JP7267677B2 - Curing agent composition and aqueous coating composition - Google Patents

Description

The present invention relates to hardener compositions and waterborne coating compositions.

In recent years, from the viewpoint of environmental protection, there is a demand for a water-based two-liquid urethane coating composition which is used as a solvent-based paint and which is cross-linked at room temperature. However, the polyisocyanate used as the curing agent in the two-liquid urethane coating composition is difficult to disperse in water. Therefore, the development of polyisocyanates having hydrophilic groups is underway.

For example, Patent Document 1 discloses a hydrophilic polyisocyanate composed of a polyisocyanate and a nonionic hydrophilic group containing an ethylene oxide repeating unit bonded to the polyisocyanate, and an ionic polyisocyanate containing substantially no water. Polyisocyanate compositions comprising surfactants are disclosed. In addition, US Pat. No. 6,200,000 discloses water-dispersible polyisocyanate mixtures containing a specific range of ethylene oxide units.

JP-A-9-328654 JP-A-5-222150

The water-based two-liquid urethane coating composition is applied to furniture and building materials, woodwork for housing, sports floors, wooden floors for housing and school facilities, trains and construction machines, agricultural vehicles, and the like. For those uses, excellent pot life when used as a coating liquid and excellent blister resistance when used as a coating film are required.
However, the hydrophilic polyisocyanate compositions described in Patent Document 1 and Patent Document 2 may have reduced pot life when used as a coating liquid and blister resistance when used as a coating film, and satisfy these requirements. was difficult.

The present invention has been made in view of the above circumstances, and is stably dispersed in water, and has excellent pot life when used as a coating liquid, and excellent appearance and blister resistance when used as a coating film. A hardener composition is provided. Provided is a water-based coating composition that contains the curing agent composition and is excellent in pot life, appearance, and blister resistance when formed into a coating film.

That is, the present invention includes the following aspects.
The curing agent composition according to the first aspect of the present invention includes (A) a hydrophilic polyisocyanate component of 79.5% by mass or more and 99.0% by mass or less relative to the total mass of solids in the composition. , 0.1% by mass or more and 20.0% by mass or less of (B) an ionic surfactant, and 0.01% by mass or more and 0.5% by mass or less of a (C) sulfonate. wherein the (A) hydrophilic polyisocyanate component is a polyisocyanate obtained from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and a reaction product of a hydrophilic compound and the (C) sulfonate is one or more compounds selected from the group consisting of compounds represented by the following general formula (I) and compounds represented by the following general formula (II), B) Excluding compounds represented by the following general formula (I) and compounds represented by the following general formula (II) from ionic surfactants.

(In general formula (I), R ¹¹ and M ¹¹⁺ are any of the combinations shown in 1) to 3) below;
1) R ¹¹ = 2-ethylhexyl and M ¹¹⁺ = Na ⁺ ;
2) R ¹¹ =2-ethylhexyl and M ¹¹⁺ =K ⁺ ; and
3) R ¹¹ =2-ethylhexyl and M ¹¹⁺ =NH ₄ ⁺ . )

(in general formula (II), R ²¹ , R ²² and M ²¹⁺ are any of the combinations shown in 4) to 6) below;
4) R ²¹ = 2-ethylhexyl, R ²² = methyl and M ²¹⁺ = Na ⁺ ;
5) R ²¹ =methyl, R ²² =2-ethylhexyl, and M ²¹⁺ =K ⁺ ; and
6) R21 ⁼ methyl, R22 ⁼ ethyl and M21 ⁺ = _NH4 ⁺ . )

The curing agent composition according to the first aspect may contain the compound represented by the general formula (I) and the compound represented by the general formula (II) as the (C) sulfonate.
In the curing agent composition according to the first aspect, the hydrophilic compound may be a compound represented by the following general formula (III).

(In general formula (III), R ³¹ is an alkylene group having 1 to 4 carbon atoms. R ³² is an alkyl group having 1 to 4 carbon atoms. n31 is 5 to 50.)

In the curing agent composition according to the first aspect, in the general formula (III), R ³¹ may be an ethylene group, and n31 may be 5 or more and 20 or less.
In the curing agent composition according to the first aspect, the polyisocyanate may have one or more functional groups selected from the group consisting of isocyanurate groups and biuret groups.
In the curing agent composition according to the first aspect, the (B) ionic surfactant is (C1-C20) ammonium alkylbenzenesulfonate, sodium (C1-C20 alkyl)benzenesulfonate, or di(C1-C20 alkyl) sodium sulfosuccinate .

（一般式（Ｉ）中、Ｒ ^１１ 及びＭ ^１１＋ は、以下の１）～３）に示す組み合わせのいずれかである；
１）Ｒ ^１１ ＝２－エチルヘキシル、及びＭ ^１１＋ ＝Ｎａ ^＋ ；
２）Ｒ ^１１ ＝２－エチルヘキシル、及びＭ ^１１＋ ＝Ｋ ^＋ ；並びに、
３）Ｒ ^１１ ＝２－エチルヘキシル、及びＭ ^１１＋ ＝ＮＨ _４ ^＋ 。）

（一般式（ＩＩ）中、Ｒ ^２１ 、Ｒ ^２２ 及びＭ ^２１＋ は、以下の４）～６）に示す組み合わせのいずれかである；
４）Ｒ ^２１ ＝２－エチルヘキシル、Ｒ ^２２ ＝メチル、及びＭ ^２１＋ ＝Ｎａ ^＋ ；
５）Ｒ ^２１ ＝メチル、Ｒ ^２２ ＝２－エチルヘキシル、及びＭ ^２１＋ ＝Ｋ ^＋ ；並びに、
６）Ｒ ^２１ ＝メチル、Ｒ ^２２ ＝エチル、及びＭ ^２１＋ ＝ＮＨ _４ ^＋ 。） A water-based coating composition according to the second aspect of the present invention comprises the curing agent composition according to the first aspect, water, and an active hydrogen group-containing compound.
The method according to the third aspect of the present invention is a method for improving the appearance and blister resistance of a coating film, and is 79.5% by mass or more and 99.0% by mass based on the total mass of solids in the composition. % or less (A) hydrophilic polyisocyanate component, 0.1% by mass or more and 20.0% by mass or less (B) ionic surfactant, and 0.01% by mass or more and 0.5% by mass or less ( C) forming a coating film using a curing agent composition containing a sulfonate, wherein the (A) hydrophilic polyisocyanate component is selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates is a reaction product of a polyisocyanate obtained from one or more diisocyanates and a hydrophilic compound, and the (C) sulfonate is a compound represented by the following general formula (I) and a compound represented by the following general formula (II) One or more compounds selected from the group consisting of the compounds represented by the compounds represented by the following general formula (I) and the compounds represented by the following general formula (II) from the (B) ionic surfactant Except .

(In general formula (I), R ¹¹ and M ¹¹⁺ are any of the combinations shown in 1) to 3) below;
1) R ¹¹ = 2-ethylhexyl and M ¹¹⁺ = Na ⁺ ;
2) R ¹¹ =2-ethylhexyl and M ¹¹⁺ =K ⁺ ; and
3) R ¹¹ =2-ethylhexyl and M ¹¹⁺ =NH ₄ ⁺ . )

(in general formula (II), R ²¹ , R ²² and M ²¹⁺ are any of the combinations shown in 4) to 6) below;
4) R ²¹ = 2-ethylhexyl, R ²² = methyl and M ²¹⁺ = Na ⁺ ;
5) R ²¹ =methyl, R ²² =2-ethylhexyl, and M ²¹⁺ =K ⁺ ; and
6) R21 ⁼ methyl, R22 ⁼ ethyl and M21 ⁺ = _NH4 ⁺ . )

The curing agent composition of the above aspect is stably dispersed in water, and has excellent pot life when used as a coating liquid, and excellent appearance and blister resistance when used as a coating film. The water-based coating composition of the above aspect is excellent in pot life, appearance and blister resistance when formed into a coating film.

EMBODIMENT OF THE INVENTION Hereinafter, the form (henceforth "this embodiment") for implementing this invention is demonstrated in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. Various modifications are possible for the present invention without departing from the gist thereof.

The amount of a particular functional group possessed by a composition or compound can be expressed herein as "molar ratio." That is, the dimension of the value obtained by dividing the number of specific functional groups possessed by the composition or compound by Avogadro's number is defined as moles. Thereby, the amount of the specified functional group is expressed as a "molar ratio" relative to the amount of other specified functional groups.
The “specific functional group possessed by the composition” refers to a specific functional group possessed by a compound contained in the composition.

As used herein, "polyol" means a compound having two or more hydroxy groups (--OH) in one molecule.
In this specification, the term "polyisocyanate" means a reactant in which a plurality of compounds having one or more isocyanate groups (--NCO) are bonded. One molecule of a compound having one or more isocyanate groups (--NCO) derived from polyisocyanate may be referred to as a monomer.

<<Curing agent composition>>
The curing agent composition of the present embodiment comprises (A) a hydrophilic polyisocyanate component of 79.5% by mass or more and 99.9% by mass or less relative to the total mass of solids in the composition, and 0.1 (B) an ionic surfactant in an amount of 0.01% to 0.5% by mass and a sulfonate (C) in an amount of 0.01% to 0.5% by mass.
The (A) hydrophilic polyisocyanate component is a reaction product of a hydrophilic compound and a polyisocyanate obtained from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.
(C) Sulfonate is a compound represented by the following general formula (I) (hereinafter sometimes referred to as "compound (I)") and a compound represented by the following general formula (II) (hereinafter referred to as "compound ( II)” is one or more compounds selected from the group consisting of

(In general formula (I), R ¹¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. M ¹¹⁺ is Na ⁺ , K ⁺ or NH ₄ ⁺ .)

(In general formula (II), R ²¹ and R ²² are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. M ²¹⁺ is Na ⁺ , K ⁺ or NH ₄ ⁺ .)

By having the above configuration, the curing agent composition of the present embodiment is stably dispersed in water, and has a pot life when used as a coating liquid, and an appearance and blister resistance when used as a coating film. Excellent.
Next, the constituent components of the curing agent composition of this embodiment will be described in detail below.

<(A) Hydrophilic polyisocyanate component>
The (A) hydrophilic polyisocyanate component contained in the curing agent composition of the present embodiment includes a polyisocyanate obtained from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and hydrophilic It is a reactant with a compound. That is, (A) the hydrophilic polyisocyanate component is a hydrophilic polyisocyanate that is a reaction product to which a hydrophilic group derived from a hydrophilic compound is added by reacting a hydrophilic compound with an isocyanate group, and an unreacted of polyisocyanates.

[Polyisocyanate]
(A) The polyisocyanate used in the production of the hydrophilic polyisocyanate component is a reactant obtained by multiple reactions of one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.
As used herein, the terms "aliphatic diisocyanate" and "alicyclic diisocyanate" mean compounds that do not contain an aromatic ring such as a benzene ring in the structure of the diisocyanate.

The aliphatic diisocyanate is not particularly limited, but preferably has 4 to 30 carbon atoms. Specific examples of aliphatic diisocyanates include tetramethylene-1,4-diisocyanate, 2-methylpentane-1,5-diisocyanate (hereinafter sometimes referred to as "MPDI"), hexamethylene diisocyanate (hereinafter, " HDI”), 2,2,4-trimethyl-hexamethylene-1,6-diisocyanate, lysine diisocyanate (hereinafter sometimes referred to as “LDI”), and the like.
The alicyclic diisocyanate is not particularly limited, but preferably has 8 or more and 30 or less carbon atoms. Specific examples of the alicyclic diisocyanate include isophorone diisocyanate (hereinafter sometimes referred to as "IPDI"), hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,4-cyclohexane diisocyanate, and the like.
These aliphatic diisocyanates and alicyclic diisocyanates may be used singly or in combination of two or more.
Among them, the diisocyanate is preferably HDI, IPDI, hydrogenated xylylene diisocyanate or hydrogenated diphenylmethane diisocyanate, and more preferably HDI, because of its industrial availability. (A) Since the polyisocyanate used in the production of the hydrophilic polyisocyanate component is obtained by reacting HDI, the appearance and weather resistance when the coating film is produced using the curing agent composition of the present embodiment tend to be better.

(Functional group of polyisocyanate)
(A) The polyisocyanate used for producing the hydrophilic polyisocyanate component preferably contains a reactant obtained by reacting two or more molecules of diisocyanate, and a reactant obtained by reacting three or more molecules of diisocyanate. It is more preferable to include As a result, curability, hardness and weather resistance tend to be more excellent when a coating film is produced using the curing agent composition of the present embodiment.

Polyisocyanates containing reactants obtained by reacting two or more diisocyanate molecules include isocyanurate groups, biuret groups, uretdione groups, oxadiazinetrione groups, iminooxadiazinedione groups, allophanate groups, urethane groups and urea groups. It can contain one or more selected from the group consisting of
Above all, it is preferable that the polyisocyanate used for producing the hydrophilic polyisocyanate component (A) contains an isocyanurate group. As a result, curability, hardness and weather resistance tend to be more excellent when a coating film is produced using the curing agent composition of the present embodiment.
Moreover, it is preferable that the polyisocyanate used for producing the hydrophilic polyisocyanate component (A) contains a biuret group. As a result, the curing agent composition of the present embodiment tends to be more excellent in water dispersion stability, curability and adhesion when formed into a coating film.

(Method for producing polyisocyanate)
1. Method for producing polyisocyanate containing 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 when it becomes

The catalyst used in the above isocyanurate-forming reaction is not particularly limited, but one exhibiting basicity is preferred. Specific examples of the catalyst include those shown in (1) to (8) below.
(1) Hydroxides of tetraalkylammonium such as tetramethylammonium and tetraethylammonium, and organic weak acid salts thereof such as acetic acid and capric acid.
(2) Hydroxylalkylammonium hydroxides such as trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium and triethylhydroxyethylammonium, and their organic weak acid salts such as acetic acid and capric acid.
(3) Alkali metal salts such as tin, zinc and lead of alkylcarboxylic acids such as acetic acid, caproic acid, octylic acid and myristic acid.
(4) metal alcoholates such as sodium and potassium;
(5) Aminosilyl group-containing compounds such as hexamethyldisilazane.
(6) Mannich bases.
(7) Mixtures of tertiary amines and epoxy compounds.
(8) Phosphorus compounds such as tributylphosphine.

The amount of the catalyst used is preferably 10 ppm or more and 11000 ppm or less with respect to the total mass of the raw material diisocyanate.
In addition, in order to terminate the isocyanurate reaction, the catalyst may be deactivated by addition of an acidic substance such as phosphoric acid or acid phosphate for neutralizing the catalyst, thermal decomposition, chemical decomposition, or the like.

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. On the other hand, when the reaction temperature is equal to or lower than the above upper limit, side reactions that cause coloration tend to be more suppressed.

After completion of the isocyanurate-forming reaction, unreacted diisocyanate monomers are preferably removed by thin film evaporator, extraction, or the like.
Further, (A) when the polyisocyanate used for producing the hydrophilic polyisocyanate component contains unreacted diisocyanate, 3.0 mass of unreacted diisocyanate with respect to the total mass of the hydrophilic polyisocyanate component (A) % or less, more preferably 1.0 mass % or less, and even more preferably 0.5 mass % or less. When the concentration of the residual unreacted diisocyanate monomer is equal to or less than the above upper limit, curability tends to be more excellent when a coating film is produced using the curing agent composition of the present embodiment.

2. Method for Producing Biuret Group-Containing Polyisocyanate The method for producing the biuret group-containing polyisocyanate is not particularly limited, but the method disclosed in Japanese Patent Publication No. 62-041496 (reference document 1) is preferably exemplified. Specifically, first, the reaction between the diisocyanate monomer and the biuretizing agent is carried out under uniform stirring. Thereafter, a polyisocyanate containing biuret groups is obtained by continuous production in which the reaction product is further introduced into a pipe reactor and the reaction proceeds in the pipe reactor under the extrusion flow.

(Physical properties of polyisocyanate)
(A) The physical properties of the polyisocyanate used in the production of the hydrophilic polyisocyanate component are described in detail below.

1. Viscosity (A) The viscosity at 25° C. of the polyisocyanate used for producing the hydrophilic polyisocyanate component is not particularly limited, but is preferably 100 mPa s or more and 30000 mPa s or less, and 500 mPa s or more and 10000 mPa s or less. is more preferable.
The viscosity at 25° C. can be measured by the method described in Examples below.

2. Isocyanate Group Content (A) The isocyanate group content of the polyisocyanate used for producing the hydrophilic polyisocyanate component is not particularly limited, but is 5.0% by mass or more and 25% by mass or less with respect to the total mass of the polyisocyanate. , more preferably 10% by mass or more and 24% by mass or less, and even more preferably 15% by mass or more and 24% by mass or less.
The isocyanate group content can be measured by the method described in Examples below.

[Hydrophilic compound]
(A) The hydrophilic polyisocyanate contained in the hydrophilic polyisocyanate component has a structural unit derived from a hydrophilic compound. This is because the hydrophilic compound is a compound having a hydrophilic group. That is, the hydrophilic group is a functional group possessed by (added to) the hydrophilic polyisocyanate obtained by reacting the hydrophilic compound with the polyisocyanate. (A) The hydrophilic polyisocyanate contained in the hydrophilic polyisocyanate component can stably disperse in water by having (adding to) a hydrophilic group.

Examples of hydrophilic groups include, but are not limited to, nonionic hydrophilic groups, cationic hydrophilic groups, and anionic hydrophilic groups.
Among them, nonionic hydrophilic groups are preferable as the hydrophilic group from the viewpoint of availability and resistance to electrical interaction with the formulation.

(Hydrophilic compound having nonionic hydrophilic group)
The hydrophilic compound having a nonionic hydrophilic group is not particularly limited, and examples thereof include monoalcohols, compounds obtained by adding alkylene oxide to hydroxyl groups of alcohols, and compounds represented by the following general formula (III) (hereinafter referred to as "compound ( III)”) and the like. Monoalcohols include, for example, methanol, ethanol, butanol, and the like. Examples of the compound obtained by adding alkylene oxide to the hydroxyl group of alcohol include alkylene glycol and dialkylene glycol. These hydrophilic compounds having a nonionic hydrophilic group also have an active hydrogen-containing group that reacts with an isocyanate group in addition to the hydrophilic group.

(In general formula (III), R ³¹ is an alkylene group having 1 to 4 carbon atoms. R ³² is an alkyl group having 1 to 4 carbon atoms. n31 is 5 to 50.)

Among them, as the hydrophilic compound having a nonionic hydrophilic group, a monoalcohol or compound (III) is preferable because it can improve the water dispersibility of the curing agent composition of the present embodiment with a small amount used, and compound (III) is more preferred.

1. Compound (III)
Compound (III) is a polyalkylene glycol monoalkyl ether. Compound (III) is described in detail below.

・^R31
In general formula (III), R ³¹ is an alkylene group having 1 to 4 carbon atoms. The alkylene group may be linear, branched, or cyclic (aliphatic cyclic group). The number of carbon atoms in the alkylene group is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and even more preferably 1 or more and 2 or less.
Specific examples of the alkylene group include methylene group, dimethylene group, trimethylene group, tetramethylene group, ethylene group, n-propylene group, isopropylene group, cyclopropylene group, n-butylene group, isobutylene group and sec-butylene. group, tert-butylene group, cyclobutylene group and the like.
Among them, the alkylene group is preferably a methylene group or an ethylene group, and more preferably an ethylene group.

・^R32
In general formula (III), R ³² is an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear, branched, or cyclic (aliphatic cyclic group). The number of carbon atoms in the alkyl group is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and even more preferably 1 or more and 2 or less.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, cyclobutyl group and the like. .
Among them, the alkyl group is preferably a methyl group or an ethyl group, more preferably a methyl group.

・n31
In general formula (III), n31 is the number of repeating alkyleneoxy groups (--R ³¹ --O--). n31 is preferably 5 or more and 50 or less, more preferably 5 or more and 30 or less, because the water dispersibility of the curing agent composition of the present embodiment and the precipitation of the curing agent composition of the present embodiment during low-temperature storage can be suppressed. More preferably, 5 or more and 20 or less is even more preferable.

Preferred examples of compound (III) include compounds represented by the following formula (III)-1 (ie, polyethylene glycol monomethyl ether).

In formula (III)-1, n311 is 5 or more and 20 or less.

(Hydrophilic compound having cationic hydrophilic group)
The hydrophilic compound having a cationic hydrophilic group is not particularly limited, but examples thereof include compounds having both a cationic group and an active hydrogen-containing group. Also, a compound having an active hydrogen-containing group such as a glycidyl group and a compound having a cationic hydrophilic group such as sulfide or phosphine may be combined as a hydrophilic compound. In this case, a compound having an isocyanate group and a compound having an active hydrogen-containing group are reacted in advance to add a functional group such as a glycidyl group. Then, a compound having a cationic hydrophilic group such as sulfide or phosphine is reacted. Among them, as the hydrophilic compound having a cationic hydrophilic group, a compound having both a cationic group and an active hydrogen-containing group is preferable from the viewpoint of ease of production.

Examples of compounds having both a cationic group and an active hydrogen-containing group include, but are not particularly limited to, dimethylethanolamine, diethylethanolamine, diethanolamine, methyldiethanolamine, and the like. Also, the tertiary amino group added using these compounds can be quaternized with, for example, dimethyl sulfate, diethyl sulfate, or the like.

The reaction between the hydrophilic compound having a cationic hydrophilic group and the polyisocyanate can be carried out in the presence of a solvent. The solvent is not particularly limited, but preferably does not contain an active hydrogen-containing group. Specific examples of solvents include ethyl acetate, propylene glycol monomethyl ether acetate, and dipropylene glycol dimethyl ether.

The cationic hydrophilic group added to the polyisocyanate is preferably neutralized with a compound having an anionic group. Examples of the anion group include, but are not particularly limited to, a carboxyl group, a sulfonic acid group, a phosphoric acid group, a halogen group, and a sulfate group.
Examples of compounds having a carboxyl group include, but are not particularly limited to, formic acid, acetic acid, propionic acid, butyric acid, and lactic acid.
The compound having a sulfone group is not particularly limited, but specifically includes ethanesulfonic acid and the like.
Examples of the compound having a phosphoric acid group include, but are not particularly limited to, phosphoric acid, acidic phosphoric acid esters, and the like.
Examples of the compound having a halogen group include, but are not particularly limited to, hydrochloric acid.
The compound having a sulfate group is not particularly limited, and examples thereof include sulfuric acid.
Among them, the compound having an anion group is preferably a compound having a carboxyl group, and more preferably acetic acid, propionic acid or butyric acid.

(Hydrophilic compound having anionic hydrophilic group)
Examples of anionic hydrophilic groups include, but are not limited to, carboxylic acid groups, sulfonic acid groups, phosphoric acid groups, halogen groups, and sulfuric acid groups.
The hydrophilic compound having an anionic hydrophilic group is not particularly limited, but examples thereof include compounds having both an anionic group and an active hydrogen-containing group. Specific examples of hydrophilic compounds having anionic hydrophilic groups include compounds having carboxylic acid groups of monohydroxycarboxylic acids and polyhydroxycarboxylic acids as anionic groups. Examples of monohydroxycarboxylic acids include 1-hydroxyacetic acid, 3-hydroxypropanoic acid, 12-hydroxy-9-octadecanoic acid, hydroxypivalic acid, lactic acid and the like. Examples of compounds having a carboxylic acid group of polyhydroxycarboxylic acid as an anion group include dimethylolacetic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolpentanoic acid, dihydroxysuccinic acid, and dimethylolpropionic acid.
Also, the hydrophilic compound having an anionic hydrophilic group may be a compound having both a sulfonic acid group and an active hydrogen-containing group. Specific examples of compounds having both a sulfonic acid group and an active hydrogen-containing group include isethionic acid and the like.
Among them, hydroxypivalic acid or dimethylolpropionic acid is preferable as the hydrophilic compound having an anionic hydrophilic group.

The anionic hydrophilic group added to the polyisocyanate is preferably neutralized with an amine compound, which is a basic substance.
Examples of the amine-based compound include, but are not particularly limited to, ammonia, water-soluble amino compounds, and the like.
Examples of water-soluble amino compounds include, but are not limited to, monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, triethanolamine, butylamine, dibutylamine, 2 - ethylhexylamine, ethylenediamine, propylenediamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, morpholine and the like. In addition, tertiary amines such as triethylamine and dimethylethanolamine may also be used.

[Diisocyanate compound having a hydroxy group]
(A) The hydrophilic polyisocyanate component includes, in addition to the hydrophilic polyisocyanate, the unreacted polyisocyanate and the hydrophilic compound, a diisocyanate exemplified in the above "polyisocyanate", and a valence of 1 to 6 with an alcohol (hereinafter sometimes referred to as "a diisocyanate compound having a hydroxy group").
Examples of alcohols having a valence of 1 or more and 6 or less include non-polymerizable polyols and polymerizable polyols. "Non-polymerizable polyol" as used herein means a polyol having no polymerizable group. On the other hand, "polymerizable polyol" means a polyol obtained by polymerizing a monomer having a polymerizable group and a hydroxyl group.
The term "polymerizable group" means a group that can form a polymer by bonding two or more monomer molecules having the group by a reaction with light, heat, or the like.

(Non-polymerizable polyol)
Examples of non-polymerized polyols include, but are not particularly limited to, monoalcohols, diols, triols, and tetraols.

1. Monoalcohols Monoalcohols are not particularly limited, but examples include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, s-butanol, n-pentanol, n-hexanol, n -octanol, n-nonanol, 2-ethylbutanol, 2,2-dimethylhexanol, 2-ethylhexanol, cyclohexanol, methylcyclohexanol, ethylcyclohexanol and the like.

2. Diols Examples of diols include, but are not limited to, 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- and diethyl-1,3-propanediol.

3. Triols Examples of triols include, but are not particularly limited to, glycerin, trimethylolpropane, and the like.

4. Tetraols The tetraols are not particularly limited, and examples thereof include pentaerythritol.

(Polymerizable polyol)
Examples of polymerized polyols include, but are not limited to, polyester polyols, polyether polyols, acrylic polyols, and polyolefin polyols.

1. Polyester polyol As the polyester polyol, for example, polyester polyol resins obtained by a condensation reaction of a dicarboxylic acid alone or a mixture of two or more kinds and a polyhydric alcohol alone or a mixture of two or more kinds of polyhydric alcohols are used. , and polycaprolactones obtained by ring-opening polymerization of ε-caprolactone.

Examples of the dicarboxylic acid include carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.
Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerin, and pentaerythritol. , 2-methylolpropanediol, ethoxylated trimethylolpropane, and the like.

2. Polyether Polyol The polyether polyol is not particularly limited, but includes, for example, those obtained by using any one of the following methods (1) to (3).
(1) Polyether polyols or polytetramethylene obtained by the reaction of at least one of the group consisting of random addition and block addition of alkylene oxide alone or in mixture to polyhydric hydroxy compound alone or in mixture using a catalyst. glycols.
(2) Polyether polyols obtained by reacting alkylene oxide with a polyamine compound (3) So-called polymers obtained by polymerizing acrylamide or the like using the polyether polyols obtained in (1) or (2) as a medium polyols.

Examples of the catalyst include hydroxides of lithium, sodium, potassium, etc., strongly basic catalysts, double metal cyanide complexes, and the like. Examples of strongly basic catalysts include alcoholates, alkylamines, and the like. Examples of double metal cyanide complexes include metal porphyrins and zinc hexacyanocobaltate complexes.
Examples of the polyhydric hydroxy compounds include diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol, sugar alcohol compounds, monosaccharides, disaccharides, trisaccharides and tetrasaccharides. Examples of sugar alcohol compounds include erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol, mannitol, galactitol, and rhamnitol. Monosaccharides include, for example, arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, ribodesose and the like. Examples of disaccharides include trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose and the like. Examples of trisaccharides include raffinose, gentianose, melezitose and the like. Examples of tetrasaccharides include stachyose and the like.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.
Examples of the polyamine compound include ethylenediamine and ethanolamines.

3. Acrylic polyol The acrylic polyol is not particularly limited. obtained by copolymerizing an ethylenically unsaturated bond-containing monomer or a mixture of other copolymerizable ethylenically unsaturated bond-containing monomers.

Examples of ethylenically unsaturated bond-containing monomers having a hydroxyl group include, but are not limited to, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxy methacrylate. butyl and the like. These may be used alone or in combination of two or more.
Among them, hydroxyethyl acrylate or hydroxyethyl methacrylate is preferable as the ethylenically unsaturated bond-containing monomer having a hydroxyl group.

Other ethylenically unsaturated bond-containing monomers copolymerizable with the polymerizable monomer include, for example, the following (i) to (vi). These may be used alone or in combination of two or more.
(i) acrylic acid esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate;
(ii) methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, and glycidyl methacrylate .
(iii) unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid;
(iv) unsaturated amides such as acrylamide, methacrylamide, N,N-methylenebisacrylamide, diacetone acrylamide, diacetone methacrylamide, maleic acid amide and maleimide;
(v) Vinyl monomers such as glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile, and dibutyl fumarate.
(vi) vinyl-based monomers having a hydrolyzable silyl group, such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane;

4. Polyolefin Polyol The polyolefin polyol is not particularly limited, and examples thereof include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene.

[(A) Method for producing hydrophilic polyisocyanate component]
(A) A method for producing a hydrophilic polyisocyanate component includes a step of mixing and reacting a polyisocyanate and a hydrophilic compound to obtain a (A) hydrophilic polyisocyanate component containing a hydrophilic polyisocyanate (hereinafter referred to as a “reaction step”). may be referred to as).
(A) The details of the steps of the method for producing the hydrophilic polyisocyanate component are described below.

(Reaction step)
In the reaction step, the polyisocyanate and the hydrophilic compound are mixed and reacted to obtain (A) the hydrophilic polyisocyanate component containing the hydrophilic polyisocyanate.
At this time, the blending amount of the hydrophilic compound with respect to the total mass of the polyisocyanate and the hydrophilic compound is preferably 2.0% by mass or more and 50% by mass or less, more preferably 5.0% by mass or more and 30% by mass or less. It is more preferably 0% by mass or more and 20% by mass or less.
When the blending amount of the hydrophilic compound relative to the total mass of the polyisocyanate and the hydrophilic compound is at least the above lower limit, the water dispersibility and water dispersion stability of the hydrophilic polyisocyanate component (A) can be further improved.
On the other hand, by reacting so that the blending amount of the hydrophilic compound with respect to the total mass of the polyisocyanate and the hydrophilic compound is equal to or less than the above upper limit, the hardness and water resistance when formed into a coating film can be improved. .

Moreover, in the reaction step, the reaction temperature and the reaction time are appropriately determined according to the progress of the reaction.
The reaction temperature is preferably 0° C. or higher and 150° C. or lower, and the reaction time is preferably 0.5 hours or longer and 48 hours or shorter.

In addition, in the reaction step, a known catalyst may be used as the case may be. Examples of catalysts include, but are not limited to, organotin compounds, organozinc compounds, organotitanium compounds, organozirconium compounds, tertiary amines, and diamines. Examples of organic tin compounds include tin octoate, tin 2-ethyl-1-hexanoate, tin ethylcaproate, tin laurate, tin palmitate, dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dimalate, dibutyltin dilaurate, dioctyltin diacetate, dioctyltin dilaurate and the like. Examples of organic zinc compounds include zinc chloride, zinc octanoate, zinc 2-ethyl-1-hexanoate, zinc 2-ethylcaproate, zinc stearate, zinc naphthenate, zinc acetylacetonate and the like. Examples of tertiary amines include triethylamine, tributylamine, N,N-diisopropylethylamine, N,N-dimethylethanolamine and the like. Examples of diamines include triethylenediamine, tetramethylethylenediamine, 1,4-diazabicyclo[2.2.2]octane and the like. These catalysts may be used singly or in combination of two or more.

[(A) Physical properties of hydrophilic polyisocyanate component]
Next, the physical properties of (A) the hydrophilic polyisocyanate composition will be described in detail below.

((A) Content of hydrophilic group derived from hydrophilic compound relative to total mass of solid content of hydrophilic polyisocyanate component)
(A) The content of hydrophilic groups possessed by the hydrophilic polyisocyanate relative to the total mass of the solid content of the hydrophilic polyisocyanate component is preferably 2.0% by mass or more and 50% by mass or less, and 5.0% by mass. % or more and 30 mass % or less, and more preferably 5.0 mass % or more and 20 mass % or less.
(A) the content of the hydrophilic groups of the hydrophilic polyisocyanate with respect to the total mass of the solid content of the hydrophilic polyisocyanate component is at least the above lower limit value, so that (A) the water dispersibility of the hydrophilic polyisocyanate component And the water dispersion stability can be improved.
On the other hand, the content of the hydrophilic groups of the hydrophilic polyisocyanate relative to the total mass of the solid content of the hydrophilic polyisocyanate component (A) is equal to or less than the upper limit, so that the curing agent composition of the present embodiment is used. It is possible to improve the hardness and water resistance when a coating film is produced by

The content of the hydrophilic group of the hydrophilic polyisocyanate relative to the total solid content of the hydrophilic polyisocyanate component (A) is the total mass of the hydrophilic compound and the total solid content of the hydrophilic polyisocyanate component. It can be calculated by multiplying the value obtained by dividing by 100. Also, (A) the content of hydrophilic groups possessed by the hydrophilic polyisocyanate with respect to the total mass of the solid content of the hydrophilic polyisocyanate component, since all of the blended hydrophilic compounds react with the polyisocyanate, the polyisocyanate and It is obtained by determining the blending amount of the hydrophilic compound with respect to the total mass of the solid content of the hydrophilic compound.

(viscosity)
The viscosity of the hydrophilic polyisocyanate component (A) at 25°C is usually 50 mPa s or more and 20000 mPa s or less when the hydrophilic polyisocyanate component (A) consists substantially only of a solid content at 25°C. , 300 mPa·s to 10000 mPa·s.
When the viscosity at 25° C. is at least the above lower limit, the curability of the coating film can be improved, while when it is at most the above upper limit, the water dispersibility and appearance of the coating film are improved. can be made better.
In addition, "consisting substantially only of solid content" here means that it consists only of solid content, or contains only a very small amount of components other than solid content (liquid component and volatile component, etc.) below the detection limit. means
(A) The viscosity at 25° C. of the hydrophilic polyisocyanate component can be measured using the method described in Examples below.
Examples of the method for controlling the viscosity at 25°C within the above range include, but are not limited to, a method of adjusting the compounding ratio of the polyisocyanate and the hydrophilic compound.

(Isocyanate group content)
The isocyanate group content in the hydrophilic polyisocyanate component (A) is usually 3.0% by mass or more and 25% by mass or less when the hydrophilic polyisocyanate component (A) consists essentially of a solid content. , preferably 7.0% by mass or more and 20% by mass or less, more preferably 13% by mass or more and 20% by mass or less.
When the isocyanate group content is within the above range, the curability and water resistance of the coating film can be further improved.
The term "isocyanate group" as used herein refers to a combination of the isocyanate group possessed by the unreacted polyisocyanate and the isocyanate group possessed by the hydrophilic polyisocyanate.
(A) The isocyanate group content of the hydrophilic polyisocyanate component can be calculated using the method described in Examples below.
Examples of the method for controlling the isocyanate group content within the above range include, but are not limited to, a method of adjusting the compounding ratio of the polyisocyanate and the hydrophilic compound.

(Number average molecular weight)
(A) The lower limit of the number average molecular weight of the hydrophilic polyisocyanate component is preferably 300 from the viewpoint of curability when used as a coating film. On the other hand, the upper limit of the number average molecular weight of the (A) hydrophilic polyisocyanate component is preferably 10,000 from the viewpoint of water dispersibility.
That is, the hydrophilic polyisocyanate component (A) preferably has a number average molecular weight of 300 or more and 10,000 or less.
(A) The number average molecular weight of the hydrophilic polyisocyanate component can be measured using the method described in the examples below.

(average number of isocyanate functional groups)
(A) The lower limit of the average number of isocyanate functional groups in the hydrophilic polyisocyanate component (hereinafter sometimes referred to as "average number of isocyanate functional groups") is, from the viewpoint of curability and water resistance when formed into a coating film, 2.0 is preferred. On the other hand, the upper limit of the average number of isocyanate functional groups is preferably 20.0 from the viewpoint of water dispersion stability and appearance of a coating film.
That is, the average number of isocyanate functional groups of the (A) hydrophilic polyisocyanate component is preferably 2.0 or more and 20.0 or less.
(A) The average number of isocyanate functional groups of the hydrophilic polyisocyanate component can be calculated using the method described in the examples below.

[(A) Content of hydrophilic polyisocyanate component]
The lower limit of the content of the hydrophilic polyisocyanate component (A) contained in the curing agent composition of the present embodiment is usually 79.5% by mass with respect to the total mass of solids in the composition. 80.0% by mass is preferred. Moreover, the upper limit of the content can usually be 99.9% by mass, preferably 99.0% by mass.
That is, the content of the (B) ionic surfactant contained in the curing agent composition of the present embodiment is 79.5% by mass or more and 99.9% by mass with respect to the total mass of solids in the composition. % or less, preferably 80.0 mass % or more and 99.0 mass % or less.

<(B) Ionic surfactant>
(B) the ionic surfactant contained in the curing agent composition of the present embodiment preferably contains substantially no water.
Here, "substantially free of water" means that it does not contain water at all, or that the water contained in the ionic surfactant reacts with the isocyanate group to prevent foaming, cloudiness, and viscosity increase. It means that it contains only a very small amount of water. As a guideline, the water content should be 1% by mass or less with respect to the total mass of the ionic surfactant.

(B) Examples of ionic surfactants include anionic surfactants, cationic surfactants, and amphoteric surfactants. (A) The method of neutralization of the hydrophilic polyisocyanate component determines whether an anionic surfactant or a cationic surfactant is preferred. That is, when the hydrophilic polyisocyanate composition is neutralized with a base, it is preferable to use an anionic surfactant, while when it is neutralized with an acid, it is preferable to use a cationic surfactant. (A) When the hydrophilic polyisocyanate component is not neutralized, any of an anionic surfactant, a cationic surfactant and an amphoteric surfactant may be used, and an amphoteric surfactant may be used. .

Suitable anionic surfactants are those of the carboxylate, sulfate, sulfonate or phosphate type.
Specific examples of anionic surfactants include (C1-C20 alkyl) ammonium benzenesulfonate, sodium (C1-C20 alkyl) benzene sulfonate, sodium (C1-C20 alkyl) disulfate, and sodium alkyldiphenyl ether disulfonate. , sodium di(C1-C20 alkyl) sulfosuccinate, sodium polyoxyethylene C6-C30 aryl ether sulfonate, ammonium polyoxyethylene C6-C30 aryl ether sulfonate, and the like, provided that they are industrially available. It can be used without any inconvenience and is not limited to the above.
Among them, the anionic surfactant is preferably ammonium (C1-C20 alkyl)benzenesulfonate, sodium (C1-C20 alkyl)benzenesulfonate or sodium di(C1-C20 alkyl)sulfosuccinate.

Quaternary ammonium salts, pyridinium salts or imidazolinium salts are suitable as cationic surfactants.
Specific examples of cationic surfactants include C1-C20 alkyltrimethylammonium bromide, C1-C30 alkylpyridinium bromide, imidazolinium laurate, etc., but industrially available ones are inconvenient. It is not limited to the above. More specific examples of cationic surfactants include alkyltrimethylammonium bromide, alkylpyridinium bromide, imidazolinium laurate, and the like.

[Content of (B) ionic surfactant]
The lower limit of the content of the (B) ionic surfactant contained in the curing agent composition of the present embodiment is the total mass of solids in the composition, when water dispersibility and coating liquid are From the viewpoint of pot life, the content can usually be 0.1% by mass, preferably 0.5% by mass. Moreover, the upper limit of the content can be usually 20% by mass, preferably 10% by mass, from the viewpoint of the appearance and water resistance of the coating film.
That is, the content of the (B) ionic surfactant contained in the curing agent composition of the present embodiment is 0.1% by mass or more and 20% by mass or less with respect to the total mass of solids in the composition. and preferably 0.5% by mass or more and 10% by mass or less.

<(C) Sulfonate>
(C) Sulfonate contained in the curing agent composition of the present embodiment is one or more compounds selected from the group consisting of compound (I) and compound (II).

(In general formula (I), R ¹¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. M ¹¹⁺ is Na ⁺ , K ⁺ or NH ₄ ⁺ .)

(In general formula (II), R ²¹ and R ²² are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. M ²¹⁺ is Na ⁺ , K ⁺ or NH ₄ ⁺ .)

[R ¹¹ , R ²¹ and R ²² ]
R ¹¹ , R ²¹ and R ²² are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. The alkyl group having 1 to 20 carbon atoms may be chain-shaped or cyclic, but chain-shaped is preferred. Moreover, the number of carbon atoms is 1 or more and 20 or less, preferably 1 or more and 12 or less. Specific examples of such alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, 2-ethylbutyl group, 2,2-dimethylhexyl group, 2- An ethylhexyl group etc. are mentioned. Among them, the alkyl group for R ¹¹ , R ²¹ and R ²² is preferably a chain alkyl group having 1 to 12 carbon atoms, such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group and isobutyl group. group, n-hexyl group or 2-ethylhexyl group are more preferred.

[M ¹¹⁺ and M ²¹⁺ ]
M ¹¹⁺ and M ²¹⁺ are each independently Na ⁺ , K ⁺ or NH ₄ ⁺ .

Preferred examples of compound (I) include compounds represented by the following formulas (I)-1 to (I)-3.

Preferred examples of compound (II) include compounds represented by formulas (II)-1 to (II)-3 below.

Moreover, the curing agent composition of the present embodiment may contain both compound (I) and compound (II) as (C) sulfonate.
In addition, the curing agent composition of the present embodiment may contain one type of compound (I) or compound (II) as (C) sulfonate alone, or may contain two or more types in combination.

[(C) Content of sulfonate]
When the curing agent composition of the present embodiment contains only compound (I) as (C) sulfonate, the lower limit of the content of compound (I) in the curing agent composition of the present embodiment is With respect to the total mass of solid content in the product, from the viewpoint of pot life when it is used as a coating liquid and blister resistance when it is used as a coating film, it can usually be 0.01% by mass, and 0.03% by mass. % by weight is preferred. On the other hand, the upper limit of the content of the compound (I) is usually 0.5% by mass, preferably 0.3% by mass, and 0.2% by mass, from the viewpoint of the appearance of the coating film. % is more preferred.
That is, when the curing agent composition of the present embodiment contains only compound (I) as (C) sulfonate, the content of compound (I) in the curing agent composition of the present embodiment is It can be 0.01% by mass to 0.5% by mass, preferably 0.03% by mass to 0.3% by mass, and 0.03% by mass or more 0.2% by mass or less is more preferable.

Further, when the curing agent composition of the present embodiment contains only compound (II) as (C) sulfonate, the lower limit of the content of compound (II) in the curing agent composition of the present embodiment is Based on the total mass of solids in the composition, from the viewpoint of pot life when it is used as a coating liquid and blister resistance when it is used as a coating film, it is usually 0.01% by mass. 0.03% by weight is preferred. On the other hand, the upper limit of the content of compound (II) is usually 0.5% by mass, preferably 0.3% by mass, and 0.2% by mass, from the viewpoint of the appearance of the coating film. % is more preferred.
That is, when the curing agent composition of the present embodiment contains only compound (II) as (C) sulfonate, the content of compound (II) in the curing agent composition of the present embodiment is It can be 0.01% by mass to 0.5% by mass, preferably 0.03% by mass to 0.3% by mass, and 0.03% by mass or more 0.2% by mass or less is more preferable.

Further, when the curing agent composition of the present embodiment contains compound (I) and compound (II) as (C) sulfonate, compound (I) and compound (II) in the curing agent composition of the present embodiment ), the lower limit of the total content of ) is usually 0.5% relative to the total mass of solids in the composition, from the viewpoint of pot life when used as a coating solution and blister resistance when used as a coating film. 01% by weight, preferably 0.03% by weight. On the other hand, the upper limit of the total content of compound (I) and compound (II) can usually be 0.5% by mass from the viewpoint of the appearance of the coating film, and 0.3% by mass is Preferably, 0.2% by mass is more preferable.
That is, when the curing agent composition of the present embodiment contains compound (I) and compound (II) as (C) sulfonate, compound (I) and compound (II) in the curing agent composition of the present embodiment ) can be 0.01% by mass or more and 0.5% by mass or less, and 0.03% by mass or more and 0.3% by mass, based on the total mass of solids in the composition. The following is preferable, and 0.03% by mass or more and 0.2% by mass or less is more preferable.

<(D) Other constituents>
In addition to (A) the hydrophilic polyisocyanate component, (B) the ionic surfactant and (C) the sulfonate, the curing agent composition of the present embodiment may further contain (D) other components. good. (D) Other components include, but are not limited to, solvents, curing accelerator catalysts, antioxidants, UV absorbers, light stabilizers, pigments, leveling agents, plasticizers, rheology control agents, polymerization Inhibitors and the like can be mentioned.

Examples of solvents include aromatic hydrocarbons, alcohol compounds, ketone compounds, ester compounds, and ethers. Examples of aromatic hydrocarbons include benzene, toluene, xylene, chlorobenzene and the like. Examples of alcohol compounds include methanol, ethanol, isopropanol, n-butanol, n-hexanol, 2-ethylhexanol and the like. Examples of ketone compounds include acetone and methyl ethyl ketone. Examples of ester compounds include ethyl acetate, n-butyl acetate, ethyl glycol acetate, methoxypropyl acetate, and 3-hydroxy-2,2,4-trimethylpentyl isoacetate. Ethers include, for example, butyl glycol, tetrahydrofuran, dioxane, ethyl glycol ether and the like.

The content of the solvent is preferably 0% by mass or more and 90% by mass or less, more preferably 0% by mass or more and 50% by mass or less, and 0% by mass or more, relative to the total mass of the curing agent composition. It is more preferably 30% by mass or less.

In addition, when the curing agent composition of the present embodiment contains a curing accelerator catalyst, an antioxidant, a light stabilizer, or a polymerization inhibitor, the content of the solvent is 0 mass with respect to the total mass of the curing agent composition. % or more and 10 mass % or less, more preferably 0 mass % or more and 5 mass % or less, and even more preferably 0 mass % or more and 2 mass % or less.

The curing acceleration catalyst is not particularly limited, but examples thereof include tin compounds, zinc compounds, titanium compounds, cobalt compounds, bismuth compounds, zirconium compounds, amine compounds and the like.
Examples of tin-based compounds include dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, dimethyltin dineodecanoate, tin bis(2-ethylhexanoate), and the like.
Examples of zinc compounds include zinc 2-ethylhexanoate and zinc naphthenate.
Examples of titanium compounds include titanium 2-ethylhexanoate and titanium diisopropoxybis(ethylacetonate).
Examples of cobalt compounds include cobalt 2-ethylhexanoate and cobalt naphthenate.
Examples of bismuth compounds include bismuth 2-ethylhexanoate and bismuth naphthenate.
Examples of zirconium compounds include zirconium tetraacetylacetonate, zirconyl 2-ethylhexanoate, and zirconyl naphthenate.

Examples of antioxidants include, but are not particularly limited to, hindered phenol compounds, phosphorus compounds, sulfur compounds, and the like.

Examples of the ultraviolet absorber include, but are not particularly limited to, benzotriazole-based compounds, triazine-based compounds, and benzophenone-based compounds.

Examples of light stabilizers include, but are not limited to, hindered amine compounds, benzotriazole compounds, triazine compounds, benzophenone compounds, and benzoate compounds.

Examples of pigments include, but are not limited to, titanium oxide, carbon black, indigo, quinacridone, pearl mica, and aluminum.

Examples of the leveling agent include, but are not limited to, silicone oil.

Examples of plasticizers include, but are not particularly limited to, phthalates, phosphoric acid compounds, polyester compounds, and the like.

Examples of rheology control agents include, but are not limited to, hydroxyethylcellulose, urea compounds, microgels, and the like.

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.

<Method for producing curing agent composition>
The method for producing the curing agent composition of the present embodiment includes a step of adding (B) an ionic surfactant and (C) a sulfonate to (A) a hydrophilic polyisocyanate component and mixing (hereinafter referred to as "adding (sometimes referred to as "process").
The steps of the method for producing the curing agent composition of the present embodiment are described in detail below.

[Addition process]
In the addition step, (B) an ionic surfactant and (C) a sulfonate are added to (A) the hydrophilic polyisocyanate component and mixed.
In the addition step, the lower limit of the amount of the (B) ionic surfactant is the total mass of the solid content of (A) the hydrophilic polyisocyanate component and (B) the ionic surfactant, and the resulting curing From the viewpoint of the water dispersibility of the agent composition and the pot life of the coating liquid, it can be usually 0.1% by mass, preferably 0.5% by mass. In addition, the upper limit of the amount of the ionic surfactant (B) to be blended is usually 20% by mass, preferably 10% by mass, from the viewpoint of the appearance and water resistance of the coating film.
That is, the amount of the (B) ionic surfactant is 0.1% by mass or more and 20% by mass with respect to the total mass of the solid content of the (A) hydrophilic polyisocyanate component and (B) the ionic surfactant. % or less, preferably 0.5 mass % or more and 10 mass % or less.

In addition, when only compound (I) is used as (C) sulfonate in the addition step, the lower limit of the compounding amount of compound (I) is With respect to the total mass of solids, from the viewpoint of pot life when used as a coating liquid and blister resistance when used as a coating film, it is usually 0.01% by mass, and 0.03% by mass is preferable. On the other hand, the upper limit of the compounding amount of compound (I) is usually 0.5% by mass, preferably 0.3% by mass, and 0.2% by mass, from the viewpoint of the appearance of the coating film. % is more preferred.
That is, when only compound (I) is used as (C) sulfonate, the compounding amount of compound (I) is It can be 0.01% by mass or more and 0.5% by mass or less, preferably 0.03% by mass or more and 0.3% by mass or less, and more preferably 0.03% by mass or more and 0.2% by mass or less.

Further, when only compound (II) is used as (C) sulfonate, the lower limit of the compounding amount of compound (II) in the curing agent composition of the present embodiment is From the viewpoint of pot life when used as a coating liquid and blister resistance when used as a coating film, it is usually 0.01% by mass, 0.03% by weight is preferred. On the other hand, the upper limit of the compounding amount of the compound (II) is usually 0.5% by mass, preferably 0.3% by mass, and 0.2% by mass, from the viewpoint of the appearance of the coating film. % is more preferred.
That is, when only compound (II) is used as (C) sulfonate, the compounding amount of compound (II) is , 0.01 mass % or more and 0.5 mass % or less, preferably 0.03 mass % or more and 0.3 mass % or less, and more preferably 0.03 mass % or more and 0.2 mass % or less.

Moreover, both compound (I) and compound (II) may be used as (C) sulfonate.
(C) When compound (I) and compound (II) are used as sulfonates, the lower limit of the total amount of compound (I) and compound (II) is From the viewpoint of the pot life of the coating liquid and the blistering resistance of the coating film, the amount can be usually 0.01% by mass and 0.01% by mass based on the total mass of solids in the compounding components. 03% by mass is preferred. On the other hand, the upper limit of the total amount of compound (I) and compound (II) can be usually 0.5% by mass, from the viewpoint of the appearance of the coating film, and 0.3% by mass. Preferably, 0.2% by mass is more preferable.
That is, when compound (I) and compound (II) are used as (C) sulfonate, the total amount of compound (I) and compound (II) is the total amount used in the production of the curing agent composition. It can be 0.01% by mass or more and 0.5% by mass or less, preferably 0.03% by mass or more and 0.3% by mass or less, and 0.03% by mass, based on the total mass of the solid content in the ingredients. More preferably, it is 0.2% by mass or less.

Moreover, the addition step may be performed after the reaction step in the above "(A) Method for producing a hydrophilic polyisocyanate component", or may be performed simultaneously with the reaction step.

≪Water-based coating composition≫
The water-based coating composition of this embodiment includes the curing agent composition of the above embodiment, water, and an active hydrogen group-containing compound.
The water-based coating composition of the present embodiment contains an active hydrogen group-containing compound, so that the isocyanate groups possessed by the hydrophilic polyisocyanate component (A) and the active hydrogen groups possessed by the active hydrogen group-containing compound can react under various conditions. and tends to be excellent in flexibility, adhesion and conformability to substrates when formed into a coating film.
The constituent components of the water-based coating composition of the present embodiment are described in detail below.

<Compound containing active hydrogen group>
The active hydrogen group-containing compound is not particularly limited as long as it is a compound in which two or more active hydrogen atoms are bonded in the molecule. Specific examples of active hydrogen group-containing compounds include polyamines, alkanolamines, polythiols, and polyols. Among them, polyol is preferable as the active hydrogen group-containing compound.

[Polyamine]
Examples of polyamines include, but are not limited to, diamines, chain polyamines having 3 or more amino groups, and cyclic polyamines. Examples of diamines include ethylenediamine, propylenediamine, butylenediamine, triethylenediamine, hexamethylenediamine, 4,4'-diaminodicyclohexylmethane, piperazine, 2-methylpiperazine, and isophoronediamine. Chain polyamines having 3 or more amino groups include, for example, bishexamethylenetriamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentamethylenehexamine, and tetrapropylenepentamine. Examples of cyclic polyamines include 1,4,7,10,13,16-hexaazacyclooctadecane, 1,4,7,10-tetraazacyclodecane, and 1,4,8,12-tetraazacyclopentadecane. , 1,4,8,11-tetraazacyclotetradecane and the like.

[Alkanolamine]
Examples of alkanolamine include, but are not limited to, monoethanolamine, diethanolamine, aminoethylethanolamine, N-(2-hydroxypropyl)ethylenediamine, mono-, di-(n- or iso-)propanolamine, ethylene glycol. rubis-propylamine, neopentanolamine, methylethanolamine and the like.

[Polythiol]
Examples of polythiols include, but are not limited to, bis-(2-hydrothioethyloxy)methane, dithioethylene glycol, dithioerythritol, dithiothreitol].

[Polyol]
Examples of polyols include, but are not limited to, polyester polyols (including polycaprolactones), acrylic polyols, polyether polyols, polyolefin polyols, fluorine polyols, polycarbonate polyols, and epoxy resins.
Polyester polyols (including polycaprolactones), acrylic polyols, polyether polyols and polyolefin polyols are the same as those exemplified in the above "(A) Hydrophilic polyisocyanate component".

(Fluorine polyol)
A fluoropolyol is a polyol containing fluorine in its molecule. Specific examples of fluorine polyols include, for example, fluoroolefins, cyclovinyl ethers, and cyclovinyl ethers disclosed in JP-A-57-34107 (reference 2) and JP-A-61-275311 (reference 3). Copolymers such as hydroxyalkyl vinyl ethers and monocarboxylic acid vinyl esters can be mentioned.

(polycarbonate polyol)
Although the polycarbonate polyol is not particularly limited, for example, it is obtained by condensation polymerization of a low-molecular-weight carbonate compound and a low-molecular-weight polyol used in the polyester polyols exemplified in the above "(A) Hydrophilic polyisocyanate component". What can be done is mentioned. Examples of low-molecular carbonate compounds include dialkyl carbonates such as dimethyl carbonate, alkylene carbonates such as ethylene carbonate, and diaryl carbonates such as diphenyl carbonate.

(Epoxy resin)
Examples of epoxy resins include, but are not limited to, novolac type epoxy resins, glycidyl ether type epoxy resins, glycol ether type epoxy resins, epoxy type aliphatic unsaturated compounds, epoxy type fatty acid esters, ester type polycarboxylic acids, Examples include aminoglycidyl type epoxy resins, β-methyl epichloro type epoxy resins, cyclic oxirane type epoxy resins, halogen type epoxy resins, resorcin type epoxy resins, and the like.

(Hydroxyl value of polyol)
The hydroxyl value of the polyol is not particularly limited, but from the viewpoint of the crosslink density and mechanical properties of the cured product, it is preferably 10 mgKOH / g or more and 300 mgKOH / g or less, and 20 mgKOH per 1 g of the water-based coating composition of the present embodiment. /g or more and 250 mgKOH/g or less, and more preferably 30 mgKOH/g or more and 200 mgKOH/g or less.

<Other components>
The water-based coating composition of the present embodiment may further contain other components in addition to the curing agent composition, water, and active hydrogen group-containing compound described above. Other constituents include, for example, other curing agents, other additives, and the like.

[Other curing agents]
Other curing agents include, for example, melamine-based curing agents and epoxy-based curing agents.

(melamine curing agent)
The melamine-based curing agent is not particularly limited, but includes, for example, a completely alkyl-etherified melamine resin, a methylol group-type melamine resin, and an imino group-type melamine resin partially containing imino groups.

When using a melamine curing agent, addition of an acidic compound is effective.
Examples of acidic compounds include carboxylic acids, sulfonic acids, acidic phosphates, and phosphites.
Examples of carboxylic acids include, but are not limited to, acetic acid, lactic acid, succinic acid, oxalic acid, maleic acid, and decanedicarboxylic acid.
Examples of sulfonic acid include, but are not particularly limited to, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenedisulfonic acid and the like.
Examples of acidic phosphates include, but are not limited to, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, dilauryl phosphate, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, and the like.
Examples of phosphites include, but are not limited to, diethyl phosphite, dibutyl phosphite, dioctyl phosphite, dilauryl phosphite, monoethyl phosphite, monobutyl phosphite, monooctyl phosphite, and monolauryl phosphite. etc.

(epoxy curing agent)
Examples of epoxy curing agents include, but are not limited to, aliphatic polyamines, alicyclic polyamines, aromatic polyamines, acid anhydrides, phenol novolacs, polymercaptans, aliphatic tertiary amines, aromatic tertiary amines, and imidazole. compounds, Lewis acid complexes, and the like.

[Other additives]
Other additives include, but are not limited to, inorganic pigments, organic pigments, extender pigments, silane coupling agents, titanium coupling agents, organic phosphates, and organic phosphites that are generally added to paints. , thickener, leveling agent, thixotropic agent, antifoaming agent, freeze stabilizer, matting agent, cross-linking reaction catalyst, anti-skinning agent, dispersant, wetting agent, filler, plasticizer, lubricant, reducing agent , antiseptic agents, antifungal agents, deodorants, anti-yellowing agents, ultraviolet absorbers, antistatic agents or charge control agents, anti-settling agents, surfactants, antioxidants, light stabilizers, polymerization inhibitors, etc. is mentioned.

<Method for producing water-based coating composition>
The method for producing the water-based coating composition of the present embodiment is not particularly limited, but includes, for example, a method of adding water and an active hydrogen compound using the above-described curing agent composition as a curing agent, and mixing.

<Physical properties of water-based coating composition>
Next, the physical properties of the water-based coating composition of this embodiment will be described in detail below.

[Isocyanate group/active hydrogen group]
In the aqueous coating composition of the present embodiment, the number of isocyanate groups possessed by the hydrophilic polyisocyanate composition in the aqueous coating composition relative to the number of moles of active hydrogen groups possessed by the active hydrogen group-containing compound in the aqueous coating composition. The molar ratio (isocyanate group/active hydrogen group) is not particularly limited, but is preferably 1/10 or more and 10/1 or less, more preferably 1/8 or more and 8/1 or less, and 1/ More preferably, it is 6 or more and 6/1 or less.
As for isocyanate group/active hydrogen, the average number of isocyanate functional groups is calculated using the method for calculating the average number of isocyanate functional groups described later in Examples. It can then be calculated by dividing the resulting average number of isocyanate functional groups by the number of moles of active hydrogen groups and multiplying by 100.

<Application>
The aqueous coating composition of the present embodiment is used as, for example, a curable composition, various surface treatment compositions, various elastomer compositions, cross-linking agents, modifiers, and additives. Examples of curable compositions include coating compositions, pressure-sensitive adhesive compositions, adhesive compositions, casting compositions and the like. Examples of various surface treatment compositions include fiber treatment agents. Examples of cross-linking agents include foam compositions.

The adherend to which the water-based coating composition of the present embodiment can be used is not particularly limited, but examples thereof include glass, various metals, porous members, various coated members, cured sealants, rubbers, Examples include leathers, fibers, non-woven fabrics, resin films and plates, UV-curing acrylic resin layers, and ink layers. Examples of various metals include aluminum, iron, galvanized steel sheets, copper, and stainless steel. Examples of porous members include wood, paper, mortar, and stone. Examples of various types of coating include fluorine coating, urethane coating, and acrylic urethane coating. Examples of cured sealants include silicone-based, modified silicone-based, and urethane-based sealants. Examples of rubbers include natural rubber and synthetic rubber. Leathers include, for example, natural leathers and artificial leathers. Examples of fibers include plant fibers, animal fibers, carbon fibers, and glass fibers. Examples of resins used as raw materials for resin films and plates include polyvinyl chloride, polyester, acryl, polycarbonate, triacetyl cellulose, and polyolefin. Examples of inks include printing inks and UV inks.

Hereinafter, the present embodiment will be described in more detail by showing specific examples and comparative examples, but the present embodiment is not limited by the following examples and comparative examples as long as the gist thereof is not exceeded. .

≪Test item≫
The hydrophilic polyisocyanate components, curing agent compositions and coating films produced in Examples and Comparative Examples were measured for physical properties and evaluated according to the methods described below.

<Physical properties>
[Physical Property 1] Viscosity The viscosity at 25° C. of the hydrophilic polyisocyanate components or curing agent compositions produced in Examples and Comparative Examples was determined using an E-type viscometer RE-80U (manufactured by Toki Sangyo Co., Ltd.). .

[Physical property 2] Solid content When the hydrophilic polyisocyanate component or curing agent composition produced in Examples and Comparative Examples was used as a sample and diluted with a solvent, the solid content was calculated according to the method shown below. .
Specifically, first, the mass (W1) [g] of the aluminum cup was accurately weighed, about 1 g of the sample was put therein, and the cup mass (W2) [g] before heat drying was accurately weighed. The cup containing the above sample was then heated in a dryer at 105° C. for 3 hours. Next, after cooling the heated cup to room temperature, the mass (W3) [g] of the cup was accurately weighed again. The mass % of the dry residue in the sample was defined as the solid content (c). The solid content was calculated using the formula (a) shown below.
In the case of no solvent dilution, the solid content was treated as substantially 100%.
Solid content (c) [% by mass] = (W2-W1)/(W3-W1) x 100 (a)

[Physical property 3] Content of ionic surfactant with respect to total mass of solid content of hydrophilic polyisocyanate component and ionic surfactant1. Content of ionic surfactant in curing agent composition (d1) [% by mass]
Using the curing agent compositions produced in Examples and Comparative Examples as samples, the content (d1) [% by mass] of the ionic surfactant in the curing agent composition was separated by liquid chromatography, followed by mass spectrometry. Measured using a device. The apparatus and conditions used are as follows.
(Measurement condition)
LC device: UPLC (trade name) manufactured by Waters
Column: Waters, ACQUITY UPLC HSS T3 C18, 1.8 μm, inner diameter 2.1 mm × length 50 mm
Flow rate: 0.3mL/min
Mobile phase: x = 10 mM ammonium acetate aqueous solution, y = acetonitrile Gradient conditions: The initial mobile phase composition ratio is x / y = 98 / 2, the ratio of b is linearly increased after sample injection, and x after 10 minutes /y=0/100.
Detection method 1: photodiode array detector, measurement wavelength is 220 nm
Detection method 2: mass spectrometer, manufactured by Waters, Synapt G2 (trade name)
Ionization mode: electrospray ionization, positive ion detection Scan range: m/z 100 to 2000

2. Content of ionic surfactant (d2) [% by mass] relative to the total mass of solid content of hydrophilic polyisocyanate component and ionic surfactant
Next, the content (d2) [mass%] of the ionic surfactant with respect to the total mass of the solid content of the hydrophilic polyisocyanate component and the ionic surfactant is the solid content (c ) [% by mass] and the content (d1) [% by mass] of the ionic surfactant in the curing agent composition measured in "1.", It was calculated using the following formula (b1) .
Content of ionic surfactant (d2) [% by mass] relative to the total mass of solid content of hydrophilic polyisocyanate component and ionic surfactant
=d1/c×100 (b1)

However, when the solid content (c) contains other components (c1) [% by mass] other than the hydrophilic polyisocyanate component and the ionic surfactant, it was calculated using the following formula (b2) .
Content of ionic surfactant (d2) [% by mass] relative to the total mass of solid content of hydrophilic polyisocyanate component and ionic surfactant
=d1/(c−c1)×100 (b2)

In the case of a curing agent composition that does not contain a solvent, the same method as in "1." The surfactant content (d2) was calculated.

[Physical property 4] Contents of compounds (I) and (II) relative to total mass of solid content of hydrophilic polyisocyanate component and ionic surfactant1. Contents (e1-I) and (e1-II) of compounds (I) and (II) in the curing agent composition [% by mass]
Using the curing agent compositions produced in Examples and Comparative Examples as samples, the contents (e1-I) and (e1-II) [% by mass] of compounds (I) and (II) in the curing agent composition were determined. , after separation by liquid chromatography, was measured using a mass spectrometer. The apparatus and conditions used are as follows.
(Measurement condition)
LC device: Nexera (trade name) manufactured by Shimadzu Corporation
Column: manufactured by Intakt, Cadenza CD-C18HT (inner diameter 2.0 mm × length 30 mm)
Flow rate: 0.3mL/min
Mobile phase: x = 10 mM ammonium acetate aqueous solution, y = acetonitrile Gradient conditions: The initial mobile phase composition ratio is x/y = 98/2, and the ratio of y is linearly increased after sample injection, and x after 10 minutes /y=0/100.
Detection method 1: Photodiode array detector, measurement wavelength is 200 nm or more and 400 nm or less Detection method 2: Mass spectrometer, manufactured by Waters, Synapt G2 (trade name)
Ionization mode: electrospray ionization, negative ion detection Scan range: m/z 50 to 1200

2. Contents of compounds (I) and (II) (e2-I) and (e2-II) with respect to the total mass of solid content of the hydrophilic polyisocyanate component and the ionic surfactant [% by mass]
Then, the contents (e2-I) and (e2-II) [% by mass] of compounds (I) and (II) with respect to the total mass of the solid content of the curing agent composition were measured in "[Physical Properties 2]". Solid content (c) [% by mass] and contents (e1-I) and (e1-II) of compounds (I) and (II) in the curing agent composition measured in "1." [% by mass] were calculated using the following formulas (f1) and (f2).
Compound (I) content (e2-I) with respect to the total mass of solid content of the curing agent composition [% by mass]
=(e2−I)/c×100 (f1)
Compound (II) content (e2-II) with respect to total mass of solid content of curing agent composition [% by mass]
=(e1-II)/c×100 (f2)

In the case of a curing agent composition that does not contain a solvent, the ratio of compounds (I) and (II) to the total mass of the solid content of the curing agent composition is determined using the same method as in "1." Contents (e2-I) and (e2-II) were calculated.

[Physical property 5] Isocyanate group content in hydrophilic polyisocyanate component1. Isocyanate group content in the curing agent composition (g1) [% by mass]
Using the curing agent compositions produced in Examples and Comparative Examples as samples, the isocyanate group content (g1) was determined according to the method described in JIS K7301-1995 (tolylene diisocyanate type prepolymer test method for thermosetting urethane elastomer). ,It was measured. A more specific measuring method is shown below.

(1) 1 g of sample ((W4) [g]) 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-containing 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 the sample titer (V1).
(5) Even when no sample was added, measurements were carried out in the same manner as in (1) to (3) above to obtain a blank titer (V2).
The isocyanate group content was calculated using the following formula (h1) from the mass (W4) of the sample and the sample titer (V1) and blank titer (V2) obtained above.
Isocyanate group content in the curing agent composition (g1) [% by mass]
= (V2-V1) x 42/(W4 x 1,000) x 100 (h1)

2. Isocyanate group content in hydrophilic polyisocyanate component (g2) [mass%]
The isocyanate group content (g2) [mass%] in the hydrophilic polyisocyanate component is the solid content (c) measured in "[Physical properties 2]" and "2." in "[Physical properties 3]". It was calculated using the following formula (h2) from the content (d2) of the ionic surfactant and the isocyanate group content (g1) in the curing agent composition measured in "1." above.
Isocyanate group content in hydrophilic polyisocyanate component (g2) [mass%]
=g1/(c/100)/(100-d2)×100 (h2)

However, when the solid content (c) contains the hydrophilic polyisocyanate component and other components other than the ionic surfactant (c1) [% by mass], it was calculated using the following formula (h3) .
Isocyanate group content in hydrophilic polyisocyanate component (g2) [mass%]
=g1/(c/100)/(100-d2-c1)×100 (h3)

In the case of a hydrophilic polyisocyanate component that does not contain an ionic surfactant or a solvent, the same measurement method as described in "1." Amount (g2) [% by mass] was calculated.

[Physical property 6] Number average molecular weight and weight average molecular weight Hydrophilic polyisocyanate containing hydrophilic polyisocyanate and unreacted polyisocyanate using hydrophilic polyisocyanate components or curing agent compositions produced in Examples and Comparative Examples as samples The number average molecular weight (j1) and weight average molecular weight (j2) of the components were measured. Specifically, the polystyrene-based number average molecular weight and weight average molecular weight were measured by gel permeation chromatography (GPC) using the following apparatus and conditions. When the curing agent composition is used as a sample, the sensitivity of the ionic surfactant is low under the following measurement conditions. Values of number average molecular weight and weight average molecular weight were used.
(Measurement condition)
Apparatus: HLC-8120GPC (trade name) manufactured by Tosoh Corporation
Column: manufactured by Tosoh Corporation, TSKgelSuperH1000 (trade name) × 1, TSKgelSuperH2000 (trade name) × 1, TSKgelSuperH3000 (trade name) × 1 Carrier: Tetrahydrofuran Detection method: Differential refractometer

[Physical Property 7] Average Number of Isocyanate Functional Groups The average number of isocyanate functional groups (k) is the number of isocyanate functional groups statistically possessed by one molecule of hydrophilic polyisocyanate. The number average molecular weight (j1) of the hydrophilic polyisocyanate measured in "[Physical properties 6]" above, and the isocyanate group content in the hydrophilic polyisocyanate component measured in "2." It was calculated from g2) using the following formula (m).
Average number of isocyanate functional groups (k) = j1 x g2/100/42 (m)

<Evaluation>
[Evaluation 1] Water Dispersibility of Hydrophilic Polyisocyanate Component or Curing Agent Composition (1) The total weight (W5) of a 100 mL flask and Yoshino paper was measured.
(2) The hydrophilic polyisocyanate component or curing agent composition produced in Examples and Comparative Examples was collected in a 100 mL flask so as to have a solid content of 16 g ((W6) [g]), deionized water 24 g 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 ((W7) [g]).
(5) Using the formula (p) shown below, the proportion (q) of the hydrophilic polyisocyanate component or the curing agent composition dispersed in water was calculated.
Percentage dispersed in water (q) [% by mass]
= 100 - (W7 - W5) / (W6 x c) x 100 (p)

(6) From the ratio (q) of the hydrophilic polyisocyanate component dispersed in water calculated in (5), the water dispersibility of the hydrophilic polyisocyanate component was evaluated according to the following evaluation criteria.
(Evaluation criteria)
○: (H) is 80% by mass or more, and water dispersion stability is good.
x: (H) is less than 80% by mass, poor in water dispersion stability.

[Evaluation 2] Water dispersion stability of hydrophilic polyisocyanate component or curing agent composition 0.1 g of hydrophilic polyisocyanate component or curing agent composition and 100 g of deionized water were weighed into a 200 mL flask. Then, propeller blades were used to stir the solution in the 200 mL flask at 600 rpm for 5 minutes to obtain an aqueous dispersion of the hydrophilic polyisocyanate component or curing agent composition. After that, it was transferred to a 50 mL glass bottle, and the state of dispersion was observed with the naked eye. The water dispersion stability of the hydrophilic polyisocyanate component or curing agent composition was evaluated according to the following evaluation criteria.
(Evaluation criteria)
◯: No change was observed even after 3 hours had passed.
Δ: Slight precipitation or separation was observed after 3 hours.
x: Precipitation or separation was observed within 3 hours.

[Evaluation 3] Pot life of coating liquid1. Preparation of white board Solvent-based two-component urethane paint (trade name “Mighty Rack (white)”, manufactured by Nippon Paint Co., Ltd.) is applied to an aluminum plate (150 mm × 75 mm × 1 mm, model number: A1050P (JIS) so that the dry film thickness is 50 μm. H4000), manufactured by Test Piece Co.) was spray-coated. After that, it was allowed to stand at 23° C. and 50% humidity for 2 weeks, and then the surface was polished with No. 1000 sandpaper to prepare a white plate.

2. Preparation of water-based coating composition For the curing agent compositions produced in Examples and Comparative Examples, an acrylic latex (manufactured by Asahi Kasei Corporation, trade name “R-5007”) having a hydroxyl value of 60 mgKOH/g per resin was added to the curing agent composition. They were mixed and stirred so that the base ratio (NCO/OH)=1.25. Then, the mixture was diluted with water to a solid content of 40% by mass to obtain a water-based coating composition.

3. Pot life of the coating liquid Let it stand in an atmosphere of 23 ° C./50% RH, and spread the water-based coating composition obtained in "2." every hour on the white plate obtained in "1." An applicator was applied so as to have a thickness of 40 μm. Then, it was dried in an atmosphere of 23° C./50% RH for 24 hours to obtain a coating film. The 60 degree glossiness of the resulting cured coating film was measured according to JIS Z8741, and the gloss retention rate was calculated based on the following formula (r).
Gloss retention rate (%) = gloss at measurement/initial gloss x 100 (r)

Next, the pot life of the coating solution was evaluated from the obtained gloss retention according to the following evaluation criteria.
(Evaluation criteria)
○: 5 hours or more until the gloss retention reaches 80% △: 3 hours or more and less than 5 hours until the gloss retention reaches 80% ×: Time until the gloss retention reaches 80% less than 3 hours

[Evaluation 4] Appearance of coating film The water-based coating composition obtained in the same manner as in "[Evaluation 3]" was applied onto a glass plate with an applicator to a thickness of 40 µm. Then, it was baked at 60° C. for 30 minutes to obtain a coating film. The obtained coating film was visually observed. The appearance of the coating film was evaluated according to the following evaluation criteria.
(Evaluation criteria)
A: Transparent, no foreign matter.
◯: Slightly cloudy.
Δ: Cloudiness, slight foreign matter, slightly low smoothness.
x: White turbidity, a large number of foreign substances, and low smoothness.

[Evaluation 5] Blister resistance of coating film 62.23 g of water-based polyl Setaqua 6515 (OH content 3.3%, non-volatile content 45%, manufactured by Nuplex Resin) was weighed into a container and stirred while leveling agent BYK-348 ( BYK) 0.10 g, Tego Wet 270 (manufactured by Evonic Tego Chemie) 0.10 g, UV absorber Tinuvin 1130 (manufactured by BASF) 0.65 g, light stabilizer Tinuvin 292 (manufactured by BASF) 0.32 g and 4.51 g water were added and stirred for 5 minutes. To this, the curing agent compositions produced in Examples and Comparative Examples were added so that the molar ratio between the isocyanate groups in the hydrophilic polyisocyanate component and the hydroxy groups in the aqueous polyol Setaqua 6515 was NCO/OH=1.5. A water-based coating composition was prepared by adding and stirring for 10 minutes. This water-based paint composition was defoamed using a vacuum defoamer under the conditions of 1500 rpm, 50 Torr, and 3 minutes. The defoamed water-based coating composition was applied with an applicator onto a glass plate while changing the dry film thickness, and the dry film thickness was measured when blisters were observed for the first time. The blister resistance of the coating film was evaluated according to the following evaluation criteria.
(Evaluation criteria)
◎: Dry film thickness of 200 μm or more when blisters are observed for the first time ○: Dry film thickness of 150 μm or more and less than 200 μm when blisters are observed for the first time △: Dry film thickness of 100 μm or more when blisters are observed for the first time Less than 150 μm ×: Dry film thickness when blister is observed for the first time is less than 100 μm

[Example 1] Production of curing agent composition 1 First, 15.5 parts by mass of polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 9.4 (manufactured by Nippon Nyukazai Co., Ltd., trade name "MPG-130") , and 80.0 parts by mass of an isocyanurate-type polyisocyanate of hexamethylene diisocyanate (HDI) (manufactured by Asahi Kasei Corporation, trade name "Duranate TPA-100"), and stirred at 110 ° C. for 3 hours under nitrogen. reacted. At this time, the blending amount of the hydrophilic compound was 16.2% by mass with respect to the total mass of the polyisocyanate and the hydrophilic compound. Next, 4.5 parts by mass of sodium dioctylsulfosuccinate and 0.20 parts by mass of 2-ethylhexyl ester of sodium sulfosuccinate (Compound (I)-1) were further added and stirred at 110°C for 10 minutes to obtain a curing agent composition. Got item 1.

The obtained curing agent composition 1 has a viscosity of 1700 mPa s, a solid content of 100% by mass, a content of compound (I) of 0.20% by mass, an isocyanate group content of 17.0% by mass, and an average number of isocyanate functional groups. was 3.0, and the content of the ionic surfactant with respect to the total mass of the hydrophilic polyisocyanate component and the ionic surfactant was 4.5% by mass.

[Examples 2 to 9] Production of Curing Agent Compositions 2 to 9 Curing agent compositions 2 to 9 were obtained in the same manner as in Example 1, except that the raw materials were blended so as to have the compositions shown in Table 1. . Table 1 shows the physical properties of the obtained curing agent compositions 2 to 9, and the evaluation results of the coating liquid and the coating film.

[Comparative Examples 1-7] Curing Agent Compositions 10-16
Curing agent compositions 10 to 16 were obtained in the same manner as in Example 1, except that the raw materials were blended so that the compositions shown in Table 2 were obtained. Table 2 shows the physical properties of the obtained curing agent compositions 10 to 16 and the evaluation results of the coating liquid and the coating film.
In Tables 1 and 2, "Duranate 24A-100" (trade name) is HDI biuret-type polyisocyanate (manufactured by Asahi Kasei Corporation). "MPG-081" is polyethylene glycol monomethyl ether (manufactured by Nippon Nyukazai Co., Ltd.) having an average number of ethylene oxide repeating units of 15.2.
Compounds (I)-1 to (I)-3 and compounds (II)-1 to (II)-3 are compounds having the structures shown below.

Compound (I)-1: R ¹¹ = 2-ethylhexyl, M ¹¹⁺ = Na ⁺
Compound (I)-2: R ¹¹ = 2-ethylhexyl, M ¹¹⁺ = K ⁺
Compound (I)-3: R ¹¹ =2-ethylhexyl, M ¹¹⁺ =NH ₄ ⁺

Compound (II)-1: R ²¹ = 2-ethylhexyl, R ²² = methyl, M ²¹⁺ = Na ⁺
Compound (II)-2: R ²¹ = methyl, R ²² = 2-ethylhexyl, M ²¹⁺ = K ⁺
Compound (II)-3: R ²¹ =methyl, R ²² =ethyl, M ²¹⁺ =NH ₄ ⁺

From Tables 1 and 2, curing agent compositions 1 to 9 each containing predetermined amounts of (A) a hydrophilic polyisocyanate component, (B) an ionic surfactant, and (C) a sulfonate (practical Examples 1 to 9) were confirmed to be stably dispersed in water and to have excellent pot life when used as coating liquids, and excellent appearance and blister resistance when used as coating films.
On the other hand, in the curing agent compositions 10 to 16 (Comparative Examples 1 to 7), all of the water dispersion stability, the pot life when used as a coating solution, and the appearance and blister resistance when used as a coating film are I didn't get a good one.
Further, curing agent compositions 1, 2, 4, 6, 8 and 9 (Example 1, 2, 4, 6, 8 and 9) are higher than the curing agent compositions 3, 5 and 7 (Examples 3, 5 and 7) in which the content is 0.07% by mass or less. was particularly excellent in blister resistance.
Further, curing agent compositions 1, 3 to 5 and 7 to 8 (Examples 1, 3 to 5 and 7 to 8) are particularly excellent in appearance when formed into a coating film than the curing agent compositions 2, 6 and 9 (Examples 2, 6 and 9) having a content of 8.0% by mass or more. rice field.

The curable composition of the present embodiment can be stably dispersed in water and is suitably used for water-based coating compositions. The aqueous coating composition of the present embodiment is suitably used as, for example, curable compositions, various surface treatment compositions, various elastomer compositions, cross-linking agents, modifiers, additives, and the like.

Claims (8)

With respect to the total mass of solids in the composition, (A) a hydrophilic polyisocyanate component of 79.5% by mass or more and 99.0% by mass or less, and 0.1% by mass or more and 20.0% by mass or less ( B) A curing agent composition comprising an ionic surfactant and 0.01% by mass or more and 0.5% by mass or less of (C) a sulfonate,
The (A) hydrophilic polyisocyanate component is a reaction product of a polyisocyanate obtained from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates and a hydrophilic compound,
The (C) sulfonate is one or more compounds selected from the group consisting of compounds represented by the following general formula (I) and compounds represented by the following general formula (II),
A curing agent composition excluding the compound represented by the following general formula (I) and the compound represented by the following general formula (II) from the ionic surfactant (B).

(In general formula (I), R ¹¹ and M ¹¹⁺ are any of the combinations shown in 1) to 3) below;
1) R ¹¹ = 2-ethylhexyl and M ¹¹⁺ = Na ⁺ ;
2) R ¹¹ =2-ethylhexyl and M ¹¹⁺ =K ⁺ ; and
3) R ¹¹ =2-ethylhexyl and M ¹¹⁺ =NH ₄ ⁺ . )

(in general formula (II), R ²¹ , R ²² and M ²¹⁺ are any of the combinations shown in 4) to 6) below;
4) R ²¹ = 2-ethylhexyl, R ²² = methyl and M ²¹⁺ = Na ⁺ ;
5) R ²¹ =methyl, R ²² =2-ethylhexyl, and M ²¹⁺ =K ⁺ ; and
6) R21 ⁼ methyl, R22 ⁼ ethyl and M21 ⁺ = _NH4 ⁺ . ) 2. The curing agent composition according to claim 1, wherein the (C) sulfonate comprises a compound represented by the general formula (I) and a compound represented by the general formula (II). 3. The curing agent composition according to claim 1, wherein the hydrophilic compound is a compound represented by the following general formula (III).

(In general formula (III), R ³¹ is an alkylene group having 1 to 4 carbon atoms. R ³² is an alkyl group having 1 to 4 carbon atoms. n31 is 5 to 50.) 4. The curing agent composition according to claim 3, wherein in the general formula (III), ^R31 is an ethylene group and n31 is 5 or more and 20 or less. The curing agent composition according to any one of claims 1 to 4, wherein the polyisocyanate has one or more functional groups selected from the group consisting of isocyanurate groups and biuret groups. Claims 1 to 3, wherein the (B) ionic surfactant is (C1-C20) ammonium alkylbenzenesulfonate, sodium (C1-C20 alkyl)benzenesulfonate, or sodium di(C1-C20 alkyl)sulfosuccinate. 6. The curing agent composition according to any one of 5. A water-based coating composition comprising the curing agent composition according to any one of claims 1 to 6, water, and an active hydrogen group-containing compound. A method for improving the appearance and blister resistance of a coating film, comprising:
With respect to the total mass of solids in the composition, (A) a hydrophilic polyisocyanate component of 79.5% by mass or more and 99.0% by mass or less, and 0.1% by mass or more and 20.0% by mass or less ( B) forming a coating film using a curing agent composition containing an ionic surfactant and 0.01% by mass or more and 0.5% by mass or less of (C) a sulfonate;
The (A) hydrophilic polyisocyanate component is a reaction product of a polyisocyanate obtained from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates and a hydrophilic compound,
The (C) sulfonate is one or more compounds selected from the group consisting of compounds represented by the following general formula (I) and compounds represented by the following general formula (II),
A method , wherein the compound represented by the following general formula (I) and the compound represented by the following general formula (II) are excluded from the ionic surfactant (B).

(In general formula (I), R ¹¹ and M ¹¹⁺ are any of the combinations shown in 1) to 3) below;
1) R ¹¹ = 2-ethylhexyl and M ¹¹⁺ = Na ⁺ ;
2) R ¹¹ =2-ethylhexyl and M ¹¹⁺ =K ⁺ ; and
3) R ¹¹ =2-ethylhexyl and M ¹¹⁺ =NH ₄ ⁺ . )

(in general formula (II), R ²¹ , R ²² and M ²¹⁺ are any of the combinations shown in 4) to 6) below;
4) R ²¹ = 2-ethylhexyl, R ²² = methyl and M ²¹⁺ = Na ⁺ ;
5) R ²¹ =methyl, R ²² =2-ethylhexyl, and M ²¹⁺ =K ⁺ ; and
6) R21 ⁼ methyl, R22 ⁼ ethyl and M21 ⁺ = _NH4 ⁺ . )