JP7395091B2 - Curing accelerator composition - Google Patents

Description

The present invention relates to curing accelerator compositions.

Conventionally, urethane resin compositions containing isocyanate compounds (for example, urethane prepolymers) have been used, for example, as waterproof materials in the construction field.
In general, urethane resin compositions are broadly classified into, for example, one-component urethane resin compositions; two-component urethane resin compositions containing an isocyanate compound (e.g., urethane prepolymer) as a main ingredient and a curing agent. .

For example, Patent Document 1 has been proposed as a urethane waterproof material composition containing a urethane prepolymer and a curing agent. Patent Document 1 describes aromatic diamines and the like as curing agents. Patent Document 1 describes that a urethane-based paint film waterproofing material composition can be used as a one-component urethane-based paint film waterproofing material composition or a two-component urethane-based paint film waterproofing material composition. .

Further, as a two-component urethane resin composition, for example, Patent Document 2 has been proposed. Patent Document 2 stipulates that the two-component room-temperature curing type is composed of a main component mainly composed of a specific isocyanate-terminated urethane prepolymer and a curing agent mainly composed of a diamine compound having a toluenediamine structure. Waterproofing compositions are described.

JP2006-249226A Japanese Patent Application Publication No. 2002-20727

On the other hand, urethane resin compositions used for waterproof materials and the like are required to have excellent curability.
Regarding the above-mentioned curability, in the case of a one-component urethane resin composition, the curing speed is slow and it takes time to start the next work, or the curability in the deep part is low because it hardens from the surface due to moisture such as moisture. There is.
In addition, in the case of a two-component urethane resin composition, since the base resin and the curing agent are mixed together, partial curing failure may occur if the mixing is not done sufficiently.

Under these circumstances, the present inventors prepared a curing accelerator composition containing an aromatic diamine with reference to Patent Documents 1 and 2, and evaluated it by using it on a urethane resin composition. It has become clear that such a curing accelerator composition may have a slow curing speed, or may have a fast curing speed but may not have a sufficient pot life.
Therefore, an object of the present invention is to provide a curing accelerator composition that, when used for a urethane resin composition, can increase the curing speed of the urethane resin composition and ensure a pot life.

As a result of intensive research aimed at solving the above problems, the present inventors discovered that a desired effect can be obtained by using a specific amount of dialkyltoluenediamine in a urethane resin composition, which led to the present invention. Ta.
The present invention is based on the above-mentioned findings, and specifically aims to solve the above-mentioned problems with the following configuration.

[1] Used for urethane resin compositions containing isocyanate compounds,
Contains dialkyltoluenediamine,
A curing accelerator composition, wherein the molar equivalent ratio (NCO/NH ₂ ) of the isocyanate group possessed by the isocyanate compound to the amino group possessed by the dialkyltoluene diamine is 100/10 to 100/70.
[2] The curing accelerator composition according to [1], further containing a dicarboxylic acid compound.
[3] The curing accelerator composition according to [2], wherein the amount of the dicarboxylic acid compound is 0.05% by mass or more and less than 1% by mass, based on the urethane resin composition.
[4] Any of [1] to [3], wherein the dicarboxylic acid compound is represented by HOOC-R-COOH, R is a hydrocarbon group, and the hydrocarbon group has 10 to 24 carbon atoms. The curing accelerator composition according to claim 1.
[5] The curing accelerator composition according to any one of [1] to [4], further containing a latent curing agent.
[6] The curing accelerator composition according to any one of [1] to [5], wherein the urethane resin composition is moisture-curable.
[7] The curing accelerator composition according to any one of [1] to [6], wherein the urethane resin composition is a one-component type.
[8] The curing accelerator composition according to any one of [1] to [7], wherein the urethane resin composition is a one-component type and further contains a latent curing agent.
[9] The curing accelerator composition according to any one of [1] to [8], wherein the molar equivalent ratio (NCO/NH ₂ ) is more than 2.0 and 10 or less.

When the curing accelerator composition of the present invention is used for a urethane resin composition, it can increase the curing speed of the urethane resin composition and ensure a pot life.

The present invention will be explained in detail below.
Note that in this specification, a numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as the lower limit and upper limit.
In this specification, unless otherwise specified, each component can be used alone or in combination of two or more of the substances corresponding to the component. When a component contains two or more types of substances, the content of the component means the total content of the two or more types of substances.
In this specification, when the curing accelerator composition of the present invention is used for a urethane resin composition, the curing speed of the urethane resin composition can be further accelerated, and/or the urethane resin composition can be used. The fact that the time can be made longer is sometimes referred to as "the effect of the present invention is better."

[Curing accelerator composition]
The curing accelerator composition of the present invention (composition of the present invention) is
Used for urethane resin compositions containing isocyanate compounds,
Contains dialkyltoluenediamine,
The curing accelerator composition has a molar equivalent ratio (NCO/NH ₂ ) of the isocyanate group possessed by the above-mentioned isocyanate compound to the amino group possessed by the above-mentioned dialkyltoluene diamine from 100/10 to 100/70.

Since the curing accelerator composition of the present invention has such a configuration, it is considered that the desired effects can be obtained. Although the reason is not clear, the present inventors investigated a diamine compound having a toluenediamine structure as an aromatic diamine contained in a curing accelerator composition used for a urethane resin composition, and found that diethyl It has been found that dialkyltoluenediamine such as toluenediamine accelerates the curing speed of urethane resin compositions more than methylthiotoluenediamine, dimethylthiotoluenediamine, and the like.
Furthermore, it has been found that although the curing speed with dialkyltoluenediamine is very fast, the pot life of the urethane resin composition can be ensured by adjusting the amount of dialkyltoluenediamine.
As described above, according to the curing accelerator composition of the present invention, by using dialkyltoluenediamine in a specific amount with respect to the urethane resin composition, the curing speed of the urethane resin composition is accelerated, and the urethane resin composition It is possible to secure the usable life of objects.
Thus, it can be said that the curing accelerator composition of the present invention can balance the curing speed and pot life of the urethane resin composition at a very high level.

The curing accelerator composition of the present invention will be explained below.
The curing accelerator composition of the present invention is used for a urethane resin composition containing an isocyanate compound. The urethane resin composition will be described later.

<Dialkyltoluenediamine>
The curing accelerator composition of the present invention contains dialkyltoluenediamine.
By containing the dialkyltoluenediamine, the curing accelerator composition of the present invention, when used for a urethane resin composition, can accelerate the curing speed of the urethane resin composition and ensure a pot life.
The above-mentioned dialkyltoluenediamine is a compound in which two alkyl groups and two amino groups (-NH ₂ ) are each directly bonded to the benzene ring constituting toluene.

The alkyl group that the dialkyltoluenediamine has is not particularly limited.
The alkyl group may be linear, branched, cyclic, or a combination thereof.
The number of carbon atoms in the alkyl group is preferably from 1 to 10, more preferably from 1 to 5, and even more preferably from 2, from the viewpoint of achieving better effects of the present invention and excellent adhesion to substrates and the like.
Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, and hexyl group.
The above-mentioned alkyl group is preferably an ethyl group from the viewpoints of superior effects of the present invention and excellent adhesion to substrates and the like.

Examples of the above-mentioned dialkyltoluenediamine include a compound represented by the following formula (1).
In formula (1), R ¹ each independently represents an alkyl group. The alkyl group as R ¹ is the same as above.

The above-mentioned dialkyltoluenediamine is preferably diethyltoluenediamine (DETDA) from the viewpoints of superior effects of the present invention and excellent adhesion to substrates and the like.
Examples of diethyltoluenediamine include 2,3-diethyltoluenediamine, 2,6-diethyltoluenediamine, 3,6-diethyltoluenediamine, and a compound represented by the following formula (2) (3,5-diethyl-2 , 4-toluenediamine or 3,5-diethyl-2,6-toluenediamine).

The above-mentioned diethyltoluene diamine is preferably a compound represented by the above formula (2) from the viewpoint of superior effects of the present invention and excellent adhesion to substrates, etc., and 3,5-diethyl-2,4-toluene. More preferred is a mixture of diamine and 3,5-diethyl-2,6-toluenediamine.

<Mole equivalent ratio (NCO/NH ₂ )>
In the present invention, the molar equivalent ratio (NCO/NH ₂ ) of the isocyanate group contained in the isocyanate compound contained in the urethane resin composition (described later) to the amino group contained in the dialkyltoluenediamine is 100/10 to 100/ It is 70.
In the curing accelerator composition of the present invention, since the molar equivalent ratio is within a predetermined range, the curing speed of the urethane resin composition is fast and the pot life of the urethane resin composition can be ensured.

The above molar equivalent ratio (NCO/NH ₂ ) is preferably more than 2.0 and 10 or less, from 2.2 to 5, from the viewpoint of achieving better effects of the present invention and excellent adhesion to substrates, etc. .0 is more preferable, and it is even more preferable that it exceeds 3.0 and is 4.0 or less.

(dicarboxylic acid compound)
The curing accelerator composition of the present invention has excellent defoaming properties when curing a urethane resin composition, or from the viewpoint of being superior to the effects of the present invention or having excellent adhesion to a substrate, etc., further contains dicarboxylic acid. It is preferable to contain an acid compound.

A dicarboxylic acid compound is a compound having two carboxy groups (-COOH).
The above carboxy group can be bonded to a hydrocarbon group.
The above hydrocarbon group is not particularly limited. Examples include aliphatic hydrocarbon groups (linear, branched, or cyclic), aromatic hydrocarbon groups, or a combination thereof.
The above-mentioned hydrocarbon group is preferably an aliphatic hydrocarbon group from the viewpoint of excellent antifoaming properties, excellent effects of the present invention, or excellent adhesion to a substrate, etc., and a branched aliphatic hydrocarbon group. is more preferable.

The number of carbon atoms in the hydrocarbon group is preferably from 3 to 24, more preferably from 10 to 23, from the viewpoint of excellent antifoaming properties, excellent effects of the present invention, or excellent adhesion to substrates, etc. 18 to 22 are more preferred. In this specification, the number of carbon atoms in the hydrocarbon group constituting the dicarboxylic acid compound does not include the number of carbon atoms constituting the carboxy group.

In the above dicarboxylic acid compound, the carboxy group is the terminal of the above hydrocarbon group (or dicarboxylic acid compound) from the viewpoint of having excellent antifoaming properties, excellent effects of the present invention, or excellent adhesion to substrates, etc. Preferably, it is bonded to.

Examples of the dicarboxylic acid compound include a compound represented by HOOC-R-COOH. In the above formula, R represents a hydrocarbon group. The hydrocarbon group as R is the same as above.

Specifically, the dicarboxylic acid compounds include, for example, linear dibasic acids (linear dicarboxylic acid compounds) such as dodecanedioic acid, eicosanedioic acid, and eicosadienedioic acid;
Branched dibasic acids (branched dicarboxylic acid compounds) such as isoeicosanedioic acid, isodocosanedioic acid, isodocosadienedioic acid, butyloctanedioic acid;
Examples include derivatives of the dibasic acids mentioned above.

Among these, branched dibasic acids (branched dicarboxylic acid compounds) are preferred because they have excellent antifoaming properties, are excellent in the effects of the present invention, or have excellent adhesion to substrates, etc. Preferably, isoeicosanedioic acid, isodocosanedioic acid (HOOC-C ₂₀ H ₄₀ -COOH. -C ₂₀ H ₄₀ - is branched), isodocosadiene dioic acid, and butyloctanedioic acid are more preferable, and isodocosane dioic acid is more preferable. preferable.

・Amount of dicarboxylic acid compound The amount of the dicarboxylic acid compound is determined from the viewpoint of excellent antifoaming properties, excellent effects of the present invention, or excellent adhesion to substrates, etc., in the urethane resin composition (total amount ), preferably 0.05% by mass or more and less than 1% by mass, more preferably 0.07 to 0.5% by mass.

The curing accelerator composition of the present invention may further contain a latent curing agent described below. When the curing accelerator composition of the present invention further contains a latent curing agent, the effects of the present invention are more excellent, and/or the composition has excellent adhesion to a base material, antifoaming property, and blistering resistance.

・Other components If necessary, the curing accelerator composition of the present invention may further contain, for example, diamines other than the above-mentioned predetermined dialkyltoluene diamines, reinforcing agents, curing catalysts, plasticizers, etc. It can contain agents, solvents, antioxidants, anti-aging agents, and pigments.
Moreover, the curing accelerator composition of the present invention may further contain a compound having an isocyanate group capped with a protective group (capped isocyanate compound). The above protecting group is not particularly limited. Examples of the isocyanate compound constituting the capped isocyanate compound include those similar to the isocyanate compounds contained in the urethane resin composition described below.
The contents of the various components mentioned above can be selected as appropriate.

Examples of reinforcing agents include titanium oxide, silicon oxide, talc, clay, quicklime, kaolin, zeolite, diatomaceous earth, finely powdered silica, hydrophobic silica, and carbon black.

Examples of the curing catalyst include organometallic catalysts.
Examples of organometallic catalysts include lead-based catalysts such as lead octate and lead octylate; organozinc compounds such as zinc octylate; and organotin compounds such as dibutyltin dilaurate and dioctyltin laurate. Compounds; organic calcium compounds such as calcium octylate and calcium neodecanoate; organic barium compounds; organic bismuth compounds and the like.

Examples of the plasticizer include diisononyl adipate (DINA), diisononyl phthalate (DINP), dioctyl phthalate (DOP), dibutyl phthalate (DBP), dilauryl phthalate (DLP), dibutylbenzyl phthalate (BBP), and dioctyl adipate ( DOA), diisodecyl adipate (DIDA), trioctyl phosphate (TOP), tris (chloroethyl) phosphate (TCEP), tris (dichloropropyl) phosphate (TDCPP), propylene glycol adipate polyester, butylene glycol adipate polyester, etc. can be mentioned.

Examples of solvents include hydrocarbon compounds such as hexane and toluene; halogenated hydrocarbon compounds such as tetrachloromethane; ketones such as acetone and methyl ethyl ketone; ethers such as diethyl ether and tetrahydrofuran; Ester; Mineral spirit etc. are mentioned.

Examples of the antioxidant include butylated hydroxytoluene (BHT), butylated hydroxytoluene anisole (BHA), diphenylamine, phenylenediamine, triphenyl phosphite, and the like.

Examples of pigments include metal oxides such as titanium dioxide, carbon black, zinc oxide, ultramarine, and red iron; sulfides of lithopone, lead, cadmium, iron, cobalt, and aluminum; hydrochlorides or sulfates thereof; Examples include azo pigments and copper phthalocyanine pigments.

One of the preferred embodiments is that the curing accelerator composition of the present invention does not substantially contain an isocyanate compound that can react with active hydrogen.
The above-mentioned "isocyanate compound capable of reacting with active hydrogen" refers to a compound having an isocyanate group capable of reacting with active hydrogen (specifically, a compound having an isocyanate group not capped with a protective group). The above-mentioned "isocyanate compound capable of reacting with active hydrogen" is the same as the isocyanate compound contained in the urethane resin composition described below.
In the present invention, "the curing accelerator composition of the present invention does not substantially contain an isocyanate compound that can react with active hydrogen" means that the content of the above-mentioned isocyanate compound is based on the total amount of the curing accelerator composition of the present invention. In contrast, it refers to 0 to 0.3% by mass.

- Method for producing the curing accelerator composition of the present invention The method for producing the curing accelerator composition of the present invention is not particularly limited. For example, the curing accelerator composition of the present invention can be produced by mixing the dialkyltoluenediamine with the dicarboxylic acid compound, the latent curing agent, etc., which can be used as needed, using a stirrer or the like. can.

<Application>
The curing accelerator composition of the present invention is used for a urethane resin composition containing an isocyanate compound.
The curing accelerator composition of the present invention can be used, for example, as an additive for urethane resin compositions (for example, one-component urethane resin compositions) or as a curing agent for two-component urethane resin compositions.

It is preferable to use the curing accelerator composition of the present invention for a moisture-curable or one-component urethane resin composition.
The curing accelerator composition of the present invention is preferably used as an additive for a one-component urethane resin composition.
When the curing accelerator composition of the present invention is used as an additive for a one-component urethane resin composition, as described above, it is possible to increase the curing speed and secure the pot life, and also to deeply cure the urethane resin composition. can improve sex.
Furthermore, in the above case, the advantage of the one-component urethane resin composition, which is that there is no partial effect failure due to poor mixing, is not impaired.

・How to use The curing accelerator composition of the present invention can be used, for example, by mixing the curing accelerator composition of the present invention with the above-mentioned urethane resin composition to obtain a mixture, and applying the above-mentioned mixture to a substrate. There are several methods.
The above mixing method, conditions, etc. are not particularly limited. The method of application to the base material is also the same. In addition, after applying the said mixture to a base material once, you may apply the said mixture again on it.
Examples of the base material include concrete, mortar, metal roofs, urethane coatings coated with top coats, balconies, rooftops, and the like.

The above mixture can be used, for example, for waterproofing materials (architectural coating waterproofing materials), civil engineering coating materials, and the like.

After applying the above mixture to a substrate, a cured product of the above mixture can be obtained by curing the above mixture under conditions of, for example, 0 to 50°C and 0 to 95% RH.
The time required for the above-mentioned curing (time available for the next step) can be, for example, 1 to 8 hours.

The cured product may further have another layer thereon. Examples of the other layer include a top coat layer, another urethane resin composition, and a primer layer.
A primer may be used on the substrate before applying the mixture.

<Urethane resin composition>
In the present invention, the urethane resin composition in which the curing accelerator composition of the present invention is used contains an isocyanate compound.

<Isocyanate compound>
The isocyanate compound contained in the urethane resin composition is a compound having an isocyanate group.
The isocyanate compound preferably has a plurality of isocyanate groups per molecule.
Examples of the isocyanate compound include low-molecular isocyanate compounds and urethane prepolymers. Examples of the low-molecular isocyanate compound include compounds similar to the polyisocyanate compounds used in the production of urethane prepolymers, which will be described later.
In one preferred embodiment, the isocyanate compound contains a urethane prepolymer.

(urethane prepolymer)
The above urethane prepolymer is not particularly limited. For example, conventionally known ones can be mentioned. Specifically, for example, a reaction product obtained by reacting a polyol compound and a polyisocyanate compound such that the isocyanate group (NCO group) is in excess with respect to the hydroxyl group (OH group) can be used. can.
The urethane prepolymer can contain 0.5 to 5% by weight of NCO groups. It is preferable that the urethane prepolymer has an NCO group at the end of the molecule.

- Polyisocyanate compound The polyisocyanate compound used in the production of the urethane prepolymer is not particularly limited as long as it has two or more isocyanate groups in the molecule.
Specific examples of the polyisocyanate compound include TDI (for example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI)), MDI ( For example, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI)), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diisocyanate Aromatic polyisocyanates such as isocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), toridine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate;
Hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis(isocyanatemethyl)cyclohexane (H ₆ XDI) , aliphatic polyisocyanates such as dicyclohexylmethane diisocyanate (H ₁₂ MDI);
These carbodiimide-modified polyisocyanates;
Examples include these isocyanurate-modified polyisocyanates.

Among these, aromatic polyisocyanates are preferred, and aromatic diisocyanates are more preferred, since the resulting urethane prepolymer has a low viscosity and is easy to handle.

-Polyol compound The polyol compound used in the production of the urethane prepolymer is not particularly limited as long as it has two or more hydroxy groups.
Examples of the polyol compound include polyether polyol, polyester polyol, polycarbonate polyol, and mixed polyols thereof.
Among these, polyether polyol is mentioned as one of the preferred embodiments.

Examples of polyether polyols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, 1,3-butanediol, 1, Polyols etc. obtained by adding at least one member selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and polyoxytetramethylene oxide to at least one member selected from the group consisting of 4-butanediol and pentaerythritol. can be mentioned. Specifically, preferred examples include polypropylene ether diol and polypropylene ether triol.

Among these, polypropylene ether diol and/or polypropylene ether triol are preferred because the resulting urethane prepolymer has an appropriate viscosity, is easy to handle, and the resulting cured product has excellent tensile properties.

In the present invention, the combination of a polyol compound and a polyisocyanate compound for producing a urethane prepolymer is selected from the group consisting of tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), and diphenylmethane diisocyanate (MDI). A preferred example is a combination of at least one type of polypropylene ether diol and/or polypropylene ether triol.

Further, in the present invention, the amounts of the polyisocyanate compound and the polyol compound when producing the urethane prepolymer are preferably such that the NCO group/OH group (mole equivalent ratio) is 1.2 to 2.5. , more preferably 1.5 to 2.2. When the molar equivalent ratio is within such a range, the urethane prepolymer obtained will have an appropriate viscosity and good storage stability.

The method for producing the urethane prepolymer is not particularly limited. For example, it can be produced by heating and stirring a polyol compound and a polyisocyanate compound in the above molar equivalent ratio at 50 to 130°C. Further, if necessary, for example, a urethanization catalyst such as an organic tin compound, organic bismuth, or amine can be used.

- Curing agent The urethane resin composition may further contain a curing agent (curing component capable of reacting with the isocyanate compound: curing agent in a narrow sense).
The above-mentioned curing agent (in a narrow sense) may include, for example, a substituent (active hydrogen-containing group) selected from the group consisting of a hydroxy group, a mercapto group, and an amino group (including an imino group. The same applies hereinafter) in the molecule. Examples include compounds having more than one.
Examples of the curing agent include polyol compounds having two or more hydroxy groups, polyamine compounds having two or more amino groups (excluding the above-mentioned dialkyltoluenediamine), latent curing agents, and the like.

In the latent curing agent, the protecting group that protects the substituent (active hydrogen-containing group) is not particularly limited. For example, conventionally known ones can be mentioned.

When the above-mentioned urethane resin composition is a one-component type, one preferred embodiment is that the one-component urethane resin composition further contains a latent curing agent.
In addition, when the above-mentioned urethane resin composition is a two-component type, the curing agent (in a broad sense) that the two-component urethane resin composition has is a curing agent in a narrow sense, such as a polyol compound having two or more hydroxy groups, A polyamine compound having two or more amino groups (excluding the above-mentioned dialkyltoluenediamine) can be contained.

...Polyol compound Examples of the polyol compound as the curing agent include the polyol compounds used in producing the urethane prepolymer described above.

...Polyamine compound Examples of the polyamine compound as the curing agent include ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6 -Hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 1,14-tetradecanediamine, 1,16-hexadecane Diamine, hexamethylene diamine, trimethylhexamethylene diamine, iminobispropylamine, methyliminobispropylamine, 1,5-diamino-2-methylpentane, isophoronediamine, 1,3-bisaminomethylcyclohexane, 1-cyclohexylamino- 3-aminopropane, 3-aminomethyl-3,3,5-trimethyl-cyclohexylamine, dimethyleneamine with norbornane skeleton, metaxylylenediamine (MXDA), hexamethylenediamine carbamate, diethylenetriamine, triethylenetetramine, tetraethylenepenta aliphatic polyamines such as amine, pentaethylenehexamine;
3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), 4,4'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,4-diaminophenol, 2,5-diaminophenol, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, tolylenediamine, etc. Examples include aromatic polyamines.

...Latent curing agent A latent curing agent generally refers to a compound whose functional group that can function as a curing agent is protected with a protective group. The above-mentioned protecting group is decomposed by heat or water, for example, to generate a curing agent.
In the present invention, one preferable embodiment is that the curing agent constituting the latent curing agent has, for example, a functional group (active hydrogen-containing group) that can react with an isocyanate group.

Examples of the latent curing agent include oxazolidine compounds and ketimine compounds.
As the latent curing agent, an oxazolidine compound is preferable from the viewpoint of being superior to the effects of the present invention and/or having excellent adhesion to a base material, antifoaming property, and blistering resistance.

...Oxazolidine compound An oxazolidine compound is a compound having an oxazolidine ring.
The oxazolidine ring can open, for example, in the presence of moisture (water) to generate a hydroxy group and a secondary amino group (-NH-).
Examples of the oxazolidine compound include N-hydroxyalkyloxazolidine, oxazolidine silyl ether, carbonate oxazolidine, ester oxazolidine; reaction products of N-hydroxyalkyloxazolidine and polyisocyanate compounds, and the like.

The above-mentioned oxazolidine compound is preferably N-hydroxyalkyl oxazolidine, from the viewpoint of superior effects of the present invention and/or excellent adhesion to substrates, antifoaming properties, and blistering resistance, and 2-alkyl-N -Hydroxyalkyloxazolidine is more preferred.

Examples of N-hydroxyalkyloxazolidine include 2-isopropyl-3-(2-hydroxyethyl)oxazolidine, 2-(1-methylbutyl)-3-(2-hydroxyethyl)oxazolidine (5BO), and 2-(2- 2-alkyl-N-hydroxyalkyloxazolidines, such as methylbutyl)-3-(2-hydroxyethyl)-5-methyloxazolidine;
2-Aryl-N-hydroxyalkyl oxazolidine (aromatic at the 2-position N-hydroxyalkyloxazolidine having a ring), and the like.
N-hydroxyalkyloxazolidine is 2-(1-methylbutyl)-3-(2-hydroxyethyl) from the viewpoint of having better effects of the present invention and/or having better adhesion to substrates and antifoaming properties. ) Oxazolidine (5BO) is preferred.

... Ketimine compound A ketimine compound is a compound having a ketimine (C=N) bond derived from an aldehyde or ketone compound and an amine compound. Ketimine compounds can generate primary amino groups, for example, by hydrolysis.

The aldehyde or ketone compound or amine compound used in the synthesis of the above ketimine compound is not particularly limited. For example, conventionally known ones can be mentioned.

(Isocyanate group/active hydrogen-containing group)
In the urethane resin composition, the curing agent (in a narrow sense) has a molar equivalent ratio (isocyanate group/active hydrogen-containing group) of the isocyanate group of the isocyanate compound (for example, urethane prepolymer) to the active hydrogen-containing group of 0. It is preferable to mix the ratio so that the ratio is 8 to 2.0, more preferably 0.9 to 1.5.

When the urethane resin composition is a one-component type and further contains a latent curing agent, the isocyanate group of the isocyanate compound relative to the active hydrogen-containing group of the (substantial) curing agent forming the latent curing agent. The molar equivalent ratio (isocyanate group/active hydrogen-containing group) is preferably from 0.8 to 2.0, more preferably from 0.9 to 1.5.
In addition, when the latent curing agent is an N-hydroxyoxazolidine compound, the "active hydrogen-containing group" of the isocyanate group/active hydrogen-containing group includes a hydroxy group and -NH- generated by ring opening of the oxazolidine ring, and A hydroxy group attached to the oxazolidine ring may be included.

・Other components In addition to the above-mentioned isocyanate compound and curing agent, the urethane resin composition may further contain reinforcing agents, curing catalysts, plasticizers, dispersants, It can contain solvents, antioxidants, anti-aging agents, and pigments.
Specific examples of the above-mentioned various components are the same as various other components that can be further contained in the curing accelerator composition of the present invention. The contents of the various components mentioned above can be selected as appropriate.
When the urethane resin composition is a two-component type, the various components described above can be added to the base resin and/or the curing agent (in a broad sense). Note that the curing agent in a broad sense means one containing at least the curing agent in the above narrow sense.

One of the preferred embodiments is that the urethane resin composition does not substantially contain dialkyltoluenediamine.
The above-mentioned dialkyltoluenediamine refers to a compound in which two alkyl groups and two amino groups (-NH ₂ ) are each bonded to a benzene ring constituting toluene. The above dialkyltoluenediamine is the same as the dialkyltoluenediamine contained in the curing accelerator composition of the present invention.
In the present invention, "the urethane resin composition does not substantially contain dialkyltoluenediamine" means that in the urethane resin composition, the content of the dialkyltoluenediamine is 0 to 0 with respect to the total amount of the urethane resin composition. It means that it is 0.3% by mass.

The above-mentioned urethane resin composition may be either one-part type or two-part type.
In a one-component urethane resin composition, all components are usually housed in one container.
A two-component urethane resin composition usually has a main component containing an isocyanate compound and a curing agent (in a broad sense) containing a curing agent (in a narrow sense).
The method for producing the urethane resin composition is not particularly limited. For example, conventionally known ones can be mentioned.

EXAMPLES The present invention will be specifically described below with reference to Examples. However, the present invention is not limited to these.

<Manufacture of curing accelerator composition>
Each component shown in the curing accelerator composition column of Table 1 below was used in the composition (parts by mass) shown in the same table, and these were mixed with a stirrer to produce a curing accelerator composition.
The value in the NCO/NH ₂ (mole equivalent ratio) column of Comparative Example 4 is the molar equivalent ratio (NCO/NH ₂ ) of the isocyanate group possessed by the isocyanate compound to the amino group possessed by dimethylthiotoluenediamine.
In preparing the next mixed solution, each of the curing accelerator compositions produced as described above was used as is.

<Preparation of mixed solution>
Each curing accelerator composition produced as described above was used for urethane resin composition 1 (one-component urethane resin composition, 10,000 parts by mass) shown in Table 1, and these were mixed. , a mixed solution was obtained.

The formulation of the urethane resin composition 1 is as follows.
- 100 parts by mass of urethane prepolymer prepared as described below - 100 parts by mass of calcium carbonate - 30 parts by mass of phthalate plasticizer - 7 parts by mass of latent curing agent - 1 part by mass of heat stabilizer - 2 parts by mass of light stabilizer・Pigment 0.1 part by mass

Preparation of urethane prepolymer 100 g of polypropylene ether triol (T4000, manufactured by Asahi Glass Co., Ltd.) with a number average molecular weight of 4000 and 150 g of polypropylene ether diol (D2000, manufactured by Asahi Glass Co., Ltd.) with a number average molecular weight of 2000 are placed in a reaction container, and plasticized. 15 g of diisononyl phthalate (DINP, manufactured by J-Plus) was added as an agent, heated to 110° C., and dehydrated for 6 hours. Next, tolylene diisocyanate (Cosmonate T80, manufactured by Mitsui Takeda Chemical Co., Ltd.) was added thereto so that the equivalent ratio of NCO groups/OH groups was 1.98, and this was heated to 80°C and heated for 12 hours under a nitrogen atmosphere. After time mixing and stirring, the urethane prepolymer was prepared. The content of NCO groups in the obtained urethane prepolymer was 3.0% by mass based on the total amount of the urethane prepolymer.

<Preparation of test specimen>
A rectangular frame measuring 10 cm long and 10 cm wide was assembled in advance on the mortar material using a polyethylene square backup material 2 cm high.
Immediately after mixing, each mixture prepared as described above is poured into the square frame until the height from the surface of the mortar material reaches 4 mm to prevent air bubbles from entering, and then the surface of the poured mixture is leveled. A test specimen was prepared according to the following procedure.

<Evaluation>
The following evaluations were performed using each test specimen produced as described above. The results are shown in Table 1.
・Pot life Immediately after production, each test specimen was placed under conditions of 20°C or 35°C and 50% RH for curing.
Immediately after the test piece was prepared, the time (pot life) until the surface of the cured test piece hardened and the material of the test piece no longer adhered to the finger when touched was measured.

...Evaluation Criteria In the present invention, if the pot life measured as described above was 15 minutes or more, it was evaluated that the pot life was secured.
If the pot life was 20 minutes or more, it was evaluated as having a longer pot life.
When the pot life was less than 15 minutes, it was evaluated that the pot life could not be secured.

・Curing speed (possible time for next process)
Immediately after production, each test specimen was placed under conditions of 20° C. and 50% RH to be cured.
Next, 0.2 kg/m ² of top coat is applied on each test piece at each time interval, and by applying the top coat, wrinkles or waves do not occur in the layer of the mixture on the test piece. (Is it possible to carry out the next process?) was visually confirmed.
The time from immediately after the preparation of each test specimen to just before the application of the top coat (limited to cases where the above wrinkles, etc. do not occur in the mixture layer of the test specimen for the first time after application of the top coat) is considered as the possible time for the next process. did.

...Evaluation Criteria In the present invention, if the next process possible time measured as described above was within 540 minutes, this was evaluated as having a fast curing speed.
When the next process possible time was within 480 minutes, this was evaluated as having a faster curing speed.
When the next process possible time was within 240 minutes, this was evaluated as having a very fast curing speed.
When the next process possible time exceeded 540 minutes, this was evaluated as having a slow curing speed.

・Pinhole @20℃
Immediately after preparation, each test specimen was placed under conditions of 20° C. and 50% RH for 24 hours to be cured.
The surface condition of each test piece after curing was visually observed to confirm the presence or absence of pinholes.

...Evaluation Criteria If the number of pinholes on the surface of each test specimen after curing was 0 or less than 10, it was evaluated as having excellent antifoaming properties, and this was designated as "A".
When the number of pinholes was 10 or more, the antifoaming property was evaluated to be poor and this was designated as "B".
Note that cases where the presence or absence of pinholes was not evaluated were indicated as "-".

・Adhesion Each mixture prepared as above was applied to a concrete piece (50 mm x 180 mm x 5 mm) (painting thickness approximately 2 mm), and after painting, it was placed under the conditions of 20 ° C. and 50% RH for 24 hours, and the concrete A first coating was applied on top of the piece.
After 24 hours, the same mixture as above was further coated on the first coating film (coating thickness: 1 mm, coating width: 25 mm), and after coating, it was further cured for 24 hours under the conditions of 20 ° C. and 50% RH. Then, a second coating film was provided on the first coating film to obtain a test piece for adhesion evaluation.
On the adhesion evaluation test piece obtained as above, a peel test was performed in which the second coating film was peeled off from the first coating film at an angle of 180°, and the peel strength (unit: N/25 mm) was measured. did.
In addition, the state of destruction after the peel test was visually observed.

・Evaluation criteria for adhesion In the present invention, when the above-mentioned state of destruction is material failure (cohesive failure) of the first or second coating film, or when the above-mentioned peel strength is 10 N/25 mm or more, the adhesion is It was evaluated as excellent and was marked with "*".
If the above-mentioned failure state is interfacial peeling (separation between the first coating film and the concrete piece) and the above-mentioned peel strength is less than 10N/25mm, the adhesion is evaluated as poor and the adhesion column is The value of peel strength (unit: N/25mm) is shown.
In addition, cases where adhesion was not evaluated were indicated as "-".
The material failure in Examples 1 to 5, 7, and 8 and Comparative Examples 1 to 3 was in the second coating film.

Details of each component shown in Table 1 are as follows.
- Urethane resin composition 1: Urethane resin composition 1 prepared as above

(Curing accelerator composition)
- Dialkyltoluenediamine 1 (DETDA): diethyltoluenediamine. Product name Heart Cure 10/DETDA. Manufactured by Hanson Group LLC. A mixture of two compounds (3,5-diethyl-2,4-toluenediamine and 3,5-diethyl-2,6-toluenediamine) represented by the following formula (2).

- Dicarboxylic acid compound 1 (IPU22): Trade name IPU-22. Long chain dibasic acid (IPU22) manufactured by Okamura Oil Co., Ltd. Branched dibasic acid. A branched alkylene group has carboxy groups at both ends. The alkylene group has 20 carbon atoms. Note that the alkylene group having 20 carbon atoms does not include carbon constituting a carboxy group.

・Latent curing agent 1: 3-(2-hydroxyethyl)-2-(1-methylbutyl)oxazolidine (5BO, manufactured by Toyo Gosei Co., Ltd.) (structure below)

・(Comparison) Dimethylthiotoluenediamine: Etacure 300 (mixture of 80% by weight of 3,5-dimethylthio-2,4-toluenediamine and 20% by weight of 3,5-dimethylthio-2,6-toluenediamine), Ethyl Corporation Company-made

As is clear from the results shown in Table 1, when Comparative Example 1 containing no dialkyltoluenediamine was used for the urethane resin composition, the curing speed of the urethane resin composition was slow.
When Comparative Example 2 in which the amount of dialkyltoluenediamine did not meet the predetermined range was used for the urethane resin composition, the curing speed of the urethane resin composition was slow.
When Comparative Example 3 in which the amount of dialkyltoluenediamine did not meet the predetermined range was used for a urethane resin composition, the pot life of the urethane resin composition was short.
When Comparative Example 4, which did not contain dialkyltoluenediamine but instead contained dimethylthiotoluenediamine, was used for the urethane resin composition, the curing speed of the urethane resin composition was slow.

On the other hand, when the curing accelerator composition of the present invention is used for a urethane resin composition, it can accelerate the curing speed of the urethane resin composition and ensure the pot life of the urethane resin composition. Ta.

Claims (2)

Used for a one-component urethane resin composition containing a urethane prepolymer having 0.5 to 5% by mass of isocyanate groups and a latent curing agent ,
Contains a dialkyltoluenediamine and a dicarboxylic acid compound ,
The molar equivalent ratio (NCO/NH ₂ ) of the isocyanate group possessed by the urethane prepolymer to the amino group possessed by the dialkyltoluene diamine is 100/10 to 100/70,
The amount of the dicarboxylic acid compound is 0.05% by mass or more and less than 1% by mass with respect to the urethane resin composition,
A curing accelerator composition , wherein the dicarboxylic acid compound is represented by HOOC-R-COOH, R is a hydrocarbon group, and the hydrocarbon group has 10 to 24 carbon atoms . The curing accelerator composition according to claim 1 , wherein the molar equivalent ratio (NCO/ _NH2 ) is more than 2.0 and 10 or less.