JPS61235476A - Cationic electrodeposition paint composition - Google Patents

Abstract

PURPOSE:To provide the title composition capable of providing a coating which cures at low temp. and excellent in water resistance, which comprises an epoxy- modified amino group-containing resin and a specific completely blocked polyisocyanate compd. CONSTITUTION:A completely blocked isocyanate compd. is obtained by reacting at 10-150 deg.C one equivalent of a polyisocyanate (e.g.: tolylene diisocyanate) with a sec. monoamine having two hydroxyl groups of the formula (wherein R1-R2 is each independently hydroxyethyl, 2-hydroxypropyl, etc.) in an amt. of one equivalent in terms of the amt. of the active hydrogen contained therein and a blocking agent having one active hydrogen (e.g.: methanol) in an amt. of 0.8-1.5 equivalents in terms of the amt. of the active hydrogen contained therein, provided that the total amt. of the active hydrogen is 1-1.2 equivalents. One equivalent of an epoxy-modified amino group-containing resin is incorporated with 0.2-2.0 equivalents of the completely blocked polyisocyanate compd. The mixture is neutralized with an acid and dissolved or dispersed in water.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a composition for cationic electrodeposition coating.

Compositions for cationic electrodeposition coatings containing point-blocked isocyanate crosslinking agents have been well known for a long time.

For example, epoxy resins having an amino group as a solubilizing group (JP-A-51-103135, JP-A-48-51)
924) and epoxy resins solubilized by quaternary ammonium groups (Japanese Patent Publication No. 54-4978, JP-A-53-65327, JP-A-53-65328)
Publications, etc.).

A composition for a cationic electrodeposition coating using as a crosslinking agent a completely blocked polyisocyanate compound produced by a reaction between a tertiary amine having a hydroxyl group as a polyfunctionalizing agent and a polyisocyanate is disclosed in JP-A-58-113264; It is disclosed in Publication No. 113266/1983.

JP-A-58-113264 discloses that the hydroxyl group is 2
The patent discloses a cationic electrodeposition coating composition in which a completely blocked polyisocyanate compound is produced by reacting a tertiary amine and a diisocyanate with a blocking agent containing active hydrogen, and is used as a crosslinking agent.

Furthermore, JP-A-58-113266 discloses a completely blocked polyisocyanate compound obtained by reacting a half-block diisocyanate having isocyanate groups with different reactivity with a tertiary amine having at least two hydroxyl groups. A cationic electrodeposition coating composition containing a crosslinking agent is disclosed.

All of these methods involve producing completely blocked polyisocyanate compounds using a tertiary amine having a hydroxyl group as an ionizable polyfunctionalizing agent, which is stable even when blended in large amounts, and which increases crosslinking efficiency. It is said that it is possible to obtain a cationic electrodeposition paint that can be cured at low temperatures.

However, JP-A-58-113264 and JP-A-58-113266 do not disclose anything about the reaction between polyisocyanate and a secondary monoamine having a hydroxyl group; It is characterized by using a tertiary amine having a hydroxyl group as the agent. Generally, a cured coating film using a crosslinking agent containing a tertiary amine having a hydroxyl group as an ionizable polyfunctionalizing agent has poor water resistance.

Practical curing conditions for these compositions are 20 to 180°C.
It takes 30 minutes. A high curing temperature is generally uneconomical in terms of energy equipment, etc., and a coating composition that cures at low temperatures is desired.

OBJECTS OF THE INVENTION The object of the present invention is to provide a novel composition containing a crosslinking agent that cures at low temperatures and has good water resistance.

Means for Solving the Problems The present invention provides (A) an epoxy-modified amino group-containing resin and (B)
) (i) a polyisocyanate, (ii) a secondary monoamine having two hydroxyl groups and (iii) 1
The present invention relates to a cationic electrodeposition coating composition containing a completely blocked boryson anate compound formed by the reaction of a blocking agent having active hydrogen atoms.

The fully blocked polyisocyanate compound used in the present invention comprises (i) a polyisocyanate, (ii) a secondary monoamine having two hydroxyl groups, and (iii)
) A reaction product consisting of a blocking agent having one active hydrogen, in which a ureido bond is generated by the reaction between the active hydrogen directly connected to the nitrogen of the secondary amine and the isocyanate group,
The ionizing ability is lost, and the secondary amine acts not as a propping agent but as a polyfunctionalizing agent that forms the backbone of the crosslinking agent. In this respect, it differs from techniques using tertiary amines.

The use of a secondary monoamine having two hydroxyl groups as a polyfunctionalizing agent provides excellent low-temperature curability and water resistance.

As an example of the epoxy-modified amino group-containing resin which is component (A) of the composition of the present invention, any resin conventionally used in electrodeposition paints can be used.

Such epoxy-modified amino group-containing resins are basically obtained by reacting an epoxy resin with a basic amino compound. The epoxy resin that can be used in the present invention is a compound having on average one or more epoxy groups per molecule, and epoxy resins having two epoxy groups are particularly preferred. Examples of useful epoxy resins include epoxy resins obtained from bisphenol A and epichlorohydrin, epoxy resins obtained from bisphenol F and epichlorohydrin, or hydrogenated bisphenol A and epichlorohydrin. Particularly preferred are epoxy resins obtained by the reaction of bisphenol A and epichlorohydrin.

The basic amino compound may be any of primary amines, secondary amines, tertiary amines, polyamines, and alkanolamines. Preferred basic amino compounds are diethylamine, diethylamine, N-methylethanolamine, jetanolamine, ethylenediamine,
Examples include diethylenetriamine, dimethylcyclohexylamine, dimethylethanolamine, diethylenetriamine, and the like. When using a polyamine such as diethylenetriamine, it is preferable to react its primary amino group with a ketone such as acetone, methyl ethyl ketone, or methyl isobutyl ketone to obtain a ketimine derivative. The ketimine production reaction proceeds easily by heating to 100° C. or higher and distilling off the produced water. When using a tertiary amine that does not have active hydrogen, it is mixed with an appropriate acid,
For example, boric acid, phosphoric acid, sulfuric acid, acetic acid, lactic acid, etc. are used instead of acid amine salts.

The amount of the amino group-containing compound to be used is determined by calculation so that it is equivalent to the terminal epoxy group.

The reaction between these basic amino compounds and epoxy resins generally occurs even when they are mixed at room temperature, but in order to complete the reaction, the temperature should be about 20-200°C, preferably 50-100°C.
It is preferable to heat at 50° C. for about 1 to 5 hours.

The above reaction and reaction product can be used, for example, in JP-A-51-1
03135, JP 55-32385, JP 53-65327, JP 53-65328
It may be manufactured by the method described in Japanese Patent Application Publication No. 52-87498 and the like. Note that when a tertiary amine is used as the basic amino compound and is reacted with an epoxy resin in the presence of an acid, a compound having a quaternary amino group is produced, which is also the epoxy-modified amino compound of the present invention. It is included in group-containing resins.

Component (B) of the composition of the present invention is a polyisocyanate obtained by reacting (1) a polyisocyanate, (ii) a secondary monoamine having two hydroxyl groups, and (iii) a blocking agent having one active hydrogen group. It is a block polyisocyanate compound.

As the polyisocyanate, all polyisocyanates conventionally used as vehicle components for electrodeposition paints can be used. Typical examples are shown below. Trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, l.

Aliphatic compounds such as 2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, ethylidene diisocyanate, butylidene diisocyanate, 1,3-cyclopenkune diisocyanate, 1,4-cyclohexane diisocyanate,
Aliphatic cyclic compounds such as 1.2-cyclohexane diisocyanate L m-phenylene diisocyanate, p-phenylene diisocyanate, 4.4°-diphenyl diisocyanate, 1.5-naphthalene diisocyanate,
1. Aromatic compounds such as 4-naphthalene diisocyanate, 4.4'-diphenylmethane diisocyanate, 2
．． Aliphatic- such as 4- or 2,6-toluene diisocyanate or mixtures thereof, 4,4"-toluidine diisocyanate, 1,4-xylene diisocyanate
Aromatic compound, dianisidine noisocyanate, 4.4
'-') Nuclear substituted aromatic compounds such as phenyl ether diisocyanate and chlorodiphenyl diisocyanate,
Triphenylmethane-4,4°4''-triisonanate, 1,3.5-)triisonanate, 2.4
．． 6-triisocyanate Triisocyanates such as toluene, 4.4°-diphenyl-dimethylmethane-2,
Examples include tetraisocyanates such as 2°, 5.5'-tetraisocyanate, and polymerized polyisocyanates such as toluene diisocyanate dimer and toluene diisocyanate trimer. Particularly preferred are those having two or more isocyanate groups having equal reactivity, such as 4,4'-diphenylmethane diisocyanate. A secondary monoamine having two hydroxyl groups (wherein R and R2 are independently -(CHtCHtOH)n, (CHtCHCHs
)n - (OH n is mainly 1, but may be 2 or more), -C
A product obtained by the addition reaction of a monoalkanol primary amine represented by HICHCH, CH8, OH OHOH RNHs (wherein R is the same as R1 or R1) and a monoepoxide can be used.

Representative examples of monoepoxides include ethylene oxide, propylene oxide, 1,2-butylene oxide, 1
．． Examples include 2-pentene oxide, styrene oxide, glycidyl ethers of alcohol or phenol, and glycidyl acrylate. Among these, jetanolamine and diisopropanolamine are preferred because they are industrially easily available. Curing is possible at a lower temperature than the reaction between the active hydrogen bonded to the nitrogen of a secondary amine such as dialkanolamine and the isocyanate group, and the reaction between the active hydrogen of the hydroxyl group and the isocyanate group. Improves the water resistance of the paint film.

As the blocking agent having one active hydrogen, suitable aliphatic, cycloaliphatic, and aromatic alkyl monoalcohols and phenolic compounds are used. For example, lower aliphatic alcohols include methyl alcohol, ethyl alcohol,
Chloroethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol,
heptyl alcohol, octyl alcohol, nonyl-3
゜3.5-Trimethylhexanol, decyl alcohol, lauryl alcohol, etc.; aromatic alkyl alcohols such as phenylcarbinol, methylphenylcarbinol, ethyl glycol monoethyl ether, ethyl glycol motuptyl ether; phenolic compounds such as phenol itself and cresol; , xylenol, nitrophenol, chlorophenol, ethylphenol, t-butylphenol, 2.5-di-t-butyl-4-hydroxytoluene, and the like.

Furthermore, lactams such as caprolactam, methyl ethyl ketone oxime, acetone oxime, cyclohexanone oxime, etc. are used.

Each component: (i) polyisocyanate, (ii) secondary monoamine having two hydroxyl groups, and (iii)
The amount of blocking agent with one active hydrogen is (ii
) and (iii) such that the sum of the equivalents of active hydrogen is at least the same as the equivalent of (i). Preferably (1)
ii) + (iii) for l equivalent of! ~1.2 equivalents are used. By doing so, a completely blocked polyisocyanate compound can be obtained.

As for the equivalent ratio of (ii) and (iii), it is appropriate that the active hydrogen equivalent of the latter is 0.8 to 1.5 to the active hydrogen equivalent 1 of (ii). By doing so, a cured film with good low temperature curability and water resistance can be obtained.

The reaction is generally carried out under conventional conditions using an isocyanate, (i) a polyisocyanate, (ii) a secondary monoamine having two hydroxyl groups, and (ii) a secondary monoamine having two hydroxyl groups;
i) The reaction order of the blocking agent with one active hydrogen is not limited. The reaction temperature is IO<0>C to 150<0>C, preferably 20<0>C to 130<0>C.

The end point of the reaction is confirmed by the disappearance of isocyanate groups by infrared light analysis.

A catalyst may be used when preparing fully blocked polyisocyanate compounds. Catalysts useful in the present invention are those suitable for forming fully blocked polyisocyanate compounds, preferably metal salts or complexes such as lead acetate, dibutyltin laurate, stannath octoate, and the like.

A solvent may be used when preparing fully blocked polyisocyanate compounds. The solvent does not react with the isocyanate and is preferably a ketone (eg methyl isobutyl ketone), an ether (eg diethyl ether of ethylene glycol) or an ester (eg ethyl acetate).

The amount of the fully blocked polyisocyanate compound which is the component (B) of the present invention is such that when the electrodeposited coating is baked, the block is removed and the amount is sufficient to react and cure with the hydroxyl groups, amino groups, etc. in the resin. Usually, 0.2 to 2.0 per equivalent of the epoxy-modified amino group-containing resin as component (A).
It is.

To prepare the composition for cationic electrodeposition coating of the present invention, (
A) Component epoxy-modified amino group-containing resin and (B)
2.) The completely blocked polyisocyanate compound as the component is mixed, and this is mixed with an appropriate acid, for example, an inorganic acid such as boric acid, phosphoric acid, sulfuric acid, or hydrochloric acid, or an organic acid such as lactic acid or acetic acid, preferably using an organic acid alone or in combination. After neutralization, dissolve or disperse in water.

In addition to the above-mentioned components, the composition for cationic electrodeposition coating according to the present invention may appropriately contain conventional additives such as pigments and solvent surfactants. Preferred pigments may be any of the conventional ones, such as inorganic pigments such as iron oxide, lead oxide, strontium chromate, carbon black, cold dust, titanium dioxide, talc, barium sulfate, or color pigments such as cadmium yellow, Examples include cadmium red and chromium yellow. Organic pigments such as phthalocyanine blue, phthalocyanine green, etc. may also be used. Also, a mixture of a plurality of pigments may be used. Pigment content in a composition is usually expressed in terms of pigment to resin ratio.

The pigment to resin ratio is usually preferably in the range of 0.01 to 5:l. other additives present in the composition at least 0.01% by weight;
Typically 0.01 to 25% by weight (based on the total weight of resin solids) may be present.

In an electrodeposition process using the composition of the invention, the composition of the invention is brought into contact with an electrically conductive anode and an electrically conductive cathode (which contains the surface to be coated).

During contact with the composition of the invention, an adherent film is deposited upon application of a voltage between the electrodes. Electrodeposition conditions may vary widely, but are generally similar to other types of electrodeposition. The applied voltage may vary widely, for example from as low as 1 volt to as high as several thousand volts. Typically about 50-500 volts.

After painting, bake at a low temperature of 140℃ or higher for 20 minutes or more.

Coating film formation can be determined by the acetone resistance of the coating, for example, by resisting rubbing with a cloth impregnated with acetone. Those that do can withstand at least 20 times, preferably 30 times or more.

By using the composition of the present invention, it is possible to impart low-temperature curability and water resistance compared to those using fully blocked polyisocyanate compounds of the prior art.

The present invention will be explained in more detail with reference to Examples. In the examples, percentages and parts are based on weight, unless otherwise indicated.

Reference Example (1) Preparation of epoxy-modified amino group-containing resin “A J” diglycidyl ether of bisphenol A (epoxy equivalent: 9
10) While stirring 1000 parts by weight and keeping it at 70°C,
Dissolved in 463 parts by weight of ethylene glycol monoethyl ether, further added 80.3 parts by weight of diethylamine,
Epoxy-modified amino group-containing resin "A" was prepared by reacting at 100°C for 2 hours.

(2) Preparation of fully blocked polyisocyanate compound: A conventional fully blocked polyisocyanate compound "mouth" Toluene diisocyanate (2,4
-To 174 parts by weight of an 80/20 mixture of toluene diisocyanate/2.6-toluene diisocyanate (TDI), 118 parts by weight of ethylene glycol monobutyl ether was gradually added dropwise to half the mixture while keeping the reaction temperature below 50°C by external cooling. Blocked isocyanate was obtained. Next, 45 parts by weight of trimethylolpropane and 0.05 parts by weight of dibutyltin dilaurate were added, and the mixture was heated at 120°C.
The reaction was carried out for 90 minutes. The obtained reaction product was diluted with 144 parts by weight of ethylene glycol monoethyl ether. This is called the completely blocked polyisocyanate "mouth".

Toluene diisocyanate (2,4
- To 174 parts by weight of an 80/20 mixture of toluene diisocyanate/2,6-toluene diisocyanate, 87 parts by weight of methyl ethyl ketone oxime was gradually added dropwise while keeping the reaction temperature below 50°C by external cooling to obtain herbal block isocyanate. . Then, 50 parts by weight of triethanolamine and 0.0 parts by weight of dibutyltin dilaurate
5 important parts were added and reacted at 100°C for 90 minutes.

The obtained reaction product was diluted with 133 parts by weight of ethylene glycol monoethyl ether. This is referred to as completely blocked polyisocyanate "C".

250 parts by weight of 4,4'-diphenylmethane diisocyanate (MD I) charged in a reaction vessel was dissolved in 60 parts by weight of methyl isobutyl ketone, and 130 parts by weight of 2-ethylhexyl alcohol was added to the reaction temperature at 60°C by external cooling.
Half-block isocyanate was obtained by gradually dropping the mixture while maintaining the temperature below.

Next, 50 parts by weight of triethanolamine and 0.05 parts by weight of diptyltin dilaurate were added, and the mixture was heated at 120°C for 2 hours.
Allowed time to react. The obtained reaction product was diluted with 24 parts by weight of ethylene glycol monoethyl ether I. This is referred to as completely blocked polyisocyanate "2".

Next, a completely blocked polyisocyanate compound of the present invention is prepared.

Completely Blocked Polyisocyanate Compound "E" To 74 parts by weight of toluene diisocyanate (an 80/20 mixture of 2,4-toluene diisocyanate/2,6-toluene diisocyanate) charged in a reaction vessel, 118 parts by weight of ethylene glycol monobutyl ether was added to the reaction temperature. While maintaining the temperature below 50° C. by external cooling, the half-block isocyanate was gradually added dropwise to obtain a half-block isocyanate. Next, 35 parts by weight of jetanolamine and 0.0 parts by weight of dibutyltin dilaurate were added.
05 parts by weight was added, and the mixture was reacted at 110° C. for 90 minutes. The obtained reaction product was diluted with 140 parts by weight of ethylene glycol monoethyl ether.

This is referred to as completely blocked polyisocyanate "E".

Completely blocked polyisocyanate compound "to" 174 parts by weight of toluene diisocyanate (80/20 mixture of 2,4-toluene diisocyanate/2,6-toluene diisocyanate) charged in a reaction vessel, 0.05 parts by weight of dibutyltin dilaurate and methyl isobutyl Ketone 55
Add 44 parts by weight of diisopropanolamine while keeping the reaction temperature below 70°C by external cooling.
Partially blocked isocyanate was obtained by gradual dropwise addition.

Next, 167 parts by weight of ethylene glycol monoethyl ether was added, and the mixture was reacted at 110° C. for 3 hours to obtain completely blocked polyisocyanate “H”.

Completely Blocked Polyisocyanate Compound "T" 250 parts by weight of 4.4''-diphenylmethane diisocyanate charged in a reaction vessel was dissolved in 60 parts by weight of methyl isobutyl ketone, and 130 parts by weight of 2-ethylhexyl alcohol was added to the reaction temperature at 60°C by external cooling. Half-block isocyanate was obtained by gradually dropping the mixture while maintaining the temperature below. Next, 35 parts by weight of jetanolamine and 0.05 parts by weight of dibutyltin dilaurate were added, and the mixture was reacted at 120°C for 2 hours. The obtained reaction product was diluted with 119 parts by weight of ethylene glycol monobutyl ether. This is referred to as completely blocked polyisocyanate "T".

Completely Blocked Polyisocyanate Compound 87 parts by weight of methyl ethyl ketone oxime was added to 174 parts by weight of toluene diisocyanate (80/20 mixture of 2,4-toluene diisocyanate/2,6-) toluene diisocyanate) charged in a reaction vessel at a reaction temperature of 5 by cooling
While maintaining the temperature at 0° C. or lower, the mixture was gradually added dropwise to obtain a half-block isocyanate. Next, 35 parts by weight of jetanolamine and 0.05 parts by weight of dibutyltin dilaurate were added, and the mixture was reacted at 100°C for 90 minutes.

The obtained reaction product was diluted with 127 parts by weight of ethylene glycol monoethyl ether. This is referred to as completely blocked polyisocyanate "H".

(3) Preparation of pigment paste "S" 150 parts by weight of epoxy-modified amino group-containing resin "I", 6.4 parts by weight of glacial acetic acid, 140 parts by weight of titanium oxide, 28 parts by weight of basic lead silicate, 42 parts by weight of carbon black And deionized water 264 times! A pigment paste "Su" having a non-volatile content of about 50% by weight was prepared using

Epoxy-modified amino group-containing resin “I” 21 prepared previously
A mixture consisting of 4 parts by weight and 143 parts by weight of fully blocked polyisocyanate compound "Ho" was neutralized with 4.6 parts by weight of glacial acetic acid, and then diluted with 138.4 parts by weight of deionized water to give a non-volatile content of about 50 parts by weight. A weight percent resin vehicle was prepared.

Next, 300 parts by weight of pigment paste SuJ, 6 parts by weight of dibutyltin dilaurate, and 1194 parts by weight of deionized water were gradually added to the mixture with stirring at room temperature to prepare composition (I) for a cationic electrodeposition coating.

Example 2 Preparation of composition (II) for cationic electrodeposition coating; Example 1-
A composition for cationic electrodeposition coating (I[) was prepared according to Example 1, except that the component "H" was used instead of the "H" compound.

Example 3 Preparation of composition (III) for cationic electrodeposition coating: Example 1
Completely blocked polyisocyanate compound in the ingredient “
A composition for cationic electrodeposition coating (I[[) was prepared in exactly the same manner except that the composition was changed to "G".

A composition for cationic electrodeposition coating (IV) was prepared in exactly the same manner as in Example 1, except that component "Q" was used instead of the fully blocked polyisocyanate compound.

Comparative Example 1 This example shows the preparation of a composition for cationic electrodeposition coating using a conventional fully blocked polyisocyanate as a crosslinking agent.

A cationic electrodeposition coating composition (V) was prepared in exactly the same manner as in Example 1, except that a conventional fully blocked polyisocyanate compound "Kuchi" was used instead of the fully blocked polyisocyanate compound of the present invention.

Comparative Example 2 This example shows the preparation of a cationic electrodeposition coating composition using a completely blocked polyisocyanate containing a tertiary amine as a crosslinking agent.

A cationic electrodeposition coating composition (Vl ) was prepared.

Similarly to Comparative Example 2, another example using a completely blocked polyisocyanate compound containing a tertiary amine is shown.

A composition for cationic electrodeposition coating (■ ) was prepared.

The components of Examples 1-4 and Comparative Examples 1-3 are summarized below.

Next, using the cationic electrodeposition coating compositions of Examples 1 to 4 and Comparative Examples 1 to 3, a cold rolled steel plate was treated with zinc phosphate in an ordinary method in an electrodeposition bath at a coating temperature of 28°C and a coating voltage of 150.
Electrodeposited under the conditions of ~300V x 3 minutes, 140 ~ 18
Each film was baked at 0° C. for 20 minutes to obtain a 20 micron coating. The cure degree and water resistance of the coating film of the obtained painted panel were evaluated. The degree of hardening was evaluated based on the number of times the coating was rubbed back and forth with acetone required for the coating to peel off, and the extent of rust or blistering after 800 hours of a salt spray test based on ASTM.

Water resistance was evaluated by a 1-square test after immersing the cured coating film in hot water at 50° C. for 240 hours.

The evaluation results are shown in Table-1.

Effects of the Invention When the electrodeposition coating composition of the present invention is used, an electrodeposition coating film can be cured at a low temperature in a short time, and the cured coating film thus obtained exhibits high acetone resistance and good water resistance.

7. Contents of correction Procedural amendment (voluntary) June 28, 1985

Claims (1)

[Claims] 1. (A) epoxy-modified amino group-containing resin and (B) (i
) A cationic electrodeposition coating composition containing a fully blocked polyisocyanate compound obtained by reacting a polyisocyanate (ii) a secondary monoamine having two hydroxyl groups and (iii) a blocking agent having one active hydrogen. thing. 2. The composition according to item 1, wherein the polyisocyanate has two or more isocyanate groups having equal reactivity. 3. The composition according to item 1, wherein the equivalent ratio of the polyisocyanate to the secondary monoamine and the blocking agent is 1:1 to 1.2. 4. The composition according to item 1, wherein the active hydrogen equivalent ratio of the secondary monoamine to the blocking agent is 1 to 0.8 to 1.5. 5. The composition according to item 1, wherein the polyisocyanate is 4,4'-diphenylmethane diisocyanate. 6. Secondary monoamines have general formulas: ▲Mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R_1 and R_2 are each independently hydroxyethyl, 2-hydroxypropyl, 2-hydroxybutyl, 2-hydroxypentyl, or 2-hydroxy-2-phenylethyl. 7. The composition according to item 1, wherein the secondary monoamine is diethanolamine or diisopropanolamine. 8. The equivalent ratio of the epoxy-modified amino group-containing resin and the fully blocked isocyanate compound is 1 to 0.2.
2.0.