Polyisocyanate composition, coating composition, and coated substrate

Abstract

The invention relates to a polyisocyanate composition, a coating composition and a coated substrate. Provided is a polyisocyanate composition which has high chromaticity, is reduced in cloudiness when stored after being diluted with a hydrophilic solvent, has good dispersibility when compounded with a main agent, and has excellent gloss and alkali resistance when formed into a coating film. The polyisocyanate composition contains a hydrophilic polyisocyanate compound, and the hydrophilic polyisocyanate compound is a reaction product of a polyisocyanate and an anionic compound having a sulfonic acid group. The polyisocyanate is derived from one or more types of diisocyanate selected from the group consisting of aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates, and the hydrophilic polyisocyanate compound contains an isocyanurate trimer (A), the mass ratio of the polyisocyanate compound (B) containing two functional groups derived from an anionic compound having a sulfonic acid group to the isocyanurate tripolymer (A) is 150 / 10000 or less.

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 protecting the global environment, labor safety and hygiene, etc., development of water-based coating agents has been actively carried out in order to reduce the amount of organic solvents used. A two-component type curable resin composition containing a hydroxyl group-containing main agent (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 coatings and adhesives.

[0003] Since it is used in the form of a water-based two-component type curable resin composition using a polyisocyanate as a curing agent, various water-dispersible polyisocyanates modified with an anionic compound to impart hydrophilicity have been reported so far.

[0004] For example, Patent Documents 1 and 2 disclose a curing agent for a water-based two-component type curable resin that imparts compatibility in a water-based main agent by containing a polyisocyanate having a specific anionic structure and a specific viscosity.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent No. 4806511

[0008] Patent Document 2: International Publication No. 2015 / 035673 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] In Patent Documents 1 and 2, the application of water-based coatings is disclosed by using a polyisocyanate composition having an anionic hydrophilic group. However, the polyisocyanate composition having an anionic hydrophilic group is highly dependent on the manufacturing method and is likely to become turbid during normal manufacturing. In addition, the water resistance and alkali resistance of the hydrophilic polyisocyanate are weak, and improvement in performance is required.

[0011] The present invention has been made in view of the above circumstances, and an object thereof is to provide a polyisocyanate composition having high chromaticity, reduced initial turbidity, good dispersibility when blended with a main agent, and excellent gloss and alkali resistance when formed into a coating film.

[0012] Solutions to the Problems

[0013] That is, the present invention includes the following aspects.

[0014] [1] A polyisocyanate composition comprising a hydrophilic polyisocyanate compound, wherein the hydrophilic polyisocyanate compound is a reaction product of a polyisocyanate and an anionic compound having a sulfonic acid group, the polyisocyanate is derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates, the hydrophilic polyisocyanate compound contains an isocyanurate trimer (A), and the mass ratio [(B) / (A)] of the polyisocyanate compound (B) containing two functional groups derived from the anionic compound having a sulfonic acid group to the isocyanurate trimer (A) is 150 / 10000 or less.

[0015] [2] The polyisocyanate composition according to [1], wherein the polyisocyanate contains a reaction product thereof with an alcohol.

[0016] [3] The polyisocyanate composition according to [2], wherein the alcohol has an average number of hydroxyl groups per molecule of 2.0 or more and 3.5 or less, and the number average molecular weight of the alcohol is 450 or less.

[0017] [4] The polyisocyanate composition according to [2] or [3], wherein the mass fraction of the alcohol in the polyisocyanate composition is 4.5% or less.

[0018] [5] The polyisocyanate composition according to any one of [1] to [4], wherein the anionic compound 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.

[0019] [6] The polyisocyanate composition according to any one of [1] to [5], wherein the sulfonic acid group of the anionic compound is neutralized with an inorganic base or an organic amine compound.

[0020] [7] The polyisocyanate composition according to any one of [1] to [6], wherein the anionic compound is a compound represented by the following general formula (1).

[0021] HO—R 11 -SO 3 H (1)

[0022] (In the general formula (1), R 11 is a hydrocarbon group having 1 or more and 10 or less carbon atoms optionally containing 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 optionally contains a ring structure. The ring structure is an aromatic ring, a five-membered or six-membered ring containing two nitrogen atoms, or a five-membered or six-membered ring containing a nitrogen atom and an oxygen atom.)

[0023] [8] The polyisocyanate composition according to any one of [1] to [7], wherein the anionic compound is a compound represented by the following general formula (2).

[0024]

[0025] (In general formula (2), R 21 and R 22 are each independently a hydrogen atom or a hydrocarbon group having 1 or more and 12 or less 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 or more and 12 or less carbon atoms which may contain a hydroxyl group.

[0026] [9] A coating composition comprising the polyisocyanate composition according to any one of [1] to [8].

[0027]

[10] A coated substrate coated with the coating composition according to [9].

[0028] Effects of the Invention

[0029] The polyisocyanate composition according to the above-described manner can provide a polyisocyanate composition having high chromaticity, reduced initial turbidity, excellent dispersibility when blended with a main agent, and excellent gloss and alkali resistance when formed into a coating film. Detailed Embodiments

[0030] Hereinafter, the manner for implementing the present invention (hereinafter referred to as "the present embodiment") will be described in detail.

[0031] It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist thereof.

[0032] <Polyisocyanate Composition>

[0033] The polyisocyanate composition of the present embodiment contains a hydrophilic polyisocyanate compound. The hydrophilic polyisocyanate compound is a reaction product obtained by reacting a polyisocyanate with an anionic compound having a sulfonic acid group.

[0034] The above-mentioned polyisocyanate is derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates. The above-mentioned hydrophilic polyisocyanate compound contains an isocyanurate trimer (A), and the mass ratio [(B) / (A)] of the polyisocyanate compound (B) containing two functional groups derived from an anionic compound having a sulfonic acid group to the above-mentioned isocyanurate trimer (A) is 150 / 10000 or less.

[0035] Hereinafter, the "hydrophilic polyisocyanate compound" may sometimes be referred to as the "hydrophilic compound".

[0036] The polyisocyanate composition of the present embodiment may contain the above-mentioned raw material polyisocyanate that has not reacted with the above-mentioned anionic compound (hereinafter also referred to as the "unreacted raw material polyisocyanate") and the above-mentioned anionic compound that has not reacted with the above-mentioned raw material polyisocyanate (hereinafter also referred to as the "unreacted anionic compound"). In addition, various physical properties or characteristics of the polyisocyanate composition of the present embodiment described below, unless otherwise specified, represent characteristics in a state including the polyisocyanate (hereinafter also referred to as the "modified polyisocyanate") obtained by the reaction of the above-mentioned raw material polyisocyanate with the above-mentioned anionic compound, the unreacted raw material polyisocyanate, and the unreacted anionic compound.

[0037] Hereinafter, each constituent will be described in detail.

[0038] 《Polyisocyanate》

[0039] The polyisocyanate constituting the hydrophilic polyisocyanate compound is derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates. It should be noted that the "polyisocyanate" mentioned here refers to a compound obtained by reacting diisocyanates with each other and, if necessary, compounds other than diisocyanates (such as alcohols, water, amines, etc.).

[0040] Examples of the aliphatic diisocyanate are not limited to the following substances, and include, for example, 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, ethyl (2,6-diisocyanato) hexanoate, 1,6-diisocyanatohexane (hereinafter also denoted as "HDI"), 1,9-diisocyanatononane, 1,12-diisocyanatododecane, 2,2,4-trimethyl-1,6-diisocyanatohexane, or 2,4,4-trimethyl-1,6-diisocyanatohexane.

[0041] As alicyclic diisocyanates, they are not limited to the following substances, and examples thereof include 1,3-bis(isocyanatomethyl)cyclohexane or 1,4-bis(isocyanatomethyl)cyclohexane (hereinafter also referred to as "hydrogenated XDI"), 1,3-diisocyanatocyclohexane or 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl-1-isocyanato-3-(isocyanatomethyl)cyclohexane (hereinafter also referred to as "IPDI"), 4,4'-diisocyanato-dicyclohexylmethane (hereinafter also referred to as "hydrogenated MDI"), 2,5-diisocyanatomethyl norbornane or 2,6-diisocyanatomethyl norbornane, etc.

[0042] Among them, from the viewpoints of weather resistance, chemical resistance, and scratch resistance, aliphatic diisocyanates are preferred, and HDI is particularly preferred.

[0043] As polyisocyanates, there is no particular limitation, and examples thereof include polyisocyanates shown in the following (a) to (h), etc.

[0044] (a) Polyisocyanates having a uretdione group obtained by cyclodimerizing two isocyanate groups;

[0045] (b) Polyisocyanates having an isocyanurate group or an iminooxadiazinedione group obtained by cyclotrimerizing three isocyanate groups;

[0046] (c) Polyisocyanates having a biuret group obtained by reacting three isocyanate groups with one water molecule;

[0047] (d) Polyisocyanates having an oxadiazinetrione group obtained by reacting two isocyanate groups with one molecule of carbon dioxide;

[0048] (e) Polyisocyanates having a plurality of urethane groups obtained by reacting one isocyanate group with one hydroxyl group;

[0049] (f) Polyisocyanates having a urethane group obtained by reacting two isocyanate groups with one hydroxyl group;

[0050] (g) Polyisocyanates having an acylurea group obtained by reacting one isocyanate group with one carboxyl group;

[0051] (h) Polyisocyanates having a urea group obtained by reacting one isocyanate group with one primary amine or secondary amine.

[0052] Among them, the polyisocyanates used in hydrophilic polyisocyanate compounds are preferably the above (b), and more preferably polyisocyanates having an isocyanurate group.

[0053] (Isocyanurate group)

[0054] The isocyanurate group is a functional group obtained by cyclic trimerization of three isocyanate groups, and refers to a structure represented by the following formula (3).

[0055]

[0056] Under the state after removing unreacted diisocyanate, relative to the total mole number (100 mol %) of isocyanurate group, allophanate group, iminooxadiazinedione group and uretdione group, the content of isocyanurate group is preferably more than 30 mol % and less than 100 mol %. The lower limit is more preferably 40 mol %, and more preferably 50 mol %. In addition, the upper limit is more preferably 95 mol %, and more preferably 90 mol %. By making the content of isocyanurate group be the above range, there is a tendency for the chemical resistance and weather resistance of the obtained coating film to be excellent.

[0057] The content of each structure derived from the isocyanate group can be 13 Specifically, the chromatographic data were obtained by using Biospin Avance 600 (trade name) manufactured by Bruker Corporation. 13 In C-NMR measurement (measurement solvent: chloroform-d, sample concentration: 60 mass / volume %, observation frequency: 150 MHz, accumulation number: 10,000 times), when the aliphatic diisocyanate is HDI, the signal of the carbon atom of the carbonyl group in the six-membered ring of the isocyanurate ring structure is confirmed at around 148.6 ppm. Since there are three identical carbon atoms in the structure, the value of 1 / 3 of the integral value corresponds to the molar fraction of the structure.

[0058] (Allophanate group)

[0059] The allophanate group is a functional group formed by the reaction of a hydroxyl group and an isocyanate group, and refers to a structure represented by the following formula (4).

[0060]

[0061] 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, relative to the total molar number (100 mol %) of the isocyanurate group, the allophanate group, the imidooxadiazinedione group and the uretdione group.

[0062] When the molar ratio of the allophanate group is within the above range, the abrasion resistance of the coating composition tends to be excellent.

[0063] The molar ratio of allophanate groups can be determined by, for example 13 It can be determined by C-NMR measurement.

[0064] (Iminooxadiazinedione group)

[0065] The iminooxadiazinedione group is a functional group obtained by cyclic trimerization of three isocyanate groups, and refers to the structure represented by the following formula (5).

[0066]

[0067] In the polyisocyanate composition of the present embodiment, relative to the total molar amount (100 mol%) of the isocyanurate group, urethane group, iminooxadiazinedione group, and uretdione group, 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. By making the molar ratio of the iminooxadiazinedione group within the above range, the viscosity is lowered and the dispersibility in preparing a coating composition is excellent. The molar ratio of the iminooxadiazinedione group can be determined by 13 13C-NMR measurement.

[0068] (Uretdione group)

[0069] The uretdione group is a functional group obtained by cyclodimerization of 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 abrasion resistance.

[0070]

[0071] In the polyisocyanate composition of the present embodiment, relative to the total molar amount (100 mol%) of the isocyanurate group, iminooxadiazinedione group, urethane group, and uretdione group, 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. By making the molar ratio of the uretdione group within the above range, the gloss and alkali resistance of the coating film in preparing a coating composition are excellent.

[0072] The molar ratio of the uretdione group can be determined by, for example, 13 13C-NMR measurement or 1 1H-NMR measurement.

[0073] Furthermore, from the viewpoint of reducing the viscosity change during compounding, the mass fraction of the uretdione dimer obtained by cyclic dimerization of two diisocyanates is preferably 0.01 mass% or more and 20.0 mass% or less.

[0074] From the viewpoint 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 further preferably 15.0% by mass or less. In addition, from the viewpoint of reducing the viscosity, it is more preferably 0.1% by mass or more, and further preferably 0.5% by mass or more. The mass fraction of the uretdione dimer can be determined by GPC.

[0075] (Other bonding groups)

[0076] In the polyisocyanate composition of the present embodiment, in addition to having the above-mentioned bonding group, it 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.

[0077] In the polyisocyanate composition of the present embodiment, relative to the total molar number (100 mol%) of the isocyanurate group, the iminooxadiazinedione group, the urethane group, and the uretdione group, the total molar ratio of the other bonding groups is preferably 0.01 mol% or more and 10 mol% or less.

[0078] The molar ratio of the other bonding groups can be determined by, for example, 13 C-NMR measurement or 1 H-NMR measurement.

[0079] The polyisocyanate may optionally contain an aliphatic triisocyanate. Examples of the aliphatic triisocyanate include 1,3,6-triisocyanatohexane, 1,8-diisocyanato-4-isocyanatomethyloctane, 2-isocyanatoethyl 2,6-diisocyanatohexanoate, and the like.

[0080] 《Anionic compound》

[0081] The anionic compound is preferably one or more sulfonic acids selected from the group consisting of sulfonic acids containing a hydroxyl group and sulfonic acids containing an amino group.

[0082] In the hydrophilic polyisocyanate compound contained in the polyisocyanate composition of the present embodiment, an anionic group derived from an anionic compound is introduced into a part of the isocyanate groups.

[0083] When the anionic compound is a sulfonic acid having a hydroxyl group, examples thereof include a compound represented by the following general formula (1) (hereinafter abbreviated as "sulfonic acid (1)") and the like.

[0084] That is, in one aspect of the present invention, the anionic compound is a compound represented by the following general formula (1).

[0085] HO-R 11 -SO 3 H (l)

[0086] In the above general formula (1), R 11 is an optionally included hydrocarbon group having 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 and having 1 or more and 10 or less carbon atoms. R 11 optionally includes a ring structure. The aforementioned ring structure is an aromatic ring, a five-membered or six-membered ring containing two nitrogen atoms, or a five-membered or six-membered ring containing a nitrogen atom and an oxygen atom.

[0087] As the hydrocarbon group having 1 or more and 10 or less carbon atoms, it may be a divalent aliphatic hydrocarbon group having 1 or more and 10 or less carbon atoms, or a divalent aromatic hydrocarbon group having 6 or more and 10 or less carbon atoms. As the divalent aliphatic hydrocarbon group having 1 or more and 10 or less carbon atoms, a linear alkylene group having 1 or more and 6 or less carbon atoms is preferred. In the case of a linear alkylene group having 1 or more and 6 or less carbon atoms, it may be a group in which a part of the linear alkylene group includes a ring structure. The alkylene group having 1 or more and 6 or less carbon atoms may be linear or branched.

[0088] Among them, as R 11 , a linear alkylene group having 1 or more and 6 or less carbon atoms, a divalent aromatic hydrocarbon group (arylene group) having 6 or more and 10 or less carbon atoms, a divalent alkylene group having 1 or more and 6 or less carbon atoms containing an aromatic ring, a divalent alkylene group having 1 or more and 6 or less carbon atoms containing a five-membered or six-membered ring containing two nitrogen atoms, or a divalent alkylene group having 1 or more and 6 or less carbon atoms containing a five-membered or six-membered ring containing a nitrogen atom and an oxygen atom is preferred.

[0089] As preferred examples of the anionic compound having a hydroxyalkylsulfonic acid group, 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, etc. can be cited.

[0090] It should be noted that these compounds are only a part of the preferred sulfonic acid (1), and the preferred sulfonic acid (1) is not limited to them.

[0091] In addition, these sulfonic acids (1) can be used alone or in combination of two or more.

[0092] Among them, as the anionic compound having a hydroxyl group, at least one selected from the group consisting of 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, hydroxybenzenesulfonic acid, and hydroxy(methyl)benzenesulfonic acid is preferred. The coating films of these anionic compounds having a hydroxyalkylsulfonic acid have good gloss.

[0093] It should be noted that when the polyisocyanate composition of the present embodiment contains two or more amine salts of sulfonic acids, the sulfonic acids (1) may be the same or different from each other.

[0094] In addition, the sulfonic acid used in the polyisocyanate containing a sulfonic acid anion group in the molecule may optionally form a salt with the amine compound described later.

[0095] When the anionic compound is a sulfonic acid having an amino group, examples thereof include compounds represented by the following general formula (2) (hereinafter abbreviated as "sulfonic acid (2)") and the like.

[0096] That is, in one aspect of the present invention, the anionic compound is a compound represented by the following general formula (2).

[0097]

[0098] In the aforementioned general formula (2), R 21 and R 23 are each independently a hydrogen atom or a hydrocarbon group having 1 or more and 12 or less carbon atoms which may optionally 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 or more and 12 or less carbon atoms which may optionally contain a hydroxyl group.

[0099] ·R 21 and R 23

[0100] In the general formula (2), R 21 and R 23 are each independently a hydrogen atom or a hydrocarbon group having 1 or more and 12 or less carbon atoms which may optionally contain a hydroxyl group. R 21 and R 23 may be the same 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 or more and 12 or less carbon atoms which may optionally contain a hydroxyl group, R 23 is a hydrogen atom. In addition, when R 23 is a hydrocarbon group having 1 or more and 12 or less carbon atoms which may optionally contain a hydroxyl group, R 21 is a hydrogen atom. In addition, R 21 and R 23 may both be hydrogen atoms.

[0101] As the hydrocarbon group having 1 or more and 12 or less carbon atoms, it may be a monovalent aliphatic hydrocarbon group having 1 or more and 12 or less carbon atoms, or a monovalent aromatic hydrocarbon group having 6 or more and 12 or less carbon atoms. As the monovalent aliphatic hydrocarbon group having 1 or more and 12 or less carbon atoms, a linear alkyl group having 1 or more and 6 or less carbon atoms or a cyclic alkyl group having 3 or more and 6 or less carbon atoms is preferred. The linear alkyl group having 1 or more and 6 or less carbon atoms may be linear or branched.

[0102] Among them, as R 21 and R 23 , they are each preferably a hydrogen atom, a linear alkyl group having 1 or more and 6 or less carbon atoms, or a cyclic alkyl group having 3 or more and 6 or less carbon atoms.

[0103] ·R 22

[0104] R 22 is an optionally hydroxy group-containing hydrocarbon group having 1 or more and 12 or less carbon atoms.

[0105] As the hydrocarbon group having 1 or more and 12 or less carbon atoms, it may be a divalent aliphatic hydrocarbon group having 1 or more and 12 or less carbon atoms, or a divalent aromatic hydrocarbon group having 6 or more and 12 or less carbon atoms. As the divalent aliphatic hydrocarbon group having 1 or more and 12 or less carbon atoms, a linear alkylene group having 1 or more and 12 or less carbon atoms is preferred. The linear alkylene group having 1 or more and 12 or less carbon atoms may be linear or branched.

[0106] Among them, as R 22 , it is preferably a divalent linear alkylene group having 1 or more and 6 or less carbon atoms or a divalent aromatic hydrocarbon group (arylene group) having 6 or more and 10 or less carbon atoms.

[0107] As preferred examples of the sulfonic acid (2), there may be mentioned, for example, 2-aminoethanesulfonic acid, 3-aminopropanesulfonic acid, 2-methylaminoethanesulfonic acid, 3-methylaminopropanesulfonic acid, 2-cyclohexylaminoethanesulfonic acid, 3-cyclohexylaminopropanesulfonic acid, 3-cyclohexylaminoisobutanesulfonic acid, 4-cyclohexylaminobutanesulfonic acid, 2-cyclohexylmethylaminoethanesulfonic acid, 3-cyclohexylmethylaminopropanesulfonic acid, 3-cyclohexylmethylaminoisobutanesulfonic acid, 4-cyclohexylmethylaminobutanesulfonic acid, 2-methylcyclohexylaminoethanesulfonic acid, 3-methylcyclohexylaminopropanesulfonic acid, 3-methylcyclohexylaminoisobutanesulfonic acid, 4-methylcyclohexylaminobutanesulfonic acid, 2-dimethylcyclohexylaminoethanesulfonic acid, 3-dimethylcyclohexylaminopropanesulfonic acid, 3-dimethylcyclohexylaminoisobutanesulfonic acid, 4-dimethylcyclohexylaminobutanesulfonic acid, 2-trimethylcyclohexylaminoethanesulfonic acid, 3-trimethylcyclohexylaminopropanesulfonic acid, 3-trimethylcyclohexylaminoisobutanesulfonic 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.

[0108] It should be noted that these compounds are merely a part of the preferred sulfonic acid (2), and the preferred sulfonic acid (2) is not limited to them.

[0109] In addition, these sulfonic acids (2) may be used singly or in combination of two or more.

[0110] Among them, as the sulfonic acid having an amino group, it is preferably 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.

[0111] In one aspect of the present invention, the sulfonic acid group of the anionic compound is preferably neutralized with an inorganic base or an organic amine compound.

[0112] As the inorganic base, there may be mentioned, for example, 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.

[0113] Examples of the organic amine compounds include straight-chain tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tritridecylamine, and tristearylamine; branched tertiary amines such as triisopropylamine, triisobutylamine, tris(2-ethylhexyl)amine, and tris(branched tridecyl)amine; tertiary amines with mixed hydrocarbon groups 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, and 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, and tricyclohexylamine; tertiary amines with aromatic ring substituents such as N,N-dimethylbenzylamine, N,N-diethylbenzylamine, N,N-dibenzylmethylamine, tribenzylamine, N,N-dimethyl-4-methylbenzylamine, N,N-dimethylphenylamine, N,N-diethylphenylamine, and 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, and quinuclidine. These organic amine compounds can be used alone or in combination of two or more.

[0114] Among them, tertiary amines having 5 or more and 30 or less carbon atoms are preferred. Specifically, for example, triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tridecylamine, triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, tri(branched tridecyl)amine, 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, etc. These preferred organic amine compounds may be used alone or in combination of two or more.

[0115] It should be noted that in the case where the polyisocyanate composition of the present embodiment contains two or more amine salts of sulfonic acids, the sulfonic acids (2) may be the same or different from each other.

[0116] Anionic compounds containing active hydrogen groups such as hydroxyl groups and amino groups have high emulsifying power, and thus high emulsifying effects can be obtained with a small amount.

[0117] If the polyisocyanate is modified with an anionic compound (a hydrophilic group derived from a hydrophilic compound is introduced into the polyisocyanate) to disperse it in water, a small amount of the anionic compound can be used, so the modification ratio will not be too high, and the film physical properties (gloss and alkali resistance) are not easily reduced.

[0118] In the polyisocyanate composition of the present embodiment, the mass fraction of the anionic compound bonded to the hydrophilic polyisocyanate compound is preferably 0.1% by mass or more and 13.0% by mass or less with respect to the total mass (100% by mass) of the polyisocyanate composition. Further, from the viewpoints of balancing dispersibility, water resistance, and weather resistance, it is preferably 0.1% by mass or more and 9.0% by mass or less, and more preferably 0.5% by mass or more and 6.0% by mass or less.

[0119] (Alcohol component)

[0120] The polyisocyanate may contain a reaction product with an alcohol.

[0121] The alcohol is a derivative component of the polyisocyanate composition.

[0122] Preferably, the aforementioned alcohol 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, chemical resistance, and dispersibility with the main agent of the polyisocyanate, the average number of hydroxyl groups of the aforementioned alcohol is preferably 2.0 or more and 3.0 or less, more preferably 2.0 or more and 2.5 or less. In addition, from the viewpoint of the dispersibility with the main agent, the number average molecular weight is preferably 400 or less, more preferably 350 or less.

[0123] Examples of the alcohol that satisfies the average number of hydroxyl groups and the number average molecular weight include diols, triols, tetraols, and polymeric alcohols. Examples of diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2 - propylene glycol, 1,3 - propylene glycol, 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 glycerol, trimethylolpropane, etc. Examples of tetraols include pentaerythritol, etc.

[0124] Examples of polymeric alcohols include polyester polyols, polyether polyols, acrylic polyols, polyolefin polyols, polycarbonate diols, etc.

[0125] Examples of polyester polyols include those obtained by the condensation reaction of a single substance or a mixture of dibasic acids 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. and a single substance or a mixture of polyols selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, glycerol, etc.; and polycaprolactones obtained by ring - opening polymerization of ε - caprolactone using a polyol, etc.

[0126] As polyether polyols, there may be mentioned, for example, polyether polyols obtained by randomly adding or block-adding, alone or as a mixture, alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide to a polyhydroxy compound, alone or as a mixture, using strong basic catalysts such as hydroxides, alkoxides, and alkylamines of lithium, sodium, potassium, etc., metal porphyrins, and complex metal cyanide complexes such as zinc hexacyanocobaltate complex; further, polyether polyols obtained by reacting polyamine compounds such as ethylenediamine with alkylene oxides; and so-called polymer polyols obtained by polymerizing acrylamide or the like using these polyethers as a medium.

[0127] As the polycarbonate diol, it has a structural unit obtained by dehydrating and condensing two alcohol groups and one carbonate group. Further, examples of the polycarbonate diol include those obtained by copolymerizing a first diol having 2 to 20 carbon atoms and a second diol having 2 to 20 carbon atoms (hereinafter also simply referred to as "two kinds of diols") with a carbonate compound.

[0128] These alcohols may be used alone or in combination of multiple kinds.

[0129] The mass fraction of the alcohol in the polyisocyanate composition of the present embodiment is preferably 4.5% by mass or less. Further, it is more preferably 0.01% by mass or more and 4.5% by mass or less. Further, from the viewpoints of chromaticity and dispersibility, it is further preferably 0.1% by mass or more and 2.5% by mass or less.

[0130] Method for Producing Polyisocyanate Component Having Each Bonding Group

[0131] (Method for Producing Polyisocyanate Component Containing Isocyanurate Group)

[0132] The catalyst for deriving a polyisocyanate component containing an isocyanurate group from a diisocyanate component is not particularly limited, and a basic catalyst is preferred. Specifically, there may be mentioned hydroxides and organic weak acid salts of tetraalkylammonium, hydroxides and organic weak acid salts of hydroxyalkylammonium, alkali metal salts of alkyl carboxylic acids, metal alkoxides, compounds containing silyl groups, Mannich bases, combined use of tertiary amines and epoxides, phosphorus compounds, etc.

[0133] Examples of the tetraalkylammonium include tetramethylammonium and tetraethylammonium.

[0134] Examples of the organic weak acid include acetic acid and capric acid.

[0135] Examples of the hydroxyalkylammonium include trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, triethylhydroxyethylammonium, etc.

[0136] Examples of the alkyl carboxylic acid include acetic acid, caproic acid, caprylic acid, myristic acid, etc.

[0137] Examples of the alkali metal salts include tin, zinc, lead, etc.

[0138] Examples of the metal alkoxides include sodium alkoxide, potassium alkoxide, etc.

[0139] Examples of the compounds containing a silylamino group include hexamethyldisilazane, etc.

[0140] Examples of the phosphorus compounds include tributylphosphine, etc.

[0141] The 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 the alcohol as required) as the raw material. In addition, in order to terminate the isocyanuration reaction, the catalyst can be deactivated by adding an acidic substance that neutralizes the catalyst, thermal decomposition, chemical decomposition, etc. Examples of the acidic substance that neutralizes the catalyst include phosphoric acid, acid phosphate, etc.

[0142] The yield of the polyisocyanate component generally tends to be 10 mass% or more and 70 mass% or less. The polyisocyanate component obtained in a higher yield tends to have a higher viscosity. The yield can be calculated based on the ratio of the mass of the obtained polyisocyanate component to the total mass of the raw material components.

[0143] The reaction temperature of the isocyanuration reaction is not particularly limited, and is preferably 50°C or higher and 200°C or lower, more preferably 50°C or higher and 150°C or lower. By setting the reaction temperature to be not lower than the above lower limit value, the reaction tends to proceed more easily, and by setting the reaction temperature to be not higher than the above upper limit value, side reactions such as coloring can be further suppressed.

[0144] After the isocyanuration reaction is completed, it is preferable to remove the unreacted diisocyanate by a thin-film evaporation tank, extraction, etc. Even when the polyisocyanate component contains unreacted diisocyanate, the content of the diisocyanate is preferably 3.0 mass% or less, more preferably 1.0 mass% or less, and further preferably 0.5 mass% or less with respect to the total mass of the polyisocyanate component. By setting the concentration of the remaining unreacted diisocyanate within the above range, the curability tends to be more excellent.

[0145] The concentration of the remaining unreacted diisocyanate is preferably 0 mass%.

[0146] That is, the concentration of the remaining 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 still more preferably 0% by mass or more and 0.5% by mass or less.

[0147] (Method for producing a polyisocyanate component containing a urethane group)

[0148] The catalyst for deriving a polyisocyanate component containing a urethane group from a diisocyanate is not particularly limited, and examples thereof include alkyl carboxylates such as tin, lead, zinc, bismuth, zirconium, and zirconium oxide groups; 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 zirconium oxide 2-ethylhexanoate salt. They can be used alone or in combination of two or more.

[0149] In addition, the above-mentioned isocyanuration reaction catalyst can also be a urethanation reaction catalyst. When the above-mentioned isocyanuration reaction catalyst is used for the urethanation reaction, a polyisocyanate component containing an isocyanurate group will of course be generated. As the urethanation reaction catalyst, from the aspect of economic production, it is preferable to use the above-mentioned isocyanuration reaction catalyst for the urethanation reaction and the isocyanurate reaction.

[0150] The compounding amount of the above-mentioned urethanation reaction catalyst relative to the mass of the charged diisocyanate is preferably 10 mass ppm or more and 1000 mass ppm or less. The lower limit value is more preferably 20 mass ppm, further preferably 40 mass ppm, and still more preferably 80 mass ppm. The upper limit value is more preferably 800 mass ppm, further preferably 600 mass ppm, and still more preferably 500 mass ppm or less.

[0151] The compounding amount of the above-mentioned urethanation reaction catalyst relative to the mass of the charged diisocyanate 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.

[0152] In addition, as the urethanation reaction temperature, it is preferably 40°C or more and 180°C or less. The lower limit value is more preferably 60°C, further preferably 80°C, and still more preferably 100°C. The upper limit value is more preferably 160°C, further preferably 140°C.

[0153] By setting the temperature of the urethanization reaction to be above the lower limit value described above, there is a tendency to maintain a higher reaction rate. By setting the temperature of the urethanization reaction to be below the upper limit value described above, there is a tendency to more effectively suppress the coloring of the polyisocyanate component and the like.

[0154] The temperature of the urethanization reaction is, for example, 80°C or higher and 160°C or lower, or 100°C or higher and 140°C or lower.

[0155] The alcohol used to form the urethane group is preferably an alcohol composed only of carbon, hydrogen, and oxygen.

[0156] Specifically, the aforementioned alcohol is not limited to the following alcohols, and examples include monohydric alcohols, polyhydric alcohols, and mixtures of these alcohols.

[0157] Specific examples of the monohydric alcohol include 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. The monohydric alcohol can be used alone or in combination of two or more.

[0158] Specific examples of the polyhydric alcohol include diols such as ethylene glycol, 1,3-butanediol, neopentyl glycol, and 2-ethylhexanediol.

[0159] In addition, the alcohol described in the embodiment can be used as a raw material to derive a polyisocyanate component having a urethane group.

[0160] "Method for Manufacturing Polyisocyanate Composition"

[0161] Examples of the method for manufacturing the polyisocyanate composition of this embodiment include the following (1) to (3).

[0162] (1) A method of performing the reaction of a diisocyanate and an anionic compound in one step.

[0163] (2) A method of manufacturing a polyisocyanate compound (I) derived from a diisocyanate component and performing the reaction thereof with an anionic compound.

[0164] (3) A method for manufacturing a polyisocyanate compound (I) derived from a diisocyanate component, and mixing a component (II) derived from the reaction thereof with an anionic compound and a polyisocyanate (III) derived from a diisocyanate in a desired mass ratio.

[0165] Among the above manufacturing methods, (2) is more preferred from the perspective of manufacturing simplicity.

[0166] In this reaction step, the reaction temperature and reaction time are appropriately determined according to the progress of the reaction. The reaction temperature is preferably 90 °C or higher and 130 °C or lower, more preferably 100 °C or higher and 125 °C or lower. The reaction time is preferably 0.5 hours or longer and 24.0 hours or shorter, more preferably 1.0 hours or longer and 12.0 hours or shorter.

[0167] In addition, in the reaction step, a known catalyst can be used as appropriate. Specific examples of the catalyst include organotin compounds such as tin octoate, tin 2-ethylhexanoate, tin ethylhexanoate, tin laurate, tin palmitate, dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin dilaurate, dioctyltin diacetate, dioctyltin dilaurate; organozinc compounds such as zinc chloride, zinc octoate, zinc 2-ethylhexanoate, zinc 2-ethylhexanoate, zinc stearate, zinc naphthenate, zinc acetylacetonate; organotitanium compounds; organozirconium compounds; tertiary amines such as triethylamine, tributylamine, N,N-diisopropylethylamine, N,N-dimethylethanolamine; diamines such as triethylenediamine, tetramethylethylenediamine, 1,4-diazabicyclo[2.2.2]octane. They can be used alone or in combination.

[0168] In the method for manufacturing the polyisocyanate composition of the present embodiment, a solvent may or may not be used. The solvent used in the method for manufacturing the polyisocyanate composition of the present embodiment may be a hydrophilic solvent or a hydrophobic solvent.

[0169] Examples of the hydrophobic solvent include, for example, mineral spirits, solvent naphtha, LAWS (Low Aromatic White Spirit), HAWS (High Aromatic White Spirit), toluene, xylene, cyclohexane, etc.; esters such as ethyl acetate, butyl acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone.

[0170] Examples of the hydrophilic solvent include alcohols such as methanol, ethanol, propanol, isopropanol, and 2-ethylhexanol; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether; and 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, and dipropylene glycol monomethyl ether acetate. They may be used alone or in combination.

[0171] (Polyisocyanate component)

[0172] As a precursor of the hydrophilic polyisocyanate compound, a polyisocyanate component (I) derived from a diisocyanate can be used. The polyisocyanate component (I) can be obtained as follows: By using the same method as the manufacturing method of the above polyisocyanate component having each bonding group, it is allowed to react together in the presence of an excess of diisocyanate, and after the reaction is completed, the unreacted diisocyanate is removed. At this time, while generating the desired bonding groups generated under each condition, other bonding groups may sometimes be generated.

[0173] (Physical properties of polyisocyanate component (I))

[0174] From the viewpoints of improving the dispersibility and pot life of the coating composition and improving the appearance and water resistance of the formed coating film, the viscosity of the polyisocyanate component (I) at 25 °C is preferably 300 mPa·s or more and 100,000 mPa·s or less.

[0175] From the viewpoints of improving the curability and chemical resistance of the cured coating film, etc., the lower limit value of the viscosity is more preferably 350 mPa·s, and further preferably 450 mPa·s. On the other hand, from the viewpoints of improving the dispersibility and solvent dilutability, the upper limit of the viscosity is more preferably 9,000 mPa·s, and further preferably 8,000 mPa·s.

[0176] The viscosity can be measured at 25 °C using, for example, a standard rotor (1°34’×R24) and an E-type viscometer (manufactured by TOKIMEC).

[0177] In the state after removing the unreacted diisocyanate component, the isocyanate group content (NCO%) of the polyisocyanate component (I) is preferably 12% by mass or more and 25% by mass or less, more preferably 14% by mass or more and 24% by mass or less, and further preferably 16% by mass or more and 24% by mass or less.

[0178] By making the isocyanate group content be not less than the above lower limit value, the water resistance, chemical resistance, and weather resistance of the coating film are further improved. On the other hand, by making it be not more than 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.

[0179] The isocyanate group content (NCO%) can be measured by the titration method described in the following examples.

[0180] 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 still more preferably 550 or more and 1,500 or less.

[0181] The number average molecular weight can be measured using, for example, GPC.

[0182] From the viewpoints of the solvent resistance of the coating film and the isocyanate group retention rate, the average functional group number 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.

[0183] The average functional group number is the number of isocyanate functional groups statistically possessed in one molecule of the polyisocyanate compound, and can be calculated using the following formula based on the number average molecular weight (Mn) and the isocyanate group content (NCO%) of the polyisocyanate compound.

[0184] [Average functional group number] = Mn × NCO% / 4200

[0185] "Method for Manufacturing Anionic Compound"

[0186] The neutralization salt of the acidic group of the anionic compound used in the polyisocyanate composition of the present embodiment is obtained by, for example, performing a neutralization reaction using a cationic compound listed in inorganic bases and organic amine compounds. Further, in the case where the neutralization salt is an amine salt of sulfonic acid, it is obtained by, for example, mixing a compound containing a sulfonic acid group and an amine compound and performing a neutralization reaction.

[0187] This neutralization reaction can be carried out in advance before reacting with the diisocyanate component or the polyisocyanate component, or can be carried out simultaneously. Alternatively, an amine compound can be added after reacting the polyisocyanate compound with the compound containing a sulfonic acid group to carry out the reaction.

[0188] In the case where the active hydrogen group is a hydroxyl group, the neutralization reaction is preferably carried out in advance before reacting with the polyisocyanate compound. In addition, in the case where the active hydrogen group is an amino group, the neutralization reaction is preferably carried out simultaneously when reacting with the polyisocyanate compound, or is carried out by adding an amine compound after reacting the polyisocyanate compound with a sulfonic acid having an active hydrogen group.

[0189] In addition, in the case where the active hydrogen group is a hydroxyl group, in this neutralization reaction, regarding the mixing ratio of the sulfonic acid having a hydroxyl group and the amine compound, the molar ratio of the amine compound to the sulfonic acid having a hydroxyl group (amine compound / sulfonic acid having a hydroxyl group molar ratio) is preferably 0.5 or more and 2.0 or less, more preferably 0.8 or more and 1.5 or less.

[0190] In the case where this neutralization reaction is carried out in advance, the temperature and time are appropriately determined according to the progress of the reaction. The temperature is usually 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.

[0191] The solvent used for preparing the amine salt of the above-mentioned compound containing a sulfonic acid group is preferably water or a hydrophilic solvent. As the hydrophilic solvent, there is no particular limitation, and examples thereof include alcohols, ether alcohols, ketones, amide solvents, etc. These solvents can be used alone or in combination.

[0192] Examples of the alcohols include methanol, ethanol, propanol, butanol, isopropyl alcohol, etc.

[0193] 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, etc.

[0194] Examples of the ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.

[0195] Examples of the amide solvents include N,N-dimethylformamide, N,N-dimethylacetamide, etc.

[0196] After the neutralization reaction, it is preferable to remove water or the hydrophilic solvent.

[0197] The hydrophilic polyisocyanate compound contains an isocyanurate trimer (A). The isocyanurate trimer (A) refers to a cyclic trimer formed by 3 diisocyanates and does not contain other compounds in its structure.

[0198] In the polyisocyanate composition of this embodiment, a polyisocyanate compound (B) is included. The polyisocyanate compound (B) contains two functional groups derived from an anionic compound having a sulfonic acid group. The mass ratio of the polyisocyanate compound (B) to the isocyanurate trimer (A) is 150 / 10,000 or less, preferably 100 / 10,000 or less, and more preferably 50 / 10,000 or less. By making the mass ratio of the polyisocyanate compound (B) within the above range, cloudiness is not likely to occur initially. There is no particular limitation on the lower limit, and it is preferably 1 / 10,000 or more.

[0199] In addition, the polyisocyanate compound (B) includes: a compound formed by the trimerization of two molecules of an anionic compound having a sulfonic acid group with each other, or a compound formed by two molecules of an anionic compound with a trimer and a pentamer, or a compound formed by two molecules of a compound having a sulfonic acid group with a trimer and other polymers, etc.

[0200] The above mass ratio is calculated as follows: According to the results obtained by measuring LC-MS and UV-MS using "UPLC" of WATERS company, the mass ratio of the polyisocyanate compound (B) to the isocyanurate trimer (A) is calculated from the area of each peak.

[0201] 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 in one molecule of the polyisocyanate composition, and can be calculated using the following formula based on the number average molecular weight (Mn) and the isocyanate group concentration (NCO group concentration) of the polyisocyanate compound.

[0202] [Average number of functional groups] = Mn × NCO% / 4,200

[0203] The isocyanate group concentration (NCO group concentration) of the aforementioned polyisocyanate composition is preferably 10.0% by mass or more and 24.0% by mass or less. In addition, from the viewpoints of balancing curability, hardness of the coating film, chemical resistance, and abrasion resistance, it is more preferably 12.0% by mass or more and 23.0% by mass or less, and further preferably 13.0% by mass or more and 22.0% by mass or less. The isocyanate group concentration (NCO group concentration) can be measured by the titration method described in the examples below.

[0204] The number average molecular weight of the aforementioned polyisocyanate composition is preferably 400 or more and 3,000 or less. In addition, from the viewpoints of balancing solvent dilutability, stretchability, and weather resistance, it is more preferably 500 or more and 2,500 or less, and further preferably 600 or more and 2,000 or less. The number average molecular weight can be measured using, for example, GPC.

[0205] "Manufacturing Method of Other Polyisocyanates"

[0206] Furthermore, the aforementioned polyisocyanate compound thus produced can be modified using a polymer polyol. A polymer polyol refers to a compound having one or more hydroxyl groups, such as a long-chain polyol. Specifically, polyester polyols, polycarbonate polyols, polyether polyols, acrylic polyols, and their copolymer polyols can be cited. These long-chain polyols can be used alone or in combination of two or more. The polyisocyanate can be further modified using an alcohol having one or more hydroxyl groups. An alcohol refers to a compound having one or more hydroxyl groups, and examples include short-chain polyols and long-chain polyols. As specific short-chain polyols, 1,2-propanediol, 1,3-butanediol, neopentyl glycol, hydroxypivalic acid neopentyl glycol ester, 2-methyl-1,3-propanediol, 2,3,5-trimethylpentanediol, ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, trimethylolpropane, glycerol, 1,1,7-trimethylolheptane, 1,2,7-trimethylolheptane, etc. can be cited. Additionally, as long-chain polyols, polyester polyols, polycarbonate polyols, polyether polyols, acrylic polyols, and their copolymer polyols can be cited. These polyols can be used alone or in combination of two or more.

[0207] "Other Constituents"

[0208] The polyisocyanate composition of the present embodiment may contain other components. As other components, there is no particular limitation, and examples include solvents, antioxidants, light stabilizers, polymerization inhibitors, surfactants, anti-peroxidants, etc.

[0209] The solvent can be a hydrophilic solvent or a hydrophobic solvent. These solvents can be used alone or in combination.

[0210] As the hydrophobic solvent, there is no particular limitation, and examples include mineral spirits, solvent naphtha, LAWS (Low Aromatic White Spirit), HAWS (High Aromatic White Spirit), toluene, xylene, cyclohexane, esters, ketones, amides.

[0211] As the esters, examples include ethyl acetate, butyl acetate, etc.

[0212] As the ketones, examples include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.

[0213] As the amides, examples include N,N-dimethylformamide, N,N-dimethylacetamide, etc.

[0214] As the hydrophilic solvent, there is no particular limitation, and examples thereof include esters of alcohols, ethers, and ether alcohols.

[0215] As the alcohols, examples thereof include methanol, ethanol, propanol, isopropanol, 2-ethylhexanol, and the like.

[0216] As the ethers, examples thereof include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, and the like.

[0217] As the esters of ether alcohols, examples thereof 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.

[0218] In the polyisocyanate composition of the present embodiment, from the viewpoint of ease of dispersion, the content of the solvent is preferably 0% by mass or more and 90% by mass or less, more preferably 0% by mass or more and 70% by mass or less, and still more preferably 0% by mass or more and 50% by mass or less with respect to the total mass of the polyisocyanate composition of the present embodiment.

[0219] In the polyisocyanate composition of the present embodiment, the total content of the antioxidant, light stabilizer, polymerization inhibitor, and 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 still 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.

[0220] <Coating composition>

[0221] The coating composition of the present embodiment contains the above polyisocyanate composition. The above coating composition preferably further contains a resin dispersed or emulsified in water.

[0222] The above polyisocyanate composition can also be used in the form of an organic solvent-based coating composition by mixing with an organic solvent and an optional resin, and is preferably used in the form of a coating composition by mixing with a resin dispersed or emulsified in water.

[0223] The coating composition of the present embodiment is excellent in gloss, water resistance, and salt spray resistance when forming a coating film by containing the above polyisocyanate composition.

[0224] Next, each constituent contained in the coating composition of the present embodiment will be described in detail below.

[0225] (Resin)

[0226] In the above coating composition, as the resin used as the main component, as long as it can be dispersed or emulsified in water, it is preferably an active hydrogen compound (polyactive hydrogen compound).

[0227] An active hydrogen compound refers to a compound having two or more active hydrogens bonded in the molecule. Examples of active hydrogen compounds include polyols, polyamines, polythiols, etc., and polyols are mostly used.

[0228] As such an active hydrogen compound, specifically, there is no particular limitation, and examples include 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, etc.

[0229] Among them, as the active hydrogen compound, acrylic resins or polyester resins are preferred.

[0230] For example, from the viewpoints of water resistance and salt spray resistance, the hydroxyl value of the polyol is preferably 50 mgKOH / g or more and 250 mgKOH / g or less in terms of the hydroxyl value in the resin component.

[0231] In addition, in the coating composition of the present embodiment, these resins can be used in combination with a melamine-based curing agent, a urethane dispersion, a urethane acrylate emulsion, etc. as needed.

[0232] In addition, these resins are preferably emulsified, dispersed or dissolved in water. For this purpose, carboxyl groups, sulfone groups, etc. contained in the resins can be neutralized.

[0233] As the neutralizing agent for neutralizing carboxyl groups, sulfone groups, etc., there is no particular limitation, and examples include ammonia, water-soluble amino compounds, etc.

[0234] 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, etc. They can be used alone or in combination of two or more.

[0235] Among them, as the neutralizing agent, a tertiary amine is preferred, and triethylamine or dimethylethanolamine is more preferred.

[0236] 《Other Components》

[0237] In the coating composition of the present embodiment, in addition to the above-mentioned polyisocyanate composition and resin, additives commonly added to coatings may be further included. Examples of such 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 (curing acceleration catalysts), 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, etc. These additives may be included alone or in combination of two or more.

[0238] "Manufacturing Method of Coating Composition"

[0239] The coating composition of the present embodiment is obtained by mixing the above-mentioned polyisocyanate composition and resin with other components as needed using a known method.

[0240] For example, in the case of a water-based matrix coating composition, additives exemplified in the above other components are added to the resin or its aqueous dispersion or aqueous solution as needed. Then, the above-mentioned polyisocyanate composition or its aqueous dispersion is added as a curing agent, and water and solvent are further added as needed to adjust the viscosity. Then, by forcibly stirring using a stirring device, a water-based coating composition can be obtained.

[0241] In the case of manufacturing a solvent-based matrix coating composition, first, additives exemplified in the above other components are added to the resin or its solvent dilution as needed. Then, the above-mentioned polyisocyanate composition is added as a curing agent, and solvent is further added as needed to adjust the viscosity. Then, by stirring manually or using a stirring device such as a stirrer, a solvent-based matrix coating composition can be obtained.

[0242] <Coated Substrate>

[0243] The coated substrate of the present embodiment is a coated substrate coated with the above-mentioned coating composition. The coated substrate of the present embodiment preferably has a coating layer containing the above-mentioned coating composition.

[0244] Since the coated substrate of the present embodiment has a coating film formed by curing the above-mentioned coating composition, it has excellent appearance and water resistance.

[0245] The coated substrate of the present embodiment can be obtained by coating the above-mentioned coating composition on a substrate using a known method such as roll coating, curtain flow coating, spray coating, BELL coating, electrostatic coating, etc., and subjecting it to a normal temperature drying or sintering process to cure it.

[0246] The coated substrate of the present embodiment may include a desired substrate, and may include a common primer before coating as appropriate.

[0247] Examples of the aforementioned substrate include metals, woods, glasses, stones, ceramic materials, concretes, calcium silicate boards, gypsum boards, rigid plastics, flexible plastics, fiber products, leather products, papers, and the like.

[0248] <Use applications>

[0249] The polyisocyanate resin composition and the coating composition of the present embodiment can be particularly used for architectural coatings, automotive coatings, automotive refinish coatings, coatings for construction machinery / agricultural machinery, coatings for plastics, adhesives, binders, building materials, household water-based coatings, other coating agents, sealants, inks, casting materials, elastomers, foams, plastic raw materials, and fiber treating agents.

[0250] Examples

[0251] Hereinafter, examples and comparative examples are given to more specifically illustrate the present invention. However, the present invention is not limited to the following examples as long as it does not exceed the gist thereof.

[0252] The physical properties and evaluations of the polyisocyanate compositions in the examples and comparative examples were measured as follows. It should be noted that, unless otherwise specifically stated, "parts" and "%" refer to "parts by mass" and "mass%".

[0253] <Measurement methods>

[0254] [Physical property 1: Viscosity]

[0255] 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.

[0256] (Rotation speed)

[0257] 100 r.p.m. (when less than 128 mPa·s)

[0258] 50 r.p.m. (when 128 mPa·s or more and less than 256 mPa·s)

[0259] 20 r.p.m. (when 256 mPa·s or more and less than 640 mPa·s)

[0260] 10 r.p.m. (when 640 mPa·s or more and less than 1280 mPa·s)

[0261] 5 r.p.m. (when 1280 mPa·s or more and less than 2560 mPa·s)

[0262] 2.5 r.p.m. (in the case of 2560 mPa·s or more and less than 5120 mPa·s)

[0263] [Physical property 2: Isocyanate group content (NCO%)]

[0264] Regarding the polyisocyanate compositions obtained in the examples and comparative examples as samples, the determination of the isocyanate group content was carried out according to the method described in JIS K7301-1995 (Test method for tolylene diisocyanate type prepolymers for thermosetting urethane elastomers). Hereinafter, a more specific method for determining the isocyanate group content (NCO%) is shown.

[0265] (1) Take 1 g (W g) of the sample and place it in a 200 mL conical flask. Add 20 mL of toluene to this flask to dissolve the sample.

[0266] (2) Then, add 20 mL of 2.0 N di-n-butylamine-toluene solution to the above flask and let it stand for 15 minutes.

[0267] (3) Add 70 mL of 2-propanol to the above flask to dissolve it and obtain a solution.

[0268] (4) For the solution obtained in the above (3), titrate it with 1 mol / L hydrochloric acid to obtain the sample titration volume (V1 mL).

[0269] (5) In the case of not adding the sample, carry out the determination in the same manner as in the above (1) to (3) to obtain the blank titration volume (V0 mL).

[0270] Based on the sample titration volume and the blank titration volume obtained above, use the following formula (A) to calculate the isocyanate group content (NCO%).

[0271] Isocyanate group content (mass%) =

[0272] (V0 - V1) × 42 / [W(1 g) × 1000] × 100 (A)

[0273] [Physical property 3: Non-volatile content]

[0274] When the polyisocyanate compositions obtained in the examples and comparative examples were used as samples and diluted with a solvent, the following method was used to calculate the nonvolatile content. First, the mass of the aluminum cup (W0 g) was precisely weighed, about 1 g of the sample was put in, 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 heated cup 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 nonvolatile content, the nonvolatile content was calculated using the following formula (B). It should be noted that when no solvent dilution was performed, the nonvolatile content was regarded as substantially 100%.

[0275] Nonvolatile content (mass %) = (W2 - W0) / (W1 - W0) × 100 (B)

[0276] [Physical property 4: Number-average molecular weight of polyisocyanate composition and polyol component]

[0277] The number-average molecular weights of the polyisocyanate composition and the polyol were obtained by GPC measurement under the measurement conditions shown below to measure the number-average molecular weight based on polystyrene.

[0278] (Measurement conditions)

[0279] Apparatus: HLC-8120GPC (trade name) of Tosoh Corporation

[0280] Column: One TSKgel SuperH1000 (trade name) of Tosoh Corporation

[0281] One TSKgel SuperH2000 (trade name)

[0282] One TSKgel SuperH3000 (trade name)

[0283] Carrier: Dimethylformamide

[0284] Detection method: Differential refractometer

[0285] [Physical property 5: Number-average molecular weight of alcohol component]

[0286] Taking the alcohol as the sample, the number-average molecular weight of the alcohol was obtained using the following formula (3). It should be noted that the hydroxyl value of the alcohol was obtained using the following (Physical property 9).

[0287] Number-average molecular weight = 2 / (hydroxyl value of alcohol × 10-3 / 56.11) … (3)

[0288] [Physical property 6: Hydroxyl value of alcohol component]

[0289] Using alcohol as the sample, the hydroxyl value of the alcohol is determined in accordance with JIS K 0070:1992. Specifically, 12.5 g of acetic anhydride is made up to volume with 50 mL of pyridine to prepare an acetylation reagent. Next, 2.5 to 5.0 g of alcohol is accurately weighed into a 100 mL eggplant-shaped flask. After adding 5 mL of the acetylation reagent and 10 mL of toluene to the eggplant-shaped flask using a volumetric pipette, a condenser is installed, and the mixture is stirred and heated at 100 °C for 1 hour. 2.5 mL of distilled water is added using a volumetric pipette, and the mixture is further heated and stirred for 10 minutes. After cooling for 2 to 3 minutes, 12.5 mL of ethanol is added, 2 to 3 drops of phenolphthalein are added as an indicator, and then titration is carried out with 0.5 mol / L ethanolic potassium hydroxide.

[0290] 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 are added to a 100 mL eggplant-shaped flask. After heating and stirring for 10 minutes, titration is carried out in the same manner. Based on the results, the hydroxyl value is calculated using the following formula (4).

[0291] OH value (mg-KOH / g) = {(b - a) × 28.05 × f} / e…(4)

[0292] 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.

[0293] [Physical property 7: Mass ratio of isocyanurate trimer (A) to polyisocyanate compound (B) containing two functional groups derived from an anionic compound having a sulfonic acid group]

[0294] Using the polyisocyanate composition as the sample, the mass ratio of the isocyanurate trimer (A) and the polyisocyanate compound (B) containing two functional groups derived from an anionic compound having a sulfonic acid group is determined using "UPLC" of WATERS Corporation. It is determined based on the measurement of LC-MS and UV-MS and the area ratio of the peaks. Calculation is carried out based on the area of each peak. The area of the polyisocyanate compound (B) is calculated based on the sum of the reaction product of the isocyanurate trimer and two anionic compounds having a sulfonic acid group, and the reaction product of the isocyanurate pentamer and two anionic compounds having a sulfonic acid group.

[0295] LC device: Manufactured by WATERS Corporation, UPLC (trade name)

[0296] Column: Manufactured by WATERS Corporation, ACQUITY UPLC BEH T3 1.7 μm C18 Inner diameter: 2.1 mm × 50 mm

[0297] Flow rate: 0.3 mL / min

[0298] Mobile phase: A = water (0.1% HCOOH), B = acetonitrile (0.1% HCOOH)

[0299] Gradient condition: The initial mobile phase composition is A / B = 98 / 2. After injecting the sample, the ratio of B is linearly increased, and A / B = 0 / 100 is prepared after 10 minutes.

[0300] MS device: manufactured by WATERS, Synapt G2

[0301] Ionization: ESI+, ESI-

[0302] [Preparation Example 1: Manufacture of coating composition]

[0303] Propylene glycol monomethyl ether diacetate was added to the polyisocyanate compositions obtained in the examples and comparative examples, and dissolved so that the solid content became 70% by mass to prepare a solution of the polyisocyanate composition. Next, 60 g of an acrylic polyol aqueous dispersion (product name: Bayhydrol A2470, hydroxyl amount per unit resin: 3.9% by mass, solid content: 45%, manufactured by Covestro) and 20 g of deionized water were measured into a container, and stirred with a stirring blade at 600 rpm for 5 minutes to prepare an acrylic polyol water diluent. Each polyisocyanate solution was added in such a ratio that the ratio of the molar amount of the isocyanate group in the polyisocyanate composition obtained in the examples and comparative examples to the molar amount of the hydroxyl group in the diluent (NCO / OH) became 1.5. Further, deionized water was added to adjust the viscosity to 20 seconds in a Ford cup (No. 4), and stirred with a stirring blade at 600 rpm for 10 minutes to obtain each coating composition. Using the prepared coating compositions, the following evaluations were carried out.

[0304] [Evaluation method]

[0305] [Evaluation 1: Chromaticity]

[0306] Regarding the chromaticity of the polyisocyanate compositions obtained in the examples and comparative examples, it was measured in the form of Hazen color number (APHA) using a colorimeter PFXi-195 manufactured by Lovibond. According to the following evaluation criteria, the chromaticity was evaluated.

[0307] (Evaluation criteria)

[0308] ◎: 30 or less

[0309] ○: More than 30 and 45 or less

[0310] △: More than 45 and 60 or less

[0311] ×: 60 or more

[0312] [Evaluation 2: Initial turbidity]

[0313] For the polyisocyanate compositions obtained in the examples and comparative examples, propylene glycol monomethyl ether acetate was used to prepare a dilution such that the solid content was 70%. Using a spectrophotometer UVmini-1240 manufactured by Shimadzu Corporation, the transmittance at a wavelength of 430 nm with an optical path length of 2 cm was measured.

[0314] (Evaluation criteria)

[0315] ◎: Transmittance is 90% or more

[0316] 〇: Transmittance is 80% or more and less than 90%

[0317] △: Transmittance is less than 80%

[0318] [Evaluation 3: Dispersibility]

[0319] The coating composition prepared in Preparation Example 1 was used to evaluate the dispersibility.

[0320] (1) Measure the mass (W0 g) of a 100 mL flask and Yoshino paper.

[0321] (2) Take 20.0 g of the coating composition and place it in a 100 mL flask, and filter it with the Yoshino paper weighed in (1).

[0322] (3) Determine the mass (g) (W1 g) of the filtration residue remaining on the Yoshino paper and the residue remaining in the 100 mL flask.

[0323] (Evaluation criteria)

[0324] ◎: Less than 0.2 g

[0325] ○: 0.2 g or more and less than 1.0 g

[0326] △: 1.0 g or more, with particles

[0327] [Evaluation 4: Coating film gloss]

[0328] On a horizontal table, for a steel plate pretreated with a sandblaster, the water-based two-component coating composition prepared in Preparation Example 1 was applied using a spray gun (spray pressure: 0.3 MPa, spray nozzle: 1.8 mm) such that the dry film thickness was 50 ± 5 μm, and it was dried for 7 days in an atmosphere of 23°C / 50% RH to obtain a coating film. Thereafter, using a gloss meter (BYK company, micro-TRI-gloss), the 60-degree gloss value was measured in accordance with GB-T6753.1-2007. The gloss of the coating film was evaluated according to the evaluation criteria shown below.

[0329] (Evaluation Criteria)

[0330] ◎: The 60-degree gloss value is 90% or more

[0331] ○: The 60-degree gloss value is 85% or more and less than 90%

[0332] △: The 60-degree gloss value is less than 85%

[0333] [Evaluation 5: Alkali Resistance]

[0334] Using the same method as in the above "Evaluation 4", each aqueous two-component coating composition was cured to obtain a coating film. The coating film was dried for 7 days in an atmosphere of 23°C / 50% RH. A steel plate having the coating film (hereinafter sometimes referred to as "coated plate") was immersed in 5% sodium hydroxide water at 23°C for 24 hours, and the condition of the coating film after removing the liquid remaining on the surface was observed. According to the following evaluation criteria, the alkali resistance of the coating film was evaluated.

[0335] (Evaluation Criteria)

[0336] ◎: Swelling and blistering occur after 3 days or more

[0337] ○: Swelling and blistering occur after 2 days or more and less than 3 days

[0338] △: Swelling and blistering occur in less than 2 days

[0339] (Synthesis of Sulfonamide)

[0340] [Synthesis Example 1]

[0341] (Synthesis of HES / TPA)

[0342] To 20 parts by mass of a 70% by mass aqueous solution of 2-hydroxyethanesulfonic acid (hereinafter sometimes abbreviated as "HES"), 10 parts by mass of 1-propanol was added and stirred to obtain a solution. Further, tripropylamine (hereinafter sometimes abbreviated as "TPA") was measured in a molar equivalent ratio of 1 with respect to HES, and diluted with the same mass of 1-propanol, and the resulting liquid was added dropwise to the aforementioned solution under stirring. Stirring was stopped 1 hour after the start of the dropwise addition, and dehydration and desolvation were carried out using an evaporator to obtain a 2-hydroxyethanesulfonic acid tripropylamine salt (hereinafter sometimes abbreviated as "HES / TPA") having a solid content of 99.8% by mass.

[0343] [Synthesis Example 2]

[0344] (Synthesis of HES / TBA)

[0345] To 20 parts by mass of a 70% by mass aqueous solution of 2-hydroxyethanesulfonic acid (hereinafter sometimes abbreviated as "HES"), 10 parts by mass of 1-propanol was added, and the mixture was stirred to obtain a solution. Further, tributylamine (hereinafter sometimes abbreviated as "TBA") was measured in a molar equivalent ratio of 1 relative to HES, diluted with the same mass of 1-propanol, and the resulting liquid was added dropwise to the above-mentioned solution under stirring. Stirring was stopped 1 hour after the start of the dropwise addition, and dehydration and desolvation were carried out using an evaporator to obtain tributylamine 2-hydroxyethanesulfonate (hereinafter sometimes abbreviated as "HES / TBA") having a solid content of 99.8% by mass.

[0346] [Synthesis Example 3]

[0347] (Production of Polyisocyanate P1)

[0348] A 2 L separable flask of Oldershaw equipped with a stirrer, a thermometer, and having a reflux head at the top and a vacuum jacket was made into a nitrogen atmosphere, and 1,000 parts by mass of HDI was charged. The temperature inside the reactor was maintained at 70 °C for 2 hours under stirring. To this, 1.0 part by mass of a solution obtained by diluting tetramethylammonium decanoate as an isocyanurating catalyst to 5% by mass with isobutanol was added, and an isocyanuration reaction was carried out. At the moment when the yield reached 25%, phosphoric acid was added to stop the reaction. The reaction solution was heated at 100 °C for 1 hour, cooled and filtered, and then unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate P1. The resulting polyisocyanate P1 had a viscosity of 1,300 mPa·s at 25 °C and an NCO content of 23.0% by mass.

[0349] [Synthesis Example 4]

[0350] (Production of Polyisocyanate P2)

[0351] The same apparatus as in Synthesis Example 3 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 under stirring. Thereafter, tetramethylammonium decanoate as a catalyst for the isocyanuration reaction was added. At the moment when the yield reached 40%, phosphoric acid was added to stop the reaction. The reaction solution was heated at 100 °C for 1 hour, cooled and filtered, and then unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate P2. The resulting polyisocyanate P2 had a viscosity of 2,600 mPa·s at 25 °C and an NCO content of 21.7% by mass.

[0352] [Synthesis Example 5]

[0353] (Production of Polyisocyanate P3)

[0354] 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 with stirring. Thereafter, 1.0 part by mass of a solution obtained by diluting tetramethylammonium caprate, which is a urethane-formation and isocyanurate-formation catalyst, to 5% by mass with isobutanol was added, and a urethane-formation 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, and after cooling and filtration, unreacted HDI was removed using a thin-film evaporation tank to obtain polyisocyanate P3. The viscosity of the obtained polyisocyanate P3 at 25 °C was 470 mPa·s, and the NCO content was 23.2% by mass.

[0355] [Synthesis Example 6]

[0356] (Production of polyisocyanate P4)

[0357] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 99.6 parts by mass of polyisocyanate P1 obtained in Synthesis Example 3 and 0.4 parts by mass of 1,3-butanediol were charged, and a urethanization reaction was carried out at 90 °C for 1 hour with stirring. Thereafter, a urethanization reaction was further carried out at 110 °C for 2 hours with stirring to obtain polyisocyanate P4. The viscosity of the obtained polyisocyanate P4 at 25 °C was 1800 mPa·s, and the NCO content was 22.5% by mass.

[0358] [Synthesis Example 7]

[0359] (Production of polyisocyanate P5)

[0360] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 98.0 parts by mass of polyisocyanate P1 obtained in Synthesis Example 3 and 2.0 parts by mass of 1,2-propanediol were charged, and a urethanization reaction was carried out at 90 °C for 1 hour with stirring. Thereafter, a urethanization reaction was further carried out at 110 °C for 2 hours with stirring to obtain polyisocyanate P5. The viscosity of the obtained polyisocyanate P5 at 25 °C was 3600 mPa·s, and the NCO content was 20.8% by mass.

[0361] [Synthesis Example 8]

[0362] (Production of polyisocyanate P6)

[0363] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, and 96.0 parts by mass of the polyisocyanate P3 obtained in Synthesis Example 5 and 4.0 parts by mass of 1,3-propanediol were charged. Under stirring, a urethanization reaction was carried out at 90°C for 1 hour. Thereafter, under stirring, a urethanization reaction was further carried out at 110°C for 2 hours to obtain polyisocyanate P6. The viscosity of the obtained polyisocyanate P6 at 25°C was 4400 mPa·s, and the NCO content was 19.5% by mass.

[0364] [Synthesis Example 9]

[0365] (Production of Polyisocyanate P7)

[0366] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, and 96.0 parts by mass of the polyisocyanate P3 obtained in Synthesis Example 5 and 4.0 parts by mass of polytetramethylene glycol "PTMG-650" (manufactured by Mitsubishi Chemical Corporation, number average molecular weight: 650) were charged. Under stirring, a urethanization reaction was carried out at 90°C for 1 hour. Thereafter, under stirring, a urethanization reaction was further carried out at 110°C for 2 hours to obtain polyisocyanate P7. The viscosity of the obtained polyisocyanate P7 at 25°C was 2600 mPa·s, and the NCO content was 21.6% by mass.

[0367] [Example 1]

[0368] (Production and Evaluation of Polyisocyanate Composition PA-1)

[0369] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 96.0 g of the polyisocyanate P1 obtained in Synthesis Example 3 and 4.0 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 were added, and the mixture was stirred at 105°C for 5 hours to carry out a reaction, obtaining polyisocyanate composition PA-1. The physical properties and evaluation results of the obtained polyisocyanate composition PA-1 are shown in Table 1.

[0370] [Example 2]

[0371] (Production and Evaluation of Polyisocyanate Composition PA-2)

[0372] Using 96.0 g of polyisocyanate P2, the mixture was stirred at 110°C for 5 hours to carry out a reaction. Except for this, the polyisocyanate composition PA-2 was obtained in the same manner as in Example 1. The physical properties and evaluation results of the obtained polyisocyanate composition PA-2 are shown in Table 1.

[0373] [Example 3]

[0374] (Production and Evaluation of Polyisocyanate Composition PA-3)

[0375] It was reacted by stirring at 120 °C for 5 hours. Except for this, a polyisocyanate composition PA-3 was obtained by the same method as in Example 1. The physical properties and evaluation results of the obtained polyisocyanate composition PA-3 are shown in Table 1.

[0376] [Example 4]

[0377] (Manufacture and evaluation of polyisocyanate composition PA-4)

[0378] It was reacted by stirring at 125 °C for 5 hours. Except for this, a polyisocyanate composition PA-4 was obtained by the same method as in Example 1. The physical properties and evaluation results of the obtained polyisocyanate composition PA-4 are shown in Table 1.

[0379] [Example 5]

[0380] (Manufacture and evaluation of polyisocyanate composition PA-5)

[0381] A nitrogen atmosphere was created in the same apparatus as in Synthesis Example 3, 90.0 g of the polyisocyanate P1 obtained in Synthesis Example 3 and 10.0 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 were added, and the mixture was stirred at 105 °C for 5 hours to carry out the reaction, obtaining a polyisocyanate composition PA-5. The physical properties and evaluation results of the obtained polyisocyanate composition PA-5 are shown in Table 1.

[0382] [Example 6]

[0383] (Manufacture and evaluation of polyisocyanate composition PA-6)

[0384] A nitrogen atmosphere was created in the same apparatus as in Synthesis Example 3, 98.0 g of the polyisocyanate P1 obtained in Synthesis Example 3 and 2.0 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 were added, and the mixture was stirred at 105 °C for 5 hours to carry out the reaction, obtaining a polyisocyanate composition PA-6. The physical properties and evaluation results of the obtained polyisocyanate composition PA-6 are shown in Table 1.

[0385] [Example 7]

[0386] (Manufacture and evaluation of polyisocyanate composition PA-7)

[0387] A nitrogen atmosphere was created in the same apparatus as in Synthesis Example 3, 98.0 g of the polyisocyanate P3 obtained in Synthesis Example 5 and 2.0 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 were added, and the mixture was stirred at 110 °C for 5 hours to carry out the reaction, obtaining a polyisocyanate composition PA-7. The physical properties and evaluation results of the obtained polyisocyanate composition PA-7 are shown in Table 1.

[0388] [Example 8]

[0389] (Production and Evaluation of Polyisocyanate Composition PA-8)

[0390] An inert gas atmosphere was created in the same apparatus as in Synthesis Example 3, and 96.0 g of polyisocyanate P4 obtained in Synthesis Example 6 and 4.0 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 were added. The mixture was stirred at 105°C for 5 hours to carry out the reaction, obtaining polyisocyanate composition PA-8. The physical properties and evaluation results of the obtained polyisocyanate composition PA-8 are shown in Table 1.

[0391] [Example 9]

[0392] (Production and Evaluation of Polyisocyanate Composition PA-9)

[0393] An inert gas atmosphere was created in the same apparatus as in Synthesis Example 3, and 97.0 g of polyisocyanate P5 obtained in Synthesis Example 7 and 3.0 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 were added. The mixture was stirred at 105°C for 5 hours to carry out the reaction, obtaining polyisocyanate composition PA-9. The physical properties and evaluation results of the obtained polyisocyanate composition PA-9 are shown in Table 2.

[0394] [Example 10]

[0395] (Production and Evaluation of Polyisocyanate Composition PA-10)

[0396] An inert gas atmosphere was created in the same apparatus as in Synthesis Example 3, and 96.0 g of polyisocyanate P6 obtained in Synthesis Example 8 and 4.0 g of tributylamine salt of 2-hydroxyethanesulfonic acid (HES / TBA) obtained in Synthesis Example 2 were added. The mixture was stirred at 105°C for 5 hours to carry out the reaction, obtaining polyisocyanate composition PA-10. The physical properties and evaluation results of the obtained polyisocyanate composition PA-10 are shown in Table 2.

[0397] [Example 11]

[0398] (Production and Evaluation of Polyisocyanate Composition PA-11)

[0399] An inert gas atmosphere was created in the same apparatus as in Synthesis Example 3, and 96.0 g of polyisocyanate P7 obtained in Synthesis Example 9 and 4.0 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 2 were added. The mixture was stirred at 105°C for 5 hours to carry out the reaction, obtaining polyisocyanate composition PA-11. The physical properties and evaluation results of the obtained polyisocyanate composition PA-11 are shown in Table 2.

[0400] [Example 12]

[0401] (Manufacture and Evaluation of Polyisocyanate Composition PA-12)

[0402] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere. 2.5 g of 3-cyclohexylaminopropanesulfonic acid (CAPS) and 1.5 g of N,N-dimethylcyclohexylamine (DMCHA) were added to 96.0 g of the polyisocyanate P1 obtained in Synthesis Example 3, and the mixture was stirred at 90 °C for 5 hours to carry out the reaction, obtaining the polyisocyanate composition PA-12. The physical properties and evaluation results of the obtained polyisocyanate composition PA-12 are shown in Table 2.

[0403] [Example 13]

[0404] (Manufacture and Evaluation of Polyisocyanate Composition PA-13)

[0405] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere. 2.6 g of 3-cyclohexylaminobutanesulfonic acid (CABS) and 1.4 g of N,N-dimethylcyclohexylamine (DMCHA) were added to 96.0 g of the polyisocyanate P1 obtained in Synthesis Example 3, and the mixture was stirred at 110 °C for 5 hours to carry out the reaction, obtaining the polyisocyanate composition PA-13. The physical properties and evaluation results of the obtained polyisocyanate composition PA-13 are shown in Table 2.

[0406] [Example 14]

[0407] (Manufacture and Evaluation of Polyisocyanate Composition PA-14)

[0408] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere. 56.0 g of the polyisocyanate P1 obtained in Synthesis Example 3 and 4.0 g of tripropylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 were added, and the mixture was stirred at 100 °C for 5 hours to carry out the reaction. Then, 40.0 g of the polyisocyanate P1 obtained in Synthesis Example 3 was added, and the mixture was stirred at 60 °C for 1 hour, obtaining the polyisocyanate composition PA-14. The physical properties and evaluation results of the obtained polyisocyanate composition PA-14 are shown in Table 2.

[0409] [Comparative Example 1]

[0410] (Manufacture and Evaluation of Polyisocyanate Composition PB-1)

[0411] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 96.0 g of polyisocyanate P1 obtained in Synthesis Example 3 and 4.0 g of tributylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 were added, and the mixture was stirred at 130 °C for 5 hours to carry out the reaction, obtaining a polyisocyanate composition PB-1. The physical properties and evaluation results of the obtained polyisocyanate composition PB-1 are shown in Table 2.

[0412] [Comparative Example 2]

[0413] (Production and Evaluation of Polyisocyanate Composition PB-2)

[0414] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 96.0 g of polyisocyanate P-3 obtained in Synthesis Example 5 and 4.0 g of tributylamine salt of 2-hydroxyethanesulfonic acid (HES / TPA) obtained in Synthesis Example 1 were added, and the mixture was stirred at 130 °C for 5 hours to carry out the reaction, obtaining a polyisocyanate composition PB-2. The physical properties and evaluation results of the obtained polyisocyanate composition PB-2 are shown in Table 2.

[0415] [Comparative Example 3]

[0416] (Production and Evaluation of Polyisocyanate Composition PB-3)

[0417] The inside of the same apparatus as in Synthesis Example 3 was made into a nitrogen atmosphere, 2.5 g of 3-cyclohexylaminopropanesulfonic acid (CAPS) and 1.5 g of N,N-dimethylcyclohexylamine (DMCHA) were added to 96.0 g of polyisocyanate P-1 obtained in Synthesis Example 3, and the mixture was stirred at 140 °C for 5 hours to carry out the reaction, obtaining a polyisocyanate composition PB-3. The physical properties and evaluation results of the obtained polyisocyanate composition PB-3 are shown in Table 2.

[0418] [Table 1]

[0419]

[0420] [Table 2]

[0421]

[0422] Industrial Applicability

[0423] According to the polyisocyanate composition of the present embodiment, a polyisocyanate composition having high chromaticity, reduced initial turbidity, good dispersibility when blended with the main agent, and excellent gloss and alkali resistance when forming a coating film is provided. In addition, an aqueous coating composition and a coated substrate obtained by using the aforementioned polyisocyanate composition can be provided.

Claims

1. A polyisocyanate composition comprising a hydrophilic polyisocyanate compound, wherein the hydrophilic polyisocyanate compound is a reaction product of a polyisocyanate and an anionic compound having a sulfonic acid group, wherein the polyisocyanate is derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates, wherein the hydrophilic polyisocyanate compound contains an isocyanurate trimer (A), and the mass ratio [(B) / (A)] of the polyisocyanate compound (B) containing two functional groups derived from the anionic compound having a sulfonic acid group to the isocyanurate trimer (A) is 150 / 10000 or less.

2. The polyisocyanate composition according to claim 1, wherein, the polyisocyanate contains a reaction product thereof with an alcohol.

3. The polyisocyanate composition according to claim 2, wherein, the alcohol has an average number of 2.0 or more and 3.5 or less hydroxyl groups per molecule, and the number average molecular weight of the alcohol is 450 or less.

4. The polyisocyanate composition according to claim 2 or 3, wherein, the mass fraction of the alcohol in the polyisocyanate composition is 4.5% or less.

5. The polyisocyanate composition according to claim 1 or 2, wherein, the anionic compound 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.

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

7. The polyisocyanate composition according to claim 1 or 2, wherein, the anionic compound is a compound represented by the following general formula (1), HO-R 11 -SO 3 H (1) In general formula (1), R 11 is a hydrocarbon group having 1 to 10 carbon atoms which optionally contains at least one member selected from the group consisting of a hydroxyl group, an ether bond, an ester bond, a carbonyl group and an imino group, and R 11 optionally contains a ring structure, and the ring structure is an aromatic ring, a five-membered or six-membered ring containing two nitrogen atoms, or a five-membered or six-membered ring containing a nitrogen atom and an oxygen atom.

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

9. A coating composition comprising the polyisocyanate composition according to claim 1 or 2.

10. A coated substrate coated with the coating composition according to claim 9.

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