JP7249793B2 - Polyisocyanate composition, coating composition and coating substrate - Google Patents

Description

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

The two-component polyurethane coating composition is cured at room temperature, and the resulting coating film has excellent abrasion resistance, chemical resistance and stain resistance. In recent years, from the viewpoint of environmental conservation, there has been a demand for a water-based normal-temperature cross-linking two-liquid urethane coating composition, which has conventionally been used as a solvent-based coating.
Anionically modified polyisocyanates to impart hydrophilicity are characterized by their easy dispersibility in water and are gaining increasing acceptance in many fields. Many methods for producing such water-dispersible polyisocyanates have been reported so far.

For example, Patent Document 1 discloses a reaction product of a polyisocyanate compound and a compound having at least one sulfonic acid group and an isocyanate group.
Patent Documents 2 and 3 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 Documents 4 and 5 disclose modified polyisocyanates obtained by reacting an aminosulfonic acid having a specific structure with a polyisocyanate.

JP-A-8-176267 JP 2015-205957 A JP 2016-017157 A Japanese Patent No. 4806511 WO2015/035673

Water-based two-liquid urethane coating compositions are used for painting furniture and building materials, woodwork for houses, wooden floors for houses and school facilities, electric trains and construction machines, agricultural vehicles, and the like. There is a need for polyisocyanate compositions that provide coatings with excellent appearance, hardness, water resistance and stain resistance.

With the polyisocyanate composition described in Patent Document 1, it is difficult to achieve both excellent pot life and dispersibility when dispersed in water or a main agent containing water.
Patent documents 2 and 3 disclose that dispersibility in water is improved by using a polyisocyanate containing sulfonic acid groups. However, since the compatibility between the sulfonic acid group and the polyisocyanate is poor, there is a problem that the synthetic product becomes turbid. If sulfonic acid or its amine salt, which is highly organic, is used to improve this turbidity, the appearance of the coating film deteriorates. There is also a problem that the hardness of is lowered.
Patent Documents 4 and 5 disclose that the use of a modified polyisocyanate obtained by reaction with an aminosulfonic acid having a specific structure improves the coating film hardness and the solvent resistance of the coating film. On the other hand, since the aminosulfonic acid having the specific structure is relatively highly hydrophobic, there is a problem that the appearance of the coating film is deteriorated. In addition, although the hydrophobicity of aminosulfonic acid is relatively high, there is also the problem of poor water resistance and stain resistance.

The present invention has been made in view of the above circumstances, and can obtain excellent pot life and dispersibility when dispersed in water or a main agent containing water, and the appearance, hardness and A polyisocyanate composition having excellent water resistance is provided. A coating composition and a coating substrate using the polyisocyanate composition are provided.

That is, the present invention includes the following aspects.
The polyisocyanate composition according to the first aspect of the present invention contains a polyisocyanate containing a sulfonate anion group in the molecule and a tertiary ammonium cation of an amine compound represented by the following general formula (1). In the polyisocyanate composition, the sulfonate anion group is bound to the polyisocyanate via a urethane group or bonded to the polyisocyanate via an allophanate group.

(In general formula (1), 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.)

A molar ratio of the urethane groups to the allophanate groups may be 50/50 or more and 99/1 or less.
The polyisocyanate may have an isocyanurate group.
The polyisocyanate containing a sulfonic acid anion group in the molecule is obtained by reacting an amine salt of a sulfonic acid having a hydroxyl group with a polyisocyanate, and the amine salt of a sulfonic acid having a hydroxyl group has a hydroxyl group. A salt of a sulfonic acid and an amine compound represented by the general formula (1) may also be used.
The sulfonic acid having a hydroxyl group may be a compound represented by the following general formula (2).

(In general formula (2), R ²¹ is a hydrocarbon group having 1 to 10 carbon atoms which may contain at least one selected from the group consisting of a hydroxyl group, an ether bond, an ester bond, a carbonyl group, and an imino group. R 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 polyisocyanate may be at least one selected from the group consisting of aliphatic polyisocyanates, alicyclic polyisocyanates, and araliphatic polyisocyanates.

A coating composition according to the second aspect of the present invention comprises the polyisocyanate composition according to the first aspect.

A coated substrate according to the third aspect of the present invention is coated with the coating composition according to the second aspect.

According to the polyisocyanate composition of the above aspect, it is possible to obtain excellent pot life and dispersibility when dispersed in water or a main agent containing water, and the polyisocyanate composition having excellent appearance, hardness and water resistance when made into a coating film. An isocyanate composition can be provided. The coating composition of the above aspect contains the polyisocyanate composition and is excellent in appearance, hardness and water resistance when formed into a coating film. The coating substrate of the above aspect is made of the coating composition, and the coating film provided on the coating substrate is excellent in appearance, hardness 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 the present embodiment comprises a polyisocyanate containing a sulfonate anion group in the molecule and an amine compound represented by the following general formula (1) (hereinafter sometimes referred to as "amine compound (1)" a) and tertiary ammonium cations. Some of the sulfonate anion groups are bonded to polyisocyanate via urethane groups, while others are bonded to polyisocyanates via allophanate groups.

(In general formula (1), 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.)

Further, the molar ratio of the urethane groups linked to the sulfonate anion groups to the allophanate groups linked to the sulfonate anion groups (molar ratio of urethane groups/allophanate groups) is 40/60 or more and 99.9/0. 1 or less, preferably 50/50 or more and 99.5/0.5 or less, more preferably 50/50 or more and 99/1 or less, and even more preferably 55/45 or more and 85/15 or less.
When the urethane group/allophanate group molar ratio is within the above range, there is a tendency that the water dispersibility is excellent, and the hardness and water resistance of the coating film are excellent.

By having the above configuration, the polyisocyanate composition of the present embodiment has excellent dispersibility when dispersed in water or a main agent containing water, as shown in the examples below. Reaction with water is suppressed (improved pot life). Moreover, by using the polyisocyanate composition of the present embodiment, a coating film having excellent appearance, hardness and water resistance can be obtained.
The term "pot life" used herein refers to compositions such as paints and adhesives, which ensure the performance of the composition before curing after the composition is prepared by mixing the main agent and the curing agent. means time. 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 constituent components of the polyisocyanate composition of the present embodiment will be described in detail.

<Isocyanate component>
The polyisocyanate composition of the present embodiment usually contains, as an isocyanate component, unreacted 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 unreacted polyisocyanate and the polyisocyanate containing a sulfonate anion group in the molecule is, for example, based on 100 moles of the isocyanate group of the raw material polyisocyanate, It can be calculated from the ratio of isocyanate groups containing sulfonate anion groups in the molecule.

[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 a hydroxyl group or an amine salt thereof with a polyisocyanate, and a hydroxyl group. It is preferably a reactant obtained by reacting an amine salt of sulfonic acid with a polyisocyanate. Moreover, as the amine salt of a sulfonic acid having a hydroxyl group, a salt of a sulfonic acid having a hydroxyl group and the amine compound (1) is preferable.

(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, HDI, IPDI, hydrogenated XDI or hydrogenated MDI is preferable as the diisocyanate.

Polyisocyanates derived from the above diisocyanates are not particularly limited, but include, 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

Above all, the polyisocyanate used for the polyisocyanate containing a sulfonate anion group in the molecule is preferably the above (b), more preferably a polyisocyanate having an isocyanurate group.

Moreover, the polyisocyanate used for the polyisocyanate containing a sulfonate anion group in the molecule may contain an aliphatic triisocyanate. Examples of the aliphatic triisocyanate include 1,3,6-triisocyanatohexane, 1,8-diisocyanato-4-isocyanatomethyloctane, 2-isocyanatoethyl-2,6-diisocyanato-hexanoate, and the like. be done.

In addition, these polyisocyanates may be modified with nonionic hydrophilic groups such as alkoxypolyalkylene glycols, or vinyl polymers having hydroxyl groups and nonionic hydrophilic groups.

Moreover, these polyisocyanates can also be used individually by 1 type or in combination of 2 or more types.

- Method for producing polyisocyanate The method for producing a polyisocyanate containing an isocyanurate group is not particularly limited. Termination and removal of unreacted diisocyanate are included.

The catalyst used in the above isocyanurate-forming reaction is not particularly limited, but preferably exhibits basicity. Specifically, tetraalkylammonium hydroxide and organic weak acid salt, hydroxyalkylammonium hydroxide and organic Examples include weak acid salts, alkali metal salts of alkylcarboxylic acids, metal alcoholates, aminosilyl group-containing compounds, Mannich bases, combined use of tertiary amines and epoxy compounds, and phosphorus 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.
Alkali metal salts include, for example, 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. 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 monomers are 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. When the residual unreacted diisocyanate monomer concentration is within the above range, curability tends to be more excellent.

(Method for producing polyisocyanate containing sulfonate anion group in molecule)
A polyisocyanate containing a sulfonic acid anion group in the molecule is obtained by reacting a sulfonic acid having a hydroxyl group or an amine salt thereof with the above diisocyanate or the above polyisocyanate. By conversion to allophanate groups, the sulfonate anion groups can be bound to the polyisocyanate via urethane groups or allophanate groups.

The temperature for conversion to allophanate groups is generally 60°C or higher and 200°C, preferably 130°C or higher and 180°C or lower. When the temperature is equal to or higher than the above lower limit, it is possible to prevent the reaction rate from slowing down and more effectively increase the average functional number of isocyanate groups presumed to be attributed to the allophanatization reaction. On the other hand, when it is equal to or less than the above upper limit, undesirable side reactions such as coloring of the obtained polyisocyanate composition can be more effectively suppressed.

The time for conversion to allophanate groups varies depending on the reaction temperature, but is generally more than 0 hours and 8 hours or less, preferably 1 hour or more and 4 hours or less.

A catalyst can also be used in the reaction for conversion to allophanate groups. As the catalyst, those having basicity are generally preferred, and for example, catalysts that promote the allophanatization reaction shown in (a) to (c) below are effective.
(i) quaternary amine compounds such as tetraalkylammonium hydroxides and organic weak acid salts;
(b) Trioctylamine, 1,4-diazabicyclo(2,2,2)octane, 1,8-diazabicyclo(5,4,0)undecene-7, 1,5-diazabicyclo(4,3,0)nonene Tertiary amine compounds such as -5 (C) Acetylacetone metal salts and metal organic weak acid salts

Examples of the organic weak acid include acetic acid and capric acid.
Examples of the metal include zinc, tin, lead, and iron.

The conversion reaction from the urethane group to the allophanate group can be carried out by appropriately selecting the above reaction conditions so that the molar ratio of the urethane group/allophanate group is within the above range.

(sulfonic acid having a hydroxyl group)
Examples of the sulfonic acid having a hydroxyl group include compounds represented by the following general formula (2) (hereinafter abbreviated as "sulfonic acid (2)").

In the above formula (2), R ²¹ is a hydrocarbon group having 1 to 10 carbon atoms which may contain at least one selected from the group consisting of a hydroxyl group, an ether bond, an ester bond, a carbonyl group, and an imino group. . R ²¹ may contain a ring structure. The ring structure 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.

・^R21
In general formula (2), R ²¹ is a hydroxyl group, an ester bond (-COO-), an ether bond (-O-), a carbonyl group (-C(=O)-), an imino group (-NR-), and It is a hydrocarbon group having 1 to 10 carbon atoms which may contain at least one selected from the group consisting of ring structures.

The hydrocarbon group having 1 to 10 carbon atoms may be a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 10 carbon atoms. There may be. 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 (2) include, for example, 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, 4-hydroxybutanesulfonic acid, 5-hydroxypentanesulfonic acid, 6-hydroxyhexanesulfonic acid, hydroxybenzene sulfonic acid, hydroxy(methyl)benzenesulfonic acid, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid, 2-hydroxy-3-morpholino and propanesulfonic acid.
These compounds are only a part of preferred sulfonic acid (2), and preferred sulfonic acid (3) is not limited to these.
Moreover, one type of these sulfonic acids (2) may be used, or two or more types may be used in combination.

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.

When the polyisocyanate composition of the present embodiment contains two or more amine salts of sulfonic acid, the sulfonic acids (2) may be the same or different.

Moreover, the sulfonic acid used for the polyisocyanate containing the sulfonic acid anion group in the molecule preferably forms a salt with the amine compound (1).

<Tertiary Ammonium Cation of Amine Compound>
The polyisocyanate composition of this embodiment contains the tertiary ammonium cation of amine compound (1). The polyisocyanate composition of the present embodiment may contain the amine compound (1) singly or in combination of two or more.

(In general formula (1), 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.)

Moreover, in the polyisocyanate composition of the present embodiment, the amine compound (1) preferably forms a salt with the sulfonic acid.

[Amine compound (1)]
(R ¹¹ , R ¹² and R ¹³ )
In general formula (1), R ¹¹ , R ¹² and R ¹³ are each independently a hydrocarbon group having 1 or more and 10 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 10 carbon atoms may be a monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 carbon atoms. good. The monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms is preferably a chain alkyl group having 1 to 10 carbon atoms or a cyclic alkyl group having 3 to 10 carbon atoms. The chain alkyl group having 1 to 10 carbon atoms may be linear or branched.

Preferred amine compounds (1) include, for example, N,N-dimethylethylamine, N,N-dimethylpropylamine, N,N-dimethylisopropylamine, N,N-dimethylbutylamine, N,N-dimethylisobutylamine, N , N-dimethyloctylamine, N,N-dimethyl-2-ethylhexylamine, N,N-dimethyllaurylamine, N,N-diethylmethylamine, N,N-diethylbutylamine, N,N-diethylhexylamine, N , N-diethyloctylamine, N,N-diethyl-2-ethylhexylamine, N,N-diethyllaurylamine, N,N-diisopropylmethylamine, N,N-diisopropylethylamine, N,N-diisopropylbutylamine, N, N-diisopropyl-2-ethylhexylamine, N-methyl-dioctylamine, N,N-dimethylallylamine, N-methyldiallylamine, tripropylamine, tripropylamine, tributylamine, N,N-diethylpropylamine, N,N -dibutylpropylamine, N,N-dipropyloctylamine, N,N-dimethylbenzylamine, N,N-diethylbenzylamine, N,N-dibenzylmethylamine, tribenzylamine, N,N-dimethyl-4 -methylbenzylamine, N,N-dimethylcyclohexylamine, N,N-diethylcyclohexylamine, N,N-dicyclohexylmethylamine, N,N-dicyclohexylethylamine, tricyclohexylamine, N-methylpyrrolidine, N-ethylpyrrolidine, N-propylpyrrolidine, N-butylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-propylpiperidine, N-butylpiperidine, N-methylmorpholine, N-ethylmorpholine, N-propylmorpholine, N-butylmorpholine, N-sec-butylmorpholine, N-tert-butylmorpholine, N-isobutylmorpholine, quinuclidine and the like. In addition, these compounds are only a part of preferable amine compound (1), and preferable amine compound (1) is not limited to these. Moreover, one type of these amine compounds (1) may be used, or two or more types may be used in combination.

Among them, N,N-dimethylpropylamine, N,N-dimethylbutylamine, N,N-dimethyl-2-ethylhexylamine, N,N-diethylmethylamine, N,N-diisopropylethylamine, N,N-diisopropyl-2 -ethylhexylamine, N,N-dimethylallylamine, tripropylamine, tributylamine, N,N-diethylpropylamine, N,N-dibutylpropylamine, N,N-dipropyloctylamine, N,N-dimethylcyclohexylamine , N,N-dicyclohexylmethylamine, N-methylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-methylmorpholine, N-ethylmorpholine or N-isobutylmorpholine are preferred.

In addition, N,N-dimethylpropylamine, N,N-dimethylbutylamine, N,N-diethylmethylamine, N,N-diisopropylethylamine, tripropylamine, tributylamine, N,N-dipropyloctylamine, N, Particular preference is given to N-dimethylcyclohexylamine or N-methylpiperidine.

[Other amine compounds]
The polyisocyanate composition of the present embodiment may contain tertiary ammonium cations of other amine compounds in addition to the tertiary ammonium cations of the amine compound (1).
Other amine compounds are not particularly limited as long as they are other than the above amine compound (1). Specific examples of other amine compounds include those shown in (a) to (b) below. Moreover, one of these other amine compounds may be used, or two or more of them may be used in combination.
(a) trimethylamine, N,N-dimethylpentylamine, N,N-dimethylhexylamine, N,N-diethylisopropylamine, N,N-diethylisobutylamine, N,N-dimethylheptylamine, N,N-dimethyl nonylamine, N,N-dimethyldecylamine, N,N-dimethylundecylamine, N,N-dimethyldodecylamine, N,N-dimethyltridecylamine, N,N-dimethylstearylamine, N,N-diethyl Pentylamine, N,N-diethylheptylamine, N,N-diethylnonylamine, N,N-diethyldecylamine, N,N-diethylundecylamine, N,N-diethyldodecylamine, N,N-diethyltri Decylamine, N,N-diethylstearylamine, N,N-dibutylmethylamine, N,N-dibutylethylamine, N,N-dibutylpentylamine, N,N-dibutylhexylamine, N,N-dibutylheptylamine, N,N-dibutyloctylamine, N,N-dibutyl-2-ethylhexylamine, N,N-dibutylnonylamine, N,N-dibutyldecylamine, N,N-dibutylundecylamine, N,N-dibutyldodecyl Tertiary amines having chain aliphatic hydrocarbon groups such as amines, N,N-dibutyltridecylamine, N,N-dibutylstearylamine, triamylamine and trihexylamine;
(b) tertiary amines having an aromatic hydrocarbon group such as N,N-dimethylphenylamine, N,N-diethylphenylamine and N,N-diphenylmethylamine;

<Method for producing amine salt of sulfonic acid>
When the sulfonic acid forms a salt with the amine compound, i.e., when it is an amine salt of sulfonic acid, it can be obtained, for example, by mixing a sulfonic acid having a hydroxyl group and an amine compound, followed by a neutralization reaction. .

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

The neutralization reaction is preferably carried out in advance before reacting with the polyisocyanate.
In the neutralization reaction, the ratio of mixing the sulfonic acid having a hydroxyl group and the amine compound is preferably such that the molar ratio of the sulfonic acid having a hydroxyl group to the amine compound is 0.5 or more and 2 or less, and 0.8 or more and 1 0.5 or less is more preferable.

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 a hydroxyl 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.

<Characteristics of polyisocyanate composition>
From the viewpoint of emulsifiability and coating film properties, the polyisocyanate composition of the present embodiment contains 0.25 mol or more and 50 mol or less of sulfonic acid having a hydroxyl group with respect to 100 mol of isocyanate groups of the raw material polyisocyanate. Preferably, the isocyanate groups are modified at a ratio of 0.5 to 20 molar amounts, more preferably the isocyanate groups are modified at a ratio of 1 to 10 molar amounts. More preferably, the isocyanate groups are modified.

In addition, the isocyanate group content of the polyisocyanate composition of the present embodiment is 10% by mass or more and 25% by mass or less from the viewpoint of the solvent resistance of the coating film when the nonvolatile matter is 100% by mass. It is preferably 15% by mass or more and 24% 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 sulfonic acid and polyisocyanate.

In addition, the number average molecular weight of the polyisocyanate (including polyisocyanate containing a sulfonate anion group in the molecule and unreacted polyisocyanate) used in the polyisocyanate composition of the present embodiment is the solvent resistance of the coating film. Therefore, it is preferably 450 or more and 2,000 or less, more preferably 500 or more and 1800 or less, and even more preferably 550 or more and 1550 or less. A method for controlling the number average molecular weight within the above range is not particularly limited, but includes, for example, a method of adjusting the compounding ratio of the sulfonic acid, the amine compound, and the polyisocyanate.
The number average molecular weight can be measured using, for example, gel permeation chromatography (GPC).

In addition, the average number of functional groups of the polyisocyanate (including modified polyisocyanate and unreacted polyisocyanate) used in the polyisocyanate composition of the present embodiment is from the viewpoint of the solvent resistance of the coating film and the isocyanate group retention rate. , is preferably from 1.8 to 6.2, more preferably from 2.0 to 5.6, and even more preferably from 2.5 to 4.6. A method for controlling the average number of functional groups within the above range is not particularly limited, but includes, for example, a method of adjusting the compounding ratio of the sulfonic acid, the amine compound, and the polyisocyanate.

In the present embodiment, the isocyanate group content, non-volatile matter and average number of functional groups can be measured by the methods described in Examples below.

<Other ingredients>
The polyisocyanate composition of the present embodiment is a composition containing the above-described polyisocyanate containing a sulfonate anion group in the molecule, an unreacted polyisocyanate, and the tertiary ammonium cation of the amine compound (1). The polyisocyanate composition of the present embodiment contains other components in addition to the above-described polyisocyanate containing a sulfonate anion group in the molecule, the unreacted polyisocyanate, and the tertiary ammonium cation of the amine compound (1). good too. Examples of other components include, but are not particularly limited to, solvents, antioxidants, light stabilizers, polymerization inhibitors, surfactants, and the like.

The solvent used in the polyisocyanate composition of the present embodiment 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 preferably 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, and 0% by mass or more and 50% by mass. It is more preferably 0% by mass or less, and further 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) phenol derivatives (especially hindered phenol compounds);
(d) sulfur-containing compounds 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, pt-butylcatechol, 2, 5-di-t-butylhydroquinone, monomethylhydroquinone, p-methoxyphenol, 2,6-di-t-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, (A) a step of mixing and reacting an amine salt of a sulfonic acid having a hydroxyl group with a polyisocyanate.

Alternatively, the method for producing the polyisocyanate composition of the present embodiment preferably includes, for example, a step of mixing and reacting (B) a sulfonic acid having a hydroxyl group, a polyisocyanate, and the amine compound (1).

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 a hydroxyl 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 step, the mixing ratio of the sulfonic acid having a hydroxyl group or its amine salt and the polyisocyanate is in the range of 2 or more and 400 or less in terms of the emulsifying property and the coating film physical properties in terms of the isocyanate group/hydroxyl molar ratio. is preferably in the range of 5 or more and 200 or less, and further preferably in the range of 10 or more and 100 or less.

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 30 minutes or longer and 48 hours or shorter. is preferred.

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

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 hydrophobic solvent include those exemplified above for other components.

Further, in the method for producing a polyisocyanate composition of the present embodiment, in addition to a sulfonic acid having a hydroxyl group, a polyisocyanate, and an amine compound, an antioxidant, a light stabilizer, a polymerization inhibitor and a surfactant At least one selected from the group consisting of may be added. Antioxidants, light stabilizers, polymerization inhibitors, and surfactants include those exemplified above for other components.

≪Coating composition≫
The coating composition of this embodiment comprises the polyisocyanate composition described above.
The coating composition of the present embodiment can be used as an organic solvent-based coating composition, but is an aqueous coating composition in which resins, which are coating film-forming components, are dissolved or dispersed in a medium containing water as the main component. It is preferable to use as 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 or polyester resins are preferable as 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, itaconic acid;
(d) unsaturated amides such as acrylamide, N-methylol acrylamide, diacetone acrylamide;
(e) Other polymerizable monomers such as glycidyl methacrylate, styrene, vinyltoluene, vinyl acetate, acrylonitrile, dibutyl fumarate, p-styrenesulfonic acid, allylsulfosuccinic acid, etc.

As the polymerization method, emulsion polymerization is generally used, 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 the polyvalent hydroxy compound in (a) include those shown in the following (i) to (vi).
(i) diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol, etc.;
(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, ribodesose;
(iv) disaccharides such as trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose;
(v) trisaccharides such as raffinose, gentianose, 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.

Examples of the cyclic ethers in (c) include 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, carboxyl groups, sulfone groups, etc. contained in resins can be neutralized.
Neutralizing agents for neutralizing carboxyl 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 individually by 1 type, and may be contained in combination of 2 or more types.

Examples of the cross-linking reaction catalyst (catalyst for accelerating curing) include, but are not limited to, the following (a) or (b).
(a) metal salts such as dibutyltin dilaurate, tin 2-ethylhexanoate, zinc 2-ethylhexanoate, 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.

≪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 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.
Hereinafter, Example 5, Example 6 and Example 8 are referred to as Reference Example 5, Reference Example 6 and Reference Example 8, respectively.

<Measurement method>
[Physical Property 1] Viscosity Viscosity was measured at 25° C. with an E-type viscometer (manufactured by Tokimec Co., Ltd.). A standard rotor (1°34′×R24) 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 property 2] Isocyanate group content Using the polyisocyanate compositions obtained in Examples and Comparative Examples as samples, the isocyanate group content was measured according to JIS K7301-1995 (Tolylene diisocyanate type prepolymer for thermosetting urethane elastomer test method). A more specific method for measuring the isocyanate group content 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 obtain a sample titration volume (V1 mL).
(5) Even when no sample was added, measurements were carried out in the same manner as in (1) to (3) above to determine the blank titer (V0 mL).
From the sample titration amount and the blank titration amount obtained above, the isocyanate group content was calculated using the following formula (A).

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

[Physical property 3] Non-volatile 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 (B) 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%.

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

[Physical property 4] Number average molecular weight (Mn)
The number average molecular weight of the polyisocyanate composition was obtained by measuring the polystyrene-based number average molecular weight by GPC measurement under the measurement conditions shown below.

(Measurement condition)
Apparatus: Tosoh Corporation HLC-8120GPC (trade name)
Column: Tosoh Corporation TSKgel SuperH1000 (trade name) x 1 TSKgel SuperH2000 (trade name) x 1 TSKgel SuperH3000 (trade name) x 1 Carrier: Tetrahydrofuran Detection method: Differential refractometer

[Physical property 5] Average number of functional groups The average number of functional groups is the number of isocyanate functional groups statistically possessed by one polyisocyanate molecule. It was calculated using the formula (C).

Average functionality = Mn x NCO%/4200 (C)

[Physical property 6] Molar ratio of urethane group / allophanate group calculated from the peak area of

<Evaluation method>
[Evaluation 1] Appearance of polyisocyanate composition The polyisocyanate compositions obtained in Examples and Comparative Examples were visually checked for foreign matter and turbidity, and evaluated according to the following evaluation criteria.

(Evaluation criteria)
○: Transparent uniform liquid △: Slightly turbid ×: Foreign matter or turbidity

[Evaluation 2] Water Dispersibility of Polyisocyanate Composition Using the polyisocyanate compositions obtained in Examples and Comparative Examples as samples, the water dispersibility was evaluated using the method shown below.
(1) The mass of the 100 mL flask and Yoshino paper was measured (W0 g).
(2) The polyisocyanate composition was collected in a 100 mL flask so as to have a solid content of 16 g (W2 g), and 24 g of deionized water was added.
(3) Using a propeller blade, the solution in the 100 mL flask was stirred at 200 rpm for 3 minutes, and then filtered through the Yoshino paper weighed in (1).
(4) The filtration residue remaining on the Yoshino paper and the residue remaining in the 100 mL flask were combined and heated in a dryer at 105°C for 1 hour to determine the mass (g) (W1g).
(5) Using the following formula (D), the proportion of the polyisocyanate composition dispersed in water was determined. In addition, in Formula (D), Y is a non volatile matter (mass %).

Percentage dispersed in water (% by mass) = {1-(W2(g)-W0(g))/(W2(16g) x Y)} x 100 (D)

(6) Next, the water dispersibility was evaluated according to the following evaluation criteria.

(Evaluation criteria)
◎: 95% by mass or more ○: 90% by mass or more and less than 95% by mass △: 80% by mass or more and less than 90% by mass ×: less than 80% by mass

[Manufacture of coating composition]
Acrylic polyol aqueous dispersion (product name: Setaqua 6510, hydroxyl value per resin: 138 mgKOH/g, manufactured by Allnex): 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 aqueous acrylic polyol dispersion (NCO/OH) was adjusted to 1.25. , 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 3] Pot life Using each coating composition obtained by the above method, a coating film having a thickness of 40 μm was applied on a glass plate every hour until gelation, and the temperature was maintained at 23 ° C. and 50% humidity. After drying in an atmosphere, the gloss of the resulting coating film was measured the next day. Immediately after the preparation of the coating composition is 0 hours, the glossiness (20 °) of the coating film at that time is G0, the glossiness after n hours is Gn, and the isocyanate group retention rate = Gn/G0 is calculated. % or more was defined as pot life. 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 4] Appearance of Coating Film Each coating composition obtained by the above method was used to coat a coating film having a thickness of 40 μm on a glass plate. Then, it was dried in an atmosphere of 23° C. and 50% humidity, and the next day, the obtained coating film was visually observed. Appearance was evaluated according to the following evaluation criteria.

(Evaluation criteria)
○: Transparent, high gloss, no spots, good smoothness △: Transparent, low gloss, no spots, poor smoothness ×: Cloudy or with spots

[Evaluation 5] Hardness of Coating Film Using each coating composition obtained by the above method, a coating film having a thickness of 40 μm was applied onto a mild steel plate. Then, it was dried in an atmosphere of 23° C. and 50% humidity, and after 7 days, the pencil hardness of the obtained coating film was measured according to JIS K 5600-5-4. The hardness increases in the following order. Those having a pencil hardness of HB or more were evaluated as having good hardness.

(Pencil hardness)
2B<B<HB<F

[Evaluation 6] Water Resistance of Coating Film Using each coating composition obtained by the above method, a glass plate was coated with an applicator so as to have 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 4", 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 △: White turbidity, no blistering ×: Blistering, white turbidity or dissolution of coating film

<Synthesis of sulfonic acid amine salt>
[Synthesis Example 1] Synthesis of HBS/TBA 1-propanol: 10 parts by mass was added to 85% by mass of an aqueous solution of 4-hydroxybenzenesulfonic acid (hereinafter sometimes abbreviated as "HBS"): 20 parts by mass. to obtain a solution. Furthermore, tributylamine (hereinafter sometimes abbreviated as “TBA”) was weighed so that the molar equivalent ratio to HBS was 1, and diluted with the same part by mass of 1-propanol. dripped into. After 1 hour from the start of dropping, stirring is stopped, dehydration and solvent removal are performed using an evaporator, and 4-hydroxybenzenesulfonic acid tributylamine salt having a solid content of 99.8% by mass (hereinafter sometimes abbreviated as "HBS/TBA"). got

[Synthesis Example 2] Synthesis of HES/DIPEA 70% by mass of 2-hydroxybenzenesulfonic acid 85 (hereinafter sometimes abbreviated as “HES”) aqueous solution: 20 parts by mass, 1-propanol: 10 parts by mass is added. and stirred to obtain a solution. Furthermore, N,N-diisopropylethylamine (hereinafter sometimes abbreviated as "DIPEA") is weighed so that the molar equivalent ratio to HES is 1, and the solution diluted with the same mass part of 1-propanol is stirred. was added dropwise to the solution in the After 1 hour from the start of dropping, stirring is stopped, dehydration and solvent removal are performed using an evaporator, and 2-hydroxyethanesulfonic acid N,N-diisopropylethylamine salt having a solid content of 99.8% by mass (hereinafter abbreviated as “HES/DIPEA”) is obtained. in some cases).

[Synthesis Example 3] Synthesis of HES/TBA The same method as in Synthesis Example 2 was used, except that tributylamine (hereinafter sometimes abbreviated as "TBA") was used instead of DIPEA. 0.8% by mass of 2-hydroxyethanesulfonic acid tributylamine salt (hereinafter sometimes abbreviated as "HES/TBA") was obtained.

[Synthesis Example 4] Synthesis of HES/TnPA Instead of DIPEA, tripropylamine (hereinafter sometimes abbreviated as "TnPA") was used in the same manner as in Synthesis Example 2 to obtain 99.8% by mass of 2-hydroxyethanesulfonic acid tripropylamine salt (hereinafter sometimes abbreviated as "HES/TnPA") was obtained.

[Synthesis Example 5] Synthesis of HES/DMCHA Solid content 99.8% by mass of 2-hydroxyethanesulfonic acid dimethylcyclohexylamine salt (hereinafter sometimes abbreviated as "HES/DMCHA") was obtained.

[Synthesis Example 6] Synthesis of HBS/DMCHA A solid content was 99.8% by mass of 4-hydroxyethanesulfonic acid tributylamine salt (hereinafter sometimes abbreviated as "HBS/DMCHA") was obtained.

[Synthesis Example 7] Synthesis of HES/N-methylpyrrolidine Using the same method as in Synthesis Example 2, except that N-methylpyrrolidine was used instead of DIPEA, a 2-hydroxy An ethanesulfonic acid N-methylpyrrolidine salt (hereinafter sometimes abbreviated as "HES/N-methylpyrrolidine") was obtained.

<Synthesis of polyisocyanate>
[Synthesis Example 8] Synthesis of polyisocyanate P-1 A four-necked flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube, and dropping funnel was set to a nitrogen atmosphere, HDI: 1000 g, and isobutanol: 4.0 g was charged, and the temperature inside the reactor was maintained at 70° C. while stirring. Tetramethylammonium capriate was added thereto, and when the yield reached 25%, 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%.

[Synthesis Example 9] Synthesis of polyisocyanate P-2 Polyisocyanate P-2 was prepared in the same manner as in Synthesis Example 8, except that phosphoric acid was added to stop the reaction when the yield reached 50%. got The resulting polyisocyanate P-2 had a viscosity of 2700 mPa·s at 25° C. and an isocyanate group content of 21.7%.

<Production of polyisocyanate composition>
[Example 1] Production of polyisocyanate composition PA-1a Polyisocyanate P-2 obtained in Synthesis Example 9: 100 parts by mass, 4-hydroxybenzenesulfonic acid tributylamine salt (HBS) obtained in Synthesis Example 1 /TBA): 7.8 parts by mass (molar equivalent ratio of isocyanate group/hydroxyl group=about 20) was added, and the reaction was carried out by stirring at 120° C. for 3 hours under reflux under nitrogen. Then, the temperature was raised to 140° C. and held for 2 hours. After that, the reflux was removed and the reaction was continued by stirring at 100° C. for 1 hour to obtain a polyisocyanate composition PA-1a.

[Example 2] Production of polyisocyanate composition PA-2a Instead of polyisocyanate P-2 obtained in Synthesis Example 9, polyisocyanate P-1 obtained in Synthesis Example 8: 100 parts by mass, Synthesis Example 7.3 parts by mass of 2-hydroxyethanesulfonic acid dimethylpropylamine salt (HES/DIPEA) obtained in Synthesis Example 2 was added in place of the HBS/TBA obtained in 1, and the mixture was stirred under reflux under nitrogen. The reaction was carried out by stirring at 120° C. for 3 hours. Then, polyisocyanate composition PA-2a was produced in the same manner as in Example 1 except that the temperature was raised to 160° C. and held for 2 hours.

[Example 3] Production of polyisocyanate composition PA-3a Instead of HBS/TBA obtained in Synthesis Example 1, 2-hydroxyethanesulfonic acid tributylamine salt (HES/TBA) obtained in Synthesis Example 3: 7.5 parts by mass was added, and the reaction was carried out by stirring at 120° C. for 3 hours under reflux under nitrogen. Then, polyisocyanate composition PA-3a was produced in the same manner as in Example 1 except that the temperature was raised to 160° C. and held for 2 hours.

[Example 4] Production of polyisocyanate composition PA-4a Instead of polyisocyanate P-2 obtained in Synthesis Example 9, polyisocyanate P-1 obtained in Synthesis Example 8: 100 parts by mass, Synthesis Example 7.5 parts by mass of the 2-hydroxyethanesulfonic acid tripropylamine salt (HES/TnPA) obtained in Synthesis Example 4 was added in place of the HBS/TBA obtained in 1, and the mixture was refluxed under nitrogen. The reaction was carried out by stirring at 120° C. for 3 hours. Then, polyisocyanate composition PA-4a was produced in the same manner as in Example 1 except that the temperature was raised to 145° C. and held for 3 hours.

[Example 5] Production of polyisocyanate composition PA-5a Instead of polyisocyanate P-2 obtained in Synthesis Example 9, polyisocyanate P-1 obtained in Synthesis Example 8: 100 parts by mass, Synthesis Example 7.3 parts by mass of 2-hydroxyethanesulfonic acid dimethylcyclohexylamine salt (HES/DMCHA) obtained in Synthesis Example 5 was added in place of the HBS/TBA obtained in 1, and the mixture was refluxed under nitrogen. The reaction was carried out by stirring at 120° C. for 3 hours. Then, polyisocyanate composition PA-5a was produced in the same manner as in Example 1, except that the temperature was raised to 130° C. and held for 1 hour.

[Example 6] Production of polyisocyanate composition PA-6a Instead of HBS/TBA obtained in Synthesis Example 1, 4-hydroxybenzenesulfonic acid dimethylcyclohexylamine salt (HBS/DMCHA) obtained in Synthesis Example 6 was used. : 7.8 parts by mass were added, and the reaction was carried out by stirring at 120°C for 3 hours under reflux under nitrogen. Then, polyisocyanate composition PA-6a was produced in the same manner as in Example 1, except that the temperature was raised to 140° C. and held for 1 hour.

[Example 7] Production of polyisocyanate composition PA-7a Instead of the HBS/TBA obtained in Synthesis Example 1, the 2-hydroxyethanesulfonic acid N-methylpyrrolidine salt (HES/N -methylpyrrolidine): A polyisocyanate composition PA-7a was produced in the same manner as in Example 1, except that 6.7 parts by mass was used.

[Example 8] Production of polyisocyanate composition PA-8a Polyisocyanate P-2 obtained in Synthesis Example 9: 100 parts by mass, HES / TBA obtained in Synthesis Example 3: 7.5 parts by mass (isocyanate The molar equivalent ratio of group/hydroxyl group=about 20) was added, and the reaction was carried out by stirring at 120° C. for 3 hours under reflux under nitrogen. Then, the temperature was raised to 160° C. and held for 4 hours. Thereafter, the reflux was removed and the reaction was continued by stirring at 100° C. for 1 hour to obtain polyisocyanate composition PA-8a.

[Comparative Example 1] Production of polyisocyanate composition PA-1b Polyisocyanate P-2 obtained in Synthesis Example 9: 100 parts by mass, HES / TBA obtained in Synthesis Example 3: 7.5 parts by mass (isocyanate The molar equivalent ratio of group/hydroxyl group=about 20) was added, and the reaction was carried out by stirring at 100° C. for 3 hours under reflux under nitrogen. Without raising the temperature, the reflux was removed and the reaction was continued by stirring at 80° C. for 1 hour to obtain a polyisocyanate composition PA-1b.

[Comparative Example 2] Production of polyisocyanate composition PA-2b Instead of HES/TBA obtained in Synthesis Example 3, the 4-hydroxybenzenesulfonic acid tributylamine salt (HBS/TBA) obtained in Synthesis Example 1: A polyisocyanate composition PA-2b was produced in the same manner as in Comparative Example 1 except that 7.8 parts by mass was used.

[Comparative Example 3] Production of polyisocyanate composition PA-3b Instead of polyisocyanate P-2 obtained in Synthesis Example 9, polyisocyanate P-1 obtained in Synthesis Example 8: 100 parts by mass, Synthesis Example Polyisocyanate composition PA- 3b was produced.

The physical properties of the polyisocyanate compositions obtained in Examples and Comparative Examples were measured using the methods described above. Table 1 shows the results. Moreover, evaluation was performed by the method described above using the obtained polyisocyanate composition. Table 1 shows the results.

From Table 1, polyisocyanate composition PA-a1 in which a sulfonate anion group is bonded to polyisocyanate via a urethane group and a polyisocyanate composition bonded to polyisocyanate via an allophanate group is mixed. -PA-a8 (Examples 1 to 8) had excellent pot life and dispersibility when dispersed in water, and had good appearance, hardness and water resistance when formed into a coating film.

Further, from a comparison of Examples 1 to 8, polyisocyanate compositions PA-a1 to PA-a4 and PA-a6 to PA-a8 having a urethane group/allophanate group ratio of 92/8 or less (Examples 1 to 4, 6 In ~8), the polyisocyanate compositions PA-a1 to PA-a4 and PA having a urethane group/allophanate group ratio of 55/45 or more and 82/18 or less have better water resistance when formed into a coating film. In -a6 and PA-a7 (Examples 1 to 4, 6 and 7), a polyisocyanate composition having better water dispersibility and a urethane group/allophanate group ratio of 55/45 or more and 70/30 or less In (Examples 2 to 4), there was a tendency for the hardness of the coating film to be particularly good.

On the other hand, in the polyisocyanate compositions PA-b1 to PA-b3 (Comparative Examples 1 to 3) in which the sulfonate anion group is bonded to the polyisocyanate only through the urethane group, the dispersibility is poor when dispersed in water. Although it was good, the pot life was poor, and the appearance of the coating film was good, but the hardness and water resistance were poor.

The polyisocyanate composition of the present embodiment can obtain excellent pot life and dispersibility when dispersed in water or a main agent containing water, and is excellent in appearance, hardness and water resistance when formed into a coating film.

Claims (7)

a polyisocyanate containing a sulfonate anion group in the molecule;
A polyisocyanate composition containing a tertiary ammonium cation of an amine compound represented by the following general formula (1),
The sulfonate anion group includes those bonded to the polyisocyanate via a urethane group and those bonded to the polyisocyanate via an allophanate group,
A polyisocyanate composition , wherein the molar ratio of the urethane groups to the allophanate groups is 50/50 or more and 85/15 or less .

(In general formula (1), 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.) 2. The polyisocyanate composition of claim 1, wherein the polyisocyanate has isocyanurate groups. The polyisocyanate containing the sulfonic acid anion group in the molecule is obtained by reacting an amine salt of sulfonic acid having a hydroxyl group with the polyisocyanate,
The polyisocyanate composition according to claim 1 or 2 , wherein the amine salt of sulfonic acid having a hydroxyl group is a salt of a sulfonic acid having a hydroxyl group and an amine compound represented by the general formula (1). 4. The polyisocyanate composition according to claim 3 , wherein the sulfonic acid having a hydroxyl group is a compound represented by the following general formula (2).

(In general formula (2), R ²¹ is a hydrocarbon group having 1 to 10 carbon atoms which may contain at least one selected from the group consisting of a hydroxyl group, an ether bond, an ester bond, a carbonyl group, and an imino group. R 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 polyisocyanate according to any one of claims 1 to 4 , wherein the polyisocyanate is at least one selected from the group consisting of aliphatic polyisocyanates, alicyclic polyisocyanates, and araliphatic polyisocyanates. Composition. A coating composition comprising the polyisocyanate composition according to any one of claims 1-5 . A coated substrate coated with the coating composition of claim 6 .