CN109384898B

CN109384898B - Hydrophilic polyisocyanate composition, curing agent composition, and aqueous coating composition

Info

Publication number: CN109384898B
Application number: CN201810893013.4A
Authority: CN
Inventors: 辻田隼也; 中岛和子
Original assignee: Asahi Kasei Corp
Current assignee: Asahi Kasei Corp
Priority date: 2017-08-08
Filing date: 2018-08-07
Publication date: 2021-03-19
Anticipated expiration: 2038-08-07
Also published as: JP2019031667A; JP7262942B2; CN109384898A

Abstract

A hydrophilic polyisocyanate composition, a curing agent composition and a water-based coating composition. Disclosed is a hydrophilic polyisocyanate composition which is stably dispersed in water and has excellent curability, hardness and appearance when a coating film is formed, comprising a hydrophilic polyisocyanate obtained by reaction of a polyisocyanate with a hydrophilic compound, the polyisocyanate is obtained from 1 or more kinds of diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and among the hydrophilic polyisocyanates, the molar ratio (B)/(a) of the hydrophilic polyisocyanate (B) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 2 or 3 molecule to the hydrophilic polyisocyanate (a) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 1 molecule is 0/100 or more and 20/80 or less.

Description

Hydrophilic polyisocyanate composition, curing agent composition, and aqueous coating composition

Technical Field

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

Background

In recent years, from the viewpoint of environmental protection, it has been expected that a room-temperature crosslinking two-component urethane coating composition used as a solvent-based coating material will be made water-based. However, in two-part urethane coating compositions, the polyisocyanate used as the curing agent is difficult to disperse in water. Therefore, the development of polyisocyanates having hydrophilic groups has been advanced.

For example, patent document 1 discloses a hydrophilic polyisocyanate containing a polyisocyanate and a nonionic hydrophilic group containing an ethylene oxide repeating unit bonded to the polyisocyanate; and a polyisocyanate composition containing an ionic surfactant substantially free of water.

In addition, patent document 2 discloses a water-dispersible polyisocyanate mixture containing ethylene oxide units in a specific range.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 9-328654

Patent document 2: japanese laid-open patent publication No. 5-222150

Disclosure of Invention

Problems to be solved by the invention

The aqueous two-component urethane coating composition is applied to furniture and building materials, woodwork for housing, sports flooring, wooden flooring for housing and school facilities, electric trains, construction machines, agricultural vehicles, and the like. In these applications, excellent curability, hardness and appearance are required in forming a coating film.

However, the polyisocyanate compositions having hydrophilic groups described in patent documents 1 and 2 sometimes have reduced curability, hardness, and appearance when forming a coating film, and it is difficult to satisfy these requirements.

The present invention has been made in view of the above circumstances, and provides: a hydrophilic polyisocyanate composition which is stably dispersed in water and has excellent curability, hardness and appearance when a coating film is formed. Providing: a curing agent composition and a water-based coating composition containing the hydrophilic polyisocyanate composition.

Means for solving the problems

That is, the present invention includes the following aspects.

The hydrophilic polyisocyanate composition according to claim 1 of the present invention contains a hydrophilic polyisocyanate obtained by the reaction of a polyisocyanate obtained from 1 or more kinds of diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and a hydrophilic compound, wherein the molar ratio ((B)/(a)) of the hydrophilic polyisocyanate (B) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 2 or 3 molecules to the hydrophilic polyisocyanate (a) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 1 molecule is 0/100 or more and 20/80 or less.

In the hydrophilic polyisocyanate composition according to claim 1, the ratio of the polyisocyanate (P) obtained from the diisocyanate 3 molecules and not reacted with the hydrophilic compound to the total mole number of the polyisocyanate (P), the hydrophilic polyisocyanate (a) and the hydrophilic polyisocyanate (B) may be 70 or more and 98 or less.

The hydrophilic compound may be a compound represented by the following general formula (I).

[ in the general formula (I), R¹Is alkylene having 1 to 4 carbon atoms, R²An alkyl group having 1 to 4 carbon atoms. n is 5 or more and 50 or less.]

In the above general formula (1), R¹May be ethylene, R²May be an ethyl group, and n may be 5 or more and 20 or less.

The aforementioned polyisocyanate may contain 1 or more selected from the group consisting of isocyanurate groups and biuret groups.

The curing agent composition according to claim 2 of the present invention comprises the hydrophilic polyisocyanate composition according to claim 1 and an ionic surfactant, and the ionic surfactant is contained in an amount of 0.1 mass% or more and 20 mass% or less based on the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant.

The water-based coating composition according to claim 3 of the present invention comprises: the hydrophilic polyisocyanate composition according to claim 1 or the curing agent composition according to claim 2; water; and, an active hydrogen compound.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the above aspect, there can be provided: a hydrophilic polyisocyanate composition which is stably dispersed in water and has excellent curability, hardness and appearance when a coating film is formed. There may be provided: a curing agent composition and a water-based coating composition containing the hydrophilic polyisocyanate composition.

Detailed Description

Hereinafter, a mode for carrying out the present invention (hereinafter, referred to as "the present embodiment") will be described in detail. The following embodiments are examples for illustrating the present invention, and the present invention is not intended to be limited to the following. The present invention can be variously modified within a range not departing from the gist thereof.

In the present specification, the amount of the specific functional group contained in the composition or the compound may be represented by "molar ratio". That is, the number of specific functional groups of the composition or compound is divided by the avocado constant, and the value of the division is defined in terms of moles. Thus, the amount of the specific functional group is expressed as a "molar ratio" with respect to the amount of the other specific functional groups.

The specific functional group of the composition means a specific functional group of a compound contained in the composition.

Hydrophilic polyisocyanate composition

The hydrophilic polyisocyanate composition according to one embodiment of the present invention contains a hydrophilic polyisocyanate obtained by the reaction of a polyisocyanate and a hydrophilic compound as described below.

The polyisocyanate is obtained from 1 or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

In the hydrophilic polyisocyanate, the molar ratio ((B)/(a)) of the hydrophilic polyisocyanate (B) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 2 or 3 molecule to the hydrophilic polyisocyanate (a) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 1 molecule is 0/100 or more and 20/80 or less.

< physical Property >

The physical properties of the hydrophilic polyisocyanate composition of the present embodiment will be described in detail below.

[(B)/(A)]

In the hydrophilic polyisocyanate composition of the present embodiment, the molar ratio ((B)/(a)) of the hydrophilic polyisocyanate (B) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 2 or 3 molecule to the hydrophilic polyisocyanate (a) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 1 molecule in the hydrophilic polyisocyanate is preferably 0/100 or more and 20/80 or less, more preferably 5/95 or more and 18/82 or less, and still more preferably 10/90 or more and 17/83 or less.

By setting (B)/(a) in the above range, the curability, appearance, hardness, water resistance and chemical resistance at the time of forming a coating film can be further improved.

(B) The value of/(A) can be calculated by the method described in the examples described later.

[(P)/{(P)+(A)+(B)}]

In the hydrophilic polyisocyanate composition of the present embodiment, the ratio of the number of moles of the polyisocyanate (P) obtained from 3 molecules of the diisocyanate and not reacted with the hydrophilic compound to the total number of moles of the polyisocyanate (P), the hydrophilic polyisocyanate (a) and the hydrophilic polyisocyanate (B) ((P)/{ (P) + (a) + (B) }) is not particularly limited, and is preferably 70 or more and 98 or less, more preferably 75 or more and 97 or less, and still more preferably 80 or more and 96 or less.

When (P)/{ (P) + (a) + (B) } is in the above range, water dispersibility, curability at the time of forming a coating film, appearance, hardness, water resistance, and chemical resistance can be further improved.

(P)/{ (P) + (A) + (B) } can be calculated by the method described in the examples described later.

The method of controlling (P)/{ (P) + (a) + (B) } to the above range is not particularly limited, and examples thereof include: a method in which a polyisocyanate is reacted with a hydrophilic compound; a method of reacting a polyisocyanate with a hydrophilic compound and then adding the polyisocyanate.

[ content of hydrophilic Compound with respect to the amount of the Total solid component ]

In the hydrophilic polyisocyanate composition of the present embodiment, the content of the hydrophilic compound with respect to the total solid content of the hydrophilic polyisocyanate composition is preferably 2.0% by mass or more and 50% by mass or less, more preferably 5.0% by mass or more and 30% by mass or less, and further preferably 5.0% by mass or more and 20% by mass or less.

When the content of the hydrophilic compound relative to the total solid content is not less than the lower limit, the hydrophilic polyisocyanate composition of the present embodiment can be more excellent in water dispersibility and water dispersion stability.

On the other hand, when the content of the hydrophilic compound relative to the total solid content is not more than the above upper limit, curability, appearance, hardness, and water resistance at the time of forming a coating film can be further improved.

The content of the hydrophilic compound with respect to the total solid content of the hydrophilic polyisocyanate composition can be calculated as follows: the mass of the hydrophilic compound is divided by the total solid content of the hydrophilic polyisocyanate composition, and the product is multiplied by 100 to calculate the amount of the hydrophilic compound.

[ viscosity ]

The viscosity at 25 ℃ of the hydrophilic polyisocyanate composition of the present embodiment is usually 50mPa · s or more and 20000mPa · s or less, and preferably 300mPa · s or more and 10000mPa · s or less, when the hydrophilic polyisocyanate composition contains substantially only a solid component at 25 ℃.

When the viscosity at 25 ℃ is not lower than the lower limit, the curability at the time of forming a coating film can be further improved, and when the viscosity is not higher than the upper limit, the water dispersibility and the appearance at the time of forming a coating film can be further improved.

Here, "substantially only solid components" means that only solid components are contained or only a very small amount of components (liquid components, volatile components, and the like) other than solid components are contained below the detection line.

The viscosity at 25 ℃ of the hydrophilic polyisocyanate composition can be measured by the method described in examples described later.

The method for controlling the viscosity at 25 ℃ to the above range is not particularly limited, and examples thereof include: a method of adjusting the mixing ratio of the polyisocyanate and the hydrophilic compound, and the like.

[ isocyanate group content ]

The isocyanate group content in the hydrophilic polyisocyanate composition of the present embodiment is usually 3.0 mass% or more and 25 mass% or less, preferably 7.0 mass% or more and 20 mass% or less, and more preferably 13 mass% or more and 20 mass% or less when the hydrophilic polyisocyanate composition substantially contains only solid components.

When the content of the isocyanate group is in the above range, curability, water resistance and chemical resistance at the time of forming a coating film can be further improved.

The "isocyanate group" as used herein includes an isocyanate group of an unreacted polyisocyanate and an isocyanate group of a hydrophilic polyisocyanate.

The isocyanate group content of the hydrophilic polyisocyanate composition can be calculated by the method described in examples described later.

The method for controlling the isocyanate group content to the above range is not particularly limited, and examples thereof include: a method of adjusting the mixing ratio of the polyisocyanate and the hydrophilic compound, and the like.

[ number average molecular weight ]

The number average molecular weight of the hydrophilic polyisocyanate composition of the present embodiment is preferably 300 or more from the viewpoint of curability in forming a coating film, and is preferably 10000 or less from the viewpoint of water dispersibility.

The number average molecular weight of the hydrophilic polyisocyanate composition can be measured by the method described in examples described later.

[ average number of isocyanate functional groups ]

The average number of isocyanate functional groups (hereinafter, sometimes referred to as "average number of isocyanate functional groups") of the hydrophilic polyisocyanate composition of the present embodiment is preferably 2.0 or more from the viewpoint of curability, water resistance and chemical resistance at the time of forming a coating film, and is preferably 20.0 or less from the viewpoint of water dispersion stability.

The average number of isocyanate functional groups of the hydrophilic polyisocyanate composition can be calculated by the method described in examples described later.

< constituent component >

Next, the constituent components of the hydrophilic polyisocyanate composition of the present embodiment will be described in detail below.

[ hydrophilic polyisocyanate ]

The hydrophilic polyisocyanate contained in the hydrophilic polyisocyanate composition of the present embodiment is a reaction product obtained by reacting a polyisocyanate with a hydrophilic compound as described below. That is, the hydrophilic polyisocyanate is a reactant to which a hydrophilic group derived from a hydrophilic compound is added by reacting the hydrophilic compound with an isocyanate group.

Polyisocyanate O

In the present specification, the "polyisocyanate" refers to a reaction product obtained by bonding a plurality of compounds having 1 or more isocyanate groups (-NCO). The molecule of compound 1 having 1 or more isocyanate groups (-NCO) constituting the polyisocyanate may be referred to as a monomer.

(Properties)

The physical properties of the polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment will be described in detail below.

Viscosity of

The viscosity at 25 ℃ of the polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment is not particularly limited, but is preferably 100 to 30000mPa · s, more preferably 500 to 10000mPa · s.

The viscosity at 25 ℃ can be measured by the method described in the examples described later.

Content of isocyanate groups

The isocyanate group content of the polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment is not particularly limited, and 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, based on the total mass of the polyisocyanate.

The isocyanate group content can be measured by the method described in examples described later.

Content of polyisocyanate derived from 3 molecules of diisocyanate

The polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment is not particularly limited, and preferably contains 20 mass% to 75 mass% of polyisocyanate derived from 3 molecules of diisocyanate, more preferably 30 mass% to 70 mass% of polyisocyanate based on the total mass of polyisocyanate, from the viewpoints of curability, appearance and hardness at the time of forming a coating film.

The content of the polyisocyanate obtained from 3 molecules of the diisocyanate can be measured by the method described in the examples described later.

(constituent Components)

The polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment is a reaction product obtained by reacting a plurality of 1 or more kinds of diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

The "aliphatic diisocyanate" and the "alicyclic diisocyanate" are compounds containing no aromatic ring such as a benzene ring in the structure of the diisocyanate.

The aliphatic diisocyanate is not particularly limited, and an aliphatic diisocyanate having 4 to 30 carbon atoms is preferable. Specific examples of the aliphatic diisocyanate include tetramethylene-1, 4-diisocyanate, 2-methylpentane-1, 5-diisocyanate (hereinafter, sometimes referred to as "MPDI"), hexamethylene diisocyanate (hereinafter, sometimes referred to as "HDI"), 2, 4-trimethyl-hexamethylene-1, 6-diisocyanate, lysine diisocyanate (hereinafter, sometimes referred to as "LDI"), and the like.

The alicyclic diisocyanate is not particularly limited, and preferably an alicyclic diisocyanate having 8 to 30 carbon atoms. Specific examples of the alicyclic diisocyanate include isophorone diisocyanate (hereinafter, may be referred to as "IPDI"), hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and 1, 4-cyclohexane diisocyanate.

These aliphatic diisocyanates and alicyclic diisocyanates may be used alone in 1 kind, or in combination in 2 or more kinds.

Among them, as the diisocyanate, HDI, IPDI, hydrogenated xylene diisocyanate or hydrogenated diphenylmethane diisocyanate is preferable for easy industrial availability, and HDI is more preferable. The polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment is obtained by reacting HDI, and thus the hydrophilic polyisocyanate composition tends to have more excellent appearance and weather resistance when formed into a coating film.

The polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment may be a reactant obtained by reacting the diisocyanate with a monohydric or hexahydric or lower alcohol.

The monohydric or higher and hexahydric or lower alcohols include nonpolymeric alcohols and polymeric alcohols. The non-polymeric alcohol is an alcohol having no polymerizable group, and the polymeric alcohol is an alcohol obtained by polymerizing a monomer having a polymerizable group and a hydroxyl group.

The non-polymeric alcohol is not particularly limited, and examples thereof include monoalcohols, diols, triols, and tetraols.

The monool is not particularly limited, and examples thereof include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, n-pentanol, n-hexanol, n-octanol, n-nonanol, 2-ethylbutanol, 2-dimethylhexanol, 2-ethylhexanol, cyclohexanol, methylcyclohexanol, ethylcyclohexanol and the like.

The diol is not particularly limited, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, 2, 3-butanediol, 2-methyl-1, 2-propanediol, 1, 5-pentanediol, 2-methyl-2, 3-butanediol, 1, 6-hexanediol, 1, 2-hexanediol, 2, 5-hexanediol, 2-methyl-2, 4-pentanediol, 2, 3-dimethyl-2, 3-butanediol, 2-ethyl-hexanediol, 1, 2-octanediol, 1, 2-decanediol, and mixtures thereof, 2,2, 4-trimethylpentanediol, 2-butyl-2-ethyl-1, 3-propanediol, 2-diethyl-1, 3-propanediol and the like.

The triol is not particularly limited, and examples thereof include glycerin and trimethylolpropane.

The tetraol is not particularly limited, and examples thereof include pentaerythritol.

The polymer alcohol is not particularly limited, and examples thereof include polyester polyol, polyether polyol, acrylic polyol, and polyolefin polyol.

Examples of the polyester polyol include: polyester polyol resins obtained by condensation reaction of a dicarboxylic acid alone or a mixture of 2 or more species with a polyhydric alcohol alone or a mixture of 2 or more species; polycaprolactone obtained by ring-opening polymerization of epsilon-caprolactone using a polyhydric alcohol, and the like.

Examples of the dicarboxylic acid include carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1, 4-cyclohexanedicarboxylic acid.

Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1, 4-butanediol, neopentyl glycol, 1, 6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerol, pentaerythritol, 2-hydroxymethylpropanediol, and ethoxylated trimethylolpropane.

The polyether polyol is not particularly limited, and examples thereof include polyether polyols obtained by any of the following methods (1) to (3).

(1) Polyether polyols or polytetramethylene glycols obtained by reacting a polyhydric hydroxyl compound alone or in a mixture with an alkylene oxide alone or in a mixture with a catalyst, by at least one member selected from the group consisting of random addition and block addition.

(2) Polyether polyols obtained by reacting alkylene oxides with polyamine compounds

(3) A so-called polymer polyol obtained by polymerizing acrylamide or the like with the polyether polyol obtained in (1) or (2) as a medium.

Examples of the catalyst include hydroxides of lithium, sodium, potassium, and the like; strong basic catalysts such as alcoholates and alkylamines; and complex metal cyanide compound complexes such as metalloporphyrin and zinc hexacyanocobaltate complexes.

Examples of the polyhydric hydroxyl compound include diglycerin, ditrimethylol propane; sugar alcohol compounds such as pentaerythritol, dipentaerythritol, erythritol, D-threitol, L-arabitol, ribitol, xylitol, sorbitol, mannitol, galactitol, and rhamnose alcohol; monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, and deoxyribose; disaccharides such as trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose and melibiose; raffinose, gentisic sugar, melezitose and the like; and tetrasaccharides such as stachyose.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.

Examples of the polyamine compound include ethylenediamine and ethanolamine.

The acrylic polyol is not particularly limited, and examples thereof include acrylic polyols obtained by polymerizing a polymerizable monomer having a hydroxyl group, or by copolymerizing a monomer having an ethylenically unsaturated bond having a hydroxyl group alone or in a mixture with another ethylenically unsaturated bond-containing monomer copolymerizable with the polymerizable monomer alone or in a mixture.

The ethylenically unsaturated bond-containing monomer having a hydroxyl group is not particularly limited, and examples thereof include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, and the like. These may be used alone, or 2 or more of them may be used in combination.

Among them, as the ethylenically unsaturated bond-containing monomer having a hydroxyl group, hydroxyethyl acrylate or hydroxyethyl methacrylate is preferable.

Examples of the other ethylenically unsaturated bond-containing monomer copolymerizable with the polymerizable monomer include the following monomers. These may be used alone, or 2 or more of them may be used in combination.

(i) And acrylic esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate.

(ii) Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate and glycidyl methacrylate.

(iii) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid.

(iv) Unsaturated amides such as acrylamide, methacrylamide, N-methylenebisacrylamide, diacetone acrylamide, diacetone methacrylamide, maleimide and maleimide.

(v) Vinyl monomers such as glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile, and dibutyl fumarate.

(vi) Vinyl monomers having a hydrolyzable silyl group such as vinyltrimethoxysilane, vinylmethyldimethoxysilane and γ - (meth) acryloyloxypropyltrimethoxysilane.

The polyolefin polyol is not particularly limited, and examples thereof include polybutadiene, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene having 2 or more hydroxyl groups.

(Structure)

The polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment preferably contains a reactant obtained by reacting 2 or more molecules of diisocyanate, and more preferably contains a reactant obtained by reacting 3 or more molecules of diisocyanate. This tends to result in a coating film having more excellent curability, hardness, water resistance, and chemical resistance.

The polyisocyanate containing a reactant obtained by reacting 2 or more molecules of diisocyanate may contain 1 or more selected from the group consisting of isocyanurate groups, biuret groups, uretdione groups, oxadiazinetrione groups, iminooxadiazinedione groups, allophanate groups, urethane groups and urea groups.

Among them, the polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment preferably contains an isocyanurate group. This tends to further improve curability, hardness and weather resistance when the polyisocyanate composition is formed into a coating film.

The polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment preferably contains a biuret group. This tends to improve the stability of water dispersion, curability in forming a coating film, appearance and water resistance.

The method for producing the isocyanurate group-containing polyisocyanate is not particularly limited, and examples thereof include: a method in which a reaction for isocyanurating a diisocyanate is carried out by using a catalyst or the like, and the reaction is stopped when a predetermined conversion rate is reached, thereby removing the unreacted diisocyanate.

The catalyst used in the isocyanuric acid esterification reaction is not particularly limited, and a catalyst showing basicity is preferable. Specific examples of the catalyst include the catalysts described below.

(1) Tetraalkylammonium hydroxides such as tetramethylammonium and tetraethylammonium, and weak organic acid salts thereof such as acetic acid and capric acid.

(2) Hydroxides of hydroxyalkylammonium such as trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, and triethylhydroxyethylammonium, and salts of organic weak acids such as acetic acid and capric acid thereof.

(3) Alkali metal salts of tin, zinc, lead and the like of alkyl carboxylic acids such as acetic acid, caproic acid, caprylic acid, myristic acid and the like.

(4) Metal alcoholates of sodium, potassium and the like.

(5) And aminosilyl-containing compounds such as hexamethyldisilazane.

(6) Mannich bases.

(7) Mixtures of tertiary amines with epoxy compounds.

(8) Phosphorus compounds such as tributylphosphine.

The amount of the catalyst to be used is preferably 10ppm to 11000ppm, based on the total mass of the diisocyanate as a raw material.

In addition, the catalyst may be inactivated by addition of an acidic substance such as phosphoric acid or an acid phosphate ester used for neutralizing the catalyst, thermal decomposition, chemical decomposition, or the like, in order to complete the isocyanuric acid esterification reaction.

The reaction temperature of the isocyanuric acid esterification reaction is not particularly limited, but is preferably 50 ℃ or higher and 200 ℃ or lower, and more preferably 50 ℃ or higher and 150 ℃ or lower. When the reaction temperature is not lower than the lower limit, the reaction tends to proceed more easily. On the other hand, when the reaction temperature is not higher than the upper limit, the occurrence of side reactions such as coloring tends to be further suppressed.

After the completion of the isocyanuric acid esterification reaction, it is preferable to remove the unreacted diisocyanate monomer by a thin film evaporation pot, extraction, or the like.

When the polyisocyanate constituting the hydrophilic polyisocyanate of the present embodiment contains unreacted diisocyanate, the content of the unreacted diisocyanate is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, and still more preferably 0.5% by mass or less, based on the total mass of the hydrophilic polyisocyanate. When the concentration of the residual unreacted diisocyanate monomer is not more than the above upper limit, the curing property tends to be more excellent.

The method for producing the biuret group-containing polyisocyanate is not particularly limited, and the following methods are preferred. Specifically, first, the reaction of the diisocyanate monomer and the biuretizing agent disclosed in Japanese patent publication No. 62-41496 (reference 1) is carried out under stirring and homogenization. Thereafter, the reaction product is further introduced into a tubular reactor, extruded in the tubular reactor and flowed down to proceed the reaction, and by this continuous production, a biuret group-containing polyisocyanate can be obtained.

O hydrophilic Compound

The hydrophilic polyisocyanate of the present embodiment has a structural unit derived from a hydrophilic compound. The hydrophilic compound thereof is derived from a compound having a hydrophilic group. That is, the hydrophilic group means a functional group (added) possessed by a hydrophilic polyisocyanate obtained by reacting a hydrophilic compound with a polyisocyanate. The hydrophilic polyisocyanate composition of the present embodiment can be stably water-dispersible by having (adding) a hydrophilic group to the hydrophilic polyisocyanate.

The hydrophilic group is not particularly limited, and examples thereof include a nonionic hydrophilic group, a cationic hydrophilic group, and an anionic hydrophilic group.

Among these, as the hydrophilic group, a nonionic hydrophilic group is preferable from the viewpoint of availability and resistance to electrical interaction with the compound.

(hydrophilic compound having nonionic hydrophilic group)

The hydrophilic compound having a nonionic hydrophilic group is not particularly limited, and examples thereof include: monoalcohols such as methanol, ethanol and butanol; a compound in which alkylene oxide is added to a hydroxyl group of an alcohol such as alkylene glycol or dialkylene glycol; and a compound represented by the following general formula (I) (hereinafter, may be referred to as "compound (I)"), and the like. These hydrophilic compounds having a nonionic hydrophilic group also have an active hydrogen group reactive with an isocyanate group.

Among these, as the hydrophilic compound having a nonionic hydrophilic group, a monool or the compound (I) is preferable, and the compound (I) is more preferable, because the water dispersibility of the hydrophilic polyisocyanate composition can be improved with a small amount.

Compound (I)

The compound (I) is a polyalkylene glycol monoalkyl ether. Details of the compound (I) are described below.

In the general formula (I), R¹Is an alkylene group having 1 to 4 carbon atoms. The alkylene group may be linear or branched, and may be cyclic (aliphatic ring group). The carbon number of the alkylene group is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and further preferably 1 or more and 2 or less.

Specific examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, a dimethylmethylene group, a cyclotrimethylene group, a tetramethylene group, a dimethylethylene group, and a cyclotetramethylene group.

Among them, the alkylene group is preferably a methylene group or an ethylene group, and more preferably an ethylene group.

In the general formula (I), R²An alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear or branched, and may be cyclic (aliphatic ring group). The carbon number of the alkyl group is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and further preferably 1 or more and 2 or less.

Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and a cyclobutyl group.

Among them, the alkyl group is preferably a methyl group or an ethyl group, and more preferably a methyl group.

In the general formula (I), n is alkyleneoxy (-R)¹-the number of repetitions of O-). The content of n is preferably 5 or more and 50 or less, more preferably 5 or more and 30 or less, and still more preferably 5 or more and 20 or less, from the viewpoint of water dispersibility of the hydrophilic polyisocyanate composition and suppression of precipitation of the hydrophilic polyisocyanate composition during low-temperature storage.

Preferable examples of the compound (I) include a compound represented by the following formula (I-1) (i.e., polyethylene glycol monoether).

HO(CH₂CH₂O)_n1CH₃···(I-1)

[ in the formula (I-1), n1 is 5 or more and 20 or less. ]

(hydrophilic compound having cationic hydrophilic group)

The hydrophilic compound having a cationic hydrophilic group is not particularly limited, and examples thereof include compounds having both a cationic group and an active hydrogen group. In addition, a compound having an active hydrogen group such as a glycidyl group and a compound having a cationic hydrophilic group such as thioether or phosphine may be used as the hydrophilic compound. In the above case, a compound having an isocyanate group and a compound having an active hydrogen group are reacted in advance to add a functional group such as a glycidyl group. Then, a compound such as thioether or phosphine is reacted. Among these, as the hydrophilic compound having a cationic hydrophilic group, a compound having both a cationic group and an active hydrogen group is preferable from the viewpoint of ease of production.

The compound having both a cationic group and an active hydrogen group is not particularly limited, and examples thereof include dimethylethanolamine, diethylethanolamine, diethanolamine, and methyldiethanolamine. The tertiary amino group added by using these compounds may be tetrasubstituted with dimethyl sulfate, diethyl sulfate, or the like.

The reaction of the hydrophilic compound having a cationic hydrophilic group with the polyisocyanate may be carried out in the presence of a solvent. The solvent is not particularly limited, and is preferably a solvent containing no active hydrogen group. Specific examples of the solvent include ethyl acetate, propylene glycol monomethyl ether acetate, and dipropylene glycol dimethyl ether.

The cationic hydrophilic groups added to the polyisocyanate are preferably neutralized with a compound having an anionic group. The anionic group is not particularly limited, and examples thereof include a carboxyl group, a sulfonic acid group, a phosphoric acid group, a halogen group, and a sulfuric acid group.

The compound having a carboxyl group is not particularly limited, and examples thereof include formic acid, acetic acid, propionic acid, butyric acid, and lactic acid.

The compound having a sulfonic acid group is not particularly limited, and specific examples thereof include ethanesulfonic acid.

The compound having a phosphoric acid group is not particularly limited, and examples thereof include phosphoric acid and acid phosphate.

The compound having a halogen group is not particularly limited, and examples thereof include hydrochloric acid.

The compound having a sulfate group is not particularly limited, and examples thereof include sulfuric acid.

Among them, as the compound having an anionic group, a compound having a carboxyl group is preferable, and acetic acid, propionic acid, or butyric acid is more preferable.

(hydrophilic compound having anionic hydrophilic group)

The anionic hydrophilic group is not particularly limited, and examples thereof include a carboxyl group, a sulfonic acid group, a phosphoric acid group, a halogen group, and a sulfuric acid group.

The hydrophilic compound having an anionic hydrophilic group is not particularly limited, and examples thereof include compounds having both an anionic group and an active hydrogen group. Specific examples of the hydrophilic compound having an anionic hydrophilic group include: monohydroxycarboxylic acids such as 1-glycolic acid, 3-hydroxypropionic acid, 12-hydroxy-9-octadecanoic acid, hydroxypivalic acid, and lactic acid; and compounds having a carboxyl group of a polyhydroxycarboxylic acid as an anionic group, such as dimethylolacetic acid, 2-dimethylolbutyric acid, 2-dimethylolvaleric acid, dihydroxysuccinic acid, dimethylolpropionic acid, and the like. Further, the hydrophilic compound having an anionic hydrophilic group may be a compound having both a sulfonic acid group and active hydrogen. Specific examples of the compound having both a sulfonic acid group and active hydrogen include hydroxyethylsulfonic acid.

Among them, as the hydrophilic compound having an anionic hydrophilic group, hydroxypivalic acid or dimethylolpropionic acid is preferable.

The anionic hydrophilic group added to the polyisocyanate is preferably neutralized with an amine compound as a basic substance.

The amine compound is not particularly limited, and examples thereof include ammonia and water-soluble amino compounds.

The water-soluble amino compound is not particularly limited, and examples thereof include monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, triethanolamine, butylamine, dibutylamine, 2-ethylhexylamine, ethylenediamine, propylenediamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, and morpholine. In addition, as tertiary amines, such as triethylamine and dimethylethanolamine, can be mentioned, and they can also be used.

< method for producing hydrophilic polyisocyanate composition >

The method for producing a hydrophilic polyisocyanate composition according to the present embodiment includes the following steps (reaction steps): the hydrophilic polyisocyanate composition containing the hydrophilic polyisocyanate is obtained by mixing and reacting the polyisocyanate with the hydrophilic compound.

The steps of the method for producing a hydrophilic polyisocyanate composition according to the present embodiment will be described in detail below.

[ reaction Process ]

In the reaction step, the hydrophilic compound is reacted so that the content of the hydrophilic compound with respect to the total solid content of the hydrophilic polyisocyanate composition to be obtained is preferably 2.0% by mass or more and 50% by mass or less, more preferably 5.0% by mass or more and 30% by mass or less, and further preferably 5.0% by mass or more and 20% by mass or less.

The hydrophilic polyisocyanate composition of the present embodiment can be made more excellent in water dispersibility and water dispersion stability by reacting the hydrophilic compound so that the content of the hydrophilic compound relative to the total solid content of the hydrophilic polyisocyanate composition obtained becomes not less than the lower limit.

On the other hand, by reacting the hydrophilic compound so that the content of the hydrophilic compound relative to the total solid content of the hydrophilic polyisocyanate composition obtained becomes the above upper limit or less, the curability, appearance, hardness and water resistance at the time of forming a coating film can be further improved.

In the reaction step, the reaction temperature and the reaction time may be determined as appropriate depending on the progress of the reaction.

The reaction temperature is preferably 0 ℃ to 150 ℃ inclusive, and the reaction time is preferably 0.5 hours to 48 hours inclusive.

In the reaction step, a known catalyst may be used, as the case may be. The catalyst is not limited to the following catalysts, and examples thereof include organic tin compounds such as tin octylate, tin 2-ethyl-1-hexanoate, tin ethylhexanoate, tin laurate, tin palmitate, dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin dilaurate, dioctyltin diacetate, and dioctyltin dilaurate; organic zinc compounds such as zinc chloride, zinc octoate, zinc 2-ethyl-1-hexanoate, zinc 2-ethylhexanoate, zinc stearate, zinc naphthenate, and zinc acetylacetonate; an organic titanium compound; an organozirconium compound; tertiary amines such as triethylamine, tributylamine, N-diisopropylethylamine, and N, N-dimethylethanolamine; diamines such as triethylenediamine, tetramethylethylenediamine, and 1, 4-diazabicyclo [2.2.2] octane. They may be used alone or in admixture thereof.

In the reaction step, in order to adjust the molar ratio ((B)/(a)) of the hydrophilic polyisocyanate (B) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 2 or 3 molecules to the hydrophilic polyisocyanate (a) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 1 molecule, it is preferable to continuously add the hydrophilic compound over a long period of time. The time required for the dropwise addition is preferably 5 minutes or more and 180 minutes or less, more preferably 15 minutes or more and 120 minutes or less, and still more preferably 30 minutes or more and 90 minutes or less.

When the time required for the dropwise addition is not less than the lower limit value, the molar concentration of the hydrophilic polyisocyanate obtained by the reaction between the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 1 molecule can be further increased among the hydrophilic polyisocyanates.

On the other hand, when the time required for the dropwise addition is not more than the above upper limit, the amount of the unreacted hydrophilic compound can be further reduced, and the time required for the reaction step can be further shortened.

Curing agent composition

The curing agent composition according to one embodiment of the present invention includes the hydrophilic polyisocyanate composition and an ionic surfactant. The curing agent composition of the present embodiment contains the ionic surfactant in an amount of 0.1 mass% to 20 mass% based on the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant.

< physical Property >

The physical properties of the curing agent composition of the present embodiment will be described in detail below.

[ content of Ionic surfactant ]

In the curing agent composition of the present embodiment, the content of the ionic surfactant with respect to the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant is preferably 0.1% by mass or more and 20% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less.

When the content of the ionic surfactant is not less than the lower limit value, the hydrophobic group forms a layer on the surface of the oil droplets of the hydrophilic polyisocyanate composition when the ionic surfactant is dispersed in water. This reduces the contact between the isocyanate groups in the hydrophilic polyisocyanate composition and water, and therefore, the retention of the isocyanate groups can be further improved.

On the other hand, when the content of the ionic surfactant is not more than the above upper limit, the amount of water taken in can be reduced, and therefore, the water resistance of the coating film can be further improved.

The content of the ionic surfactant can be calculated by the method described in examples described later.

< constituent component >

Next, the components of the curing agent composition of the present embodiment will be described in detail below.

[ Ionic surfactant ]

The ionic surfactant contained in the curing agent composition of the present embodiment preferably contains substantially no water.

Here, "substantially no water" means that water is not contained at all, or only a very small amount of water is contained to such an extent that water contained in the ionic surfactant and the isocyanate group do not react to cause foaming, cloudiness, and an increase in viscosity. As a standard thereof, the content of water with respect to the total mass of the ionic surfactant may be 1 mass% or less.

Examples of the ionic surfactant include anionic surfactants, cationic surfactants, and amphoteric surfactants. Which of the anionic surfactant and the cationic surfactant is preferable is determined according to the neutralization method of the hydrophilic polyisocyanate composition. That is, when the hydrophilic polyisocyanate composition is neutralized with a base, an anionic surfactant is preferably used, and when the hydrophilic polyisocyanate composition is neutralized with an acid, a cationic surfactant is preferably used. When the hydrophilic polyisocyanate composition is not neutralized, an anionic surfactant, a cationic surfactant, or an amphoteric surfactant may be used.

As the anionic surfactant, a carboxylate type, a sulfate type, a sulfonate type or a phosphate type is suitable.

Specific examples of the anionic surfactant include, but are not limited to, ammonium (C1-C20 alkyl) benzenesulfonate, sodium (C1-C20 alkyl) benzenesulfonate, sodium (C1-C20 alkyl) disulfate, sodium alkyldiphenylether disulfonate, sodium di (C1-C20 alkyl) sulfosuccinate, sodium polyoxyethylene C6-C30 aryl ether sulfonate, and ammonium polyoxyethylene C6-C30 aryl ether sulfonate, which can be used suitably as long as they are industrially available.

Among them, preferred anionic surfactants are ammonium (C1-C20 alkyl) benzenesulfonates, sodium (C1-C20 alkyl) benzenesulfonates, or sodium di (C1-C20 alkyl) sulfosuccinates.

As the cationic surfactant, a quaternary ammonium salt, a pyridinium salt or an imidazolinium salt is suitable.

Specific examples of the cationic surfactant include, but are not limited to, C1-C20 alkyltrimethylammonium bromide, C1-C30 alkylpyridinium bromide, imidazolinium laurate, and the like, which can be used suitably as long as they are industrially available. More specifically, examples of the cationic surfactant include alkyltrimethylammonium bromide, alkylpyridinium bromide, imidazolinium laurate, and the like.

Examples of the amphoteric surfactant include carboxylate type, sulfate type, sulfonate type, and phosphate type.

[ other ingredients ]

The curing agent composition of the present embodiment may further contain other components in addition to the hydrophilic polyisocyanate composition and the ionic surfactant. The other components are not limited to the following, and examples thereof include solvents, curing accelerating catalysts, antioxidants, ultraviolet absorbers, light stabilizers, pigments, leveling agents, plasticizers, rheology control agents, polymerization inhibitors, and the like.

Examples of the solvent include aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; alcohol compounds such as methanol, ethanol, isopropanol, n-butanol, n-hexanol, and 2-ethylhexanol; ketone compounds such as acetone and methyl ethyl ketone; ester compounds such as ethyl acetate, n-butyl acetate, ethylene glycol acetate, methoxypropyl acetate, and isobutyric acid-3-hydroxy-2, 2, 4-trimethylpentyl ester; ethers such as butanediol, tetrahydrofuran, dioxane, glycol ethers, etc.

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, based on the total mass of the curing agent composition of the present embodiment.

When the curing agent composition of the present embodiment contains a curing accelerator catalyst, an antioxidant, a light stabilizer, and a polymerization inhibitor, the content of the solvent is preferably 0 mass% or more and 10 mass% or less, more preferably 0 mass% or more and 5 mass% or less, and still more preferably 0 mass% or more and 2 mass% or less, based on the total mass of the hydrophilic polyisocyanate composition.

The curing accelerating catalyst is not particularly limited, and examples thereof include tin compounds such as dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, tin dimethyldineodecanoate and tin bis (2-ethylhexanoate); zinc compounds such as zinc 2-ethylhexanoate and zinc naphthenate; titanium compounds such as titanium 2-ethylhexanoate and titanium diisopropoxybis (ethylacetonate); cobalt compounds such as cobalt 2-ethylhexanoate and cobalt naphthenate; bismuth compounds such as bismuth 2-ethylhexanoate and bismuth naphthenate; zirconium compounds such as zirconium tetraacetylacetonate, zirconium 2-ethylhexanoate, zirconium naphthenate and the like; amine compounds, and the like.

The antioxidant is not particularly limited, and examples thereof include hindered phenol compounds, phosphorus compounds, and sulfur compounds.

The ultraviolet absorber is not particularly limited, and examples thereof include benzotriazole compounds, triazine compounds, and benzophenone 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 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 phthalic acid esters, phosphoric acid compounds, and polyester compounds.

The rheology control agent is not particularly limited, and examples thereof include hydroxyethyl cellulose, urea compounds, microgels, and the like.

Examples of the polymerization inhibitor include p-phenylenediphenols, phenols, cresols, o-phenylenediphenols, benzoquinones, and the like. Specific examples of the polymerization inhibitor include benzoquinone, hydroquinone, p-toluquinone, p-xylylquinone, naphthoquinone, 2, 6-dichloroquinone, hydroquinone, trimethylhydroquinone, catechol, p-tert-butylcatechol, 2, 5-di-tert-butylhydroquinone, monomethylhydroquinone, p-methoxyphenol, 2, 6-di-tert-butyl-p-cresol, and hydroquinone monomethyl ether.

< method for producing curing agent composition >

The curing agent composition of the present embodiment includes the following steps (addition step): the ionic surfactant is added to and mixed with the hydrophilic polyisocyanate composition to obtain a curing agent composition.

The addition step may be performed after the reaction step in the above-described method for producing a hydrophilic polyisocyanate composition, or may be performed simultaneously with the reaction step.

The process of the method for producing the curing agent composition of the present embodiment will be described in detail below.

[ adding step ]

In the addition step, the ionic surfactant is added so that the content of the ionic surfactant is preferably 0.1 mass% or more and 20 mass% or less, more preferably 0.5 mass% or more and 10 mass% or less, based on the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant.

When the content of the ionic surfactant is not less than the lower limit, the hydrophobic group forms a layer on the surface of the polyisocyanate oil droplets when the ionic surfactant is dispersed in water. This reduces the contact of the isocyanate group in the polyisocyanate with water, and therefore, the retention of the isocyanate group becomes higher.

On the other hand, the water intake amount can be reduced by adding the ionic surfactant so that the content thereof becomes equal to or less than the upper limit value, and therefore, the water resistance of the coating film is further improved.

Water-based coating composition

An aqueous coating composition according to an embodiment of the present invention includes: the hydrophilic polyisocyanate composition of the above embodiment or the curing agent composition of the above embodiment; water; and, an active hydrogen compound.

The aqueous coating composition of the present embodiment contains an active hydrogen compound, and the isocyanate group of the hydrophilic polyisocyanate composition and the active hydrogen of the active hydrogen compound react under various conditions, so that the aqueous coating composition tends to have excellent hardness, water resistance, chemical resistance, and appearance when a coating film is formed.

< physical Property >

The physical properties of the aqueous coating composition of the present embodiment are described in detail below.

[ isocyanate group/active hydrogen group ]

In the aqueous coating composition of the present embodiment, the ratio of the number of isocyanate groups of the hydrophilic polyisocyanate in the aqueous coating composition to the number of active hydrogen groups of the active hydrogen compound in the aqueous coating composition (isocyanate groups/active hydrogen groups) is not particularly limited, but is preferably 1/10 or more and 10/1 or less, more preferably 1/8 or more and 8/1 or less, and still more preferably 1/6 or more and 6/1 or less.

The isocyanate group/active hydrogen group can be calculated as follows: the average number of isocyanate functional groups was calculated by the method for calculating the average number of isocyanate functional groups described in examples described later. Next, the average number of isocyanate functional groups obtained was divided by the number of active hydrogen groups and multiplied by 100, thereby calculating the average number of isocyanate functional groups.

< constituent component >

Next, the constituent components of the aqueous coating composition of the present embodiment will be described in detail below.

[ active Hydrogen Compound ]

The active hydrogen compound is not particularly limited as long as it is a compound in which 2 or more active hydrogens are bonded in the molecule. Specific examples of the active hydrogen compound include polyamines, alkanolamines, polythiols, and polyols. Among them, as the active hydrogen compound, a polyhydric alcohol is preferable.

O polyamine

The polyamine is not particularly limited, and examples thereof include diamines such as ethylenediamine, propylenediamine, butylenediamine, triethylenediamine, hexamethylenediamine, 4' -diaminodicyclohexylmethane, piperazine, 2-methylpiperazine, and isophoronediamine; linear polyamines having 3 or more amino groups such as bishexamethylenetriamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentamethylenehexamine, and tetrapropylenepentamine; cyclic polyamines such as 1,4,7,10,13, 16-hexaazacyclooctadecane, 1,4,7, 10-tetraazacyclodecane, 1,4,8, 12-tetraazacyclopentadecane, and 1,4,8, 11-tetraazacyclotetradecane.

Orthoolamines

The alkanolamine is not particularly limited, and examples thereof include monoethanolamine, diethanolamine, aminoethylethanolamine, N- (2-hydroxypropyl) ethylenediamine, mono- (N-or iso-) propanolamine, di- (N-or iso-) propanolamine, ethyleneglycol-bis-propylamine, neopentanolamine, and methylethanolamine.

O polythiol

The polythiol is not particularly limited, and examples thereof include bis- (2-mercaptoethoxy) methane, dithioethylene glycol, dithioerythritol, dithiothreitol, and the like.

O polyol

The polyol is not particularly limited, and examples thereof include polyester polyols (including polycaprolactones), acrylic polyols, polyether polyols, polyolefin polyols, fluorine polyols, polycarbonate polyols, and epoxy resins.

The polyester polyol (including polycaprolactone), acrylic polyol, polyether polyol and polyolefin polyol may be the same as those exemplified for the hydrophilic polyisocyanate composition.

(Fluoropolyol)

The fluorine polyol is a polyol containing fluorine in the molecule. Specific examples of the fluorine polyol include copolymers of a fluoroolefin, a cyclic vinyl ether, a hydroxyalkyl vinyl ether, a vinyl ester of a monocarboxylic acid, and the like disclosed in Japanese patent application laid-open Nos. 57-34107 (reference 2) and 61-275311 (reference 3).

(polycarbonate polyol)

The polycarbonate polyol is not particularly limited, and examples thereof include: and a low-molecular-weight carbonate compound such as a dialkyl carbonate such as dimethyl carbonate, an alkylene carbonate such as ethylene carbonate, or a diaryl carbonate such as diphenyl carbonate, and a low-molecular-weight polyol used in the polyester polyol are subjected to polycondensation.

(epoxy resin)

The epoxy resin is not particularly limited, and examples thereof include 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, an ester type polycarboxylic acid, an amino glycidyl type epoxy resin, a β -methyloxyhalogen type epoxy resin, a cyclic oxysilane type epoxy resin, a halogen type epoxy resin, and a resorcinol type epoxy resin.

Hydroxyl number of polyol

The hydroxyl value of the polyol is not particularly limited, and from the viewpoint of the crosslink density and mechanical properties of the cured product, the hydroxyl value of the polyol in the aqueous coating composition of the present embodiment is preferably 10mgKOH/g or more and 300mgKOH/g or less, more preferably 20mgKOH/g or more and 250mgKOH/g or less, and further preferably 30mgKOH/g or more and 200mgKOH/g or less, per 1g of the aqueous coating composition.

[ other ingredients ]

The aqueous coating composition of the present embodiment may further contain other components in addition to the hydrophilic polyisocyanate composition or the curing agent composition, water, and the active hydrogen compound. Examples of the other components include other curing agents such as melamine-based curing agents and epoxy-based curing agents; other additives, and the like.

O other curing agent

(Melamine curing agent)

The melamine-based curing agent is not particularly limited, and examples thereof include a fully alkyl etherified melamine resin, a methylol type melamine resin, and an imino type melamine resin having imino groups in a part thereof.

When a melamine-based curing agent is used, it is effective to add an acidic compound.

Examples of the acidic compound include carboxylic acids, sulfonic acids, acid phosphates, and phosphites.

The carboxylic acid is not particularly limited, and examples thereof include acetic acid, lactic acid, succinic acid, oxalic acid, maleic acid, and sebacic acid.

The sulfonic acid is not particularly limited, and examples thereof include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenedisulfonic acid, and the like.

The acid phosphate 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 is not particularly limited, and examples thereof include diethyl phosphite, dibutyl phosphite, dioctyl phosphite, dilauryl phosphite, monoethyl phosphite, monobutyl phosphite, monooctyl phosphite, monolauryl phosphite, and the like.

(epoxy curing agent)

The epoxy curing agent is not particularly limited, and examples thereof include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, acid anhydrides, phenol novolaks, polythiols, aliphatic tertiary amines, aromatic tertiary amines, imidazole compounds, and lewis acid complexes.

Other additives

The other additives are not particularly limited, and examples thereof include various additives generally added to paints, such as inorganic pigments, organic pigments, extender pigments, silane coupling agents, titanium coupling agents, organic phosphates, organic phosphites, thickeners, leveling agents, thixotropic agents, antifoaming agents, freeze stabilizers, flatting agents, crosslinking reaction catalysts, anti-skinning agents, dispersants, wetting agents, fillers, plasticizers, lubricants, reducing agents, preservatives, mildewproofing agents, deodorants, anti-yellowing agents, ultraviolet absorbers, antistatic agents or static electricity control agents, anti-settling agents, surfactants, antioxidants, light stabilizers, and polymerization inhibitors.

< method for producing aqueous coating composition >

The method for producing the aqueous coating composition of the present embodiment is not particularly limited, and examples thereof include: and a method of adding water and an active hydrogen compound to the hydrophilic polyisocyanate composition or the curing agent composition and mixing them.

< use >)

The water-based coating composition of the present embodiment can be used as a curable composition such as a coating composition, an adhesive composition, a casting composition, or the like; various surface treatment agent compositions such as fiber treatment agents; various elastomeric compositions; crosslinking agents such as foam compositions; a modifier; and (4) using the additive.

The adherend usable in the water-based coating composition of the present embodiment is not particularly limited, and examples thereof include glass; various metals such as aluminum, iron, zinc steel plate, copper, stainless steel, etc.; porous members such as wood, paper, mortar, stone, and the like; members subjected to fluorine coating, urethane acrylate coating, or the like; a cured sealing material such as a silicone-based cured product, a modified silicone-based cured product, or a urethane-based cured product; rubbers such as natural rubber and synthetic rubber; leather such as natural leather and artificial leather; fibers such as plant-based fibers, animal-based fibers, carbon fibers, glass fibers, and nonwoven fabrics; films and sheets of resins such as polyvinyl chloride, polyester, acrylic, polycarbonate, triacetyl cellulose, and polyolefin; an ultraviolet-curable acrylic resin layer; ink layers such as printing ink layers and UV ink layers, and the like.

Examples

The present embodiment will be described in more detail below by showing 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.

Test items

The hydrophilic polyisocyanate compositions, curing agent compositions and coating films produced in examples and comparative examples were subjected to measurement and evaluation of physical properties by the following methods.

Physical Properties 1 viscosity

The viscosity at 25 ℃ of the hydrophilic polyisocyanate compositions or the curing agent compositions prepared in examples and comparative examples was determined using an E-type viscometer RE-80U (manufactured by Toyobo industries Co., Ltd.).

< Property 2 > solid content

When the hydrophilic polyisocyanate compositions or the curing agent compositions produced in examples and comparative examples were used as samples and diluted with a solvent, the solid content was calculated by the following method.

Specifically, first, the mass of the aluminum cup (W1) [ g ] was precisely measured, about 1g of the sample was added, and the mass of the cup (W2) [ g ] before heat drying was precisely measured. Next, the cup to which the above sample was added was heated in a drier at 105 ℃ for 3 hours. Subsequently, the heated cup was cooled to room temperature, and the mass (W3) [ g ] of the cup was precisely measured again. The mass% of the dry residue in the sample was defined as a solid content (C). The solid content was calculated by using the following formula (a).

When the solvent is not diluted, the solid content is substantially 100%.

Solid component (C) [ mass% ] ═ (W2-W1)/(W3-W1) × 100 · (a)

< physical Property 3 > content of ionic surfactant based on total solid content of hydrophilic polyisocyanate composition and ionic surfactant

1. The content of the ionic surfactant in the curing agent composition (D1) [ mass% ]

The curing agent compositions produced in examples and comparative examples were used as samples, and the content (D1) [ mass%) of the ionic surfactant in the curing agent compositions was measured by liquid chromatography and then measured by a mass spectrometer. The apparatus and conditions used are as follows.

(measurement conditions)

An LC device: product of Waters corporation, UPLC (trade name)

Column: ACQUITY UPLC HSS T3C 18, available from Waters corporation, 1.8 μm, inner diameter 2.1 mm. times.length 50mm

Flow rate: 0.3 mL/min

Mobile phase: 10mM ammonium acetate solution in water, b acetonitrile

Gradient conditions: the initial mobile phase composition ratio was set at a/b of 98/2, and the ratio of b after sample injection was increased linearly, and after 10 minutes, the ratio was set at a/b of 0/100.

The detection method 1: photodiode array detector with measurement wavelength of 220nm

The detection method 2 comprises the following steps: mass spectrometer manufactured by Waters corporation, Synapt G2 (trade name)

Ionization mode: electrospray ionization, positive ion detection

Scanning range: m/z 100 to 2000

2. Content of ionic surfactant relative to total solid content of hydrophilic polyisocyanate composition and ionic surfactant

Next, the content of the ionic surfactant (D2) [ mass% ] with respect to the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant was calculated from the solid content (C) [ mass% ] measured in "property 2" and the content of the ionic surfactant (D1) [ mass% ] measured in "1." of the curing agent composition using the following formula (b 1).

The content of the ionic surfactant (D2) [ mass% ] relative to the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant

＝D1/C×100···(b1)

When the solid component (C) contains a component (C1) [ mass% ] other than the hydrophilic polyisocyanate composition and the ionic surfactant, the solid component (C) is calculated by using the formula (b2) shown below.

＝D1/(C-C1)×100···(b2)

< Property 4 > content of isocyanate group in hydrophilic polyisocyanate composition

1. Isocyanate group content in curing agent composition

The curing agent compositions prepared in examples and comparative examples were used as samples, and the isocyanate group content (E1) was measured according to the method described in JIS K7301-1995 (test method of toluene diisocyanate type prepolymer for thermosetting urethane elastomer). Hereinafter, a more specific measurement method will be described.

(1) A200 mL Erlenmeyer flask was charged with 1g of a sample ((W4) [ g ]), and 20mL of toluene was added to the flask to dissolve the sample.

(2) Then, 20mL of a 2.0N toluene-containing di-N-butylamine solution was added to the flask, and the mixture was allowed to stand for 15 minutes.

(3) To the flask was added 70mL of 2-propanol, which was dissolved to give a solution.

(4) The solution obtained in (3) above was titrated with 1mol/L hydrochloric acid to obtain a sample titer (V1).

(5) When no sample was added, the measurement was performed in the same manner as in (1) to (3) above to obtain a blank titration amount (V2).

The isocyanate group content was calculated from the mass (W4) of the sample, and the sample titration amount (V1) and the blank titration amount (V2) obtained above, using the formula (c1) shown below.

Isocyanate group content (E1) [ Mass% ]in the curing agent composition

＝(V2-V1)×42/(W4×1000)×100···(c1)

2. Isocyanate group content in hydrophilic polyisocyanate composition

The isocyanate group content (E2) [ mass% ] in the hydrophilic polyisocyanate composition was calculated from the solid content (C) measured in "property 2", the content (D2) of the ionic surfactant measured in "property 3" and the isocyanate group content (E1) in the curing agent composition measured in "property 1", using the following formula (C2).

Isocyanate group content (E2) [ Mass% ] in hydrophilic polyisocyanate composition

＝E1/(C/100)/(100-D2)×100···(c2)

When the solid component (C) contains a component (C1) [ mass% ] other than the hydrophilic polyisocyanate composition and the ionic surfactant, the solid component (C) is calculated by using the formula (C3) shown below.

＝E1/(C/100)/(100-D2-C1)×100···(c3)

In the case of a hydrophilic polyisocyanate composition containing neither an ionic surfactant nor a solvent, the isocyanate group content (E2) [ mass% ] in the hydrophilic polyisocyanate composition was calculated by the same method as the measurement method described in the above "1.

Physical Properties 5, number average molecular weight and weight average molecular weight

The hydrophilic polyisocyanate compositions or curing agent compositions produced in examples and comparative examples were used as samples, and the number average molecular weight (F1) and weight average molecular weight (F2) of the hydrophilic polyisocyanate composition containing the hydrophilic polyisocyanate and the unreacted polyisocyanate were measured. Specifically, the number average molecular weight and the weight average molecular weight based on polystyrene were measured by Gel Permeation Chromatography (GPC) using the following apparatus and conditions. In the case of using the curing agent composition as a sample, the sensitivity of the ionic surfactant is low under the following measurement conditions, and therefore, the obtained value of the weight average molecular weight is taken as the value of the number average molecular weight and the weight average molecular weight of the hydrophilic polyisocyanate in the curing agent composition.

(measurement conditions)

The device comprises the following steps: HLC-8120GPC (trade name) manufactured by Tosoh corporation

Column: TSKgelSuperH1000 (trade name). times.1, TSKgelSuperH2000 (trade name). times.1, TSKgelSuperH3000 (trade name). times.1, available from Tosoh corporation

Carrier: tetrahydrofuran (THF)

The detection method comprises the following steps: differential refractometer

< physical Property 6 > average number of isocyanate functional groups

The average number of isocyanate functional groups (G) is the number of isocyanate functional groups statistically present in the molecule of the hydrophilic polyisocyanate 1. The number average molecular weight (F1) of the hydrophilic polyisocyanate measured in the "property 5" and the isocyanate group content (E2) [ mass% ] in the hydrophilic polyisocyanate composition measured in the "property 4" were calculated using the following formula (d).

Average number of isocyanate functional groups (G) ═ F1 XE 2/100/42. cndot. (d)

< Property 7 > (B)/(A)

By using a hydrophilic polyisocyanate composition or a curing agent composition as a sample, the molar ratio ((B)/(a)) of the hydrophilic polyisocyanate (B) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 2 or 3 molecule in the composition to the hydrophilic polyisocyanate (a) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 1 molecule was calculated. Specifically, first, a sample is separated by liquid chromatography, and then measured by a mass spectrometer, and the molar ratio ((B)/(a)) is calculated. When the curing agent composition is used as a sample, the sensitivity of the ionic surfactant is low under the following measurement conditions, and therefore the obtained molar ratio is used as the value of the molar ratio in the curing agent composition. The apparatus and conditions used are as follows.

(measurement conditions)

An LC device: product of Waters corporation, UPLC (trade name)

Flow rate: 0.3 mL/min

Mobile phase: 10mM ammonium acetate solution in water, b acetonitrile

Ionization mode: electrospray ionization, negative ion detection

Scanning range: m/z 100 to 2000

< physic property 8 > (P)/{ (P) + (A) + (B) }

The hydrophilic polyisocyanate composition or the curing agent composition was sampled and the molar ratio ((P)/{ (P) + (A) + (B) } was determined by the same analysis method as that for Property 7.

Here, (P) is a polyisocyanate which is derived from 3 molecules of diisocyanate in the composition and which has not reacted with a hydrophilic compound.

(A) As described above, the hydrophilic polyisocyanate in the composition is obtained by the reaction of the polyisocyanate derived from diisocyanate 3 molecules with the hydrophilic compound 1 molecules.

(B) As described above, the hydrophilic polyisocyanate in the composition is obtained by reacting the polyisocyanate derived from diisocyanate 3 molecules with the above-mentioned hydrophilic compound 2 or 3 molecules.

< evaluation 1 > Water-dispersibility of hydrophilic polyisocyanate composition or curing agent composition

(1) The total mass of the 100mL flask and the Ji Ye paper was measured (W5).

(2) The hydrophilic polyisocyanate compositions and curing agent compositions produced in examples and comparative examples were collected in a 100mL flask so that the solid content was 16g ((W6) [ g ]), and 24g of deionized water was added thereto.

(3) After stirring the solution in the 100mL flask at 200rpm for 3 minutes using a propeller, the solution was filtered through the Jiefei paper weighed in (1).

(4) The filtration residue remaining on the piece of guipure paper and the residue remaining in the 100mL flask were heated in a drier at 105 ℃ for 1 hour to determine the mass ((W7) [ g ]).

(5) The proportion (H) of the hydrophilic polyisocyanate composition or the curing agent composition dispersed in water was calculated using the following formula (e).

Proportion (H) dispersed in Water [% by mass ]

＝100-(W7-W5)/(W6×C)×100···(e)

(6) From the proportion (H) of the hydrophilic polyisocyanate composition dispersed in water calculated in (5), the water dispersibility of the hydrophilic polyisocyanate composition was evaluated according to the following evaluation criteria.

(evaluation criteria)

O: (H) 80% by mass or more, and the water dispersion stability is good.

And (delta): (H) 60 to less than 80% by mass, and has good water dispersion stability.

X: (H) less than 60% by mass, the water dispersion stability is poor.

< evaluation 2 > Water Dispersion stability of hydrophilic polyisocyanate composition or curing agent composition

0.1g of the hydrophilic polyisocyanate composition or the curing agent composition and 100g of deionized water were weighed in a 200mL flask. Subsequently, the solution in the 200mL flask was stirred at 600rpm for 5 minutes by using a propeller blade to obtain an aqueous dispersion of the hydrophilic polyisocyanate composition or the curing agent composition. Thereafter, the mixture was transferred to a 50mL glass bottle, and the dispersion state was visually observed. The water dispersion stability of the hydrophilic polyisocyanate composition or the curing agent composition was evaluated according to the following evaluation criteria.

(evaluation criteria)

O: no change was observed after 3 hours.

And (delta): after 3 hours, a slight precipitation or separation was observed.

X: precipitation or separation was visible within 3 hours.

< evaluation 3 > appearance of coating film

Each of the aqueous coating compositions produced in examples and comparative examples was applied by applicator onto a glass plate to a thickness of 40 μm. Next, the mixture was baked at 60 ℃ for 30 minutes to obtain a coating film. The resulting coating film was visually observed. The appearance of the coating film was evaluated according to the following evaluation criteria.

(evaluation criteria)

Very good: transparent and has no foreign matter.

O: slightly cloudy.

And (delta): whitish and slightly turbid, slightly contaminated, and slightly less smooth.

X: white turbidity, a large amount of foreign matter, and low smoothness.

< evaluation 4 > curing Property of coating film

Each of the aqueous coating compositions produced in examples and comparative examples was applied by applicator coating onto a polypropylene plate to a thickness of 40 μm. Subsequently, the coating film was dried in an atmosphere of 23 ℃/50% RH for 24 hours. Subsequently, the resulting coating film was immersed in acetone at 20 ℃ for 24 hours. Then, the ratio of the mass of the undissolved portion to the mass before immersion [ mass% ]wascalculated. The curability of the coating film was evaluated based on the calculated ratio and the following evaluation criteria.

(evaluation criteria)

Very good: 80% by mass or more, and excellent curability.

O: 70% by mass or more and less than 80% by mass, and the curability is very good.

And (delta): 60 to less than 70% by mass, and good curability.

X: less than 60% by mass, the curability is poor.

< evaluation 5 > hardness of coating film

Each of the aqueous coating compositions prepared in examples and comparative examples was applied to a glass plate by an applicator so that the thickness thereof became 40 μm. Subsequently, the coating film was dried in an atmosphere of 23 ℃/50% RH for 7 days. Subsequently, the hardness of the resulting coating film was measured using a Koenig hardness tester (product name, BYK Garder).

< evaluation 6 > Water resistance of the coating film

Each of the aqueous coating compositions prepared in examples and comparative examples was applied to a glass plate by an applicator so that the thickness thereof became 40 μm. Subsequently, the coating film was dried in an atmosphere of 23 ℃/50% RH for 7 days. Next, a silicon O-ring having a diameter of 20mm was placed on the obtained coating film, and 0.5g of water was poured thereinto. Subsequently, the film was left at 23 ℃ for 24 hours, and the appearance of the coating film was observed after removing the water remaining on the surface. The water resistance of the coating film was evaluated according to the following evaluation criteria. In the above "evaluation 3", since visual evaluation cannot be performed when the appearance of the coating film is x, it is regarded as impossible to measure.

(evaluation criteria)

O: there was no change.

X: foaming, clouding or coating film dissolution occurs.

Here, "blistering" means blisters and expansion which occur on the surface of the coating film.

< evaluation 7 > chemical resistance of coating film

Each of the aqueous coating compositions prepared in examples and comparative examples was applied to a glass plate by an applicator so that the thickness thereof became 40 μm. Subsequently, the coating film was dried in an atmosphere of 23 ℃/50% RH for 7 days. Then, a cotton ball having a diameter of 10mm containing 1g of xylene was placed on the obtained coating film for 5 minutes, and the appearance of the coating film after removing the xylene remaining on the surface was observed. The chemical resistance of the coating film was evaluated according to the following evaluation criteria. In the above "evaluation 3", since visual evaluation cannot be performed when the appearance of the coating film is x, it is regarded as impossible to measure.

(evaluation criteria)

O: transparent, without pits

And (delta): slightly whitish and turbid or slightly depressed

X: with whitish and turbid or depressed

Example 1 production of hydrophilic polyisocyanate composition 1-1 and aqueous coating composition 1-1

(1) Production of hydrophilic polyisocyanate composition 1-1

First, a polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 9.4 (product name "MPG-130" manufactured by japan emulsifier corporation) and a polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 4.2 (product name "MPG" manufactured by japan emulsifier corporation) were mixed at a mass ratio of 17.3: 82.7 to give a mixture of polyethylene glycol monomethyl ethers with an average number of ethylene oxide repeat units of 5.1. Then, 18.0 parts by mass of the above-mentioned polyethylene glycol monomethyl ether mixture was added to a mixture of 32.0 parts by mass of an isocyanurate type polyisocyanate of Hexamethylene Diisocyanate (HDI) (manufactured by Asahi chemical Co., Ltd., "Duranate TPA-100 (trade name)") and 48.0 parts by mass of an isocyanurate type polyisocyanate of HDI (manufactured by Asahi chemical Co., Ltd., "Duranate TSA-100 (trade name)") under stirring for 60 minutes, which were heated to 110 ℃. The reaction mixture was further stirred at 110 ℃ for 1 hour to obtain a hydrophilic polyisocyanate composition 1-1.

The hydrophilic polyisocyanate compositions 1 to 1 were obtained as follows: the viscosity was 1400 mPas, the solid content was 100 mass%, the isocyanate group content was 14.6 mass%, the average number of isocyanate functional groups was 2.4, the number-average molecular weight was 690, (B)/(A) was 15/85, (P)/{ (P) + (A) + (B) } was 85.2. Their physical properties are also shown in table 1 below.

(2) Production of aqueous coating composition 1-1

The hydrophilic polyisocyanate composition obtained in (1) was compounded with Acrylic Latex (trade name "R-5007" manufactured by Asahi Kasei corporation) having a hydroxyl value of 60mgKOH/g as a unit resin so that the ratio of functional groups (NCO/OH) was 1.25. Subsequently, the mixture was diluted with water to a solid content of 40 mass% to obtain an aqueous coating composition 1-1. Using the obtained aqueous coating composition 1-1, a coating film was produced, and the coating film was evaluated according to the evaluation items described above. The results are shown in table 1 below.

EXAMPLE 2 production of curing agent composition 2-1 and aqueous coating composition 2-1

(1) Production of curing agent composition 2-1

Polyethylene glycol monomethyl ether (manufactured by Nippon emulsifier Co., Ltd., "MPG-130 (trade name)") having an average number of ethylene oxide repeating units of 9.4, and a methanol solution of dioctyl sodium sulfosuccinate (manufactured by Nippon emulsifier Co., Ltd., "Newcol 290M (trade name)") having a solid content of 70 mass% were 9 in terms of a solid content mass ratio: 1, and mixing. Then, the volatile components (water and methanol) in the methanol solution of dioctyl sodium sulfosuccinate were removed by distillation under reduced pressure at 120 ℃ and 20 torr to obtain polyethylene glycol monomethyl ether containing an ionic surfactant. Then, to 80.0 parts by mass of an isocyanurate type polyisocyanate (manufactured by Asahi chemical Co., Ltd., "Duranate TPA-100 (trade name)") of HDI heated to 120 ℃ was added 20.0 parts by mass of the above ionic surfactant-containing polyethylene glycol monomethyl ether for 90 minutes under stirring. Further, the mixture was stirred at 120 ℃ for 1 hour to react, thereby obtaining a curing agent composition 2-1.

The obtained curing agent composition 2-1 had a viscosity of 1900 mPas, a solid content of 100% by mass, and a content of the ionic surfactant of 2.0% by mass based on the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant.

In addition, the hydrophilic polyisocyanate composition in the obtained curing agent composition 2-1 was as follows: the isocyanate group content was 16.8% by mass, the average number of isocyanate functional groups was 2.9, the number-average molecular weight was 725, the (B)/(A) was 11/89, and the (P)/{ (P) + (A) + (B) } was 91.5. Their physical properties are also shown in table 1 below.

(2) Production of aqueous coating composition 2-1

Using the curing agent composition 2-1 obtained in (2), an aqueous coating composition 2-1 was obtained in the same manner as described in (2) of example 1. Using the obtained aqueous coating composition 2-1, a coating film was produced, and the coating film was evaluated according to the evaluation items described above. The results are shown in table 1 below.

EXAMPLE 3 production of curing agent composition 3-1 and aqueous coating composition 3-1

(1) Production of curing agent composition 3-1

Polyethylene glycol monomethyl ether (manufactured by Nippon emulsifier Co., Ltd., "MPG-081 (trade name)") having an average number of ethylene oxide repeating units of 15.0, and a methanol solution of dioctyl sodium sulfosuccinate (manufactured by Nippon emulsifier Co., Ltd., "Newcol 290M (trade name)") having a solid content of 70 mass% were 2: 1, and mixing. Then, the volatile components (water and methanol) in the methanol solution of dioctyl sodium sulfosuccinate were removed by distillation under reduced pressure at 120 ℃ and 20 torr to obtain polyethylene glycol monomethyl ether containing an ionic surfactant. Then, to 76.9 parts by mass of a biuret type polyisocyanate (manufactured by Asahi chemical Co., Ltd., "Duranate 24A-100 (trade name)") of HDI heated to 90 ℃ was added 23.1 parts by mass of the above ionic surfactant-containing polyethylene glycol monomethyl ether over 120 minutes under stirring. Further, the mixture was stirred at 90 ℃ for 3 hours to effect a reaction, thereby obtaining a curing agent composition 3-1.

The obtained curing agent composition 3-1 had a viscosity of 4000 mPas, a solid content of 100% by mass, and a content of the ionic surfactant based on the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant of 7.7% by mass.

The hydrophilic polyisocyanate composition in the obtained curing agent composition 3-1 was as follows: the isocyanate group content was 17.9% by mass, the average number of isocyanate functional groups was 3.1, the number-average molecular weight was 730, the (B)/(A) was 13/87, and the (P)/{ (P) + (A) + (B) } was 93.6. Their physical properties are also shown in table 1 below.

(2) Production of aqueous coating composition 3-1

Using the curing agent composition 3-1 obtained in (2), an aqueous coating composition 3-1 was obtained in the same manner as described in (2) of example 1. Using the obtained aqueous coating composition 3-1, a coating film was produced, and the coating film was evaluated according to the evaluation items described above. The results are shown in table 1 below.

EXAMPLE 4 production of hydrophilic polyisocyanate composition 4-1 and aqueous coating composition 4-1

(1) Production of hydrophilic polyisocyanate composition 4-1

First, a polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 9.4 (product name "MPG-130" manufactured by japan emulsifier corporation) and a polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 4.2 (product name "MPG" manufactured by japan emulsifier corporation) were mixed at a mass ratio of 17.3: 82.7 to give a mixture of polyethylene glycol monomethyl ethers with an average number of ethylene oxide repeat units of 5.1. Then, 18.0 parts by mass of the above-mentioned polyethylene glycol monomethyl ether mixture was added to a mixture of 32.0 parts by mass of an isocyanurate type polyisocyanate (manufactured by Asahi chemical Co., Ltd., "Duranate TPA-100 (trade name)") of Hexamethylene Diisocyanate (HDI) heated to 110 ℃ and 48.0 parts by mass of an isocyanurate type polyisocyanate (manufactured by Asahi chemical Co., Ltd., "Duranate TSA-100 (trade name)") of HDI under stirring for 40 minutes. The reaction mixture was further stirred at 110 ℃ for 1 hour to obtain a hydrophilic polyisocyanate composition 4-1.

The hydrophilic polyisocyanate composition 4-1 obtained was as follows: viscosity was 1540 mPas, solid content was 100% by mass, isocyanate group content was 14.6% by mass, average number of isocyanate functional groups was 2.4, number-average molecular weight was 690, (B)/(A) was 19/81, (P)/{ (P) + (A) + (B) } was 85.6. Their physical properties are also shown in table 1 below.

(2) Production of aqueous coating composition 4-1

Using the hydrophilic polyisocyanate composition obtained in (1), an aqueous coating composition 4-1 was obtained in the same manner as described in (2) of example 1. Using the obtained aqueous coating composition 4-1, a coating film was produced, and the coating film was evaluated according to the evaluation items described above. The results are shown in table 1 below.

EXAMPLE 5 production of curing agent composition 5-1 and aqueous coating composition 5-1

(1) Production of curing agent composition 5-1

Polyethylene glycol monomethyl ether (manufactured by Nippon emulsifier Co., Ltd., "MPG-130 (trade name)") having an average number of ethylene oxide repeating units of 9.4, and a methanol solution of dioctyl sodium sulfosuccinate (manufactured by Nippon emulsifier Co., Ltd., "Newcol 290M (trade name)") having a solid content of 70 mass% were 9 in terms of a solid content mass ratio: 1, and mixing. Then, the volatile components (water and methanol) in the methanol solution of dioctyl sodium sulfosuccinate were removed by distillation under reduced pressure at 120 ℃ and 20 torr to obtain polyethylene glycol monomethyl ether containing an ionic surfactant. Then, 93.0 parts by mass of an isocyanurate type polyisocyanate (manufactured by Asahi chemical Co., Ltd., "Duranate TPA-100 (trade name)") of HDI and 7.0 parts by mass of the above ionic surfactant-containing polyethylene glycol monomethyl ether were mixed at room temperature, and the mixture was heated to 120 ℃. Then, the mixture was stirred for 3 hours to carry out a reaction, thereby obtaining a curing agent composition 5-1.

The obtained curing agent composition 5-1 had a viscosity of 1500 mPas, a solid content of 100% by mass, and a content of the ionic surfactant based on the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant of 2.0% by mass.

The hydrophilic polyisocyanate composition in the obtained curing agent composition 5-1 was as follows: the isocyanate group content was 20.8% by mass, the average number of isocyanate functional groups was 3.1, the number-average molecular weight was 630, the (B)/(A) was 8/92, and the (P)/{ (P) + (A) + (B) } was 96.9. Their physical properties are also shown in table 1 below.

(2) Production of aqueous coating composition 5-1

Using the curing agent composition 5-1 obtained in (2), an aqueous coating composition 5-1 was obtained in the same manner as described in (2) of example 1. Using the obtained aqueous coating composition 5-1, a coating film was produced, and the coating film was evaluated according to the evaluation items described above. The results are shown in table 1 below.

Comparative example 1 production of hydrophilic polyisocyanate composition 1-2 and aqueous coating composition 1-2

(1) Production of hydrophilic polyisocyanate composition 1-2

First, a polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 9.4 (manufactured by Nippon emulsifier Co., Ltd., "MPG-130 (trade name)") and a polyethylene glycol monomethyl ether having an average number of ethylene oxide repeating units of 4.2 (manufactured by Nippon emulsifier Co., Ltd., "MPG (trade name)") were mixed in a mass ratio of 17.3: 82.7 to give a mixture of polyethylene glycol monomethyl ethers with an average number of ethylene oxide repeat units of 5.1. Subsequently, 32.0 parts by mass of an HDI isocyanurate type polyisocyanate (manufactured by Asahi chemical Co., Ltd., "Duranate TPA-100 (trade name)") and 48.0 parts by mass of an HDI isocyanurate type polyisocyanate (manufactured by Asahi chemical Co., Ltd., "Duranate TSA-100 (trade name)") were mixed at room temperature with 18.0 parts by mass of the above polyethylene glycol monomethyl ether mixture, and the mixture was heated to 110 ℃. Then, the reaction mixture was stirred for 3 hours to obtain a hydrophilic polyisocyanate composition 1-2.

The hydrophilic polyisocyanate compositions 1 to 2 obtained were as follows: the viscosity was 1700 mPas, the solid content was 100% by mass, the isocyanate group content was 14.6% by mass, the average number of isocyanate functional groups was 2.4, the number-average molecular weight was 690, (B)/(A) was 22/78, (P)/{ (P) + (A) + (B) } was 86.1. Their physical properties are also shown in table 1 below.

(2) Production of aqueous coating composition 1-2

The hydrophilic polyisocyanate composition 1-2 obtained in (1) was compounded with Acrylic Latex (trade name "R-5007" manufactured by Asahi Kasei corporation) having a hydroxyl value of 60mgKOH/g as a unit resin so that the ratio of functional groups (NCO/OH) was 1.25. Subsequently, the mixture was diluted with water to a solid content of 40 mass% to obtain an aqueous coating composition 1-2. Using the obtained aqueous coating composition 1-2, a coating film was produced, and the coating film was evaluated according to the evaluation items described above. The results are shown in table 1 below.

Comparative example 2 production of curing agent composition 2-2 and aqueous coating composition 2-2

(1) Production of curing agent composition 2-2

Polyethylene glycol monomethyl ether (manufactured by Nippon emulsifier Co., Ltd., "MPG-130 (trade name)") having an average number of ethylene oxide repeating units of 9.4, and a methanol solution of dioctyl sodium sulfosuccinate (manufactured by Nippon emulsifier Co., Ltd., "Newcol 290M (trade name)") having a solid content of 70 mass% were 9 in terms of a solid content mass ratio: 1, and mixing. Then, the volatile components (water and methanol) in the methanol solution of dioctyl sodium sulfosuccinate were removed by distillation under reduced pressure at 120 ℃ and 20 torr to obtain polyethylene glycol monomethyl ether containing an ionic surfactant. Then, 80.0 parts by mass of an isocyanurate type polyisocyanate (manufactured by Asahi Kasei Co., Ltd., "Duranate TPA-100 (trade name)") of HDI and 20.0 parts by mass of the above ionic surfactant-containing polyethylene glycol monomethyl ether were mixed at room temperature, and the mixture was heated to 120 ℃. Then, the mixture was stirred for 3 hours to carry out a reaction, thereby obtaining a curing agent composition 2-2.

The obtained curing agent composition 2-2 had a viscosity of 2200 mPas, a solid content of 100% by mass, and a content of the ionic surfactant of 2.0% by mass based on the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant.

The hydrophilic polyisocyanate composition in the obtained curing agent composition 2-2 was as follows: the isocyanate group content was 16.8% by mass, the average number of isocyanate functional groups was 2.9, the number-average molecular weight was 725, the (B)/(A) was 24/76, and the (P)/{ (P) + (A) + (B) } was 92.4. Their physical properties are also shown in table 1 below.

(2) Production of aqueous coating composition 2-2

Using the curing agent composition 2-2 obtained in (2), an aqueous coating composition 2-2 was obtained in the same manner as in (2) of example 1. Using the obtained aqueous coating composition 2-2, a coating film was produced, and the coating film was evaluated according to the evaluation items described above. The results are shown in table 1 below.

Comparative example 3 production of curing agent composition 3-2 and aqueous coating composition 3-2

(1) Production of curing agent composition 3-2

Polyethylene glycol monomethyl ether (manufactured by Nippon emulsifier Co., Ltd., "MPG-081 (trade name)") having an average number of ethylene oxide repeating units of 15.0 and a dioctyl sodium sulfosuccinate methanol solution (manufactured by Nippon emulsifier Co., Ltd., "Newcol 290M (trade name)") having a solid content of 70 mass% were mixed in such a manner that the solid content mass ratio was 2: 1, and mixing. Then, the volatile components (water and methanol) in the methanol solution of dioctyl sodium sulfosuccinate were removed by distillation under reduced pressure at 120 ℃ and 20 torr to obtain polyethylene glycol monomethyl ether containing an ionic surfactant. Then, 76.9 parts by mass of a biuret type polyisocyanate (manufactured by Asahi Kasei Co., Ltd., "Duranate 24A-100 (trade name)") of HDI and 23.1 parts by mass of the ionic surfactant-containing polyethylene glycol monomethyl ether were mixed at room temperature, and the mixture was heated to 90 ℃. Then, the mixture was stirred for 6 hours to carry out a reaction, thereby obtaining a curing agent composition 3-2.

The obtained curing agent composition 3-2 had a viscosity of 4500mPa · s, a solid content of 100 mass%, and a content of the ionic surfactant relative to the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant of 7.7 mass%.

The hydrophilic polyisocyanate composition in the obtained curing agent composition 3-2 was as follows: the isocyanate group content was 17.9% by mass, the average number of isocyanate functional groups was 3.1, the number-average molecular weight was 730, the (B)/(A) was 30/70, and the (P)/{ (P) + (A) + (B) } was 94.4. Their physical properties are also shown in table 1 below.

(2) Production of aqueous coating composition 3-2

Using the curing agent composition 3-2 obtained in (2), an aqueous coating composition 3-2 was obtained in the same manner as in (2) of example 1. Using the obtained aqueous coating composition 3-2, a coating film was produced, and the coating film was evaluated according to the evaluation items described above. The results are shown in table 1 below.

[ Table 1]

From Table 1, when example 1 and comparative example 1 were compared, the raw materials were the same, and physical properties 1,2, 4, 5 and 6 were about the same.

However, the hydrophilic polyisocyanate composition of example 1 having physical properties 7((B)/(a)) of 20/80 or less was excellent in water dispersibility and water stability. The obtained coating film is excellent in appearance, curability, water resistance and chemical resistance. In addition, in example 1 containing the hydrophilic polyisocyanate composition obtained from the isocyanurate type polyisocyanate of HDI, the appearance of the obtained coating film was transparent and was particularly excellent.

On the other hand, the hydrophilic polyisocyanate composition of comparative example 1 having physical property 7((B)/(a)) of more than 20/80 is excellent in water dispersibility and water stability. However, the resulting coating film has poor curability and chemical resistance. In comparative example 1, the ratio of the mass of the undissolved portion after acetone impregnation to the mass before acetone impregnation was less than 60 mass%, and the curability was particularly poor.

Further, the hardness of the coating film was 80 in example 1 and 70 in comparative example 1, and example 1 was good.

When example 2 is compared with comparative example 2, the raw materials are the same and the physical properties are about the same from 1 to 6.

However, the curing agent composition of example 2 having physical properties 7((B)/(a)) of 20/80 or less was excellent in water dispersibility and water stability. The obtained coating film is excellent in appearance, curability, water resistance and chemical resistance. In addition, in example 2 containing the hydrophilic polyisocyanate composition obtained from the isocyanurate type polyisocyanate of HDI, the appearance of the obtained coating film was transparent and was particularly excellent. In example 2, which is a curing agent composition containing an ionic surfactant, the mass ratio of the undissolved portion after acetone impregnation to the mass before acetone impregnation was 80 mass% or more of the obtained coating film, and the curing property was particularly excellent.

On the other hand, the curing agent composition of comparative example 2, which had the physical property 7((B)/(A)) of more than 20/80, was excellent in water dispersibility and water stability. However, the resulting coating film is poor in curability, water resistance and chemical resistance. In comparative example 2, the resulting coating film was foamed, cloudiness and dissolution of the coating film were observed, and the water resistance was particularly poor.

Further, the hardness of the coating film was 105 in example 2, 97 in comparative example 2, and example 2 was good.

When example 3 is compared with comparative example 3, the raw materials are the same and the physical properties are about the same from 1 to 6.

However, the curing agent composition of example 3 having physical properties 7((B)/(a)) of 20/80 or less was excellent in water dispersibility and water stability. The obtained coating film is excellent in appearance, curability, water resistance and chemical resistance. In example 3, which is a curing agent composition containing an ionic surfactant, the mass ratio of the undissolved portion after acetone impregnation to the mass before acetone impregnation was 80 mass% or more of the obtained coating film, and the curing property was particularly excellent.

On the other hand, the curing agent composition of comparative example 3 having physical property 7((B)/(A)) of more than 20/80 is inferior in water stability. In addition, the obtained coating film was inferior in appearance, curability, water resistance and chemical resistance. In comparative example 3, the obtained coating film was cloudy and had a large amount of foreign matter, and the smoothness was low and the appearance was particularly poor.

Further, the hardness of the coating film was 72 in example 3 and 64 in comparative example 3, and example 3 was good.

When example 1 is compared with example 4, the raw materials are the same and the physical properties 1 to 6 are the same.

However, the hydrophilic polyisocyanate composition of example 1 having the property 7((B)/(A)) of 15/85 was particularly excellent in appearance and curability of the resulting coating film, as compared with the hydrophilic polyisocyanate composition of example 4 having the property ((B)/(A)) of 19/81.

When example 2 is compared with example 5, the raw materials are the same and the physical properties are about the same from 1 to 6.

However, the curing agent composition of example 2 having the property 7((B)/(A)) of 11/89 has particularly good water dispersibility as compared with the curing agent composition of example 5 having the property ((B)/(A)) of 8/92. The obtained coating film is particularly excellent in appearance, curability, hardness and chemical resistance.

On the other hand, the hardness of the coating film was 105 in example 2 and 112 in example 5, and example 5 was particularly good.

As described above, it was confirmed that the hydrophilic polyisocyanate composition or the curable composition of the present embodiment was stably dispersed in water. In addition, it was confirmed that the coating film obtained from the hydrophilic polyisocyanate composition or the curable composition of the present embodiment is excellent in curability, hardness, and appearance.

Industrial applicability

The hydrophilic polyisocyanate composition and the curable composition of the present embodiment can be stably dispersed in water, and are suitable for aqueous coating compositions. The water-based coating composition can be used as a curable composition such as a coating composition, an adhesive composition, a casting composition, or the like; various surface treatment agent compositions such as fiber treatment agents; various elastomeric compositions; crosslinking agents such as foam compositions; a modifier; additives, and the like.

Claims

1. A hydrophilic polyisocyanate composition comprising a hydrophilic polyisocyanate obtained by the reaction of a polyisocyanate obtained from 1 or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates with a hydrophilic compound,

wherein the molar ratio (B)/(A) of the hydrophilic polyisocyanate (B) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 2 or 3 molecule to the hydrophilic polyisocyanate (A) obtained by the reaction of the polyisocyanate obtained from the diisocyanate 3 molecule and the hydrophilic compound 1 molecule is 5/95 or more and 20/80 or less,

the hydrophilic compound is derived from a compound having a hydrophilic group, which is a nonionic hydrophilic group, a cationic hydrophilic group, or an anionic hydrophilic group.

2. The hydrophilic polyisocyanate composition according to claim 1, wherein the ratio (P)/{ (P) + (A) + (B) } of polyisocyanate (P) obtained from 3 molecules of the diisocyanate and not reacted with the hydrophilic compound to the total molar number of the polyisocyanate (P), the hydrophilic polyisocyanate (A) and the hydrophilic polyisocyanate (B) is 70 or more and 98 or less.

3. The hydrophilic polyisocyanate composition according to claim 1 or 2, wherein the hydrophilic compound is a compound represented by the following general formula (I),

in the general formula (I), R¹Is alkylene having 1 to 4 carbon atoms, R²Is an alkyl group having 1 to 4 carbon atoms, and n is 5 to 50 carbon atoms.

4. According to claim 3The hydrophilic polyisocyanate composition described above, wherein in the general formula (I), R¹Is an ethylene group, and n is 5 or more and 20 or less.

5. The hydrophilic polyisocyanate composition according to any one of claims 1,2 and 4, wherein the polyisocyanate contains 1 or more selected from the group consisting of isocyanurate groups and biuret groups.

6. The hydrophilic polyisocyanate composition according to claim 3, wherein the polyisocyanate contains 1 or more selected from the group consisting of isocyanurate groups and biuret groups.

7. A curing agent composition comprising: the hydrophilic polyisocyanate composition and the ionic surfactant according to any one of claims 1 to 6, wherein the ionic surfactant is contained in an amount of 0.1 mass% or more and 20 mass% or less relative to the total solid content of the hydrophilic polyisocyanate composition and the ionic surfactant.

8. An aqueous coating composition comprising: the hydrophilic polyisocyanate composition of any one of claims 1 to 6 or the curing agent composition of claim 7; water; and, an active hydrogen compound.