CN111978509B - Polyisocyanate composition, coating composition and coating film - Google Patents

Abstract

The invention provides a polyisocyanate composition, a coating composition and a coating film which are excellent in drying property and corrosion resistance when the coating film is formed. The polyisocyanate composition is a polyisocyanate composition containing a polyisocyanate derived from the following components (a) to (c): (a) an aliphatic diisocyanate; (b) an alicyclic diisocyanate; (c) a hydrophilic compound; the mass ratio (a)/(b) of the component (a) to the component (b) is 10/90 or more and 90/10 or less, the average number of isocyanate groups is 3.0 or more, and the content of the component having a number average molecular weight of 600 or less is 15% by mass or more relative to the total mass of the composition.

Description

Polyisocyanate composition, coating composition and coating film

Technical Field

The present invention relates to a polyisocyanate composition, a coating composition and a coating film.

Background

Polyisocyanate compositions obtained from aliphatic diisocyanates or alicyclic diisocyanates are used as curing agent components in two-component polyurethane coating compositions. Since a coating film obtained from the coating composition exhibits excellent properties such as weather resistance, chemical resistance, and abrasion resistance, these polyisocyanate compositions are widely used as a coating material, an ink, an adhesive, and the like.

In recent years, global environmental problems have been more and more emphasized, and a water-based two-component polyurethane coating composition in which an organic solvent is not used or the amount of the organic solvent used is reduced has been used. Conventionally, as a curing agent component of a water-based two-component type polyurethane coating composition, a polyisocyanate composition having a hydrophilic group having an isocyanate-reactive active hydrogen group such as a polyalkylene oxide polyether alcohol introduced into a polyisocyanate structure has been used.

Patent documents 1 to 3 disclose a polyisocyanate composition having emulsifying properties, which is obtained from an aliphatic diisocyanate and an alicyclic diisocyanate, and an aqueous two-component polyurethane coating composition using the polyisocyanate composition as a curing agent component.

Patent document 1 discloses a polyisocyanate composition which is a mixture of a hydrophilized polyisocyanate and a non-hydrophilized polyisocyanate, has ethylene oxide repeating units each having 10.6 to 15.4 ethylene oxide repeating units in number, and is water-dispersible.

Patent document 2 discloses a polyisocyanate composition in which polyether chains having 9.0 ethylene oxide repeating units are introduced, and the content of polyisocyanate derived from an alicyclic polyisocyanate is 40 mass% or more and 100 mass% or less of the entire polyisocyanate mixture. It is known that the drying property of a coating film using the polyisocyanate composition as a curing agent component is improved.

Documents of the prior art

Patent document

[ patent document 1] Japanese patent application laid-open No. 8-085716

[ patent document 2] Japanese patent application laid-open No. 10-130353

[ patent document 3] Japanese patent No. 4295218

Disclosure of Invention

Problems to be solved by the invention

However, a coating composition using a polyisocyanate composition having a polyisocyanate derived from an aliphatic diisocyanate as a main skeleton and a hydrophilic group derived from a polyalkylene oxide polyether alcohol introduced thereinto tends to have a reduced drying property of a coating film.

Further, a coating composition using a polyisocyanate composition containing an alicyclic diisocyanate tends to improve the service life and the drying property of a coating film when the coating composition is prepared into a coating, but the coating film physical properties such as corrosion resistance may be insufficient.

The present invention has been made in view of the above circumstances, and provides a polyisocyanate composition excellent in drying property and corrosion resistance when formed into a coating film, and a coating composition and a coating film using the polyisocyanate composition.

Means for solving the problems

That is, the present invention includes the following aspects.

The polyisocyanate composition according to embodiment 1 of the present invention is: a polyisocyanate composition comprising a polyisocyanate derived from the following components (a) to (c):

(a) an aliphatic diisocyanate;

(b) an alicyclic diisocyanate;

(c) a hydrophilic compound;

the mass ratio (a)/(b) of the component (a) to the component (b) is 10/90 or more and 90/10 or less,

an average number of isocyanate groups of 3.0 or more, and

the content of the component having a number average molecular weight of 600 or less is 15% by mass or more relative to the total mass of the composition.

The hydrophilic compound (c) may be a monofunctional polyalkylene oxide polyether alcohol having an average number of alkylene oxide repeating units of 7.0 or more and 20.0 or less.

The polyisocyanate may contain polyisocyanate X having an average number of isocyanate groups of less than 3.5 and polyisocyanate Y having an average number of isocyanate groups of 3.5 or more.

The coating composition of the 2 nd aspect of the present invention contains the polyisocyanate composition of the 1 st aspect.

The coating film of the 3 rd aspect of the present invention is obtained by curing the coating composition of the 2 nd aspect.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the polyisocyanate composition of the above aspect, a polyisocyanate composition excellent in drying property and corrosion resistance when formed into a coating film can be provided. The coating composition of the above embodiment contains the polyisocyanate composition, and is excellent in drying property and corrosion resistance when formed into a coating film. The coating film of the above embodiment is excellent in drying property and corrosion resistance.

Detailed Description

Hereinafter, a specific embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described in detail. The present invention is not limited to the following embodiments. The present invention can be implemented with appropriate modifications within the scope of the gist of the present invention.

In the present specification, the term "polyol" refers to a compound having 2 or more hydroxyl groups (-OH).

In the present specification, the "polyisocyanate" refers to a reaction product obtained by combining a plurality of monomer compounds (monomers) having 1 or more isocyanate groups (-NCO).

< polyisocyanate composition >

The polyisocyanate composition of the present embodiment contains a polyisocyanate derived from the following components (a) to (c).

(a) An aliphatic diisocyanate;

(b) an alicyclic diisocyanate;

(c) hydrophilic compounds

In the polyisocyanate composition of the present embodiment, the mass ratio (a)/(b) of the component (a) to the component (b) is 10/90 or more and 90/10 or less. When the mass ratio (a)/(b) is in the above range, a polyisocyanate composition excellent in drying property and corrosion resistance when formed into a coating film can be provided while maintaining good water dispersibility and a long service life when formed into a coating composition.

In general, the "service life" refers to a time period for ensuring the performance of a composition before curing after the composition is prepared by mixing a main component and a curing agent in the composition such as a coating material or an adhesive. Also known as pot life.

The mass ratio (a)/(b) is preferably 20/80 or more and 87/13 or less, more preferably 30/70 or more and 84/16 or less, still more preferably 40/60 or more and 81/19 or less, and particularly preferably 50/50 or more and 78/22 or less.

The mass ratio (a)/(b) can be calculated by the method described in examples described later.

The average number of isocyanate groups in the polyisocyanate composition of the present embodiment is 3.0 or more. When the average number of isocyanate groups is not less than the lower limit, the crosslinking density of the resulting coating film can be increased, and a polyisocyanate composition having excellent corrosion resistance can be provided.

The average number of isocyanate groups is preferably 3.0 or more and 4.0 or less, more preferably 3.1 or more and 3.8 or less, and further preferably 3.2 or more and 3.6 or less.

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

In the polyisocyanate composition of the present embodiment, the content of the component having a number average molecular weight of 600 or less (hereinafter, may be abbreviated as "the content of the component having a number average molecular weight of 600 or less") is preferably 15% by mass or more, more preferably 18% by mass or more, further preferably 21% by mass or more, and particularly preferably 24% by mass or more, based on the total mass of the composition.

When the content of the component having a number average molecular weight of 600 or less is not less than the lower limit, the compatibility with the polyol to be used can be further improved, and a polyisocyanate composition having further excellent corrosion resistance can be provided.

The upper limit of the content of the component having a number average molecular weight of 600 or less is not particularly limited, and may be, for example, 50% by mass or 40% by mass.

The content of the component having a number average molecular weight of 600 or less can be calculated by the method described in the examples described later.

In the polyisocyanate composition of the present embodiment, in order to further improve the corrosion resistance, the polyisocyanate preferably contains polyisocyanate X having an average number of isocyanate groups of less than 3.5 and polyisocyanate Y having an average number of isocyanate groups of 3.5 or more. Mixtures of the above-mentioned polyisocyanates of different average numbers of isocyanate groups can be prepared easily.

The average number of isocyanate groups of the polyisocyanate X is preferably 2.8 or more and less than 3.5, more preferably 2.9 or more and less than 3.5.

The average number of isocyanate groups of the polyisocyanate Y is more preferably 3.6 or more and 5.0 or less, and still more preferably 3.7 or more and 4.5 or less.

The content of the polyisocyanate Y is preferably 4% by mass or more, more preferably 8% by mass or more, further preferably 12% by mass or more, and particularly preferably 16% by mass or more, based on the total mass of the polyisocyanate X and the polyisocyanate Y.

On the other hand, the upper limit of the content of the polyisocyanate Y is not particularly limited, and for example, 50 mass% or less, 43 mass% or less, 36 mass% or less, and 30 mass% or less may be used.

The polyisocyanate composition of the present embodiment has good water dispersibility by addition of the constituent unit derived from the hydrophilic compound.

In the present specification, "water-dispersibility" means a property of dispersing in water such as an O/W type polyisocyanate composition. The water dispersibility can be evaluated by, for example, adding the polyisocyanate composition to water and mechanically stirring the mixture with a stick, a hand-held stirrer, or the like to confirm whether or not the polyisocyanate composition is dispersed in water, as shown in examples described later. The term "O/W type" as used herein means an oil-in-water emulsion having water as a continuous phase.

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

< polyisocyanates >

The polyisocyanate contained in the polyisocyanate composition of the present embodiment is derived from the above-mentioned components (a) to (c), that is, is a reaction product of the above-mentioned components (a) to (c). The polyisocyanate contained in the polyisocyanate composition of the present embodiment is a hydrophilic polyisocyanate in which a hydrophilic group derived from the component (c) is introduced into at least a part of the polyisocyanate.

In the present specification, "derived" includes: a prepolymerization reaction of the component (a), a prepolymerization reaction of the component (b), an addition reaction of a prepolymer of the component (a) and the component (c), an addition reaction of a prepolymer of the component (b) and the component (c), an addition reaction of a substance obtained by simultaneously prepolymerizing the component (a) and the component (b) with the component (c), and a polymerization reaction of a substance obtained by adding a mixture of the component (a) and the component (b) to the component (c).

Examples of the "prepolymerization reaction" and the "polymerization reaction" include: a reaction of generating a uretdione group obtained by cyclodimerization of 2 isocyanate groups, and a reaction of generating an isocyanurate group or an iminooxadiazinedione group obtained by cyclodimerization of 3 isocyanate groups; a reaction for producing a biuret group obtained by reacting 3 isocyanate groups with 1 water molecule; a reaction for producing an oxadiazinetrione group obtained by reacting 2 isocyanate groups with 1 molecule of carbon dioxide; a reaction to produce a carbamate group obtained by reacting 1 isocyanate group with 1 hydroxyl group; a reaction to produce allophanate groups obtained by reacting 2 isocyanate groups with 1 hydroxyl group; a reaction of generating an acylureido group obtained by reacting 1 isocyanate group with 1 carboxyl group; a reaction in which a urea group obtained by reacting 1 isocyanate group with 1 primary or secondary amine is formed, and the like. These may be used in combination of 1 or more than 2.

The addition reaction includes at least 1 reaction selected from the group consisting of the above-mentioned reaction to form a urethane group and the above-mentioned reaction to form an allophanate group.

[ component (a): aliphatic diisocyanate

The aliphatic diisocyanate is a diisocyanate compound formed of a saturated hydrocarbon group containing no cyclic structure. Polyisocyanates derived from aliphatic diisocyanates tend to become low viscosity.

Examples of the aliphatic diisocyanate include: 1, 4-diisocyanatobutane, 1, 5-diisocyanatopentane, ethyl (2, 6-diisocyanato) hexanoate, 1, 6-diisocyanatohexane (hereinafter sometimes abbreviated as "HDI"), 1, 9-diisocyanatononane, 1, 12-diisocyanatododecane, 2, 4-or 2,4, 4-trimethyl-1, 6-diisocyanatohexane and the like. Among them, as the aliphatic diisocyanate, HDI is particularly preferable because it is industrially available and excellent in weather resistance and flexibility of a coating film.

[ component (b): alicyclic diisocyanates

The alicyclic diisocyanate is a diisocyanate compound containing one or more saturated hydrocarbon rings.

Examples of the alicyclic diisocyanate include: 1, 3-or 1, 4-bis (isocyanatomethyl) cyclohexane (hereinafter sometimes abbreviated as "hydrogenated XDI"), 1, 3-or 1, 4-diisocyanatocyclohexane, 3,5, 5-trimethyl-1-isocyanato-3- (isocyanatomethyl) cyclohexane (hereinafter sometimes abbreviated as "IPDI"), 4-4' -diisocyanato-dicyclohexylmethane (hereinafter sometimes abbreviated as "hydrogenated MDI"), 2, 5-or 2, 6-diisocyanatomethylnorbornane and the like. Among them, as the alicyclic diisocyanate, IPDI is preferable because it is commercially available.

Hereinafter, the aliphatic diisocyanate and the alicyclic diisocyanate may be collectively referred to as "diisocyanate".

[ component (c): hydrophilic compound

The hydrophilic compound is a compound having a hydrophilic group in a molecule. In order to react with 1 isocyanate group, the hydrophilic compound preferably has 1 or more active hydrogen groups for reacting with an isocyanate group of the polyisocyanate per 1 molecule. Specific examples of the active hydrogen group include: hydroxyl, mercapto, carboxylic acid group, amino, thiol group.

The hydrophilic compound is not particularly limited, and examples thereof include: anionic compounds, cationic compounds, and nonionic compounds. These hydrophilic compounds can be used alone in 1, also can be used in 2 or more combinations. Among these, anionic compounds or nonionic compounds are preferable, and nonionic compounds are most preferable in view of the service life after blending of the coating material.

(anionic Compound)

The anionic compound is not particularly limited, and examples thereof include: a carboxylic acid group-containing compound, a phosphoric acid group-containing compound, a sulfonic acid group-containing compound, and the like.

The carboxylic acid group-containing compound is not particularly limited, and examples thereof include: monohydroxycarboxylic acids such as 1-hydroxyacetic acid, 3-hydroxypropionic acid, 12-hydroxy-9-octadecanoic acid, hydroxypivalic acid, and lactic acid; hydroxyl group-containing carboxylic acids such as polyhydroxycarboxylic acids such as dimethylolacetic acid, 2-dimethylolbutyric acid, 2-dimethylolvaleric acid, dihydroxysuccinic acid, dimethylolpropionic acid, and the like. Among them, hydroxypivalic acid or dimethylolpropionic acid is preferable.

The phosphoric acid group-containing compound is not particularly limited, and examples thereof include: acid phosphates, acid phosphites, acid hypophosphites, specific polyether phosphonates (for example, a compound commercially available under the trade name RHODAFAC (registered trademark), and the like). Among them, acidic phosphate esters are preferred.

The lower limit of the content of the phosphorus atom in the polyisocyanate composition is preferably 0.03 mass%, more preferably 0.05 mass%, and still more preferably 0.1 mass% with respect to the total amount (100 mass%) of the polyisocyanate composition, from the viewpoint of water dispersibility. When the content of the phosphorus atom is not less than the lower limit, the interface tension is lowered, and thus the water dispersibility tends to be more excellent.

On the other hand, in the polyisocyanate composition, the upper limit of the content of phosphorus atoms is preferably 6.0% by mass, more preferably 3.0% by mass, and still more preferably 1.0% by mass, based on the total amount (100% by mass) of the polyisocyanate composition, from the viewpoint of the physical properties of the coating film. When the content of the phosphorus atom is not more than the above upper limit, the isocyanate group used for crosslinking tends to be increased, and the coating film tends to have more favorable physical properties.

That is, the content of phosphorus atoms in the polyisocyanate composition is preferably 0.03 mass% or more and 6.0 mass% or less, more preferably 0.05 mass% or more and 3.0 mass% or less, and still more preferably 0.1 mass% or more and 1.0 mass% or less, with respect to the total amount (100 mass%) of the polyisocyanate composition.

The method of controlling the content of phosphorus atoms in the above range is not limited to the following method, and for example, a method of adjusting the blending ratio of the phosphoric acid group-containing compound and the raw material polyisocyanate compound is mentioned. The content of phosphorus atoms was measured by inductively coupled plasma emission spectrometry (ICP-AES).

The sulfonic acid group-containing compound is not particularly limited, and examples thereof include: hydroxyl-containing sulfonic acids, amino-containing sulfonic acids, and the like. Among them, sulfonic acids containing at least 1 selected from the group consisting of amino groups and hydroxyl groups are preferable.

The lower limit of the content of the sulfur atom in the polyisocyanate composition is preferably 0.03 mass%, more preferably 0.05 mass%, and still more preferably 0.08 mass% with respect to the total mass (100 mass%) of the polyisocyanate composition from the viewpoint of water dispersibility. When the content of the sulfur atom is not less than the lower limit, the interface tension is decreased, and thus the water dispersibility tends to be more excellent.

On the other hand, in the polyisocyanate composition, the upper limit of the content of sulfur atoms is preferably 3.0% by mass, more preferably 2.5% by mass, and still more preferably 2.0% by mass, based on the total mass (100% by mass) of the polyisocyanate composition, from the viewpoint of the physical properties of the coating film. When the content of the sulfur atom is not more than the above upper limit, the isocyanate group used for crosslinking tends to be increased, and the coating film tends to have more favorable physical properties.

That is, the content of sulfur atoms in the polyisocyanate composition is preferably 0.03 mass% or more and 3.0 mass% or less, more preferably 0.05 mass% or more and 2.5 mass% or less, and still more preferably 0.08 mass% or more and 2.0 mass% or less, based on the total mass (100 mass%) of the polyisocyanate composition.

The method of controlling the content of sulfur atoms within the above range is not limited to the following method, and for example, a method of adjusting the blending ratio of the sulfonic acid group-containing compound to the raw material polyisocyanate compound is mentioned. The content of sulfur atoms can be measured by Ion Chromatography (IC).

The acidic groups such as the carboxylic acid group, phosphoric acid group and sulfonic acid group of the anionic compound are preferably neutralized with an inorganic base or an organic amine compound.

Examples of the inorganic base include: alkali metals such as lithium, sodium, potassium, rubidium, and cesium; alkaline earth metals such as magnesium, calcium, strontium, and barium; metals such as manganese, iron, cobalt, nickel, copper, zinc, silver, cadmium, lead, aluminum, and the like; ammonia.

Examples of the organic amine compound include: linear tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tridecylamine, and tristearylamine; branched tertiary amines such as triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, and tri (branched tridecyl) amine; n, N-dimethylethylamine, N-dimethylpropylamine, N-dimethylisopropylamine, N-dimethylbutylamine, N-dimethylisobutylamine, N-dimethyloctylamine, N-dimethyl-2-ethylhexylamine, N-dimethyllaurylamine, N-dimethyl (branched) tridecylamine, N-dimethylstearylamine, tertiary amines having a mixed hydrocarbon group such as N, N-diethylbutylamine, N-diethylhexylamine, N-diethyloctylamine, N-diethyl-2-ethylhexylamine, N-diethyllaurylamine, N-diisopropylmethylamine, N-diisopropylethylamine, N-diisopropylbutylamine, and N, N-diisopropyl-2-ethylhexylamine; alicyclic tertiary amines such as N, N-dimethylcyclohexylamine, N-diethylbenzylamine, N-diethylcyclohexylamine, N-dicyclohexylmethylamine, N-dicyclohexylethylamine, and tricyclohexylamine; tertiary amines having an aromatic ring substituent such as N, N-dimethylbenzylamine, N-diethylbenzylamine, N-dibenzylmethylamine, tribenzylamine, N-dimethyl-4-methylbenzylamine, N-dimethylaniline, N-diethylaniline, and N, N-diphenylmethylamine; and cyclic amines such as N-methylpyrrolidine, N-ethylpyrrolidine, N-propylpyrrolidine, N-butylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-propylpiperidine, N-butylpiperidine, N-methylmorpholine, N-ethylmorpholine, N-propylmorpholine, N-butylmorpholine, N-sec-butylmorpholine, N-tert-butylmorpholine, N-isobutyl morpholine, and quinuclidine. These organic amine compounds can be used alone in 1, or can be used in combination of 2 or more.

Among them, tertiary amines having 5 to 30 carbon atoms are preferable, and specific examples thereof include: triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tridecylamine, triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, tri (branched tridecyl) amine, N-dimethylpropylamine, N-dimethylisopropylamine, N-dimethylbutylamine, N-dimethylisobutylamine, N-dimethyloctylamine, N-dimethyl-2-ethylhexylamine, N-dimethyllaurylamine, N-dimethyl (branched) tridecylamine, N-dimethylstearylamine, N-diethylbutylamine, N-diethylhexylamine, N-diethyloctylamine, N-diethyl-2-ethylhexylamine, N-diethyllaurylamine, N, n-diisopropylmethylamine, N-diisopropylethylamine, N-dimethylcyclohexylamine, N-diethylcyclohexylamine, N-dicyclohexylmethylamine, N-dicyclohexylethylamine, N-dimethylbenzylamine, N-diethylbenzylamine, N-dibenzylmethylamine, tribenzylamine, N-dimethylaniline, N-diethylaniline, N-diphenylmethylamine, N-methylpiperidine, N-ethylpiperidine, N-methylmorpholine, N-ethylmorpholine, quinuclidine, pyridine, quinoline, and the like. These preferred organic amine compounds may be used alone in 1 kind, or 2 or more kinds may be used in combination.

In order to disperse the polyisocyanate compound in water, the polyisocyanate compound is modified with a hydrophilic compound (hydrophilic groups derived from the hydrophilic compound are introduced into the polyisocyanate compound) at a ratio not too high, and thus the deterioration of the physical properties (hardness, water resistance and solvent resistance) of the coating film tends to be suppressed. That is, since the anionic compound has a high emulsifying power, a high emulsifying effect can be obtained with a small amount.

The method of reacting the raw material polyisocyanate compound with the anionic compound is not limited to the following method, and for example, a method of reacting a terminal isocyanate group of the polyisocyanate of the raw material polyisocyanate compound with an active hydrogen group of the anionic compound is exemplified.

(cationic Compound)

The cationic compound is not particularly limited, and examples thereof include: hydroxyl group-containing amine compounds such as dimethylethanolamine, diethylethanolamine, diethanolamine, methyldiethanolamine, N, N-dimethylaminohexanol, N, N-dimethylaminoethoxyethanol, N, N, N' -trimethylaminoethylethanolamine, and N-methyl-N- (dimethylaminopropyl) aminoethanol. Of these, dimethylethanolamine, diethylethanolamine, N-dimethylaminohexanol, N-dimethylaminoethoxyethanol or N, N-dimethylaminoethoxyethanol are preferred. The tertiary amino group (cationic hydrophilic group) introduced into the polyisocyanate derived from the cationic compound may be quaternized with dimethyl sulfate, diethyl sulfate, or the like.

The tertiary amino group of the cationic compound is preferably neutralized with a compound having an anionic group. The anionic group is not particularly limited, and examples thereof include: carboxyl group, sulfonic group, phosphoric group, halogen group, sulfuric group and the like. The compound having the carboxyl group is not particularly limited, and examples thereof include: formic acid, acetic acid, propionic acid, butyric acid, lactic acid, and the like. The compound having the sulfonic acid group is not particularly limited, and examples thereof include: ethanesulfonic acid, and the like. The compound having a phosphate group is not particularly limited, and examples thereof include: phosphoric acid, acidic phosphoric acid esters, and the like. The compound having a halogen group is not particularly limited, and examples thereof include: hydrochloric acid, and the like. The compound having a sulfate group is not particularly limited, and examples thereof include: sulfuric acid, and the like. Among them, a compound having a carboxyl group is preferable, and acetic acid, propionic acid, or butyric acid is more preferable.

(nonionic Compound)

The nonionic compound is not particularly limited, and examples thereof include: polyalkylene oxide polyether alcohols. The number of hydroxyl groups of the polyalkylene oxide polyether alcohol is preferably 1, that is, a monofunctional polyalkylene oxide polyether alcohol, from the viewpoint of reducing the viscosity of the polyisocyanate composition. Preferred monofunctional polyalkylene oxide polyether alcohols are those of the general formula (I).

R¹¹-O-(R¹²-O)_n11-H (I)

In the above general formula (I), R¹¹An alkyl group or an aryl group having 1 to 30 carbon atoms. R¹²An alkylene group having 1 to 5 carbon atoms. n11 is a number of 7.0 to 20.0 inclusive.

(R¹¹)

As R¹¹Wherein the number of carbon atoms of the alkyl group and the aryl group is 1 to 30 inclusiveFrom the viewpoint of increasing the hydrophilicity of the polyisocyanate, it is preferably 1 or more and 20 or less, more preferably 1 or more and 15 or less, and still more preferably 1 or more and 12 or less.

As R¹¹The alkyl group in (2) may be linear or cyclic. The chain alkyl group may be linear or branched. Examples of the linear alkyl group include: methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl and the like. Examples of the branched alkyl group include: isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, isohexyl, and the like. Examples of the cyclic alkyl group include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

As R¹¹Examples of the aryl group in (1) include: phenyl, naphthyl, anthryl, phenanthryl, and the like.

Further, the aryl group may have at least 1 hydrocarbon group selected from the group consisting of an alkyl group, an alkenyl group, and an aryl group as a substituent. Examples of the substituted aryl group include: tolyl, xylyl, biphenyl, styryl, styrylphenyl, and the like.

Among them, as R¹¹The alkyl group is preferably a chain alkyl group or an unsubstituted or substituted aryl group, more preferably a linear alkyl group, a phenyl group, a naphthyl group, a styryl group or a styrylphenyl group, still more preferably a linear alkyl group having 1 to 12 carbon atoms, and particularly preferably a methyl group or an ethyl group.

(R¹²)

As R¹²The alkylene group having 1 to 5 carbon atoms in (b) may be a chain or a ring. The chain alkylene group may be linear or branched. Examples of the linear alkylene group include: methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and the like. Examples of the branched alkylene group include: 1-methylethylene (propylene), 1-methyltrimethylene, 2-methyltrimethylene, 1-dimethylethylene, 1-methyltetramethylene, 2-methyltetramethylene and the like. As cyclic alkylene, e.g.Examples thereof include: cyclopropyl ene, cyclobutyl ene, cyclopentyl ene, and the like.

Among them, as R¹²The alkylene group is preferably a chain alkylene group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 3 carbon atoms, and particularly preferably a methylene group or an ethylene group.

(n11)

n11 is the average number of alkylene oxide repeating units and is a number of 7.0 to 20.0 inclusive.

The lower limit value of n11 is 7.0, preferably 7.5, and more preferably 8.0. On the other hand, the upper limit value of n11 is 20.0, preferably 15.0, and more preferably 12.0. That is, n11 is 7.0 or more and 20.0 or less, preferably 7.5 or more and 15.0 or less, and more preferably 8.0 or more and 12.0 or less. When n11 is in the above range, the polyisocyanate composition of the present embodiment has better water dispersibility, lower crystallinity, and easier handling. The average number of alkylene oxide repeating units can be calculated by the method described in examples described later.

Examples of monofunctional polyalkylene oxide polyether alcohols include: polymethylene glycol monomethyl ether, polyethylene glycol monoethyl ether, polyethylene glycol monopropyl ether, polyethylene glycol monolauryl ether, polyethylene glycol phenyl ether, polyethylene glycol alkylphenyl ether, polyethylene glycol phenyl ether, polyethylene glycol styryl phenyl ether, polyethylene glycol naphthyl ether, polyoxyethylene-oxypropylene (at least either of random and block polymerization) glycol monomethyl ether, polyoxyethylene-oxytetramethylene (at least either of random and block polymerization) glycol polytetramethylene glycol monomethyl ether, and the like. Furthermore, as the monofunctional polyalkylene oxide polyether alcohol, a nonionic surfactant having a group containing 2 or more aromatic rings such as a (mono-, di-, tri-, tetra-or penta) -styrenated phenyl group, a mono (or di-or tri) -styryl-methyl-phenyl group, a tribenzylphenyl group, a β -naphthyl group, and the like can be used. These monofunctional polyalkylene oxide polyether alcohols may be used alone in 1 kind, or in combination of 2 or more kinds.

The lower limit of the molecular weight of the monofunctional polyalkylene oxide polyether alcohol is preferably 150, more preferably 194, still more preferably 216, and particularly preferably 238. On the other hand, the upper limit of the molecular weight is preferably 2500, more preferably 2000, still more preferably 1000, and particularly preferably 800.

That is, the molecular weight of the monofunctional polyalkylene oxide polyether alcohol is preferably 150 or more and 2500 or less, more preferably 194 or more and 2000 or less, still more preferably 216 or more and 1000 or less, and particularly preferably 238 or more and 800 or less.

By setting the molecular weight in the above range, the polyisocyanate composition of the present embodiment has better water dispersibility, lower crystallinity, and easier handling.

The amount of monofunctional polyalkylene oxide polyether alcohol introduced into the polyisocyanate included in the polyisocyanate composition of the present embodiment can be represented by the ratio of monofunctional polyalkylene oxide polyether alcohol introduced into the polyisocyanate at an equivalent weight of 100 isocyanate groups.

The lower limit of the amount of incorporation is preferably 1% by mass, more preferably 2% by mass, still more preferably 5% by mass, and particularly preferably 8% by mass. On the other hand, the upper limit of the introduction amount is preferably 80% by mass, more preferably 60% by mass, still more preferably 40% by mass, and particularly preferably 15% by mass.

That is, the amount of monofunctional polyalkylene oxide polyether alcohol introduced is preferably 1 mass% or more and 80 mass% or less, more preferably 2 mass% or more and 60 mass% or less, still more preferably 5 mass% or more and 40 mass% or less, and particularly preferably 8 mass% or more and 15 mass% or less.

When the amount of the polyisocyanate composition of the present embodiment is not less than the lower limit, the water dispersibility of the polyisocyanate composition of the present embodiment is further improved, and when the amount of the polyisocyanate composition is not more than the upper limit, the curability of the composition tends to be further improved when the composition is used as a curing agent for an aqueous two-component polyurethane coating composition.

The amount of monofunctional polyalkylene oxide polyether alcohol introduced can be calculated, for example, by the following method.

Specifically, the peak area ratio of the polyisocyanate composition as a sample can be determined from the area ratio of the peaks of the non-introduced polyisocyanate at 220nm by Liquid Chromatography (LC), the polyisocyanate introduced with 1 monofunctional polyalkylene oxide polyether alcohol, the polyisocyanate introduced with 2 monofunctional polyalkylene oxide polyether alcohols and the polyisocyanate introduced with 3 or more monofunctional polyalkylene oxide polyether alcohols. Examples of the measurement conditions based on LC include the following conditions.

(measurement conditions)

An LC device: manufactured by Waters Corp, UPLC (trade name)

A chromatographic column: 2.1mm inner diameter x 50mm length of ACQUITY UPLC HSST 31.8 μm C18 manufactured by Waters Corp

Flow rate: 0.3mL/min

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

Gradual change conditions: the initial mobile phase composition was a/B of 98/2, the ratio of B was increased linearly after sample injection, and a/B was 0/100 after 10 minutes.

The detection method comprises the following steps: photodiode array detector with measurement wavelength of 220nm

< other ingredients >

(Ionic surfactant)

The polyisocyanate composition of the present embodiment may further contain an ionic surfactant substantially free of water in addition to the polyisocyanate.

By containing the ionic surfactant, the dispersion stability of oil droplets of polyisocyanate is significantly improved when dispersed in water, and water can be prevented from entering the oil droplets of polyisocyanate. This can significantly improve the service life of the aqueous two-component polyurethane coating composition. In addition, the water resistance can be further improved by reducing the particle size of oil droplets of the polyisocyanate.

Examples of the ionic surfactant include: the anionic surfactant, the cationic surfactant, and the amphoteric surfactant are preferably selected from the anionic surfactant and the cationic surfactant according to the method of neutralizing the aqueous emulsion. That is, when the aqueous emulsion is neutralized with a base, an anionic surfactant is more preferably used, and when the aqueous emulsion is neutralized with an acid, a cationic surfactant is more preferably used. When the aqueous emulsion is not neutralized, both can be used.

The anionic surfactant is preferably a carboxylate type, a sulfate type, a sulfonate type, or a phosphate type. Specific examples of the compound include, but are not limited to, the following compounds: 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, ammonium polyoxyethylene C6-C30 aryl ether sulfonate, and the like. Among them, preferable compounds as the anionic surfactant are ammonium (C1-C20 alkyl) benzenesulfonate, sodium (C1-C20 alkyl) benzenesulfonate, or sodium di (C1-C20 alkyl) sulfosuccinate, and they can be used without inconvenience as long as they are commercially available.

The cationic surfactant is preferably a quaternary ammonium salt, a pyridinium salt, or an imidazolinium salt. Specific examples of the compound include, but are not limited to, the following compounds: C1-C20 alkyltrimethylammonium bromide, C1-C30 alkylpyridinium bromide, imidazolinium laurate, and the like. More specific examples of the compound include: alkyl trimethyl ammonium bromide, alkyl pyridinium bromide, imidazolinium laurate, and the like.

(organic solvent)

The polyisocyanate composition of the present embodiment may further contain an organic solvent in addition to the polyisocyanate.

By containing the organic solvent, the viscosity of the polyisocyanate composition is made lower, and hence the water dispersibility is further improved. In addition, the remaining ratio of isocyanate groups in the case of dispersing the polyisocyanate composition in water tends to be further increased, and the service life of the aqueous two-component polyurethane coating composition tends to be further improved.

The organic solvent contained in the polyisocyanate composition of the present embodiment may be any solvent that does not have a functional group that reacts with an isocyanate group and is compatible with the polyisocyanate composition of the present embodiment.

Examples of such organic solvents include: ester compounds, ether compounds, ketone compounds, aromatic compounds, polyethylene glycol dialkyl ether compounds, polyethylene glycol dicarboxylic acid ester compounds, and the like. Examples of the ester compound include: butyl acetate, isobutyl acetate, amyl acetate, methoxypropyl acetate, 3-methoxybutyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, butyl propionate, butyl butyrate, dioctyl adipate, diisopropyl glutarate, and the like. Examples of the ether compound include: diisopropyl ether, dibutyl ether, dioxane, diethoxyethane, and the like. Examples of the ketone compound include: 2-pentanone, 3-pentanone, 2-hexanone, methyl isobutyl ketone, 2-heptanone, 4-heptanone, diisobutyl ketone, isophorone, cyclohexanone, methylcyclohexanone, and the like. Examples of the aromatic compound include: benzene, toluene, xylene, ethylbenzene, butylbenzene, p-cymene, and the like. Examples of the polyethylene glycol dialkyl ether compounds include: diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, diethylene glycol dibutyl ether, and the like. Examples of the compounds of polyethylene glycol dicarboxylic acid esters include: diethylene glycol diacetate and the like.

Among them, organic solvents having a hydrocarbon group having 7 or more carbon atoms are preferable because they have a low volatilization rate and cause leveling to further improve the appearance of the coating film surface. Further, as the organic solvent, an organic solvent containing an ester is more preferable because the compatibility with the aqueous base compound is further improved. Accordingly, the organic solvent is preferably an organic solvent containing an ester having 7 or more carbon atoms, and particularly preferably an organic solvent composed of only an ester having 7 or more carbon atoms.

The lower limit of the content of the organic solvent in the polyisocyanate composition of the present embodiment is preferably 1 mass%, more preferably 5 mass%, still more preferably 10 mass%, and most preferably 15 mass% with respect to the total mass of the polyisocyanate composition. On the other hand, the upper limit of the content of the organic solvent is preferably 70% by mass, more preferably 60% by mass, still more preferably 50% by mass, and most preferably 40% by mass, based on the total mass of the polyisocyanate composition.

That is, the lower limit of the content of the organic solvent in the polyisocyanate composition of the present embodiment is preferably 1% by mass or more and 70% by mass or less, more preferably 5% by mass or more and 60% by mass or less, still more preferably 10% by mass or more and 50% by mass or less, and most preferably 15% by mass or more and 40% by mass or less, based on the total mass of the polyisocyanate composition.

By setting the content of the organic solvent to the above range, the viscosity of the polyisocyanate composition is reduced, the service life of the aqueous two-component polyurethane coating composition is further improved, and the content of the organic solvent can be more effectively suppressed from becoming too large.

< method for producing polyisocyanate composition >

The polyisocyanate composition of the present embodiment has the component (a), the component (b), and the component (c) as essential components, and thus can be produced, for example, by the methods shown in the following (i) to (iv).

(i) A method in which the component (a) is prepolymerized and the component (b) is prepolymerized, and then the component (c) is subjected to addition reaction and polymerization reaction with the component (a) prepolymer and the component (b) prepolymer, respectively;

(ii) a method in which the component (a) is prepolymerized and the component (b) is prepolymerized, the component (c) is added to the prepolymer of the component (a) and the component (c) is polyaddition the prepolymer of the component (b) and the component (c) are prepolymerized, and then the components are finally mixed and polymerized;

(iii) a method in which the component (a) and the component (b) are simultaneously subjected to prepolymerization, and then the resulting mixed prepolymer is simultaneously subjected to addition reaction and polymerization reaction with the component (c);

(iv) a method of simultaneously carrying out an addition reaction and a polymerization reaction of a mixture of the component (a) and the component (b) with the component (c).

Among them, the method (i) is preferable because the mixing ratio of the polyisocyanate derived from the component (a) and the polyisocyanate derived from the component (b) can be easily adjusted and the production efficiency is good.

In addition, in the product produced by the method shown in any one of the above (i) to (iv), the prepolymer of the component (a) and the addition reaction product of the prepolymer of the component (a) and the component (c) may be further appropriately mixed. Thus, a polyisocyanate composition having a content of components having a number average molecular weight of 600 or less and an average number of isocyanate groups within the above-mentioned ranges can be easily produced.

In the obtained polyisocyanate composition, it is preferable to mix a polyisocyanate having a number average molecular weight of 600 or less derived from an aliphatic polyisocyanate so that the content of the component having a number average molecular weight of 600 or less is 15% by mass or more based on the total mass of the composition.

The amount of polyisocyanate having a number average molecular weight of 600 or less is preferably 4% by mass or more and 50% by mass or less, more preferably 8% by mass or more and 43% by mass or less, still more preferably 12% by mass or more and 36% by mass or less, and particularly preferably 16% by mass or more and 30% by mass or less, based on the total mass of the polyisocyanates.

The polyisocyanate having a number average molecular weight of 650 or less preferably has a uretdione skeleton together with an isocyanurate skeleton for the purpose of reducing the molecular weight. From the viewpoint of productivity, it is preferable that after the isocyanuric acid esterification reaction is performed, the isocyanuric acid esterification catalyst is deactivated, and then heated at 140 ℃ to 170 ℃ for 1 hour to 3 hours to perform uretdionization.

The polyisocyanate having a number average molecular weight of 650 or less may or may not have a hydrophilic group in the polyisocyanate skeleton, and it is preferable not to have a hydrophilic group in order to keep the average number of isocyanate groups high.

Further, in the polyisocyanate composition of the present embodiment, for the purpose of forming a coating film having a high crosslinking density and improving corrosion resistance, it is preferable to mix the polyisocyanate X having an average number of isocyanate groups of less than 3.5 and the polyisocyanate Y having an average number of isocyanate groups of 3.5 or more. Among them, the average number of isocyanate groups of the polyisocyanate Y is more preferably 3.6 or more and 5.0 or less, and further preferably 3.7 or more and 4.5 or less.

The content of the polyisocyanate Y based on the total mass of the polyisocyanate X and the polyisocyanate Y is preferably 4% by mass or more and 50% by mass or less, more preferably 8% by mass or more and 43% by mass or less, still more preferably 12% by mass or more and 36% by mass or less, and particularly preferably 16% by mass or more and 30% by mass or less.

In the method for producing the polyisocyanate composition of the present embodiment, the ionic surfactant and the organic solvent may be added as necessary. The time of addition is not particularly limited, and may be added during or after synthesis of the polyisocyanate.

< Properties of polyisocyanate composition >

[ isocyanate group content ]

The lower limit of the isocyanate group content in 100% by mass of the solid content of the polyisocyanate composition of the present embodiment is preferably 5% by mass, more preferably 6% by mass, and still more preferably 7% by mass. On the other hand, the upper limit value of the isocyanate group content in 100% by mass of the solid content is preferably 25% by mass, more preferably 24% by mass, and still more preferably 23% by mass.

That is, the isocyanate group content of the polyisocyanate composition of the present embodiment is preferably 5% by mass or more and 25% by mass or less, more preferably 6% by mass or more and 24% by mass or less, and further preferably 7% by mass or more and 23% by mass or less.

When the content of the isocyanate group is in the above range, the curing rate when the polyisocyanate composition of the present embodiment is used as a curing agent or the toughness when the polyisocyanate composition is formed into a coating such as a coating film can be more effectively achieved. The isocyanate group content can be measured by the method described in examples described later.

[ number average molecular weight ]

The lower limit of the number average molecular weight of the polyisocyanate composition of the present embodiment is preferably 500, more preferably 600, and still more preferably 700. On the other hand, the upper limit of the number average molecular weight is preferably 5000, more preferably 3000, and still more preferably 2000.

That is, the number average molecular weight of the polyisocyanate composition of the present embodiment is preferably 500 or more and 5000 or less, more preferably 600 or more and 3000 or less, and further preferably 700 or more and 2000 or less.

By setting the number average molecular weight in the above range, the crosslinking property when the polyisocyanate composition of the present embodiment is used as a curing agent is further improved, and a viscosity which is easier to handle is formed. The number average molecular weight can be measured by gel permeation chromatography (hereinafter sometimes abbreviated as "GPC").

[ viscosity ]

The lower limit of the viscosity of the polyisocyanate composition of the present embodiment at 25 ℃ at 100 mass% of the solid content is preferably 100 mPas, more preferably 130 mPas, and still more preferably 150 mPas. On the other hand, the upper limit of the viscosity at 25 ℃ of 100 mass% of the solid content is preferably 50000 mPas, more preferably 25000 mPas, still more preferably 10000 mPas, and particularly preferably 5000 mPas.

That is, the viscosity of the polyisocyanate composition of the present embodiment at 25 ℃ is preferably 100mPa · s or more and 50000mPa · s or less, more preferably 130mPa · s or more and 25000mPa · s or less, further preferably 150mPa · s or more and 10000mPa · s or less, and particularly preferably 150mPa · s or more and 5000mPa · s or less.

By setting the viscosity at 25 ℃ in the above range, the polyisocyanate composition of the present embodiment can be made more dispersible in water, and the content of diisocyanate or organic solvent having low crosslinking ability can be further reduced. The viscosity can be measured by the method described in examples described later.

< uses of use >

The polyisocyanate composition of the present embodiment can be used as a raw material for, for example, a coating material, an ink, an adhesive, a casting material, an elastomer, a foam, a plastic material, or the like.

< coating composition >)

The coating composition of the present embodiment includes the above polyisocyanate composition.

The polyisocyanate composition can be suitably used as a curing agent for a coating composition.

The coating composition of the present embodiment can provide a coating film having excellent drying properties and corrosion resistance by including the polyisocyanate composition.

The coating composition is obtained by, for example, mixing a water-based polyol as a main component with the polyisocyanate composition as a curing agent component.

As the aqueous polyol used in the coating composition, all substances containing a hydroxyl group represented by latex, emulsion, dispersion, water-soluble resin are included. Specific examples of the aqueous polyol include: polyvinylidene chloride copolymers, polyvinyl chloride copolymers, vinyl acetate copolymers, water-soluble acrylic resins, water-soluble polyester resins, urethane dispersions, acrylic emulsions, fluorine copolymer emulsions, styrene butadiene copolymer latexes, acrylonitrile butadiene copolymers, rubber latexes, polybutadiene copolymers, urethane acrylic emulsions, and copolymers or mixtures thereof.

Among them, as the aqueous polyol, one which exhibits a latex, an emulsion or a dispersion is preferable because of excellent workability and water resistance. Among them, acrylic emulsions, fluorine copolymer emulsions, urethane dispersions, or polymers thereof are particularly preferable because they are particularly excellent in weatherability, gloss, and toughness when formed into a coating film.

In the case of using the aqueous polyol represented by a latex, an emulsion or a dispersion, the lower limit of the particle diameter thereof is preferably 5nm, more preferably 10nm, and still more preferably 40 nm. On the other hand, the upper limit of the particle size is preferably 1.0. mu.m, more preferably 500nm, and still more preferably 300 nm.

That is, the particle diameter is preferably 5nm or more and 1.0 μm or less, more preferably 10nm or more and 500nm or less, and still more preferably 40nm or more and 300nm or less.

By setting the particle diameter in the above range, the gloss of the coating film can be improved and the water resistance can be improved. In addition, the stability as a latex, emulsion or dispersion is also more sufficient.

The lower limit of the hydroxyl value of the aqueous polyol is preferably 1mgKOH/g, more preferably 5mgKOH/g, and still more preferably 10 mgKOH/g. On the other hand, the upper limit of the hydroxyl value is preferably 300mgKOH/g, more preferably 200mgKOH/g, and still more preferably 150 mgKOH/g.

That is, the hydroxyl value of the aqueous polyol is preferably 1mgKOH/g or more and 300mgKOH/g or less, more preferably 5mgKOH/g or more and 200mgKOH/g or less, and still more preferably 10mgKOH/g or more and 150mgKOH/g or less.

By setting the hydroxyl value of the aqueous polyol to the above range, the crosslinking point becomes more sufficient, and a softer and tougher coating film can be obtained.

In the coating composition of the present embodiment, the lower limit of the molar ratio of the isocyanate group of the polyisocyanate composition to the hydroxyl group of the aqueous polyol (isocyanate group/hydroxyl group) is preferably 0.5, more preferably 0.8, and still more preferably 1.0. On the other hand, the upper limit of the molar ratio is preferably 4.0, more preferably 3.0, and still more preferably 2.0.

That is, the molar ratio of the isocyanate group of the polyisocyanate composition to the hydroxyl group of the aqueous polyol (isocyanate group/hydroxyl group) is preferably 0.5 or more and 4.0 or less, more preferably 0.8 or more and 3.0 or less, and further preferably 1.0 or more and 2.0 or less.

By setting the molar ratio (isocyanate group/hydroxyl group) in the above range, crosslinking points are more sufficient, and a softer and tougher coating film can be obtained.

The coating composition of the present embodiment may further contain various known and conventional additives for coating materials, depending on the use, method of use, and the like of the polyisocyanate composition. Examples of the additive for coating materials include: thickening agent, leveling agent, thixotropic agent, defoaming agent, freeze stabilizer, delustering agent, crosslinking reaction catalyst, anti-skinning agent, dispersant, wetting agent, light stabilizer, antioxidant, ultraviolet absorber, filler, plasticizer, lubricant, reducing agent, preservative, antifungal agent, deodorant, anti-yellowing agent, antistatic agent, charge control agent, or the like. These additives may be appropriately selected and used within a range that does not interfere with the effects exerted by the polyisocyanate composition of the present embodiment.

The coating composition of the present embodiment (particularly, the water-based two-component polyurethane coating composition) is excellent in adhesion to a base material such as a metal, a plastic, or an old coating film. Further, the coating film obtained from the coating composition of the present embodiment is less likely to cause foaming (film swelling) when immersed in water.

Therefore, the polyisocyanate composition of the present embodiment can be used as a raw material for paints, inks, adhesives, casting materials, elastomers, foams, plastic materials, and the like.

Among them, the polyisocyanate composition of the present embodiment is suitable for a coating composition or an aqueous adhesive composition.

That is, in one embodiment, the present invention provides an aqueous adhesive composition containing the polyisocyanate composition.

Further, the coating composition can be used for architectural coatings, heavy duty anticorrosive coatings, automotive coatings, and home appliance coatings (particularly, coatings for information home appliances such as personal computers and mobile phones). In addition, the intermediate coating composition is particularly suitable for automobile bodies, metal parts for automobiles, plastic parts for automobiles, metal parts for information household appliances, or plastic parts for information household appliances.

< coating film >)

The coating film of the present embodiment is obtained by curing the coating composition.

The coating film of the present embodiment is obtained by curing the above coating composition, and therefore, it always exhibits stable quality and is excellent in drying property and corrosion resistance.

< method for producing coating film >

The method for producing a coating film of the present embodiment includes a step of curing the coating composition.

The coating film of the present embodiment can be produced by applying the coating composition to a substrate by a known coating method such as roll coating, curtain coating, spray coating, spin-cup coating, or electrostatic coating, and then curing the coating composition.

The substrate is not particularly limited, and examples thereof include a molded article obtained by molding a material such as metal (e.g., a steel sheet or a surface-treated steel sheet), plastic, wood, a film, or an inorganic material. The shape of these molded articles is not particularly limited, and may be a molded article having a small thickness such as a film, a sheet, or a plate, or a molded article having a large thickness such as a cylinder or a three-dimensional structure. Further, a hollow molded article such as a hose may be used.

Examples

Hereinafter, the present embodiment will be described in more detail by way of specific examples and comparative examples, but the present embodiment is not limited to the following examples and comparative examples at all, unless the gist of the present embodiment is exceeded.

< evaluation of physical Properties of polyisocyanate composition >

The polyisocyanate components obtained in the synthesis examples and the polyisocyanate compositions obtained in the examples and comparative examples were subjected to the following measurements and evaluations for various physical properties.

[ Property 1]

(viscosity)

The viscosity was measured at 25 ℃ using an E-type viscometer (manufactured by Tokimec inc.). A standard rotor (1 ° 34' xr 24) was used. The rotational speeds are as follows.

(rotational speed)

100r.p.m. (less than 128 mPa. s)

50r.p.m. (128 mPas or more and less than 256 mPas)

20r.p.m. (256 mPas or more and less than 640 mPas)

10r.p.m. (640 mPas or more and less than 1280 mPas)

5r.p.m. (1280 mPas or more and less than 2560 mPas)

2.5r.p.m. (2560 mPas or more and less than 5120 mPas)

[ Property 2]

(solid component)

The polyisocyanate composition was used as a sample, and in the case of solvent dilution, the mass of an aluminum cup was precisely measured (W0 g). About 1g of the sample was added, and the mass of the cup before heat drying (W1g) was accurately weighed. The cup containing the sample was heated in a drier at 105 ℃ for 3 hours. After cooling the heated cup to room temperature, the mass of the cup was accurately weighed again (W2 g). Using the accurately weighed masses, the mass% of the dry residue in the sample was calculated as a solid content according to the following formula.

Solid content (% by mass) of (W2-W0)/(W1-W0) × 100

[ Property 3]

(NCO content of polyisocyanate composition)

The NCO content (mass%) of the polyisocyanate composition was determined by neutralizing the isocyanate group in each isocyanate component with an excess of 2N amine and then back-titrating the resultant with 1N hydrochloric acid.

[ Property 4]

(HDI/IPDI ratio)

The mass ratio of the HDI-derived constituent unit to the IPDI-derived constituent unit (HDI/IPDI) in the polyisocyanate and the polyisocyanate composition was calculated using the method shown below. First, the molar ratio of HDI and IPDI per unit mass of polyisocyanate was calculated by pyrolysis GC/MS measurement under the measurement conditions shown below. Then, according to the HDI multiplied by the respective molar ratio: 168. IPDI: the value obtained at 222 calculates the mass ratio of the constituent elements.

(pyrolysis GC/MS measurement conditions)

A pyrolysis device: PY-2010D from Frontier Laboratories Ltd

Pyrolysis temperature: 600 deg.C

GC：HP-6890

A chromatographic column: DB-10.25 x 30m 0.25 μm

Temperature: heating at 50 deg.C (0min) -320 deg.C (3min) and 10 deg.C/min

MS：JEOL Automass II

[ Property 5]

(average number of isocyanate groups (Fn) of polyisocyanate composition)

The average number of isocyanate groups (Fn) of the polyisocyanate composition was determined using the following formula. In the formula, "Mn" represents a number average molecular weight.

Average number of isocyanate groups (Fn) ═ Mn X NCO content X0.01)/42

[ Property 6]

(content of component having number average molecular weight of 600 or less)

The number average molecular weight of the polyisocyanate composition was determined by GPC under the following measurement conditions based on polystyrene.

(measurement conditions)

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

A chromatographic column: "TSKgel SuperH 1000" (trade name). times.1, manufactured by Tosoh corporation

"TSKgel SuperH 2000" (trade name). times.1 root

"TSKgel SuperH 3000" (trade name). times.1 root

Liquid carrying: tetrahydrofuran (THF)

The detection method comprises the following steps: differential refractometer

Sample concentration: 5 wt/vol%

The detection method comprises the following steps: differential refractometer

Outflow volume: 0.6mL/min

Column temperature: 40 deg.C

Then, using the obtained molecular weights, the contents (mass%) of components having a number average molecular weight of 600 or less were determined from the following formula.

Content (mass%) of components having number average molecular weight of 600 or less

(mass of component having number average molecular weight of 600 or less)/(total mass of polyisocyanate composition) × 100

[ Property 7]

(average number of Ethylene Oxide (EO) repeating units (EO number))

The average number of Ethylene Oxide (EO) repeating units (EO number) introduced into the polyisocyanate composition was calculated by the following method. Specifically, the polyisocyanate composition was used as a sample and determined by proton Nuclear Magnetic Resonance (NMR) under the measurement conditions shown below. Here, the average number of ethylene oxide repeating units (EO number) in the polyisocyanate composition was determined by correlating the integrated value of the relative intensity corresponding to the alkylene group with the integrated value of the relative intensity corresponding to the alkyl group.

(measurement conditions)

NMR apparatus: bruker Biospin Avance600 (trade name)

And (3) observing a nucleus:¹H

frequency: 600MHz

Solvent: CDCl₃

Cumulative number of times: 256 times

[ evaluation 1]

(dispersibility in Water)

The emulsifiability of the polyisocyanate composition in water was measured for the 50% particle diameter by NANORAC UPA-EX150 (manufactured by NIGHT CORPORATION) and evaluated according to the following evaluation criteria.

(evaluation criteria)

O: the particle diameter is less than 200nm

X: particle size of 200nm or more

< evaluation of coating composition and coating film >

With respect to the polyisocyanate compositions obtained in examples and comparative examples, a water-based two-component type polyurethane coating composition was prepared according to the procedure shown below, and the service life was evaluated. Further, a coating film was prepared using the water-based two-component polyurethane coating composition, and the drying property and the corrosion resistance were evaluated.

[ preparation of Water-based two-component polyurethane coating composition ]

The polyisocyanate compositions obtained in examples and comparative examples were compounded with Setaqua6510 (trade name, acrylic polyol, solid content 42%, hydroxyl group 4.2% by mass, manufactured by ALLNEX NETHERLANDS b.v.) so that the ratio of functional groups (NCO/OH) was 1.4. Further, deionized water was added to the mixture so that the solid content was 40%, and the mixture was stirred at 1000rpm for 5 minutes using a dispersing blade to prepare a water-based two-component polyurethane coating composition.

[ evaluation 2]

(service life)

Each water-based two-component polyurethane coating composition was stored in an atmosphere of 23 ℃/50% RH for 6 hours. Next, the isocyanate group retention of the water-based two-component polyurethane coating composition after storage was calculated by using FT-IR4200 (manufactured by Nippon Seiko Co., Ltd.), and evaluated according to the following evaluation criteria. Calculate 2200cm^-1Relative to the height of 3000cm of isocyanate groups^-1The ratio of the heights of the alkyl groups in the vicinity was taken as the isocyanate group retention ratio.

(evaluation criteria)

Very good: the retention rate of isocyanate groups is 80% or more

O: the retention rate of isocyanate groups is more than 70% and less than 80%

And (delta): the retention rate of isocyanate groups is more than 60% and less than 70%

X: the retention rate of isocyanate groups is less than 60 percent

[ preparation of coating film for evaluation of drying Property ]

Using each aqueous two-component type polyurethane coating composition, a coating film having a thickness of about 30 μm or more and 50 μm or less was applied to various substrates (glass plates and mild steel), and dried in an atmosphere of 23 ℃/50% RH for 7 days to obtain a coating film.

[ evaluation 3]

(film drying Property)

The drying properties of the coating film formed on the glass plate were evaluated by a finger-touch drying property test every 0.5 hours until the coating film became tack-free.

(evaluation criteria)

Very good: within 5 hours

O: 5.5 hours or more and 6.5 hours or less

X: over 7 hours

[ evaluation 4]

(salt Water spray test (Corrosion resistance))

As a substrate, a polished steel sheet (150 mm. times.70 mm) of cold-rolled steel sheet prescribed in JIS K5600-1-4(SPCC) was used, and each of the aqueous two-component type polyurethane coating compositions thus prepared was applied as a coating film having a dry film thickness of 35. + -.5. mu.m, and dried in an atmosphere of 23 ℃/50% RH for 7 days to obtain a coated sheet. The resulting coated plate was cross-hatched in accordance with JIS K5600-7-1, and then tested under the measurement conditions shown below. The state of the coating film after the test was confirmed and evaluated according to the evaluation criteria shown below.

(measurement conditions)

The device comprises the following steps: STP-90V (trade name) (Suga Test Instruments Co., Ltd.)

Temperature: 35 +/-1 DEG C

Spraying liquid: 5% neutralizing saline (pH6.5 ~ 7.2)

Spraying time: 72 hours

(evaluation criteria)

Very good: without change

O: expansion is generated at a part of the lattice-defining portion

And (delta): rust and swelling on a part of the scribed part

X: rust and swelling on the whole of the scribed part

< Synthesis of polyisocyanate component >

[ Synthesis example 1]

(Synthesis of polyisocyanate component p-1)

The HDI is added in a nitrogen atmosphere in a four-neck flask provided with a stirrer, a thermometer, a reflux condenser tube, a nitrogen inlet tube and a dropping funnel: 1000g, 1, 3-butanediol: 36g, the temperature in the reactor was kept at 70 ℃ with stirring. 10% isobutanol to which was continuously added the isocyanurateing catalyst tetramethylammonium decanoate over 100 minutes: 1.0g, phosphoric acid was added to the reaction mixture at a point where the isocyanate content (NCO%) in the reaction mixture was 36.5% by mass, and the reaction was stopped. After the reaction solution was filtered, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate. Then, to the resulting polyisocyanate: 83.5g of polyethylene glycol monomethyl ether (product name: MPG-130, manufactured by Nippon emulsifier Co., Ltd.) having an average number of ethylene oxide repeating units of 9.4 was added: 15.0g, dioctyl sodium sulfosuccinate: 1.5g, 2-Methoxy-1-methylethyl acetate (1-Methoxy-2-propyl acetate; PGMEA): 42.9g was subjected to urethanization at 100 ℃ for 4 hours to give a polyisocyanate component p-1. The obtained polyisocyanate component p-1 was 70% by mass in solid content, 12.0% by mass in isocyanate group content, 800 mPas in viscosity, 3.7 in average number of isocyanate groups, 20% by mass in content of components having a number average molecular weight of 600 or less, and 9 EO numbers introduced into the polyisocyanate component. Further, the obtained polyisocyanate component p-1 had dispersibility in water.

[ Synthesis example 2]

(Synthesis of polyisocyanate component p-2)

HDI isocyanurate type polyisocyanate (DURANATE TPA-100, manufactured by Asahi Kasei K.K.) was reacted in a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel in a nitrogen atmosphere: 100g of IPDI isocyanurate type polyisocyanate (Vestanat T1890/100, manufactured by Evonik Industries): 300g and PGMEA: 125g of the mixture was mixed and stirred at 80 ℃ for 1 hour, thereby obtaining a uniform dissolved solution. To the homogeneous solution, methoxypolyethylene glycol (TN555, ethylene oxide repeating unit: 9, manufactured by Nippon emulsifier Co., Ltd.) and sodium dialkylsulfosuccinate (Newcol 290M, solid content 70 mass%, manufactured by Nippon emulsifier Co., Ltd.) were mixed in a solid content mass ratio of 3: the resulting composition mixed in the manner of 1: 51.4g of methoxypolyethylene glycol (MPG-081, ethylene oxide repeating unit: 15, manufactured by Nippon emulsifier Co., Ltd.): 48.6g, and 2-ethylhexyl acid phosphate (JP-508T, manufactured by Tokyo chemical industries, Ltd.): 0.04g, and urethanization was carried out at 110 ℃ for 6 hours. Finally, PGMEA was added to the reaction: 89.3g of this polyisocyanate component p-2 was obtained. The obtained polyisocyanate component p-2 was 70% by mass of the solid content, 9.2% by mass of the isocyanate group content, 370 mPas viscosity, average number of isocyanate groups 2.9, content of the component having a number average molecular weight of 600 or less was 1% by mass, and the number of EO introduced into the polyisocyanate component was 12. Further, the obtained polyisocyanate component p-2 had dispersibility in water.

[ Synthesis example 3]

(Synthesis of polyisocyanate component p-3)

The HDI is added in a nitrogen atmosphere in a four-neck flask provided with a stirrer, a thermometer, a reflux condenser tube, a nitrogen inlet tube and a dropping funnel: 6,000g and isobutanol: 7.0g, the temperature in the reactor was maintained at 80 ℃ for 2 hours with stirring. Subsequently, 5.0g of a solution prepared by diluting trimethyl-2-methyl-2-hydroxyethylammonium hydroxide, which is an isocyanurateing catalyst, with isobutanol to 5% by mass was added to conduct isocyanurateing. Then, phosphoric acid was added to the reaction mixture at a point at which the NCO content of the reaction mixture was 44.6 mass%, and the reaction was stopped. Subsequently, the reaction solution was further kept at 150 ℃ for 2 hours. After cooling the reaction solution, the reaction solution was filtered to remove precipitates, and then purified 2 times at 160 ℃ under 0.2Torr in a thin film evaporator, and then the obtained polyisocyanate was diluted to 70 mass% with PGMEA to obtain a polyisocyanate component p-3. The obtained polyisocyanate component p-3 was 70% by mass of the solid content, the content of isocyanate groups was 16.2% by mass, the viscosity was 45 mPas, the average number of isocyanate groups was 3.0, and the content of components having a number average molecular weight of 600 or less was 77% by mass. Further, the resulting polyisocyanate component p-3 does not have dispersibility in water.

[ Synthesis example 4]

(Synthesis of polyisocyanate component p-4)

HDI isocyanurate type polyisocyanate (DURANATE TKA-100, manufactured by Asahi Kasei K.K.) was added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube, and a dropping funnel in a nitrogen atmosphere: 100g of methoxypolyethylene glycol (SGG-06009, ethylene oxide repeating unit: 8, manufactured by Nippon emulsifier Co., Ltd.): 14.9g and JP-508T: 0.009g, PGMEA: 49.3g was subjected to urethanization at 110 ℃ for 6 hours under stirring to give a polyisocyanate component p-4. The obtained polyisocyanate component p-4 was 70% by mass of the solid content, 11.9% by mass of the isocyanate group content, 150 mPas in viscosity, 3.0 for the average number of isocyanate groups, 50% by mass of the component having a number average molecular weight of 600 or less, and 8 EO numbers introduced into the polyisocyanate component. Further, the obtained polyisocyanate component p-4 had dispersibility in water.

[ Synthesis example 5]

(Synthesis of polyisocyanate component p-5)

In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, a nitrogen atmosphere was changed to Vestanat T1890/100: 100.0g and PGMEA: 29.1g of the mixture was mixed and stirred at 80 ℃ for 1 hour, whereby a uniform dissolved solution was obtained. For the homogeneous solution, TN 555: 7.5g, MPG-081: 8.7g and JP-508T: 0.009g, 6 hours carbamation reaction at 110 ℃. Finally, PGMEA was added to the reaction solution: 20.8g, a polyisocyanate component p-5 was obtained. The obtained polyisocyanate component p-5 was 70% by mass of the solid content, 7.9% by mass of the isocyanate group content, 1170 mPas viscosity, average number of isocyanate groups 2.9, 1% by mass of the component having a number average molecular weight of 600 or less, and 12 EO numbers introduced into the polyisocyanate component. Further, the obtained polyisocyanate component p-5 had dispersibility in water.

[ Synthesis example 6]

(Synthesis of Hydroxyethanesulfonic acid/dimethylcyclohexylamine a-1)

To a 70 mass% aqueous solution of hydroxyethanesulfonic acid (HES): 20 parts by mass of 1-propanol: 10 parts by mass and stirred to obtain a solution. Further, a liquid obtained by weighing dimethylcyclohexylamine (hereinafter, sometimes abbreviated as "DMCHA") so that the molar equivalent ratio to HES is 1 and diluting the weighed dimethyl cyclohexylamine with the same mass part of 1-propanol was added dropwise to the solution while stirring. Stirring was stopped 1 hour after the start of the dropwise addition, and dehydration and solvent removal were carried out by an evaporator to obtain dimethylcyclohexylamine 2-hydroxyethanesulfonate (HES/DMCHA) a-1 having a solid content of 99.8 mass%.

Synthesis example 7 Synthesis of polyisocyanate component p-6

The HDI is added in a nitrogen atmosphere in a four-neck flask provided with a stirrer, a thermometer, a reflux condenser tube, a nitrogen inlet tube and a dropping funnel: 1000g, 1, 3-butanediol: 36g, the temperature in the reactor was kept at 70 ℃ with stirring. 10% isobutanol to which was continuously added the isocyanurateing catalyst tetramethylammonium decanoate over 100 minutes: 1.0g, phosphoric acid was added to the reaction mixture at a point where the isocyanate content (NCO%) in the reaction mixture was 36.5% by mass, and the reaction was stopped. After the reaction solution was filtered, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate. Then, to the resulting polyisocyanate: to 100g, HES/DMCHAa-1 obtained in Synthesis example 6 was added in such a manner that the molar equivalent ratio of isocyanate group/hydroxyl group was about 15: 8.0g, stirring for 3 hours at 120 ℃ under nitrogen and reflux to react, removing reflux, and stirring for 1 hour at 100 ℃ to continue the reaction. After the reaction is finished, cooling to 50 ℃, and finally adding PGMEA: 46.3g, a polyisocyanate component p-6 was obtained. The obtained polyisocyanate component p-6 was 70% by mass in solid content, 13.1% by mass in isocyanate group content, 750 mPas in viscosity, 4.2 in average number of isocyanate groups, and 20% by mass in content of components having a number average molecular weight of 600 or less. Further, the obtained polyisocyanate component p-6 had dispersibility in water.

Synthesis example 8 Synthesis of polyisocyanate component p-7

In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, a nitrogen atmosphere was changed to Vestanat T1890/100: 100.0g and PGMEA: 42.9g of the mixture was mixed, and the mixture was stirred at 80 ℃ for 1 hour, whereby a uniform dissolved solution was obtained. Then, the reaction mixture was cooled to obtain polyisocyanate component p-7. The obtained polyisocyanate component p-7 was 70% by mass of the solid content, 12.1% by mass of the isocyanate group content, 1170 mPas viscosity, 3.2 average number of isocyanate groups, and 1% by mass of the component having a number average molecular weight of 600 or less. Further, the obtained polyisocyanate component p-7 had no dispersibility in water.

< production of polyisocyanate composition >

[ example 1]

(production of polyisocyanate composition P-a 1)

The polyisocyanate component p-1 obtained in the above synthesis example was added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel in a nitrogen atmosphere: 400g, polyisocyanate component p-2: 300g and polyisocyanate component p-3: 300g, stirred at 40 ℃ for 1 hour to give a polyisocyanate composition P-a 1. The polyisocyanate composition P-a1 thus obtained had a solid content of 70% by mass, an isocyanate group content of 12.4% by mass, a viscosity of 400 mPas, an average number of isocyanate groups of 3.3, a content of components having a number average molecular weight of 600 or less of 31% by mass, and 8 EO numbers introduced into the polyisocyanate composition. Furthermore, the resulting polyisocyanate composition P-a1 has dispersibility in water.

[ example 2]

(production of polyisocyanate composition P-a 2)

The polyisocyanate component p-2 obtained in the above synthesis example was added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel in a nitrogen atmosphere: 500g and polyisocyanate component p-4: 500g, and stirred at 40 ℃ for 1 hour to synthesize a polyisocyanate composition P-a 2. The polyisocyanate composition P-a2 thus obtained had a solid content of 70% by mass, an isocyanate group content of 10.5% by mass, a viscosity of 250 mPas, an average number of isocyanate groups of 3.0, a content of components having a number average molecular weight of 600 or less of 26% by mass, and a number of EO groups introduced into the polyisocyanate composition of 10. Furthermore, the resulting polyisocyanate composition P-a2 has dispersibility in water.

[ example 3]

(production of polyisocyanate composition P-a 3)

The polyisocyanate component p-1 obtained in the above synthesis example was added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel in a nitrogen atmosphere: 250g, polyisocyanate component p-2: 500g and polyisocyanate component p-3: 250g, and stirred at 40 ℃ for 1 hour to synthesize a polyisocyanate composition P-a 3. The polyisocyanate composition P-a3 thus obtained had a solid content of 70% by mass, an isocyanate group content of 11.6% by mass, a viscosity of 300 mPas, an average number of isocyanate groups of 3.1, a content of components having a number average molecular weight of 600 or less of 25% by mass, and 8 EO numbers introduced into the polyisocyanate composition. Furthermore, the resulting polyisocyanate composition P-a3 has dispersibility in water.

[ example 4]

(production of polyisocyanate composition P-a 4)

The polyisocyanate component p-7 obtained in the above synthesis example was added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel in a nitrogen atmosphere: 400g, polyisocyanate component p-8: 300g and polyisocyanate component p-3: 300g, stirred at 40 ℃ for 1 hour to give a polyisocyanate composition P-a 4. The polyisocyanate composition P-a4 contained 70% by mass of the solid content, 13.7% by mass of the isocyanate group content, 380 mPas in viscosity, 3.4 as the average number of isocyanate groups, and 31% by mass of the component having a number average molecular weight of 600 or less. Furthermore, the resulting polyisocyanate composition P-a4 has dispersibility in water.

Comparative example 1

(production of polyisocyanate composition P-b 1)

The polyisocyanate component P-4 obtained in the synthesis example was used as the polyisocyanate composition P-b 1.

Comparative example 2

(production of polyisocyanate composition P-b 2)

The polyisocyanate component P-5 obtained in the synthesis example was used as the polyisocyanate composition P-b 2.

Comparative example 3

(production of polyisocyanate composition P-b 3)

The polyisocyanate component p-1 obtained in the above synthesis example was added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel in a nitrogen atmosphere: 500g and polyisocyanate component p-2: 500g, and stirred at 40 ℃ for 1 hour to synthesize a polyisocyanate composition P-b 3. The polyisocyanate composition P-b3 thus obtained had a solid content of 70% by mass, an isocyanate group content of 10.6% by mass, a viscosity of 550 mPas, an average number of isocyanate groups of 3.3, a content of components having a number average molecular weight of 600 or less of 11% by mass, and 11 EO numbers introduced into the polyisocyanate composition. Furthermore, the resulting polyisocyanate composition P-b3 has dispersibility in water.

Comparative example 4

(production of polyisocyanate composition P-b 4)

The polyisocyanate component p-1 obtained in the above synthesis example was added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel in a nitrogen atmosphere: 100g, polyisocyanate component p-2: 800g and polyisocyanate component p-3: 100g, and stirred at 40 ℃ for 1 hour to synthesize a polyisocyanate composition P-b 4. The polyisocyanate composition P-b4 thus obtained had a solid content of 70% by mass, an isocyanate group content of 10.2% by mass, a viscosity of 360 mPas, an average number of isocyanate groups of 3.0, a content of components having a number average molecular weight of 600 or less of 11% by mass, and a number of EO groups introduced into the polyisocyanate composition of 10. Furthermore, the resulting polyisocyanate composition P-b4 has dispersibility in water.

The polyisocyanate compositions obtained in examples and comparative examples were evaluated by the evaluation methods described above. The results are shown in table 1 below.

[ Table 1]

According to Table 1, the polyisocyanate compositions P-a1 to P-a4 (examples 1 to 4) derived from the components (a) to (c) and having a mass ratio (a)/(b) of 10/90 or more and 90/10 or less, an average number of isocyanate groups of 3.0 or more, and a content of components having a number average molecular weight of 600 or less of 15% by mass or more have dispersibility in water, and are excellent in service life when they are prepared into coating compositions, and drying properties and corrosion resistance when they are prepared into coating films.

Furthermore, the polyisocyanate compositions P-a1 to P-a3 (examples 1 to 3) using a nonionic hydrophilic compound (monofunctional polyalkylene oxide polyether alcohol) as component (c) exhibited particularly good service lives compared with the polyisocyanate composition P-a4 (example 4) using an anionic hydrophilic compound (sulfonic acid amine salt) as component (c).

Furthermore, the polyisocyanate compositions P-a2 and P-a3 (examples 2 and 3) having a mass ratio (a)/(b) of 63/37-65/35 (inclusive) exhibited particularly good drying properties when they were formed into coating films, as compared with the polyisocyanate compositions P-a1 and P-a4 (examples 1 and 4) having a mass ratio (a)/(b) of 80/20 (inclusive).

Furthermore, the polyisocyanate compositions P-a1, P-a3 and P-a4 (examples 1,3 and 4) having a mass ratio (a)/(b) of 65/35 or more exhibited particularly good corrosion resistance when they were formed into coating films, as compared with the polyisocyanate composition P-a2 (example 2) having a mass ratio (a)/(b) of 65/35 or less.

On the other hand, the polyisocyanate compositions P-b1 to P-b2 (comparative examples 1 to 2) having a mass ratio (a)/(b) of less than 10/90 or more than 90/10 and the polyisocyanate compositions P-b3 to P-b4 (comparative examples 3 to 4) having a content of the component having a number average molecular weight of 600 or less of less than 15% by mass were all excellent in drying property and corrosion resistance when no coating film was formed.

Industrial applicability

According to the polyisocyanate composition of the present embodiment, a polyisocyanate composition excellent in drying property and corrosion resistance when formed into a coating film can be provided. The polyisocyanate composition of the present embodiment can be used as a raw material for, for example, a coating material, an ink, an adhesive, a casting material, an elastomer, a foam, a plastic material, or the like. The coating composition of the present embodiment contains the polyisocyanate composition, and is suitable as a coating material for buildings, heavy duty anticorrosive, general industrial, automobiles, and home appliances.

Claims (5)

1. A polyisocyanate composition comprising a polyisocyanate derived from the following components (a) to (c):

(a) an aliphatic diisocyanate;

(b) an alicyclic diisocyanate;

(c) a hydrophilic compound having an active hydrogen group for reacting with an isocyanate group;

a mass ratio (a)/(b) of the component (a) to the component (b) is 10/90 or more and 90/10 or less,

an average number of isocyanate groups is 3.0 or more, and,

the content of the component having a number average molecular weight of 600 or less is 15% by mass or more relative to the total mass of the composition.

2. The polyisocyanate composition according to claim 1, wherein the (c) hydrophilic compound is a monofunctional polyalkylene oxide polyether alcohol having an average number of alkylene oxide-based repeating units of 7.0 or more and 20.0 or less.

3. The polyisocyanate composition according to claim 1 or 2, wherein the polyisocyanate contains polyisocyanate X having an average number of isocyanate groups of less than 3.5 and polyisocyanate Y having an average number of isocyanate groups of 3.5 or more.

4. A coating composition comprising the polyisocyanate composition of any one of claims 1 to 3.

5. A coating film obtained by curing the coating composition according to claim 4.