JP2020070440A - Polyisocyanate composition, coating composition and aqueous adhesive composition - Google Patents

Abstract

To provide a polyisocyanate composition excellent in a pot life when made into a coating composition and also excellent in hardness and water resistance when made into a coating film, while having emulsifiability to water and stability.SOLUTION: A polyisocyanate composition includes polyisocyanate derived from following components (a)-(c): (a) aliphatic diisocyanate; (b) alicyclic diisocyanate; and (c) monofunctional polyalkylene oxide polyether alcohol having a number of alkylene oxide repeating unit of 10.0-20.0. A mass ratio (a)/(b) of the component (a) to the component (b) is 1/99-30/70.SELECTED DRAWING: None

Description

  The present invention relates to a polyisocyanate composition, a coating composition and a water-based adhesive composition.

A polyisocyanate composition obtained from an aliphatic diisocyanate or an alicyclic diisocyanate is used as a curing agent component in a two-component polyurethane coating composition. Since the 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 coatings, inks, adhesives, etc. It is being appreciated.
In recent years, global environmental issues have become highly conscious, and water-based two-component polyurethane coating compositions that do not use an organic solvent or have a reduced amount of the organic solvent are used. Conventionally, a polyisocyanate composition in which a hydrophilic group having an isocyanate-reactive active hydrogen group such as polyalkylene oxide polyether alcohol is introduced into a polyisocyanate structure is used as a curing agent component of an aqueous two-component polyurethane coating composition. Has been.

In Patent Documents 1 to 3, a polyisocyanate composition obtained from an aliphatic diisocyanate and an alicyclic diisocyanate and having an emulsifying property, and an aqueous two-component polyurethane coating composition using the polyisocyanate composition as a curing agent component The thing is disclosed.
Patent Document 1 is a mixture of a hydrophilized polyisocyanate and a non-hydrophilized polyisocyanate, which has a number average of 10.6 to 15.4 ethylene oxide repeating units and is water-dispersible. Various polyisocyanate compositions are disclosed.
In Patent Document 2, a polyether chain having a number average of 9.0 ethylene oxide repeating units is introduced, and the content of the polyisocyanate obtained from the alicyclic polyisocyanate is 40% by mass of the entire polyisocyanate mixture. A polyisocyanate composition of 100% by mass or less is disclosed. It has been shown that the hardness of a coating film using the polyisocyanate composition as a curing agent component is improved.

JP-A-8-085716 JP, 10-130353, A Japanese Patent No. 4295218

However, a polyisocyanate obtained from an aliphatic diisocyanate as a main skeleton, a curing agent component consisting of a polyisocyanate composition having a hydrophilic group derived from polyalkylene oxide polyether alcohol introduced therein, and an aqueous dispersion of a polyol are mainly used. The coating composition obtained by mixing the main ingredient as an ingredient contains a large amount of the above-mentioned hydrophilic groups introduced to improve the emulsifying property in water. Therefore, the coating film obtained from the coating composition has a problem that the water resistance and the surface hardness are low.
In addition, in any of Patent Documents 1 to 3, the emulsification and stability of the polyisocyanate composition in water, and the water resistance when formed into a coating film have not been verified.

  The present invention has been made in view of the above circumstances, while having emulsification and stability in water, pot life when formed into a coating composition, and hardness and water resistance when formed into a coating film. Provided is a polyisocyanate composition having excellent properties. A coating composition and an adhesive composition using the polyisocyanate composition are provided.

That is, the present invention includes the following aspects.
The polyisocyanate composition according to the first aspect of the present invention is a polyisocyanate composition containing a polyisocyanate derived from the following components (a) to (c), wherein (a) an aliphatic diisocyanate; (b) Alicyclic diisocyanate; (c) monofunctional polyalkylene oxide polyether alcohol having an alkylene oxide repeating unit number of 10.0 or more and 20.0 or less; a mass ratio of the component (a) to the component (b) (a ) / (B) is 1/99 or more and 30/70 or less.
The polyisocyanate composition according to the first aspect may further include an organic solvent containing an ester having 7 or more carbon atoms.

The coating composition according to the second aspect of the present invention includes the polyisocyanate composition according to the first aspect.
The coating composition according to the second aspect may be for home information appliances or automobiles.
The coating composition according to the second aspect may be an intermediate coating for metal parts for information home appliances, plastic parts for information home appliances, car bodies, metal parts for cars or plastic parts for cars.

  The water-based adhesive composition according to the third aspect of the present invention includes the polyisocyanate composition according to the first aspect.

  According to the polyisocyanate composition of the above aspect, while having the emulsifying property and stability in water, the pot life when formed into a coating composition, and the polyisocyanate excellent in hardness and water resistance when formed into a coating film. A composition can be provided. The coating composition and the adhesive composition of the above aspect are excellent in pot life, and hardness and water resistance when formed into a coating film.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to this embodiment described below. The present invention can be appropriately modified and implemented within the scope of the gist.

In addition, in this specification, a "polyol" means a compound having two or more hydroxyl groups (-OH).
In the present specification, the “polyisocyanate” means a reaction product in which a plurality of monomer compounds (monomers) having one or more isocyanate groups (—NCO) are bound.

<< Polyisocyanate composition >>
The polyisocyanate composition of this embodiment contains a polyisocyanate derived from the following components (a) to (c).
(A) aliphatic diisocyanate;
(B) alicyclic diisocyanate;
(C) Monofunctional polyalkylene oxide polyether alcohol having an alkylene oxide repeating unit number of 10.0 or more and 20.0 or less

In the polyisocyanate composition of the present embodiment, the mass ratio (a) / (b) of the component (a) to the component (b) is 1/99 or more and 30/70 or less.
When the mass ratio (a) / (b) is in the above range, the pot life when formed into a coating composition and the hardness and the hardness when formed into a coating film while having emulsifying properties and stability in water. It is possible to provide a polyisocyanate composition having excellent water resistance.
The lower limit of the mass ratio (a) / (b) is that the smaller the mass ratio of the component (a) to the component (b) is, the more excellent the pot life in a coating composition and the hardness in a coating film are. , 1/99, preferably 5/95, more preferably 10/90. On the other hand, as for the upper limit value of the mass ratio (a) / (b), the larger the mass ratio of the component (a) to the component (b) is, the better the emulsifying property in water and the stability are. Since it is excellent in adhesiveness, it is 30/70, preferably 25/75, more preferably 20/80.
That is, the mass ratio (a) / (b) is 1/99 or more and 30/70 or less, preferably 5/95 or more and 25/75 or less, and more preferably 10/90 or more and 20/80 or less.

  Incidentally, in general, "pot life" is the time during which the composition as a coating composition, adhesive, etc. is prepared by mixing the main agent and the curing agent, and then the performance is ensured as the composition before curing. Means Also called pot life.

  Each component of the polyisocyanate composition of this embodiment will be described in detail below.

<Polyisocyanate>
The polyisocyanate contained in the polyisocyanate composition of the present embodiment is derived from the components (a) to (c), that is, the reaction product of the components (a) to (c). The polyisocyanate contained in the polyisocyanate composition of the present embodiment is a hydrophilic polyisocyanate in which a hydrophilic group (polyalkylene oxide unit) derived from the component (c) is introduced into at least a part of the polyisocyanate. is there.

In the present specification, "induction" includes prepolymerization reaction of component (a), prepolymerization reaction of component (b), addition reaction of prepolymer of component (a) and component (c), Addition reaction between the prepolymer of the component (b) and the component (c), addition reaction between the prepolymer of the component (a) and the component (b) and the component (c), the component (a) and the component (c). The polymerization reaction of the addition reaction of the mixture of b) with the component (c) is included.
"Prepolymerization reaction" and "polymerization reaction" include a reaction for producing a uretdione group obtained by cyclizing and dimerizing two isocyanate groups, and an isocyanurate obtained by cyclizing and trimerizing three isocyanate groups. Group or iminooxadiazinedione group forming reaction, 3 isocyanate group and biuret group obtained by reacting 1 water molecule, 2 isocyanate group reacting with 1 molecule of carbon dioxide Obtained by reacting one isocyanate group with one hydroxyl group to obtain a urethane group obtained with two isocyanate groups and one hydroxyl group To produce allophanate groups that are reacted with one isocyanate group and one carboxy group Reaction to produce are acylurea groups, reaction or the like to generate one isocyanate group and one primary or secondary amine and urea groups obtained by reacting the like. These may be used alone or in combination of two or more.
The addition reaction includes at least one reaction selected from the group consisting of a reaction forming the urethane group and a reaction forming the allophanate group.

[Component (a): Aliphatic diisocyanate]
The aliphatic diisocyanate is a diisocyanate compound having a saturated hydrocarbon group that does not contain a cyclic structure. Polyisocyanates derived from aliphatic diisocyanates tend to have low viscosities.
Examples of the aliphatic diisocyanate include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, ethyl (2,6-diisocyanato) hexanoate, 1,6-diisocyanatohexane (hereinafter, referred to as “HDI”). May be abbreviated), 1,9-diisocyanatononane, 1,12-diisocyanatododecane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, etc. Is mentioned. Among them, as the aliphatic diisocyanate, HDI is particularly preferable because it is industrially easily available and has excellent weather resistance and flexibility of the coating film.

[Component (b): alicyclic diisocyanate]
Alicyclic diisocyanates are diisocyanate compounds 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, "Hydrogenated MDI" may be abbreviated), 2,5- or 2,6-diisocyanatomethylnorbornane and the like. Among them, IPDI is preferable as the alicyclic diisocyanate because it is industrially easily available.
Hereinafter, the aliphatic diisocyanate and the alicyclic diisocyanate may be collectively referred to as “diisocyanate”.

[Component (c): monofunctional polyalkylene oxide polyether alcohol]
The monofunctional polyalkylene oxide polyether alcohol is a compound represented by the following general formula (I).

In the general formula (I), R ¹¹ is an alkyl group or an aryl group having 1 to 30 carbon atoms. R ¹² is an alkylene group having 1 to 5 carbon atoms. n11 is a number of 10.0 or more and 20.0 or less.

(R ¹¹ )
The carbon number of the alkyl group and the aryl group in R ¹¹ is 1 or more and 30 or less, and from the viewpoint of improving the hydrophilicity of the polyisocyanate, 1 or more and 20 or less is preferable, 1 or more and 15 or less is more preferable, and 1 or more and 12 The following is more preferable.
The alkyl group for R ¹¹ may be chain-like or cyclic. The chain alkyl group may be linear or branched. Examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group. , N-decyl group, n-undecyl group, n-dodecyl group and the like. Examples of the branched chain alkyl group include an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, and an isohexyl group. Examples of the cyclic alkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and the like.
Examples of the aryl group for R ¹¹ include a phenyl group, a naphthyl group, an anthranyl group, a phenanthryl group, and the like.
Further, the aryl group may have at least one hydrocarbon group selected from the group consisting of an alkyl group, an alkenyl group and an aryl group as a substituent. Examples of the aryl group having a substituent include a tolyl group, a xylyl group, a biphenyl group, a styryl group, a styrylphenyl group and the like.
Among them, R ¹¹ is preferably a chain alkyl group or an unsubstituted or substituted aryl group, more preferably a straight chain alkyl group, a phenyl group, a naphthyl group, a styryl group or a styrylphenyl group, and having 1 to 12 carbon atoms. The linear alkyl group of is more preferable, and the methyl group or the ethyl group is particularly preferable.

(R ¹² )
The alkylene group having 1 to 5 carbon atoms in R ¹² may be chain-like or cyclic. The chain alkylene group may be linear or branched. Examples of the linear alkylene group include methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group and the like. Examples of the branched alkylene group include 1-methylethylene group (propylene group), 1-methyltrimethylene group, 2-methyltrimethylene group, 1,1-dimethylethylene group, 1-methyltetramethylene group, 2 -Methyltetramethylene group and the like. Examples of the cyclic alkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group and the like.
Among them, R ¹² is preferably a chain alkylene group, more preferably a straight chain alkylene group, further preferably a straight chain alkylene group having 1 to 3 carbon atoms, 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 10.0 or more and 20.0 or less. n11 can be calculated using the method described in Examples described later.
The lower limit of n11 is 10.0, preferably 11.0, and more preferably 11.5. On the other hand, the upper limit of n11 is 20.0, preferably 17.0, and more preferably 15.0.
That is, n11 is 10.0 or more and 20.0 or less, preferably 11.0 or more and 17.0 or less, and more preferably 11.5 or more and 15.0 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.

  Examples of such monofunctional polyalkylene oxide polyether alcohols include polymethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether, polyethylene glycol monopropyl ether, polyethylene glycol monomethyl ether. Lauryl ether, polyethylene glycol phenyl ether, polyethylene glycol alkyl phenyl ether, polyethylene glycol phenyl phenyl ether, polyethylene glycol styryl phenyl ether, polyethylene glycol naphthyl ether, polyoxyethylene-oxypropylene (random and / or block ) Glycol monomethyl ether, polyoxyethylene-o Shi tetramethylene (at least one of polymerization mode of random and block) glycol polybutylene glycolate - monomethyl ether, and the like. Further, as the monofunctional polyalkylene oxide polyether alcohol, (mono-, di-, tri-, tetra- or penta) -styrenated phenyl group, mono (or di- or tri) styryl-methyl-phenyl group, tribenzylphenyl group, β -A nonionic surfactant having a group containing two or more aromatic rings such as a naphthyl group may be used. These monofunctional polyalkylene oxide polyether alcohols may be used alone or in combination of two or more.

The lower limit of the molecular weight of the monofunctional polyalkylene oxide polyether alcohol is preferably 150, more preferably 194, further preferably 216, and particularly preferably 238. On the other hand, the upper limit of the molecular weight is preferably 2500, more preferably 2000, even 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, further preferably 216 or more and 1000 or less, and particularly preferably 238 or more and 800 or less.
When the molecular weight is within the above range, the polyisocyanate composition of the present embodiment has better water dispersibility, lower crystallinity and easier handling.

In the polyisocyanate contained in the polyisocyanate composition of the present embodiment, the amount of the monofunctional polyalkylene oxide polyether alcohol introduced is such that the monofunctional polyalkylene oxide polyether alcohol is 100 equivalents of the isocyanate group of the polyisocyanate. It can be expressed as the ratio introduced.
The lower limit of the amount introduced is preferably 1% by mass, more preferably 2% by mass, further preferably 5% by mass, and particularly preferably 8% by mass. On the other hand, the upper limit of the amount introduced is preferably 80% by mass, more preferably 60% by mass, further preferably 40% by mass, and particularly preferably 15% by mass.
That is, the introduction amount of the monofunctional polyalkylene oxide polyether alcohol is preferably 1% by mass or more and 80% by mass or less, more preferably 2% by mass or more and 60% by mass or less, and further preferably 5% by mass or more and 40% by mass or less. , 8 mass% or more and 15 mass% or less are particularly preferable.
When the amount introduced is equal to or more than the above lower limit, the water dispersibility of the polyisocyanate composition of the present embodiment becomes higher, while the amount introduced is equal to or less than the above upper limit, an aqueous two-component polyurethane paint When used as a curing agent for the composition, the curability tends to be higher.
The introduced amount of the monofunctional polyalkylene oxide polyether alcohol can be calculated, for example, using the following method.
Specifically, using a polyisocyanate composition as a sample, a polyisocyanate that has not been introduced, a polyisocyanate in which one monofunctional polyalkylene oxide polyether alcohol is introduced, and two in which it is introduced at 220 nm in liquid chromatography (LC) It can be determined from the peak area ratio of the introduced polyisocyanate and the polyisocyanate of three or more introduced. Examples of measurement conditions by LC include the following.

(Measurement condition)
LC device: Waters Co., UPLC (trade name)
Column: ACQUITY UPLC HSS T3 1.8 μm manufactured by Waters
C18 inner diameter 2.1 mm x length 50 mm
Flow rate: 0.3 mL / min
Mobile phase: A = 10 mM ammonium acetate aqueous solution, B = acetonitrile Gradient conditions: Initial mobile phase composition was A / B = 98/2, the ratio of B was linearly increased after sample injection, and after 10 minutes, A / B B = 0/100.
Detection method: Photodiode array detector, measurement wavelength is 220 nm

The polyisocyanate composition of the present embodiment has good water dispersibility because the hydrophilic group (polyalkylene oxide unit) derived from the monofunctional polyalkylene oxide polyether alcohol is introduced.
In addition, in this specification, "water dispersibility" means the property which can be dispersed in water so that a polyisocyanate composition may be an O / W type. Water dispersibility, as shown in Examples described below, for example, by adding a polyisocyanate composition to water, by mechanically stirring using a rod or a hand mixer, to determine whether or not to disperse in water. It can be evaluated by checking. The "O / W type" here means an oil-in-water emulsion having water as a continuous phase.

<Other ingredients>
(Ionic surfactant)
The polyisocyanate composition of the present embodiment can further contain an ionic surfactant containing substantially no water, in addition to the above polyisocyanate.
By containing an ionic surfactant, the dispersion stability of the polyisocyanate oil droplets is significantly improved when dispersed in water, and it is possible to prevent water from entering the polyisocyanate oil droplets. it can. As a result, the pot life of the water-based two-component polyurethane coating composition can be significantly improved. Further, the particle size of the oil droplets of polyisocyanate is reduced, and the water resistance can be further improved.

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

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

  Suitable cationic surfactants are quaternary ammonium salts, pyridinium salts and imidazolinium salts. Specific compounds include, but are not limited to, C1-C20 alkyltrimethylammonium bromide, C1-C30 alkylpyridinium bromide, and imidazolinium laurate. More specific compounds include, for example, alkyltrimethylammonium bromide, alkylpyridinium bromide, imidazolinium laurate and the like.

(Organic solvent)
The polyisocyanate composition of this embodiment may further contain an organic solvent in addition to the above polyisocyanate.
By containing the organic solvent, the viscosity of the polyisocyanate composition is further lowered, so that the water dispersibility is further improved. In addition, the residual ratio of isocyanate groups when the polyisocyanate composition is dispersed in water becomes higher, and the pot life of the water-based two-component polyurethane coating composition tends to be further improved.

The organic solvent contained in the polyisocyanate composition of the present embodiment may be one 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, and polyethylene glycol dicarboxylate compounds. Examples of the ester compound include butyl acetate, isobutyl acetate, pentyl 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, methylisobutylketone, 2-heptanone, 4-heptanone, diisobutylketone, isophorone, cyclohexanone, and methylcyclohexanone. Examples of the aromatic compound include benzene, toluene, xylene, ethylbenzene, butylbenzene, p-cymene and the like. Examples of the polyethylene glycol dialkyl ether-based compound include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, diethylene glycol dibutyl ether, and the like. Examples of the polyethylene glycol dicarboxylate compound include diethylene glycol diacetate.
Among them, as the organic solvent, an organic solvent having a hydrocarbon group having 7 or more carbon atoms is preferable because the volatilization rate of the organic solvent is relatively slow and the leveling causes the appearance of the coating film surface to be further improved. In addition, as the organic solvent, an ester-containing organic solvent is more preferable because the compatibility with the water-based main agent is further improved. From these, as the organic solvent, an organic solvent containing an ester having 7 or more carbon atoms is more preferable, and an organic solvent consisting of only an ester having 7 or more carbon atoms is particularly preferable.

The lower limit of the content of the organic solvent in the polyisocyanate composition of the present embodiment is preferably 1% by mass, more preferably 3% by mass, and further preferably 5% by mass, based on 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, and further preferably 50% 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 with respect to the total mass of the polyisocyanate composition, and 3% by mass or more and 60% by mass. % Or less is more preferable, and 5% by mass or more and 50% by mass or less is further preferable.
When the content of the organic solvent is in the above range, the viscosity of the polyisocyanate composition becomes lower, the pot life when the water-based two-component polyurethane coating composition is further improved, and the content of the organic solvent. It is possible to more effectively suppress an excessive increase in the amount.

<Method for producing polyisocyanate composition>
The polyisocyanate composition of the present embodiment can be produced, for example, by the methods described in (i) to (iv) below.
(I) After performing the prepolymerization reaction of the component (a) and the prepolymerization reaction of the component (b), respectively, the prepolymer of the component (a) and the prepolymer of the component (b), and the component (c). The simultaneous addition reaction and polymerization reaction of
(Ii) The prepolymerization reaction of the component (a) and the prepolymerization reaction of the component (b) are respectively performed, and further, the addition reaction between the prepolymer of the component (a) and the component (c), and the component (b) A) each carrying out an addition reaction between the prepolymer and the component (c), and finally mixing them to carry out a polymerization reaction;
(Iii) A method in which the component (a) and the component (b) are simultaneously prepolymerized, and then the resulting mixed prepolymer and the component (c) are simultaneously added and polymerized.
(Iv) Method of simultaneously performing addition reaction and polymerization reaction of a mixture of component (a) and component (b) with component (c)

  Among them, as the method for producing the polyisocyanate composition of the present embodiment, it is easy to prepare the compounding ratio of the polyisocyanate derived from the component (a) and the polyisocyanate derived from the component (b), and The method (i) is preferable because it has good efficiency.

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

<Characteristics of polyisocyanate composition>
[Isocyanate group content]
The lower limit of the isocyanate group content of the polyisocyanate composition of the present embodiment is preferably 5% by mass, more preferably 6% by mass, and even more preferably 7% by mass. On the other hand, the upper limit of the isocyanate group content is preferably 25% by mass, more preferably 24% by mass, further 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 isocyanate group content is in the above range, the curing speed when the polyisocyanate composition of the present embodiment is used as a curing agent, or the toughness when used as a coating with a coating film is more effective. Can be achieved.

[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 700, and even more preferably 900. On the other hand, the upper limit of the number average molecular weight is preferably 10,000, more preferably 7,000, still more preferably 5,000.
That is, the number average molecular weight of the polyisocyanate composition of the present embodiment is preferably 500 or more and 10,000 or less, more preferably 700 or more and 7,000 or less, and further preferably 900 or more and 5000 or less.
When the number average molecular weight is within the above range, the crosslinkability when the polyisocyanate composition of the present embodiment is used as a curing agent is further improved, and the viscosity becomes easier to handle.

[viscosity]
The lower limit of the viscosity of the polyisocyanate composition of the present embodiment at 25 ° C. is preferably 100 mPa · s, more preferably 130 mPa · s, and even more preferably 150 mPa · s. On the other hand, the upper limit of the viscosity at 25 ° C. is preferably 40000 mPa · s, more preferably 20000 mPa · s, further preferably 10000 mPa · s, and particularly preferably 5000 mPa · s.
That is, the viscosity of the polyisocyanate composition of the present embodiment at 25 ° C. is preferably 100 mPa · s or more and 40000 mPa · s or less, more preferably 130 mPa · s or more and 20000 mPa · s or less, and further preferably 150 mPa · s or more and 10000 mPa · s or less. It is preferably 150 mPa · s or more and 5000 mPa · s or less.
When the viscosity at 25 ° C. is in the above range, the polyisocyanate composition of the present embodiment has better dispersibility in water, and the content of diisocyanate or organic solvent having a low crosslinking ability can be further reduced. it can.

<Use>
The polyisocyanate composition of this embodiment can be used as a curing agent for a coating composition (particularly, an aqueous two-component polyurethane coating composition).
That is, in one embodiment, the present invention provides a coating composition containing the above polyisocyanate composition.

  The coating composition can be obtained, for example, by mixing an aqueous polyol, which is a main component, and the above polyisocyanate composition, which is a curing agent component.

The water-based polyol used in the coating composition includes all those having a hydroxyl group and expressed as latex, emulsion, dispersion, and water-soluble resin. Specifically as the aqueous polyol, for example, polyvinylidene chloride copolymer, polyvinyl chloride copolymer, vinyl acetate copolymer, water-soluble acrylic resin, water-soluble polyester resin, urethane dispersion, acrylic emulsion, fluorine copolymer Examples thereof include a combined emulsion, a styrene-butadiene copolymer latex, an acrylonitrile-butadiene copolymer, a rubber latex, a polybutadiene copolymer, a urethane acrylic emulsion, and a copolymer or mixture thereof.
Among them, as the aqueous polyol, those expressed as latex, emulsion or dispersion are preferable because they are excellent in operability and water resistance. Among them, acrylic emulsions, fluorocopolymer emulsions, urethane dispersions or polymers thereof are particularly preferable because they are particularly excellent in weather resistance, gloss and toughness when formed into a coating film.
When an aqueous polyol expressed as latex, emulsion or dispersion is used, the lower limit value of the particle diameter thereof is preferably 5 nm, more preferably 10 nm, further preferably 40 nm. On the other hand, the upper limit value of the particle diameter is preferably 1.0 μm, more preferably 500 nm, further preferably 300 nm.
That is, the particle size is preferably 5 nm or more and 1.0 μm or less, more preferably 10 nm or more and 500 nm or less, and further preferably 40 nm or more and 300 nm or less.
When the particle diameter is in the above range, the gloss of the coating film is higher and the water resistance is more excellent. Further, the stability as a latex, emulsion or dispersion becomes more sufficient.

The lower limit of the hydroxyl value of the aqueous polyol is preferably 1 mgKOH / g, more preferably 5 mgKOH / g, and even more preferably 10 mgKOH / g. On the other hand, the upper limit of the hydroxyl value is preferably 300 mgKOH / g, more preferably 200 mgKOH / g, and even more preferably 150 mgKOH / g.
That is, the hydroxyl value of the aqueous polyol is preferably 1 mgKOH / g or more and 300 mgKOH / g or less, more preferably 5 mgKOH / g or more and 200 mgKOH / g or less, and further preferably 10 mgKOH / g or more and 150 mgKOH / g or less.
When the hydroxyl value of the aqueous polyol is in the above range, the crosslinking point becomes more sufficient, and a more flexible and tough 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 0.3, more preferably 0.5, .6 is more preferred. On the other hand, the upper limit of the molar ratio is preferably 5.0, more preferably 3.0, and even more preferably 2.5.
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 0.3 or more and 5.0 or less, more preferably 0.5 or more and 3.0 or less, and It is more preferably 0.6 or more and 2.5 or less.
When the molar ratio (isocyanate group / hydroxyl group) is in the above range, the crosslinking point becomes more sufficient, and a more flexible and tough coating film can be obtained.

  In addition to the above polyisocyanate composition, the coating composition of the present embodiment may contain various known and conventional additives for coatings, depending on the application and method of use. Examples of additives for paints include thickeners, leveling agents, thixotropic agents, antifoaming agents, freeze stabilizers, matting agents, crosslinking reaction catalysts, antiskinning agents, dispersants, wetting agents, light stabilizers. , Antioxidants, ultraviolet absorbers, fillers, plasticizers, lubricants, reducing agents, antiseptics, antifungal agents, deodorants, anti-yellowing agents, antistatic agents, charge control agents and the like. These additives can be appropriately selected and used within a range that does not impair the effects of the polyisocyanate composition of the present embodiment.

The coating composition of the present embodiment (particularly the water-based two-component polyurethane coating composition) has excellent adhesion to substrates such as metals, plastics, old coating films and the like. In addition, the coating film obtained from the coating composition of the present embodiment is less likely to cause blistering (coating 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 a water-based adhesive composition.
That is, in one embodiment, the present invention provides a water-based adhesive composition containing the above polyisocyanate composition.
In addition, the coating composition can be used in architectural coatings, heavy-duty anticorrosive coatings, automotive coatings, household appliances coatings (particularly, coatings for information household appliances such as personal computers and mobile phones). Further, it is particularly suitable as an intermediate coating for automobile bodies, automobile metal parts, automobile plastic parts, metal parts for information home appliances or plastic parts for information home appliances.

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

<Physical properties and evaluation of polyisocyanate composition>
Regarding the polyisocyanate compositions obtained in Examples and Comparative Examples, various physical properties and evaluations were measured and evaluated as follows.

[Physical Properties 1] Viscosity The viscosity was measured at 25 ° C. by an E-type viscometer (manufactured by Tokimec Co., Ltd.). A standard rotor (1 ° 34 'x R24) was used. The number of rotations is as follows.

(Number of rotations)
100r. p. m. (When less than 128 mPa · s)
50r. p. m. (When 128 mPa · s or more and less than 256 mPa · s)
20r. p. m. (When 256 mPa · s or more and less than 640 mPa · s)
10r. p. m. (When 640 mPa · s or more and less than 1280 mPa · s)
5r. p. m. (When 1280 mPa · s or more and less than 2560 mPa · s)
2.5 r. p. m. (When 2560 mPa · s or more and less than 5120 mPa · s)

[Physical Properties 2] Isocyanate Group Content Polyisocyanate composition: About 1 g or more and about 3 g or less was precisely weighed (Wg). Next, 20 mL of toluene was added to the polyisocyanate composition and dissolved. Then, 10 mL of a 2N toluene solution of di-n-butylamine was added to the toluene solution containing the polyisocyanate composition, and after mixing, the mixture was allowed to stand at room temperature for 15 minutes. Then, 70 mL of isopropyl alcohol was added to this mixed solution and mixed. This solution was titrated with a 1N hydrochloric acid solution (factor F) as an indicator, and the obtained titration value was defined as "V2 mL". The same operation was performed without using polyisocyanate, and the obtained titration value was defined as "V1 mL". The isocyanate group content of the polyisocyanate composition was calculated from the following formula (1) using these titrated values.

  Isocyanate group content (mass%) = (V1-V2) x F x 42 / (W x 1000) x 100 (1)

[Physical Properties 3] Solid Content When the polyisocyanate composition was used as a sample and diluted with a solvent, the mass of an aluminum cup was precisely weighed (W0 g). About 1 g of a sample was put into the cup and the weight of the cup before heating and drying was precisely weighed (W1 g). The cup containing the above sample was heated for 3 hours in a dryer at 105 ° C. After cooling the heated cup to room temperature, the mass of the cup was precisely weighed again (W2g). The mass% of the dry residue in the sample was calculated as the solid content from the following formula (2) using the respective precisely weighed masses.

  Solid content (mass%) = (W2-W0) / (W1-W0) x 100 (2)

[Physical Properties 4] Average number of ethylene oxide (EO) repeating units (EO number)
The average number (EO number) of ethylene oxide (EO) repeating units introduced into the polyisocyanate composition was calculated by the following method. Specifically, the polyisocyanate composition was used as a sample and was determined by proton nuclear magnetic resonance (NMR) under the following measurement conditions. Here, the average number (EO number) of ethylene oxide repeating units in the polyisocyanate composition was obtained by associating the integral value of the relative intensity corresponding to the alkylene group with the integral value of the relative intensity corresponding to the alkyl group. ..

(Measurement condition)
NMR device: Bruker Biospin Avance 600 (trade name)
Observation nucleus: 1H
Frequency: 600MHz
Solvent: CDCl ₃
Total number of times: 256 times

[Evaluation 1] Emulsification in water Regarding the emulsification in water of the polyisocyanate composition, 50% particle diameter was measured by Nanotrac UPA-EX150 (manufactured by Nikkiso Co., Ltd.) and evaluated according to the following evaluation criteria.

(Evaluation criteria)
A: Particle size less than 100 nm B: Particle size 100 nm or more and less than 200 nm X: Particle size 200 nm or more

[Evaluation 2] Single Appearance of Polyisocyanate Composition In order to evaluate the stability of the polyisocyanate composition itself, the appearance of a synthetic polyisocyanate composition having a solid content of 90% or more and 100% or less is visually observed and It was evaluated according to the evaluation criteria.

(Evaluation criteria)
○: Transparent and no turbidity ×: Turbidity

<Evaluation of coating composition and coating film>
With respect to the polyisocyanate compositions obtained in Examples and Comparative Examples, an aqueous two-component polyurethane coating composition was prepared according to the following procedure, and pot life was evaluated. Further, a coating film was prepared using the water-based two-component polyurethane coating composition, and the hardness, adhesion and water resistance were evaluated.

[Preparation of water-based two-component polyurethane coating composition]
For the polyisocyanate compositions obtained in Examples and Comparative Examples, Setaqua 6510 (trade name, acrylic polyol, solid content 42%, hydroxyl group 4.2% by mass, manufactured by Allnex Co.) was used as a functional group ratio (NCO / OH) = It was blended so as to be 1.25. Furthermore, deionized water was added to this mixture so that the solid content was 40%, and the mixture was stirred at 1000 rpm for 5 minutes using a disper blade to prepare an aqueous two-component polyurethane coating composition.

[Evaluation 3] Pot life Each aqueous two-component polyurethane coating composition was stored for 5 hours in an atmosphere of 23 ° C / 50% RH. Next, the isocyanate retention rate of the water-based two-component polyurethane coating composition after storage was calculated using FT-IR4200 (manufactured by JASCO Corporation), and evaluated according to the following evaluation criteria. The ratio of the height of the isocyanate group at 2200 cm ^-1 to the height of the alkyl group near 3000 cm ^-1 was calculated as the isocyanate retention rate.

(Evaluation criteria)
◯: Isocyanate retention rate is 84% or more ×: Isocyanate retention rate is less than 84%

[Preparation of coating film]
Using each water-based two-component polyurethane coating composition, a coating film having a thickness of 30 μm or more and 50 μm or less is coated on various substrates (glass plate and mild steel) and baked at 100 ° C. for 30 minutes to obtain a cured coating film. It was The cured coating film was dried for 4 days in an atmosphere of 23 ° C./50% RH to obtain a coating film.

[Evaluation 4] König hardness The König hardness of the coating film formed on the glass plate was measured at 23 ° C. by a fully automatic pendulum hardness tester manufactured by TQC and evaluated according to the following evaluation criteria.

(Evaluation criteria)
○: 135 times or more △: 125 times or more but less than 135 times ×: less than 125 times

[Evaluation 5] Adhesion An adhesion test of a coating film formed on mild steel was performed according to JIS K5600-5-6, and evaluated according to the following evaluation criteria.

(Evaluation criteria)
◯: Peeling coating film, no floating X: Peeling coating film

[Evaluation 6] A rubber ring was placed on the coating film prepared on the water-resistant glass plate, and deionized water was added dropwise to the central portion. After soaking at 23 ° C. for 24 hours, the state of the blister generated between the glass substrate / coating film was evaluated according to the following evaluation criteria.

(Evaluation criteria)
○: No blister swelling ×: With blister swelling

<Production of polyisocyanate composition>
The polyisocyanate compositions produced in Examples and Comparative Examples were produced according to the following synthetic procedure. Moreover, the measurement results and evaluation results of the physical properties of each polyisocyanate composition P-1a to P-6a and P-1b to P-7b, and the evaluation of the coating composition and the coating film obtained from each polyisocyanate composition The results are shown in Tables 1 and 2.

[Example 1] Production of polyisocyanate composition P-1a The inside of a four-necked flask equipped with a stirrer, thermometer, and cooling tube was replaced with nitrogen, and HDI isocyanurate type polyisocyanate (Duranate TKA-100, Asahi Kasei Corporation) (Manufactured by the company): 100 parts by mass, IPDI isocyanurate type polyisocyanate (Vestanat T1890 / 100, manufactured by Evonik): 233.3 parts by mass, and propylene glycol 1-monomethyl ether 2-acetate (1-Methoxy-2-propoxyl). Acetate; PGMEA): 96.9 parts by mass were mixed and stirred at 80 ° C. for 1 hour to obtain a uniform solution. Methoxypolyethylene glycol (MPG-130, ethylene oxide repeating unit: 9 pieces, manufactured by Nippon Emulsifier Co., Ltd.): 35.3 parts by mass, and methoxypolyethylene glycol (MPG-081, ethylene oxide repeating unit: 15 pieces, manufactured by Nippon Emulsifier Co., Ltd.): 19.0 parts by mass, and 2-ethylhexyl acid phosphate (JP-508T, manufactured by Johoku Chemical Industry Co., Ltd.): 0.05 g were mixed, and a urethanization reaction was performed at 110 ° C. for 6 hours. I went. Lastly, 69.2 parts by mass of PGMEA was added to the reaction solution to obtain a polyisocyanate composition P-1a. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 9.3 mass% and a viscosity of 450 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Example 2] Production of polyisocyanate composition P-2a The inside of a four-necked flask equipped with a stirrer, a thermometer, and a cooling tube was replaced with nitrogen, and HDI isocyanurate type polyisocyanate (Duranate TPA-100, Asahi Kasei Corporation) (Manufactured by the company): 100 parts by mass, Vestanat T1890 / 100: 300 parts by mass, and PGMEA: 125 parts by mass were mixed and stirred at 80 ° C. for 1 hour to obtain a uniform solution. Composition: 51 in which MPG-130 and sodium dialkylsulfosuccinate (Newcol 290M, solid content 70%, manufactured by Nippon Emulsifier Co., Ltd.) were mixed into this homogeneous solution at a solid content mass ratio of 3: 1. 0.4 parts by mass, MPG-081: 48.6 parts by mass, and JP-508T: 0.04 g were mixed, and a urethanization reaction was performed at 110 ° C. for 6 hours. Finally, 89.3 parts by mass of PGMEA was added to the reaction solution to obtain a polyisocyanate composition P-2a. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 9.2 mass% and a viscosity of 370 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Example 3] Production of polyisocyanate composition P-3a Vestanat T1890 / 100: 400 parts by mass, MPG-130: 37.7 parts by mass, and MPG-081: 43.7 parts by mass were changed to PGMEA. Instead, polyisocyanate composition P-3a was produced under the same conditions as in Example 1, except that butyl propionate: 249.1 parts by mass was used. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 10.0 mass% and a viscosity of 190 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Example 4] Production of polyisocyanate composition P-4a Vestanat T1890 / 100: changed to 300 parts by mass and PGMEA: 179.4 parts by mass, and M-1000 (ethylene oxide repeating unit: 22 pieces, manufactured by NOF CORPORATION): 47.2 parts by mass, and MPG-081: 17.9 parts by mass except that the polyisocyanate composition P-4a was produced under the same conditions as in Example 1. did. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 9.4 mass% and a viscosity of 650 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Example 5] Production of polyisocyanate composition P-5a Vestanat T1890 / 100: 566.7 parts by mass and PGMEA: 332.2 parts by mass, and M-1000: 40.2 as methoxypolyethylene glycol. Polyisocyanate composition P-5a was manufactured on the same conditions as Example 1 except having used mass part and MPG-081: 68.4 mass part. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 7.6 mass% and a viscosity of 1700 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Example 6] Production of polyisocyanate composition P-6a Vestanat T1890 / 100: 1900 parts by mass, and PGMEA: 996.7 parts by mass, and as methoxypolyethylene glycol, MPG-081: 325.6 parts by mass. Polyisocyanate composition P-6a was produced under the same conditions as in Example 1 except that was used. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 8.7% by mass and a viscosity of 880 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Comparative Example 1] Production of polyisocyanate composition P-1b The inside of a four-necked flask equipped with a stirrer, a thermometer, and a cooling tube was replaced with nitrogen, and Duranate TKA-100: 100 parts by mass, and PGMEA: 20. 0.1 parts by mass was mixed and stirred at 80 ° C. for 1 hour to obtain a uniform solution. To this homogeneous solution, methoxypolyethylene glycol (M-400, ethylene oxide repeating unit: 8.4, manufactured by NOF CORPORATION): 14.9 parts by mass, and JP-508T: 0.009 g were mixed, Urethane reaction was carried out at 110 ° C. for 6 hours. Finally, PGMEA: 14.4 mass parts was added to the reaction liquid, and the polyisocyanate composition P-1b was obtained. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 11.9 mass% and a viscosity of 150 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Comparative Example 2] Production of polyisocyanate composition P-2b Vestanat T1890 / 100: 42.9 parts by mass, and PGMEA: changed to 71.2 parts by mass, and MPG-130: 10.8 as methoxypolyethylene glycol. Polyisocyanate composition P-2b was produced under the same conditions as in Example 1 except that parts by mass and MPG-081: 12.5 parts by mass were used. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 10.6 mass% and a viscosity of 200 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Comparative Example 3] Production of polyisocyanate composition P-3b Vestanat T1890 / 100: 150.0 parts by mass, and PGMEA: changed to 124.6 parts by mass, and MPG-081: 40.7 as methoxypolyethylene glycol. Polyisocyanate composition P-3b was produced under the same conditions as in Example 1 except that parts by mass were used. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 10.3% by mass and a viscosity of 270 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Comparative Example 4] Production of polyisocyanate composition P-4b Vestanat T1890 / 100: 400.0 parts by mass, and PGMEA: 224.3 parts by mass, and MPG-130: 81.4 as methoxypolyethylene glycol. Polyisocyanate composition P-4b was produced under the same conditions as in Example 1 except that parts by mass were used. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 8.6% by mass and a viscosity of 1050 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Comparative Example 5] Production of polyisocyanate composition P-5b The interior of a four-necked flask equipped with a stirrer, a thermometer, and a cooling tube was replaced with nitrogen, and Vestanat T1890 / 100: 100.0 parts by mass, and PGMEA. : 29.1 parts by mass were mixed and stirred at 80 ° C. for 1 hour to obtain a uniform solution. MPG-130: 7.5 parts by mass, MPG-081: 8.7 parts by mass, and JP-508T: 0.009 g were mixed with this homogeneous solution, and a urethanization reaction was carried out at 110 ° C. for 6 hours. .. Finally, PGMEA: 20.8 mass parts was added to the reaction liquid, and polyisocyanate composition P-5b was obtained. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 7.9 mass% and a viscosity of 1170 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Comparative Example 6] Production of polyisocyanate composition P-6b Vestanat T1890 / 100: 42.9 parts by mass and PGMEA: 64.1 parts by mass, and M-1000: 16.9 as methoxypolyethylene glycol. Polyisocyanate composition P-6b was produced under the same conditions as in Example 1 except that parts by mass and MPG-081: 6.4 parts by mass were used. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 10.2% by mass and a viscosity of 250 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

[Comparative Example 7] Production of polyisocyanate composition P-7b Vestanat T1890 / 100: 66.7 parts by weight and PGMEA: 74.8 parts by weight, and M-1000: 27.1 parts by weight as methoxypolyethylene glycol. Polyisocyanate composition P-7b was produced under the same conditions as in Example 1 except that parts were used. The obtained polyisocyanate composition was a pale yellow liquid, had an isocyanate group content of 10.4 mass% and a viscosity of 200 mPa · s. The obtained polyisocyanate composition had dispersibility in water.

From Table 1 and Table 2, polyisocyanate compositions P-1a to P-6a derived from the components (a) to (c) and having a mass ratio (a) / (b) of 1/99 or more and 30/70 or less. (Examples 1 to 6) had emulsifiability and stability in water, and had excellent pot life when used as a coating composition, and hardness and water resistance when used as a coating film.
In addition, the polyisocyanate compositions P-1a to P-5a (Examples 1 to 5) in which the mass ratio (a) / (b) is more than 5/95 and 30/70 or less have mass ratios (a) / (b). ) Was 5/95, the adhesiveness when formed into a coating film was particularly good as compared with the polyisocyanate composition P-6a (Example 6).

On the other hand, polyisocyanate compositions P-1b to P-3b and P-5b to P-7b having a mass ratio (a) / (b) of less than 1/99 or more than 30/70 (Comparative Examples 1 to 3 and In Nos. 5 to 7), the emulsifiability and stability in water, the pot life when used as a coating composition, and the hardness and water resistance when used as a coating film were not all satisfactory.
Further, in the polyisocyanate composition P-4b (Comparative Example 4) in which the mass ratio (a) / (b) is 1/99 or more and 30/70 or less, but the EO number is less than 10.0, the The emulsifying property and stability, and the hardness and water resistance of the coating film were good, but the pot life of the coating composition was poor.

  According to the polyisocyanate composition of the present embodiment, while having the emulsifying property and stability in water, the pot life of the coating composition, and the hardness and water resistance of the coating film are excellent. An isocyanate composition can be provided. The polyisocyanate composition of this embodiment can be used as a raw material for paints, inks, adhesives, casting materials, elastomers, foams, plastic materials, and the like. The coating composition of the present embodiment is suitable as a coating for construction, heavy corrosion protection, automobiles, home appliances (particularly for information home appliances such as personal computers and mobile phones).

Claims (6)

A polyisocyanate composition comprising a polyisocyanate derived from the following components (a) to (c):
(A) aliphatic diisocyanate;
(B) alicyclic diisocyanate;
(C) a monofunctional polyalkylene oxide polyether alcohol having an alkylene oxide repeating unit number of 10.0 or more and 20.0 or less;
A polyisocyanate composition in which a mass ratio (a) / (b) of the component (a) to the component (b) is 1/99 or more and 30/70 or less.   The polyisocyanate composition according to claim 1, further comprising an organic solvent containing an ester having 7 or more carbon atoms.   A coating composition comprising the polyisocyanate composition according to claim 1 or 2.   The coating composition according to claim 3, which is used for information home appliances or automobiles.   The coating composition according to claim 3 or 4 for intermediate coating of metal parts for information home appliances, plastic parts for information home appliances, car bodies, metal parts for cars or plastic parts for cars.   A water-based adhesive composition containing the polyisocyanate composition according to claim 1.