Polyisocyanate composition, coating composition, and coated substrate

Abstract

To provide a polyisocyanate composition which exhibits good dispersibility when blended with a main agent, has a long pot life, and is excellent in scratch resistance.SOLUTION: The polyisocyanate composition contains a polyisocyanate component (I) and a polyisocyanate component (II). The polyisocyanate component (I) is a derivative derived from an aliphatic diisocyanate (a) and a hydrophilic compound (c). The polyisocyanate component (II) is a derivative derived from an alicyclic diisocyanate (b). The mass ratio [(I) / (II)] of the polyisocyanate component (I) to the polyisocyanate component (II) is 35 / 65 or more and 65 / 35 or less. The mass fraction of the hydrophilic compound (c) is 3.0 mass% or more and 8.0 mass% or less based on the total mass of the polyisocyanate composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polyisocyanate composition, a coating composition, and a coated substrate.

Background Art

[0002] In recent years, from the viewpoints of improving global environmental protection and labor safety and hygiene, development of water-based coating agents has been actively carried out to reduce the amount of organic solvents used. A two-component curable resin composition composed of a main component containing a hydroxyl group (so-called polyol) and a polyisocyanate as a curing agent can be cured even at room temperature and exhibits excellent mechanical properties, chemical resistance, durability, etc., and thus is widely used in various applications such as paints and adhesives.

[0003] In order to be used as a water-based two-component curable resin composition using polyisocyanate as a curing agent, many water-dispersible polyisocyanates modified with polyalkylene oxide polyether alcohol or an anionic compound to impart hydrophilicity have been reported so far.

[0004] For example, Patent Documents 1 and 2 disclose curing agents for water-based two-component curable resins, which are aliphatic or alicyclic polyisocyanates and have ethylene oxide repeating units to impart compatibility with a water-based main component. Patent Document 3 discloses a curing agent for a water-based two-component curable resin, which contains a polyisocyanate having a specific anion structure and a specific viscosity to impart compatibility with a water-based main component.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] However, polyisocyanate compositions having a hydrophilic group derived from polyalkylene oxide ether alcohol disclosed in Patent Documents 1 and 2 tend to have low drying property of the coating film, and further, there is a problem that the coating film physical properties such as corrosion resistance are insufficient due to the inclusion of alicyclic diisocyanate. In addition, the curing agent for aqueous two-component type curable resin disclosed in Patent Document 3 has a problem that the pot life is shortened although the dispersibility is improved by having an anion structure.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a polyisocyanate composition having good dispersibility, a long pot life, and excellent scratch resistance when blended with a main agent.

MEANS FOR SOLVING THE PROBLEMS

[0008] That is, the present invention includes the following aspects. [1] A polyisocyanate composition comprising a polyisocyanate component (I) and a polyisocyanate component (II), wherein the polyisocyanate component (I) is a derivative derived from an aliphatic diisocyanate (a) and an anionic compound (c), and the polyisocyanate component (II) is a derivative derived from an alicyclic diisocyanate (b), and the mass ratio [(I) / (II)] of the polyisocyanate component (I) to the polyisocyanate component (II) is 35 / 65 or more and 65 / 35 or less, and the mass fraction of the anionic compound (c) with respect to the total mass of the polyisocyanate composition is 3.0% by mass or more and 8.0% by mass or less. [2] The polyisocyanate composition according to [1], wherein the mass ratio [(I) / (II)] is 40 / 60 or more and 60 / 40 or less. [3] The mass fraction of components with a number average molecular weight of 600 or less with respect to the total mass of the polyisocyanate composition is 30% by mass or less, the polyisocyanate composition according to [1] or [2]. [4] The polyisocyanate component (II) is a derivative derived from an alicyclic diisocyanate (b) and optionally a polyether alcohol (d) containing an ethylene oxide group, the polyisocyanate composition according to any one of [1] to [3]. [5] The mass fraction of the polyether alcohol (d) with respect to the polyisocyanate component (II) is 15.0% by mass or less, the polyisocyanate composition according to [4]. [6] The polyisocyanate component (I) includes a reaction product with an alcohol, the polyisocyanate composition according to any one of [1] to [5]. [7] The mass fraction of the alcohol with respect to the polyisocyanate component (I) is 4.5% by mass or less, the polyisocyanate composition according to [6]. [8] The alcohol has an average number of 2.0 or more and 3.5 or less hydroxyl groups per molecule and a number average molecular weight of 450 or less, the polyisocyanate composition according to [7]. [9] The anionic compound (c) is one or more sulfonic acids selected from the group consisting of sulfonic acids containing a hydroxyl group and sulfonic acids containing an amino group, the polyisocyanate composition according to any one of [1] to [8].

[10] The sulfonic acid group of the anionic compound (c) is neutralized with an inorganic base or an organic amine compound, the polyisocyanate composition according to any one of [1] to [9].

[11] The anionic compound (c) is a compound represented by the following general formula (1), the polyisocyanate composition according to any one of [1] to

[10] . [Chemical formula] (In general formula (1), R 11is a hydrocarbon group having 1 to 10 carbon atoms which may contain at least one selected from the group consisting of a hydroxyl group, an ether bond, an ester bond, a carbonyl group, and an imino group. R 11 may contain a ring structure. The ring structure is an aromatic ring, a 5-membered or 6-membered ring containing two nitrogen atoms, or a 5-membered or 6-membered ring containing a nitrogen atom and an oxygen atom.)

[12] The polyisocyanate composition according to any one of [1] to

[11] , wherein the anionic compound (c) is a compound represented by the following general formula (2).

Chemical formula

[13] The polyisocyanate composition according to any one of [1] to

[12] , which contains an organic solvent and the content of the organic solvent is 50% by mass or less.)

[14] The polyisocyanate composition according to

[13] , wherein the organic solvent contains propylene glycol diacetate.)

[15] A coating composition containing the polyisocyanate composition according to

[13] or

[14] .

[16] A coated substrate coated with the coating composition according to

[15] .

Advantages of the Invention

[0009] According to the polyisocyanate composition of the above aspect, when blended with a main agent, a polyisocyanate composition having good dispersibility, a long pot life, and excellent scratch resistance can be provided.)

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist thereof.

[0011] <Polyisocyanate composition> The polyisocyanate composition of the present embodiment contains a polyisocyanate component (I) and a polyisocyanate component (II). The polyisocyanate component (I) is a derivative derived from an aliphatic diisocyanate (a) and an anionic compound (c). The polyisocyanate component (II) is a derivative derived from an alicyclic diisocyanate (b). The mass ratio [(I) / (II)] of the polyisocyanate component (I) to the polyisocyanate component (II) is 35 / 65 or more and 65 / 35 or less, and more preferably 40 / 60 or more and 60 / 40 or less.

[0012] When the mass ratio [(I) / (II)] is within the above range, it is possible to provide a polyisocyanate composition having a long pot life and excellent drying properties, hardness, and scratch resistance when formed into a coating film. Generally, the "pot life" means the time during which the performance of a composition of a paint or an adhesive is maintained as a composition before curing after mixing the main agent and the curing agent liquid. It is also called the pot life. The mass ratio [(I) / (II)] can be calculated using the method described in the examples below.

[0013] The mass fraction of the anionic compound (c) with respect to the total mass of the polyisocyanate composition is 3.0% by mass or more and 8.0% by mass or less. From the viewpoint of improving the dispersibility and coating film gloss when blended with the main agent, the mass fraction of the anionic compound (c) is preferably 3.5% by mass or more, and more preferably 4.0% by mass or more. Further, from the viewpoint of improving the initial water resistance and pot life, the mass fraction of the anionic compound (c) is more preferably 6.0% by mass or less, and even more preferably 5.0% by mass or less.

[0014] One aspect of the polyisocyanate composition of the present embodiment may contain a raw material polyisocyanate that has not reacted with the anionic compound (c) (hereinafter also referred to as "unreacted raw material polyisocyanate"), and an anionic compound (c) that has not reacted with the raw material polyisocyanate (hereinafter also referred to as "unreacted anionic compound"). In addition, unless otherwise specified, various physical properties or characteristics of the polyisocyanate composition of the present embodiment described below are characteristics indicating a state containing a polyisocyanate (hereinafter also referred to as "modified polyisocyanate") obtained by the reaction of the above raw material polyisocyanate and the above anionic compound, unreacted raw material polyisocyanate, and unreacted anionic compound.

[0015] One aspect of the polyisocyanate composition of the present embodiment preferably has a mass fraction of components with a number average molecular weight of 600 or less of 30% by mass or less, more preferably 27% by mass or less, and even more preferably 25% by mass or less, based on the total mass of the polyisocyanate composition. Hereinafter, components with a number average molecular weight of 600 or less may be referred to as "low molecular weight components". The low molecular weight component is, for example, the above-mentioned unreacted raw material polyisocyanate. When the mass fraction of the low molecular weight component is equal to or less than the above upper limit value, good dispersibility can be achieved when blended with the main agent, the pot life is long, and a polyisocyanate composition with good gloss can be provided when formed into a coating film. The content of the low molecular weight component can be calculated using the method described in the examples below.

[0016] The following will explain in detail each constituent component of the polyisocyanate composition of the present embodiment.

[0017] ≪Polyisocyanate≫ The polyisocyanate composition of the present embodiment contains a polyisocyanate component (I) and a polyisocyanate component (II).

[0018] (Polyisocyanate component (I)) The polyisocyanate component (I) is a derivative derived from an aliphatic diisocyanate (a) and an anionic compound (c). Here, the "polyisocyanate" means a compound obtained by reacting diisocyanates with each other and, if necessary, compounds other than diisocyanates (for example, alcohols, water, amines, etc.).

[0019] Examples of the aliphatic diisocyanate of the polyisocyanate component (I) include, but are not limited to, 1,4-diisocyanatobutane, 1,5-diisocyanatopentane (hereinafter also referred to as "PDI"), ethyl (2,6 - diisocyanato) hexanoate, 1,6 - diisocyanatohexane (hereinafter also referred to as "HDI"), 1,9 - diisocyanatononane, 1,12 - diisocyanatododecane, 2,2,4 - or 2,4,4 - trimethyl - 1,6 - diisocyanatohexane, etc.

[0020] Among them, aliphatic diisocyanates are preferable in terms of weather resistance, chemical resistance, and scratch resistance, and particularly HDI and PDI are preferable.

[0021] The polyisocyanate is not particularly limited, and examples include polyisocyanates shown in the following (a) to (h), etc. (a) A polyisocyanate having a uretdione group obtained by cyclodimerizing two isocyanate groups; (b) A polyisocyanate having an isocyanurate group or an iminooxadiazinedione group obtained by cyclotrimerizing three isocyanate groups; (c) A polyisocyanate having a biuret group obtained by reacting three isocyanate groups with one water molecule; (d) A polyisocyanate having an oxadiazinetrione group obtained by reacting two isocyanate groups with one molecule of carbon dioxide; (e) A polyisocyanate having a plurality of urethane groups obtained by reacting one isocyanate group with one hydroxyl group; (f) Polyisocyanate having an allophanate group obtained by reacting two isocyanate groups with one hydroxyl group; (g) Polyisocyanate having an acylurea group obtained by reacting one isocyanate group with one carboxyl group; (h) Polyisocyanate having a urea group obtained by reacting one isocyanate group with one primary or secondary amine

[0022] Among them, the polyisocyanate used in the hydrophilic polyisocyanate compound is preferably the above (b), and more preferably a polyisocyanate having an isocyanurate group.

[0023] (Isocyanurate group) The isocyanurate group is a functional group obtained by cyclotrimerizing three isocyanate groups, and refers to a structure represented by the following formula (3).

[0024] [Chemical formula]

[0025] In a state where unreacted diisocyanate is removed, with respect to the total number of moles (100 mol%) of the isocyanurate group, allophanate group, iminooxadiazinedione group, and uretdione group, the content of the isocyanurate group is preferably 30 mol% or more and 100 mol% or less. The lower limit is more preferably 40 mol%, and even more preferably 50 mol%. Also, the upper limit is more preferably 95 mol%, and even more preferably 90 mol%. When the content of the isocyanurate group is within the above range, the resulting coating film tends to have excellent chemical resistance and weather resistance.

[0026] The content ratio of each structure derived from the isocyanate group can be determined by 13 C-NMR measurement. Specifically, Biospin Avance600 (trade name) manufactured by Bruker was used. 13In the measurement of 13C-NMR (measurement solvent: chloroform-d, sample concentration: 60 mass / volume%, observation frequency: 150 MHz, number of integrations: 10,000 times), when the aliphatic diisocyanate is HDI, a signal of the carbon atom of the carbonyl group in the 6-membered ring is observed at around 148.6 ppm for the isocyanurate ring structure. Since there are three identical carbon atoms in the structure, 1 / 3 of the integration value corresponds to the molar fraction of the structure.

[0027] (Allophanate group) The allophanate group is a functional group formed by the reaction of a hydroxyl group and an isocyanate group, and refers to the structure represented by the following formula (4).

[0028] [Chemical formula]

[0029] In the polyisocyanate composition of the present embodiment, the molar ratio of the allophanate group is preferably 0.1 mol% or more and 20.0 mol% or less, and more preferably 0.5 mol% or more and 16.0 mol% or less, based on the total number of moles (100 mol%) of the isocyanurate group, allophanate group, iminooxadiazinedione group, and uretdione group. When the molar ratio of the allophanate group is within the above range, the coating composition tends to have excellent scratch resistance. The molar ratio of the allophanate group can be determined, for example, 13 by 13C-NMR measurement.

[0030] (Iminooxadiazinedione group) The iminooxadiazinedione group is a functional group obtained by cyclotrimerizing three isocyanate groups, and refers to the structure represented by the following formula (5).

[0031] [Chemical formula]

[0032] In the polyisocyanate composition of the present embodiment, the molar ratio of the iminooxadiazinedione group is preferably 0.1 mol% or more and 40.0 mol% or less, more preferably 0.5 mol% or more and 30.0 mol% or less, based on the total number of moles (100 mol%) of the isocyanurate group, allophanate group, iminooxadiazinedione group, and uretdione group. When the molar ratio of the iminooxadiazinedione group is within the above range, the viscosity is reduced and the dispersibility in the coating composition is excellent. The molar ratio of the iminooxadiazinedione group is 13 can be determined by 13C-NMR measurement.

[0033] (uretdione group) The uretdione group is a functional group obtained by cyclodimerizing two isocyanate groups, and refers to the structure represented by the following formula (6). The polyisocyanate having a uretdione group has a low viscosity and the cured coating film has good scratch resistance.

[0034] [Chemical formula]

[0035] In the polyisocyanate composition of the present embodiment, the molar ratio of the uretdione group is preferably 0.5 mol% or more and 30.0 mol% or less, more preferably 1.0 mol% or more and 25.0 mol% or less, based on the total number of moles (100 mol%) of the isocyanurate group, iminooxadiazinedione group, allophanate group, and uretdione group. When the molar ratio of the uretdione group is within the above range, the coating film in the coating composition is excellent in gloss and alkali resistance. The molar ratio of the uretdione group can be determined, for example, by 13 13C-NMR measurement, or 1 1H-NMR measurement.

[0036] Furthermore, from the viewpoint of reducing the viscosity change during compounding, the mass fraction of the uretdione dimer obtained by cyclodimerizing two diisocyanates is preferably 0.01% by mass or more and 20.0% by mass or less.

[0037] From the viewpoints of improving the gloss and alkali resistance of the coating film, the upper limit value of the mass fraction of the uretdione dimer is more preferably 18.0% by mass or less, and even more preferably 15.0% by mass or less. Also, from the viewpoint of reducing the viscosity, it is more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more. The mass fraction of the uretdione dimer can be determined by GPC.

[0038] (Other bonding groups) In addition to the above-described bonding groups, the polyisocyanate composition of the present embodiment may further have one or more bonding groups selected from the group consisting of a urethane group, a biuret group, a urea group, an acylurea group, and an oxadiazinetrione group. In the polyisocyanate composition of the present embodiment, the total molar ratio of the other bonding groups is preferably 0.01 mol% or more and 10 mol% or less with respect to the total number of moles (100 mol%) of the isocyanurate group, iminooxadiazinedione group, allophanate group, and uretdione group. The molar ratio of the other bonding groups can be determined, for example, 13 by C-NMR measurement, or 1 by H-NMR measurement.

[0039] ≪Anionic compound≫ In order to improve the chromaticity of the curing agent of the polyisocyanate composition of the present embodiment, the dispersibility when compounded with the main agent, and the coating film gloss, the polyisocyanate component (I) contains a reaction product with an anionic compound (c). The anionic compound (c) is preferably at least one sulfonic acid selected from the group consisting of sulfonic acids containing a hydroxyl group and sulfonic acids containing an amino group.

[0040] The sulfonic acid group of the anionic compound (c) can be obtained from a neutralization reaction with one or more sulfonic acids selected from the group consisting of sulfonic acids containing a hydroxyl group and sulfonic acids containing an amino group.

[0041] In the hydrophilic polyisocyanate compound contained in the polyisocyanate composition of the present embodiment, anionic groups derived from anionic compounds are introduced into a part of the isocyanate groups.

[0042] When the anionic compound is a sulfonic acid containing a hydroxyl group, for example, a compound represented by the following general formula (1) (hereinafter abbreviated as "sulfonic acid (1)") and the like can be mentioned. That is, in one aspect of the present invention, the anionic compound is a compound represented by the following general formula (1).

[0043]

Chemical formula

[0044] In the general formula (1), R 11 is a hydrocarbon group having 1 to 10 carbon atoms which may contain at least one selected from the group consisting of a hydroxyl group, an ether bond, an ester bond, a carbonyl group, and an imino group. R 11 may contain a ring structure. The ring structure is an aromatic ring, a 5-membered or 6-membered ring containing two nitrogen atoms, or a 5-membered or 6-membered ring containing a nitrogen atom and an oxygen atom.

[0045] The hydrocarbon group having 1 to 10 carbon atoms may be a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 10 carbon atoms. The divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms is preferably a chain alkylene group having 1 to 6 carbon atoms. When it is a chain alkylene group having 1 to 6 carbon atoms, a group containing a ring structure may be included in a part of the chain alkylene group. The alkylene group having 1 to 6 carbon atoms may be linear or branched.

[0046] Among them, R 11 is preferably a linear alkylene group having 1 to 6 carbon atoms, a divalent aromatic hydrocarbon group (arylene group) having 6 to 10 carbon atoms, a divalent alkylene group having 1 to 6 carbon atoms and containing an aromatic ring, a divalent alkylene group having 1 to 6 carbon atoms and containing a 5-membered or 6-membered ring containing two nitrogen atoms, or a divalent alkylene group having 1 to 6 carbon atoms and containing a 5-membered or 6-membered ring containing a nitrogen atom and an oxygen atom.

[0047] Preferred examples of the anionic compound having a hydroxyalkylsulfonic acid group include, for example, 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, 4-hydroxybutanesulfonic acid, 5-hydroxypentanesulfonic acid, 6-hydroxyhexanesulfonic acid, hydroxybenzenesulfonic acid, hydroxy(methyl)benzenesulfonic acid, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid, 2-hydroxy-3-morpholinopropanesulfonic acid, and the like. These compounds are only a part of the preferred sulfonic acid (1), and the preferred sulfonic acid (1) is not limited to these. Also, these sulfonic acids (1) may be used alone or in combination of two or more.

[0048] Among them, the anionic compound having a hydroxy group is preferably at least one selected from the group consisting of 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, hydroxybenzenesulfonic acid, and hydroxy(methyl)benzenesulfonic acid. These anionic compounds having a hydroxyalkylsulfonic acid have good chromaticity of the curing agent and good gloss of the coating film.

[0049] In addition, when the polyisocyanate composition of the present embodiment contains two or more amine salts of sulfonic acid, the sulfonic acids (1) may be the same or different from each other.

[0050] In addition, the sulfonic acid used in the polyisocyanate containing a sulfonic acid anion group in the molecule may form a salt with an amine compound described later.

[0051] When the anionic compound is a sulfonic acid having an amino group, for example, compounds represented by the following general formula (2) (hereinafter abbreviated as "sulfonic acid (2)") and the like can be mentioned. That is, in one aspect of the present invention, the anionic compound is a compound represented by the following general formula (2).

[0052] [Chemical formula]

[0053] In the general formula (2), R 21 and R 23 are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group. At least one of R 21 and R 23 is a hydrogen atom. R 22 is a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group.

[0054] ·R 21 and R 23 In the general formula (2), R 21 and R 23 are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group. R 21 and R 23 may be the same as or different from each other. At least one of R 21 and R 23 is a hydrogen atom. That is, when R 21 is a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group, R 23 is a hydrogen atom. Also, when R 23 is a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group, R 21 is a hydrogen atom. Also, R 21 and R23 Any of them may be a hydrogen atom.

[0055] The hydrocarbon group having 1 to 12 carbon atoms may be a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms. The monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms is preferably a linear alkyl group having 1 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms. The linear alkyl group having 1 to 6 carbon atoms may be linear or branched.

[0056] Among them, R 21 and R 23 are preferably a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, or a cyclic alkyl group having 3 to 6 carbon atoms, respectively.

[0057] ·R 22 R 22 is a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group. The hydrocarbon group having 1 to 12 carbon atoms may be a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. The divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms is preferably a linear alkylene group having 1 to 12 carbon atoms. The linear alkyl group having 1 to 12 carbon atoms may be linear or branched. Among them, R 22 is preferably a divalent linear alkylene group having 1 to 6 carbon atoms or a divalent aromatic hydrocarbon group (arylene group) having 6 to 10 carbon atoms.

[0058] Preferred sulfonic acids (2) include, for example, 2-aminoethanesulfonic acid, 3-aminopropanesulfonic acid, 2-methylaminoethanesulfonic acid, 3-methylaminopropanesulfonic acid, 2-cyclohexylaminoethanesulfonic acid, 3-cyclohexylaminopropanesulfonic acid, 3-cyclohexylaminoisobutylsulfonic acid, 4-cyclohexylaminobutanesulfonic acid, 2-cyclohexylmethylaminoethanesulfonic acid, 3-cyclohexylmethylaminopropanesulfonic acid, 3-cyclohexylmethylaminoisobutylsulfonic acid, 4-cyclohexylmethylaminobutanesulfonic acid, 2-methylcyclohexylaminoethanesulfonic acid, 3-methylcyclohexylaminopropanesulfonic acid, 3-methylcyclohexylaminoisobutylsulfonic acid, 4-methylcyclohexylaminobutanesulfonic acid, 2-dimethylcyclohexylaminoethanesulfonic acid, 3-dimethylcyclohexylaminopropanesulfonic acid, 3-dimethylcyclohexylaminoisobutylsulfonic acid, 4-dimethylcyclohexylaminobutanesulfonic acid, 2-trimethylcyclohexylaminoethanesulfonic acid, 3-trimethylcyclohexylaminopropanesulfonic acid, 3-trimethylcyclohexylaminoisobutylsulfonic acid, 4-trimethylcyclohexylaminobutanesulfonic acid, 2-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 4-aminobenzenesulfonic acid, 2-(methylamino)benzenesulfonic acid, 3-(methylamino)benzenesulfonic acid, 4-(methylamino)benzenesulfonic acid, amino-methylbenzenesulfonic acid, amino-dimethylbenzenesulfonic acid, aminonaphthalenesulfonic acid, and the like. These compounds are only a part of the preferred sulfonic acids (2), and the preferred sulfonic acids (2) are not limited to these. Also, one of these sulfonic acids (2) may be used, or two or more of them may be used in combination.

[0059] Among them, as the sulfonic acid having an amino group, at least one selected from the group consisting of 2-cyclohexylaminoethanesulfonic acid, 3-cyclohexylaminopropanesulfonic acid, 4-cyclohexylaminobutanesulfonic acid, 3-cyclohexylmethylaminopropanesulfonic acid, 3-(p-methylcyclohexylamino)propanesulfonic acid, 3-(3,3,5-trimethylcyclohexylamino)propanesulfonic acid, 4-(p-methylcyclohexylamino)butanesulfonic acid, 2-aminobenzenesulfonic acid, 2-amino-5-methylbenzenesulfonic acid, 2-amino-3,5-dimethylbenzenesulfonic acid, 5-amino-2-methylbenzenesulfonic acid (4-aminotoluene-2-sulfonic acid), 4-amino-2-methylbenzenesulfonic acid (5-aminotoluene-2-sulfonic acid), and 2-aminonaphthalene-4-sulfonic acid is preferably used.

[0060] In one aspect of the present invention, it is preferable that the sulfonic acid group of the anionic compound is neutralized with an inorganic base or an organic amine compound.

[0061] Examples of the inorganic base include alkali metals such as lithium, sodium, potassium, rubidium, and cesium; alkaline earth metals such as magnesium, calcium, strontium, and barium; metals such as manganese, iron, cobalt, nickel, copper, zinc, silver, cadmium, lead, and aluminum; and ammonia.

[0062] Examples of the organic amine compound include linear tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tritridecylamine, tristearylamine; branched tertiary amines such as triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, tribranched tridecylamine; tertiary amines having a mixed hydrocarbon group such as N,N-dimethylethylamine, N,N-dimethylpropylamine, N,N-dimethylisopropylamine, N,N-dimethylbutylamine, N,N-dimethylisobutylamine, N,N-dimethyloctylamine, N,N-dimethyl-2-ethylhexylamine, N,N-dimethyllaurylamine, N,N-dimethyl(branched)tridecylamine, N,N-dimethylstearylamine, N,N-diethylbutylamine, N,N-diethylhexylamine, N,N-diethyloctylamine, N,N-diethyl-2-ethylhexylamine, N,N-diethyllaurylamine, N,N-diisopropylmethylamine, N,N-diisopropylethylamine, N,N-diisopropylbutylamine, N,N-diisopropyl-2-ethylhexylamine; alicyclic tertiary amines such as N,N-dimethylcyclohexylamine, N,N-diethylbenzylamine, N,N-diethylcyclohexylamine, N,N-dicyclohexylmethylamine, N,N-dicyclohexylethylamine, tricyclohexylamine; tertiary amines having an aromatic ring substituent such as N,N-dimethylbenzylamine, N,N-diethylbenzylamine, N,N-dibenzylmethylamine, tribenzylamine, N,N-dimethyl-4-methylbenzylamine, N,N-dimethylphenylamine, N,N-diethylphenylamine, N,N-diphenylmethylamine; cyclic amines such as N-methylpyrrolidine, N-ethylpyrrolidine, N-propylpyrrolidine, N-butylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-propylpiperidine, N-butylpiperidine, N-methylmorpholine, N-ethylmorpholine, N-propylmorpholine, N-butylmorpholine, N-sec-butylmorpholine, N-tert-butylmorpholine, N-isobutylmorpholine, quinuclidine, etc.These organic amine compounds may be used alone or in combination of two or more.

[0063] Among them, tertiary amines having 5 to 30 carbon atoms are preferable. Specifically, for example, triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tridecylamine, triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, tri-branched tridecylamine, N,N-dimethylpropylamine, N,N-dimethylisopropylamine, N,N-dimethylbutylamine, N,N-dimethylisobutylamine, N,N-dimethyloctylamine, N,N-dimethyl-2-ethylhexylamine, N,N-dimethyllaurylamine, N,N-dimethyl(branched)tridecylamine, N,N-dimethylstearylamine, N,N-diethylbutylamine, N,N-diethylhexylamine, N,N-diethyloctylamine, N,N-diethyl-2-ethylhexylamine, N,N-diethyllaurylamine, N,N-diisopropylmethylamine, N,N-diisopropylethylamine, N,N-dimethylcyclohexylamine, N,N-diethylcyclohexylamine, N,N-dicyclohexylmethylamine, N,N-dicyclohexylethylamine, N,N-dimethylbenzylamine, N,N-diethylbenzylamine, N,N-dibenzylmethylamine, tribenzylamine, N,N-dimethylphenylamine, N,N-diethylphenylamine, N,N-diphenylmethylamine, N-methylpiperidine, N-ethylpiperidine, N-methylmorpholine, N-ethylmorpholine, quinuclidine, pyridine, quinoline and the like can be mentioned. These preferable organic amine compounds may be used alone or in combination of two or more.

[0064] In addition, when the polyisocyanate composition of this embodiment contains two or more amine salts of sulfonic acid, the sulfonic acids (2) may be the same as or different from each other.

[0065] Anionic compounds containing active hydrogen groups such as carboxyl groups and amino groups have high emulsifying power, so a high emulsifying effect can be obtained with a small amount. In order to disperse polyisocyanate in water, when it is modified with an anionic compound (introducing a hydrophilic group derived from a hydrophilic compound into the polyisocyanate), the amount of the anionic compound used can be small, so the modification ratio does not become too high, and the physical properties of the coating film (gloss and alkali resistance) are less likely to deteriorate.

[0066] In the polyisocyanate composition of this embodiment, the mass fraction of the anionic compound bonded to the hydrophilic polyisocyanate compound is preferably 3.0% by mass or more and 8.0% by mass or less with respect to the total mass (100% by mass) of the polyisocyanate composition. Further, from the viewpoint of achieving both dispersibility, water resistance, and pot life when blended with the main agent, 3.5% by mass or more and 7.0% by mass or less is preferable, and 4.0% by mass or more and 6.0% by mass or less is more preferable.

[0067] (Alcohol component) Also, in the polyisocyanate composition of this embodiment, in order to improve the chromaticity of the curing agent, dispersibility, initial water resistance, and scratch resistance when blended with the main agent, the polyisocyanate component (I) preferably contains a reaction product with alcohol. The alcohol is an induced component of the polyisocyanate component (I). The mass fraction of the alcohol with respect to the polyisocyanate component (I) is preferably 4.5% by mass or less, and more preferably 2.5% by mass or less.

[0068] The alcohol preferably has an average number of hydroxyl groups per molecule of 2.0 or more and 3.5 or less, and a number average molecular weight of 450 or less. From the viewpoints of the chromaticity, initial water resistance, and scratch resistance of the polyisocyanate, the average number of hydroxyl groups of the alcohol is preferably 2.0 or more and 3.0 or less, and more preferably 2.0 or more and 2.5 or less. Also, from the viewpoint of dispersibility with the main agent, the number average molecular weight is preferably 400 or less, and more preferably 350 or less.

[0069] Examples of alcohols that satisfy the average number of hydroxyl groups and the number average molecular weight include diols, triols, tetraols, and polymerized alcohols. Examples of diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,2-propanediol, 1,5-pentanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, neopentyl glycol, 2-methyl-2,3-butanediol, 1,6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, 3-methyl-1,5-pentanediol, 2-ethyl-hexanediol, 1,2-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,2-decanediol, 2,2,4-trimethylpentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, etc. Examples of triols include glycerin, trimethylolpropane, etc. Examples of tetraols include pentaerythritol, etc.

[0070] Examples of polymerized alcohols include polyester polyols, polyether polyols, acrylic polyols, polyolefin polyols, polycarbonate diols, etc.

[0071] Examples of the polyester polyol include a polyester polyol obtained by a condensation reaction of a dibasic acid selected from the group consisting of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic acid, isophthalic acid, terephthalic acid, etc. alone or as a mixture, and a polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, glycerin, etc. alone or as a mixture, and polycaprolactones obtained by ring-opening polymerization of ε-caprolactone using a polyhydric alcohol, etc.

[0072] Examples of the polyether polyol include polyether polyols obtained by randomly or block-adding a single or a mixture of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, styrene oxide, etc. to a single or a mixture of polyhydroxy compounds using a strongly basic catalyst such as hydroxides, alcoholates, alkylamines, etc. of lithium, sodium, potassium, etc., or a complex metal cyanide complex such as metal porphyrin, zinc hexacyanocobaltate complex, etc., further polyether polyols obtained by reacting an alkylene oxide with a polyamine compound such as ethylenediamines, etc., and so-called polymer polyols obtained by polymerizing acrylamide, etc. using these polyethers as a medium.

[0073] The polycarbonate diol has a structural unit in which two alcohol groups and one carbonate group are dehydrated and condensed, repeating. Also, examples of the polycarbonate diol include those obtained by copolymerizing a first diol having 2 to 20 carbon atoms, a second diol having 2 to 20 carbon atoms (hereinafter, also simply referred to as "two kinds of diols"), and a carbonate compound.

[0074] These alcohols may be used alone or in combination of a plurality.

[0075] The mass fraction of the alcohol in the polyisocyanate composition of the present embodiment is preferably 4.5% by mass or less, more preferably 2.5% by mass or less, from the viewpoints of the chromaticity of the curing agent, initial water resistance, and scratch resistance.

[0076] (Polyisocyanate component (II)) The polyisocyanate component (II) is a derivative derived from an alicyclic diisocyanate (b). Examples of the alicyclic diisocyanate (b) include, but are not limited to, 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane (hereinafter may be abbreviated as "hydrogenated XDI"), 1,3- or 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl-1-isocyanato-3-(isocyanatomethyl)cyclohexane (hereinafter may be abbreviated as "IPDI"), 4,4'-diisocyanato-dicyclohexylmethane (hereinafter may be abbreviated as "hydrogenated MDI"), 2,5- or 2,6-diisocyanatomethylnorbornane, and the like. These alicyclic diisocyanates may be used alone or in combination of two or more.

[0077] In the polyisocyanate composition of the present embodiment, in order to improve the dispersibility, initial water resistance, and pot life when blended with the main agent, the polyisocyanate component (II) preferably contains a reaction product with a polyether alcohol (d) containing an ethylene oxide group. The mass fraction of the polyether alcohol (d) with respect to the polyisocyanate component (II) is preferably 15.0% by mass or less, more preferably 12.5% by mass or less, and even more preferably 10.0% by mass or less. The polyether alcohol (d) is preferably a monofunctional polyalkylene oxide polyether alcohol having an average number of alkylene oxide repeating units of 7.0 or more and 15.0 or less in order to improve the dispersibility, initial water resistance, and pot life when blended with the main agent.

[0078] ≪Method for Producing Polyisocyanate Component Having Each Bonding Group≫ (Method for Producing Polyisocyanate Component Containing Isocyanurate Group) The catalyst for inducing a polyisocyanate component containing an isocyanurate group from a diisocyanate component is not particularly limited, but those showing basicity are preferable. Specifically, hydroxides and organic weak acid salts of tetraalkylammonium, hydroxides and organic weak acid salts of hydroxyalkylammonium, alkali metal salts of alkylcarboxylic acids, metal alcoholates, aminosilyl group-containing compounds, Mannich bases, combined use of tertiary amines and epoxy compounds, phosphorus compounds, etc. may be mentioned.

[0079] Examples of tetraalkylammonium include tetramethylammonium, tetraethylammonium, etc.

[0080] Examples of organic weak acids include acetic acid, capric acid, etc.

[0081] Examples of hydroxyalkylammonium include trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, triethylhydroxyethylammonium, etc.

[0082] Examples of alkylcarboxylic acids include acetic acid, caproic acid, octylic acid, myristic acid, etc.

[0083] Examples of alkali metal salts include tin, zinc, lead, etc.

[0084] Examples of metal alcoholates include sodium alcoholate, potassium alcoholate, etc.

[0085] Examples of aminosilyl group-containing compounds include hexamethyldisilazane, etc.

[0086] Examples of the phosphorus compound include tributylphosphine and the like.

[0087] The usage amount of these catalysts is preferably 10 mass ppm or more and 10000 mass ppm or less with respect to the total mass of the diisocyanate (and alcohol as required), which is the raw material. Further, in order to terminate the isocyanuration reaction, the catalyst may be inactivated by adding an acidic substance that neutralizes the catalyst, thermal decomposition, chemical decomposition, or the like. Examples of the acidic substance that neutralizes the catalyst include phosphoric acid, acidic phosphate ester, and the like.

[0088] The yield of the polyisocyanate component generally tends to be 10% by mass or more and 70% by mass or less. The polyisocyanate component obtained in a higher yield tends to have a higher viscosity. The yield can be calculated from the ratio of the mass of the obtained polyisocyanate component to the total mass of the raw material components.

[0089] The reaction temperature of the isocyanuration reaction is not particularly limited, but is preferably 50°C or higher and 200°C or lower, and more preferably 50°C or higher and 150°C or lower. When the reaction temperature is at or above the lower limit value, the reaction tends to proceed more easily, and when the reaction temperature is at or below the upper limit value, side reactions that cause coloring can be more effectively suppressed.

[0090] After completion of the isocyanuration reaction, it is preferable to remove unreacted diisocyanate by means of a thin-film evaporation tank, extraction, or the like. Even when the polyisocyanate component contains unreacted diisocyanate, the content of diisocyanate is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, and even more preferably 0.5% by mass or less with respect to the total mass of the polyisocyanate component. When the residual unreacted diisocyanate concentration is within the above range, the curability tends to be more excellent.

[0091] The residual unreacted diisocyanate concentration is preferably 0% by mass. That is, the concentration of the residual unreacted diisocyanate is preferably 0% by mass or more and 3.0% by mass or less, more preferably 0% by mass or more and 1.0% by mass or less, and even more preferably 0% by mass or more and 0.5% by mass or less.

[0092] (Process for Producing a Polyisocyanate Component Containing Allophanate Groups) The catalyst for inducing a polyisocyanate component containing an allophanate group from a diisocyanate is not particularly limited. For example, alkyl carboxylates such as tin, lead, zinc, bismuth, zirconium, and zirconyl; organotin compounds such as tin 2-ethylhexanoate and dibutyltin dilaurate; organolead compounds such as lead 2-ethylhexanoate; organozinc compounds such as zinc 2-ethylhexanoate; bismuth 2-ethylhexanoate, zirconium 2-ethylhexanoate, and zirconyl 2-ethylhexanoate can be mentioned. These can be used alone or in combination of two or more.

[0093] Also, the above-mentioned isocyanuration reaction catalyst can also serve as an allophanatization reaction catalyst. When performing an allophanatization reaction using the above-mentioned isocyanuration reaction catalyst, a polyisocyanate component containing an isocyanurate group is of course also produced. From the perspective of economical production, it is preferable to perform an allophanatization reaction and an isocyanuration reaction using the above-mentioned isocyanuration reaction catalyst as the allophanatization reaction catalyst.

[0094] The compounding amount of the above-mentioned allophanatization reaction catalyst is preferably 10 ppm by mass or more and 1000 ppm by mass or less based on the mass of the charged diisocyanate. The lower limit value is more preferably 20 ppm by mass, even more preferably 40 ppm by mass, and still more preferably 80 ppm by mass. The upper limit value is more preferably 800 ppm by mass, even more preferably 600 ppm by mass, and still more preferably 500 ppm by mass or less.

[0095] The blending amount of the allophanatization reaction catalyst described above is, for example, 20 mass ppm or more and 800 mass ppm or less, 40 mass ppm or more and 600 mass ppm or less, 80 mass ppm or more and 500 mass ppm or less, based on the mass of the charged diisocyanate.

[0096] Also, the allophanatization reaction temperature is preferably 40°C or more and 180°C or less. The lower limit value is more preferably 60°C, still more preferably 80°C, and even more preferably 100°C. The upper limit value is more preferably 160°C, still more preferably 140°C. When the allophanatization reaction temperature is at or above the above lower limit value, the reaction rate tends to be maintained higher. When the allophanatization reaction temperature is at or below the above upper limit value, coloring of the polyisocyanate component and the like can be more effectively suppressed.

[0097] The allophanatization reaction temperature is, for example, 80°C or more and 160°C or less, 100°C or more and 140°C or less.

[0098] The alcohol used for forming the allophanate group is preferably an alcohol formed only of carbon, hydrogen, and oxygen. Specific examples of the alcohol include, but are not limited to, for example, monoalcohol, polyol, and mixtures of these alcohols.

[0099] As the monoalcohol, specifically, for example, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-methyl-1-propanol, 2-butanol, 1-pentanol, 3-methyl-1-butanol, 2-methyl-1-butanol, 2,2-dimethyl-1-propanol, 2-pentanol, 3-methyl-2-butanol, 3-pentanol, 2-methyl-2-butanol, 1-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 4-methyl-1-pentanol, 2,2-dimethyl-1-butanol, 2-ethyl-1-butanol, 2-hexanol, 3-hexanol, 3-methyl-2-pentanol, 4-methyl-2-pentanol, 2-methyl-3-pentanol, 3,3-dimethyl-2-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, 1-octanol, 6-methyl-1-heptanol, 2-ethylhexanol can be mentioned. The monoalcohol may be used alone or in combination of two or more kinds.

[0100] As the polyol, specifically, for example, dialcohols such as ethylene glycol, 1,3-butanediol, neopentyl glycol, 2-ethylhexanediol can be mentioned.

[0101] Also, it is possible to use alcohol as a raw material and derive it as a polyisocyanate component having an allophanate group.

[0102] In the method for producing the polyisocyanate composition of the present embodiment, a solvent may or may not be used. The solvent used in the method for producing the polyisocyanate composition of the present embodiment may be a hydrophilic solvent or a hydrophobic solvent. As hydrophobic solvents, for example, mineral spirit, solvent naphtha, LAWS (Low Aromatic White Spirit), HAWS (High Aromatic White Spirit), toluene, xylene, cyclohexane, etc.; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone can be mentioned.

[0103] As hydrophilic solvents, for example, alcohols such as methanol, ethanol, propanol, isopropanol, 2-ethylhexanol, etc.; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, etc.; esters of ether alcohols such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, etc. These can be used alone or in combination.

[0104] (Polyisocyanate component) As a precursor of the hydrophilic polyisocyanate compound, a polyisocyanate component (i) derived from diisocyanate may be used. This polyisocyanate component (i) can be obtained by reacting at once in the presence of an excess of diisocyanate in the same manner as the production method of the polyisocyanate component having each of the above-mentioned linking groups, and removing the unreacted diisocyanate after the reaction. At that time, other linking groups may be generated simultaneously with the desired linking group generated under each condition.

[0105] (Physical properties of polyisocyanate component (i)) From the viewpoint of improving the dispersibility and pot life of the coating composition, as well as the appearance and water resistance of the coating film, the viscosity of the polyisocyanate component (i) at 25°C is preferably 1,000 mPa·s or more and 50,000 mPa·s or less.

[0106] From the viewpoint of improving curability and chemical resistance of the cured coating film, etc., the lower limit value of the viscosity is more preferably 1,000 mPa·s, and even more preferably 2,000 mPa·s. On the other hand, from the viewpoint of improving dispersibility and solvent dilutability, the upper limit of the viscosity is more preferably 35,000 mPa·s, and even more preferably 20,000 mPa·s.

[0107] The viscosity can be measured at 25°C with an E-type viscometer (manufactured by Tokimec, Inc.) using a standard rotor (1°34’×R24), for example.

[0108] In the state excluding the unreacted diisocyanate component, the isocyanate group content (NCO%) of the polyisocyanate component (i) is preferably 12% by mass or more and 22% by mass or less, more preferably 14% by mass or more and 21% by mass or less, and even more preferably 16% by mass or more and 20% by mass or less.

[0109] When the isocyanate group content is at least the above lower limit value, the water resistance, chemical resistance, and weather resistance of the coating film are further improved. On the other hand, when it is at most the above upper limit value, the dispersibility and solvent dilutability of the coating composition are further improved, and the appearance of the coating film becomes better.

[0110] The isocyanate group content (NCO%) can be measured by the titration method described in the examples below.

[0111] From the viewpoint of the solvent resistance of the coating film, the number average molecular weight of the polyisocyanate component (i) is preferably 450 or more and 2,000 or less, more preferably 500 or more and 1,800 or less, and even more preferably 550 or more and 1,500 or less.

[0112] The number average molecular weight can be measured, for example, using GPC.

[0113] From the viewpoints of the solvent resistance of the coating film and the isocyanate group retention rate, the average number of functional groups of the polyisocyanate component (i) is preferably 1.8 or more and 6.2 or less, more preferably 2.0 or more and 5.6 or less, and still more preferably 2.5 or more and 4.6 or less.

[0114] The average number of functional groups is the number of isocyanate functional groups statistically possessed by one molecule of the polyisocyanate compound, and can be calculated from the number average molecular weight (Mn) and the isocyanate group content (NCO%) of the polyisocyanate compound using the following formula.

[0115] [Average number of functional groups] = Mn × NCO% / 4200

[0116] ≪Production method of anionic compound (c)≫ The neutralized salt of the acidic group bonded to the anionic compound (c) used in the polyisocyanate composition of the present embodiment can be obtained, for example, by subjecting it to a neutralization reaction with a cationic compound such as an inorganic base or an organic amine compound. Further, when the neutralized salt is an amine salt of sulfonic acid, it can be obtained, for example, by mixing a compound containing a sulfonic acid group and an amine compound and subjecting them to a neutralization reaction.

[0117] The neutralization reaction may be carried out in advance before reacting with the diisocyanate component or the polyisocyanate component, or may be carried out simultaneously. Alternatively, it may be carried out by adding an amine compound after reacting the polyisocyanate compound with the compound containing a sulfonic acid group.

[0118] When the active hydrogen group is a hydroxyl group, it is preferable to carry out the neutralization reaction in advance before reacting with the polyisocyanate compound. When the active hydrogen group is an amino group, it is preferable to carry out the neutralization reaction simultaneously when reacting with the polyisocyanate compound, or to carry out the reaction by adding an amine compound after reacting the polyisocyanate compound with a sulfonic acid having an active hydrogen group.

[0119] Also, when the active hydrogen group is a hydroxyl group, in the neutralization reaction, the mixing ratio of the sulfonic acid having a hydroxyl group and the amine compound is preferably such that the molar ratio of the amine compound to the sulfonic acid having a hydroxyl group (molar ratio of amine compound / sulfonic acid having a hydroxyl group) is 0.5 or more and 2.0 or less, and more preferably 0.8 or more and 1.5 or less.

[0120] When the neutralization reaction is carried out in advance, the temperature and time can be appropriately determined according to the progress of the reaction. Usually, the temperature is preferably about 0°C or more and 100°C or less, and the mixing time is preferably about 10 minutes or more and 24 hours or less.

[0121] The solvent used in the preparation of the amine salt of the compound containing the sulfonic acid group is preferably water or a hydrophilic solvent. The hydrophilic solvent is not particularly limited, and examples thereof include alcohols, ether alcohols, ketones, amide solvents, and the like. These solvents can be used alone or in combination.

[0122] Examples of the alcohols include methanol, ethanol, propanol, butanol, isopropanol, and the like.

[0123] Examples of the ether alcohols include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, and the like.

[0124] Examples of the ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like.

[0125] Examples of the amide solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and the like.

[0126] After the neutralization reaction, it is preferable to remove water or a hydrophilic solvent.

[0127] The average number of isocyanate groups in the polyisocyanate composition of this embodiment is preferably 2.0 or more and 6.0 or less. The average number of isocyanate groups is the number of isocyanate groups statistically possessed by one molecule of the polyisocyanate composition, and can be calculated from the number average molecular weight (Mn) and the isocyanate group concentration (NCO group concentration) of the polyisocyanate compound using the following formula.

[0128] [Average functionality]=Mn×NCO% / 4,200

[0129] The isocyanate group concentration (NCO group concentration) of the polyisocyanate composition is preferably 10.0% by mass or more and 24.0% by mass or less. Further, from the viewpoint of achieving both curability and the hardness, chemical resistance, and scratch resistance of the coating film, 12.0% by mass or more and 23.0% by mass or less is more preferable, and 13.0% by mass or more and 22.0% by mass or less is even more preferable. The isocyanate group concentration (NCO group concentration) can be measured by the titration method described in the examples below.

[0130] The number average molecular weight of the polyisocyanate composition is preferably 400 or more and 3,000 or less. Further, from the viewpoint of achieving both solvent dilutability and extensibility and weather resistance, 500 or more and 2,500 or less is more preferable, and 600 or more and 2,000 or less is even more preferable. The number average molecular weight can be measured using, for example, GPC.

[0131] ≪Other methods for producing polyisocyanates≫ The generated polyisocyanate compound may be modified with a high molecular weight polyol. A high molecular weight polyol is a compound having one or more hydroxyl groups, and examples thereof include long-chain polyols, specifically polyester polyols, polycarbonate polyols, polyether polyols, acrylic polyols, and copolyols thereof. These long-chain polyols may be used alone or in combination of two or more. The polyisocyanate may be further modified with an alcohol having one or more hydroxyl groups. An alcohol is a compound having one or more hydroxyl groups, and examples thereof include short-chain polyols and long-chain polyols. Specific examples of short-chain polyols include 1,2-propylene glycol, 1,3-butylene glycol, neopentyl glycol, hydroxy pivalic acid ester of neopentyl glycol, 2-methyl-1,3-propanediol, 2,3,5-trimethylpentanediol, ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butylene diol, 1,5-pentanediol, 1,6-hexanediol, trimethylolpropane, glycerin, 1,1,7-trimethylolheptane, 1,2,7-trimethylolheptane, and the like. Examples of long-chain polyols include polyester polyols, polycarbonate polyols, polyether polyols, acrylic polyols, and copolyols thereof. These polyols may be used alone or in combination of two or more.

[0132] ≪Other Components≫ The polyisocyanate composition of this embodiment may contain other components. The other components are not particularly limited, and examples thereof include solvents, antioxidants, light stabilizers, polymerization inhibitors, surfactants, and antioxidants.

[0133] The solvent includes organic solvents generally used as paint solvents, and may be a hydrophilic solvent or a hydrophobic solvent. These solvents can be used alone or in combination. Among them, hydrophilic solvents are preferred.

[0134] The hydrophilic solvent is not particularly limited, and examples thereof include alcohols, ethers, and esters of ether alcohols.

[0135] Examples of the ethers include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, and the like.

[0136] Examples of the esters of ether alcohols include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, and the like. Among them, from the viewpoint of improving dispersibility and pot life, propylene glycol diacetate, propylene glycol monomethyl ether acetate, and the like are preferable as the organic solvent.

[0137] In the polyisocyanate composition of the present embodiment, the content of the organic solvent is preferably 50% by mass or less, more preferably 49% by mass or less, and even more preferably 48% by mass or less, based on the total mass of the polyisocyanate composition of the present embodiment, from the viewpoint of improving the ease of dispersion and the pot life. Also, the content of the organic solvent is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, based on the total mass of the polyisocyanate composition of the present embodiment.

[0138] In the polyisocyanate composition of the present embodiment, the total content of the antioxidant, the light stabilizer, the polymerization inhibitor, and the surfactant is preferably 0% by mass or more and 10% by mass or less, more preferably 0% by mass or more and 5% by mass or less, and even more preferably 0% by mass or more and 2% by mass or less with respect to the total mass of the polyisocyanate composition of the present embodiment.

[0139] <Coating composition> The coating composition of the present embodiment contains the above-mentioned polyisocyanate composition. The coating composition preferably further contains a resin dispersed or emulsified in water.

[0140] The above-mentioned polyisocyanate composition can be mixed with an organic solvent and optionally a resin to be used as an organic solvent-based coating composition, but it is preferably mixed with a resin dispersed or emulsified in water and used as a coating composition.

[0141] By containing the above-mentioned polyisocyanate composition, the coating composition of the present embodiment is excellent in gloss, water resistance, and salt water spray resistance when formed into a coating film.

[0142] Next, the details of each component contained in the coating composition of the present embodiment will be described below.

[0143] (Resin) In the above coating composition, the resin used as the main component may be any resin that can be dispersed or emulsified in water, but an active hydrogen compound (polyvalent active hydrogen compound) is preferred.

[0144] An active hydrogen compound is a compound in which two or more active hydrogens are bonded in the molecule. Examples of the active hydrogen compound include polyols, polyamines, polythiols, etc., but polyols are mostly used.

[0145] Specific examples of such active hydrogen compounds are not particularly limited, and include, for example, acrylic resins, polyester resins, polyether resins, epoxy resins, fluororesins, polyurethane resins, polyvinylidene chloride copolymers, polyvinyl chloride copolymers, vinyl acetate copolymers, acrylonitrile-butadiene copolymers, polybutadiene copolymers, styrene-butadiene copolymers, and the like.

[0146] Among them, as the active hydrogen compound, acrylic resins or polyester resins are preferred. For example, in terms of water resistance and salt water spray resistance, the hydroxyl value of the polyol is preferably 50 mgKOH / g or more and 250 mgKOH / g or less as the hydroxyl value in the resin content.

[0147] In addition, in the coating composition of the present embodiment, these resins can be used in combination with resins such as melamine-based curing agents, urethane dispersions, and urethane acrylate emulsions, as necessary.

[0148] Moreover, it is preferable that these resins are emulsified, dispersed, or dissolved in water. For this purpose, carboxyl groups, sulfone groups, etc. contained in the resins can be neutralized.

[0149] The neutralizing agent for neutralizing carboxyl groups, sulfone groups, etc. is not particularly limited, and examples include ammonia, water-soluble amino compounds, and the like.

[0150] Examples of water-soluble amino compounds include monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, triethanolamine, butylamine, dibutylamine, 2-ethylhexylamine, ethylenediamine, propylenediamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, and the like. These can be used alone or in combination of two or more.

[0151] Among these, as the neutralizing agent, a tertiary amine is preferable, and triethylamine or dimethylethanolamine is more preferable.

[0152] ≪Other Components≫ In addition to the above-mentioned polyisocyanate composition and resins, the coating composition of the present embodiment may further contain additives generally added to paints. Examples of the additives include extender pigments, silane coupling agents, titanium coupling agents, organic phosphates, organic phosphites, thickeners, leveling agents, thixotropic agents, defoamers, freeze stabilizers, matting agents, crosslinking reaction catalysts (catalysts for promoting curing), anti-skinning agents, dispersants, wetting agents, fillers, plasticizers, lubricants, reducing agents, preservatives, fungicides, deodorants, anti-yellowing agents, ultraviolet absorbers, antistatic agents or charge control agents, anti-settling agents, surfactants, antioxidants, light stabilizers, polymerization inhibitors, and the like. These additives may be contained alone or in combination of two or more.

[0153] ≪Method for Producing Coating Composition≫ The coating composition of the present embodiment can be obtained by mixing the above polyisocyanate composition and resins, and, if necessary, other components and the like using a known method.

[0154] For example, in the case of an aqueous-based coating composition, additives exemplified by the above other components are added to resins or their aqueous dispersions or water-soluble substances as necessary. Next, the above polyisocyanate composition or its aqueous dispersion is added as a curing agent, and, if necessary, water or a solvent is further added to adjust the viscosity. Then, by forcibly stirring with a stirring device, an aqueous coating composition can be obtained.

[0155] When manufacturing a solvent-based coating composition, first, additives exemplified by the above other components are added to resins or their solvent dilutions as necessary. Next, the above polyisocyanate composition is added as a curing agent, and if necessary, a solvent is further added to adjust the viscosity. Then, by stirring using manual stirring or a stirring device such as a magnetic stirrer, a solvent-based coating composition can be obtained.

[0156] <Coating substrate> The coating substrate of this embodiment is a coating substrate coated with the above-described coating composition. The coating substrate of this embodiment preferably has a coating layer containing the above-described coating composition.

[0157] Since the coating substrate of this embodiment includes a coating film formed by curing the above-described coating composition, it is excellent in appearance and water resistance.

[0158] The coating substrate of this embodiment can be obtained by applying the above-described coating composition onto a substrate using a known method such as roll coating, curtain flow coating, spray coating, bell coating, electrostatic coating, etc., and curing it through a normal drying or baking process at room temperature.

[0159] The coating substrate of this embodiment may include a desired substrate and, optionally, a normal primer before coating.

[0160] Examples of the substrate include metals, woods, glasses, stones, ceramic materials, concretes, calcium silicate boards and gypsum boards, rigid and flexible plastics, fiber products, leather products, papers, and the like.

[0161] <Usage> The polyisocyanate resin composition and coating composition of this embodiment can be used particularly in architectural paints, automotive paints, automotive repair paints, paints for construction machinery and agricultural machinery, paints for plastics, adhesives, binders, building materials, household water-based paints, other coating agents, sealing agents, inks, casting materials, elastomers, foams, plastic raw materials, and fiber treatment agents.

Examples

[0162] Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[0163] The physical properties and evaluations of the polyisocyanate composition in the examples and comparative examples were measured as follows. Unless otherwise specified, "parts" and "%" mean "parts by mass" and "mass%".

[0164] <Measurement method> [Physical property 1: Viscosity] The viscosity was measured at 25°C using an E-type viscometer (manufactured by Tokimec, Inc.). A standard rotor (1°34’×R24) was used. The rotation speeds are as follows.

[0165] (Rotation speed) 100 r.p.m. (when less than 128 mPa·s) 50 r.p.m. (when 128 mPa·s or more and less than 256 mPa·s) 20 r.p.m. (when 256 mPa·s or more and less than 640 mPa·s) 10 r.p.m. (when 640 mPa·s or more and less than 1280 mPa·s) 5 r.p.m. (when 1280 mPa·s or more and less than 2560 mPa·s) 2.5 r.p.m. (when 2560 mPa·s or more and less than 5120 mPa·s)

[0166] [Physical property 2: Isocyanate group content (NCO%)] Using the polyisocyanate compositions obtained in the examples and comparative examples as samples, the isocyanate group content was measured according to the method described in JIS K7301-1995 (Test Method for Toluene Diisocyanate Type Prepolymer for Thermosetting Urethane Elastomers). The following shows a more specific method for measuring the isocyanate group content (NCO%).

[0167] (1) Weigh 1 g (W g) of the sample into a 200 mL Erlenmeyer flask, add 20 mL of toluene to the flask, and dissolve the sample. (2) Then, add 20 mL of a 2.0 N di-n-butylamine·toluene solution to the above flask and let it stand for 15 minutes. (3) Add 70 mL of 2-propanol to the above flask, dissolve it to obtain a solution. (4) Titrate the solution obtained in (3) above with 1 mol / L hydrochloric acid to obtain the sample titration volume (V1 mL). (5) Even when no sample is added, perform the measurement in the same manner as in (1) to (3) above to obtain the blank titration volume (V0 mL). From the sample titration volume and blank titration volume obtained above, the isocyanate group content (NCO%) was calculated using the following formula (A).

[0168] Isocyanate group content (mass%) = (V0 - V1) × 42 / [W(1 g) × 1000] × 100 (A)

[0169] [Physical Property 3: Non-volatile Content] Using the polyisocyanate compositions obtained in the examples and comparative examples as samples, when diluted with a solvent, the non-volatile content was calculated using the method shown below. First, the mass of an aluminum cup was precisely weighed (W0 g), about 1 g of the sample was placed in it, and the mass of the cup before heating and drying (W1 g) was precisely weighed. Next, the cup containing the sample was heated in a dryer at 105 °C for 3 hours. Then, after cooling the cup after heating to room temperature, the mass of the cup was precisely weighed again (W2 g). Then, taking the mass % of the dry residue in the sample as the non-volatile content, the non-volatile content was calculated using the following formula (B). In the case without solvent dilution, the non-volatile content was treated as being substantially 100%. Non-volatile content (mass %) = (W2 - W0) / (W1 - W0) × 100 (B)

[0170] [Physical Property 4: Polyisocyanate Composition, Number-Average Molecular Weight of Polyol Component, and Mass Fraction of Component with Number-Average Molecular Weight of 600 or Less] The number-average molecular weight of the polyol component and the mass fraction of the component with a number-average molecular weight of 600 or less in the polyisocyanate composition were obtained by measuring the number-average molecular weight based on polystyrene by GPC measurement under the measurement conditions shown below.

[0171] (Measurement Conditions) Apparatus: Tosoh Corporation HLC-8120GPC (trade name) Column: Tosoh Corporation TSKgel SuperH1000 (trade name) × 1 piece TSKgel SuperH2000 (trade name) × 1 piece TSKgel SuperH3000 (trade name) × 1 piece Carrier: Dimethylformamide Detection Method: Differential Refractometer

[0172] [Physical Property 5: Number-Average Molecular Weight of Alcohol Component] Using the alcohol as a sample, the number-average molecular weight of the alcohol was determined by the following formula (3). The hydroxyl value of the alcohol was determined by the following (Physical Property 9). Number-average molecular weight = 2 / (hydroxyl value of alcohol × 10 - 3 / 56.11) ···(3)

[0173] [Physical property 6: Hydroxyl value of alcohol component] Using alcohol as the sample, the hydroxyl value of the alcohol was determined according to JIS K 0070:1992. Specifically, 12.5 g of acetic anhydride was made up to 50 mL with pyridine to prepare an acetylation reagent. Next, 2.5 - 5.0 g of alcohol was precisely weighed into a 100 mL eggplant flask. After adding 5 mL of the acetylation reagent and 10 mL of toluene to the eggplant flask with a whole pipette, a condenser was attached and the mixture was stirred and heated at 100 °C for 1 hr. 2.5 mL of distilled water was added with a whole pipette, and the mixture was further heated and stirred for 10 min. After cooling for 2 - 3 min, 12.5 mL of ethanol was added, 2 - 3 drops of phenolphthalein were added as an indicator, and then titration was carried out with 0.5 mol / L ethanolic potassium hydroxide. On the other hand, as a blank test, 5 mL of the acetylation reagent, 10 mL of toluene, and 2.5 mL of distilled water were placed in a 100 mL eggplant flask, heated and stirred for 10 min, and then the same titration was carried out. Based on this result, the hydroxyl value was calculated by the following formula (4). OH value (mg-KOH / g) = {(b - a) × 28.05 × f} / e ···(4) In formula (4), a represents the titration volume (mL) of the sample, b represents the titration volume (mL) of the blank test, e represents the sample mass (g), and f represents the factor of the titrant.

[0174] [Physical property 7] (HDI / IPDI ratio) The mass ratio (HDI / IPDI) of the structural unit derived from HDI to the structural unit derived from IPDI in the polyisocyanate and the polyisocyanate composition was calculated using the following method. First, the molar ratios of HDI and IPDI per unit mass of the polyisocyanate were calculated by pyrolysis GC / MS measurement under the measurement conditions shown below. Next, the mass ratio of the structural units was calculated from the values obtained by multiplying each molar ratio by HDI: 168 and IPDI: 222. (Pyrolysis GC / MS measurement conditions) Pyrolysis device: Frontier Lab PY-2010D Pyrolysis temperature: 600 °C GC: HP-6890 Column: DB-1 0.25×30m 0.25μm Temperature: 50°C (0 min) to 320°C (3 min), heating at 10°C / min MS: JEOL Automass II

[0175] [Physical Property 8] (Qualitative analysis of amine compounds) The amine compounds contained in the polyisocyanate compositions obtained in the examples and comparative examples were qualitatively analyzed from the measurement of mass spectrometry after separation by pyrolysis gas chromatography using the following apparatus and conditions. Pyrolysis apparatus: FRONTIER LAB Py3030D Heating temperature: 600°C Heating atmosphere: He GC / MS apparatus: Agilent6890 / MSD5975C Column: DB-1 Column temperature: 40°C (5 min) → heating at 20°C / min → 300°C (held for 11 min) Column flow rate: 1.0 mL / min Inlet temperature: 320°C Injection method: Split method (split ratio; 1 / 50) Ion source temperature: 230°C Interface temperature: 300°C Ionization method: Electron ionization method Sample amount: 0.3 mg

[0176] [Physical Property 9] (Average number of ethylene oxide (EO) repeating units (EO number)) The average number of ethylene oxide (EO) repeating units (EO number) introduced into the polyisocyanate composition was calculated by the following method. Specifically, using the polyisocyanate composition as a sample, it was determined by proton nuclear magnetic resonance (NMR) under the measurement conditions shown below. Here, by correlating the integral value of the relative intensity corresponding to the alkylene group and the integral value of the relative intensity corresponding to the alkyl group, the average number of ethylene oxide repeating units (EO number) in the polyisocyanate composition was determined.

[0177] (Measurement conditions) NMR apparatus: Bruker Biospin Avance600 (trade name) Observed nucleus: 1H Frequency: 600 MHz Solvent: CDCl3 Number of integrations: 256 times

[0178] [Preparation Example 1: Preparation of Pigment Dispersion] In a SUS cup, 249 parts by mass of deionized water, 700 parts by mass of pigment (R-902, manufactured by Dupont), 49 parts by mass of dispersant (BYK-190, manufactured by BYK Chemie), 2.0 parts by mass of antifoaming agent (Tego Airex 902W, manufactured by Evonik Industries), 400 parts by mass of 1 mm and 0.5 mm beads were added respectively. Stirred with a disper at 3000 rpm for 60 minutes. Then, stirred with a sand mill until the particle size reached 10 μm to obtain a pigment dispersion.

[0179] [Preparation Example 2: Preparation of Resin Dispersion] In a SUS cup, 650 parts by mass of aqueous acrylic polyol (Bayhydrol A2470, manufactured by Covestro), 340 parts by mass of the pigment dispersion prepared in [Preparation Example 1], 2.0 parts by mass of antifoaming agent (BYK-024, manufactured by BYK Chemie), 2.0 parts by mass of wetting agent (BYK-346, manufactured by BYK Chemie), and 3.0 parts by mass of rheology agent (B299, manufactured by Elmentis) were added. Stirred with a disper at 2000 rpm for 30 minutes to obtain a resin dispersion.

[0180] [Preparation Example 3: Preparation of Coating Composition] An organic solvent was added to the polyisocyanate compositions obtained in the examples and comparative examples, and solutions of the polyisocyanate compositions were prepared as shown in Table 1. Next, 100 g of the resin dispersion prepared in Preparation Example 2 above was weighed, and each polyisocyanate solution was added at a ratio such that the ratio (NCO / OH) of the molar amount of isocyanate groups in the polyisocyanate compositions obtained in the examples and comparative examples to the molar amount of hydroxyl groups in this resin dispersion was 1.5, and the mixture was stirred at 600 rpm for 5 minutes. Further, deionized water was added and adjusted so that the viscosity at 25 °C was 25 seconds using a Ford cup (No. 4), and the mixture was stirred at 600 rpm for 5 minutes using a propeller blade to obtain each coating composition. The following evaluations were performed using the prepared coating compositions.

[0181] <Evaluation method> [Evaluation 1: Colority] The colority of the polyisocyanate compositions obtained in the examples and comparative examples was measured as the Hazen color number (APHA) using a colorimeter PFXi-195 manufactured by Lovibond. The colority was evaluated according to the evaluation criteria shown below.

[0182] (Evaluation criteria) ◎: 20 or less ○: 20 or more and 40 or less △: 40 or more and 60 or less ×: 60 or more

[0183] [Evaluation 2: Dispersibility] The coating composition produced in Preparation Example 3 was used to evaluate the dispersibility. (1) The mass of a 100 mL flask and Yoshino paper was measured (W0 g). (2) 20.0 g of the coating composition was taken in a 100 mL flask and filtered through the Yoshino paper weighed in (1). (3) The mass (g) of the filtration residue remaining on the Yoshino paper and the residue remaining in the 100 mL flask was determined (W1 g). (Evaluation criteria) ◎: Less than 0.2 g ○: 0.2 g or more and less than 0.5 g △: 0.5 g or more and less than 1.0 g ×: 1.0 g or more with lumps

[0184] [Evaluation 3: Coating Gloss] On a horizontal table, the water-based two-component coating composition produced in Preparation Example 3 was applied to the pre-treated steel plate with an air spray gun (spray pressure: 0.3 MPa, spray nozzle: 1.8 mm) so that the dry film thickness became 50 ± 5 μm, and then dried in an atmosphere of 23°C and 50% RH for 7 days to obtain a coating film. Thereafter, using a gloss meter (BYK micro-TRI-gloss), the 60-degree gloss value was measured according to GB-T6753.1-2007. The gloss of the coating film was evaluated according to the evaluation criteria shown below.

[0185] (Evaluation Criteria) ◎: 60-degree gloss value is 90% or more ○: 60-degree gloss value is 85% or more and less than 90% △: 60-degree gloss value is 80% or more and less than 85% ×: 60-degree gloss value is less than 80%

[0186] [Evaluation 4: Pencil Hardness] Using the same method as in the above "Evaluation 3", a coating film obtained by curing each polyisocyanate composition was obtained. It was dried in an atmosphere of 23°C / 50% RH for 7 days to obtain a coating film. Thereafter, it was evaluated according to GB-T6379-2006. The pencil hardness of the coating film was evaluated according to the evaluation criteria shown below.

[0187] (Evaluation Criteria) ◎: H or higher ○: F △: HB ×: B or lower, or unable to measure

[0188] [Evaluation 5: Pot Life] Using the polyisocyanate compositions produced in the examples and comparative examples, the pot life was evaluated by the coating viscosity and the coating gloss. The polyisocyanate composition was allowed to stand in an atmosphere of 35°C / 50% RH. Immediately after standing, it was set as 0 hour, and the viscosity and coating gloss after 3 hours were confirmed. The coating viscosity was evaluated using the same method as in the above "Physical Property 1". The coating gloss was evaluated using the same method as in the above "Evaluation 3". When the value of the viscosity ratio is low, it is preferably evaluated that the pot life is long. Specifically, the viscosity ratio is preferably 250% or more and less than 300%, more preferably 200% or more and less than 250%, and particularly preferably less than 200%. Also, when the viscosity ratio is 300% or more, the pot life is short and it is evaluated as defective.

[0189] The higher the 60° gloss retention rate, the longer the pot life and the more preferably it is evaluated. Specifically, the 60° gloss retention rate is preferably 70% or more and less than 80%, more preferably 80% or more and less than 90%, and particularly preferably 90% or more. Also, when the 60° gloss retention rate is less than 70%, the pot life is short and it is evaluated as defective.

[0190] [Evaluation 6: Initial water resistance] Using the same method as in the above "Evaluation 3", a coating film obtained by curing each polyisocyanate composition was obtained. Next, in accordance with GB-T1773-1993, a steel plate with a coating film (hereinafter sometimes referred to as a "coated plate") was immersed in water at 23°C for 24 hours, and the state of the coating film after removing the water remaining on the surface was observed. The water resistance of the coating film was evaluated according to the following evaluation criteria. In addition, "blister" in the following evaluation criteria means water bubbles or swellings generated on the surface of the coating film.

[0191] (Evaluation criteria) ◎: No blistering for 4 days or more ○: No blistering for 2 days or more and less than 4 days △: Swelling and blistering for 1 day or more and less than 2 days ×: Swelling and blistering for less than 1 day

[0192] [Evaluation 7: Scratch resistance] Using the same method as in the above "Evaluation 3", a coating film obtained by curing each polyisocyanate composition was obtained. Next, using an RCA abrasion tester (manufactured by JFE Technoresearch Co., Ltd.), the obtained coating film was continuously rubbed by point contact until the surface was scratched, and the number of rubbing times until a scratch could be confirmed was measured. The scratch resistance of the coating film was evaluated according to the following evaluation criteria. Paper moving speed: approximately 60 mm / s Pressing force: 275 g Pressing condition: discontinuous (1 cycle is 4 seconds (pressing for 2 seconds, releasing pressure for 2 seconds))

[0193] It is evaluated that the more the number of rubbing times, the better the scratch resistance. Specifically, the number of rubbing times is preferably 80 or more and less than 100, more preferably 100 or more and less than 150, and particularly preferably 150 or more. When the number of rubbing times is less than 80, the scratch resistance is evaluated as poor.

[0194] <Synthesis of sulfonic acid amine> [Synthesis Example 1] (Synthesis of HES / TPA) To an aqueous solution of 20 parts by mass of 70% by mass of 2-hydroxyethanesulfonic acid (hereinafter may be abbreviated as "HES"), 10 parts by mass of 1-propanol was added and stirred to obtain a solution. Further, tripropylamine (hereinafter may be abbreviated as "TPA") was weighed in a molar equivalent ratio of 1 to HES, and a solution diluted with the same mass part of 1-propanol was added dropwise to the above solution during stirring. Stirring was stopped 1 hour after the start of dropping, and dehydration and desolvation were performed with an evaporator to obtain a 2-hydroxyethanesulfonic acid tripropylamine salt (hereinafter may be abbreviated as "HES / TPA") with a solid content of 99.8% by mass.

[0195] [Synthesis Example 2] (Synthesis of HES / TBA) To an aqueous solution of 20 parts by mass of 70% by mass of 2-hydroxyethanesulfonic acid (hereinafter may be abbreviated as "HES"), 10 parts by mass of 1-propanol was added and stirred to obtain a solution. Further, tributylamine (hereinafter may be abbreviated as "TBA") was weighed in a molar equivalent ratio of 1 to HES, and a solution diluted with the same mass part of 1-propanol was added dropwise to the above solution during stirring. Stirring was stopped 1 hour after the start of dropping, and dehydration and desolvation were performed with an evaporator to obtain a 2-hydroxyethanesulfonic acid tributylamine salt (hereinafter may be abbreviated as "HES / TBA") with a solid content of 99.8% by mass.

[0196] [Synthesis Example 3] (Production of Polyisocyanate P1) The inside of a 2 L four-necked flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet tube, and dropping funnel was made into a nitrogen atmosphere, 1,000 parts by mass of HDI and 3.1 parts by mass of 2-ethylhexanol were charged, and the temperature inside the reactor was maintained at 70 °C for 2 hours with stirring. Thereafter, tetramethylammonium caprylate, which is an isocyanuration reaction catalyst, was added, and when the yield reached 43% by mass, phosphoric acid was added to stop the reaction. The reaction solution was heated at 100 °C for 1 hour, cooled, filtered, and unreacted HDI was removed using a thin-film evaporator to obtain a polyisocyanate. To 94.6 g of the obtained polyisocyanate, 5.4 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 was added, and the mixture was stirred at 105 °C for 5 hours to carry out the reaction, thereby obtaining a polyisocyanate composition P1. The viscosity of the obtained polyisocyanate P1 at 25 °C was 8,100 mPa·s, and the NCO content was 19.2% by mass.

[0197] [Synthesis Example 4] (Production of Polyisocyanate P2) A polyisocyanate composition P2 was obtained in the same manner as in Synthesis Example 3, except that the addition amount of the polyisocyanate was changed to 88.5 g and the addition amount of HES / TPA was changed to 11.5 g. The viscosity of the obtained polyisocyanate P2 at 25 °C was 17,600 mPa·s, and the NCO content was 17.6% by mass.

[0198] [Synthesis Example 5] (Production of Polyisocyanate P3) A polyisocyanate composition P3 was obtained in the same manner as in Synthesis Example 3, except that the addition amount of the polyisocyanate was changed to 92.7 g and the addition amount of HES / TPA was changed to 7.3 g. The viscosity of the obtained polyisocyanate P3 at 25 °C was 9,200 mPa·s, and the NCO content was 19.0% by mass.

[0199] [Synthesis Example 6] (Production of Polyisocyanate P4) A polyisocyanate composition P4 was obtained in the same manner as in Synthesis Example 3, except that the addition amount of HES / TBA was changed to 7.3 g. The viscosity of the obtained polyisocyanate P4 at 25°C was 9,800 mPa·s, and the NCO content was 19.3% by mass.

[0200] [Synthesis Example 7] (Production of Polyisocyanate P5) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 1,000 parts by mass of HDI was charged, and the temperature inside the reactor was maintained at 70°C for 2 hours with stirring. A solution obtained by diluting tetramethylammonium caprylate to 5% by mass with isobutanol as an isocyanuration catalyst was added in an amount of 1.0 part by mass, and an isocyanuration reaction was carried out. When the yield reached 25% by mass, phosphoric acid was added to stop the reaction. The reaction solution was heated at 100°C for 1 hour, cooled and filtered, and unreacted HDI was removed using a thin-film evaporator to obtain a polyisocyanate. To the obtained 92.7 g of polyisocyanate, 7.3 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 was added, and the mixture was stirred at 105°C for 5 hours to carry out the reaction, obtaining a polyisocyanate composition P5. The viscosity of the obtained polyisocyanate P5 at 25°C was 4,400 mPa·s, and the NCO content was 20.2% by mass.

[0201] [Synthesis Example 8] (Production of Polyisocyanate P6) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 1,000 parts by mass of HDI and 1.5 parts by mass of 2-ethylhexanol were charged, and a urethanization reaction was carried out at 90 °C for 1 hour under stirring. Then, 1.0 part by mass of a solution obtained by diluting tetramethylammonium caprylate to 5% by mass with isobutanol as an allophanatization and isocyanurate formation catalyst was added, and an allophanatization and isocyanurate formation reaction was carried out. When the increase in the refractive index of the reaction solution reached 0.012, phosphoric acid was added to stop the reaction. The reaction solution was heated at 160 °C for 1 hour, cooled and filtered, and then unreacted HDI was removed using a thin-film evaporator to obtain a polyisocyanate. To 90.2 g of the obtained polyisocyanate, 2.5 g of 1,3-butanediol was added, and the mixture was stirred at 90 °C for 1 hour to carry out a reaction. Then, 7.3 g of 2-hydroxyethanesulfonic acid tripropylamine salt (HES / TPA) was added, and the mixture was stirred at 105 °C for 5 hours to carry out a reaction, obtaining a polyisocyanate composition P6. The viscosity of the obtained polyisocyanate P6 at 25 °C was 5,800 mPa·s, and the NCO content was 17.6% by mass.

[0202] [Synthesis Example 9] (Production of Polyisocyanate P7) A polyisocyanate composition P7 was obtained in the same manner as in Synthesis Example 8, except that the addition amount of the polyisocyanate was changed to 88.2 g, the addition amount of 1,3-butanediol was changed to 4.5 g, and the addition amount of HES / TPA was changed to 7.3 g. The viscosity of the obtained polyisocyanate P7 at 25 °C was 18,800 mPa·s, and the NCO content was 15.2% by mass.

[0203] [Synthesis Example 10] (Production of Polyisocyanate P8) A polyisocyanate similar to that in Synthesis Example 3 was produced. To the obtained 92.7 g of polyisocyanate, 4.6 g of 3 - cyclohexylaminopropanesulfonic acid (CAPS) and 2.7 g of N,N - dimethylcyclohexylamine (DMCHA) were added, and the mixture was stirred at 90 °C for 5 hours to conduct a reaction, obtaining a polyisocyanate composition P8. The viscosity of the obtained polyisocyanate P8 at 25 °C was 6,500 mPa·s, and the NCO content was 19.3 mass%.

[0204] [Synthesis Example 11] (Production of Polyisocyanate P9) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 1000 g of 1,5 - pentamethylene diisocyanate (1,5 - PDI) and 1.6 g of isobutanol were added, and the mixture was stirred at 80 °C for 2 hours to conduct a reaction. Next, to the obtained reaction solution, 0.26 g of DABCO - TMR (N - (2 - hydroxypropyl)-N,N,N - trimethylammonium - 2 - ethylhexanoate, manufactured by Air Products) as an isocyanurate formation catalyst was added, and the reaction was carried out at 80 - 86 °C for 2 hours. And it was confirmed by measuring the isocyanate group content that 12% of the isocyanate groups had been converted. Then, 0.30 g of o - toluenesulfonic acid was added to the reaction solution to stop the reaction. The unreacted 1,5 - PDI was removed from the reaction solution using a thin - film evaporator to obtain a polyisocyanate. To the obtained 92.6 g of polyisocyanate, 7.4 g of tripropylamine salt of 2 - hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 was added, and the mixture was stirred at 105 °C for 5 hours to conduct a reaction, obtaining a polyisocyanate composition P9. The viscosity of the obtained polyisocyanate P9 at 25 °C was 33,400 mPa·s, and the NCO content was 19.0 mass%.

[0205] [Synthesis Example 12] (Production of Polyisocyanate P10) A polyisocyanate composition P3 was obtained in the same manner as in Synthesis Example 3, except that the addition amount of the polyisocyanate was changed to 96.6 g and the addition amount of HES / TPA was changed to 3.4 g. The viscosity of the obtained polyisocyanate P3 at 25°C was 3,800 mPa·s, and the NCO content was 20.6% by mass.

[0206] [Synthesis Example 13] (Production of Polyisocyanate P11) A polyisocyanate composition P11 was obtained in the same manner as in Synthesis Example 3, except that the addition amount of the polyisocyanate was changed to 84.6 g and the addition amount of HES / TPA was changed to 15.4 g. The viscosity of the obtained polyisocyanate P11 at 25°C was 28,600 mPa·s, and the NCO content was 15.8% by mass.

[0207] [Synthesis Example 14] (Production of Polyisocyanate D1) A commercially available VESTANAT T-1890 / 100 (isocyanurate derivative of isophorone diisocyanate, manufactured by Evonik) was used as polyisocyanate D1.

[0208] [Synthesis Example 15] (Production of Polyisocyanate D2) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 564 parts by mass of a commercially available VESTANAT T-1890 / 100 (isocyanurate derivative of isophorone diisocyanate, manufactured by Evonik) and 265 parts by mass of PMA were added, and the mixture was stirred at 90°C for 2 hours to obtain a homogeneous solution. Further, 36 parts by mass of polyethylene glycol monomethyl ether (manufactured by Nippon Emulsion Co., Ltd., trade name "MPG-130") having an average number of ethylene oxide repeating units of 9.0 and 0.05 g of 2-ethylhexyl acid phosphate (JP-508T, manufactured by Johoku Chemical Industry Co., Ltd.) were added, and the reaction was carried out by stirring at 105°C for 4 hours. Then, the solvent was removed by distillation at a vacuum degree of 1 kPa to obtain a polyisocyanate composition D2. The viscosity of the obtained polyisocyanate D2 at 25°C was 560,000 mPa·s, and the NCO content was 15.4% by mass.

[0209] [Synthesis Example 16] (Production of Polyisocyanate D3) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 540 parts by mass of commercially available VESTANAT T-1890 / 100 (isocyanurate derivative of isophorone diisocyanate, manufactured by Evonik) and 230 parts of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 60 parts by mass of polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 8.0 (manufactured by Nippon Emulsion Co., Ltd., trade name "SGG-06009") and 0.05 g of 2-ethylhexyl acid phosphate (JP-508T, manufactured by Johoku Chemical Industry Co., Ltd.) were added, and the mixture was stirred at 105 °C for 4 hours to carry out the reaction. Thereafter, distillation was carried out at a vacuum degree of 1 kPa to remove the solvent, and a polyisocyanate composition D3 was obtained. The viscosity of the obtained polyisocyanate D3 at 25 °C was 380,000 mPa·s, and the NCO content was 14.3% by mass.

[0210] [Synthesis Example 17] (Production of Polyisocyanate D4) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 510 parts by mass of commercially available VESTANAT T-1890 / 100 (isocyanurate derivative of isophorone diisocyanate, manufactured by Evonik) and 219 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 90 parts by mass of polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 9.0 (manufactured by Nippon Emulsion Co., Ltd., trade name "MPG-130") and 2-ethylhexyl acid phosphate (JP-508T, manufactured by Johoku Chemical Industry Co., Ltd.): 0.05 g were added, and the mixture was stirred at 105 °C for 4 hours to carry out the reaction. Thereafter, distillation was carried out at a vacuum degree of 1 kPa to remove the solvent, and a polyisocyanate composition D4 was obtained. The viscosity of the obtained polyisocyanate D4 at 25 °C was 210,800 mPa·s, and the NCO content was 13.1% by mass.

[0211] [Synthesis Example 18] (Production of Polyisocyanate D5) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 540 parts by mass of commercially available VESTANAT T-1890 / 100 (isocyanurate derivative of isophorone diisocyanate, manufactured by Evonik) and 230 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, polyethylene glycol monomethyl ether with an average number of ethylene oxide repeating units of 9.0 (manufactured by Nippon Emulsion Co., Ltd., trade name "MPG-130") and sodium dialkyl sulfosuccinate (Newcol 290M, solid content 70%, manufactured by Nippon Emulsion Co., Ltd.) were mixed so that the solid content mass ratio was 3:1: 60 parts by mass of the composition and 0.05 g of 2-ethylhexyl acid phosphate (JP-508T, manufactured by Johoku Chemical Industry Co., Ltd.) were added, and the mixture was stirred at 105 °C for 4 hours to carry out the reaction. Then, distillation was carried out at a vacuum degree of 1 kPa to remove the solvent, and polyisocyanate composition D5 was obtained. The viscosity of the obtained polyisocyanate D5 at 25 °C was 430,600 mPa·s, and the NCO content was 14.6% by mass.

[0212] [Example 1] (Production and Evaluation of Polyisocyanate Composition PA-1) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 245 parts by mass of D1 and 105 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 455 parts by mass of P1 and 195 parts by mass of PGDA (propylene glycol diacetate) were added, and the mixture was stirred at 60 °C for 2 hours to obtain polyisocyanate composition PA-1 as a homogeneous solution. The physical properties and evaluation results of the obtained polyisocyanate composition PA-1 are shown in the following table.

[0213] [Example 2] (Production and Evaluation of Polyisocyanate Composition PA-2) A polyisocyanate composition PA-2 was obtained in the same manner as in Example 1, except that 455 parts by mass of polyisocyanate P2 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PA-2 are shown in the following table.

[0214] [Example 3] (Production and Evaluation of Polyisocyanate Composition PA-3) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 315 parts by mass of D1 and 135 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 385 parts by mass of P3 and 165 parts by mass of PGDA were added, and the mixture was stirred at 60 °C for 2 hours to obtain a polyisocyanate composition PA-3 as a homogeneous solution. The physical properties and evaluation results of the obtained polyisocyanate composition PA-3 are shown in the following table.

[0215] [Example 4] (Production and Evaluation of Polyisocyanate Composition PA-4) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 455 parts by mass of D1 and 150 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 245 parts by mass of P2 and 150 parts by mass of PGDA were added, and the mixture was stirred at 60 °C for 2 hours to obtain a polyisocyanate composition PA-4 as a homogeneous solution. The physical properties and evaluation results of the obtained polyisocyanate composition PA-3 are shown in the following table.

[0216] [Example 5] (Production and Evaluation of Polyisocyanate Composition PA-5) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 270 parts by mass of D1 and 180 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 330 parts by mass of P3 and 220 parts by mass of PGDA were added, and the mixture was stirred at 60 °C for 2 hours to obtain a polyisocyanate composition PA-5 as a homogeneous solution. The physical properties and evaluation results of the obtained polyisocyanate composition PA-5 are shown in the following table.

[0217] [Example 6] (Production and Evaluation of Polyisocyanate Composition PA-6) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 225 parts by mass of D1 and 225 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 275 parts by mass of P4 and 275 parts by mass of PGDA were added, and the mixture was stirred at 60 °C for 2 hours to obtain a polyisocyanate composition PA-6 of a homogeneous solution. The physical properties and evaluation results of the obtained polyisocyanate composition PA-6 are shown in the following table.

[0218] [Example 7] (Production and Evaluation of Polyisocyanate Composition PA-7) A polyisocyanate composition PA-7 was obtained in the same manner as in Example 3, except that 385 parts by mass of polyisocyanate P5 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PA-7 are shown in the following table.

[0219] [Example 8] (Production and Evaluation of Polyisocyanate Composition PA-8) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 350 parts by mass of D1 and 150 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 350 parts by mass of P6 and 150 parts by mass of PGDA were added, and the mixture was stirred at 60 °C for 2 hours to obtain a polyisocyanate composition PA-8 of a homogeneous solution. The physical properties and evaluation results of the obtained polyisocyanate composition PA-8 are shown in the following table.

[0220] [Example 9] (Production and Evaluation of Polyisocyanate Composition PA-9) A polyisocyanate composition PA-9 was obtained in the same manner as in Example 8, except that 350 parts by mass of polyisocyanate P7 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PA-9 are shown in the following table.

[0221] [Example 10] (Production and Evaluation of Polyisocyanate Composition PA-10) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 315 parts by mass of D1 and 135 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 385 parts by mass of P3 and 165 parts by mass of PMA were added, and the mixture was stirred at 60 °C for 2 hours to obtain a polyisocyanate composition PA-10 of a homogeneous solution. The physical properties and evaluation results of the obtained polyisocyanate composition PA-10 are shown in the following table.

[0222] [Example 11] (Production and Evaluation of Polyisocyanate Composition PA-11) A polyisocyanate composition PA-11 was obtained in the same manner as in Example 3, except that 385 parts by mass of polyisocyanate P8 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PA-11 are shown in the following table.

[0223] [Example 12] (Production and Evaluation of Polyisocyanate Composition PA-12) A polyisocyanate composition PA-12 was obtained in the same manner as in Example 3, except that 385 parts by mass of polyisocyanate P9 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PA-12 are shown in the following table.

[0224] [Example 13] (Production and Evaluation of Polyisocyanate Composition PA-13) A polyisocyanate composition PA-13 was obtained in the same manner as in Example 3, except that 315 parts by mass of polyisocyanate D2 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PA-13 are shown in the following table.

[0225] [Example 14] (Production and Evaluation of Polyisocyanate Composition PA-14) A polyisocyanate composition PA-14 was obtained in the same manner as in Example 3, except that 315 parts by mass of polyisocyanate D3 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PA-14 are shown in the following table.

[0226] [Example 15] (Production and Evaluation of Polyisocyanate Composition PA-15) A polyisocyanate composition PA-15 was obtained in the same manner as in Example 3, except that 315 parts by mass of polyisocyanate D4 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PA-15 are shown in the following table.

[0227] [Example 16] (Production and Evaluation of Polyisocyanate Composition PA-16) A polyisocyanate composition PA-16 was obtained in the same manner as in Example 3, except that 315 parts by mass of polyisocyanate D5 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PA-16 are shown in the following table.

[0228] [Comparative Example 1] (Production and Evaluation of Polyisocyanate Composition PB-1) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 210 parts by mass of D1 and 90 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 490 parts by mass of P10 and 210 parts by mass of PGDA were added, and the mixture was stirred at 60 °C for 2 hours to obtain a polyisocyanate composition PB-1 as a homogeneous solution. The physical properties and evaluation results of the obtained polyisocyanate composition PB-1 are shown in the following table.

[0229] [Comparative Example 2] (Production and Evaluation of Polyisocyanate Composition PB-2) The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 245 parts by mass of D1 and 105 parts by mass of PMA were added, and the mixture was stirred at 90 °C for 2 hours to obtain a homogeneous solution. To this homogeneous solution, 455 parts by mass of P10 and 195 parts by mass of PGDA were added, and the mixture was stirred at 60 °C for 2 hours to obtain a polyisocyanate composition PB-2 as a homogeneous solution. The physical properties and evaluation results of the obtained polyisocyanate composition PB-2 are shown in the following table.

[0230] [Comparative Example 3] (Production and Evaluation of Polyisocyanate Composition PB-3) A polyisocyanate composition PB-3 was obtained in the same manner as in Comparative Example 1, except that 490 parts by mass of polyisocyanate P1 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PB-3 are shown in the following table.

[0231] [Comparative Example 4] (Production and Evaluation of Polyisocyanate Composition PB-4) A polyisocyanate composition PB-4 was obtained in the same manner as in Comparative Example 2, except that 455 parts by mass of polyisocyanate P11 was used. The physical properties and evaluation results of the obtained polyisocyanate composition PB-4 are shown in the following table.

[0232] In the following table, the mass fraction of the anionic compound (c) is the mass fraction of the anionic compound (c) with respect to the total mass of the polyisocyanate composition.

[0233] [Table 1]

[0234] [Table 2]

[0235] [Table 3] [Industrial Applicability]

[0236] According to the polyisocyanate composition of the present embodiment, a polyisocyanate composition having a high chromaticity, good dispersibility when blended with a main agent, a long pot life, and excellent gloss, drying property, hardness, initial water resistance, and scratch resistance when formed into a coating film is provided. Further, an aqueous coating composition and a coated substrate using the polyisocyanate composition can be provided.

Claims

1. A polyisocyanate composition comprising a polyisocyanate component (I) and a polyisocyanate component (II), wherein the polyisocyanate component (I) is a derivative derived from an aliphatic diisocyanate (a) and an anionic compound (c), the polyisocyanate component (II) is a derivative derived from an alicyclic diisocyanate (b), the mass ratio [(I) / (II)] of the polyisocyanate component (I) to the polyisocyanate component (II) is 35 / 65 or more and 65 / 35 or less, and the mass fraction of the anionic compound (c) based on the total mass of the polyisocyanate composition is 3.0% by mass or more and 8.0% by mass or less. The polyisocyanate composition.

2. The polyisocyanate composition according to claim 1, wherein the mass ratio [(I) / (II)] is 40 / 60 or more and 60 / 40 or less.

3. The polyisocyanate composition according to claim 1 or 2, wherein the mass fraction of a component having a number average molecular weight of 600 or less based on the total mass of the polyisocyanate composition is 30% by mass or less.

4. The polyisocyanate composition according to claim 1 or 2, wherein the polyisocyanate component (II) is a derivative derived from an alicyclic diisocyanate (b) and an optionally ethylene oxide group-containing polyether alcohol (d).

5. The polyisocyanate composition according to claim 4, wherein the mass fraction of the polyether alcohol (d) with respect to the polyisocyanate component (II) is 15.0% or less.

6. The polyisocyanate composition according to claim 1 or 2, wherein the polyisocyanate component (I) contains a reaction product with an alcohol.

7. The polyisocyanate composition according to claim 6, wherein the mass fraction of the alcohol with respect to the polyisocyanate component (I) is 4.5% by mass or less.

8. The polyisocyanate composition according to claim 7, wherein the alcohol has an average number of 2.0 or more and 3.5 or less hydroxyl groups per molecule and a number average molecular weight of 450 or less.

9. The polyisocyanate composition according to claim 1 or 2, wherein the anionic compound (c) is at least one sulfonic acid selected from the group consisting of a sulfonic acid containing a hydroxyl group and a sulfonic acid containing an amino group.

10. The polyisocyanate composition according to claim 1 or 2, wherein the sulfonic acid group of the anionic compound (c) is neutralized with an inorganic base or an organic amine compound.

11. The polyisocyanate composition according to claim 1 or 2, wherein the anionic compound (c) is a compound represented by the following general formula (1). 【Chemical 1】 (In general formula (1), R １１ is a hydrocarbon group having 1 to 10 carbon atoms which may contain at least one selected from the group consisting of a hydroxyl group, an ether bond, an ester bond, a carbonyl group, and an imino group. R １１ may contain a ring structure. The ring structure is an aromatic ring, a 5-membered or 6-membered ring containing two nitrogen atoms, or a 5-membered or 6-membered ring containing a nitrogen atom and an oxygen atom.)

12. The polyisocyanate composition according to claim 1 or 2, wherein the anionic compound (c) is a compound represented by the following general formula (2). [Chemical 2] (In general formula (2), R ２１ and R ２２ are, independently of each other, a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group. At least one of R ２２ and R ２３ is a hydrogen atom. R ２３ is a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group.)

13. The polyisocyanate composition according to claim 1 or 2, which contains an organic solvent and the content of the organic solvent is 50% by mass or less.

14. The polyisocyanate composition according to claim 13, wherein the organic solvent contains propylene glycol diacetate.

15. A coating composition comprising the polyisocyanate composition according to claim 13.

16. A coated substrate coated with the coating composition according to claim 15.

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