

[0093] When the desired yield is reached, a deactivator for the uretdione-forming reaction catalyst, such as phosphoric acid or methyl paratoluenesulfonate, is added to terminate the uretdione-forming reaction.

[0094] The catalyst is used in an amount of preferably 10 ppm by mass to 10,000 ppm by mass, more preferably 10 ppm by mass to 1,000 ppm by mass, and even more preferably 10 ppm by mass to 500 ppm by mass, relative to the mass of the charged diisocyanate.

[0095] The uretdione formation reaction is preferably carried out at a temperature of 20° C. or higher and 120° C. or lower. The lower limit of the reaction temperature is more preferably 25° C., even more preferably 30° C., and even more preferably 35° C. The upper limit of the reaction temperature is more preferably 110° C., even more preferably 100° C., and even more preferably 90° C. When the uretdione formation reaction temperature is equal to or lower than the upper limit, changes in properties such as coloration tend to be more effectively suppressed.

[0096] Alternatively, uretdione groups can be obtained by heating diisocyanate without using the above-mentioned uretdione reaction catalyst. The heating temperature is preferably 130°C or higher and 180°C or lower. The lower limit of the heating temperature is more preferably 140°C, even more preferably 145°C, even more preferably 150°C, and even more preferably 155°C. The upper limit of the heating temperature is more preferably 170°C, even more preferably 165°C, even more preferably 162°C, and even more preferably 160°C.

[0097] Furthermore, the heating time is preferably 0.2 hours or more and 8.0 hours or less. The lower limit of the heating time is more preferably 0.4 hours, even more preferably 0.6 hours, even more preferably 0.8 hours, and even more preferably 1.0 hour. The upper limit of the heating time is more preferably 6.0 hours, even more preferably 4.0 hours, even more preferably 3.0 hours, and even more preferably 2.0 hours. By setting the heating time to the above lower limit or more, it tends to be possible to further achieve a low viscosity, and by setting it to the above upper limit or less, it tends to be possible to further suppress coloration of the polyisocyanate itself.

[0098] When the polyisocyanate composition of the present embodiment is obtained without using a uretdione formation reaction catalyst, it is preferable to remove unreacted diisocyanate after the uretdione formation reaction by heating alone and the above-described isocyanurate formation reaction are completed, from the viewpoints of reducing the concentration of unreacted diisocyanate, reducing the rate of change in molecular weight of the obtained polyisocyanate composition after storage, and reducing yellowing during high-temperature baking.

[0099] (4) Method for producing polyisocyanate compounds containing iminooxadiazinedione groups The catalyst for deriving a polyisocyanate containing an iminooxadiazinedione group from a diisocyanate is not particularly limited, but for example, the following catalyst (i) or (ii), which is generally known as an iminooxadiazinedione reaction catalyst, can be used.

[0100] (i) (Poly)hydrogen fluorides represented by the general formula M[Fn] or M[Fn(HF)m], such as tetramethylammonium fluoride hydrate and tetraethylammonium fluoride (wherein m and n are integers satisfying the relationship m / n>0, and M represents an n-charged cation (mixture) or one or more radicals with a total valence of n). (ii) Compounds comprising a compound of the general formula R1-CR'2-C(O)O-, or the general formula R2=CR'-C(O)O- (wherein R1 and R2 are optionally branched, cyclic, and / or unsaturated perfluoroalkyl groups having 1 to 30 carbon atoms, and R' is the same or different and is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and an aryl group, and optionally containing a heteroatom), such as 3,3,3-trifluorocarboxylic acid; 4,4,4,3,3-pentafluorobutanoic acid; 5,5,5,4,4,3,3-heptafluoropentanoic acid; or 3,3-difluoroprop-2-enoic acid, and a quaternary ammonium cation or a quaternary phosphonium cation.

[0101] From the viewpoint of availability, the above (i) is preferred, and from the viewpoint of safety, the above (ii) is preferred. The amount of the iminooxadiazinedione reaction catalyst added is preferably 10 ppm or more and 1000 ppm or less relative to the mass of the charged diisocyanate, with the lower limit being more preferably 20 ppm, even more preferably 40 ppm, and still more preferably 80 ppm. The upper limit is more preferably 800 ppm, even more preferably 600 ppm, and even more preferably 500 ppm or less.

[0102] The temperature for the iminooxadiazinedione formation reaction is preferably 40°C or higher and 120°C or lower. The lower limit is more preferably 50° C., and even more preferably 55° C. The upper limit is more preferably 100° C., and even more preferably 90° C., and even more preferably 80° C. By setting the iminooxadiazinedione reaction temperature to 40°C or higher, it tends to be possible to maintain a high reaction rate. By setting the iminooxadiazinedione reaction temperature to 120°C or lower, it tends to be possible to effectively suppress coloration of the polyisocyanate, etc.

[0103] <Blocking reaction> The reaction step of the present embodiment between the polyisocyanate compound and the blocking agent can be carried out regardless of the presence or absence of a solvent. When a solvent is used, it is preferable to use a solvent that is inactive to the isocyanate group. In the blocking reaction, organic metal salts of tin, zinc, lead, etc., metal alcoholates such as sodium methylate, sodium ethylate, sodium phenolate, potassium methylate, etc., and tertiary amines may be used as catalysts. At least a portion of the catalyst used in the blocking reaction may be neutralized with an acidic compound such as those described below. Neutralization is preferable because it improves the thermal stability of the blocked polyisocyanate component. Examples of acidic compounds include inorganic acids such as hydrochloric acid, phosphorous acid, and phosphoric acid; sulfonic acids such as methanesulfonic acid and p-toluenesulfonic acid; and phosphate esters such as ethyl phosphate, diethyl phosphate, isopropyl phosphate, diisopropyl phosphate, butyl phosphate, dibutyl phosphate, 2-ethylhexyl phosphate, and di(2-ethylhexyl) phosphate. The amount of the acidic compound is preferably in the range of 0.3 to 3 equivalents, more preferably 0.5 to 2 equivalents, and even more preferably 0.7 to 1.5 equivalents, relative to the catalyst. The reaction temperature is preferably −20° C. or higher and 150° C. or lower, and the reaction time is preferably 30 minutes or higher and 48 hours or lower.

[0104] <Resin composition> A resin composition according to one embodiment of the present invention contains the blocked polyisocyanate composition according to one embodiment of the present invention and a polyol.

[0105] <Polyol> The polyol contained in the resin composition is preferably a polyol containing two or more active hydrogen atoms in the molecule that are reactive with the isocyanate groups contained in the blocked polyisocyanate composition, and the isocyanate groups and the polyol react with each other to form a crosslinked coating film.

[0106] Examples of the polyol include, but are not limited to, acrylic polyol, polyester polyol, polyether polyol, polyolefin polyol, epoxy polyol, and fluorine polyol.

[0107] Examples of acrylic polyols include, but are not limited to, acrylic esters having active hydrogen, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate, or monoacrylic or monomethacrylic esters of glycerin, and monoacrylic or monomethacrylic esters of trimethylolpropane, either alone or in combination; acrylic esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxypropyl methacrylate, and 4-hydroxypropyl methacrylate; Examples of the acrylic polyol include acrylic polyols obtained by polymerizing, alone or in combination, a methacrylic acid ester having an active hydrogen such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, and the like, in the presence or absence of a monomer selected from the group consisting of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid, unsaturated amides such as acrylamide, N-methylolacrylamide, and diacetoneacrylamide, and other polymerizable monomers such as glycidyl methacrylate, styrene, vinyltoluene, vinyl acetate, acrylonitrile, and dibutyl fumarate.

[0108] Examples of polyester polyols include, but are not limited to, polyester polyols obtained by the condensation reaction of a dibasic acid selected from the group consisting of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, and terephthalic acid, or a polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, and glycerin, or a polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, and glycerin. These polyester polyols can be modified with aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and polyisocyanates obtained therefrom. In this case, polyester polyols modified with aliphatic diisocyanates, alicyclic diisocyanates, and polyisocyanates obtained therefrom are particularly preferred in terms of weather resistance, yellowing resistance, and the like.

[0109] Examples of polyether polyols include, but are not limited to, polyether polyols obtained by randomly or block-adding alkylene oxides, such as ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide, either alone or in combination, to a polyol having a molecular weight of 500 or less using a strong basic catalyst, such as a hydroxide of lithium, sodium, or potassium, an alcoholate, or an alkylamine, or a composite metal cyanide complex, such as a metal porphyrin or a zinc hexacyanocobaltate complex; polyether polyols obtained by reacting alkylene oxides with polyamine compounds, such as ethylenediamines; and so-called polymer polyols obtained by polymerizing acrylamide or the like using these polyethers as a medium.

[0110] Examples of polyolefin polyols include, but are not limited to, polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene.

[0111] Examples of epoxy polyols include, but are not limited to, novolak type, β-methylepicro type, cyclic oxirane type, glycidyl ether type, glycol ether type, epoxy type of aliphatic unsaturated compound, epoxidized fatty acid ester type, polycarboxylic acid ester type, aminoglycidyl type, halogenated type, resorcinol type, and compounds obtained by modifying these with an amino compound, a polyamide compound, or the like.

[0112] The fluorine polyol is a polyol containing fluorine in the molecule, and examples thereof include, but are not limited to, copolymers of fluoroolefin, cyclohexyl vinyl ether, hydroxyalkyl vinyl ether, and monocarboxylic acid vinyl ester, as disclosed in U.S. Pat. No. 4,345,057 and European Patent No. 180,962.

[0113] The fluorine polyol is a polymer compound containing fluorine in the molecule, and is not limited, but preferably has two or more hydroxyl groups in one molecule. Examples include copolymers of fluoroolefin and vinyl ether, copolymers of fluoroolefin and vinyl ester, copolymers of fluoroolefin and (meth)acrylic acid ester, etc., and include those that are soluble in solvents.

[0114] The fluorine content of the fluorine polyol is preferably 2.0% by mass or more and 50% by mass or less. From the viewpoint of obtaining a coating film having excellent blocking resistance, the fluorine content of the fluorine polyol is more preferably 5.0% by mass or more, and even more preferably 10.0% by mass or more. Furthermore, from the viewpoint of obtaining a coating film having excellent compatibility with the base resin, curability, and solvent resistance, the fluorine content of the fluorine polyol is more preferably 45% by mass or less, and even more preferably 40% by mass or less.

[0115] Examples of fluorine-containing polyols that can be used include those disclosed in U.S. Patent No. 4,345,057 and European Patent No. 180,962, Lumiflon LF100, LF200, LF400, LF600, and 800 from AGC Corporation, Zeffle GK-500, GK-510, GK-550, GK-570, and GK-580 from Daikin Industries, Ltd., Cefralcoat 703 and 705 from Central Glass Co., Ltd., and Fluonate K-700, K-702, K-704, K-705, K-707, and WZQ-660 from DIC Corporation. Fluorine-containing polyols may be used alone or in combination of two or more.

[0116] [Fluoropolyol content] Among these fluorine polyols, materials containing 10% by mass or more of fluorine are preferred in terms of achieving both curability and blocking resistance. In such cases, by setting the fluorine content and hydroxyl value within the above-mentioned ranges, it is possible to exhibit the desired performance.

[0117] [Hydroxyl value] In this embodiment, the fluorine polyol used as a constituent component of the resin composition preferably has a hydroxyl value of 30 to 200 mgKOH / g and an acid value of 0 to 30 mgKOH / g. Two or more of these polyols may be used in combination. Among them, the polyol used preferably has a hydroxyl value of 50 to 150 mgKOH / g and an acid value of 2 to 20 mgKOH / g, from the viewpoints of curability, crosslink density, and solvent resistance.

[0118] In one embodiment of the present invention, the resin composition has a molar ratio (NCO / OH) of isocyanate groups bonded to blocking agent (b) of the blocked polyisocyanate composition to hydroxyl groups of the polyol of 0.4 / 1.0 or more and 1.2 / 1.0 or less. From the viewpoint of simultaneously achieving compatibility with the base resin and obtaining a coating film that is excellent in curability, crosslink density, blocking resistance, and solvent resistance, the molar ratio is more preferably 0.20 / 1.0 or more and 1.0 / 1.0 or less, and even more preferably 0.30 / 1.0 or more and 0.90 / 1.0 or less.

[0119] The resin composition of the present embodiment contains the blocked polyisocyanate composition of the present embodiment and a polyol, but may also contain other polyvalent active hydrogen compounds than the polyol, such as polyamines, alkanolamines, polythiols, and polyols. Among these, polyols are preferred.

[0120] The polyamine is not particularly limited, but examples thereof include diamines such as ethylenediamine, propylenediamine, butylenediamine, triethylenediamine, hexamethylenediamine, 4,4'-diaminodicyclohexylmethane, piperazine, 2-methylpiperazine, and isophoronediamine; chain polyamines having three or more amino groups such as bishexamethylenetriamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentamethylenehexamine, and tetrapropylenepentamine; and cyclic polyamines such as 1,4,7,10,13,16-hexaazacyclooctadecane, 1,4,7,10-tetraazacyclodecane, 1,4,8,12-tetraazacyclopentadecane, and 1,4,8,11-tetraazacyclotetradecane.

[0121] Examples of alkanolamines include, but are not limited to, monoethanolamine, diethanolamine, aminoethylethanolamine, N-(2-hydroxypropyl)ethylenediamine, mono-, di-(n- or iso-)propanolamine, ethylene glycol-bis-propylamine, neopentanolamine, and methylethanolamine.

[0122] Examples of polythiols include, but are not limited to, bis-(2-hydrothioethyloxy)methane, dithioethylene glycol, dithioerythritol, and dithiothreitol.

[0123] <Other hardeners> In addition to the blocked polyisocyanate composition, the resin composition of this embodiment may contain other curing agents, such as a melamine-based curing agent or an epoxy-based curing agent. The melamine-based curing agent is not particularly limited, but examples thereof include fully alkyl-etherified melamine resins, methylol group-type melamine resins, and imino group-type melamine resins having imino groups in some portions. When using a melamine-based curing agent in combination, it is effective to add an acidic compound. Specific examples of the acidic compound include carboxylic acids, sulfonic acids, acidic phosphates, and phosphites.

[0124] Examples of carboxylic acids include, but are not limited to, acetic acid, lactic acid, succinic acid, oxalic acid, maleic acid, and decanedicarboxylic acid. Examples of sulfonic acids include, but are not limited to, paratoluenesulfonic acid, dodecylbenzenesulfonic acid, and dinonylnaphthalenedisulfonic acid. Examples of acidic phosphate esters include, but are not limited to, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, dilauryl phosphate, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, and monooctyl phosphate. Examples of phosphite esters include, but are not limited to, diethyl phosphite, dibutyl phosphite, dioctyl phosphite, dilauryl phosphite, monoethyl phosphite, monobutyl phosphite, monooctyl phosphite, and monolauryl phosphite.

[0125] The epoxy curing agent is not particularly limited, but examples thereof include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, acid anhydrides, phenol novolac, polymercaptans, aliphatic tertiary amines, aromatic tertiary amines, imidazole compounds, and Lewis acid complexes.

[0126] <Other ingredients> In addition to the blocked polyisocyanate composition and the polyol, the resin composition of the present embodiment may contain, depending on the purpose and application, various additives used in the relevant technical field, such as solvents, color pigments, dyes, silane coupling agents for improving adhesion of the coating film, ultraviolet absorbers, curing accelerators, light stabilizers, matting agents, coating surface hydrophilizing agents, catalysts for curing acceleration, drying improvers, leveling agents, antioxidants, plasticizers, surfactants, etc., within the scope of the present invention. Examples of the solvent include aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, ketone solvents, ester solvents, aromatic solvents, glycol solvents, ether solvents, halogenated hydrocarbon solvents, pyrrolidone solvents, amide solvents, sulfoxide solvents, lactone solvents, and amine solvents.

[0127] Examples of the aliphatic hydrocarbon solvent include hexane, heptane, and octane.

[0128] Examples of the alicyclic hydrocarbon solvent include cyclohexane and methylcyclohexane.

[0129] Examples of ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and diacetone alcohol.

[0130] Examples of the ester solvent include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, methyl lactate, and ethyl lactate.

[0131] Examples of aromatic solvents include toluene, xylene, diethylbenzene, mesitylene, anisole, benzyl alcohol, phenyl glycol, and chlorobenzene.

[0132] Examples of glycol-based solvents include ethylene glycol monoethyl ether acetate, 3-methyl-3-methoxybutyl acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, isobutanol, butyl glycol, N-methylpyrrolidone, butyl diglycol, butyl diglycol acetate, ether acetate, ethylene glycol monoisopropyl ether acetate, ethylene glycol mono-n-butyl ether acetate, ethylene glycol diacetate, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol di-n-propyl ether, ethylene glycol diisopropyl ether, ethylene glycol di-n-butyl ether, ethylene glycol methyl ethyl ether, ethylene glycol methyl isopropyl ether, ethylene glycol methyl ethyl-n-butyl ether, ethylene glycol ethyl-n-propyl ether, ethylene glycol ethyl isopropyl ether, ethylene glycol ethyl-n-butyl ether, ethylene glycol-n-propyl-n-butyl ether, ethylene glycol isopropyl-n-butyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-propyl ether acetate, diethylene glycol monoisopropyl ether acetate, diethylene glycol mono-n-butyl ether acetate, diethylene glycol diacetate, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol diisopropyl ether, diethylene glycol di-n-butyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl isopropyl ether, diethylene glycol methyl-n-propyl ether, diethylene glycol methyl-n-butyl ether, diethylene glycol ethyl isopropyl ether,Diethylene glycol ethyl-n-propyl ether, diethylene glycol ethyl-n-butyl ether, diethylene glycol-n-propyl-n-butyl ether, diethylene glycol isopropyl-n-butyl ether, and propylene glycol-based propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol monoisopropyl ether acetate, propylene glycol mono-n-butyl ether acetate, propylene glycol diacetate, propylene glycol diethyl ether, propylene glycol di-n-propyl ether, propylene glycol diisopropyl ether, propylene glycol di-n-butyl ether, propylene glycol methyl ethyl ether, propylene glycol methyl isopropyl ether, propylene glycol methyl-n-butyl ether, propylene glycol ethyl-n-propyl ether, propylene glycol ethyl isopropyl ether, propylene glycol ethyl-n-butyl ether, and propylene glycol-n-propyl dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol mono-n-propyl ether acetate, dipropylene glycol monoisopropyl ether acetate, dipropylene glycol mono-n-butyl ether acetate, dipropylene glycol diacetate, dipropylene glycol diethyl ether, dipropylene glycol di-n-propyl ether, dipropylene glycol diisopropyl ether, dipropylene glycol di-n-butyl ether, dipropylene glycol methyl ethyl ether, dipropylene glycol methyl isopropyl ether, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl-n-butyl ether, dipropylene glycol ethyl isopropyl ether, dipropylene glycol ethyl-n-propyl ether, dipropylene glycol ethyl-n-butyl ether, dipropylene glycol-n-propyl-n-butyl ether,Dipropylene glycol isopropyl n-butyl ether, etc.

[0133] Examples of the ether solvent include diethyl ether, tetrahydrofuran, and dioxane.

[0134] Examples of halogenated hydrocarbon solvents include dichloromethane, 1,2-dichloroethane, and chloroform.

[0135] An example of the pyrrolidone solvent is N-methyl-2-pyrrolidone.

[0136] Examples of amide solvents include N,N-dimethylacetamide, N,N-dimethylformamide, and 1,3-dimethyl-2-imidazolidinone. Examples of sulfoxide solvents include dimethyl sulfoxide. Examples of lactone solvents include γ-butyrolactone. Examples of amine solvents include morpholine.

[0137] The boiling point of the solvent used in the resin composition of this embodiment is preferably 70° C. or higher and 250° C. or lower. A low boiling point tends to provide high curability and blocking resistance. A high boiling point also tends to form a coating film with good appearance.

[0138] The color pigment may be an inorganic pigment or an organic pigment. Examples of inorganic pigments include carbon black and titanium oxide, which have good weather resistance. Examples of organic pigments include phthalocyanine blue, phthalocyanine green, quinacridone red, indanthrene orange, and isoindolinone yellow.

[0139] Examples of silane coupling agents include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, ureidopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, methyltriethoxysilane, and methyltrimethoxysilane.

[0140] Examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, triazine-based, and cyanoacrylate-based ultraviolet absorbers.

[0141] Examples of light stabilizers include hindered amine-based light stabilizers, and specific commercially available products include ADK STAB LA62 and ADK STAB LA67 (trade names, all manufactured by Adeka Argus Chemical Co., Ltd.), TINUVIN 292, TINUVIN 144, TINUVIN 123, and TINUVIN 440 (trade names, all manufactured by Chiba Specialty Chemicals Corporation), and SANOL LS765 (trade name, manufactured by Sankyo Lifetech Co., Ltd.).

[0142] The matting agent may be, for example, ultrafine powder synthetic silica, and when used, it is possible to form a coating film with an elegant semi-gloss or matte finish.

[0143] As the coating surface hydrophilizing agent, a silicate compound is preferred. When a coating film is produced using the coating composition of this embodiment, the inclusion of a silicate compound makes the coating film surface hydrophilic, and resistance to rain streak staining is exhibited. Since the silicate compound reacts with hydroxyl groups, when mixed in advance, it is preferable to add it to the polyisocyanate composition, which is the curing agent component. Alternatively, it may be mixed simultaneously when mixing the polyol, which is the main component, and the polyisocyanate composition, which is the curing agent component. Examples of silicate compounds include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, tetra-tert-butoxysilane, dimethoxydiethoxysilane, tetraphenoxysilane, and condensates thereof. Among these, the silicate compound is preferably a condensate of tetramethoxysilane or a condensate of tetraethoxysilane, since the surface of the coating film formed therefrom tends to become hydrophilic.

[0144] The catalyst for accelerating curing includes, but is not limited to, metal salts, tertiary amines, and the like. Examples of metal salts include dibutyltin dilaurate, tin 2-ethylhexanoate, zinc 2-ethylhexanoate, and cobalt salts. Examples of tertiary amines include triethylamine, pyridine, methylpyridine, benzyldimethylamine, N,N-dimethylcyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N,N'-endoethylenepiperazine, and N,N'-dimethylpiperazine.

[0145] Examples of drying improvers include CAB (cellulose acetate butyrate) and NC (nitrocellulose).

[0146] The leveling agent is not particularly limited, but examples thereof include silicone, aerosil, wax, stearates, polysiloxanes, and the like.

[0147] The plasticizer is not particularly limited, but examples thereof include phthalate esters, phosphate esters, fatty acid esters, pyromellitic acid esters, epoxy-based plasticizers, polyether-based plasticizers, liquid rubber, and non-aromatic paraffin oil.

[0148] Examples of phthalate esters include dioctyl phthalate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, diundecyl phthalate, and diisononyl phthalate.

[0149] Examples of phosphoric acid esters include tricresyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trimethylhexyl phosphate, tris-chloroethyl phosphate, and tris-dichloropropyl phosphate.

[0150] Examples of fatty acid esters include trimellitic acid esters, dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl azelate, dioctyl azelate, dioctyl sebacate, di-2-ethylhexyl sebacate, methyl acetyl ricinocate, etc. Examples of trimellitic acid esters include trimellitic acid octyl ester, trimellitic acid isodecyl ester, etc.

[0151] Examples of pyromellitic acid esters include pyromellitic acid octyl ester. Examples of epoxy plasticizers include epoxidized soybean oil, epoxidized linseed oil, and epoxidized fatty acid alkyl esters.

[0152] Examples of polyether plasticizers include adipic acid ether esters and polyethers. Examples of liquid rubber include liquid NBR, liquid acrylic rubber, and liquid polybutadiene.

[0153] Examples of surfactants include known anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0154] <Cured resin> The cured resin of one embodiment of the present invention is a cured resin obtained by curing the resin composition of one embodiment of the present invention described above.

[0155] <Method for producing cured resin film> The method for producing a cured resin film of the present embodiment is a method including a step of curing the resin composition.

[0156] The cured resin film of the present embodiment can be produced by applying the resin composition to a substrate, a material to be coated, or an adherend using a known coating or application method such as spray coating, air spray coating, brush coating, immersion coating, roll coating, curtain flow coating, bell coating, electrostatic coating, comma coating, or gravure coating, and then curing the applied resin composition.

[0157] <Laminate> One aspect of the present invention is a laminate comprising one or more films formed on a substrate, the films being made of the cured resin of the above aspect of the present invention. The thickness of each resin film is, for example, 1 μm or more and 50 μm or less.

[0158] Examples of the substrate material include glass, various metals, porous materials, materials with various coatings, cured sealants, rubbers, leather, fibers, nonwoven fabrics, resin films and plates, ultraviolet-curable acrylic resin layers, and layers made of inks.

[0159] Examples of the various metals include aluminum, iron, galvanized steel, copper, and stainless steel. Examples of porous materials include wood, paper, mortar, and stone. Examples of various coatings include fluorine coating, urethane coating, and acrylic urethane coating. Examples of the cured sealant include silicone-based, modified silicone-based, and urethane-based sealants. Examples of the rubbers include natural rubber and synthetic rubber.

[0160] Examples of leathers include natural leather and artificial leather. Examples of fibers include plant fibers, animal fibers, carbon fibers, and glass fibers. Examples of resins that can be used as raw materials for resin films and plates include polyvinyl chloride, polyester, acrylic, polycarbonate, triacetyl cellulose, polyolefin, and the like. Examples of inks include printing inks and UV inks.

[0161] The laminate of this embodiment can be obtained by coating the above-mentioned resin compositions having different compositions onto an adherend using a known method such as roll coating, curtain flow coating, spray coating, bell coating, or electrostatic coating, and then heating and curing the layers, or by coating all of the layers and then heating and curing them all at once.

[0162] The laminate of this embodiment may include, in addition to the resin film, other layers made of known components, such as a primer layer, an adhesive layer, and a decorative layer. [Example]

[0163] The materials used in the examples and comparative examples are described as follows. HDI: Hexamethylene diisocyanate Setalux 1152 SS-60: Allnex, solid content 60% by mass, hydroxyl value of resin component is 138.6 mg KOH / g Zeffle GK-570: Daikin Industries, Ltd., solid content 65% by mass, hydroxyl value: 63 mg KOH / g, fluorination rate 26% Dioctyltin dilaurate: Neostan U-810 Dioctyltin dilaurate

[0164] <Synthesis Example 1-1> (Synthesis of polyisocyanate compound P-1) A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet was purged with nitrogen and charged with 100 parts of HDI. The temperature inside the reactor was maintained at 60°C while stirring, and tetrabutylammonium acetate was added. When the yield reached 28%, phosphoric acid was added to terminate the reaction. The reaction solution was filtered, and unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate compound P-1. Polyisocyanate compound P-1 had an isocyanate group content of 20.0% by mass, a viscosity of 2000 mPa·s at 25°C, and an average number of isocyanate groups of 3.2.

[0165] <Synthesis Example 1-2> (Synthesis of polyisocyanate compound P-2) A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet, and dropping funnel was conditioned with nitrogen and charged with 1,100 parts by mass of HDI and 1.2 parts by mass of 1,3-butanediol. The temperature inside the reactor was maintained at 80°C for 2 hours with stirring. The temperature inside the reactor was then maintained at 60°C, and tetrabutylammonium acetate was added. When the yield reached 50%, phosphoric acid was added to terminate the reaction. The reaction solution was filtered, and unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate compound P-2. Polyisocyanate compound P-2 had an isocyanate group content of 20.0% by mass, a viscosity of 4,000 mPas at 25°C, and an average number of isocyanate groups of 4.5.

[0166] <Synthesis Example 1-3> (Synthesis of polyisocyanate compound P-3) A reaction vessel similar to that used in Synthesis Example 1-1 was charged with 100 g of HDI and 10 g of polycaprolactone-based polyester triol (product name: PLACCEL 303, number average molecular weight: 300, number of hydroxyl groups: 3, manufactured by Daicel Corporation). The temperature inside the reactor was maintained at 90°C for 1 hour with stirring to allow for a pre-reaction. The temperature inside the reactor was then maintained at 80°C, and tetramethylammonium caprylate, an isocyanuration reaction catalyst, was added. When the yield reached 48%, 85% phosphoric acid was added to terminate the reaction. The reaction solution was filtered, and unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate compound P-3. Polyisocyanate compound P-3 had an isocyanate group content of 18.1% by mass, a viscosity at 25°C of 20,000 mPas, and an average number of isocyanate groups of 5.3.

[0167] <Synthesis Example 1-4> (Synthesis of polyisocyanate compound P-4) A four-neck flask equipped with a stirrer, thermometer, and condenser was charged with 300 g of HDI and 12.4 g of 1,4-butanediol, and the mixture was stirred at 130 °C for 1 hour to conduct a urethane reaction. After the urethane reaction was completed, 0.11 g of a 20% solids solution of 2-ethylhexanoic acid zirconyl in mineral spirits (Nihon Kagaku Sangyo Co., Ltd., product name "Nikka Octix Zirconium 12% (T)" diluted with mineral spirits) was added as a catalyst to conduct the allophanation reaction. When the yield reached 32%, phosphoric acid was added to terminate the reaction. The reaction solution was filtered, and unreacted HDI was removed using a thin-film distillation apparatus to obtain polyisocyanate compound P-4. Polyisocyanate compound P-4 had an isocyanate group content of 20.1%, a viscosity at 25 °C of 1600 mPa·s, and an average number of isocyanate groups of 2.3.

[0168] <Synthesis Example 1-5> (Synthesis of polyisocyanate compound P-5) A four-neck flask equipped with a stirrer, thermometer, and condenser was charged with 300 g of HDI and 67 g of HP-1030 (polyether polyol, Asahi Denka). The mixture was stirred at 120°C for 5 hours and then heated to 160°C for an additional 2 hours. The reaction mixture was filtered, and unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate compound P-5. Polyisocyanate compound P-5 had an isocyanate group content of 12.0%, a viscosity of 30,000 mPa.s at 25°C, and an average number of isocyanate groups of 7.2.

[0169] <Synthesis Example 2-A1> (Synthesis of Blocked Polyisocyanate Component A-1) A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet was conditioned under a nitrogen atmosphere and charged with 100 parts by weight of polyisocyanate P-3, 60 parts by weight of diethyl malonate, 11 parts by weight of ethyl acetoacetate, and 38 parts by weight of xylene. 0.8 parts by weight of 28% sodium methylate solution was added at room temperature at a rate of 0.16 parts by weight / min, and the mixture was allowed to react at 60°C for 6 hours. 70 parts by weight of n-butanol was then added, and stirring was continued at that temperature for 2 hours. 0.8 parts by weight of mono(2-ethylhexyl)phosphate was added to the mixture, yielding blocked polyisocyanate A-1 with an effective NCO content of 6.9% and a solids concentration of 60% by weight. The physical properties of the resulting blocked polyisocyanate A-1 are shown in Table 1.

[0170] <Synthesis example 2-A2> (Synthesis of Blocked Polyisocyanate Component A-2) A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet was conditioned under a nitrogen atmosphere and charged with 100 parts by weight of polyisocyanate P-1, 88 parts by weight of diethyl malonate, 2 parts by weight of ethyl acetoacetate, and 40 parts by weight of toluene. 0.8 parts by weight of 28% sodium methylate solution was added at room temperature at a rate of 0.16 parts by weight / min, and the mixture was allowed to react at 60°C for 6 hours. 80 parts by weight of isobutanol was then added and the mixture was stirred at that temperature for 2 hours. 0.8 parts by weight of mono(2-ethylhexyl)phosphate was added to the mixture to obtain blocked polyisocyanate A-2 with an effective NCO content of 7.5% and a solids concentration of 60% by weight. The physical properties of the resulting blocked polyisocyanate A-2 are shown in Table 1.

[0171] <Synthesis example 2-A3> (Synthesis of Blocked Polyisocyanate Component A-3) A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet was conditioned under a nitrogen atmosphere and charged with 100 parts by weight of polyisocyanate P-1, 90 parts by weight of diethyl malonate, and 40 parts by weight of toluene. 0.8 parts by weight of 28% sodium methylate solution was added at room temperature at a rate of 0.16 parts by weight / min, and the mixture was allowed to react at 60°C for 6 hours. 80 parts by weight of isobutanol was then added, and stirring was continued at that temperature for 2 hours. 0.8 parts by weight of mono(2-ethylhexyl)phosphate was added to the mixture, yielding blocked polyisocyanate A-3 with an effective NCO content of 7.5% and a solids concentration of 60% by weight. The physical properties of the resulting blocked polyisocyanate A-3 are shown in Table 1.

[0172] <Synthesis Example 2-B1 to 3, 5, 6> A reaction vessel similar to that used in Synthesis Example 1-1 was charged with 100 parts by mass of each of the polyisocyanate components P-1 to P-3, P-5, and P-6 synthesized in Synthesis Examples 1-1 to 1-3, P-5, and P-6, respectively, and the mixture was maintained at 80°C. 3,5-dimethylpyrazole (3,5-DMP) was added in a molar ratio of 1.05 times the molar ratio of the isocyanate in each polyisocyanate component, and the mixture was stirred for 30 minutes. After confirming that the characteristic absorption of the isocyanate group had disappeared by infrared spectroscopy, butyl acetate was added in a ratio that resulted in a solids content of 70% by mass, and the mixture was stirred to obtain blocked polyisocyanates B-1 to B-3, B-5, and B-6, respectively. The physical properties of the resulting blocked polyisocyanates B-1 to B-3, B-5, and B-6 are shown in Table 2.

[0173] <Synthesis example 2-B4> A reaction vessel similar to that used in Synthesis Example 1-1 was charged with 100 parts by mass of the polyisocyanate component P-1 synthesized in Synthesis Example 1-1 and 30 parts by mass of n-butyl acetate, and the mixture was maintained at 60°C. Next, methyl ethyl ketoxime was added in a molar ratio of 1.05 times the amount of isocyanate in the polyisocyanate component, and the mixture was stirred for 30 minutes. The disappearance of the characteristic absorption of the isocyanate group was confirmed by infrared spectroscopy, yielding blocked polyisocyanate B-4. The physical properties of the resulting blocked polyisocyanate B-4 are shown in Table 2.

[0174] <Synthesis Example 3> A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube was conditioned with a nitrogen atmosphere, and 100 parts by weight of polyisocyanate P-1, 62 parts by weight of diethyl malonate, 1.4 parts by weight of ethyl acetoacetate, and 28 parts by weight of toluene were added. 0.6 parts by weight of 28% sodium methylate solution was added at room temperature at a rate of 0.1 parts by weight / min, and the mixture was allowed to react at 60°C for 6 hours. 80 parts by weight of isobutanol was then added, and stirring was continued at that temperature for 2 hours. 0.8 parts by weight of mono(2-ethylhexyl)phosphate was then added. The mixture was then heated to 80°C, and 3,5-dimethylpyrazole (3,5-DMP) was added at a ratio of 75 / 25 (total moles of diethyl malonate and ethyl acetoacetate / moles of 3,5-DMP), followed by stirring for 30 minutes. Blocked polyisocyanate AB-1 was thus obtained. The physical properties of the resulting blocked polyisocyanate component AB-1 are shown in Table 2.

[0175] <Synthesis Example 4> A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube was conditioned with a nitrogen atmosphere, and 100 parts by weight of polyisocyanate P-1, 64 parts by weight of diethyl malonate, and 28 parts by weight of toluene were added. 0.6 parts by weight of 28% sodium methylate solution was added at room temperature at a rate of 0.1 parts by weight / min, and the mixture was allowed to react at 60°C for 6 hours. 80 parts by weight of isobutanol was then added, and stirring was continued at that temperature for 2 hours. 0.8 parts by weight of mono(2-ethylhexyl)phosphate was then added. The mixture was then heated to 80°C, and 3,5-dimethylpyrazole (3,5-DMP) was added at a ratio of diethyl malonate moles / 3,5-DMP moles = 75 / 25, followed by stirring for 30 minutes. Blocked polyisocyanate AB-2 was thus obtained. The physical properties of the resulting blocked polyisocyanate component AB-2 are shown in Table 2.

[0176] [Property 1: Isocyanate group content (NCO%)] The polyisocyanate compounds obtained in the synthesis examples and the polyisocyanate compositions obtained in the examples and comparative examples were used as samples to measure the isocyanate group content according to the method described in JIS K7301-1995 (Test method for tolylene diisocyanate prepolymers for thermosetting urethane elastomers). A more specific method for measuring the isocyanate group content (NCO%) is described below.

[0177] (1) 1 g (Wg) of sample was placed in a 200 mL Erlenmeyer flask, and 20 mL of toluene was added to the flask to dissolve the sample. (2) Then, 20 mL of a 2.0 N di-n-butylamine-toluene solution was added to the flask and allowed to stand for 15 minutes. (3) 70 mL of 2-propanol was added to the flask and dissolved to obtain a solution. (4) The solution obtained in (3) above was titrated with 1 mol / L hydrochloric acid to determine the sample titer (V1mL). (5) Even when no sample was added, measurements were carried out in the same manner as in (1) to (3) above, and the blank titer (V0 mL) was determined. The isocyanate group content (NCO%) was calculated from the sample titer and blank titer determined above using the following formula. Isocyanate group content (mass%) = (V0 - V1) x 42 / [W (1 g) x 1000] x 100

[0178] [Property 2: Blocked isocyanate group content (effective NCO content)] The effective NCO content of the resulting blocked polyisocyanate composition was determined as follows. The effective NCO content (mass%) here quantifies the amount of blocked isocyanate groups present in the blocked polyisocyanate component after the blocking reaction that can participate in the crosslinking reaction, and is expressed as the mass% of isocyanate groups. The effective NCO content was calculated using the formula shown below. In the formula shown below, "S" represents the non-volatile content (mass%) of the blocked polyisocyanate component. "W1" represents the mass (g) of the polyisocyanate used in the reaction. "A" represents the isocyanate group content (mass%) of the polyisocyanate. "W2" represents the mass (g) of the blocked polyisocyanate after the blocking reaction. Effective NCO content (mass%) = {S × (W1 × A)} / W2

[0179] [Property 3: Isocyanurate group mole fraction %] The obtained polyisocyanate composition was subjected to a polymerization reaction using Biospin Avance 600 (trade name) manufactured by Bruker. 13 C-NMR measurements were carried out under the following specific measurement conditions:

[0180] (Measurement conditions) 13 C-NMR device: AVANCE600 (manufactured by Bruker) Cryoprobe (Bruker) CryoProbe® CPDUL 600S3-C / HD-05Z Resonance frequency: 150MHz Concentration: 60wt / vol% Shift standard: CDCl3 (77 ppm) Accumulation count: 10,000 times Pulse program: zgpg30 (proton fully decoupled, waiting time 2 seconds)

[0181] The integral values ​​of the following signals were divided by the number of carbon atoms being measured to determine the respective molar fractions relative to the total (100 mol%) of isocyanurate groups, iminooxadiazinedione groups, allophanate groups, and uretdione groups. Using the obtained molar fractions, the total content of uretdione groups and allophanate groups relative to the total molar amount of isocyanurate groups, iminooxadiazinedione groups, uretdione groups, and allophanate groups, as well as the molar ratio of uretdione groups to allophanate groups (molar ratio of uretdione groups / allophanate groups) were calculated.

[0182] Isocyanurate group: (integrated value around 148.6 ppm) ÷ 3 Iminooxadiazinedione group: (integrated value around 135.5 ppm) ÷ 1 Allophanate group: (integrated value around 154 ppm) ÷ 1 Uretdione structure: (integral value around 157 ppm) ÷ 2

[0183] [Property 4: Average number of isocyanate groups per molecule] The average number of isocyanate groups per molecule of the polyisocyanate composition was calculated from the following formula based on the number average molecular weight (Mn) and post isocyanate group content (NCO%) of the polyisocyanate composition measured as described above. [Average number of isocyanate groups per molecule] = Mn × NCO% / 4,200

[0184] (Method for measuring number average molecular weight Mn) The number average molecular weight is a number average molecular weight based on polystyrene measured by gel permeation chromatography (GPC) using the following apparatus. The specific measurement conditions for the GPC measurement were as follows.

[0185] Equipment: Tosoh Corporation, HLC-802A Columns: Tosoh Corporation, G1000HXL x 1, G2000HXL x 1, G3000HXL x 1 Carrier: Tetrahydrofuran Detection method: differential refractometer

[0186] [Physical Property 5: Molar ratio of structure derived from blocking agent (a), structure derived from blocking agent (b), and structure derived from blocking agent (c)] Blocked polyisocyanate composition 1 H-NMR and 13C-NMR was measured, and the number of moles of the structure derived from blocking agent (a), the structure derived from blocking agent (b), and the structure derived from blocking agent (c) were calculated from the areas of the peaks attributable to: an amino group (H-NMR, around 4.8 ppm) resulting from a urethane bond obtained by bonding a monohydric alcohol compound and an isocyanate group; an amino group adjacent to an amide form formed by bonding an isocyanate group and diethyl malonate (H-NMR, around 7.3 ppm: keto form, around 8.0 ppm: diamide diester form, around 9.8 ppm: enol form); and an amino group adjacent to an amide form formed by bonding an isocyanate group and ethyl acetoacetate (H-NMR, around 7.2 ppm: keto form, around 9.2 ppm: enol form); and a urea group obtained by bonding an isocyanate group and blocking agent (b) (C-NMR (around 159 ppm)). Here, the number of moles of the structure derived from the blocking agent (a) is the sum of the following (a1) and (a2).

[0187] (a1) The number of bonding structures (number of moles) between an isocyanate group and a malonate diester compound was calculated from the number of amino groups adjacent to an amide formed by bonding an isocyanate group with diethyl malonate (1H-NMR, peak area around 7.3 ppm + peak area around 8.0 ppm / 2 + peak area around 9.8 ppm: the peak around 8.0 ppm (diamide diester) has a structure having two amino groups in one bonding structure, so half of the peak area was used as the number of bonding structures).

[0188] (a2) The number of bond structures (number of moles) between an isocyanate group and an acetoacetate compound, calculated from the number of amino groups adjacent to an amide formed by bonding an isocyanate group with ethyl acetoacetate (1H-NMR, peak area around 7.2 ppm + peak area around 9.2 ppm).

[0189] The number of moles of the structure derived from the blocking agent (b) is (b1) below. (b1) The number of urethane bond structures (number of moles) between an isocyanate group and a monohydric alcohol compound, calculated from the number of amino groups (peak area at about 4.8 ppm by 1H-NMR) resulting from urethane bonds formed by bonding an isocyanate group with n-butanol, isobutanol, or isopropanol.

[0190] The number of moles of the structure derived from the blocking agent (c) is (c1) below. (c1) The number of bond structures (number of moles) between the isocyanate group and the blocking agent (b) calculated from the urea group (13C-NMR, peak area around 159 ppm) obtained by bonding the isocyanate group and the blocking agent (b).

[0191] Using the number of moles obtained above, the molar ratio of the structure derived from blocking agent (a) to the structure derived from blocking agent (b) (blocking agent (a) / blocking agent (b)) was calculated. Similarly, the molar ratio of the structure derived from blocking agent (c) to the total amount of the structure derived from blocking agent (a), the structure derived from blocking agent (b), and the structure derived from blocking agent (c) was determined.

[0192] The NMR equipment and measurement conditions are as follows. Device: JEOL “JEOL-ECZ500(SC)” (product name) Solvent: deuterated chloroform Accumulation count: 256 times Sample concentration: 5.0% by mass Chemical shift standard: tetramethylsilane was set as 0 ppm.

[0193] [Preparation Example 1] Parts by weight of each blocked polyisocyanate composition shown in Tables 3 to 7 were mixed by stirring at 60°C for 1 hour and then stored at 23°C for 10 days. Next, the blocked polyisocyanate composition prepared above and parts by weight of a polyol shown in Tables 3 to 8 were weighed out. Then, parts by weight of butyl acetate shown in Tables 3 to 7 were added, and the mixture was stirred at 600 rpm for 10 minutes using a propeller blade to obtain a resin composition.

[0194] [Preparation Example 2] Blocked polyisocyanate composition A, blocked polyisocyanate composition B, and polyol were weighed out in the parts by mass shown in Table 8. Then, butyl acetate was added in a proportion such that the solid content was 50% by mass, and the mixture was stirred at 600 rpm using a propeller blade for 10 minutes to obtain a resin composition.

[0195] [Evaluation 1: Compatibility with polyols (compatibility in coating film)] The resin compositions prepared in the Preparation Examples were applied to white boards so that the film thickness after drying was 15 μm, and after baking at 170°C for 2 minutes and allowing to cool to 23°C, the 60° gloss value was measured under the conditions of JIS Z8741 using a glossmeter (Digital Variable Glossmeter UDV-6P (trade name) manufactured by Suga Test Instruments Co., Ltd.). The appearance was evaluated according to the following evaluation criteria.

[0196] (Evaluation criteria) A: 60 degree gloss value is 92% or more B: 60 degree gloss value is 60% or more but less than 92% C: 60 degree gloss value is less than 60%

[0197] [Evaluation 2: Hardening] The resin composition prepared in Preparation Example was applied to a glass plate so that the film thickness after drying was 15 μm, and after baking at 170°C for 2 minutes and 5 minutes had passed, a cotton ball (cylindrical, 2.5 cm in diameter, 2.0 cm in height) was placed on the coating, and a 100 g weight was placed on top of it for 60 seconds. The weight and cotton were then removed, and the marks left by the cotton on the coating were observed.

[0198] (Evaluation criteria) A: I couldn't see any traces. B: A small mark remained C: The mark was clearly visible

[0199] [Evaluation 3: Gel fraction] The resin composition prepared in the Preparation Example was applied to a PP plate to a dry film thickness of 40 μm, and the plate was baked at 170°C for 2 minutes. After 1 hour at 23°C, the coating was peeled off and its mass was measured. This coating (film) was immersed in acetone at 23°C for 24 hours. This coating was dried at 105°C for 60 minutes, and its mass was then measured. Curability was evaluated as the ratio of the mass after immersion to the mass before immersion (gel fraction: %).

[0200] [Rating 4: Water resistance] The resin composition prepared in each Preparation Example was applied to a glass plate so that the dried film thickness was 15 μm, baked at 170°C for 2 minutes, and then allowed to cool to 23°C. A 20 mm diameter silicone O-ring was then placed on the resulting coating, and 0.5 g of water was poured into it. The coating was then left at 23°C for 24 hours, and the remaining water on the surface was removed, after which the coating was observed. The water resistance of the coating was evaluated according to the following evaluation criteria. Regarding the evaluation criteria, "blister" refers to bubbles or swelling that appear on the surface of the coating.

[0201] (Evaluation criteria) A: No change B: Blisters appear C: Paint film dissolution

[0202] [Rating 5: Acid resistance] The resin composition prepared in each Preparation Example was applied to a glass plate so that the dried film thickness was 15 μm, baked at 170°C for 2 minutes, and then allowed to cool to 23°C. A 20 mm diameter silicone O-ring was then placed on the resulting coating, and 0.5 g of a 10% aqueous sulfuric acid solution was poured into it. The coating was then left at 23°C for 24 hours, and the remaining water on the surface was removed, after which the coating was observed. The water resistance of the coating was evaluated according to the following evaluation criteria. Regarding the evaluation criteria, "blister" refers to bubbles or swelling that appear on the surface of the coating.

[0203] (Evaluation criteria) A: No change B: Blisters appear C: Paint film dissolution

[0204] [Rating 6: Alkali resistance] The resin composition prepared in each Preparation Example was applied to a glass plate so that the dried film thickness was 15 μm, baked at 170°C for 2 minutes, and then allowed to cool to 23°C. A 20 mm diameter silicone O-ring was then placed on the resulting coating, and 0.5 g of a 10% aqueous sodium hydroxide solution was poured into it. The coating was then left at 23°C for 24 hours, and the remaining water on the surface was removed, after which the coating was observed. The water resistance of the coating was evaluated according to the following evaluation criteria. Regarding the evaluation criteria, "blister" refers to bubbles or swelling that appear on the surface of the coating.

[0205] (Evaluation criteria) A: No change B: Blisters appear C: Paint film dissolution

[0206] [Evaluation 7: Solvent resistance] The resin compositions prepared in the Preparation Examples were applied to glass plates so that the film thickness after drying was 15 μm, and after baking at 170° C. for 2 minutes, the plates were allowed to cool to 23° C. Next, a cotton swab soaked in ethanol was used to rub the surface of the coating back and forth 100 times over a 1 cm length, and the appearance of the coating was then evaluated according to the following criteria.

[0207] (Evaluation criteria) A: No change B: Blisters appear C: Paint film dissolution

[0208] [Evaluation 8: Adhesion after highly accelerated life testing] The resin composition prepared in the Preparation Example was applied to a PET film to a dry thickness of 15 μm, baked at 170°C for 2 minutes, and then allowed to cool to 23°C. The cross section of the coating was then sealed with Nitoflon tape and placed in a highly accelerated life tester (ESPEC Corporation, EHS-412M). After 48 hours at 121°C and 100% humidity, the test specimen was removed. Next, using a utility knife, 11 cuts were made on the test surface, reaching down to the substrate, with 1 mm spacing between the cuts, creating 100 grids. Cellophane tape was firmly pressed onto the grids, and the edge of the tape was quickly peeled off at a 45° angle. The condition of the grids was evaluated by comparing it with a standard diagram.

[0209] (Evaluation criteria) A: None of the grids are peeling off. B: The coating has peeled off partially or completely along the cut line. 15% to less than 50% C: The coating has peeled off partially or completely along the cut line. 50% or more

[0210] [Rating 9: Blocking resistance] The blocking resistance was evaluated by a method according to JIS K5600-3-5. A 50 μm-thick PET film coated to a dry film thickness of 15 μm was baked at 110°C for 10 minutes, then left to cool at 23°C for 24 hours. This coated film was cut into 40 mm x 40 mm pieces, and the coated and uncoated sides of the resulting two pieces were placed one on top of the other, with a 40 mm diameter weight (500 g) with a smooth bottom placed on top. The pieces were placed in a 40°C / 60% RH oven for 72 hours, then left to cool at 23°C for 24 hours. The coated film was then peeled off, and the remaining residue was visually inspected to evaluate blocking resistance.

[0211] (Evaluation criteria) A: No traces of paint remaining B: Less than 30% of the paint film remains on the unpainted surface. C: 30% or more of the paint film remains on the unpainted surface.

[0212] <Examples 1 to 26> A coating composition was prepared according to the formulation described in Preparation Example 1. This coating composition was evaluated according to evaluation methods 1 to 9. The results are shown in Tables 3 to 8.

[0213] Example 27 A coating composition was prepared according to the formulation described in Preparation Example 2. This coating composition was evaluated according to evaluation methods 1 to 9. The results are shown in Table 8.

[0214] <Comparative Examples 1 to 4> A coating composition was prepared according to the formulation described in Preparation Example 1. This coating composition was evaluated according to evaluation methods 1 to 9. The results are shown in Table 9.

[0215] In the table below, "BPI" is an abbreviation for blocked polyisocyanate.

[0216] [Table 1]

[0217] [Table 2]

[0218] [Table 3]

[0219] [Table 4]

[0220] [Table 5]

[0221] [Table 6]

[0222] [Table 7]

[0223] [Table 8]

[0224] [Table 9]

[0225] For Examples 1 to 27, the results of Evaluation 2 were all A or B, confirming that curability was maintained under high-temperature, short-time baking conditions. Furthermore, for Examples 1 to 27, the results of Evaluation 8 were all A or B, confirming that the crosslinked coating film formed had excellent adhesion to the substrate. Furthermore, for Examples 1 to 27, the results of Evaluations 4 to 7 were all A or B, confirming that they exhibited chemical resistance and long-term moist heat resistance.

[0226] In contrast, Comparative Example 1, in which the ratio of blocking agent (a) / blocking agent (b) did not satisfy the present invention, received C ratings for 6 to 8, and Comparative Example 2 received C ratings for 2 and all of 4 to 9. Furthermore, Comparative Examples 3 and 4, which used a blocking agent (a) containing only a malonic acid diester compound but not a β-ketoester compound, had poor compatibility with the base resin and were given a rating of C.

Claims

1. A blocked polyisocyanate composition in which an isocyanate group of a polyisocyanate compound is blocked with a blocking agent, the polyisocyanate compound is a polyisocyanate compound derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, The blocking agent includes a blocking agent (a) and a blocking agent (b), The blocking agent (a) is an active methylene-based compound, and the active methylene-based compound includes a malonic acid diester compound and a β-ketoester compound; The malonic acid diester compound is at least one selected from the group consisting of malonic acid diester compounds represented by the following formula (1): The β-keto ester compound is at least one selected from the group consisting of β-keto ester compounds represented by the following formula (2): the blocking agent (b) is a thermally dissociating blocking agent, a blocked polyisocyanate composition, wherein the molar ratio of the structure derived from the blocking agent (a) to the structure derived from the blocking agent (b) (blocking agent (a) / blocking agent (b)) is 20 / 80 to 90 / 10. 【Chemical 1】 [In formula (1), R １ and R ２ R each independently represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a benzyl group. １ and R ２ may be the same or different. 【Chemistry 2】 [In formula (2), R ３ and R ４ R each independently represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a benzyl group. ３ and R ４ may be the same or different.

2. R in the formula (1) １ and R ２ are the same and are a methyl group, an ethyl group, or an isopropyl group, and R ３ and R ４ The blocked polyisocyanate composition according to claim 1 , wherein is a methyl group or an ethyl group.

3. 3. The blocked polyisocyanate composition according to claim 1, wherein the blocking agent (b) is at least one selected from the group consisting of oxime compounds, acid amide compounds, amine compounds, imidazole compounds, and pyrazole compounds.

4. the blocking agent further contains a blocking agent (c), and the blocking agent (c) is a monohydric alcohol-based compound; 3. The blocked polyisocyanate composition according to claim 1 or 2, wherein the molar ratio of the structure derived from the blocking agent (c) to the total amount of the structure derived from the blocking agent (a), the structure derived from the blocking agent (b), and the structure derived from the blocking agent (c) is 3 mol % or more and less than 10 mol %.

5. 3. The blocked polyisocyanate composition according to claim 1, wherein the polyisocyanate compound has an average number of isocyanate functional groups of 2.5 or more and 6.0 or less.

6. contains an isocyanurate group and at least one selected from the group consisting of an allophanate group, a uretdione group, a uretoneimino group, a urethane group, a biuret group, a urea group, and an iminooxadiazinedione group, 3. The blocked polyisocyanate composition according to claim 1, wherein the blocked polyisocyanate composition contains 30% to 90% isocyanurate groups relative to 100% of the total number of moles of isocyanurate groups, allophanate groups, uretdione groups, uretoneimino groups, urethane groups, biuret groups, urea groups, and iminooxadiazinedione groups.

7. 3. The blocked polyisocyanate composition according to claim 1 or 2, comprising a blocked polyisocyanate composition (A) derived from the blocking agent (a) and a blocked polyisocyanate composition (B) derived from the blocking agent (b).

8. 3. The blocked polyisocyanate composition according to claim 1, further comprising the blocking agent (b) that has not reacted with the polyisocyanate compound.

9. A resin composition comprising the blocked polyisocyanate composition according to claim 1 and a polyol.

10. 10. The resin composition according to claim 9, wherein the molar ratio (NCO / OH) of the isocyanate groups bonded to the blocking agent (b) in the blocked polyisocyanate composition to the hydroxyl groups of the polyol is 0.4 / 1.0 or more and 1.2 / 1.0 or less.

11. A cured resin obtained by curing the resin composition according to claim 9 or 10.

12. A laminate comprising one or more layers of a film made of the cured resin according to claim 11 laminated on a substrate.

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