JP7420567B2 - Water-dispersed block isocyanate composition - Google Patents

Description

The present invention relates to a water-dispersible blocked isocyanate composition.

Conventionally, it has been known to disperse blocked isocyanate in water using a dispersant to prepare an aqueous dispersion of blocked isocyanate.

For example, a water-dispersed block is produced by emulsifying a block isocyanate prepared by reacting a trimethylolpropane adduct of xylylene diisocyanate with 3,5-dimethylpyrazole by adding an aqueous dispersant solution in which a dispersant is dissolved. Isocyanate compositions have been proposed (see, for example, Patent Document 1 (Example 1)).

Japanese Patent Application Publication No. 2011-208050

In a water-dispersed blocked isocyanate composition as described in Patent Document 1, the polyisocyanate used for preparing the blocked isocyanate is appropriately selected in order to ensure properties suitable for the intended use.

However, in the water-dispersible blocked isocyanate composition described in Patent Document 1, when an isocyanurate derivative of xylylene diisocyanate is selected as the polyisocyanate, it is difficult to ensure the water dispersibility of the blocked isocyanate.

Therefore, consideration has been given to reacting an isocyanurate derivative of xylylene diisocyanate with a polyoxyethylene compound to introduce an oxyethylene group as a hydrophilic group. However, when an oxyethylene group is introduced into the isocyanurate derivative of xylylene diisocyanate, there is a problem in that the swelling resistance under high humidity conditions decreases in polyurethane paints containing water-dispersed blocked isocyanate compositions.

The present invention provides a water-dispersible block isocyanate composition that can provide a polyurethane resin with swelling resistance under high humidity conditions while ensuring excellent water dispersibility.

The present invention [1] includes a blocked isocyanate in which isocyanate groups of the polyisocyanate are blocked with a blocking agent, and a surfactant, and the polyisocyanate contains an isocyanurate derivative of xylylene diisocyanate and a polyoxyethylene compound. The water-dispersed block isocyanate composition includes a reaction product, and the content of oxyethylene groups in the reaction product is more than 0% by mass and less than 15% by mass.

The present invention [2] includes the water-dispersed blocked isocyanate composition according to the above [1], wherein the isocyanurate derivative of xylylene diisocyanate is modified with an alcohol.

The present invention [3] provides the water-dispersed block according to the above [2], wherein the amount of modification of the alcohol in the isocyanurate derivative of xylylene diisocyanate is 0.1% by mass or more and 8.5% by mass or less. Contains an isocyanate composition.

The present invention [4] includes the water-dispersed blocked isocyanate composition according to the above [2] or [3], wherein the alcohol includes a divalent aliphatic alcohol.

The present invention [5] provides the water according to any one of [1] to [4] above, wherein the surfactant contains an aromatic nonionic surfactant having an HLB of 16 or more and having a hydroxy group at the end of the molecule. Contains a dispersed block isocyanate composition.

The present invention [6] provides the water according to any one of [1] to [4] above, wherein the surfactant contains an aromatic nonionic surfactant having an HLB of less than 16 and having a hydroxy group at the end of the molecule. Contains a dispersed block isocyanate composition.

The present invention [7] provides any one of the above [1] to [6], wherein the content ratio of the surfactant is 3 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the blocked isocyanate. The water-dispersible block isocyanate composition described in .

The water-dispersed blocked isocyanate composition of the present invention is a blocked isocyanate in which a polyisocyanate is blocked with a blocking agent, and the polyisocyanate contains a reaction product of an isocyanurate derivative of xylylene diisocyanate and a polyoxyethylene compound. The reaction product contains a blocked isocyanate and a surfactant, and the content of oxyethylene groups in the reaction product is within the above range.

Therefore, it is possible to provide the polyurethane resin with expansion resistance under high humidity conditions while ensuring excellent water dispersibility.

The water-dispersible blocked isocyanate composition of the present invention contains a blocked isocyanate and a surfactant as essential components. In blocked isocyanates, the isocyanate groups of polyisocyanate are blocked with a blocking agent. That is, the blocked isocyanate includes a reaction product of a polyisocyanate and a blocking agent, and preferably consists of a reaction product of a polyisocyanate and a blocking agent.

(1) Polyisocyanate Below, first, polyisocyanate before being blocked with a blocking agent will be explained.

The polyisocyanate includes a reaction product of an isocyanurate derivative of xylylene diisocyanate and a polyoxyethylene compound (hereinafter referred to as a hydrophilic group-containing isocyanate derivative), and preferably consists of a hydrophilic group-containing isocyanate derivative.

(1-1) Isocyanurate derivative of xylylene diisocyanate The isocyanurate derivative of xylylene diisocyanate mainly includes isocyanurate of xylylene diisocyanate. In addition, the isocyanurate derivative of xylylene diisocyanate allows the iminooxadiazinedione of xylylene diisocyanate, which is inevitably produced as a by-product, and unreacted xylylene diisocyanate to be contained in the isocyanurate conversion of xylylene diisocyanate, which will be described later. do.

That is, the isocyanurate derivative of xylylene diisocyanate includes, for example, 92% by mass or more of isocyanurate of xylylene diisocyanate, 6% by mass or less of iminooxadiazinedione, and 2% by mass or less of unreacted xylylene diisocyanate. and preferably consists of them.

Xylylene diisocyanate includes 1,2-xylylene diisocyanate (o-XDI), 1,3-xylylene diisocyanate (m-XDI), and 1,4-xylylene diisocyanate (p-XDI) as structural isomers. . The structural isomers of xylylene diisocyanate may be used alone or in combination of two or more.

Preferred examples of xylylene diisocyanate include 1,3-xylylene diisocyanate. That is, the xylylene diisocyanate preferably contains 1,3-xylylene diisocyanate, and more preferably consists of 1,3-xylylene diisocyanate.

Next, a method for preparing an isocyanurate derivative of xylylene diisocyanate, specifically a method for preparing an isocyanurate derivative of xylylene diisocyanate that has not been modified with an alcohol (described later) will be described.

To prepare an isocyanurate derivative of xylylene diisocyanate, xylylene diisocyanate is subjected to an isocyanurate reaction in the presence of an isocyanurate catalyst.

The isocyanurate-forming catalyst is not particularly limited as long as it activates isocyanurate-formation. Examples of isocyanurate catalysts include triethylamine, tributylamine, triethylenediamine, secondary amine copolymers (e.g., secondary amines such as dialkylamine, and monomers copolymerizable with secondary amines (e.g., phenol). tertiary amines such as polycondensates of , formaldehyde, etc.), Mannich bases such as 2-dimethylaminomethylphenol, 2,4,6-tris(dimethylaminomethyl)phenol, e.g. tetramethylammonium, tetraethylammonium , tetraalkylammonium hydroxides such as tetrabutylammonium, trimethylbenzylammonium, and tributylbenzylammonium, and their weak organic acid salts, such as trimethylhydroxypropylammonium (also known as: N-(2-hydroxypropyl)-N,N,N- trimethylammonium), trimethylhydroxyethylammonium, triethylhydroxypropylammonium, triethylhydroxyethylammonium, and their organic weak acid salts, such as acetic acid, caproic acid, octylic acid, myristic acid, naphthenic acid, etc. Metal salts of alkyl carboxylic acids (e.g. alkali metal salts, magnesium salts, tin salts, zinc salts, lead salts, etc.), metal chelate compounds of β-diketones, e.g. chloride, such as aluminum acetylacetone, lithium acetylacetone, etc. Friedel-Crafts catalysts such as aluminum, boron trifluoride, organometallic compounds such as titanium tetrabutyrate, tributylantimony oxide, aminosilyl group-containing compounds such as hexamethylsilazane, tetrabutylphosphonium hydrogen difluoride, etc. Examples include halogen-substituted organic phosphorus compounds such as. Isocyanurate catalysts can be used alone or in combination of two or more.

Among such isocyanuration catalysts, preferred are tetraalkylammonium hydroxides and trialkylhydroxyalkylammonium hydroxides, more preferred are tetraalkylammonium hydroxides, and particularly preferred are tetraalkylammonium hydroxides. , tetrabutylammonium hydroxide.

The blending ratio of the isocyanurating catalyst (calculated as 100% by mass of active ingredients) is, for example, 0.001 parts by mass or more, preferably 0.008 parts by mass or more, more preferably, The amount is 0.015 parts by mass or more, for example, 0.1 parts by mass or less, preferably 0.026 parts by mass or less, and more preferably 0.022 parts by mass or less.

The isocyanurate catalyst may be added in its entirety at the charging stage (initial stage) of the isocyanurate reaction, or may be added in multiple portions during the isocyanurate reaction. The above blending ratio is the blending ratio (feeding ratio) of the isocyanurate catalyst added before the start of the isocyanurate reaction (initial stage) and the blending ratio (additional ratio) of the isocyanurate catalyst added during the isocyanurate reaction. This is the total blending ratio of

Such an isocyanurate reaction is carried out, for example, in an inert gas (eg, nitrogen gas, argon gas, etc.) atmosphere.

Further, the reaction temperature of the isocyanurate reaction is, for example, 20°C or higher, preferably 40°C or higher, more preferably 60°C or higher, for example, 90°C or lower, and preferably 80°C or lower. The reaction pressure is, for example, atmospheric pressure. The reaction time is, for example, 0.5 hours or more, preferably 1 hour or more, more preferably 2 hours or more, for example 12 hours or less, preferably 10 hours or less, and even more preferably 8 hours or less.

In such an isocyanuration reaction, a promoter and a stabilizer can be added.

Examples of the cocatalyst include organic phosphites, and more specifically, aliphatic organic phosphites, aromatic organic phosphites, and the like. The promoter can be used alone or in combination of two or more.

Examples of aliphatic organic phosphites include triethyl phosphite, tributyl phosphite, tris (2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite, tris (tridecyl) phosphite, tristearyl phosphite, etc. derived from aliphatic polyhydric alcohols such as distearyl pentaerythrityl diphosphite, di-dodecyl pentaerythritol diphosphite, di-tridecyl pentaerythritol diphosphite, tripentaerythritol triphosphite, etc. Further, alicyclic polyphosphites such as hydrogenated bisphenol A phosphite polymer (molecular weight 2,400 to 3,000), tris(2,3-dichloropropyl) phosphite, and the like can be mentioned. Aliphatic organic phosphites can be used alone or in combination of two or more.

Among the aliphatic organic phosphites, alkyl monophosphites are preferred, and tridecyl phosphites are more preferred.

Examples of the aromatic organic phosphite include triphenyl phosphite, tris(nonylphenyl) phosphite, tris(2,4-di-t-butylphenyl) phosphite, diphenyldecyl phosphite, and diphenyl(tridecyl) phosphite. From aromatic polyhydric alcohols such as dinonylphenyl pentaerythritol diphosphite, tetraphenyl tetra tridecyl pentaerythrityl tetraphosphite, tetraphenyl dipropylene glycol diphosphite, etc. Derived di-, tri- or tetraphosphites, furthermore, for example, di-alkyl bisphenol A diphosphites having 1 to 20 carbon atoms, 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl) Examples include diphosphites derived from bisphenol compounds such as -di-tridecyl) phosphite. Aromatic organic phosphites can be used alone or in combination of two or more.

Among aromatic organic phosphite esters, di-, tri-, or tetraphosphites derived from aromatic polyhydric alcohols are preferred, and tetraphenyl dipropylene glycol diphosphite is more preferred.

The blending ratio of the co-catalyst is, for example, 0.01 parts by mass or more, preferably 0.03 parts by mass or more, and, for example, 0.1 parts by mass or less, preferably 0.01 parts by mass or more, based on 100 parts by mass of xylylene diisocyanate. 07 parts by mass or less.

As a stabilizer, for example, a hindered phenolic antioxidant, more specifically, 2,6-di(tert-butyl)-4-methylphenol (also known as dibutylhydroxytoluene, hereinafter abbreviated as BHT) may be used. ), Irganox 1010, Irganox 1076, Irganox 1135, and Irganox 245 (trade names, manufactured by Ciba Japan). The stabilizers can be used alone or in combination of two or more.

The blending ratio of the stabilizer is, for example, 0.01 part by mass or more, preferably 0.02 part by mass or more, but not more than 0.05 part by mass, preferably 0.01 part by mass or more, for example, 0.05 part by mass or less, based on 100 parts by mass of xylylene diisocyanate. 03 parts by mass or less.

Furthermore, in the isocyanurate reaction, known additives may be added in an appropriate ratio and at any timing, if necessary.

Examples of known additives include organic solvents (described later), catalyst deactivators (eg, phosphoric acid, monochloroacetic acid, dodecylbenzenesulfonic acid, p-toluenesulfonic acid, benzoyl chloride, etc.).

As a result, xylylene diisocyanate is converted into isocyanurate to produce isocyanurate of xylylene diisocyanate.

The conversion rate of isocyanate groups (isocyanurate conversion rate) in such an isocyanurate reaction is, for example, 10% by mass or more, preferably 15% by mass or more, more preferably 25% by mass or more, for example, 40% by mass. The content is preferably 33% by mass or less. Note that the conversion rate of isocyanate groups can be measured according to the method described in Examples described later (the same applies hereinafter).

Through the above steps, a reaction solution (reaction mixture) containing an isocyanurate derivative of xylylene diisocyanate is prepared.

The concentration of free isocyanate groups (isocyanate group concentration) in the reaction solution of such an isocyanurate reaction is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 25% by mass or more, for example, It is 50% by mass or less, preferably 40% by mass or less. Note that the isocyanate group concentration can be measured according to the method described in the Examples described below (the same applies hereinafter).

The reaction solution contains unreacted xylylene diisocyanate in addition to isocyanurate of xylylene diisocyanate. Furthermore, the reaction solution may contain the above-mentioned known additives.

Therefore, the reaction solution for the isocyanurate reaction is preferably purified by a known purification method. Examples of purification methods include thin film distillation (Smith distillation) and extraction, with thin film distillation being preferred.

When the reaction solution is purified by thin film distillation, the distillation yield is, for example, 30% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, for example, 80% by mass or less, preferably 70% by mass or more. % by mass or less. Note that the distillation yield can be measured in accordance with the method described in Examples below.

Through the above steps, an isocyanurate derivative of xylylene diisocyanate is prepared.

The isocyanurate derivative of xylylene diisocyanate is an isocyanurate derivative of xylylene diisocyanate that has not been modified with an alcohol (described later). In the following, isocyanurate derivatives of xylylene diisocyanate that have not been modified with alcohols are referred to as alcohol-unmodified XDI isocyanurate derivatives, and isocyanurate derivatives of xylylene diisocyanate that have been modified with alcohols (described later) are referred to as alcohol-modified XDI isocyanurate derivatives. Distinguished as an isocyanurate derivative.

Alcohol-unmodified XDI isocyanurate derivatives mainly contain isocyanurate mononuclear bodies. Furthermore, the alcohol-unmodified XDI isocyanurate derivative can include isocyanurate polynuclear bodies.

An isocyanurate mononuclear substance is a compound in which three molecules of xylylene diisocyanate form one isocyanurate ring, and that isocyanurate ring is not bonded to other isocyanurate rings, and xylylene diisocyanate via the isocyanurate ring It is a trimer of.

An isocyanurate polynuclear substance is a compound in which an isocyanurate mononuclear substance is combined with another isocyanurate mononuclear substance. Isocyanurate polynuclear bodies are distinguished based on the number of isocyanurate mononuclear bodies bound together, for example, isocyanurate dinuclear bodies bound together with two isocyanurate mononuclear bodies, and isocyanurate mononuclear bodies bound together with n isocyanurate mononuclear bodies. Examples include isocyanurate n-nuclear bodies.

In a chromatogram obtained by gel permeation chromatography measurement of such an isocyanurate derivative, the area of a peak having a peak top with a polystyrene equivalent molecular weight of 400 to 1000, preferably 600 to 900, is calculated based on the area of the total peak. The area ratio (hereinafter referred to as trimolecular body area ratio) corresponds to the content ratio of isocyanurate mononuclear bodies to the total amount of isocyanurate derivatives.

The area ratio of trimolecular bodies in the isocyanurate derivative is, for example, 25% or more, preferably 30% or more, and, for example, 70% or less, preferably 60% or less.

In addition, the trimolecular body area ratio was obtained by measuring the molecular weight distribution of the isocyanurate derivative using a gel permeation chromatograph (GPC) equipped with a differential refractive index detector (RID) in accordance with the examples described later. It can be calculated as the peak area ratio in the obtained chromatogram (chart) (the same applies hereinafter).

The average number of functional groups of isocyanate groups in such an isocyanurate derivative is, for example, 2 or more, preferably 2.2 or more, but, for example, 4.0 or less, preferably 3.5 or less.

Further, the concentration of free isocyanate groups (isocyanate group concentration) in the isocyanurate derivative is, for example, 5% by mass or more, preferably 10% by mass or more, more preferably 15% by mass or more, for example, 40% by mass or less, Preferably, it is 35% by mass or less.

(1-2) Isocyanurate derivative of alcohol-modified xylylene diisocyanate (alcohol-modified XDI isocyanurate derivative)
The isocyanurate derivative of xylylene diisocyanate described above is preferably modified with an alcohol.

When isocyanurate derivatives are modified with alcohols, it is possible to improve the film-forming properties of polyurethane resin raw materials containing water-dispersed blocked isocyanate compositions, while also improving the swelling resistance of the coating film under high-humidity conditions. can be reliably achieved.

Preferably, the alcohols include aliphatic alcohols.

Examples of the aliphatic alcohol include monovalent aliphatic alcohol, divalent aliphatic alcohol, trivalent aliphatic alcohol, and tetravalent or higher aliphatic alcohol. Aliphatic alcohols can be used alone or in combination of two or more.

Examples of monovalent aliphatic alcohols include linear monovalent aliphatic alcohols and branched monovalent aliphatic alcohols.

Examples of linear monohydric aliphatic alcohols include methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, n-dodecanol (lauryl alcohol), n-tridecanol, n-tetradecanol, n-pentadecanol, n-hexadecanol, n-heptadecanol, n-octadecanol (stearyl alcohol), Examples include n-nonadecanol and eicosanol.

Examples of branched monovalent aliphatic alcohols include isopropanol (also known as isopropyl alcohol, IPA), isobutanol (also known as isobutyl alcohol, IBA), sec-butanol, tert-butanol, isopentanol, isohexanol, and isoheptanol. Nor, isooctanol, 2-ethylhexanol (also known as 2-ethylhexyl alcohol, 2-EHA), isononanol, isodecanol, 5-ethyl-2-nonanol, trimethylnonyl alcohol, 2-hexyldecanol, 3,9-diethyl-6- Examples include tridecanol, 2-isoheptyl isoundecanol, 2-octyldodecanol, and other branched alkanols (C (number of carbon atoms, hereinafter the same) 5 to 20).

Examples of divalent aliphatic alcohols include ethylene glycol, 1,3-propanediol (1,3-PG), 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1, Linear dihydric aliphatic alcohols such as 4-dihydroxy-2-butene, diethylene glycol, triethylene glycol, dipropylene glycol, and other linear alkane (C7-20) diols, such as 1,2-propane Diol, 1,3-butylene glycol (also known as 1,3-butanediol, 1,3-BG), 1,2-butylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol (MPD), 2,2,4-trimethyl-1,3-pentanediol (TMPD), 3,3-dimethylolheptane, 2,6-dimethyl-1-octene-3,8-diol, and other branched alkanes (C7- 20) Branched dihydric aliphatic alcohols such as diols, such as 1,3- or 1,4-cyclohexanedimethanol and mixtures thereof, 1,3- or 1,4-cyclohexanediol and mixtures thereof, hydrogen Examples include alicyclic dihydric aliphatic alcohols such as bisphenol A.

Examples of trivalent aliphatic alcohols include glycerin and trimethylolpropane. Examples of tetrahydric or higher aliphatic alcohols include tetramethylolmethane, D-sorbitol, xylitol, and D-mannitol.

As long as such aliphatic alcohol has one or more hydroxy groups in its molecule, other molecular structures do not contain aromatic rings as long as they do not interfere with the excellent effects of the present invention. There are no particular limitations other than this, and for example, the molecule may contain an ester group, an ether group, a cyclohexane ring, or the like.

Therefore, the aliphatic alcohol is, for example, an addition polymer (random and/or block polymer of two or more types of alkylene oxide) of the above-mentioned monovalent aliphatic alcohol and an alkylene oxide (such as propylene oxide). Includes ether group-containing monohydric aliphatic alcohols, ester group-containing monohydric aliphatic alcohols that are addition polymers of the above-mentioned monohydric aliphatic alcohols and lactones (eg, ε-caprolactone, δ-valerolactone, etc.).

The number of carbon atoms in the aliphatic alcohol is, for example, 1 or more, preferably 2 or more, and, for example, 6 or less, preferably 4 or less.

Among such aliphatic alcohols, monovalent aliphatic alcohols and divalent aliphatic alcohols are preferably mentioned, and branched monovalent aliphatic alcohols and branched divalent aliphatic alcohols are more preferably mentioned. Mention may be made of alcohols, particularly preferably isobutanol and 1,3-butylene glycol.

Furthermore, when monovalent aliphatic alcohols and divalent aliphatic alcohols are compared, divalent aliphatic alcohols are more preferred. That is, the alcohol preferably includes a divalent aliphatic alcohol (branched divalent aliphatic alcohol, 1,3-butylene glycol), and more preferably includes a divalent aliphatic alcohol (branched divalent aliphatic alcohol, 1,3-butylene glycol). aliphatic alcohol, 1,3-butylene glycol).

When the alcohol that modifies the isocyanurate derivative contains a divalent aliphatic alcohol, the solvent resistance of the coating film can be reliably improved.

Next, a method for preparing an isocyanurate derivative of xylylene diisocyanate (alcohol-modified XDI isocyanurate derivative) modified with alcohol will be described.

Examples of methods for preparing alcohol-modified XDI isocyanurate derivatives include a method in which xylylene diisocyanate and an alcohol are subjected to a urethanization reaction, and then the reaction product is subjected to an isocyanurate reaction; Examples include a method of preparing an unmodified XDI isocyanurate derivative and subjecting the alcohol unmodified XDI isocyanurate derivative and alcohol to a urethane reaction.

Among these methods, a preferred method is to subject xylylene diisocyanate and alcohol to a urethane reaction, and then subject the reaction product to an isocyanurate reaction.

Specifically, first, xylylene diisocyanate and alcohol are blended, and the xylylene diisocyanate and alcohol are subjected to a urethane reaction in such a proportion that free isocyanate groups remain.

The equivalent ratio (NCO/OH) of the isocyanate group of xylylene diisocyanate to the hydroxyl group of alcohol is, for example, 3 or more, preferably 5 or more, more preferably 15 or more, for example, 600 or less, preferably 500 or less. , more preferably 200 or less, particularly preferably 100 or less.

The blending ratio of the alcohol is, for example, 0.05 parts by mass or more, preferably 0.10 parts by mass or more, more preferably 0.50 parts by mass or more, for example 10 parts by mass or more, based on 100 parts by mass of xylylene diisocyanate. The amount is not more than 8 parts by weight, preferably not more than 8 parts by weight, and more preferably not more than 3 parts by weight.

Further, the urethanization reaction is performed, for example, in an inert gas (eg, nitrogen gas, argon gas, etc.) atmosphere.

The reaction temperature is, for example, room temperature (25°C) or higher, preferably 40°C or higher, for example, 100°C or lower, preferably 90°C or lower. The reaction pressure is, for example, atmospheric pressure. The reaction time is, for example, 0.05 hours or more, preferably 0.2 hours or more, for example, 10 hours or less, preferably 6 hours or less, and more preferably 2 hours or less.

In such a urethanization reaction, the above-mentioned co-catalyst and the above-mentioned stabilizer can be added at the above-mentioned mixing ratio, and if necessary, a known urethanization catalyst may be added at an appropriate ratio.

Furthermore, in the urethanization reaction, the above-mentioned alcohols and active hydrogen group-containing compounds (for example, thiols, oximes, lactams, phenols, β-diketones, etc.) can be used in combination.

As a result, the xylylene diisocyanate and the alcohol undergo a urethanization reaction to produce a reaction product between the xylylene diisocyanate and the alcohol (alcohol-modified xylylene diisocyanate).

The conversion rate of isocyanate groups (urethane conversion rate) in such a urethanization reaction is, for example, 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more, e.g. , 25% by mass or less, preferably 20% by mass or less, more preferably 10% by mass or less.

Through the above steps, a reaction solution (reaction mixture) containing alcohol-modified xylylene diisocyanate is prepared.

The concentration of free isocyanate groups (isocyanate group concentration) in the reaction solution for such urethanization reaction is, for example, 20% by mass or more, preferably 30% by mass or more, more preferably 40% by mass or more, for example, 60% by mass or more. It is not more than 50% by mass, preferably not more than 50% by mass.

The reaction solution for such a urethanization reaction contains unreacted xylylene diisocyanate (alcohol-unmodified xylylene diisocyanate) and alcohol-modified xylylene diisocyanate.

Next, the above-described isocyanurate catalyst is blended into the reaction solution for the urethanization reaction at the above-described blending ratio. Then, xylylene diisocyanate and alcohol-modified xylylene diisocyanate are subjected to an isocyanurate reaction under the above reaction conditions.

As a result, the alcohol-unmodified xylylene diisocyanate undergoes an isocyanurate reaction to produce alcohol-unmodified XDI isocyanurate, and the alcohol-modified xylylene diisocyanate undergoes an isocyanurate reaction to produce alcohol-modified XDI isocyanurate. Note that alcohol-modified XDI isocyanurate will be described in detail later.

The range of the isocyanurate conversion rate in such an isocyanurate conversion reaction is the same as the range of the isocyanurate conversion rate described above.

Further, the sum of the urethane conversion rate and the isocyanurate conversion rate (conversion rate (reaction rate) of isocyanate groups) is, for example, 15% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, e.g. , 60% by mass or less, preferably 50% by mass or less.

Through the above steps, a reaction solution (reaction mixture) containing the alcohol-modified XDI isocyanurate derivative is prepared.

The concentration of free isocyanate groups (isocyanate group concentration) in the reaction solution of such an isocyanurate reaction is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 25% by mass or more, for example, It is 50% by mass or less, preferably 40% by mass or less.

The reaction solution for the isocyanurate formation reaction contains alcohol-unmodified XDI isocyanurate and alcohol-modified XDI isocyanurate. Furthermore, the reaction solution for the isocyanurate reaction may contain xylylene diisocyanate, alcohol-modified xylylene diisocyanate, the above-mentioned known additives, and the like.

Therefore, the reaction solution for the isocyanurate reaction is preferably purified by the above-described purification method. The range of the distillation yield is the same as the range of the distillation yield described above.

Through the above steps, an isocyanurate derivative containing the above-mentioned alcohol-unmodified XDI isocyanurate derivative and alcohol-modified XDI isocyanurate derivative is prepared.

The alcohol-modified XDI isocyanurate derivative is a reaction product of the above-mentioned alcohol-unmodified XDI isocyanurate derivative and alcohol. Examples of alcohol-modified XDI isocyanurate derivatives include alcohol-modified isocyanurate mononuclear products, alcohol-modified isocyanurate polynuclear products, and the like. In the following, isocyanurate mononuclear bodies and isocyanurate polynuclear bodies that have not been modified with alcohols are referred to as alcohol-unmodified isocyanurate mononuclear bodies and alcohol-unmodified isocyanurate polynuclear bodies.

The alcohol-modified isocyanurate mononuclear substance has one isocyanurate ring to which at least one alcohol is bonded. An alcohol-modified isocyanurate mononuclear substance is, for example, a compound in which an alcohol-modified xylylene diisocyanate (3-n) molecule and a xylylene diisocyanate n molecule form an isocyanurate ring, and xylylene diisocyanate via the isocyanurate ring. It is a trimolecular body. Note that n is an integer from 0 to 2.

An alcohol-modified isocyanurate polynuclear substance is a compound having two or more isocyanurate rings, and at least one alcohol is bonded to these isocyanurate rings. The alcohol-modified isocyanurate polynuclear substance is, for example, a compound in which an alcohol-modified isocyanurate mononuclear substance and at least one alcohol-modified isocyanurate mononuclear substance or an alcohol-undenatured isocyanurate mononuclear substance are bonded.

More specifically, when the alcohol is a monovalent aliphatic alcohol, examples of alcohol-modified isocyanurate polynuclear bodies include direct bond type alcohol-modified isocyanurate polynuclear bodies.

A directly bonded alcohol-modified isocyanurate mononuclear substance is a compound in which the isocyanate group of an alcohol-modified isocyanurate mononuclear substance serves as another alcohol-modified isocyanurate mononuclear substance or an alcohol-unmodified isocyanurate mononuclear substance. In other words, in a directly bonded alcohol-modified isocyanurate polynuclear substance, the isocyanurate ring of the alcohol-modified isocyanurate mononuclear substance and the isocyanurate ring of the alcohol-modified isocyanurate mononuclear substance or the alcohol-unmodified isocyanurate mononuclear substance are 1 They are bonded through two xylylene diisocyanate skeletons.

In addition, when the alcohol is a divalent aliphatic alcohol, examples of the alcohol-modified isocyanurate polynuclear product include the same direct bond type alcohol-modified isocyanurate polynuclear product as described above, and the cross-linked alcohol-modified isocyanurate dinuclear product. Can be mentioned.

The cross-linked alcohol-modified isocyanurate mononuclear substance is characterized in that the isocyanate group of the alcohol-modified isocyanurate mononuclear substance and the isocyanate group of the alcohol-modified isocyanurate mononuclear substance or the alcohol-unmodified isocyanurate mononuclear substance are divalent aliphatic It is a compound that reacts and bonds with each of the hydroxyl groups of alcohol. In other words, in the crosslinked alcohol-modified isocyanurate mononuclear substance, an alcohol-modified isocyanurate mononuclear substance and an alcohol-modified isocyanurate mononuclear substance or an alcohol-undenatured isocyanurate mononuclear substance are bonded together via a divalent aliphatic alcohol. are combined.

In addition, in the urethanization reaction and/or isocyanurate reaction described above, alcohol-modified xylylene diisocyanate and/or alcohol-modified XDI isocyanurate derivative and xylylene diisocyanate and/or alcohol-modified xylylene diisocyanate react to form allophanate. may be generated. In this case, the isocyanurate derivative includes allophanate.

The trimolecular body area ratio of isocyanurate derivatives including alcohol-modified XDI isocyanurate derivatives is determined by the content of alcohol-unmodified isocyanurate mononuclear bodies and the content of alcohol-modified isocyanurate mononuclear bodies with respect to the total amount of isocyanurate derivatives. , corresponds to the total amount of allophanate containing the three molecules described above.

The trimolecular body area ratio in isocyanurate derivatives including alcohol-modified XDI isocyanurate derivatives is, for example, 30% or more, preferably 35% or more, for example, 60% or less, preferably 55% or less, more preferably 52 % or less.

Further, the average number of functional groups of isocyanate groups in the isocyanurate derivative including the alcohol-modified XDI isocyanurate derivative is, for example, 2 or more, preferably 2.2 or more, for example, 4.0 or less, preferably 3.5 or less. be.

Further, the concentration of free isocyanate groups (isocyanate group concentration) in the isocyanurate derivative including the alcohol-modified XDI isocyanurate derivative is, for example, 5% by mass or more, preferably 10% by mass or more, more preferably 15% by mass or more. , for example, 40% by mass or less, preferably 35% by mass or less, more preferably 25% by mass or less.

Further, the amount of modification of alcohol in the isocyanurate derivative including the alcohol-modified XDI isocyanurate derivative is, for example, 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.7% by mass or more. , for example, 20% by mass or less, preferably 15% by mass or less, more preferably 10.0% by mass or less, particularly preferably 8.5% by mass or less. Note that the amount of modification of alcohol is the ratio (mass ratio) of parts by mass of alcohol to parts by mass of xylylene diisocyanate in the isocyanurate derivative, and can be measured according to the method described in Examples described below. Furthermore, the amount of denaturation of alcohols can also be calculated by ¹ H-NMR measurement, for example, as described in paragraph [0086] of Japanese Patent No. 6161788.

When the amount of modification of the alcohol is at least the above lower limit, it is possible to improve the film-forming properties of the polyurethane resin raw material containing the water-dispersed block isocyanate composition, while also improving the swelling resistance of the coating film under high humidity conditions. You can definitely make improvements. When the amount of modification of the alcohol is below the above upper limit, it is possible to reliably improve the weather resistance of the coating film, and it is also possible to reliably improve the swelling resistance of the coating film under high humidity conditions.

Moreover, a compound containing a sulfonamide group can be added to the isocyanurate derivative in an appropriate ratio, if necessary.

Examples of compounds containing a sulfonamide group include aromatic sulfonamides and aliphatic sulfonamides. Compounds containing sulfonamide groups can be used alone or in combination of two or more.

Aromatic sulfonamides include, for example, benzenesulfonamide, dimethylbenzenesulfonamide, sulfanilamide, o- and p-toluenesulfonamide, hydroxynaphthalenesulfonamide, naphthalene-1-sulfonamide, naphthalene-2-sulfonamide, m -Nitrobenzenesulfonamide, p-chlorobenzenesulfonamide and the like.

Examples of aliphatic sulfonamides include methanesulfonamide, N,N-dimethylmethanesulfonamide, N,N-dimethylethanesulfonamide, N,N-diethylmethanesulfonamide, N-methoxymethanesulfonamide, and N-dodecyl. Examples include methanesulfonamide, N-cyclohexyl-1-butanesulfonamide, and 2-aminoethanesulfonamide.

Moreover, the isocyanurate derivative can be prepared as a diluted solution of the isocyanurate derivative by diluting it with an organic solvent if necessary.

Examples of organic solvents include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, nitrites such as acetonitrile, alkyl esters such as methyl acetate, ethyl acetate, butyl acetate, and isobutyl acetate, and n-hexane. , aliphatic hydrocarbons such as n-heptane and octane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, aromatic hydrocarbons such as toluene, xylene, and ethylbenzene, such as methyl cellosolve acetate, Glycol ether esters such as ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropionate ethers such as diethyl ether, tetrahydrofuran, dioxane, halogenated aliphatic hydrocarbons such as methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, methylene iodide, dichloroethane, etc. Examples include polar aprotons such as N-methylpyrrolidone, dimethylformamide, N,N'-dimethylacetamide, dimethylsulfoxide, and hexamethylphosphonylamide.

(1-2) Polyoxyethylene compound A polyoxyethylene compound has at least three consecutive oxyethylene groups (ethylene oxide groups) and an active hydrogen group (e.g., hydroxyl group, amino group, etc.) that can react with an isocyanate group. .

Examples of the polyoxyethylene compound include polyoxyethylene group-containing polyols, polyoxyethylene group-containing polyamines, one-end-blocked polyoxyethylene glycol, and one-end-blocked polyoxyethylene diamine.

Polyoxyethylene group-containing polyols include, for example, polyoxyethylene glycol, polyoxyethylene triol, random and/or block copolymers of ethylene oxide and propylene oxide (for example, polyoxypropylene polyoxyethylene copolymer diols or triols, Examples include oxypropylene polyoxyethylene block polymer diol or triol, Pluronic type polypropylene glycol or triol obtained by addition polymerizing ethylene oxide to the terminal of polypropylene glycol, etc.

Examples of polyoxyethylene group-containing polyamines include polyoxyalkylene ether diamines such as polyoxyethylene ether diamine.

Examples of one-end-blocked polyoxyethylene glycol include alkoxypolyethylene glycol (poly(oxyethylene) alkyl ether) that is one-end-blocked with an alkyl group having 1 to 20 carbon atoms, and specifically, methoxypolyethylene glycol (poly(oxyethylene) methyl ether), ethoxypolyethylene glycol (poly(oxyethylene) ethyl ether), and the like.

Examples of the one-terminally blocked polyoxyethylene diamine include polyoxyethylene diamine which is one-terminally blocked with an alkoxy group having 1 to 20 carbon atoms.

Such polyoxyethylene compounds can be used alone or in combination of two or more.

Preferable examples of the polyoxyethylene compound include polyoxyethylene group-containing polyols and polyoxyethylene glycols blocked at one end, more preferably polyoxyethylene glycols blocked at one end, and particularly preferably alkoxypolyethylene glycols. Examples include glycol (poly(oxyethylene) alkyl ether), and particularly preferred is methoxypolyethylene glycol.

The number average molecular weight of such a polyoxyethylene compound is, for example, 200 or more, preferably 300 or more, and, for example, 2,000 or less, preferably 1,000 or less. Note that the number average molecular weight (in terms of polystyrene) of the polyoxyethylene compound can be measured by gel permeation chromatography.

(1-3) Preparation of polyisocyanate Next, preparation of polyisocyanate will be explained.

As described above, polyisocyanate includes a reaction product of an isocyanurate derivative and a polyoxyethylene compound (hydrophilic group-containing isocyanate derivative).

To prepare a polyisocyanate containing a hydrophilic group-containing isocyanate derivative, the above-described isocyanurate derivative and the above-described polyoxyethylene compound are reacted in such a proportion that free isocyanate groups remain.

The equivalent ratio of the active hydrogen groups of the polyoxyethylene compound to the free isocyanate groups of the isocyanurate derivative (active hydrogen groups/NCO) is, for example, 0.01 or more, preferably 0.05 or more, for example, 0.30. It is preferably 0.20 or less.

The blending ratio of the polyoxyethylene compound is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 25 parts by mass or more, for example, 70 parts by mass or less, based on 100 parts by mass of the isocyanurate derivative. Preferably it is 60 parts by mass or less, more preferably 55 parts by mass or less.

Further, the reaction between the isocyanurate derivative and the polyoxyethylene compound is carried out, for example, in an inert gas (for example, nitrogen gas, argon gas, etc.) atmosphere, for example, in the presence of the above-mentioned organic solvent.

Among such organic solvents, ketones are preferred, and methyl isobutyl ketone is more preferred.

The addition ratio of the organic solvent is, for example, 1 part by mass or more, preferably 10 parts by mass or more, for example, 100 parts by mass or less, preferably 50 parts by mass or less, more preferably , 30 parts by mass or less.

The reaction temperature is, for example, 50°C or higher, preferably 70°C or higher, and, for example, 150°C or lower, preferably 110°C or lower. The reaction pressure is, for example, atmospheric pressure. The reaction time is, for example, 0.5 hours or more, preferably 1 hour or more, for example, 120 hours or less, preferably 72 hours or less.

The completion of the reaction can be determined, for example, by the fact that the amount of isocyanate measured by titration does not change.

Note that the isocyanurate derivative and the polyoxyethylene compound can also be reacted in the absence of a solvent.

As a result, the isocyanate group of the isocyanurate derivative of xylylene diisocyanate (alcohol-unmodified XDI isocyanurate derivative and/or alcohol-modified XDI isocyanurate derivative) and the active hydrogen group of the polyoxyethylene compound react, and two or more A hydrophilic group-containing isocyanate derivative in which free isocyanate groups remain is produced.

By the above steps, a polyisocyanate containing a hydrophilic group-containing isocyanate derivative is prepared.

When the isocyanurate derivative includes an alcohol-unmodified XDI isocyanurate derivative and does not include an alcohol-modified XDI isocyanurate derivative, the hydrophilic group-containing isocyanate derivative is a reaction product of an alcohol-unmodified XDI isocyanurate derivative and a polyoxyethylene compound. (alcohol-unmodified hydrophilic group-containing isocyanate derivatives), and does not contain the reaction product of alcohol-modified XDI isocyanurate derivatives and polyoxyethylene compounds (alcohol-modified hydrophilic group-containing isocyanate derivatives). In this case, the polyisocyanate may contain, for example, an unreacted alcohol-unmodified XDI isocyanurate derivative in addition to the alcohol-unmodified hydrophilic group-containing isocyanate derivative.

In addition, when the isocyanurate derivative includes an alcohol-unmodified XDI isocyanurate derivative and an alcohol-modified XDI isocyanurate derivative, the hydrophilic group-containing isocyanate derivative includes an alcohol-unmodified hydrophilic group-containing isocyanate derivative and an alcohol-modified hydrophilic group-containing isocyanate derivative. isocyanate derivatives. In this case, the polyisocyanate includes, in addition to the alcohol-unmodified hydrophilic group-containing isocyanate derivative and the alcohol-modified hydrophilic group-containing isocyanate derivative, for example, unreacted alcohol-unmodified XDI isocyanurate derivative and/or unreacted alcohol-modified XDI Can include isocyanurate derivatives.

The content ratio (solid content equivalent) of the hydrophilic group-containing isocyanate derivative in the polyisocyanate is, for example, 20% by mass or more, preferably 30% by mass or more, for example, 95% by mass or less, preferably 90% by mass or less. .

The average number of free isocyanate groups in the polyisocyanate is, for example, 2 or more, preferably 2.2 or more, but, for example, 4.0 or less, preferably 3.5 or less.

The isocyanate group concentration (in terms of solid content) in the polyisocyanate is, for example, 5% by mass or more, preferably 7% by mass or more, for example, 30% by mass or less, preferably 25% by mass or less, more preferably 20% by mass. It is as follows.

The content of oxyethylene groups in the polyisocyanate (in terms of solid content) exceeds 0% by mass, preferably 1% by mass or more, more preferably 3% by mass or less, 15% by mass or less, preferably 13% by mass. % or less, more preferably 8% by mass or less. In addition, the content of oxyethylene groups in the polyisocyanate can be calculated based on the method described in Examples described later.

When the content of oxyethylene groups in the polyisocyanate is within the above range, it is possible to ensure excellent water dispersibility while providing the coating film with excellent swelling resistance under high humidity conditions.

Further, the amount of modification of alcohol in the polyisocyanate is, for example, 0.07% by mass or more, preferably 0.14% by mass or more, for example, 6.0% by mass or less, preferably 5.4% by mass or less. be. In addition, the amount of modification of alcohol in polyisocyanate can be calculated by the following formula.

Amount of alcohol modification in polyisocyanate (mass %) = Modification amount of alcohol in isocyanurate derivative (mass %) x amount of polyoxyethylene compound charged (parts by mass) / amount of hydrophilic group-containing isocyanate derivative charged (mass) part) x 100
In addition, in general, the amount of denaturation of alcohols in isocyanurate derivatives can also be calculated by ¹ H-NMR measurement.

(2) Blocking agent The blocking agent has an active group that can react with an isocyanate group, and reacts with the free isocyanate group of the polyisocyanate described above to form a latent isocyanate group. That is, a blocked isocyanate contains latent isocyanate groups that are blocked by a blocking agent.

Examples of the blocking agent include the first blocking agent and the second blocking agent described in JP-A-2017-82208, and specifically, guanidine compounds, imidazole compounds, alcohol compounds, phenol compounds, Active methylene compounds, amine compounds, imine compounds, oxime compounds, carbamate compounds, urea compounds, acid amide (lactam) compounds, acid imide compounds, triazole compounds, pyrazole compounds, mercaptan compounds compounds, bisulfites, imidazoline compounds, and pyrimidine compounds. The blocking agents can be used alone or in combination.

Examples of the guanidine-based compound include guanidine, 1-alkylguanidine such as 1-methylguanidine, 1-arylguanidine such as 1-phenylguanidine, and 1,3-dialkyl guanidine such as 1,3-dimethylguanidine. Guanidine, e.g. 1,3-diphenylguanidine, 1,3-diarylguanidine such as 1,3-di(o-tolyl)-guanidine, e.g. 1,1-dimethylguanidine, 1,1-diethylguanidine, etc. , 1-dialkylguanidine, 1,2,3-trialkylguanidine, such as 1,2,3-trimethylguanidine, 1,2,3-triarylguanidine, such as 1,2,3-triphenylguanidine. , for example 1,1,3,3-tetraalkylguanidine such as 1,1,3,3-tetramethylguanidine, for example 1,5,7-triazabicyclo[4.4.0]deca-5- Examples include en.

Examples of imidazole compounds include imidazole, benzimidazole, 2-methylimidazole, 4-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2- Examples include amine-imidazole.

Examples of alcohol compounds include methanol, ethanol, 2-propanol, n-butanol, s-butanol, 2-ethylhexyl alcohol, 1- or 2-octanol, cyclohexyl alcohol, ethylene glycol, benzyl alcohol, 2,2, 2-Trifluoroethanol, 2,2,2-trichloroethanol, 2-(hydroxymethyl)furan, 2-methoxyethanol, methoxypropanol, 2-ethoxyethanol, n-propoxyethanol, 2-butoxyethanol, 2-ethoxyethoxy Ethanol, 2-ethoxybutoxyethanol, butoxyethoxyethanol, 2-butoxyethylethanol, 2-butoxyethoxyethanol, N,N-dibutyl-2-hydroxyacetamide, N-hydroxysuccinimide, N-morpholineethanol, 2,2-dimethyl Examples include -1,3-dioxolane-4-methanol, 3-oxazolidineethanol, 2-hydroxymethylpyridine, furfuryl alcohol, 12-hydroxystearic acid, triphenylsilanol, and 2-hydroxyethyl methacrylate.

Examples of phenolic compounds include phenol, cresol, ethylphenol, n-propylphenol, isopropylphenol, n-butylphenol, s-butylphenol, t-butylphenol, n-hexylphenol, 2-ethylhexylphenol, n-octylphenol, n- Nonylphenol, di-n-propylphenol, diisopropylphenol, isopropylcresol, di-n-butylphenol, di-s-butylphenol, di-t-butylphenol, di-n-octylphenol, di-2-ethylhexylphenol, di-n- Nonylphenol, nitrophenol, bromophenol, chlorophenol, fluorophenol, dimethylphenol, styrenated phenol, methyl salicylate, methyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, 2-ethylhexyl hydroxybenzoate, 4-[ (dimethylamino)methyl]phenol, 4-[(dimethylamino)methyl]nonylphenol, bis(4-hydroxyphenyl)acetic acid, 2-hydroxypyridine, 2- or 8-hydroxyquinoline, 2-chloro-3-pyridinol, pyridine -2-thiol and the like.

Examples of active methylene compounds include Meldrum's acid, dimethyl malonate, diethyl malonate, di-n-butyl malonate, di-t-butyl malonate, di-2-ethylhexyl malonate, methyl n-butyl malonate, Ethyl n-butyl malonate, methyl s-butyl malonate, ethyl s-butyl malonate, methyl t-butyl malonate, ethyl t-butyl malonate, diethyl methylmalonate, dibenzyl malonate, diphenyl malonate, malonic acid Dialkyl malonates such as benzylmethyl, ethylphenyl malonate, t-butylphenyl malonate, isopropylidene malonate, such as methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetate, isopropyl acetoacetate, n-butyl acetoacetate , alkyl acetoacetates such as t-butyl acetoacetate, benzyl acetoacetate, and phenyl acetoacetate, such as 2-acetoacetoxyethyl methacrylate, acetylacetone, and ethyl cyanoacetate.

Examples of amine compounds include dibutylamine, diphenylamine, aniline, N-methylaniline, carbazole, bis(2,2,6,6-tetramethylpiperidinyl)amine, di-n-propylamine, diisopropylamine, isopropyl Ethylamine, 2,2,4- or 2,2,5-trimethylhexamethyleneamine, N-isopropylcyclohexylamine, dicyclohexylamine, bis(3,5,5-trimethylcyclohexyl)amine, piperidine, 2,6-dimethylpiperidine , t-butylmethylamine, t-butylethylamine, t-butylpropylamine, t-butylbutylamine, t-butylbenzylamine, t-butylphenylamine, 2,2,6-trimethylpiperidine, 2,2,6, 6-tetramethylpiperidine, (dimethylamino)-2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethyl-4-piperidine, 6-methyl-2-piperidine, 6-aminocaproic acid Examples include.

Examples of imine compounds include ethyleneimine, polyethyleneimine, and 1,4,5,6-tetrahydropyrimidine.

Examples of oxime compounds include formaldoxime, acetaldoxime, acetoxime, methylethylketoxime, cyclohexanoneoxime, diacetylmonoxime, penzophenoxime, 2,2,6,6-tetramethylcyclohexanoneoxime, diisopropylketoneoxime, Methyl t-butyl ketone oxime, diisobutyl ketone oxime, methyl isobutyl ketone oxime, methyl isopropyl ketone oxime, methyl 2,4-dimethylpentyl ketone oxime, methyl 3-ethyl heptyl ketone oxime, methyl isoamyl ketone oxime, n-amyl ketone oxime , 2,2,4,4-tetramethyl-1,3-cyclobutanedione monooxime, 4,4'-dimethoxybenzophenone oxime, 2-heptanone oxime and the like.

Examples of carbamic acid compounds include phenyl N-phenylcarbamate.

Examples of urea compounds include urea, thiourea, and ethylene urea.

Examples of acid amide (lactam) compounds include acetanilide, N-methylacetamide, acetamide, ε-caprolactam, δ-valerolactam, γ-butyrolactam, pyrrolidone, 2,5-piperazinedione, and laurolactam. .

Examples of acid imide compounds include succinimide, maleimide, and phthalimide.

Examples of triazole compounds include 1,2,4-triazole and benzotriazole.

Examples of pyrazole compounds include pyrazole, 3,5-dimethylpyrazole, 3,5-diisopropylpyrazole, 3,5-diphenylpyrazole, 3,5-di-t-butylpyrazole, 3-methylpyrazole, 4-benzyl- Examples include 3,5-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, 4-bromo-3,5-dimethylpyrazole, and 3-methyl-5-phenylpyrazole.

Examples of mercaptan compounds include butyl mercaptan, dodecyl mercaptan, hexyl mercaptan, and the like.

Examples of bisulfites include sodium bisulfite.

Examples of imidazoline compounds include 2-methylimidazoline and 2-phenylimidazoline.

Examples of pyrimidine compounds include 2-methyl-1,4,5,6-tetrahydropyrimidine.

Among such blocking agents, oxime compounds and pyrazole compounds are preferred, methyl ethyl ketoxime and 3,5-dimethyl pyrazole are more preferred, and 3,5-dimethyl pyrazole is particularly preferred. can be mentioned.

That is, the blocking agent preferably contains a pyrazole compound and/or an oxime compound, more preferably 3,5-dimethylpyrazole and/or methylethylketoxime, and particularly preferably 3,5-dimethylpyrazole. include. Further, the blocking agent preferably consists of a pyrazole compound (3,5-dimethylpyrazole) and/or an oxime compound (methyl ethyl ketoxime).

When the blocking agent contains a pyrazole compound and/or an oxime compound, excellent mechanical properties, solvent resistance, weather resistance, and swelling resistance under high humidity conditions can be more reliably imparted to the coating film. In particular, when the blocking agent contains a pyrazole compound, the weather resistance of the coating film and the expansion resistance under high humidity conditions can be further improved.

The dissociation temperature of the blocking agent is, for example, 150°C or lower, preferably 140°C or lower, and, for example, 60°C or higher. Note that the dissociation temperature of the blocking agent can be measured by the following method (the same applies hereinafter).

Blocked isocyanate is applied to a silicon wafer, and while heating, the temperature at which isocyanate groups are regenerated is observed by IR measurement. If the regenerated isocyanate groups cannot be observed, the blocking agent can be obtained by mixing it with a known polyol, coating the mixture on a silicon wafer, and observing the temperature at which the hydroxyl groups of the polyol react by IR measurement while heating. The dissociation temperature of can be measured.

(3) Production of block isocyanate Next, production of block isocyanate will be explained.

To produce the blocked isocyanate, the above polyisocyanate and the above blocking agent are reacted.

The equivalent ratio of the active group capable of reacting with the isocyanate group in the blocking agent to the isocyanate group of the polyisocyanate (active group/isocyanate group) is, for example, 0.2 or more, preferably 0.5 or more, for example, 1.5. Below, it is preferably 1.2 or less, more preferably 1.1 or less.

Further, the reaction between the polyisocyanate and the blocking agent is carried out, for example, in an inert gas (eg, nitrogen gas, argon gas, etc.) atmosphere.

The reaction temperature is, for example, 0°C or higher, preferably 20°C or higher, and, for example, 80°C or lower, preferably 60°C or lower. The reaction pressure is, for example, atmospheric pressure. The reaction time is, for example, 0.5 hours or more, preferably 1.0 hours or more, and, for example, 24 hours or less, preferably 12 hours or less.

This produces latent isocyanate groups blocked by the blocking agent.

In addition, when two or more types of blocking agents are used in combination, the two or more types of blocking agents may be reacted with the polyisocyanate at the same time, or the two types of blocking agents may be reacted with the polyisocyanate sequentially.

Furthermore, the completion of the reaction can be determined by, for example, employing infrared spectroscopy and confirming the disappearance or reduction of isocyanate groups.

Furthermore, the above reaction may be carried out without a solvent or, for example, in the presence of a solvent. Examples of the solvent include the above-mentioned organic solvents and plasticizers. The solvents can be used alone or in combination of two or more.

Examples of the plasticizer include the plasticizers described in paragraphs [0109] to [0117] of JP-A No. 2017-82208. Plasticizers can be used alone or in combination of two or more.

By the above steps, a blocked isocyanate in which the isocyanate groups of the polyisocyanate are blocked by a blocking agent is prepared.

When the polyisocyanate contains an alcohol-unmodified hydrophilic group-containing isocyanate derivative and does not contain an alcohol-modified hydrophilic group-containing isocyanate derivative, the blocked isocyanate is a reaction product of an alcohol-unmodified hydrophilic group-containing isocyanate derivative and a blocking agent. including.

In addition, when the polyisocyanate includes an alcohol-unmodified hydrophilic group-containing isocyanate derivative and an alcohol-modified hydrophilic group-containing isocyanate derivative, the blocked isocyanate is a reaction product of the alcohol-unmodified hydrophilic group-containing isocyanate derivative and the blocking agent, Contains a reaction product of an alcohol-modified hydrophilic group-containing isocyanate derivative and a blocking agent.

Note that the block isocyanate is a water-dispersible block isocyanate and does not contain water or an organic solvent.

The content of oxyethylene groups (in terms of solid content) in such a blocked isocyanate is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, and, for example, 20% by mass or less, preferably 15% by mass. % or less. Note that the content of oxyethylene groups in the blocked isocyanate can be calculated using the following formula.

Content of oxyethylene group in blocked isocyanate (mass%) = Content of polyoxyethylene compound in hydrophilic group-containing polyisocyanurate derivative (mass%) × Charge amount of hydrophilic group-containing polyisocyanurate derivative (mass parts) /[amount of hydrophilic group-containing polyisocyanurate derivative (parts by mass)+amount of blocking agent (parts by mass)]×100.

Further, the amount of modification of alcohol in the blocked isocyanate is, for example, 0.075% by mass or more, preferably 0.13% by mass or more, for example, 4.5% by mass or less, preferably 4.1% by mass or less. be. Note that the amount of denaturation of alcohol in the blocked isocyanate can be calculated using the following formula.

Modification rate of alcohol in blocked isocyanate (mass %) = Content of alcohol in hydrophilic group-containing polyisocyanurate derivative (mass %) × Charge amount of hydrophilic group-containing polyisocyanurate derivative (mass parts) / [Hydrophilic group-containing polyisocyanurate derivative Amount of the polyisocyanurate derivative containing a functional group (parts by mass)+amount of the blocking agent (parts by mass)]×100.

(4) Surfactant A surfactant is blended to disperse (emulsify) the blocked isocyanate in water.

Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.

Examples of the nonionic surfactant include aromatic nonionic surfactants, non-aromatic nonionic surfactants, and the like.

Examples of the aromatic nonionic surfactant include aromatic nonionic surfactants with an HLB of 16 or more having a hydroxy group at the end of the molecule, aromatic nonionic surfactants having an HLB of less than 16 and having a hydroxy group at the end of the molecule, and the like.

The molecular structure of aromatic nonionic surfactants with HLB of 16 or higher having a hydroxyl group at the molecular terminal includes, for example, polyoxyethylene alkylphenyl such as polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene dibutylphenyl ether, etc. Ethers, such as polyoxyethylene aryl such as polyoxyethylene styryl phenyl ether (polyoxyethylene styrenated phenyl ether, polyoxyethylene distyrenated phenyl ether, etc.), polyoxyethylene benzylphenyl ether, polyoxyethylene cumyl phenyl ether, etc. Examples include phenyl ether.

The aromatic nonionic surfactant having a hydroxyl group at the molecular end and having an HLB of 16 or more has an HLB of 16 or more, preferably 17 or more, more preferably 18 or more, and for example 20 or less.

A commercially available aromatic nonionic surfactant having an HLB of 16 or higher and having a hydroxyl group at the end of the molecule can also be used. As a commercially available aromatic nonionic surfactant having a hydroxyl group at the molecular end and having an HLB of 16 or more, for example, Emulgen A-500 (polyoxyethylene distyrenated phenyl ether, solid content concentration: 100% by mass, HLB: 18.0, (manufactured by Kao Corporation), CP-20 (polyoxyethylene cumyl phenyl ether, solid content concentration: 100% by mass, HLB: 16.3, manufactured by Toho Chemical Industry Co., Ltd.), Neugen EA177 (polyoxyethylene styrylphenyl ether, solid content Concentration:: 100% by mass, HLB: 17.0, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

Examples of the molecular structure of the aromatic nonionic surfactant having a hydroxyl group at the molecular end and having an HLB of less than 16 include, for example, the same molecular structure as the above-mentioned aromatic nonionic surfactant having an HLB of 16 or more and having a hydroxy group at the molecular end. .

The HLB of the aromatic nonionic surfactant having a hydroxyl group at the end of the molecule and having an HLB of less than 16 is less than 16, preferably less than 15, for example, 4 or more, preferably 8 or more.

A commercially available aromatic nonionic surfactant having an HLB of less than 16 and having a hydroxy group at the end of the molecule can also be used. As a commercially available aromatic nonionic surfactant having a hydroxy group at the molecular end and having an HLB of less than 16, for example, Nonal 912A (polyoxyethylene cumyl phenyl ether, solid content concentration: 100% by mass, HLB: 14.3, Toho Chemical Co., Ltd. (manufactured by Kogyo Co., Ltd.), and Neugen EA87 (polyoxyethylene styryl phenyl ether, solid content concentration: 100% by mass, HLB: 10.6, made by Daiichi Kogyo Seiyaku Co., Ltd.).

Examples of non-aromatic nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene hydrogenated castor oil, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sucrose fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, polyoxy Examples include ethylene glycerin fatty acid ester and polyoxyethylene glycol fatty acid ester.

Examples of anionic surfactants include fatty acid salts such as sodium laurate, sodium stearate, potassium stearate, sodium oleate, potassium oleate, alkyl sulfate salts such as sodium lauryl sulfate, polyoxyethylene alkyl Sulfate ester salts, such as ether sulfate sodium salts (such as sodium polyoxyethylene lauryl ether sulfate), e.g. alkylbenzene sulfonates, such as alkylbenzenesulfonate sodium salts (such as sodium dodecylbenzenesulfonate), e.g. sodium dialkyl sulfosuccinate. Examples include sulfonic acid salts such as sulfosuccinic acid ester salts.

Examples of cationic surfactants include quaternary ammonium salts such as lauryltrimethylammonium chloride.

Examples of amphoteric surfactants include alkyl betaines such as lauryl betaine.

Surfactants can be used alone or in combination of two or more.

Among such surfactants, preferred are nonionic surfactants, more preferred are aromatic nonionic surfactants, and particularly preferred are aromatic surfactants having an HLB of 16 or higher and having a hydroxy group at the molecular terminal. group nonionic surfactants, and aromatic nonionic surfactants with an HLB of less than 16 having a hydroxy group at the end of the molecule, particularly preferably aromatic nonionic surfactants having an HLB of 16 or more and having a hydroxy group at the end of the molecule, and , and the combined use of an aromatic nonionic surfactant having an HLB of less than 16 and having a hydroxyl group at the molecular end.

In other words, the surfactant is particularly preferably an aromatic nonionic surfactant with an HLB of 16 or more that has a hydroxy group at the end of the molecule, and/or an aromatic nonionic surfactant with an HLB of less than 16 that has a hydroxy group at the end of the molecule. Particularly preferably, aromatic nonionic surfactants having an HLB of 16 or more have a hydroxy group at the end of the molecule, and aromatic nonionic surfactants having an HLB of less than 16 and have a hydroxy group at the end of the molecule.

When the surfactant contains an aromatic nonionic surfactant having an HLB of 16 or more and having a hydroxyl group at the molecular end, a coating film with good emulsion stability and excellent rubbing resistance can be formed. When the surfactant contains an aromatic nonionic surfactant having an HLB of less than 16 and having a hydroxy group at the molecular end, a coating film with excellent rubbing resistance can be formed.

Furthermore, when the surfactant contains an aromatic nonionic surfactant with a HLB of 16 or higher and a hydroxy group at the molecular end and an aromatic nonionic surfactant with an HLB of less than 16 and a hydroxy group at the molecular end, the water-dispersed blocked isocyanate composition While it is possible to improve the film-forming properties of polyurethane resin raw materials containing substances, it is possible to reliably improve the expansion resistance of the coating film under high-humidity conditions.

When the surfactant contains an aromatic nonionic surfactant with a HLB of 16 or more having a hydroxy group at the end of the molecule, and an aromatic nonionic surfactant with an HLB of less than 16 having a hydroxy group at the end of the molecule, The content ratio of the aromatic nonionic surfactant having an HLB of 16 or more is, for example, 0.1 part by mass or more, preferably, for 1 part by mass of the aromatic nonionic surfactant having an HLB of less than 16 and having a hydroxy group at the molecular terminal. 0.5 parts by mass or more, more preferably 1 part by mass or more, still more preferably 1.5 parts by mass or more, for example 50 parts by mass or less, preferably 45 parts by mass or less, more preferably 20 parts by mass or less , more preferably 15 parts by mass or less, particularly preferably 5 parts by mass or less.

The content ratio of the surfactant is, for example, 1 part by mass or more, preferably 3 parts by mass or more, for example, 40 parts by mass or less, preferably 30 parts by mass or less, more preferably , 20 parts by mass or less.

When the content of the surfactant is at least the above lower limit, it is possible to ensure excellent water dispersibility and to reliably impart excellent swelling resistance under high humidity conditions to the coating film. When the content of the surfactant is at most the above upper limit, it is possible to reliably impart excellent solvent resistance to the coating film, and more reliably impart expansion resistance under high humidity conditions.

(5) Production of water-dispersed block isocyanate composition Next, production of the water-dispersed block isocyanate composition will be explained.

To prepare a water-dispersed blocked isocyanate composition, the blocked isocyanate is emulsified in water with a surfactant.

Specifically, first, the above surfactant is dissolved in water to prepare a dispersant aqueous solution (surfactant aqueous solution), and the dispersant aqueous solution and the above blocked isocyanate are mixed in the above ratio. , blend.

Next, for example, using a stirrer such as a homomixer or a homodisper, the blocked isocyanate and the dispersant aqueous solution are mixed and stirred, and if necessary, water is further blended and emulsified to prepare a blocked isocyanate emulsion.

Note that additives such as an antifoaming agent may be added to the blocked isocyanate emulsion if necessary. The blending ratio of additives is not particularly limited, and is appropriately determined depending on the purpose and use.

After that, if the blocked isocyanate emulsion contains an organic solvent (for example, if the reaction solution obtained by reacting the polyisocyanate and the blocking agent in an organic solvent is used as it is as the blocked isocyanate), The organic solvent is removed by volatilization, for example, by heating the blocked isocyanate emulsion under reduced pressure.

As a result, a water-dispersed block isocyanate composition in which the block isocyanate is emulsified in water is produced.

In the water-dispersed block isocyanate composition, the volume average particle diameter of the block isocyanate is, for example, 450 nm or less, preferably 400 nm, more preferably 300 nm or less, particularly preferably 250 nm or less, for example, 50 nm or more.

<Polyurethane resin raw material>
Such a water-dispersed blocked isocyanate composition can be used, for example, as a known resin raw material such as a polyurethane resin raw material, and is preferably used as a two-component polyurethane resin raw material.

The two-component polyurethane resin raw material is a kit (two-component polyurethane resin composition, two-component polyurethane coating composition). The two-component polyurethane resin raw material is one in which separately prepared part A (curing agent) and part B (base resin) are blended immediately before use.

The polyisocyanate component consists of, for example, the water-dispersed block isocyanate composition described above.

The polyol component includes, for example, a macropolyol, and is preferably prepared by dispersing the macropolyol in water. That is, the polyol component includes a macropolyol and water.

The macropolyol is a high molecular weight polyol having a number average molecular weight of 250 or more, preferably 400 or more, for example 10,000 or less.

Examples of macropolyols include polyester polyols, vegetable oil-based polyester polyols, polycaprolactone polyols, polyether polyols, polycarbonate polyols, acrylic polyols, and urethane-modified polyols. Macropolyols can be used alone or in combination of two or more.

Examples of polyester polyols include polybasic acids (e.g. adipic acid, sebacic acid, phthalic acid, isophthalic acid, etc.) and polyhydric alcohols (e.g. low molecular weight polyols such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol). Examples include esterification reaction products with.

Examples of vegetable oil-based polyester polyols include hydroxyl group-containing vegetable oil fatty acids (for example, castor oil fatty acids containing ricinoleic acid, hydrogenated castor oil fatty acids containing 12-hydroxystearic acid, etc.) using the above-mentioned low molecular weight polyol as an initiator. Examples include condensation reaction products of hydroxycarboxylic acids.

Examples of polycaprolactone polyols include ring-opening polymers of lactones (eg, ε-caprolactone, γ-valerolactone, etc.) using the above-mentioned low molecular weight polyols as initiators.

Examples of polyether polyols include ring-opening polymers of alkylene oxides using the above-mentioned low molecular weight polyols as initiators.

Examples of polycarbonate polyols include ring-opening polymers of ethylene carbonate using the above-mentioned low molecular weight polyols as initiators.

Examples of acrylic polyols include copolymers of hydroxyl group-containing acrylates and copolymerizable vinyl monomers that can be copolymerized with the hydroxyl group-containing acrylates.

Urethane-modified polyols are, for example, reaction products of the above-mentioned macropolyols and known polyisocyanates, and include, for example, polyester-type polyurethane polyols, polyether-type polyurethane polyols, polycarbonate-type polyurethane polyols, and polyacrylic-type polyurethane polyols. Examples include polyurethane polyols, polyester polyether type polyurethane polyols, and the like.

Among such macropolyols, acrylic polyols are preferred.

In addition, if necessary, one or both of the isocyanate component (curing agent) and the polyol compound (base ingredient) may be added with, for example, a reaction solvent, a catalyst, an epoxy resin, a coating improver, a leveling agent, and an antifoaming agent. Additives such as stabilizers such as antioxidants and ultraviolet absorbers, thickeners, anti-settling agents, plasticizers, surfactants, pigments, fillers, organic or inorganic fine particles, and anti-mold agents may be added as appropriate. I can do it. The amount of additives to be added is appropriately determined depending on the purpose and use.

In such a two-component polyurethane resin raw material, a polyisocyanate component (curing agent) and a polyol component (base resin) are blended at the time of use.

The blending ratio of the polyisocyanate component (curing agent) and the polyol component (main ingredient) is such that, for example, the equivalent ratio of the latent isocyanate group of the block isocyanate to the hydroxyl group of the macropolyol (latent isocyanate group/hydroxyl group) is, for example, 0.1. As mentioned above, the ratio is preferably 0.5 or more, for example, 5 or less, and preferably 3 or less.

Then, the mixture of the polyisocyanate component and the polyol component is applied to the object to be coated by a known coating method (for example, spray coating, dip coating, spin coating, rotary atomization coating, curtain coating, etc.). It forms a coating film by being coated and dried. Thereafter, the coating film is cured by heating and, if necessary, aged.

The heating temperature is, for example, 60°C or higher, preferably 80°C or higher, and, for example, 150°C or lower, preferably 130°C or lower.

As described above, a coating film (cured coating film, polyurethane resin) is formed from the two-component polyurethane resin raw material containing the water-dispersed blocked isocyanate composition. Such a coating film has particularly excellent swelling resistance under high humidity conditions. Note that the high humidity condition means a condition in which the relative humidity at a predetermined temperature is 70% or more.

Therefore, the two-component polyurethane resin raw material is particularly suitable for use in applications exposed to high humidity conditions. More specifically, two-component polyurethane resin raw materials are used for paint raw materials (for example, paint raw materials for food packaging inks, etc.), adhesive raw materials (for example, food packaging films and paper, plastic bottles, cans, bottles, etc.). raw materials for adhesives for packaging materials, etc.).

<Effect>
The water-dispersed blocked isocyanate composition described above is a block isocyanate in which a polyisocyanate is blocked with a blocking agent, and the polyisocyanate is a block containing a reaction product of an isocyanurate derivative of xylylene diisocyanate and a polyoxyethylene compound. The reaction product contains an isocyanate and a surfactant, and the content of oxyethylene groups in the reaction product is within the above range.

Therefore, it is possible to provide the polyurethane resin with expansion resistance under high humidity conditions while ensuring excellent water dispersibility.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited thereto. Specific numerical values such as blending ratios (content ratios), physical property values, parameters, etc. used in the following description are the corresponding blending ratios (content ratios) described in the above "Details of Carrying Out the Invention". ), physical property values, parameters, etc. can be replaced with the upper limit value (value defined as "less than" or "less than") or lower limit value (value defined as "more than" or "exceeding"). can. Note that "parts" and "%" are based on mass unless otherwise specified.

In addition, the measurement method and calculation method employed in each Example and each Comparative Example are described below.

<Distillation yield>
The distillation yield of the isocyanurate derivative is determined by measuring the mass of the reaction solution (pre-distillation solution) and isocyanurate derivative (post-distillation solution), and calculating the ratio of the mass of the isocyanurate derivative to the mass of the reaction solution using the following formula. I asked for it.
Distillation yield (mass %) of isocyanurate derivative = (mass of isocyanurate derivative (mass parts) / mass of reaction solution (mass parts)) × 100
<Amount of denaturation of alcohol (alcohol denaturation amount)>
The ratio (parts by mass) of alcohol in the reaction solution was calculated as the charged mass of alcohol to 100 parts by mass of xylylene diisocyanate. Further, the amount of alcohol modification in the isocyanurate derivative (the amount of alcohol modification of the isocyanurate derivative) was calculated using the following formula.
Amount of alcohol denaturation of isocyanurate derivative (mass %) = (ratio of alcohols in reaction solution (mass parts) / distillation yield (mass %)) × 100
<Isocyanate group concentration and isocyanate group conversion rate (reaction rate)>
The isocyanate group concentrations of the charging solution, reaction solution, and isocyanurate derivative were each measured in accordance with the n-dibutylamine method of JIS K-1556 (2006). In addition, the conversion rate (reaction rate) of isocyanate groups was determined by calculating the rate of decrease in the isocyanate group concentration of the reaction solution or isocyanurate derivative with respect to the isocyanate group concentration of the charging solution.

Note that the conversion rate of isocyanate groups after blending the alcohol and before blending the isocyanurate catalyst is the urethane conversion rate, and the conversion rate of the isocyanate groups after blending the isocyanurate catalyst is the isocyanurate conversion rate.

<Trimolecular body area ratio>
A sample of an isocyanurate derivative is measured by gel permeation chromatography (GPC), and in the obtained chromatogram (chart), the area of the peak with a peak top of polystyrene equivalent molecular weight between 400 and 1000, relative to the area of all peaks. From the ratio, the area ratio of trimolecular bodies was determined.

In addition, the trimolecular body area ratio is the area of the peak whose peak top is between 26.8 minutes and 27.1 minutes in the chromatogram (chart) obtained with the following apparatus, relative to the area of all peaks. It is also the rate.

In the GPC measurement, about 0.04 g of a sample was taken, and after methylurethanization with methanol, excess methanol was removed, and 10 mL of tetrahydrofuran was added to dissolve it. Then, the obtained solution was subjected to GPC measurement under the following conditions.
(1) Analyzer: Alliance (manufactured by Waters)
(2) Pump: Alliance 2695 (manufactured by Waters)
(3) Detector: 2414 type differential refraction detector (manufactured by Waters)
(4) Eluent: Tetrahydrofuran
(5) Separation column: Plgel GUARD + Plgel 5 μm Mixed-C x 3 (50 x 7.5 mm, 300 x 7.5 mm) Manufacturer: Polymer Laboratories, product number: PL1110-6500
(6) Measurement temperature: 40℃
(7) Flow rate: 1mL/min
(8) Sample injection amount, injection concentration: 100μL, 1mg/mL
(9) Analysis device: EMPOWER data processing device (manufactured by Waters)
・System correction (1) Standard material name: Polystyrene
(2) Calibration curve creation method: Using TOSOH's TSK standard Polystyrene with different molecular weights, create a graph of retention time versus molecular weight.

<Oxyethylene group content in the reaction product of polyisocyanate derivative and polyoxyethylene compound>
The oxyethylene group content in the reaction product was calculated using the following formula.
Oxyethylene group content (% by mass) = Amount of polyoxyethylene compound charged (parts by mass) / [Amount of polyisocyanate derivative charged (parts by mass) + Amount of polyoxyethylene compound charged (parts by mass)] x 100
<Preparation of isocyanurate derivative>
Preparation example 1
1,3-xylylene diisocyanate (m-XDI, Mitsui Chemicals, Inc.) was added to a reactor equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a cooling tube under a nitrogen atmosphere so that the formulation shown in Table 1 was obtained. ), antioxidant (2,6-di(tert-butyl)-4-methylphenol, BHT, hindered phenolic antioxidant), and co-catalyst (tetraphenyl dipropylene glycol diphosphite, organic Phosphate ester (trade name: JPP-100, manufactured by Johoku Kagaku Kogyo Co., Ltd.) was charged. Note that the concentration of isocyanate groups in this charging liquid was 44.7% by mass.

Next, a 37% by mass solution of tetrabutylammonium hydroxide (TBAOH) was added to this charging liquid as an isocyanurate catalyst so that the solid content would be as shown in Table 1, and then the formulation shown in Table 1 was added. The isocyanurate reaction was carried out under reaction conditions (reaction initiation temperature, maximum temperature reached, and reaction time).

Next, the obtained reaction solution is passed through a thin film distillation apparatus (temperature 150°C, vacuum degree 50 Pa) to remove unreacted xylylene diisocyanate, etc., and to obtain an isocyanurate derivative of xylylene diisocyanate (XDI nurate). Prepared. Note that the distillation yield is shown in Table 1.

Further, Table 1 shows the conversion rate of isocyanate groups (ie, isocyanurate conversion rate), the amount of alcohol modification in the isocyanurate derivative, the isocyanate group concentration, and the trimolecular body area ratio in this reaction.

Preparation examples 2 to 7
1,3-xylylene diisocyanate (m-XDI, Mitsui Chemicals, Inc.) was added to a reactor equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a cooling tube under a nitrogen atmosphere so that the formulation shown in Table 1 was obtained. ), the antioxidant shown in Table 1, and the promoter shown in Table 1 were charged. Note that Table 1 shows the isocyanate group concentration in the charging solution for the urethanization reaction.

Next, alcohols were added to this charging liquid so as to have the formulation shown in Table 1, and a urethane reaction was carried out under the reaction conditions (reaction temperature and reaction time) shown in Table 1. Table 1 shows the equivalent ratio (NCO/OH) of the isocyanate group of 1,3-xylylene diisocyanate to the hydroxyl group of 1,3-butanediol.

Then, the temperature of the reaction solution was lowered to 60°C. Table 1 shows the isocyanate group concentration of the reaction solution after the urethanization reaction.

Next, a 37% by mass solution of tetrabutylammonium hydroxide (TBAOH) was added to the reaction solution as an isocyanurate catalyst so that the solid content was the primary addition amount shown in Table 1. Isocyanurate reaction was carried out. Thereafter, the above methanol solution of TBAOH was added to the reaction solution so that the secondary addition amount shown in Table 1 was obtained in terms of solid content, and after the reaction time shown in Table 1 had elapsed from the start of the reaction, the isocyanurate formation reaction was carried out. was terminated. Table 1 shows the reaction initiation temperature and maximum temperature reached for the isocyanurate reaction, and the isocyanate group concentration of the reaction solution after the isocyanurate reaction.

Next, the obtained reaction solution is passed through a thin film distillation apparatus (temperature 150° C., vacuum degree 50 Pa) to remove unreacted xylylene diisocyanate, etc., to obtain isocyanurate of xylylene diisocyanate modified with alcohol. A derivative (XDI Nurate) was prepared. Note that the distillation yield is shown in Table 1.

Table 1 shows the conversion rate of isocyanate groups (urethane conversion rate and isocyanurate conversion rate), the amount of alcohol modification in the isocyanurate derivative, the isocyanate group concentration, and the trimolecular body area ratio in this reaction.

Details of the abbreviations in Table 1 are given below.

m-XDI: 1,3-xylylene diisocyanate (manufactured by Mitsui Chemicals),
1,3-BG: 1,3-butanediol, manufactured by Tokyo Kasei Kogyo Co., Ltd.
IBA: Isobutyl alcohol, manufactured by Tokyo Kasei Kogyo Co., Ltd.
JPP-100: Tetraphenyl dipropylene glycol diphosphite (aromatic organic phosphite, manufactured by Johoku Kagaku Kogyo Co., Ltd., trade name),
JP-310: Tridecyl phosphite (aliphatic organic phosphite, manufactured by Johoku Kagaku Kogyo Co., Ltd., trade name),
BHT: 2,6-di(tert-butyl)-4-methylphenol (also known as dibutylhydroxytoluene, BHT, hindered phenolic antioxidant),
Irg1076: Irganox 1076 (hindered phenol antioxidant, manufactured by Ciba Japan, trade name),
TBAOH: Tetrabutylammonium hydroxide.

<Preparation of other isocyanate derivatives>
Preparation example 8
Takenate D-170N (isocyanurate derivative of hexamethylene diisocyanate (HDI), solid content 100% by mass, isocyanate group content 20.7%, manufactured by Mitsui Chemicals) was prepared as an isocyanate derivative.

Preparation example 9
Takenate D-110N (trimethylolpropane (TMP) adduct of xylylene diisocyanate, isocyanate group content 11.5% by mass, solid content 75% by mass, solvent: ethyl acetate, manufactured by Mitsui Chemicals) was prepared as an isocyanate derivative. did.

<Preparation of water-dispersed block isocyanate composition>
Examples 1 to 17 and Comparative Examples 1 to 10
The isocyanate derivatives (isocyanurate derivatives or other isocyanates) of each preparation example shown in Tables 2 and 3 were placed in a 2 L reactor equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet tube at room temperature (25°C). 500 parts by mass of derivative) and 92.9 parts by mass of methyl isobutyl ketone (MIBK, solvent) were charged, and further, the oxyethylene group content (EO%) in the reaction product became the values shown in Tables 2 and 3. Poly(oxyethylene) methyl ether (methoxypolyethylene glycol, MePEG1000, polyoxyethylene compound) having a number average molecular weight of 1000 was charged.

Next, this charged solution was heated to 90° C. to cause the isocyanate derivative and poly(oxyethylene) methyl ether to undergo a urethane reaction until there was no change in the amount of remaining isocyanate.

As described above, an MIBK solution of a hydrophilic group-containing isocyanate derivative (reaction product) was prepared.

Next, 223 parts by mass of MIBK was added to 619 parts by mass of the MIBK solution of the hydrophilic group-containing isocyanate derivative and stirred, and then the blocking agents shown in Tables 2 and 3 were added to the isocyanate group possessed by the hydrophilic group-containing isocyanate derivative. It was added in such amount.

Thereafter, the isocyanate group and the blocking agent were reacted at 40° C. for 2 hours. Thereafter, by measuring the FT-IR spectrum, it was confirmed that the isocyanate groups had disappeared.

As described above, a MIBK solution of blocked isocyanate was prepared. The solid content concentration of the MIBK solution of blocked isocyanate was 70% by mass.

Next, the surfactants shown in Tables 2 and 3 were added to 500 parts by mass of the MIBK solution of blocked isocyanate at room temperature (25°C) while stirring with a homomixer (rotation speed: 4000 rpm). After adding in portions over 60 minutes to obtain the recipe shown, 645 parts by mass of water was added in portions over 30 minutes to emulsify.

Thereafter, 0.2 parts by mass of an antifoaming agent (trade name BYK-022, manufactured by BYK Chemie) was added to the emulsion containing the blocked isocyanate and the surfactant, and the mixture was stirred at a rotation speed of 1000 rpm for 1 hour. Next, under reduced pressure conditions, the emulsion is heated in a 50°C hot water bath to distill off the organic solvent (MIBK) and a portion of the water to form an aqueous dispersion of blocked isocyanate (polyisocyanate component). ) was prepared. The solid content concentration of this aqueous dispersion was 40% by mass.

<Evaluation>
1. Emulsion Stability The water dispersion of the blocked isocyanate of each Example and each Comparative Example was allowed to stand at 40° C. for one week, and then the water dispersibility of the blocked isocyanate was evaluated according to the following criteria. The results are shown in Tables 2 and 3.
○: No phase separation or sediment.
△: There is some sediment.
×: Most of the sample is sedimented and separated.

2. Film Formability Test A dispersion liquid (polyol component) in which acrylic polyol (trade name: RE4788, manufactured by Mitsui Chemicals, Inc.) was dispersed in water was prepared.

Next, the aqueous dispersion of the blocked isocyanate (polyisocyanate component) of each example and each comparative example is added to the acrylic polyol dispersion (polyol component) so that the hydroxyl groups of the acrylic polyol and the latent isocyanate groups of the blocked isocyanate are equal in amount. A polyurethane coating composition was prepared by adding as follows and stirring for 30 minutes. Note that the solid content concentration of the final polyurethane coating composition was 30% by mass.

The polyurethane coating composition prepared as described above was applied onto a tin plate using a 100 μm applicator, dried at 23° C. for 3 hours, and then cured at 150° C. for 30 minutes. Thereafter, the cured coating was aged for 7 days at 23° C. and 55% relative humidity.

Then, the film formability of the coating film was evaluated based on the following criteria. The results are shown in Tables 2 and 3.
○: A uniform coating film is formed.
Δ: An uneven coating film with streak-like cracks and peeling was formed on a part of the surface of the coating film.

3. Tack A coating film was formed on a tin plate in the same manner as in the film-forming test described above. The feel of each cured coating film was evaluated based on the following criteria. The results are shown in Tables 2 and 3.
○: No tackiness.
△: It has tackiness, but it does not stick to the finger even if the finger is pressed against the coating and then pulled up.
×: It has tackiness, and when you press your finger against the coating film and then pull it up, it sticks to your finger.

4. MEK Rubbing Test A coating film was formed on a tin plate in the same manner as the above film-forming test. Then, each cured coating film was rubbed with gauze soaked in methyl ethyl ketone (MEK), and the number of times until peeling or abrasion occurred on the coating film surface was visually measured, and evaluated using the following criteria. The results are shown in Tables 2 and 3.
○: The number of times of rubbing is 200 times or more △: The number of times of rubbing is 100 times or more and less than 200 times ×: The number of times of rubbing is less than 100 times 5. Weather Resistance Test A coating film was formed on a PMMA board in the same manner as the film forming test described above, except that the tin plate was replaced with a PMMA board. Then, each cured coating film was tested using an accelerated weathering tester (Dew Panel Light Control Weather Meter, manufactured by Suga Test Instruments Co., Ltd.) during the day (60°C x 10% relative humidity x 4 hours x light irradiation) and at night. The treatment was performed for 600 hours in a cycle of (50° C. x 95% relative humidity x 4 hours x no light irradiation). The coating film before and after the treatment was measured using a color difference meter (SE2000, manufactured by Nippon Denshoku Kogyo Co., Ltd.), and the color difference (ΔE) before and after the treatment was evaluated according to the following criteria. The results are shown in Tables 2 and 3.
○: ΔE is less than 5.0 △: ΔE is 5.0 or more and less than 10.0 ×: ΔE is 10.0 or more 6. Pencil hardness test A coating film was formed on a tin plate in the same manner as in the film-forming test described above. Then, the pencil hardness of the coating film was measured based on JIS K5600-5-4 and evaluated using the following criteria. The results are shown in Tables 2 and 3.
○: Pencil hardness is HB or more ×: Pencil hardness is B or less 7. Coefficient of Wet Thermal Expansion The aqueous dispersion of blocked isocyanate (polyisocyanate component) of each example and each comparative example was added to the aqueous dispersion of polyurethane polyol (polyol component, W-5661, solid content 35% by mass, manufactured by Mitsui Chemicals). A polyurethane coating composition was prepared by adding polyurethane polyol/blocked isocyanate so that the solid content ratio was 5/3 and stirring for 30 minutes. The concentration of the polyurethane coating composition was adjusted by diluting it with water so that the final solid content concentration was 30% by mass.

Next, the polyurethane coating composition was applied onto a polypropylene plate using a 100 μm applicator, dried at 23° C. for 3 hours, and then cured at 150° C. for 30 minutes. Thereafter, the cured coating was aged for 7 days at 23° C. and 55% relative humidity.

Next, a test piece (20 mm x 20 mm) was cut out from the polypropylene plate on which the coating film was formed, and the coefficient of wet thermal expansion was measured using a NETZSCH TMA-4000SE at a temperature of 25°C and a humidity of 80% for 3 hours. It was measured and evaluated based on the following criteria. The results are shown in Tables 2 and 3.
〇: Moist thermal expansion coefficient is less than 2.0% △: Moist thermal expansion coefficient is 2.0% or more and less than 3.0 ×: Moist thermal expansion coefficient is 3.0% or more

Details of the abbreviations in Tables 2 and 3 are given below. Note that items that overlap with those in Table 1 will be omitted.

DMP: 3,5-dimethylpyrazole, manufactured by Tokyo Chemical Industry Co., Ltd.
MEKO: Methyl ethyl ketoxime, manufactured by Tokyo Kasei Kogyo Co., Ltd.
MePEG1000: poly(oxyethylene) methyl ether, number average molecular weight 1000, manufactured by Toho Chemical Industry Co., Ltd.

Claims (7)

Blocked isocyanate in which the isocyanate groups of polyisocyanate are blocked with a blocking agent;
a surfactant;
The polyisocyanate includes a reaction product of an isocyanurate derivative of xylylene diisocyanate and a polyoxyethylene compound,
A water-dispersed block isocyanate composition, wherein the content of oxyethylene groups in the reaction product is more than 0% by mass and less than 15% by mass. 2. The water-dispersed block isocyanate composition according to claim 1, wherein the isocyanurate derivative of xylylene diisocyanate is modified with an alcohol (excluding the polyoxyethylene compound) . The water-dispersed block isocyanate composition according to claim 2, wherein the amount of modification of the alcohol in the isocyanurate derivative of xylylene diisocyanate is 0.1% by mass or more and 8.5% by mass or less. . The water-dispersed block isocyanate composition according to claim 2 or 3, wherein the alcohol contains a divalent aliphatic alcohol. The water-dispersed blocked isocyanate composition according to any one of claims 1 to 4, wherein the surfactant contains an aromatic nonionic surfactant having an HLB of 16 or more and having a hydroxy group at the molecular end. thing. The water-dispersed blocked isocyanate composition according to any one of claims 1 to 4, wherein the surfactant contains an aromatic nonionic surfactant having an HLB of less than 16 and having a hydroxy group at the molecular end. thing. The aqueous dispersion according to any one of claims 1 to 6, wherein the content of the surfactant is 3 parts by mass or more and 30 parts by mass or less based on 100 parts by mass of the blocked isocyanate. Type-blocked isocyanate composition.