JP2018193426A - Block polyisocyanate composition, method for producing the same, coating composition, and cured product - Google Patents

Abstract

To provide a block polyisocyanate composition that achieves all of low-temperature curability and moisture stability, and yellow discoloration resistance.SOLUTION: A block polyisocyanate composition contains at least one block isocyanate, represented by general formula (I) [where, R is a residue excluding an isocyanate group of a polyisocyanate formed from one or more selected from an aliphatic isocyanate, an alicyclic isocyanate, and an aromatic isocyanate, A is a structural unit of a residue excluding one active hydrogen of active hydrogen methylene of malonic diester, B is a structural unit of a residue excluding one active hydrogen of active hydrogen methylene of malonic ester having a nitrogen-containing heterocyclic amide structure, the total of m and n is 2.0 or more and 20 or less, and n/m is 0.01 or more and less than 1.0].SELECTED DRAWING: None

Description

  The present invention relates to a block polyisocyanate composition, a method for producing the same, a coating composition, and a cured product.

  The polyisocyanate composition is widely used for baking coating as a heat-crosslinking type curing agent together with a melamine curing agent. In recent years, it has been pointed out that formalin is generated when a melamine-based curing agent is used, and block polyisocyanate compositions are attracting attention from the viewpoints of the global environment, safety, hygiene, and the like. Conventionally, oximes, phenols, alcohols, lactams, and pyrazoles are known as blocking agents for the block polyisocyanate composition. However, since the block polyisocyanate composition formed using the conventional blocking agent generally requires a high baking temperature of 130 ° C. or higher, the energy cost is very high. Moreover, there is a limitation that a block polyisocyanate composition that requires high-temperature baking cannot be used for processing into a plastic having low heat resistance.

  In order to overcome such drawbacks, as a block polyisocyanate composition capable of lowering the baking temperature, a block polyisocyanate composition containing malonic acid diester as a blocking agent (Patent Document 1), and isobutanoyl acetate as a blocking agent Block polyisocyanate compositions (Patent Document 2), block polyisocyanate compositions having an amide structure (Patent Document 3), and the like have been proposed.

JP 57-121065 A JP 2009-155408 A JP 2011-178895 A

  However, the block polyisocyanate compositions of the inventions of Patent Documents 1 to 3 are yellowed when used as a curing agent for single-layer or multi-layer coatings and when baked (overbaked) at an excessive temperature. Was a problem.

  The present invention has been made in view of the above circumstances, is cured at a low temperature, and the yellowing of the coating film after film formation is suppressed even at a high temperature, that is, low temperature curability, moisture stability, and yellowing resistance. It aims at providing the method of manufacturing a coating film using the composition containing the block polyisocyanate in which all were compatible, and the said composition.

  As a result of intensive research, the inventor has found that a coating film formed from a composition containing at least one block polyisocyanate having a specific structure has both low-temperature curability, moisture stability, and yellowing resistance. As a result, the present invention has been completed.

That is, the present invention has the following configuration.
[1] A blocked polyisocyanate composition comprising at least one blocked isocyanate represented by the following general formula (I):

[In the formula (I),
R is a residue excluding an isocyanate group of a polyisocyanate formed from one or more selected from aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate;
A is a keto isomer represented by the following general formula (II) or an enol isomer thereof, and a plurality of A present in one molecule may be the same or different from each other,
B is a keto compound represented by the following general formula (III) or an enol isomer thereof, and a plurality of B present in one molecule may be the same or different from each other;
The total of m and n is 2.0 or more and 20 or less, and n / m is 0.01 or more and less than 1.0. ]

[In the formula (II),
R ₁ and R ₂ may be the same or different and are each independently an alkyl group having 1 to 8 carbon atoms, a phenyl group, or a benzyl group. ]

[In the formula (III),
R ₁ is an alkyl group having 1 to 8 carbon atoms, a phenyl group or a benzyl group,
R ₃ and R ₄ may be the same or different, and may contain at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. R ₃ and R ₄ are bonded to each other to form a 5- or 6-membered cycloalkyl group, or together with a nitrogen atom sandwiched between R ₃ and R ₄ , A bridging member may be formed which is added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain nitrogen or oxygen atoms. ]
[2] The block polyisocyanate composition according to [1], wherein R ₃ and R _{4 in} the general formula (III) are both branched alkyl groups having 3 to 6 carbon atoms.
[3] The blocked polyisocyanate composition of [1] or [2], wherein R ₃ and R ₄ of the general formula (III) together form a linked structure represented by the following general formula (IV) .

[Wherein, R ₅ , R ₆ , R ₇ and R ₈ each independently represents a hydrogen atom or a methyl group. However, at least one of R ₅ , R ₆ , R ₇ , and R ₈ is a methyl group. ]
[4] The block polyisocyanate composition according to any one of [1] to [3], further including at least one block polyisocyanate represented by the following general formula (V).

[In the formula, R is a residue excluding an isocyanate group of a polyisocyanate formed from one or more selected from aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate;
A is a keto isomer represented by the general formula (II) or an enol isomer thereof, and a plurality of A present in one molecule may be the same or different from each other;
B is a keto isomer represented by the general formula (III) or an enol isomer thereof, and a plurality of B present in one molecule may be the same or different from each other;
C is a keto body represented by the following general formula (VI), and a plurality of C present in one molecule may be the same or different from each other,
The sum of m, n, and o is 2.0 or more and 20 or less. However, m, n, and o are not all zero. ]

[Wherein R ₉ is a residue excluding active hydrogen of the active hydrogen-containing hydrophilic compound. ]
[5] The block polyisocyanate composition according to [4], wherein (m + n) / o is 1 or more and 49 or less and n / m is 0.01 or more and less than 1.0 in the general formula (V). object.
[6] The basic compound (e) having an acid dissociation constant (pKa) of 7.0 to 8.5 is contained in an amount of 10 mol% or more based on the number of moles based on the isocyanate group of the block polyisocyanate composition. ,
The number of moles is
The block polyisocyanate represented by the general formula (I) is the number of moles based on the isocyanate group in the polyisocyanate that is a precursor of the block polyisocyanate,
About the block polyisocyanate shown by the said general formula (V), on the basis of the isocyanate group used as the structure represented by said A and the structure represented by said B in the polyisocyanate which is the precursor of the said block polyisocyanate The block polyisocyanate composition according to any one of [1] to [5], wherein
[7] A coating composition comprising the block polyisocyanate composition according to any one of [1] to [6] and a polyol.
[8] The coating composition according to [7], which is an aqueous coating composition.
[9] A method for producing a coating film using the coating composition according to [7] or [8].
[10] A cured product obtained by curing the coating composition of [7] or [8].
[11] Malonic acid represented by the following general formula (VII) in polyisocyanate (a) formed from one or more selected from the group consisting of aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate A first step in which the diester (b) is added and reacted in an amount of 75 to 150 mol% based on the isocyanate group of the polyisocyanate (a);
A second step of reacting the product obtained in the first step with one or more of the organic amine compounds (c) represented by the following general formula (VIII):
The manufacturing method of block polyisocyanate composition containing this.

[In formula, R < ₁ > and R < ₂ > may be same or different, and are respectively independently a C1-C8 alkyl group, a phenyl group, or a benzyl group. ]

[In Formula (VIII), R ₃ and R ₄ may be the same or different, and may contain at least one selected from the group consisting of an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. A hydrocarbon group having 1 to 30 carbon atoms, and R ₃ and R ₄ are bonded to each other to form a 5- or 6-membered cycloalkyl group, or sandwiched between R ₃ and R ₄ Together with the nitrogen atom, a bridging member may be formed which is added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain a nitrogen atom or an oxygen atom. ]
[12] In the first step, the polyisocyanate (a), the malonic acid diester (b), and the active hydrogen-containing hydrophilic compound (d) are combined with the malonic acid diester (b) and the active hydrogen-containing hydrophilic compound. As a total amount of the functional compound (d), 77 to 150 mol% is added to the isocyanate group of the polyisocyanate (a), the polyisocyanate (a), the malonic acid diester (b), and the active hydrogen. The method for producing a block polyisocyanate composition according to [11], which is a step of reacting the contained hydrophilic compound (d).
[13] The block of [12], wherein the first step is a step of reacting the malonic acid diester (b) after the reaction of the polyisocyanate (a) and the active hydrogen-containing hydrophilic compound (d). A method for producing a polyisocyanate composition.
[14] In the second step, one or more of the organic amine compound (c) is added in an amount of 50 to 500 mol% based on the isocyanate group of the polyisocyanate (a), and obtained in the first step. The manufacturing method of the block polyisocyanate composition in any one of said [11]-[13] made to react with the obtained product.
[15] The block polyisocyanate composition according to any one of [11] to [14], wherein the organic amine compound (c) is removed and purified as a third step after the first step and the second step. Manufacturing method.
[16] Removal and purification of the organic amine compound (c) and the alcohol compound dissociated by the reaction of the ester group of the product obtained in the first step and the organic amine compound (c) in the third step The method for producing the block polyisocyanate composition according to [15], wherein:
[17] The block polyisocyanate composition according to [15] or [16], wherein a basic compound (e) having an acid dissociation constant (pKa) of 7.0 to 8.5 is added after the third step. Manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, the coating film containing the block polyisocyanate in which all of low-temperature curability, moisture stability, and yellowing resistance were compatible can be provided.

  The present invention is described in detail below. 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.

(Block polyisocyanate composition)
The block polyisocyanate composition according to the present invention contains at least one block polyisocyanate represented by the following general formula (I).

  The block polyisocyanate composition according to the present invention contains at least one block polyisocyanate represented by the general formula (I), so that both low temperature curability, moisture stability, and yellowing resistance are compatible. There is an effect. In particular, in a coating process, for example, in a multilayer coating film forming process, when a coating film using the block polyisocyanate composition is formed and then subjected to a heating process of 120 ° C. or more, yellowing while maintaining moisture stability. Can be effectively prevented.

  In general formula (I), R is a residue except the isocyanate group of the polyisocyanate formed from 1 type, or 2 or more types chosen from aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate.

  Examples of the aliphatic isocyanate include aliphatic diisocyanate, lysine triisocyanate (hereinafter referred to as LTI), 4-isocyanatomethyl-1,8-octamethylene diisocyanate (trimer triisocyanate: hereinafter referred to as TTI), bis (2- Isocyanatoethyl) 2-isocyanatoglutarate (glutamate triisocyanate: hereinafter referred to as GTI). Of these, aliphatic diisocyanates are preferred.

  The aliphatic diisocyanate preferably has 4 to 30 carbon atoms. For example, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (hereinafter referred to as HDI), 2,2,4-trimethyl-1,6- Examples include diisocyanatohexane and lysine diisocyanate. Of these, HDI is preferred because of its industrial availability. An aliphatic diisocyanate may be used independently and may use 2 or more types together.

  As the alicyclic isocyanate, for example, alicyclic diisocyanates shown below are mainly used. As said alicyclic diisocyanate, a C8-C30 thing is mentioned suitably, for example, Specifically, isophorone diisocyanate (it describes as IPDI below), 1, 3-bis (isocyanatomethyl) -cyclohexane. 4,4'-dicyclohexylmethane diisocyanate, norbornene diisocyanate, hydrogenated xylylene diisocyanate and the like. Of these, IPDI is preferred from the viewpoint of weather resistance and industrial availability. An alicyclic diisocyanate may be used independently and may use 2 or more types together.

  As the aromatic isocyanate, for example, aromatic diisocyanates shown below are mainly used. Examples of the aromatic diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, and the like. An aromatic diisocyanate may be used independently and may use 2 or more types together.

  Among these isocyanates, aliphatic isocyanates and alicyclic isocyanates are preferable from the viewpoint of excellent weather resistance.

  As for the isocyanate group average number of the polyisocyanate formed from 1 type, or 2 or more types chosen from these isocyanate, 2.0-20 are preferable. The lower limit of the average number of isocyanate groups is more preferably 2.3, still more preferably 2.5, and still more preferably 3.0. The upper limit of the average number of isocyanate groups is more preferably 15 and even more preferably 10. When the lower limit of the average number of isocyanate groups is 2.0 or more, the crosslinkability is improved, and the desired coating film properties can be obtained. On the other hand, when the upper limit of the average number of isocyanate groups is 20 or less, the cohesive force is prevented from becoming too high, and a smooth coating film can be obtained.

  The said isocyanate group average number is calculated | required by the following numerical formula.

  Examples of the polyisocyanate serving as the residue represented by R in the general formula (I) include triisocyanates such as LTI, TTI, GTI, and derivatives thereof, biuret bond, urea bond, isocyanurate bond, uretdione, and the like. Examples include oligomers of diisocyanates produced by forming bonds, urethane bonds, allophanate bonds, oxadiazine trione bonds, and the like. A polyisocyanate having a biuret bond is obtained by reacting a so-called biuretizing agent such as water, t-butanol or urea with a diisocyanate at a molar ratio of biuretizing agent / isocyanate group of the diisocyanate of about 1/2 to about 1/100. Thereafter, unreacted diisocyanate can be removed and purified. A polyisocyanate having an isocyanurate bond is obtained by, for example, carrying out a cyclic trimerization reaction with a catalyst or the like, stopping the reaction when the conversion rate is about 5 to about 80% by mass, and removing and purifying unreacted diisocyanate. It is done. In this case, 1 to 6 valent alcohol compounds can be used in combination.

As the catalyst for the isocyanuration reaction, those having basicity are generally preferred. Examples of the catalyst include
(1) Tetraalkylammonium hydroxide such as tetramethylammonium, tetraethylammonium, and trimethylbenzylammonium, and weak organic acid salts such as acetic acid and capric acid,
(2) Hydroxyalkylammonium hydroxides such as trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium and triethylhydroxyethylammonium, and weak organic acid salts such as acetic acid and capric acid,
(3) alkyl metal salts of alkyl carboxylic acids such as tin, zinc, lead and the like,
(4) Metal alcoholates such as sodium and potassium,
(5) Aminosilyl group-containing compound such as hexamethyldisilazane,
(6) Mannich bases,
(7) Combined use of tertiary amines and epoxy compounds,
(8) Phosphorus compounds such as tributylphosphine and the like may be mentioned, and two or more may be used in combination.

  When the catalyst may adversely affect the properties of the paint or coating film, it is preferable to neutralize the catalyst with an acidic compound or the like. Examples of the acidic compound include inorganic acids such as hydrochloric acid, phosphorous acid, and phosphoric acid, sulfonic acids such as methanesulfonic acid, p-toluenesulfonic acid, p-toluenesulfonic acid methyl ester, p-toluenesulfonic acid ethyl ester, and the like. Derivatives, ethyl phosphate, diethyl phosphate, isopropyl phosphate, diisopropyl phosphate, butyl phosphate, dibutyl phosphate, 2-ethylhexyl phosphate, di (2-ethylhexyl) phosphate, isodecyl phosphate, diisodecyl phosphate, oleyl acid phosphate, tetracosyl acid phosphate, ethyl There are glycol acid phosphate, butyl pyrophosphate, butyl phosphite and the like, and two or more kinds may be used in combination.

  The polyisocyanate having a urethane bond is, for example, a di-isocyanate having a bivalent to hexavalent alcoholic compound such as trimethylolpropane and the molar ratio of hydroxyl group of the alcoholic compound / isocyanate group of the diisocyanate is about 1/2 to about 1 /. After reacting at 100, unreacted diisocyanate can be removed and purified.

  Derivatives of LTI, TTI and GTI are also produced in the same manner as polyisocyanates derived from diisocyanates. In the case of these triisocyanates, removal and purification of unreacted triisocyanates is not always necessary.

  M and n in the general formula (I) are each independently a positive number. In the blocked isocyanate represented by the general formula (I), n / m is preferably 0.01 or more and less than 1.0. The minimum value of n / m is preferably 0.01 or more, but more preferably 0.04 or more. The maximum value of n / m is preferably less than 1.0, but more preferably less than 0.4. By setting n / m within this range, the coating film obtained by curing the block polyisocyanate composition according to the present invention containing the blocked isocyanate represented by the general formula (I) has excellent yellowing resistance.

  The blocked isocyanate represented by the general formula (I) includes, as the substituent A, the keto compound represented by the general formula (II) or an enol isomer thereof. A plurality of substituents A present in one molecule may be the same as or different from each other.

The structural unit represented by the general formula (II) represents a keto body, and enol isomers of the structural unit include all keto-enol tautomers. For example, a structure in which a proton of a methine group becomes an enol body on the amide group side and a structure in which an enolic body on the ester group side is included. Of the substituent A in the entire blocked isocyanate represented by the general formula (I) contained in the blocked polyisocyanate composition according to the present invention, the composition ratio of the keto body is preferably 50% or more, more preferably Is 75% or more, more preferably 90% or more. The composition ratio of the keto body and enol body can be determined by ¹ H-NMR.

R ₁ and R ₂ in the general formula (II) may be the same or different and are each independently an alkyl group having 1 to 8 carbon atoms, a phenyl group, or a benzyl group. From the viewpoint of maintaining a high effective NCO content (hereinafter also referred to as “effective NCO%”) and compatibility with the main agent and the like, R ₁ and R ₂ are the same or different alkyl groups having 1 to 8 carbon atoms. More preferably, they are the same or different alkyl groups having 1 to 4 carbon atoms, more preferably each independently a methyl group or an ethyl group, and more preferably both are ethyl groups. Further preferred.

  Effective NCO% in this embodiment is the mass% of the isocyanate group which exists potentially with respect to the total mass of a block polyisocyanate composition. The potentially present isocyanate group means an isocyanate group when it is assumed that the blocked isocyanate group contained in the blocked polyisocyanate composition is not bonded to the blocking agent.

  The blocked isocyanate represented by the general formula (I) includes, as the substituent B, the keto compound represented by the general formula (III) or an enol isomer thereof. A plurality of substituents B present in a molecule may be the same as or different from each other.

The structural unit represented by the general formula (II) represents a keto body, and enol isomers of the structural unit include all keto-enol tautomers. For example, a structure in which a proton of a methine group becomes an enol body on the amide group side and a structure in which an enolic body on the ester group side is included. Among the substituents B in the entire blocked isocyanate represented by the general formula (I) contained in the blocked polyisocyanate composition according to the present invention, the composition ratio of the keto body is preferably 50% or more, more preferably Is 75% or more, more preferably 90% or more. The composition ratio of the keto body and enol body can be determined by ¹ H-NMR.

R ₁ in the general formula (III) is an alkyl group having 1 to 8 carbon atoms, a phenyl group, or a benzyl group. From the viewpoint of maintaining a high effective NCO content and compatibility with the main agent and the like, R ₁ is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. Further, a methyl group or an ethyl group is more preferable, and an ethyl group is still more preferable.

R ₃ and R ₄ in the general formula (III) may be the same or different and may contain at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. R ₄ and R ₅ are bonded to each other to form a 5- or 6-membered cycloalkyl group, or together with a nitrogen atom sandwiched between R ₃ and R ₄ Thus, a bridging member may be formed which is added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain a nitrogen atom or an oxygen atom. Among them, R ₃ and R ₄ may be the same or different, and may contain at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. Group or together with the nitrogen atom bound to R ₃ and R ₄ to form a bridging member that is added to a 3-, 4-, 5- or 6-membered ring that may contain a nitrogen or oxygen atom It is preferable to do.

Here, R ₃ and R ₄ in the general formula (III) are divided into a structure that exists independently (hereinafter also referred to as an independent structure) and a structure that is connected (hereinafter also referred to as a connected structure). explain.

R ₃ and R _{4 in} the general formula (III) in the case of an independent structure may be the same or different, and may include at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. It is a good hydrocarbon group having 1 to 30 carbon atoms. When R ₃ and R ₄ are alkyl groups having 30 or less carbon atoms, it is possible to suppress a decrease in effective NCO% and maintain high compatibility with the main agent and the like when used as a paint.

R ₃ and R ₄ are preferably the same or different hydrocarbon group having 1 to 8 carbon atoms, more preferably the same or different branched alkyl group having 3 to 6 carbon atoms, More preferably, they are the same or different branched alkyl groups having 3 to 4 carbon atoms. Among them, R ₃ and R ₄ is preferably a both number 3-6 branched alkyl group carbon atoms, and particularly preferably an isopropyl group.

When R ₃ and R ₄ are a hydrocarbon group having 1 to 30 carbon atoms containing at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group, the ether bond, the ester bond, Of the hydroxyl group, carbonyl group, and thiol group, an ether bond and an ester bond are preferable.

The group consisting of R ₃ and R ₄ and the nitrogen atom in the general formula (III) in the case of a linking structure is a residue excluding the active hydrogen of the cyclic secondary amine containing a nitrogen atom shown below.
Examples of the cyclic secondary amine include azabicyclo compounds such as 2-azabicyclo [2.1.1] hexane and 7-azabicyclo [2.2.1] heptane;
Aziridine, azetidine, pyrrolidine, 2-methylpyrrolidine, 3-pyrroldiol, 2-pyrrolidone, proline, 4-hydroxyproline, piperidine, 2-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 4-benzylpiperidine, 2 , 4-dimethylpiperidine, 3,5-dimethylpiperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, 3-piperidinemethanol, 2-piperidineethanol, 4-piperidineethanol, 4-piperidinol 2-piperidone, 4-piperidone, 4-piperidinecarboxylic acid methyl ester, 4-piperidinecarboxylic acid ethyl ester, 2,2,6,6-tetramethyl-4-piperidone, 4-piperidinopiperidine, decahydroquinoline Piperazine N-methylpiperazine, N-ethylpiperazine, N-allylpiperazine, N-isobutylpiperazine, N-cyclohexylpiperazine, N-cyclopentylpiperazine, N-phenylpiperazine, 1- (2-pyridyl) piperazine, 1- (4-pyridyl) ) Piperazine, 1- (2-pyrimidyl) piperazine, N-methylhomopiperazine, N-acetylhomopiperazine, N-butyrylhomopiperazine, oxazolidine, morpholine, imidazolidine, 2-imidazolidone, hydantoin, 1-methylhydantoin, 5 -Saturated cyclic secondary amines such as methylhydantoin, creatinine, paravanic acid, urazole, thiazolidine, thiaridine;
Pyrrole, 2-methylpyrrole, 2,4-dimethylpyrrole, 3,4-dimethylpyrrole, 2-acetylpyrrole, 2-pyrrolecarboxylic acid, indole, 3H-indole, 3-methylindole, 2-phenylindole, 3- Hydroxylindole, 3-indoleacetic acid, indoline, 2-indolinone, isatin, α-cisatin oxime, isoindole, isoindoline, 1-isoindolinone, carbazole, 1,2,3,4-tetrahydroquinoline, 1,2,3 , 4-tetrahydroisoquinoline, 9-acridone, pyrazole, 3,5-dimethylpyrazole, imidazole, benzimidazole, benzimidazolone, 1H-1,2,3-triazole, 1H-1,2,4-triazole, benzotriazole Tetrazo , Purine, xanthine, phenoxazine, isatoic anhydride, benzothiazoline, 2-benzothiazolone, phenothiazine, 5,10-dihydro-phenazine, beta-carboline, aromatic secondary amines, such as perimidine;
2-pyrroline, 3-pyrroline, dihydropyridine, 2-pyrazoline, 5-pyrazolone, 2-imidazoline, 4H-1,4-oxazine, 4H-1,4-thiazine, 2H, 6H-1,5,2-dithiazine Such unsaturated bond-containing cyclic secondary amines; and the like.

  Among these cyclic secondary amines, aziridine, azetidine, pyrrolidine, 2-methylpyrrolidine, 3-pyrroldiol, 2-pyrrolidone, proline, 4-hydroxyproline, piperidine, 2-methylpiperidine, 3-methylpiperidine, 4- Methylpiperidine, 4-benzylpiperidine, 2,4-dimethylpiperidine, 3,5-dimethylpiperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, 3-piperidinemethanol, 2-piperidineethanol 4-piperidineethanol, 4-piperidinol, 2-piperidone, 4-piperidone, 4-piperidinecarboxylic acid methyl ester, 4-piperidinecarboxylic acid ethyl ester, 2,2,6,6-tetramethyl-4-piperidone, 4, -Piperidinopiperidine Decahydroquinoline, piperazine, N-methylpiperazine, N-ethylpiperazine, N-allylpiperazine, N-isobutylpiperazine, N-cyclohexylpiperazine, N-cyclopentylpiperazine, N-phenylpiperazine, 1- (2-pyridyl) piperazine, 1- (4-pyridyl) piperazine, 1- (2-pyrimidyl) piperazine, N-methylhomopiperazine, N-acetylhomopiperazine, N-butyrylhomopiperazine, oxazolidine, morpholine, imidazolidine, 2-imidazolidone, hydantoin, 1-methylhydantoin, 5-methylhydantoin, creatinine, parabanic acid, urazole, thiazolidine, and thiaridine are preferable.

Among these cyclic secondary amines, aziridine, azetidine, pyrrolidine, 2-methylpyrrolidine, piperidine, 2-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 4-benzylpiperidine, 2,4-dimethylpiperidine 3,5-dimethylpiperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, 4-piperidinecarboxylic acid methyl ester, 4-piperidinecarboxylic acid ethyl ester, 2,2,6,6 -Tetramethyl-4-piperidone, 4-piperidinopiperidine, piperazine, N-methylpiperazine, N-ethylpiperazine, N-allylpiperazine, N-isobutylpiperazine, N-cyclohexylpiperazine, N-cyclopentylpiperazine, N-phenyl Piperazine, 1- 2-pyridyl) piperazine, 1- (4-pyridyl) piperazine, 1- (2-pyrimidyl) piperazine, N- methyl homopiperazine, N- acetyl homopiperazine, more preferably N- butyryl homopiperazine,
Pyrrolidine, 2-methylpyrrolidine, piperidine, 2-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 2,4-dimethylpiperidine, 3,5-dimethylpiperidine, 2,6-dimethylpiperidine, 2,2,6 , 6-tetramethylpiperidine is more preferred,
2-methylpiperidine, 2,6-dimethylpiperidine, and 2,2,6,6-tetramethylpiperidine are even more preferable.

  As shown above, examples of the cyclic secondary amine containing a nitrogen atom include saturated cyclic secondary amines, aromatic secondary amines, and unsaturated bond-containing cyclic secondary amines. preferable. Of the saturated cyclic secondary amines, secondary amines containing only one nitrogen atom are preferred, secondary amines that are 5-membered or 6-membered rings are more preferred, and a structure represented by the following general formula (IV) is preferred. A secondary amine having is more preferable. The secondary amine having the structure represented by the general formula (IV) is a piperidine derivative in which the 2,6-position is a hydrogen atom or a methyl group, and at least one of the 2,6-positions is a methyl group. . Specific examples of the secondary amine having a structure represented by the general formula (IV) include the aforementioned 2-methylpiperidine, 2,6-dimethylpiperidine, and 2,2,6,6-tetramethylpiperidine.

In general formula (IV), R < ₅ > -R < ₈ > is a hydrogen atom or a methyl group each independently. However, at least one of R _{5 to} R ₈ is a methyl group.
That is, in the alkyl substituent on the nitrogen atom in the general formula (III), it is preferable that at least one of the carbon atoms adjacent to the nitrogen atom is bonded to two or more carbon atoms.

  The block polyisocyanate composition according to the present invention is a block polyisocyanate composition having a keto isomer represented by the following general formula (IX) or an enol isomer thereof as an alternative to the keto isomer represented by the general formula (III) or an enol isomer thereof. A part of isocyanate may be contained.

In General Formula (IX), R ₃ and R ₄ may be the same or different, and may contain at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. R ₃ and R ₄ together form a 5- or 6-membered cycloalkyl group or together with a nitrogen atom bonded to R ₃ and R ₄ In addition, a bridging member may be formed which is added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain a nitrogen atom or an oxygen atom.

In general formula (IX), R ₁₀ and R ₁₁ may be the same or different and are each independently selected from a hydrogen atom or optionally an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. It is a C1-C30 hydrocarbon group which may contain at least 1 type. R ₁₀ and R ₁₁ together form a 5- or 6-membered cycloalkyl group, or together with the nitrogen atom bonded to R ₁₀ and R ₁₁ , a nitrogen atom or oxygen A bridging member may be formed which is added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain atoms.

  In the block polyisocyanate composition according to the present invention, the content of the block polyisocyanate in which the substituent A in the general formula (I) is the general formula (IX) suppresses crystallization while maintaining low-temperature curability. In view of the above, it is preferably 50% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, and still more preferably 10% by mass or less.

  The block polyisocyanate composition according to the present invention comprises at least one block polyisocyanate having a substituent C having a specific structure represented by the following general formula (V) from the viewpoint of further enhancing dispersibility in the aqueous coating composition. It is preferable to include. The definition in the block polyisocyanate of the general formula (V) is included in the scope of the definition in the general formula (I).

  A and B in the general formula (V) are each a substituent represented by the general formula (I), and C is a structural unit represented by the following general formula (VI). A plurality of A present in one block polyisocyanate of the general formula (V) may be the same as or different from each other. Similarly, a plurality of B present in one molecule of the block polyisocyanate of the general formula (V) may be the same or different from each other, and a plurality of C present in one molecule of the block polyisocyanate of the general formula (V) are They may be the same or different from each other.

R ₉ in the general formula (VI) is a residue excluding active hydrogen of the active hydrogen-containing hydrophilic compound.

  The active hydrogen-containing hydrophilic compound serving as the structural unit represented by C in the general formula (VI) is selected from nonionic hydrophilic compounds, anionic hydrophilic compounds, and cationic hydrophilic compounds. Among these, from the viewpoint of ease of production, nonionic hydrophilic compounds and anionic hydrophilic compounds are preferable, and nonionic hydrophilic compounds are more preferable. These hydrophilic compounds may be used alone or in combination of two or more.

  Examples of nonionic hydrophilic compounds include polyethylene glycol compounds having at least three consecutive ethylene oxide groups. Furthermore, the number average molecular weight of the nonionic hydrophilic compound is preferably 200 to 2,000. The lower limit of the number average molecular weight is more preferably 300, still more preferably 400. The upper limit of the number average molecular weight is more preferably 1500, still more preferably 1200, and still more preferably 1000. When the lower limit of the number average molecular weight is 200 or more, sufficient water dispersibility of the composition can be obtained. On the other hand, when the upper limit of the number average molecular weight is 2000 or less, it is possible to suppress a decrease in coating properties such as water resistance after baking.

  The polyethylene glycol compound may contain other oxyalkylene groups, specifically oxypropylene groups, oxystyrene groups, etc., in the ethylene oxide repeating unit. In that case, the ethylene oxide group molar ratio is preferably 60 mol% or more, more preferably 70 mol% or more, and further preferably 80 mol% or more. Since the compoundability in the aqueous coating composition can be improved efficiently, the ethylene oxide group molar ratio is preferably high.

  Examples of the polyethylene glycol compounds include monoalkoxy polyethylene glycol, polyethylene glycol or triol, so-called pluronic type polypropylene glycol or triol obtained by addition polymerization of ethylene oxide at the end of polypropylene glycol, polyoxypropylene polyoxyethylene copolymer diol or triol, polyol. Examples thereof include oxypropylene polyoxyethylene block polymer diol or triol. Among these, monoalkoxy polyethylene glycol and polyethylene glycol are preferable, and monoalkoxy polyethylene glycol is more preferable.

  Monoalkoxy polyethylene glycol is obtained by adding monoalcohol to one end of polyethylene glycol. As said monoalcohol, C1-C8 monoalcohol is preferable, C1-C6 monoalcohol is more preferable, C1-C4 monoalcohol is further more preferable, Methanol and ethanol are still more preferable. Accordingly, among the monoalkoxy polyethylene glycols, monomethoxy polyethylene glycol and monoethoxy polyethylene glycol are preferable, and monomethoxy polyethylene glycol is more preferable.

  Among these polyethylene glycol compounds used as the active hydrogen-containing hydrophilic compound, a polyethylene glycol compound in which a monoalcohol having 1 to 4 carbon atoms is added to one end having a number average molecular weight of 200 to 2000 is particularly preferable.

  Specific examples of polyethylene glycol include PEG200, 300, 400, 600, 1000, 2000 manufactured by Nippon Oil & Fats Co., Ltd. Moreover, as monomethoxy polyethylene glycol, Nippon Oil & Fats Co., Ltd. UNIOX M400, 550, 1000, 2000, the product MPG-081 of Nippon Emulsifier Co., Ltd. is mentioned.

  Examples of the anionic hydrophilic compound include a carboxylic acid group-containing compound and a sulfonic acid group-containing compound.

  Examples of the carboxylic acid group-containing compound include monohydroxycarboxylic acid, dihydroxycarboxylic acid, and derivatives thereof. Among the carboxylic acid group-containing compounds, monohydroxycarboxylic acid or dihydroxycarboxylic acid is preferable, and monohydroxycarboxylic acid is more preferable.

  Specific examples of the carboxylic acid-containing compound include hydroxypivalic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, or derivatives such as polycaprolactone diol and polyether polyol using these as initiators. Is mentioned. When using a carboxylic acid group containing compound, it is preferable to neutralize with a neutralizing agent after manufacture of a block polyisocyanate composition. Examples of the neutralizing agent include tertiary amines such as alkali metals, alkaline earth metals, ammonia, trimethylamine, triethylamine, and dimethylethanolamine.

  Examples of the sulfonic acid group-containing compound include aminoethylsulfonic acid, ethylenediamino-propyl-β-ethylsulfonic acid, 1,3-propylenediamine-β-ethylsulfonic acid, N, N-bis (2-hydroxyethyl). ) -2-aminoethanesulfonic acid. When a sulfonic acid group-containing compound is used, it is preferably neutralized with a neutralizing agent after the production of the block polyisocyanate composition as described above. Examples of the neutralizing agent include tertiary amines such as alkali metals, alkaline earth metals, ammonia, trimethylamine, triethylamine, and dimethylethanolamine.

  When the carboxylic acid group-containing compound is compared with the sulfonic acid group-containing compound, the carboxylic acid group-containing compound is preferable from the viewpoint of ease of production and compoundability in the aqueous coating composition.

  Examples of the cationic hydrophilic compound include a hydroxyl group-containing amino compound. Specific examples of the hydroxyl group-containing amino compound include dimethylethanolamine, diethylethanolamine, and hydroxypyridine. When using a hydroxyl-containing amino compound, it is preferable to neutralize with a neutralizing agent after manufacture of a block polyisocyanate composition like the above. Examples of the neutralizing agent include organic acids such as acetic acid, propionic acid, butanoic acid, and 2-ethylhexanoic acid.

  Examples of the active hydrogen of the active hydrogen-containing hydrophilic compound include a hydrogen atom of a hydroxyl group as long as it is a nonionic hydrophilic compound. In the case of hydroxypivalic acid which is an anionic hydrophilic compound, a hydrogen atom of a hydroxyl group is exemplified, and in the case of aminoethylsulfonic acid, a hydrogen atom of an amino group is exemplified. If it is dimethylethanolamine which is a cationic hydrophilic compound, the hydrogen atom of a hydroxyl group is illustrated. That is, the residue excluding active hydrogen of the active hydrogen-containing hydrophilic compound refers to a residue obtained by removing each active hydrogen from a nonionic, anionic, or cationic active hydrogen-containing hydrophilic compound.

  The total of m, n, and o in the general formula (V) is a value corresponding to the average number of isocyanate groups of the polyisocyanate that is the residue represented by R, and is preferably 2.0 to 20. . The lower limit value of the average number is more preferably 2.3, still more preferably 2.5, and even more preferably 3.0. The upper limit of the average number is more preferably 15, and further preferably 10. In addition, m, n, and o here mean the statistical average number with respect to R of A, B, and C, respectively.

  M, n and o in the general formula (V) are each independently a positive number. When the total of m, n, and o in the general formula (V) is 2.0 or more, a decrease in crosslinkability can be suppressed, and the desired coating film properties can be obtained. On the other hand, when the total of m, n, and o in the general formula (IV) is 20 or less, the cohesive force can be prevented from becoming too high, and a smooth coating film can be obtained. Further, neither m nor o is 0. n may be 0, but is preferably not 0. When m and o are not 0, the low temperature curability and the storage stability in the case of a water-based coating composition are kept good. Moreover, since o is not 0, generation | occurrence | production of isolation | separation, sedimentation, etc. in the case of setting it as an aqueous coating liquid composition can be avoided.

  In addition, the block polyisocyanate composition according to the present invention includes those in which some isocyanate groups remain. The preferred amount of the residual isocyanate group varies depending on the purpose of use, but when blended with a polyol or the like and used as a one-pack coating composition, from the viewpoint of ensuring storage stability, 20 moles of the isocyanate groups before blocking. %, Preferably 10 mol% or less, more preferably 5 mol% or less, and even more preferably no residual isocyanate group.

  When the block polyisocyanate contained in the block polyisocyanate composition according to the present invention is the block polyisocyanate represented by the general formula (I), for example, the following two production methods (hereinafter referred to as “production method 1” and “ (Referred to as “Production Method 2”).

  Production method 1 is a polyisocyanate that is a residue represented by R in general formula (I), that is, one or two selected from the group consisting of aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate. After reacting the polyisocyanate (a) formed as described above with the malonic acid diester (b) represented by the following general formula (VII), the organic amine compound (c) represented by the following general formula (VIII) is reacted. And producing a block polyisocyanate.

In General Formula (VII), R ₁ and R ₂ may be the same or different and each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, or a benzyl group.

In general formula (VIII), R ₃ and R ₄ may be the same or different, and may contain at least one selected from the group consisting of an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. A good hydrocarbon group having 1 to 30 carbon atoms, and R ₃ and R ₄ are bonded to each other to form a 5- or 6-membered cycloalkyl group, or bonded to R ₃ and R ₄ . A bridging member may be formed together with a nitrogen atom and added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain a nitrogen or oxygen atom.

  Production method 2 is a residue represented by R in formula (I), that is, formed from one or more selected from the group consisting of aliphatic isocyanates, alicyclic isocyanates, and aromatic isocyanates. This is a method for producing a block polyisocyanate by reacting the polyisocyanate (a) thus prepared with a compound represented by the following general formula (X).

In the general formula (X), _{R 1} is 1-8C alkyl carbon atoms, a phenyl group or a benzyl group. R ₃ and R ₄ may be the same or different and may contain at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. R ₃ and R ₄ are bonded to each other to form a 5- or 6-membered cycloalkyl group or a nitrogen atom bonded to R ₃ and R ₄ to form a nitrogen or oxygen atom. You may form the bridge member added to the 3-membered, 4-membered, 5-membered, or 6-membered ring which may be contained.

Of the production methods 1 and 2, production method 1 is more preferable because of the ease of production. The production method 1 will be described below.
Production method 1 is represented by a polyisocyanate (a) having one or more selected from the group consisting of an aliphatic polyisocyanate, an alicyclic polyisocyanate, and an aromatic polyisocyanate as a skeleton and a general formula (VII). 1st process which adds 75-150 mol% of malonic acid diester (b) with respect to the isocyanate group of polyisocyanate (a), and makes the isocyanate group of polyisocyanate (a) and malonic acid diester (b) react is included. .
In the production method 1, following the first step, the product obtained in the first step is reacted with one or more of the organic amine compounds (c) represented by the general formula (X). 2 steps are included.

  The amount of malonic acid diester (b) added in the first step is based on the isocyanate group in the polyisocyanate (a) that is the residue represented by R in the general formula (I) (or general formula (VII)). 75 to 150 mol%. The lower limit of the amount added is preferably 90 mol%, more preferably 95 mol%, and even more preferably 100 mol%. The upper limit of the amount added is preferably 130 mol%, more preferably 120 mol%, and even more preferably 110 mol%. When the addition amount is 75 mol% or more, deterioration of low-temperature curability can be prevented. Moreover, when the addition amount is 150 mol% or less, it is possible to suppress adverse effects on coating film properties such as water resistance of the baked coating film.

  In the first step, when introducing the substituent C of the general formula (VI), the malonic acid diester (b) and the active hydrogen-containing hydrophilic compound (d) are mixed with the malonic acid diester (b) and the active hydrogen. As a total amount of the hydrophilic compound (d), 77 to 150 mol% is added to the isocyanate group of the polyisocyanate (a), the polyisocyanate (a), the malonic acid diester (b), and the active hydrogen. A step of reacting the contained hydrophilic compound (d) is preferred. The lower limit of the total amount is more preferably 90 mol%, further preferably 95 mol%, and still more preferably 100 mol%. The upper limit of the total amount is more preferably 130 mol%, further preferably 120 mol%, and still more preferably 110 mol%. When the total amount of the compounds is 77 mol% or more, deterioration of the low-temperature curability of the composition can be prevented. Moreover, when the total amount of the said compound is 150 mol% or less, the bad influence with respect to coating film physical properties, such as water resistance of a baking coating film, can be suppressed. The active hydrogen-containing hydrophilic compound used in the first step has a function of improving the compoundability in the aqueous coating composition.

  The addition amount of the active hydrogen-containing hydrophilic compound (d) is 2 to 50 mol% based on the number of moles of active hydrogen with respect to the isocyanate group in the polyisocyanate (a) which is a precursor of the block polyisocyanate. Is preferred. The upper limit of the amount added is more preferably 40 mol%, and even more preferably 35 mol%. When the addition amount is 2 mol% or more, sufficient water dispersibility of the composition can be obtained. Moreover, when the said addition amount is 50 mol% or less, the fall of a crosslinking density can be suppressed and desired physical properties, such as the water resistance of a coating film, can be obtained.

  The active hydrogen-containing hydrophilic compound (d) in the first step is selected from the aforementioned nonionic hydrophilic compounds, anionic hydrophilic compounds, and cationic hydrophilic compounds. Among these, from the viewpoint of ease of production, nonionic hydrophilic compounds and anionic hydrophilic compounds are preferable, and nonionic hydrophilic compounds are more preferable. These hydrophilic compounds may be used alone or in combination of two or more.

  In the first step, when the substituent C of the general formula (VI) is introduced, the malonic acid diester (b) is reacted after the reaction of the polyisocyanate (a) and the active hydrogen-containing hydrophilic compound (d). It is preferable.

  In the first step, when the substituent C of the general formula (VI) is introduced, the addition amount of the malonic acid diester (b) is 75 with respect to the isocyanate group in the polyisocyanate (a) which is the precursor of the block polyisocyanate. It is preferable that it is -148 mol%. The lower limit of the amount added is more preferably 88 mol%, and even more preferably 98 mol%. When the addition amount is 75 mol% or more, it is possible to prevent a decrease in the crosslinking density and obtain desired physical properties such as water resistance of the coating film. When the addition amount is 148 mol% or less, adverse effects on the physical properties of the coating film, such as water resistance, can be suppressed.

The malonic acid diester (b) in the first step is represented by the general formula (VII).
Specifically, R ₁ and R ₂ are each independently an alkyl group having 1 to 8 carbon atoms, a phenyl group, or a benzyl group. R ₁ and R ₂ may be the same or different. From the viewpoint of availability, R ₁ and R ₂ are preferably the same group.

When R ₁ and R ₂ are alkyl groups having 8 or less carbon atoms, it is possible to suppress a decrease in effective NCO% and to prevent deterioration in compatibility with the main agent and the like when used as a paint. Among these, R ₁ and R ₂ are preferably the same or different alkyl groups having 1 to 8 carbon atoms, more preferably the same or different alkyl groups having 1 to 4 carbon atoms, It is more preferably each independently a methyl group or an ethyl group, and even more preferably an ethyl group.

  Examples of the malonic acid diester (b) include dimethyl malonate, diethyl malonate, di-n-propyl malonate, diisopropyl malonate, di-n-butyl malonate, diisobutyl malonate, di-t-butyl malonate, and malonic acid. Examples thereof include methyl t-butyl ester, di-n-hexyl malonate, di-2-ethylhexyl malonate, diphenyl malonate, dibenzyl malonate, and the like. Among them, dimethyl malonate, diethyl malonate, di-n-propyl malonate, diisopropyl malonate, di-n-butyl malonate, diisobutyl malonate, di-t-butyl malonate, methyl t-butyl malonate, malonic acid Di n-hexyl and di-2-ethylhexyl malonate are preferred. More preferably, it is dimethyl malonate, diethyl malonate, di-n-propyl malonate, diisopropyl malonate, di-n-butyl malonate, diisobutyl malonate, di-t-butyl malonate, methyl t-butyl malonate. More preferred are dimethyl malonate and diethyl malonate, and even more preferred is diethyl malonate. The malonic acid diester shown above can be used alone or in combination of two or more.

  The reaction in the first step can be performed regardless of the presence or absence of a solvent. When using a solvent, it is preferable to use a solvent which is inert to the isocyanate group and hardly hydrolyzes. Preferred solvents include, for example, ether solvents such as propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone.

  For the reaction in the first step, a reaction catalyst can be used. Examples of the reaction catalyst include organic metal salts such as tin, zinc and lead, metal alcoholates, and tertiary amines.

  When the reaction catalyst may adversely affect the properties of the paint or coating film, it is preferable to deactivate the catalyst with an acidic compound or the like. Examples of acidic compounds in this case include inorganic acids such as hydrochloric acid, phosphorous acid, and phosphoric acid; sulfonic acids such as methanesulfonic acid, p-toluenesulfonic acid, p-toluenesulfonic acid methyl ester, and p-toluenesulfonic acid ethyl ester. Or derivatives thereof; ethyl phosphate, diethyl phosphate, isopropyl phosphate, diisopropyl phosphate, butyl phosphate, dibutyl phosphate, 2-ethylhexyl phosphate, di (2-ethylhexyl) phosphate, isodecyl phosphate, diisodecyl phosphate, oleyl acid phosphate, tetracosyl acid phosphate , Ethyl glycol acid phosphate, butyl pyrophosphate, butyl phosphite and the like. Two or more of these acidic compounds may be used in combination.

  The reaction in the first step can generally be performed at a reaction temperature of -20 to 150 ° C. The reaction temperature is preferably 0 to 100 ° C, more preferably 40 to 80 ° C. By performing the reaction at 150 ° C. or lower, side reactions can be suppressed, and by performing the reaction at −20 ° C. or higher, the reaction rate can be kept high.

  The composition ratio of m and n in the general formula (I) depends on the mole% of the malonic acid diester (b) added to the isocyanate group in the polyisocyanate (a) in the first step and the reaction rate. However, when finally mixing the block polyisocyanate composition synthesize | combined in another reaction tank, and making it the block polyisocyanate composition which concerns on this invention, it also depends on a mixing ratio. The composition ratio of n / m depends not only on the mol% of malonic acid diester (b) added to the isocyanate group in the polyisocyanate (a) in the first step, but also on the reaction rate thereof. It is preferable to confirm the isocyanate residual rate at the end of the first step. When the unreacted isocyanate group remains, the organic amine (c) in the second step is obtained from the reaction between the isocyanate group produced in the first step and the ester part of the reaction product of the malonic acid diester (b). Also preferentially react with isocyanate groups. In this invention, since it is preferable that the ratio of m is high and there are few residual isocyanate groups, it is more preferable to perform a 2nd process, after confirming that the isocyanate group has lose | disappeared in the 1st process.

  Next, the 2nd process of the manufacturing method 1 is demonstrated. The addition amount of the organic amine compound (c) represented by the general formula (VIII) in the second step is 1 to 300 mol% with respect to the isocyanate group of the polyisocyanate (a) which is a precursor of the block polyisocyanate. Is preferred. The lower limit of the amount added is more preferably 2 mol%, and even more preferably 3 mol%. The upper limit of the addition amount is more preferably 200 mol%, further preferably 150 mol%, and still more preferably 100 mol%. When the addition amount is 1 mol% or more, moisture stability can be kept high. When the addition amount is 300 mol% or less, the amount of free amine in the block polyisocyanate composition can be reduced, and coloring of the baked coating film can be prevented.

  The organic amine (c) used in the second step is added mainly for the reaction between the ester part of the reaction product of the polyisocyanate and the malonic acid diester (b) after the first step. However, when an isocyanate group remains after the first step, the remaining isocyanate group may react with the organic amine (c) used in the second step. In that case, it becomes the substituent B in general formula (I) (or general formula (IV)).

  Moreover, when the malonic acid diester (b) with respect to the isocyanate group in the polyisocyanate (a) is added in an amount exceeding 100 mol% in the first step, the malonic acid diester (b) remains after the first step. . In that case, a malonic acid monoester monoamide or malonic acid diamide, which is a reaction product of the malonic acid diester (b) remaining after the first step and the organic amine compound (c) added in the second step, is converted into a block polyisocyanate composition. Some of them may be included.

The organic amine compound (c) used in the second step is represented by the general formula (VIII). Specifically, in the organic amine compound (c) represented by the general formula (VIII), R ₃ and R ₄ may be the same or different, and an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group A hydrocarbon group having 1 to 30 carbon atoms which may contain at least one selected from R ₃ and R ₄ are bonded to each other to form a 5- or 6-membered cycloalkyl group, or R ₃ and R _4. In addition to the nitrogen atom bonded to the, it forms a bridging member added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain a nitrogen or oxygen atom. Among these, R ₃ and R ₄ may be the same or different, and may contain at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. It is a hydrogen group, or together with the nitrogen atom bonded to R ₃ and R ₄ , it forms a bridging member added to a 3-membered, 4-membered, 5-membered or 6-membered ring that may contain nitrogen or oxygen atoms. Is preferred.

  The organic amine compound (c) is roughly classified into a chain secondary amine compound and a cyclic secondary amine compound containing a nitrogen atom.

First, the chain secondary amine compound will be described. R ₃ and R ₄ in the chain secondary amine compound represented by the general formula (VIII) may be the same or different and are at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. It is a C1-C30 hydrocarbon which may contain. Among these, independently, it is preferable that it is a C1-C8 hydrocarbon. R ₃ and R ₄ are more preferably the same or different branched alkyl groups having 3 to 6 carbon atoms, and more preferably the same or different branched alkyl groups having 3 to 4 carbon atoms. More preferably, it is an isopropyl group. When R ₃ and R ₄ are hydrocarbons having 30 or less carbon atoms, a decrease in effective NCO% can be suppressed and compatibility with the main agent and the like when used as a paint can be kept high.

  Examples of the chain secondary amine compound used in the present invention include dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, dioctylamine, dilaurylamine, ditridecylamine, and distearylamine. Linear secondary amines; branched like diisopropylamine, diisobutylamine, di (2-butylamine), di (t-butyl) amine, di (2-ethylhexyl) amine, dicyclohexylamine, di (2-methylcyclohexyl) amine Secondary amine; secondary amine containing unsaturated double bond such as diallylamine; methylethylamine, N-methylisopropylamine, methyl t-butylamine, N-methylhexylamine, ethyl t-butylamine, N-ethylhexylamine, N- D Such as ru-1,2-dimethylpropylamine, N-ethylisoamylamine, N-ethyllaurylamine, N-ethylstearylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine, Nt-butylcyclohexylamine Asymmetric secondary amine: diphenylamine, dibenzylamine, methylbenzylamine, ethylbenzylamine, t-butylbenzylamine, N-methylaniline, N-ethylaniline, N-cyclohexylaniline, 3- (benzylamino) propionic acid ethyl ester Secondary amines having an aromatic substituent such as: 2- (hydroxymethylamino) ethanol, diethanolamine, N-methylethanolamine, 4-methylaminobutanol, N-ethylethanolamine, N-propyl ether Noruamin, N- isopropyl ethanolamine, N- butyl ethanolamine, and the like.

  Among the chain secondary amine compounds, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, dioctylamine, diisopropylamine, diisobutylamine, di (2-butylamine), di (t-butyl) Amine, di (2-ethylhexyl) amine, dicyclohexylamine, di (2-methylcyclohexyl) amine, diallylamine, methylethylamine, N-methylisopropylamine, methyl t-butylamine, N-methylhexylamine, ethyl t-butylamine, N -Ethylhexylamine, N-ethyl-1,2-dimethylpropylamine, N-ethylisoamylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine, Nt-butylcyclohexyl Amine, diphenylamine, dibenzylamine, methylbenzylamine, ethylbenzylamine, t-butylbenzylamine, N-methylaniline, N-ethylaniline, 2- (hydroxymethylamino) ethanol, diethanolamine, N-methylethanolamine, 4 -Methylaminobutanol, N-ethylethanolamine, N-propylethanolamine, N-isopropylethanolamine, N-butylethanolamine are preferred. More preferred are diisopropylamine, diisobutylamine, di (2-butylamine), di (t-butyl) amine, dicyclohexylamine, Nt-butylcyclohexylamine, and more preferred are diisopropylamine, diisobutylamine, di ( 2-butylamine) and di (t-butyl) amine, and more preferably diisopropylamine.

Next, the cyclic secondary amine compound containing a nitrogen atom will be described. As the cyclic secondary amine compound containing a nitrogen atom, in general formula (VIII), R ₃ and R ₄ are taken together to form a 5- or 6-membered cycloalkyl group, or together with a nitrogen atom, It forms a bridging member that is added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain nitrogen or oxygen atoms.

  Specific examples of the cyclic secondary amine compound containing a nitrogen atom include 2-azabicyclo [2.1.1] hexane, azabicyclo compounds such as 7-azabicyclo [2.2.1] heptane, aziridine, azetidine, and pyrrolidine. 2-methylpyrrolidine, 3-pyrroldiol, 2-pyrrolidone, proline, 4-hydroxyproline, piperidine, 2-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 4-benzylpiperidine, 2,4-dimethylpiperidine 3,5-dimethylpiperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, 3-piperidinemethanol, 2-piperidineethanol, 4-piperidineethanol, 4-piperidinol, 2-piperidone, 4-piperidone, 4-piperidinecarboxylic acid Methyl ester, 4-piperidinecarboxylic acid ethyl ester, 2,2,6,6-tetramethyl-4-piperidone, 4-piperidinopiperidine, decahydroquinoline, piperazine, N-methylpiperazine, N-ethylpiperazine, N -Allylpiperazine, N-isobutylpiperazine, N-cyclohexylpiperazine, N-cyclopentylpiperazine, N-phenylpiperazine, 1- (2-pyridyl) piperazine, 1- (4-pyridyl) piperazine, 1- (2-pyrimidyl) piperazine N-methylhomopiperazine, N-acetylhomopiperazine, N-butyrylhomopiperazine, oxazolidine, morpholine, imidazolidine, 2-imidazolidone, hydantoin, 1-methylhydantoin, 5-methylhydantoin, creatinine, paraban , Saturated cyclic secondary amines such as urazole, thiazolidine, thiaridine; pyrrole, 2-methylpyrrole, 2,4-dimethylpyrrole, 3,4-dimethylpyrrole, 2-acetylpyrrole, 2-pyrrolecarboxylic acid, indole, 3H -Indole, 3-methylindole, 2-phenylindole, 3-hydroxylindole, 3-indoleacetic acid, indoline, 2-indolinone, isatin, α-cisatin oxime, isoindole, isoindoline, 1-isoindolinone, carbazole, 1 , 2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroisoquinoline, 9-acridone, pyrazole, 3,5-dimethylpyrazole, imidazole, benzimidazole, benzimidazolone, 1H-1,2,3 -Triazo Like 1H-1,2,4-triazole, benzotriazole, tetrazole, purine, xanthine, phenoxazine, isatoic acid, benzothiazoline, 2-benzothiazolone, phenothiazine, 5,10-dihydrophenazine, β-carboline, perimidine Aromatic secondary amine, 2-pyrroline, 3-pyrroline, dihydropyridine, 2-pyrazoline, 5-pyrazolone, 2-imidazoline, 4H-1,4-oxazine, 4H-1,4-thiazine, 2H, 6H-1 , 5,2-dithiazine-containing unsaturated secondary cyclic amines; and the like.

  Among the cyclic secondary amine compounds containing a nitrogen atom, aziridines, azetidines, pyrrolidines, 2-methylpyrrolidines, 3-pyrroldiols, 2-pyrrolidones, prolines, 4-hydroxyprolines, piperidines, 2-methylpiperidines, 3-methyls. Piperidine, 4-methylpiperidine, 4-benzylpiperidine, 2,4-dimethylpiperidine, 3,5-dimethylpiperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, 3-piperidinemethanol, 2-piperidineethanol, 4-piperidineethanol, 4-piperidinol, 2-piperidone, 4-piperidone, 4-piperidinecarboxylic acid methyl ester, 4-piperidinecarboxylic acid ethyl ester, 2,2,6,6-tetramethyl-4 -Piperidone, 4-pipe Dinopiperidine, decahydroquinoline, piperazine, N-methylpiperazine, N-ethylpiperazine, N-allylpiperazine, N-isobutylpiperazine, N-cyclohexylpiperazine, N-cyclopentylpiperazine, N-phenylpiperazine, 1- (2-pyridyl ) Piperazine, 1- (4-pyridyl) piperazine, 1- (2-pyrimidyl) piperazine, N-methylhomopiperazine, N-acetylhomopiperazine, N-butyrylhomopiperazine, oxazolidine, morpholine, imidazolidine, 2-imidazolidone Hydantoin, 1-methylhydantoin, 5-methylhydantoin, creatinine, parabanic acid, urazole, thiazolidine and thiaridine are preferred.

  Among the cyclic secondary amine compounds containing a nitrogen atom, more preferably, aziridine, azetidine, pyrrolidine, 2-methylpyrrolidine, piperidine, 2-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 4-benzylpiperidine, 2,4-dimethylpiperidine, 3,5-dimethylpiperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, 4-piperidinecarboxylic acid methyl ester, 4-piperidinecarboxylic acid ethyl ester, 2 , 2,6,6-tetramethyl-4-piperidone, 4-piperidinopiperidine, piperazine, N-methylpiperazine, N-ethylpiperazine, N-allylpiperazine, N-isobutylpiperazine, N-cyclohexylpiperazine, N- Cyclopentyl piperazine, N Phenylpiperazine, 1- (2-pyridyl) piperazine, 1- (4-pyridyl) piperazine, 1- (2-pyrimidyl) piperazine, N-methylhomopiperazine, N-acetylhomopiperazine, N-butyrylhomopiperazine More preferably, pyrrolidine, 2-methylpyrrolidine, piperidine, 2-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 2,4-dimethylpiperidine, 3,5-dimethylpiperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine is more preferable, and 2-methylpiperidine, 2,6-dimethylpiperidine, and 2,2,6,6-tetramethylpiperidine are more preferable.

Examples of the cyclic secondary amine compound containing a nitrogen atom include saturated cyclic secondary amines, aromatic secondary amines and unsaturated bond-containing cyclic secondary amines, as shown in the above-mentioned specific examples. Secondary amines are preferred. Of the saturated cyclic secondary amines, secondary amines containing only one nitrogen atom are preferred, secondary amines having a 5-membered ring or 6-membered ring are more preferred, and 2,6 represented by the following general formula (X) A secondary amine which is a piperidine derivative in which the substituent represented by R _{5 to} R ₈ at the position is a hydrogen atom or a methyl group and at least one of R _{5 to} R ₈ is a methyl group is more preferable. . Specific examples of the compound name include 2-methylpiperidine, 2,6-dimethylpiperidine, and 2,2,6,6-tetramethylpiperidine described above.

In general formula (XI), R ₅ , R ₆ , R ₇ and R ₈ are each independently a hydrogen atom or a methyl group. However, at least one of R ₅ , R ₆ , R ₇ , and R ₈ is a methyl group.

  In the 2nd process of the manufacturing method 1, the chain amine compound shown above and the cyclic amine compound containing a nitrogen atom can also be used independently, and it can also be used in combination of 2 or more types. Similarly to the reaction in the first step, the reaction in the second step can be performed regardless of the presence or absence of a solvent. When using a solvent, it is preferable to use a solvent which is inert to the isocyanate group and hardly hydrolyzes. Preferred solvents include, for example, ether solvents such as propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone.

  In the reaction of the second step of production method 1, the catalyst described above can be used for the first step. However, when used, the reaction solution may be colored, so the catalyst may not be used. preferable. When a catalyst is used in the first step, it is preferable to carry out the second step after deactivation with an acidic compound or the like.

  The reaction in the second step can be generally performed at a reaction temperature of -20 to 150 ° C. as in the first step. The reaction temperature is preferably 0 to 100 ° C, more preferably 40 to 80 ° C. By performing the reaction at 150 ° C. or lower, side reactions can be suppressed, and by performing the reaction at −20 ° C. or higher, the reaction rate can be kept high.

  After the reaction in the second step of the production method 1, as the third step, the remaining organic amine compound and / or the reaction between the ester group of the reaction product of polyisocyanate and malonic acid diester produced in the first step and the organic amine compound In order to reduce the amount of the alcohol compound dissociated by (that is, the reaction in the second step), it is preferable to carry out removal purification and the like.

  In order to improve moisture stability when used as a solvent-based paint, and storage stability when used as an aqueous paint composition (inhibition of gas generation amount, suppression of change in coating pH), after the reaction in the second step. The remaining organic amine compound (c) is preferably subjected to removal purification by heating at 20 to 80 ° C. under reduced pressure to reduce the remaining amount. The residual amount of the organic amine compound (c) is preferably 50 mol% or less, more preferably 30 mol% or less, and even more preferably 10 mol% or less based on the blocked isocyanate group of the blocked polyisocyanate. The number of moles of the blocked isocyanate group in this case indicates the number of moles based on the isocyanate group derived from the polyisocyanate which is the precursor for the general formula (I), and is the precursor for the general formula (V). The number of moles based on the isocyanate group that forms the partial structure represented by A and B in the polyisocyanate is shown.

  In addition, with respect to the alcohol compound dissociated by the reaction of the ester group of the polyisocyanate and malonic acid diester produced in the first step and the organic amine compound, moisture stability when used as a solvent-based paint, In order to improve the storage stability (suppression of gas generation amount and suppression of change in coating solution pH) when used as a coating composition, it is preferable to reduce the residual amount as with the remaining organic amine compound. The residual amount of the alcohol compound is preferably 80 mol% or less, more preferably 50 mol% or less, still more preferably 30 mol% or less, still more preferably 10 mol% or less, based on the blocked isocyanate group of the block polyisocyanate. .

  The block polyisocyanate composition containing the block polyisocyanate represented by the general formula (V) is added to the general formula (V) in addition to the method for producing the block polyisocyanate composition containing the block polyisocyanate represented by the general formula (I). Including the step of introducing the indicated substituent C. In that case, the reaction of the isocyanate group of the polyisocyanate (a) with the active hydrogen-containing hydrophilic compound (d), the reaction with the malonic acid diester (b) and / or the organic amine compound (c) can be carried out simultaneously, after pre-performed either reaction can also be carried out a second reaction. Among them, it is preferable to react the malonic acid diester (b) and / or the organic amine compound (c) after reacting the isocyanate group and the active hydrogen-containing hydrophilic compound (d).

  Moreover, the block polyisocyanate composition according to the present invention may be produced collectively by any of the production methods described above, or may be mixed with separately produced block polyisocyanate compositions.

  The block polyisocyanate composition according to the present invention is used alone or mixed with a block polyisocyanate derived from two or more kinds of block agents selected from existing active methylene-based, oxime-based, amine-based and pyrazole-based blocking agents. You can also

  When a large amount of existing oxime-based block polyisocyanate, amine-based block polyisocyanate, and pyrazole-based block polyisocyanate are mixed, the low-temperature curability may be lowered. Therefore, the mixing amount of the block polyisocyanate other than the block polyisocyanate according to the general formula (I) or the general formula (V) is preferably less than 50 mol%, more preferably with respect to the total amount of these block polyisocyanates. Is less than 20 mol%, more preferably less than 10 mol%.

  Examples of the existing active methylene blocking agent include dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone. Among the active methylene-based blocking agents, dimethyl malonate and diethyl malonate are preferable because of excellent low-temperature curability. Examples of the oxime blocking agent include formaldehyde oxime, acetoald oxime, acetone oxime, methyl ethyl ketoxime, and cyclohexanone oxime.

  Examples of the amine blocking agent include diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, isopropylethylamine, and the like. Examples of the pyrazole-based blocking agent include pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole and the like.

  The number average molecular weight of the block polyisocyanate composition according to the present invention is preferably 500 to 5,000. The lower limit of the number average molecular weight is more preferably 700, still more preferably 800, and still more preferably 1,000. The upper limit of the number average molecular weight is more preferably 4,000, further preferably 3,000, and further preferably 2,000. If the number average molecular weight is 500 or more, the number of functional groups of the blocked isocyanate group per molecule can be ensured to be 2.0 or more, and if the number average molecular weight is 5,000 or less, the viscosity can be increased. Can be suppressed.

  The viscosity of the block polyisocyanate composition according to the present invention is 100 to 1,000 mPa · s / 25 ° C. with a resin solid content of 60% by mass diluted with a solvent or the like. When the viscosity is 100 mPa · s / 25 ° C. or higher, the number of functional groups of blocked isocyanate groups per molecule of 2.0 or more can be secured, and by being 1,000 mPa · s / 25 ° C. or lower. , Blending into paint becomes easy.

  Improves moisture stability when the block polyisocyanate composition according to the present invention is used in solvent-based paints, and storage stability when used in aqueous paint compositions (inhibition of gas generation and pH change of coating liquid) Therefore, it is preferable to add a basic compound (e) having an acid dissociation constant (pKa) of 7.0 to 8.5. Moreover, it is preferable that the said basic compound (e) is mixed 10 mol% or more with respect to the block isocyanate group of a block polyisocyanate composition. The acid dissociation constant (pKa) here is a value measured at 20 ° C. by potentiometric titration.

  Block polyisocyanate composition in which 10 mol% or more of basic compound (e) having an acid dissociation constant (pKa) of 7.0 to 8.5 is mixed with a block isocyanate group of a specific active methylene block polyisocyanate composition However, it was a surprising result that the storage stability as a water-based coating composition was greatly improved while maintaining the low-temperature curability and the curability retention after storage was high.

  Specific examples of the basic compound (e) having a pKa of 7.0 to 8.5 include morpholine (pKa: 8.4), N-allyl morpholine (pKa: 7.1), and N-methylmorpholine (pKa: 7. 4), morpholine derivatives such as N-ethylmorpholine (pKa: 7.7), triallylamine (pKa: 8.3), triethanolamine (PKa: 7.8), 2-methylimidazole (pKa: 7.8) ), Phthalamide (pKa: 8.3) and the like are preferable. Among the basic compounds (e), N-allylmorpholine, N-methylmorpholine, N-ethylmorpholine, triethanolamine, and 2-methylimidazole are more preferable, and N-methylmorpholine and N-ethylmorpholine are more preferable.

  The upper limit value of the pKa of the basic compound (e) used in the block polyisocyanate composition according to the present invention is more preferably 8.3, and even more preferably 8.0. When the pKa of the basic compound (e) is 7.0 or more, the storage stability is improved. When the pKa of the basic compound (e) is 8.5 or less, it is possible to prevent the pH at the time of blending the aqueous coating composition from becoming too high.

  The mixing amount of the basic compound (e) is preferably 10 mol% or more based on the blocked isocyanate group of the blocked polyisocyanate composition. The lower limit value of the mixing amount of the basic compound (e) is more preferably 20 mol%, further preferably 30 mol%. As an upper limit of a basic compound (e), Preferably it is 500 mol%, More preferably, it is 400 mol%, More preferably, it is 300 mol%. The number of moles of the blocked isocyanate group in this case is the number of moles based on the isocyanate group derived from the polyisocyanate that is the precursor for the general formula (I), and the precursor for the general formula (VI). It is the number of moles based on the isocyanate group that forms the partial structures of A and B in the polyisocyanate.

  Moreover, you may mix a basic compound with pKa exceeding 8.5 partially in the block polyisocyanate composition based on this invention. The mixing amount is preferably 100 mol% or less, more preferably 50 mol% or less, still more preferably 30 mol% or less, based on the blocked isocyanate group of the block polyisocyanate composition. More preferably, it is at most mol%.

  The basic compound (e) having a pKa of 7.0 to 8.5 existing in the block polyisocyanate composition according to the present invention is preferably added after the first step and the second step are completed. More preferably, after the second step and the third step are completed.

  In the block polyisocyanate composition according to the present invention, the composition containing the block polyisocyanate having the structure of the general formula (I) or the general formula (V) is used as a coating composition, thereby maintaining low-temperature curability. However, yellowing resistance during overbaking can be remarkably improved. Patent Document 3 discloses a co-block polyisocyanate composition having (α) diisopropylamine, (β) active methylene compound, and (γ) oxime as a blocking agent (based on the molar equivalent of the isocyanate group of the polyisocyanate composition). , Α + β + γ = 100 mol%). However, the block polyisocyanate contained in the composition according to the present invention is greatly different in that it has the structure of A in the general formula (I).

  The block polyisocyanate composition according to the present invention forms a coating composition by blending with at least one of polyol, polyamine and alkanolamine.

  Furthermore, in order to improve the storage stability when blended with a polyol, the block polyisocyanate composition in the present invention may contain a monohydric alcohol compound. Examples of the monohydric alcohol compound include aliphatic, alicyclic, and aromatic monohydric alcohol compounds, and aliphatic monohydric alcohol compounds are preferable.

  As the aliphatic monohydric alcohol compound, for example, a monohydric alcohol compound having 1 to 20 carbon atoms is preferable. Specifically, methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, t-butanol, 2-ethyl-1-propanol, n-amyl alcohol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol , Saturated alcohols such as 3-methyl-2-butanol and 2,2-dimethyl-1-propanol; ethers such as 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol and 3,6-dioxa-1-heptanol Alcohol; etc. The addition amount is preferably 0.2 to 10 times the molar amount of the blocked isocyanate group contained in the composition.

  Furthermore, the coating composition according to the present invention can be used as an aqueous coating composition in which a block polyisocyanate composition and at least one of a polyol, a polyamine, and an alkanolamine are dissolved or dispersed in water. When the coating composition according to the present invention is used as an aqueous coating composition, in order to improve the compoundability in the aqueous coating composition, the block polyisocyanate composition according to the present invention is free from surfactants and water. You may use the solvent etc. which show the tendency of miscibility. Examples of the surfactant include anionic properties such as aliphatic soap, rosin acid soap, alkyl sulfonate, dialkylaryl sulfonate, alkylsulfosuccinate, polyoxyethylene alkyl sulfate, and polyoxyethylene alkylaryl sulfate. Surfactant; Nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, and polyoxyethylene oxypropylene block copolymer are listed. Solvents that tend to be miscible with water include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, isobutanol, butyl glycol, and N-methylpyrrolidone. Butyl diglycol or butyl diglycol acetate.

  Among the solvents, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, isobutanol, butyl glycol, N-methylpyrrolidone, and butyl diglycol are preferable, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, More preferred are propylene glycol dimethyl ether and dipropylene glycol dimethyl ether. These solvents may be used alone or in combination of two or more. Moreover, the solvent of esters, such as ethyl acetate, acetic acid-n-butyl, and cellosolve acetate, is not preferable because the solvent itself may be hydrolyzed during storage.

  The block polyisocyanate composition thus prepared becomes a main component of the coating composition together with at least one of polyol, polyamine and alkanolamine. Among these, it is preferable that a polyol is included. Examples of the polyol include polyester polyol, acrylic polyol, polyether polyol, polyolefin polyol, fluorine polyol, polycarbonate polyol, and polyurethane polyol.

  As the polyester polyol, for example, a dibasic acid selected from the group of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, or a mixture thereof Polyester polyol obtained by a condensation reaction with a single or mixture of polyhydric alcohols selected from the group of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, glycerin, and the like, and for example, polyhydric alcohol And polycaprolactones obtained by ring-opening polymerization of ε-caprolactone.

  As the acrylic polyol, for example, an ethylenically unsaturated bond-containing monomer having a hydroxyl group alone or a mixture thereof and another ethylenically unsaturated bond-containing monomer copolymerizable therewith can be used. What is obtained by polymerizing is mentioned.

  Examples of the ethylenically unsaturated bond-containing monomer having a hydroxyl group include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxybutyl methacrylate. Can be mentioned. Among the ethylenically unsaturated bond-containing monomers, hydroxyethyl acrylate and hydroxyethyl methacrylate are preferable.

  Examples of other ethylenically unsaturated bond-containing monomers copolymerizable with the monomer include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, acrylic acid-n-butyl, and acrylic acid. Acrylic esters such as isobutyl, acrylic acid-n-hexyl, cyclohexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, benzyl acrylate, and phenyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacryl Isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid n-hexyl, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, benzyl methacrylate, phenyl methacrylate, etc. Unsaturated carboxylic acid such as tacrylic acid ester, acrylic acid, methacrylic acid, maleic acid, itaconic acid; acrylamide, methacrylamide, N, N-methylenebisacrylamide, diacetone acrylamide, diacetone methacrylamide, maleic amide, maleimide, etc. Unsaturated amides; vinyl monomers such as glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile, dibutyl fumarate; and vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ- (meth) acryloxypropyl And vinyl monomers having a hydrolyzable silyl group such as trimethoxysilane.

  As the polyether polyols, a polybasic hydroxy compound may be used alone or in a mixture, for example, a hydroxide such as lithium, sodium or potassium, a strong basic catalyst such as an alcoholate or an alkylamine, ethylene oxide, propylene oxide, Polyether polyols obtained by adding alkylene oxides such as butylene oxide, cyclohexene oxide, styrene oxide alone or in mixture; polyether polyols obtained by reacting alkylene oxide with a polyfunctional compound such as ethylenediamine; and And so-called polymer polyols obtained by polymerizing acrylamide or the like using these polyethers as a medium.

Examples of the polyvalent hydroxy compound include:
(1) Diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol, etc.
(2) Sugar alcohol compounds such as erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol, mannitol, galactitol, rhamnitol,
(3) monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, ribodesose,
(4) disaccharides such as trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose,
(5) trisaccharides such as raffinose, gentianose, and meletitose,
(6) Tetrasaccharides such as stachyose.

  Examples of the polyolefin polyol include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene. The number of hydroxyl groups (hereinafter, the average number of hydroxyl groups) possessed by one statistical molecule of polyol is preferably 2 or more. When the average number of hydroxyl groups of the polyol is 2 or more, a decrease in the crosslinking density of the obtained coating film can be suppressed.

  The fluorine polyol is a polyol containing fluorine in the molecule. For example, fluoroolefin, cyclovinyl ether, hydroxyalkyl vinyl ether, monocarboxylic acid disclosed in JP-A-57-34107 and JP-A-61-275111. Copolymers such as vinyl esters are exemplified.

Polycarbonate polyols include, for example, dialkyl carbonates such as dimethyl carbonate, alkylene carbonates such as ethylene carbonate, low molecular carbonate compounds such as diaryl carbonates such as diphenyl carbonate, and low molecular polyols used in the aforementioned polyester polyols. The thing obtained by superposition | polymerization is mentioned.
The polyurethane polyol can be obtained by a conventional method, for example, by reacting a polyol with a polyisocyanate. Examples of the polyol not containing a carboxyl group include ethylene glycol and propylene glycol as low molecular weights, and examples of the high molecular weight include acrylic polyol, polyester polyol, and polyether polyol.

  The hydroxyl value per resin of the polyol is preferably 10 to 300 mgKOH / resin g. When the hydroxyl value per resin is 10 mgKOH / g or more of the resin, it is possible to prevent the crosslink density from being reduced and sufficiently achieve the target physical properties according to the present invention. On the other hand, when the hydroxyl value per resin is 300 mgKOH / resin g or less, an excessive increase in the cross-linking density can be suppressed, and the mechanical properties of the coating film can be maintained at a high level.

  The acid value per resin of the polyol is preferably 5 to 150 mgKOH / resin g, more preferably 8 to 120 mgKOH / resin g, and still more preferably 10 to 100 mgKOH / resin g. When the acid value is 5 mgKOH / resin g or more, water dispersibility is kept high, and when the acid value is 150 mgKOH / resin g or less, a decrease in water resistance of the coating film can be prevented.

  Of the polyols listed above, acrylic polyols and polyester polyols are preferred. In the coating composition in the case of using a polyol, the equivalent ratio of the blocked isocyanate group to the hydroxyl group of the polyol is usually set to 10: 1 to 1:10.

As the polyamine, those having two or more primary amino groups or secondary amino groups in one molecule are used, and among them, those having three or more in one molecule are preferable.
Specific examples of polyamines include ethylenediamine, propylenediamine, butylenediamine, triethylenediamine, hexamethylenediamine, 4,4′-diaminodicyclohexylmethane, piperazine, diamines such as 2-methylpiperazine, isophoronediamine, bishexamethylenetriamine, Chain polyamines having three or more amino groups such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentamethylenehexamine, tetrapropylenepentamine, 1,4,7,10,13,16-hexaazacyclooctadecane Cyclic polyamines such as 1,4,7,10-tetraazacyclodecane, 1,4,8,12-tetraazacyclopentadecane and 1,4,8,11-tetraazacyclotetradecane. The

  The alkanolamine means a compound having an amino group and a hydroxyl group in one molecule. Examples of the alkanolamine include monoethanolamine, diethanolamine, aminoethylethanolamine, N- (2-hydroxypropyl) ethylenediamine, mono-, di- (n- or iso-) propanolamine, ethylene glycol-bis-propylamine, Examples include neopentanolamine and methylethanolamine.

  When the block polyisocyanate composition and the polyol according to the present invention are used in an aqueous coating composition, the blending method of the block polyisocyanate composition and the polyol may be performed by mixing and dispersing the block polyisocyanate composition in the polyol as it is. The block polyisocyanate composition may be once mixed with water and then mixed with the polyol.

  It is preferable that pH of the aqueous coating material composition containing the block polyisocyanate composition containing the block polyisocyanate represented by general formula (V) is 7.0-9.0. The lower limit of the pH is more preferably 7.5, and even more preferably 8.0. The upper limit of the pH is more preferably 8.8, and even more preferably 8.6. It is preferable that the pH of the water-based coating composition is 7.0 to 9.0 because the stability of additives such as pigments such as aluminum and rheology control agents can be maintained.

  Moreover, you may add the said basic compound (e) of pKa7.0-8.5 at the time of water-based coating composition blending. In that case, you may use together with the basic compound (e2) in which pKa exceeds 8.5. The composition ratio of the weak basic compound (e) to the sum of the weak basic compound (e) and the basic compound (e2) (total basic composition) is preferably 20 mol% or more.

The lower limit of the constituent ratio of the weakly basic compound (e) is preferably 30 mol%, more preferably 40 mol%, still more preferably 50 mol%. In the present invention, the weakly basic compound (e) is added in an amount of 20 mol% or more in the total basic composition, so that it is in excess of the formation of a neutral salt of the total acidic content present in each component in the coating. Is also preferable because the pH of the prepared coating composition does not become too high. Examples of the acidic group to be neutralized include a carbonyl group and a sulfonyl group, among which a carbonyl group is preferable. Moreover, about the carboxyl group in the case of the polyol which has a carboxyl group, the addition amount of all the basic compositions can be determined on the basis of the acid component of the preparation at the time of polyol manufacture.
The addition amount of the total basic composition is preferably 30 mol% or more with respect to 100 mol% of the total acidic content of the basic group present in each component in the paint. The lower limit of the amount added is more preferably 50 mol%, still more preferably 70 mol%, still more preferably 100 mol% or more. Moreover, as an upper limit of addition amount, Preferably it is 500 mol%, More preferably, it is 400 mol%, More preferably, it is 300 mol%.

  An existing melamine resin, epoxy resin, and polyurethane resin can be blended with the coating composition containing the block polyisocyanate composition according to the present invention. Moreover, when the polyol mentioned above has a carboxyl group, an oxazoline group containing compound and a carbodiimide group containing compound can be mix | blended. Moreover, when the polyol mentioned above has a carbonyl group, a hydrazide group containing compound and a semicarbazide group containing compound can be mix | blended. These compounds can be blended not only alone but also two or more compounds.

  Examples of the melamine resin include a partial or completely methylolated melamine resin obtained by a reaction between melamine and an aldehyde. Examples of the aldehyde include formaldehyde and paraformaldehyde. Moreover, what methylated the methylol group of this methylolation melamine resin partially or completely etherified with alcohol can also be used. Examples of alcohols used for etherification include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-ethylbutanol, 2-ethylhexanol and the like.

  Specific examples of the melamine resin include Cymel 303, Cymel 323, Cymel 325, Cymel 327, Cymel 350, Cymel 370, Cymel 380, Cymel 385, Cymel 212, Cymel 251, Cymel 254, My Coat manufactured by Nippon Cytec Industries, Ltd. 776 (all are trade names).

  When a melamine curing agent is used in combination, an acidic compound is effective as a catalyst for curing. Specific examples of the acidic compound include carboxylic acid, sulfonic acid, acidic phosphate ester, and phosphite ester.

  Typical examples of the carboxylic acid include acetic acid, lactic acid, succinic acid, oxalic acid, maleic acid, and decanedicarboxylic acid. Typical examples of the sulfonic acid include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, and dinonylnaphthalenedisulfonic acid. Examples of acidic phosphate esters include dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, dilauryl phosphate, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, and monooctyl phosphate. Typical examples of phosphites include diethyl phosphite, dibutyl phosphite, dioctyl phosphite, dilauryl phosphite, monoethyl phosphite, monobutyl phosphite, monooctyl phosphite and monolauryl phosphite. Can be mentioned.

  The epoxy resin is not particularly limited as long as it is a resin having two or more epoxy groups in one molecule, and a known one can be used. Examples of the epoxy resin include a bisphenol type epoxy resin obtained by adding epoxychlorohydrin to bisphenol, a novolak type epoxy resin obtained by adding epichlorohydrin to a phenol novolac resin, and polyethylene glycol diglycidyl ether. The epoxy resin can be used after being dispersed in water as necessary.

  The polyurethane resin is not limited as long as it is generally used in paints. For example, a polyurethane resin obtained by reacting an isocyanate group with a polyol to extend the chain is preferable. The polyurethane resin includes those having a carboxyl group obtained by using a carboxyl group-containing polyol as part of the polyol, and those having a hydroxyl group at the terminal. The polyurethane resin having a carboxyl group is preferably neutralized with a basic substance. Examples of commercially available products include Superflex series 110, 150, and 460S (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Neoletz R9649, R966 (trade name, manufactured by Avicia).

  Examples of the oxazoline group-containing compound include a polymer compound having at least two oxazoline groups in the side chain, and a monomer compound having at least two oxazoline groups in the molecule.

  The carbodiimide group-containing compound can be obtained, for example, by subjecting the isocyanate groups of the polyisocyanate compound to a carbon dioxide removal reaction. Examples of commercially available carbodiimide group-containing compounds include Carbodilite V-02, Carbodilite V-02-L2, Carbodilite V-04, Carbodilite E-01, Carbodilite E-02 (all manufactured by Nisshinbo Co., Ltd., trade names), and the like. Can be mentioned.

The hydrazide group-containing compound includes a compound having at least 2, preferably 2 to 10, hydrazide groups represented by —CO—NH—NH ₂ in one molecule. Examples of the hydrazide group-containing compound include saturated dicarboxylic acid dihydrazides having 2 to 18 carbon atoms such as oxalic acid dihydrazide, malonic acid dihydrazide, glutaric acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide; maleic acid dihydrazide Monoolefinic unsaturated dicarboxylic acid dihydrazides such as fumaric acid dihydrazide and itaconic acid dihydrazide; and polyhydrazides obtained by reacting a low polymer having a carboxylic acid lower alkyl ester group with hydrazine or hydrazine hydrate. .

The semicarbazide group-containing compound includes a compound having at least two, preferably 2 to 10, semicarbazide groups represented by —NH—CO—NH—NH ₂ in one molecule. As a semicarbazide group-containing compound, for example, bissemicarbazide; a diisocyanate such as hexamethylene diisocyanate or isophorone diisocyanate or a polyisocyanate compound derived therefrom is reacted with an N, N-substituted hydrazine such as N, N-dimethylhydrazine or the hydrazine exemplified above. And polyfunctional semicarbazide obtained by the reaction.

  The coating composition according to the present invention includes an antioxidant, for example, hindered phenol, etc .; an ultraviolet absorber, for example, benzotriazole, benzophenone, etc .; a pigment, for example, titanium oxide, carbon black, indigo, quinacridone, as necessary. Metal powder pigments such as aluminum; rheology control agents such as hydroxyethyl cellulose, urea compounds, and microgels: curing accelerators such as tin compounds, zinc compounds, and amine compounds may be included. .

  The coating composition prepared in this manner is applied to a material such as a steel plate, surface-treated steel plate and other metals and plastics, inorganic materials, etc. by roll coating, curtain flow coating, spray coating, electrostatic coating, bell coating, etc. It is suitably used as an intermediate coating or top coating.

  In addition, this coating composition further imparts cosmetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, adhesion, etc. to pre-coated metal, automobile coating, plastic coating, etc. that contain rust-proof steel plates. Preferably used. The coating composition is also useful as a raw material for urethane such as adhesives, pressure-sensitive adhesives, elastomers, foams, and surface treatment agents.

  The coating composition according to the present invention forms a coating film through a baking process after coating by roll coating, curtain flow coating, spray coating, electrostatic coating, bell coating or the like. A cured product is obtained by curing the coating composition according to the present invention. The coating composition preferably has a cross-linked coating film formed through a baking process. The crosslinked coating film after curing of the coating composition is characterized by having not only a polyisocyanate-derived urethane bond before the blocking reaction but also polar groups such as an amide bond and an ester bond derived from a blocked isocyanate group. Therefore, the cross-linked coating film formed from the coating composition according to the present invention is used when performing multilayer coating or recoating in addition to chemical resistance, heat resistance, water resistance, etc., which are the characteristics of general urethane cross-linked coating films. In addition, hydrogen bonding between layers is possible, and the adhesion between layers is excellent. Even in the coating film in which the crosslinked structure is not completely formed after the baking step, since it has the above-mentioned polar group, it is excellent in adhesion as well as the crosslinked coating film at the time of lamination coating or recoating.

  In addition, when several layers of coating liquid are laminated by wet-on-wet as in the coating of a new automobile line, an organic amine compound is present in the coating composition according to the present invention or in the crosslinked coating film after curing. There is also the possibility of acting as a catalyst for the crosslinking reaction of the lower layer or the upper layer.

  Hereinafter, the present invention will be described in more detail based on examples. However, the present invention is not limited to the following examples. First, measurement and evaluation methods for various physical properties will be described.

<Measurement and evaluation methods for various physical properties>
(Measurement of number average molecular weight)
The number average molecular weight of the polyisocyanate is a polystyrene-based number average molecular weight measured by gel permeation chromatography (hereinafter referred to as GPC) using the following apparatus.

Equipment: Tosoh Corporation HLC-8120GPC (trade name)
Column: Tosoh Corporation TSKgel SuperH1000 (trade name) x 1
TSKgel SuperH2000 (trade name) x 1
TSKgel SuperH3000 (trade name) x 1 Carrier: Tetrahydrofuran Detection method: Differential refractometer

  The number average molecular weight of the polyol is a polystyrene-based number average molecular weight measured by GPC measurement described below.

Equipment: Tosoh Corporation HLC-8120GPC (trade name)
Column: Tosoh Corporation TSKgel SuperHM-H (trade name) x 2 Carrier: N, N-dimethylformamide Detection method: differential refractometer

(Measurement of viscosity)
It measured at 25 degreeC using E type | mold viscosity meter RE-85R (made by Toki Sangyo Co., Ltd.). When the viscosity was less than 5 Pa · s, a standard rotor (1 ° 34 ′ × R24) was used, and the rotational speed was as follows.

100r. p. m. (If less than 128 mPa · s)
50r. p. m. (In the case of 128 mPa · s or more and less than 256 mPa · s)
20r. p. m. (In the case of 256 mPa · s or more and less than 640 mPa · s)
10r. p. m. (In the case of 640 mPa · s or more and less than 1,280 mPa · s)
5r. p. m. (In the case of 1,280 mPa · s or more and less than 2,560 mPa · s)
2.5r. p. m. (In the case of 2,560 mPa · s or more and less than 5,120 mPa · s)

  When the viscosity was 5 Pa · s or higher, a high viscosity rotor (3 ° × R14) was used, and the rotation speed was as follows.

50r. p. m. (In the case of 5 Pa · s or more and less than 10 Pa · s)
20r. p. m. (10 Pa · s or more and less than 25 Pa · s)
10r. p. m. (In the case of 25 Pa · s or more and less than 50 Pa · s)
5r. p. m. (In the case of 50 Pa · s or more and less than 100 Pa · s)
2.5r. p. m. (In the case of 100 Pa · s or more and less than 200 Pa · s)
1.0r. p. m. (In the case of 200 Pa · s or more and less than 500 Pa · s)
0.5r. p. m. (In the case of 500 Pa · s or more and less than 1,000 Pa · s)

(Calculation of effective NCO% (when substituent C is not included))
Effective NCO% here is used to quantify the amount of blocked isocyanate groups that can participate in the crosslinking reaction present in the blocked polyisocyanate composition after the blocking reaction, and is expressed as mass% of isocyanate groups, It is calculated by the following formula. When diluted with a solvent or the like, the value in the diluted state is described.

  ([Solid content of block polyisocyanate composition (mass%)] × [mass of polyisocyanate used in reaction × isocyanate group content of precursor polyisocyanate (mass%)]) / [block poly after blocking reaction Resin mass of isocyanate composition]

(Calculation of effective NCO% (when containing substituent C))
The effective NCO% here is used for quantifying the amount of blocked isocyanate groups that can participate in the crosslinking reaction present in the blocked polyisocyanate composition after the blocking reaction. It is expressed as mass% of the isocyanate group derived from B and is calculated by the following formula. When diluted with a solvent or the like, the value in the diluted state is described.

  ([Solid content (mass%) of block polyisocyanate composition] x [mass of polyisocyanate used in reaction] x [isocyanate group content to be a structural unit represented by A and B among polyisocyanates of precursor ( Mass%)])) / [resin mass of block polyisocyanate composition after blocking reaction]

(N / m ratio of block polyisocyanate (when substituent C is not contained))
Remaining mole% of isocyanate group (p) after reaction in the first step in the production method 1, reaction mole% (q) of the organic amine compound after the second step, mole% added to the isocyanate group of the organic amine compound in the second step When (r), it was calculated from the following equation.

  In the case of p ≠ 0, the organic amine compound reacts preferentially with the remaining isocyanate group, and therefore the amount of the organic amine compound needs to be considered from the reaction amount of the organic amine compound. Therefore, it calculated as n = {(q * r) -p} and n / m = {(q * r) -p} / (100-n). The remaining mole% of isocyanate groups after the first step is quantified by infrared spectrum measurement of the reaction solution, and the reaction rate of the organic amine compound is quantified by gas chromatograph measurement of the amount of the organic amine compound decreased after the second step. Calculated by.

Device: Shimadzu GC-14A (trade name)
Column: DB-1 (trade name) manufactured by Shimadzu GC

  In addition, the block polyisocyanate which has a substituent shown by general formula (IX) can be produced | generated when 2 mol equivalent of the organic amine of a 2nd process reacts with 1 mol equivalent of malonic acid diester part. However, when a secondary amine is used as the organic amine in the second step from the experimental results with the model compound (using n-hexyl isocyanate as the isocyanate component), it is probably 1% by mass of the total of the blocked polyisocyanate due to steric hindrance. It turns out that it only produces: Therefore, in the calculation of the n / m ratio, the formation of a blocked polyisocyanate having a substituent of general formula (IX) was ignored.

  Further, the malonic acid diester remaining in the first step can react with the organic amine compound added in the second step. However, since the total amount of malonic acid monoester monoamide and malonic acid diamide is 1% by mass or less according to the gas chromatographic measurement of the model experimental example, n / m of the secondary amine is used as the organic amine. In the calculation, the decrease in organic amine due to this reaction was ignored.

(N / m, o ratio of block polyisocyanate (when substituent C is included))
-Composition ratio of o It calculated by measuring the residual mole% of an isocyanate group by the infrared vector measurement before and behind reaction of an active hydrogen containing hydrophilic compound.
-Composition ratio of n / m When p ≠ 0, the organic amine compound reacts preferentially with the remaining isocyanate group, and therefore the amount of the organic amine compound needs to be taken into consideration from the reaction amount of the organic amine compound. Therefore, it calculated as n = {(q * r) -p}, m = (100- (n + o)) (the definition of p, q, r is as above-mentioned). The residual mole% of isocyanate groups after the malonic acid diester reaction is quantified by infrared spectrum measurement of the reaction solution, and the reaction rate of the organic amine compound is quantified by gas chromatographic measurement of the amount of the organic amine compound reduced after the second step. Calculated by. In addition, the block polyisocyanate, malonic acid monoester monoamide, and malonic acid diamide having a substituent of the general formula (IX) were ignored for the same reason as described above.

Device: Shimadzu GC-14A (trade name)
Column: DB-1 (trade name) manufactured by Shimadzu GC

(Structure identification of block polyisocyanate: NMR measurement)
The structure of the block polyisocyanate was identified from ¹ H-NMR measurement using the following apparatus. Chemical shift standard: Tetramethylsilane was 0 ppm.
The keto methine proton of the reaction product of the isocyanate group and malonic acid diester, which was the product of the first step, was observed near 4.3 ppm, and the enol proton was observed around 16.5 ppm. Further, the methine proton of the keto form of the substituent A of the general formula (II), which is the product after the second step, was observed around 4.5 ppm, and the proton of the enol form was observed around 19.2 ppm. From the integrated values of these peaks, the reaction ratio in the second step and the abundance ratio of keto and enol bodies were confirmed.

Equipment: ECS-400 (trade name) manufactured by JEOL
Solvent: Deuterated chloroform Accumulated times: 128 Sample concentration: 5% by mass
Chemical shift standard: Tetramethylsilane was 0 ppm.

(Gel fraction)
The prepared coating solution was dried and then applied with an applicator to a film thickness of 40 μm and baked at 90 ° C. for 30 minutes to obtain a cured coating film. The cured coating film was baked, allowed to stand at 20 ° C. for 1 hour, immersed in acetone at 20 ° C. for 24 hours, and then the value of the undissolved part mass relative to the mass before immersion was calculated. The case where the initial gel fraction was 85% or more was rated as ◎, the case where it was 75% or more and less than 85%, ○, the case where it was 60% or more and less than 75%, and the case where it was less than 60%. The initial gel fraction is an index of low temperature curability, and the higher the low temperature curability, the higher the initial gel fraction.

(Moisture stability test)
30 mmol of the block polyisocyanate composition as an effective NCO group was taken, and 5.4 g of water (corresponding to 300 mmol) was added thereto, and then diethylene glycol dimethyl ether was added so that the total mass of the solution became 200 g, followed by stirring. Thus, a test solution was obtained. Transfer the solution to a 300 cc Erlenmeyer flask, and fix the tip of the measuring pipette fixed with a silicone rubber stopper with the tip immersed in the liquid surface. The amount of gas generated was measured based on the height of the surface. The case where it was stored at 40 ° C. for 10 days and the amount of gas (carbon dioxide gas) generated during that period was less than 24 cc was marked as ◯, the case where it was 24 cc or more and less than 32 cc was marked as x.

(Anti-yellowing resistance after baking)
A solvent-based two-component urethane paint (polyol: acrylic polyol-based urethane; trade name “Mighty rack (white)”, manufactured by Nippon Paint Co., Ltd.) was spray-coated with an aluminum plate so as to have a thickness of 50 μm. Then, after leaving still at 23 degreeC and 50% humidity conditions for 2 weeks, the surface was grind | polished with the 1000th sandpaper, and the white board was produced.
Next, after the coating solution is dried and coated with an applicator so as to have a film thickness of 50 μm, baked at 160 ° C. for 30 minutes, a color difference meter (digital colorimetric color difference meter manufactured by Suga Test Instruments Co., Ltd.) is used to The b value of the coating film including the coating film was defined as yellowing resistance. When the b value is less than 3.0, the mark is ◯, when the b value is 3.0 or more and less than 4.0, the mark is Δ.

(Production Example 1) (Production of HDI isocyanurate type polyisocyanate)
The inside of a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was purged with nitrogen, charged with 1000 g of HDI, and stirred at 60 ° C., 0.1 g of trimethylbenzylammonium hydroxide as a catalyst Was added. After 4 hours, when the conversion rate of the reaction solution reached 38%, 0.2 g of phosphoric acid was added to stop the reaction. Thereafter, the reaction solution was filtered, and unreacted HDI monomer was removed by thin film distillation.
The obtained polyisocyanate had a viscosity at 25 ° C. of 2,700 mPa · s, an isocyanate group content of 22.2% by mass, a number average molecular weight of 650, and an average number of isocyanate groups of 3.4. Thereafter, the presence of an isocyanurate bond was confirmed by NMR measurement.

(Production Example 2) (Production of HDI urethane bond, allophanate bond-containing isocyanurate type polyisocyanate)
A nitrogen atmosphere is set in the same apparatus as described in Production Example 1, and HDI: 1000 parts by mass, trimethylolpropane (molecular weight 134) 22 parts by mass as a trihydric alcohol is charged, and the temperature in the reactor is maintained at 90 ° C. for 1 hour with stirring. Urethane-ized. Thereafter, the temperature of the reaction solution was kept at 60 ° C., trimethylbenzylammonium hydroxide was added as an isocyanuration catalyst, and phosphoric acid was added when the conversion rate reached 48% to stop the reaction. Then, after filtering a reaction liquid, unreacted HDI was removed with the thin film distillation apparatus.
The obtained polyisocyanate had a viscosity at 25 ° C. of 25,000 mPa · s, an isocyanate group content of 19.9% by mass, a number average molecular weight of 1080, and an average number of isocyanate groups of 5.1. Thereafter, the presence of urethane bond, allophanate bond and isocyanurate bond was confirmed by NMR measurement.

(Production Example 3) (Production of Block Polyisocyanate Composition)
A nitrogen atmosphere was established in the same apparatus as described in Production Example 1, and 100 parts by mass of the polyisocyanate obtained in Production Example 1 (in this case, the number of moles of isocyanate groups of the polyisocyanate is 100), n-butyl acetate 81.0 Part by mass and 88.9 parts by mass of diethyl malonate (corresponding to 105 mol% of the isocyanate groups in the polyisocyanate) were charged and maintained at 60 ° C. Thereafter, 0.77 parts by mass of 28% sodium methylate was added and held for 4 hours. As a result of measuring the infrared spectrum, disappearance of the isocyanate group was confirmed, and 0.76 parts by mass of 2-ethylhexyl phosphate was added.
Subsequently, 0.76 parts by mass of diisopropylamine (corresponding to 0.9 mol% of the isocyanate group in the polyisocyanate) was added, and the reaction solution temperature was maintained at 70 ° C. for 5 hours. This reaction solution was analyzed by gas chromatography, and it was confirmed that the reaction rate of diisopropylamine was 70%. Thereafter, 38.8 parts of n-butanol was added to obtain a block polyisocyanate composition having a solid content of 60% by mass. Table 1 shows the effective NCO% of the obtained block polyisocyanate composition.
Separately, the block polyisocyanate composition was transferred to an eggplant flask, and distilled off under reduced pressure at 60 ° C. and 10 hPa for 60 minutes using an evaporator to remove most of the solvent, followed by NMR measurement. . As a result, n / m in the general formula (I) was 0.01.

(Production Examples 4 to 12) (Production of block polyisocyanate composition)
It carried out similarly to manufacture example 3 except having used the component and input amount which were shown to Tables 1-3. Tables 1 to 3 show effective NCO% of the obtained block polyisocyanate composition and n / m in the general formula (I) of the block polyisocyanate.

(Production Example 13) (Production of block polyisocyanate composition)
A nitrogen atmosphere was established in the same apparatus as described in Production Example 1, and 100 parts by mass of the polyisocyanate obtained in Production Example 1 (in this case, the number of moles of isocyanate groups of the polyisocyanate is 100), n-butyl acetate 83.0 Part by mass and 88.9 parts by mass of diethyl malonate (corresponding to 105 mol% of the isocyanate groups in the polyisocyanate) were charged and maintained at 60 ° C. Thereafter, 0.77 parts by mass of 28% sodium methylate was added and held for 4 hours. As a result of measuring the infrared spectrum, disappearance of the isocyanate group was confirmed, and 0.76 parts by mass of 2-ethylhexyl phosphate was added. Thereafter, 35.6 parts of n-butanol was added to obtain a block polyisocyanate composition having a solid concentration of 60% by mass. Table 3 shows effective NCO% of the obtained block polyisocyanate composition and n / m in the general formula (I) of the block polyisocyanate.

(Production Example 14) (Production of Block Polyisocyanate Composition)
The same procedure as in Production Example 12 was carried out except that the components and input amounts shown in Table 1 were used. Table 3 shows effective NCO% of the obtained block polyisocyanate composition and n / m in the general formula (I) of the block polyisocyanate.

The comment of * part in Tables 1-3 is as follows.
* 1 mol% of (number of moles of each compound) / (number of moles of isocyanate group of polyisocyanate)
* 2 2-ethylhexyl phosphate (trade name of Johoku Chemical Industry)
* 3 Mass% (calculated value) of effective NCO groups as a formulation shown in Table 1
* 4 DEM: diethyl malonate (R1: ethyl group, R2: ethyl group)
* 5 DIPM: Diisopropyl malonate (R1: isopropyl group, R2: isopropyl group)
* 6 DIPA: diisopropylamine (R3: isopropyl group, R4: isopropyl group)
* 7 VESTANAT T1890 / 100 (Isocyanurate type polyisocyanate composition of isophorone diisocyanate: trade name of Evonik Degussa)

(Production Example 15) (Production of Block Polyisocyanate Composition)
A nitrogen atmosphere is produced in the same apparatus as in Production Example 1, and 100 parts by mass of the polyisocyanate obtained in Production Example 1 (in this case, the number of moles of isocyanate groups in the polyisocyanate is 100), monomethoxypolyethylene having a number average molecular weight of 400 21.2 parts by weight of glycol (Nippon Yushi Co., Ltd. trade name “Uniox M400”) (corresponding to 10 mol% of the isocyanate group in polyisocyanate) and 92.7 parts by weight of diethylene glycol dimethyl ether are kept at 80 ° C. for 6 hours did. Thereafter, the reaction liquid temperature was cooled to 60 ° C., 80.4 parts by mass of diethyl malonate (corresponding to 95 mol% of isocyanate groups in polyisocyanate), 0.88 parts by mass of 28% methanol solution of sodium methylate were added, After holding for 4 hours, 0.86 parts by mass of 2-ethylhexyl phosphate was added. Thereafter, 0.73 parts by mass of diisopropylamine (corresponding to 85 mol% of the isocyanate group in the polyisocyanate) was added, and the temperature of the reaction solution was raised to 70 ° C. and held for 5 hours. This reaction solution was analyzed by gas chromatography, and it was confirmed that the reaction rate of diisopropylamine was 70%. Thereafter, 34.9 parts by mass of n-butanol was added to obtain a block polyisocyanate composition having a solid content concentration of 60% by mass. Table 4 shows the physical properties of the obtained block polyisocyanate composition and the structure of formula (V) of the block polyisocyanate.

(Production Examples 16 to 28) (Production of block polyisocyanate composition)
It carried out similarly to manufacture example 15 except having used the component and input amount shown to Tables 4-7. Tables 4 to 7 show the effective NCO% of the obtained block polyisocyanate composition and n / m in the general formula (V) of the block polyisocyanate.

(Production Example 29) (Production of block polyisocyanate composition)
100 parts by mass of the polyisocyanate obtained in Production Example 1 (the number of moles of isocyanate groups in the polyisocyanate in this case is assumed to be 100), monomethoxy having a number average molecular weight of 400, using the same apparatus as described in Production Example 1 21.2 parts by mass of polyethylene glycol (trade name “Uniox M400” of NOF Corporation) (corresponding to 10 mol% of isocyanate group in polyisocyanate) and 95.5 parts by mass of diethylene glycol dimethyl ether were charged at 80 ° C. for 6 hours. Retained. Thereafter, the reaction liquid temperature was cooled to 60 ° C., 80.5 parts by mass of diethyl malonate (corresponding to 95 mol% of the isocyanate group in polyisocyanate), 0.77 parts by mass of 28% methanol solution of sodium methylate were added, After holding for 4 hours, 0.76 parts by mass of 2-ethylhexyl phosphate was added. Thereafter, 32.1 parts by mass of n-butanol was added to obtain a block polyisocyanate composition having a solid content concentration of 60% by mass. Table 7 shows effective NCO% of the obtained block polyisocyanate composition and n / m in the general formula (V) of the block polyisocyanate.

(Production Example 30) (Production of block polyisocyanate composition)
The same procedure as in Production Example 27 was performed except that the components and input amounts shown in Table 1 were used. Table 7 shows effective NCO% of the obtained block polyisocyanate composition and n / m in the general formula (V) of the block polyisocyanate.

The annotations of * part in Tables 4 to 7 are as follows.
* 1 mol% of (number of moles of each compound) / (number of moles of isocyanate group of polyisocyanate)
* 2 2-ethylhexyl phosphate (trade name of Johoku Chemical Industry)
* 3 Mass% (calculated value) of effective NCO groups as a formulation shown in Table 2
* 4 DEM: diethyl malonate (R1: ethyl group, R2: ethyl group)
* 5 DIPM: Diisopropyl malonate (R1: isopropyl group, R2: isopropyl group)
* 6 DIPA: diisopropylamine (R3: isopropyl group, R4: isopropyl group)
* 7 VESTANAT T1890 / 100 (Isocyanurate type polyisocyanate composition of isophorone diisocyanate: trade name of Evonik Degussa)
* 8 DMDG: Diethylene glycol dimethyl ether * 9 DPDM: Dipropylene glycol dimethyl ether * 10 UNIOX M400 (monomethoxypolyethylene glycol having a number average molecular weight of 400: trade name of NOF Corporation (“M400” in the table))
* 11 MPG-081 (monomethoxy polyethylene glycol having a number average molecular weight of 680: trade name of Nippon Emulsifier Co., Ltd.)
* 12 UNIOX M1000 (Monomethoxypolyethylene glycol having a number average molecular weight of 1000: trade name of Nippon Oil & Fat Co., Ltd. (“M1000” in the table))
* 13 UNIOX M550 (Monomethoxypolyethylene glycol having a number average molecular weight of 550: trade name of Nippon Oil & Fat Co., Ltd. (“M550” in the table))

(Examples 1-9, Comparative Examples 1-3) (Evaluation of Block Polyisocyanate Composition)
As the main agent 1, acrylic polyol (trade name “Setalux 1767” of Nuplex Resins, resin concentration of 65% by mass, hydroxyl value per resin 150 mgKOH / g), and the block polyisocyanate composition obtained in Example 1, The ratio of the hydroxyl equivalent molar equivalent G of the main agent to the molar equivalent equivalent H of the effective NCO group of the block polyisocyanate composition is blended so that H / G = 1.0, and the coating solids content is 40% by mass with butyl acetate. It was adjusted. The prepared coating solution was measured for the initial gel fraction, moisture stability, and yellowing resistance by the above methods. The results are shown in Table 8.

  As shown in Table 8, the coating solution prepared from the blocked isocyanate compositions of Production Examples 3 to 11 containing the blocked isocyanate represented by the general formula (I) has an initial gel fraction, moisture stability, and yellowing resistance. Both were good. On the other hand, the coating solutions prepared from the blocked isocyanate compositions of Production Examples 13 and 14 containing the blocked isocyanate having no substituent B had good initial gel fraction and yellowing resistance, Stability was low. On the other hand, the coating solution prepared from the blocked isocyanate composition of Production Example 12 containing a blocked isocyanate having a higher ratio of substituent B (n / m> 1.0) than the blocked isocyanate represented by the general formula (I) is The initial gel fraction and moisture stability were good, but the yellowing resistance was poor.

(Examples 10-22, Comparative Examples 4-6) (Evaluation of Block Polyisocyanate Composition)
As main ingredient 2, acrylic emulsion (hydroxyl value per resin: 40 mg KOH / g, acid value per resin: 13 mg KOH / g resin, Tg: 20 ° C., number average molecular weight: 100,000, resin concentration: 42% by mass, pH 8.5 with dimethylethanolamine. 100 parts by mass and the block polyisocyanate composition obtained in Example 45, the ratio of the molar equivalent G of the main component 2 to the molar equivalent H of the effective NCO group of the block polyisocyanate composition is H / G. = 0.3 and adjusted so that the solid content of the paint was 35% by mass with water. Further, final adjustment was performed while adding dimethylethanolamine so that the pH of the coating solution was 8.5. The prepared coating solution was measured for the initial gel fraction, moisture stability, and yellowing resistance by the above methods. The results are shown in Table 9.

  As shown in Table 9, the coating solution prepared from the blocked isocyanate compositions of Production Examples 15 to 27 containing the blocked isocyanate represented by the general formula (I) has an initial gel fraction, moisture stability, and yellowing resistance. Both were good. In contrast, the coating solutions prepared from the blocked isocyanate compositions of Production Examples 29 and 30 containing the blocked isocyanate having no substituent B had good initial gel fraction and yellowing resistance, Stability was low. On the other hand, the coating solution prepared from the blocked isocyanate composition of Production Example 28 containing a blocked isocyanate having a higher ratio of substituent B (n / m> 1.0) than the blocked isocyanate represented by the general formula (I) is: The initial gel fraction and moisture stability were good, but the yellowing resistance was poor.

  The block polyisocyanate composition according to the present invention can be suitably used as a coating composition excellent in low-temperature curability, moisture stability, and yellowing resistance after high-temperature baking.

Claims (17)

A blocked polyisocyanate composition comprising at least one blocked isocyanate represented by the following general formula (I):

[In the formula (I),
R is a residue excluding an isocyanate group of a polyisocyanate formed from one or more selected from aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate;
A is a keto isomer represented by the following general formula (II) or an enol isomer thereof, and a plurality of A present in one molecule may be the same or different from each other,
B is a keto compound represented by the following general formula (III) or an enol isomer thereof, and a plurality of B present in one molecule may be the same or different from each other;
The total of m and n is 2.0 or more and 20 or less, and n / m is 0.01 or more and less than 1.0. ]

[In the formula (II),
R ₁ and R ₂ may be the same or different and are each independently an alkyl group having 1 to 8 carbon atoms, a phenyl group, or a benzyl group. ]

[In the formula (III),
R ₁ is an alkyl group having 1 to 8 carbon atoms, a phenyl group or a benzyl group,
R ₃ and R ₄ may be the same or different, and may contain at least one selected from an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. R ₃ and R ₄ are bonded to each other to form a 5- or 6-membered cycloalkyl group, or together with a nitrogen atom sandwiched between R ₃ and R ₄ , A bridging member may be formed which is added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain nitrogen or oxygen atoms. ] The block polyisocyanate composition according to claim 1, wherein R ₃ and R _{4 in} the general formula (III) are both branched alkyl groups having 3 to 6 carbon atoms. The block polyisocyanate composition according to claim 1, wherein R ₃ and R ₄ of the general formula (III) together form a connecting structure represented by the following general formula (IV).

[Wherein, R ₅ , R ₆ , R ₇ and R ₈ each independently represents a hydrogen atom or a methyl group. However, at least one of R ₅ , R ₆ , R ₇ , and R ₈ is a methyl group. ] Furthermore, the block polyisocyanate composition of any one of Claims 1-3 containing the at least 1 sort (s) of block polyisocyanate shown by the following general formula (V).

[In the formula, R is a residue excluding an isocyanate group of a polyisocyanate formed from one or more selected from aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate;
A is a keto isomer represented by the general formula (II) or an enol isomer thereof, and a plurality of A present in one molecule may be the same or different from each other;
B is a keto isomer represented by the general formula (III) or an enol isomer thereof, and a plurality of B present in one molecule may be the same or different from each other;
C is a keto body represented by the following general formula (VI), and a plurality of C present in one molecule may be the same or different from each other,
The sum of m, n, and o is 2.0 or more and 20 or less. However, m, n, and o are not all zero. ]

[Wherein R ₉ is a residue excluding active hydrogen of the active hydrogen-containing hydrophilic compound. ]   The block polyisocyanate composition according to claim 4, wherein in the general formula (V), (m + n) / o is 1 or more and 49 or less, and n / m is 0.01 or more and less than 1.0. Containing 10 mol% or more of the basic compound (e) having an acid dissociation constant (pKa) of 7.0 to 8.5 based on the number of moles based on the isocyanate group of the block polyisocyanate composition;
The number of moles is
The block polyisocyanate represented by the general formula (I) is the number of moles based on the isocyanate group in the polyisocyanate that is a precursor of the block polyisocyanate,
About the block polyisocyanate shown by the said general formula (V), on the basis of the isocyanate group used as the structure represented by said A and the structure represented by said B in the polyisocyanate which is the precursor of the said block polyisocyanate The number of moles
The block polyisocyanate composition according to any one of claims 1 to 5.   The block polyisocyanate composition of any one of Claims 1-6, and the coating composition containing a polyol.   The coating composition according to claim 7, which is an aqueous coating composition.   The manufacturing method of a coating film using the coating composition of Claim 7 or 8.   Hardened | cured material which hardened the coating composition of Claim 7 or 8. Malonic acid diester (b) represented by the following general formula (VII) is added to polyisocyanate (a) formed from one or more selected from the group consisting of aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate. ) Is added in an amount of 75 to 150 mol% with respect to the isocyanate group of the polyisocyanate (a), and is reacted,
A second step of reacting the product obtained in the first step with one or more of the organic amine compounds (c) represented by the following general formula (VIII):
The manufacturing method of block polyisocyanate composition containing this.

[In Formula (VII), R ₁ and R ₂ may be the same or different and each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, or a benzyl group. ]

[In Formula (VIII), R ₃ and R ₄ may be the same or different, and may contain at least one selected from the group consisting of an ether bond, an ester bond, a hydroxyl group, a carbonyl group, and a thiol group. A hydrocarbon group having 1 to 30 carbon atoms, and R ₃ and R ₄ are bonded to each other to form a 5- or 6-membered cycloalkyl group, or sandwiched between R ₃ and R ₄ Together with the nitrogen atom, a bridging member may be formed which is added to a 3-membered, 4-membered, 5-membered or 6-membered ring which may contain a nitrogen or oxygen atom. ]   In the first step, the polyisocyanate (a), the malonic acid diester (b), and the active hydrogen-containing hydrophilic compound (d) are combined with the malonic acid diester (b) and the active hydrogen-containing hydrophilic compound ( As a total amount of d), 77 to 150 mol% is added to the isocyanate group of the polyisocyanate (a), the polyisocyanate (a), the malonic acid diester (b), and the active hydrogen-containing hydrophilic property. The manufacturing method of the block polyisocyanate composition of Claim 11 which is a process with which a compound (d) is made to react.   The block polyisocyanate according to claim 12, wherein the first step is a step of reacting the malonic acid diester (b) after the reaction of the polyisocyanate (a) and the active hydrogen-containing hydrophilic compound (d). A method for producing the composition.   In the second step, one or more of the organic amine compound (c) is added in an amount of 50 to 500 mol% based on the isocyanate group of the polyisocyanate (a), and the product obtained in the first step The manufacturing method of the block polyisocyanate composition of any one of Claims 11-13 made to react with a thing.   The block polyisocyanate composition according to any one of claims 11 to 14, wherein after the first step and the second step, the organic amine compound (c) is removed and purified as a third step. Method.   In the third step, the organic amine compound (c) and the alcohol compound dissociated by the reaction between the ester group of the product obtained in the first step and the organic amine compound (c) are purified. The manufacturing method of the block polyisocyanate composition of Claim 15.   The manufacturing method of the block polyisocyanate composition of Claim 15 or 16 which adds the basic compound (e) whose acid dissociation constant (pKa) is 7.0-8.5 after the said 3rd process.