Modified polyisocyanates, coatings and painted metal materials

Abstract

The present invention addresses the problem of providing a modified polyisocyanate which is applicable to a coating material for single application, the coating material exhibiting high adhesion even to a nonferrous metal. The present invention provides: a modified polyisocyanate which is a reaction product that is obtained using, as a starting material, a component that contains (a1) an alkoxysilane having a primary amino group, (a2) an unsaturated carboxylic acid alkyl ester or (a3) a saturated carboxylic acid alkyl ester, and (a4) a polyisocyanate, wherein the unsaturated carboxylic acid alkyl ester (a2) is composed of at least one compound that is selected from the group consisting of (a2-1) a branched alkyl ester of an unsaturated dicarboxylic acid and (a2-2) a branched alkyl ester of an unsaturated monocarboxylic acid, the branched alkyl ester optionally containing a heteroatom, or an alkyl ester having a cyclic structure; a method for producing this modified polyisocyanate; and a coating which contains this modified polyisocyanate.

Description

[Technical Field]

[0001] The present invention relates to modified polyisocyanates, coatings and painted metal materials. [Background technology]

[0002] Polyisocyanate compounds are highly reactive substances and are widely used as raw materials for chemical products such as polyurethane foams, sealants, adhesives, paints, etc. In recent years, modified polyisocyanates have been developed that have been modified in various ways depending on the functions required of these chemical products.

[0003] For example, Patent Document 1 describes a modified polyisocyanate, a silyl isocyanate obtained by reacting a polyisocyanate with a silane starting material, and discloses that this silyl isocyanate has good adhesion to glass and is useful as a fixing agent to be used in combination with polyurethane resins.

[0004] Furthermore, Patent Document 2 describes a reaction product of an amino-alkylalkoxysilane with a maleic acid ester or a fumaric acid ester, and discloses that this reaction product is useful as a modifier for polyisocyanates.

[0005] Patent Document 3 discloses a crosslinkable silyl group-containing urethane resin mixture obtained by reacting a compound containing two or more active hydrogens and one or more crosslinkable silyl groups in the molecule with an acrylic compound and / or a methacrylic compound, thereby obtaining a compound containing one or more active hydrogens and one or more crosslinkable silyl groups in the molecule, with an isocyanate group-containing urethane prepolymer obtained by reacting an organic polyisocyanate with a polymer polyol under conditions where the isocyanate group is in excess relative to the active hydrogen. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-212141 [Patent Document 2] Japanese Patent Application Publication No. 6-211879 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-323040 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, the development of direct-to-metal coating has been anticipated. Direct-to-metal coating is a coating that forms a protective film that combines corrosion resistance and weather resistance by simply applying a single type of paint directly to the metal surface. Metal coating typically involves a multi-layer finish, first applying a primer to inhibit rust and then a topcoat that provides excellent weather resistance and finish. In contrast, direct-to-metal coating achieves the desired performance with a single coat, thereby reducing the number of processes and shortening construction time. However, the corrosion resistance and weather resistance of a coating are generally incompatible, making it difficult to achieve both. Furthermore, nonferrous metals have the problem of poor adhesion and peeling compared to ferrous metals, making it extremely difficult to develop a coating that combines excellent adhesion to nonferrous metals with corrosion resistance and weather resistance.

[0008] The above Patent Documents 1 to 3 disclose various modified polyisocyanates, but do not disclose modified polyisocyanates that are applicable to one-coat paints that also have high adhesion to non-ferrous metals. [Means for solving the problem]

[0009] The present inventors have conducted extensive research into the above-mentioned problems. As a result, they have arrived at the use of a modified polyisocyanate modified with an alkoxysilane having a primary amino group and a specific unsaturated carboxylic acid alkyl ester or a saturated carboxylic acid alkyl ester. They have also found that this modified polyisocyanate is an excellent metal adhesion material, and that coatings containing this material have excellent adhesion to not only iron but also non-ferrous metals.

[0010] That is, the present invention is Item 1 1. A modified polyisocyanate for use with an active hydrogen-containing compound as a curing agent for a coating, comprising: The present invention relates to a reaction product using as raw materials components containing an alkoxysilane (a1) having a primary amino group, an unsaturated carboxylic acid alkyl ester (a2) or a saturated carboxylic acid alkyl ester (a3), and a polyisocyanate (a4), wherein the unsaturated carboxylic acid alkyl ester (a2) is Branched alkyl esters of unsaturated dicarboxylic acids (a2-1), and Branched alkyl esters or alkyl esters having a cyclic structure, which may contain a heteroatom, of unsaturated monocarboxylic acids (a2-2) At least one selected from the group consisting of Modified polyisocyanate. Section 2 Item 2. The modified polyisocyanate according to Item 1, wherein the alkoxysilane (a1) having a primary amino group is a compound represented by the following formula (1):

[0011] [ka]

[0012] In formula (1), R 1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and n is an integer of 0 to 2. Section 3 Item 3. The modified polyisocyanate according to Item 1 or 2, wherein the branched alkyl ester of an unsaturated dicarboxylic acid (a2-1) is a compound represented by the following formula (2): R 4 OC(=O)-HC=CH-C(=O)-OR 5 (2)

[0013] In formula (2), R 4 and R 5 are the same or different and are branched alkyl groups having 1 to 8 carbon atoms. Section 4 Item 3. The modified polyisocyanate according to Item 1 or 2, wherein the branched alkyl ester or cyclic alkyl ester (a2-2) of the unsaturated monocarboxylic acid, which may contain a heteroatom, is a compound represented by the following formula (3): H2C=CH-C(=O)-OR 6 (3)

[0014] In formula (3), R 6 represents a group obtained by incorporating a heteroatom (e.g., oxygen atom, nitrogen atom, sulfur atom) into the molecule of a branched alkyl group having 3 to 18 carbon atoms or an alkyl group having a cyclic structure, or an alkyl group having 1 to 18 carbon atoms and a branched or cyclic structure or an arylalkyl group. Section 5 Item 3. The modified polyisocyanate according to Item 1 or 2, wherein the saturated carboxylic acid alkyl ester (a3) ​​is a compound represented by the following formula (4): R 7 -C(=O)-OR 8 (4)

[0015] In formula (4), R 7 and R 8are the same or different and represent an alkyl group having 1 to 18 carbon atoms and having no unsaturated group, or a group having 1 to 18 carbon atoms and containing a heteroatom such as an oxygen atom, nitrogen atom or sulfur atom in the molecule of an alkyl group or arylalkyl group having 1 to 18 carbon atoms and having no unsaturated group. Section 6 Item 5. The modified polyisocyanate according to any one of Items 1 to 4, wherein a secondary amino group of an N-position-modified alkoxysilane formed by adducting a primary amino group of the alkoxysilane (a1) to an unsaturated carbon-carbon bond of the unsaturated carboxylic acid alkyl ester (a2) is adducted to an isocyanate group of the polyisocyanate (a4). Section 7 Item 6. The modified polyisocyanate according to any one of Items 1, 2, and 5, wherein the modified polyisocyanate has a structure in which a secondary amide group of an N-position-modified alkoxysilane formed by reacting a primary amino group of the alkoxysilane (a1) with an ester group of the saturated carboxylic acid alkyl ester (a3) ​​is adducted to an isocyanate group of the polyisocyanate (a4). Section 8 Item 7. The modified polyisocyanate according to Item 6, wherein the unsaturated carboxylic acid alkyl ester (a2) is a branched alkyl ester of an unsaturated dicarboxylic acid (a2-1), and the N-position-modified alkoxysilane is a compound represented by the following formula (5):

[0016] [ka]

[0017] In formula (5), R 1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and R 4 and R 5are the same or different and each represents a branched alkyl group having 1 to 8 carbon atoms; and n is an integer of 0 to 2. Section 9 Item 9. The modified polyisocyanate according to any one of Items 6 to 8, wherein the reaction ratio of the N-position-modified alkoxysilane having a secondary amino group with the polyisocyanate (a4) is such that the number of moles of secondary amino groups is 40 or less per 100 moles of isocyanate groups. Section 10 Item 7. The modified polyisocyanate according to Item 6, wherein the unsaturated carboxylic acid alkyl ester (a2) is a branched alkyl ester of an unsaturated monocarboxylic acid which may contain a heteroatom or an alkyl ester (a2-2) having a cyclic structure, and the N-position-modified alkoxysilane is a compound represented by the following formula (6):

[0018] [ka]

[0019] In formula (6), R 1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and R 6 is a group obtained by incorporating a heteroatom, such as an oxygen atom, nitrogen atom or sulfur atom, into the molecule of an alkyl group having a branched or cyclic structure and having 3 to 18 carbon atoms, which may contain a heteroatom, or an alkyl group having a branched or cyclic structure and having 1 to 18 carbon atoms, or an arylalkyl group, and n is an integer of 0 to 2. Section 11 Item 11. The modified polyisocyanate according to any one of Items 6 to 10, wherein the reaction ratio of the mixture containing the N-position-modified alkoxysilane having a secondary amino group with the polyisocyanate (a4) is such that the total number of moles of primary amino groups and secondary amino groups per 100 moles of isocyanate groups is 40 moles or less. Section 12 Item 8. The modified polyisocyanate according to Item 7, wherein the N-position modified alkoxysilane obtained by reacting the alkoxysilane (a1) with the saturated carboxylic acid alkyl ester (a3) ​​is an N-position acyl modified product having a secondary amide group and represented by the following formula (7):

[0020] [ka]

[0021] In formula (7), R 1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; n is an integer of 0 to 2; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and R 7 represents an alkyl group having 1 to 18 carbon atoms and containing no unsaturated groups, or a group having 1 to 18 carbon atoms and containing a heteroatom such as an oxygen atom, nitrogen atom or sulfur atom in the alkyl molecule, and containing no unsaturated groups. Section 13 A step (1) of reacting an alkoxysilane (a1) having a primary amino group with a saturated carboxylic acid alkyl ester (a3) ​​in the presence of a basic catalyst; Step (2) of adding an acidic compound; Step (3) of removing a part or all of the alcohol produced as a by-product to prepare an intermediate containing an N-acyl-modified product represented by the following formula (7): Step (4) of reacting the intermediate with polyisocyanate (a4). Item 13. The modified polyisocyanate according to Item 1 or 12, produced by

[0022] [ka]

[0023] In formula (7), R1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, n is an integer of 0 to 2, and R 7 represents an alkyl group having 1 to 18 carbon atoms and having no unsaturated group, or a group having 1 to 18 carbon atoms and containing a heteroatom such as an oxygen atom, nitrogen atom or sulfur atom in the alkyl molecule, and having no unsaturated group. Section 14 Item 14. The modified polyisocyanate according to Item 12 or 13, wherein the reaction ratio of the N-acyl-modified product with the polyisocyanate (a4) is such that the total number of moles of secondary amide groups and primary amino groups per 100 moles of isocyanate groups is 40 moles or less. Section 15 A step (1) of reacting an alkoxysilane (a1) having a primary amino group with a saturated carboxylic acid alkyl ester (a3) ​​in the presence of a basic catalyst; Step (2) of adding an acidic compound; Step (3) of removing a part or all of the alcohol produced as a by-product to prepare an intermediate containing an N-acyl-modified product represented by the following formula (7): Step (4) of reacting the intermediate with polyisocyanate (a4). Item 2. The method for producing a modified polyisocyanate according to Item 1,

[0024] [ka]

[0025] In formula (7), R 1 and R 2are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, n is an integer of 0 to 2, and R 7 represents an alkyl group having 1 to 18 carbon atoms and containing no unsaturated groups, or a group having 1 to 18 carbon atoms and containing a heteroatom such as an oxygen atom, nitrogen atom or sulfur atom in the alkyl molecule, and containing no unsaturated groups. Section 16 Item 7. The modified polyisocyanate according to Item 6, wherein the unsaturated carboxylic acid alkyl ester (a2) is a branched alkyl ester or an alkyl ester (a2-2) having a cyclic structure, which may contain a heteroatom, of an unsaturated monocarboxylic acid, and the reaction of the N-position-modified alkoxysilane having a secondary amino group with the polyisocyanate (a4) is carried out in the presence of the alkoxysilane (a1) having a primary amino group and a by-product, a tertiary amino group-containing compound represented by the following formula (8):

[0026] [ka]

[0027] In formula (8), R 1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and R 6 is a group obtained by incorporating a heteroatom, such as an oxygen atom, nitrogen atom or sulfur atom, into the molecule of an alkyl group having a branched or cyclic structure and having 3 to 18 carbon atoms, which may contain a heteroatom, or an alkyl group having a branched or cyclic structure and having 1 to 18 carbon atoms, or an arylalkyl group, and n is an integer of 0 to 2. Section 17 Item 15. The modified polyisocyanate according to any one of Items 1, 2, 5, 7, 12, 13, and 14, wherein the saturated carboxylic acid alkyl ester (a3) ​​is an alkyl ester of a linear carboxylic acid having two or more hydrogen atoms at the α-position, or an alkyl ester of a branched carboxylic acid having two hydrogen atoms at the α-position. Section 18 Item 16. The method for producing a modified polyisocyanate according to Item 15, wherein the saturated carboxylic acid alkyl ester (a3) ​​is an alkyl ester of a linear carboxylic acid having two or more hydrogen atoms at the α-position. Section 19 18. A coating comprising an active hydrogen-containing compound and the modified polyisocyanate according to any one of items 1 to 14 and items 16 to 17. Section 20 Item 20. The coating according to item 19, wherein the active hydrogen-containing compound comprises an acrylic polyol and / or a bisaspartic acid ester derivative. Section 21 Item 21. The coating according to item 19 or 20, further comprising at least one selected from the group consisting of a rust inhibitor, a catalyst, a color pigment, and an extender pigment. Section 22 Item 22. The coating according to any one of items 19 to 21, which is a one-coat paint. Section 23 23. A protective coating film obtained by curing the coating according to any one of items 19 to 22. Section 24 23. A coated metal material, comprising the protective coating film according to any one of items 19 to 22 formed on a metal substrate. Regarding. [Effects of the Invention]

[0028] As used herein, the singular forms (a, an, the, etc.) include both the singular and the plural, unless otherwise specified herein or clearly contradictory in the context. The modified polyisocyanate of the present invention has excellent storage stability and can be used as a metal adhesion improver for coatings. By using this modified polyisocyanate, a coating can be obtained that forms a protective coating film with excellent adhesion to not only ferrous but also non-ferrous metals. DETAILED DESCRIPTION OF THE INVENTION

[0029] The modified polyisocyanate of the present invention is a reaction product obtained by using, as raw materials, components including an alkoxysilane (a1) having a primary amino group, an unsaturated carboxylic acid alkyl ester (a2) or a saturated carboxylic acid alkyl ester (a3), and a polyisocyanate (a4).

[0030] The raw material for the modified polyisocyanate of the present invention contains an unsaturated carboxylic acid alkyl ester (a2) or a saturated carboxylic acid alkyl ester (a3) ​​as the carboxylic acid alkyl ester. In a first embodiment, the present invention provides a modified polyisocyanate using the unsaturated carboxylic acid alkyl ester (a2) as the raw material (referred to as modified polyisocyanate (X)). In a second embodiment, the present invention provides a modified polyisocyanate using the saturated carboxylic acid alkyl ester (a3) ​​as the raw material (referred to as modified polyisocyanate (Y)).

[0031] When the unsaturated carboxylic acid alkyl ester (a2) is used as the carboxylic acid alkyl ester, the unsaturated carboxylic acid alkyl ester (a2) is Branched alkyl esters of unsaturated dicarboxylic acids (a2-1), and Branched alkyl esters or alkyl esters having a cyclic structure, which may contain a heteroatom, of unsaturated monocarboxylic acids (a2-2) At least one selected from the group consisting of:

[0032] In the present invention, by using the unsaturated carboxylic acid alkyl ester (a2) or the saturated carboxylic acid alkyl ester (a3) ​​as a modifier, a modified polyisocyanate can be obtained that can be stably diluted in an organic solvent and has excellent storage stability, and together with an active hydrogen group-containing compound described below, it is possible to form a protective coating film that has excellent adhesion to various metal substrates.

[0033] In the present invention, when a group in a general formula such as Formula (1) or Formula (5) is substituted, unless otherwise specified, examples of the substituent include an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an amino group, a monoalkylamino group, a dialkylamino group, a carboxyl group, a hydroxyl group, a hydroxyalkyl group, a hydroxyalkoxy group, an aryl group, an aryloxy group, and a heteroaryl group.

[0034] In the present invention, unless otherwise specified, each substituent may include the following: Unless otherwise specified, the alkyl group refers to a linear, branched, or cyclic saturated hydrocarbon group. The number of carbon atoms in the alkyl group is not particularly limited, and examples include 1 to 18, 1 to 10, 1 to 8, 1 to 6, 1 to 4, and 1 to 3. Examples of such alkyl groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of cycloalkyl groups include cyclic hydrocarbon groups in which all carbon-carbon bonds are single bonds. Examples of the number of carbon atoms include 3 to 8. More specific examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of the hydroxyalkyl group include the above-mentioned alkyl groups substituted with one or more (for example, 1 to 3, 1 to 2, 1, etc.) hydroxyl groups. Examples of the alkoxy group include alkoxy, in which the alkyl moiety is the alkyl group described above. Examples of hydroxyalkoxy groups include the above-mentioned alkoxy groups substituted with one or more (for example, 1 to 3, 1 to 2, 1, etc.) hydroxyl groups. The alkenyl group refers to a linear or branched hydrocarbon group having a carbon-carbon double bond. The number of carbon atoms in the alkenyl group is not particularly limited, and examples thereof include 2 to 18, 2 to 10, 2 to 8, 2 to 6, 2 to 4, and 2 to 3. The number of carbon-carbon double bonds in the alkenyl group is not limited, and examples thereof include 1 to 2, and preferably 1. Examples of such alkenyl groups include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 1-pentenyl, 1,4-pentadienyl, 1-hexenyl, 1-heptenyl, 1-octenyl, 1-nonenyl, 1-decenyl, 2-undecenyl, 3-dodecenyl, 1-tridecenyl, 2-tetradecenyl, 3-pentadecenyl, 1-hexadecenyl, 2-heptadecenyl, and 3-octadecenyl groups. The alkynyl group refers to a linear or branched hydrocarbon group having a carbon-carbon triple bond. The number of carbon atoms in the alkyl group is not particularly limited, and examples thereof include 2 to 18, 2 to 10, 2 to 8, 2 to 6, 2 to 4, and 2 to 3. The number of carbon-carbon triple bonds in the alkynyl group is not limited, and examples thereof include 1 to 2, and preferably 1. Examples of such alkoxy groups include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 1-pentynyl, 1,4-pentadiynyl, 1-hexynyl, 1-heptynyl, 1-octynyl, 1-nonynyl, 1-decynyl, 2-undecynyl, 3-dodecynyl, 1-tridecynyl, 2-tetradecynyl, 3-pentadecynyl, 1-hexadecynyl, 2-heptadecynyl, and 3-octadecynyl groups. Examples of cycloalkenyl groups include cyclic hydrocarbon groups having a carbon-carbon double bond and all other carbon-carbon bonds being single bonds. The number of carbon atoms may be, for example, 3 to 8. The number of carbon-carbon double bonds in the cycloalkenyl group is not limited, but may be, for example, 1 to 2, preferably 1. More specifically, examples of cycloalkyl groups include cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cyclohexedienyl, cycloheptenyl, and cyclooctenyl groups. The term "aryl group" refers to a monovalent group formed by eliminating one hydrogen atom from a monocyclic or polycyclic aromatic hydrocarbon compound, and examples thereof include those having 6 to 18 carbon atoms. In the present invention, the monocyclic or polycyclic aromatic hydrocarbon compound may be any hydrocarbon containing an aromatic ring, and the group having a cyclic structure may be substituted with one or more (e.g., 1 to 3, 1 to 2, or 1) acyclic hydrocarbons (e.g., linear or branched alkyl groups, alkenyl groups, alkynyl groups, etc. (preferably linear or branched alkyl groups, etc.)). Similarly, in the present invention, the term "aryl group" includes not only groups having a cyclic structure, but also groups formed by substituting one or more acyclic hydrocarbons on a group having a cyclic structure. Examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a diphenyl group, a methylphenyl group, a dimethylphenyl group, and a dodecylphenyl group. Examples of the arylalkyl group include the aforementioned alkyl groups having one or more (typically one) aryl groups. Examples of heteroaryl groups include groups having a 5- to 14-membered saturated or unsaturated ring structure containing at least one atom (e.g., 1 to 3, 1 to 2, 1, etc.) selected from the group consisting of oxygen, nitrogen, and sulfur atoms. Examples include tetrahydrofuryl, dihydrobenzofuranyl, pyridinyl, pyrimidinyl, thiophenyl, oxathiolanyl, quinolinyl, and benzoquinolinyl. The heteroaryl group may be a monocyclic or bicyclic group. An alkyl group having a cyclic structure refers to a hydrocarbon group having a cyclic structure in at least a part of its structure. Preferably, it does not have a carbon-carbon double bond. The alkyl group having a cyclic structure may be a group consisting of a hydrocarbon having a cyclic structure (e.g., a cycloalkyl group, a bicycloalkyl group, etc.), or may be a group in which the group consisting of a hydrocarbon having a cyclic structure is substituted with (e.g., 1 to 5, preferably 1 to 4) hydrocarbon groups (e.g., alkyl groups (preferably alkyl groups having 1 to 3 carbon atoms)). The number of carbon atoms in the alkyl group having a cyclic structure is not limited, but may be, for example, 6 to 23, preferably 6 to 11. Examples of bicycloalkyl groups include monovalent groups obtained by removing one hydrogen atom from a fused ring having 5 to 8 carbon atoms, such as bicyclo[1.1.1]pentanyl, bicyclo[2.1.1]hexanyl, bicyclo[2.2.1]heptanyl, and bicyclo[2.2.2]octanyl.

[0035] <Alkoxysilane (a1) having a primary amino group> In the present invention, the alkoxysilane (a1) having a primary amino group is a compound represented by the following formula (1).

[0036] [ka]

[0037] In formula (1), R1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and n is an integer of 0 to 2.

[0038] Specific examples of compound (a1) include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyl-methyldiethoxysilane, 3-aminopropyl-methyldimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, 4-amino-3,3-dimethylbutyltriethoxysilane, and combinations thereof. 3-Aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane are particularly preferred.

[0039] <Unsaturated carboxylic acid alkyl ester (a2)> In the present invention, the unsaturated carboxylic acid alkyl ester (a2) is Branched alkyl esters of unsaturated dicarboxylic acids (a2-1), and The alkyl ester is at least one selected from the group consisting of branched alkyl esters of unsaturated monocarboxylic acids which may contain a hetero atom or alkyl esters having a cyclic structure (a2-2).

[0040] <Branched alkyl ester of unsaturated dicarboxylic acid (a2-1)> The branched alkyl ester (a2-1) of unsaturated dicarboxylic acid is a branched alkyl ester of fumaric acid or maleic acid, and examples thereof include compounds represented by the following formula (2).

[0041] R 4 OC(=O)-HC=CH-C(=O)-OR 5 (2)

[0042] In formula (2), R4 and R 5 are the same or different and are branched alkyl groups having 1 to 8 carbon atoms.

[0043] As used herein, the term "branched alkyl group" refers to an alkyl group in which the carbon skeleton constituting the alkyl group is branched. Examples of the branched alkyl group include an i-propyl group, a 1-methylpropyl group, an i-butyl group, a t-butyl group, an i-pentyl group, a t-pentyl group, and a 2-ethylhexyl group.

[0044] <Branched alkyl ester or alkyl ester having a cyclic structure which may contain a heteroatom of unsaturated monocarboxylic acid (a2-2)> In the present invention, the branched alkyl ester or alkyl ester having a cyclic structure (a2-2) of the unsaturated monocarboxylic acid, which may contain a hetero atom, is specifically a compound represented by the following formula (3). H2C=CH-C(=O)-OR 6 (3)

[0045] In formula (3), R 6 represents a group in which a heteroatom, such as an oxygen atom, nitrogen atom, or sulfur atom, is contained in the molecule of a branched alkyl group having 3 to 18 carbon atoms or an alkyl group having a cyclic structure, or an alkyl group having 1 to 18 carbon atoms and a branched or cyclic structure.

[0046] Examples of the branched alkyl group include an i-propyl group, a 1-methylpropyl group, an i-butyl group, a t-butyl group, an i-pentyl group, a t-pentyl group, a 2-ethylhexyl group, an i-nonyl group, an i-decyl group, an i-tridecyl group, an i-stearyl group, etc. Examples of the alkyl group having a cyclic structure include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a benzyl group, a trimethylcyclohexyl group, an isobornyl group, a dicyclopentanyl group, an adamantyl group, etc. A group containing a heteroatom, such as an oxygen atom, nitrogen atom, or sulfur atom, in an alkyl or arylalkyl group refers to a group in which some of the carbon atoms (typically carbon atoms other than terminal portions) contained in the alkyl or arylalkyl group (typically carbon atoms in the alkyl group portion) are substituted with heteroatoms or groups consisting of heteroatoms and hydrogen (e.g., -O-, -N=, -NH-, -S-, etc.). For example, a dimethylaminoethyl group corresponds to a group in which the carbon atom at position 3 of an isopentyl group is substituted with -N=. The substitution of the above carbon atoms with heteroatoms (e.g., oxygen atoms, nitrogen atoms, sulfur atoms, etc.) or groups consisting of heteroatoms and hydrogen can occur at one or more positions (e.g., 1 to 3 positions, 1 to 2 positions, or 1 position). The carbon number in a "group containing a heteroatom in an alkyl or arylalkyl group" refers to the number of carbon atoms in the structure in which some of the carbon atoms contained in the alkyl or arylalkyl group are substituted with heteroatoms or groups consisting of heteroatoms and hydrogen (e.g., a dimethylaminoethyl group has 4 carbon atoms). Examples of the group containing a hetero atom in the alkyl group molecule include a tetrahydrofurfuryl group, a phenoxyethyl group, and a dimethylaminoethyl group.

[0047] <Saturated carboxylic acid alkyl ester (a3)> In the present invention, examples of the saturated carboxylic acid alkyl ester (a3) ​​include compounds represented by the following formula (4). R 7 -C(=O)-OR 8 (4)

[0048] In formula (4), R 7 and R 8 R are the same or different and represent an alkyl group having 1 to 18 carbon atoms or a group having 1 to 18 carbon atoms and containing a heteroatom such as an oxygen atom, nitrogen atom or sulfur atom in the alkyl molecule. 7 and R 8 or a group containing a hetero atom, such as an oxygen atom, a nitrogen atom or a sulfur atom in the alkyl group molecule does not have an unsaturated group.

[0049] Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a 1-methylpropyl group, an n-butyl group, an i-butyl group, a t-butyl group, an n-pentyl group, an i-pentyl group, a t-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, an i-nonyl group, an n-decyl group, an i-decyl group, an n-undecyl group, an n-dodecyl group, an i-tridecyl group, an i-stearyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a trimethylcyclohexyl group, an isobornyl group, an adamantyl group, and a 2,2,4-trimethylpentyl group. Examples of groups containing a heteroatom in the alkyl or arylalkyl molecule include a tetrahydrofurfuryl group, a phenoxyethyl group, and a dimethylaminoethyl group.

[0050] Specific examples of saturated carboxylic acid alkyl esters (a3) ​​include methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-pentyl acetate, i-pentyl acetate, cyclohexyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, 1-methylpentyl acetate (also known as sec-hexyl acetate), 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 3-methoxybutyl acetate, 3-ethoxybutyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, i-propyl propionate, n-butyl propionate, i-butyl propionate, n-pentyl propionate, i-pentyl propionate, and methyl butyrate. Examples of suitable esters include methyl butyrate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, i-butyl butyrate, t-butyl butyrate, methyl valerate, ethyl valerate, methyl octanoate, methyl laurate, methoxypropyl acetate, ethyl 3-ethoxypropionate, butyl glycol acetate, butyl diglycol acetate, methyl i-valerate, ethyl i-valerate, methyl 3,3,5-trimethylhexanoate, methyl i-butyrate, ethyl i-butyrate, i-butyl i-butyrate, n-butyl i-butyrate, t-butyl i-butyrate, methyl 2-ethylhexanoate, methyl pivalate, ethyl 2-hydroxy-2-methylpropionate, methyl neodecanoate, and combinations thereof.

[0051] The saturated carboxylic acid alkyl ester (a3) ​​is preferably a linear alkyl ester of a carboxylic acid having two or more hydrogen atoms at the α-position, or a branched alkyl ester of a carboxylic acid having two hydrogen atoms at the α-position. Compared with a branched alkyl ester having only one hydrogen atom at the α-position, a carboxylic acid alkyl ester of such a structure is less affected by steric hindrance at the α-position, and is therefore preferred because it allows the reaction with the alkoxysilane (a1) to proceed at an appropriate rate.

[0052] Specific examples of alkyl esters of linear carboxylic acids having two or more hydrogen atoms at the α-position include methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-pentyl acetate, i-pentyl acetate, cyclohexyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, 1-methylpentyl acetate (also known as sec-hexyl acetate), 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 3-methoxybutyl acetate, 3-ethoxybutyl acetate, methyl propionate, and ethyl propionate. Examples of suitable olefin copolymers include olefin copolymers such as n-propyl propionate, i-propyl propionate, n-butyl propionate, i-butyl propionate, n-pentyl propionate, i-pentyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, i-butyl butyrate, t-butyl butyrate, methyl valerate, ethyl valerate, methyl octanoate, methyl laurate, methoxypropyl acetate, ethyl 3-ethoxypropionate, butyl glycol acetate, butyl diglycol acetate, and combinations thereof.

[0053] Specific examples of alkyl esters of branched carboxylic acids having two hydrogen atoms at the α-position include methyl i-valerate, ethyl i-valerate, methyl 3,3,5-trimethylhexanoate, and combinations thereof.

[0054] <Polyisocyanate (a4)> In the present invention, the polyisocyanate (a4) is a compound having at least two isocyanate groups in one molecule. Examples of the polyisocyanate (a4) include aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, aromatic polyisocyanates, and derivatives thereof, as well as combinations thereof.

[0055] Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, dimer acid diisocyanate, methyl 2,6-diisocyanatohexanoate (trivial name: lysine diisocyanate), aliphatic diisocyanates such as 2-isocyanatoethyl 2,6-diisocyanatohexanoate, 1,6-diisocyanato-3-isocyanatomethylhexane, 1,4,8-triisocyanatooctane, 1,6,11-triisocyanatoundecane, 1,8-diisocyanato-4-isocyanatomethyloctane, 1,3,6-triisocyanatohexane, and 2,5,7-trimethyl-1,8-diisocyanato-5-isocyanatomethyloctane.

[0056] Examples of the alicyclic polyisocyanate include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (common name: isophorone diisocyanate), 4-methyl-1,3-cyclohexylene diisocyanate (common name: hydrogenated TDI), 2-methyl-1,3-cyclohexylene diisocyanate, Alicyclic diisocyanates such as 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane (common name: hydrogenated xylylene diisocyanate) or a mixture thereof, methylenebis(4,1-cyclohexanediyl)diisocyanate (common name: hydrogenated MDI), and norbornane diisocyanate; 1,3,5-triisocyanatocyclohexane, 1,3,5-trimethylisocyanatocyclohexane, 2-(3-isocyanatopropyl)- 2,5-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 2-(3-isocyanatopropyl)-2,6-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 3-(3-isocyanatopropyl)-2,5-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 5-(2-isocyanatoethyl)-2-isocyanatomethyl-3-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane, 6-(2-isocyanatoethyl)-bicyclo(2.2.1)heptane Examples include alicyclic triisocyanates such as (2-isocyanatoethyl)-2-isocyanatomethyl-3-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane, 5-(2-isocyanatoethyl)-2-isocyanatomethyl-2-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane, and 6-(2-isocyanatoethyl)-2-isocyanatomethyl-2-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane.

[0057] Examples of the aromatic aliphatic polyisocyanate include aromatic aliphatic diisocyanates such as methylenebis(4,1-phenylene)diisocyanate (common name: MDI), 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω,ω'-diisocyanato-1,4-diethylbenzene, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene (common name: tetramethylxylylene diisocyanate) or a mixture thereof; and aromatic aliphatic triisocyanates such as 1,3,5-triisocyanatomethylbenzene.

[0058] Examples of the aromatic polyisocyanate include aromatic diisocyanates such as m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 2,4-tolylene diisocyanate (common name: 2,4-TDI), 2,6-tolylene diisocyanate (common name: 2,6-TDI), or mixtures thereof, 4,4'-toluidine diisocyanate, and 4,4'-diphenyl ether diisocyanate; aromatic triisocyanates such as triphenylmethane-4,4',4''-triisocyanate, 1,3,5-triisocyanatobenzene, and 2,4,6-triisocyanatotoluene; and aromatic tetraisocyanates such as 4,4'-diphenylmethane-2,2',5,5'-tetraisocyanate.

[0059] Furthermore, examples of the polyisocyanate derivatives include dimers, trimers, biurets, allophanates, uretdione, uretoimine, isocyanurate, oxadiazinetrione, etc. of the above-mentioned polyisocyanates, as well as polymethylene polyphenyl polyisocyanates (crude MDI, polymeric MDI), crude TDI, etc. Furthermore, the polyisocyanate derivatives may be modified with polyol compounds including known diols or triols and / or monool compounds in order to adjust the number of functional groups of the isocyanate groups or to adjust compatibility or physical properties.

[0060] The polyisocyanate (a4) is preferably a polyisocyanate derivative having an isocyanate group content of 10% by mass or more, 12% by mass or more, 30% by mass or less, or 25% by mass or less.

[0061] Here, the isocyanate group content of the polyisocyanate (a4) is the amount of isocyanate groups in the polyisocyanate (a4) expressed as a mass fraction. The isocyanate group content can be measured according to a catalog value or the method for determining isocyanate group content in JIS K1603-1.

[0062] <Modified polyisocyanate and its manufacturing method> In the present invention, in a first embodiment, the modified polyisocyanate is a reaction product (referred to as modified polyisocyanate (X)) using as raw materials components containing an alkoxysilane (a1) having a primary amino group, an unsaturated carboxylic acid alkyl ester (a2), and a polyisocyanate (a4), and is preferably a modified polyisocyanate in which a secondary amino group of an N-position modified alkoxysilane represented by formula (5) or (6), in which the primary amino group of the alkoxysilane (a1) is added to the unsaturated carbon-carbon bond of the unsaturated carboxylic acid alkyl ester (a2), is adducted to the isocyanate group of the polyisocyanate (a4):

[0063] [ka]

[0064] In formula (5), R 1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and R 4 and R 5 are the same or different and each represents a branched alkyl group having 1 to 8 carbon atoms; and n is an integer of 0 to 2.

[0065] [ka]

[0066] In formula (6), R 1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and R 6 is a group obtained by incorporating a heteroatom into the molecule of an alkyl group having a branched or cyclic structure and having 1 to 18 carbon atoms, or an alkyl group or arylalkyl group having a branched or cyclic structure and having 1 to 18 carbon atoms, and n is an integer of 0 to 2.

[0067] Alternatively, in a second embodiment, the reaction product (referred to as modified polyisocyanate (Y)) is made from raw materials containing an alkoxysilane (a1) having a primary amino group, a saturated carboxylic acid alkyl ester (a3), and a polyisocyanate (a4), and is preferably a modified polyisocyanate in which an N-position modified alkoxysilane obtained by reacting an alkoxysilane (a1) with a saturated carboxylic acid alkyl ester (a3) ​​is an N-position acyl modified compound having a secondary amide group, represented by the following formula (7), and the secondary amide group is adducted to the isocyanate group of the polyisocyanate (a4).

[0068] [ka]

[0069] In formula (7), R 1 and R 2are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; n is an integer of 0 to 2; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and R 7 represents an alkyl group having 1 to 18 carbon atoms and having no unsaturated group, or a group having 1 to 18 carbon atoms and having a heteroatom in the alkyl molecule and having no unsaturated group.

[0070] The modified polyisocyanate (X) or (Y) may be produced by simultaneously reacting an alkoxysilane (a1) having a primary amino group, an unsaturated carboxylic acid alkyl ester (a2) or a saturated carboxylic acid alkyl ester (a3), and a polyisocyanate (a4). However, a preferred production method involves first reacting an alkoxysilane (a1) with an unsaturated carboxylic acid alkyl ester (a2) or a saturated carboxylic acid alkyl ester (a3) ​​to obtain an N-position-modified alkoxysilane having a secondary amino group or a secondary amide group, and then reacting this with a polyisocyanate (a4).

[0071] Manufacturing method of modified polyisocyanate (X): In the modified polyisocyanate (X), the blending ratio of the alkoxysilane (a1) having a primary amino group to the unsaturated carboxylic acid alkyl ester (a2) is preferably within a range of, for example, 0.7 mol or more, 0.85 mol or more, 1.5 mol or less, and 1.25 mol or less of the unsaturated carboxylic acid alkyl ester (a2) per 1 mol of the alkoxysilane (a1) having a primary amino group.

[0072] Furthermore, when the unsaturated carboxylic acid alkyl ester (a2) in the modified polyisocyanate (X) is a branched alkyl ester (a2-1) of an unsaturated dicarboxylic acid, the reaction ratio of the N-position-modified alkoxysilane having a secondary amino group to the polyisocyanate (a4) is preferably adjusted so that the number of secondary amino groups is 40 moles or less, preferably 3 moles or more and 35 moles or less, per 100 moles of isocyanate groups, in terms of the adhesion of the coating to iron and non-ferrous metals, curing properties, and storage stability of the modified polyisocyanate.

[0073] In the modified polyisocyanate (X), when the unsaturated carboxylic acid alkyl ester (a2) is a branched alkyl ester or an alkyl ester (a2-2) having a cyclic structure, which may contain a heteroatom of an unsaturated monocarboxylic acid, the reaction of the alkoxysilane (a1) having a primary amino group with the unsaturated carboxylic acid alkyl ester (a2) may produce, as a by-product, a compound represented by the following formula (8) in addition to the N-position-modified alkoxysilane represented by formula (6), and accordingly, a mixture containing the N-position-modified alkoxysilane mixed with unreacted alkoxysilane (a1) having a primary amino group may be obtained.

[0074] [ka]

[0075] In formula (8), R 1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, and R 6 is a group obtained by incorporating a heteroatom into the molecule of an alkyl group having a branched or cyclic structure and having 1 to 18 carbon atoms, or an alkyl group or arylalkyl group having a branched or cyclic structure and having 1 to 18 carbon atoms, and n is an integer of 0 to 2.

[0076] Therefore, in this case, the reaction of the N-position-modified alkoxysilane having a secondary amino group with the polyisocyanate (a4) is carried out in the coexistence of the unreacted alkoxysilane (a1) having a primary amino group and the by-product tertiary amino group-containing compound represented by formula (8).

[0077] In the modified polyisocyanate (X), when the unsaturated carboxylic acid alkyl ester (a2) is a branched alkyl ester or an alkyl ester (a2-2) having a cyclic structure, which may contain a heteroatom of an unsaturated monocarboxylic acid, the reaction ratio of the mixture containing the N-position-modified alkoxysilane with the polyisocyanate (a4) is preferably adjusted so that the total number of moles of primary amino groups and secondary amino groups per 100 moles of isocyanate groups is 40 moles or less, preferably 3 moles or more and 35 moles or less, in terms of the adhesion of the coating to iron and non-ferrous metals, curability, and storage stability of the modified polyisocyanate (X).

[0078] The reaction of an alkoxysilane (a1) having a primary amino group with an unsaturated carboxylic acid alkyl ester (a2) to obtain an N-position-modified alkoxysilane can be carried out at 0 to 110°C, optionally with air blown in. The reaction time varies depending on the temperature, but is typically between 1 hour and 2 weeks. The reaction can be carried out by adding the unsaturated carboxylic acid alkyl ester (a2) to the alkoxysilane (a1) having a primary amino group, or by adding the alkoxysilane (a1) having a primary amino group to the unsaturated carboxylic acid alkyl ester (a2). To prevent polymerization of the unsaturated carboxylic acid alkyl ester (a2), a small amount of a known aromatic polymerization inhibitor such as methoquinone or a nitroso compound such as N-oxyl may be present, if necessary.

[0079] The reaction of the N-position-modified alkoxysilane obtained from the alkoxysilane (a1) having a primary amino group and the unsaturated carboxylic acid alkyl ester (a2) with the polyisocyanate (a4) is not particularly limited and can be carried out under known and conventional reaction conditions. Specifically, the N-position-modified alkylalkoxysilane and the polyisocyanate (a4) are stirred and mixed at 0 to 80°C for 0.1 to 5 hours, either all at once or while being added dropwise. Depending on the desired performance, the N-position-modified alkoxysilane may be added to the polyisocyanate (a4), or the polyisocyanate (a4) may be added to the N-position-modified alkoxysilane. This reaction may also use a Lewis acid catalyst, a basic catalyst, or an organic solvent, as needed. The resulting mixture containing the reaction product may be aged at 0 to 80°C for 1 day to 1 month, as needed.

[0080] Manufacturing method of modified polyisocyanate (Y): In the reaction of an alkoxysilane (a1) having a primary amino group with a saturated carboxylic acid alkyl ester (a3) ​​to obtain an N-position modified alkoxysilane, the blending ratio of the alkoxysilane (a1) having a primary amino group to the saturated carboxylic acid alkyl ester (a3) ​​is preferably within the range of, for example, 0.7 moles or more, 0.85 moles or more, 1.5 moles or less, and 1.25 moles or less of the saturated carboxylic acid alkyl ester (a3) ​​per mole of the alkoxysilane (a1) having a primary amino group.

[0081] The reaction of the alkoxysilane (a1) having a primary amino group with the saturated carboxylic acid alkyl ester (a3) ​​may be carried out by heating to 100 to 250°C, or by adding a basic catalyst or Lewis acid catalyst at 0 to 160°C. Adding a catalyst is preferable because a basic catalyst is more effective in small amounts. In either case, the reaction may be carried out under pressurized conditions as needed. To suppress coloration, the reaction may be carried out in the presence of a known antioxidant, such as methoquinone. The reaction time varies depending on the temperature and other conditions, but is typically about 1 hour to 3 days. It is then preferable to mix the components all at once or dropwise, and then, if necessary, combine this with aging.

[0082] When a basic catalyst or Lewis acid catalyst is added, it may be added after mixing the alkoxysilane (a1) having a primary amino group with the saturated carboxylic acid alkyl ester (a3), or it may be added in advance to the alkoxysilane (a1) having a primary amino group and then mixed with the saturated carboxylic acid alkyl ester (a3), or it may be added in advance to the saturated carboxylic acid alkyl ester (a3) ​​and then mixed with the alkoxysilane (a1) having a primary amino group.

[0083] In the present invention, the modified polyisocyanate (Y) is A step (1) of reacting an alkoxysilane (a1) having a primary amino group with a saturated carboxylic acid alkyl ester (a3) ​​in the presence of a basic catalyst; Step (2) of adding an acidic compound to the mixture containing the reaction product obtained in Step (1) as needed; and Step (3) of removing a part or all of the alcohol produced as a by-product to prepare an intermediate containing an N-acyl-modified product represented by the following formula (7): Step (4) of reacting the intermediate with polyisocyanate (a4). It is preferably produced by

[0084] [ka]

[0085] In formula (7), R 1 and R 2 are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R 3 is a linear or branched alkylene group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, n is an integer of 0 to 2, and R 7 represents an alkyl group having 1 to 18 carbon atoms and containing no unsaturated groups, or a group having 1 to 18 carbon atoms and containing a heteroatom such as an oxygen atom, nitrogen atom or sulfur atom in the alkyl molecule, and containing no unsaturated groups.

[0086] By using such a production method, a modified polyisocyanate having excellent adhesion to non-ferrous metals can be easily obtained.

[0087] Examples of the basic catalyst added in step (1) include metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and calcium hydroxide; carbonates such as sodium carbonate and potassium carbonate; bicarbonates such as sodium bicarbonate and potassium bicarbonate; metal alkoxides such as sodium methoxide and potassium t-butoxide; organic metals such as butyllithium; potassium silanolate; ammonia gas, aqueous ammonia, methylamine, trimethylamine, triethylamine, and nitrogen compounds such as 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) and 1,5-diazabicyclo[4.3.0]-5-nonene (DBN). These basic catalysts may be used without dissolving them in an organic solvent, or may be added by dissolving them in advance in a solvent such as water; alcohols such as methanol and ethanol; esters such as methyl acetate and ethyl acetate; or ethers such as tetrahydrofuran, cyclopentyl methyl ether, and trimethyl orthoacetate.

[0088] Examples of the acidic compound added in step (2) include inorganic Bronsted acids such as hydrogen chloride, hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; organic Bronsted acids such as carboxylic acids, alkylsulfonic acids, arylsulfonic acids, monoalkylphosphoric acids, dialkylphosphoric acids, and arylphosphonic acids; and acyl chlorides such as acetyl chloride and benzoyl chloride. These acidic compounds may be used without dissolving in an organic solvent, or may be added after being dissolved in advance in a solvent such as water; alcohols such as methanol and ethanol; esters such as methyl acetate and ethyl acetate; or ethers such as tetrahydrofuran, cyclopentyl methyl ether, and trimethyl orthoacetate. The acidic compound is preferably added before step (3), but may also be added during step (3).

[0089] In step (3), heating and, if necessary, reducing the pressure removes part or all of the alcohol by-produced in step (1), as well as, if necessary, the alkoxysilane (a1) having a primary amino group and / or saturated carboxylic acid alkyl ester (a3) ​​remaining as unreacted raw materials. In the present invention, removal can be achieved by either concentration or distillation. Concentration is a method of removing compounds to be removed from the system while leaving desired compounds in the system. In contrast, distillation is a method of extracting desired compounds from the system. While distillation produces highly purified N-acyl modified compounds, it requires complex processes and equipment, requires large amounts of energy, and imposes a heavy environmental burden. Concentration, on the other hand, not only contains impurities such as catalyst residues, but also, in some cases, contains unreacted alkoxysilane (a1) having a primary amino group and saturated carboxylic acid alkyl ester (a3). Therefore, the N-acyl modified compounds are obtained as crude N-acyl modified compounds with low purity. However, the process and equipment required are simple, require less energy, and impose a low environmental burden. From the viewpoint of ease of production, it is more advantageous to remove the components by using a concentration method.

[0090] In the present invention, even if step (3) is carried out by concentration rather than distillation, it is possible to provide a modified polyisocyanate as a coating curing agent with sufficient performance by reaction with polyisocyanate (a4). Meanwhile, in order to further improve the corrosion prevention or corrosion resistance of the coating film, the crude N-acyl-modified product obtained by using a branched carboxylic acid ester having two hydrogen atoms at the α-position as the saturated carboxylic acid alkyl ester (a3) ​​may be purified by distillation as necessary before use. Meanwhile, the crude N-acyl-modified product obtained by using a linear carboxylic acid ester having two or more hydrogen atoms at the α-position as the saturated carboxylic acid alkyl ester (a3) ​​is more preferred from the viewpoint of ease of production, since it is easy to obtain a coating film that exhibits extremely high corrosion prevention and weather resistance even when used without purification by distillation.

[0091] Step (4) may be carried out at 40 to 200°C without the addition of a catalyst, or at 20 to 140°C with the addition of a basic catalyst or Lewis acid catalyst. Adding a catalyst in step (4) is preferred because a small amount of Lewis acid catalyst is effective. Known Lewis acid catalysts can be used, including tin compounds such as dialkyltin dicarboxylate, monoalkyltin tricarboxylate, dialkyltin oxide, and tin dicarboxylate; zinc compounds such as zinc dicarboxylate and zinc di(acetylacetonate); zirconium compounds such as zirconium tetraalkoxide, dialkoxyzirconium di(acetylacetonate), and zirconium tetra(acetylacetonate); titanium compounds such as titanium tetraalkoxide, dialkoxytitanium di(acetylacetonate), and titanium tetra(acetylacetonate); aluminum compounds such as aluminum tri(acetylacetonate); and bismuth compounds such as bismuth tricarboxylate.

[0092] In each of steps (1), (2), (3) and (4), a filtration operation may be added as necessary, and a known filtering material can be used for the filtration operation.

[0093] In the production of the modified polyisocyanate (Y), the reaction ratio of the purified N-position-modified alkoxysilane or crude N-position-modified alkoxysilane obtained from the alkoxysilane (a1) having a primary amino group and the saturated carboxylic acid alkyl ester (a3) ​​with the polyisocyanate (a4) is preferably adjusted so that the total number of moles of secondary amide groups and primary amino groups is 40 moles or less, preferably 3 moles or more and 35 moles or less, per 100 moles of isocyanate groups.

[0094] As described above, the modified polyisocyanate of the present invention is preferably produced via an N-position-modified alkoxysilane having a secondary amino group or a secondary amide group, such as the modified polyisocyanate (X) or the modified polyisocyanate (Y), which is effective in improving compatibility with active hydrogen group-containing compounds and organic solvents, which will be described later. Furthermore, in order to enhance stability, the modified polyisocyanate of the present invention may be produced by reacting the N-position-modified alkoxysilane having a secondary amino group or a secondary amide group with a polyisocyanate, and then subsequently adding the above-mentioned acidic compound, if necessary.

[0095] When obtaining the N-position modified alkoxysilane, in order to adjust the performance of the coating film obtained by using a modified polyisocyanate as a curing agent, the alkoxysilane (a1) having a primary amino group may be reacted with an alkoxysilane having both a primary amino group and a secondary amino group, such as 3-(2-aminoethylamino)propyltrialkoxysilane, in combination with the unsaturated carboxylic acid alkyl ester (a2) or the saturated carboxylic acid alkyl ester (a3).

[0096] The amount of isocyanate groups in the modified polyisocyanate of the present invention is preferably, for example, in the range of 1.0 mmol or more, 2.0 mmol or more per gram of the nonvolatile content of the modified polyisocyanate, from the viewpoints of the curability of the coating film, adhesion to nonferrous metals, weather resistance, and corrosion resistance. The upper limit of the amount of isocyanate groups in the modified polyisocyanate is not limited, but can be designed to be, for example, in the range of 5.5 mmol or less, 5.0 mmol or less, per gram of the nonvolatile content of the modified polyisocyanate.

[0097] The amount of isocyanate groups in a modified polyisocyanate can be determined, for example, by adding 10 ml of a 0.1 mol / L dibutylamine solution to 0.1 g of a sample to react with the NCO groups, and then titrating the remaining dibutylamine with an aqueous hydrochloric acid solution using bromophenol blue as a titration indicator.

[0098] In this specification, the nonvolatile content is the residue remaining after removing volatile components such as organic solvents, and can be measured according to the standard of JIS K 5601 1-2 (heating temperature: 125°C, heating time: 60 minutes).

[0099] In the present invention, an organic solvent can be used as a reaction solvent for producing the modified polyisocyanate or as a dilution solvent for diluting the modified polyisocyanate to a viscosity suitable for use as a coating material curing agent. Examples of the organic solvent include aliphatic solvents such as n-butane, n-hexane, n-heptane, n-octane, cyclopentane, cyclohexane, and cyclobutane; aromatic solvents such as toluene and xylene; ketone solvents such as methyl i-butyl ketone; ether solvents such as n-butyl ether, dioxane, and cyclopentyl methyl ether; ester solvents such as ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and butyl carbitol acetate; ketone solvents such as methyl ethyl ketone, methyl i-butyl ketone, and di-i-butyl ketone; and combinations thereof. In addition, organic solvents with weak dissolving power, commonly referred to as weak solvents in the paint industry, such as gasoline, kerosene, coal tar naphtha (including solvent naphtha), petroleum ether, petroleum naphtha, petroleum benzine, turpentine oil, and mineral spirits (including mineral thinner, petroleum spirits, white spirits, and mineral turpentine), can also be used satisfactorily.

[0100] In the present invention, the organic solvent can be contained in either the base resin or the curing agent. However, the amount of the organic solvent contained in the curing agent is preferably 200 parts by weight or less, preferably 10 parts by weight or more and 100 parts by weight or less, based on 100 parts by weight of the nonvolatile content of the modified polyisocyanate. In a typical embodiment, the modified polyisocyanate of the present invention is used as a curing agent for a coating. Accordingly, in one embodiment, the present invention provides a curing agent containing the modified polyisocyanate. In such an embodiment, the curing agent of the present invention is preferably used in combination with an active hydrogen-containing compound. Furthermore, in the present invention, the modified polyisocyanate may be used alone as a curing agent, or a curing agent composition may be used that further contains the above-mentioned solvent, catalyst, UV absorber, light stabilizer, viscosity modifier, surface modifier, dehydrating agent, etc. in addition to the modified polyisocyanate. These components other than the modified polyisocyanate may be used alone or in combination. In an embodiment of the curing agent composition, the content of the modified polyisocyanate in the composition is not limited, and can be set within a range, for example, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, etc.

[0101] <Active hydrogen group-containing compounds> In the present invention, the active hydrogen group-containing compound is a compound used as a binder component together with the modified polyisocyanate. It is not particularly limited as long as it has an active hydrogen group, and may be any compound commonly known and commonly used in the coatings field. Here, the active hydrogen group refers to a group capable of reacting with the isocyanate group of the modified polyisocyanate, such as a hydroxy group, a primary or secondary amino group, or a thiol group. Specific examples of the active hydrogen group-containing compound include acrylic polyols, polyester polyols, polyether polyols, polycarbonate polyols, epoxy polyols, polyol compounds such as dihydroxyalkanes, trihydroxyalkanes, and dihydroxycycloalkanes; acrylic resins with pendant amino groups, polyallylamine, polyether polyamines, polylysine, and polyvinylamines; polymers having multiple secondary amino groups with aspartic acid ester structures; and polyamino compounds such as diaminoalkanes, diaminocycloalkanes, dialkylene triamines, trialkylene tetraamines, and bisaspartic acid ester derivatives. These compounds may be used alone or in combination.

[0102] Among these, the active hydrogen group-containing compound preferably contains an acrylic polyol and / or a bisaspartic acid ester derivative from the viewpoints of improving the weather resistance of the coating film to be formed, improving compatibility in the paint, increasing the nonvolatile concentration of the paint, controlling the reaction rate with the isocyanate group, etc. Furthermore, in order to adjust the flexibility of the coating film, etc., a polyester polyol or a polyether polyol may be used in combination, if necessary.

[0103] The acrylic polyol may be produced, for example, by copolymerizing a hydroxyl group-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer (a polymerizable unsaturated monomer other than a hydroxyl group-containing polymerizable unsaturated monomer), or a commercially available product may be used.

[0104] The hydroxyl group-containing polymerizable unsaturated monomer is a compound having one or more hydroxyl groups and one or more polymerizable unsaturated groups per molecule. Examples of the hydroxyl group-containing polymerizable unsaturated monomer include monoesters of (meth)acrylic acid with dihydric alcohols having 2 to 8 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; ε-caprolactone-modified monoesters of (meth)acrylic acid with dihydric alcohols having 2 to 8 carbon atoms; adducts of (meth)acrylic acid with epoxy group-containing compounds (e.g., "Cardura E10P" (trade name, manufactured by Hexion, neodecanoic acid glycidyl ester); N-hydroxymethyl (meth)acrylamide; allyl alcohol; and (meth)acrylates having a polyoxyethylene chain with a hydroxyl group at the molecular terminal.

[0105] As other polymerizable unsaturated monomers copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer, for example, the following monomers (1) to (7) can be used. These polymerizable unsaturated monomers can be used alone or in combination of two or more.

[0106] (1) Acid group-containing polymerizable unsaturated monomer The acid group-containing polymerizable unsaturated monomer is a compound having one or more acid groups and one or more polymerizable unsaturated groups per molecule. Examples of such monomers include carboxyl group-containing monomers such as (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, and maleic anhydride; sulfonic acid group-containing monomers such as vinyl sulfonic acid and 2-sulfoethyl (meth)acrylate; and acidic phosphate ester monomers such as 2-(meth)acryloyloxyethyl acid phosphate, 2-(meth)acryloyloxypropyl acid phosphate, 2-(meth)acryloyloxy-3-chloropropyl acid phosphate, and 2-methacryloyloxyethylphenyl phosphoric acid. These monomers can be used alone or in combination.

[0107] (2) Esterification products of acrylic acid or methacrylic acid with monohydric alcohols having 1 to 20 carbon atoms Specific examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, i-octyl (meth)acrylate, i-myristyl (meth)acrylate, stearyl (meth)acrylate, "isostearyl acrylate" (trade name, manufactured by Osaka Organic Chemical Industry Ltd.), lauryl (meth)acrylate, tridecyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate.

[0108] (3) Alkoxysilyl group-containing polymerizable unsaturated monomer The alkoxysilyl group-containing polymerizable unsaturated monomer is a compound having one or more alkoxysilyl groups and one or more polymerizable unsaturated groups in one molecule. Examples of the alkoxysilyl group-containing polymerizable unsaturated monomer include vinyltrimethoxysilane, vinyltriethoxysilane, acryloxyethyltrimethoxysilane, methacryloxyethyltrimethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltriethoxysilane, methacryloxypropyltriethoxysilane, and vinyltris(β-methoxyethoxy)silane.

[0109] (4) Aromatic vinyl monomers Specific examples include styrene, α-methylstyrene, and vinyltoluene. When an aromatic vinyl monomer is used as a constituent component, the blending ratio thereof is preferably within the range of 3% by mass or more, 5% by mass or more, 50% by mass or less, and 40% by mass or less, based on the total amount of the monomer components.

[0110] (5) Glycidyl group-containing polymerizable unsaturated monomer The glycidyl group-containing polymerizable unsaturated monomer is a compound having one or more glycidyl groups and one or more polymerizable unsaturated groups in one molecule, and specific examples thereof include glycidyl acrylate and glycidyl methacrylate.

[0111] (6) Polymerizable unsaturated group-containing nitrogen atom-containing compound Examples include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-[3-(dimethylamino)propyl](meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetone(meth)acrylamide, N,N-dimethylaminoethyl(meth)acrylate, vinylpyridine, vinylimidazole, acrylonitrile, and methacrylonitrile.

[0112] (7) Other vinyl compounds For example, vinyl acetate, vinyl propionate, vinyl chloride, vinyl versatate, etc. can be mentioned.

[0113] In the present invention, the polymerizable unsaturated monomer refers to a monomer having one or more (e.g., 1 to 4) polymerizable unsaturated groups. The polymerizable unsaturated group refers to an unsaturated group that can undergo radical polymerization. Examples of such polymerizable unsaturated groups include vinyl groups, (meth)acryloyl groups, (meth)acrylamide groups, vinyl ether groups, allyl groups, propenyl groups, i-propenyl groups, and maleimide groups.

[0114] In addition, in this specification, "(meth)acrylate" means acrylate or methacrylate. "(meth)acrylic acid" means acrylic acid or methacrylic acid. "(meth)acryloyl" means acryloyl or methacryloyl. "(meth)acrylamide" means acrylamide or methacrylamide.

[0115] From the viewpoint of the weather resistance and corrosion resistance of the coating film to be formed, the acrylic polyol preferably has a hydroxyl value in the range of 5 mgKOH / g or more, 10 mgKOH / g or more, 160 mgKOH / g or less, and 100 mgKOH / g or less, and a weight average molecular weight in the range of 3,000 or more, 10,000 or more, 100,000 or less, and 50,000 or less.

[0116] In this specification, the weight-average molecular weight is a value calculated from a chromatogram measured by gel permeation chromatography using the weight-average molecular weight of standard polystyrene as a reference. The gel permeation chromatograph used was an "HLC8120GPC" (manufactured by Tosoh Corporation). Four columns, "TSKgel G-4000HXL," "TSKgel G-3000HXL," "TSKgel G-2500HXL," and "TSKgel G-2000HXL" (all manufactured by Tosoh Corporation, trade names), were used. The conditions for the analysis were: mobile phase: tetrahydrofuran, measurement temperature: 40°C, flow rate: 1 mL / min, and detector: RI.

[0117] The bisaspartic acid ester derivative may be any derivative in which a maleic acid diester or a fumaric acid diester is added to an aspartic acid compound having two amino groups, and examples thereof include tetraethyl N,N'-(methylenedi-4,1-cyclohexanediyl)-bisaspartate, tetraethyl N,N'-(methylenebis(2-methyl-di-4,1-cyclohexanediyl))-bisaspartate, and tetraethyl N,N'-(2-methyl-1,5-pentanediyl)-bisaspartate. More specific examples include Desmophen NH 1420, Desmophen NH 1520, Desmophen NH 1220, Desmophen NH 1422, Desmophen NH 1423LF, Desmophen NH 1720, Desmophen NH 1723LF, Desmophen NH 1523LF, and Desmophen NH 1521, all manufactured by Covestro; and Amicure IC-133, Amicure IC-166, and Amicure IC-186 (all trade names) manufactured by Evonik.

[0118] <Coating> The present invention provides a coating comprising an active hydrogen-containing compound and the modified polyisocyanate. The coating of the present invention also encompasses a two-component composition comprising a curing agent containing the modified polyisocyanate and a base component containing the active hydrogen group-containing compound, which are stored separately. In a typical embodiment, the coating of the present invention is obtained by mixing the curing agent containing the modified polyisocyanate and the base component containing the active hydrogen group-containing compound, which are stored separately, before application. The coating of the present invention can also be referred to as a paint composition. The ratio of use is preferably such that the equivalent ratio of the modified polyisocyanate is 0.5 or more, or 0.7 or more, based on 1 equivalent of the active hydrogen group contained in the active hydrogen group-containing compound. The equivalent ratio of the modified polyisocyanate is not limited, based on 1 equivalent of the active hydrogen group contained in the active hydrogen group-containing compound, but can be designed to be, for example, 2.5 or less, or 1.5 or less.

[0119] The coating of the present invention may further contain, as necessary, an anti-rust agent, a catalyst, a coloring pigment, an extender pigment, a luster pigment, a dispersant, an ultraviolet absorber, a light stabilizer, an anti-foaming agent, a viscosity modifier, a surface modifier, a dehydrating agent, an organic solvent, a crosslinking agent, a binder component other than the active hydrogen group-containing compound, and the like.

[0120] Among these, rust inhibitors that are known in the field of paints can be used as rust inhibitors and are commercially available. The rust inhibitors may be inorganic or organic compounds, and there are no limitations on their form, such as single compounds, composite compounds, compositions using a combination of these compounds, or compositions obtained by baking a combination of these compounds. Specific examples include phosphate-based metal compounds such as zinc phosphate, magnesium phosphate, magnesium ammonium phosphate-co-eutectoid, magnesium monohydrogen phosphate, magnesium dihydrogen phosphate, magnesium calcium phosphate-co-eutectoid, magnesium phosphate-cobalt phosphate, magnesium phosphate-nickel phosphate-eutectoid, calcium phosphate, calcium ammonium phosphate, calcium monohydrogen phosphate, calcium dihydrogen phosphate, calcium fluoride phosphate chloride, aluminum phosphate, and aluminum hydrogen phosphate; Phosphite-based metal compounds such as magnesium phosphite, calcium phosphite, magnesium-calcium phosphite co-eutectoid, basic zinc phosphite, barium phosphite, manganese phosphite, calcium hypophosphite, etc.; Metal silicates such as calcium silicate, zinc silicate, aluminum silicate, aluminum orthosilicate, hydrated aluminum silicate, aluminosilicate, borosilicate, beryllosilicate, calcium aluminum silicate, sodium aluminum silicate, beryllium aluminum silicate, sodium silicate, calcium orthosilicate, calcium metasilicate, calcium sodium silicate, zirconium silicate, magnesium orthosilicate, magnesium metasilicate, manganese silicate, and barium silicate; metal ion-exchanged silica compounds such as magnesium ion-exchanged silica and calcium ion-exchanged silica; condensed phosphate metal compounds such as aluminum dihydrogen tripolyphosphate, aluminum dihydrogen tripolyphosphate magnesium oxide complex, aluminum tripolyphosphate, aluminum dihydrogen tripolyphosphate zinc oxide complex; vanadium-based metal compounds such as vanadium pentoxide, calcium vanadate, magnesium vanadate, ammonium metavanadate, fired products of manganese oxide and vanadium oxide, fired products of calcium phosphate and vanadium oxide; Aluminum molybdate, calcium molybdate, aluminum phosphomolybdate, etc. Molybdate metal compounds; Zinc, zinc oxide and other zinc-based compounds; Silica, colloidal silica and other silica-based compounds; complex metal iron oxides such as complex iron oxides of iron oxide and magnesium oxide, complex iron oxides of iron oxide and calcium oxide, and complex iron oxides of iron oxide and zinc oxide; Sulfur-containing organic compounds such as triazole compounds, thiol compounds, thiadiazole compounds, and thiazole compounds; The following can be mentioned:

[0121] When the coating of the present invention contains the above-mentioned rust inhibitor, the amount of the rust inhibitor blended is preferably within a range of 1 part by mass or more, 3 parts by mass or more, 70 parts by mass or less, and 60 parts by mass or less, based on 100 parts by mass of the nonvolatile content of the active hydrogen-containing compound.

[0122] As the catalyst, compounds conventionally known for use in coatings can be used, specifically, organometallic compounds and amine compounds.

[0123] Examples of organometallic compounds include diacetyltin diacetate, diacetyltin dioctoate, dioctyltin diacetate, dioctyltin di(2-ethylhexanoate), dioctyltin dilaurate, dioctyltin dineodecanoate, dioctyltin oxide, dibutyltin diacetate, dibutyltin di(2-ethylhexanoate), dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin oxide, dibutyltin sulfide, dibutyltin fatty acid salts, tin octoate, zinc octoate, zinc naphthenate, zinc fatty acids, bismuth octanoate, bismuth 2-ethylhexanoate, bismuth oleate, bismuth neodecanoate, bismuth versatate, bismuth naphthenate, cobalt naphthenate, calcium octoate, copper naphthenate, and tetra(2-ethylhexyl) titanate.

[0124] Examples of the amine compound include aliphatic amines such as trimethylamine, triethylamine, 2-(dimethylamino)ethyl methacrylate, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonene, 1-methylpiperidine, and 1-methylpyrrolidine, pyridine, 4-dimethylaminopyridine, 4-(1-piperidyl)pyridine, N-methylimidazole, and N,N-dimethylaniline.

[0125] When the coating of the present invention contains the above-mentioned catalyst, the content of the catalyst is preferably in the range of 0.005 mass % or more, 0.01 mass % or more, 2 mass % or less, and 1 mass % or less, relative to the non-volatile mass of the active hydrogen group-containing compound.

[0126] Examples of color pigments include titanium oxide, zinc white, carbon black, red iron oxide, cadmium red, molybdenum red, chrome yellow, chromium oxide, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindoline pigments, threne pigments, and perylene pigments.

[0127] Examples of extender pigments include talc, clay, kaolin, baryta, barium sulfate, barium carbonate, calcium carbonate, and alumina white.

[0128] Examples of the luster pigment include aluminum pigments, mica pigments, mica pigments coated with titanium oxide, and aluminum oxide pigments coated with titanium oxide.

[0129] Examples of the dehydrating agent include compounds that consume water by chemically reacting with water, and compounds that physically adsorb water. Examples of the former include trimethyl orthoformate, triethyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, toluenesulfonyl isocyanate, vinyltrimethoxysilane, and vinyltriethoxysilane, and examples of the latter include zeolite and molecular sieves.

[0130] <Painting> The modified polyisocyanate of the present invention has excellent adhesion to metal substrates, and thus coatings containing the same are used for painting metal substrates. Metal substrates include both ferrous and non-ferrous metals. Specific examples include steel, galvanized steel, stainless steel, magnesium alloys, aluminum, and aluminum alloys. These may be surface-treated with phosphates, chromates, or the like. Metal substrates also include metal components constituting existing structures, which have old paint films or rust remaining on their surfaces.

[0131] The coating of the present invention can be diluted with an organic solvent or the like to a viscosity suitable for application, and applied by methods such as air spray coating, airless spray coating, electrostatic coating, brush coating, roller coating, lysine gun, and all-purpose gun. Drying can be performed at room temperature, but heat drying is also possible. Room temperature, which varies depending on the atmospheric temperature of the environment in which the coating is performed, refers to a temperature at which no temperature manipulation such as forced heating or cooling is performed, while heat drying refers to a temperature at which forced heating is performed using equipment such as a drying oven.

[0132] Because the coating of the present invention has excellent adhesion, it is possible to omit the application of a primer paint before applying the coating. Furthermore, because the coating of the present invention also has excellent weather resistance, it is also possible to omit the application of a topcoat paint after applying the coating. The coating of the present invention can form a protective coating film with excellent corrosion resistance and weather resistance on a metal substrate by itself, allowing for a single-layer finish and being applicable as a one-coat paint. Therefore, the present invention provides a cured product of the aforementioned coating. This cured product can be used as a protective coating. The present invention also provides a coated article (a coated article comprising a substrate and a cured product of the aforementioned coating disposed on the substrate) in which the cured product of the aforementioned coating is formed on a substrate. The coated article is preferably a painted metal material in which the cured product of the aforementioned coating is formed on a metal substrate. [Example]

[0133] The present invention will be further described below with reference to examples. However, the present invention is not limited to these examples. Herein, "parts" and "%" mean "parts by mass" and "% by mass," respectively.

[0134] [Preparation of modified polyisocyanate curing agent solution using alkyl ester of unsaturated dicarboxylic acid] Example 1 179 parts of 3-aminopropyltrimethoxysilane and 0.07 parts of methoquinone were placed in a flask and heated to 80°C. Air was introduced into the liquid and the mixture was stirred while bubbling. 220 parts of di-i-propyl fumarate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 80°C for 1 hour and further aged at 50°C for 1 week to obtain 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane (alkoxysilane N-position modified compound represented by formula (5) where R 2 is a methyl group, R 3 is a propylene group, R 4 and R 5 399 parts of a mixture containing 95% of compounds in which n is both an i-propyl group and n is 0 was obtained. In a separate flask, 400 parts of mineral spirits, 320 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate polyisocyanate, manufactured by Asahi Kasei Corporation, isocyanate group content 20.6 wt%) were added and stirred at room temperature. 359 parts of a mixture containing 95% 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane was added dropwise over two hours. The mixture was then held at 60°C for one hour and cooled to room temperature, yielding a polyisocyanate curing agent solution (HE-1) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in 1 g of the curing agent solution (HE-1) was 1.10 mmol / g (2.02 mmol / g in terms of nonvolatile content).

[0135] Example 2 179 parts of 3-aminopropyltrimethoxysilane and 0.07 parts of methoquinone were placed in a flask and heated to 80°C. Air was introduced into the liquid and the mixture was stirred while bubbling. 251 parts of di(1-methylpropyl) fumarate was added dropwise to the mixture over 2 hours, and the mixture was then maintained at 80°C for 1 hour and further aged at 50°C for 1 week to obtain 3-(N-(1,2-bis(1-methylpropoxycarbonyl)ethyl)amino)propyltrimethoxysilane (alkoxysilane N-position modified compound represented by formula (5), R 2 is a methyl group, R 3 is a propylene group, R 4 and R 5This yielded 430 parts of a mixture containing 95% N-(N-(1,2-bis(1-methylpropoxycarbonyl)ethyl)amino)propyltrimethoxysilane) (a compound in which n is a 1-methylpropyl group and n is 0). In a separate flask, 400 parts of mineral spirits, 320 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., product name), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate polyisocyanate, manufactured by Asahi Kasei Corporation, product name, isocyanate group content 20.6 wt%) were added and stirred at room temperature. To this mixture, 387 parts of a mixture containing 95% 3-(N-(1,2-bis(1-methylpropoxycarbonyl)ethyl)amino)propyltrimethoxysilane was added dropwise over 2 hours, and the mixture was then held at 60°C for 1 hour and cooled to room temperature to yield a polyisocyanate curing agent solution (HE-2) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in 1 g of the curing agent solution (HE-2) was 1.08 mmol / g (1.96 mmol / g in terms of nonvolatile content).

[0136] Example 3 89.5 parts of 3-aminopropyltrimethoxysilane and 0.04 parts of methoquinone were placed in a flask and heated to 80°C. Air was introduced into the liquid and the mixture was stirred while bubbling. 110 parts of di-i-propyl fumarate was added dropwise to the mixture over 2 hours, and the mixture was then maintained at 80°C for 1 hour and further aged at 50°C for 1 week to obtain 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane (alkoxysilane N-position modified compound represented by formula (5) where R 2 is a methyl group, R 3 is a propylene group, R 4 and R 5This yielded 199 parts of a mixture containing 95% 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane (a compound in which n is an i-propyl group and n is 0). In a separate flask, 320 parts of mineral spirits, 256 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., product name), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate polyisocyanate, manufactured by Asahi Kasei Corporation, product name, isocyanate group content 20.6 wt%) were added and stirred at room temperature. To this mixture, 162 parts of a mixture containing 95% 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane was added dropwise over 2 hours, and the mixture was then held at 60°C for 1 hour and cooled to room temperature to yield a polyisocyanate curing agent solution (HE-3) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in 1 g of the hardener solution (HE-3) was 1.78 mmol / g (3.26 mmol / g in terms of nonvolatile content).

[0137] Example 4 89.5 parts of 3-aminopropyltrimethoxysilane and 0.04 parts of methoquinone were placed in a flask and heated to 80°C. Air was introduced into the liquid and the mixture was stirred while bubbling. 110 parts of di-i-propyl fumarate was added dropwise to the mixture over 2 hours, and the mixture was then maintained at 80°C for 1 hour and further aged at 50°C for 1 week to obtain 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane (alkoxysilane N-position modified compound represented by formula (5) where R 2 is a methyl group, R 3 is a propylene group, R 4 and R 5This yielded 199 parts of a mixture containing 95% N-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane) (a compound in which n is an i-propyl group and n is 0). In a separate flask, 280 parts of mineral spirits, 224 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., product name), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate polyisocyanate, manufactured by Asahi Kasei Corporation, product name, isocyanate group content 20.6 wt%) were added and stirred at room temperature. To this mixture, 108 parts of a mixture containing 95% N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane was added dropwise over 2 hours, and the mixture was then held at 60°C for 1 hour and cooled to room temperature to yield a polyisocyanate curing agent solution (HE-4) with a nonvolatile content of 56%. The concentration of isocyanate groups contained in 1 g of the curing agent solution (HE-4) was 2.09 mmol / g (3.72 mmol / g in terms of nonvolatile content).

[0138] Example 5 221 parts of 3-aminopropyltriethoxysilane and 0.07 parts of methoquinone were placed in a flask and heated to 80°C. Air was introduced into the liquid and the mixture was stirred while bubbling. 220 parts of di-i-propyl fumarate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 80°C for 1 hour and further aged at 50°C for 1 week to obtain 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltriethoxysilane (alkoxysilane N-position modified compound represented by formula (5) where R 2 is an ethyl group, R 3 is a propylene group, R 4 and R 5This yielded 441 parts of a mixture containing 95% 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltriethoxysilane (a compound in which n is an i-propyl group and n is 0). A separate flask was charged with 400 parts of mineral spirits, 320 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., product name), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate polyisocyanate, manufactured by Asahi Kasei Corporation, product name, isocyanate group content 20.6 wt%), and the mixture was stirred at room temperature. To this mixture, 397 parts of a mixture containing 95% 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltriethoxysilane was added dropwise over 2 hours, followed by holding at 60°C for 1 hour and cooling to room temperature to yield a polyisocyanate curing agent solution (HE-5) with a nonvolatile content of 56%. The concentration of isocyanate groups contained in 1 g of the hardener solution (HE-5) was 1.08 mmol / g (1.94 mmol / g in terms of nonvolatile content).

[0139] Example 6 179 parts of 3-aminopropyltrimethoxysilane and 0.07 parts of methoquinone were placed in a flask and heated to 80°C. Air was introduced into the liquid and the mixture was stirred while bubbling. 260 parts of di-i-propyl fumarate was added dropwise to the mixture over 2 hours, and the mixture was then maintained at 80°C for 1 hour and further aged at 50°C for 1 week to obtain 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane (alkoxysilane N-position modified compound represented by formula (5) where R 2 is a methyl group, R 3 is a propylene group, R 4 and R 5 Thus, 439 parts of a mixture containing 86% of compounds in which n is both an i-propyl group and n is 0 was obtained. In a separate flask, 400 parts of mineral spirits, 280 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate polyisocyanate, manufactured by Asahi Kasei Corporation, isocyanate group content 20.6 wt%) were added and stirred at room temperature. 394 parts of a mixture containing 86% 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane was added dropwise over two hours. The mixture was then held at 60°C for one hour and cooled to room temperature to yield a polyisocyanate curing agent solution (HE-6) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in 1 g of the hardener solution (HE-6) was 1.11 mmol / g (2.03 mmol / g in terms of nonvolatile content).

[0140] Example 7 179 parts of 3-aminopropyltrimethoxysilane and 0.07 parts of methoquinone were placed in a flask and heated to 80°C. Air was introduced into the liquid and the mixture was stirred while bubbling. 180 parts of di-i-propyl fumarate was added dropwise to the mixture over 2 hours, and the mixture was then maintained at 80°C for 1 hour and further aged at 50°C for 1 week to obtain 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane (alkoxysilane N-position modified compound represented by formula (5) where R 2 is a methyl group, R 3 is a propylene group, R 4 and R 5 359 parts of a mixture containing 99% of compounds in which n is both an i-propyl group and n is 0 was obtained. In a separate flask, 400 parts of mineral spirits, 320 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate polyisocyanate, manufactured by Asahi Kasei Corporation, isocyanate group content 20.6 wt%) were added and stirred at room temperature. 323 parts of a mixture containing 99% 3-(N-(1,2-bis(i-propoxycarbonyl)ethyl)amino)propyltrimethoxysilane was added dropwise over two hours. The mixture was then heated to 60°C for one hour and cooled to room temperature to yield a polyisocyanate curing agent solution (HE-7) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in 1 g of the hardener solution (HE-7) was 1.13 mmol / g (2.06 mmol / g in terms of nonvolatile content).

[0141] Comparative Example 1 179 parts of 3-aminopropyltrimethoxysilane and 0.07 parts of methoquinone were placed in a flask, heated to 80°C, and air was introduced into the liquid and bubbled while stirring. 189 parts of diethyl fumarate were added dropwise to the mixture over 2 hours, and the mixture was then maintained at 80°C for 1 hour and further aged at 50°C for 1 week to obtain 3-(N-(1,2-bis(ethoxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the case of an alkoxysilane N-position modified product represented by formula (5), R 2 is a methyl group, R 3 is a propylene group, R 4 and R 5 368 parts of a mixture containing 95% of the compound (wherein n is 0 and both correspond to ethyl groups) was obtained. In a separate flask, 400 parts of mineral spirits, 320 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate-type polyisocyanate, manufactured by Asahi Kasei Corporation, isocyanate group content 20.6 wt%) were added and stirred at room temperature. 331 parts of a mixture containing 95% 3-(N-(1,2-bis(ethoxycarbonyl)ethyl)amino)propyltrimethoxysilane was added dropwise over two hours. The mixture was then heated to 60°C for one hour and cooled to room temperature to yield a polyisocyanate curing agent solution (HR-1) modified with a linear alkyl ester of an unsaturated dicarboxylic acid (nonvolatile content: 54%). The concentration of isocyanate groups contained in 1 g of the curing agent solution (HR-1) was 1.12 mmol / g (2.08 mmol / g in terms of nonvolatile content).

[0142] Comparative Example 2 179 parts of 3-aminopropyltrimethoxysilane and 0.07 parts of methoquinone were placed in a flask, heated to 80°C, and air was introduced into the liquid to bubble and stir. 251 parts of dibutyl maleate was added dropwise to the mixture over 2 hours, and the mixture was then maintained at 80°C for 1 hour and further aged at 50°C for 1 week to obtain 3-(N-(1,2-bis(butoxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the case of an alkoxysilane N-position modified product represented by formula (5), R 2 is a methyl group, R 3 is a propylene group, R 4 and R 5 430 parts of a mixture containing 95% of the compound (wherein n is 0 and both correspond to n-butyl groups) was obtained. In a separate flask, 400 parts of mineral spirits, 320 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate-type polyisocyanate, manufactured by Asahi Kasei Corporation, isocyanate group content 20.6 wt%) were added and stirred at room temperature. 387 parts of a mixture containing 95% 3-(N-(1,2-bis(butoxycarbonyl)ethyl)amino)propyltrimethoxysilane was added dropwise over two hours. The mixture was then held at 60°C for two hours and cooled to room temperature to yield a polyisocyanate curing agent solution (HR-2) modified with a linear alkyl ester of unsaturated dicarboxylic acid (nonvolatile content 55%). The concentration of isocyanate groups contained in 1 g of the curing agent solution (HR-2) was 1.08 mmol / g (1.96 mmol / g in terms of nonvolatile content).

[0143] Comparative Example 3 A container was charged with 400 parts mineral spirits, 320 parts "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 880 parts "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate-type polyisocyanate, manufactured by Asahi Kasei Corporation, isocyanate group content 20.6 wt%), and stirred at room temperature to obtain a polyisocyanate curing agent solution (HR-3) (nonvolatile content 55%) that was not modified with aminoalkoxysilane or unsaturated carboxylic acid dialkyl ester. The isocyanate group concentration per gram of curing agent solution (HR-3) was 2.70 mmol / g (4.90 mmol / g in terms of nonvolatile content).

[0144] Comparative Example 4 179 parts of 3-aminopropyltrimethoxysilane and 0.07 parts of methoquinone were placed in a flask, the temperature was raised to 80° C., and air was introduced into the liquid to bubble and stir, yielding 179 parts of a mixture. In a separate flask, 400 parts of mineral spirits, 180 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 550 parts of "Duranate TSA-100" (a hexamethylene diisocyanate-modified isocyanurate-type polyisocyanate, manufactured by Asahi Kasei Corporation, isocyanate group content 20.6 wt%) were added and stirred at room temperature. 161 parts of the above mixture containing 3-aminopropyltrimethoxysilane were added dropwise over 2 hours, and the mixture was then held at 60°C for 1 hour and cooled to room temperature in an attempt to obtain an aminoalkoxysilane-modified, but unsaturated carboxylic acid dialkyl ester-unmodified polyisocyanate curing agent solution (HR-4) (nonvolatile content 54%). However, the curing agent precipitated, resulting in a non-uniform solution that was unusable as a curing agent, and further evaluation was discontinued. The concentration of isocyanate groups in 1 g of the hardener solution (HR-4) was 1.39 mmol / g (2.56 mmol / g in terms of nonvolatile matter).

[0145] Table 1 below shows the composition, blending molar ratio or reaction molar ratio, state and residual NCO rate of each curing agent solution obtained in the examples and comparative examples.

[0146] [Table 1]

[0147] (Note 1) Primary amino group / unsaturated carbon-carbon bond Actual reaction molar ratio: This represents the molar ratio of aminoalkoxysilane added to unsaturated carboxylic acid dialkyl ester. If an excess of unsaturated carboxylic acid dialkyl ester is added, the excess will not undergo the addition reaction and will remain unreacted, so the numerical value will differ between the reaction ratio and the compounding ratio. (Note 2) Amino group / isocyanate group reaction molar ratio: Here, amino group refers to the total amount of amino groups, i.e., the total amount of primary amino groups derived from alkoxysilanes having unreacted amino groups and 1,2-bis(alkoxycarbonyl)ethylamino groups.

[0148] [Evaluation items] (*) State of hardener solution Each hardener solution was sealed in a 250 ml glass bottle and evaluated according to the following criteria. In the table, a rank of ◯ was judged as passing, and ranks of × and XX were judged as failing. The condition was visually observed at the initial stage (immediately after production) and after one year of storage in a sealed, thermostatic chamber at 25°C and 60% humidity. ○: No two-layer separation, cloudiness, or precipitates were observed in the hardener solution, and no abnormalities were observed. ×: Either two layers were separated or the hardener solution was cloudy. ××: The hardener precipitated from the hardener solution. (*) Residual NCO rate in hardener solution The polyisocyanate curing agent solutions obtained in Examples 1 to 7 and Comparative Examples 1 to 4 were calculated using the following formula. The larger the value, the better. [(Total number of moles of NCO groups contained in the curing agent solution 12 months after its preparation) / (Total number of moles of NCO groups contained in the curing agent solution immediately after its preparation)] x 100 (%) The storage conditions were 25°C and 60% humidity. The total number of moles of NCO groups was calculated by adding 10 ml of 0.1 mol / L dibutylamine solution to 0.1 g of the sample to react with the NCO groups, and then titrating the remaining dibutylamine with aqueous hydrochloric acid using bromophenol blue as a titration indicator.

[0149] [Production of modified polyisocyanate curing agent solution using alkyl ester of unsaturated monocarboxylic acid] Example 8 179 parts of 3-aminopropyltrimethoxysilane, 0.07 parts of methoquinone, and 6 parts of "Swasol 1000" (a naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 128 parts of i-butyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3 is a propylene group, R 6is an i-butyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 313 parts containing two compounds (a compound in which n is an i-butyl group and n is 0) in a molar ratio of 74 / 13 / 13 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.78 mmol. Into another flask were placed 282 parts of mineral spirits, 231 parts of "Swasol 1000" (naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" (hexamethylene diisocyanate-modified isocyanurate polyisocyanate, product name, manufactured by Asahi Kasei Corporation, isocyanate group content 20.6 wt%), and the mixture was stirred at room temperature. To this was added dropwise 132 parts of a mixture containing 3-(N-(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in a molar ratio of 74 / 13 / 13 over 2 hours, followed by holding at 60°C for 2 hours and cooling to room temperature to obtain a polyisocyanate curing agent solution (HE-8) with a nonvolatile content of 55%. The concentration of isocyanate groups in the curing agent solution (HE-8) was 1.82 mmol / g (3.31 mmol / g in terms of nonvolatile content).

[0150] Example 9 179 parts of 3-aminopropyltrimethoxysilane, 0.07 parts of methoquinone, and 6 parts of "Swasol 1000" (a naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 128 parts of t-butyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(t-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3is a propylene group, R 6 is a t-butyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(t-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 313 parts containing two compounds (a compound in which n is a t-butyl group and n is 0) in a molar ratio of 78 / 11 / 11 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.84 mmol. In a separate flask, 281 parts of mineral spirits, 230 parts of "Swasol 1000" (a naphtha-based solvent manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were added and stirred at room temperature. To this mixture, 130 parts of a mixture containing 3-(N-(2-(t-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(t-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in a molar ratio of 78 / 11 / 11 were added dropwise over two hours. The mixture was then maintained at 60°C for two hours and cooled to room temperature, yielding a polyisocyanate curing agent solution (HE-9) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in the hardener solution (HE-9) was 1.83 mmol / g (3.32 mmol / g in terms of nonvolatile content).

[0151] Example 10 89.5 parts of 3-aminopropyltrimethoxysilane, 0.04 parts of methoquinone, and 4 parts of "Swasol 1000" (a naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 92 parts of 2-ethylhexyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(2-ethylhexyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3 is a propylene group, R 6is a 2-ethylhexyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(2-ethylhexyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 186 parts containing two compounds (a compound in which n is a 2-ethylhexyl group and n is 0) in a molar ratio of 66 / 17 / 17 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.24 mmol. In a separate flask, 296 parts of mineral spirits, 242 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were placed and stirred at room temperature. To this was added dropwise 164 parts of a mixture containing 3-(N-(2-(2-ethylhexyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(2-ethylhexyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in a molar ratio of 66 / 17 / 17 over two hours. The mixture was then maintained at 60°C for two hours and cooled to room temperature, yielding a polyisocyanate curing agent solution (HE-10) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in the hardener solution (HE-10) was 1.73 mmol / g (3.15 mmol / g in terms of nonvolatile content).

[0152] Example 11 89.5 parts of 3-aminopropyltrimethoxysilane, 0.04 parts of methoquinone, and 4 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., trade name) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 104 parts of isobornyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3 is a propylene group, R 6is an isobornyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 198 parts containing two compounds (a compound in which n is an isobornyl group and n is 0) in a molar ratio of 74 / 13 / 13 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.20 mmol. In a separate flask, 297 parts of mineral spirits, 243 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were placed and stirred at room temperature. To this was added dropwise 167 parts of a mixture containing 3-(N-(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in a molar ratio of 74 / 13 / 13 over two hours. The mixture was then maintained at 60°C for two hours and cooled to room temperature, yielding a polyisocyanate curing agent solution (HE-11) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in the hardener solution (HE-11) was 1.73 mmol / g (3.14 mmol / g in terms of nonvolatile content).

[0153] Example 12 221 parts of 3-aminopropyltriethoxysilane, 0.07 parts of methoquinone, and 7 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., trade name) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 128 parts of i-butyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3 is a propylene group, R 6is an i-butyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 This yielded 356 parts of a mixture containing two primary amino groups (a compound in which n is an i-butyl group and n is 0) in a molar ratio of 80 / 10 / 10. The total amount of (primary amino groups + secondary amino groups) per gram of the mixture was 2.53 mmol. In a separate flask, 298 parts of mineral spirits, 235 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., trade name), and 500 parts of "Duranate TSA-100" were placed and stirred at room temperature. To this was added dropwise 145 parts of a mixture containing 3-(N-(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in an 80 / 10 / 10 molar ratio over 2 hours, followed by holding at 60°C for 2 hours and cooling to room temperature to obtain a polyisocyanate curing agent solution (HE-12) with a nonvolatile content of 55%. The concentration of isocyanate groups in the curing agent solution (HE-12) was 1.78 mmol / g (3.24 mmol / g in terms of nonvolatile content).

[0154] Example 13 179 parts of 3-aminopropyltrimethoxysilane, 0.07 parts of methoquinone, and 6 parts of "Swasol 1000" (a naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 128 parts of t-butyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(t-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3 is a propylene group, R 6is a t-butyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(t-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 313 parts containing two compounds (a compound in which n is a t-butyl group and n is 0) in a molar ratio of 78 / 11 / 11 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.84 mmol. In a separate flask, 348 parts of mineral spirits, 284 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were placed and stirred at room temperature. To this was added dropwise 285 parts of a mixture containing 3-(N-(2-(t-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(t-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in a molar ratio of 78 / 11 / 11 over two hours. The mixture was then maintained at 60°C for two hours and cooled to room temperature, yielding a polyisocyanate curing agent solution (HE-13) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in the hardener solution (HE-13) was 1.16 mmol / g (2.11 mmol / g in terms of nonvolatile content).

[0155] Example 14 89.5 parts of 3-aminopropyltrimethoxysilane, 0.04 parts of methoquinone, and 4 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., trade name) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 104 parts of isobornyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3 is a propylene group, R 6is an isobornyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 198 parts containing two compounds (a compound in which n is an isobornyl group and n is 0) in a molar ratio of 74 / 13 / 13 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.20 mmol. In a separate flask, 273 parts of mineral spirits, 223 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were placed and stirred at room temperature. To this was added dropwise 111 parts of a mixture containing 3-(N-(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in a molar ratio of 74 / 13 / 13 over two hours. The mixture was then maintained at 60°C for two hours and cooled to room temperature, yielding a polyisocyanate curing agent solution (HE-14) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in the curing agent solution (HE14) was 1.99 mmol / g (3.62 mmol / g in terms of nonvolatile content).

[0156] Example 15 179 parts of 3-aminopropyltrimethoxysilane, 0.07 parts of methoquinone, and 6 parts of "Swasol 1000" (a naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 141 parts of i-butyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3 is a propylene group, R 6is an i-butyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 326 parts containing two compounds (a compound in which n is an i-butyl group and n is 0) in a molar ratio of 77 / 6 / 17 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.55 mmol. In a separate flask, 308 parts of mineral spirits, 252 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were placed and stirred at room temperature. To this was added dropwise 192 parts of a mixture containing 3-(N-(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(i-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in a molar ratio of 77 / 6 / 17 over two hours. The mixture was then held at 60°C for two hours and cooled to room temperature, yielding a polyisocyanate curing agent solution (HE-15) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in the hardener solution (HE-15) was 1.57 mmol / g (2.85 mmol / g in terms of nonvolatile content).

[0157] Example 16 110.5 parts of 3-aminopropyltriethoxysilane, 0.04 parts of methoquinone, and 4 parts of "Swasol 1000" (a naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 93.6 parts of isobornyl acrylate was added dropwise over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3 is a propylene group, R 6is an isobornyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the N-position modified alkoxysilane represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 208 parts containing two compounds (a compound in which n is an isobornyl group and n is 0) in a molar ratio of 80 / 15 / 5 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.28 mmol. In a separate flask, 271 parts of mineral spirits, 222 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were placed and stirred at room temperature. To this was added dropwise 108 parts of a mixture containing 3-(N-(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(isobornyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in an 80 / 15 / 15 molar ratio over 2 hours. The mixture was then maintained at 60°C for 2 hours and cooled to room temperature to yield a polyisocyanate curing agent solution (HE-16) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in the hardener solution (HE-16) was 2.01 mmol / g (3.65 mmol / g in terms of nonvolatile content).

[0158] Comparative Example 5 179 parts of 3-aminopropyltrimethoxysilane, 0.07 parts of methoquinone, and 6 parts of "Swasol 1000" (a naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 128 parts of n-butyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(n-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6)). 2 is a methyl group, R 3 is a propylene group, R 6is an n-butyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(n-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 313 parts containing two compounds (a compound where n is an n-butyl group and n is 0) in a molar ratio of 66 / 17 / 17 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.65 mmol. In a separate flask, 285 parts of mineral spirits, 233 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were placed and stirred at room temperature. To this was added dropwise 139 parts of a mixture containing 3-(N-(2-(n-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(n-butyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in a molar ratio of 66 / 17 / 17 over two hours. The mixture was then maintained at 60°C for two hours and cooled to room temperature, yielding a polyisocyanate curing agent solution (HR-5) with a nonvolatile content of 55%. The concentration of isocyanate groups contained in the curing agent solution (HR-5) was 1.80 mmol / g (3.28 mmol / g in terms of nonvolatile content).

[0159] Comparative Example 6 179 parts of 3-aminopropyltrimethoxysilane, 0.07 parts of methoquinone, and 6 parts of "Swasol 1000" (a naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.) were placed in a flask, and air was introduced into the liquid to bubble and stir it. 100 parts of ethyl acrylate was added dropwise to the mixture over 2 hours, and the mixture was then kept at 50°C for 1 hour. The mixture was then further aged at 50°C for 1 week to obtain 3-(N-(2-(ethyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (an alkoxysilane N-position modified product represented by formula (6) where R 2 is a methyl group, R 3 is a propylene group, R 6is an ethyl group, and n is 0) / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(ethyloxycarbonyl)ethyl)amino)propyltrimethoxysilane (in the compound represented by formula (8), R 2 is a methyl group, R 3 is a propylene group, R 6 A mixture of 285 parts containing two compounds (a compound in which n is an ethyl group and n is 0) in a molar ratio of 66 / 17 / 17 was obtained. The total amount of (primary amino groups + secondary amino groups) in 1 g of the mixture was 2.91 mmol. In a separate flask, 297 parts of mineral spirits, 243 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were added and stirred at room temperature. To this mixture, 169 parts of a mixture containing 3-(N-(2-(ethyloxycarbonyl)ethyl)amino)propyltrimethoxysilane / 3-aminopropyltrimethoxysilane / 3-(N,N-di(2-(ethyloxycarbonyl)ethyl)amino)propyltrimethoxysilane in a molar ratio of 66 / 17 / 17 were added dropwise over 2 hours. The mixture was then held at 60°C for 2 hours and cooled to room temperature to yield a polyisocyanate curing agent solution (HR-6) with a nonvolatile content of 55%. The isocyanate group concentration in the curing agent solution (HR-6) was 1.62 mmol / g (2.95 mmol / g in terms of nonvolatile content).

[0160] Comparative Example 7 A container was charged with 225 parts of mineral spirits, 184 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., trade name), and 500 parts of "Duranate TSA-100." The mixture was stirred at room temperature to obtain a polyisocyanate curing agent solution (HR-7) (non-volatile content: 55%) that had not been modified with aminoalkoxysilane or unsaturated carboxylic acid dialkyl ester. The concentration of isocyanate groups per gram of curing agent solution (HR-7) was 2.70 mmol / g (4.91 mmol / g in terms of non-volatile content).

[0161] Comparative Example 8 179 parts of 3-aminopropyltrimethoxysilane, 0.07 parts of methoquinone, and 4 parts of "Swasol 1000" (naphtha-based solvent, product name, manufactured by Maruzen Petrochemical Co., Ltd.) were placed in a flask, heated to 80°C, and air was introduced into the liquid to bubble and stir, yielding 183 parts of a mixture. In a separate flask, 254 parts of mineral spirits, 208 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd.), and 500 parts of "Duranate TSA-100" were placed and stirred at room temperature. 67 parts of the mixture containing 3-aminopropyltrimethoxysilane were added dropwise over two hours, and the mixture was then held at 60°C for one hour and cooled to room temperature in an attempt to obtain a polyisocyanate curing agent solution (HR-8) (non-volatile content: 54%) that had been modified with aminoalkoxysilane but not modified with unsaturated carboxylic acid dialkyl ester. However, the curing agent precipitated, resulting in a non-uniform solution that was unusable as a curing agent, and further evaluation was discontinued.

[0162] [Table 2]

[0163] (Note 3) The molar ratio of 3-(N-(2-(alkoxycarbonyl)ethyl)amino)propyltrialkoxysilane / 3-aminopropyltrialkoxysilane / 3-(N,N-di(2-(alkoxycarbonyl)ethyl)amino)propyltrialkoxysilane in the mixture was calculated by converting the proton integral value of H NMR (proton nuclear magnetic resonance analysis). [Evaluation items] (*) State of hardener solution After production, each hardener solution was sealed in a 250 ml glass bottle and stored in a sealed condition in a thermostatic chamber at 20°C and 60% humidity for 3 months. The condition after storage in a sealed condition in a thermostatic chamber at 5°C and 60% humidity for 2 weeks was also visually observed. In the table, ◯ rank was judged as passing, and × and XX ranks were judged as failing. ○: No two-layer separation, cloudiness, or precipitates were observed in the hardener solution, and no abnormalities were observed. ×: Either two layers were separated or the hardener solution was cloudy. ××: Starch syrup-like polymer precipitated from the hardener solution.

[0164] [Production of modified polyisocyanates using saturated carboxylic acid alkyl esters] Example 17 A flask under a nitrogen atmosphere was charged with 89 parts of methyl acetate, a linear saturated ester, and 179 parts of 3-aminopropyltrimethoxysilane, and the mixture was stirred at room temperature. 0.58 parts of a 28% methanol solution of sodium methoxide was added as a catalyst, and the mixture was stirred. The temperature was raised to 70°C and aged for one day. The conversion of 3-aminopropyltrimethoxysilane was 97%, and methanol was by-produced in an amount roughly equimolar to the reacted 3-aminopropyltrimethoxysilane. Subsequently, 1.1 parts of bis(2-ethylhexyl)phosphoric acid was added as an acidic compound, and the mixture was concentrated under reduced pressure at 50°C to 70°C to remove the methanol and remaining methyl acetate. As a result, crude 3-acetamidopropyltrimethoxysilane (R in formula (7)) containing catalyst-derived residue was obtained as an N-acyl-modified intermediate. 2 is a methyl group, R 3 is a propylene group, R 7 This yielded 222 parts of a compound in which n is a methyl group and n is 0. In a separate flask under a nitrogen atmosphere, 250 parts of mineral spirits, 204 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., trade name), and 500 parts of "Duranate TSA-100" were added and stirred at room temperature. 55 parts of crude 3-acetamidopropyltrimethoxysilane was added and heated at 110°C for 10 hours to adduct the secondary amide groups to isocyanate groups, yielding a polyisocyanate curing agent solution (HE-17) with a nonvolatile content of 55%. The isocyanate group concentration in the curing agent solution (HE-17) was 2.14 mmol / g (3.89 mmol / g in terms of nonvolatile content).

[0165] Example 18 A flask under a nitrogen atmosphere was charged with 89 parts of methyl acetate, a linear saturated ester, and 179 parts of 3-aminopropyltrimethoxysilane, and the mixture was stirred at room temperature. 0.58 parts of a 28% methanol solution of sodium methoxide was added as a catalyst, and the mixture was stirred. The temperature was raised to 70°C and aged for one day. The conversion of 3-aminopropyltrimethoxysilane was 97%, and methanol was by-produced in an amount roughly equimolar to the reacted 3-aminopropyltrimethoxysilane. Subsequently, 0.58 parts of p-toluenesulfonic acid was added as an acidic compound, and the mixture was concentrated under reduced pressure at 50°C to 70°C to remove the methanol and remaining methyl acetate. As a result, crude 3-acetamidopropyltrimethoxysilane (R in formula (7)) containing catalyst-derived residue was obtained as an N-acyl-modified intermediate. 2 is a methyl group, R 3 is a propylene group, R 7 This yielded 222 parts of a compound in which n is a methyl group and n is 0. In a separate flask under a nitrogen atmosphere, 62 parts of butyl acetate and 500 parts of Duranate TSA-100 were placed and stirred at room temperature. 55 parts of crude 3-acetamidopropyltrimethoxysilane was added and heated at 110°C for 7 hours to adduct the secondary amide groups to isocyanate groups, yielding a polyisocyanate curing agent solution (HE-18) with a nonvolatile content of 90%. The concentration of isocyanate groups in the curing agent solution (HE-18) was 3.49 mmol / g (3.88 mmol / g in terms of nonvolatile content).

[0166] Example 19 A flask under a nitrogen atmosphere was charged with 89 parts of methyl acetate, a linear saturated ester, and 179 parts of 3-aminopropyltrimethoxysilane, and the mixture was stirred at room temperature. 0.58 parts of a 28% methanol solution of sodium methoxide was added as a catalyst, and the mixture was stirred. The temperature was raised to 70°C and aged for one day. The conversion of 3-aminopropyltrimethoxysilane was 97%, and methanol was by-produced in an amount roughly equimolar to the reacted 3-aminopropyltrimethoxysilane. Subsequently, 1.1 parts of bis(2-ethylhexyl)phosphoric acid was added as an acidic compound, and the mixture was concentrated under reduced pressure at 50°C to 70°C to remove the methanol and remaining methyl acetate. As a result, crude 3-acetamidopropyltrimethoxysilane (R in formula (7)) containing catalyst-derived residue was obtained as an N-acyl-modified intermediate. 2 is a methyl group, R 3 is a propylene group, R 7 This yielded 222 parts of a compound in which n is a methyl group and n is 0. In a separate flask under a nitrogen atmosphere, 62 parts of butyl acetate and 500 parts of Duranate TSA-100 were placed and stirred at room temperature. 55 parts of crude 3-acetamidopropyltrimethoxysilane was added and heated at 110°C for 7 hours to adduct the secondary amide groups to isocyanate groups, yielding a polyisocyanate curing agent solution (HE-19) with a nonvolatile content of 90%. The concentration of isocyanate groups in the curing agent solution (HE-19) was 3.49 mmol / g (3.88 mmol / g in terms of nonvolatile content).

[0167] Example 20 A flask under a nitrogen atmosphere was charged with 89 parts of methyl acetate, a linear saturated ester, and 179 parts of 3-aminopropyltrimethoxysilane, and the mixture was stirred at room temperature. 0.58 parts of a 28% methanol solution of sodium methoxide was added as a catalyst, and the mixture was stirred. The temperature was raised to 70°C and aged for one day. The conversion of 3-aminopropyltrimethoxysilane was 97%, and methanol was by-produced in an amount roughly equimolar to the reacted 3-aminopropyltrimethoxysilane. Subsequently, 1.03 parts of dodecylbenzenesulfonic acid was added as an acidic compound, and the mixture was concentrated under reduced pressure at 50°C to 70°C to remove the methanol and remaining methyl acetate. As a result, crude 3-acetamidopropyltrimethoxysilane (R in formula (7)) containing catalyst-derived residue was obtained as an N-acyl-modified intermediate. 2 is a methyl group, R 3 is a propylene group, R 7 This yielded 222 parts of a compound in which n is a methyl group and n is 0. In a separate flask under a nitrogen atmosphere, 62 parts of butyl acetate and 500 parts of Duranate TSA-100 were placed and stirred at room temperature. 55 parts of crude 3-acetamidopropyltrimethoxysilane was added and heated at 110°C for 7 hours to adduct the secondary amide groups to isocyanate groups, yielding a polyisocyanate curing agent solution (HE-20) with a nonvolatile content of 90%. The concentration of isocyanate groups in the curing agent solution (HE-20) was 3.49 mmol / g (3.88 mmol / g in terms of nonvolatile content).

[0168] Example 21 A flask under a nitrogen atmosphere was charged with 190 parts of methyl octanoate, a linear saturated ester, and 179 parts of 3-aminopropyltrimethoxysilane, and the mixture was stirred at room temperature. 1.16 parts of a 28% methanol solution of sodium methoxide was added as a catalyst, and the mixture was stirred. The temperature was raised to 70°C and the mixture was aged for 2 days. The conversion rate of 3-aminopropyltrimethoxysilane was 94%, and methanol was by-produced in an amount roughly equimolar to the reacted 3-aminopropyltrimethoxysilane. Subsequently, 2.2 parts of bis(2-ethylhexyl)phosphoric acid was added as an acidic compound, and the mixture was concentrated by removing the methanol under reduced pressure at 50°C to 70°C. As a result, crude 3-octanamidopropyltrimethoxysilane (R in formula (7)) containing catalyst-derived residue was obtained as an N-acyl-modified intermediate. 2 is a methyl group, R 3 is a propylene group, R 7 This yielded 331 parts of a compound in which n is a heptyl group and n is 0. In a separate flask under a nitrogen atmosphere, 65 parts of butyl acetate and 500 parts of Duranate TSA-100 were placed and stirred at room temperature. To this was added 82 parts of crude 3-octanamidopropyltrimethoxysilane, and the mixture was heated at 110°C for 12 hours to adduct the secondary amide groups to isocyanate groups. After cooling, the mixture was filtered through filter paper to yield a polyisocyanate curing agent solution (HE-21) with a nonvolatile content of 90%. The concentration of isocyanate groups in the curing agent solution (HE-21) was 3.18 mmol / g (3.53 mmol / g in terms of nonvolatile content).

[0169] Example 22 A flask under a nitrogen atmosphere was charged with 106 parts of methyl propionate, a linear saturated ester, and 179 parts of 3-aminopropyltrimethoxysilane, and the mixture was stirred at room temperature. 0.58 parts of a 28% methanol solution of sodium methoxide was added as a catalyst, and the mixture was stirred. The temperature was raised to 70°C and aged for 2 days. The conversion of 3-aminopropyltrimethoxysilane was 97%, and methanol was by-produced in an amount roughly equimolar to the reacted 3-aminopropyltrimethoxysilane. Subsequently, 1.1 parts of bis(2-ethylhexyl)phosphoric acid was added as an acidic compound, and the mixture was concentrated under reduced pressure at 50°C to 80°C to remove the methanol and remaining methyl propionate. As a result, crude 3-propanamidopropyltrimethoxysilane (R in formula (7)) containing catalyst-derived residue was obtained as an N-acyl-modified intermediate. 2 is a methyl group, R 3 is a propylene group, R 7 This yielded 236 parts of a compound in which n is an ethyl group and n is 0. In a separate flask under a nitrogen atmosphere, 60 parts of butyl acetate and 500 parts of Duranate TSA-100 were placed and stirred at room temperature. To this was added 41 parts of crude 3-propanamidopropyltrimethoxysilane, and the mixture was heated at 110°C for 9 hours to adduct the secondary amide groups with isocyanate groups, yielding a polyisocyanate curing agent solution (HE-22) with a nonvolatile content of 90%. The concentration of isocyanate groups in the curing agent solution (HE-22) was 3.67 mmol / g (4.08 mmol / g in terms of nonvolatile content).

[0170] Example 23 A flask under a nitrogen atmosphere was charged with 96 parts of methyl acetate, a linear saturated ester, and 179 parts of 3-aminopropyltrimethoxysilane, and the mixture was stirred at room temperature. 0.58 parts of a 28% methanol solution of sodium methoxide was added as a catalyst, and the mixture was stirred. The temperature was raised to 70°C and aged for one day. The conversion of 3-aminopropyltrimethoxysilane was 98%, and methanol was by-produced in an amount roughly equimolar to the reacted 3-aminopropyltrimethoxysilane. Subsequently, 1.1 parts of bis(2-ethylhexyl)phosphoric acid was added as an acidic compound, and the mixture was concentrated by removing methanol and remaining methyl acetate under reduced pressure at 50°C to 70°C. Further, vacuum distillation was carried out at a vacuum of 4 mmHg to obtain purified 3-acetamidopropyltrimethoxysilane (R in formula (7)) as an N-acyl-modified intermediate. 2 is a methyl group, R 3 is a propylene group, R 7 A compound in which n is a methyl group and n is 0 was obtained (200 parts). In a separate flask under a nitrogen atmosphere, 114 parts of propylene glycol monomethyl ether acetate and 500 parts of "Sumidur N-3300" (a hexamethylene diisocyanate-based isocyanurate polyisocyanate, manufactured by Sumitomo Covestro Urethane Co., Ltd., trade name, isocyanate group content 21.8 wt%) were added and stirred at room temperature. 144 parts of purified 3-acetamidopropyltrimethoxysilane was added and heated at 110°C for 9 hours to adduct the secondary amide groups to isocyanate groups, yielding a polyisocyanate curing agent solution (HE-23) with a nonvolatile content of 85%. The isocyanate group concentration in the curing agent solution (HE-23) was 2.50 mmol / g (2.94 mmol / g in terms of nonvolatile content).

[0171] Example 24 A flask under a nitrogen atmosphere was charged with 206 parts of methyl 3,3,5-trimethylhexanoate, a branched saturated ester with two hydrogen atoms at the α-position, and 179 parts of 3-aminopropyltrimethoxysilane, and the mixture was stirred at room temperature. 1.16 parts of a 28% methanol solution of sodium methoxide was added as a catalyst, and the mixture was stirred. The temperature was raised to 70°C and aged for two days. The conversion rate of 3-aminopropyltrimethoxysilane was 71%, and methanol was by-produced in an amount roughly equimolar to the reacted 3-aminopropyltrimethoxysilane. Subsequently, 2.2 parts of bis(2-ethylhexyl)phosphoric acid was added as an acidic compound, and the mixture was concentrated by removing methanol under reduced pressure at 50°C to 70°C. Further, the mixture was distilled under reduced pressure at a vacuum of 4 mmHg to obtain purified 3-(3,3,5-trimethylhexanamido)propyltrimethoxysilane (R in formula (7)) as an N-acyl-modified intermediate. 2 is a methyl group, R 3 is a propylene group, R 7 This yielded 170 parts of a compound in which n is 2,2,4-trimethylpentyl and n is 0. In a separate flask under a nitrogen atmosphere, 64 parts of butyl acetate and 500 parts of Duranate TSA-100 were placed and stirred at room temperature. 79 parts of purified 3-(3,3,5-trimethylhexanamido)propyltrimethoxysilane was added and heated at 110°C for 9 hours to adduct the secondary amide groups to isocyanate groups, yielding a polyisocyanate curing agent solution (HE-24) with a nonvolatile content of 90%. The concentration of isocyanate groups in the curing agent solution (HE-24) was 3.39 mmol / g (3.77 mmol / g in terms of nonvolatile content).

[0172] Example 25 Crude 3-acetamidopropyltrimethoxysilane (R in formula (7)) was obtained as an N-acyl-modified intermediate in the same manner as in Example 17, except that bis(2-ethylhexyl)phosphoric acid was not added. 2 is a methyl group, R 3 is a propylene group, R 7This yielded 222 parts of a compound where n is a methyl group and n is 0. In a separate flask under a nitrogen atmosphere, 62 parts of propylene glycol monomethyl ether acetate and 500 parts of Duranate TSA-100 were placed and stirred at room temperature. 55 parts of crude 3-acetamidopropyltrimethoxysilane was added and heated at 110°C for 7 hours to adduct the secondary amide groups to isocyanate groups, yielding a polyisocyanate curing agent solution (HE-25) with a nonvolatile content of 90%. The concentration of isocyanate groups in the curing agent solution (HE-25) was 3.13 mmol / g (3.48 mmol / g in terms of nonvolatile content).

[0173] Example 26 In a flask under a nitrogen atmosphere, 206 parts of methyl 3,3,5-trimethylhexanoate, a branched saturated ester with two hydrogen atoms at the α-position, and 179 parts of 3-aminopropyltrimethoxysilane were placed and stirred at room temperature. To this was added 1.16 parts of a 28% methanol solution of sodium methoxide as a catalyst, and the mixture was stirred. The temperature was raised to 70°C and aged for 2 days. The conversion rate of 3-aminopropyltrimethoxysilane was 71%, and methanol was by-produced in an amount roughly equimolar to the reacted 3-aminopropyltrimethoxysilane. Subsequently, 2.2 parts of bis(2-ethylhexyl)phosphoric acid was added as an acidic compound, and the mixture was concentrated at 50°C to 70°C under reduced pressure to remove methanol. This produced crude 3-(3,3,5-trimethylhexanamido)propyltrimethoxysilane (R in formula (7)) containing catalyst-derived residue as an N-acyl-modified intermediate. 2 is a methyl group, R 3 is a propylene group, R 7This yielded 365 parts of a compound in which n is 2,2,4-trimethylpentyl and n is 0. Because this was not purified by distillation, a large amount of 3-aminopropyltrimethoxysilane from the raw materials remained, resulting in a mixture of 71 mol% 3-(3,3,5-trimethylhexanamido)propyltrimethoxysilane and 29 mol% 3-aminopropyltrimethoxysilane. In a separate flask under a nitrogen atmosphere, 65 parts of propylene glycol monomethyl ether acetate and 500 parts of Duranate TSA-100 were placed and stirred at room temperature. To this was added 90 parts of crude 3-(3,3,5-trimethylhexanamido)propyltrimethoxysilane, and the mixture was heated at 110°C for 7 hours to adduct the secondary amide groups to isocyanate groups, yielding a polyisocyanate curing agent solution (HE-26) with a nonvolatile concentration of 90%. The concentration of isocyanate groups contained in the hardener solution (HE-26) was 3.25 mmol / g (3.61 mmol / g in terms of nonvolatile content).

[0174] Comparative Example 9 56 parts of butyl acetate and 500 parts of Duranate TSA-100 were placed in a flask under a nitrogen atmosphere and stirred at room temperature to obtain a polyisocyanate curing agent solution (HR-9) with a nonvolatile content of 90%. The concentration of isocyanate groups in the curing agent solution (HR-9) was 4.46 mmol / g (4.96 mmol / g in terms of nonvolatile content).

[0175] Comparative Example 10 A flask under a nitrogen atmosphere was charged with 248 parts of mineral spirits, 198 parts of "Swasol 1000" (a naphtha-based solvent, manufactured by Maruzen Petrochemical Co., Ltd., product name), and 500 parts of "Duranate TSA-100," and the mixture was stirred at room temperature. 44.3 parts of 3-aminopropyltrimethoxysilane was added dropwise to the mixture, yielding a curing agent solution (HR-10). However, a starch syrup-like substance precipitated, and the study was discontinued.

[0176] [Table 3]

[0177] [Evaluation items] (*) Formation of N-acyl derivatives The production rate (%) of N-acyl modified products in Examples 17 to 26 was calculated and evaluated according to the following criteria. In the table, GOOD, FAIR, and POOR have the following meanings. The higher the production rate (%), the better the result. Good: 80% or more, Fair: 30% or more but less than 80% Poor: Less than 30%.

[0178] (*)Easy production of intermediates containing N-acyl modified compounds The ease of production of the polyisocyanate curing agent solutions obtained in Examples 17 to 26 was evaluated according to the following criteria. AA and A were judged to be acceptable. In addition, Y in the column for whether or not a distillation apparatus was used means that a distillation apparatus was used, and N means that a distillation apparatus was not used. AA: Can be produced without distillation equipment. A: It is possible to manufacture it by using a distillation device. B: The production rate of N-acyl modified compounds is low, making them difficult to manufacture even with a distillation apparatus. (*) Isocyanate group stability at 20℃ The NCO residual rate in the polyisocyanate curing agent solutions obtained in Examples 17 to 26 and Comparative Example 9 after 3 months at 20°C was measured in the same manner as in Example 1 and evaluated according to the following criteria: The higher the residual rate (%), the better the result.

[0179] Good: 95% or above, Fair: 90% or above but less than 95%, Poor: less than 90%.

[0180] [Clear coating manufacturing] Examples 27 to 57 and Comparative Examples 11 to 18 The main agent was prepared according to the formulation shown in Tables 4, 5, and 6 below, and the polyisocyanate curing agent solutions (HE-1) to (HE-26), (HR-1) to (HR-3), (HR-5) to (HR-7), and (HR-9) that had been prepared for three days were mixed together to obtain clear coatings (U-1) to (U-41). Similarly, the main components listed in Table 4 were mixed with old polyisocyanate curing agent solutions (HE-1) to (HE-7) and (HR-3) that had been produced 12 months earlier to produce clear coatings (U'-1) to (U'-9) and (U'-12). In addition, the main components listed in Table 5 were mixed with old polyisocyanate curing agent solutions (HE-8) to (HE-16) and (HR-5) to (HR-7) that had been produced three months earlier to produce clear coatings (U'-13) to (U'-26). Similarly, polyisocyanate curing agent solutions (HE-8) to (HE-16) and (HR-7) stored in a sealed container at 5°C for two weeks after preparation were mixed with the base resins listed in Table 5 to produce clear coatings (U´´-13) to (U´´-23) and (U´´-26). Similarly, the base resins listed in Table 6 were mixed with polyisocyanate curing agent solutions (HE-17) to (HE-26) and (HR-9) that had been produced three months earlier to produce clear coatings (U'-27) to (U'-41).

[0181] The values ​​in Tables 4, 5 and 6 are not the mass of the non-volatile components but the total mass including the volatile components.

[0182] [Table 4]

[0183] [Table 5]

[0184] [Table 6]

[0185] (Note 4) Polyol solution 1: styrene / i-butyl methacrylate / 2-ethylhexyl acrylate / hydroxyethyl methacrylate = 30 / 30 / 30 / 10 copolymer solution, weight average molecular weight 20,000, hydroxyl value per non-volatile content 43 mg KOH / g, non-volatile content 50%, solvent: mineral spirits / "Swasol 1000" mass ratio = 1 / 1 (Note 5) Polyol solution 2: styrene / i-butyl methacrylate / 2-ethylhexyl acrylate / hydroxyethyl methacrylate / acrylic acid = 30 / 35 / 29 / 5 / 1 copolymer solution, weight average molecular weight 20,000, hydroxyl value per non-volatile matter 22 mg KOH / g, non-volatile matter concentration 50%, solvent: mineral spirits / "Swasol 1000" mass ratio = 1 / 1 (Note 6) Aspartic acid ester 1: Desmophen NH1523LF (N,N'-(methylenebis(2-methyl-di-4,1-cyclohexanediyl))-bisaspartic acid tetraethyl ester, content >99%, amine value 200 mg KOH / g, manufactured by Covestro. (Note 7) Neostan U-830: Trade name, manufactured by Nitto Kasei Co., Ltd., dioctyl tin compound (Note 8) Aspartic acid ester 2: Desmophen NH1423LF (N,N'-(methylenebis(di-4,1-cyclohexanediyl))-bisaspartic acid tetraethyl ester, content >99%, amine value 205 mg KOH / g) manufactured by Covestro.

[0186] [Performance evaluation] The clear coatings obtained in the above Examples and Comparative Examples were subjected to the following performance evaluation tests. In these tests, the coating was carried out immediately after mixing the base resin and curing agent. (*)Curability Each clear coating was applied to a glass plate using a 200μm applicator, dried for 7 days in a chamber at 23℃ and 50% humidity, and the resulting coating film was peeled off from the glass plate. This coating film was wrapped in a 200-mesh stainless steel wire netting and immersed in a mixed solution of acetone / methanol (mass ratio = 1 / 1) for 24 hours. After that, the wire netting with the coating film wrapped around it was removed and dried at 100℃ for 1 hour, and the insoluble content was measured from the mass of the coating film remaining on the wire netting. ◎ and ◯ were ranked as pass, and △ and × were ranked as fail. ◎: Insoluble fraction 85% or more 〇: Insoluble content is 70% or more and less than 85% △: Insoluble content is 55% or more and less than 70% ×: Insoluble content less than 55%. (*)Adhesiveness Two types of metal plates were prepared as substrates: ferrous metal: degreased SPCC-SD (cold-rolled steel plate with a dull finish), and non-ferrous metal: 5052P aluminum plate sanded with 240 grit sandpaper (3.2 mm x 70 mm x 150 mm). Each clear coating was applied to each metal plate using a 200 μm applicator, and then dried for 7 days in a chamber at a room temperature of 23°C and a humidity of 50%, to obtain the respective test coated plates. A total of 100 squares, 10 squares x 10 squares, were cut into a 2mm wide grid using a cutter from above the coating film, and a peel test was performed three times in which adhesive tape was applied and then peeled off, and the number of squares that did not peel off was counted. Ranks of ◎ and ◯ were considered to be pass, and ranks of △ and × were considered to be fail. ◎: 100 squares 〇: 75 to 99 squares △: 51 to 74 squares ×: 50 squares or less (*)Water-resistant adhesion Two types of metal plates, iron and aluminum, were prepared in the same manner as the metal plates used in the above adhesion test. Each clear coating was applied to each metal plate using a 200 μm applicator, and then dried for 7 days in a chamber at a room temperature of 23°C and a humidity of 50%, to obtain each test coated plate. Each test plate was immersed in 40°C warm water for 3 days, then immersed in 20°C water for 1 hour, removed, and the water on the surface of the coating was wiped off. Immediately, a cutter was used to cut 100 squares (10 x 10 squares) in a 2mm wide grid pattern from above the coating. A peel test was then performed three times in which adhesive tape was applied and then peeled off, and the number of squares that did not peel off was counted. ◎ and ◯ ranks were judged as passing, while △ and × ranks were judged as failing. ◎: 100 squares 〇: 75 to 99 squares △: 51 to 74 squares ×: 50 squares or less.

[0187] [Manufacturing of one-coat coating] Examples 60 to 92 and Comparative Examples 19 to 26 The base resin was prepared according to the formulation shown in Tables 7, 8, and 9 below, and the polyisocyanate curing agent solutions (HE-1) to (HE-26), (HR-1) to (HR-3), (HR-5) to (HR-7), and (HR-9) that had been prepared three days earlier were mixed to obtain single-coat coatings (U-42) to (U-82). Similarly, the polyisocyanate curing agent solutions (HE-1) to (HE-7) and (HR-3) that were 12 months old after production were mixed with the base resins listed in Table 7 to produce one-coat coatings (U'-42) to (U'-50) and (U'-53), respectively. Additionally, the base resins listed in Table 8 were mixed with the polyisocyanate curing agent solutions (HE-8) to (HE-16) and (HR-5) to (HR-7) that had been produced three months earlier to produce single-coat coatings (U'-54) to (U'-67). Similarly, polyisocyanate curing agent solutions (HE-8) to (HE-16) and (HR-7) stored in a sealed container at 5°C for two weeks after preparation were mixed with the base resins listed in Table 8 to produce single-coat coatings (U´´-54) to (U´´-64) and (U´´-67), respectively. Similarly, the base resins listed in Table 9 were mixed with the polyisocyanate curing agent solutions (HE-17) to (HE-26) and (HR-9) that had been produced three months earlier to produce single-coat coatings (U'-68) to (U'-82).

[0188] The values ​​in Tables 7, 8 and 9 are not the mass of the non-volatile components but the total mass including the volatile components.

[0189] [Table 7]

[0190] [Table 8]

[0191] [Table 9]

[0192] (Note 9) Anti-rust pigment composition: magnesium phosphate / "Silysia 710" (silica, Fuji Silysia Chemical Co., Ltd., trade name) / calcium silicate = 50 / 30 / 20 mixed and modified.

[0193] [Performance evaluation] (*)Curability: The curability test was carried out in the same manner as in the above-mentioned clear coating, and was evaluated according to the same criteria. (*)Corrosion resistance: On a zinc phosphate treated SPCC steel plate (3.2mm x 70mm x 150mm), the base agent and hardener were mixed and applied in one coat of 100g / m2 within 30 minutes. 2 After curing at 20°C for 7 days, an 8cm long cut was made with a cutter down to the base material to prepare a test panel. The test panel was then tested in a 5% salt spray tester at 35°C for 240 hours, after which the appearance of the test panel was observed and rated on a 4-point scale. ◎: The maximum width of rust (one side) progressing from the cut is less than 15 mm, and there are no abnormalities in the general area. ○: The maximum width of rust (one side) progressing from the cut is 15 to less than 20 mm, and there are no abnormalities in the general area. △: The maximum width of rust (on one side) progressing from the cut area is less than 20 mm, but blisters and rust have occurred in the general area. ×: The maximum width of rust (on one side) that has progressed from the cut part exceeds 20 mm, and blisters and rust have appeared in the general part. (*)Weather resistance On zinc phosphate-treated SPCC steel sheet, mix the base agent and hardener, and apply one coat of each at 100g / m within 30 minutes. 2 The paint was brush-painted and then cured at 20°C for 7 days to obtain a test painted panel. The test coated plate was irradiated for 300 hours in accordance with the accelerated weather resistance test of JIS K 5600, 7-7 (xenon lamp method), and then the test coated plate was evaluated according to the following criteria. ◎: No change in gloss is observed compared to the initial state ○: A change in gloss is observed compared to the initial state, but it is not noticeable. △: A clear change in gloss is observed compared to the initial state. ×: The change in gloss is significant compared to the initial state.

Claims

1. 1. A modified polyisocyanate for use with an active hydrogen-containing compound as a curing agent for a coating, comprising: A modified polyisocyanate that is a reaction product of raw materials containing an alkoxysilane (a1) having a primary amino group, a saturated carboxylic acid alkyl ester (a3), and a polyisocyanate (a4) (excluding polyisocyanates based on 1,5-diisocyanatopentane), a modified polyisocyanate having a structure in which a secondary amide group of an N-position-modified alkoxysilane obtained by reacting a primary amino group of the alkoxysilane (a1) with an ester group of the saturated carboxylic acid alkyl ester (a3) ​​is adducted to an isocyanate group of the polyisocyanate (a4); and The N-position modified alkoxysilane is an N-position acyl modified alkoxysilane having a secondary amide group and represented by the following formula (7): Modified polyisocyanate. 【Chemical 1】 In formula (7), R １ and R ２ are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R ３ is a linear or branched alkylene group having 1 to 8 carbon atoms, n is an integer of 0 to 2, and R ７ represents an alkyl group having 1 to 18 carbon atoms and having no unsaturated group, or a group having 1 to 18 carbon atoms and containing a heteroatom in the molecule of an alkyl group or arylalkyl group having 1 to 18 carbon atoms and having no unsaturated group.

2. The modified polyisocyanate according to claim 1, wherein the alkoxysilane (a1) having a primary amino group is a compound represented by the following formula (1): 【Chemistry 2】 In formula (1), R １ and R ２ are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R ３ is a linear or branched alkylene group having 1 to 8 carbon atoms, and n is an integer of 0 to 2.

3. The modified polyisocyanate according to claim 1, wherein the saturated carboxylic acid alkyl ester (a3) ​​is a compound represented by the following formula (4): R ７ -C(=O)-OR ８ (4) In formula (4), R ７ and R ８ are the same or different and represent an alkyl group having 1 to 18 carbon atoms and having no unsaturated group, or a group having 1 to 18 carbon atoms and having a heteroatom in the alkyl molecule and having no unsaturated group.

4. 2. The modified polyisocyanate according to claim 1, wherein the reaction ratio of the N-position-modified alkoxysilane having a secondary amide group to the polyisocyanate (a4) is such that the number of moles of secondary amide groups is 40 or less per 100 moles of isocyanate groups.

5. A method for producing the modified polyisocyanate described in claim 1, comprising: a step (1) of reacting an alkoxysilane (a1) having a primary amino group with a saturated carboxylic acid alkyl ester (a3) ​​in the presence of a basic catalyst; a step (2) of adding an acidic compound; a step (3) of removing some or all of the alcohol produced as a by-product to prepare an intermediate containing an N-acyl modified product represented by the following formula (7); and a step (4) of reacting the intermediate with a polyisocyanate (a4). 【Chemistry 3】 In formula (7), R １ and R ２ are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R ３ is a linear or branched alkylene group having 1 to 8 carbon atoms, n is an integer of 0 to 2, and R ７ represents an alkyl group having 1 to 18 carbon atoms and having no unsaturated group, or a group having 1 to 18 carbon atoms and containing a heteroatom in the alkyl group molecule and having no unsaturated group.

6. The method according to claim 5, wherein the step (3) is carried out by removing a part or all of the alcohol produced as a by-product by concentration, without distillation, to prepare an intermediate containing an N-acyl-modified product represented by the following formula (7): 【Chemistry 4】 In formula (7), R １ and R ２ are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R ３ is a linear or branched alkylene group having 1 to 8 carbon atoms, n is an integer of 0 to 2, and R ７ represents an alkyl group having 1 to 18 carbon atoms and having no unsaturated group, or a group having 1 to 18 carbon atoms and containing a heteroatom in the alkyl group molecule and having no unsaturated group.

7. 2. The modified polyisocyanate according to claim 1, wherein the reaction ratio of the N-acyl modified product with the polyisocyanate (a4) is such that the total number of moles of secondary amide groups and primary amino groups per 100 moles of isocyanate groups is 40 moles or less.

8. A curing agent composition comprising the modified polyisocyanate of claim 1 and a basic catalyst, The basic catalyst is a metal hydroxide, a metal carbonate, a metal hydrogen carbonate, a metal alkoxide, an organic metal, a potassium silanolate, or a nitrogen compound; Hardener composition.

9. 9. The hardener composition of claim 8, further comprising an acidic compound, The hardener composition, wherein the acidic compound is an inorganic Bronsted acid, an organic Bronsted acid, or an acyl chloride.

10. 2. A method for producing a modified polyisocyanate according to claim 1, comprising: a step (1) of reacting an alkoxysilane (a1) having a primary amino group with a saturated carboxylic acid alkyl ester (a3) ​​in the presence of a basic catalyst; a step (2) of adding an acidic compound; a step (3) of removing a part or all of the alcohol produced as a by-product to prepare an intermediate containing an N-acyl-modified product represented by the following formula (7); and a step (4) of reacting the intermediate with a polyisocyanate (a4). 【Chemistry 5】 In formula (7), R １ and R ２ are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R ３ is a linear or branched alkylene group having 1 to 8 carbon atoms, n is an integer of 0 to 2, and R ７ indicates an alkyl group having 1 to 18 carbon atoms and having no unsaturated group, or a group having 1 to 18 carbon atoms and containing a heteroatom in the alkyl group molecule, and having no unsaturated group.

11. The method according to claim 10, wherein the step (3) is carried out by removing a part or all of the alcohol produced as a by-product by concentration, without distillation, to prepare an intermediate containing an N-acyl-modified product represented by the following formula (7): 【Chemistry 6】 In formula (7), R １ and R ２ are the same or different and each represents an optionally substituted linear or branched alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, cycloalkynyl group, aryl group, or heteroaryl group having 1 to 18 carbon atoms; R ３ is a linear or branched alkylene group having 1 to 8 carbon atoms, n is an integer of 0 to 2, and R ７ represents an alkyl group having 1 to 18 carbon atoms and having no unsaturated group, or a group having 1 to 18 carbon atoms and containing a heteroatom in the alkyl group molecule and having no unsaturated group.

12. The modified polyisocyanate according to claim 1, wherein the saturated carboxylic acid alkyl ester (a3) ​​is an alkyl ester of a linear carboxylic acid having two or more hydrogen atoms at the α-position, or an alkyl ester of a branched carboxylic acid having two hydrogen atoms at the α-position.

13. The method according to claim 10, wherein the saturated carboxylic acid alkyl ester (a3) ​​is an alkyl ester of a linear carboxylic acid having two or more hydrogen atoms at the α-position.

14. A coating comprising an active hydrogen-containing compound and the modified polyisocyanate according to any one of claims 1 to 7 and 12 or the curing agent composition according to claim 8 or 9.

15. The coating of claim 14, wherein the active hydrogen-containing compound comprises an acrylic polyol and / or a bisaspartic acid ester derivative.

16. 15. The coating of claim 14, further comprising at least one member selected from the group consisting of a rust inhibitor, a catalyst, a color pigment, and an extender pigment.

17. 15. The coating of claim 14 which is a one-coat paint.

18. A protective coating film obtained by curing the coating according to claim 14.

19. A coated metal material having the protective coating film of claim 18 formed on a metal substrate.

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