WO2018070533A1 - Polyisocyanate composition, coating composition, and coating film - Google Patents

Abstract

This polyisocyanate composition in which the average number of isocyanate groups is not less than 3.1 but less than 20, and the ratio (Vp/Vh) of a reaction speed (Vp) between the polyisocyanate composition and a primary alcohol with respect to the reaction speed (Vh) between a polyisocyanate derived from hexamethylene diisocyanate and a primary alcohol is not lower than 4 but lower than 300, exhibits excellent drying properties, provides excellent bubbling resistance and sagging resistance to a coating liquid, and provides excellent yellowing resistance to a coating film.

Description

Polyisocyanate composition, coating composition, and coating film

The present invention relates to a polyisocyanate composition, a coating composition, and a coating film.
This application claims priority based on Japanese Patent Application No. 2016-203112 for which it applied to Japan on October 14, 2016, and uses the content here.

Conventionally, a urethane coating film formed from a polyurethane coating has excellent flexibility, chemical resistance, and contamination resistance, and is represented by hexamethylene diisocyanate (hereinafter also referred to as HDI). A coating film using a non-yellowing polyisocyanate obtained from an aliphatic diisocyanate as a curing agent is further excellent in weather resistance, and its demand is increasing.
2. Description of the Related Art In recent years, technological development for reducing the viscosity of polyisocyanates used as curing agents has been actively carried out due to an increase in global environmental protection. This is because the amount of the organic solvent used in the coating composition can be reduced by reducing the viscosity of the polyisocyanate (Patent Documents 1 and 2).
In order to solve the above problems, a technique for maintaining the number of functional groups of isocyanate groups and reducing the viscosity is disclosed (Patent Document 3).
In order to solve these problems, a low-viscosity triisocyanate compound alone (Patent Documents 4-6) or a technique for converting a part of these triisocyanate compounds to isocyanurate (Patent Document 7) is disclosed. When these are used, those satisfying low viscosity and a certain degree of drying are obtained.
Moreover, the technique (patent document 8) using diphenylmethane diisocyanate as an isocyanate group which shows high reactivity is disclosed, and what shows very excellent drying property is obtained.

Japanese Patent Laid-Open No. 05-222007 Japanese Patent No. 3055197 Japanese Patent No. 5178200 Japanese Examined Patent Publication No. 63-15264 JP-A-53-135931 Japanese Patent Laid-Open No. 60-44561 Japanese Patent Application Laid-Open No. 10-87782 Japanese Patent Publication No. 63-35673

However, when the polyisocyanate disclosed in Patent Documents 1 and 2 is used, there is a problem that the drying property is lowered due to a decrease in the number of functional groups of the isocyanate group.
Further, in the polyisocyanate disclosed in Patent Document 3, further reduction in viscosity has been desired.
Even in the triisocyanates and polyisocyanates disclosed in Patent Documents 4 to 7, it is difficult to simultaneously solve the demands for lowering the viscosity and drying properties, and in particular, there is a problem of low sagging resistance.
Furthermore, the polyisocyanate disclosed in Patent Document 8 has a problem that the coating film is yellowed over time, and further has a problem of low resistance to cracking. “Wackiness” means a phenomenon in which small foamy blisters or holes are formed when a coating film is cured or dried.
This invention is made | formed in view of the said situation, Comprising: It aims at providing the polyisocyanate which is excellent in drying property, resistance of a coating liquid, sagging resistance of a coating liquid, and coating yellowing resistance.

As a result of intensive studies, the present inventors have found that a polyisocyanate composition having a specific structure can achieve the above-mentioned problems, and have come to achieve the present invention.
That is, the present invention is as follows.

[1] Reaction of polyisocyanate composition and primary alcohol with respect to reaction rate (Vh) of polyisocyanate derived from hexamethylene diisocyanate and primary alcohol having an average number of isocyanate groups of 3.1 or more and less than 20 A polyisocyanate composition having a ratio of velocity (Vp) (Vp / Vh) of 4 or more and less than 300.
[2] Polyisocyanate composition according to [1], having a viscosity at 25 ° C. of 30 mPa · s or more and less than 3000 mPa · s [3] Isocyanurate structure, allophanate structure, iminodioxadiazinedione structure, and burette structure The isocyanate composition according to [1] or [2], comprising at least one selected from the group consisting of:
[4] The composition according to any one of [1] to [3], comprising a polyisocyanate compound obtained from a triisocyanate represented by the following general formula (I) and / or a diisocyanate represented by the following general formula (II): Polyisocyanate composition.

In the general formula (I), a plurality of Y ¹¹ are each independently a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain an ester structure and / or an ether structure. The plurality of Y ¹¹ may be the same or different. However, at least one of the plurality of Y ¹¹ includes an ester structure. R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms.

OCN-Y ²¹ -NCO (II)
In the general formula (II), Y ²¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms including an ester structure.
[5] The triisocyanate represented by the following general formula (I) -1 and / or the diisocyanate represented by the following general formula (II) -1 further includes [1] to [4] Polyisocyanate composition.

In the general formula (I) -1, a plurality of Y ¹² are each independently a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain an ester structure and / or an ether structure. The plurality of Y ¹² may be the same or different. R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms.

OCN-Y ²² -NCO (II) -1
In general formula (II) -1, Y ²² is a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain an ester structure.
[6] A coating composition comprising the polyisocyanate composition according to any one of [1] to [5] and a polyol.
[7] A coating film obtained by curing the coating composition according to [6].

According to the present invention, it is possible to provide a polyisocyanate composition that is excellent in drying property, resistance to coating liquid, sagging resistance of coating liquid, and yellowing resistance to coating film.

Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof.

In this specification, “polyisocyanate” refers to a polymer in which a plurality of monomers having one or more isocyanate groups (—NCO) are bonded.
In this specification, “polyol” refers to a compound having two or more hydroxy groups (—OH).

<Polyisocyanate composition>
The polyisocyanate composition of this embodiment has an isocyanate group average number of 3.1 or more and less than 20, and is a polyisocyanate composition with respect to the reaction rate (Vh) of a polyisocyanate derived from hexamethylene diisocyanate and a primary alcohol. The ratio (Vp / Vh) of the reaction rate (Vp) between the primary alcohol and the primary alcohol is 4 or more and less than 300.
From the viewpoint of the drying property and sagging resistance of the coating film, the above (Vp / Vh) is preferably 4.5 or more, and more preferably 5 or more. Moreover, from the viewpoint of the usable time of the paint and the resistance to cracking, the above (Vp / Vh) is preferably less than 100, and more preferably less than 20.

The reaction rate (Vp) between the polyisocyanate composition and the primary alcohol is measured by the following method.
The polyisocyanate composition is mixed so that the molar ratio of NCO groups to OH groups of the primary alcohol is 1, and heated and stirred at 70 ° C., the residual ratio of NCO groups is measured, and the rate of decrease is the reaction rate (Vp). And The residual ratio of NCO groups can be determined by measuring the NCO content.
Similarly, the reaction rate (Vh) between a polyisocyanate derived from hexamethylene diisocyanate and a primary alcohol is also measured by the following method.
Mix so that the molar ratio of NCO group of polyisocyanate derived from hexamethylene diisocyanate to OH group of primary alcohol is 1, stir at 70 ° C, measure the residual ratio of NCO group, The reaction rate (Vh) is used. The residual ratio of NCO groups can be determined by measuring the NCO content.
Examples of the primary alcohol include 1-butanol, iso-butanol, 2-ethylhexanol and the like. As the polyisocyanate derived from hexamethylene diisocyanate, trade names “Duranate TKA-100” and “Duranate TPA-100” manufactured by Asahi Kasei are used.

The average number of isocyanate groups in the polyisocyanate composition of the present embodiment is 3.1 or more and less than 20. From the viewpoint of sagging resistance of the coating film, it is preferably 3.5 or more, more preferably 3.8 or more, particularly preferably 4 or more, and particularly preferably 5 or more. Moreover, from a viewpoint of making workability | operativity favorable, less than 18 is preferable, less than 16 is more preferable, less than 13 is especially preferable, and less than 10 is especially preferable.
The average number of isocyanate groups can be determined from the isocyanate content and the number average molecular weight. Specifically, it is determined by the following formula.
Isocyanate group average number = [number average molecular weight (Mn) × NCO content (mass%) × 0.01] / 42

In said formula, a number average molecular weight is calculated | required by the polystyrene reference | standard by GPC measurement.
The NCO content is determined by back titration with 1N hydrochloric acid after neutralizing the isocyanate group in the measurement sample with an excess of 2N amine.

The viscosity at 25 ° C. of the polyisocyanate composition of the present embodiment is preferably 30 mPa · s or more and 3000 mPa · s or less. From the viewpoint of the drying property of the coating film, it is more preferably 40 mPa · s or more, and further preferably 60 mPa · s or more. Moreover, from a viewpoint of making workability | operativity favorable, it is more preferable that it is 2000 mPa * s or less. The viscosity can be measured by using an E-type viscometer (manufactured by Tokimec).

The polyisocyanate composition of the present embodiment preferably contains a polyisocyanate compound containing at least one selected from the group consisting of an isocyanurate structure, an allophanate structure, an iminodioxadiazinedione structure, and a burette structure. The isocyanurate structure, allophanate structure, iminodioxadiazinedione structure, and burette structure are represented by the following formulas (III), (IV), (V), and (VI), respectively. Among them, a polyisocyanate compound having an isocyanurate structure and / or an iminodioxadiazinedione structure is preferable from the viewpoint of weather resistance, and a polyisocyanate compound having an allophanate structure from the viewpoint of penetration into the lower layer of the multilayer coating film. preferable.

In the above formula, * represents a bond to a carbon atom in the polyisocyanate compound. R ² is a residue obtained by removing one hydroxy group from a monohydric or higher alcohol.

As a method for forming an isocyanurate structure or an iminooxadiazinedione structure, there is a method using a catalyst. For example, the following catalysts (1) to (10) generally known as catalysts can be used.
(1) Tetramethylammonium fluoride hydrate, tetraethylammonium fluoride, or the like (poly) hydrogen fluoride represented by the general formula M [Fn] or general formula M [Fn (HF) m] , M and n are integers satisfying the relationship of m / n> 0, and M represents an n-charged cation (mixture) or one or more radicals having a total n-valence.)
(2) 3,3,3-trifluorocarboxylic acid; 4,4,4,3,3-pentafluorobutanoic acid; 5,5,5,4,4,3,3-heptafluoropentanoic acid; General formula R1-CR′2-C (O) O— such as 3-difluoroprop-2-enoic acid, or general formula R2 = CR′-C (O) O— (wherein R1 and R2 are A branched, cyclic, and / or unsaturated perfluoroalkyl group having 1 to 30 carbon atoms as necessary, and R ′ is the same or different and is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and A compound selected from the group consisting of aryl groups and containing a heteroatom as necessary.) And a quaternary ammonium cation or a quaternary phosphonium cation.

(3) tetraalkylammonium hydroxides such as tetramethylammonium, tetraethylammonium and tetrabutylammonium; organic weak acid salts such as acetates, octylates, myristates and benzoates;
(4) Hydroxyalkylammonium hydroxides such as trimethylhydroxyethylammonium, trimethylhydroxypropylammonium, triethylhydroxyethylammonium and triethylhydroxypropylammonium; weak organic acids such as acetates, octylates, myristates and benzoates salt,
(5) metal salts such as tin, zinc and lead of alkyl carboxylic acids such as acetic acid, caproic acid, octylic acid and myristic acid,
(6) Metal alcoholates such as sodium and potassium,
(7) Aminosilyl group-containing compound such as hexamethylene disilazane,
(8) Mannich bases,
(9) Combined use of tertiary amines and epoxy compounds,
(10) Phosphorus compounds such as tributylphosphine and the like.

Tetramethylammonium fluoride hydrate is preferred from the viewpoint of availability, and (2) is preferred from the viewpoint of safety. From the viewpoint of hardly generating unnecessary by-products, an organic weak acid salt of quaternary ammonium is preferable, and an organic acid salt of benzyltrimethylammonium and an organic acid salt of tetramethylammonium are more preferable.
The reaction temperature is preferably 40 to 120 ° C. As a lower limit of temperature, it is more preferable that it is 50 degreeC, More preferably, it is 55 degreeC. Moreover, as an upper limit of temperature, it is more preferable that it is 100 degreeC, More preferably, it is 90 degreeC, More preferably, it is 80 degreeC. When the reaction temperature is 40 ° C. or higher, the reaction rate can be maintained, and when the reaction temperature is 120 ° C. or lower, coloring of the polyisocyanate composition can be suppressed.
Although reaction is not specifically limited, For example, it stops by addition of acidic compounds, such as phosphoric acid and acidic phosphate ester.

Examples of a method for generating an allophanate structure include a heating method and a method using a catalyst. The allophanatization catalyst is not particularly limited, but at least one compound selected from the group consisting of a zirconyl compound represented by the following general formula (VII) and a zirconium alcoholate represented by the following general formula (VIII) is used. To do. In order to obtain a polyisocyanate composition having a higher production ratio of allophanate structure, it is preferable to use a zirconyl compound.
A zirconyl compound is a compound having the structure of the following general formula (VII).

In general formula (VII), R ³¹ and R ³² are each independently an alkylcarboniumoxy group, an alkoxy group, an alkyl group, a halogen group, or a hydrogen residue of an inorganic acid.

In the present specification, the “alkylcarboniumoxy group” means a residue obtained by removing hydrogen from an organic carboxylic acid. That is, when R ³¹ and R ^{32 in} the general formula (VII) are both alkylcarboniumoxy groups, the zirconium compound is a zirconyl carboxylate.
Examples of the organic carboxylic acid include aliphatic carboxylic acids, alicyclic carboxylic acids, unsaturated carboxylic acids, hydroxyl group-containing carboxylic acids, halogenated alkyl carboxylic acids, and the like, as well as polybasic acid carboxylic acids such as dicarboxylic acids and tricarboxylic acids. Also includes acids.

Specific examples of the zirconyl compound include zirconyl halide, zirconyl carboxylate, dialkyl zirconyl, zirconyl dialcolate, zirconyl carbonate, lead zirconyl sulfate, zirconyl nitrate and the like. Of these, zirconylcarboxylate is preferable.

Examples of zirconyl carboxylates include zirconyl formate, zirconyl acetate, zirconyl propionate, zirconyl butanoate, zirconyl pentanoate, zirconyl hexanoate, zirconyl caproate, zirconyl octoate, zirconyl 2-ethylhexanoate, zirconyl decanoate, Saturated aliphatic carboxylates such as zirconyl dodecanoate, zirconyl tetradecanoate, zirconyl pentadecanoate, saturated cyclic carboxylic acids such as zirconyl cyclohexanecarboxylate and zirconyl cyclopentanecarboxylate, mixtures of the above carboxylates such as zirconyl naphthenate, olein Such as unsaturated aliphatic carboxylates such as zirconyl linoleate, zirconyl linoleate, zirconyl linoleate, zirconyl benzoate, zirconyl toluate, zirconyl diphenyl acetate, etc. Aromatic carboxylic acid salts. Among them, as the zirconyl compound, zirconyl naphthenate, zirconyl 2-ethylhexanoate, and zirconyl acetate are particularly preferable from the viewpoint of industrial availability.
Zirconium alcoholate is a compound having the structure of the following general formula (VIII).

In general formula (VIII), R ⁴¹ , R ⁴² , R ⁴³ and R ⁴⁴ are each independently an alkyl group, an alkene group, or an alkyne group.

Examples of the alcohol used as a raw material for zirconium alcoholate include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, iso-butanol, 1-pentanol, 2-pentanol, isoamyl alcohol, 1 -Saturated aliphatic alcohols such as hexanol, 2-hexanol, 1-heptanol, 1-octanol, 2-ethyl-1-hexanol, 3,3,5-trimethyl-1-hexanol, tridecanol, pentadecanol, cyclohexanol, etc. And saturated aliphatic alcohols such as ethanal, propanal, butanal and 2-hydroxyethyl acrylate. In addition, ethylene glycol, propanediol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,6-cyclohexanediol, 1,4-cyclohexanediol, etc. Polyhydric alcohols such as diols and triols such as glycerin can also be used.

Among these, as the zirconium alcoholate, tetra-n-propoxyzirconium, tetraisopropoxyzirconium, tetra-n-propoxyzirconium, and tetra-n-butoxyzirconium are preferable from the viewpoint of industrial availability.
The allophanatization reaction temperature is preferably 60 ° C. or higher and 160 ° C. or lower, more preferably 70 ° C. or higher and 160 ° C. or lower, and particularly preferably 80 ° C. or higher and 160 ° C. or lower. It is preferable that the amount is not more than the above upper limit because there are few side reactions, and the resulting polyisocyanate composition can be effectively prevented from being colored.

The allophanatization reaction is not particularly limited, but for example, by adding acidic compounds such as phosphoric acid acidic compounds, sulfuric acid, nitric acid, chloroacetic acid, benzoyl chloride, sulfonic acid ester agents, or ion exchange resins, chelating agents, chelating resins, etc. Stop.
Here, examples of the phosphoric acid acidic compound include phosphoric acid, pyrophosphoric acid, metaphosphoric acid, polyphosphoric acid, and alkyl esters thereof. In this embodiment, at least one of these phosphoric acid acidic compounds is used as a terminator. It is preferable to use for.

As a method for forming a burette structure, there is a method using a buret agent. The buretizing agent is not particularly limited, and examples thereof include water, monovalent tertiary alcohol, formic acid, hydrogen sulfide, organic primary monoamine, and organic primary diamine. In the reaction, 6 moles or more of isocyanate groups are preferable and 10 moles or more can be more preferably used with respect to 1 mole of the buret agent. In the present embodiment, it is particularly preferably 10 mol or more and 80 mol or less. If it is more than the said lower limit, it will become low viscosity enough, and if it is below the said upper limit, sclerosis | hardenability can be maintained when it is set as a coating composition.
A solvent can be used in the burette reaction. The solvent dissolves the triisocyanate monomer or diisocyanate monomer and a buret agent such as water and can be formed into a uniform phase under the reaction conditions.

Specific examples of this solvent include, for example, ethylene glycol-based ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, ethylene glycol monoisopropyl ether acetate, ethylene glycol mono-n- Butyl ether acetate, ethylene glycol diacetate, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol di-n-propyl ether, ethylene glycol diisopropyl ether, ethylene glycol di-n-butyl ether, ethylene glycol methyl ethyl ether, ethylene glycol methyl isopropyl ether , Ethylene glycol methyl-n-but Ether, ethylene glycol ethyl-n-propyl ether, ethylene glycol ethyl isopropyl ether, ethylene glycol ethyl-n-butyl ether, ethylene glycol-n-propyl-n-butyl ether, ethylene glycol isopropyl-n-butyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol Monoethyl ether acetate, diethylene glycol mono-n-propyl ether acetate, diethylene glycol monoisopropyl ether acetate, diethylene glycol mono-n-butyl ether acetate, diethylene glycol diacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n Propyl ether, diethylene glycol diisopropyl ether, diethylene glycol di-n-butyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl isopropyl ether, diethylene glycol methyl n-propyl ether, diethylene glycol methyl n-butyl ether, diethylene glycol ethyl isopropyl ether, diethylene glycol ethyl isopropyl ether Examples include ether, diethylene glycol ethyl-n-butyl ether, diethylene glycol-n-propyl-n-butyl ether, and diethylene glycol isopropyl-n-butyl ether.

Preferred ethylene glycol solvents include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol diacetate, diethylene glycol dimethyl ether and the like. Further, phosphoric acid-based trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate and the like can be mentioned, and trimethyl phosphate and triethyl phosphate are preferable. These may be used alone or in admixture of two or more.

The bullet reaction temperature is preferably 70 ° C. or higher and 200 ° C. or lower, more preferably 90 ° C. or higher and 180 ° C. or lower. It is preferable that it is not more than the above upper limit value because it tends to effectively prevent coloring and the like.

The polyisocyanate composition of the present embodiment preferably contains a polyisocyanate compound obtained from a triisocyanate represented by the following general formula (I) and / or a diisocyanate represented by the following general formula (II).

In the general formula (I), a plurality of Y ¹¹ are each independently a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain an ester structure and / or an ether structure. The plurality of Y ¹¹ may be the same or different. However, at least one of the plurality of Y ¹¹ includes an ester structure. R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms.

・ General formula (I)
^{[Y 11]}
In the general formula (I), a plurality of Y ¹¹ may each independently contain a single bond or an ester structure [—C (═O) —O—] and / or an ether structure (—O—). It is a divalent hydrocarbon group having 1 to 20 carbon atoms. A plurality of Y ¹¹ may be the same or different. However, at least one of the plurality of Y ¹¹ includes an ester structure.
Examples of the divalent hydrocarbon group having 1 to 20 carbon atoms including an ester structure and / or an ether structure include groups represented by — (CH ₂ ) _n1 —X— (CH ₂ ) _n2 — (where n1 and n2 are each Independently, it is an integer of 0 to 10. However, both n1 and n2 are not 0, and it is preferable that the side of n1 and n2 bonded to the NCO is 1 or more. Is an ester group or an ether group.
When it is desired to increase the reaction rate, X is preferably an ester group.
n1 and n2 are preferably from 0 to 4, and more preferably from 0 to 2. As a combination of n1 and n2, for example, a combination of n1 = 0 and n2 = 2, a combination of n1 = 2 and n2 = 2 is preferable.

[R ¹ ]
R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. The hydrocarbon group of R ^1, is not particularly limited, an alkyl group, an alkenyl group, an alkynyl group. R ¹ is preferably a hydrogen atom.

The molecular weight of the triisocyanate represented by the general formula (I) in the present embodiment is preferably 139 or more and 1000 or less.
The lower limit of the molecular weight is preferably 150 or more, more preferably 180 or more, and particularly preferably 200 or more. The upper limit of the molecular weight is preferably 800 or less, more preferably 600 or less, and particularly preferably 400 or less. When the molecular weight is equal to or higher than the lower limit, the crystallinity is easily suppressed. Moreover, it becomes easy to achieve low viscosity because molecular weight is below the said upper limit.

In order for the triisocyanate represented by the general formula (I) in the present embodiment to have a low viscosity, it is preferable that a plurality of hydrocarbon groups in Y ¹¹ have an aliphatic group or an aromatic group. R ¹ is preferably hydrogen.
Further, in order to improve the weather resistance when used as a curing agent for a coating composition, it is preferable that a plurality of hydrocarbon groups in Y ¹¹ have an aliphatic group and / or an alicyclic group.
In addition, in order to maintain heat resistance, it is preferable that at least one of Y ¹¹ has a hydrocarbon group containing an ester structure.

Examples of the triisocyanate represented by the general formula (I) in this embodiment include, for example, bis (2-isocyanatoethyl) 2-isocyanatoglutarate (hereinafter referred to as GTI) disclosed in Japanese Patent Publication No. 4-1033. And lysine triisocyanate (hereinafter referred to as LTI, molecular weight 267) disclosed in JP-A-53-135931.

Among these, GTI and LTI are particularly preferable from the viewpoint of further improving the reactivity of the isocyanate group.
In order to maintain hydrolysis resistance, at least one of the plurality of Y ¹¹ preferably has a hydrocarbon group containing an ether structure.

・ General formula (II)
OCN-Y ²¹ -NCO (II)
In the general formula (II), Y ²¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms including an ester structure.

[Y ²¹ ]
In the general formula (II), Y ²¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms including an ester structure.
The diisocyanate represented by the general formula (II) in the present embodiment has an ester structure in order to increase the reactivity of the isocyanate group when used as a curing agent for a coating composition.
Further, since a low viscosity, aliphatic hydrocarbon group in Y ²¹ is in the structure, preferably has an aromatic group, for holding the heat resistance and Y ^21, hydrocarbon group having an ester structure Have
Examples that fall under this classification include lysine diisocyanate (hereinafter LDI).

The triisocyanate represented by the general formula (I) or the diisocyanate represented by the general formula (II) in the present embodiment can be obtained by isocyanate conversion of an amine such as an amino acid derivative. As the amino acid derivative, for example, 2,5-diaminovaleric acid, 2,6-diaminohexanoic acid, aspartic acid, glutamic acid and the like can be used. Since these amino acids are diamine monocarboxylic acids or monoamine dicarboxylic acids, the number of amino groups can be controlled by esterifying the carboxyl group with an alkanolamine such as ethanolamine or esterifying the carboxyl group with methanol or the like, for example. can do. The resulting amine having an ester group can be converted to a triisocyanate or diisocyanate containing an ester structure by phosgenation or the like.

The polyisocyanate composition of the present embodiment is, for example, 1) In addition to the above-described method of producing a isocyanate-containing compound having a highly reactive NCO group such as GTI by polyisocyanate, 2) the above LTI, LDI, etc. After reacting 0.4 to 0.6 mol% of the NCO group of the isocyanate group-containing compound with a thermal dissociator, the isocyanate group is converted to isocyanurate, and then the polyisoisocyanate is dissociated by heating or the like. There are methods for producing compounds. Examples of the thermal dissociator include methyl ethyl ketoxime.

In addition to the above, the polyisocyanate compound may include a uretdione structure and / or a urethane structure. The uretdione structure and the urethane structure are represented by the following formulas (IX) and (X), respectively.

In the above formula, * represents a bond to a carbon atom in the polyisocyanate compound.

The polyisocyanate composition of the present embodiment may further contain unreacted triisocyanate represented by the general formula (I) -1 or diisocyanate represented by the general formula (II) -1.

In the general formula (I) -1, a plurality of Y ¹² are each independently a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain an ester structure and / or an ether structure. The plurality of Y ¹² may be the same or different. R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms.

OCN-Y ²² -NCO (II) -1
In general formula (II) -1, Y ²² is a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain an ester structure.

In the general formula (I) -1, Y ¹² may or may not contain an ester structure and / or an ether structure. In this embodiment, it is preferable that at least one of the plurality of Y ¹² includes an ester structure and / or an ether structure.
In the general formula (II) -1, Y ²² may or may not contain an ester structure and / or an ether structure. In the present embodiment, Y ²² preferably includes an ester structure.

When a known polyisocyanate composition is made from a volatile diisocyanate such as 1,6-hexamethylene diisocyanate, 1,5-pentane diisocyanate, or isophorone diisocyanate, the unreacted starting diisocyanate is finalized, for example, by distillation. It is necessary to remove from the product to a degree of less than 2% by weight, preferably less than 1% by weight, based on the total weight of the polyisocyanate composition. However, when producing the polyisocyanate composition of the present embodiment, since the reaction rate of the polyisocyanate composition of the present embodiment is high, the crosslinking ability of the polyisocyanate composition of the present embodiment with the polyol is not necessarily reduced. There is no need to remove it.
When removing unreacted triisocyanate, it can be separated from the polyisocyanate composition by thin film distillation or solvent extraction.

The content of the polyisocyanate compound relative to the total mass of the polyisocyanate composition of the present embodiment is preferably 1% by mass or more and 100% by mass or less, more preferably 5% by mass or more and 90% by mass or less. It is particularly preferable that the content is not less than 80% by mass. Above the lower limit, the drying property of the coating film tends to be excellent, and below the upper limit, the viscosity is low and the workability tends to be excellent.
The content of unreacted triisocyanate with respect to the total mass of the polyisocyanate composition of the present embodiment is preferably more than 0% by mass and less than 100% by mass, preferably 5% by mass or more and 90% by mass or less. More preferably, the content is 8% by mass or more and 80% by mass or less. Above the lower limit, there is a tendency for resistance to cracking, and below the upper limit, there is a tendency for sagging resistance to be excellent.
The molar ratio (A) of the ester structure in the polyisocyanate composition of the present embodiment, the molar ratio (B) of the isocyanate group, and the average number of isocyanates (Fn), and (A / B) × Fn is 2.6 or more. Preferably, it is 3.4 or more, more preferably 3.9 or more. Within this range, the sagging resistance of the coating liquid tends to be more excellent.

<Block polyisocyanate composition>
The polyisocyanate composition of this embodiment can protect an isocyanate group with a blocking agent, and can make it a block polyisocyanate composition. Examples of the blocking agent include alcohol, alkylphenol, phenol, active methylene, mercaptan, acid amide, acid imide, imidazole, urea, oxime, amine, imide, and pyrazole compounds. Can be mentioned. Examples of more specific blocking agents are shown below.
(1) Alcohol system: alcohols such as methanol, ethanol, 2-propanol, n-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxy ethanol, 2-butoxyethanol, (2) Alkylphenol-based mono- and dialkylphenols having an alkyl group having 4 or more carbon atoms as a substituent, such as n-propylphenol, iso-propylphenol, n-butylphenol, sec-butylphenol, t-butylphenol Monoalkylphenols such as n-hexylphenol, 2-ethylhexylphenol, n-octylphenol, n-nonylphenol, di-n-propylphenol, diisopropylphenol, isopropyl creso , Di -n- butylphenol, di -t- butylphenol, di -sec- butylphenol, di -n- octylphenol, di-2-ethylhexyl phenol, dialkylphenols such as di -n- nonylphenol,
(3) phenolic: phenol, cresol, ethylphenol, styrenated phenol, hydroxybenzoic acid ester, etc. (4) active methylene, dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone, etc. ( 5) mercaptan series; butyl mercaptan, dodecyl mercaptan, etc. (6) acid amide series; acetanilide, acetic acid amide, ε-caprolactam, δ-valerolactam, γ-butyrolactam, etc. (7) acid imide series; succinimide, malein Acid imides, etc. (8) imidazole series; imidazole, 2-methylimidazole, etc. (9) urea series; urea, thiourea, ethylene urea, etc. (10) oxime series; formaldoxime, acetaldoxime, acetoxime, Methyl ethyl ketoxime Cyclohexanone oxime, etc. (11) amine series; diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, isopropylethylamine, etc. (12) imine series; ethyleneimine, polyethyleneimine etc., (13) bisulfite; heavy Examples include sodium sulfite, (14) pyrazole series; pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole, etc., (15) triazole series; 3,5-dimethyl-1,2,4-triazole, and the like.

The blocking reaction between the polyisocyanate composition and the blocking agent can be performed regardless of the presence or absence of a solvent. When using a solvent, it is necessary to use a solvent inert to the isocyanate group. In the blocking reaction, organometallic salts such as tin, zinc and lead, tertiary amine compounds, alkali metal alcoholates such as sodium, and the like may be used as catalysts. The reaction can generally be carried out at −20 to 150 ° C., preferably 30 to 100 ° C. Above −20 ° C., the reaction rate tends to increase, and below 150 ° C., no side reaction tends to occur.

Among the above-mentioned blocking agents, from the viewpoints of availability, viscosity of the produced block polyisocyanate composition, reaction temperature, and reaction time, oxime compounds, acid amide compounds, amine compounds, active methylene compounds, and It preferably contains at least one selected from the group consisting of pyrazole compounds, more preferably methyl ethyl ketoxime, ε-caprolactam, diethyl malonate, ethyl acetoacetate, diisopropylamine, 3,5-dimethylpyrazole, methyl ethyl ketoxime, diisopropyl Amines and 3,5-dimethylpyrazole are more preferable, and 3,5-dimethylpyrazole is particularly preferable from the viewpoint of achieving both low-temperature curability and compatibility with polyol. You may use a heat dissociable blocking agent individually or in combination of 2 or more types.

<Hydrophilic polyisocyanate composition>
The polyisocyanate composition of the present embodiment is a hydrophilic polyisocyanate composition having a hydrophilic group added by reacting an active hydrogen group and a hydrophilic group-containing compound (hydrophilic group-containing compound) with an isocyanate group. Can do.
Although it does not specifically limit as a hydrophilic group containing compound which can react with an isocyanate group, The compound containing a nonionic, cationic, and anionic hydrophilic group is mentioned.
Although it does not specifically limit as a compound which introduce | transduces a nonionic hydrophilic group, For example, the compound etc. which added ethylene oxide to the hydroxyl group of alcohol, such as methanol, ethanol, butanol, ethylene glycol, diethylene glycol, etc. are mentioned. These have active hydrogens that react with isocyanate groups. Among these, monoalcohols that can improve the water dispersibility of the hydrophilic polyisocyanate composition with a small amount of use are preferred. The addition number of ethylene oxide is preferably 4 to 30, and more preferably 4 to 20. When the number of additions of ethylene oxide is 4 or more, the aqueous solution tends to be easily secured. Moreover, when the addition number of ethylene oxide is 30 or less, the precipitate of the hydrophilic polyisocyanate composition tends not to occur during low-temperature storage.

For the introduction of the cationic hydrophilic group, a method using a compound having both a cationic group and a functional group having hydrogen that reacts with the isocyanate group, or a functional group such as a glycidyl group is added to the isocyanate group in advance. Thereafter, there is a method of reacting this functional group with a specific compound such as sulfide or phosphine. Among these, a method using a compound having both a cationic group and a hydrogen that reacts with an isocyanate group is easy.

The functional group having hydrogen that reacts with the isocyanate group is not particularly limited, and examples thereof include a hydroxyl group and a thiol group. The compound having both a cationic hydrophilic group and a functional group having hydrogen that reacts with an isocyanate group is not particularly limited. For example, dimethylethanolamine, diethylethanolamine, diethanolamine, methyldiethanolamine, N, N-dimethylaminohexanol, N, N-dimethylaminoethoxyethanol, N, N-dimethylaminoethoxyethoxyethanol, N, N, N′-trimethylaminoethylethanolamine, N-methyl-N- (dimethylaminopropyl) aminoethanol and the like can be mentioned. The tertiary amino group (cationic hydrophilic group) introduced into the aqueous block polyisocyanate can be quaternized with dimethyl sulfate, diethyl sulfate or the like.

Of these, a tertiary amino group is preferred as the cationic hydrophilic group. When the hydrophilic polyisocyanate composition has a tertiary amino group, a compound such as an anionic compound used for neutralization described later tends to be volatilized by heating, and as a result, the water resistance tends to be further improved.

The cationic hydrophilic group can be introduced in the presence of a solvent. In this case, the solvent preferably does not contain a functional group capable of reacting with an isocyanate group. These solvents are not particularly limited, and examples thereof include ethyl acetate, propylene glycol monomethyl ether acetate, dipropylene glycol dimethyl ether and the like.

The cationic hydrophilic group introduced into the hydrophilic polyisocyanate composition is preferably neutralized with a compound having an anionic group. The anionic group is not particularly limited, and examples thereof include a carboxyl group, a sulfonic acid group, a phosphoric acid group, a halogen group, and a sulfuric acid group. Although it does not specifically limit as a compound which has the said carboxyl group, For example, formic acid, an acetic acid, propionic acid, a butyric acid, lactic acid etc. are mentioned. The compound having a sulfone group is not particularly limited, and examples thereof include ethanesulfonic acid. Furthermore, although it does not specifically limit as a compound which has the said adjacent acid group, For example, an adjacent acid, an acidic adjacent acid ester, etc. are mentioned. Furthermore, the compound having a halogen group is not particularly limited, and examples thereof include hydrochloric acid. Furthermore, the compound having a sulfate group is not particularly limited, and examples thereof include sulfuric acid. Of these, compounds having one carboxyl group are preferable, and acetic acid, propionic acid, and butyric acid are more preferable.

The anionic hydrophilic group is not particularly limited, and examples thereof include a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, a halogen group, and a sulfuric acid group. The block polyisocyanate having an anionic hydrophilic group is obtained, for example, by reacting an active hydrogen that reacts with an isocyanate group and an active hydrogen of a compound having both an anionic group and an isocyanate group of a precursor polyisocyanate composition. be able to.

The compound having both an active hydrogen and a carboxylic acid group is not particularly limited. For example, monohydroxy such as 1-hydroxyacetic acid, 3-hydroxypropanoic acid, 12-hydroxy-9-octadecanoic acid, hydroxypivalic acid, and lactic acid. Carboxylic acid; and polyhydroxycarboxylic acids such as dimethylolacetic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolpentanoic acid, dihydroxysuccinic acid and dimethylolpropionic acid. Of these, hydroxypivalic acid and dimethylolpropionic acid are preferable.

Although it does not specifically limit as a compound which has both active hydrogen and a sulfonic acid group, For example, isethionic acid etc. are mentioned.

The anionic hydrophilic group introduced into the hydrophilic polyisocyanate composition is not particularly limited, but can be neutralized with, for example, an amine compound that is a basic substance. Although it does not specifically limit as this amine compound, For example, ammonia and a water-soluble amino compound are mentioned. The water-soluble amino compound is not particularly limited. For example, monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, triethanolamine, butylamine, dibutylamine, 2 -Primary amines or secondary amines such as ethylhexylamine, ethylenediamine, propylenediamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, morpholine; tertiary amines such as triethylamine, dimethylethanolamine and the like.

In addition to the isocyanate compound mentioned above, the polyisocyanate composition of this embodiment can further contain a different isocyanate compound.
Examples of the different isocyanate compound include di-isocyanate having an aliphatic, alicyclic or aromatic isocyanate group, tri-isocyanate having an aliphatic isocyanate group, or poly-isocyanate. Examples of the diisocyanate having an aliphatic, alicyclic or aromatic isocyanate group include tetramethylene diisocyanate (TMDI), pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexane- 1,6-diisocyanate, 2-methylpentane-1,5-diisocyanate (MPDI), 1,3-bis (isocyanatomethyl) -cyclohexane (1,3-H6-XDI), 3 (4) -isocyanatomethyl -1-methyl-cyclohexyl isocyanate (IMCI); isophorone diisocyanate (IPDI), bis (isocyanatomethyl) -norbornane (NBDI), 1,3-bis (isocyanatomethyl) -benzene, 1,3-bis ( 2-Isocyanatopropyl- ) Benzene and 4,4'-dicyclohexylmethane diisocyanate (H12MDI), and the like lysine diisocyanate (LDI). Of these, HDI and IPDI are preferred because of weather resistance and industrial availability. These diisocyanates may be used alone or in combination of two or more.
Examples of the triisocyanate having an aliphatic isocyanate group include 4-isocyanatomethyl-1,8-octamethylene diisocyanate (hereinafter referred to as “NTI”) disclosed in Japanese Patent Publication No. 63-15264. Molecular weight 251), 1,3,6-hexamethylene triisocyanate (hereinafter sometimes referred to as “HTI”, molecular weight 209) disclosed in JP-A-57-198760. Among these, NTI is preferable because of industrial availability. These triisocyanates may be used alone or in combination of two or more.

The polyisocyanate is obtained by polymerizing the diisocyanate having an aliphatic, alicyclic or aromatic isocyanate group, or a triisocyanate having an aliphatic isocyanate group by using a catalyst or heating. The molecule includes an isocyanurate structure, a uretdione structure, an allophanate structure, an iminodioxadiazinedione structure, a urethane structure, a burette structure, and the like. Among these, those having an isocyanurate structure are preferable from the viewpoint of weather resistance.

<Other compounds>
The polyisocyanate composition of the present embodiment includes one or more compounds selected from the group consisting of unsaturated bond-containing compounds, inert compounds, metal atoms, basic amino compounds, and carbon dioxide, based on the polyisocyanate compound. It is preferable to contain 0.0 mass ppm or more and 1.0 × 10 ⁴ mass ppm or less from the viewpoint of preventing coloring during long-term storage and improving long-term storage stability. The lower limit of the content range is more preferably 3.0 mass ppm or more, more preferably 5.0 mass ppm or more, still more preferably 10 mass ppm or more, The upper limit of the range is more preferably 5.0 × 10 ³ mass ppm or less, further preferably 3.0 × 10 ³ mass ppm or less, and 1.0 × 10 ³ mass ppm or less. Even more preferred.

The unsaturated bond-containing compound of the present embodiment is preferably a compound in which the unsaturated bond is a carbon-carbon unsaturated bond, a carbon-nitrogen unsaturated bond, or a carbon-oxygen unsaturated bond. is there. From the viewpoint of the stability of the compound, the unsaturated bond is preferably a compound in which the double bond is a carbon-carbon double bond (C═C) or a carbon-oxygen double bond (C═O). More preferred. Moreover, it is preferable that the carbon atom which comprises this compound has couple | bonded with three or more atoms.
In general, the carbon-carbon double bond may be a carbon-carbon double bond constituting an aromatic ring, but the unsaturated bond contained in the unsaturated bond-containing compound of the present embodiment is: It does not contain the carbon-carbon double bond constituting the aromatic ring.
Examples of the compound having a double bond between carbon and oxygen include carbonic acid derivatives. Examples of the carbonic acid derivative include urea compounds, carbonic acid esters, N-unsubstituted carbamic acid esters, and N-substituted carbamic acid esters.

Inactive compounds of this embodiment are classified into the following compounds A to G.
The hydrocarbon compounds are compounds A and B, the ether compounds and sulfide compounds are the following compounds C to E, the halogenated hydrocarbon compounds are the following compounds F, silicon-containing hydrocarbon compounds, silicon-containing ether compounds and silicon-containing sulfide compounds. Are classified into the following compounds G, respectively. The compounds A to G listed here do not contain an unsaturated bond other than the aromatic ring, and do not include the compounds having the unsaturated bond described above.
Compound A: An aliphatic hydrocarbon compound having a linear, branched or cyclic structure.
Compound B: An aromatic hydrocarbon compound which may be substituted with an aliphatic hydrocarbon group.
Compound C: A compound having an ether bond or sulfide bond and an aliphatic hydrocarbon group, wherein the same or different aliphatic hydrocarbon compounds are bonded via an ether bond or a sulfide bond.
Compound D: A compound having an ether bond or a sulfide bond and an aromatic hydrocarbon group, wherein the same or different aromatic hydrocarbon compounds are bonded via an ether bond or a sulfide bond.
Compound E: A compound having an ether bond or sulfide bond, an aliphatic hydrocarbon group, and an aromatic hydrocarbon group.
Compound F: A halide in which at least one hydrogen atom constituting an aliphatic hydrocarbon compound or at least one hydrogen atom constituting an aromatic hydrocarbon compound is substituted with a halogen atom.
Compound G: A compound in which some or all of the carbon atoms of Compounds A to E are substituted with silicon atoms.

The metal atom of this embodiment may exist as a metal ion or may exist as a single metal atom. One type of metal atom may be used, or a plurality of types of metal atoms may be combined. As the metal atom, a metal atom capable of taking a valence of 2 to 4 is preferable, and among these, one or more metals selected from iron, cobalt, nickel, zinc, tin, copper, and titanium are more preferable.

The basic amino compound of this embodiment is a derivative of ammonia, a compound in which one hydrogen is substituted with an alkyl group or an aryl group (primary), a compound in which two hydrogens are substituted (secondary), and three There are compounds that are both substituted (tertiary). The basic amino compounds that can be preferably used in the present invention are secondary and tertiary amino compounds, and aliphatic amines, aromatic amines, heterocyclic amines, and basic amino acids can be preferably used.

Carbon dioxide may be dissolved in a polyisocyanate at normal pressure, or may be dissolved in a pressurized state in a pressure vessel. Since the use of carbon dioxide containing moisture may cause hydrolysis of the polyisocyanate compound, the amount of moisture contained in the carbon dioxide is preferably managed as necessary.

The halogen atom content of the polyisocyanate composition of the present embodiment is preferably 1.0 × 10 ² mass ppm or less from the viewpoint of preventing coloring. The halogen atom is not particularly limited, but is preferably chlorine and / or bromine, and may be at least one ion and / or compound selected from chlorine ion, bromine ion, hydrolyzable chlorine, and hydrolyzable bromine. More preferred. Examples of hydrolyzed chlorine include a carbamoyl chloride compound in which hydrogen chloride is added to an isocyanate group, and examples of hydrolyzable bromine include a carbamoyl bromide compound in which hydrogen bromide is added to an isocyanate group.

<Coating composition, coating film>
The polyisocyanate composition of the present embodiment can also be suitably used as a curing agent for coating compositions. That is, it can be set as the coating composition containing the polyisocyanate composition of this embodiment. The resin component of the coating composition preferably contains a compound having two or more active hydrogens having reactivity with an isocyanate group in the molecule. Examples of the compound having two or more active hydrogens in the molecule include polyols, polyamines, polythiols and the like. Among these, a polyol is preferable. Specific examples of the polyol include polyester polyol, polyether polyol, acrylic polyol, polyolefin polyol, and fluorine polyol.
The coating composition using the polyisocyanate composition of this embodiment can be used for both a solvent base and an aqueous base.

In the case of a solvent-based coating composition, a resin containing a compound having two or more active hydrogens in the molecule, or a solvent dilution thereof, if necessary, other resins, catalysts, pigments, leveling agents, The polyisocyanate composition of the present embodiment is added as a curing agent to an additive such as an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, and a surfactant, and if necessary, a solvent is further added. The solvent-based coating composition can be obtained by adjusting the viscosity and adding the mixture by hand stirring or stirring using a stirring device such as Mazelar.

In the case of a water-based coating composition, an aqueous dispersion of a resin containing a compound having two or more active hydrogen atoms in the molecule, or an aqueous solution, if necessary, other resins, catalysts, pigments, leveling In addition to additives such as an agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, and a surfactant, the polyisocyanate composition of the present embodiment is added as a curing agent, and if necessary, After further adding water or a solvent, a water-based coating composition can be obtained by forcibly stirring with a stirring device.

Examples of the polyester polyol include dibasic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid, etc. Mixture with ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol It can be obtained by subjecting a polyhydric alcohol such as ethoxylated trimethylolpropane alone or a mixture to a condensation reaction. For example, the condensation reaction can be carried out by combining the above components and heating at about 160-220 ° C. Furthermore, for example, polycaprolactones obtained by ring-opening polymerization of lactones such as ε-caprolactone using a polyhydric alcohol can also be used as the polyester polyol. These polyester polyols can be modified using aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and polyisocyanates obtained therefrom. In this case, aliphatic diisocyanate, alicyclic diisocyanate, and polyisocyanate obtained from these are particularly preferable from the viewpoints of weather resistance, yellowing resistance, and the like. When used as a water-based base paint, a part of the remaining carboxylic acid such as dibasic acid is left and neutralized with a base such as amine or ammonia, so that it is water-soluble or water-dispersible. It can be a resin.

Examples of the polyether polyol include polyhydric hydroxy compounds alone or in mixture, for example, hydroxide (lithium, sodium, potassium, etc.), strong basic catalyst (alcolate, alkylamine, etc.), double metal cyanide complex (metal) Random or block addition of alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, styrene oxide, etc.) alone or in mixture to polyvalent hydroxy compounds using porphyrin, hexacyanocobaltate zinc complex, etc.) Polyether polyols obtained; polyether polyols obtained by reacting a polyamine compound (ethylenediamine, etc.) with an alkylene oxide; and acrylamide using these polyether polyols as a medium The polymerized obtained, so-called polymer polyols, and the like.

Examples of the polyvalent hydroxy compound include (i), for example, diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol, etc. (ii), for example, erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol, Sugar alcohol compounds such as mannitol, galactitol, rhamnitol, (iii) monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, ribodesource, (iv) eg trehalose Disaccharides such as sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose, (v) trisaccharides such as, for example, raffinose, gentianose, meletitose, vi) For example, tetrasaccharides such as stachyose, and the like.

The acrylic polyol can be obtained, for example, by copolymerizing a polymerizable monomer having one or more active hydrogens in one molecule and another monomer copolymerizable with the polymerizable monomer.

Acrylic polyol is, for example, acrylic acid esters having active hydrogen (such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate) or methacrylic esters having active hydrogen. (Such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate), glycerin, trimethylolpropane, etc. (Meth) acrylic acid esters having polyvalent active hydrogen such as triol (meth) acrylic acid monoester; polyether polyols (polyethylene glycol, polypropylene glycol, polybutylene glycol, etc.) and the above active hydrogen Monoethers with (meth) acrylic acid esters; adducts of glycidyl (meth) acrylate and monobasic acids such as acetic acid, propionic acid, p-tert-butylbenzoic acid; As an essential component, one or more selected from the group consisting of adducts obtained by ring-opening polymerization of lactones (ε-caprolactam, γ-valerolactone, etc.) with active hydrogen of acrylate esters, as required (Meth) acrylic acid esters (methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, methacrylic acid-n -Butyl, isobutyl methacrylate, methacrylic acid-n-hexyl, methacrylate Cyclohexyl acid, lauryl methacrylate, glycidyl methacrylate, etc.), unsaturated carboxylic acids (acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc.), unsaturated amides (acrylamide, N-methylolacrylamide, diacetone acrylamide, etc.), Or vinyl monomers having a hydrolyzable silyl group (vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ- (meth) acrylopropyltrimethoxysilane, etc.), other polymerizable monomers (styrene, vinyltoluene, vinyl acetate, One or more selected from the group consisting of (acrylonitrile, dibutyl fumarate, etc.) can be obtained by copolymerization by a conventional method.

For example, an acrylic polyol can be obtained by solution polymerization of the above monomer components in the presence of a radical polymerization initiator such as a known peroxide or azo compound, and diluting with an organic solvent as necessary. Can do. In the case of obtaining an aqueous base acrylic polyol, it can be produced by a known method such as solution polymerization of an olefinically unsaturated compound and conversion to an aqueous layer or emulsion polymerization. In that case, water solubility or water dispersibility can be imparted by neutralizing an acidic moiety such as a carboxylic acid-containing monomer such as acrylic acid or methacrylic acid or a sulfonic acid-containing monomer with an amine or ammonia.

The fluorine polyol is a polyol containing fluorine in the molecule. For example, fluoroolefin, cyclovinyl ether, hydroxyalkyl vinyl ether disclosed in JP-A-57-34107 and JP-A-61-215311, Examples thereof include copolymers such as monocarboxylic acid vinyl esters.

The hydroxyl value of the polyol is not particularly limited, but is preferably 10 mgKOH / g or more and 200 mgKOH / g or less. Among these, the lower limit is more preferably 20 mgKOH / g, and particularly preferably 30 mgKOH / g. The acid value of the polyol is preferably 0 mgKOH / g or more and 30 mgKOH / g or less. The hydroxyl value and acid value can be measured according to JIS K1557.

Among the above, as the polyol, acrylic polyol is preferable from the viewpoint of weather resistance, chemical resistance, and hardness, and polyester polyol is preferable from the viewpoint of mechanical strength and oil resistance.

The equivalent ratio (NCO / OH ratio) of the isocyanate group of the polyisocyanate composition of the present embodiment to the hydroxyl group of the polyol is preferably 0.2 to 5.0, more preferably 0.4 to 3.0, and 0 .5 to 2.0 is particularly preferable. When the equivalent ratio is equal to or greater than the lower limit, a tougher coating film can be obtained. When the equivalent ratio is not more than the above upper limit, the smoothness of the coating film can be further improved.
A melamine curing agent such as a complete alkyl type, a methylol type alkyl, or an imino group type alkyl can be added to the coating composition as necessary.

The compound having two or more active hydrogen atoms in the molecule, the polyisocyanate composition of the present embodiment, and the coating composition can all be used by mixing with an organic solvent. The organic solvent preferably has no functional group that reacts with a hydroxyl group and an isocyanate group. Moreover, it is preferable to be compatible with the polyisocyanate composition. Examples of such organic solvents include ester compounds, ether compounds, ketone compounds, aromatic compounds, ethylene glycol dialkyl ether compounds, polyethylene glycol dicarboxylate compounds, hydrocarbon solvents generally used as paint solvents. And aromatic solvents.

The compound having two or more active hydrogens in the molecule, the polyisocyanate composition of the present embodiment, and the coating composition are all catalysts in a range that does not impair the effects of the present embodiment, depending on the purpose and application. In addition, various additives used in the technical field such as pigments, leveling agents, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, and surfactants may be mixed and used.
Examples of the catalyst for accelerating the curing include metal salts such as dibutyltin dilaurate, tin 2-ethylhexanoate, zinc 2-ethylhexanoate, cobalt salt; triethylamine, pyridine, methylpyridine, benzyldimethylamine, N, N— And tertiary amines such as dimethylcyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N, N′-endoethylenepiperazine, N, N′-dimethylpiperazine, and the like.
The curing accelerating catalyst used in the coating composition using the polyisocyanate composition of the present embodiment as a curing agent is preferably 0.5% by mass or less based on the solid component of the polyisocyanate composition, More preferably, it is 0.1 mass% or less, More preferably, it is 0.05 mass% or less, It is especially preferable that it is 0.01 mass% or less. By being below the above-mentioned numerical value, it tends to be excellent in resistance to cracking and the usable time of the paint.

The coating composition using the polyisocyanate composition of the present embodiment as a curing agent can be used as a coating such as roll coating, curtain flow coating, spray coating, bell coating, and electrostatic coating. For example, it is useful as a primer or a top intermediate coating material for materials such as metal (steel plate, surface-treated steel plate, etc.), plastic, wood, film, inorganic material and the like. Further, it is also useful as a paint for imparting cosmetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, etc. to pre-coated metals including rust-proof steel plates and automobile coatings. It is also useful as a urethane raw material for adhesives, pressure-sensitive adhesives, elastomers, foams, surface treatment agents and the like.

Hereinafter, the present embodiment will be described more specifically with specific examples and comparative examples. However, the present embodiment is not limited to the following examples and comparative examples unless they exceed the gist of the present embodiment. Absent. The physical properties of the polyisocyanate compositions in Examples and Comparative Examples were measured as follows. Unless otherwise specified, “parts” and “%” mean “parts by mass” and “mass%”.

<Viscosity>
The viscosity was measured at 25 ° C. using an E-type viscometer (manufactured by Tokimec). In the measurement, a standard rotor (1 ° 34 ′ × R24) was used. The number of revolutions is as follows.
100 rpm (when less than 128 mPa · s)
50 rpm (in the case of 128 mPa · s to 256 mPa · s)
20 rpm (in the case of 256 mPa · s to 640 mPa · s)
10 rpm (from 640 mPa · s to 1280 mPa · s)
5 rpm (in the case of 1280 mPa · s to 2560 mPa · s)

<NCO content>
The NCO content (mass%) was determined by back titration with 1N hydrochloric acid after neutralizing the isocyanate group in the measurement sample with excess 2N amine.

<Calculated NCO content>
The NCO content of the polyisocyanate composition used during the synthesis of the block polyisocyanate composition was determined by the above method, and the NCO-containing mass [A] was determined from the charged polyisocyanate composition.
The calculated NCO content was determined by the following formula.
Calculated NCO content (mass%) = 100 × NCO content [A] / total charge mass

<Ratio of reaction rate (Vp) of polyisocyanate composition and primary alcohol to reaction rate (Vh) of polyisocyanate derived from hexamethylene diisocyanate and primary alcohol (Vp / Vh)>
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was placed in a nitrogen atmosphere. 50 g of Duranate (registered trademark) TKA-100 manufactured by Asahi Kasei Co., Ltd., 33.6 g of 2-ethylhexanol, butyl acetate Charge 83.6 g and raise the temperature to 70 ° C. The NCO content after reaching 70 ° C. is measured, and the NCO group reduction rate (= reaction rate) is determined (Vh). Further, the inside of a four-necked flask equipped with another stirrer, thermometer, reflux condenser, and nitrogen blowing tube was put in a nitrogen atmosphere, and the molar ratio of NCO group of the polyisocyanate composition to OH group of 2-ethylhexanol was 1. Then, butyl acetate having a total mass of the polyisocyanate composition and 2-ethylhexanol is added, and the temperature is raised to 70 ° C. The NCO content rate after reaching 70 ° C. is measured, and the decrease rate (= reaction rate) of NCO groups is determined (Vp).
The value calculated by (Vp) / (Vh) was determined as the reaction rate ratio.

<Number average molecular weight>
The number average molecular weight was determined based on polystyrene standards by GPC measurement using the following apparatus.
Equipment: “HLC-8120GPC” (trade name) manufactured by Tosoh Corporation
Column: "TSKgel SuperH1000" (trade name) x 1 manufactured by Tosoh Corporation "TSKgel SuperH2000" (trade name) x 1 "TSKgel SuperH3000" (trade name) x 1 Carrier: Tetrahydrofuran Detection method: Differential refractometer Sample Concentration: 5wt / vol%
Outflow amount: 0.6 mL / min
Column temperature: 30 ° C.

<Average number of isocyanate groups>
The average number of isocyanate groups (Fn) was determined by the following formula.
Isocyanate group average number (Fn) = [number average molecular weight (Mn) × NCO content (mass%) × 0.01] / 42

<Qualitative methods for isocyanurate structure, allophanate structure, iminodioxadiazinedione structure, burette structure>
Using a Biospin Avance 600 (trade name) manufactured by Bruker, ¹³ C-NMR was measured to confirm the presence or absence of an isocyanurate structure, an allophanate structure, an iminooxadiazinedione structure, and a burette structure.
Specific measurement conditions were as follows.
¹³ C-NMR apparatus: AVANCE 600 (manufactured by Bruker)
Cryoprobe (Bruker)
Cryo Probe
CPDUUL
600S3-C / HD-05Z
Resonance frequency: 150 MHz
Concentration: 60 wt / vol%
Shift standard: CDCl3 (77 ppm)
Integration count: 10,000 times Pulse program: zgpg30 (proton complete decoupling method, waiting time 2 sec)
Judgment was made based on the presence or absence of the following signals.
Isocyanurate structure: Around 148.5 ppm Allophanate structure: Around 154 ppm Iminooxadiazinedione structure: Around 144.5 ppm Bullet structure: Around 156.1 ppm

<Method for measuring molar ratio of ester structure to isocyanate structure>
Using a Biospin Avance 600 (trade name) manufactured by Bruker, ¹³ C-NMR was measured to determine the ratio of the carbon element in the isocyanate group and the ester structure. An example of the calculation method of the measurement method is shown below, but the peak position varies depending on the apparatus used, the measurement conditions, and the substance used. Therefore, it is necessary to appropriately calibrate using a standard substance or the like.
Specific measurement conditions were as follows.
¹³ C-NMR apparatus: AVANCE 600 (manufactured by Bruker)
Cryoprobe (Bruker)
Cryo Probe
CPDUUL
600S3-C / HD-05Z
Resonance frequency: 150 MHz
Concentration: 60 wt / vol%
Shift standard: CDCl3 (77 ppm)
Integration count: 10,000 times Pulse program: zgpg30 (proton complete decoupling method, waiting time 2 sec)
The integrated value of the following signals was divided by the number of carbons being measured, and each molar ratio was determined from the value.
Isocyanate group: around 130-140 ppm: integral value / 1
Ester structure: around 170 ppm: integral value ÷ 1
Subsequently, the molar ratio (A / B) was calculated | required from the molar ratio (A) of the obtained ester structure, and the molar ratio (B) of an isocyanate group.

<Evaluation of minimum film thickness for cracking and minimum film thickness for sagging>
Acrylic polyol (Nuplex Resin's trade name “SETALUX1753”, resin concentration 70%, hydroxyl value 138.6 mgKOH / g) and each of the polyisocyanate compositions were blended at an isocyanate group / hydroxyl equivalent ratio of 1.0. The coating liquid viscosity was adjusted to 200 mPa · s / 25 ° C. with butyl acetate. Prepare a dull steel plate (150 mm x 450 mm x thickness 0.8 mm; use the steel plate in landscape orientation) with holes prepared with a diameter of 5 mm at intervals of 2 cm in a row 3 cm from the end. The coating solution is applied to the steel sheet with an inclination so as to obtain a film thickness in the range of 25 μm to 70 μm. After finishing the coating, the plate was stood for 15 minutes in a state where the coating plate was set up so that the hole was at the top, and then heated at 160 ° C. for 20 minutes to prepare a test plate.

The minimum film thickness at which the wrinkles were generated was evaluated by visually observing the occurrence of the wrinkle marks on the coated film after heat curing, and evaluating the minimum film thickness (μm) where the wrinkle marks were generated. The minimum film thickness at which the crack occurred was 60 μm or more, ◯, 50 μm or more and less than 60 μm, Δ, and less than 50 μm, x.
The sagging property was evaluated by visually observing the sagging trace of the coating film from the lower end of the hole and by the film thickness (μm) where the length from the lower end of the sagging trace was 5 mm or more. The minimum sagging generation film thickness of 50 μm or more was evaluated as “◯”, and the thickness less than 50 μm was evaluated as “×”.

<Evaluation of yellowing of coating film>
A coating liquid similar to the above is prepared, a white tile plate is prepared, and the coating liquid is applied so as to obtain a film thickness of 35 μm. After painting, it was placed horizontally and allowed to stand for 15 minutes. Then, it heated at 100 degreeC for 30 minutes, and produced the test board. Using a SM color meter (SM-P45 type) manufactured by Suga Test Instruments Co., Ltd., the b value (b1) of the obtained test plate was measured with a measurement hole diameter of 50 mm as a reference, and then a dryer at 50 ° C. The b value (b2) was measured every week for up to 8 weeks.
The yellowing of the coating film was judged at the time when b2-b1 exceeded 2. The time exceeding 2 was marked as ◯ for 4 weeks or more, and x for less than 4 weeks.

<Dryability evaluation method of polyisocyanate composition>
Acrylic polyol (Nuplex Resin's trade name “SETALUX1753”, resin concentration 70%, hydroxyl value 138.6 mgKOH / g) and each of the polyisocyanate compositions were blended at an isocyanate group / hydroxyl equivalent ratio of 1.0. The solid content was adjusted to 50 mass% with butyl acetate. The prepared coating composition was applied on a glass plate to a dry film thickness of 40 μm, and then cured at 23 ° C./50% RH. After a specific time, a cotton ball (a cylindrical shape having a diameter of 2.5 cm and a height of 2.0 cm) was placed on the coating film, and a 100 g weight was placed on the cotton ball for 60 seconds. Thereafter, the weight and cotton were removed, and the cotton marks remaining on the coating film were observed. ◎ when the trace is completely invisible within 7 hours, ◎ when over 7 to 9 hours, △ over 10 to 10 hours, and over 10 hours The case where there existed was set as x.

<Storage stability evaluation method>
300 g of the polyisocyanate composition was placed in a 500 mL container, purged with nitrogen, and stored at 23 ° C. for 300 days.
When the change in the number average molecular weight (after storage / before storage) was less than 1.5, it was judged that the storage stability was good.

(Synthesis Example 1) Synthesis of GTI Glutamate hydrochloride 275 g, ethanolamine hydrochloride 800 g, and toluene 150 ml were placed in a four-necked flask equipped with a stirrer, a thermometer, and a gas introduction tube. The mixture was heated to reflux at 110 ° C. for 24 hours until no longer azeotroped. The resulting reaction mixture was recrystallized in a mixture of methanol and ethanol to obtain 270 g of bis (2-aminoethyl) glutamate trihydrochloride. 85 g of this bis (2-aminoethyl) glutamate trihydrochloride is suspended in 680 g of o-dichlorobenzene, and the temperature of the reaction solution is raised while stirring. When the temperature reaches 135 ° C., phosgene is added at a rate of 0.8 mol / hour. The reaction product was filtered, concentrated under reduced pressure, and further purified with a thin film evaporator to obtain 54 g of GTI. The NCO content was 39.8% by mass.

(Synthesis Example 2) Synthesis of LTI In a four-necked flask equipped with a stirrer, thermometer, and gas introduction tube, ethanolamine (122.2 g), o-dichlorobenzene (100 ml) and toluene (420 ml) were placed, and ice-cooled hydrogen chloride gas was added. And ethanolamine was converted to the hydrochloride salt. Next, 182.5 g of lysine hydrochloride was added, the reaction solution was heated to 80 ° C., ethanolamine hydrochloride was dissolved, and hydrogen chloride gas was introduced to form lysine dihydrochloride. Further, hydrogen chloride gas was passed at 20 to 30 ml / min, the reaction solution was heated to 116 ° C., and this temperature was maintained until no water was distilled off. The resulting reaction mixture was recrystallized in a mixture of methanol and ethanol to obtain 165 g of lysine β-aminoethyl ester trihydrochloride. 100 g of this lysine β-aminoethyl ester trihydrochloride is suspended as fine powder in 1200 ml of o-dichlorobenzene, and the temperature of the reaction solution is raised while stirring. When reaching 120 ° C., phosgene is added at 0.4 mol / hour. Blowing was started at a rate, maintained for 10 hours, and then heated to 150 ° C. The suspension was almost dissolved. After cooling, the mixture was filtered, and the dissolved phosgene and the solvent were distilled off under reduced pressure. After vacuum distillation, 80.4 g of colorless and transparent LTI having a boiling point of 155 to 157 ° C./0.022 mmHg was obtained. The NCO content of this product was 47.1% by weight.

(Synthesis Example 3) NTI Synthesis 1060 g of 4-aminomethyl-1,8-octamethylenediamine (hereinafter referred to as triamine) was added to 1500 g of methanol in a four-necked flask equipped with a stirrer, thermometer, and gas introduction tube. After dissolving, 1800 ml of 35% concentrated hydrochloric acid was gradually added dropwise while cooling. Methanol and water were removed under reduced pressure, and the mixture was concentrated and dried at 60 ° C./5 mmHg for 24 hours. As a result, white solid triamine hydrochloride was obtained. 650 g of the resulting triamine hydrochloride was suspended in 5000 g of o-dichlorobenzene as a fine powder, the temperature of the reaction solution was increased while stirring, and when it reached 100 ° C., phosgene began to be injected at a rate of 200 g / Hr. Further, the temperature was raised and maintained at 180 ° C., and phosgene was continuously blown in for 12 hours. Dissolved phosgene and the solvent were distilled off under reduced pressure, followed by vacuum distillation to obtain colorless and transparent 4-isocyanatomethyl-1,8-octanemethylene diisocyanate (hereinafter “NTI”) having a boiling point of 161 to 163 ° C./1.2 mmHg. 420 g of this product was obtained, and the NCO content of this product was 50.0% by mass.

Example 1
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was placed in a nitrogen atmosphere, 50 g of GTI and 0.05 g of isobutanol were charged as monomers, and the temperature was maintained at 80 ° C. for 2 hours. Thereafter, 5 mg of benzyltrimethylammonium capric acid was added to carry out the reaction, and dibutyl phosphoric acid was added to stop the reaction when the NCO content was 35% by mass. The reaction solution was further maintained at 120 ° C. for 15 minutes to obtain polyisocyanate P-1. The resulting polyisocyanate P-1 has a viscosity of 320 mPa · s / 25 ° C., an average number of isocyanate groups (Fn) of 4.8, and has an isocyanurate structure, an allophanate structure, and an iminodioxadiazinedione structure. It could be confirmed. Further, the reaction rate ratio (Vp / Vh) was 5, the molar ratio of the ester structure to the isocyanate structure was 1.1, and (A / B) × Fn was 5.2.
Polyisocyanate composition P-1 had a crack generation minimum film thickness evaluation result of ◯, a sagging generation minimum film thickness evaluation result of ◯, a coating yellowing evaluation result of ◯, and a drying property evaluation result of ◎. These results are shown in Table 1.

(Example 2)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was placed in a nitrogen atmosphere, and charged with 50 g of GTI, 10 g of trimethyl phosphate, 10 g of ethylene glycol monomethyl ether acetate, and 0.6 g of water as temperature. Was held at 90 ° C. for 1 hour. Thereafter, the temperature was raised to 160 ° C. and maintained for 2 hours to obtain polyisocyanate P-2. The obtained polyisocyanate P-2 had an NCO content of 34% by mass, a viscosity of 340 mPa · s / 25 ° C., an average number of isocyanate groups (Fn) of 4.1, and a burette structure could be confirmed. . Further, the reaction rate ratio (Vp / Vh) was 4.5, the molar ratio of the ester structure to the isocyanate structure was 0.9, and (A / B) × Fn was 3.8.
Polyisocyanate composition P-2 had a crack generation minimum film thickness evaluation result of ◯, a sagging generation minimum film thickness evaluation result of ◯, a coating yellowing evaluation result of ◯, and a drying property evaluation result of ◯. These results are shown in Table 1.

(Example 3)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was placed in a nitrogen atmosphere, 50 g of GTI and 0.05 g of isobutanol were charged as monomers, and the temperature was maintained at 80 ° C. for 2 hours. Thereafter, 5 mg of benzyltrimethylammonium capric acid was added for reaction, and dibutyl phosphoric acid was added to stop the reaction when the NCO content was 38% by mass. The reaction solution was further maintained at 120 ° C. for 15 minutes to obtain polyisocyanate P-3. The resulting polyisocyanate P-3 has a viscosity of 270 mPa · s / 25 ° C., an average number of isocyanate groups (Fn) of 3.8, and has an isocyanurate structure, an allophanate structure, and an iminodioxadiazinedione structure. It could be confirmed. Further, the reaction rate ratio (Vp / Vh) was 5, the molar ratio of the ester structure to the isocyanate structure was 0.9, and (A / B) × Fn was 3.3.
For the polyisocyanate composition P-3, the evaluation result for the minimum film thickness for occurrence of cracking was ◯, the evaluation result for minimum film thickness for sagging generation was ◯, the evaluation result for coating yellowing was ◯, and the evaluation result for drying property was ◯. These results are shown in Table 1.

Example 4
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was placed in a nitrogen atmosphere, 50 g of GTI and 0.05 g of isobutanol were charged as monomers, and the temperature was maintained at 80 ° C. for 2 hours. Thereafter, 5 mg of benzyltrimethylammonium capric acid was added to carry out the reaction, and dibutyl phosphoric acid was added to stop the reaction when the NCO content was 30% by mass. The reaction solution was further maintained at 120 ° C. for 15 minutes to obtain polyisocyanate P-4. The resulting polyisocyanate P-4 has a viscosity of 550 mPa · s / 25 ° C., an average number of isocyanate groups (Fn) of 5.8, and has an isocyanurate structure, an allophanate structure, and an iminodioxadiazinedione structure. It could be confirmed. Further, the reaction rate ratio (Vp / Vh) was 4.7, the molar ratio of the ester structure to the isocyanate structure was 1.3, and (A / B) × Fn was 7.4.
Polyisocyanate composition P-4 had a crack generation minimum film thickness evaluation result of Δ, a sagging generation minimum film thickness evaluation result of ◯, a coating yellowing evaluation result of ◯, and a drying property evaluation result of ◎. These results are shown in Table 1.

(Example 5)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was put into a nitrogen atmosphere, charged with 50 g of LTI and 50 g of toluene as monomers, and heated to 50 ° C., and then stirred with methyl ethyl ketoxime 29.3g was dripped and hold | maintained at 50 degreeC for 1 hour. Next, 0.05 g of isobutanol was charged, and the temperature was maintained at 80 ° C. for 2 hours. Thereafter, 5 mg of benzyltrimethylammonium capric acid was added for reaction, and dibutyl phosphoric acid was added at the point of 2 hours to stop the reaction. Thereafter, the temperature was raised to 150 ° C. and vacuum distillation was carried out to distill off methyl ethyl ketoxime and toluene to obtain a polyisocyanate composition P-5. The obtained polyisocyanate P-5 has an NCO content of 42% by mass, a viscosity of 120 mPa · s / 25 ° C., an average number of isocyanate groups (Fn) of 4.4, and isocyanurate structure and allophanate structure. The iminodioxadiazinedione structure was confirmed. Furthermore, the reaction rate ratio (Vp / Vh) was 4.4, the molar ratio of the ester structure to the isocyanate structure was 0.5, and (A / B) × Fn was 2.6.
With regard to the polyisocyanate composition P-5, the evaluation result of the minimum film thickness for occurrence of cracking was ◯, the evaluation result of minimum film thickness for sagging generation was ◯, the evaluation result of coating yellowing was ◯, and the evaluation result of drying property was ◯. These results are shown in Table 1.

(Example 6)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was put into a nitrogen atmosphere, charged with 50 g of LTI and 50 g of toluene as monomers, and heated to 50 ° C., and then stirred with methyl ethyl ketoxime 31.6g was dripped and it hold | maintained at 50 degreeC for 1 hour. Next, 0.05 g of isobutanol was charged, and the temperature was maintained at 80 ° C. for 4 hours. Thereafter, 5 mg of benzyltrimethylammonium capric acid was added to react, and dibutyl phosphoric acid was added at 4 hours to stop the reaction. Thereafter, the temperature was raised to 150 ° C. and vacuum distillation was performed to distill off methyl ethyl ketoxime and toluene to obtain a polyisocyanate composition P-6. The obtained polyisocyanate P-6 has an NCO content of 37% by mass, a viscosity of 400 mPa · s / 25 ° C., an average number of isocyanate groups (Fn) of 6.2, an isocyanurate structure, and an allophanate structure. The iminodioxadiazinedione structure was confirmed. Further, the reaction rate ratio (Vp / Vh) was 5.0, the molar ratio of the ester structure to the isocyanate structure was 0.6, and (A / B) × Fn was 3.9.
With regard to the polyisocyanate composition P-6, the evaluation results for the minimum film thickness for occurrence of cracking were ○, the evaluation result for minimum thickness of sagging generation was ○, the evaluation result for yellowing of the coating film was ○, and the evaluation result for drying property was ◎. These results are shown in Table 1.

(Example 7)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was put into a nitrogen atmosphere, charged with 50 g of LTI and 50 g of toluene as monomers, and heated to 50 ° C., and then stirred with methyl ethyl ketoxime 31.6g was dripped and it hold | maintained at 50 degreeC for 1 hour. Next, 0.05 g of isobutanol was charged and the temperature was maintained at 80 ° C. for 8 hours. Thereafter, 5 mg of benzyltrimethylammonium capric acid was added for reaction, and dibutyl phosphoric acid was added at 8 hours to stop the reaction. Thereafter, the temperature was raised to 150 ° C., and vacuum distillation was carried out to distill off methyl ethyl ketoxime and toluene to obtain a polyisocyanate composition P-7. The obtained polyisocyanate P-7 has an NCO content of 35% by mass, a viscosity of 1800 mPa · s / 25 ° C., an average number of isocyanate groups (Fn) of 8.5, an isocyanurate structure, and an allophanate structure. The iminodioxadiazinedione structure was confirmed. Further, the reaction rate ratio (Vp / Vh) was 5.9, the molar ratio of the ester structure to the isocyanate structure was 1, and (A / B) × Fn was 8.5.
With regard to the polyisocyanate composition P-7, the evaluation result of the minimum film thickness for occurrence of cracking was Δ, the evaluation result of minimum film thickness for sagging generation was ◯, the evaluation result of coating yellowing was ◯, and the evaluation result of drying property was ◎. These results are shown in Table 1.

(Comparative Example 1)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was placed in a nitrogen atmosphere, and 50 g of LTI and 0.05 g of isobutanol were charged as monomers, and the temperature was maintained at 80 ° C. for 2 hours. Thereafter, 5 mg of benzyltrimethylammonium capric acid was added for reaction, and dibutyl phosphoric acid was added to stop the reaction when the NCO content was 40% by mass. The reaction solution was further maintained at 120 ° C. for 15 minutes to obtain polyisocyanate P-8. The resulting polyisocyanate P-8 has a viscosity of 114 mPa · s / 25 ° C., an average isocyanate group number (Fn) of 4.3, and has an isocyanurate structure, an allophanate structure, and an iminodioxadiazinedione structure. It could be confirmed. Furthermore, the reaction rate ratio (Vp / Vh) was 3.2, the molar ratio of the ester structure to the isocyanate structure was 0.5, and (A / B) × Fn was 2.2.
For the polyisocyanate composition P-8, the evaluation results for the minimum film thickness for occurrence of cracking were ◯, the evaluation result for minimum film thickness for sagging generation was x, the evaluation result for coating yellowing was ◯, and the evaluation result for drying property was △. These results are shown in Table 2.

(Comparative Example 2)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube is placed in a nitrogen atmosphere, and 50 g of LTI, 10 g of trimethyl phosphate, 9 g of ethylene glycol monomethyl ether acetate, and 0.5 g of water are charged as the temperature. Was held at 90 ° C. for 1 hour. Thereafter, the temperature was raised to 160 ° C. and held for 2 hours to obtain polyisocyanate P-9. The obtained polyisocyanate P-9 had an NCO content of 39% by mass, a viscosity of 230 mPa · s / 25 ° C., an isocyanate group average number (Fn) of 4.9, and a burette structure could be confirmed. . Further, the reaction rate ratio (Vp / Vh) was 3.1, the molar ratio of the ester structure to the isocyanate structure was 0.5, and (A / B) × Fn was 2.5.
For the polyisocyanate composition P-9, the evaluation result for the minimum film thickness for occurrence of cracking was ◯, the evaluation result for minimum film thickness for sagging generation was x, the evaluation result for coating yellowing was ◯, and the evaluation result for drying property was △. These results are shown in Table 2.

(Comparative Example 3)
A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen blowing tube was placed in a nitrogen atmosphere, 50 g of NTI and 0.05 g of isobutanol were charged as monomers, and the temperature was maintained at 80 ° C. for 2 hours. Thereafter, 5 mg of benzyltrimethylammonium capric acid was added for reaction, and dibutyl phosphoric acid was added to stop the reaction when the NCO content was 44% by mass. The reaction solution was further maintained at 120 ° C. for 15 minutes to obtain polyisocyanate P-10. The resulting polyisocyanate P-10 has a viscosity of 44 mPa · s / 25 ° C. and an isocyanate group average number (Fn) of 4.7, and has an isocyanurate structure, an allophanate structure, and an iminodioxadiazinedione structure. It could be confirmed. Further, the reaction rate ratio (Vp / Vh) was 1, the molar ratio of the ester structure to the isocyanate structure was 0, and (A / B) × Fn was 0.
For the polyisocyanate composition P-10, the evaluation result of the minimum film thickness for occurrence of cracking was ◯, the evaluation result of minimum film thickness for sagging generation was x, the evaluation result of coating yellowing was ◯, and the evaluation result of drying property was x. These results are shown in Table 2.

(Comparative Example 4)
The GTI synthesized in Synthesis Example 1 was used alone. When the GTI synthesized in Synthesis Example 1 is used alone, it is described as “P-11” in Table 1. The viscosity of GTI was 200 mPa · s / 25 ° C., the average number of isocyanate groups (Fn) was 3, and the isocyanurate structure, allophanate structure, iminodioxadiazinedione structure and burette structure could not be confirmed. Further, the reaction rate ratio (Vp / Vh) was 5, the molar ratio of the ester structure to the isocyanate structure was 0.7, and (A / B) × Fn was 2.0. The evaluation results of the minimum GTI film thickness of the GTI were ◯, the evaluation result of the minimum sagging film thickness was x, the evaluation result of yellowing of the coating film was ◯, and the dryness evaluation result was ◯. These results are shown in Table 2.

(Comparative Example 5)
Polymethylene polyphenyl polyisocyanate (MDI) was used alone. The case where MDI was used alone was described as “P-12” in Table 1. MDI has an NCO content of 31.2% by mass, a viscosity of 50 mPa · s / 25 ° C., an average number of isocyanate groups (Fn) of 3, isocyanurate structure, allophanate structure, iminodioxadiazinedione The structure could not be confirmed. Furthermore, the reaction rate ratio (Vp / Vh) was 280, the molar ratio of the ester structure to the isocyanate structure was 0, and (A / B) × Fn was 0. The evaluation result of the minimum film thickness of MDI was x, the evaluation result of sagging minimum film thickness was ◯, the evaluation result of coating yellowing was x, and the dryness evaluation result was ◎. These results are shown in Table 2.

In Tables 1 and 2 above, the structure of the polyisocyanate composition is shown in the qualitative column of the structure. A is an isocyanurate structure, B is an allophanate structure, C is an iminodioxadiazinedione structure, and D is a burette. Each structure is shown.

(Example 8)
0.03 g of 2,2,4-trimethylpentane was added to 300 g of the polyisocyanate composition P-5 obtained in Example 5 to obtain a polyisocyanate composition P-13.
This polyisocyanate composition P-13 has a minimum film thickness evaluation result of ◯, a minimum film thickness evaluation result of sagging generation, a film yellowing evaluation result of ◯, a dryness evaluation result of ◯, and a storage stability evaluation result. Was good.

Example 9
0.03 g of hexadecane was added to 300 g of the polyisocyanate composition P-5 obtained in Example 5 to obtain a polyisocyanate composition P-14.
This polyisocyanate composition P-14 has a minimum film thickness evaluation result of ワ, a minimum film thickness evaluation result of sagging generation of ◯, a coating yellowness evaluation result of ◯, a dryness evaluation result of ◯, and a storage stability evaluation result Was good.

(Synthesis Example 4)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube is placed in a nitrogen atmosphere, charged with 20 g of LTI, heated to 60 ° C., added with 7.2 g of methanol, and stirred for 4 hours. And N-substituted carbamic acid ester C-1 was obtained.

(Example 10)
0.03 g of N-substituted carbamic acid ester C-1 was added to 300 g of polyisocyanate composition P-5 obtained in Example 5 to obtain polyisocyanate composition P-15.
This polyisocyanate composition P-15 has a minimum film thickness evaluation result of ワ, a minimum film thickness evaluation result of sagging generation of ◯, a coating yellowness evaluation result of ◯, a dryness evaluation result of ◯, and a storage stability evaluation result Was good.

ADVANTAGE OF THE INVENTION According to this invention, the polyisocyanate composition which is excellent in drying property, the peeling resistance of a coating liquid, the sagging resistance of a coating liquid, and the yellowing resistance of a coating film can be provided.
The coating composition using the polyisocyanate composition of the present invention as a curing agent can be used as a coating such as roll coating, curtain flow coating, spray coating, bell coating, and electrostatic coating. Furthermore, it can be used as a primer or top intermediate coating material for metals such as steel plates and surface-treated steel plates, and materials such as plastics, wood, films, and inorganic materials. Furthermore, it is also useful as a paint for imparting heat resistance, cosmetic properties (surface smoothness, sharpness), etc. to pre-coated metal including rust-proof steel plates, automobile coating, and the like. Furthermore, it is also useful as a urethane raw material for adhesives, pressure-sensitive adhesives, elastomers, foams, surface treatment agents and the like.

Claims (7)

The average number of isocyanate groups is 3.1 or more and less than 20, and the reaction rate (Vp) between the polyisocyanate composition and the primary alcohol relative to the reaction rate (Vh) between the polyisocyanate derived from hexamethylene diisocyanate and the primary alcohol. ) Ratio (Vp / Vh) of 4 or more and less than 300. The polyisocyanate composition according to claim 1, wherein the viscosity at 25 ° C is 30 mPa · s or more and less than 3000 mPa · s. The isocyanate composition according to claim 1 or 2, comprising at least one selected from the group consisting of an isocyanurate structure, an allophanate structure, an iminodioxadiazinedione structure, and a burette structure. The polyisocyanate composition according to any one of claims 1 to 3, comprising a polyisocyanate compound obtained from a triisocyanate represented by the following general formula (I) and / or a diisocyanate represented by the following general formula (II): .

In the general formula (I), a plurality of Y ¹¹ are each independently a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain an ester structure and / or an ether structure. The plurality of Y ¹¹ may be the same or different. However, at least one of the plurality of Y ¹¹ includes an ester structure. R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms.
OCN-Y ²¹ -NCO (II)
In the general formula (II), Y ²¹ is a C 1-20 divalent hydrocarbon group containing an ester structure. The polyisocyanate composition according to any one of claims 1 to 4, further comprising a triisocyanate represented by the following general formula (I) -1 and / or a diisocyanate represented by the following general formula (II) -1.

In the general formula (I) -1, a plurality of Y ¹² are each independently a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain an ester structure and / or an ether structure. The plurality of Y ¹² may be the same or different. R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms.
OCN-Y ²² -NCO (II) -1
In general formula (II) -1, Y ²² is a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain an ester structure. A coating composition comprising the polyisocyanate composition according to any one of claims 1 to 5 and a polyol. A coating film obtained by curing the coating composition according to claim 6.