JPS6244766B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel epoxy resin derivative, and more particularly, it contains a specific ketiminated or aldiminated primary amino group and hydroxyl group at the terminal end, which is suitable as a coating film forming component in a resin composition for cationic electrodeposition coating. This invention relates to epoxy resin derivatives. Epoxy resins have various excellent properties such as less volume shrinkage upon curing, strong adhesion to various materials, excellent mechanical properties, high chemical resistance, and good electrical insulation properties. It is widely used in the fields of adhesives, paints, cast products, etc. For example, bisphenol A/epichlorohydrin type epoxy resins are widely used as base resins for cationic electrodeposition paints due to their excellent coating properties such as corrosion resistance and adhesion. Specific examples thereof include, for example, a resin composition (Japanese Unexamined Patent Application Publication No. 51-113) consisting of a reaction product of an epoxy resin and a primary or secondary amine, and a blocked polyisocyanate.
-103135); Epoxy resin, primary and/or
Alternatively, a self-curing resin composition comprising a reaction product of a secondary amine and a partially blocked polyisocyanate (Japanese Patent Publication No. 52-6306) may be mentioned. However, the electrodeposition coating films obtained using these resin compositions have poor surface smoothness, flexibility, bath stability,
It is practically insufficient in terms of throwing power, etc. In addition, as a resin composition similar to the resin composition described in the above-mentioned Japanese Patent Publication No. 52-6306,
The publication discloses an acid-neutralized amino group-containing resin obtained by reacting an epoxy group-containing resin with a polyamine derivative having at least one primary amino group and a secondary amino group blocked by ketimination. An aqueous resin composition for electrodeposition obtained by further adding a partially blocked polyisocyanate to a resin is disclosed. According to this aqueous resin composition, in principle, the resin can be dispersed in water with a low degree of neutralization, and the PH and throwing power of the electrodeposition bath can be improved to some extent. It has been shown that as a result of the increased activity against, considerable improvements can be made in terms of improving the curability of the coating film. but,
It is very difficult to quantitatively react the epoxy group-containing resin with the secondary amino groups in the ketiminated polyamine derivative, and in reality, unreacted polyamine derivatives are present in the aqueous resin composition. Inconveniences occur, such as significant thickening due to remaining or forced completion of the reaction, and it is almost impossible to fully exhibit the above-mentioned improvements. In order to improve the defects of the compositions described in the above-mentioned publications, the present applicant previously proposed in Japanese Patent Publication No. 53-8568 that an amine-added epoxy resin was mixed with or reacted with an amino group-containing polyamide resin, and further We have proposed a resin composition for cationic electrodeposition coatings to which blocked polyisocyanate has been added, and have also proposed a composition for electrodeposition coatings having similar constituents to the composition described in the above-mentioned Japanese Patent Publication No. 53-8568. Akira
52-77144 and JP-A-52-101238, at least two of a reaction product of an epoxy resin and a basic amino compound, a basic amino group-containing polyamide resin, and a partially blocked isocyanate are disclosed.
discloses a resin composition for cationic electrodeposition paint containing as a main component a mixture of the reaction product of the inventor and the remaining components;
A polyether having specific properties is blended into the amine-added epoxy resin - fatty acid or amino group-containing polyamide resin - partially blocked polyisocyanate resin composition system, thereby making the painted surface smooth without impairing the corrosion resistance of the paint film. We proposed a technology that significantly improves sexual performance. However, in recent years, the demands on the performance of resin compositions for electrodeposition coatings in the market have become increasingly strict, and the present inventors have developed the performance of resin compositions for cationic electrodeposition coatings, that is, corrosion resistance, As a result of extensive research to further improve bath stability, low-temperature curing properties, etc., and to provide products that fully satisfy current market demands, we have found that the primary amino acids in the base resin We found that the above performance improved significantly as the ratio of primary amino groups to total amino groups in the base resin increased. An epoxy resin into which a protected (that is, ketiminated or aldiminated) primary amino group was introduced was synthesized, a resin composition for cationic electrodeposition coating was prepared using this as a base resin, and cationic electrodeposition coating was performed. However, not only various properties such as bath stability, throwing power, and low-temperature curing properties, but also physical properties such as adhesion, corrosion resistance, flexibility, and impact resistance of the formed coating films have been significantly improved. It was found that it satisfactorily withstands market demands. Therefore, according to the present invention, the general formula In the formula, R ₁ and R ₂ each independently represent a hydrogen atom or a hydrocarbon group with or without a monovalent ether group having 1 to 9 carbon atoms, or R ₁ and
R ₂ together represent an alkylene group having 4 to 9 carbon atoms; R ₃ represents a hydrocarbon group having or not having a (m+n+1)-valent ether group having 1 to 18 carbon atoms; R ₄ represents a lower alkylene group, ether group, carbonyl group or sulfonyl group; Y is

[Formula] or

There is provided an epoxy resin derivative represented by the formula: where m is an integer of 1 to 3; n is 0 or an integer of 1 to 3; and p is a number of 0 to 15. In addition, in this specification, the term "epoxy resin" refers to a resin at the end of a molecular chain that is a viscous liquid or solid at room temperature.

[Formula] means an epoxy compound having an epoxy group. Furthermore, the term "lower" means that the compound or group to which this term is attached has 6 or less carbon atoms, preferably 4 or less carbon atoms. In the above formula (), the "monovalent hydrocarbon group" represented by R ₁ and/or R ₂ is a ketone or aldehyde that is commonly used as a protecting group for a primary amino group by ketimination or aldimination. Preferred are ketone or aldehyde hydrocarbon residues from which the protecting group is removed by a simple operation such as hydrolysis with an acid to give a free primary amino group. Such hydrocarbon residues may be of any type, linear or cyclic or combinations thereof, and have 1 to 9, preferably 1 to 6 carbon atoms, for example methyl , ethyl, n-propyl, isopropyl, n
- Straight chain or branched lower alkyl groups such as butyl, isobutyl, sec-butyl, tert-butyl; Cycloalkyl groups having 5 to 9 carbon atoms such as cyclopentyl and cyclohexyl; phenyl, tolyl, xylyl, etc. Examples include aryl groups; aralkyl groups such as benzyl and phenethyl; and hydrocarbon groups having ether groups such as furyl and tetrahydrofuryl groups. Among these, a linear or branched lower alkyl group in which R ₁ is methyl or ethyl, and R ₂ is ethyl, propyl, isopropyl, butyl, or isobutyl is preferred. Further, the alkylene group formed by R ₁ and R ₂ together corresponds to the remaining part of the cyclic ketone excluding the carbonyl group, and has 4 to 9 carbon atoms, preferably 4 to 5 carbon atoms, Specifically, 1,4-butylene,
1,5-pentylene, etc. are included. Therefore, the ketimine or aldimine moiety in the above formula ()

Specific examples of [Formula] include the following:

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

[Formula] Also, “(m+n+1)” represented by R ₃
"valent hydrocarbon group" includes or does not contain an ether bond after removing the primary amino group and hydroxyl group from a hydroxyamino compound containing m primary amino groups and (n+1) hydroxyl groups. Corresponds to a hydrocarbon residue, which may be of any type, chain or cyclic or a combination thereof, containing from 1 to 18 carbon atoms, preferably from 2 to 9 carbon atoms. have Such hydrocarbon groups include:
For example, −CH ₂ −CH ₂ −,

[Formula] −CH ₂ −CH ₂ −CH ₂ −,

【formula】

[Formula] −CH ₂ −CH ₂ −CH ₂ −CH ₂ −

【formula】

Carbon such as [formula] Saturated aliphatic hydrocarbon group having 2 to 9 atoms; alicyclic

【formula】

【formula】

【formula】

[Formula] Alicyclic hydrocarbon group with or without an ether group having 5 to 9 carbon atoms; aromatic

【formula】

Aromatics such as [formula] Hydrocarbon group; aromatic aliphatic

【formula】

【formula】

Aroaliphatic hydrocarbon groups such as [Formula];

【formula】

【formula】

【formula】

[Formula] An alicyclic hydrocarbon group having 5 to 9 carbon atoms which may contain an ether bond;

【formula】

Aromatic hydrocarbon groups such as [Formula];

【formula】

【formula】

Examples include aromatic aliphatic hydrocarbon groups such as [Formula]. On the other hand, the number m of primary amino groups in the above hydroxy-primary amine compound ( _H2N ) _-nR3- (OH) _o+1 is 1 to ₃ , preferably 1 to 2, and the number m of primary amino groups is 1 to 3, preferably 1 to 2. n in the number n+1 is 0 or an integer of 1 to 3, preferably 0 or 1. Therefore, the formula of the terminal of the epoxy resin of the above formula ()

The following can be cited as partial specific examples of [Formula]: Such. Furthermore, the "lower alkylene group" represented by R ₄ in formula () may be either linear or branched, such as -CH ₂ -,
CH ₂ CH ₂ −

【formula】 【formula】

[Formula] - CH ₂ CH ₂ CH ₂ CH ₂ - etc. are included. On the other hand, p representing the number of repeating units or degree of polymerization of the epoxy resin moiety of the epoxy resin derivative of formula () is a number of 0 to 15, preferably 0 to 9, more preferably 1 to 4, and the epoxy resin derivative When is obtained in the form of a so-called resin having a high molecular weight, p may represent the average degree of polymerization, in which case it will be particularly expressed in the following description. Representative examples of the epoxy resin derivative of the formula () provided by the present invention include the following, excluding those described in Examples below. (In the above formula, p has the above-mentioned meaning) According to the present invention, the epoxy resin derivative of the above formula () has the general formula In the formula, R ₄ and p have the above meanings, and the epoxy resin represented by the general formula In the formula, R ₁ , R ₂ , R ₃ , m and n have the above-mentioned meanings. It can be produced by reacting with a compound represented by the following. The reaction between the epoxy resin of the above formula () and the compound of the formula () can be carried out in the absence of a solvent or in a suitable solvent, such as a ketone solvent such as methyl ethyl ketone or methyl isobutyl ketone, or an aromatic hydrocarbon such as toluene or xylene. It can be carried out in a solvent. The reaction temperature can vary widely depending on the epoxy resin used and/or the type of compound of formula (), but it is generally about 100 ml under normal pressure.
80°C to the reflux temperature of the reaction mixture, preferably 120°C
It is advantageous to choose a temperature within the range ~180°C. The amount of the compound of formula () to be used for the epoxy resin of formula () is the amount of the compound of formula () to be introduced, that is, the amount of Y in the epoxy resin derivative of formula ()

[Formula] or

Depending on whether [formula] is the epoxy group 1 in the epoxy resin of formula ()
In the former case, the compound of formula () is generally 1/
4 to 1/n+1 mol, preferably 1/2 to 3/4 mol;
In the latter case, it can generally be used in a proportion of 1/n+1 to 1 mol, preferably 3/4 to 1 mol.
Here n has the same meaning as in the compound of formula (). In addition, when reacting the epoxy resin of formula () with the compound of formula (), if necessary, as a reaction accelerator, for example, tertiary amine such as tri-n-butylamine, benzyldimethylamine; tetrabutylammonium bromide. Quaternary ammonium salts such as; Lewis acids such as etherified boron trifluoride may be used in an amount of up to 1%, preferably up to 0.5% based on the reaction mixture. Through the reaction described above, ring-opening addition occurs between at least one of the epoxy groups in the epoxy resin of formula () and one of the hydroxyl groups in the compound of formula (), and the desired epoxy resin derivative of formula () is produced. can get. The produced epoxy resin derivative can be separated from the reaction mixture by methods known per se, such as distillation and extraction. As the epoxy resin of the formula () used as a starting material in the above reaction, commercially known ones can be used, and those having an epoxy equivalent generally in the range of 150 to 4000, preferably 200 to 2000 are used. Used to advantage. For example, epoxy resin Epikote 828 (bisphenol A type, average molecular weight about 380, epoxy equivalent weight about 190), Epikote 1001 (bisphenol A type, average molecular weight about 900, epoxy equivalent weight about 475), manufactured by Ciel Chemical Co., Ltd. 1002 (bisphenol A type, average molecular weight approximately 1300, epoxy equivalent approximately 650), Epikote 1004 (bisphenol A type, average molecular weight approximately 1400, epoxy equivalent approximately 950), Epikote 1007 (bisphenol A type, average molecular weight approximately 2900, Epoxy resin: Epiclon 830 (bisphenol F type, average molecular weight: about 360, epoxy equivalent: about 180), manufactured by Dainippon Ink Chemical Co., Ltd., can be used. things can be used. (In the above formula, p has the above-mentioned meaning) On the other hand, the compound of formula () has the following general formula (H ₂ N-) _n R ₃ -(OH) _o+1 () where R ₃ , m and n have the meanings given above;
The hydroxy-primary amine compound represented by the following general formula In the formula, R ₁ and R ₂ have the above-mentioned meanings, and a carbonyl compound (ketone or aldehyde) represented by the above and a method known per se [for example, J.Org.
Chem., 19 , 1054-76 (1954)]. The reaction between the compound of formula () and the compound of formula () can usually be carried out in a suitable solvent, for example, a non-aqueous solvent such as toluene, xylene, n-hexane, n-heptane. The reaction temperature can be varied widely depending on the type of starting compound, etc., but generally a temperature in the range of 40°C to the reflux temperature of the reaction mixture, preferably 80 to 200°C, can be used, especially reflux temperature. It is preferable to carry out this by accelerating the dehydration reaction. The amount of the compound of formula () to be used relative to the compound of formula () is not strict, but in general, the compound of formula () is used in a range of mmole or more, preferably from m to 1.5 mmole, per mole of the compound of formula (). Advantageously, an amount of m is the number of primary amino groups in the compound of formula (). Examples of the compound of formula () used as a starting material in the above reaction include 1-aminoethanol, 2-aminoethanol, 1-amino-
2-propanol, 2-amino-1-propanol, 3-amino-1-propanol, 2-amino-1-butanol, 2-amino-2-methyl-1
-propanol, 5-amino-1-pentanol, 4-methyl-4-amino-1-pentanol, 3-amino-2-ethyl-1,3-propanediol, o(m·p)-aminophenol, o
(m.p)-aminobenzyl alcohol, 2-amino-p-cresol, 4-amino-m-cresol, 6-amino-m-cresol, 5-amino-
1-naphthol, 8-amino-2-naphthol,
Examples include o(p)-aminophenethyl alcohol, 2-aminomethyl-5-hydroxymethyltetrahydrofuran, and the like. In addition, examples of the compound of formula () include acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone,
Examples include cyclohexanone, acetaldehyde, propionaldehyde, benzaldehyde, and furfural. The compound of formula () thus produced can be separated from the reaction mixture by a method known per se, for example, fractional distillation, or can be directly subjected to the reaction with the epoxy resin of formula (). The epoxy resin derivative of the formula () provided by the present invention has a primary amino group protected by ketimination or aldimination,
It can be used as a film-forming base resin for cationic electrodeposition coating. For example, the epoxy resin derivative of formula () has at least two isocyanate groups in one molecule as a curing agent, at least one of which is blocked and more than one free isocyanate group. By combining it with a partially or completely blocked polyisocyanate compound, a resin composition for cationic electrodeposition coating can be obtained. Further, as another use of the epoxy resin derivative of the present invention, it is useful as a moisture-curable adhesive or paint by mixing it with a polyisocyanate or an epoxy resin. Partially or completely blocked polyisocyanate compounds that can be used in the preparation of such cationic electrodeposition coating resin compositions include those that are stable at room temperature but reactive with amino groups or hydroxyl groups of resinous products at high temperatures. Any polyisocyanate may be used. The completely or partially blocked polyisocyanate compound described above can be produced by blocking polyisocyanate with a blocking agent by a method known per se. Suitable polyisocyanates that can be used in this case include, for example, trimethylene. Aliphatic diisocyanates such as diisocyanate, tetramethylene diisocyanate and hexamethylene diisocyanate; cycloalkylene diisocyanates such as 1,4-cyclohexane diisocyanate; aromatic diisocyanates such as m-phenylene diisocyanate and 1,4-naphthalene diisocyanate; 4. 4'-diphenylmethane diisocyanate, 2,4-(or 2,6
-) Aliphatic-aromatic diisocyanates such as tolylene diisocyanate and 1,4-xylylene diisocyanate: adducts of the above diisocyanates with polyols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, and pentaerythritol: etc. Known organic polyisocyanates can be mentioned. On the other hand, volatile low-molecular active hydrogen compounds are used as blocking agents for polyisocyanates, examples of which include methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, benzyl alcohol, ethylene glycol monoethyl ether, and ethylene glycol. Mention may be made of aliphatic or aromatic monoalcohols such as monobutyl ether, hydroxy tertiary amines such as dimethyl or diethylaminoethanol, oximes such as acetoxime, methyl ethyl ketone oxime, phenols, cresols, and the like. When preparing a resin composition for cationic electrodeposition coating from the epoxy resin derivative of the present invention and the above-mentioned partially or completely blocked polyisocyanate compound, the two may be mixed as is and used as a clear electrodeposition coating composition. , generally pigments;
It can be used as an electrodeposition coating composition by adding other commonly used additives. Pigments that can be added include those commonly used in electrodeposition paints, such as colored pigments such as red iron, titanium white, and carbon black; extender pigments such as talc, clay, and mica; and chromic acid. Rust-inhibiting pigments such as lead, strontium chromate, and basic lead silicate are used, and these can be used in any amount. In addition, lead,
Salts of metals such as tin, bismuth, iron, manganese, etc. and organic or inorganic acids (e.g. acetic acid, naphthenic acid, hydrochloric acid, nitric acid, etc.); oxides of the metals; hydroxides of the metals added as hardening accelerators You can also.
In addition, although the present composition does not normally require the addition of a surfactant, if desired, a small amount of a known surfactant (for example, a nonionic active agent) commonly used in cationic electrodeposition paints may be added. Furthermore, a coating film flow agent (for example, an acrylic acid alkyl ester copolymer, a polyalkyl siloxane) may be added as necessary. The resin composition for electrodeposition coating prepared as described above can be prepared using acids such as formic acid, acetic acid, hydroxyacetic acid,
Water-soluble lower aliphatic monocarboxylic acids such as propionic acid, butyric acid, and lactic acid; aliphatic dicarboxylic acids such as oxalic acid, succinic acid, fumaric acid, and maleic acid; aromatic carboxylic acids such as benzoic acid and phthalic acid; benzenesulfonic acid, Organic sulfonic acids such as p-toluenesulfonic acid; neutralization with inorganic acids such as phosphoric acid, sulfuric acid, and hydrochloric acid, especially the water-soluble aliphatic monocarboxylic acids mentioned above, to form a stable aqueous bath for electrodeposition coating. can do. Through this neutralization treatment, the primary amino groups blocked by carbonyl compounds in the epoxy resin derivatives present in the resinous product are hydrolyzed to produce strongly basic primary amino groups, which The amino groups are then neutralized. Therefore, the amount of the acid required for neutralization is at least the amount necessary to solubilize or stably finely disperse the present composition, that is, the resinous product as a coating film-forming component, in the aqueous medium. In addition, the amount is preferably less than or equal to the amount necessary to completely neutralize the amino groups present in the resinous product, and specifically, the amount is about 0.1 to 100% based on the amine value of the resinous product. A range of 0.6 equivalent % is preferred. Regarding the pH of the resulting aqueous bath, it is advantageous to neutralize the aqueous bath so that the pH of the aqueous bath is generally within the range of about 3 to about 8, preferably about 5 to about 7. When the above composition is neutralized with an acid and dissolved or dispersed in an aqueous medium, the concentration of total resin solids in the aqueous bath is generally 3 to 30% by weight, preferably 5% by weight.
~20% by weight. The aqueous bath for electrodeposition coating prepared in this way can be used as an electrodeposition coating bath capable of electrodeposition on a cathode of which the object to be coated is used as a cathode. As the method and apparatus for applying electrodeposition coating to the object to be coated using this aqueous bath, known methods and apparatuses conventionally used in cathodic electrodeposition coating can be used. In this case, it is desirable to use the object to be coated as a cathode and to use a carbon plate as an anode. The electrodeposition coating conditions that can be used are not particularly limited, but generally the bath temperature:
20~30℃, voltage: 100~400V (preferably 200~
300V), current density: 0.01 to 3A/ ^dm2 , energizing time:
1 to 5 minutes, polar area ratio (A/C): 2/1 to 1/
2. Distance between electrodes: 10-100cm, preferably electrodeposited under stirring. After cleaning, the coating film deposited on the cathode is maintained at a temperature of about 140 to about 250°C, preferably about 170 to about 200°C.
It can be baked and hardened. During this baking process, the isocyanate groups of the blocked polyisocyanate present in the resin of the coating film release alcohol, which is a blocking agent, and undergo a crosslinking reaction with the amino groups, amide groups, hydroxyl groups, etc. present in the resin, resulting in hardening. The above-mentioned electrodeposition coating resin composition prepared from the epoxy resin derivative of the present invention can be used for coating various metal products, such as ordinary zinc phosphate treated steel sheets, as well as other coatings. It is particularly suitable for electrodeposition coating of easily corroded steel plates such as iron phosphate treated steel plates and untreated steel plates, and provides a coating film with excellent throwing power and outstanding corrosion resistance to these steel plates. Can be done. This is a significant advantage not achieved with conventional electrodeposition coating compositions. Furthermore, the composition is suitable for electrocoating substrates such as galvanized steel, tin-plated steel, aluminum, copper and copper alloys,
A coating film with excellent throwing power, corrosion resistance, etc. can be formed. Furthermore, the epoxy resin derivative of the present invention can be mixed with a polyisocyanate or an epoxy resin to form a moisture-curable adhesive or paint. The present invention will be described in more detail below with reference to Examples, but it should be understood that the scope of the present invention is not limited thereby. In the examples, "parts" and "%" represent "parts by weight" and "% by weight." Example 1 61 parts (1 mole) of monoethanolamine, 100 parts (1 mole) of methyl isobutyl ketone, and 14.3 parts of toluene were added to a reactor, and the mixture was heated to reflux with stirring to carry out the reaction while removing distilled water. I did it.
The PH of the reactant is measured using PH test paper, and when it becomes almost neutral (PH about 8), the reaction is stopped and the ketimine compound containing a hydroxyl group is extracted.

I got [formula]. Hereinafter, this compound will be abbreviated as "ketimine compound A." On the other hand, put the following structure in another reaction vessel. Epoxy resin (manufactured by Ciel Chemical Co., Ltd., product name: Epicote 828, = 0 epoxy equivalent approximately 190)
380 parts and 70 parts of toluene were added to dissolve the epoxy resin. The mixture was then heated to reflux to completely remove water, and then toluene was removed under reduced pressure.
To the epoxy resin thus obtained, 288 parts of the above ketimine compound A was added and reacted at 160°C for 2 hours to obtain an epoxy resin derivative having the following structure. The infrared absorption spectrum of the purified epoxy resin derivative obtained by completely removing unreacted ketimine compound A is shown in FIG. 1A. The infrared absorption spectrum of the epoxy resin (Epicote 828) is shown in FIG. 1B. Example 2 The following structure in the reaction vessel Epoxy resin (manufactured by Ciel Chemical Co., Ltd., trade name: Epicote 1002, = 2.5 epoxy equivalent approx.
650) An epoxy resin solution prepared by adding 1,300 parts of toluene and 260 parts of toluene is heated to reflux to dehydrate it, and then the solvent is removed under reduced pressure. To this was added 290 parts of the ketimine compound A used in Example 1, and the mixture was allowed to react at 130° C. for 2 hours until the free ketimine compound A was substantially eliminated to obtain an epoxy resin derivative having the following structure. The infrared absorption spectrum of a purified product obtained by purifying the epoxy resin derivative thus obtained and completely removing unreacted ketimine compound A is as shown in FIG. 2A. Also, epoxy resin (Epicote 1002)
The infrared absorption spectrum of is shown in FIG. 2B. Example 3 The reactor has the following structure. Epoxy resin (manufactured by Ciel Chemical Co., Ltd., trade name, Epicote 1001, = 2, epoxy equivalent: approx.
500) and 130 parts of methyl isobutyl ketone were added to dissolve the epoxy resin. This product was then heated under reflux to completely remove water, and then methyl isobutyl ketone was removed under reduced pressure. To the epoxy resin thus obtained, 145 parts of the ketimine compound A used in Example 1 was added and reacted at 160° C. for 2 hours until free ketimine compound A was substantially eliminated to obtain an epoxy resin derivative having the following structure. The epoxy resin derivative thus obtained was purified to remove unreacted ketimine compound A.The characteristic absorption band of the infrared absorption spectrum of the purified product from which A was removed is as follows: ν ^KBr _nax (cm ^-1 ) :3450, 1603, 1510, 1250, 94
0,
880, 830. Example 4 A mixture of 75 parts (1 mol) of 1-hydroxypropylamine, 100 parts (1 mol) of methyl isobutyl ketone, and 15.7 parts of toluene was heated to reflux, and while removing distilled water, the reaction product was almost 100% as measured by PH test paper. Neutral (PH
Let it react until about 8).

A hydroxyl group-containing ketimine compound of the formula was obtained. This compound is hereinafter abbreviated as "ketimine compound B." 1000 parts of the epoxy resin (Epicote 1001) used in Example 3 and 100 parts of toluene were added to another reaction vessel to dissolve the epoxy resin. This was heated to reflux to completely remove water, and then toluene was removed under reduced pressure. To the epoxy resin thus obtained, 290 parts of the above ketimine compound B and 1 part of dimethylbenzylamine were added, and the mixture was reacted at 130°C for 2 hours until free ketimine compound B was substantially eliminated to obtain an epoxy resin derivative having the following structure. Ta. The characteristic absorption band of the infrared absorption spectrum of the purified product obtained by refining the epoxy resin derivative thus obtained and completely removing the unreacted ketimine compound B is as follows: ν ^KBr _nax (cm ^-1 ): 3450, 1605, 1510, 1250, 95
0,
920, 890, 830. Reference Example 1 To 104 parts of the ethylene glycol monobutyl ether solution of the epoxy resin derivative obtained in Example 1 (solid content 77%), Desmodyur L (3 moles of 2,4-tolylene diisocyanate manufactured by Bayer and 1 mole of trimethylolpropane) was added. adduct) of 2-
20 parts of isocyanate curing agent completely blocked with ethylhexanol and dibutyltin dilaurate
After adding 2.5 parts and heating and mixing at 40-50℃ until completely homogeneous, add 1.5 g of acetic acid to neutralize, then add deionized water with sufficient stirring to reduce the solid content.
An aqueous dispersion of 20% and pH 6.1 was obtained. 30 of this stuff
After stirring in the open for 1 day at ℃, it was used as an electrodeposition bath. This electrodeposition bath was used to electrodeposit on an untreated steel plate to a film thickness of 20 μm, and the film was baked at 170° C. for 20 minutes and subjected to a salt spray resistance test. Throwing property (pipe method): 22.0cm Salt spray resistance: Passed for 500 hours Salt spray resistance was tested in accordance with JIS, Z2371, and the cleave width from the cut part was within 20 mm on one side, and the coating film outside the cut part was tested. Fukure is on the 8th floor
(ASTM) The test was considered to have passed if the following conditions were met.

[Brief explanation of the drawing]

Figure 1A is an infrared absorption spectrum of the epoxy resin derivative of the present invention obtained in Example 1, and Figure 1B is an infrared absorption spectrum of the epoxy resin (Epicote 828) used as a starting material in Example 1. . Figure 2A is an infrared absorption spectrum of the epoxy resin derivative of the present invention obtained in Example 2, and Figure 2B is an infrared absorption spectrum of the epoxy resin (Epicote 1002) used as a starting material in Example 2. .

Claims (1)

[Claims] 1. General formula In the formula, R ₁ and R ₂ each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 9 carbon atoms, a furyl group or a tetrahydrofuryl group,
R ₁ and R ₂ together represent an alkylene group having 4 to 9 carbon atoms; R ₃ represents a (m+n+1)-valent hydrocarbon group having 1 to 18 carbon atoms; and m=1; When n=0, R ₃ may further represent [Formula] or [Formula]; R ₄ represents a lower alkylene group, an oxygen atom, a carbonyl group, or a sulfonyl group; Y is m is an integer of 1 to 3; n is 0 or an integer of 1 to 3; p is a number of 0 to 15. An epoxy resin derivative represented by the following. 2 General formula In the formula, R ₄ represents a lower alkylene group, an oxygen atom, a carbonyl group or a sulfonyl group; p is 0 to
The epoxy resin represented by the general formula In the formula, R ₁ and R ₂ each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 9 carbon atoms, a furyl group or a tetrahydrofuryl group, or R ₁ and R ₂ are taken together. represents an alkylene group having 4 to 9 carbon atoms; R ₃ represents an alkylene group having 1 to 9 carbon atoms;
Represents 18 (m+n+1)-valent hydrocarbon groups,
When m=1 and n=0, R ₃ may further represent [Formula] or [Formula]; m is an integer of 1 to 3; n is 0 or an integer of 1 to 3; A general formula characterized by reacting with a compound represented by In the formula, Y represents [Formula] or [Formula]; R ₁ , R ₂ , R ₃ , R ₄ , m, n and p have the above-mentioned meanings. A method for producing an epoxy resin derivative represented by the following formula.