JP3051939B2 - Method for producing curable resin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a polymer having a blocked isocyanate group and a hydroxyl group, which are complementary reactive groups, in one molecule, and particularly useful as a resin for water-based paints. The present invention relates to a novel method for producing a curable resin.

Prior art and its problems Blocked isocyanate group-containing unsaturated monomer, hydroxyl group-containing unsaturated monomer and tertiary amino group and / or 4
A tertiary ammonium group-containing unsaturated monomer is copolymerized to introduce a complementary reactive group into the same molecule, and then the tertiary amino group is neutralized with an acid or the like. An aqueous crosslinkable curable composition dissolved in a mixture of the above is already known (JP-A-64-87606).

However, since an α-methylstyrene derivative is used as the blocked isocyanate group-containing unsaturated monomer, the use of an azo-based polymerization initiator results in an insufficient polymerization rate. If a peroxide or dialkyl peroxycarbonate initiator is used to increase the polymerization rate,
Since it is necessary to carry out the polymerization at a high temperature of 100 ° C. or higher, the blocking agent is dissociated during the polymerization reaction, and the regenerated isocyanate group and the hydroxyl group react with each other due to the presence of a tertiary amino group, thereby increasing the viscosity and It is not preferable because it gels.
In addition, when an isocyanate group-containing unsaturated monomer blocked with an oxime-based blocking agent is used, the blocking agent dissociates even at a low temperature of about 100 ° C., and reacts with the hydroxyl group-containing monomer during the polymerization reaction to gel. There is. In particular, when an isocyanate group-containing polymerizable monomer blocked with a blocking agent such as a phenolic or oxime-based polymer is used, the polymerization reaction is at a high temperature (about 120 to 140 ° C.), so there is a disadvantage that the color is significantly colored during the polymerization. In addition, since the dissociation temperature increases with other blocking agents, it is necessary to heat the self-curable resin to a higher temperature (about 170 ° C. or higher) in order to cure the resin.
It is difficult to obtain a low-temperature (about 120 ° C or lower) curable resin. On the other hand, as is well known, the importance of water-based paints from the viewpoints of air pollution prevention and resource saving is increasing, but water-soluble melamine resin is mainly used as the crosslinking agent, and curability and coating performance are important. There is a problem in terms. Further, it is difficult to use a conventional blocked isocyanate crosslinking agent in an aqueous system.

Means for Solving the Problems In view of the circumstances described above, the present inventors have conducted intensive studies and as a result, solved the problems such as gelation and coloring during the polymerization reaction and further reduction of the polymerization rate, and at 120 ° C. The invention of a method for producing a cationic self-curable resin which has a blocked isocyanate group and a hydroxyl group in one molecule and can be dissolved or dispersed in water, which can be cured even when heated at a low temperature below. .

That is, the present invention blocks a part of the isocyanate group in a polymer skeleton having a glycidyl group and two or more isocyanate groups in one molecule and having a number average molecular weight of 500 to 50,000, and then the glycidyl group and the remaining A method for producing a self-curable resin, characterized by reacting an alkanolamine with an unblocked isocyanate group of the above to introduce a blocked isocyanate group and a secondary or tertiary amino group or a quaternary ammonium base and a hydroxyl group in one molecule, Blocking all the isocyanate groups in the polymer skeleton having a glycidyl group and two or more isocyanate groups in a molecule and having a number average molecular weight of 500 to 50,000, and then reacting the glycidyl group with an alkanolamine to form one molecule Introducing a blocked isocyanate group and a secondary or tertiary amino group or a quaternary ammonium base and a hydroxyl group into A method for producing a self-curable resin, characterized by blocking all of the isocyanate groups in a polymer skeleton having a number average molecular weight of 500 to 50,000 having a glycidyl group and two or more isocyanate groups in one molecule, Then, a method for producing a self-curable resin, comprising reacting a glycidyl group with a primary to tertiary amine to introduce a blocked isocyanate group and a secondary or tertiary amino group or a quaternary ammonium base and a hydroxyl group in one molecule. And a method for producing an aqueous self-curable resin in which an amino group in the self-curable resin obtained by any one of the above methods is neutralized with an acid component.

The composition, production method, application, and the like of the self-curable resin of the present invention will be described in detail.

A polymer having a glycidyl group and two or more isocyanate groups in one molecule and having a number average molecular weight of 500 to 50,000 (hereinafter, sometimes abbreviated as “NCO polymer”) is a glycidyl group-containing polymerizable unsaturated polymer. Monomers (hereinafter sometimes abbreviated as “GC monomers”) and isocyanate group-containing polymerizable unsaturated monomers (hereinafter sometimes abbreviated as “NCO monomers”) as essential components And, if necessary, copolymerization with another monomer.

First, the GC monomer is a compound having at least one glycidyl group and at least one polymerizable unsaturated bond in one molecule. Specifically, 3,4-epoxycyclohexylmethyl (meth) acrylate, aryl glycidyl ether and Glycidyl (meth) acrylate and the like can be mentioned. It is preferable that this GC monomer does not have a functional group that easily reacts with an isocyanate group.

The NCO monomer is a compound having at least one free isocyanate group and at least one polymerizable unsaturated bond in one molecule, for example, methacryloyl isocyanate, 2-isocyanatoethyl methacrylate, m- or p-isopropenyl. One or two or more selected from -α, α'-dimethylbenzyl isocyanate, and a 1: 1 adduct in a molar ratio of a hydroxyl group-containing vinyl monomer to a diisocyanate compound;
Particularly, m- or p-isopropenyl-α, α'-dimethylbenzyl isocyanate is preferred.

The NCO polymer contains the above-mentioned GC monomer and NCO monomer as essential components. However, if necessary, another monomer may be used in combination.

Other monomers react easily active hydrogen (e.g. -OH, NH, -NH _2, -COOH, etc.) with an isocyanate group does not have a polymerizable monomer and a by e.g. styrene, alpha-methyl styrene, Aromatic vinyl monomers such as vinyl toluene; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate; (Meth) acrylic esters such as stearyl (meth) acrylate, cyclohexyl (meth) acrylate, and benzyl (meth) acrylate; viscose 3F, 3MF, 8F and 8MF (all manufactured by Osaka Organic Chemical Company, trade name ), Perfluorocyclohexyl (meth) acrylate, N-2
-Fluorinated vinyl monomers such as propyl perfluorooctanesulfonamidoethyl (meth) acrylate, vinyl fluoride and vinylidene fluoride; nitrogen-containing vinyl monomers such as N, N'-diethyl (meth) acrylamide; Vinyl ether monomers such as vinyl ethyl ether and vinyl butyl ether; and alkyl etherified methylol acrylamide, (meth) acrylamide, (meth) acrylic acid chloride, vinyl chloride, vinylidene chloride, (meth) acrylonitrile, and γ-methacryloxy Alkyltrimethoxysilane and the like can be mentioned. Depending on the desired performance, they are appropriately selected and used alone or in combination of two or more.

The composition ratio of the monomer in the NCO polymer may be within a range having one or more glycidyl groups and two or more isocyanate groups in one molecule of the polymer, and specifically,
Based on the total amount of the above three monomers, the GC monomer is 3 to 30.
% By weight, especially 5-20% by weight, NCO monomer 5-60% by weight,
Especially 20-55% by weight and other monomers 92-10% by weight,
Particularly, 75 to 25% by weight is preferable.

The NCO polymer is produced by copolymerizing the above monomer components in an inert organic solvent having no active hydrogen.

The inert organic solvent means a solvent having no functional group (for example, a hydroxyl group, an amino group, a carboxyl group, etc.) that reacts with an isocyanate group, such as an aliphatic hydrocarbon-based, aromatic-based, ester-based, and ketone-based solvent. One or a mixture of two or more solvents selected from organic solvents such as those described above.

If the resin of the present invention is used for an aqueous paint, the organic solvent used for this copolymer is preferably a hydrophilic or water-soluble solvent, for example, diethylene glycol dimethyl ether,
Ethylene glycol dimethyl ether and the like can be mentioned.
However, these two types of solvents need to be careful because if a peroxide initiator is used, there is a danger of explosion during the reaction. Other examples include N-methyl-2-pyrrolidone, dimethylformamide, methyl cellosolve acetate, and the like. Since these hydrophilic solvents may contain water, they are preferably dehydrated in advance.

When these solvents are used at the time of polymerization, they can be directly diluted with water.

On the other hand, at the time of polymerization, a copolymer is synthesized in a water-insoluble organic solvent, and after the reaction is completed, the solvent is removed under reduced pressure or the like and concentrated or
A powder obtained by a spray drying method or the like can be converted into an aqueous liquid by a method of dissolving or dispersing in water or a mixture of water and a hydrophilic organic solvent, or by an azeotropic method.

As the water-insoluble organic solvent in this case, for example, toluene, xylene, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl amyl ketone,
Diethyl ketone, ethyl butyl ketone, ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, cellosolve acetate, carbitol acetate, heptane, cyclohexane and the like can be used.

The copolymerization reaction of the above monomer components for producing an NCO polymer is usually carried out at a temperature of 50 to 180 ° C. using a radical polymerization initiator. The molecular weight is adjusted by adjusting the reaction concentration, the amount of the initiator and the like. Generally, the reaction concentration is in the range of 20 to 80% by weight of the polymer.

Radical polymerization initiator, for example, benzoyl peroxide,
Organic peroxides such as lauroyl peroxide, caproyl peroxide, t-butyl peroctoate, diacetyl peroxide; azobisisobutyronitrile, azobis α, γ-dimethylvaleronitrile, dimethyl α, α'-azoisobutyi An azo catalyst such as a rate; a dialkyl peroxydicarbonate such as diisopropyl peroxycarbonate; and a redox initiator are used.

The concentration of the polymerization initiator is preferably in the range of 0.01 to 15% by weight, particularly 0.1 to 10% by weight of the total monomers.

Instead of using a polymerization initiator, an electron beam, ultraviolet light, or the like may be used, or ionic polymerization or group transfer polymerization may be used.

The copolymerization reaction is usually performed at a temperature of 50 to 180 ° C. However, when isopropenyl-α, α′-dimethylbenzyl isocyanate is used, a peroxide-based or carbonate-based initiator is used to increase the polymerization rate, and the reaction temperature is as high as 100 ° C. or more. It is preferably performed under More preferably, when an acrylate-based monomer is used, an NCO polymer having a high conversion can be easily obtained.

The molecular weight of the NCO polymer is 500 to 50,000 in number average molecular weight,
Preferably, it is in the range of 1,000 to 30,000, and if it is less than 500, the mechanical strength and weather resistance of the cured coating film obtained using these deteriorate, and if it is more than 50,000, the viscosity of the copolymer solution becomes extremely high. In addition, conversion to aqueous becomes difficult.

This NCO polymer has a glycidyl group and an isocyanate group, but does not contain any active hydrogen that easily reacts with the isocyanate group.

The self-curable resin of the present invention has a blocked isocyanate group and a secondary or tertiary amino group or a quaternary ammonium salt group and a hydroxyl group in one molecule, and the resin has an isocyanate group contained in the NCO polymer. Block some of the
Then, an alkanolamine is reacted with the glycidyl group and the remaining isocyanate group (self-curable resin (A)), or all the isocyanate groups are blocked, and then the glycidyl group is reacted with the alkanolamine (self-curable resin (B)). Or by reacting a primary to tertiary amine [self-curable resin (C)].

The self-curable resin (A) is obtained by blocking a part of the isocyanate group in the NCO polymer skeleton and then reacting the glycidyl group and the remaining unblocked isocyanate group with an alkanolamine.

The glycidyl group, the free unblocked isocyanate group, and the blocked isocyanate group coexist in the NCO polymer after reacting the blocking agent with a part of the free isocyanate group contained in the NCO polymer.

As the blocking agent, for example, phenol, cresol, xylenol, p-ethylphenol, o-isopropylphenol, p-tert-butylphenol, p-
Phenols such as tert-octylphenol, thymol, p-naphthol, p-nitrophenol, p-chlorophenol; methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, butyl cellosolve, methyl carbitol, benzyl alcohol, phenyl cellosolve, Alcohols such as furfuryl alcohol and cyclohexanol; active methylenes such as dimethyl malonate, diethyl malonate and ethyl acetoacetate; mercaptans such as butyl mercaptan, thiophenol, tert-dodecyl mercaptan; acetanilide, acetanisidide, acetate amide;
Acid amides such as benzamide; imides such as succinimide and maleic imide; amines such as diphenylamine, phenylnaphthylamine, aniline and carbazole; imidazoles such as imidazole and 2-ethylimidazole; urea, thiourea and ethylene urea Urea such as N-phenylcarbamate, carbamates such as 2-oxazolidone; imines such as ethyleneimine; oximes such as formaldoxime, acetoaldoxime, methylethylketoxime, cyclohexanone oxime; sodium bisulfite And sulfites such as potassium bisulfite; lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, and β-propiolactam; and particularly preferred is phenol. System, lactam system, alcohol system,
Oxime type.

The reaction between the NCO polymer and the blocking agent is carried out by mixing the blocking agent in an organic solution of the NCO polymer and usually at a temperature of 20 to 150 ° C. If necessary, a tin-based catalyst may be used.

The amount of the blocking agent to be added is calculated in advance according to the amount of hydroxyl groups to be introduced into the NCO polymer in the next step, and the number of moles of the isocyanate group to be blocked is determined in advance to determine the amount of the blocking agent to be added. Specifically, it is preferable to determine the blending amount so that 5-95 mol%, preferably 20-80 mol% of the free isocyanate groups contained in the NCO polymer is blocked.

Next, the remaining unblocked isocyanate groups and glycidyl groups contained in the partially blocked NCO polymer as described above are reacted with alkanolamine to further add hydroxyl groups and secondary or tertiary amino groups to the blocked isocyanate group-containing NCO polymer. Alternatively, the self-curable resin (A) of the present invention can be obtained by introducing a quaternary ammonium base.

As the alkanolamine, a primary or secondary amine can be used. For example, 2- (methylamino) ethanol, 2- (n-butylamino) ethanol,
Mono- or di-alkanolamines such as (dodecylamino) ethanol, mono (or di) ethanolamine, diisopropanolamine, and 4-piperidineethanol are preferred. Among them, particularly preferred is 2- (methylamino) ethanol. And diethanolamine.

Since the reaction between the isocyanate group or glycidyl group and the amino group of the alkanolamine is very fast, it is usually completed in a short time at about room temperature. In this step, both functional groups (blocked isocyanate group and hydroxyl group) are introduced into the NCO polymer. Therefore, if the reaction with the alkanolamine proceeds at an unnecessarily high temperature, the blocking agent partially dissociates and a reaction between the two functional groups may occur, resulting in thickening or gelling. It is preferred to do so.

The alkanolamine is preferably used in an amount necessary to react with all of the unblocked isocyanate groups and glycidyl groups remaining in the NCO polymer after blocking in principle. Also, among the alkanolamines, the use of dialkanolamines allows the introduction of twice as many hydroxyl groups as monoalkanolamines, resulting in high efficiency.

In the self-curable resin (A), the degree of crosslinking as a self-crosslinkable coating film is the highest if the amounts of the blocked isocyanate groups and the hydroxyl groups are made equal, but when used for paints and adhesives, It is preferable that one of the functional groups becomes excessive in consideration of the adhesion to the polymer, specifically, the hydroxyl value (mgKOH / g) is 20 to 250, and the isocyanate value (g / 1000g) is 15 ~ 250, amine value (mgKOH / g) 25 ~ 1
00 is suitable.

The self-curing resin (B) blocks all of the isocyanate groups in the NCO polymer skeleton and then reacts the glycidyl group with an alkanolamine to form a secondary or tertiary amino group or quaternary ammonium base with a hydroxyl group. Obtained by introduction.

The blocking of the isocyanate group can be carried out in the same manner as described above, except that the blocking agent is used so that all of the isocyanate groups can be blocked.

In addition, NC that blocks all isocyanate groups
The alkanolamine which reacts with the glycidyl group in the O polymer and the reaction conditions can be performed in the same manner as described above.

In the self-curable resin (B), the degree of cross-linking as a self-cross-linkable coating film is the highest when the amounts of the blocked isocyanate groups and the hydroxyl groups are made equal, but when used in paints and adhesives, It is preferable that one of the functional groups becomes excessive in consideration of the adhesion to the polymer, specifically, the hydroxyl value (mgKOH / g) is 20 to 250, and the isocyanate value (g / 1000g) is 15 ~ 250, amine value (mgKOH / g) 25 ~ 1
00 is suitable.

The self-curable resin (C) blocks all of the isocyanate groups in the NCO polymer skeleton and then reacts the glycidyl group with a primary to tertiary amine to form a secondary or tertiary amino group or quaternary amino group.
It is obtained by introducing a quaternary ammonium base, a blocked isocyanate group and a hydroxyl group.

The method of blocking all isocyanate groups in the NCO polymer can be performed in the same manner as in the resin (B).

As the primary to tertiary amines capable of reacting with the glycidyl group, those exemplified below are preferable.

Primary or secondary amines include ammonia; lower alkylamines such as methylamine, ethylamine, isopropylamine, n-butylamine, dimethylamine, diethylamine, diisopropylamine, di-
alicyclic amines such as cyclohexylamine; heterocyclic amines such as morpholine and pyridine; and tertiary amines such as trialkylamines such as trimethylamine, triethylamine, triisopropylamine and triisopropylamine. -N-propylamine, tri-n-butylamine; N-alkylmorpholine,
For example, N-methylmorpholine, N-ethylmorpholine; N
Dialkylalkanolamines, such as N, N-dimethylethanolamine, N-diethylethanolamine;
And mixtures of two or more of these. Of these, secondary or tertiary amines are preferably used.

The amine is preferably reacted with all of the glycidyl groups, but any unreacted glycidyl groups may remain. When the amine reacts with the glycidyl group, the ring is opened to form a hydroxyl group and a secondary or tertiary amino group or a quaternary ammonium base.

In the self-curable resin (C), the degree of cross-linking as a self-cross-linkable coating film is the highest when the amounts of the blocked isocyanate groups and the hydroxyl groups are made equal, but when used in paints and adhesives, It is preferable that one of the functional groups becomes excessive in consideration of the adhesion to the polymer, specifically, the hydroxyl value (mgKOH / g) is 20 to 250, and the isocyanate value (g / 1000g) is 15 ~ 250, amine value (mgKOH / g) 25 ~ 1
00 is suitable.

The self-curing resin of the present invention has one or more blocked isocyanate groups, hydroxyl groups, and one or more secondary or tertiary amino groups and / or quaternary ammonium bases in one molecule. The dissociation regenerates the isocyanate group, which reacts with the above-mentioned hydroxyl group and undergoes three-dimensional self-crosslinking and curing. The heating temperature is not particularly limited as long as the blocking agent dissociates, specifically 80 ° C.
The above is preferred. Thus, the resin is stable at room temperature and does not self-cure.

Further, the self-curable resin of the present invention can be used by dissolving or dispersing in an organic solvent. Further, since the molecule has a secondary or tertiary amino group and / or a quaternary ammonium base in the molecule, the secondary or tertiary amino group is dissolved in water when neutralized with an acid component such as acetic acid, formic acid and lactic acid. It becomes dispersible and can be used as an aqueous solution (an organic solvent may coexist). A quaternary ammonium base can be formed by reacting a tertiary amine with a glycidyl group and then neutralizing with the acid component, which can be dissolved or dispersed in water.

 The self-curing resin is used for paints, adhesives and the like.

For use in paints, if necessary, pigments, fillers,
It can be used as a one-pack type paint by adding a surface conditioner, a deterioration inhibitor and the like. Further, a polyol (for example, an acrylic resin, a polyester resin, or a fluororesin), a reactive diluent, and a crosslinking agent (for example, melamine plast, block isocyanate, epoxy, polybasic acid, or alkoxysilane) can be combined. . Also, various curing catalysts can be used.

The paints, adhesives and the like made of these are cured at a temperature of 50 to 200 ° C., preferably 80 to 150 ° C. to give a three-dimensional crosslinked body.

The NCO polymer of the present invention does not gel at all because a polymerizable monomer having an active hydrogen or a solvent is not used in the NCO monomer polymerization reaction system. Also,
In the present invention, since a blocking agent is reacted with the NCO polymer,
The blocking agent may be heated to a temperature necessary to react with the isocyanate group.For example, a blocking agent that is easily colored at a high temperature such as a phenolic or oxime type blocks the isocyanate group at about 100 ° C. or less without heating to a high temperature. Can be made, has no coloring, and has a low temperature (about 100 ° C
This is advantageous for low-temperature curing because it dissociates in the following. Further, even with a blocking agent having a high dissociation temperature, the reaction between the blocking agent and the NCO polymer is easily performed and does not cause gelation at all. In addition, since it has a secondary or tertiary amino group or a quaternary ammonium base, it can be easily made water-soluble and can be used as a cationic electrodeposition paint.

Examples Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[Parts] and [%] in Examples and Comparative Examples are based on weight in principle.

Example 1 A reactor equipped with a stirrer, a reflux condenser and a thermometer was charged with 30 parts of methyl cellosolve acetate, heated and maintained at 130 ° C., and 50 parts of m-isopropenyl-α, α′-dimethylbenzyl isocyanate was added. n-butyl methacrylate 30
, A mixture of 8 parts of 2-ethylhexyl methacrylate, 12 parts of glycidyl methacrylate, and 3.5 parts of t-butylperoxyisopropyl carbonate (manufactured by Gunze Akzo) was added dropwise over 3 hours.

Then, a mixed solution consisting of 5 parts of methyl ethyl ketone and 1.0 part of t-butylperoxyisopropyl carbonate was added dropwise over 1 hour, and after aging for 1 hour,
After cooling to 30 ° C., a solution of an NCO polymer having a number average molecular weight of 6,500 was obtained.

While stirring the polymer solution at 80 ° C, 21.6 parts of methyl ethyl ketone oxime was added dropwise over 15 minutes and the mixture was aged for 2 hours. Then, 8.9 parts of diethanolamine was added dropwise over 15 minutes and aged at 80 ° C for 30 minutes. The reaction was completed [self-curable resin (B)].

Neutralize by adding 5.0 parts of acetic acid, then add 65 parts of ion-exchanged water.
The parts were added with stirring.

The obtained resin liquid was a slightly yellowish fine particle dispersion liquid. The Gardner viscosity was P, and no thickening was observed even after storage at 30 ° C. for one month.

The resin had a hydroxyl value of 94.8 mg KOH / 1 g resin, an isocyanate value of 104.4 / 1000 g resin, and an amine value of 47.4 mg KOH / 1 g resin.

Example 2 Under the same conditions as in Example 1, 21.6 parts of methyl ethyl ketone oxime was added dropwise to the NCO polymer solution of Example 1 over 15 minutes, and the mixture was aged for 2 hours. Then, 3.7 parts of N, N-dimethylethanolamine was added dropwise over 15 minutes, and the mixture was aged at 50 ° C. for 2 hours to complete the reaction. Neutralize by adding 2.53 parts of acetic acid,
Then, 65 parts of ion-exchanged water was added with stirring [self-curable resin (C)].

The resulting liquid was a slightly bluish, almost transparent dispersion.

Hydroxyl value 23.7mgKOH / 1g resin, isocyanate value 104.
4 g / 1000 g resin, amine value 23.3 mg KOH / 1 g resin.

Example 3 While stirring the solution of the NCO polymer obtained in Example 1 at 80 ° C, 16.23 parts of methyl ethyl ketone oxime was added dropwise over 15 minutes, aged for 2 hours, and 15.43 parts of diethanolamine was added for 15 minutes. It was added dropwise as needed, and aged at 80 ° C. for 30 minutes to complete the reaction.

Neutralize by adding 8.82 parts of acetic acid.
The portion was added while stirring [self-curable resin (A)].

The obtained resin liquid was a slightly yellowish fine particle dispersion liquid. The Gardner viscosity was P, and no thickening was observed even after storage at 30 ° C. for one month.

The resin had a hydroxyl value of 164.9 mg KOH / 1 g resin, an isocyanate value of 78.3 g / 1000 g resin, and an amine value of 47.4 mg KOH / 1 g resin.

Comparative Example 1 65 parts of methyl ethyl ketone was placed in a reactor equipped with a stirrer, a reflux condenser and a thermometer, and heated and maintained at 80 ° C.
-Isocyanate ethyl methacrylate 20 parts, styrene
A mixture of 15 parts, 22 parts of n-butyl methacrylate, 15 parts of 2-hydroxyethyl acrylate, 20 parts of 2-ethylhexyl acrylate, 8 parts of dimethylaminoethyl methacrylate and 2.5 parts of azobis α, γ-dimethylvaleronitrile was dropped over 3 hours. Then, polymerization was attempted, but gelation occurred 30 minutes after the dropping was started.

Comparative Example 2 In Example 1, 2- (methylamino) ethanol was added before methyl ethyl ketone oxime was added to the NCO polymer solution, and the mixture gelled one hour later.

Performance test results The storage stability of the system in which dibutyltin dilaurate was added as a curing catalyst to each of the resin liquids of Examples 1 to 3 with and without the addition of 0.2 part per 100 parts of the resin solid content, and these liquids were dried on a tin plate. The gel was applied so that the thickness became about 60 μm, and baked at 120 ° C. and 140 ° C. for 30 minutes, and the gel fraction was measured.

 The results are shown in Table 1.

In Table 1, the storage stability was determined to be good if the increase in viscosity after storage at 30 ° C. for one month was 2 or less with a Gardner viscometer (20 ° C.) as compared to before storage. In addition, the gel fraction was measured by extracting with acetone at a reflux temperature for 7 hours.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08G 18/83 C08G 18/80

Claims (4)

(57) [Claims] Claims: 1. Blocking a part of the isocyanate group in a polymer skeleton having a glycidyl group and two or more isocyanate groups in one molecule and having a number average molecular weight of 500 to 50,000,
Then, a glycanol group and the remaining unblocked isocyanate group are reacted with an alkanolamine to introduce a blocked isocyanate group and a secondary or tertiary amino group or a quaternary ammonium base and a hydroxyl group into one molecule. Method of manufacturing resin. 2. Blocking all the isocyanate groups in a polymer skeleton having a glycidyl group and two or more isocyanate groups in one molecule and having a number average molecular weight of 500 to 50,000,
Then, a glycanol group is reacted with an alkanolamine to introduce a blocked isocyanate group and a secondary or tertiary amino group or a quaternary ammonium base and a hydroxyl group into one molecule, and a method for producing a self-curable resin. 3. Blocking all of the isocyanate groups in a polymer skeleton having a glycidyl group and two or more isocyanate groups in one molecule and having a number average molecular weight of 500 to 50,000,
Then, a method for producing a self-curable resin, comprising reacting a glycidyl group with a primary to tertiary amine to introduce a blocked isocyanate group and a secondary or tertiary amino group or a quaternary ammonium base and a hydroxyl group in one molecule. . 4. A method for producing an aqueous self-curable resin, wherein an amino group in the self-curable resin obtained by the method according to claim 1 is neutralized with an acid component.