JPS6112723A - Curing agent for epoxy resin - Google Patents

Abstract

PURPOSE:The titled curing agent having improved chemical resistance and adhesivity free from skin irritation, selected from a ketimine compound and an aldimine compound of a hydroxyl group-containing polyamine, and an addition product of the compound and a monoepoxide. CONSTITUTION:A curing agent consisting of at least one selected from the group consisting of a ketimine compound of a hydroxyl group-containing polyamide synthesized from a polyamine and an epihalohydrin or a glycerin dihalohydrin, an aldimine compound of the hydroxyl group-containing polyamine, or an addition product of the ketimine compound and a monoepoxide, and an addition product of the aldimine compound and a monoepoxide. EFFECT:A curing agent having a long pot life, and provides a cured material having improved solvent resistance, quick-drying properties, and coating performance of thick film.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an epoxy resin curing agent with excellent various properties, specifically, it is not irritating to the skin itself, has a long pot life of a resin composition before curing when blended with an epoxy resin, An epoxy resin curing agent that can provide a cured product with excellent quick drying (fast curing) and thick film coating properties, as well as excellent chemical resistance, solvent resistance, adhesion, etc., and is especially suitable for paints. We aim to provide the following.

(Field of Industrial Application) Since the epoxy resin curing agent of the present invention has various properties that are well balanced on average, it can be widely and advantageously used as a curing agent for various epoxy resins used in various fields. It is particularly excellent as a room temperature curing agent for epoxy resin paints.

(Prior Art) Epoxy resins have various excellent properties and are therefore widely used in various fields, and various curing agents are also known and used.

In particular, curing agents for epoxy resins for paints are required to have the following properties.

■Skin irritation The hardening agent itself has little skin irritation.

■ Chemical resistance, solvent resistance A curing agent that can provide a cured product with excellent chemical resistance and solvent resistance.

■ Adhesion It must be able to provide a cured product with excellent adhesion.

■　Pot life A resin composition containing a curing agent has a long pot life.

■ Quick-drying The resin composition should be able to provide a resin composition that dries quickly after painting, so-called excellent quick-drying properties. This is a requirement that conflicts with the long pot life.

■ Thick film coating ability Ability to coat as thick a film as possible in one coat.

■Solvent-free or high-solid paint The product must have characteristics suitable for solvent-free or high-solid paint.

Conventionally, aliphatic amine-based and polyamide-based curing agents have been used as room-temperature curing agents for engineering resins.
Aliphatic amine curing agents exhibit the above-mentioned properties of ``excellent chemical and solvent resistance,'' ``quick drying,'' and ``suitable for use in solvent-free or high solids paints,'' but ``skin irritation.'' ,
■Poor pot life and ■Thick film coating properties are extremely poor. ■Adhesion is also insufficient.

In addition, polyamide hardeners are excellent in terms of skin irritation, adhesion, short pot life, chemical resistance, solvent resistance, quick drying properties, ■Poor in terms of thick film coating performance and ■performance and workability for solvent-free or high solids paints.

It is also known to react an aliphatic polyamine with an aliphatic ketone or an aliphatic aldehyde to form a ketoimine compound or an aldimine compound, which is then used as an epoxy resin curing agent. However, such ketoimine type or aldimine type curing agents are inferior in (1) skin irritation, (2) adhesion, (2) thick film coating properties, and (2) insufficient quick drying properties.

In addition, there are also ketoimine compounds or aldimine compounds having a hydroxyl group in the side chain bonded to the nitrogen atom of the main chain, which are obtained by reacting a ketoimine compound or aldimine compound obtained by reacting a polyamine with a ketone or aldehyde and a monoepoxide. Known as an epoxy resin curing agent (Japanese Patent Publication No. 38-20975),
It is already commercially available (for example, Pikia H-3, a product of Yuka Shell Epoxy Co., Ltd.). However, such curing agents also have ■ significantly poor thick film coating properties, ■ skin irritation, and ■
The adhesion is not sufficient, and also the quick-drying property is not sufficient.

Furthermore, it has already been proposed to use a reaction product of metaxylylene diamine and epichlorohydrin as an epoxy resin curing agent (Japanese Unexamined Patent Publication No. 58-204022). Although this curing agent has many excellent properties, it has the major drawback of (1) extremely short pot life.

(Problems to be Solved by the Invention) In short, epoxy resin curing agents, particularly room-temperature curing agents used in epoxy resin paint curing agents, are already well known, but the above I couldn't see anything that could satisfy all of the characteristics. The present invention aims to provide an epoxy resin curing agent that can satisfy all of these properties (1) to (4) in a well-balanced manner.

(Means for Solving the Problems) As a result of extensive research in order to solve the above problems, the present inventors have made ketoimine by reacting a hydroxyl group-containing polyamine obtained by the reaction of a polyamine with an epihalohydrin or the like with a ketone or an aldehyde. The present invention was achieved based on the knowledge that compounds or aldimine compounds, or compounds obtained by addition-reacting these compounds with monoepoxides, are excellent epoxy resin curing agents that have the above-mentioned various properties in a well-balanced manner. This is what I did.

That is, the epoxy resin curing agent of the present invention includes ketoimine compounds of a hydroxyl group-containing polyamine synthesized from a polyamine and epihalohydrin or glycerin dihalohydrin that may have a substituent, aldimine compounds of the hydroxyl group-containing polyamine, and the ketoimine compound. and monoepoxide addition reaction products of the aldimine compound.

Examples of the polyamine used in the present invention include aliphatic polyamines, polyamines having a cycloaliphatic ring, and polyamines having an aromatic ring, and primary noamines having up to 20 carbon atoms are particularly preferred. Specific examples of the polyamine include xylylene diamine, m-phenylene diamine, diaminodiphenylsulfone, diaminodiphenylmethane, triaminobenzene, 2,3-diaminotoluene, 2,2'-diaminodiphenyl, 3-diamino-4- Isopropylbenzene, 1,3-diamino-4,
5-diethylbenzene, diaminostilbene, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diaminopyridine,
Diaminodicyclohexylmethane, polyoxypropylene diamine, polyoxypropylene diamine, 1,3-
Examples of shrimp bromohydrin used in the present invention include bisaminomethylcyclohexane, pronogundiamine, influoronzoamine, and addition reaction products of polyepoxide and polyamine containing amine hydrogen.
Examples include epichlorohydrin and epibromohydrin, and examples of epino-rohydrin having a substituent include β-methylepichlorohydrin and β-methylepibromohydrin. Furthermore, these epino-lohydrins or epino-lohydrins with substituents
Glycerin dichlorohydrin, such as glycerin dichlorohydrin, can also be used instead of lohydrin.

Among these compounds to be reacted with diamine, especially preferred is evino-rohydrin, especially epichlorohydrin, from the viewpoint of ease of reaction and availability.

Ketones used in the present invention include aliphatic ketones, ketones having an aromatic ring, ketones having a cycloaliphatic ring, etc. These ketones include at least 2 carbon atoms, preferably at least 4 carbon atoms. Included are diketones having two keto groups separated from each other by atoms. Preferred ketones are those having 3 to 25 carbon atoms, especially those having 3 to 12 carbon atoms.

Specific examples include methyl ethyl ketone, methyl isobutyl ketone, dimethyl ketone, diethyl ketone, dibutyl ketone, diimbutyl ketone, methyl isopropyl ketone, ethyl butyl ketone, methyl octyl ketone,
Methylphenylketone, methylcyclohexylketone,
Dioctyl ketone, aryl methyl ketone, methylcyclohexenyl ketone, methoxymethyl butyl ketone, 1
．． Examples include 20-eicosandione and 1,18-octadecanedione.

The aldehydes used in the present invention include aliphatic mono- and dialdehydes, mono- and dialdehydes having a cycloaliphatic ring or an aromatic ring, and these aldehydes are those having 2 to 20 carbon atoms, especially those having 2 to 20 carbon atoms. 12
Preferably something that you own. Specific examples thereof include acetaldehyde, propionaldehyde, chloropionaldehyde, butyraldehyde, isobutyraldehyde, valeroaldehyde, hezotoinaldehyde, methacrolein, nicotinic aldehyde, cinchonine aldehyde,
-birancarboxylicaldehyde, tetrahydropyran-2-carboxylicaldehyde, crotonalhyde,
Acrolein, benzaldehyde, 1-natutaldehyde, decorenedialdehyde, glutaraldehyde, 1-
Cyclohexene-1-carboxyaldehyde, and 2.
Examples include 4-heptadiene-1-carboxaldehyde.

Examples of the monoepoxide used in the present invention include compounds represented by the following general formulas.

In each of the above formulas, A and A are hydrogen, a hydrocarbon group,
It is a halogenated hydrocarbon group, and AI is a divalent hydrocarbon group or a divalent halogen hydrocarbon group.

More specifically, the preferred monoepoxides include monoepoxy-substituted hydrocarbons, such as those having 12 carbon atoms.
up to 12 alkylene oxides, epoxycyclohexane, epoxyglobinbenzene, etc.; ethers containing oxy groups, such as monoepoxy-substituted alkyl ethers of aliphatic, cycloaliphatic and aromatic-hydric alcohols having up to 12 carbon atoms , monoepoxy-substituted alkyl ethers of -hydric phenols, aliphatic, cycloaliphatic and aromatic polyhydric alcohols (including partially esterified or etherified polyhydric alcohols) and monoepoxy-substituted polyhydric phenols Monoethers with alkyl alcohols (e.g. glycidyl ethers); esters containing epoxy groups, such as monoepoxy-substituted alkyl esters of aliphatic, cycloaliphatic and aromatic monocarboxylic acids (e.g. glycidyl acrylate, glycidyl methacrylate, glycidyl caprolate, glycidyl benzoate, etc.), monoepoxy-substituted alkyl esters of aliphatic, cycloaliphatic and aromatic polycarboxylic acids partially esterified with alkanols (e.g. monoglycisol esters of tar acid, maleic acid, isophthalic acid and succinic acid), alkyl and alkenyl esters of epoxy-substituted monocarboxylic acids (such as 1,2-epoxyzolopionic acid, epoxybutyric acid and epoxypentanonic acid) (alkyl and alkenyl esters); monoepoxides containing one or more halodane atoms, especially chlorine atoms, such as epichlorohydrin, interchlorophenyl glycidyl ether, hexachlorocyclohexylglycidyl ether, and the like.

In the production reaction of the epoxy resin curing agent in the present invention, cyamine represented by the general formula % formula % (in the formula indicates a blurred organic group) is used as the polyamine, epichlorohydrin is used as the epihalohydrin, and the general formula ( In the formula, R2 and R3 each represent an organic group.) As the aldehyde, an aldehyde represented by the general formula (In the formula, R represents an organic group) was used, and as the monoepoxide, a general An example of using a monoepoxide represented by the formula (in the formula, R5 represents hydrogen or a methyl group, and X represents an organic group) is represented by the following formula (in the formula).

n represents a number from 1 to 20. ).

First stage reaction-I ((4 H Second stage reaction (II) or H (R') Third stage reaction (I or (III') Even if the reaction is performed using glycerin dichlorohydrin instead, a polyamine substantially the same as the hydroxyl group-containing polyamine represented by the above general formula (1) can be obtained.

The reaction products (It) and (1) in the second stage and the reaction products (ID and (l/) in the third stage) are all the epoxy resin curing agent of the present invention, and the reaction products of these thing(
11), (I'), (1) and (■) can be used alone as the curing agent of the present invention, or two or more of these can be appropriately mixed and used as the curing agent of the present invention. can do.

In addition, the reaction product (II) used in the present invention described in 2.
, (II'), (1) and (II') can be expressed by the following general formula if they are combined using a common general formula.

In the above formula, R' represents an organic group introduced based on the diamine used, R2 represents an organic group introduced based on the ketone or aldehyde used, and R represents an organic group introduced based on the ketone or aldehyde used. or represents a hydrogen atom, and n represents a number from 1 to 20. Further, R4 represents hydrogen or a group represented by the general formula % (wherein, X is an organic group introduced based on the monoepoxide used, and R represents hydrogen or a methyl group).

To explain in detail the reaction for producing the epoxy resin curing agent of the present invention, the first step reaction for producing a hydroxyl group-containing polyamine is usually carried out in the presence of an alkali metal hydroxide. In theory, the reaction can be carried out using glycerol dihalohydrin or glycerin dihalohydrin (hereinafter referred to as [
Sometimes referred to collectively as "ebichlorhuman 9-phosphorus, etc." ), the reaction is 2 moles of polyamine per 1 mole of
In the actual reaction, an excess amount of polyamine is used, for example, 2 to 20 moles, preferably 5 to 15 moles, in order to completely react the evino-10 hydrin. Note that unreacted polyamine used in excess is recovered by distillation or the like after the reaction.

The first reaction conditions will be described in detail for the case where epichlorohydrin is mainly used for the reaction.The reaction temperature is usually 20 to 200°C, preferably 40 to 120°C.

For example, in the case of the reaction of aliphatic polyamines such as ethylenediamine, diethylenetriamine, and triethylenetetramine with evichlorhydrinone, the reaction is completed in 1 to 6 hours at 30 to 120°C in the presence of an alkali catalyst. In the case of the reaction of low molecular weight alicyclic polyamines, such as inphoron cyamine and bisaminocyclohexane, toepichlorohydrin may be reacted at lower temperatures, e.g.
The reaction is completed at 0°C, often between 30 and 60°C. However, in this case, unless the reaction is carefully controlled, there is a risk of inducing a rapid reaction. Further, the reaction between aromatic polyamines such as diaminodiphenylmethane, metaphenylenediamine, etc. and epichlorohydrin is usually completed at 40 to 120°C, often at 40 to 80°C, in 2 to 10 hours. In this case as well, in order to easily control the reaction, it is desirable to carry out the reaction at a relatively low temperature and over a somewhat longer period of time.

Next, the second stage reaction of the present invention, that is, the reaction between the hydroxyl group-containing polyamine and the ketone or aldehyde, is a reaction of 1 mole of the hydroxyl group-containing polyamine and 2 moles of the ketone or aldehyde. React with. The reaction temperature is generally 10 to 180°C, preferably 40 to 120°C, and the reaction time is 1 to 10 hours.

In the third stage reaction of the present invention, that is, the addition reaction of the ketoimine compound or aldimine compound and the monoepoxide, the monoepoxide is usually 0.1 to 20 moles, preferably 0.1 to 20 moles, per mole of the ketoimine compound or aldimine compound. 5 to 10 moles are added and reacted.

The reaction temperature is usually 30 to 180°C, preferably 40°C.
-120°C, reaction time is usually 2 to 18 hours.

(Functions and Effects) The epoxy resin curing agent of the present invention can exhibit the following excellent effects.

(1) As exemplified in the above reaction formula, the long-chain compound obtained by the first-stage reaction is further increased in molecular weight by the second-stage reaction. Compared to the amine-based curing agent, the cured resin has excellent flexibility and adhesion, less cracks occur after complete curing, and good chemical and solvent resistance.

(11) By using the ketoimine or aldimine type, the usable life of the epoxy resin composition before curing is significantly longer.

It contains hydroxyl groups directly connected to the main chain, and this hydroxyl group acts to accelerate hardening, so it has excellent quick drying properties after painting.

11J Since the molecular chain is long, the epoxy resin has excellent thick film coating properties. In other words, because conventional amine curing agents and conventional ketoimine or aldimine type curing agents have relatively short molecular chains, the surface hardens quickly and when thick films are made, the surface that is in contact with air is hardened, so the air required for curing is The inside does not harden because the moisture inside is not supplied to the inside. Further, even if water, glycol, phenol, etc. are added in advance to such conventional amine curing agents or conventional ketoimine or aldimine type curing agents, the curing speed cannot be dramatically improved (see Table 5). On the other hand,
If water, glycol, phenol, etc. are added to the curing agent of the present invention, even thick films can be rapidly cured even on white objects (see Table 5).

υ Due to its high molecular weight, it is less irritating to the skin.

Attachment) Due to its low viscosity, it has excellent workability, making it suitable for solvent-free or high-solid paints. In other words, with conventional curing agents, those with low molecular weight give a cured product that is too hard and have poor properties of the cured product), while those with high molecular weight have good properties of the cured product, but have poor workability due to their high viscosity. However, since the curing agent of the present invention is a polymer and has a low viscosity, it is suitable for use in solvent-free or high-solid paints in terms of workability and properties of the cured product.

Since the curing agent of the present invention is excellent in the various properties described above, it can be advantageously used as a curing agent for various epoxy resins used in various applications. especially,
It is an excellent curing agent for epoxy resin paints because it can be easily cured to the inside even at room temperature through the synergistic action of moisture in the air or pre-added water, glycol, phenol, etc., at room temperature. There is. In addition, monoamine, polyamine, hydroxylamine, etc. can be used together with the niboxy resin curing agent of the present invention depending on the intended use.

Note that there are no particular restrictions on the epoxy resin in which the curing agent of the present invention is used. For example, glycidyl ether type, glycidyl ester type, glycidyl amine type epoxy resins obtained by the reaction of polyhydric phenol, polyhydric alcohol, polyhydric carboxylic acid, polyhydric amine, etc. with epihalohydrin, and various other non-glycidyl type epoxy resins. Any curing agent of the present invention can be effectively used for resins.

(Examples, etc.) Next, the present invention will be described in further detail with reference to Examples and Experimental Examples.

Example 1 8 mol of m-xylylene/diamine and 50% caustic soda aqueous solution 82F! (1.02 mol including caustic soda)
The mixture was placed in a four-hole flask equipped with a stirrer, a dropping funnel, a thermometer and a condenser, and epichlorohydrin 93.f (1 mol) was added dropwise over 1 hour while stirring under a nitrogen atmosphere. The reaction temperature during the dropwise addition was maintained at 60° C., and even after the completion of the dropwise addition, the mixture was stirred at this temperature for 2 hours to allow the reaction to occur.

Next, maintain the temperature of the contents of 72 suf at 90 to 100°C,
Water was distilled off under reduced pressure of approximately 100 w+lHH.

The salt precipitated in the residual solution after distillation was removed by filtration, and the resulting mother liquor was kept at 130°C and distilled under reduced pressure of about 2.5 mHg to remove excess m-kylylene diamine. 305 g of a colorless, transparent, viscous liquid was obtained as a residue from the pot. The amine value was 665 (~KOH/1 s or less).

Next, methyl isobutyl ketone 186. P was added and placed in a four-loaf flask, a stirrer, a thermometer, and a water separator were attached to the flask, and the reaction was carried out at 80 to 180° C. with stirring for about 10 hours until no water came out.

Viscosity that can be used as the curing agent of the present invention: 2 poise (2 poise)
5° C.) and 457 g of a reaction product with an amine value of 442 were obtained.

Example 2 1136 g of 1,3-bisaminomethylcyclohexane (
8 mol) and 82 g of a 50% caustic soda aqueous solution (1.02 mol as caustic soda) using a stirrer, a dropping funnel,
Add 93% epichlorohydrin to a 21 quart flask equipped with a thermometer and condenser and stir under nitrogen atmosphere.
y (1 mol) was added dropwise over 1 hour. The temperature during the dropwise addition was maintained at 50°C, and the reaction was continued at this temperature for 2 hours with stirring even after the dropwise addition was completed.

The temperature of the contents of the flask was then kept at 90-100° C. and water was distilled off under reduced pressure of about 50 copper HH.

The precipitated salt in the pot residue was removed by filtration, and the mother liquor was
Excess 1,3-bisaminomethylcyclohexane was removed by distillation at a temperature of 0.degree. C. under reduced pressure of about 1 fnnHg. 311 g of a colorless and transparent liquid reaction product having an amine value of 650 was obtained as a residue in the pot.

This reaction product 311! i and methyl isobutyl ketone 1
83 g were placed in 21 three-necked flasks equipped with a thermometer, a condenser, and a stirrer, and reacted at a temperature of 80-120° C. for about 10 hours until no water distilled out. 461 g of a transparent, low-viscosity liquid was obtained as the reaction product, and its amine value was 658. This product could be used as a curing agent in the present invention.

Example 3 The final reaction products ioo, p and 7-enyl glycidyl ether 40II obtained in Example 1 were placed in 21 three-necked flasks equipped with a thermometer and a condenser, and reacted at 80-120°C for about 2 hours. I let it happen.

A colorless and transparent liquid 138I having an amine value of 316 was obtained as a reaction product, which could be used as a curing agent in the present invention.

Example 4 100.9 g of the final reaction product obtained in Example 1 and 40 g of glycidyl ether of ortho-secondary-butylphenol were reacted as in Example 3.

As a reaction product, 139 g of a colorless and transparent liquid having a viscosity of 18 poise (at 25° C.) and an amine value of 315 was obtained, which could be used as a curing agent in the present invention.

Example 5 Intermediate reaction product 2 with amine value 665 obtained in Example 1
Add 172y of n-butyraldehyde to 84g,
The mixture was placed in a four-bottle flask, equipped with a stirrer, a thermometer, and a condenser, and allowed to react at a temperature of 35 to 120°C for about 10 hours until no water came out.

A colorless and transparent liquid 460y having an amine value of 435 was obtained as a reaction product, which could be used as a curing agent in the present invention.

Experimental Example 1 Each curing agent obtained in Example 1 and Example 2, and for comparison, a ketoimine compound of metaxylylene diamine and methyl isobutyl lactone, and a commercially available curing agent, Ebicure H.
-3 (trade name of Yuka Shell Ekishi Co., Ltd.) and the intermediate product of aminated 665 obtained in Example 1 were used as curing agents, and these curing agents were mixed with commercially available epoxy resins (Yuka Shell Ekishi Co., Ltd.). Each epoxy resin composition obtained by kneading with Shell Epoxy Co., Ltd. (trade name: Epicoat 802, epoxy equivalent: 198, viscosity: 11 poise) was coated on a glass plate [to a thickness of 50 μm, and 75% at room temperature (25°C) The pencil hardness of the cured coating film was measured at regular intervals after being left in RH air. In addition, the pot life (time until it becomes dull) of each of the above-mentioned epoxy resin compositions was measured when the compositions were left at 25°C.

The results are shown in Table 1.

Table 1 Reaction product with ton This is one type of known ketoimine type curing agent.

*2...Product name of epoxy resin curing agent manufactured by Yuka Shell Epoxy Co., Ltd. This curing agent is one of the curing agents described in Japanese Patent Publication No. 38-20975.

*3: This is a curing agent described in JP-A-58-204022.

As is clear from the results in Table 1, the curing agents of Examples 1 and 2 were used as conventional ketimine type curing agents and
Compared to the curing agent described in Publication No. 0975, it is significantly superior in quick-drying properties after painting. Also, JP-A-58-2040
It has a significantly longer pot life than the curing agent described in Publication No. 22.

Experimental Example 2 The same commercially available epoxy resin (Epicote 802) used in Experimental Example 1 was mixed with the commercially available curing agent Ebiquia H3, the curing agent obtained in Example 1, and the curing agent obtained in Example 2 as shown in Table 2. An epoxy resin composition to which the curing agent obtained in Example 3 or the curing agent obtained in Example 3 was added, or a commercially available curing accelerator [Yuka Shell Epoxy Co., Ltd. trade name Pikiea 3010, Tris (2, 4,6-dimethylaminomethyl)phenol] is added to each. The resin composition was applied to a glass plate with a thickness of 50 μm, and then left in a room at 10°C and 60% RI.
The pencil hardness of the coating film was measured at regular intervals.

The results are shown in Table 2.

Table 2 Note 2 to Table 2 *...Product name: Ebicure 3010 manufactured by Yuka Shell Epoxy Co., Ltd. [:) Lis(diaminomethyl)phenol] As is clear from the results of Table 2, Example 1.2 The curing agents No. 3 and 3 have extremely excellent quick-drying properties, and there is almost no difference in curing speed whether or not an accelerator is added. This indicates that these curing itself has an accelerating effect, which is considered to be due to the action of the hydroxyl group directly connected to the main chain.

Experimental Example 3 As shown in Table 3, commercially available Ebicor) was used as the resin base material.
802 (this is a diluent input low viscosity type).

), or Epicoat 807 (trade name of Yuka Shell Epoxy Co., Ltd., non-diluent, low viscosity type), respectively 0.5
A commercially available curing agent Ebiki Air H-3, the curing agent obtained in Example 1, or the curing agent obtained in Example 4 were added to these. Each of the obtained epoxy resin compositions was placed on a 25 x 350 x 2 m glass plate for curing speed and pencil hardness tests, and on a 150 x 70 x 0.6 m cold rolled steel plate for other tests using a doctor blade. The film was applied to a film thickness of 50 μm using the following methods, and left in air at 20° C. and 75% RH for 7 days. The curing speed and pencil hardness tests were conducted by measuring the curing speed and hardness at regular intervals.

For the other tests, each test was conducted on the coating film after curing. The results were as shown in Table 3.

In addition, physical property (blister) tests in boiling water resistance tests, moisture resistance tests, and salt spray tests are conducted in accordance with ASTM D-714-
56, and the evaluation was expressed using the following symbols.

Excellent (] m
was displayed as "5°30'".

Further, in the impact test, for example, an indication of rlop, 1 indicates that floating occurred when an impact of 172 inches in diameter 5001I was applied to the 10 boxes.

As is clear from the results in Table 3, the hardening agents of Examples have better adhesion, boiling water resistance, moisture resistance, and
Excellent in salt water spray resistance, etc.

Experimental Example 4 A commercially available solvent-type epoxy resin (Yuka Shell Epoxy Co., Ltd. trade name Ebiko 1001-X-75) prepared by dissolving a solid epoxy resin in a xylene solvent was added with the curing agent obtained in Example 1 or a commercially available A curing agent, Ebicure H-3, was blended in the proportions shown in Table 4. Each of the obtained resin compositions was applied to a glass plate and a cold-rolled steel plate to a thickness of 50 μm in the same manner as in Experimental Example 3, and various physical property tests of the coating film were conducted in accordance with the method in Experimental Example 3. Did.

The results are shown in Table 4.

Table 4 Note to Table 4: Ebicoat 100X-75 (xylene 25%
As is clear from the results in Table 4, the curing agent of Example 1 provides a cured coating film with excellent chemical resistance.

- Experimental Example 5 As shown in Table 5, commercially available Epicoat 802 was added with or without water, and the curing agent obtained in Example 1 or the commercially available curing agent Ebicure H-3 was added to these, respectively. Each epoxy resin composition was prepared. Each of the epoxy resin compositions was applied to a glass plate to a film thickness of 36 μm or 300 μm and left in air at 5° C. and 72% RH to be cured.

The results are shown in Table 5.The curing agent of Example 1 took a shorter curing time and gave a cured product with higher hardness.

Furthermore, the curing agent of Example 1 is more excellent in the effect of accelerating curing by adding water.

Claims (1)

[Claims] 1) Ketoimine compounds of a hydroxyl group-containing polyamine synthesized from a polyamine and epihalohydrin or glycerine dihalohydrin that may have a substituent, aldimine compounds of the hydroxyl group-containing polyamine, monoepoxide addition reaction products of the ketoimine compound, and at least one kind selected from the group consisting of monoepoxide addition reaction products of the aldimine compound.