CN1066465C - Modified epoxy resins having a blocked isocyanate moiety and a cationic group and their use in cathodic electrodeposition paints - Google Patents

Abstract

Polyglycidyl epoxy resins are modified to contain blocked isocyanate moieties attached to the resin backbone through oxazolidinone rings formed by the reaction of epoxy resins with asymmetric blocked diisocyanates. Further reaction with a cationic active hydrogen compound yields a modified epoxy resin containing cationic groups in addition to blocked isocyanate moieties. Modified epoxy resins are added to cathodic electrodeposition coatings as cationic binder resins or pigment dispersants.

Description

Modified epoxy resins containing blocked isocyanate moieties and cationic groups and their use in cathodic electrodeposition coatings

The invention relates to a modified epoxy resin used for electrodeposition paint and a preparation method thereof.

The invention also relates to cathodic electrodeposition coatings and pigment pastes containing the modified epoxy resins.

Modified epoxy resins formulated in cathodic electrodeposition coatings can be prepared by conventional methods, such as reacting epoxy resins with first active hydrogen compounds, such as alkylphenols, monocarboxylic acids or hydroxycarboxylic acids, to open part of the epoxides. ring, which is then reacted with a second active hydrogen compound, such as a primary or secondary amine, to open the remaining epoxide ring. The obtained modified resin is mixed with a cross-linking agent, such as melamine resin pentablock organic polyisocyanate, electro-applied on the substrate, and baked at high temperature to obtain a cured film. Modified epoxy resins of this type have the disadvantage that they only react with crosslinkers at higher temperatures. It is likewise known to prepare self-crosslinkable modified epoxy resins by attaching semi-blocked diisocyanates to secondary alcoholic hydroxyl groups formed by ring opening reactions of epoxy rings. This resin also has some disadvantages in that the blocked isocyanate moieties linked by urethane linkages tend to be at least partially eluted when the film is baked at temperatures above 200°C.

An important requirement when manufacturing coatings is pigment deposition. Usually this is accomplished by grinding the pigment with part of the carrier constituting the paint and a suitable solvent or thinner and other additives in a paint mill to prepare a pigment paste. Then, the pigment paste is mixed with the remainder of the vehicle and other additives to prepare a paint in which pigment particles are dispersed. The most serious problem encountered in pigmentation of coatings is the agglomeration or sedimentation of pigment particles, which can lead to reduced storage stability, troubles during application, reduced surface finish, deterioration over time, and the like. Coalescence can occur during grinding, mixing, storage or electrodeposition steps. The particle-to-particle interactions cause the pigment particles to agglomerate. In order to delay or control the interaction, the dispersant resin must contain a hydrophobic part in its structure, so that the dispersant resin is well adsorbed on the surface of the pigment particles. It is also necessary to make the dispersant resin contain a hydrophilic part to achieve stable dispersion in the aqueous medium.

Japanese Patent Publication No. 4978/1979 discloses a modified epoxy resin used as a pigment dispersant. This resin is prepared by linking the blocked isocyanate moiety to the modified epoxy resin through urethane linkage, which is composed of half-blocked diisocyanate and alkanol located in the main chain of resin or at the end of resin. The hydroxyl groups on the reaction form. However, when heated to baking temperatures, the blocked isocyanate moiety tends to precipitate diisocyanate monomers, causing various problems such as increased thermogravimetric loss or subsequent yellowing of the applied topcoat system.

The present invention provides a modified epoxy resin comprising a blocked isocyanate moiety and a cationic group attached to the end of the resin. The unique feature of the modified epoxy resin of the present invention is that the blocked isocyanate moiety is attached to the resin through the thermally stable oxazolidone ring formed by reaction with the epoxy ring. Therefore, precipitation of the blocked isocyanate moiety does not occur because the half-blocked diisocyanate is added to the alcoholic hydroxyl group.

In another aspect, the present invention provides a modified epoxy resin containing at least one blocked isocyanate moiety linked by an oxazolidone ring formed from the epoxy ring of a polyglycidyl epoxy resin. It is partially formed by reacting with an isocyano group of an organic diisocyanate, and the rest of the isocyano group is reversibly or irreversibly blocked. The modified epoxy resin further contains ring-opening of the remaining epoxy ring and cationic active hydrogen At least one cationic group introduced by the reaction. Modified epoxy resins of this type can be incorporated into anodic electrodeposition coatings as cationic binder resins.

In another aspect, the present invention provides a method for manufacturing modified epoxy resin, the method may further comprise the steps:

An epoxy resin containing many glycidyl groups is reacted with an asymmetrically blocked organic diisocyanate containing a first blocked isocyanate group and a second blocked isocyanate group, the second blocked isocyanate the acyl group is less reactive than the first blocked isocyanate group and is a stoichiometric amount less than the ratio of the first blocked isocyanate group to glycidyl groups; and

The resulting product is reacted with a cationic active hydrogen compound to introduce a cationic group through a ring-opening reaction of the remaining epoxy ring with the cationic active hydrogen compound.

The invention also provides a cathodic electrodeposition coating and a pigment paste containing the modified epoxy resin of the invention.

In order to facilitate a better understanding, the method for making the modified epoxy resin of the present invention will be described with a model reaction diagram, wherein the starting epoxy resin is a diglycidyl ether epoxy resin (I), and the diisocyanate compound has been prepared from a monohydric alcohol The full block of the blocking agent forms a symmetrical diurethane (II).

In the first step, epoxy resin (I) as described below reacts with diurethane;

In the second step, as described below, the product (III) of the first step is reacted with, for example, a _secondary amine HN(R″) to obtain the desired modified epoxy resin (IV);

In the above equation, R is the residue of diglycidyl epoxy resin, R' is the residue of organic diisocyanate, _R1 and _R2 are the residues of monoalcohol used as the first and second blocking agent, and R " is a secondary amine residue.

starting resin

The modified epoxy resins of the present invention are manufactured starting from epoxy resins containing many glycidyl groups. Typical examples thereof include polyphenol polyglycidyl ether type epoxy resins prepared by reacting polycyclic polyphenols such as bisphenol A, bisphenol F, bisphenol S, phenol novolac or cresol novolak with epichlorohydrin . Various bisphenol epoxy resins are commercially available, including EPIKOTE 827 (epoxy equivalent weight 180-190), EPIKOTE 1001 (epoxy equivalent weight 450-500), EPIKOTE 1010 (epoxy equivalent weight 3000-4000), all produced by YuKa Shell Epoxy K.K. Sales. Epoxy resins that can be used also include polyglycidyl ethers of aliphatic polyols, such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, pentaerythritol, polyglycol etc., and polyglycidyl esters of aliphatic, cycloaliphatic or aromatic polycarboxylic acids.

Used as starting resins, difunctional epoxy resins can be chain-extended by reacting with difunctional polyols, polycarboxylic acids, polyisocyanates, polyphenols or polyamines. Examples of difunctional polyols include difunctional polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, their random or block copolymers, or bisphenol A-ethylene oxide or propylene oxide Adducts, difunctional polyester polyol obtained by polycondensation reaction of dicarboxylic acid or anhydride with glycol, and polycaprolactone diol obtained by polymerization of ε-caprolactone initiated by glycol. The molecular weight of these bifunctional polyols is preferably 300-3000. Bisphenols such as bisphenol A or bisphenol F and aliphatic or aromatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, dodecanedioic acid, dimers, phthalic acid, isophthalic acid or Both terephthalic acids can be used in chain extension reactions.

The chain growth reaction of difunctional epoxy resin and organic diisocyanate in Iwakura et al, J. Polymer Sci., Part A-1, 4, 751 (1966) and Sander et al., J. Appl. Polymer Sci., 9.1984 (1966) is disclosed. The chain-extended epoxy resins obtained from these reactions contain many oxazolidinone rings in the resin backbone.

The molecular weight of the starting epoxy resin is usually 150-2,000, preferably 150-1,500.

first step

In the first step, the epoxy moiety of the starting resin is reacted with a blocked diisocyanate compound. Examples of usable diisocyanates include aromatic diisocyanates such as toluene diisocyanate (TDI), xylyl diisocyanate (XDI), 4,4'-diphenylmethane diisocyanate (MDI) and the like; and Aliphatic and cycloaliphatic diisocyanates such as hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), 4,4-methylene bis(cyclohexyl isocyanate), trimethylhexamethylene diisocyanate, etc. .

Various blocking agents are well known in the literature, examples of which include aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, 2-ethylhexanol, ethylene glycol monobutyl ether, cyclohexanol, etc. ; phenols such as phenol, nitrophenol, ethylphenol, etc.; oximes such as methyl ethyl ketone oxime; and lactams such as ε-caprolactam; tertiary-amino alkanolamines such as dimethylethanolamine, diethylethanolamine and dipropylethanolamine ; and secondary amines such as diethylamine, dibutylamine and di-tert-butylamine can be used.

The reaction reported by Iwakura et al. supra is also the reaction of epoxy resin with blocked diisocyanate, diurethane. In this case, however, the two blocked isocyanate groups are not blocked, and the epoxy resin is chain-extended by reaction with the unblocked diisocyanate. In contrast to this reaction, the first step of the present invention is carried out in which a preferred one of the first and second blocked isocyanato groups reacts with the epoxy ring, while the rest remains blocked. This can be achieved by blocking the first and second isocyanato groups with different blocking agents. In a preferred embodiment, the first isocyanato group is blocked with methanol or ethanol. The second isocyanate group can be blocked with an aliphatic monohydric alcohol containing at least 4 carbon atoms, such as butanol or 2-ethylhexanol, an alkylphenol such as cresol or nonylphenol, a glycol monohydric ether such as ethylene glycol Mono-2-ethylhexyl ether or propylene glycol mono-2-ethylhexyl ether, oximes such as dimethyl ketoxime, methyl ethyl ketoxime or methyl isobutyl ketoxime, caprolactam, etc. Preferably, methanol or ethanol is reacted with other blocking agents prior to the reaction.

Electrodeposition coatings usually contain a heat flow enhancer such as an aliphatic monohydric alcohol containing 4 or more carbon atoms, an alkylphenol or a glycol monohydric ether. The present invention adds these flow enhancers to the resin in the manner described above. Alternatively, the first isocyanate group can be blocked with methanol or ethanol to form a blocked isocyanate that preferentially reacts with epoxy groups, while the second isocyanate can be blocked with an active hydride to form an irreversibly blocked blocked isocyanate Acyl. Examples of such active hydrogen compounds include primary amines such as methylamine, octylamine or polyoxyalkylene monoamines, and aliphatic monocarboxylic acids such as octanoic acid or 2-ethylhexanoic acid.

The molar ratio of blocked diisocyanate to epoxy resin will vary depending on the properties of the particular resin and the diisocyanate used and the desired amine equivalent weight in the modified epoxy resin. However, the molar ratio of second blocked isocyanato groups to epoxy groups should always be less than one. In other words, the epoxy moiety should remain unreacted in the reaction product of the first step. The reaction is preferably carried out at a temperature of 60°C-200°C, and a decanter is preferably used to remove the produced by-product methanol or ethanol from the reaction system. Preferably, the resin undergoes chain extension after reaction with the asymmetric blocked diisocyanate, as described above.

In the second step, the remaining epoxy rings in the product of the first step are opened using a cationic active hydrogen compound. Examples of useful cationic active hydrogen compounds include primary or secondary amines such as butylamine, octylamine, diethylamine, dibutylamine, methylbutylamine, monoethanolamine, diethanolamine or N-methylethanolamine, tertiary amine-acid addition Salt formation such as triethylamine hydrochloride or N,N-dimethylethanolamine acetate, and sulfide-acid mixtures such as diethylsulfide-acetic acid mixture. It is also possible to use ketimines of primary amines such as aminoethylethanolamine or diethylenetriamine. Mixtures of these amines and ketimines may also be used. It should be noted that when a primary amine is used, it makes the resin too viscous since it also acts as a chain extender. For use as a binder resin, it is better to make the obtained modified resin contain amine equivalents of 0.3-4.0meq/g. If the number of equivalents of amine is too low, emulsification or dispersion in an aqueous medium becomes difficult. Conversely, if the equivalent number of amine is too high, it is almost impossible to obtain a film with satisfactory waterproof performance.

Modified resins containing quaternary ammonium or sulfonium moieties are useful as pigment paste dispersants. To this end, the remaining epoxy ring or product ring of the first step can be opened by reaction with a tertiary amine-acid addition salt or mixture or a sulfide-acid mixture. Preferred tertiary amines and sulfides for this purpose include aliphatic tertiary amines containing hydroxy substituents such as dimethylethanolamine or diethylethanolamine and aliphatic sulfides containing hydroxy substituents such as thiodiethanol , 1-(2-hydroxyethylthio)-2,3-propanediol, 1-(2-hydroxyethylthio)-2-propanol, 1-(2-hydroxypropylthio)-2,3-propanediol , 1-(2-hydroxyethylthio)-2-butanol, 1-(2-hydroxyethylthio)-3-butoxy-1-propanol. Examples of preferable carboxylic acids include formic acid, lactic acid, acetic acid, propionic acid, butyric acid, dimethylolpropionic acid, N-acetylglycine, N-acetyl-β-alanine and the like. The modified resin used for the purpose of pigment dispersion should contain 0.5-1.5 meq/g of alkali equivalents.

Electrodeposition coating

Modified epoxy resins contain two blocked isocyanates and cationic moieties that crosslink themselves or with the aid of external linkers such as blocked polyisocyanates or melamine resins. When formulated in cathodic electrodeposition coatings, their characteristic properties are revealed to the greatest extent. As mentioned earlier, commonly used modified epoxy resins are not satisfactory in reactivity with crosslinking agents. The modified epoxy resin of the present invention is very satisfactory not only in reactivity with a crosslinking agent but also in other properties including emulsifiability, thermal fluidity, corrosion resistance and heat resistance.

In order to prepare the electrodeposition coating, the modified resin of the present invention is dispersed in an aqueous medium containing a neutralizing agent together with a crosslinking agent, and a typical crosslinking agent is etherified methylolmelamine resin or blocked polyisocyanate. The neutralizing agent is of course an acid such as hydrochloric acid, nitric acid, phosphoric acid, formic acid, acetic acid, lactic acid, sulfamic acid or acetylglycine.

The amount of crosslinking agent must be sufficient to obtain a rigid film by crosslinking reaction with amino, hydroxyl or carboxyl groups contained in the resin, usually in an amount of 5-50% by weight of the solid modified resin. The amount of neutralizing agent is at least 20%, preferably 30-60%, which can realize the neutralization of the modified resin.

When the block polyisocyanate is used as a crosslinking agent, the coating formulation may contain 0.1-5% by weight of the block polyisocyanate as a catalyst, such as dibutyltin dilaurate, dibutyltin oxide or other urethane cracking catalysts. Coating formulations can, of course, contain many conventional additives as required for their particular application. Examples thereof include coloring pigments such as titanium dioxide, carbon black or iron oxide; antirust pigments such as basic lead silicate or lead phosphomolybdate; extender pigments such as kaolin, talc or clay; and other additives such as water-miscible organic solvents, surfactants , antioxidants, UV absorbers, etc. The resulting water-based coatings can be applied to substrates not only by electrodeposition processes but also by spraying, dipping and other conventional methods.

Pigment paste

When the carrier resin of pigment paste is used in cathodic electrodeposition paint, the modified resin containing quaternary ammonium or sulfonium cationic groups shows better performance than existing resins. This is because the blocked isocyanate moiety is attached to the main chain of the resin through a thermally stable oxazolidone ring, so it is difficult to separate out from the resin when the paint film is baked.

Pigment pastes can be prepared by conventional methods by dispersing pigment, carrier resin and deionized water to a particle size of less than 10 microns. The pigment may be a mixture of an extender pigment, a color pigment and an antirust pigment mixed in a suitable ratio as exemplified above. The ratio of solid carrier resin to pigment is usually 1:1-1:10. The resulting pigment paste can be added not only to paints using the binder resin as the modified resin of the present invention, but also to other paints containing acrylic, epoxy or polybutadiene binder resins. When the pigment paste is added to other coatings disclosed in Japanese Patent Application JP-A-05306327, because the binder resin disclosed here also contains an oxazolidinone ring, and due to the similarity of the chemical structure with the pigment paste carrier It has good compatibility and can achieve special benefits.

The following examples are intended to further illustrate the invention without limiting them thereto. All parts and percentages are by weight unless otherwise indicated. All epoxy equivalent weights and amine or base equivalent weights herein are on a dry basis.

(Example 1)

In the flask equipped with stirrer, condenser, nitrogen tube, thermometer and dropping funnel, add 54.0g 2,4-/2,6-cresyl diisocyanate (80:20 weight ratio), 136g methyl isobutyl base ketone (MIBK) and 0.05 g of dibutyltin dilaurate. To the mixture was added dropwise 10.9 g of methanol over 30 minutes with stirring and bubbling with nitrogen. During this time, the internal temperature rose to 60°C. After continuing the reaction for 30 minutes, add 54.0 g of ethylene glycol mono-2-ethylhexyl ether dropwise within 1 hour, and make it react at 60-65° C. until the absorption peak of isocyanate group disappears on the IR spectrum. Then add 285g of epoxy equivalent of 475 bisphenol A epoxy resin, 380g of epoxy equivalent of 950 bisphenol A epoxy resin and 0.62g of benzyldimethylamine in the flask. Then, the mixture was reacted at 120° C., and the produced methanol by-product was distilled off until the epoxy equivalent reached 1120. After cooling, 29.1 g of diethanolamine, 21.5 g of N-methylethanolamine and 32.9 g of hydroethylethanolamine ketimine (79% solution in MIBK) were added to the mixture and allowed to react at 110° C. for 2 hours. IR spectrum confirmed the absorption of oxazolidinone carbonyl at 1750cm ^-1 . The product was diluted with MIBK until it was 80% non-volatile, and a cationic resin A with a number average molecular weight of 2600 and an amine equivalent of 99 meq/100 g was obtained.

Example 2

Similar to Example 1, 57.4 g of 2.4/2,6-cresyl diisocyanate (80:20 weight ratio) were reacted with 11.6 g of methanol and then with 60.8 g of ethylene glycol monobutyl ether. The obtained asymmetric blocked diisocyanate was reacted with 309 g of bisphenol F epoxy resin having an epoxy equivalent of 475 and 332 g of bisphenol F epoxy resin having an epoxy equivalent of 950. The product was further reacted with 27.0 g diethanolamine, 20.0 g N-methylethanolamine and 32.9 g aminoethylethanolamine ketimine (79% solution in MIBK), then diluted with MIBK to 80% non-volatile. Cationic resin B having a number average molecular weight of 2400 and an amine equivalent of 97 meq/100 g was obtained.

Example 3

Into a flask equipped with a stirrer, condenser, nitrogen tube, thermometer and dropping funnel, add 77.5 g of 4,4′-diphenylmethane diisocyanate, 136 g of methyl isobutyl ketone (MIBK) and 0.05 g of dibutyltin diisocyanate laurate. To the mixture was added dropwise 10.9 g of methanol over 30 minutes with stirring and bubbling with nitrogen. During this time, the internal temperature rose to 80C. After continuing the reaction for 30 minutes, 52.2 g of ethylene glycol mono-2-ethylhexyl ether was added dropwise within 1 hour to make it react at 80-85° C. until the absorption peak of isocyanoyl on the IR spectrum disappeared. Subsequently, 309.0 g of bisphenol F epoxy resin with an epoxy equivalent of 475, 3323 g of bisphenol F epoxy resin with an epoxy equivalent of 950 and 0.62 g of benzyldimethylamine were added to the flask. Then, the mixture was reacted at 120° C., and the produced methanol by-product was distilled off until the epoxy equivalent reached 1116. After cooling, 14.6 g of diethanolamine, 31.8 g of N-methylethanolamine and 32.9 g of aminoethylethanolamine ketimine (79% solution in MIBK) were added to the mixture and allowed to react at 110° C. for 2 hours. IR spectrum confirmed the absorption of oxazolidinone carbonyl at 1750cm ^-1 . Diluted to 80% non-volatile, to obtain a cationic resin C with a number average molecular weight of 2700 and an amine equivalent of 98meq/100g.

Example 4

Similar to Example 1, 82.5 g of 4,4'-diphenylmethane diisocyanate was first reacted with 10.5 g of methanol, and then reacted with a mixture of 34.8 g of ethylene glycol-2-ethylhexyl ether and 11.3 g of ε-caprolactam . The resulting blocked diisocyanate was reacted with a mixture of 285 g of bisphenol F epoxy resin having an epoxy equivalent weight of 475 and 380 g of bisphenol F epoxy resin having an epoxy equivalent weight of 950. The product was further reacted with a mixture of 13.9 g diethanolamine, 28.9 g N-methylethanolamine and 22.0 g aminoethylethanolamine ketimine (79% solution in MIBK) and diluted to 80% non-volatile with MIBK. Cationic resin D having a number average molecular weight of 2600 and an amine equivalent of 95 meq/100 g was obtained.

Example 5

Similar to Example 1, first 57.0g 2,4-/2,6-cresyl diisocyanate (80:20 by weight) was reacted with 10.5g methanol, and then with 54.0g ethylene glycol one-2- Ethylhexyl ether reacts to obtain blocked diisocyanates. This blocked diisocyanate was reacted with a chain-extended epoxy resin with an epoxy equivalent weight of 1200, which was composed of 1012.0 g of bisphenol A epoxy resin with an epoxy equivalent weight of 650 and 86.0 g of bisphenol A- Ethylene oxide adduct (BPE-100, sold by Sanyo Chemical Industries, Ltd.) reaction obtains, the product is further with 29.1g diethanolamine, 21.5gN-methylethanolamine and 32.9g aminoethylethanolamine ketimine (79% solution in MIBK) mixture was reacted and diluted to 80% non-volatile to obtain cationic resin E with a number average molecular weight of 2800 and an amine equivalent weight of 98 meq/100 g.

Comparative Example 1

In the same reactor as used in Example 1, 285.0 g of bisphenol A epoxy resin with an epoxy equivalent weight of 475, 77.0 g of p-nonylphenol and 82.4 g of MIBK were charged. After mixing under heating to form a solution, the mixture was reacted at 150°C in the presence of 3.0 g of N,N-dimethylbenzylamine until the epoxy equivalent reached 1140. After cooling, 19.2 g of diethanolamine, 27.0 g of N-methylethanolamine and 30.6 g of aminoethylethanolamine ketimine (79% solution in MIBK) were added to the mixture and allowed to react at 110° C. for 2 hours. And diluted with MIBK to 90% non-volatile. Cationic resin a having a number average molecular weight of 2100 and an amine equivalent of 90 meq/100 g was obtained.

Comparative Example 2

Except that 99.0g of 12-hydroxystearic acid was used to replace 77.0g of p-nonylphenol in the first step, and the amounts of diethanolamine, N-methylethanolamine and aminoethylethanolamine ketimine added were 27.9g, 19.8 g and 31.5g, according to the steps of Comparative Example 1, the number average molecular weight was 2700 and the amine equivalent was 90meq/100g cationic resin b.

Comparative Example 3

In the same reactor as used in Example 1, 26.1 g of toluene 2,4-/2,6-diisocyanate (80:20 by weight) and 13.0 g of MIBK were charged. To the mixture was added dropwise 26.1 g of ethylene glycol mono-2-ethylhexyl ether over 1 hour with stirring and bubbling with nitrogen. During this time, the internal temperature rose to 60°C. A half-block diisocyanate solution with an NCO equivalent of 350 was obtained. In this solution, 95.0g epoxy equivalent is the bisphenol A epoxy resin of 475 and 750g epoxy equivalent is the solution that the bisphenol A epoxy resin of 950 is dissolved in 150.0g MIBK. The mixture was reacted at 120° C. until the NCO absorption disappeared on the IR spectrum. After cooling to 110°C, the mixture was further reacted with 35.4g diethanolamine, 25.2g N-methylethanolamine and 40.0g aminoethylethanolamine ketimine (75% solution in MIBK) for 2 hours and diluted to 85.0% Not volatile. Cationic resin c having a number average molecular weight of 2800 and an amine equivalent of 100 meq/100 g was obtained.

Pigment paste

In the three-necked flask that stirrer is housed, reflux condenser and thermometer, add 740g epoxy equivalent and be the bisphenol A epoxy resin (EPIKOTE 828 of 190, YuKa Shell E-poxy K.K.), 211g bisphenol A, 48g MIBK and 1.5 g benzyldimethylamine. The mixture was reacted at 170°C for 2 hours. The resulting epoxy equivalent of 700 was mixed with 244g of thiodiethanol, 268g of dimethylolpropionic acid and 50g of deionized water, and reacted at 60°C for 5 hours and then with ethylene glycol monobutyl ether Dilute to 30% solids.

Prepare the pigment paste by grinding the following mixture

Component Amount, g

Pigment dispersion resin 200.0 (60g solid)

Carbon black 4.0

Kaolin 36.0

TiO ₂ 150.0

Basic lead silicate 10.0

Deionized water 33.3

Synthesis of crosslinkers

Cross-linking agent Ⅰ:

In the same reactor as used in Example 1, 125.0 g of 4,4'-diphenylmethane diisocyanate, 75.0 g of MIBK and 0.05 g of dibutyltin dilaurate were charged. A mixture of 45.2 g of ε-caprolactam, 47.2 g of ethylene glycol monobutyl ether, 4.0 g of methanol and 4.4 g of trimethylolpropane was added dropwise to the mixture with stirring and nitrogen bubbling. During this time, the internal temperature rose to 60°C. The reaction was continued for 1 hour until the NCO absorption disappeared on the IR spectrum. The resulting product is hereinafter referred to as crosslinker I.

Cross-linking agent Ⅱ:

Similar to the above, in 32 g of MIBK, 199 g of hexamethylene diisocyanate trimer (CORONATE HX, sold by Nippon Polyurethane K.K.) was blocked with 87.0 g of methyl ethyl ketoxime. The resulting product is hereinafter referred to as crosslinker II.

Example 6

Thoroughly mix 148.0 grams of Crosslinker I as a solid, 252.0 grams of Cationic Resin A as a solid, and 5.0 grams of dibutyltin oxide. After heating to 80°C, the mixture was emulsified by slowly adding 266.6 g of deionized water containing 6.24 g of acetic acid with stirring, and then diluted to 36% solids with 455 g of deionized water. Evaporate the emulsion in vacuum to remove the organic solvent, adjust to 36% solids with deionized water, mix with 270g of the above pigment paste, and finally dilute to 20% non-volatile with 1400g of deionized water and 32g of ethylene glycol monohexyl ether , to prepare cathodic electrodeposition paint.

The paint was electro-applied on the zinc phosphate-treated steel plate as the cathode, with a dry film thickness of 20 microns, baked under the conditions listed in Table 1, and its performance was tested. The experimental results measured by the spectrometer and the particle size of the emulsion before mixing with the pigment paste are listed in Table 1. Embodiment 7-10 and comparative example 3-5

The coatings of various formulations listed in Table 1 were prepared as in Example 6. In all examples and comparative examples, the ratio of cationic resin/crosslinking agent in the coating was 63/37. The results obtained are listed in Table 1.

Table 1 Plastise Example Comparison Example 6 7 8 9 10 A B C cationic resin A B C D E F G H cross -linking agent Ⅰ Ⅱ Ⅱ Ⅰ Ⅰ performance emulsion particles 1) 80 100 130 120 85 250 130 100 size, NM vulcanization performance 2) 150 × 20min, good, good, good gloss, good gloss 160 × 20min, good, good, good, good performance 3) 0.22 0.25 0.22 0.21 0.23 0.24 0.25ra, μm, 160 × 20min. Salt spray 4) Nothing and no 160 × 20mm changes. Changing changes. ×20min

Notes to Table 1

1) Measured by Hitachi Spectrometer Model V-1110

2) After baking at 175° C. for 20 minutes, the vulcanized film was rubbed back and forth 30 times with an acetone-impregnated fabric. When changes were observed on the surface of the film, the vulcanization performance was considered good.

3) Measured by Surface Roughness MeterModel E-30A sold by Toyo Seimitsu K.K.

4) According to JIS-Z 2371

5) The inner surface of the cylindrical metal can be sprayed with conventional white paint (alkyd melamine-based white paint sold by Nippon Point Co., Ltol) applied to automobile bodies as an intermediate coat. This can be transferred and placed on the experimental sample plate. After vulcanization at 140°C for 20 minutes, the yellowness of the coating film applied to the inner surface can be observed with the naked eye.

Example 11

In a flask equipped with a stirrer, condenser, nitrogen tube, thermometer and dropping funnel, add 66.1g 2,4-/2,6-cresyl diisocyanate (80:20 weight ratio), 53.3g methyl isocyanate Butyl ketone (MIBK) and 0.12 g of dibutyltin dilaurate. To the mixture was added dropwise 13.6 g of methanol over 30 minutes with stirring and bubbling with nitrogen. During this time, the internal temperature rose to 60°C. After continuing the reaction for 30 minutes, 46.8 g of 2-ethylhexanol was added dropwise within 1 hour and allowed to react at 60-65° C. until the absorption peak of isocyanoyl on the IR spectrum disappeared. Subsequently, 310 g of bisphenol A epoxy resin with an epoxy equivalent of 188 and 0.8 g of benzyldimethylamine were added into the flask. Then, the mixture was reacted at 120-125° C., and the produced methanol by-product was distilled off until the epoxy equivalent reached 338. IR spectrum confirmed the absorption of oxazolidinone carbonyl at 1750cm ^-1 . Then, 57.0 g of bisphenol A was added to the mixture and reacted at 120° C. until the epoxy equivalent reached 640. After cooling, react the product with a solution of 92.3g dithioethanol and 100.5g dimethylol propionic acid dissolved in 108.0g deionized water at 65°C until the acid value reaches less than 5, and then use 1:1 ethylene dimethanol The mixture of alcohol monobutyl ether and dipropylene glycol monobutyl ether was diluted to 60% non-volatile. Pigment dispersion resin F having an alkali equivalent of 78 meq/100 g was obtained.

Example 12

In a flask equipped with a stirrer, condenser, nitrogen tube, thermometer and dropping funnel, add 62.6g 2,4-/2,6-cresyl diisocyanate (80:20 weight ratio), 55.1g methyl isocyanate Butyl ketone (MIBK) and 0.12 g of dibutyltin dilaurate. To the mixture was added dropwise 13.6 g of methanol over 30 minutes with stirring and bubbling with nitrogen. During this time, the internal temperature rose to 60°C. After continuing the reaction for 30 minutes, 62.6 g of ethylene glycol mono-2-ethylhexyl ether was added dropwise within 1 hour to make it react at 60-65° C. until the absorption peak of isocyanoyl on the IR spectrum disappeared. Subsequently, 310 g of bisphenol A epoxy resin with an epoxy equivalent of 188 and 0.8 g of benzyldimethylamine were added into the flask. Then, the mixture was reacted at 120° C., and the produced methanol by-product was distilled off until the epoxy equivalent reached 350. Then, 57.0 g of bisphenol A was added to the mixture and reacted at 120° C. until the epoxy equivalent weight reached 660. After cooling, the product was reacted at 65°C with a solution of 102.2gl-(2-hydroxyethylthio)-2-propanol and 100.5g dimethylolpropionic acid dissolved in 108.0g deionized water until the acid value reach less than 5, and then dilute to 60% non-volatile with a 1:1 mixture of ethylene glycol monobutyl ether and dipropylene glycol monobutyl ether to obtain pigment dispersion resin G.

Example 13

The procedure of Example 11 was followed using the following substances:

name name number of copies

TDI 66.1

Methanol 13.6

Diethylene glycol mono-2-ethylhexyl ether 78.5

Dibutyltin dilaurate 0.12

MIBK 56.9

Bisphenol A epoxy resin (E.E.=188) 310.2

Bisphenol A 57.0

Dimethylbenzylamine 0.8

1-(2-Hydroxyethylthio)-2,3-propanediol 114.0

Dimethylolpropionic acid 100.5

Deionized water 108.0

Total 726.3

The product was diluted to 60% non-volatile with a 1:1 mixture of ethylene glycol monobutyl ether and dipropylene glycol monobutyl ether to obtain pigment dispersion resin H. Alkali equivalent = 72.3meq/100g.

Example 14

The procedure of Example 11 was followed using the following substances:

name name number of copies

TDI 66.1

Methanol 13.6

Ethylene glycol mono-2-ethylhexyl ether 62.6

Dibutyltin dilaurate 0.12

MIBK 55.1

Bisphenol A epoxy resin (E.E.=188) 310.2

Bisphenol A 57.0

Dimethylbenzylamine 0.8

1-(2-Hydroxyethylthio)-2,3-propanediol 124.5

Dimethylolpropionic acid 100.5

Deionized water 108.0

Total 720.0

The product was diluted to 60% non-volatile with a 1:1 mixture of ethylene glycol monobutyl ether and dipropylene glycol monobutyl ether to obtain pigment dispersion resin I. Alkali equivalent = 72.9meq/100g.

Example 15

The procedure of Example 11 was followed using the following substances:

name name number of copies

MDI 95.0

Methanol 13.6

Ethylene glycol mono-2-ethylhexyl ether 62.6

Dibutyltin dilaurate 0.12

MIBK 58.3

Bisphenol A epoxy resin (E.E.=188) 310.2

Bisphenol A 57.0

Dithioethanol 92.3

Dimethylolpropionic acid 100.5

Deionized water 108.0

Total 717.6

The product was diluted to 60% non-volatile with a 1:1 mixture of ethylene glycol monobutyl ether and dipropylene glycol monobutyl ether to obtain pigment dispersion resin J. Alkali equivalent = 72.0meq/100g.

Example 16

The procedure of Example 11 was followed using the following substances:

name name number of copies

TDI 66.1

Methanol 13.6

Ethylene glycol-2-ethylhexyl ether 62.6

Dibutyltin dilaurate 0.12

MIBK 67.0

Bisphenol A epoxy resin (E.E.=475) 475.0

Dimethylbenzylamine 0.8

1-(2-Hydroxyethylthio)-2-propanol 81.7

Dimethylolpropionic acid 80.4

Deionized water 113.0

Total 765.8

The product was diluted to 60% non-volatile with a 1:1 mixture of ethylene glycol monobutyl ether and dipropylene glycol monobutyl ether to obtain pigment dispersion resin K. Alkali equivalent = 55.0meq/100g.

Example 17

The procedure of Example 11 was followed using the following substances:

name name number of copies

TDI 26.1

Methanol 5.44

Ethylene glycol-2-ethylhexyl ether 24.4

Dibutyltin dilaurate 0.12

Bisphenol A epoxy resin (E.E.=188) 310.2

Bisphenol A 57.0

Dimethylbenzylamine 0.8

1-(2-Hydroxyethylthio)-2-propanol 121.8

Dimethylolpropionic acid 132.7

Deionized water 129.6

Total 672.0

The product was diluted to 60% non-volatile with a 1:1 mixture of ethylene glycol monobutyl ether and dipropylene glycol monobutyl ether to obtain pigment dispersion resin L. Alkali equivalent = 146.0meq/100g.

Example 18

In a flask equipped with a stirrer, condenser, nitrogen tube, thermometer and dropping funnel, add 62.6g 2,4-/2,6-cresyl diisocyanate (80:20 weight ratio), 55.1g methyl isocyanate Butyl ketone (MIBK) and 0.12 g butyltin dilaurate. To the mixture was added dropwise 13.6 g of methanol over 30 minutes with stirring and bubbling with nitrogen. During this time, the internal temperature rose to 60°C. After continuing the reaction for 30 minutes, 62.6 g of ethylene glycol mono-2-ethylhexyl ether was added dropwise within 1 hour to make it react at 60-65° C. until the absorption peak of isocyanoyl group disappeared in the IR spectrum. Subsequently, 475.0 g of bisphenol A epoxy resin with an epoxy equivalent of 475 and 0.8 g of benzyldimethylamine were added into the flask. Then, the mixture was reacted at 125° C., and the produced methanol by-product was distilled off until the epoxy equivalent reached 1010. After cooling, 62.3g of dimethylethanolamine, 63.0g of lactic acid and 108.0g of deionized water were added to the mixture to react at 80°C until the acid value reached less than 1. The product was reacted with 1:1 ethylene glycol monobutyl ether at 80°C until the acid value reached less than 1. The product was diluted to 60% non-volatile with a 1:1 mixture of ethylene glycol monobutyl ether and dipropylene glycol monobutyl ether to obtain a pigment dispersion resin M.

Example 19

In a flask equipped with a stirrer, condenser, nitrogen tube, thermometer and dropping funnel, add 62.6g 2,4-/2,6-cresyl diisocyanate (80:20 weight ratio), 55.1g methyl isocyanate Butyl ketone (MIBK) and 0.12 g of dibutyltin dilaurate. To the mixture was added dropwise 13.6 g of methanol over 30 minutes with stirring and bubbling with nitrogen. During this time, the internal temperature rose to 60°C. After continuing the reaction for 30 minutes, 62.6 g of ethylene glycol mono-2-ethylhexyl ether was added dropwise within 1 hour to make it react at 60-65° C. until the absorption peak of isocyanoyl group disappeared in the IR spectrum. Subsequently, 475.0 g of bisphenol A epoxy resin with an epoxy equivalent of 475 and 0.8 g of benzyldimethylamine were added into the flask. Then, the mixture was reacted at 120° C., and the produced methanol by-product was distilled off until the epoxy equivalent reached 1010. After cooling, 51.89 g of N-methylethanolamine was added to the mixture and allowed to react until no epoxy groups were detected on the IR spectrum. The product is further reacted with a solution of 101.0 g of glycidol and 90 g of lactic acid dissolved in 108.0 g of deionized water until the acid value reaches less than 1, and finally with a mixture of 1:1 ethylene glycol monobutyl ether and dipropylene glycol monobutyl ether The mixture was diluted to 60% non-volatile to obtain Pigment Dispersion Resin N.

Example 20

The procedure of Example 18 was followed using the following materials:

name name number of copies

TDI 26.1

Methanol 5.44

Ethylene glycol-2-ethylhexyl ether 24.4

Dibutyltin dilaurate 0.12

MIBK 190.5

Bisphenol A epoxy resin (E.E.=950) 950.0

Dimethylbenzylamine 0.8

Dimethylethanolamine 62.3

Lactic acid (60%) 63.0

Total 1204.0

The product was diluted to 60% non-volatile with a 1:1 mixture of ethylene glycol monobutyl ether and dipropylene glycol monobutyl ether to obtain pigment dispersion resin O. Alkali equivalent = 48.0meq/100g.

Comparative Example 7

Substance Parts Solid

EPON 828 533.2 533.2

Bisphenol A 199.6 199.6

Nonylphenol 19.2 19.2

Ethyltriphenylsulfonium iodide 0.75 —

Propylene glycol monobutyl ether 201.6 —

Thiodiethanol 122.1 122.1

Dimethylolpropionic acid 134.1 134.1

Deionized water 30.6 -

Heat EPON 828, bisphenol A and nonylphenol in a reactor at 107°C, and maintain this temperature until the bisphenol A dissolves. After addition of ethyltriphenylsulfonium iodide, the mixture was heated to 125°C and cooled to 75°C, followed by the addition of a mixture of propylene glycol monobutyl ether, dithioethanol, dimethylolpropionic acid and deionized water. The mixture was reacted at 70-75°C until the acid value reached less than 3, cooled, and diluted to 30% solids with deionized water to obtain pigment dispersion resin paint P.

Comparative Example 8

step 1:

Substance Solid

In MIBK 2-ethylhexanol-semi-block TDI 320.0 304.0

Dimethylethanolamine 87.2 87.2

75% Lactic Acid 117.6 88.2

Ethylene glycol monobutyl ether 39.2 —

In the reactor under stirring, dimethylethanolamine was added dropwise into 2-ethylhexanol-semi-block TDI, and an exothermic reaction occurred. After stirring at 80° C. for 1 hour, the mixture was further reacted with lactic acid in ethylene glycol monobutyl ether for 30 minutes at 65° C. under stirring to obtain a quaternizing agent.

Step 2:

Substance Parts Solid

EPON 829 710.0 681.2

Bisphenol A 289.6 298.6

In MIBK 2-ethylhexanol-semi-block TDI 406.4 386.1

Quaternizing agent from step 1 496.3 421.9

Deionized water 71.2 —

Ethylene glycol monobutyl ether 56.76 —

Under nitrogen atmosphere, react EPON 829 with bisphenol A at 150-160°C for 1 hour, after cooling to 120°C, react the product with 2-ethylhexanol-semi-block TDI and homogenize at 85-95°C. Then add the quaternizing agent of step 1 into the reaction mixture and allow it to react at 80-85° C. until the acid value reaches less than 1. The resulting product is hereinafter referred to as Pigment Dispersion Resin Paint Q.

Examples 21-30 and Comparative Examples 9-10

Pigment paste

Pigment pastes were prepared by grinding the following mixtures in a sand mill to a particle size of less than 10 microns, and their properties were evaluated. The results are listed in Table 2.

Substance Quantity

Pigment dispersion resin 125.0 (60.0% solid)

Deionized water 400.0

Carbon black 8.5

Kaolin 72.0

Titanium dioxide 345.0

Aluminum phosphomolybdate 75.0

Binder resin:

In a flask equipped with a stirrer, a condenser, a nitrogen tube, a thermometer and a dropping funnel, add 285.0 g of epoxy resin with an epoxy equivalent of 475 and an oxazolidinone ring equivalent of 650, made from bisphenol A epoxy resin and TDI Containing the epoxy resin of oxazolidinone ring, 380.0g epoxy equivalent is the bisphenol A epoxy resin 77.0g p-nonylphenol and 82.4g MIBK. After adding 3.0g benzyldimethylamine, make the mixture at 130 ℃ Under reaction until the epoxy equivalent reaches 1140, after cooling, this mixture is mixed with 19.2g diethanolamine, 27.0gN-methylethanolamine and 30.6g aminoethylethanolamine ketimine (79% solution in MIBK) at 110°C The mixture was reacted for 2 hours. The product was diluted to 90% non-volatile with MIBK.

crosslinking agent

Crosslinker II of Examples 6-10 and Comparative Examples 3-6 were used.

Primary emulsion:

The above-mentioned binder resin and crosslinking agent were mixed at a solid ratio of 68:36, and ethylene glycol monohexyl ether in an amount corresponding to 2% of solid was added to the mixture. After adding acetic acid to neutralize 42.5%, the mixture was diluted slowly with deionized water and the MIBK was evaporated in vacuo to 36.0% solids.

Evaluation of paint

Mix 2000.0g of the above main emulsion, 460.0g of the above pigment paste and 2252.0g of deionized water to prepare various cathode coatings.

The coating was electro-applied on the zinc phosphate-treated chilled steel plate to a dry film thickness of 20 microns, and baked at 160°C for 10 minutes to test the properties of the coating film. The results are listed in Table 2.

Table 2

Example Comparative Example

21 22 23 24 25 26 27 28 29 30 9 10

Pigment Resin F G H I J K L M N O O P Q

Thermal stability1) good good good good good good good good good good good good bad

Dispersion Stability2) Good Good Good Good Good Good Good Good Good Good Good No Good

Coulombic efficiency3) good good good good good good good good good good good bad good

Salt Spray4) Good Good Good Good Good Good Good Good Good Good Good No

Yellowing 5)

At 160℃ good good good good good good good good good good good good bad

At 180℃ good good good good good good good good good good good bad

Notes to Table 2:

1) Thermal stability within 20 minutes at 220°C

Good: no diisocyanate precipitation

Bad: There is precipitation of diisocyanate

2) Storage stability of the pigment paste after standing for 2 weeks at 40°C

Good: no deposition

Bad: lump deposition or phase separation

3) Deposition efficiency expressed in mg/coulomb under the condition of obtaining a film thickness of 20 microns

Good: >35mg/coulomb

Bad: <35mg/coulomb

4) According to JIS-Z 2371

good: no change

Bad: Blisters all over the area

5) Spray the white paint of the middle layer on the film sample which is baked at 160°C for 10 minutes or baked at 180°C for 20 minutes, and then baked at 140°C for 20 minutes. The yellowness of the white paint film was determined visually in comparison to a reference panel coated directly with the white paint.

Good: no yellowing

Fair: slight yellowing

Bad: Visible yellowing

Example 31

In the flask equipped with stirrer, condenser, nitrogen tube, thermometer and dropping funnel, add 54.0g 2,4-/2,6-cresyl diisocyanate (80:20 weight ratio), 136g methyl isobutyl base ketone (MIBK) and 0.05 g of dibutyltin dilaurate. To the mixture was added dropwise 10.9 g of methanol over 30 minutes with stirring and bubbling with nitrogen. During this time, the internal temperature rose to 60°C. After continuing the reaction for 30 minutes, 36.2 g of dibutylamine was added dropwise within 1 hour, and reacted at 60-65° C. until the absorption peak of isocyanate group disappeared in the IR spectrum. Then add 285g of epoxy equivalent of 475 bisphenol A epoxy resin, 380g of epoxy equivalent of 950 bisphenol A epoxy resin and 0.62g of benzyldimethylamine in the flask. Then, the mixture was reacted at 120° C., and the produced methanol by-product was distilled off until the epoxy equivalent reached 1120. After cooling, 29.1 g of diethanolamine, 21.5 g of N-methylethanolamine and 32.9 g of aminoethylethanolamine ketimine (79% solution in MIBK) were added to the mixture and allowed to react at 110° C. for 2 hours. IR spectrum confirmed the absorption of oxazolidinone carbonyl at 1750cm ^-1 . The product was diluted with MIBK to 80% non-volatility, and the cationic resin thus obtained showed satisfactory emulsifying properties.

Example 32

In the flask equipped with stirrer, condenser, nitrogen tube, thermometer and dropping funnel, add 54.0g 2,4-/2,6-cresyl diisocyanate (80:20 weight ratio), 136g methyl isobutyl base ketone (MIBK) and 0.05 g of dibutyltin dilaurate. To the mixture was added dropwise 10.9 g of methanol over 30 minutes with stirring and bubbling with nitrogen. During this time, the internal temperature rose to 60°C. After continuing the reaction for 30 minutes, 40.4 g of octanoic acid was added dropwise within 1 hour to make it react at 60-65° C. until the absorption peak of isocyanate group disappeared in the IR spectrum. Then add 285g of epoxy equivalent of 475 bisphenol A epoxy resin, 380g of epoxy equivalent of 950 bisphenol A epoxy resin and 0.62g of benzyldimethylamine in the flask. Then, the mixture was reacted at 120° C., and the produced methanol by-product was distilled off until the epoxy equivalent reached 1120. After cooling, 29.1 g of diethanolamine, 21.5 g of N-methylethanolamine and 32.9 g of aminoethylethanolamine ketimine (79% solution in MIBK) were added to the mixture and allowed to react at 110° C. for 2 hours. IR spectrum confirmed the absorption of oxazolidinone carbonyl at 1750cm ^-1 . The product was diluted with MIBK to 80% non-volatility, and the cationic resin thus obtained showed satisfactory emulsifying properties.

Claims (13)

1. modified epoxy; comprise at least one blocked isocyanate moiety that Tong Guo oxazolidone ring connects; Suo Shu De oxazolidone ring is formed by the isocyanide acyl group reaction of the epoxy group(ing) of many glycidyl epoxies part with organic diisocyanate; then by block reversibly or irreversibly, this modified epoxy further contains at least one cation radical of being introduced by the ring-opening reaction of remaining oxirane ring and cation activity hydrogen compound to other isocyanate group.

2. modified epoxy as claimed in claim 1, wherein said many glycidyl epoxies are the many glycidyl ether epoxy of polyphenol, aliphatic series how pure many glycidyl ether epoxy, many glycidyls of poly carboxylic acid ester epoxy resin or its chainpropagation product.

3. modified epoxy as claimed in claim 1, wherein said other isocyanide acyl group is reversibly used butanols, 2-Ethylhexyl Alcohol, alkylphenol, glycol monobasic ether, ketoxime or lactan block.

4. modified epoxy as claimed in claim 1, wherein said other isocyanide acyl group be irreversibly with primary amine or secondary amine, uncle's aminoalkanol, or aliphatic monocarboxylic acid's block.

5. modified epoxy as claimed in claim 1, the wherein said cation activity hydrogen compound that is used to open the residual epoxide ring is a primary amine, secondary amine, the mixture of the acid salt of tertiary amine or sulfide-acid.

6. a method for preparing modified epoxy comprises the steps:

To contain the organic diisocyanate reaction of the Resins, epoxy and the asymmetric block of many glycidyls, described vulcabond contains the first block isocyanide acyl group and the second block isocyanide acyl group, the specific activity first block isocyanide acyl group of this second isocyanide acyl group is little, and than the described first block isocyanide acyl group stoichiometric number little with the ratio of glycidyl; With

The product and the cation activity reactive hydrogen compound of gained are introduced cation radical with the ring-opening reaction by residual epoxide ring and described positively charged ion hydrogen compound.

7. method as claimed in claim 6, wherein said Resins, epoxy are the many glycidyl ether epoxy of polyphenol, the how pure many glycidyl ether epoxy of aliphatic series, many glycidyls of poly carboxylic acid ester epoxy resin, or its chainpropagation product.

8. method as claimed in claim 6, the wherein said first isocyanide acyl group is with methyl alcohol or ethanol block.

9. method as claimed in claim 6, the wherein said second isocyanide acyl group is reversibly used butanols, 2-Ethylhexyl Alcohol, alkylphenol, glycol-first ether, ketoxime or lactan block.

10. method as claimed in claim 6, the wherein said second isocyanide acyl group be irreversibly with primary amine or secondary amine, uncle's aminoalkanol, or aliphatic monocarboxylic acid's block.

11. method as claimed in claim 6, wherein said cation activity hydrogen compound is primary amine or secondary amine, the acid salt of tertiary amine, or the mixture of sulfide-acid.

12. the described modified resin of claim 1 is as the application of the aqueous dispersion of cathode electrodeposition paint.

13. the described modified epoxy of claim 1 is as the application of the vector resin of pigment paste, described pigment paste is the form of the dispersion of pigment in the described vector resin aqueous solution.