JPWO2019065467A1 - Blocked isocyanate composition, coating composition and coating film - Google Patents

Abstract

In the present invention, formula (I) (in the formula, a plurality of Y1's each independently represents a divalent hydrocarbon group having 1 to 20 carbon atoms and optionally containing a single bond, an ester structure or the like. Y1 may be the same or different, provided that at least one of the plurality of Y1 includes an ester structure, and R1 represents a hydrogen atom or a monovalent hydrocarbon having 1 to 12 carbons. Group) and a general formula (II) (in the formula, Y2 is a divalent hydrocarbon group having 1 to 20 carbon atoms including an ester structure and the like). Provided is a blocked isocyanate composition containing a blocked isocyanate compound obtained from one or more selected from the group consisting of diisocyanate compounds and a heat dissociable blocking agent. [Chemical 1] [Chemical 2]

Description

The present invention relates to a blocked isocyanate composition, a coating composition, and a coating film.
Priority is claimed on Japanese Patent Application No. 2017-190471, filed Sep. 29, 2017, the content of which is incorporated herein by reference.

Conventionally, urethane coatings formed from polyurethane coatings have very good flexibility, chemical resistance and stain resistance. In addition, a coating film using a non-yellowing polyisocyanate obtained from an aliphatic diisocyanate typified by 1,6-diisocyanatohexane (hereinafter sometimes referred to as “HDI”) as a curing agent has a further improved weather resistance. The demand is on the rise.
Further, a blocked polyisocyanate can be obtained by blocking the isocyanate group of the polyisocyanate with a heat-dissociable blocking agent. The blocked polyisocyanate does not react at room temperature even when mixed with an active hydrogen compound as a main agent, and the blocking agent is dissociated by heating, the isocyanate group is regenerated, and the curing proceeds. For this reason, it is possible to store in a state where the main agent and the curing agent are mixed in advance. As an example of the above blocked isocyanate, a blocked isocyanate composition as disclosed in Patent Document 1 has been proposed. Further, as an example of forming a crosslinked coating film at a relatively low temperature, block isocyanate compositions as disclosed in Patent Documents 2 and 3 have been proposed.

JP-A-2-620 (TPA oxime) EP-A-159117 (Pila) Japanese Patent No. 4671668

However, the blocked isocyanate composition described in Patent Literature 1 requires a high baking temperature for curing and has insufficient low-temperature curability. Further, the blocked isocyanate compositions described in Patent Documents 2 and 3 have low-temperature curability, but have a problem in compatibility with a highly polar main agent.
The present invention has been made in view of the above circumstances, and provides a blocked isocyanate composition that is excellent in compatibility with polar polyols and that can provide a coating film having good low-temperature curability and appearance. Further, the present invention provides a coating composition and a coating film using the blocked isocyanate composition.

That is, the present invention includes the following aspects.
The blocked isocyanate composition according to the first aspect of the present invention has at least one selected from the group consisting of a triisocyanate compound represented by the following general formula (I) and a diisocyanate compound represented by the following general formula (II). It contains a blocked isocyanate compound obtained from one kind and a heat dissociable blocking agent.

［一般式（Ｉ）中、複数あるＹ^１は、それぞれ独立に、単結合、又は、エステル構造及びエーテル構造からなる群より選択される１種以上を含んでもよい炭素数１〜２０の２価の炭化水素基である。複数あるＹ^１は、それぞれ同一であってもよく異なっていてもよい。但し、複数あるＹ^１のうち１つ以上は、エステル構造を含む。Ｒ^１は、水素原子又は炭素数１〜１２の１価の炭化水素基である。］

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

［一般式（ＩＩ）中、Ｙ^２はエステル構造及びカルボン酸からなる群より選択される少なくとも１種を含む炭素数１〜２０の２価の炭化水素基である。］

[In the general formula (II), Y ² is a divalent hydrocarbon group having 1 to 20 carbon atoms and containing at least one selected from the group consisting of an ester structure and a carboxylic acid. ]

The heat dissociable blocking agent may be at least one selected from the group consisting of oxime compounds, acid amide compounds, amine compounds, imidazole compounds, triazole compounds and pyrazole compounds.
A coating composition according to a second aspect of the present invention includes the blocked isocyanate composition according to the first aspect and an active hydrogen compound.
The coating film according to the third aspect of the present invention is obtained by curing the coating composition according to the second aspect.

According to the above aspect, it is possible to provide a blocked isocyanate composition which is excellent in crystallinity and can provide a coating film having good low-temperature curability and appearance. Further, a coating composition and a coating film using the blocked isocyanate composition can be provided.

  Hereinafter, a mode for carrying out the present invention (hereinafter, simply referred to as “the present embodiment”) will be described in detail. The following embodiment is an exemplification for describing the present invention, and is not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the invention.

<< block isocyanate composition >>
The blocked isocyanate composition according to one embodiment of the present invention includes a triisocyanate compound represented by the following general formula (I) (hereinafter, may be referred to as “triisocyanate compound (I)”) and the following general formula (I). Blocked isocyanate obtained from at least one selected from the group consisting of diisocyanate compounds represented by the formula (II) (hereinafter sometimes referred to as “diisocyanate compound (II)”) and a heat dissociable blocking agent Including compounds.

［一般式（Ｉ）中、複数あるＹ^１は、それぞれ独立に、単結合、又は、エステル構造及びエーテル構造からなる群より選択される１種以上を含んでもよい炭素数１〜２０の２価の炭化水素基である。複数あるＹ^１は、それぞれ同一であってもよく異なっていてもよい。但し、複数あるＹ^１のうち１つ以上は、エステル構造を含む。Ｒ^１は、水素原子又は炭素数１〜１２の１価の炭化水素基である。］

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

［一般式（ＩＩ）中、Ｙ^２はエステル構造及びカルボン酸からなる群より選択される少なくとも１種を含む炭素数１〜２０の２価の炭化水素基である。］

[In the general formula (II), Y ² is a divalent hydrocarbon group having 1 to 20 carbon atoms and containing at least one selected from the group consisting of an ester structure and a carboxylic acid. ]

The blocked isocyanate composition of the present embodiment has excellent compatibility with polar polyols, and by using the blocked isocyanate composition of the present embodiment, a coating film having good low-temperature curability can be obtained.
Next, the physical properties and components of the blocked isocyanate composition of the present embodiment will be described in detail below.

<Physical properties>
[Average number of isocyanate groups (average number of NCO groups)]
The average number of NCO groups (average number of functional groups) per molecule of the blocked isocyanate compound contained in the blocked isocyanate composition of the present embodiment is preferably 2.0 or more and less than 3.0 from the viewpoint of low-temperature curability, and 2.1 or more. It is more preferably less than 3.0, particularly preferably 2.2 or more and less than 3.0.

[Effective NCO content]
In the blocked isocyanate composition of the present embodiment, the effective NCO content is not particularly limited, but is preferably 15% by mass or more and 35% by mass or less since the low-temperature curability of the obtained coating film is improved. , 17% by mass or more and 33% by mass or less, more preferably 20% by mass or more and 30% by mass or less, particularly preferably 21% by mass or more and 29% by mass or less.
The effective NCO content can be calculated using the following equation (A).

Effective NCO content [% by mass]
= {(Content of triisocyanate compound) × (NCO content of triisocyanate compound)} / (total mass of blocked isocyanate composition) (A)

<Components>
[Blocked isocyanate compound]
As the blocked isocyanate compound contained in the blocked isocyanate composition of the present embodiment, at least one selected from the group consisting of the above-mentioned triisocyanate compound (I) and diisocyanate compound (II) is reacted with a heat-dissociable blocking agent. It is obtained by making it block.
Here, "thermal dissociation" means that the blocking agent bonded to the isocyanate group is dissociated by heating, and the isocyanate group is regenerated. The temperature required for dissociation depends on the structure of the blocking agent, but is, for example, 40 ° C to 300 ° C. A coating film obtained from the heat dissociable blocked isocyanate tends to have excellent weather resistance and impact resistance.

・ Triisocyanate compound (I)
(Y ¹ )
In the general formula (I), each of the plurality of Y ¹ may independently include a single bond or one or more selected from the group consisting of an ester structure (—COO—) and an ether structure (—O—). It is a good divalent hydrocarbon group having 1 to 20 carbon atoms. A plurality of Y ¹ may be the same or different. However, at least ^one of the plurality of Y ¹ includes an ester structure. When at least one of a plurality of Y ¹ has an ester structure, the reactivity of the isocyanate group when the blocked isocyanate composition of the present embodiment is used as a curing agent for a coating composition can be further increased.

When Y ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms that does not include at least one selected from the group consisting of an ester structure and an ether structure, the divalent hydrocarbon group having 1 to 20 carbon atoms May be an aliphatic group or an aromatic group. The aliphatic group may be linear, branched or cyclic.
Examples of the linear or branched aliphatic group include an alkanediyl group (alkylene group) and an alkylidene group.
Examples of the cyclic aliphatic group include a cycloalkylene group.

Examples of the aromatic group include an arylene group such as a phenylene group.
When Y ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms and containing at least one selected from the group consisting of the ester structure and the ether structure, for example, it is represented by the following general formula (III). (Hereinafter, may be referred to as “group (III)”) ”.

基（ＩＩＩ）において、−（ＣＨ_２）_ｎ１−のＸと反対の結合手が上記一般式（Ｉ）中のＣと結合しており、−（ＣＨ_２）_ｎ２−のＸと反対の結合手が上記一般式（Ｉ）中のＮＣＯと結合している。また、１≦ｎ１＋ｎ２≦２０となる整数である。すなわち、ｎ１及びｎ２の両方とも０になることはなく、ＮＣＯと結合している側であるｎ２は１以上であることが好ましい。

In the group (III), a bond opposite to X in — (CH ₂ ) _n1 — is bonded to C in the general formula (I), and a bond opposite to X in — (CH ₂ ) _n2 —. Is bonded to NCO in the general formula (I). Further, it is an integer satisfying 1 ≦ n1 + n2 ≦ 20. That is, both n1 and n2 do not become 0, and n2, which is the side bonded to the NCO, is preferably 1 or more.

Among them, n1 and n2 are each independently preferably an integer of 0 to 20, more preferably an integer of 0 to 4, and further preferably an integer of 0 to 2.
As a combination of n1 and n2, for example, a combination of n1 = 0 and n2 = 2, and a combination of n1 = 2 and n2 = 2 are preferable.
In the group (III), X is an ester structure or an ether structure. Among them, X preferably has an ester structure because the reaction rate is increased.

When at least ^one of the plurality of Y ¹ has an ester structure or an ether structure, the heat resistance of the blocked isocyanate composition of the present embodiment can be further improved.
When at least ^one of the plurality of Y ¹ has an ether structure, the hydrolysis resistance of the blocked isocyanate composition of the present embodiment can be further improved.

(R ¹ )
R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. The hydrocarbon group for R ¹ is not particularly limited, and includes an alkyl group, an alkenyl group, an alkynyl group, and the like. Among them, a hydrogen atom is preferable as R ¹ .
In the present embodiment, a preferable example of the triisocyanate compound (I) in which at least one of a plurality of Y ¹ has an ester structure is disclosed in, for example, Japanese Patent Publication No. 4-1033 (Reference Document 1). Bis (2-isocyanatoethyl) 2-isocyanatoglutarate (hereinafter referred to as "GTI", molecular weight 311), and lysine tris disclosed in JP-A-53-135931 (Reference Document 2). Isocyanate (hereinafter, referred to as “LTI”, molecular weight 267) and the like.

-Molecular weight of triisocyanate compound In this embodiment, the molecular weight of the triisocyanate compound is preferably 139 or more and 1000 or less, more preferably 150 or more and 800 or less, further preferably 180 or more and 600 or less, and 200 It is particularly preferable that the number be 400 or more and 400 or less.

When the molecular weight of the triisocyanate compound is equal to or more than the lower limit, a coating film having higher hardness can be obtained from the blocked isocyanate composition of the present embodiment. A coating can be obtained.

・ Diisocyanate compound (II)
^(Y 2)
In the general formula (II), Y ² is a divalent hydrocarbon having 1 to 20 carbon atoms including at least one selected from the group consisting of an ester structure (—COO—) and a carboxylic acid (—COOH). Group. When Y ² has an ester structure, the reactivity of isocyanate groups when the blocked isocyanate composition of the present embodiment is used as a curing agent for a coating composition can be further increased. Further, when Y ² is a hydrocarbon group having an ester structure, a coating film having more excellent heat resistance can be obtained from the blocked isocyanate composition of the present embodiment.

As the divalent hydrocarbon group having 1 to 20 carbon atoms constituting Y ^{2, the same} as the divalent hydrocarbon group having 1 to 20 carbon atoms exemplified for Y ¹ can be mentioned.
Among them, the divalent hydrocarbon group having 1 to 20 carbon atoms constituting Y ² is preferably an aliphatic group, an alicyclic group or an aromatic group.
In the present embodiment, specifically, as a preferable example of the diisocyanate compound (II) in which Y ² is a hydrocarbon group having at least one selected from the group consisting of an ester structure and a carboxylic acid, for example, lysine diisocyanate (hereinafter, referred to as , "LDI") (molecular weight 212).

-Method for producing triisocyanate compound (I) and diisocyanate compound (II) The triisocyanate compound (I) and the diisocyanate compound (II) contained in the blocked isocyanate composition of the present embodiment can be obtained, for example, by converting an amine such as an amino acid derivative into an isocyanate. Can be obtained.

Examples of the amino acid derivative include 2,5-diaminovaleric acid, 2,6-diaminohexanoic acid, aspartic acid, and glutamic acid. These amino acid derivatives are diamine monocarboxylic acids or monoamine dicarboxylic acids. Therefore, the number of amino groups can be controlled by esterifying the carboxy group with an alkanolamine such as ethanolamine or by esterifying the carboxyl group with methanol or the like. The obtained triamine having an ester group can be converted into a triisocyanate compound or a diisocyanate compound having an ester structure by phosgenation of an amine or the like.

-Thermal dissociative blocking agent Examples of the blocking agent include (1) oxime compounds, (2) alcohol compounds, (3) acid amide compounds, (4) acid imide compounds, (5) phenol compounds, (6) amine compounds, (7) active methylene compounds, (8) imidazole compounds, (9) triazole compounds, (10) pyrazole compounds, and the like. One type of the blocking agent may be used, or two or more types may be used in a desired ratio.

More specifically, examples of the blocking agent include the following.
(1) Oxime compounds: formaldoxime, acetoaldoxime, acetoxime, methyl ethyl ketoxime, cyclohexanone oxime and the like.
(2) Alcohol compounds: methanol, ethanol, 2-propanol, n-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol and the like.
(3) Acid amide compounds: acetanilide, acetate amide, ε-caprolactam, δ-valerolactam, γ-butyrolactam and the like.

(4) Acid imide compounds: succinimide, maleic imide and the like.
(5) Phenol compounds: phenol, cresol, ethyl phenol, butyl phenol, nonyl phenol, dinonyl phenol, styrenated phenol, hydroxybenzoate, and the like.
(6) Amine compounds: diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, isopropylethylamine and the like.
(7) Active methylene compounds: dimethyl malonate, diethyl malonate, diisopropyl malonate, di-tert-butyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone and the like.

(8) Imidazole compounds: imidazole, 2-methylimidazole, 2-ethylimidazole and the like.
(9) Triazole compounds: 1,2,4-triazole, 3-amino-1,2,4-triazole, 3-amino-5-phenyl-1,2,4-triazole, 1,2,3-triazole And 1H-benzotriazole.
(10) Pyrazole compounds pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole and the like.

Among them, oxime compounds, acid amide compounds, amine compounds, imidazole compounds, triazole compounds or pyrazoles from the viewpoint of availability and crystallinity of the blocked isocyanate composition, and low-temperature curability of the resulting coating film. Based compounds are preferred, and methyl ethyl ketoxime, diisopropylamine, imidazole or 3,5-dimethylpyrazole is more preferred.

[Method for producing blocked isocyanate compound]
The blocked isocyanate compound contained in the blocked isocyanate composition of the present embodiment, for example, reacts the above-described triisocyanate or diisocyanate with a heat dissociable blocking agent to block the isocyanate group of the above-described triisocyanate compound or diisocyanate compound. And the like.
In the blocking reaction, all or part of the isocyanate groups of the above-described triisocyanate compound or diisocyanate compound may be blocked, but it is preferable that all of the isocyanate groups are blocked.

When all the isocyanate groups are blocked, (mol number of heat dissociable blocking agent) / (mol number of isocyanate group contained in triisocyanate) is preferably from 1.0 to 1.5. When the blocking agent is blended so as to have the above ratio, the excess or unreacted blocking agent remains.
The blocking reaction may be carried out without a solvent, and if necessary, an organic solvent having no reactivity with an isocyanate group may be used.

The organic solvent is not particularly limited, but specific examples include the following.
(I) Aliphatic hydrocarbon solvents such as hexane, heptane and octane.
(Ii) Alicyclic hydrocarbon solvents such as cyclohexane and methylcyclohexane.
(Iii) Ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.
(Iv) Ester solvents such as methyl acetate, ethyl acetate, butyl acetate, and isobutyl acetate.

(V) aromatic solvents such as toluene, xylene, diethylbenzene, mesitylene, anisole and chlorobenzene;
(Vi) glycol solvents such as ethylene glycol monoethyl ether acetate, 3-methyl-3-methoxybutyl acetate, and propylene glycol monomethyl ether acetate;
(Vii) Ether solvents such as diethyl ether, tetrahydrofuran and dioxane.

(Viii) Halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane and chloroform.
(Ix) a pyrrolidone-based solvent such as N-methyl-2-pyrrolidone;
(X) Amide solvents such as N, N-dimethylacetamide and N, N-dimethylformamide.
(Xi) Sulfoxide solvents such as dimethyl sulfoxide.
(Xii) lactone solvents such as γ-butyrolactone.
(Xiii) amine solvents such as morpholine.

The above organic solvents may be used alone or as a mixture of two or more. Further, the organic solvent can be removed after the reaction.
In the blocking reaction, a catalyst may be used.
Examples of the catalyst include, but are not limited to, organic metal salts such as tin, zinc, and lead; tertiary amine compounds; and alkali metal alcoholates such as sodium.

The blocked isocyanate composition of the present embodiment may be a blocked isocyanate compound (hereinafter, may be referred to as “blocked isocyanate compound (I)”) obtained from a triisocyanate compound (I) and a heat dissociable blocking agent. It is preferable to include a blocked isocyanate compound obtained from the diisocyanate compound (II) and the heat dissociable blocking agent (hereinafter, may be referred to as “blocked isocyanate compound (II)”).

In the blocked isocyanate composition of the present embodiment, the weight ratio of the blocked isocyanate compound (II) to the total weight of the blocked isocyanate compound (I) and the blocked isocyanate compound (II) is preferably 0.2% or more, and more preferably 0.5%. The above is more preferable. When it is at least this lower limit, the compatibility with the polar polyol tends to be excellent. The weight ratio is preferably 10% or less, more preferably 5% or less. When the content is equal to or less than the upper limit, the low-temperature curability tends to be excellent.

  The blocked isocyanate composition of the present embodiment is selected from the group consisting of a structure represented by the following general formula (IV) and an isocyanurate structure, a burette structure, a uretdione structure, an iminooxadiazinedione structure, a urethane structure, and an allophanate structure. A blocked isocyanate compound obtained from a polyisocyanate compound containing at least one kind and a blocking agent can be included.

［一般式（ＩＶ）中、複数あるＹ^１は、それぞれ独立に、単結合、又は、エステル構造及びエーテル構造からなる群より選択される１種以上を含んでもよい炭素数１〜２０の２価の炭化水素基である。複数あるＹ^１は、それぞれ同一であってもよく異なっていてもよい。但し、複数あるＹ^１のうち１つ以上は、エステル構造を含む。Ｒ^１は、水素原子又は炭素数１〜１２の１価の炭化水素基である。］
一般式（ＩＶ）中、Ｙ^１およびＲ^１は、上述した一般式（Ｉ）におけるＹ^１およびＲ^１と同じである。

[In the general formula (IV), a plurality of Y ¹ are each independently a single bond or a divalent having 1 to 20 carbon atoms which may include one or more selected from the group consisting of an ester structure and an ether structure. Is a hydrocarbon group. A plurality of Y ¹ may be the same or different. However, at least ^one of the plurality of Y ¹ includes an ester structure. R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. ]
In Formula (IV), Y ¹ and R ¹ are the same as Y ¹ and R ¹ in Formula (I) described above.

<Other additives>
The blocked isocyanate composition of the present embodiment, in addition to the above-described blocked isocyanate compound, further depends on the purpose and application, and further includes a curing acceleration catalyst, an antioxidant, an ultraviolet absorber, a light stabilizer, a pigment, a leveling agent, and a plasticizer. Agents, rheology control agents, and various additives such as surfactants.

The curing acceleration catalyst is not particularly limited, and examples thereof include the following.
(I) Tin compounds such as dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, dimethyltin dineodecanoate, and tin bis (2-ethylhexanoate).
(Ii) Zinc compounds such as zinc 2-ethylhexanoate and zinc naphthenate.
(Iii) Titanium compounds such as titanium 2-ethylhexanoate and titanium diisopropoxybis (ethylacetonate).
(Iv) Cobalt compounds such as cobalt 2-ethylhexanoate and cobalt naphthenate.
(V) Bismuth compounds such as bismuth 2-ethylhexanoate and bismuth naphthenate.

(Vi) Zirconium compounds such as zirconium tetraacetylacetonate, zirconyl 2-ethylhexanoate and zirconyl naphthenate.
(Vii) amines such as triethylamine, pyridine, methylpyridine, benzyldimethylamine, N, N-dimethylcyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N, N′-endoethylenepiperazine, N, N′-dimethylpiperazine Compound.
Although it does not specifically limit as said antioxidant, For example, a hindered phenol compound, a phosphorus compound, a sulfur compound, etc. are mentioned.

The ultraviolet absorber is not particularly limited, and examples thereof include a benzotriazole-based compound, a triazine-based compound, and a benzophenone-based compound.
The light stabilizer is not particularly limited, and examples thereof include a hindered amine compound, a benzotriazole compound, a triazine compound, a benzophenone compound, and a benzoate compound.
Examples of the pigment include, but are not particularly limited to, titanium oxide, carbon black, indigo, quinacridone, pearl mica, and aluminum.

The leveling agent is not particularly limited, and includes, for example, silicone oil.
Although it does not specifically limit as said plasticizer, For example, a phthalic acid ester, a phosphoric acid type compound, a polyester type compound, etc. are mentioned.
The rheology control agent is not particularly limited, but examples include hydroxyethyl cellulose, urea compounds, microgels and the like.
Although it does not specifically limit as said surfactant, For example, well-known anionic surfactant, cationic surfactant, amphoteric surfactant, etc. are mentioned.

<Production method of blocked isocyanate composition>
The blocked isocyanate composition of the present embodiment can be obtained by adding the above-mentioned various additives to the above-mentioned blocked isocyanate compound alone or, if necessary, mixing with the above-mentioned blocked isocyanate compound.

Further, in the blocked isocyanate compound used in the production of the blocked isocyanate composition of the present embodiment, at least one of the heat dissociable blocking agent and the organic solvent may remain, and the heat dissociable blocking agent and the organic solvent May be removed, and a material consisting of only a blocked isocyanate compound may be used.

<Application>
The blocked isocyanate composition of the present embodiment is, for example, a curable composition such as a coating composition, a pressure-sensitive adhesive composition, an adhesive composition, a casting composition; various surface treatment compositions such as a fiber treatment agent; Various elastomer compositions; crosslinking agents for foam compositions and the like; modifiers; additives and the like.

  Use fields of the pressure-sensitive adhesive composition and the adhesive composition containing the blocked isocyanate composition of the present embodiment include, for example, automobiles, building materials, home appliances, woodwork, solar cell laminates, and the like. In particular, optical members for liquid crystal displays of home appliances such as televisions, personal computers, digital cameras, and mobile phones need to be laminated with films and plates of various adherends in order to exhibit various functions. Since sufficient adhesiveness or adhesiveness is required between the film and the plate of the various adherends, the adhesive composition and the adhesive composition containing the blocked isocyanate composition of the present embodiment are preferably used.

The adherend to which the curable composition containing the blocked isocyanate composition of the present embodiment is used is not particularly limited, and examples thereof include the following.
(I) glass.
(Ii) Various metals such as aluminum, iron, zinc steel plate, copper, and stainless steel.
(Iii) Porous members such as wood, paper, mortar, and stone.

(Iv) A member that has been subjected to fluorine coating, urethane coating, acrylic urethane coating, or the like.
(V) A cured silicone material such as a silicone-based cured product, a modified silicone-based cured product, or a urethane-based cured product.
(Vi) Rubbers such as vinyl chloride, natural rubber, and synthetic rubber.
(Vii) Leathers such as natural leather and artificial leather.
(Viii) Fibers such as plant fibers, animal fibers, carbon fibers, and glass fibers.

(Ix) Non-woven fabrics, films and plates of resins such as polyester, acrylic, polycarbonate, triacetyl cellulose, polyolefin and the like.
(X) Inks such as UV-curable acrylic resin layer, printing ink, UV ink, etc.

≪Paint composition≫
The coating composition in one embodiment of the present invention contains the above-mentioned blocked isocyanate composition and an active hydrogen compound.
The coating composition of the present embodiment can obtain a coating film having good low-temperature curability and appearance by including the above-mentioned blocked isocyanate composition as a curing agent.
In the coating composition of the present embodiment, components other than the blocked isocyanate composition will be described in detail below.

<Components>
[Active hydrogen compound]
The active hydrogen compound contained in the coating composition of the present embodiment may be a compound in which two or more active hydrogens are bonded in a molecule. Specific examples of the active hydrogen compound include polyamine, alkanolamine, polythiol, and polyol.
Among them, a polyol is preferable as the active hydrogen compound.

-Polyamine The polyamine is not particularly limited, and examples thereof include the following.
(I) Diamines such as ethylenediamine, propylenediamine, butylenediamine, triethylenediamine, hexamethylenediamine, 4,4′-diaminodicyclohexylmethane, piperazine, 2-methylpiperazine, and isophoronediamine.
(Ii) Chain polyamines having three or more amino groups, such as bishexamethylenetriamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentamethylenehexamine, and tetrapropylenepentamine.

(Iii) 1,4,7,10,13,16-hexaazacyclooctadecane, 1,4,7,10-tetraazacyclodecane, 1,4,8,12-tetraazacyclopentadecane, 1,4, Cyclic polyamines such as 8,11-tetraazacyclotetradecane;
-Alkanolamine The above-mentioned alkanolamine is not particularly limited. For example, monoethanolamine, diethanolamine, aminoethylethanolamine, N- (2-hydroxypropyl) ethylenediamine, mono-, di- (n- or iso-) propanol Amines, ethylene glycol-bis-propylamine, neopentanolamine, methylethanolamine and the like.

-Polythiol The polythiol is not particularly limited, and examples thereof include bis- (2-hydrothioethyloxy) methane, dithioethylene glycol, dithioerythritol, and dithiothreitol.
-Polyol The above polyol is not particularly limited, but examples include polyester polyol, acrylic polyol, polyether polyol, polyolefin polyol, fluorine polyol, polycarbonate polyol, epoxy resin and the like.

(Polyester polyol)
The polyester polyol is not particularly limited, but is obtained, for example, by a condensation reaction of a dibasic acid alone or a mixture with a polyhydric alcohol alone or a mixture.
The dibasic acid is not particularly limited. For example, dibasic acid is selected from the group consisting of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, and terephthalic acid. Basic acids are mentioned.
The polyhydric alcohol is not particularly limited, but specific examples include polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, and glycerin.

Alternatively, for example, polycaprolactones obtained by ring-opening polymerization of a lactone such as ε-caprolactone using a polyhydric alcohol can also be used as the polyester polyol.
(Acrylic polyol)
The acrylic polyol is not particularly limited, for example, a polymerized or copolymerized monomer or a mixture of ethylenically unsaturated bond-containing monomers having a hydroxyl group, or an ethylenically unsaturated bond having a hydroxyl group Examples thereof include those obtained by copolymerizing a monomer alone or a mixture thereof with another monomer or a mixture of other ethylenically unsaturated bond-containing monomers copolymerizable therewith.

  Examples of the ethylenically unsaturated bond-containing monomer having a hydroxyl group include, but are not particularly limited to, for example, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, methacrylic acid Hydroxybutyl acid and the like. These may be used alone or in combination of two or more.

Among them, the ethylenically unsaturated bond-containing monomer having a hydroxyl group is preferably hydroxyethyl acrylate or hydroxyethyl methacrylate.
The other ethylenically unsaturated bond-containing monomer copolymerizable with the above-mentioned ethylenically unsaturated bond-containing monomer having a hydroxyl group is not particularly limited, and examples thereof include the following. These may be used alone or in combination of two or more.

(I) Methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, acrylic acid Acrylic esters such as lauryl, benzyl acrylate and phenyl acrylate.
(Ii) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid Methacrylic esters such as lauryl, benzyl methacrylate and phenyl methacrylate.

(Iii) unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid.
(Iv) unsaturated amides such as acrylamide, methacrylamide, N, N-methylenebisacrylamide, diacetone acrylamide, diacetone methacrylamide, maleic amide, and maleimide;
(V) Vinyl monomers such as glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile, and dibutyl fumarate.

(Vi) Vinyl monomers having a hydrolyzable silyl group such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, and γ- (meth) acryloxypropyltrimethoxysilane.
(Polyether polyol)
Although it does not specifically limit as said polyether polyol, For example, it can obtain using any one of the following methods (1)-(3).
(1) A method in which a polyether polyol is obtained by adding an alkylene oxide alone or a mixture to a polyhydric hydroxy compound alone or as a mixture using a catalyst.

Examples of the catalyst include hydroxides (such as lithium, sodium and potassium) and strong basic catalysts (such as alcoholates and alkylamines).
Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.

(2) A method of reacting an alkylene oxide with a polyfunctional compound to obtain polyether polyols.
Examples of the polyfunctional compound include ethylene diamines.
Examples of the alkylene oxide include those similar to those exemplified in (1).
(3) A method in which acrylamide or the like is polymerized using the polyether polyols obtained in (1) or (2) as a medium to obtain so-called polymer polyols.

Examples of the polyvalent hydroxy compound include the following.
(I) Diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol and the like.
(Ii) Sugar alcohol compounds such as erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol, mannitol, galactitol, and rhamnitol.
(Iii) Monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, ribodeose and the like.

(Iv) Disaccharides such as trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose and melibiose.
(V) Trisaccharides such as raffinose, gentianose and meletitose.
(Vi) tetrasaccharides such as stachyose;

(Polyolefin polyol)
Examples of the polyolefin polyol include, but are not limited to, polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene having two or more hydroxyl groups, polyisoprene having two or more hydroxyl groups, and hydrogenated polyisoprene having two or more hydroxyl groups. And the like.

(Fluorine polyol)
The fluorine polyol is not particularly limited, but may be any polyol containing fluorine in the molecule. Specific examples of the fluorine polyol include fluoroolefins, cyclovinyl ethers, and hydroxyalkyls disclosed in JP-A-57-34107 (Reference Document 5) and JP-A-61-275311 (Reference Document 6). Copolymers such as vinyl ether and vinyl monocarboxylate are exemplified.

(Polycarbonate polyol)
Although it does not specifically limit as said polycarbonate polyol, For example, what is obtained by polycondensing a low molecular carbonate compound and the polyhydric alcohol used for the above-mentioned polyester polyol is mentioned.
Examples of the low molecular carbonate compound include dialkyl carbonates such as dimethyl carbonate; alkylene carbonates such as ethylene carbonate; diaryl carbonates such as diphenyl carbonate.

(Epoxy resin)
The epoxy resin is not particularly limited, for example, novolak type, glycidyl ether type, glycol ether type, epoxy type of aliphatic unsaturated compound, fatty acid ester type, polycarboxylic acid ester type, aminoglycidyl type, β- Epoxy resins such as methyl epichloro-type, cyclic oxirane-type, halogen-type and resorcin-type are exemplified.

(Hydroxyl value of polyol)
The hydroxyl value of the polyol is preferably from 10 mgKOH / g to 300 mgKOH / g per coating composition in view of the crosslinking density and mechanical properties of the obtained coating film.
Molar equivalent ratio of NCO group to active hydrogen group Molar equivalent ratio of NCO group in the blocked isocyanate composition contained in the coating composition of the present embodiment to active hydrogen group in the active hydrogen compound (NCO group / active hydrogen) Group) may usually be 10: 1 to 1:10.

[Other additives]
The coating composition of the present embodiment can further include other curing agents such as a melamine-based curing agent and an epoxy-based curing agent, in addition to the above-described blocked isocyanate composition and the above-described active hydrogen compound.
The melamine-based curing agent is not particularly limited, and examples thereof include, for example, fully alkyl etherified melamine resins, methylol-based melamine resins, and imino-based melamine resins partially having an imino group.

When the coating composition of the present embodiment contains a melamine-based curing agent, it is effective to further contain an acidic compound.
Although it does not specifically limit as said acidic compound, For example, carboxylic acid, sulfonic acid, acidic phosphoric acid ester, phosphite, etc. are mentioned.
Although it does not specifically limit as said carboxylic acid, For example, acetic acid, lactic acid, succinic acid, oxalic acid, maleic acid, decane dicarboxylic acid, etc. are mentioned.
Although it does not specifically limit as said sulfonic acid, For example, paratoluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenedisulfonic acid, etc. are mentioned.

Examples of the acidic phosphate ester include, but are not particularly limited to, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, dilauryl phosphate, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, and the like.
Examples of the phosphite include, but are not particularly limited to, for example, diethyl phosphite, dibutyl phosphite, dioctyl phosphite, dilauryl phosphite, monoethyl phosphite, monobutyl phosphite, monooctyl phosphite, monolauryl phosphite. Fight and the like.

The epoxy curing agent is not particularly limited, for example, aliphatic polyamine, alicyclic polyamine, aromatic polyamine, acid anhydride, phenol novolak, polymercaptan, aliphatic tertiary amine, aromatic tertiary amine, Imidazole compounds, Lewis acid complexes and the like.
<Production method of coating composition>
The method for producing the coating composition of the present embodiment is not particularly limited. For example, the composition is produced by mixing the above-mentioned blocked isocyanate composition as a main ingredient, an active hydrogen compound, and further, if necessary, the above-mentioned other additives. be able to. When the active hydrogen compound and the other additives are mixed, they may be solventless, as in a powder coating, or may be mixed using a solvent. Examples of the solvent include those similar to the organic solvents exemplified in the above-described method for producing a blocked isocyanate compound.

<Application>
The coating composition of the present embodiment is, for example, roll coating, curtain flow coating, spray coating, electrostatic coating, by a known coating method such as bell coating, by coating on various materials, as a primer, intermediate coating or top coating. It is preferably used.
Further, the coating composition of the present embodiment is, for example, a prepainted metal containing a rust-resistant steel plate, a painted portion of a car, a painted portion of a plastic, etc., cosmetics, weather resistance, acid resistance, rust resistance, chipping resistance, It is also useful as a paint for providing adhesion and the like.

≪Coating film≫
The coating film in one embodiment of the present invention is obtained by curing the above-mentioned coating composition.
The coating film of the present embodiment has good low-temperature curability.
The coating film of the present embodiment can be obtained, for example, by the following method.
First, the above-mentioned coating composition is applied by a known method such as roll coating, curtain flow coating, spray coating, bell coating, electrostatic coating, etc. to form a coating film. Next, by heating the formed coating film, the heat dissociable blocking agent bonded to the isocyanate group of the above-mentioned blocked isocyanate compound is dissociated. Next, the isocyanate group dissociated by the heat dissociable blocking agent reacts with the active hydrogen in the active hydrogen compound contained in the coating composition, whereby the coating is cured to obtain a coating film.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.
≪Evaluation items≫
According to the method described below, the blocked isocyanate compositions produced in the Examples and Comparative Examples, the coating composition containing the blocked isocyanate composition and the coating film obtained by curing the coating composition, each physical properties and each An evaluation was performed.

<Effective NCO content of blocked isocyanate composition>
The effective NCO content (% by mass) was calculated using the following equation (A ′).
Effective NCO content = {(content of triisocyanate compound or polyisocyanate) × (NCO content of triisocyanate compound or polyisocyanate)} / (total mass of blocked isocyanate composition) (A ′)

<Weight ratio of blocked isocyanate compound (II)>
The ratio of the area value of the blocked isocyanate (II) to the sum of the area values of the blocked isocyanate (I) and the blocked isocyanate (II) was determined by gas chromatography using GC-2014 manufactured by Shimadzu Corporation. An example of the measurement method is shown below. Since the peak position changes depending on the device used, the measurement conditions, and the substance used, it is necessary to appropriately calibrate using a standard substance or the like.
Specific measurement conditions were as follows.
Apparatus: GC-2014 (manufactured by Shimadzu)
Column: DB-1
Injection temperature: 300 ° C
Detection temperature: 300 ° C
Column flow rate: 1.0 mL / min Column temperature: After heating at 60 ° C. (holding 2 minutes), heating up to 300 ° C. (10 ° C./min), holding for 10 minutes Internal standard: anisole Sample preparation: 0.1 g sample / 0 internal standard .1 g / dehydrated acetone 5 g

<Evaluation 1: Compatibility with polar polyol>
A blocked isocyanate composition and a polycarbonate polyol (trade name “Duranol T5620” of Asahi Kasei Co., Ltd.) were blended at a solid content ratio of 1: 1 and prepared with butyl acetate to a coating solution solid content of 50%. The prepared coating solution was applied to a glass plate with a dry film thickness of 60 μm, and the transparency of the coating film after 30 days at 30 ° C. was measured and evaluated with a haze meter (** manufactured by **). The evaluation criteria for compatibility with polar polyols are as follows.
(Evaluation criteria for compatibility with polar polyols)
：: less than 0.3 △: 0.3 or more and less than 0.5 ×: 0.5 or more

<Evaluation 2: Low-temperature curability (gel fraction)>
A polyester polyol (trade name “SETAL6306” from Allnex) and a blocked isocyanate composition are blended at an equivalent ratio of effective isocyanate groups / hydroxyl groups of 1.0, and the coating liquid solid content is adjusted to 45% by weight with butyl acetate. did. The prepared coating solution was applied to an aluminum plate with a dry film thickness of 40 μm, and baked at 140 ° C. for 30 minutes to obtain a coating film. The obtained coating film was peeled off from the aluminum plate, and the residual film ratio after immersion in acetone at 23 ° C. for 24 hours was calculated and defined as a gel fraction. The evaluation criteria for the low-temperature curability are as follows.

(Evaluation criteria for low-temperature curability)
：: Gel fraction is 80% or more Δ: Gel fraction is 75% or more and less than 80% X: Gel fraction is less than 75%

[Synthesis Example 1] Synthesis of LTI In a four-necked flask equipped with a stirrer, a thermometer, and a gas inlet tube, 122.2 g of ethanolamine, 100 mL of o-dichlorobenzene, and 420 mL of toluene were charged, and ice-cooled hydrogen chloride gas was added. The ethanolamine was converted to the hydrochloride. Next, 182.5 g of lysine hydrochloride was added, and the reaction solution was heated to 80 ° C. to dissolve ethanolamine hydrochloride, and hydrogen chloride gas was introduced to obtain lysine dihydrochloride. Then, hydrogen chloride gas was passed at a rate of 20 to 30 mL / min, and the reaction solution was heated to a temperature of 116 ° C. and maintained at this temperature until no more water distilled. Next, 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 was suspended as fine powder in 1200 mL of o-dichlorobenzene, and the reaction solution was heated while stirring. Next, when the reaction solution reached 120 ° C., phosgene was started to be blown in at a rate of 0.4 mol / hour and maintained for 10 hours. Next, the temperature of the reaction solution was raised to 150 ° C. to almost dissolve lysine β-aminoethyl ester trihydrochloride in the reaction solution. Then, after cooling, filtration was performed, and the dissolved phosgene and the solvent were distilled off under reduced pressure. Next, 80.4 g of a colorless and transparent LTI having a boiling point of 155 to 157 ° C./0.022 mmHg was obtained by vacuum distillation. The NCO content of the LTI was 47.1% by weight.

[Synthesis Example 2] Synthesis of HDI-based polyisocyanate A 4-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube was set to a nitrogen atmosphere, 500 g of HDI was charged, and tetramethylammonium was stirred at 60 ° C. 0.08 g of capriate was added. Next, stirring was continued at 60 ° C. for 4 hours to advance the reaction. Then, when the conversion to polyisocyanate became 40% by measuring the isocyanate group content and the refractive index of the reaction solution, 0.2 g of phosphoric acid was added to stop the reaction. Next, after filtering the reaction solution, unreacted HDI was removed at a first time of 160 ° C. (27 Pa) and a second time of 150 ° C. (13 Pa) to obtain an HDI-based isocyanurate-type polyisocyanate. The viscosity of the obtained HDI-based isocyanurate-type polyisocyanate was 2,300 mPa · s / 25 ° C., and the NCO content was 20.4% by mass.

[Example 1] Production of blocked isocyanate composition 1 The inside of a four-necked flask equipped with a stirrer, a thermometer, and a gas introduction tube was purged with nitrogen, and 100.0 parts by mass of LTI and 2,6-diisocyanatohexane 0.18 parts by mass of the acid methyl ester and 109.9 parts by mass of 3,5-dimethylpyrazole were added, and the mixture was stirred at 100 ° C. for 2 hours to carry out a reaction. After the completion of the reaction, 89.1 parts by mass of butyl acetate was added and mixed so as to be uniform to obtain a blocked isocyanate composition 1. In the obtained blocked isocyanate composition 1, the weight ratio of the blocked isocyanate (II) was 0.23%, and the effective NCO content was 22.7%. Further, the compatibility with the polar polyol was Δ and the low-temperature curability was Δ.

[Examples 2 to 9 and Comparative Examples 1 to 3] Production of Blocked Isocyanate Compositions 2 to 12 A method similar to that of Example 1 was used except that the types and the used masses of the isocyanate and the blocking agent were as shown in Table 1. Using these, blocked isocyanate compositions 2 to 12 were produced. Table 1 below shows the weight ratio of the blocked isocyanate (II) and the effective NCO content of each of the obtained blocked isocyanate compositions. In addition, the results of compatibility with polar polyols and low-temperature curability are shown in Table 1 below.

  From the above, it was confirmed that the blocked isocyanate composition of the present embodiment was excellent in compatibility with the polar polyol and obtained a coating film having good low-temperature curability.

Since the blocked isocyanate composition of the present embodiment has excellent compatibility with polar polyols and is excellent in low-temperature curing, it is suitably used as a curing agent in a coating composition.

Claims (6)

A triisocyanate compound represented by the following general formula (I), and at least one selected from the group consisting of a diisocyanate compound represented by the following general formula (II):
A blocked isocyanate composition comprising a blocked isocyanate compound obtained from a heat-dissociable blocking agent.

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

[In the general formula (II), Y ² is a divalent hydrocarbon group having 1 to 20 carbon atoms and containing at least one selected from the group consisting of an ester structure and a carboxylic acid. ]   The block according to claim 1, wherein the heat dissociable blocking agent is at least one selected from the group consisting of an oxime compound, an acid amide compound, an amine compound, an imidazole compound, a triazole compound, and a pyrazole compound. Isocyanate composition. A blocked isocyanate compound (I) obtained from the triisocyanate compound represented by the general formula (I) and the heat dissociable blocking agent, and
Blocked isocyanate compound (II) obtained from the diisocyanate compound represented by the general formula (II) and the heat dissociable blocking agent
The blocked isocyanate composition according to claim 1, comprising:   The block according to claim 3, wherein a weight ratio of the blocked isocyanate compound (II) to the total weight of the blocked isocyanate compound (I) and the blocked isocyanate compound (II) is 0.2% or more and less than 10%. Isocyanate composition.   A coating composition comprising the blocked isocyanate composition according to any one of claims 1 to 4 and an active hydrogen compound.   A coating film obtained by curing the coating composition according to claim 5.