JP2023083901A - Polyisocyanate composition, coating composition and coating substrate - Google Patents

Abstract

To provide a polyisocyanate composition that has high clarity, giving a coating composition having a long pot life and giving a coating layer having a good appearance and water resistance.SOLUTION: A polyisocyanate composition comprises a polyisocyanate comprising a sulfonic acid anion group in each molecule, and a tertiary ammonium cation of an amine compound. Relative to total mass of the polyisocyanate composition, the polyisocyanate composition comprises an inorganic acid or an inorganic acid compound of 0.1 mass ppm or more and 100 mass ppm or less.SELECTED DRAWING: None

Description

The present invention relates to polyisocyanate compositions, coating compositions and coating substrates.

A coating film obtained from a two-component polyurethane composition using a polyisocyanate composition derived from an aliphatic diisocyanate or an alicyclic diisocyanate as a curing agent has excellent weather resistance, chemical resistance, abrasion resistance, etc. performance. Therefore, it is widely used as paint, ink and adhesive. In recent years, there has been a growing awareness of global environmental problems, and water-based two-component polyurethane compositions that do not use organic solvents or that use a reduced amount of organic solvents have been proposed. However, in the case of water-based two-component polyurethane compositions, compared to solvent-based two-component polyurethane compositions, they are less likely to disperse in water, more likely to react with water, and have a shorter pot life. there is a point Therefore, there is a demand for a polyisocyanate composition that is highly dispersible in water and suppresses the reaction between isocyanate groups and water in a water-dispersed state.

For example, Patent Documents 1 and 2 propose a water-dispersible polyisocyanate compound and a water-based two-component polyurethane composition using the same as a method for producing a water-based two-component polyurethane composition. . Patent Documents 3 and 4 disclose a polyisocyanate composition containing a modified polyisocyanate obtained by reacting an amine salt of a sulfonic acid having a hydroxyl group with a polyisocyanate. Patent Literature 5 discloses a hydrophilic polyisocyanate with a low color number, which is used in combination with a peroxide decomposer.

JP-A-05-222150 Japanese Patent Application Laid-Open No. 09-328654 JP 2015-205957 A JP 2016-017157 A JP 2019-189866 A

However, the compositions described in Patent Literature 1 and Patent Literature 2 have a problem that the hardness of the coated film containing them is low. Patent Documents 3 and 4 disclose that the use of a polyisocyanate containing a sulfonic acid group improves the dispersibility in water, but the compatibility between the sulfonic acid group and the polyisocyanate However, since the polyisocyanate is poor, there is a problem that turbidity occurs in the synthesized polyisocyanate. Further, Patent Document 5 discloses that a modified polyisocyanate obtained by reacting with an aminosulfonic acid having a specific structure improves coating film hardness and solvent resistance of the coating film. However, since an aminosulfonic acid with a specific structure is used, there is a problem that the water resistance of the coating film is poor.

The present invention has been made in view of the above circumstances, and the polyisocyanate composition has good transparency, pot life when used as a coating composition, and excellent appearance and water resistance when used as a coating film. I will provide a.

That is, the present invention includes the following aspects.
(1) a polyisocyanate containing a sulfonate anion group in the molecule;
a tertiary ammonium cation of an amine compound;
A polyisocyanate composition comprising
A polyisocyanate composition containing an inorganic acid or an inorganic acid compound in an amount of 0.1 mass ppm or more and 100 mass ppm or less relative to the total mass of the polyisocyanate composition.
(2) The inorganic acid is one or more acids selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, sulfamic acid, hydrofluoric acid, sulfurous acid, and perchloric acid. Isocyanate composition.
(3) The polyisocyanate composition according to (1) or (2), wherein the amine compound contains a compound represented by the following general formula (I).

(In general formula (I), R ¹¹ , R ¹² and R ¹³ are each independently a hydrocarbon group having 1 to 10 carbon atoms which may contain an ether bond. R ¹¹ , R ¹² and R ¹³ At least one selected from the group consisting of may contain a ring structure, and two or more selected from the group consisting of R ¹¹ , R ¹² and R ¹³ may combine with each other to form a ring structure. The structure is an aromatic ring, a cycloalkyl group ^having 5 or 6 carbon atoms, ^{a 5- or 6-membered ring in which R 11 and R 12 are bonded} to each other, ^or It is a multi-membered polycycle.)

(4) The polyisocyanate composition according to any one of (1) to (3), wherein the amine compound contains a compound represented by the following general formula (I-1).

(In general formula (I-1), R ¹¹¹ and R ¹¹² are each independently a hydrocarbon group having 1 to 8 carbon atoms which may contain an ether bond. From the group consisting of R ¹¹¹ and R ¹¹² At least one selected may contain a ring structure, and R ¹¹¹ and R ¹¹² may combine to form a ring structure, which may be an aromatic ring or a cycloalkyl group having 5 or 6 carbon atoms. , or a 5- or 6-membered ring in which R ¹¹¹ and R ¹¹² are bonded to each other.)

(5) The polyisocyanate containing the sulfonic acid anion group in the molecule is obtained by reacting an amine salt of sulfonic acid having an active hydrogen group with the polyisocyanate,
According to (4), wherein the amine salt of sulfonic acid having an active hydrogen group is a compound represented by the general formula (I) or a salt with the compound represented by the general formula (I-1). Polyisocyanate composition.
(6) The polyisocyanate composition according to (5), wherein the active hydrogen group is a hydroxyl group.
(7) The polyisocyanate composition according to (5) or (6), wherein the sulfonic acid having an active hydrogen group is a compound represented by the following general formula (II).

(In general formula (II), R ²¹ is a hydrocarbon group having 1 to 10 carbon atoms and 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 ²¹ may contain a ring structure, which is an aromatic ring, a 5- or 6-membered ring containing two nitrogen atoms, or a 5- or 6-membered ring containing a nitrogen atom and an oxygen atom. is a membered ring.)

(8) Any one of (1) to (4), wherein the polyisocyanate containing a sulfonic acid anion group in the molecule is obtained by reacting a sulfonic acid having an active hydrogen group with a polyisocyanate. The polyisocyanate composition according to .
(9) The polyisocyanate composition according to (8), wherein the active hydrogen group is an amino group.
(10) The polyisocyanate composition according to (8) or (9), wherein the sulfonic acid having an active hydrogen group is a compound represented by the following general formula (III).

(In general formula (III), R ³¹ and R ³² are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group. Of R ³² and R ³³ At least one is a hydrogen atom.R ³³ is a hydrocarbon group having 1 or more and 12 or less carbon atoms which may contain a hydroxyl group.)

(11) The polyisocyanate composition according to any one of (1) to (10), which is used as a curing agent for water-based two-component polyurethane compositions.
(12) A coating composition comprising the polyisocyanate composition according to any one of (1) to (11) and resins.
(13) A coated substrate coated with the coating composition according to (12).

According to the polyisocyanate composition of the above aspect, it is possible to provide a polyisocyanate composition that has good transparency, pot life when used as a coating composition, and excellent appearance and water resistance when used as a coating film. can. The coating composition of the above aspect contains the polyisocyanate composition and is excellent in pot life, appearance and water resistance when formed into a coating film. The coating base material of the above aspect has a coating film formed by curing the coating composition, and has excellent appearance and water resistance.

EMBODIMENT OF THE INVENTION Hereinafter, the form (henceforth "this embodiment") for implementing this invention is demonstrated in detail. In addition, the present invention is not limited to the following embodiments. The present invention can be modified appropriately within the scope of its gist.

<<Polyisocyanate composition>>
The polyisocyanate composition of this embodiment is
a polyisocyanate containing a sulfonate anion group in the molecule;
a tertiary ammonium cation of an amine compound;
including
0.1 mass ppm or more and 100 mass ppm or less of inorganic acid or inorganic acid compound is included with respect to the total mass of the polyisocyanate composition.

In the polyisocyanate composition of the present embodiment, the inorganic acid or inorganic acid compound is derived from raw materials used in the production of sulfonic acid, or mixed or by-produced in the process of producing the polyisocyanate composition. . Alternatively, it may be added so that the content of the inorganic acid or inorganic acid compound is within the above range.

In the polyisocyanate composition of the present embodiment, the content of the inorganic acid or inorganic acid compound is 0.1 mass ppm or more and 100 mass ppm or less, and 0.1 mass ppm, relative to the total mass of the polyisocyanate composition. 90 mass ppm or less is preferable, 1 mass ppm or more and 80 mass ppm or less is more preferable, and 2 mass ppm or more and 50 mass ppm or less is more preferable.
When the content of the inorganic acid or inorganic acid compound is at least the above lower limit, the pot life of the coating composition can be improved. Appearance and water resistance when formed into a film can be improved.
In addition, in the polyisocyanate composition of this embodiment, when both an inorganic acid and an inorganic acid compound are contained, their total content is within the above range. Moreover, even when two or more kinds of inorganic acids and inorganic acid compounds are contained, the total content thereof is within the above range.

The content of inorganic acids or inorganic acid compounds can be measured by ion chromatography-mass spectrometry (IC-MS). Specifically, it can be measured using the following apparatus and conditions.

(Measurement condition)
IC device: ICS-1500 (trade name) manufactured by Thermo Fisher Scientific Co., Ltd.
Column: AS12A
Mobile phase _: 2.7 mmol/L _Na2CO3 , 0.3 mmol/L _NaHCO3
Flow rate: 1.5mL/min
Sample injection volume: 1 mL
Suppressor: AERS-500
Detector: Electrical conductivity detector Pretreatment method: The sample is combusted in a furnace, and the combustion gas is absorbed into the absorption liquid.

By having the above configuration, the polyisocyanate composition of the present embodiment has good transparency, as shown in the examples below, a coating composition having an excellent pot life is obtained, and appearance and water resistance are obtained. Excellent coatings are obtained.

Incidentally, the "pot life" referred to here means, in a composition such as a paint or an adhesive, after preparing a composition by mixing a main agent and a curing agent, ensuring performance as a composition before curing. It means time and is also called pot life. As shown in Examples below, by measuring the time during which 80% or more of the isocyanate groups in the coating composition prepared by mixing the polyisocyanate composition (curing agent) of the present embodiment and the main agent are retained, can be evaluated.

The polyisocyanate composition of the present embodiment usually contains unreacted polyisocyanate (hereinafter sometimes referred to as unmodified polyisocyanate), that is, polyisocyanate containing no sulfonate anion group in the molecule. In addition, unless otherwise specified, the various properties of the polyisocyanate composition of the present embodiment, which will be described later, are the polyisocyanate containing the sulfonate anion group in the molecule and the unreacted polyisocyanate (the sulfonate anion group in the molecule It is a characteristic in a state containing polyisocyanate not contained in
Further, in the polyisocyanate composition of the present embodiment, the ratio of the unmodified polyisocyanate and the polyisocyanate containing a sulfonate anion group in the molecule is, for example, with respect to 100 moles of the isocyanate group of the raw polyisocyanate, It can be calculated from the ratio of isocyanate groups containing sulfonate anion groups in the molecule.

The constituent components of the polyisocyanate composition of the present embodiment will be described in detail.

<Polyisocyanate containing a sulfonic acid anion group in the molecule>
The polyisocyanate containing a sulfonic acid anion group in the molecule contained in the polyisocyanate composition of the present embodiment is a reactant obtained by reacting a sulfonic acid having an active hydrogen group or an amine salt thereof with a polyisocyanate. .

[Polyisocyanate]
The polyisocyanate used for the polyisocyanate containing a sulfonate anion group in the molecule is not particularly limited, but for example, it is derived from at least one diisocyanate selected from aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates. and polyisocyanates. The polyisocyanate used for the polyisocyanate containing a sulfonate anion group in the molecule is selected from the group consisting of aliphatic polyisocyanates, alicyclic polyisocyanates and aromatic polyisocyanates from the viewpoint of industrial availability. At least one is preferred.

Examples of aliphatic diisocyanates include, but are not limited to, 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, ethyl (2,6-diisocyanato)hexanoate, 1,6-diisocyanatohexane ( 1,9-diisocyanatononane, 1,12-diisocyanatododecane, 2,2,4- or 2,4,4-trimethyl-1,6-di isocyanatohexane and the like.

Although the alicyclic diisocyanate is not particularly limited, for example, 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane (hereinafter sometimes referred to as "hydrogenated XDI"), 1,3- 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl 1-isocyanato-3-(isocyanatomethyl)cyclohexane (hereinafter sometimes referred to as "IPDI"), 4-4'-diisocyanato-dicyclohexylmethane (hereinafter sometimes referred to as "hydrogenated MDI"), 2,5- or 2,6-diisocyanatomethylnorbornane, and the like.

Examples of the aromatic diisocyanate include, but are not particularly limited to, xylylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and the like.

Among them, the diisocyanate is preferably HDI, IPDI, hydrogenated XDI or hydrogenated MDI, more preferably HDI or IPDI, from the viewpoint of weather resistance.

Moreover, an aliphatic triisocyanate may be included as the polyisocyanate compound. Examples of aliphatic triisocyanates include 1,3,6-triisocyanatohexane, 1,8-diisocyanato-4-isocyanatomethyloctane, 2-isocyanatoethyl-2,6-diisocyanato-hexanoate, and the like. .

Moreover, these polyisocyanate compounds can also be used individually or in combination of 2 or more types.

The polyisocyanate compound derived from the above diisocyanate is not particularly limited, but includes, for example, the following polyisocyanates (a) to (h).
(a) a polyisocyanate having uretdione groups obtained by cyclodimerizing two isocyanate groups;
(b) a polyisocyanate having an isocyanurate group or an iminooxadiazinedione group obtained by cyclotrimerization of three isocyanate groups;
(c) a polyisocyanate having biuret groups obtained by reacting three isocyanate groups with one water molecule;
(d) a polyisocyanate having oxadiazinetrione groups obtained by reacting two isocyanate groups with one molecule of carbon dioxide;
(e) a polyisocyanate having a plurality of urethane groups obtained by reacting one isocyanate group with one hydroxyl group;
(f) a polyisocyanate having allophanate groups obtained by reacting two isocyanate groups with one hydroxyl group;
(g) a polyisocyanate having an acyl urea group obtained by reacting one isocyanate group with one carboxyl group;
(h) Polyisocyanate having urea groups obtained by reacting one isocyanate group with one primary or secondary amine

Among them, the polyisocyanate compound preferably has an isocyanurate group, an uretdione group, or an allophanate group in the molecule.

The uretdione group is a functional group obtained by cyclodimerizing two isocyanate groups and has a structure represented by the following formula (a). Polyisocyanates having uretdione groups have low viscosity and good dispersibility.
An isocyanurate group is a functional group obtained by cyclotrimerizing three isocyanate groups, and has a structure represented by the following formula (b1).
The iminooxadiazinedione group is a functional group obtained by cyclotrimerization of three isocyanate groups and has a structure represented by the following formula (b2).
An allophanate group is a functional group formed by a reaction between a hydroxyl group of an alcohol and an isocyanate group, and has a structure represented by the following formula (f).
In each formula, a wavy line represents a bond, which is a binding site to a residue other than one isocyanate group of polyisocyanate.

In the polyisocyanate composition of the present embodiment, the molar ratio of isocyanurate groups to the total molar amount (100 mol %) of isocyanurate groups, iminooxadiazinedione groups, uretdione groups and allophanate groups is 70. It is preferably 0 mol % or more and 90.0 mol % or less, more preferably 80.0 mol % or more and 88.0 mol % or less. When the molar ratio of isocyanurate groups is within the above range, the resulting coating film is more excellent in water resistance and hardness.

In the polyisocyanate composition of the present embodiment, the molar ratio of iminooxadiazinedione groups to the total molar amount (100 mol%) of isocyanurate groups, iminooxadiazinedione groups, uretdione groups, and allophanate groups is , preferably 1.0 mol % or more and 3.5 mol % or less, more preferably 2.0 mol % or more and 3.0 mol % or less.

In the polyisocyanate composition of the present embodiment, the molar ratio of allophanate groups to the total molar amount (100 mol%) of isocyanurate groups, iminooxadiazinedione groups, uretdione groups, and allophanate groups is 0.1. It is preferably mol % or more and 30.0 mol % or less, more preferably 1.0 mol % or more and 20.0 mol % or less.
In the polyisocyanate composition of the present embodiment, the molar ratio of uretdione groups to the total molar amount (100 mol%) of isocyanurate groups, iminooxadiazinedione groups, uretdione groups, and allophanate groups is 0.1. It is preferably 0.2 mol % or more and 25.0 mol % or less, more preferably 0.2 mol % or more and 25.0 mol % or less.

In the polyisocyanate composition of the present embodiment, the total content of uretdione groups and allophanate groups is , preferably 1.0 mol % or more and 30.0 mol % or less, more preferably 2.0 mol % or more and 25.0 mol % or less.
The molar ratio of uretdione groups to allophanate groups (uretdione groups/allophanate groups) is preferably 0.1 or more and 20.0 or less, more preferably 0.2 or more and 10.0 or less, and 0.3. It is more preferable that it is not less than 5.0 and not more than 5.0. When the total content of uretdione groups and allophanate groups and the ratio of uretdione groups/allophanate groups are within the above ranges, the pot life of the polyisocyanate composition is longer, and the resulting coating film is more excellent in gloss and water resistance.

The content of each structure derived from isocyanate groups in the polyisocyanate composition of the present embodiment can be determined by ¹³ C-NMR measurement. Specifically, using Biospin Avance 600 (trade name) manufactured by Bruker, measurement is performed under the following measurement conditions.

(Measurement condition)
¹³ C-NMR device: AVANCE600 (manufactured by Bruker)
Cryoprobe (manufactured by Bruker)
CryoProbe®
CPDUL
600S3-C/HD-05Z
Resonance frequency: 150MHz
Concentration: 60wt/vol%
Shift reference: CDCl ₃ (77 ppm)
Number of times of integration: 10000 times Pulse program: zgpg30 (proton complete decoupling method, waiting time 2 sec)

The integrated value of the following signals is divided by the number of carbon atoms being measured to obtain each mole fraction with respect to the total (100 mol%) of the isocyanurate group, iminooxadiazinedione group, allophanate group, and uretdione group. . Using the obtained mole fractions, the total content of uretdione groups and allophanate groups with respect to the total molar amount of isocyanurate groups, iminooxadiazinedione groups, uretdione groups, and allophanate groups, and uretdione with respect to allophanate groups The molar ratio of the groups (molar ratio of uretdione groups/allophanate groups) is calculated.

Isocyanurate group: (Integral value around 148.6 ppm) ÷ 3
Iminooxadiazinedione group: (Integral value near 135.5 ppm)/1
Allophanate group: (Integral value around 154 ppm) ÷ 1
Uretdione structure: (Integral value near 157 ppm) ÷ 2

(Method for producing polyisocyanate compound)
(1) Method for producing a polyisocyanate containing an isocyanurate group The method for producing a polyisocyanate containing an isocyanurate group is not particularly limited. A method of terminating the reaction and removing unreacted diisocyanate is exemplified.

The catalyst used for the isocyanurate-forming reaction is not particularly limited, but preferably exhibits basicity, and specifically, tetraalkylammonium hydroxide and organic weak acid salt, hydroxyalkylammonium hydroxide and organic weak acid salt. , alkali metal salts of alkylcarboxylic acids, metal alcoholates, aminosilyl group-containing compounds, Mannich bases, combined use of tertiary amines and epoxy compounds, and phosphorus compounds.
Examples of tetraalkylammonium include tetramethylammonium and tetraethylammonium.
Examples of weak organic acids include acetic acid and capric acid. Hydroxyalkylammonium includes, for example, trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, triethylhydroxyethylammonium and the like.
Examples of alkylcarboxylic acids include acetic acid, caproic acid, octylic acid, myristic acid and the like.
Examples of metals constituting alkali metal salts include tin, zinc, and lead.
Examples of metal alcoholates include sodium alcoholate, potassium alcoholate and the like.
Examples of aminosilyl group-containing compounds include hexamethyldisilazane and the like.
Examples of phosphorus compounds include tributylphosphine and the like.

The amount of these catalysts used is preferably 10 ppm or more and 1.0% or less with respect to the total mass of the raw materials, diisocyanate (and alcohol, if necessary). In addition, in order to terminate the isocyanurate reaction, the catalyst may be inactivated by addition of an acidic substance that neutralizes the catalyst, thermal decomposition, chemical decomposition, or the like. Acidic substances that neutralize the catalyst include, for example, phosphoric acid and acid phosphate esters.

The yield of polyisocyanate generally tends to be 10% by mass or more and 70% by mass or less, preferably 35% by mass or more and 60% by mass or less. Polyisocyanates obtained in higher yields tend to be more viscous. The yield can be calculated from the mass ratio of the obtained polyisocyanate to the total mass of the raw material components.

Although the reaction temperature for the isocyanurate-forming reaction is not particularly limited, it is preferably 50° C. or higher and 200° C. or lower, and more preferably 50° C. or higher and 150° C. or lower. When the reaction temperature is equal to or higher than the above lower limit, the reaction tends to proceed more easily, and when the reaction temperature is equal to or lower than the above upper limit, side reactions that cause coloration tend to be more suppressed. be.

After completion of the isocyanurate-forming reaction, unreacted diisocyanate is preferably removed by thin film evaporator, extraction, or the like. Even if the polyisocyanate contains unreacted diisocyanate, the content of the diisocyanate is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, relative to the total mass of the polyisocyanate. , is more preferably 0.5% by mass or less. Curability tends to be more excellent when the residual unreacted diisocyanate concentration is within the above range.

After completion of the isocyanurate-forming reaction, unreacted diisocyanate is preferably removed by thin film evaporator, extraction, or the like. Even if the polyisocyanate contains unreacted diisocyanate, the content of the diisocyanate is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, relative to the total mass of the polyisocyanate. , is more preferably 0.5% by mass or less. Curability tends to be more excellent when the residual unreacted diisocyanate concentration is within the above range.
Residual unreacted diisocyanate concentration can be determined by gas chromatography analysis.

(2) Method for Producing Polyisocyanate Containing Allophanate Groups As a method for producing polyisocyanate containing allophanate groups, for example, alcohol is added to diisocyanate and an allophanatization reaction catalyst is used.

Alcohols used to form allophanate groups are preferably alcohols formed only from carbon, hydrogen and oxygen.
Specific examples of the alcohol include, but are not limited to, monoalcohols, dialcohols, and the like. These alcohols may be used individually by 1 type, and may be used in combination of 2 or more types.
Examples of monoalcohols include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol and the like.
Examples of dialcohols include ethylene glycol, 1,3-butanediol, neopentyl glycol, 2-ethylhexanediol and the like.
Among them, the alcohol is preferably a monoalcohol, more preferably a monoalcohol having a molecular weight of 200 or less.

The molar ratio of the isocyanate groups of the diisocyanate to the hydroxyl groups of the alcohol is preferably 10/1 or more and 1000/1 or less, more preferably 100/1 or more and 1000/1 or less. When the said molar ratio is more than the said lower limit, an isocyanate group average number (average functional group number) can be ensured more fully. When the molar ratio is equal to or less than the above upper limit, there is an effect that the surface hardness is excellent.

Examples of the allophanatization reaction catalyst include, but are not limited to, alkyl carboxylates of tin, lead, zinc, bismuth, zirconium, zirconyl, and the like.
Examples of alkyl carboxylates of tin (organotin compounds) include tin 2-ethylhexanoate and dibutyltin dilaurate.
Examples of lead alkyl carboxylates (organic lead compounds) include lead 2-ethylhexanoate.
Examples of zinc alkylcarboxylates (organozinc compounds) include zinc 2-ethylhexanoate and the like.
Bismuth alkyl carboxylates include, for example, bismuth 2-ethylhexanoate.
Examples of alkyl carboxylates of zirconium include zirconium 2-ethylhexanoate and the like.
Alkyl carboxylates of zirconyl include, for example, zirconyl 2-ethylhexanoate. These catalysts can be used alone or in combination of two or more.

In addition, the above isocyanurate-forming reaction catalyst can also serve as an allophanat-forming reaction catalyst. When the allophanatization reaction is performed using the above isocyanurate reaction catalyst, an isocyanurate type polyisocyanate is naturally produced.
Above all, it is preferable from the standpoint of economic production to perform the allophanatization reaction and the isocyanurate formation reaction using the above isocyanuration reaction catalyst as the allophanatization reaction catalyst.

The upper limit of the amount of the above allophanatization reaction catalyst used is preferably 10000 ppm by mass, more preferably 1000 ppm by mass, and even more preferably 500 ppm by mass relative to the mass of the charged diisocyanate. On the other hand, the lower limit of the amount of the isocyanurate reaction catalyst used is not particularly limited, but may be, for example, 10 mass ppm.

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

That is, the allophanatization reaction temperature is preferably 60° C. or higher and 160° C. or lower, more preferably 70° C. or higher and 155° C. or lower, even more preferably 80° C. or higher and 150° C. or lower, and particularly preferably 90° C. or higher and 145° C. or lower.
When the allophanatization reaction temperature is at least the above lower limit, it is possible to further improve the reaction rate. When the allophanatization reaction temperature is equal to or lower than the above upper limit, there is a tendency to more effectively suppress changes in properties such as coloring of the polyisocyanate.

The lower limit of the allophanatization reaction time is preferably 0.2 hours, more preferably 0.4 hours, still more preferably 0.6 hours, particularly preferably 0.8 hours, and most preferably 1 hour. On the other hand, the upper limit of the allophanatization reaction time is preferably 8 hours, more preferably 6 hours, still more preferably 4 hours, particularly preferably 3 hours, and most preferably 2 hours.
That is, the allophanatization reaction time is preferably 0.2 hours or more and 8 hours or less, more preferably 0.4 hours or more and 6 hours or less, further preferably 0.6 hours or more and 4 hours or less, and 0.8 hours or more and 3 hours. The following are particularly preferable, and 1 hour or more and 2 hours or less are most preferable.
When the allophanatization reaction time is at least the above lower limit, the viscosity of the polyisocyanate can be made lower. tend to be suppressed.

When the desired yield is obtained, a deactivator for the allophanatization reaction catalyst such as phosphoric acid or methyl p-toluenesulfonate is added to terminate the allophanatization reaction.

In the polyisocyanate, the molar ratio of allophanate groups to isocyanurate groups (hereinafter sometimes referred to as "allophanate groups/isocyanurate groups") is 0.50 or less from the viewpoint of improving crosslinkability. preferable. The allophanate group/isocyanurate group molar ratio can be measured by a ¹³ C-NMR measurement method.

(3) Method for Producing Polyisocyanate Containing Uretdione Group Examples of the method for producing polyisocyanate containing uretdione group include a method using a uretdione reaction catalyst.

Examples of specific compounds of the uretdione reaction catalyst include, but are not limited to, the tertiary phosphines, trialkylphosphines such as tri-n-butylphosphine and tri-n-octylphosphine; tris-(dimethyl tris(dialkylamino)phosphine such as amino)phosphine; and cycloalkylphosphine such as cyclohexyl-di-n-hexylphosphine.
Many of these compounds also accelerate the isocyanuration reaction at the same time to produce isocyanurate group-containing polyisocyanates in addition to uretdione group-containing polyisocyanates.

When the desired yield is obtained, a deactivator for the uretdione reaction catalyst such as phosphoric acid or methyl p-toluenesulfonate is added to terminate the uretdione formation reaction.

The amount of the catalyst described above is preferably 10 mass ppm or more and 10000 mass ppm or less, more preferably 10 mass ppm or more and 1000 mass ppm or less, still more preferably 10 mass ppm or more and 500 mass ppm or less with respect to the mass of the charged diisocyanate. use in

It is preferable to carry out the uretdiionization reaction at a temperature of 20°C or higher and 120°C or lower. The lower limit of the reaction temperature is more preferably 25°C, still more preferably 30°C, and even more preferably 35°C. Also, the upper limit of the reaction temperature is more preferably 110°C, still more preferably 100°C, and even more preferably 90°C. When the uretdione-forming reaction temperature is equal to or lower than the above upper limit, there is a tendency that changes in properties such as coloring can be further suppressed.

Further, uretdione groups can also be obtained by heating diisocyanate without using the uretdione reaction catalyst as described above. The heating temperature is preferably 130° C. or higher and 180° C. or lower. The lower limit of the heating temperature is more preferably 140°C, still more preferably 145°C, even more preferably 150°C, still more preferably 155°C. Also, the upper limit of the heating temperature is more preferably 170°C, still more preferably 165°C, even more preferably 162°C, and even more preferably 160°C.

Also, the heating time is preferably 0.2 hours or more and 8.0 hours or less. The lower limit of the heating time is more preferably 0.4 hours, still more preferably 0.6 hours, even more preferably 0.8 hours, still more preferably 1.0 hours. The upper limit of the heating time is more preferably 6.0 hours, still more preferably 4.0 hours, even more preferably 3.0 hours, still more preferably 2.0 hours. By setting the heating time to the above lower limit or more, it tends to be possible to further reduce the viscosity, and by setting it to the above upper limit or less, it tends to be possible to further suppress the coloring of the polyisocyanate itself.

When obtaining the polyisocyanate composition of the present embodiment without using a uretdione reaction catalyst, after the uretdione reaction by heating alone and the isocyanurate reaction described above are completed, unreacted diisocyanate can be removed. It is preferable from the viewpoints of reducing the concentration of unreacted diisocyanate, reducing the rate of change in molecular weight of the resulting polyisocyanate composition after storage, and reducing yellowing during high-temperature baking.

(Physical properties of polyisocyanate compound)
The viscosity of the polyisocyanate compound at 25° C. is 300 mPa·s or more and 5,000 mPa·s or less from the viewpoint of improving the dispersibility and pot life of the coating composition and improving the appearance and water resistance of the coating film. preferable.
The lower limit of the viscosity is more preferably 500 mPa·s, still more preferably 1,000 mPa·s, from the viewpoint of improving the water resistance, weather resistance, etc. of the formed coating film. On the other hand, the upper limit of the viscosity is more preferably 4,000 mPa·s, still more preferably 3,000 mPa·s, from the viewpoint of improving dispersibility and pot life.
The viscosity of the polyisocyanate compound can be measured, for example, at 25° C. with an E-type viscometer (manufactured by Tokimec Co., Ltd.) using a standard rotor (1°34′×R24).

With the unreacted aliphatic diisocyanate removed, the isocyanate group content (NCO%) of the polyisocyanate compound is preferably 18% by mass or more and 25% by mass or less, more preferably 19% by mass or more and 24% by mass or less. % by mass or more and 24 mass % or less is more preferable.
When the isocyanate group content is at least the above lower limit, the water resistance, chemical resistance, and weather resistance of a coating film are further improved. On the other hand, when it is equal to or less than the above upper limit, the dispersibility and pot life of the coating composition are further improved, and the appearance of the coating film is improved.
The isocyanate group content (NCO %) of the polyisocyanate compound can be measured by the titration method described in the examples below.

The number average molecular weight of the polyisocyanate compound is preferably 450 or more and 4000 or less, more preferably 500 or more and 3500 or less, and even more preferably 550 or more and 3000 or less, from the viewpoint of solvent resistance of the coating film.
The number average molecular weight can be measured using, for example, gel permeation chromatography (GPC).

The average number of functional groups of the polyisocyanate compound is preferably 1.8 or more and 6.2 or less, more preferably 2.0 or more and 5.6 or less, from the viewpoint of the solvent resistance of the coating film and the isocyanate group retention rate. 2.5 or more and 4.6 or less are more preferable.
The average number of functional groups is the number of isocyanate functional groups statistically possessed by one molecule of the polyisocyanate compound. can be calculated.

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

[Sulfonic acid having an active hydrogen group]
In the sulfonic acid having an active hydrogen group used for the polyisocyanate containing a sulfonate anion group in the molecule, examples of the active hydrogen group include an amino group, a carboxyl group, and a hydroxyl group. Among them, the active hydrogen group is preferably at least one selected from the group consisting of amino groups and hydroxyl groups.

(Sulfonic Acid (II) Having a Hydroxyl Group)
When the active hydrogen group is a hydroxyl group, examples of the sulfonic acid having a hydroxyl group include compounds represented by the following general formula (II) (hereinafter abbreviated as "sulfonic acid having a hydroxyl group (II)"), and the like. be done.

(In general formula (II), R ²¹ is a hydrocarbon group having 1 to 10 carbon atoms and 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 ²¹ may contain a ring structure, which is an aromatic ring, a 5- or 6-membered ring containing two nitrogen atoms, or a 5- or 6-membered ring containing a nitrogen atom and an oxygen atom. is a membered ring.)

The hydrocarbon group having 1 to 10 carbon atoms in R ²¹ may be a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 divalent carbon atoms. It may be a hydrogen group. The divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms is preferably a chain alkylene group having 1 to 6 carbon atoms. When it is a chain alkylene group having 1 or more and 6 or less carbon atoms, it may be a group containing a ring structure as part of the chain alkylene group. The alkylene group having 1 to 6 carbon atoms may be linear or branched.

Among them, R ²¹ includes a chain alkylene group having 1 to 6 carbon atoms, a divalent aromatic hydrocarbon group having 6 to 10 carbon atoms (arylene group), and a divalent carbon number of 1 or more including an aromatic ring. 10 or less alkylene group, a divalent C1-6 alkylene group containing a 5- or 6-membered ring containing two nitrogen atoms, or a 5- or 6-membered ring containing a nitrogen atom and an oxygen atom It is preferably a ring-containing divalent alkylene group having 1 to 6 carbon atoms.

Preferred sulfonic acids (II) containing a hydroxyl group include, for example, 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, 4-hydroxybutanesulfonic acid, 5-hydroxypentanesulfonic acid, 6-hydroxyhexanesulfonic acid, Hydroxybenzenesulfonic acid, hydroxy(methyl)benzenesulfonic acid, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid, 2-hydroxy-3 - morpholinopropanesulfonic acid, certain polyether sulfonates (eg those sold under the trade name Tegomer® (The Goldschmidt AG, Essen, Germany)), and the like.
Among them, the sulfonic acid having a hydroxyl group is at least one selected from the group consisting of 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, hydroxybenzenesulfonic acid, and hydroxy(methyl)benzenesulfonic acid. is preferred.

Moreover, the sulfonic acid (II) having a hydroxyl group, which is used in the polyisocyanate containing a sulfonate anion group in the molecule, may form a salt with an amine compound described below. That is, an amine salt of sulfonic acid (II) having a hydroxyl group may be used as a starting material for a polyisocyanate containing a sulfonic acid anion group in the molecule. When two or more amine salts of sulfonic acid (II) having a hydroxyl group are used, the sulfonic acids (II) having a hydroxyl group may be the same or different.

(Sulfonic acid (III) containing an amino group)
Examples of the amino group-containing sulfonic acid include compounds represented by the following general formula (III) (hereinafter sometimes referred to as "amino group-containing sulfonic acid (III)").

In general formula (III), R ³¹ and R ³² 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 ^R32 and ^R33 is a hydrogen atom. R ³³ is a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group.

In general formula (III), R ³¹ and R ³² 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. R ³¹ and R ³² may be the same or different. At least one of R ³¹ and R ³² is a hydrogen atom. That is, when R ³¹ is a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group, R ³² is a hydrogen atom. Further, when R ³² is a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group, R ³¹ is a hydrogen atom. Also, both R ³¹ and R ³² may be hydrogen atoms.

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

Among them, R ³¹ and R ³² are each preferably a hydrogen atom, a chain alkyl group having 1 to 6 carbon atoms, or a cyclic alkyl group having 3 to 6 carbon atoms.

R ³³ is a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group.
The hydrocarbon group having 1 to 12 carbon atoms may be a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. There may be. The divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms is preferably a chain alkylene group having 1 to 12 carbon atoms. The chain alkyl group having 1 to 12 carbon atoms may be linear or branched.
Among them, R ³³ is preferably a chain alkylene group having 1 to 6 divalent carbon atoms or an aromatic hydrocarbon group (arylene group) having 6 to 10 divalent carbon atoms.

Preferred amino group-containing sulfonic acids (III) include, for example, 2-aminoethanesulfonic acid, 3-aminopropanesulfonic acid, 2-methylaminoethanesulfonic acid, 3-methylaminopropanesulfonic acid, 2-cyclohexylamino ethanesulfonic acid, 3-cyclohexylaminopropanesulfonic acid, 3-cyclohexylaminoisobutylsulfonic acid, 4-cyclohexylaminobutanesulfonic acid, 2-cyclohexylmethylaminoethanesulfonic acid, 3-cyclohexylmethylaminopropanesulfonic acid, 3-cyclohexylmethyl aminoisobutylsulfonic acid, 4-cyclohexylmethylaminobutanesulfonic acid, 2-methylcyclohexylaminoethanesulfonic acid, 3-methylcyclohexylaminopropanesulfonic acid, 3-methylcyclohexylaminoisobutylsulfonic acid, 4-methylcyclohexylaminobutanesulfonic acid, 2-dimethylcyclohexylaminoethanesulfonic acid, 3-dimethylcyclohexylaminopropanesulfonic acid, 3-dimethylcyclohexylaminoisobutylsulfonic acid, 4-dimethylcyclohexylaminobutanesulfonic acid, 2-trimethylcyclohexylaminoethanesulfonic acid, 3-trimethylcyclohexylamino Propanesulfonic acid, 3-trimethylcyclohexylaminoisobutylsulfonic acid, 4-trimethylcyclohexylaminobutanesulfonic acid, 2-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 4-aminobenzenesulfonic acid, 2-(methylamino)benzene sulfonic acid, 3-(methylamino)benzenesulfonic acid, 4-(methylamino)benzenesulfonic acid, amino-methylbenzenesulfonic acid, amino-dimethylbenzenesulfonic acid, aminonaphthalenesulfonic acid and the like.

Among them, sulfonic acids having an amino group include 2-cyclohexylaminoethanesulfonic acid, 3-cyclohexylaminopropanesulfonic acid, 4-cyclohexylaminobutanesulfonic acid, 3-cyclohexylmethylaminopropanesulfonic acid, 3-(p-methyl cyclohexylamino)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 It is preferably at least one selected from the group consisting of (5-aminotoluene-2-sulfonic acid) and 2-aminonaphthalene-4-sulfonic acid.

<Amine compound>
The polyisocyanate composition of this embodiment includes tertiary ammonium cations of amine compounds. The polyisocyanate composition of the present embodiment may contain a single tertiary ammonium cation of an amine compound, or may contain two or more tertiary ammonium cations.

As used herein, the term "tertiary ammonium cation of an amine compound" means protonated amine compounds by coordinating protons (H ⁺ ) to "N" in the amine compounds.

The tertiary ammonium cation of the amine compound may form a salt with the sulfonate anion group.

[Amine compound (I)]
Examples of the amine compound include compounds represented by the following general formula (I) (hereinafter sometimes referred to as "amine compound (I)").

(In general formula (I), R ¹¹ , R ¹² and R ¹³ are each independently a hydrocarbon group having 1 to 10 carbon atoms which may contain an ether bond. R ¹¹ , R ¹² and R ¹³ At least one selected from the group consisting of may contain a ring structure, and two or more selected from the group consisting of R ¹¹ , R ¹² and R ¹³ may combine with each other to form a ring structure. The structure is an aromatic ring, a cycloalkyl group ^having 5 or 6 carbon atoms, ^{a 5- or 6-membered ring in which R 11 and R 12 are bonded} to each other, ^or It is a multi-membered polycycle.)

(R ¹¹ , R ¹² and R ¹³ )
In general formula (I), R ¹¹ , R ¹² and R ¹³ are each independently a hydrocarbon group having 1 or more and 6 or less carbon atoms which may contain an ether bond. R ¹¹ , R ¹² and R ¹³ may be the same or different.

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

Preferred amine compounds (I) include, for example, those shown in (a) to (d) below. In addition, these compounds are only a part of preferable amine compound (I), and preferable amine compound (I) is not limited to these.

(a) trimethylamine, N,N-dimethylethylamine, N,N-dimethylpropylamine, N,N-dimethylisopropylamine, N,N-dimethylbutylamine, N,N-dimethylisobutylamine, N,N-dimethylpentylamine , N,N-dimethylhexylamine, N,N-dimethylheptylamine, N,N-dimethyloctylamine, N,N-dimethyl-2-ethylhexylamine, N,N-dimethylnonylamine, N,N-dimethyldecyl Amine, N,N-diethylmethylamine, triethylamine, N,N-diethylpropylamine, N,N-diethylisopropylamine, N,N-diethylbutylamine, N,N-diethylisobutylamine, N,N-diisopropylmethylamine , N,N-diisopropylethylamine, N,N-diethylpentylamine, N,N-diethylhexylamine, N,N-diethylheptylamine, N,N-diethyloctylamine, N,N-diethyl-2-ethylhexylamine , N,N-diethylnonylamine, N,N-diethyldecylamine, tripropylamine, N,N-diisopropylbutylamine, N,N-diisopropyl-2-ethylhexylamine, N,N-dibutylmethylamine, N,N -dibutylethylamine, N,N-dibutylpropylamine, tributylamine, N,N-dibutylpentylamine, N,N-dibutylhexylamine, N,N-dibutylheptylamine, N,N-dibutyloctylamine, N,N -Chain aliphatic carbonization of dibutyl-2-ethylhexylamine, N,N-dibutylnonylamine, N,N-dibutyldecylamine, N,N-dimethylallylamine, N-methyldiallylamine, triamylamine, trihexylamine, etc. tertiary amines having a hydrogen group;
(b) Tertiary amines having a cycloaliphatic hydrocarbon group such as N,N-dimethylcyclohexylamine, N,N-diethylcyclohexylamine, N,N-dicyclohexylmethylamine, N,N-dicyclohexylethylamine and tricyclohexylamine kind;
(c) N,N-dimethylbenzylamine, N,N-diethylbenzylamine, N,N-dibenzylmethylamine, tribenzylamine, N,N-dimethyl-4-methylbenzylamine, N,N-dimethylphenyl Tertiary amines having an aromatic hydrocarbon group such as amine, N,N-diethylphenylamine, N,N-diphenylmethylamine;
(d) N-methylpyrrolidine, N-ethylpyrrolidine, N-propylpyrrolidine, N-butylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-propylpiperidine, N-methylmorpholine, N-ethylmorpholine, N- Cyclic amines such as propylmorpholine, N-butylmorpholine, N-sec-butylmorpholine, N-tert-butylmorpholine, N-isobutylmorpholine and quinuclidine.

Moreover, these amine compounds may be used alone or in combination of two or more.

Among them, the amine compound (I) is preferably at least one selected from the group consisting of an amine compound containing a chain aliphatic hydrocarbon group and an amine compound containing a cyclic aliphatic hydrocarbon group.
The amine compound containing a chain aliphatic hydrocarbon group is preferably at least one selected from the group consisting of tripropylamine, tributylamine, and N,N-diisopropylethylamine.
The amine compound containing a cycloaliphatic hydrocarbon group is preferably at least one selected from the group consisting of N,N-dimethylcyclohexylamine and N,N-diethylcyclohexylamine.
These amine compounds tend to further improve emulsifying power.

[Amine compound (I-1)]
The polyisocyanate composition of the present embodiment contains a compound represented by the general formula (I-1) (hereinafter sometimes referred to as "amine compound (I-1)") as the amine compound (I). is preferred.

（一般式（Ｉ－１）中、Ｒ^１１１及びＲ^１１２は、互いに独立して、エーテル結合を含んでもよい炭素数１以上８以下の炭化水素基である。Ｒ^１１１及びＲ^１１２からなる群より選ばれる少なくとも１つが環構造を含んでいてもよく、Ｒ^１１１及びＲ^１１２は互いに結合して環構造を形成してよい。前記環構造は、芳香族環、炭素数５若しくは６のシクロアルキル基、又は、Ｒ^１１１及びＲ^１１２が互いに結合した５員環若しくは６員環である。）

(In general formula (I-1), R ¹¹¹ and R ¹¹² are each independently a hydrocarbon group having 1 to 8 carbon atoms which may contain an ether bond. From the group consisting of R ¹¹¹ and R ¹¹² At least one selected may contain a ring structure, and R ¹¹¹ and R ¹¹² may combine to form a ring structure, which may be an aromatic ring or a cycloalkyl group having 5 or 6 carbon atoms. , or a 5- or 6-membered ring in which R ¹¹¹ and R ¹¹² are bonded to each other.)

(R ¹¹¹ and R ¹¹² )
R ¹¹¹ and R ¹¹² are each independently a hydrocarbon group having 1 to 8 carbon atoms which may contain an ether bond.

The hydrocarbon group having 1 to 8 carbon atoms may be a monovalent aliphatic hydrocarbon group having 1 to 8 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 10 carbon atoms, etc. may be The monovalent aliphatic hydrocarbon group having 1 to 8 carbon atoms is preferably a chain alkyl group having 1 to 8 carbon atoms or a cyclic alkyl group having 3 to 8 carbon atoms. The chain alkyl group having 1 to 8 carbon atoms may be linear or branched.

Preferred amine compounds (I-1) include, for example, N,N-diethylpropylamine, N,N-dibutylpropylamine, dimethylpropylamine, N-propylpyrrolidine, N-propylpiperidine, N-propylmorpholine and the like. be done. These compounds are only a part of the preferred amine compound (I-1), and the preferred amine compound (I-1) is not limited to these.

Among them, the amine compound (I-1) is preferably at least one selected from the group consisting of N,N-dipropyloctylamine and tripropylamine.

[Method for producing amine salt of sulfonic acid]
When the sulfonic acid forms a salt with the amine compound, that is, when it is an amine salt of sulfonic acid, for example, a sulfonic acid having an active hydrogen group and an amine compound are mixed and neutralized. can get.

The neutralization reaction may be carried out in advance before reacting with the polyisocyanate compound. Alternatively, it may be carried out simultaneously with the reaction with the polyisocyanate compound. Alternatively, the amine compound may be added after reacting the polyisocyanate compound with a sulfonic acid having an active hydrogen group.

When the active hydrogen group is a hydroxyl group, the neutralization reaction is preferably carried out in advance before reacting with the polyisocyanate compound. Further, when the active hydrogen group is an amino group, the neutralization reaction is carried out simultaneously with the reaction with the polyisocyanate compound, or the amine compound is reacted after the polyisocyanate compound is reacted with a sulfonic acid having an active hydrogen group. It is preferable to carry out by adding.

Further, when the active hydrogen group is a hydroxyl group, the ratio of mixing the sulfonic acid having a hydroxyl group and the amine compound in the neutralization reaction is the molar ratio of the amine compound to the sulfonic acid having a hydroxyl group (amine compound/hydroxyl group-containing sulfonic acid molar ratio) is preferably 0.5 or more and 2.0 or less, more preferably 0.8 or more and 1.5 or less.

When the neutralization reaction is carried out in advance, the temperature and time can be appropriately determined according to the progress of the reaction, but the temperature is preferably about 0° C. or higher and 100° C. or lower, and the mixing time is 10 minutes or longer. About 24 hours or less is preferable.

Water or a hydrophilic solvent is preferable as the solvent used in the preparation of the amine salt of sulfonic acid having an active hydrogen group. Examples of hydrophilic solvents include, but are not limited to, alcohols, ether alcohols, ketones, amide solvents, and the like. These solvents can be used alone or in combination.
Examples of alcohols include methanol, ethanol, propanol, butanol, isopropanol and the like.
Examples of 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, and dipropylene glycol monomethyl ether. is mentioned.
Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone and the like.
Examples of amide solvents include N,N-dimethylformamide and N,N-dimethylacetamide.

It is preferable to remove water or the hydrophilic solvent after the neutralization reaction.

<Inorganic acid and inorganic acid compound>
Examples of inorganic acids contained in the polyisocyanate composition of the present embodiment include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, sulfamic acid, hydrofluoric acid, sulfurous acid, and perchloric acid. Among them, sulfuric acid or hydrochloric acid is preferred.

The inorganic acid is derived from the raw material used for producing the sulfonic acid, or is mixed or by-produced during the production process of the polyisocyanate composition. Alternatively, the inorganic acid or inorganic acid compound may be added so that the content is within the above range.

Inorganic acids are often present as inorganic acid compounds in polyisocyanate compositions. Examples of inorganic acid compounds include inorganic acid amine salts, inorganic acid metal salts, and inorganic acid organic salts.

Inorganic acids often do not react with polyisocyanates, but they may.

<Other components>
The polyisocyanate composition of the present embodiment contains other components in addition to the polyisocyanate containing a sulfonate anion group in the molecule, the tertiary ammonium cation of the amine compound, and the inorganic acid or inorganic acid compound. good too. Examples of other components include, but are not limited to, solvents, antioxidants, light stabilizers, polymerization inhibitors, surfactants, antioxidants, and the like.

The solvent may be a hydrophilic solvent or a hydrophobic solvent. These solvents can be used alone or in combination.

Examples of the hydrophobic solvent include, but are not limited to, mineral spirits, solvent naphtha, LAWS (Low Aromatic White Spirit), HAWS (High Aromatic White Spirit), toluene, xylene, cyclohexane, esters, ketones, and amides. mentioned.
Examples of esters include ethyl acetate and butyl acetate.
Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like.
Examples of amides include N,N-dimethylformamide and N,N-dimethylacetamide.

Examples of the hydrophilic solvent include, but are not particularly limited to, alcohols, ethers, and esters of ether alcohols.
Examples of alcohols include methanol, ethanol, propanol, isopropanol, 2-ethylhexanol and the like.
Examples of ethers include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether.
Esters of ether alcohols include, for example, 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, and propylene glycol. monomethyl ether acetate, dipropylene glycol monomethyl ether acetate and the like.

In the polyisocyanate composition of the present embodiment, the solvent content is 0% by mass or more and 90% by mass or less with respect to the total mass of the polyisocyanate composition of the present embodiment from the viewpoint of ease of dispersion. It is preferably 0% by mass or more and 50% by mass or less, and even more preferably 0% by mass or more and 30% by mass or less.

Examples of antioxidants and light stabilizers include those shown in (a) to (e) below. These may be contained singly or in combination of two or more.
(a) Aliphatic, aromatic or alkyl-substituted aromatic esters of phosphoric acid or phosphorous acid and hypophosphorous acid derivatives.
(b) phosphorus compounds such as phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonates, dialkylpentaerythritol diphosphites, dialkylbisphenol A diphosphites;
(c) Phenolic derivatives (especially hindered phenol compounds).
(d) Compounds containing sulfur, such as thioether compounds, dithioate compounds, mercaptobenzimidazole compounds, thiocarbanilide compounds, and thiodipropionates.
(e) Tin-based compounds such as tin malate and dibutyltin monoxide.

Examples of polymerization inhibitors include hydroquinones, phenols, cresols, catechols, and benzoquinones. Specific examples of polymerization inhibitors include benzoquinone, p-benzoquinone, p-toluquinone, p-xyloquinone, naphthoquinone, 2,6-dichloroquinone, hydroquinone, trimethylhydroquinone, catechol, p-tert-butylcatechol, 2, 5-di-tert-butyl hydroquinone, monomethyl hydroquinone, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, hydroquinone monomethyl ether and the like. These may be contained singly or in combination of two or more.

Examples of surfactants include known anionic surfactants, cationic surfactants, and amphoteric surfactants.

In the polyisocyanate composition of the present embodiment, the total content of antioxidants, light stabilizers, polymerization inhibitors and surfactants is 0% by mass or more with respect to the total mass of the polyisocyanate composition of the present embodiment. It is preferably 10% by mass or less, more preferably 0% by mass or more and 5% by mass or less, and even more preferably 0% by mass or more and 2% by mass or less.

<Method for producing polyisocyanate composition>
The method for producing the polyisocyanate composition of the present embodiment preferably includes, for example, the step (A) of mixing and reacting an amine salt of a sulfonic acid having an active hydrogen group and a polyisocyanate.

Alternatively, the method for producing the polyisocyanate composition of the present embodiment preferably includes a step (B) of mixing and reacting, for example, a sulfonic acid having an active hydrogen group, a polyisocyanate, and an amine compound.

In step (A), the amine salt of sulfonic acid is preferably prepared in advance before being added to the polyisocyanate. Moreover, in the step (B), the sulfonic acid having an active hydrogen group and the amine compound may be added to the polyisocyanate simultaneously or sequentially.
Among them, the step (A) is preferable, and the amine salt of sulfonic acid is more preferably prepared in advance and then added to the polyisocyanate.

In the reaction between the polyisocyanate compound and the sulfonic acid having an active hydrogen group (hereinafter sometimes referred to as the "reaction step"), the mixing ratio of the sulfonic acid having an active hydrogen group or its amine salt and the polyisocyanate compound is , From the viewpoint of pot life and dispersibility, the molar ratio of isocyanate group / active hydrogen group is preferably in the range of 2 to 400, more preferably in the range of 5 to 200, and 10 to 100 The following range is more preferable.

In the reaction step, the reaction temperature and reaction time are appropriately determined according to the progress of the reaction, but the reaction temperature is preferably 0° C. or higher and 150° C. or lower, and the reaction time is preferably 30 minutes or longer and 48 hours or shorter. preferable.

In addition, in the reaction step, a conventional known catalyst may be used as the case may be. The catalyst is not particularly limited, but includes, for example, the following (a) to (f). These may be used singly or in combination.
(a) Tin octoate, tin 2-ethyl-1-hexanoate, tin ethylcaproate, tin laurate, tin palmitate, dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dimalate, dibutyltin dilaurate, dioctyltin di Organotin compounds such as acetate and dioctyltin dilaurate;
(b) organic zinc compounds such as zinc chloride, zinc octoate, zinc 2-ethyl-1-hexanoate, zinc 2-ethylcaproate, zinc stearate, zinc naphthenate, zinc acetylacetonate;
(c) an organotitanium compound;
(d) an organozirconium compound;
(e) tertiary amines such as triethylamine, tributylamine, N,N-diisopropylethylamine, N,N-dimethylethanolamine;
(f) diamines such as triethylenediamine, tetramethylethylenediamine, 1,4-diazabicyclo[2.2.2]octane;

In the method for producing the polyisocyanate composition of the present embodiment, the inorganic acid or inorganic acid compound may be controlled so that its content is within the above range depending on the origin of raw materials, or the inorganic acid or inorganic acid compound may be added so that the content is within the above range.

A solvent may or may not be used in the method for producing the polyisocyanate composition of the present embodiment. The solvent used in the method for producing the polyisocyanate composition of the present embodiment may be a hydrophilic solvent or a hydrophobic solvent. Examples of the hydrophilic solvent and the hydrophobic solvent include those exemplified in the above other constituent components.

Further, in the method for producing the polyisocyanate composition of the present embodiment, in addition to the polyisocyanate containing a sulfonate anion group in the molecule, the tertiary ammonium cation of the amine compound, and the inorganic acid or inorganic acid compound, further oxidation At least one selected from the group consisting of inhibitors, light stabilizers, polymerization inhibitors and surfactants may be added. Antioxidants, light stabilizers, polymerization inhibitors and surfactants are the same as those exemplified above for other components.

<Characteristics of polyisocyanate composition>
The isocyanate group content of the polyisocyanate composition of the present embodiment is 10.0% by mass or more and 25.0% by mass or less from the viewpoint of the solvent resistance of the coating film when the nonvolatile matter is 100% by mass. is preferred, and more preferably 15.0% by mass or more and 20.0% by mass or less. Methods for controlling the isocyanate group content within the above range include, but are not limited to, adjusting the compounding ratio of the sulfonic acid having an active hydrogen group and the polyisocyanate compound.

In addition, in this embodiment, the isocyanate group content can be measured by the method described in Examples below.

<Application>
The polyisocyanate composition of the present embodiment has good transparency, and has excellent pot life when used as a coating composition, and excellent appearance and water resistance when used as a coating film. can be suitably used as a curing agent or the like.

≪Coating composition≫
The coating composition of this embodiment contains the polyisocyanate composition described above and resins.

By including the polyisocyanate composition described above, the coating composition of the present embodiment is excellent in pot life, appearance and water resistance when formed into a coating film.

The coating composition of the present embodiment can also be used as an organic solvent-based coating composition. It is preferably used as a dissolved or dispersed aqueous coating composition. Architectural paints, automotive paints, automotive refinish paints, plastic paints, adhesives, adhesives, building materials, household water-based paints, other coatings, sealants, inks, casting materials, elastomers, foams, plastic raw materials , can also be used in textile treatment agents.

<Resins>
The resins of the main agent are not particularly limited, but examples include acrylic resins, polyester resins, polyether resins, epoxy resins, fluororesins, polyurethane resins, polyvinylidene chloride copolymers, polyvinyl chloride copolymers, polymers, vinyl acetate copolymers, acrylonitrile-butadiene copolymers, polybutadiene copolymers, styrene-butadiene copolymers, and the like.
Among them, acrylic resins, polyester resins or polyether resins are preferable as the resins.

[Acrylic resins]
Examples of acrylic resins include, but are not particularly limited to, acrylic resins obtained by polymerizing a single polymer selected from the following polymerizable monomers (a) to (e) or a mixture thereof. These acrylic resins may be used alone or in combination.
(a) methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate (Meth)acrylic acid esters such as
(b) 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, (meth)acrylate (meth)acrylic acid esters having active hydrogen such as 4-hydroxybutyl acrylate;
(c) unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid;
(d) Unsaturated amides such as acrylamide, N-methylol acrylamide and diacetone acrylamide.
(e) other polymerizable monomers such as glycidyl methacrylate, styrene, vinyltoluene, vinyl acetate, acrylonitrile, dibutyl fumarate, p-styrenesulfonic acid, allylsulfosuccinic acid;

Emulsion polymerization is a common method for polymerizing these monomers, but suspension polymerization, dispersion polymerization, and solution polymerization can also be used. Emulsion polymerization can also be carried out stepwise.

[Polyester resins]
Examples of polyester resins include, but are not particularly limited to, polyester resins obtained by a condensation reaction of a carboxylic acid alone or in mixture with a polyhydric alcohol alone or in mixture.

Examples of the carboxylic acid include succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid.

Examples of the polyhydric alcohol include diols, triols, tetraols and the like.
Diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3- butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,2-propanediol, 1,5-pentanediol, 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, 2-ethyl-hexanediol, 1, 2-octanediol, 1,2-decanediol, 2,2,4-trimethylpentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, etc. is mentioned.
Examples of triols include glycerin and trimethylolpropane.
Tetraols include, for example, diglycerin, dimethylolpropane, pentaerythritol and the like.

Alternatively, for example, polycaprolactones obtained by ring-opening polymerization of ε-caprolactone on hydroxyl groups of low-molecular-weight polyols can also be used as polyester resins.

[Polyether resins]
Examples of polyether resins include those shown in (a) to (d) below.
(a) Polyether polyols obtained by adding alkylene oxides alone or in mixtures to polyhydric hydroxy compounds alone or in mixtures using a strongly basic catalyst.
(b) Polyether polyols obtained by reacting a polyamine compound with an alkylene oxide.
(c) Polyether polyols obtained by ring-opening polymerization of cyclic ethers.
(d) So-called polymer polyols obtained by polymerizing acrylamide or the like using the polyether polyols obtained in (a) to (c) as a medium.

Examples of polyvalent hydroxy compounds in (a) include those shown in (i) to (vi) below.
(i) diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol and the like;
(ii) Sugar alcohol compounds such as erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol, mannitol, galactitol and rhamnitol.
(iii) monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose and ribodeose;
(iv) Disaccharides such as trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose and melibiose.
(v) trisaccharides such as raffinose, gentianose and melezitose;
(vi) tetrasaccharides such as stachyose;

Examples of the strongly basic catalyst in (a) include alkali metal hydroxides, alcoholates, and alkylamines. Alkali metals include, for example, lithium, sodium, potassium and the like.

Examples of the alkylene oxide in (a) include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.

Examples of the polyamine compound in (b) include ethylenediamines.

Cyclic ethers in (c) include, for example, tetrahydrofuran.

Moreover, in the coating composition of the present embodiment, these resins can be used in combination with resins such as melamine-based curing agents, urethane dispersions, and urethane acrylic emulsions, if necessary.

Moreover, these resins are preferably emulsified, dispersed or dissolved in water. Therefore, carboxy groups, sulfone groups, etc. contained in resins can be neutralized.
Neutralizing agents for neutralizing carboxy groups, sulfone groups and the like are not particularly limited, but examples thereof include ammonia and water-soluble amino compounds.
Examples of water-soluble amino compounds include monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, triethanolamine, butylamine, dibutylamine, 2-ethylhexylamine, and ethylenediamine. , propylenediamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, morpholine and the like. These may be used alone or in combination of two or more.
Among them, the neutralizing agent is preferably a tertiary amine, more preferably triethylamine or dimethylethanolamine.

<Other ingredients>
In addition to the polyisocyanate composition and resins described above, the coating composition of the present embodiment may further contain additives commonly added to paints. Examples of such additives include inorganic pigments, organic pigments, extender pigments, silane coupling agents, titanium coupling agents, organic phosphates, organic phosphites, thickeners, leveling agents, thixotropic agents, and Foaming agents, freeze stabilizers, matting agents, cross-linking reaction catalysts (catalysts for curing acceleration), anti-skinning agents, dispersants, wetting agents, fillers, plasticizers, lubricants, reducing agents, preservatives, antifungal agents agents, deodorants, anti-yellowing agents, ultraviolet absorbers, anti-static agents or charge control agents, anti-settling agents and the like. These additives may be contained singly or in combination of two or more.

The cross-linking reaction catalyst (catalyst for accelerating curing) is not limited to the following, but includes, for example, those shown in (a) or (b) below.
(a) metal salts such as dibutyltin dilaurate, tin 2-ethylhexanoate, zinc 2-ethylhexanoate and cobalt salts;
(b) triethylamine, pyridine, methylpyridine, benzyldimethylamine, N,N-dimethylcyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N,N'-endoethylenepiperazine, N,N'-dimethylpiperazine, etc. class amines.

The coating composition of the present embodiment may further contain a surfactant in addition to the polyisocyanate composition and resins described above in order to improve dispersibility in paint.

In order to improve the storage stability of the paint, the coating composition of the present embodiment may further contain an antioxidant, a light stabilizer, and a polymerization inhibitor in addition to the polyisocyanate composition and resins described above.

<Method for producing coating composition>
The coating composition of the present embodiment can be obtained by mixing the polyisocyanate composition and resins described above and, if necessary, other components using a known method.

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

When preparing a solvent-based coating composition, first, the additives exemplified above as other components are added to the resins or their solvent dilutions, if necessary. Next, the above polyisocyanate composition is added as a curing agent, and if necessary, a solvent is further added to adjust the viscosity. A solvent-based coating composition can then be obtained by hand stirring or stirring with a stirring device such as a Masellar.

≪Coating substrate≫
The coated substrate of this embodiment is a coated substrate coated with the coating composition described above. The coating substrate of the present embodiment preferably has a coating layer containing the coating composition described above.

The coating substrate of the present embodiment has a coating film formed by curing the coating composition described above, and therefore has excellent appearance and water resistance.

The coating substrate of the present embodiment is obtained by coating the above-described coating composition on a substrate using a known method such as roll coating, curtain flow coating, spray coating, bell coating, electrostatic coating, and drying at room temperature. Alternatively, it can be obtained by hardening through a baking process.

The coating substrate of this embodiment may comprise the desired substrate and optionally a conventional primer prior to coating.
Examples of the substrate include metal, wood, glass, stone, ceramic materials, concrete, hard and flexible plastics, textile products, leather products, and paper.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
The physical properties and evaluation of the polyisocyanate compositions in Examples and Comparative Examples were measured as follows. "Parts" and "%" mean "mass parts" and "mass%" unless otherwise specified.

<Measurement method>
[Physical properties 1]
(Content of inorganic acid or inorganic acid compound)
Using the polyisocyanate compositions obtained in Examples and Comparative Examples as samples, the inorganic acid or inorganic acid compound content in the polyisocyanate composition was determined by ion chromatography-mass spectrometry ( IC-MS).

(Measurement condition)
IC device: ICS-1500 (trade name) manufactured by Thermo Fisher Scientific Co., Ltd.
Column: AS12A
_Mobile phase: 2.7 mmol/L _Na2CO3 , 0.3 mmol/L _NaHCO3
Flow rate: 1.5mL/min
Sample injection volume: 1 mL
Suppressor: AERS-500
Detector: electrical conductivity detector Pretreatment method: The sample was combusted in a furnace, and the combustion gas was absorbed into the absorbent.

[Physical properties 2]
(viscosity)
The viscosity was measured at 25° C. with an E-type viscometer (manufactured by Tokimec Co., Ltd.). A standard rotor (1°34′×R ² 4) was used. The number of revolutions is as follows.

(Number of revolutions)
100r. p. m. (When less than 128 mPa s)
50r. p. m. (In the case of 128 mPa s or more and less than 256 mPa s)
20r. p. m. (In the case of 256 mPa·s or more and less than 640 mPa·s)
10r. p. m. (640 mPa·s or more and less than 1280 mPa·s)
5r. p. m. (In the case of 1280 mPa s or more and less than 2560 mPa s)
2.5r. p. m. (In the case of 2560 mPa s or more and less than 5120 mPa s)

[Physical properties 3]
(Isocyanate group content (NCO%))
Using the polyisocyanate compounds obtained in the Synthesis Examples and the polyisocyanate compositions obtained in the Examples and Comparative Examples as samples, the isocyanate group content was measured according to JIS K7301-1995 (Torylene for thermosetting urethane elastomers). Isocyanate type prepolymer test method). A more specific method for measuring the isocyanate group content (NCO%) is shown below.

(1) 1 g (Wg) of sample was collected in a 200 mL Erlenmeyer flask, and 20 mL of toluene was added to the flask to dissolve the sample.
(2) After that, 20 mL of a 2.0 N di-n-butylamine/toluene solution was added to the flask, and the mixture was allowed to stand for 15 minutes.
(3) 70 mL of 2-propanol was added to the flask and dissolved to obtain a solution.
(4) The solution obtained in (3) above was titrated with 1 mol/L hydrochloric acid to determine the sample titer (V ₁ mL).
(5) Even when no sample was added, measurements were performed in the same manner as in (1) to (3) above to determine the blank titer (V ₀ mL).

The isocyanate group content (NCO%) was calculated using the following formula from the sample titration amount and the blank titration amount obtained above.

"Isocyanate group content (mass%)"
= (V ₀ -V ₁ ) x 42/[W (1 g) x 1000] x 100
[Physical properties 4]
(Nonvolatile content)
When the polyisocyanate compositions obtained in Examples and Comparative Examples were used as samples and diluted with a solvent, the non-volatile content was calculated using the method shown below. First, the mass of an aluminum cup was accurately weighed (W0 g), about 1 g of a sample was put therein, and the cup mass (W1 g) before heat drying was accurately weighed. The cup containing the sample was then 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 accurately weighed again (W2 g). Then, the non-volatile content was calculated using the formula shown below, with the mass % of the dry residue in the sample as the non-volatile content. In the case of no solvent dilution, the non-volatile content was treated as substantially 100% by mass.

"Non-volatile content (mass%)" = (W2-W0) / (W1-W0) x 100

[Physical properties 5]
(molar equivalent ratio)
The molar equivalent ratio of isocyanate groups to active hydrogen groups (isocyanate group/hydroxy group molar equivalent ratio) during the production of the polyisocyanate compositions of Examples and Comparative Examples was calculated by the following method.
(1) The mass of the polyisocyanate used in Examples or Comparative Examples was W3 (unit: parts by mass), and the isocyanate group content of the polyisocyanate was NCO% (unit: mass%).
(2) The mass of the neutralized salt or sulfonic acid used in Examples or Comparative Examples was W4 (unit: parts by mass), and the molecular weight of the neutralized salt or sulfonic acid was M.
The molar equivalent ratio of isocyanate group/hydroxyl group at this time was calculated from the following formula.

"Molar equivalent ratio of isocyanate group / hydroxyl group"
= (W3 x NCO%/42)/(W4/M)

<Evaluation method>
[Evaluation 1]
(turbidity (transmittance))
The turbidity of a mixed solution of 70 parts by mass of the polyisocyanate composition and 30 parts by mass of propylene glycol monomethyl ether acetate was measured as transmittance (%) at 550 nm in UV measurement using JASCO V-650. The transparency was judged to be good when the transmittance was 90% or more.

[Manufacture of coating composition]
Acrylic polyol aqueous dispersion (manufactured by Covestro, product name “Bihydrol A2470”, hydroxyl value per resin: 128.7 mgKOH/g): 40 g was weighed into a container. Then, the ratio of the molar amount of isocyanate groups in the polyisocyanate compositions obtained in Examples and Comparative Examples to the molar amount of hydroxyl groups in the acrylic polyol aqueous dispersion (NCO/OH) was adjusted to 1.5. , was added to each polyisocyanate composition. Further, deionized water was added so that the solid content in the coating composition was 42% by mass, and the mixture was stirred at 600 rpm for 10 minutes using a propeller blade to obtain each coating composition. The following evaluation was performed using the produced coating composition.

[Evaluation 2]
(pot life)
Changes in the concentration of isocyanate groups in the coating composition were measured by infrared absorption spectrum measurement using FT/IR ⁴ 200 type A (trade name) manufactured by JASCO Corporation (detector: TGS, number of integrations: 16 times, resolution: 4 cm ^{− 1} ), it was calculated from the intensity ratio of the isocyanate absorption peak (wave number around 2271 cm ⁻¹ ) to the isocyanurate absorption peak (wave number around 1686 cm ⁻¹ ). Immediately after preparation of the coating composition is defined as 0 hours, the absorption peak intensity of isocyanate at that time/the absorption peak intensity of isocyanurate at that time = X0, and the peak intensity ratio after n hours = Xn, and "retention rate of isocyanate group" = Xn /X0 was calculated. The time during which the retention rate of isocyanate groups was maintained at 80% or more was measured, and the pot life was evaluated according to the following evaluation criteria.

(Evaluation criteria)
○: 4 hours or more △: 2 hours or more and less than 4 hours ×: less than 2 hours

[Evaluation 3]
(Appearance of coating film)
Using each coating composition, a white board was coated with a coating film having a thickness of 40 μm. Then, it was dried in an atmosphere of 23° C. and 50% humidity. After drying overnight, the coating film obtained the next day was measured using a gloss meter (digital gonio gloss meter UDV-6P (trade name) manufactured by Suga Test Instruments Co., Ltd.) under the conditions of JIS Z8741. The gloss value was measured at 60 degrees. It was measured. Appearance was evaluated according to the following evaluation criteria.

(Evaluation criteria)
○: 60 degree gloss value is 92% or more △: 60 degree gloss value is 85% or more and less than 92% ×: 60 degree gloss value is less than 85%

[Evaluation 4]
(Water resistance of coating film)
Each coating composition was applied to a glass plate with an applicator to a thickness of 40 μm. Then, it was dried in an atmosphere of 23° C. and 50% humidity for 7 days to obtain a coating film. Then, a silicon O-ring having a diameter of 20 mm was placed on the obtained coating film, and 0.5 g of water was poured into it. Then, it was left at 23° C. for 24 hours, and the state of the coating film was observed after water remaining on the surface was removed. The water resistance of the coating film was evaluated according to the following evaluation criteria. However, when the appearance of the coating film was x in the above "evaluation 3", visual evaluation was impossible, so measurement was not possible. Regarding the evaluation criteria, "blister" means blisters or blisters on the surface of the coating film.

(Evaluation criteria)
○: No change △: Gloss faded ×: Blistering occurred, cloudiness or dissolution of coating film

<Synthesis of sulfonic acid amine salt>
[Synthesis Example 1-1]
10 parts by mass of 1-propanol was added to 20 parts by mass of a 70% by mass aqueous solution of 2-hydroxyethanesulfonic acid (hereinafter sometimes abbreviated as “HES”) and stirred to obtain a solution. Furthermore, dimethylcyclohexylamine (hereinafter sometimes abbreviated as "DMCHA") is weighed so that the molar equivalent ratio to HES is 1, and the liquid diluted with the same part by weight of 1-propanol is added to the stirring solution. It was added dropwise to the solution. After 1 hour from the start of dropping, stirring is stopped, dehydration and solvent removal are performed with an evaporator, and 2-hydroxyethanesulfonic acid dimethylcyclohexylamine salt having a solid content of 99.8% by mass (hereinafter, sometimes abbreviated as "HES/DMCHA") ).

[Synthesis Example 1-2]
(Synthesis of HBS/TnPA)
10 parts by mass of 1-propanol was added to 20 parts by mass of an 85% by mass 4-hydroxybenzenesulfonic acid (hereinafter sometimes abbreviated as “HBS”) aqueous solution and stirred to obtain a solution. Furthermore, tripropylamine (hereinafter sometimes abbreviated as “TnPA”) was weighed so that the molar equivalent ratio to HBS was 1, and diluted with the same mass part of 1-propanol. It was added dropwise to the solution. After 1 hour from the start of dropping, stirring is stopped, dehydration and solvent removal are performed using an evaporator, and 4-hydroxybenzenesulfonic acid dimethylcyclohexylamine salt having a solid content of 99.8% by mass (hereinafter, may be abbreviated as "HBS/TnPA"). ).

<Synthesis of polyisocyanate>
[Synthesis Example 2-1]
(Synthesis of polyisocyanate P-1)
A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel was set to a nitrogen atmosphere, HDI: 1000 g, and isobutanol: 4.0 g were charged, and the temperature in the reactor was adjusted while stirring. was held at 70°C. Tetramethylammonium capriate was added thereto, and when the yield reached 25% by mass, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate P-1. The resulting polyisocyanate P-1 had a viscosity of 1500 mPa·s at 25° C. and an isocyanate group content of 23.1 mass %.

[Synthesis Example 2-2]
(Synthesis of polyisocyanate P-2)
Polyisocyanate P-2 was obtained in the same manner as in Synthesis Example 2-1, except that phosphoric acid was added to stop the reaction when the yield reached 50% by mass. The resulting polyisocyanate P-2 had a viscosity of 2700 mPa·s at 25° C. and an isocyanate group content of 21.7 mass %.

<Production of polyisocyanate composition>
[Example 1]
(Production of polyisocyanate composition PA-a1)
Polyisocyanate P-1 obtained in Synthesis Example 2-1: 100 parts by mass, so that the molar equivalent ratio of isocyanate group / hydroxyl group is 25, 2-hydroxyethanesulfonic acid obtained in Synthesis Example 1-1 Dimethylcyclohexylamine salt (HES/DMCHA): 6.8 parts by mass was added, and the reaction was carried out by stirring at 120°C for 3 hours under reflux under nitrogen, removing the reflux and stirring at 100°C for 1 hour. continued. After completion of the reaction, the temperature was lowered to 50° C. and sulfuric acid and a sulfuric acid compound were added to obtain a polyisocyanate composition PA-a1. IC-MS measurement revealed that the content of sulfuric acid and sulfate compounds was 2 mass ppm.

[Example 2]
(Production of polyisocyanate composition PA-a2)
Using the same method as in Example 1 except that the amount of sulfuric acid and sulfuric acid compound added was changed and the content of sulfuric acid and sulfuric acid compound was 10 ppm by mass by IC-MS measurement, a polyisocyanate composition was obtained. PA-a2 was produced.

[Example 3]
(Production of polyisocyanate composition PA-a3)
Using the same method as in Example 1 except that the amount of sulfuric acid and sulfuric acid compound added was changed and the content of sulfuric acid and sulfuric acid compound was 20 ppm by mass by IC-MS measurement, a polyisocyanate composition was obtained. PA-a3 was produced.

[Example 4]
(Production of polyisocyanate composition PA-a4)
Using the same method as in Example 1 except that the amount of sulfuric acid and sulfuric acid compound added was changed and the content of sulfuric acid and sulfuric acid compound was 50 ppm by mass by IC-MS measurement, a polyisocyanate composition was obtained. PA-a4 was produced.

[Example 5]
(Production of polyisocyanate composition PA-a5)
Polyisocyanate P-2 obtained in Synthesis Example 2-2: 100 parts by mass, so that the molar equivalent ratio of isocyanate group / hydroxyl group is 20, 4-hydroxybenzenesulfonic acid obtained in Synthesis Example 1-2 Tripropylamine salt (HBS/TnPA): 7.2 parts by mass was added, and the reaction was carried out by stirring at 120°C for 3 hours under reflux under nitrogen. continued. After completion of the reaction, the temperature was lowered to 50° C., sulfuric acid and a sulfuric acid compound were added, and polyisocyanate composition PA-a5 was obtained. IC-MS measurement revealed that the content of sulfuric acid and sulfate compounds was 10 mass ppm.

[Example 6]
(Production of polyisocyanate composition PA-a6)
Polyisocyanate composition was prepared using the same method as in Example 5 except that the amount of sulfuric acid and sulfuric acid compound added was changed and the content of sulfuric acid and sulfuric acid compound was 20 mass ppm by IC-MS measurement. PA-a6 was produced.

[Example 7]
(Production of polyisocyanate composition PA-a7)
Using the same method as in Example 5, except that the amount of sulfuric acid and sulfuric acid compound added was changed and the content of sulfuric acid and sulfuric acid compound was 50 ppm by mass by IC-MS measurement, a polyisocyanate composition was obtained. PA-a7 was produced.

[Example 8]
(Production of polyisocyanate composition PA-a8)
Polyisocyanate P-1 obtained in Synthesis Example 2-1: 100 parts by mass, 3-cyclohexyl so that the ratio of the molar amount of isocyanate groups to the molar amount of amino groups (isocyanate group / amino group) is 20 Aminopropanesulfonic acid (hereinafter sometimes abbreviated as “CAPS”): 6.1 parts by mass and DMCHA: 3.5 parts by mass were added, and the mixture was heated at 100° C. for 5 hours under reflux in a nitrogen atmosphere. The reaction was carried out with stirring. After completion of the reaction, the temperature was lowered to 50° C., sulfuric acid and sulfuric acid compound, and hydrochloric acid and hydrochloric acid compound were added to produce polyisocyanate composition PA-a8. According to IC-MS measurement, the content of sulfuric acid and sulfuric acid compounds was 10 mass ppm, and the content of hydrochloric acid and hydrochloric acid compounds was 15 mass ppm.

[Example 9]
(Production of polyisocyanate composition PA-a9)
By changing the added amounts of sulfuric acid and sulfate compounds, and hydrochloric acid and hydrochloric acid compounds, IC-MS measurement revealed that the content of sulfuric acid and sulfate compounds was 20 ppm by mass, and the content of hydrochloric acid and hydrochloric acid compounds was 30 mass ppm. A polyisocyanate composition PA-a9 was produced using the same method as in Example 8 except that it was ppm.

[Example 10]
(Production of polyisocyanate composition PA-a10)
By changing the added amounts of sulfuric acid and sulfate compounds, and hydrochloric acid and hydrochloric acid compounds, the content of sulfuric acid and sulfate compounds is 30 ppm by mass, and the content of hydrochloric acid and hydrochloric acid compounds is 50 mass ppm by IC-MS measurement. A polyisocyanate composition PA-a10 was produced using the same method as in Example 8, except that it was ppm.

[Example 11]
Polyisocyanate P-1 obtained in Synthesis Example 2-1: 100 parts by mass, so that the molar equivalent ratio of isocyanate group / hydroxyl group is 20, 2-hydroxyethanesulfonic acid obtained in Synthesis Example 1-1 Dimethylcyclohexylamine salt (HES/DMCH): 3.8 parts by mass and 4-hydroxybenzenesulfonic acid tributylamine salt (HBS/TBA) obtained in Synthesis Example 1-2: 3.7 parts by mass were added, and nitrogen Under reflux, the mixture was stirred at 120° C. for 3 hours to carry out the reaction. After completion of the reaction, the temperature was lowered to 50° C., sulfuric acid and a sulfuric acid compound were added, and polyisocyanate composition PA-a11 was obtained. IC-MS measurement revealed that the content of sulfuric acid and sulfate compounds was 20 mass ppm.

[Example 12]
Polyisocyanate P-1 obtained in Synthesis Example 2-1: 100 parts by mass, so that the molar equivalent ratio of isocyanate group / hydroxyl group is 20, 4-hydroxybenzenesulfonic acid obtained in Synthesis Example 1-2 Tributylamine salt (HBS/TBA): 3.8 parts by mass, CAPS: 3.26 parts by mass, and DMCHA: 1.84 parts by mass were added and stirred at 120°C for 3 hours under reflux under nitrogen. The reaction was allowed to continue by removing the reflux and stirring at 100° C. for 1 hour. After completion of the reaction, the temperature was lowered to 50° C. and sulfuric acid and a sulfuric acid compound were added to obtain a polyisocyanate composition PA-a12. IC-MS measurement revealed that the content of sulfuric acid and sulfate compounds was 25 mass ppm.

[Comparative Example 1]
(Production of polyisocyanate composition PA-b1)
Polyisocyanate P-1 obtained in Synthesis Example 2-1: 100 parts by mass, so that the molar equivalent ratio of isocyanate group / hydroxyl group is 25, 2-hydroxyethanesulfonic acid obtained in Synthesis Example 1-1 Dimethylcyclohexylamine salt (HES/DMCHA): 6.8 parts by mass was added, and the reaction was carried out by stirring at 120°C for 3 hours under reflux under nitrogen, removing the reflux and stirring at 100°C for 1 hour. was continued to produce a polyisocyanate composition PA-b1. According to IC-MS measurement, the content of sulfuric acid and sulfuric acid compounds was 0 ppm by mass, and the content of hydrochloric acid and hydrochloric acid compounds was 0 mass ppm.

[Comparative Example 2]
(Production of polyisocyanate composition PA-b2)
A polyisocyanate composition was prepared using the same method as in Comparative Example 1 except that the amount of sulfuric acid and sulfuric acid compound added was changed and the content of sulfuric acid and sulfuric acid compound was 150 mass ppm by IC-MS measurement. PA-b2 was produced.

[Comparative Example 3]
(Production of polyisocyanate composition PA-b3)
A polyisocyanate composition was prepared using the same method as in Comparative Example 1 except that the amount of sulfuric acid and sulfuric acid compound added was changed and the content of sulfuric acid and sulfuric acid compound was 300 ppm by mass by IC-MS measurement. PA-b3 was produced.

[Comparative Example 4]
(Production of polyisocyanate composition PA-b4)
Polyisocyanate P-1 obtained in Synthesis Example 2-1: 100 parts by mass, so that the molar equivalent ratio of isocyanate group / hydroxyl group is 20, 4-hydroxybenzenesulfonic acid obtained in Synthesis Example 1-2 Tripropylamine salt (HBS/TnPA): 7.6 parts by mass was added, and the reaction was carried out by stirring at 120°C for 3 hours under reflux under nitrogen. continued. After completion of the reaction, the temperature was lowered to 50° C. to produce polyisocyanate composition PA-b4. According to IC-MS measurement, the content of sulfuric acid and sulfuric acid compounds was 0 ppm by mass, and the content of hydrochloric acid and hydrochloric acid compounds was 0 mass ppm.

[Comparative Example 5]
(Production of polyisocyanate composition PA-b5)
Sulfuric acid and a sulfuric acid compound were added, and according to IC-MS measurement, the same method as in Comparative Example 4 was used except that the content of sulfuric acid and a sulfuric acid compound was 200 ppm by mass, to obtain a polyisocyanate composition PA-b2. manufactured.

[Comparative Example 6]
(Production of polyisocyanate composition PA-b6)
Sulfuric acid and a sulfuric acid compound were added, and the polyisocyanate composition PA-b6 was prepared using the same method as in Comparative Example 4 except that the content of sulfuric acid and a sulfuric acid compound was 500 mass ppm by IC-MS measurement. manufactured.

[Comparative Example 7]
(Production of polyisocyanate composition PA-b7)
Polyisocyanate P-1 obtained in Synthesis Example 2-1: 100 parts by mass, 3-cyclohexyl so that the ratio of the molar amount of isocyanate groups to the molar amount of amino groups (isocyanate group / amino group) is 20 Aminopropanesulfonic acid (hereinafter sometimes abbreviated as “CAPS”): 6.1 parts by mass and DMCHA: 3.5 parts by mass were added, and the mixture was heated at 100° C. for 5 hours under reflux in a nitrogen atmosphere. The reaction was carried out with stirring. After completion of the reaction, the temperature was lowered to 50° C., sulfuric acid and sulfuric acid compound, and hydrochloric acid and hydrochloric acid compound were added to produce polyisocyanate composition PA-a7. According to IC-MS measurement, the content of sulfuric acid and sulfuric acid compounds was 200 mass ppm, and the content of hydrochloric acid and hydrochloric acid compounds was 200 mass ppm.

The physical properties of the polyisocyanate compositions obtained in the above Examples and Comparative Examples were measured using the methods described above, and evaluated by the methods described above. The results are shown in the table below.

As shown in the table, a polyisocyanate composition PA-a1 containing a polyisocyanate containing a sulfonic acid anion group in the molecule, a tertiary ammonium cation of an amine compound, and a specific amount of an inorganic acid or an inorganic acid compound ~ PA-a12 (Examples 1 to 12) had good transparency, pot life when made into a coating composition, and excellent appearance and water resistance when made into a coating film.

On the other hand, it contains a polyisocyanate containing a sulfonate anion group in the molecule and a tertiary ammonium cation of an amine compound, but the content of the inorganic acid and the inorganic acid compound is less than 0.1 mass ppm or 100 mass ppm In the polyisocyanate compositions PA-b1 to PA-b7 (Comparative Examples 1 to 7), which are super, the transparency, the pot life when used as a coating composition, and the appearance and water resistance when used as a coating film are all However, no good results were obtained.

According to the polyisocyanate composition of the present embodiment, transparency is good, pot life when it is made into a coating composition, and appearance and water resistance when made into a coating film are provided. can be done.

Claims (13)

a polyisocyanate containing a sulfonate anion group in the molecule;
a tertiary ammonium cation of an amine compound;
A polyisocyanate composition comprising
A polyisocyanate composition containing an inorganic acid or an inorganic acid compound in an amount of 0.1 mass ppm or more and 100 mass ppm or less relative to the total mass of the polyisocyanate composition. The polyisocyanate composition according to claim 1, wherein the inorganic acid is one or more acids selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, sulfamic acid, hydrofluoric acid, sulfurous acid, and perchloric acid. . The polyisocyanate composition according to claim 1 or 2, wherein the amine compound contains a compound represented by the following general formula (I).

(In general formula (I), R ¹¹ , R ¹² and R ¹³ are each independently a hydrocarbon group having 1 to 10 carbon atoms which may contain an ether bond. R ¹¹ , R ¹² and R ¹³ At least one selected from the group consisting of may contain a ring structure, and two or more selected from the group consisting of R ¹¹ , R ¹² and R ¹³ may combine with each other to form a ring structure. The structure is an aromatic ring, a cycloalkyl group having 5 or 6 carbon atoms, ^{a 5- or 6-membered ring in which R 11 and R 12 are bonded} to each other ^{, or} It is a multi-membered polycycle.) The polyisocyanate composition according to any one of claims 1 to 3, wherein the amine compound contains a compound represented by the following general formula (I-1).

(In general formula (I-1), R ¹¹¹ and R ¹¹² are each independently a hydrocarbon group having 1 to 8 carbon atoms which may contain an ether bond. From the group consisting of R ¹¹¹ and R ¹¹² At least one selected may contain a ring structure, and R ¹¹¹ and R ¹¹² may combine to form a ring structure, which may be an aromatic ring or a cycloalkyl group having 5 or 6 carbon atoms. , or a 5- or 6-membered ring in which R ¹¹¹ and R ¹¹² are bonded to each other.) The polyisocyanate containing the sulfonic acid anion group in the molecule is obtained by reacting an amine salt of sulfonic acid having an active hydrogen group with the polyisocyanate,
The amine salt of sulfonic acid having an active hydrogen group is a compound represented by the general formula (I) or a salt with the compound represented by the general formula (I-1), according to claim 4. Polyisocyanate composition. 6. The polyisocyanate composition of claim 5, wherein said active hydrogen groups are hydroxyl groups. The polyisocyanate composition according to claim 5 or 6, wherein the sulfonic acid having an active hydrogen group is a compound represented by the following general formula (II).

(In general formula (II), R ²¹ is a hydrocarbon group having 1 to 10 carbon atoms and 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 ²¹ may contain a ring structure, which is an aromatic ring, a 5- or 6-membered ring containing two nitrogen atoms, or a 5- or 6-membered ring containing a nitrogen atom and an oxygen atom. is a membered ring.) 5. The polyisocyanate according to any one of claims 1 to 4, wherein the polyisocyanate containing a sulfonic acid anion group in the molecule is obtained by reacting a sulfonic acid having an active hydrogen group with a polyisocyanate. Composition. 9. The polyisocyanate composition of claim 8, wherein said active hydrogen groups are amino groups. The polyisocyanate composition according to claim 8 or 9, wherein the sulfonic acid having an active hydrogen group is a compound represented by the following general formula (III).

(In general formula (III), R ³¹ and R ³² are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group. Of R ³² and R ³³ At least one is a hydrogen atom.R ³³ is a hydrocarbon group having 1 or more and 12 or less carbon atoms which may contain a hydroxyl group.) The polyisocyanate composition according to any one of claims 1 to 10, which is used as a curing agent for a water-based two-component polyurethane composition. A coating composition comprising the polyisocyanate composition according to any one of claims 1 to 11 and resins. A coated substrate coated with the coating composition of claim 12 .