JP7058571B2 - Water dispersion block polyisocyanate composition, water dispersion, water-based coating composition and coating base material - Google Patents

Description

The present invention relates to an aqueous dispersion block polyisocyanate composition, an aqueous dispersion, an aqueous coating composition and a coating substrate.

In recent years, from the viewpoint of environmental protection, it is desired that the room temperature crosslinked type two-component urethane coating composition used as a solvent-based paint is water-based. However, in the two-component urethane coating composition, the polyisocyanate used as a curing agent is difficult to disperse in water. Therefore, the development of a polyisocyanate composition having a hydrophilic group is underway (see, for example, Patent Document 1 and Patent Document 2).

International Publication No. 2001/088006 International Publication No. 2016/104485 Japanese Unexamined Patent Publication No. 57-034107 Japanese Unexamined Patent Publication No. 61-275311

H. Schnell, “Chemistry and Physics of Polycarbonates.”, Polymer Reviews, Vol. 9, Interscience Publishers, 1964, p9-20.

However, the polyisocyanate compositions described in Patent Documents 1 and 2 have insufficient water dispersibility by hand stirring and storage stability in a coated state.

The present invention has been made in view of the above circumstances, has good compatibility, has storage stability when used as a coating solution containing an amphipathic solvent, and has an appearance and hardness when used as a coating film. And an aqueous dispersion block polyisocyanate composition having excellent adhesion is provided. Provided are an aqueous dispersion using the aqueous dispersion block polyisocyanate composition, an aqueous coating composition, and a coating base material.

That is, the present invention includes the following aspects.
The water-dispersed blocked polyisocyanate composition according to the first aspect of the present invention contains a blocked polyisocyanate obtained from a polyisocyanate and a heat-dissociating blocking agent, and satisfies the conditions shown in 1) to 4) below.
1) The proportion of constituent units derived from at least one diisocyanate monomer selected from the group consisting of aliphatic diisocyanate monomers and alicyclic diisocyanate monomers and derived from polyisocyanates containing an allophanate group and an isocyanurate group. 46% by mass or more and 60% by mass or less with respect to the total mass of the blocked polyisocyanate;
2) The molar ratio of allophanate group / (alofanate group + isocyanurate group) is 2/100 or more and 40/100 or less;
3) The ratio of the structural unit derived from the polycarbonate diol is 2% by mass or more and 15% by mass or less with respect to the total mass of the blocked polyisocyanate;
4) In the blocked polyisocyanate, the aliphatic diisocyanate monomer containing a structural unit derived from a hydrophilic compound may be hexamethylene diisocyanate.
The hydrophilic compound is a poly (oxyalkylene) monoalkyl ether, and the ratio of the structural unit derived from the poly (oxyalkylene) monoalkyl ether is 5% by mass or more with respect to the total mass of the blocked polyisocyanate. It may be 26% by mass or less.
The poly (oxyalkylene) monoalkyl ether may be a compound represented by the following general formula (1).

(In the general formula (1), R ¹¹ is an alkylene group having 1 or more and 4 or less carbon atoms. R ¹² is an alkyl group having 1 or more and 4 or less carbon atoms. N 11 is a number of 6.0 or more and 20.0 or less. Is.)

The polyisocyanate may further contain a urethane group, and the molar ratio of (urethane group) / (urethane group + allophanate group + isocyanurate group) may be 10/100 or more and 25/100 or less.
The heat-dissociable blocking agent may contain one or more selected from the group consisting of an oxime-based compound, a pyrazole-based compound, an active methylene-based compound, an amine-based compound, and an acid amide-based compound.
The heat dissociative blocking agent may be a pyrazole-based compound or an oxime-based compound.
The allophanate group may be a functional group formed by reacting a hydroxyl group of an alcohol with an isocyanate group of the diisocyanate monomer.

The aqueous dispersion according to the second aspect of the present invention contains the aqueous dispersion block polyisocyanate composition according to the first aspect and a solvent.

The water-based coating composition according to the third aspect of the present invention contains the water-dispersed blocked polyisocyanate composition according to the first aspect and at least one main agent.

The coating base material according to the fourth aspect of the present invention includes a base material and a coating film coated with the water-based coating composition according to the third aspect.

According to the water-dispersed blocked polyisocyanate composition of the above aspect, the compatibility is good, the storage stability when the coating liquid contains an amphipathic solvent, and the appearance, hardness and adhesion when the coating film is formed. It is possible to provide a water-dispersed blocked polyisocyanate composition having excellent properties. The aqueous dispersion and the aqueous coating composition of the above-mentioned embodiment are excellent in storage stability. The coating substrate of the above aspect includes a coating film having excellent appearance, hardness and adhesion.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be modified in various ways without departing from the gist thereof.

In the present specification, the amount of a specific functional group contained in a composition or a compound can be expressed as a "molar ratio". That is, the dimension of the value obtained by dividing the number of specific functional groups of the composition or compound by the Avogadro's number is defined as the molar ratio. Thereby, the amount of the specific functional group is expressed as a "molar ratio" with respect to the amount of other specific functional groups. The specific functional group of the composition means the specific functional group of the compound contained in the composition.

In addition, in this specification, a "polyol" means a compound having two or more hydroxy groups (-OH).
As used herein, the term "polyisocyanate" means a reaction product to which a plurality of monomer compounds having an isocyanate group (-NCO) are bonded.

≪Block polyisocyanate composition≫
The blocked polyisocyanate composition of the present embodiment contains a blocked polyisocyanate obtained from a polyisocyanate and a heat-dissociating blocking agent, and satisfies the conditions shown in 1) to 4) below.
1) The proportion of constituent units derived from at least one diisocyanate monomer selected from the group consisting of aliphatic diisocyanate monomers and alicyclic diisocyanate monomers and derived from polyisocyanates containing an allophanate group and an isocyanurate group. 46% by mass or more and 60% by mass or less with respect to the total mass of the blocked polyisocyanate;
2) The molar ratio of allophanate group / (alofanate group + isocyanurate group) is 2/100 or more and 40/100 or less;
3) The ratio of the structural unit derived from the polycarbonate diol is 2% by mass or more and 15% by mass or less with respect to the total mass of the blocked polyisocyanate;
4) The blocked polyisocyanate contains a structural unit derived from a hydrophilic compound.

The blocked polyisocyanate composition of the present embodiment has the above-mentioned structure, so that it has good compatibility, storage stability when it is made into a coating liquid containing an amphipathic solvent, and appearance when it is made into a coating film. Excellent in hardness and adhesion.
The details of each composition of the polyisocyanate composition of the present embodiment will be described below.

<Block polyisocyanate>
The blocked polyisocyanate contained in the blocked polyisocyanate composition of the present embodiment is a reaction product of polyisocyanate, polycarbonate diol, heat dissociative blocking agent and hydrophilic compound. That is, in the blocked isocyanate, the polycarbonate diol is bonded to the polyisocyanate via the urethane group, the hydrophilic compound is bonded to the polyisocyanate via the urethane group, and at least a part of the isocyanate in the polyisocyanate is bonded. The group is blocked with a blocking agent.

[Polyisocyanate]
The polyisocyanate used for producing a blocked polyisocyanate is a reaction product obtained by reacting a plurality of monomer compounds having an isocyanate group (-NCO) (hereinafter, may be referred to as "isocyanate monomer"). Further, the polyisocyanate also includes a reactant obtained by reacting a plurality of isocyanate monomers with a compound other than the isocyanate monomer (for example, alcohol, water, amine, etc.).

The isocyanate monomer having 4 to 30 carbon atoms is preferable. Specific examples of the isocyanate monomer include the following. These isocyanate monomers may be used alone or in combination of two or more.
(1) Aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate (MDI), 1,5-naphthalenediocyanate, tolylene diisocyanate (TDI), xylylene diisocyanate, m-tetramethylxylylene diisocyanate (TMXDI) (2) ) 1,4-Tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate (hereinafter sometimes referred to as "HDI"), 1,9-nonamethylene diisocyanate, 1,12-dodeca Methylene diisocyanate, 2,2,4-trimethyl-1,6-diisocyanatohexane, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, 2-methylpentane-1,5-diisocyanate (MPDI) ), Lisine diisocyanate (hereinafter, may be referred to as "LDI") and other aliphatic diisocyanates (3) Isophorone diisocyanate (hereinafter, may be referred to as "IPDI"), 1,3- or 1,4-bis (hereinafter, may be referred to as "IPDI"). Diisocyanate Methyl) Cyclohexane (hereinafter sometimes referred to as "hydrogenated XDI"), 1,3- or 1,4-cyclohexanediisocyanate, 4,4'-dicyclohexylmethane diisocyanate (hereinafter referred to as "hydrogenated MDI") ), 2,5- or 2,6-diisocyanate norbornan, 2,5- or 2,6-di (isocyanatemethyl) norbornan and other alicyclic diisocyanates (4) 4-isocyanatemethyl-1,8-octa Methylene diisocyanate (hereinafter sometimes referred to as "NTI"), 1,3,6-hexamethylene triisocyanate (hereinafter sometimes referred to as "HTI"), bis (2-isocyanatoethyl) 2-isocyanato Triisocyanates such as glutarate (hereinafter, may be referred to as "GTI") and lysine triisocyanate (hereinafter, may be referred to as "LTI").

Among them, since it is industrially easily available, the isocyanate monomer is preferably one or more kinds of diisocyanates selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates and alicyclic diisocyanates, and aliphatic diisocyanates and alicyclic diisocyanates are preferable. HDI, IPDI, hydrogenated XDI or hydrogenated MDI are even more preferred because one or more diisocyanates selected from the group consisting of group diisocyanates are more preferred and tend to be less prone to yellowing.

Further, the polyisocyanate used for producing the blocked polyisocyanate contains an allophanate group and an isocyanurate group. The lower limit of the molar ratio of allophanate group / (alofanate group + isocyanate group) is 2/100, preferably 3/100, from the viewpoint of water dispersibility and storage stability when used as a coating liquid. 100 is more preferable.
The upper limit of the molar ratio is 40/100, preferably 35/100, and more preferably 30/100, from the viewpoint of hardness when the coating film is formed.
That is, the molar ratio of allophanate group / (alofanate group + isocyanate group) is 2/100 or more and 40/100 or less, preferably 3/100 or more and 35/100 or less, and 4/100 or more and 30/100 or less. preferable.
When the molar ratio is at least the above lower limit value, the dispersibility in water is improved and the dispersion can be easily performed. Therefore, the compatibility with the main agent, the appearance as a coating film, and the storage stability as a coating liquid containing an amphipathic solvent tend to be more excellent. When the molar ratio is not more than the upper limit value, the hardness of the coating film tends to be more excellent.

In general, the "isocyanurate group" is a functional group formed by reacting three isocyanate groups, and is a group represented by the following formula (I).
In general, the "alofanate group" is a functional group formed by reacting a hydroxyl group of an alcohol with an isocyanate group, and is a group represented by the following formula (II).

In addition to the allophanate group and the isocyanurate group, the polyisocyanate used for producing the blocked polyisocyanate is composed of a uretdione group, an iminooxadiazinedione group, a biuret group, an oxadiazine trione group, a urethane group, an acylurea group and a urea group. It may contain one or more functional groups selected from the group.

In general, the "uretdione group" is a functional group formed by reacting two isocyanate groups, and is a group represented by the following formula (III).
In general, the "iminooxadiazinedione group" is a functional group obtained by reacting three isocyanate groups, and the "iminooxadiazinedione group" is a group represented by the following formula (IV). be.
In general, the "biuret group" is a functional group formed by reacting three isocyanate groups with a biuret agent, and is a group represented by the following formula (V).
In general, the "oxadiazine trione group" is a functional group formed by reacting two isocyanate groups with one molecule of carbon dioxide, and is a group represented by the following formula (VI).
Generally, the "urethane group" is a functional group formed by reacting one isocyanate group with one hydroxyl group, and is a group represented by the following formula (VII).
In general, the "acylurea group" is a functional group formed by reacting one isocyanate group with one carboxyl group, and is a group represented by the following formula (VIII).
In general, the "urea group" is a functional group formed by reacting one isocyanate group with one primary or secondary amine, and is a group represented by the following formula (IX).

In the polyisocyanate composition of the present embodiment, from the viewpoint of maintaining good hardness when formed into a coating film, it is derived from at least one diisocyanate monomer selected from the group consisting of an aliphatic diisocyanate monomer and an alicyclic diisocyanate monomer. Moreover, the lower limit of the ratio of the structural unit derived from the polyisocyanate containing an allophanate group and the isocyanurate group is 46% by mass, preferably 47% by mass, preferably 50% by mass, based on the total mass of the blocked polyisocyanate. Is more preferable.
On the other hand, from the viewpoint of improving the appearance of the obtained coating film, the upper limit of the ratio of the constituent units derived from the polyisocyanate is 60% by mass and 57% by mass with respect to the total mass of the blocked polyisocyanate. Is preferable.
That is, the ratio of the structural unit derived from the polyisocyanate is 46% by mass or more and 60% by mass or less, preferably 47% by mass or more and 57% by mass or less, and 50% by mass, based on the total mass of the blocked polyisocyanate. More preferably 57% by mass or less.
When the ratio of the constituent units derived from the polyisocyanate is at least the above lower limit value, the hardness of the coating film tends to be better. On the other hand, when the ratio of the constituent units derived from the polyisocyanate is not more than the above upper limit value, the storage stability when the paint contains an amphipathic solvent and the appearance when the coating film is obtained are better. Tend.

(Manufacturing method of polyisocyanate)
The method for producing polyisocyanate will be described in detail below.
The polyisocyanate is, for example, subjected to an isocyanurate-forming reaction for forming an isocyanurate group from the isocyanate group of the isocyanate monomer and an allophanate-forming reaction for forming an allophanate group from the isocyanate group and the hydroxyl group of the alcohol in the presence of an excess isocyanate monomer. It can be obtained by removing the unreacted isocyanate monomer after the reaction is completed. That is, the polyisocyanate obtained by the above reaction is a reaction product in which a plurality of the above isocyanate monomers are bonded and has an allophanate group and an isocyanurate group.
Further, the above reactions may be carried out separately, and the obtained polyisocyanates may be mixed at a specific ratio.
From the viewpoint of simplicity of production, it is preferable to carry out the above reaction at once to obtain a polyisocyanate, and from the viewpoint of freely adjusting the molar ratio of each functional group, it is preferable to separately produce and then mix.

〇 Method for producing isocyanurate group-containing polyisocyanate A polyisocyanate having an isocyanurate group can be produced by a known method, and specifically, it is produced by increasing the amount of the above isocyanate monomer with an isocyanurate-forming reaction catalyst. can do.

The isocyanurate-forming reaction catalyst is not particularly limited, but generally, a catalyst having basicity is preferable. Specific examples of the isocyanurate-forming reaction catalyst include those shown below.
(1) Hydrooxide of tetraalkylammonium such as tetramethylammonium, tetraethylammonium, tetrabutylammonium, and acetate, propionate, octylate, capricate, myristate, and benzoic acid of the tetraalkylammonate. Organic weak acid salts such as salts.
(2) Hydroxide of aryltrialkylammonium such as benzyltrimethylammonium and trimethylphenylammonium, and acetate, propionate, octylate, capricate, myristate, and benzoate of the aryltrialkylammonate. Organic weak salts such as.
(3) Hydroxide of hydroxyalkylammonium such as trimethylhydroxyethylammonium, trimethylhydroxypropylammonium, triethylhydroxyethylammonium, triethylhydroxypropylammonium, and acetate, propionate, octylate, caprin of the hydroxyalkylammonate. Organic weak salts such as acid salts, myristates and benzoates.
(4) Metal salts of alkylcarboxylic acids such as acetic acid, propionic acid, caproic acid, octyl acid, caproic acid and myristic acid such as tin, zinc and lead.
(5) Metallic alcoholates such as sodium and potassium.
(6) Aminosilyl group-containing compound such as hexamethylene disilazane.
(7) Mannich bases.
(8) A mixture of tertiary amines and an epoxy compound.
(9) Phosphoric compounds such as tributylphosphine.

Among them, from the viewpoint of catalytic efficiency and less likely to generate unnecessary by-products, the quaternary ammonium hydroxide or organic weak acid salt is preferable as the isocyanurate-forming reaction catalyst, and the tetraalkylammonium hydroxide and tetraalkylammonium are used. An organic weak acid salt or a metal salt of an alkyl carboxylic acid is more preferable, and an organic weak acid salt of tetraalkylammonium is further preferable.

The amount of the isocyanurate-forming reaction catalyst added is preferably 10 ppm or more and 1000 ppm or less, more preferably 10 ppm or more and 500 ppm or less, still more preferably 10 ppm or more and 100 ppm or less, based on the total mass of the charged isocyanate monomers. When the addition amount is not more than the above upper limit value, it tends to be more excellent in the simplicity of the manufacturing process. Further, when the addition amount is at least the above lower limit value, the reaction efficiency tends to be better.

The isocyanurate-forming reaction temperature is preferably 50 ° C. or higher and 120 ° C. or lower, and more preferably 60 ° C. or higher and 90 ° C. or lower. When the isocyanurate-forming reaction temperature is not more than the above upper limit value, coloring of polyisocyanate and the like tend to be more effectively suppressed.

When the desired conversion rate (the ratio of the mass of the polyisocyanate produced in the isocyanurate-forming reaction to the mass of the charged isocyanate monomer) is reached, the isocyanurate-forming reaction is carried out with an acidic compound (for example, phosphoric acid, acidic phosphoric acid). It is stopped by the addition of (ester, etc.).
In order to obtain polyisocyanate, it is necessary to stop the progress of the reaction at an early stage. However, since the initial reaction rate of the isocyanurate-forming reaction is very fast, it is difficult to stop the progress of the reaction at the initial stage, and it is necessary to carefully select the reaction conditions, especially the addition amount and method of the catalyst. be. For example, a method of dividing and adding the catalyst at regular time intervals is recommended as a suitable method.
The conversion rate of the isocyanurate-forming reaction is preferably 55% or less, more preferably 45% or less, from the viewpoint of low viscosity and curability when obtained as a coating composition.

Examples of the reaction terminator include a compound showing acidity of phosphate, a monoalkyl or dialkyl ester of a compound showing acidity of phosphate, acetic halide, benzoyl chloride, a sulfonic acid ester, sulfuric acid and the like. Examples of the compound showing phosphoric acid acidity include phosphoric acid, pyrophosphoric acid, metaphosphoric acid, polyphosphoric acid and the like. Examples of the halogenated acetic acid include monochloroacetic acid and the like.
By using a reaction terminator, the storage stability of the obtained polyisocyanate tends to be further improved.

〇 Method for producing polyisocyanate containing an allophanate group A polyisocyanate having an allophanate group can be produced by a known method. Specifically, the above isocyanate monomer and an alcohol are mixed and allophanated with an allophanate reaction catalyst. It can be manufactured by. As in the method for producing a polyisocyanate having an isocyanurate group, a reaction terminator can be used after the reaction is completed.

The alcohol used to form the allophanate group is preferably an alcohol formed only of carbon, hydrogen and oxygen.
Specific examples of the alcohol include, but are not limited to, non-polymerizable alcohols and polymerizable alcohols. The term "non-polymerizable alcohol" as used herein means an alcohol having no polymerizable group. On the other hand, the "polymerizable alcohol" means an alcohol obtained by polymerizing a monomer having a polymerizable group and a hydroxyl group. These alcohols may be used alone or in combination of two or more.

Examples of the non-polymerizable alcohol include monoalcohols, diols, triols, tetraols and the like.
Examples of monoalcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, n-pentanol, n-hexanol, n-octanol, n-nonanol and 2-ethylbutanol. , 2,2-Dimethylhexanol, 2-ethylhexanol, cyclohexanol, methylcyclohexanol, ethylcyclohexanol and the like.
Examples of diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, and 1, 3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,2-propanediol, 1,5-pentanediol, 2-methyl-2,3-butanediol, 1, 6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, 2-ethyl-hexanediol, 1,2-octanediol, 1,2-decanediol, 2,2,4-trimethylpentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propane Examples include diol.
Examples of triols include glycerin, trimethylolpropane and the like.
Examples of the tetraols include pentaerythritol and the like.

The polymerizable alcohol is not particularly limited, and examples thereof include polyester polyols, polyether polyols, acrylic polyols, epoxy resins, fluorine polyols, polycarbonate polyols, and polyolefin polyols. Examples of the polyolefin polyols include hydroxyl-terminated polybutadiene and hydrogenated products thereof.

Among them, as the alcohol, monoalcohols, polymerizable alcohols or mixtures thereof are preferable.

Examples of the allophanate formation reaction catalyst include, but are not limited to, alkyl carboxylates such as tin, lead, zinc, bismuth, zirconium, and zirconyl.
Examples of the tin alkylcarboxylic acid salt (organic tin compound) include tin 2-ethylhexanoate and dibutyltin dilaurate.
Examples of the lead alkylcarboxylic acid salt (organolead compound) include lead 2-ethylhexanoate.
Examples of the alkylcarboxylate (organozinc compound) of zinc include zinc 2-ethylhexanoate and the like.
Examples of the alkylcarboxylate of bismuth include bismuth 2-ethylhexanoate.
Examples of the alkylcarboxylate of zirconium include zirconium 2-ethylhexanoate.
Examples of the alkylcarboxylate of zirconyl include zirconyl 2-ethylhexanoate. These catalysts may be used alone or in combination of two or more.
Further, the isocyanurate-forming reaction catalyst can also be an allophanate-forming reaction catalyst. When the allophanate formation reaction is carried out using the above-mentioned isocyanurate-forming reaction catalyst, an isocyanurate group-containing polyisocyanate is naturally produced.
Above all, it is economically preferable to carry out the allophanate-forming reaction and the isocyanurate-forming reaction using the above-mentioned isocyanurate-forming reaction catalyst as the allophanate-forming reaction catalyst.

The lower limit of the amount of the allophanation reaction catalyst used is preferably 10 mass ppm, more preferably 20 mass ppm, further preferably 40 mass ppm, and particularly preferably 80 mass ppm with respect to the mass of the charged isocyanate monomer. ..
The upper limit of the amount of the allophanation reaction catalyst used is preferably 1000 mass ppm, more preferably 800 mass ppm, further preferably 600 mass ppm, and particularly preferably 500 mass ppm with respect to the mass of the charged isocyanate monomer. ..
That is, the amount of the above-mentioned allophanate reaction catalyst used is preferably 10% by mass or more and 1000% by mass or less, more preferably 20% by mass or more and 800% by mass or less, and more preferably 40% by mass or more with respect to the mass of the charged isocyanate monomer. It is more preferably 600 mass ppm or less, and particularly preferably 80 mass ppm or more and 500 mass ppm or less.

The lower limit of the allophanate reaction temperature is preferably 40 ° C, more preferably 60 ° C, even more preferably 80 ° C, and particularly preferably 100 ° C.
The upper limit of the allophanate reaction temperature is preferably 180 ° C, more preferably 160 ° C, and even more preferably 140 ° C.
That is, the allophanate reaction temperature is preferably 40 ° C. or higher and 180 ° C. or lower, more preferably 60 ° C. or higher and 160 ° C. or lower, further preferably 80 ° C. or higher and 140 ° C. or lower, and particularly preferably 100 ° C. or higher and 140 ° C. or lower.
When the allophanate reaction temperature is equal to or higher than the above lower limit, the reaction rate can be further improved. When the allophanate reaction temperature is not more than the above upper limit value, coloring of polyisocyanate and the like can be more effectively suppressed.

〇 Other polyisocyanates having functional groups Have one or more functional groups selected from the group consisting of uretdione groups, iminooxadiazinedione groups, biuret groups, oxadiazinetrione groups, urethane groups, acylurea groups and urea groups. Polyisocyanate can also be produced by a known method.
For example, a polyisocyanate having a urethane group can be produced by mixing the above isocyanate monomer and an alcohol and adding a urethanization reaction catalyst as needed.
As the alcohol, the same alcohol as those exemplified in the method for producing a polyisocyanate having an allophanate group can be used.
The urethanization reaction catalyst is not particularly limited, and examples thereof include tin-based compounds, zinc-based compounds, and amine-based compounds.
The urethanization reaction temperature can be 40 ° C. or higher and 180 ° C. or lower, preferably 50 ° C. or higher and 160 ° C. or lower, and more preferably 60 ° C. or higher and 120 ° C. or lower.
When the urethanization reaction temperature is not more than the above upper limit value, coloring of polyisocyanate and the like can be more effectively suppressed.
The urethanization reaction time is preferably 30 minutes or more and 4 hours or less, more preferably 1 hour or more and 3 hours or less, and further preferably 1 hour or more and 2 hours or less.

The unreacted isocyanate monomer can be removed from the reaction solution after completion of the reaction by thin film distillation, extraction or the like to obtain polyisocyanate. It is preferable to remove the unreacted isocyanate monomer from the viewpoint of safety.

[Polycarbonate diol]
Polycarbonate diols used in the production of blocked polyisocyanates have repeating structural units formed by dehydration condensation of two hydroxyl groups (-OH) and one carbonate group (-O- (C = O) -O-). ..

The number average molecular weight of the polycarbonate diol is not particularly limited, but is preferably 300 or more and 3000 or less, more preferably 400 or more and 2500 or less, and further preferably 500 or more and 2000 or less. When the number average molecular weight is within the above range, the flexibility and workability of the obtained water-based coating composition tend to be more excellent. The number average molecular weight can be calculated by the method described in Examples described later.

Further, the polycarbonate diol is simply "2" by combining the first diol having 2 or more and 20 or less carbon atoms and the second diol having 2 or more and 20 or less carbon atoms (hereinafter, the first diol and the second diol). It may be referred to as "seed diol") and a carbonate compound, and a reaction product obtained by copolymerizing the mixture is preferable. This tends to improve workability. The second diol is a diol having 2 or more carbon atoms and 20 or less carbon atoms other than the first diol, and excludes the same diol as the first diol.

The lower limit of the ratio of the constituent units derived from the polycarbonate diol is 2.0 mass with respect to the total mass of the blocked polyisocyanate from the viewpoint of storage stability when made into a paint and adhesion when made into a coating film. %, More preferably 3.5% by mass, more preferably 5.0% by mass. On the other hand, the upper limit of the ratio of the constituent units derived from the polycarbonate diol is 15.0% by mass, preferably 13.5% by mass, preferably 12.0% by mass from the viewpoint of hardness when formed into a coating film. More preferred.
That is, the proportion of the structural unit derived from the polycarbonate diol is 2.0% by mass or more and 15.0% by mass or less, preferably 3.5% by mass or more and 13.5% by mass or less, and 5.0% by mass or more. More preferably, it is 12.0% by mass or less.
When the ratio of the constituent units derived from the polycarbonate diol is equal to or higher than the above lower limit, it is possible to have an intramolecular hydrogen bond, and the storage stability when the paint contains an amphipathic solvent and the coating film are used. Adhesion tends to be better. When the ratio of the constituent units derived from the polycarbonate diol is not more than the above upper limit value, the number of isocyanate groups used for crosslinking increases, and the hardness of the coating film tends to be better.

(Manufacturing method of polycarbonate diol)
The method for producing the polycarbonate diol is not particularly limited, and for example, a method in which two types of diols and a carbonate compound are reacted at least one of a dealcohol reaction and a dephenolization reaction, and two types of high-molecular-weight polycarbonate polyols. Examples thereof include a method of transesterification reaction using the diol of the above. Further, the method for reacting the two diols with the carbonate compound is not particularly limited, and a known method can be mentioned, and any of the various methods described in Non-Patent Document 1 may be used.

The two types of diols are not particularly limited, and examples thereof include at least one type of diol selected from the group consisting of aliphatic diols and aromatic diols. Of these, an alkylene glycol having two hydroxyl groups and having 2 or more and 20 or less carbon atoms is preferable. By using the alkylene glycol, the weather resistance and chemical resistance when the water-dispersed blocked polyisocyanate composition is used as a coating film tend to be more excellent. The alkylene group constituting the alkylene glycol may be linear, may be branched, may be cyclic, or may be a combination thereof. These diols may be used alone or in combination of two or more.

Specific examples of the two types of diols are not particularly limited, but for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1, 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 2-ethyl-1,6-hexanediol , 2-Methyl-1,3 Propanediol, 3-Methyl-1,5-Pentanediol, Neopentyl Glycol, 1,3-Cyclohexanediol, 1,4-Cyclohexanediol, 2,2'-Bis (4-hydroxy) Cyclohexyl) -propane, p-xylylenediol, p-tetrachloroxylylenediol, 1,4-dimethylolcyclohexane, bishydroxymethyltetrachloride, di (2-hydroxyethyl) dimethylhydantin, diethyleneglycol, dipropylene glycol, polypropylene glycol , Polytetramethylene glycol, 2,6'-dihydroxyethylhexyl ether, 2,4'-dihydroxyethylbutyl ether, 2,5'-dihydroxyethylpentyl ether, 2,3'-dihydroxy-2', 2'-dimethylethylpropyl Examples include ether and thioglycol.
Among them, as the diol, a diol having 2 or more and 11 or less carbon atoms is preferable, and a diol having 3 or more and 6 or less carbon atoms is more preferable.

The combination of the two diols is not particularly limited, but is a combination of a diol having 5 carbon atoms and a diol having 6 carbon atoms, a combination of two or more isomers of a diol having 4 carbon atoms, or a combination of 4 carbon atoms. A combination of a diol and a diol having 6 carbon atoms is preferable. By using such two kinds of diols, the extensibility, heat resistance and water resistance (hydrolysis resistance) when the water-dispersed blocked polyisocyanate composition is used as a coating film tend to be more excellent.
Specific preferred combinations of these two diols include, for example, from 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and 2-methyl-1,3propanediol. Examples thereof include a combination of two different types of diols selected from the group. Among them, the combination of 1,6-hexanediol and 1,5-pentanediol, the combination of 1,6-hexanediol and 1,4-butanediol, or the combination of 1,4-butanediol and 2-methyl-1. , 3 A combination of propanediol is preferred.

The carbonate compound is not particularly limited, and examples thereof include alkylene carbonate, dialkyl carbonate, diaryl carbonate, and phosgene, and more specifically, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, and diphenyl carbonate. Can be mentioned. Of these, diethyl carbonate is preferable from the viewpoint of ease of production.

[Hydrophilic compound]
Examples of the hydrophilic compound used for producing the blocked polyisocyanate include nonionic hydrophilic compounds, anionic hydrophilic compounds, and cationic hydrophilic compounds. These hydrophilic compounds may be used alone or in combination of two or more. Among them, a nonionic hydrophilic compound or an anionic hydrophilic compound is preferable, and a nonionic hydrophilic compound is more preferable, from the viewpoint of ease of production.

(Nonion-based hydrophilic compound)
Examples of the nonionic hydrophilic compound include poly (oxyalkylene) glycol and poly (oxyalkylene) monoalkyl ether. A poly (oxyalkylene) monoalkyl ether is preferable from the viewpoint of lowering the viscosity of the water-dispersed blocked polyisocyanate composition.

〇Poly (oxyalkylene) monoalkyl ether The poly (oxyalkylene) monoalkyl ether is not particularly limited, but is a compound represented by the following general formula (1) (hereinafter, “poly (oxyalkylene) monoalkyl ether (1)). May be referred to as).

In the general formula (1), R ¹¹ is an alkylene group having 1 or more and 4 or less carbon atoms. R ¹² is an alkyl group having 1 or more carbon atoms and 4 or less carbon atoms. n11 is a number of 6.0 or more and 20.0 or less.

・ R ¹¹
In the general formula (1), R ¹¹ is an alkylene group having 1 or more and 4 or less carbon atoms. The alkylene group may be linear, branched, or cyclic (aliphatic ring group). The carbon number of the alkylene group is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and further preferably 1 or more and 2 or less.
Specific examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, a dimethylmethylene group, a cyclotrimethylene group, a tetramethylene group, a dimethylethylene group, a cyclotetramethylene group and the like.
Among them, as the alkylene group, a methylene group or an ethylene group is preferable, and an ethylene group is more preferable.

・ R ¹²
In the general formula (1), R ¹² is an alkyl group having 1 or more and 4 or less carbon atoms. The alkyl group may be linear, branched, or cyclic (aliphatic ring group). The number of carbon atoms of the alkyl group is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and further preferably 1 or more and 2 or less.
Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a cyclobutyl group and the like. ..
Among them, as the alkyl group, a methyl group or an ethyl group is preferable, and a methyl group is more preferable.

・ N11
In the general formula (1), n11 is the number of repetitions of the alkyleneoxy group (-R ¹¹ -O-). The poly (oxyalkylene) monoalkyl ether (1) is not a single component but an aggregate of substances having different degrees of polymerization. Therefore, n11 represents the average value of the degree of polymerization.
As the lower limit of n11, 5.0 is preferable, 5.2 is more preferable, 5.4 is more preferable, and 6.0 is particularly preferable, from the viewpoint of imparting hydrophilicity.
On the other hand, the upper limit of n11 is preferably 20.0, more preferably 18.0, and even more preferably 16.0, from the viewpoint of water dispersibility and hardness when formed into a coating film.
That is, n11 is preferably 5.0 or more and 20.0 or less, more preferably 5.2 or more and 18.0 or less, further preferably 5.4 or more and 16.0 or less, and particularly preferably 6.0 or more and 16.0 or less. preferable.
When n11 is at least the above lower limit value, the emulsifying power is increased, so that the dispersibility is improved and the dispersion can be easily performed. Therefore, the dispersibility in the main agent is further improved, and the appearance of the coating film tends to be better. When n11 is not more than the above upper limit value, it is possible to further prevent an excessive increase in viscosity such as gelation, and it tends to be easily dispersed. Further, the hardness of the coating film tends to be more excellent.

Preferred examples of the poly (oxyalkylene) monoalkyl ether (1) include compounds represented by the following formula (1) -1 (that is, polyethylene glycol monomethyl ether).

In equation (1) -1, n111 is 6.0 or more and 20.0 or less.

Commercially available products of poly (oxyalkylene) alkyl ether include, for example, NOF Corporation's trade names "Uniox M400", "Uniox M550", "Uniox M1000", "Uniox M2000", and NOF Corporation. The product names "MPG-081", "MPG-130" and the like can be mentioned.

The lower limit of the number average molecular weight of the poly (oxyalkylene) monoalkyl ether is preferably 200, more preferably 300, and even more preferably 400 from the viewpoint of dispersibility.
On the other hand, the upper limit of the number average molecular weight is preferably 2000, more preferably 1200, and even more preferably 1000 from the viewpoint of hardness when the coating film is formed.
That is, the number average molecular weight is preferably 200 or more and 2000 or less, more preferably 300 or more and 1200 or less, and further preferably 400 or more and 1000 or less.

When the hydrophilic compound is a poly (oxyalkylene) monoalkyl ether, the lower limit of the proportion of the constituent units derived from the poly (oxyalkylene) monoalkyl ether is the viewpoint of water dispersibility and appearance when formed into a coating film. Therefore, 5.0% by mass is preferable, 6.0% by mass is more preferable, and 7.0% by mass is further preferable with respect to the total mass of the blocked polyisocyanate.
On the other hand, the upper limit of the ratio of the constituent units derived from the poly (oxyalkylene) monoalkyl ether is the total mass of the blocked polyisocyanate from the viewpoint of storage stability when the coating solution contains an amphipathic solvent. 26.0% by mass is preferable, 22.5% by mass is more preferable, and 20.0% by mass is further preferable.
That is, the ratio of the constituent units derived from the poly (oxyalkylene) monoalkyl ether is preferably 5.0% by mass or more and 26.0% by mass or less, and 6.0% by mass, based on the total mass of the blocked polyisocyanate. It is more preferably 22.5% by mass or less, and further preferably 7.0% by mass or more and 20.0% by mass or less.
When the proportion of the structural unit derived from the poly (oxyalkylene) monoalkyl ether is at least the above lower limit value%, the water dispersibility tends to be further improved and the appearance as a coating film tends to be better. .. When the ratio of the constituent units derived from the poly (oxyalkylene) monoalkyl ether is not more than the above upper limit value, the storage stability tends to be better when the coating liquid contains an amphipathic solvent.

(Anionic hydrophilic compound)
Examples of the anionic hydrophilic compound include a carboxy group-containing compound and a sulfonic acid group-containing compound. Among them, as the anionic hydrophilic compound, a carboxylic acid group-containing compound is preferable from the viewpoint of ease of production and compoundability in water-based paints. Examples of the carboxy group-containing compound include monohydroxycarboxylic acid, dihydroxycarboxylic acid and derivatives thereof. Among them, as the carboxy group-containing compound, monohydroxycarboxylic acid or dihydroxycarboxylic acid is preferable, and monohydroxycarboxylic acid is more preferable.

When a carboxylic acid group-containing compound or a sulfonic acid group-containing compound is used, it is preferable to neutralize with a neutralizing agent after producing the aqueous dispersion block polyisocyanate composition. Examples of the neutralizing agent include alkali metals, alkaline earth metals, ammonia and tertiary amines. Examples of the tertiary amine include trimethylamine, triethylamine, dimethylethanolamine and the like.

(Cationic hydrophilic compound)
Examples of the cationic hydrophilic compound include a hydroxyl group-containing amino compound.
When a hydroxyl group-containing amino compound is used, it is preferable to neutralize it with a neutralizing agent after producing the water-dispersed blocked polyisocyanate composition. Examples of the neutralizing agent include organic acids such as acetic acid, propionic acid, butanoic acid and 2-ethylhexanoic acid.

(Mole ratio of urethane group / (urethane group + allophanate group + isocyanurate group))
The blocked polyisocyanate has a urethane group formed by reacting the hydrophilic group of the hydrophilic compound with the isocyanate group of the polyisocyanate. Further, the blocked polyisocyanate may have a urethane group derived from the polyisocyanate, as described in the above-mentioned polyisocyanate.
In the water-dispersed blocked polyisocyanate composition of the present embodiment, the lower limit of the molar ratio of urethane group / (urethane group + allophanate group + isocyanurate group) is when a coating liquid containing water-dispersible and amphoteric solvent is used. From the viewpoint of storage stability, 10/100 is preferable, 12/100 is more preferable, and 14/100 is even more preferable.
The upper limit of the molar ratio is preferably 25/100, preferably 22/100, and even more preferably 20/100, from the viewpoint of hardness when the coating film is formed.
That is, the molar ratio of urethane group / (urethane group + allophanate group + isocyanurate group) is preferably 10/100 or more and 25/100 or less, preferably 12/100 or more and 22/100 or less, and 14/100 or more and 20/100. The following is more preferable.
When the molar ratio is at least the above lower limit value, the dispersibility in water is further improved and the dispersion can be easily performed. Therefore, the dispersibility in the main agent, the storage stability when the coating liquid contains an amphipathic solvent, and the appearance when the coating film is formed tend to be more excellent. On the other hand, when the molar ratio is not more than the upper limit value, the hardness of the coating film tends to be more excellent.

[Thermal dissociative blocking agent]
In the blocked polyisocyanate, at least a part of the isocyanate group is blocked by the heat dissociating blocking agent. The thermally dissociable blocking agent is a compound having one active hydrogen in the molecule, and has a property of dissociating from an isocyanate group by heating. Specific examples of the heat dissociable blocking agent include alcohol compounds, alkylphenol compounds, phenol compounds, active methylene compounds, mercaptan compounds, acid amide compounds, acid imide compounds, imidazole compounds, and urea compounds. Examples thereof include compounds, oxime compounds, amine compounds, imine compounds, pyrazole compounds and the like.

More specific examples of the heat dissociative blocking agent include the compounds shown below. These blocking agents may be used alone or in combination of two or more.
(1) Alcohol-based compounds: methanol, ethanol, 2-propanol, n-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol.
(2) Alkylphenol-based compounds: Mono or dialkylphenols having an alkyl group having 4 or more carbon atoms as a substituent. For example, monoalkylphenols such as n-propylphenol, i-propylphenol, n-butylphenol, sec-butylphenol, t-butylphenol, n-hexylphenol, 2-ethylhexylphenol, n-octylphenol, n-nonylphenol; -Dialkylphenols such as propylphenol, diisopropylphenol, isopropylcresol, di-n-butylphenol, di-t-butylphenol, di-sec-butylphenol, di-n-octylphenol, di-2-ethylhexylphenol, di-n-nonylphenol, etc. Kind.
(3) Phenolic compounds: phenol, cresol, ethylphenol, styrenated phenol, hydroxybenzoic acid ester.
(4) Active methylene compound: dimethyl malonate, diethyl malonate, methyl acetoacetic acid, ethyl acetoacetate, acetylacetone.
(5) Melcaptan compounds: Butyl mercaptan, dodecyl mercaptan.
(6) Acid amide compounds: acetanilide, acetate amide, ε-caprolactam, δ-valerolactam, γ-butyrolactam.
(7) Imide-based compounds: succinimide and maleic acid imide.
(8) Imidazole compounds: imidazole, 2-methylimidazole.
(9) Urea-based compounds: urea, thiourea, ethyleneurea.
(10) Oxime-based compounds: formaldehyde, acetaldoxime, acetoxime, methylethylketooxime, cyclohexanone oxime.
(11) Amine-based compounds: diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, isopropylethylamine.
(12) Imine-based compounds: ethyleneimine, polyethyleneimine.
(13) Pyrazole-based compounds: pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole.

Among them, the heat dissociable blocking agent preferably contains at least one selected from the group consisting of an oxime-based compound, a pyrazole-based compound, an active methylene-based compound, an amine-based compound and an acid amide-based compound, and preferably contains an amphoteric solvent. From the viewpoint of storage stability when the coating solution contains the mixture, a pyrazole-based compound or an oxime-based compound is more preferable.

<Manufacturing method of blocked polyisocyanate composition>
The blocked polyisocyanate composition is not particularly limited, but is obtained, for example, by reacting the polyisocyanate, the hydrophilic compound, the polycarbonate diol, and the heat dissociating blocking agent.
The reaction of the isocyanate group of the polyisocyanate with the hydrophilic group of the hydrophilic compound or the hydroxyl group of the polycarbonate diol and the reaction of the isocyanate group of the polyisocyanate with the thermally dissociable blocking agent can be carried out at the same time, and either reaction can be performed in advance. A second reaction can also be performed after the above. Among them, each obtained after first reacting the isocyanate group with the hydrophilic group of the hydrophilic compound and the hydroxyl group of the polycarbonate diol to obtain a polyisocyanate having a constituent unit derived from the hydrophilic compound and the polycarbonate diol. It is preferable to carry out the reaction between the polyisocyanate having a constituent unit and the heat-dissociable blocking agent.

In the reaction step, for example, an organic metal salt such as tin, zinc, or lead; a tertiary amine compound; an alkali metal alcoholate such as sodium may be used as a catalyst.
The reaction temperature in the reaction step is preferably −20 ° C. or higher and 150 ° C. or lower, more preferably 30 ° C. or higher and 100 ° C. or lower. When the reaction temperature is equal to or higher than the above lower limit, the reactivity tends to be higher. Further, when the reaction temperature is not more than the above upper limit value, the side reaction tends to be further suppressed.
It is preferable to completely react with polyisocyanate so that the hydrophilic compound does not remain in an unreacted state. Since it does not remain in an unreacted state, it tends to further suppress the decrease in water dispersion stability of the water-dispersed blocked polyisocyanate composition and further suppress the decrease in curability when used as a coating composition.

<Use>
The blocked polyisocyanate composition of the present embodiment is, for example, a curable composition such as a coating composition, a pressure-sensitive adhesive composition, an adhesive composition, a casting agent composition; and various surface treatment agent compositions such as a fiber treatment agent. Used as various elastomer compositions; cross-linking agents for foam compositions, etc .; modifiers; additives, etc.

When used as a coating composition, it is not particularly limited, but is suitably used as a primer, an intermediate coating, a top coating, etc. for various materials by roll coating, curtain flow coating, spray coating, electrostatic coating, bell coating, etc. .. In addition, this coating composition further imparts cosmetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, adhesion, etc. to pre-coated metal including rust-preventive steel sheets, automobile coatings, and plastic coatings. , Suitable for use.

When used as a pressure-sensitive adhesive composition and an adhesive composition, it is not particularly limited, but is used for adhering, for example, automobiles, building materials, home appliances, woodworking, laminates for solar cells, and the like. In particular, optical members for liquid crystal displays of home appliances such as televisions, personal computers, digital cameras, and mobile phones exhibit various functions, so that it is necessary to stack films and plates of various adherends. Therefore, since sufficient adhesiveness or adhesiveness is required between the films and plates of various adherends, the water-dispersed blocked polyisocyanate composition of the present embodiment can be used as an adhesive composition and an adhesive composition. It is preferably used.

When used as a curable composition, the target adherend is not particularly limited, but for example, glass; various metals such as aluminum, iron, zinc steel plate, copper, and stainless steel; wood, paper, mortar, and ceramic. Porous members such as materials, concrete, stones; members coated with fluorine, urethane, acrylic urethane, etc .; hardened sealants such as silicone-based cured products, modified silicone-based cured products, urethane-based cured products; vinyl chloride , Natural rubber, synthetic rubber and other rubbers; natural leather, artificial leather and other leathers; plant-based fibers, animal-based fibers, carbon fibers, glass fibers, non-woven fabrics and other fibers; polyester, acrylic, polycarbonate, triacetyl cellulose , Films and plates of resins such as polyolefins; UV curable acrylic resin layers; printing inks, inks such as UV inks and the like.

≪Water dispersion≫
The aqueous dispersion of the present embodiment contains the above aqueous dispersion block polyisocyanate composition and a solvent.
The aqueous dispersion can be obtained, for example, by adding water and a solvent to the aqueous dispersion blocked isocyanate composition. Such a solvent is not particularly limited, but for example, 1-methylpyrrolidone, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 3-methoxy-. 3-Methyl-1-butanol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, propylene glycol dimethyl ether, methyl ethyl ketone, acetone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, ethanol, methanol , Iso-propanol, 1-propanol, iso-butanol, 1-butanol, 2-ethylhexanol, cyclohexanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1, Examples thereof include 3-butanediol, ethyl acetate, isopropyl acetate, butyl acetate, pentane, hexane, cyclohexane, and mineral spirit. These solvents may be used alone or in combination of two or more. From the viewpoint of dispersibility in water, dipropylene glycol dimethyl ether, propylene glycol dimethyl ether or dipropylene glycol monomethyl ether is preferable.

≪Water-based coating composition≫
The water-based coating composition of the present embodiment contains the above-mentioned water-dispersed blocked polyisocyanate composition and a main agent. Further, the water-based coating composition of the present embodiment may contain water in addition to the above-mentioned water-dispersed blocked polyisocyanate composition and the main agent, and resins which are coating film-forming components in a solvent mainly containing water (s). The main agent) is dissolved or dispersed. The water-based coating composition of the present embodiment may further contain an organic solvent in addition to water. As the organic solvent, an amphipathic solvent is preferable. Examples of the amphipathic solvent include those similar to those exemplified in the above aqueous dispersion.

<Main agent>
The main agent contained in the aqueous coating composition of the present embodiment is not particularly limited as long as it is a compound in which two or more active hydrogen-containing groups are bonded in the molecule, and for example, polyamine, alkanolamine, polythiol, polyol, etc. Examples thereof include polyvinylidene chloride copolymer, polyvinyl chloride copolymer, vinyl acetate copolymer, acrylonitrile butadiene copolymer, polybutadiene copolymer, styrene butadiene copolymer and the like. Above all, it is preferable that the main agent contains a polyol.

[Polyamine]
Specific examples of the polyamine include diamines, chain polyamines having three or more amino groups, and cyclic polyamines.
Examples of the diamines include ethylenediamine, propylenediamine, butylenediamine, triethylenediamine, hexamethylenediamine, 4,4'-diaminodicyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine and the like.
Examples of chain polyamines having three or more amino groups include bishexamethylenetriamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentamethylenehexamine, tetrapropylenepentamine and the like.
Examples of cyclic polyamines include 1,4,7,10,13,16-hexaazacyclooctadecane, 1,4,7,10-tetraazacyclodecane, and 1,4,8,12-tetraazacyclopentadecane. , 1,4,8,11-tetraazacyclotetradecane and the like.

[Alkanolamine]
As used herein, the term "alkanolamine" means a compound having an amino group and a hydroxyl group in one molecule. Specific examples of the alkanolamine include monoethanolamine, diethanolamine, aminoethylethanolamine, N- (2-hydroxypropyl) ethylenediamine, mono- or di- (-n- or-iso-) propanolamine, and ethylene glycol. -Bis-propylamine, neopentanolamine, methylethanolamine and the like can be mentioned.

[Polythiol]
The polythiol is not particularly limited, and examples thereof include bis- (2-hydrothioethyroxy) methane, dithioethylene glycol, dithioerythritol, and dithiothreitol].

[Polyol]
Examples of the polyols include polyester polyols, acrylic polyols, polyether polyols, fluorine polyols, polyolefin polyols, polycarbonate polyols, polyurethane polyols, epoxy resins and the like. Of these, acrylic resins or polyester resins are preferable.

(Polyester polyols)
Examples of the polyester polyols include, but are not limited to, products obtained by a condensation reaction between a dibasic acid alone or a mixture and a polyhydric alcohol alone or a mixture.
The dibasic acid is not particularly limited, but is at least one selected from the group consisting of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic acid anhydride, isophthalic acid, and terephthalic acid. Species dibasic acid can be mentioned.
The polyhydric alcohol is not particularly limited, and examples thereof include at least one polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, and glycerin.
Further, as the polyhydric alcohol, non-saccharides, sugar alcohol-based compounds, monosaccharides, disaccharides, trisaccharides, tetrasaccharides and the like may be further used. Examples of non-saccharides include diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol and the like. Examples of the sugar alcohol compound include erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol, mannitol, galactitol, ramnitol and the like. Examples of the monosaccharide include arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, ribodesource and the like. Examples of the disaccharide include trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose and the like. Examples of the trisaccharide include raffinose, gentianose, meletitos and the like. Examples of the tetrasaccharide include stachyose and the like.

(Acrylic polyols)
The acrylic polyols are not particularly limited, but 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 are used alone. Alternatively, a copolymer of a mixture may be used.
The ethylenically unsaturated bond-containing monomer having a hydroxyl group is not particularly limited, and for example, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxy methacrylate. Examples include butyl.
The other ethylenically unsaturated bond-containing monomer copolymerizable with the ethylenically unsaturated bond-containing monomer having a hydroxyl group is not particularly limited, and is, for example, an acrylic acid ester, a methacrylic acid ester, or an unsaturated carboxylic acid. , Unsaturated amides, vinyl monomers, vinyl monomers having a hydrolyzable silyl group.
Examples of the acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, -n-butyl acrylate, isobutyl acrylate, -n-hexyl acrylate, cyclohexyl acrylate, and -2 acrylate. -Ethylhexyl, lauryl acrylate, benzyl acrylate, phenyl acrylate and the like can be mentioned.
Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, -n-butyl methacrylate, isobutyl methacrylate, -n-hexyl methacrylate, cyclohexyl methacrylate, and -2 methacrylic acid. -Ethylhexyl, lauryl methacrylate, benzyl methacrylate, phenyl methacrylate and the like can be mentioned.
Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, itaconic acid and the like.
Examples of unsaturated amides include acrylamide, methacrylamide, N, N-methylenebisacrylamide, diacetoneacrylamide, diacetonemethacrylamide, maleic acid amide, maleimide and the like.
Examples of the vinyl-based monomer include glycidyl methacrylate, styrene, vinyltoluene, vinyl acetate, acrylonitrile, dibutyl fumarate and the like.
Examples of the vinyl-based monomer having a hydrolyzable silyl group include vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, and the like.

(Polyether polyols)
The polyether polyols are not particularly limited, for example, as the polyether polyols, but for example, a hydroxide of an alkali metal or a strongly basic catalyst is used to alkylene the polyhydric alcohol alone or as a mixture. Polyether polyols obtained by adding a single or a mixture of oxides, polyether polyols obtained by reacting a polyamine compound with an alkylene oxide, and so-called polymer polyols obtained by polymerizing acrylamide or the like using the above-mentioned polyethers as a medium. Kind is mentioned.
Examples of the alkali metal include lithium, sodium, potassium and the like.
Examples of the strongly basic catalyst include alcoholates, alkylamines and the like.
Examples of the polyhydric alcohol include those similar to those exemplified in the above polyester polyols.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, styrene oxide and the like.
Examples of the polyamine compound include ethylenediamines.

(Fluorine polyols)
Fluoropolycarbonates are polyols containing fluorine in their molecules, and are copolymers of, for example, fluoroolefins, cyclovinyl ethers, hydroxyalkyl vinyl ethers, monocarboxylic acid vinyl esters and the like disclosed in Patent Documents 3 and 4. Can be mentioned.

(Polyolefin polyols)
Examples of the polyolefin polyols include hydroxyl-terminated polybutadiene and hydrogenated products thereof.

(Polycarbonate polyol)
The polycarbonate polyol is not particularly limited, and examples thereof include a small molecule carbonate compound and one obtained by polycondensing the small molecule carbonate compound.
Examples of the small molecule carbonate compound include dialkyl carbonate, alkylene carbonate, diaryl carbonate and the like.
Examples of the dialkyl carbonate include dimethyl carbonate and the like.
Examples of the alkylene carbonate include ethylene carbonate and the like.
Examples of the diaryl carbonate include diphenyl carbonate and the like.

(Polyurethane polyols)
The polyurethane polyols are not particularly limited, but can be obtained, for example, by reacting a polyol containing no carboxy group with an isocyanate component by a conventional method. Alternatively, a polyurethane polyol having a carboxy group can be used by neutralizing it with a basic substance.
Examples of the polyol containing no carboxy group include ethylene glycol and propylene glycol as low molecular weight ones. Further, for example, examples of high molecular weight ones include acrylic polyols, polyester polyols, and polyether polyols.
The polyurethane polyols may be in the form of an emulsion such as urethane dispersion or urethane acrylic emulsion.

(Epoxy resins)
As used herein, the term "epoxy resin" means a resin having two or more epoxy groups in one molecule. Specifically, as the epoxy resins, for example, glycidyl ether-based epoxy resin, cyclic aliphatic epoxy resin, glycidyl ester-based resin, glycidyl amine-based resin, heterocyclic epoxy resin, and these epoxy resins are amino compounds and polyamide compounds. Examples thereof include resins modified by the above.
Examples of the glycidyl ether-based epoxy resin include bisphenol A type, bisphenol F type, bisphenol AD type, phenol novolak type, and cresol novolak type.
Examples of the cyclic aliphatic epoxy resin include alicyclic diepoxy acetals and alicyclic diepoxy adipates.
Examples of the glycidyl ester-based resin include phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, diglycidyl-p-oxybenzoic acid, and dimer acid glycidyl ester.
Examples of the glycidylamine-based resin include N, N-diglycidylaniline, tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol and the like.
Examples of the heterocyclic epoxy resin include a hydantoin type epoxy resin and triglycidyl isocyanurate. Examples of the hydantoin type epoxy resin include diglycidyl hydantoin and glycidyl glycidoxyalkyl hydantoin.

It is preferable that the resin as the main agent neutralizes the carboxyl group, sulfone group and the like contained in the resin in order to emulsify, disperse or dissolve in water.
The neutralizing agent for neutralizing the carboxyl group or the sulfone group is not limited to the following, but for example, ammonia, monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, etc. Examples thereof include isopropylamine, diisopropylamine, triethanolamine, butylamine, dibutylamine, 2-ethylhexylamine, ethylenediamine, propylenediamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, morpholin and the like. These neutralizers can be used alone or in combination of two or more. As the neutralizing agent, a tertiary amine is preferable, and triethylamine or dimethylethanolamine is more preferable.

<Other components>
[Melamine resin]
The water-based coating composition of the present embodiment may further contain a known melamine resin in addition to the water-dispersed blocked polyisocyanate composition and the main agent.
Examples of the melamine resin include partially or completely methylolated melamine resins obtained by reacting melamine with aldehydes. Examples of the aldehyde include formaldehyde and paraformaldehyde.
Further, a methylol group of this moiety or a completely methylolated melamine resin partially or completely etherified with alcohol can also be used. Examples of the alcohol used for etherification include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-ethylbutanol, 2-ethylhexanol and the like.

[Other additives]
In addition to the block polyisocyanate composition and the main agent, the aqueous coating composition of the present embodiment further comprises an inorganic pigment, an organic pigment, an extender pigment, a silane coupling agent, and a titanium coupling, depending on the purpose and use thereof. Agents, organic phosphates, organic phosphites, thickeners, leveling agents, thixotropic agents, defoaming agents, freeze stabilizers, matting agents, cross-linking reaction catalysts, anti-skin agents, dispersants, wetting agents , Fillers, plasticizers, lubricants, phosphoric acids, preservatives, fungicides, deodorants, anti-yellowing agents, UV absorbers, antistatic agents or antistatic agents, antisettling agents, etc. It can contain various additives added to the paint. A surfactant may be further added to improve the dispersibility in the paint, and an antioxidant, a light stabilizer, and a polymerization inhibitor may be further added to improve the storage stability of the paint. good.

<Manufacturing method of water-based coating composition>
As a method for producing a water-based coating composition, when a polyol is used as a main agent, for example, the water-dispersed blocked isocyanate composition may be mixed and dispersed as it is in the polyol, and the water-dispersed blocked isocyanate composition is once used as a solvent (particularly,). After mixing with water and an amphoteric solvent, it may be mixed with a polyol.

<Use>
The water-based coating composition of the present embodiment is, for example, a building paint, an automobile paint, an automobile repair paint, a plastic paint, an adhesive, an adhesive, a household water-based paint, other coating agents, a sealing agent, an ink, Note. It can be used for mold materials, elastomers, foams, plastic raw materials, and fiber treatment agents.

≪Coating base material≫
The coating substrate of the present embodiment includes a substrate and a coating film coated with the above-mentioned water-based coating composition. The coating film is excellent in appearance (for example, gloss, etc.), hardness and adhesion.

Examples of the base material include those similar to those exemplified as the adherend in the above-mentioned use of the water-dispersed blocked polyisocyanate composition.

The coating base material of the present embodiment is obtained by coating various base materials with the above-mentioned water-based coating composition by roll coating, curtain flow coating, spray coating, electrostatic coating, bell coating, or the like and curing the coating substrate. When the above-mentioned aqueous coating composition is heated, the thermally dissociable blocking agent bonded to the isocyanate group of the blocked polyisocyanate contained in the aqueous coating composition is dissociated, and the dissociated isocyanate group and the main agent (particularly, polyol) have it. A coating film can be formed on the substrate by reacting with an active hydrogen-containing group (particularly, a hydroxyl group).

The coated substrate of the present embodiment may be provided with a usual primer between the coating film and the substrate, if necessary.

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

<Measurement method and evaluation method of physical properties>
Various physical properties and evaluations in Examples and Comparative Examples were measured and evaluated as follows.

[Physical characteristics 1] Yield The yield of the polyisocyanate obtained in each synthesis example was calculated from the following formula.
Yield (%) = mass of obtained polyisocyanate / total mass of charged raw materials x 100

[Physical characteristics 2] Viscosity The viscosity was measured at 25 ° C. using an E-type viscometer (manufactured by Tokimec Co., Ltd.). A standard rotor (1 ° 34'x R24) was used for the measurement. The rotation speed is as follows.

(Rotation speed)
100r. p. m. (When less than 128 mPa · s)
50r. p. m. (When 128 mPa ・ s or more and less than 256 mPa ・ s)
20r. p. m. (When 256 mPa · s or more and less than 640 mPa · s)
10r. p. m. (When 640 mPa ・ s or more and less than 1280 mPa ・ s)
5r. p. m. (When 1280 mPa · s or more and less than 2560 mPa · s)
2.5r. p. m. (In the case of 2560 mPa · s or more and less than 5120 mPa · s)
1.0r. p. m. (When 5120 mPa ・ s or more and less than 10240 mPa ・ s)
0.5r. p. m. (When 10240 mPa ・ s or more and less than 20480 mPa ・ s)

[Physical characteristics 3] Isocyanate group concentration 1 to 3 g of a polyisocyanate precursor was precisely weighed (Wg) in an Erlenmeyer flask, and then 20 mL of toluene was added to dissolve the polyisocyanate. Then, 10 mL of a toluene solution of 2N-butylamine is added, and after mixing, the mixture is allowed to stand at room temperature for 15 minutes. 70 mL of isopropyl alcohol was added and mixed. This solution was titrated with a 1N hydrochloric acid solution (Factor F) as an indicator. This titration value was set to (V2 mL), the same operation was performed without polyisocyanate, and this titration value was set to (V1 mL), and the isocyanate group content of the polyisocyanate was calculated from the following formula.

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

[Physical characteristics 4] Number average molecular weight of polyisocyanate Using polyisocyanate as a sample, the number average molecular weight of polyisocyanate was determined as the number average molecular weight based on polystyrene by gel permeation chromatograph measurement using the following measurement conditions.

(Measurement condition)
Equipment: HLC-802A (manufactured by Tosoh)
Column: G1000HXL x 1 (manufactured by Tosoh)
G2000HXL x 1 (manufactured by Tosoh)
G3000HXL x 1 (manufactured by Tosoh)
Carrier: Tetrahydrofuran Flow rate: 0.6 mL / min Sample concentration: 1.0% by mass
Injection volume: 20 μL
Temperature: 40 ° C
Detection method: Differential refractometer

[Physical characteristics 5] Non-volatile content When the polyisocyanate composition was used as a sample and diluted with a solvent, the mass of the aluminum cup was precisely weighed, about 1 g of the sample was added, and the mass of the cup before heating and drying was precisely weighed. The cup containing the above sample was heated in a dryer at 105 ° C. for 3 hours. After cooling the heated cup to room temperature, the mass of the cup was weighed again. The non-volatile content was calculated from the following formula, with the mass% of the dry residue in the sample as the non-volatile content. In the case of no solvent dilution, the non-volatile content was treated as being substantially 100%.

Non-volatile content (mass%) = (cup mass after heating and drying-aluminum cup mass) / (cup mass before heating and drying-aluminum cup mass) x 100%

[Physical characteristics 6] Average number of isocyanate functional groups of polyisocyanate Using polyisocyanate as a sample, the average number of isocyanate functional groups was determined by the following formula.

Average number of isocyanate groups = average number of polyisocyanates Molecular weight (Mn) x isocyanate group content (% by mass) x 0.01) / 42

[Physical Properties 7] Molar ratio of functional group Using polyisocyanate or water-dispersed blocked polyisocyanate composition as a sample, using FT-NMR AVANCE 600 manufactured by Bruker, deuterated chloroform CDCl ₃ as a solvent, concentration 5% by mass, 600 MHz, integration The proton nuclear magnetic resonance spectrum was measured 256 times, and the molar ratio of the number of functional groups of the isocyanate group and the urethane group was confirmed. The area ratios of the following signals were measured for each functional group based on the total protons at the β and γ positions derived from HDI.

Isocyanurate group: Area ratio of signal of hydrogen atom of methylene group derived from HDI adjacent to isocyanurate group near 3.85 ppm Alofanate group: Area ratio of signal of hydrogen atom bonded to nitrogen of allophanate group near 8.50 ppm Urethane group: Area ratio of signal of hydrogen atom bonded to nitrogen of urethane group around 4.90ppm

Next, the isocyanurate group has an area ratio of 1/6, and the allophanate group and the urethane group have the area ratio as the number of moles, and the molar ratio of the allophanate group / (alofanate group + isocyanurate group) and the urethane group / (urethane group +). The molar ratio of allophanate group + isocyanurate group) was calculated.

[Physical characteristics 8] Number average molecular weight of polycarbonate diol The number average molecular weight of the polycarbonate diol was calculated from the following formula using the polycarbonate diol as a sample. The hydroxyl value of the polycarbonate diol was measured by using the method described in "Physical Properties 9" described later.

Number average molecular weight = 2 / (hydroxyl value of polycarbonate diol x 10 ^-3 / 56.11)

[Physical characteristics 9] Hydroxyl value of polycarbonate diol Using the polycarbonate diol as a sample, the hydroxyl value of the polycarbonate diol was determined according to JIS K 0070: 1992. Specifically, 12.5 g of acetic anhydride was added up with 50 mL of pyridine to prepare an acetylation reagent. Next, 2.5 to 5.0 g of the polycarbonate diol produced in the synthetic example was precisely weighed in a 100 mL eggplant flask. After adding 5 mL of the acetylation reagent and 10 mL of toluene to the eggplant flask with a whole pipette, a cooling tube was attached, and the mixture was heated with stirring at 100 ° C. for 1 hr. 2.5 mL of distilled water was added with a whole pipette, and the mixture was further heated and stirred for 10 minutes. After cooling for 2 to 3 minutes, 12.5 mL of ethanol was added, 2 to 3 drops of phenolphthalein was added as an indicator, and then titration was performed with 0.5 mol / L ethanolic potassium hydroxide.

On the other hand, as a blank test, 5 mL of acetylation reagent, 10 mL of toluene, and 2.5 mL of distilled water were placed in a 100 mL eggplant flask, heated and stirred for 10 minutes, and then titrated in the same manner. Based on this result, the hydroxyl value was calculated by the following formula.

OH value (mg-KOH / g) = {(ba) x 28.05 x f} / e

In the above formula, a represents the titration amount (mL) of the sample, b represents the titration amount (mL) of the blank test, e represents the mass (g) of the sample, and f represents the factor of the titration solution. Represents.

[Physical characteristics 10] Copolymerization composition of polycarbonate diol The copolymerization composition of the polycarbonate diol was measured as follows using the polycarbonate diol as a sample. 1 g of a sample was taken in a 100 mL eggplant flask, 30 g of ethanol and 4 g of potassium hydroxide were added, and the reaction was carried out at 100 ° C. for 1 hr. After cooling to room temperature, 2-3 drops of phenolphthalein was added to the indicator and neutralized with hydrochloric acid. After cooling in a refrigerator for 1 hr, the precipitated salt was removed by filtration and analyzed by gas chromatography. The analysis was performed using gas chromatography GC-14B (manufactured by Shimadzu Corporation) equipped with DB-WAX (manufactured by J & W) as a column, using diethylene glycol diethyl ester as an internal standard, and using a detector as a FID. The temperature rise profile of the column was maintained at 60 ° C. for 5 minutes and then heated to 250 ° C. at 10 ° C./min.

[Manufacturing of water-based coating composition]
In order to evaluate the water-dispersed blocked polyisocyanate compositions obtained in Examples 1 to 15 and Comparative Examples 1 to 7, a water-based coating composition was prepared.
Specifically, Setaqua6510 (trade name manufactured by Allnex, acrylic polyol, solid content 42%, hydroxyl group 4.2% by mass) was added to each of the aqueous dispersion block polyisocyanate compositions obtained in Examples and Comparative Examples. It was blended so that the functional group ratio (NCO / OH) = 1.00. Further, deionized water was added to this mixture so that the solid content was 42%, and the mixture was stirred at 500 rpm for 5 minutes using a disper blade to prepare an aqueous coating composition.

[Evaluation 1] Compatibility with the main agent The water-based coating composition was measured for particle size by Nanotrack UPA-EX150 (manufactured by Nikkiso Co., Ltd.), and the compatibility was evaluated according to the following evaluation criteria.

(Evaluation criteria)
A: Particle size is 100 nm or less B: Particle size is more than 100 nm and 150 nm or less C: Particle size is more than 150 nm

[Evaluation 2] Storage stability when solvent is contained (confirmation of layer separation)
The aqueous coating composition was stored at 50 ° C. for 2 weeks and the storage stability was evaluated. The evaluation criteria were as follows. In addition, when precipitation or the like occurred in the water-based coating composition, it was evaluated as "not evaluable". Moreover, since the curing agent is diluted with a solvent (amphipathic solvent), this evaluation is an evaluation of storage stability when the solvent is contained.

(Evaluation criteria)
A: No precipitate was generated.
B: Precipitation was generated.
C: Layer splitting occurred.

[Evaluation 3] The hardness water-based coating composition was coated with a coating film having a thickness of 40 μm on a glass plate and dried in an atmosphere of 23 ° C./50% RH for 7 days. The pencil hardness test was performed according to JIS-K-5600-5-4. The evaluation criteria were as follows.

(Evaluation criteria)
A: H or more B: B or more H or less C: B or less

[Evaluation 4] Luster of coating film The water-based coating composition is coated on a glass plate with an applicator so as to have a thickness of 50 μm, set at room temperature for 15 minutes, and then baked at 160 ° C. for 30 minutes to cure the coating film. Got
Gloss was measured at a defined angle (60 °) using the trade name "SUGA UGV-6P" manufactured by Suga. The evaluation criteria were as follows.

(Evaluation criteria)
A: 90 or more B: 80 or more and less than 90 C: less than 80

[Evaluation 5] Adhesion of coating film The water-based coating composition is coated on a mild steel plate with an applicator so that it has a thickness of 50 μm, allowed to stand at room temperature for 15 minutes, and then baked at 160 ° C. for 30 minutes for curing coating. Obtained a membrane. The adhesion test was performed according to JIS K5600-5-6. The evaluation criteria were as follows.

(Evaluation criteria)
A: More than 90 out of 100 squares remained.
B: Less than 90 squares remained in 100 squares.

<Synthesis of raw materials>
[Synthesis Example 1] Synthesis of polyisocyanate A-1 The inside of a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel is made into a nitrogen atmosphere, and HDI: 1000 g, 2-ethylhexanol: 3.2 g was charged, and the temperature inside the reactor was maintained at 80 ° C. for 2 hours under stirring. Then, tetramethylammonium capriate, which is an isocyanurate-forming reaction catalyst, was added, and when the yield reached 40%, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate A-1. The obtained polyisocyanate A-1 had a viscosity at 25 ° C. of 2700 mPa · s, an isocyanate group concentration of 21.7%, a number average molecular weight of 670, and an average isocyanate group number of 3.5.

[Synthesis Example 2] Synthesis of polyisocyanate A-2 The inside of a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel is made into a nitrogen atmosphere, and HDI: 1000 g, 2-ethylhexanol: 10.0 g was charged, and the temperature inside the reactor was maintained at 80 ° C. for 2 hours under stirring. Then, tetramethylammonium capriate, which is an isocyanurate-forming reaction catalyst, was added, and when the yield reached 42%, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate A-2. The obtained polyisocyanate A-2 had a viscosity at 25 ° C. of 2300 mPa · s, an isocyanate group concentration of 21.5%, a number average molecular weight of 665, and an average isocyanate group number of 3.4.

[Synthesis Example 3] Synthesis of polyisocyanate A-3 The inside of a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel is made into a nitrogen atmosphere, and HDI: 1000 g, 2-ethylhexanol: 30.0 g was charged, and the temperature inside the reactor was maintained at 80 ° C. for 2 hours under stirring. Then, tetramethylammonium capriate, which is an isocyanurate-forming reaction catalyst, was added, and when the yield reached 34%, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate A-3. The obtained polyisocyanate A-3 had a viscosity at 25 ° C. of 1500 mPa · s, an isocyanate group concentration of 20.7%, a number average molecular weight of 590, and an average isocyanate group number of 2.9.

[Synthesis Example 4] Synthesis of polyisocyanate A-4 The inside of a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel is made into a nitrogen atmosphere, and HDI: 1000 g, 2-ethylhexanol: 40.0 g was charged, and the temperature inside the reactor was maintained at 80 ° C. for 2 hours under stirring. Then, tetramethylammonium capriate, which is an isocyanurate-forming reaction catalyst, was added, and when the yield reached 31%, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate A-4. The obtained polyisocyanate A-4 had a viscosity at 25 ° C. of 1100 mPa · s, an isocyanate group concentration of 20.1%, a number average molecular weight of 560, and an average isocyanate group number of 2.7.

[Synthesis Example 5] Synthesis of polyisocyanate A-5 The inside of a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel is made into a nitrogen atmosphere, and HDI: 1000 g, 1,3-butane is used. 10.0 g of diol was charged, and the temperature inside the reactor was maintained at 80 ° C. for 2 hours under stirring. Then, tetramethylammonium capriate, which is an isocyanurate-forming reaction catalyst, was added, and when the yield reached 42%, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate A-5. The obtained polyisocyanate A-5 had a viscosity at 25 ° C. of 3150 mPa · s, an isocyanate group concentration of 21.0%, a number average molecular weight of 744, and an average isocyanate group number of 3.7.

[Synthesis Example 6] Synthesis of polyisocyanate A-6 The inside of a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel is made into a nitrogen atmosphere, and HDI: 920 g, IPDI: 80 g, 2 -Ethylhexanol: 10.0 g was charged, and the temperature inside the reactor was maintained at 80 ° C. for 2 hours with stirring. Then, tetramethylammonium capriate, which is an isocyanurate-forming reaction catalyst, was added, and when the yield reached 40%, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI and IPDI were removed using a thin film evaporator to obtain polyisocyanate A-6. The obtained polyisocyanate A-6 had a viscosity at 25 ° C. of 2900 mPa · s, an isocyanate group concentration of 21.5%, a number average molecular weight of 680, and an average isocyanate group number of 3.5.

[Synthesis Example 7] Synthesis of polyisocyanate A-7 The inside of a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel is made into a nitrogen atmosphere, HDI: 1000 g is charged, and a reaction under stirring is performed. The temperature inside the vessel was maintained at 80 ° C., tetramethylammonium capriate, which is an isocyanurate-forming reaction catalyst, was added, and when the yield reached 41%, phosphoric acid was added to stop the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate A-7. The obtained polyisocyanate A-7 had a viscosity at 25 ° C. of 2650 mPa · s, an isocyanate group concentration of 21.7%, a number average molecular weight of 672, and an average isocyanate group number of 3.5.

[Synthesis Example 8] Synthesis of polyisocyanate A-8 The inside of a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel is made into a nitrogen atmosphere, and HDI: 1000 g, 2-ethylhexanol: 40.0 g was charged, and the temperature inside the reactor was maintained at 80 ° C. for 2 hours under stirring. Then, tetramethylammonium capriate, which is an isocyanurate-forming reaction catalyst, was added, and when the yield reached 29%, phosphoric acid was added to terminate the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate A-8. The obtained polyisocyanate A-8 had a viscosity at 25 ° C. of 850 mPa · s, an isocyanate group concentration of 20.2%, a number average molecular weight of 540, and an average isocyanate group number of 2.6.

Table 1 below shows various physical properties of the polyisocyanates A-1 to A-8 obtained in Synthesis Examples 1 to 8.

[Synthesis Example 9] Synthesis of Polycarbonate Diol B-1 382 g of 1,5-pentanediol and 1,6-hexanediol are placed in a 2 L separable flask equipped with a stirrer, a thermometer, and an older show with a vacuum jacket having a reflux head on the crown. After charging 433 g and 650 g of ethylene carbonate and stirring and dissolving at 70 ° C., 0.015 g of lead acetate trihydrate was added as a catalyst. The mixture was heated in an oil bath set at 175 ° C., and reacted for 12 hours at an internal temperature of 140 ° C. in a flask and a vacuum degree of 1.0 to 1.5 kPa while removing a part of the distillate from the reflux head at a reflux ratio of 4. After that, the older show was replaced with a simple distillation apparatus, heated in an oil bath set at 180 ° C., the internal temperature of the flask was 140 to 150 ° C., the degree of vacuum was lowered to 0.5 kPa, and the diol remaining in the separable flask was used. Ethylene carbonate was removed. Then, the setting of the oil bath was raised to 185 ° C., and the reaction was carried out at an internal temperature of 160 to 165 ° C. in the flask for another 1.5 hours while removing the diol produced. By this reaction, polycarbonate diol B-1, which is a viscous liquid at room temperature, was obtained. The obtained polycarbonate diol B-1 had a hydroxyl value of 224.4 (molecular weight 500) and a copolymerization composition of 1,5-pentanediol / 1,6-hexanediol = 50/50 (molar ratio).

[Synthesis Example 10] Synthesis of Polycarbonate Diol B-2 In Synthesis Example 9, after replacing the solder show with a simple distillation apparatus, the oil bath setting was raised to 185 ° C, and the internal temperature of the flask was set to 160 to 165 ° C. Polycarbonate diol B-2 was synthesized by the same method as in Synthesis Example 9, except that the time for removing the diol was set to 2.3 hours. The obtained polycarbonate diol B-2 had a hydroxyl value of 56.1 (molecular weight 1000) and a copolymer composition of 1,5-pentanediol / 1,6-hexanediol = 50/50 (molar ratio).

<Manufacturing of water-dispersed blocked polyisocyanate composition>
[Example 1] Production of water-dispersed blocked polyisocyanate composition Polyisocyanate A-1: 100.0 g obtained in Synthesis Example 1 and polycarbonate diol obtained in Synthesis Example 9 were placed in the same reactor as in Synthesis Example 1. B-1: 12.9 g, polyethylene oxide which is a hydrophilic compound (manufactured by Nippon Embroidery Co., Ltd., trade name "MPG-081", average number of ethylene oxide repeating units: 15.0): 35.7 g, nitrogen atmosphere. It was kept at 110 ° C. for 3 hours. Then, the mixture was stirred at 80 ° C. under a nitrogen atmosphere. 40.6 g of 3,5-dimethylpyrazole was added as a blocking agent, and the mixture was stirred. After confirming that the characteristic absorption of the isocyanate group had disappeared in the infrared spectrum, 80.3 g of dipropylene glycol monomethyl ether was added, and the mixture was further stirred for 30 minutes. As a result, an aqueous dispersion blocked polyisocyanate composition was obtained. The solid content of the obtained water-dispersed blocked polyisocyanate composition was 69.8%. Further, a water-based coating composition was prepared using the water-dispersed blocked polyisocyanate composition, and evaluated according to the above method. The evaluation results are shown in Table 2.

[Examples 2 to 15 and Comparative Examples 1 to 7] Production of water-dispersed blocked polyisocyanate composition Examples except that the polyisocyanate, polycarbonate diol, polyethylene oxide, blocking agent and solvent shown in Tables 2 and 3 were used. The reaction was carried out in the same manner as in No. 1 to obtain each aqueous dispersion blocked polyisocyanate composition. A water-based coating composition was prepared using the obtained water-dispersed blocked polyisocyanate composition, and evaluated according to the above method. The evaluation results are shown in Tables 2 and 3.
The symbols shown in Tables 2 and 3 are as follows.
C-1: Made by Nippon Emulsorium Co., Ltd., trade name "MPG-081", average number of ethylene oxide repeating units 15.0
C-2: Made by Nippon Emulsorium Co., Ltd., trade name "MPG-130", average number of ethylene oxide repeating units 9.0
D-1: 3,5-dimethylpyrazole D-2: methylethylketooxime

From Tables 2 and 3, the water-dispersed blocked polyisocyanate compositions of Examples 1 to 15 have good compatibility, storage stability when containing a solvent, and hardness, gloss and adhesion when formed into a coating film. Both sexes were excellent.
In the water-dispersed blocked polyisocyanate compositions of Examples 2, 8 and 11, the structural unit derived from the polycarbonate diol is more than 6.3% by mass based on the total mass of the blocked polyisocyanate. The dispersion-blocked polyisocyanate composition was particularly excellent in storage stability when it contained a solvent and in adhesion when it was formed into a coating film.
The water-dispersed blocked polyisocyanate compositions of Examples 1 to 6 contain polyisocyanates A-1 to A-3 and A-6 derived from HDI or IPDI and 2-ethylhexanol, and contain an allophanate group / allophanate group + isocyanate. The water-dispersed blocked polyisocyanates of Examples 1 to 3 and 6 having a molar ratio of nurate groups of 4/100 to 30/100 were particularly excellent in hardness when used as a coating film.
In the water-dispersed blocked polyisocyanate compositions of Examples 2, 8 and 12, the proportion of the structural unit derived from the polyisocyanate is more than 50.4% by mass with respect to the total mass of the blocked polyisocyanate. The water-dispersed blocked polyisocyanate composition of No. 1 was particularly excellent in hardness when formed into a coating film.
In the aqueous dispersion blocked polyisocyanate compositions of Examples 2, 7, 11 and 13, the structural unit derived from the polycarbonate diol is 6.8% by mass with respect to the total mass of the blocked polyisocyanate, and polyethylene. The water-dispersed blocked polyisocyanate composition of Example 2 in which the structural unit derived from the oxide is 18.7% by mass with respect to the total mass of the blocked polyisocyanate is particularly excellent in gloss when used as a coating film. rice field.

On the other hand, the water-dispersed blocked polyisocyanate composition of Comparative Example 1 having no allophanate group has compatibility and storage stability when containing a solvent as compared with the water-dispersed blocked polyisocyanate composition of Example 1 having an allophanate group. Was inferior.
The water-dispersed blocked polyisocyanate composition of Comparative Example 2 having an allophanate group / allophanate group + isocyanurate group molar ratio of 45/100 has an allophanate group / allophanate group + isocyanurate group molar ratio of 4/100 to 40/ Compared with the water-dispersed blocked polyisocyanate composition of Examples 1 to 6, which is 100, the hardness of the coating film was inferior.
The water-dispersed blocked polyisocyanate composition of Comparative Example 3 having no structural unit derived from polyethylene oxide, which is a hydrophilic compound, is the water-dispersed blocked polyisocyanate composition of Example 2 having a structural unit derived from polyethylene oxide. Compared with, the compatibility, the storage stability when containing a solvent, and the gloss and adhesion when used as a coating film were inferior.
The ratio of the structural unit derived from the polyisocyanate is less than 46% by mass with respect to the total mass of the blocked polyisocyanate. The aqueous dispersion blocked polyisocyanate composition of Comparative Example 4 or the structural unit derived from the polycarbonate diol. In the water-dispersed blocked polyisocyanate composition of Comparative Example 5 which does not have, the proportion of the structural unit derived from the polyisocyanate is 46% by mass or more with respect to the total mass of the blocked polyisocyanate, and is from the polycarbonate diol. Compared with the water-dispersed blocked polyisocyanate composition of Example 2 having an induced structural unit, the storage stability when containing a solvent and the hardness, gloss and adhesion when formed into a coating film were inferior.
The water-dispersed blocked polyisocyanate composition of Comparative Example 6 in which the proportion of the structural unit derived from the polycarbonate diol is more than 15% by mass with respect to the total mass of the blocked polyisocyanate is the structural unit derived from the polycarbonate diol. Compared with the water-dispersed blocked polyisocyanate composition of Example 2 in which the ratio is 15% by mass or less with respect to the total mass of the blocked polyisocyanate, the storage stability when the solvent is contained and the hardness when the coating film is formed. Was inferior.
The proportion of the constituent units derived from the polyisocyanate is less than 46% by mass with respect to the total mass of the blocked polyisocyanate, and the proportion of the constituent units derived from the polycarbonate diol is the total mass of the blocked polyisocyanate. On the other hand, in the water-dispersed blocked polyisocyanate composition of Comparative Example 7, which is more than 15% by mass, the ratio of the structural units derived from the polyisocyanate is 46% by mass or more with respect to the total mass of the blocked polyisocyanate. Moreover, when the proportion of the structural unit derived from the polycarbonate diol is 15% by mass or less with respect to the total mass of the blocked polyisocyanate, as compared with the aqueous dispersion blocked polyisocyanate composition of Example 2, when the solvent is contained. The storage stability of the polycarbonate, and the hardness and adhesion of the coating film were inferior.

The water-dispersed blocked polyisocyanate composition of the present embodiment is, for example, a curable composition such as a paint composition, a pressure-sensitive adhesive composition, an adhesive composition, a casting agent composition; and various surface treatment agents such as a fiber treatment agent. It is suitably used as a composition; various elastomer compositions; a cross-linking agent for foam compositions and the like; a modifier; an additive and the like.

Claims (11)

A water-dispersed blocked polyisocyanate composition containing a blocked polyisocyanate obtained from a polyisocyanate and a heat-dissociating blocking agent and satisfying the conditions shown in 1) to 4) below.
1) The proportion of constituent units derived from at least one diisocyanate monomer selected from the group consisting of aliphatic diisocyanate monomers and alicyclic diisocyanate monomers and derived from polyisocyanates containing an allophanate group and an isocyanurate group. 46% by mass or more and 60% by mass or less with respect to the total mass of the blocked polyisocyanate;
2) The molar ratio of allophanate group / (alofanate group + isocyanurate group) is 2/100 or more and 40/100 or less;
3) The proportion of the structural unit derived from the polycarbonate diol is 2% by mass or more and 15% by mass or less with respect to the total mass of the blocked polyisocyanate;
4) The blocked polyisocyanate contains a structural unit derived from a hydrophilic compound. The water-dispersed blocked polyisocyanate composition according to claim 1, wherein the aliphatic diisocyanate monomer is hexamethylene diisocyanate. The hydrophilic compound is a poly (oxyalkylene) monoalkyl ether, and the hydrophilic compound is a poly (oxyalkylene) monoalkyl ether.
The water according to claim 1 or 2, wherein the proportion of the structural unit derived from the poly (oxyalkylene) monoalkyl ether is 5% by mass or more and 26% by mass or less with respect to the total mass of the blocked polyisocyanate. Dispersion block polyisocyanate composition. The water-dispersed blocked polyisocyanate composition according to claim 3, wherein the poly (oxyalkylene) monoalkyl ether is a compound represented by the following general formula (1).

(In the general formula (1), R ¹¹ is an alkylene group having 1 or more and 4 or less carbon atoms. R ¹² is an alkyl group having 1 or more and 4 or less carbon atoms. N 11 is a number of 6.0 or more and 20.0 or less. Is.) The polyisocyanate further contains a urethane group and contains
The aqueous dispersion block polyisocyanate according to any one of claims 1 to 4, wherein the molar ratio of (urethane group) / (urethane group + allophanate group + isocyanurate group) is 10/100 or more and 25/100 or less. Composition. Any one of claims 1 to 5, wherein the heat-dissociable blocking agent comprises at least one selected from the group consisting of an oxime-based compound, a pyrazole-based compound, an active methylene-based compound, an amine-based compound, and an acid amide-based compound. The aqueous dispersion blocked polyisocyanate composition according to the section. The aqueous dispersion-blocking polyisocyanate composition according to any one of claims 1 to 6, wherein the heat-dissociating blocking agent is a pyrazole-based compound or an oxime-based compound. The water-dispersed blocked polyisocyanate composition according to any one of claims 1 to 7, wherein the allophanate group is a functional group formed by reacting a hydroxyl group of an alcohol with an isocyanate group of the diisocyanate monomer. An aqueous dispersion containing the aqueous dispersion block polyisocyanate composition according to any one of claims 1 to 8 and a solvent. A water-based coating composition comprising the water-dispersed blocked polyisocyanate composition according to any one of claims 1 to 8 and at least one main agent. A coated substrate comprising a substrate and a coating film coated with the aqueous coating composition of claim 10 .