JP7092613B2 - Hydrophilic polyisocyanate composition, curing agent composition and water-based coating composition - Google Patents

Description

The present invention relates to hydrophilic polyisocyanate compositions, curing agent compositions and water-based coating compositions.

In recent years, from the viewpoint of environmental protection, it is desired that the room temperature crosslinked type two-component urethane coating composition used as a solvent-based paint is water-based. However, in the two-component urethane coating composition, the polyisocyanate used as a curing agent is difficult to disperse in water. Therefore, the development of polyisocyanate having a hydrophilic group is underway.

For example, in Patent Document 1, a hydrophilic polyisocyanate composed of a polyisocyanate, a nonionic hydrophilic group containing an ethylene oxide repeating unit, and a polyisocyanate composed of an ionic surfactant substantially free of water. The composition is disclosed. Further, Patent Document 2 discloses a polyisocyanate mixture that can be dispersed in water containing a specific range of ethylene oxide units. Further, Patent Document 3 discloses a water-dispersible polyisocyanate mixture in which a polyether chain containing an ethylene oxide repeating unit is bonded to a polyisocyanate molecule via an allophanate group.

Japanese Unexamined Patent Publication No. 9-328654 Japanese Unexamined Patent Publication No. 5-222150 Japanese Patent No. 4735447 Japanese Unexamined Patent Publication No. 57-34107 Japanese Unexamined Patent Publication No. 61-275311

The water-based two-component urethane coating composition is applied to furniture and building materials, woodworking for houses, sports floors, wooden floors for houses and school facilities, trains and construction machines, agricultural vehicles, plastics and the like. In those applications, it is required to have excellent compatibility with the main agent of the curing agent, appearance as a coating film, dryness, and a balance between hardness and extensibility. However, the polyisocyanate composition having a hydrophilic group described in Patent Document 1, Patent Document 2 and Patent Document 3 has compatibility with the main agent and appearance, dryness, hardness and extensibility when formed into a coating film. It was difficult to meet these requirements because the balance of these conditions may be reduced.

The present invention has been made in view of the above circumstances, and is stably dispersed in water, has compatibility with a main agent, and has an appearance, drying property, hardness and elongation as a coating film. Provided is a hydrophilic polyisocyanate composition having an excellent balance with sex.

That is, the present invention includes the following aspects.
The hydrophilic polyisocyanate composition according to the first aspect of the present invention contains, on average, a polyisocyanate obtained from at least one diisocyanate selected from the group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate and a non-polymerizable diol. A hydrophilic polyisocyanate composition obtained by reaction with a polyethylene glycol monoalkyl ether containing 5 or more and 25 or less ethylene oxide repeating units.
The polyisocyanate contains polyisocyanate X represented by the following general formula (1), and contains.
The ratio X / (X + Y) of the molar amount of polyisocyanate X to the total molar amount of the polyisocyanate X and the polyisocyanate Y represented by the following general formula (2) is 0.8 or more and 1.0 or less.
The polyisocyanate contains an isocyanurate group and at least one functional group selected from the group consisting of a urethane group and an allophanate group.
The molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) is 0.25 or more and 0.75 or less.
The average number of isocyanate functional groups of the hydrophilic polyisocyanate composition is 3.3 or more and 10.0 or less, and
The content of the structural unit derived from the polyethylene glycol monoalkyl ether is 5% by mass or more and 20% by mass or less with respect to the total solid content of the hydrophilic polyisocyanate composition.

(In the general formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ are residues independently of the diisocyanate excluding the isocyanate group. R ¹⁵ is the non-polymerizable diol. It is a residue excluding two hydroxyl groups of.)

(In the general formula (2), R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ are residues independently of the diisocyanate excluding the isocyanate group. R ²⁵ is the hydroxyl group of the non-polymerizable diol. Residues excluding two.)

The non-polymerizable diol may be at least one diol selected from the group consisting of an aliphatic diol having 2 or more and 10 or less carbon atoms and an alicyclic diol.

The curing agent composition according to the second aspect of the present invention contains the hydrophilic polyisocyanate composition according to the first aspect and the ionic surfactant, and the hydrophilic polyisocyanate composition and the ionic surfactant. The content of the ionic surfactant is 0.1% by mass or more and 10% by mass or less with respect to the total solid content of the activator.

The water-based coating composition according to the third aspect of the present invention includes the hydrophilic polyisocyanate composition according to the first aspect, the curing agent composition according to the second aspect, water, and an active hydrogen group-containing compound. ,including.
The active hydrogen group-containing compound may be a polyol having a hydroxyl value of 30 mgKOH / g or more and 200 mgKOH / g or less.

According to the hydrophilic polyisocyanate composition of the above aspect, it is stably dispersed in water, has compatibility with the main agent, and has appearance, drying property, hardness and extensibility as a coating film. It is possible to provide a hydrophilic polyisocyanate composition having an excellent balance. According to the curing agent composition of the above aspect, it is stably dispersed in water, has compatibility with the main agent, and has an appearance, dryness, and a balance between hardness and extensibility when formed into a coating film. An excellent curing agent composition can be provided. According to the water-based coating composition of the above aspect, it is possible to provide a water-based coating composition having an excellent balance of appearance, dryness, hardness and extensibility when formed into a coating film.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described 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. The present invention can be modified in various ways without departing from the gist thereof.

In the present specification, the amount of a specific functional group contained in a composition or a compound can be expressed as a "molar ratio". That is, the dimension of the value obtained by dividing the number of specific functional groups of the composition or compound by the Avogadro's number is defined as a mole. Thereby, the amount of the specific functional group is expressed as a "molar ratio" with respect to the amount of other specific functional groups. The specific functional group of the composition means the specific functional group of the compound contained in the composition.

In addition, in this specification, "polyol" means a compound which has two or more hydroxy groups (-OH) in one molecule.
As used herein, the term "non-polymerizable alcohol" means an alcohol that does not have a polymerizable group. The term "polymerizable group" as used herein means a group capable of forming a polymer by binding two or more monomer molecules having the group by a reaction such as light or heat.

As used herein, the term "polyisocyanate" means a reaction product in which a plurality of monomer compounds (isocyanate monomers) having one or more isocyanate groups (-NCO) are bonded.
As used herein, the term "hydrophilic polyisocyanate" means a polyisocyanate to which a hydrophilic group derived from a hydrophilic compound has been added. That is, the polyisocyanate includes a hydrophilic polyisocyanate and a hydrophilic group-free polyisocyanate.
In the present specification, "aliphatic diisocyanate" and "aliphatic diisocyanate" mean a compound which does not contain an aromatic ring such as a benzene ring in its structure.

<< Hydrophilic polyisocyanate composition >>
The hydrophilic polyisocyanate composition of the present embodiment is a hydrophilic polyisocyanate composition containing a hydrophilic polyisocyanate obtained by the reaction of the polyisocyanate and the polyethylene glycol monoalkyl ether. The polyisocyanate is a reaction product of at least one diisocyanate selected from the group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate and a non-polymerizable diol. The polyethylene glycol monoalkyl ether contains 5 or more and 25 or less ethylene oxide repeating units on average. Further, the hydrophilic polyisocyanate composition of the present embodiment satisfies the conditions shown below.
1) The polyisocyanate contains a polyisocyanate X represented by the following general formula (1) (hereinafter, may be simply referred to as "polyisocyanate X").
Ratio X / (X + Y) of the molar amount of polyisocyanate X to the total molar amount of the polyisocyanate X and the polyisocyanate Y represented by the following general formula (2) (hereinafter, may be simply referred to as “polyisocyanate Y”). ) Is 0.8 or more and 1.0 or less;
2) The polyisocyanate contains an isocyanurate group and at least one functional group selected from the group consisting of a urethane group and an allophanate group.
The molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) is 0.25 or more and 0.75 or less;
3) The average number of isocyanate functional groups in the hydrophilic polyisocyanate composition is 3.3 or more and 10.0 or less;
4) The content of the structural unit derived from the polyethylene glycol monoalkyl ether is 5% by mass or more and 20% by mass or less with respect to the total solid content of the hydrophilic polyisocyanate composition.

(In the general formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ are residues independently of the diisocyanate excluding the isocyanate group. R ¹⁵ is the non-polymerizable diol. It is a residue excluding two hydroxyl groups of.)

(In the general formula (2), R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ are residues independently of the diisocyanate excluding the isocyanate group. R ²⁵ is the hydroxyl group of the non-polymerizable diol. Residues excluding two.)

By having the above-mentioned structure, the hydrophilic polyisocyanate composition of the present embodiment stably disperses in water, is compatible with the main agent, and has an appearance, dryness, and dryness when formed into a coating film. Excellent balance between hardness and extensibility.
Hereinafter, each component contained in the hydrophilic polyisocyanate composition of the present embodiment will be described in detail.

<Hydrophilic polyisocyanate>
The hydrophilic polyisocyanate is a product in which polyethylene glycol monoalkyl ether, which is a hydrophilic compound, is bonded to a polyisocyanate molecule via a urethane group. The polyisocyanate used for producing the hydrophilic polyisocyanate is a reaction product of at least one diisocyanate selected from the group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate and a non-polymerizable diol. The polyisocyanate used for producing the hydrophilic polyisocyanate preferably has an isocyanurate group, and further preferably has an isocyanurate group and an allophanate group derived from a non-polymerizable diol in the same molecule.

[Diisocyanate]
The aliphatic diisocyanate is not particularly limited, but preferably has 4 or more and 30 or less carbon atoms. Specific examples of the aliphatic diisocyanate include tetramethylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, hexamethylene diisocyanate (hereinafter, may be referred to as "HDI"), 2,2,4. -Trimethyl-hexamethylene-1,6-diisocyanate, lysine diisocyanate and the like can be mentioned.

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, may be referred to as “IPDI”), hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and 1,4-cyclohexane diisocyanate.

In addition, these diisocyanates may be used individually by 1 type or in combination of 2 or more types.

Among them, as the diisocyanate, HDI, IPDI, hydrogenated xylylene diisocyanate, or hydrogenated diphenylmethane diisocyanate is preferable, and HDI is more preferable, because it is easily available industrially. By using HDI, the appearance and weather resistance when the hydrophilic polyisocyanate composition is used as a coating film tend to be more excellent.

[Non-polymerizable diol]
The non-polymerizable diol is not particularly limited, and is, for example, ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, and 1,2-butanediol. , 1,3-Butanediol, 1,4-Butanediol, 2,3-Butanediol, 2-Methyl-1,2-Propylenediol, 1,5-Pentanediol, 2-Methyl-2,3-Butanediol , 1,6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, 2-ethyl- Hexanediol, 1,2-octanediol, 1,2-decanediol, 2,2,4-trimethylpentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1, Examples thereof include 3-propanediol.
Among them, the non-polymerizable diol is an aliphatic compound having 2 or more and 10 or less carbon atoms from the viewpoint of compatibility with the main agent, appearance as a coating film, dryness, and balance between hardness and extensibility. At least one diol selected from the group consisting of diols and aliphatic diols is preferable, and 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, or 1,6-hexanediol is preferable. More preferred.

In addition to the above non-polymerizable diol, other non-polymerizable alcohols such as monoalcohols, triols, tetraols and the like may be contained.
The monoalcohols are not particularly limited, but for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, n-pentanol, n-hexanol, n-octanol, n-nonanol. , 2-Ethylbutanol, 2,2-dimethylhexanol, 2-ethylhexanol, cyclohexanol, methylcyclohexanol, ethylcyclohexanol and the like. Among them, isobutanol or 2-ethylhexanol is preferable as the monoalcohols.
The triols are not particularly limited, and examples thereof include glycerin and trimethylolpropane.
The tetraols are not particularly limited, and examples thereof include pentaerythritol and the like.

[Polyisocyanate X and Polyisocyanate Y]
The polyisocyanate used for producing the hydrophilic polyisocyanate contains the polyisocyanate X represented by the following general formula (1). Further, the polyisocyanate used for producing the hydrophilic polyisocyanate may contain the polyisocyanate Y represented by the following general formula (2).
The ratio X / (X + Y) of the molar amount of polyisocyanate X to the total molar amount of polyisocyanate X and polyisocyanate Y is the compatibility with the main agent, and the appearance, dryness, and hardness of the coating film. From the viewpoint of balance with extensibility, it is 0.8 or more and 1.0 or less, preferably 0.82 or more and 1.0 or less, more preferably 0.85 or more and 1.0 or less, and 0.88 or more and 1.0. The following is more preferable, and 0.9 or more and 1.0 or less are particularly preferable. When the ratio of X / (X + Y) is at least the above lower limit value, the extensibility of the obtained coating film can be made better.
The ratio of X / (X + Y) can be measured by liquid chromatography-mass spectrum (LC / MS) as shown in Examples described later.

(In the general formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ are residues independently of the diisocyanate excluding the isocyanate group. R ¹⁵ is the non-polymerizable diol. It is a residue excluding two hydroxyl groups of.)

(In the general formula (2), R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ are residues independently of the diisocyanate excluding the isocyanate group. R ²⁵ is the hydroxyl group of the non-polymerizable diol. Residues excluding two.)

(R ¹¹ , R ¹² , R ¹³ and R ¹⁴ )
In the general formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ are residues independently of the diisocyanate excluding the isocyanate group. That is, each of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ independently has a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group which may contain an ester bond. Is. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ may be the same or different, respectively. Above all, it is preferable that R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ are the same because they are easy to synthesize.

The divalent aliphatic hydrocarbon group which may contain an ester bond in R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ preferably has 4 or more and 30 or less carbon atoms. Further, the divalent aliphatic hydrocarbon group which may contain an ester bond may be linear or branched.
Specific examples of the divalent aliphatic hydrocarbon group containing no ester bond include a tetramethylene group, a pentamethylene group, a hexamethylene group, and a trimethylhexamethylene group.
Specific examples of the divalent aliphatic hydrocarbon group containing an ester bond include a methoxycarbonylpentamethylene group and the like.
Among them, a hexamethylene group is preferable as the aliphatic hydrocarbon group which may contain an ester bond in R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ .

The alicyclic hydrocarbon group in R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ preferably has 8 or more carbon atoms and 30 or less carbon atoms. Specific examples of the alicyclic hydrocarbon group include a cyclohexylene group, a dimethylcyclohexylene group, a trimethylcyclohexylene group, a dicyclohexylmethylene group and the like. Among them, as the alicyclic hydrocarbon group in R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ , a dimethylcyclohexylene group, a trimethylcyclohexylene group or a dicyclohexylmethylene group is preferable.

Of these, hexamethylene groups are preferable as R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ .

(R ¹⁵ )
In the general formula ( ¹ ), R15 is a residue excluding two hydroxyl groups of the non-polymerizable diol. That is, R ¹⁵ is a divalent hydrocarbon group, and an alkylene group having 2 or more carbon atoms and 10 or less carbon atoms is preferable. R ¹⁵ may be linear or branched. Specifically, as ^R15 , for example, an ethylene group, a 1,3-trimethylene group, a 1,2-propylene group, a 1,4-tetramethylene group, a 1,3-butylene group, a 1,5-pentamethylene group, Examples thereof include a 1,6-hexamethylene group, a 1.8-octamethylene group and a 2-ethyl-1,3-hexamethylene group. Of these, a 1,3-trimethylene group, a 1,4-tetramethylene group, a 1,3-butylene group, a 1,5-pentamethylene group, or a 1,6-hexamethylene group is preferable, and a 1,3-butylene group is preferable. Is more preferable.

(R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ )
In the general formula (2), R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ are independent residues excluding the isocyanate group of the diisocyanate. That is, R ²¹ , R ²² , R ²³ , R ²⁴ , and R ²⁶ are each independently a divalent aliphatic hydrocarbon group that may contain an ester bond, or a divalent aliphatic hydrocarbon group. R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ may be the same or different, respectively. Above all, it is preferable that R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ are the same because they are easy to synthesize.

Examples of the divalent aliphatic hydrocarbon group which may contain an ester bond in R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ include the above-mentioned "R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R". ¹⁷ ”is similar to that exemplified. Among them, a hexamethylene group is preferable as the divalent aliphatic hydrocarbon group which may contain an ester bond in R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ .

The alicyclic hydrocarbon groups in R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ are exemplified in the above-mentioned "R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ ". Similar things can be mentioned. Among them, as the alicyclic hydrocarbon group in R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ , a dimethylcyclohexylene group, a trimethylcyclohexylene group or a dicyclohexylmethylene group is preferable.

Of these, hexamethylene groups are preferable as R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ .

(R ²⁵ )
In the general formula (2), R ²⁵ is a residue excluding two hydroxyl groups of the non-polymerizable diol. Examples of the R ²⁵ include the same as those exemplified in the above “R ¹⁵ ”. Among them, as ^R25 , 1,3-trimethylene group, 1,4-tetramethylene group, 1,3-butylene group, 1,5-pentamethylene group, or 1,6-hexamethylene group is preferable. , 3-butylene group is more preferable.

Preferred polyisocyanate X includes, for example, a compound represented by the following general formula (1-1).
Preferred polyisocyanate Y includes, for example, a compound represented by the following general formula (2-1).

(In the general formula (1-1), R ¹¹⁵ is a residue excluding two hydroxyl groups of 1,3-butanediol.)

(In the general formula (2-1), ^R215 is a residue excluding two hydroxyl groups of 1,3-butanediol.)

[Functional group]
The polyisocyanate used in the production of the hydrophilic polyisocyanate contains an isocyanurate group and at least one functional group selected from the group consisting of a urethane group and an allophanate group. At this time, the molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) is 0.25 or more and 0.75 or less, preferably 0.28 or more and 0.70 or less, and 0.30 or more and 0. It is more preferably .65 or less, further preferably 0.32 or more and 0.60 or less, and particularly preferably 0.32 or more and 0.55 or less.
When the molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) is not less than the above lower limit value, the coating film hardness can be further improved, while when it is not more than the above upper limit value, it is possible to further improve the coating film hardness. The extensibility of the coating film can be improved.
The molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) can be measured by C13-NMR as shown ⁱⁿ Examples described later.

In general, the "isocyanurate group" is a functional group formed by reacting three isocyanate groups, and is a group represented by the following formula (3).
Generally, the "urethane group" is a functional group formed by reacting one isocyanate group with one hydroxyl group, and is a group represented by the following formula (4).
In general, the "alofanate group" is a functional group formed by reacting a hydroxyl group of an alcohol with an isocyanate group, and is a group represented by the following formula (5).

Further, as the polyisocyanate used for producing the hydrophilic polyisocyanate, the polyisocyanate obtained from three diisocyanate molecules (hereinafter, may be referred to as “diisocyanate trimer”) is compatible with the main agent and the coating film. From the viewpoint of appearance, dryness, and balance between hardness and extensibility, it is preferable to contain 5% by mass or more and 20% by mass or less with respect to the total mass of the polyisocyanate used for production. It is more preferable to contain% or more and 20% by mass or less.
The content of the diisocyanate trimer can be measured by gel permeation chromatography (hereinafter, may be abbreviated as "GPC").

[Manufacturing method of polyisocyanate X]
The method for producing polyisocyanate X, that is, a polyisocyanate having an isocyanurate group and an allophanate group is not particularly limited, but for example, after adding a diisocyanate and a non-polymerizable diol, isocyanurate-forming with an isocyanurate-forming catalyst or the like. A method in which the reaction and the allophanation reaction are carried out at the same time and the reaction is stopped when the conversion rate reaches a predetermined value, or a diisocyanate is added and the isocyanurate conversion reaction is carried out with an isocyanurate-forming catalyst or the like, and then the non-polymerizable diol and allophanate are used. Examples thereof include a method of adding the chemical catalysts in this order to carry out an allophanate formation reaction.

The catalyst used for the above-mentioned isocyanurate-forming reaction is not particularly limited, but a catalyst exhibiting basicity is preferable, and specifically, a tetraalkylammonium hydroxide and an organic weak acid salt, a hydroxyalkylammonium hydroxide and an organic catalyst are preferable. Examples thereof include weak acid salts, alkali metal salts of alkylcarboxylic acids, metal alcoholates, aminosilyl group-containing compounds, Mannig bases, combined use of tertiary amines and epoxy compounds, and phosphorus compounds.
Examples of the tetraalkylammonium include tetramethylammonium and tetraethylammonium.
Examples of the organic weak acid include acetic acid and capric acid.
Examples of hydroxyalkylammonium include trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, triethylhydroxyethylammonium and the like.
Examples of the alkylcarboxylic acid include acetic acid, caproic acid, octyl acid, myristic acid and the like.
Examples of the alkali metal salt include tin, zinc, lead and the like.
Examples of the metal alcoholate include sodium alcoholate and potassium alcoholate.
Examples of the aminosilyl group-containing compound include hexamethyldisilazane and the like.
Examples of the phosphorus compound include tributylphosphine and the like.

Further, in order to allow the allophanation reaction to proceed at a high ratio, it is preferable that the isocyanurate-forming reaction catalyst used is diluted with a monoalcohol compound and continuously added over a certain period of time.
The dilution ratio of the catalyst is preferably 0.1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 25% by mass or less, further preferably 2% by mass or more and 15% by mass or less, and 3% by mass or more and 12% by mass or less. The following are particularly preferred. The time for continuously adding the catalyst is preferably 20 minutes or more and 240 minutes or less, more preferably 30 minutes or more and 180 minutes or less, and further preferably 45 minutes or more and 150 minutes or less.
The amount of these catalysts used is preferably 0.001% or more and 1.0% or less with respect to the total mass of the raw materials diisocyanate and non-polymerizable diol. Further, in order to terminate the isocyanurate-forming reaction, the catalyst may be inactivated by addition of an acidic substance that neutralizes the catalyst, thermal decomposition, chemical decomposition, or the like. Examples of the acidic substance that neutralizes the catalyst include phosphoric acid and acidic phosphoric acid esters.

The reaction temperature of the isocyanurate-forming reaction is not particularly limited, but is preferably 50 ° C. or higher and 200 ° C. or lower, and more preferably 50 ° C. or higher and 150 ° C. or lower. When the reaction temperature is at least the above lower limit, the reaction tends to proceed more easily, and when the reaction temperature is at least the above upper limit, side reactions that cause coloring tend to be more suppressed. be.

Examples of the catalyst used in the above allophanation reaction include lead, zinc, bismuth, tin, zirconyl, and zirconium carboxylates. The amount of the allophanate-forming catalyst used is preferably 0.005 part by mass or more and 0.1 part by mass or less with respect to 100 parts by mass of the product obtained by the isocyanurate-forming reaction.
The allophanate reaction temperature is preferably 50 ° C. or higher and 180 ° C. or lower, more preferably 80 ° C. or higher and 150 ° C. or lower, from the viewpoint of suppressing side reactions and manufacturing efficiency.

After completion of the isocyanurate-forming reaction and the allophanate-forming reaction, it is preferable to remove the unreacted diisocyanate by a thin-film evaporation can, extraction or the like. Even when the polyisocyanate contains unreacted diisocyanate, the residual unreacted diisocyanate concentration is preferably 3.0% by mass or less, preferably 1.0% by mass or less, based on the total mass of the polyisocyanate. More preferably, 0.5% by mass or less is further preferable. When the residual unreacted diisocyanate concentration is within the above range, the curability tends to be more excellent.

[Manufacturing method of polyisocyanate Y]
The method for producing polyisocyanate Y, that is, a polyisocyanate having an isocyanurate group, an allophanate group, and a urethane group is not particularly limited, but for example, after adding a diisocyanate and a non-polymerizable diol, an isocyanurate-forming catalyst and urethane are added. A method of simultaneously performing an isocyanurate-forming reaction, an allophanate-forming reaction and a urethanization reaction with a conversion catalyst or the like and stopping the reaction when a predetermined conversion rate is reached, or a method of adding a diisocyanate and isocyanurate-forming catalyst or the like. Examples thereof include a method in which a nurateization reaction is carried out, then a non-polymerizable diol and an allophanation catalyst are added in this order to carry out an allophanation reaction, and then a urethanization catalyst is added to carry out the urethanization reaction.

The reaction conditions for the isocyanurate-forming reaction and the allophanate-forming reaction include the same conditions as those exemplified in the above-mentioned "Method for producing polyisocyanate X".

The catalyst used in the urethanization reaction is not particularly limited, and examples thereof include tin-based compounds, zinc-based compounds, and amine-based compounds.
The urethanization reaction temperature is preferably 50 ° C. or higher and 160 ° C. or lower, and more preferably 60 ° C. or higher and 120 ° C. or lower.
When the urethanization reaction temperature is not more than the above upper limit value, coloring of polyisocyanate and the like tend to be suppressed more effectively.
The urethanization reaction time is preferably 30 minutes or more and 4 hours or less, more preferably 1 hour or more and 3 hours or less, and further preferably 1 hour or more and 2 hours or less.

After completion of the isocyanurate-forming reaction, allophanation-forming reaction and urethanization reaction, it is preferable to remove the unreacted diisocyanate by a thin-film evaporation can, extraction or the like. Even when the polyisocyanate contains unreacted diisocyanate, the residual unreacted diisocyanate concentration is preferably 3.0% by mass or less, preferably 1.0% by mass or less, based on the total mass of the polyisocyanate. More preferably, 0.5% by mass or less is further preferable. When the residual unreacted diisocyanate concentration is within the above range, the curability tends to be more excellent.

[Physical characteristics of polyisocyanate]
The physical properties referred to here are the physical properties of all compounds having an isocyanate group, such as the polyisocyanate contained in the composition and other compounds having an isocyanate group other than the polyisocyanate.
For example, when the polyisocyanate used for producing the hydrophilic polyisocyanate consists only of the polyisocyanate X, it is the physical characteristics of the polyisocyanate X. In addition to the polyisocyanate X, when a polyisocyanate other than the polyisocyanate X (for example, polyisocyanate Y) or a monomer such as diisocyanate is contained, it is the physical characteristics of the mixture.

(viscosity)
The viscosity of the polyisocyanate is not particularly limited, but is preferably 100 mPa · s or more and 30,000 mPa · s or less, and more preferably 500 mPa · s or more and 20000 mPa · s or less at 25 ° C.
The viscosity at 25 ° C. can be measured by the method described in Examples described later.

(Isocyanate group content)
The isocyanate group content of the polyisocyanate is not particularly limited, but is preferably 5.0% by mass or more and 25% by mass or less, more preferably 10% by mass or more and 24% by mass or less, and further 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 described later.

<Hydrophilic compound>
The hydrophilic polyisocyanate contained in the hydrophilic polyisocyanate composition of the present embodiment has a structural unit derived from the hydrophilic compound. The structural unit derived from the hydrophilic compound referred to here refers to a portion of the hydrophilic compound excluding the functional group containing the hydrophilic group and forming a bond with the polyisocyanate. As a result, the hydrophilic polyisocyanate composition can obtain stable water dispersibility.

The hydrophilic compound used in the hydrophilic polyisocyanate composition of the present embodiment is a polyethylene glycol monoalkyl ether containing 5 or more and 25 or less ethylene oxide (-C ₂ H ₄ O-) repeating units on average. The number of repeating units of ethylene oxide is determined from the viewpoints of water dispersibility, water dispersion stability, compatibility with the main agent, appearance as a coating film, dryness, and a balance between hardness and extensibility. Usually, it is 5 or more and 25 or less, preferably 5 or more and 17 or less, and more preferably 5 or more and 15 or less.

In the hydrophilic polyisocyanate composition of the present embodiment, the structural unit derived from the hydrophilic compound (specifically, the structural unit derived from polyethylene glycol monoalkyl ether) with respect to the total solid content of the hydrophilic polyisocyanate composition. The lower limit of the content is 5.0% by mass, preferably 8.0% by mass, from the viewpoint of water dispersibility and water dispersion stability. Further, the upper limit of the content of the structural unit derived from the hydrophilic compound with respect to the total solid content of the hydrophilic polyisocyanate composition is from the viewpoint of curability, appearance, hardness, and water resistance when used as a coating film. , 20% by mass, preferably 18% by mass.
That is, in the hydrophilic polyisocyanate composition of the present embodiment, the hydrophilic compound component is 5.0% by mass or more and 20% by mass or less, and 8.0% by mass, based on the total solid content of the hydrophilic polyisocyanate composition. It is preferably 18% by mass or more and 18% by mass or less.

<Method for producing hydrophilic polyisocyanate composition>
The method for producing a hydrophilic polyisocyanate composition of the present embodiment is a step of mixing and reacting the polyisocyanate with the hydrophilic compound to obtain a hydrophilic polyisocyanate composition containing a modified (hydrophilic) polyisocyanate. (Reaction step) is provided.

In the reaction step, the reaction temperature and the reaction time are appropriately determined according to the progress of the reaction, but the reaction temperature is preferably 0 ° C. or higher and 150 ° C. or lower, and the reaction time is preferably 0.5 hour or higher and 48 hours or lower.

Further, in the reaction step, a known catalyst may be used in some cases. Examples of the catalyst include, but are not limited to, organic tin compounds, organic zinc compounds, organic titanium compounds, organic zirconium compounds, tertiary amines, diamines and the like.
Examples of the organic tin compound include tin octanate, tin 2-ethyl-1-hexanoate, tin ethylcaproate, tin laurate, tin palmitate, dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin zimarate, and dibutyltin. Examples thereof include dilaurate, dioctyltin diacetate, and dioctyltin dilaurate.
Examples of the organic zinc compound include zinc chloride, zinc octanate, zinc 2-ethyl-1-hexaneate, zinc 2-ethylcaproate, zinc stearate, zinc naphthenate, zinc acetylacetate and the like.
Examples of tertiary amines include triethylamine, tributylamine, N, N-diisopropylethylamine, N, N-dimethylethanolamine and the like.
Examples of the diamines include triethylenediamine, tetramethylethylenediamine, 1,4-diazabicyclo [2.2.2] octane and the like.
These catalysts may be used alone or in combination.

Further, the obtained hydrophilic polyisocyanate composition may contain a hydrophilic group-free polyisocyanate and a compound having an isocyanate group other than the polyisocyanate. Examples of the hydrophilic group-free polyisocyanate include unreacted polyisocyanate X used for producing hydrophilic polyisocyanate, unreacted polyisocyanate Y, and polyisocyanates other than polyisocyanate X and polyisocyanate Y. included. In addition, other compounds having an isocyanate group include, for example, unreacted diisocyanate used in the production of polyisocyanate X.

<Physical characteristics of hydrophilic polyisocyanate composition>
[viscosity]
In the hydrophilic polyisocyanate composition of the present embodiment, the lower limit of the viscosity at 25 ° C. is substantially non-volatile (hereinafter, may be referred to as “solid content”) from the viewpoint of curability when formed into a coating film. In a state of 100%, it is usually 50 mPa · s, preferably 300 mPa · s. On the other hand, the upper limit of the viscosity at 25 ° C. is usually 30,000 mPa · s, preferably 20000 mPa · s, from the viewpoint of water dispersibility and appearance when formed into a coating film.
That is, the viscosity of the hydrophilic polyisocyanate composition of the present embodiment at 25 ° C. is usually 50 mPa · s or more and 30,000 mPa · s or less, and 300 mPa · s or more and 20000 mPa · s in a state where the non-volatile content is substantially 100%. The following is preferred.
The viscosity of the hydrophilic polyisocyanate composition at 25 ° C. can be measured by the method described in Examples described later.

The method for controlling the viscosity at 25 ° C. within the above range is not limited to the following, and examples thereof include a method for adjusting the compounding ratio of the polyisocyanate and the hydrophilic compound.

[Isocyanate group content]
In the hydrophilic polyisocyanate composition of the present embodiment, the isocyanate group content is usually 3.0% by mass or more and 25% by mass or less, and 7.0% by mass or more in a state where the non-volatile content is substantially 100%. 20% by mass or less is preferable, and 13% by mass or more and 20% by mass or less is more preferable. When the isocyanate group content is in the above range, the curability, water resistance, and chemical resistance of the coating film are further improved.
The term "isocyanate group" as used herein refers to a combination of an isocyanate group of unreacted polyisocyanate and an isocyanate group of modified polyisocyanate. The isocyanate group content of the hydrophilic polyisocyanate composition can be measured by the method described in Examples described later.

The method for controlling the isocyanate group content within the above range is not limited to the following, and examples thereof include a method for adjusting the compounding ratio of the polyisocyanate and the hydrophilic compound.

[Average number of isocyanate functional groups]
In the hydrophilic polyisocyanate composition of the present embodiment, the lower limit of the average number of isocyanate functional groups (hereinafter, may be referred to as "average number of isocyanate functional groups") is the dryness, hardness, and water resistance of a coating film. From the viewpoint of property and chemical resistance, it is 3.3, preferably 3.4, more preferably 3.5, still more preferably 3.6, and particularly preferably 3.7.
On the other hand, the upper limit of the average number of isocyanate functional groups is 10.0, preferably 8 is preferable, 6 is more preferable, 5 is more preferable, and 4.5 is particularly preferable, from the viewpoint of water dispersion stability.
That is, the average number of isocyanate functional groups is 3.3 or more and 10.0 or less, preferably 3.4 or more and 8 or less, more preferably 3.5 or more and 6 or less, still more preferably 3.6 or more and 5 or less. 7 or more and 4.5 or less are particularly preferable.
The average number of isocyanate functional groups in the hydrophilic polyisocyanate composition can be measured by the method described in Examples described later.

≪Curing agent composition≫
The curing agent composition of the present embodiment contains the above-mentioned hydrophilic polyisocyanate composition and an ionic surfactant.

<Ionic surfactant>
In the curing agent composition of the present embodiment, the lower limit of the content of the ionic surfactant is set with respect to the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant from the viewpoint of the retention rate of isocyanate groups. It is 0.1% by mass, preferably 0.5% by mass. On the other hand, the upper limit of the content of the ionic surfactant is 10% by mass, preferably 5% by mass, from the viewpoint of water resistance of the coating film.
That is, the content of the ionic surfactant is 0.1% by mass or more and 10% by mass or less, and 0.5% by mass, based on the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant. It is preferably 5% by mass or less.
When the content of the ionic surfactant is equal to or higher than the above lower limit, the hydrophobic group forms a layer on the surface of the oil droplet of the hydrophilic polyisocyanate composition when dispersed in water, and the hydrophilic polyisocyanate composition is formed. Since the contact between the isocyanate group in the substance and water is reduced, the retention of the isocyanate group becomes higher. On the other hand, when the content of the ionic surfactant is not more than the above upper limit value, the amount of water drawn in can be reduced, so that the water resistance of the coating film is further improved.
The content of the ionic surfactant can be measured by the method described in Examples described later.

It is preferable that the ionic surfactant contains substantially no water. "Substantially water-free" in the present embodiment means that water is not contained at all, or water contained in an ionic surfactant reacts with an isocyanate group to prevent foaming, cloudiness and viscosity increase. It means that it contains only a certain amount of water. As a guide, the content of water with respect to the mass of the ionic surfactant is 1% by mass or less.

Examples of the ionic surfactant include anionic surfactants, cationic surfactants, and amphoteric surfactants. Among the anionic surfactants and cationic surfactants, depending on the method for neutralizing an aqueous emulsion, Which is preferable is decided. That is, it is preferable to use an anionic surfactant when the aqueous emulsion is neutralized with a base, and a cationic surfactant when the aqueous emulsion is neutralized with an acid. Either may be used if the aqueous emulsion is not neutralized.

As the anionic surfactant, a carboxylate type, a sulfate type, a sulfonate type, and a phosphate type are suitable. Specific compounds are not limited to the following, but are, for example, (C1-C20 alkyl) ammonium benzenesulfonate, (C1-C20 alkyl) sodium benzenesulfonate, (C1-C20 alkyl) sodium disulfate, alkyl. Examples thereof include diphenyl ether disulfonate sodium, di (C1-C20 alkyl) sodium sulfosuccinate, polyoxyethylene C6-C30 aryl ether sulfonate sodium, polyoxyethylene C6-C30 aryl ether ammonium sulfonate and the like. Among them, preferred as the anionic surfactant are (C1-C20 alkyl) ammonium benzenesulfonate, (C1-C20 alkyl) sodium benzenesulfonate, and di (C1-C20 alkyl) sodium sulfosuccinate. , Anything that is industrially available can be used without any inconvenience.

As the cationic surfactant, a quaternary ammonium salt, a pyridinium salt, and an imidazolinium salt are suitable. Specific examples of the compound include, but are not limited to, C1-C20 alkyltrimethylammonium bromide, C1-C30 alkylpyridinium bromide, imidazolinium laurate and the like. More specific compounds include, for example, alkyltrimethylammonium bromide, alkylpyridinium bromide, imidazolinium laurate and the like.

<Solvents and other additives>
The curing agent composition of the present embodiment may further contain a solvent and other additives in addition to the hydrophilic polyisocyanate composition and the ionic surfactant. Examples of other additives include curing accelerators, antioxidants, ultraviolet absorbers, light stabilizers, polymerization inhibitors, pigments, plasticizers, rheology control agents and the like.

[solvent]
Examples of the solvent include aromatic hydrocarbons, alcohol compounds, ketone compounds, ester compounds, ethers and the like.
Examples of aromatic hydrocarbons include benzene, toluene, xylene, chlorobenzene and the like.
Examples of the alcohol compound include methanol, ethanol, isopropanol, n-butanol, n-hexanol, 2-ethylhexanol and the like.
Examples of the ketone compound include acetone, methyl ethyl ketone and the like.
Examples of the ester compound include ethyl acetate, -n-butyl acetate, ethyl glycol acetate, methoxypropyl acetate, 3-hydroxy-2 isoacetate, 2, 4-trimethylpentyl and the like.
Examples of ethers include 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 further preferably 0% by mass or more and 30% by mass or less with respect to the total mass of the curing agent composition. preferable.

[Other additives]
One or more other additives selected from the group consisting of a curing accelerator, an antioxidant, an ultraviolet absorber, a light stabilizer, a polymerization inhibitor, a pigment, a plasticizer, and a rhology control agent in the curing agent composition of the present embodiment. When, the content of other additives in the curing agent composition is preferably 0% by mass or more and 10% by mass or less, and 0% by mass or more and 5% by mass or less, based on the total mass of the curing agent composition. Is more preferable, and 0% by mass or more and 2% by mass or less is further preferable.

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

The antioxidant is not particularly limited, and examples thereof include hindered phenol-based compounds, phosphorus-based compounds, and sulfur-based compounds.
The ultraviolet absorber is not particularly limited, and examples thereof include benzotriazole-based compounds, triazine-based compounds, and benzophenone-based compounds.
The light stabilizer is not particularly limited, and examples thereof include hindered amine compounds, benzotriazole compounds, triazine compounds, benzophenone compounds, and benzoate compounds.
The polymerization inhibitor is not particularly limited, and is, for example, an aliphatic, aromatic or alkyl group-substituted aromatic ester of phosphoric acid or phosphoric acid, a hypophosphite derivative, a phosphorus compound, or a phenol-based derivative (particularly, a hindered phenol compound). , Sulfur-containing compounds, tin-based compounds and the like.
The pigment is not particularly limited, and examples thereof include titanium oxide, carbon black, indigo, quinacridone, pearl mica, and aluminum.
The leveling agent is not particularly limited, and examples thereof include silicone oil and the like.
The plasticizer is not particularly limited, and examples thereof include phthalates, phosphoric acid-based compounds, polyester-based compounds, and the like.
The rheology control agent is not particularly limited, and examples thereof include hydroxyethyl cellulose, urea compounds, and microgels.

<Manufacturing method of curing agent composition>
The method for producing a curing agent composition of the present embodiment includes a step (addition step) of adding an ionic surfactant to the hydrophilic polyisocyanate composition and mixing the mixture to obtain a curing agent composition. Further, the reaction step in the above-mentioned method for producing a hydrophilic polyisocyanate composition and the above-mentioned addition step can be performed at the same time.

In the addition step, the lower limit of the addition amount of the ionic surfactant is 0.1 mass by mass with respect to the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant from the viewpoint of the retention rate of isocyanate groups. %, Preferably 0.5% by mass. On the other hand, the upper limit of the amount of the ionic surfactant added is 10% by mass, preferably 5% by mass, from the viewpoint of water resistance of the coating film.
That is, the amount of the ionic surfactant added is 0.1% by mass or more and 10% by mass or less, and 0.5% by mass, based on the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant. It is preferably 5% by mass or less.
When the amount of the ionic surfactant added is not more than the above lower limit, the hydrophobic group forms a layer on the surface of the oil droplet of the hydrophilic polyisocyanate composition when dispersed in water, and the hydrophilic polyisocyanate composition is formed. Since the contact between the isocyanate group in the substance and water is reduced, the retention of the isocyanate group becomes higher. On the other hand, when the amount of the ionic surfactant added is not more than the above upper limit value, the amount of water drawn in can be reduced, so that the water resistance of the coating film is further improved.

≪Water-based coating composition≫
The aqueous coating composition of the present embodiment contains the hydrophilic polyisocyanate composition or the curing agent composition, water, and an active hydrogen group-containing compound.

By containing the active hydrogen group-containing compound, the aqueous coating composition of the present embodiment contains the isocyanate group of the hydrophilic polyisocyanate composition and the active hydrogen group of the active hydrogen group-containing compound under various conditions. It tends to be excellent in hardness, water resistance, chemical resistance and appearance when reacted to form a coating film.

<Active hydrogen group-containing compound>
The active hydrogen group-containing compound (hereinafter, may be referred to as “multivalent active hydrogen group-containing compound”) is not particularly limited as long as it is a compound in which two or more active hydrogen groups are bonded in the molecule. Specific examples of the active hydrogen group-containing compound include polyamines, alkanolamines, polythiols, polyols and the like. Among them, the polyol is preferable as the active hydrogen group-containing compound.

[Polyamine]
The polyamine is not particularly limited, and examples thereof include diamines, chain polyamines having three or more amino groups, and cyclic polyamines.
Examples of the diamines include ethylenediamine, propylenediamine, butylenediamine, triethylenediamine, hexamethylenediamine, 4,4'-diaminodicyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine and the like.
Examples of chain polyamines having three or more amino groups include bishexamethylenetriamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentamethylenehexamine, tetrapropylenepentamine and the like.
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]
The alkanolamine is not particularly limited, and is, for example, monoethanolamine, diethanolamine, aminoethylethanolamine, N- (2-hydroxypropyl) ethylenediamine, mono-, di- (n- or iso-) propanolamine, and ethyleneglyco. Rubis-propylamine, neopentanolamine, methylethanolamine and the like can be mentioned.

[Polythiol]
The polythiol is not particularly limited, and examples thereof include bis- (2-hydrothioethyroxy) methane, dithioethylene glycol, dithioerythritol, and dithiothreitol.

[Polyol]
The polyol is not particularly limited, and examples thereof include polyester polyols, polycaprolactones, acrylic polyols, polyether polyols, polyolefin polyols, fluorine polyols, polycarbonate polyols, epoxy resins and the like.

(Polyester polyol)
The polyester polyol is not particularly limited, and examples thereof include products obtained by a condensation reaction between a dibasic acid alone or a mixture and a polyhydric alcohol alone or a mixture.
The dibasic acid is not particularly limited, but is at least one selected from the group consisting of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic acid anhydride, isophthalic acid, and terephthalic acid. Species dibasic acid can be mentioned.
The polyhydric alcohol is not particularly limited, and examples thereof include at least one polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, and glycerin.

(Polycaprolactones)
The polycaprolactones are not particularly limited, and examples thereof include products obtained by ring-opening polymerization of ε-caprolactone using a polyhydric alcohol.

(Acrylic polyol)
The acrylic polyol is not particularly limited, and is, for example, a single or a mixture of an ethylenically unsaturated bond-containing monomer having a hydroxyl group and another ethylenically unsaturated bond-containing monomer copolymerizable therewith. Alternatively, a copolymer of a mixture may be used.
The ethylenically unsaturated bond-containing monomer having a hydroxyl group is not particularly limited, and for example, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and methacrylic acid. Hydroxybutyl and the like can be mentioned. Among them, hydroxyethyl acrylate or hydroxyethyl methacrylate is preferable as the ethylenically unsaturated bond-containing monomer having a hydroxyl group.

The other ethylenically unsaturated bond-containing monomer copolymerizable with the ethylenically unsaturated bond-containing monomer having a hydroxyl group is not particularly limited, and is, for example, an acrylic acid ester, a methacrylic acid ester, or an unsaturated carboxylic acid. Examples thereof include acids, unsaturated amides, vinyl-based monomers, and vinyl-based monomers having a hydrolyzable silyl group.
Examples of the acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, -n-butyl acrylate, isobutyl acrylate, -n-hexyl acrylate, cyclohexyl acrylate, and -2 acrylate. -Ethylhexyl, lauryl acrylate, benzyl acrylate, phenyl acrylate and the like can be mentioned.
Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, -n-butyl methacrylate, isobutyl methacrylate, -n-hexyl methacrylate, cyclohexyl methacrylate, and -2 methacrylic acid. -Ethylhexyl, lauryl methacrylate, benzyl methacrylate, phenyl methacrylate and the like can be mentioned.
Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, itaconic acid and the like.
Examples of unsaturated amides include acrylamide, methacrylamide, N, N-methylenebisacrylamide, diacetoneacrylamide, diacetonemethacrylamide, maleic acid amide, maleimide and the like.
Examples of the vinyl-based monomer include glycidyl methacrylate, styrene, vinyltoluene, vinyl acetate, acrylonitrile, dibutyl fumarate and the like.
Examples of the vinyl-based monomer having a hydrolyzable silyl group include vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, and the like.

(Polyether polyol)
The polyether polyol is not particularly limited, but for example, an alkali metal hydroxide or a strongly basic catalyst is used to add the alkylene oxide alone or the mixture to the polyvalent hydroxy compound alone or the mixture. Examples thereof include polyether polyols obtained by reacting a polyfunctional compound with an alkylene oxide, and so-called polymer polyols obtained by polymerizing acrylamide or the like using the above-mentioned polyethers as a medium.

Examples of the alkali metal include lithium, sodium, potassium and the like.
Examples of the strong basic catalyst include alcoholates, alkylamines and the like.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, styrene oxide and the like.
Examples of the polyfunctional compound include ethylenediamines.

Specific examples of the polyvalent hydroxy compound include sugar alcohol compounds, monosaccharides, disaccharides, trisaccharides, and tetrasaccharides.
Examples of the sugar alcohol-based compound include diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol, erythritol, D-threitol, L-arabinitol, rivitol, xylitol, sorbitol, mannitol, galactitol, ramnitol and the like. ..
Examples of the monosaccharide include arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, ribodesource and the like.
Examples of the disaccharide include trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose and the like.
Examples of the trisaccharide include raffinose, gentianose, meletitos and the like.
Examples of the tetrasaccharide include stachyose and the like.

(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.

(Fluorine polyol)
The fluorine polyol is a polyol containing fluorine in the molecule, and for example, a copolymer such as fluoroolefin, cyclovinyl ether, hydroxyalkyl vinyl ether, and monocarboxylic acid vinyl ester disclosed in Patent Document 4 and Patent Document 5 can be used. Can be mentioned.

(Polycarbonate polyol)
The polycarbonate polyol is not particularly limited, and examples thereof include those obtained by polycondensing a low molecular weight carbonate compound and the low molecular weight polyol used for the polyester polyol described above.
Examples of the small molecule carbonate compound include dialkyl carbonate, alkylene carbonate, diaryl carbonate and the like.
Examples of the dialkyl carbonate include dimethyl carbonate and the like.
Examples of the alkylene carbonate include ethylene carbonate and the like.
Examples of the diaryl carbonate include diphenyl carbonate and the like.

(Epoxy resin)
The epoxy resin is not particularly limited, but for example, a novolak type epoxy resin, a glycidyl ether type epoxy resin, a glycol ether type epoxy resin, an epoxy type aliphatic unsaturated compound, an epoxy type fatty acid ester, and a polyvalent carboxylic acid ester type epoxy resin. , Aminoglycidyl type epoxy resin, β-methylepiclo type epoxy resin, cyclic oxylan type epoxy resin, halogen type epoxy resin, resorcin type epoxy resin and other epoxy resins can be mentioned.

[Hydroxyl value of polyol]
The hydroxyl value of the polyol is not particularly limited, but is preferably 30 mgKOH / g or more and 200 mgKOH / g or less, more preferably 40 mgKOH / g or more and 170 mgKOH / g or less, from the viewpoint of the crosslink density of the cured product and the mechanical characteristics. It is preferable, and more preferably 50 mgKOH / g or more and 150 mgKOH / g or less.

[Mole ratio of isocyanate group / active hydrogen group]
In the water-based coating composition, the ratio of the number of moles of isocyanate groups contained in the water-based coating composition to the number of moles of active hydrogen groups contained in the active hydrogen group-containing compound in the water-based coating composition is not particularly limited. However, 1/10 or more and 10/1 or less are preferable, 1/8 or more and 8/1 or less are more preferable, and 1/6 or more and 6/1 or less are further preferable. The molar ratio of isocyanate group / active hydrogen group can be calculated by the following formula (H).

Mole ratio of isocyanate group / active hydrogen group = (Z1 x isocyanate group content x 561) / (Z2 x polyol hydroxyl value x 42) ... (H)

In the formula (H), Z1 is the input mass of the polyisocyanate, and Z2 is the input mass of the polyol.

<Other curing agents>
The water-based coating composition may contain other curing agents such as a melamine-based curing agent and an epoxy-based curing agent.

[Melamine-based curing agent]
The melamine-based curing agent is not particularly limited, and examples thereof include a completely alkyl etherified melamine resin, a methylol-based melamine resin, and an imino-based melamine resin having an imino group in part. When a melamine-based curing agent is used in combination, it is effective to add an acidic compound. Specific examples of the acidic compound include carboxylic acid, sulfonic acid, acidic phosphoric acid ester, and sulphate ester.

The carboxylic acid is not particularly limited, and examples thereof include acetic acid, lactic acid, succinic acid, oxalic acid, maleic acid, and decandicarboxylic acid.
The sulfonic acid is not particularly limited, and examples thereof include paratoluenesulfonic acid, dodecylbenzenesulfonic acid, and dinonylnaphthalenedisulfonic acid.
The acidic phosphoric acid ester is not particularly limited, and examples thereof include dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, dilauryl phosphate, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, and monooctyl phosphate.
The phosphite ester is not particularly limited, and is, for example, diethyl phosphite, dibutyl phosphite, dioctyl phosphite, dilauryl phosphite, monoethyl phosphite, monobutyl phosphite, monooctyl phosphite, monolauryl phosphite. And so on.

[Epoxy curing agent]
The epoxy-based curing agent is not particularly limited, and for example, aliphatic polyamines, alicyclic polyamines, aromatic polyamines, acid anhydrides, phenol novolacs, polymercaptans, aliphatic tertiary amines, aromatic tertiary amines, and imidazoles. Examples thereof include compounds and Lewis acid complexes.

<Other additives>
The water-based coating composition may further contain other additives, depending on the intended use and purpose. The additive is not particularly limited, and examples thereof include a curable composition, various surface treatment agent compositions, various elastomer compositions, a cross-linking agent, and a modifier.
Examples of the curable composition include a coating composition, a pressure-sensitive adhesive composition, an adhesive composition, a casting composition and the like.
Examples of various surface treatment agent compositions include fiber treatment agents and the like.
Examples of the cross-linking agent include a foam composition and the like.

<Manufacturing method of water-based coating composition>
The method for producing the aqueous coating composition is not particularly limited, but for example, the above-mentioned hydrophilic polyisocyanate composition or the above-mentioned curing agent composition is added as a curing agent, and an active hydrogen group-containing compound is added as a main agent and mixed. The method can be mentioned.

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

The adherend to which the water-based coating composition can be used is not particularly limited, and for example, glass, various metals, porous members, various coated members, cured sealants, rubbers, leathers, fibers, etc. , Resin films and plates, UV curable acrylic resin layers, inks and the like.

Examples of various metals include aluminum, iron, galvanized steel sheet, copper, stainless steel and the like.
Examples of the porous member include wood, paper, mortar, stone and the like.
Examples of the member coated with various kinds include a member coated with fluorine coating, urethane coating, acrylic urethane coating and the like.
Examples of the cured sealant include a silicone-based cured product, a modified silicone-based cured product, and a urethane-based cured product.
Examples of rubbers include vinyl chloride, natural rubber, synthetic rubber and the like.
Examples of leathers include natural leathers and artificial leathers.
Examples of the fibers include non-woven fabrics, plant fibers, animal fibers, carbon fibers, glass fibers and the like.
Examples of the resins include polyester, acrylic, polycarbonate, triacetyl cellulose, polyolefin and the like.
Examples of the inks include printing inks, UV inks and the like.

Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples, but the present embodiment is not limited to the following examples and comparative examples as long as the gist of the present embodiment is not exceeded. ..
Various physical properties and evaluations in Examples and Comparative Examples were measured and evaluated as follows.

<Physical characteristics and evaluation>
[Physical Properties 1] Viscosity Using a hydrophilic polyisocyanate composition or a curing agent composition as a sample, the viscosity of the hydrophilic polyisocyanate composition at 25 ° C. was measured using an E-type viscometer RE-80U (manufactured by Toki Sangyo Co., Ltd.). I asked.

[Physical characteristics 2] Non-volatile content When the hydrophilic polyisocyanate composition or the curing agent composition is used as a sample and diluted with a solvent, the mass (W0 g) of the aluminum cup is precisely weighed, about 1 g of the sample is added, and the sample is heated. The cup mass (W1 g) before drying was precisely weighed. The cup containing the above sample was heated in a dryer at 105 ° C. for 3 hours. After cooling the heated cup to room temperature, the mass (W2 g) of the cup was precisely weighed again. The mass% of the dry residue in the sample was defined as the non-volatile content. The method for calculating the non-volatile content is as shown in the following formula (A). In the case of no solvent dilution, the non-volatile content was treated as being substantially 100%.

Non-volatile content (mass%) = (W2-W0) / (W1-W0) × 100% ・ ・ ・ (A)

[Physical characteristics 3-1] Content of ionic surfactant in the curing agent composition: x1 (mass%)
Using the curing agent composition as a sample, the content of the ionic surfactant (x1 (mass%)) was determined from the measurement of mass spectrometry after separation by liquid chromatography.
The equipment and conditions used are as follows.

(Device and conditions)
LC device: Waters, UPLC (trade name)
Column: Made by Waters, ACQUITY UPLC HSS T3 1.8 μm C18 Inner diameter 2.1 mm x Length 50 mm
Flow velocity: 0.3 mL / min
Mobile phase: a = 10 mM ammonium acetate aqueous solution, b = acetonitrile gradient condition: Initial mobile phase composition ratio is a / b = 98/2, the ratio of b is linearly increased after sample injection, and a after 10 minutes. / B = 0/100.
Detection method 1: Photodiode array detector, measurement wavelength 220 nm
Detection method 2: Mass spectrometer, Waters, Synapt G2 (trade name)
Ionization mode: Electrospray ionization, positive ion detection Scan range: m / z 100 to 2000

[Physical characteristics 3-2] Content of the ionic surfactant with respect to the total mass of the hydrophilic polyisocyanate composition and the ionic surfactant: x2 (mass%)
The content of the ionic surfactant (x2 (mass%)) when the total mass of the hydrophilic polyisocyanate composition and the ionic surfactant in the curing agent composition is used as a population is "physical property 2". Calculated using the following formula (B-1) from the non-volatile content (mass%) measured in 1 and the content of the ionic surfactant measured in "Physical characteristics 3-1": x1 (mass%). ..

Ionic surfactant content: x2 (% by mass)
= X1 / (nonvolatile content) x 100% ・ ・ ・ (B-1)

However, when the non-volatile component contained other components other than the hydrophilic polyisocyanate composition and the ionic surfactant, it was calculated using the following formula (B-2).

Ionic surfactant content: x2 (% by mass)
= X1 / {(nonvolatile content)-(other components)} x 100% ・ ・ ・ (B-2)

In the case of the curing agent composition containing no solvent, it was determined by the same measurement as in "Physical Properties 3-1".

[Physical characteristics 4-1] Isocyanate group content in the curing agent composition: y1 (mass%)
Using the curing agent composition as a sample, the measurement of the isocyanate group content was carried out according to the method described in JIS K7301-1995 (Torrange isocyanate type prepolymer test method for thermosetting urethane elastomer). A more specific method for measuring the isocyanate group content is shown below.
(1) 1 g of a sample was collected in a 200 mL triangular flask, and 20 mL of toluene was added to the flask to dissolve the sample.
(2) After that, 20 mL of a 2.0 N di-n-butylamine-toluene solution was added to the flask, and the flask was allowed to stand for 15 minutes.
(3) 70 mL of 2-propanol was added to the flask and dissolved to obtain a solution.
(4) The solution obtained in (3) above was titrated with 1 mol / L hydrochloric acid to determine the sample drop titer (V1 mL).
(5) Even when no sample was added, the measurement was carried out in the same manner as in (1) to (3) above, and the blank titration amount (V0 mL) was determined.

The isocyanate group content (y1 (mass%)) was calculated from the sample titration and the blank titration obtained above using the following formula (C-1).

Isocyanate group content in the curing agent composition: y1 (% by mass)
= {(V0－V1) × 42 / (1g × 1000)} × 100% ・ ・ ・ (C-1)

[Physical characteristics 4-2] Isocyanate group content in hydrophilic polyisocyanate composition: y2 (mass%)
When the hydrophilic polyisocyanate composition is used as the population, the isocyanate group content is the non-volatile content (mass%) measured in "Physical characteristics 2" and the ionic surfactant content measured in "Physical characteristics 3-2". It was calculated from the ratio: x2 (mass%) and the isocyanate group content in the curing agent composition measured in "Physical characteristics 4-1": y1 (mass%) using the following formula (C-2). ..

Isocyanate group content in hydrophilic polyisocyanate composition: y2 (% by mass)
= [Y1 / {(nonvolatile content) / 100} / (100-x2)] × 100% ・ ・ ・ (C-2)

However, when the non-volatile component contained other components other than the hydrophilic polyisocyanate composition and the ionic surfactant, it was calculated using the following formula (C-3).

Isocyanate group content in hydrophilic polyisocyanate composition: y2 (% by mass)
= [Y1 / {(nonvolatile content) / 100} / {100-x2- (other components)}] × 100% ・ ・ ・ (C-3)

In the case of a hydrophilic polyisocyanate composition containing neither an ionic surfactant nor a solvent, it was determined by the same measurement as in "Physical characteristics 4-1".

[Physical characteristics 5] Average number of isocyanate functional groups First, the number average molecular weight of polyisocyanate was measured by GPC under the measurement conditions shown below.

(Measurement condition)
Equipment: "HLC-8120GPC" manufactured by Tosoh (trade name)
Column: "TSKgel SuperH1000" (product name) manufactured by Tosoh Co., Ltd. x 1
"TSKgel SuperH2000" (product name) x 1
"TSKgel SuperH3000" (trade name) x 1 Carrier: Tetrahydrofuran Detection method: Differential refractometer Sample concentration: 5 wt / vol%
Detection method: Parallax refractometer Outflow: 0.6 mL / min
Column temperature: 30 ° C

The average number of isocyanate functional groups is the number of isocyanate functional groups statistically possessed by one hydrophilic polyisocyanate molecule. From the number average molecular weight (Mn) of the polyisocyanate measured using GPC and the isocyanate group content in the hydrophilic polyisocyanate composition measured in "Physical characteristics 4-2": y2 (mass%), the following It was calculated using the formula (D).

Average number of isocyanate functional groups = {(Mn × y2) / 100%} / 42 ・ ・ ・ (D)

[Physical characteristics 6] Mole ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) ¹³ C-N using Bruker's Biospin Avance 600 (trade name).
By measuring MR, the molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) was determined. The specific measurement conditions were as follows.

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

The integral value of the following signals was divided by the number of carbons being measured, and the molar amount of each functional group was obtained from the value.
-Isocyanurate group: Integral value of 148.5 ppm or more and 149.0 ppm or less / 3
-Urethane group: Integral value of 155.7 ppm or more and 156.1 ppm or less / 1
-Alofanate group: Integral value of 153.5 ppm or more and 154.0 ppm or less / 1

From the molar amount of each functional group obtained, the molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) was calculated.

[Physical characteristics 7] Mole ratio of X / (X + Y) The molar ratio of X / (X + Y) was determined according to the following method.
Specifically, the terminal isocyanate groups of polyisocyanate X and polyisocyanate Y in the hydrophilic polyisocyanate composition or the curing agent composition are replaced with methanol, and the terminal isocyanate groups are analyzed by liquid chromatography-mass spectrometry (LC / MS). did. The sample preparation method and measurement method are described below.

(1) Sample preparation method 100 mg of the hydrophilic polyisocyanate composition or the curing agent composition was weighed, and methanol was added so as to be 10 mg / mL. Then, the mixture was allowed to stand for 2 days to completely react the existing isocyanate groups with methanol to prepare a methanol solution.

(2) Measurement method The methanol solution obtained above was measured under the following measurement conditions.

(Measurement condition)
・ LC
Equipment: Agilent 1100 series
Column: Phenomenex, Kinex 2.6μ XB-C18 100A
(Inner diameter 2.1 mm, length 50 mm)
Column temperature: 40 ° C
Detection: 220nm
Flow rate: 0.35 mL / min Mobile phase: Below, the gradient of liquids A and B.
A = water (0.05% formic acid), B = acetonitrile (0.05% formic acid)
Injection volume: 1 μL

・ MS
Equipment: Waters, Synapt G2
Ionization: ESI
Mode: Positive
Scan range: from m / z 250 to 2000

From the measurement results of LC-MS, a methanol adduct of polyisocyanate X (compound α; a compound represented by the following general formula (1-1a)) and a methanol adduct of polyisocyanate Y (compound β; the following general formula). The ratio of the area of compound α to the total area of (compound represented by 2-1a) (α / α + β) was calculated, and the area ratio was defined as the molar ratio of X / (X + Y).

(In the general formula (1-1a), R ¹¹⁵ is a residue excluding two hydroxyl groups of 1,3-butanediol.)

(In the general formula (2-1a), ^R215 is a residue excluding two hydroxyl groups of 1,3-butanediol.)

[Evaluation 1] Water dispersibility The water dispersibility of the hydrophilic polyisocyanate composition or the curing agent composition was evaluated by the procedure shown in (1) to (5) below.
(1) The total mass (w0 (g)) of the 100 mL flask and Yoshino paper was measured.
(2) Each hydrophilic polyisocyanate composition or each curing agent composition obtained in Examples and Comparative Examples was collected in a 100 mL flask so as to be 16 g in terms of solid content, and 24 g of deionized water was added.
(3) Using propeller blades, the solution in the 100 mL flask was stirred at 200 rpm for 3 minutes, and then filtered through Yoshino paper weighed in (1).
(4) The filtration residue remaining on Yoshino paper and the residue remaining on the 100 mL flask were combined and heated in a dryer at 105 ° C. for 1 hour to determine the mass (w1 (g)).
(5) Using the non-volatile content (% by mass) obtained in "Physical characteristics 2", the ratio of each composition containing the hydrophilic polyisocyanate dispersed in water was determined from the following formula (G).

Percentage dispersed in water (mass%)
= 100%-(w1g－w0g) / (16g × (nonvolatile content)) × 100% ・ ・ ・ (G)

The ratio (% by mass) dispersed in the obtained water was evaluated according to the following evaluation criteria.

(Evaluation criteria)
◯: 80% by mass or more, good water dispersion.
X: Less than 80% by mass, inferior in water dispersion.

[Evaluation 2] Appearance of coating film (1) Production of water-based coating composition In a 200 mL plastic container, an acrylic dispersion having a hydroxyl value of 140 mgKOH / g per resin (manufactured by Allnex, trade name "Macrynal VSM 2521w / 42WA") : 78.7 parts by mass, leveling agent (manufactured by Allnex, trade name "Additor VXW 4971"): 0.2 parts by mass, surface tension adjuster (manufactured by Allnex, trade name "Additor VXW 6503N"): 0.5 By mass, 50% butyl glycol solution of UV absorber (BASF, trade name "Tinuvin 1130"): 2.3 parts by mass, 50% of hindered amine light stabilizer (BASF, trade name "Tinuvin 292") A butyl glycol solution: 0.8 parts by mass and deionized water: 17.5 parts by mass were charged, and the mixture was stirred at 1000 rpm for 5 minutes using a disper blade. Next, the hydrophilic polyisocyanate composition or the curing agent composition synthesized in Examples and Comparative Examples was blended so that the functional group ratio (NCO / OH) = 1.25, and the solid content was 40% by mass with water. Diluting to give an aqueous coating composition.

(2) Production of Coating Film The above water-based coating composition was coated on a glass plate with an applicator so as to have a thickness of 40 μm, and fired at 60 ° C. for 30 minutes to obtain a coating film.

(3) Appearance evaluation of the coating film The obtained coating film was visually evaluated. The evaluation criteria are as follows.

(Evaluation criteria)
○: Transparent, no foreign matter △: Transparent, with foreign matter ×: White turbidity

[Evaluation 3] Dryness of coating film (1) Production of coating film Using the water-based coating composition obtained in (1) of "Evaluation 2", a coating film having a thickness of 40 μm is coated on a Garden steel plate. Then, it was baked at 60 ° C. for 30 minutes.

(2) Evaluation of drying property of the coating film Next, using the trade name "Drying Time Tester Model 415" manufactured by Ericssen Co., Ltd., the time until the drying stage reaches 6 is set by a method compliant with DIN EN ISO 9117-5. It was measured. The evaluation criteria are as follows.

(Evaluation criteria)
⊚: less than 4.5 hours ○: 4.5 hours or more and less than 6 hours △: 6 hours or more and less than 24 hours ×: 24 hours or more

[Evaluation 4] Hardness of coating film (1) Production of coating film Using the water-based coating composition obtained in (1) of "Evaluation 2", a coating film having a thickness of 40 μm was coated on a glass plate. It was baked at 60 ° C. for 30 minutes. Then, it was dried in the atmosphere of 23 ° C./50%RH for 7 days to obtain a coating film.

(2) Evaluation of hardness of coating film The pencil hardness of the obtained coating film was measured according to ASTM D3363. The hardness increases in the following order.

(hardness)
2B <B <HB <H

[Evaluation 5] Distensibility of coating film Using the water-based coating composition obtained in (1) of "Evaluation 2", a coating film having a thickness of 40 μm was coated on a polypropylene plate and fired at 60 ° C. for 30 minutes. did. Then, it was dried in the atmosphere of 23 ° C./50%RH for 7 days to obtain a coating film.

(2) Evaluation of extensibility of the coating film The breaking elongation of the coating film peeled to the following dimensions was measured using the trade name TENSILON RTE-1210 manufactured by A & D. The measurement conditions were as follows. The evaluation criteria are as follows.

(Measurement condition)
Tensile speed: 20 mm / min
Sample dimensions: length 20 mm x width 10 mm x thickness 40 μm
Temperature 23 ℃ / Humidity 50%

(Evaluation criteria)
◯: Breaking elongation of the coating film (film) is 20% or more Δ: Breaking elongation of the coating film (film) is 10% or more and less than 20% ×: Breaking elongation of the coating film (film) is less than 10%

An excellent balance between hardness and extensibility means that the pencil hardness is B or more and the extensibility is 〇 or more.

[Example 1] Production of curing agent composition S-a1 (1) Production of polyisocyanate P-a1 Nitrogen in a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube and a dropping funnel. The atmosphere was adjusted, HDI: 1000 g, 1,3-butanediol: 36 g were charged, and the temperature inside the reactor was maintained at 70 ° C. under stirring. To this, 10% isobutanol of the isocyanurate-forming catalyst tetramethylammonium capriate: 1.0 g was continuously added over 100 minutes, and the isocyanate content (NCO%) of the reaction solution became 36.5% by mass. At this point, phosphoric acid was added and the reaction was stopped. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate P-a1.

(2) Production of Curing Agent Composition S-a1 Polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 9.4 in 1: 83.5 g of polyisocyanate P-a (manufactured by Nippon Embroidery Co., Ltd., trade name "MPG") −130 ”)): 15.0 g, sodium dioctyl sulfosuccinate: 1.5 g, and butyl acetate 1.1 g were added and subjected to a styrene reaction at 100 ° C. for 4 hours to obtain a curing agent composition S—a1.

The obtained curing agent composition S-a1 has an isocyanate group content of 17.2%, a viscosity of 9800 mPa · s, an average number of isocyanate functional groups of 3.7, and polyethylene in a state of 100% non-volatile content (solid content). The glycol monomethyl ether content was 15.0% by mass, the molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) was 0.50, and the molar ratio of X / X + Y was 0.94. Further, a water-based coating composition and a coating film were prepared and evaluated according to the method described above. The results are shown in Table 1.

[Example 2] Production of curing agent composition S-a2 (1) Production of polyisocyanate P-a2 HDI: 1000 g and 1,3-butanediol: 36 g are charged in the same reactor as in Example 1 and stirred. The temperature inside the lower reactor was maintained at 70 ° C. To this, 10% isobutanol of the isocyanurate-forming catalyst tetramethylammonium capriate: 1.0 g was continuously added over 100 minutes, and the isocyanate content (NCO%) of the reaction solution became 32.1% by mass. At this point, phosphoric acid was added and the reaction was stopped. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate P-a2.

(2) Production of Curing Agent Composition S-a2 MPG-130: 9.1 g having an average number of ethylene oxide repeating units of 9.4 in polyisocyanate P-a2: 90.0 g, sodium dioctylsulfosuccinate: 0. 9 g was added and subjected to a urethanization reaction at 100 ° C. for 4 hours to obtain a curing agent composition S-a2.

The hydrophilic polyisocyanate composition in the obtained curing agent composition S-a2 has an isocyanate group content of 15.7%, a viscosity of 14000 mPa · s, and an average number of isocyanate functional groups: 4 in a state of 100% solid content. 1. Polyethylene glycol monomethyl ether content: 10.1% by mass, isocyanate group / (isocyanurate group + urethane group + allophanate group) molar ratio: 0.50, X / X + Y molar ratio: 0.93. there were. Further, a water-based coating composition and a coating film were prepared and evaluated according to the method described above. The results are shown in Table 1.

[Example 3] Production of curing agent composition S-a3 (1) Production of polyisocyanate P-a3 HDI: 1000 g and 1,3-butanediol: 48 g are charged in the same reactor as in Example 1 and stirred. The temperature inside the lower reactor was maintained at 70 ° C. To this, 10% isobutanol of the isocyanurate-forming catalyst tetramethylammonium capriate: 1.0 g was continuously added over 100 minutes, and the isocyanate content (NCO%) of the reaction solution became 34.7% by mass. At this point, phosphoric acid was added and the reaction was stopped. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate P-a3.

(2) Production of Curing Agent Composition S-a3 Polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 15.0 in polyisocyanate P-a3: 83.0 g (manufactured by Nippon Emulsorium Co., Ltd., trade name "MPG" −081 ”)): 15.0 g and sodium dioctyl sulfosuccinate: 2.0 g were added and subjected to a urethanization reaction at 120 ° C. for 3 hours to obtain a curing agent composition S-a3.

The hydrophilic polyisocyanate composition in the obtained curing agent composition S-a3 has an isocyanate group content of 13.5%, a viscosity of 7000 mPa · s, and an average number of isocyanate functional groups: 3 in a state of 100% solid content. 9.9, Polyethylene glycol monomethyl ether content: 15.3% by mass, Isocyanurate group / (isocyanurate group + urethane group + allophanate group) molar ratio: 0.33, X / X + Y molar ratio: 0.91 there were. Further, a water-based coating composition and a coating film were prepared and evaluated according to the method described above. The results are shown in Table 1.

[Comparative Example 1] Production of hydrophilic polyisocyanate composition S-b1 (1) Production of polyisocyanate P-b1 In a four-necked flask equipped with a stirrer, a thermometer, a reflux cooling tube, a nitrogen blowing tube and a dropping funnel. Was brought into a nitrogen atmosphere, HDI: 1000 g was charged, and the temperature inside the reactor was maintained at 70 ° C. under stirring. To this was added isocyanurate-forming catalyst tetramethylammonium capriate: 0.1 g, and when the isocyanate content (NCO%) of the reaction solution reached 43.5% by mass, dibutyl phosphate was added to terminate the reaction. Then, 20 g of isobutanol and 0.5 g of zirconium 2-ethylhexanoate (20% 2-ethylhexanol solution) as an allophanate catalyst were charged, and the temperature was raised to 130 ° C. and held for 3 hours under a nitrogen atmosphere. Then, phosphoric acid was added to stop the reaction, and the reaction solution was filtered. Then, unreacted HDI was removed from the filtrate using a thin film evaporator to obtain polyisocyanate P-b1.

(2) Production of Hydrophilic Polyisocyanate Composition S-b1 MPG-130: 15.0 g having an average number of ethylene oxide repeating units (EO average number) of 9.4 is added to polyisocyanate P-b1: 85.0 g. The mixture was added and subjected to a urethanization reaction at 120 ° C. for 3 hours to obtain a hydrophilic polyisocyanate composition S-b1.

The obtained hydrophilic polyisocyanate composition S-b1 has an isocyanate group content of 18.6%, a viscosity of 6000 mPa · s, an average number of isocyanate functional groups of 3.6, and a polyethylene glycol monomethyl ether content (EO content). ): 15% by mass, the molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group): 0.62, and the molar ratio of X / X + Y was not detected. Further, a water-based coating composition and a coating film were prepared and evaluated according to the method described above. The results are shown in Table 1.

[Comparative Example 2] Production of Hydrophilic Polyisocyanate Composition S-b2 (1) Production of Polyisocyanate P-b2 HDI: 1000 g and 2-ethylhexanol: 30 g are charged in the same reactor as in Example 1 and stirred. The temperature inside the lower reactor was maintained at 70 ° C. To this was added isocyanurate-forming catalyst tetramethylammonium capriate: 0.1 g, and when the isocyanate content (NCO%) of the reaction solution reached 43.1% by mass, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate P-b2.

(2) Production of Hydrophilic Polyisocyanate Composition S-b2 MPG-081: 12.0 g having an average number of ethylene oxide repeating units of 15.0 was added to polyisocyanate P-b2: 88.0 g at 120 ° C. The reaction was carried out with a urethanization reaction for 3 hours to obtain a hydrophilic polyisocyanate composition S-b2.

The obtained hydrophilic polyisocyanate composition S-b2 has an isocyanate group content of 16.4%, a viscosity of 600 mPa · s, an average number of isocyanate functional groups: 2.5, and a polyethylene glycol monomethyl ether content of 12.0 mass. %, Isocyanurate group / (isocyanurate group + urethane group + allophanate group) molar ratio: 0.70, and the molar ratio of X / X + Y was not detected. Further, a water-based coating composition and a coating film were prepared and evaluated according to the method described above. The results are shown in Table 1.

[Comparative Example 3] Production of Curing Agent Composition S-b3 (1) Production of Polyisocyanate P-b3 HDI: 1000 g was charged into the same reactor as in Example 1 and the temperature inside the reactor was set to 70 ° C. under stirring. Retained. To this, 0.1 g of isocyanurate-forming catalyst tetramethylammonium capriate was added, and when the isocyanate content (NCO%) of the reaction solution reached 43.5% by mass, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate q. Further, HDI: 1000 g and 1,3-butanediol: 36 g were charged in the same reactor as in Example 1, and then 0.5 g of allophanation catalyst zirconium 2-ethylhexanoate (20% 2-ethylhexanol solution) was charged. Was charged, the temperature was raised to 130 ° C. under a nitrogen atmosphere, and the temperature was maintained for 3 hours. Then, phosphoric acid was added to stop the reaction, and the unreacted HDI was removed using a thin-film evaporator obtained by filtering the reaction solution to obtain a polyisocyanate r. Then, polyisocyanate q: 55.0 g and polyisocyanate r: 45.0 g were added to the reactor, and the mixture was stirred at 50 ° C. for 1 hour to obtain polyisocyanate P-b3.

(2) Production of Curing Agent Composition S-b3 MPG-130: 9.1 g having an average number of ethylene oxide repeating units of 9.4 in polyisocyanate P-b3: 90.0 g, sodium dioctylsulfosuccinate: 0. A urethanization reaction was carried out at 9 g at 100 ° C. for 4 hours to obtain a curing agent composition S-b3.

The hydrophilic polyisocyanate composition in the obtained curing agent composition S-b3 has an isocyanate group content of 15.5%, a viscosity of 6000 mPa · s, and an average number of isocyanate functional groups: 3 in a state of 100% solid content. .5, Polyethylene glycol monomethyl ether content: 10.1% by mass, isocyanurate group / (isocyanurate group + urethane group + allophanate group) molar ratio: 0.50, and the molar ratio of X / X + Y was detected. There wasn't. Further, a water-based coating composition and a coating film were prepared and evaluated according to the method described above. The results are shown in Table 1.

[Comparative Example 4] Production of Curing Agent Composition S-b4 (1) Production of Polyisocyanate P-b4 HDI: 1000 g and 1,3-butanediol: 65 g were charged into the same reactor as in Example 1 and stirred. The temperature inside the lower reactor was maintained at 70 ° C. To this, 0.1 g of isocyanurate-forming catalyst tetramethylammonium capriate was added, and 10% isobutanol of isocyanurate-forming catalyst tetramethylammonium capriate: 1.0 g was continuously added over 100 minutes to react. Phosphoric acid was added when the isocyanate content (NCO%) of the liquid reached 31.5% by mass, and the reaction was stopped. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate P-b4.

(2) Production of Curing Agent Composition S-b4 MPG-130: 13.7 g having an average number of ethylene oxide repeating units of 9.4 in polyisocyanate P-b4: 86.0 g, sodium dioctylsulfosuccinate: 0. 25 g was added and subjected to a urethanization reaction at 100 ° C. for 4 hours to obtain a curing agent composition S-b4.

The hydrophilic polyisocyanate composition in the obtained curing agent composition S-b4 has an isocyanate group content of 16.5%, a viscosity of 3700 mPa · s, and an average number of isocyanate functional groups: 3 in a state of 100% solid content. .5, Polyethylene glycol monomethyl ether content: 13.7% by mass, Isocyanurate group / (isocyanurate group + urethane group + allophanate group) molar ratio: 0.15, X / X + Y molar ratio: 0.88 there were. Further, a water-based coating composition and a coating film were prepared and evaluated according to the method described above. The results are shown in Table 1.

[Comparative Example 5] Production of Curing Agent Composition S-b5 (1) Production of Polyisocyanate P-b5 HDI: 1000 g and 1,3-butanediol: 12 g were charged into the same reactor as in Example 1 and stirred. The temperature inside the lower reactor was maintained at 70 ° C. To this, 10% isobutanol of the isocyanurate-forming catalyst tetramethylammonium capriate: 1.0 g was continuously added over 100 minutes, and the isocyanate content (NCO%) of the reaction solution became 37.6% by mass. At this point, phosphoric acid was added and the reaction was stopped. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate P-b5.

(2) Production of Curing Agent Composition S-b5 MPG-130: 13.0 g having an average number of ethylene oxide repeating units of 9.4 g and sodium dioctyl sulfosuccinate: 1 in polyisocyanate P-b5: 86.0 g. 0 g was added and subjected to a urethanization reaction at 100 ° C. for 4 hours to obtain a curing agent composition S-b5.

The hydrophilic polyisocyanate composition in the obtained curing agent composition S-b5 has an isocyanate group content of 16.5%, a viscosity of 6300 mPa · s, and an average number of isocyanate functional groups: 3 in a state of 100% solid content. .5, Polyethylene glycol monomethyl ether content: 13.1% by mass, Isocyanurate group / (isocyanurate group + urethane group + allophanate group) molar ratio: 0.80, X / X + Y molar ratio: 0.90 there were. Further, a water-based coating composition and a coating film were prepared and evaluated according to the method described above. The results are shown in Table 1.

[Comparative Example 6] Production of Curing Agent Composition S-b6 (1) Production of Polyisocyanate P-b6 HDI: 1000 g and 1,3-butanediol: 36 g were charged into the same reactor as in Example 1 and stirred. The temperature inside the lower reactor was maintained at 70 ° C. To this, 0.1 g of isocyanurate-forming catalyst tetramethylammonium capriate was added, and when the isocyanate content (NCO%) of the reaction solution reached 32.1% by mass, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate P-b6.

(2) Production of Curing Agent Composition S-b6 MPG-130: 9.1 g having an average number of ethylene oxide repeating units of 9.4 in polyisocyanate P-b6: 90.0 g, sodium dioctylsulfosuccinate: 0. A urethanization reaction was carried out at 9 g at 100 ° C. for 4 hours to obtain a curing agent composition S-b6.

The hydrophilic polyisocyanate composition in the obtained curing agent composition S-b6 has an isocyanate group content of 15.6%, a viscosity of 15,000 mPa · s, and an average number of isocyanate functional groups: 4 in a state of 100% solid content. 0.0, Polyethylene glycol monomethyl ether content: 10.1% by mass, Isocyanurate group / (isocyanurate group + urethane group + allophanate group) molar ratio: 0.51, X / X + Y molar ratio: 0.64. rice field. Further, a water-based coating composition and a coating film were prepared and evaluated according to the method described above. The results are shown in Table 1.

From Table 1, in the curing agent compositions S-a1 to S-a3 (Examples 1 to 3), the curing agent compositions are stably dispersed in water, have compatibility with the main agent, and have an appearance as a coating film. Excellent in dryness and balance between hardness and extensibility.
Further, the curing agent compositions S-a1 and S-a2 (Examples 1 and 2) having a molar ratio of isocyanurate / (urethane + allophanate + isocyanurate) of 0.50 are areocyanurate / (urethane + allophanate +). The hardness of the coating film was particularly better than that of the curing agent composition S-a3 (Example 3) having a molar ratio of isocyanurate) of 0.33.
Further, the curing agent composition S-a2 (Example 2) having an average isocyanate functional number of 4.1 is a curing agent composition S-a1 and S-a3 (implementation) having an average isocyanate functional number of less than 4.0. The drying property when used as a coating film was particularly better than in Examples 1 and 3).

On the other hand, the hydrophilic polyisocyanate compositions S-b1 and S-b2 (Comparative Examples 1 and 2) and the curing agent compositions S-b3 to S-b6 (Comparative Examples 3 to 6) are stable in water. Although they were dispersed, no excellent coating film was obtained in terms of appearance, dryness, and balance between hardness and extensibility, and the extensibility of the coating film was particularly poor.

The hydrophilic polyisocyanate composition and the curing agent composition of the present embodiment are stably dispersed in water, have compatibility with the main agent, and have an appearance, dryness, hardness and extensibility as a coating film. Excellent balance with. The water-based coating composition of the present embodiment is suitably used as, for example, a curable composition, various surface treatment agent compositions, various elastomer compositions, cross-linking agents, modifiers, additives and the like.

Claims (5)

Polyethylene glycol mono containing at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, polyisocyanates obtained from non-polymerizable diols, and an average of 5 or more and 25 or less ethylene oxide repeating units. A hydrophilic polyisocyanate composition obtained by reaction with an alkyl ether.
The polyisocyanate contains polyisocyanate X represented by the following general formula (1), and contains.
The ratio X / (X + Y) of the molar amount of polyisocyanate X to the total molar amount of the polyisocyanate X and the polyisocyanate Y represented by the following general formula (2) is 0.8 or more and 1.0 or less.
The polyisocyanate contains an isocyanurate group and at least one functional group selected from the group consisting of a urethane group and an allophanate group.
The molar ratio of isocyanurate group / (isocyanurate group + urethane group + allophanate group) is 0.25 or more and 0.75 or less.
The average number of isocyanate functional groups of the hydrophilic polyisocyanate composition is 3.3 or more and 10.0 or less, and
A hydrophilic polyisocyanate composition having a content of structural units derived from the polyethylene glycol monoalkyl ether of 5% by mass or more and 20% by mass or less with respect to the total solid content of the hydrophilic polyisocyanate composition.

(In the general formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁶ and R ¹⁷ are residues independently of the diisocyanate excluding the isocyanate group. R ¹⁵ is the non-polymerizable diol. It is a residue excluding two hydroxyl groups of.)

(In the general formula (2), R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁶ are residues independently of the diisocyanate excluding the isocyanate group. R ²⁵ is the hydroxyl group of the non-polymerizable diol. Residues excluding two.) The hydrophilic polyisocyanate composition according to claim 1, wherein the non-polymerizable diol is at least one diol selected from the group consisting of an aliphatic diol having 2 or more and 10 or less carbon atoms and an alicyclic diol. The hydrophilic polyisocyanate composition according to claim 1 or 2, and an ionic surfactant are included.
A curing agent composition in which the content of the ionic surfactant is 0.1% by mass or more and 10% by mass or less with respect to the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant. A water-based coating composition comprising the hydrophilic polyisocyanate composition according to claim 1 or 2, or the curing agent composition according to claim 3, water, and an active hydrogen group-containing compound. The water-based coating composition according to claim 4, wherein the active hydrogen group-containing compound is a polyol having a hydroxyl value of 30 mgKOH / g or more and 200 mgKOH / g or less.