KR102229059B1 - Electrodeposition Resin Composition and Electrodeposition Paint Comprising The Same - Google Patents

Abstract

The present invention includes an epoxy resin, a urethane-based curing agent, a polyol compound, and an amine compound, and the urethane-based curing agent is an isocyanate compound blocked with a straight-chain alcohol containing at least three ether groups (-O-) in the molecule. It relates to an electrodeposition resin composition and an electrodeposition coating comprising the same.

Description

Electrodeposition Resin Composition and Electrodeposition Paint Comprising The Same {Electrodeposition Resin Composition and Electrodeposition Paint Comprising The Same}

The present invention relates to an electrodeposition resin composition and an electrodeposition coating comprising the same.

In order to protect the metallic material from corrosion and to maintain its aesthetics throughout its use, its surface is usually painted. Electrodeposition coating, compared with air spray coating or electrostatic spray coating, has excellent coating properties and less environmental pollution, and thus has been widely used as a primer coating. Particularly, since cationic electrodeposition coating can be continuously applied, it is widely used as a method of pre-coating a large-sized, high-corrosion-resistance coating object such as an automobile body.

The cationic electrodeposition coating composition is generally obtained by dispersing a binder component including a cationic resin and a curing agent in an aqueous medium including a neutralizing agent such as an organic acid. Electrodeposition coating is performed by immersing an object to be painted as a negative electrode in the cationic electrodeposition coating composition and applying a voltage. When a voltage is applied between the electrodes in the painting process, an electrodeposited coating film is deposited on the surface of the cathode (to be coated) by an electrochemical reaction. Since a curing agent is contained in the electrodeposition coating film thus formed together with a cationic resin, the coating film is cured by firing the coating film after the electrodeposition coating is completed, and a desired cured coating film is formed.

A urethane-based curing agent containing isocyanate blocked as a curing agent used for electrodeposition coating is used, and a curing agent containing isocyanate blocked with alcohol having one or two ether groups in the molecule as a blocking agent for blocking isocyanate is used. However, although this has good workability and an effect of improving corrosion resistance, there is a problem that the effect of improving the appearance of the coating film is not recognized (Korean Patent Publication No. 0211079).

Accordingly, attention has been focused on the development of a cationic electrodeposition resin to increase the flexibility during electrodeposition coating and at the same time improve the appearance properties of the coating film.

Korean Patent Publication No. 0211079

An object of the present invention is to provide an electrodeposition resin composition capable of improving appearance properties while increasing the flexibility of a coating film during electrodeposition coating. In addition, it provides an electrodeposition coating comprising the electrodeposition resin composition and the pigment paste composition.

The present invention includes an epoxy resin, a urethane-based curing agent, a polyol compound, and an amine compound, and the urethane-based curing agent includes an isocyanate compound blocked with a straight-chain alcohol containing at least three ether groups (-O-) in the molecule. It provides an electrodeposition resin composition.

In addition, the present invention provides an electrodeposition coating comprising the electrodeposition resin composition and the pigment paste composition.

The electrodeposition resin composition of the present invention uses a urethane-based curing agent containing an isocyanate-based compound blocked with a straight-chain alcohol containing at least three ether groups (-O-) in the molecule, so that the surface roughness, gloss, etc. of the electrodeposition coating film are used. It is possible to improve the physical properties of the exterior. In addition, by using the urethane-based curing agent as described above, there is an effect that coating workability is improved and flexibility can be provided to the electrodeposited coating film.

Hereinafter, the present invention will be described in detail.

One. Electrodeposition resin composition

The present invention provides an electrodeposition resin composition.

The electrodeposition resin composition of the present invention contains an epoxy resin, a urethane-based curing agent, a polyol compound, and an amine compound.

The content of the solid content of the electrodeposition resin composition may be 30 to 50% by weight, specifically 30 to 40% by weight. When the solid content of the electrodeposition resin composition is less than 30% by weight, the viscosity may be lowered, resulting in problems with storage and workability, and when it exceeds 50% by weight, a problem may occur in the appearance of the coating film and the use of the paint may become difficult. have.

The viscosity of the electrodeposited resin composition may be 40 to 140 cPs at 25°C. If the viscosity of the electrodeposition resin composition is less than 40 cPs, problems may occur in storage and workability of the paint, and if it exceeds 140 cPs, problems may occur in the appearance of the coating film.

The electrical conductivity of the electrodeposition resin composition may be 2,200 to 2,800 µs/cm, and the turbidity may be 100 ntu (nephelometry turbidity unit) or less.

<Epoxy resin>

The epoxy resin contained in the electrodeposition resin composition of the present invention is a base resin (main resin) component that is cured to form a coating film, and serves to impart physical properties such as excellent adhesion and heat resistance to the finally formed coating film.

The epoxy resin is a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol novolak type epoxy resin, a cresol novolac type epoxy resin, an alkylphenol novolak type epoxy resin, a naphthalene type epoxy resin, or a dicyclopentadiene type epoxy. It may be resin or the like. Specifically, for the excellent appearance of the coating film, it is preferable that the epoxy resin contains a bisphenol-type epoxy resin.

The epoxy resin may have an epoxy equivalent weight (EEW) of 150 to 250 g/eq., and preferably 180 to 200 g/eq. The epoxy equivalent of the epoxy resin is 150 g/eq. If the amount is less than the urethane-based curing agent and crosslinking does not occur well, there is a problem that the curability is deteriorated, 250 g/eq. If it is exceeded, a problem may occur in appearance such as roughness of the surface of the coating film.

The epoxy resin may have a viscosity of 10,000 to 20,000 cPs at 25°C, and preferably 11,000 to 15,000 cPs. When the viscosity of the epoxy resin is less than 10,000 cPs, a problem may occur in the flexibility of the coating film, and when it exceeds 20,000 cPs, there is a concern that the appearance of the coating film may not be smooth.

<Urethane curing agent>

The urethane-based curing agent contained in the electrodeposition resin composition of the present invention is a component that serves to crosslink and cure the base resin (epoxy resin), and may include an isocyanate-based compound.

In particular, the isocyanate-based compound may be blocked with a blocking agent such as alcohol for the purpose of blocking the isocyanate group (-NCO) contained in the isocyanate-based compound from reacting with active hydrogen at room temperature and self-polymerization easily.

Among them, the isocyanate-based compound may be blocked with a straight-chain alcohol containing at least three ether groups (-O-) in the molecule. As described above, when the isocyanate-based compound is blocked with a straight-chain alcohol containing at least three ether groups in its molecule, it has a linear molecular structure, so that the flexibility of the coating film may be excellent.

A straight-chain alcohol containing at least three ether groups (-O-) in the molecule may be represented by the following formula (1).

[Formula 1]

In Formula 1,

R is a straight-chain alkyl group having 4 to 10 carbon atoms,

n is 3 to 10.

R may be a straight-chain butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, or a decyl group.

The n may be 3 to 8, 3 to 6, and 3 to 4.

The straight-chain alcohol containing at least three ether groups (-O-) in the molecule may include at least one selected from triethylene glycol monobutyl ether and tetraethylene glycol monobutyl ether.

The isocyanate-based compound may be a monomeric isocyanate or a polymeric isocyanate. For example, the isocyanate compound is methyl bisphenyl diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diphenyl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, 2 ,4-toluene diisocyanate, 2,6-toluene diisocyanate, p-phenylene isocyanate, diphenylmethane-4,4'-diisocyanate, triphenylmethane-4,4',4"-triisocyanate, or these It may be an isocyanate of a monomer such as a mixture of, or a polymerized isocyanate such as polymethylene polyphenyl isocyanate.

On the other hand, the urethane-based curing agent may include a compound obtained by reacting the isocyanate-based compound and a straight-chain alcohol containing at least three ether groups (-O-) in the molecule in a weight ratio of 1:1 to 1:2. I can.

The urethane-based curing agent may include a compound obtained by reacting a linear alcohol containing at least three ether groups (-O-) in a larger amount than the isocyanate-based compound. Specifically, the isocyanate-based compound and a straight-chain alcohol containing at least three ether groups (-O-) in the molecule may react in a weight ratio of greater than 1:1 and less than 1:2, and more specifically 1: It can react in a weight ratio of more than 1 and not more than 1:1.6.

When the reaction weight ratio of the isocyanate-based compound and a straight-chain alcohol containing at least three ether groups (-O-) in the molecule is less than 1:1, flexibility cannot be imparted to the coating film, and is greater than 1:2. There may be a problem that the appearance of the coating film is deteriorated.

The epoxy resin and the urethane-based curing agent may be included in a weight ratio of 1:1 to 1:3. When the weight ratio of the epoxy resin and the urethane-based curing agent is less than 1:1, the appearance of the coating film becomes rough, the curing property is poor, and the coating film rise property is low, and when it exceeds 1:3, the internal coating property is poor. And, there may be a problem that the stability of the resin is deteriorated, such as precipitation in the electrodeposited resin composition.

<Polyol compound>

The polyol compound contained in the electrodeposition resin composition of the present invention helps to extend the chain of the base resin, the epoxy resin, to impart flexibility to the coating film, and enhances water dispersibility to improve workability as well as the appearance of the coating film. can do.

As the polyol compound, as long as it contains at least two hydroxy groups in the compound, it may be used without limitation, and for example, ethylene glycol, propylene glycol, butylene glycol, bisphenol A, ethoxylated bisphenol A ( Ethoxylated BPA), bisphenol A-ethylene oxide adduct, glycerol, trimethylol propane (TMP), or a mixture thereof.

The polyol compound may be included in an amount of 50 to 90 parts by weight based on 100 parts by weight of the epoxy resin, and more specifically, may be included in an amount of 60 to 80 parts by weight. When the content of the polyol compound is less than 50 parts by weight, the chain extension effect of the epoxy resin may be reduced and the appearance of the coating film may be rough, and when the content of the polyol compound is more than 90 parts by weight, the internal paintability of the coating film may be inferior.

<Amine compound>

The amine compound contained in the electrodeposition resin composition of the present invention can be used as a polymerization raw material reacting with an epoxy resin.

The amine compound may be used without limitation as long as it is commonly used in the electrodeposition resin composition. The amine compound may be, for example, a primary amine; Secondary amine; Ketimine derivatives obtained by reacting a primary amine with a ketone compound; Or it may be a mixture of these.

In addition, the amine compound may be a monoamine compound, a diamine compound, a triamine compound, a tetraamine compound, or a mixture thereof, for example diethanolamine, methylethyleneamine, dimethylpropanediamine, benzylamine, n-butyl Amine, aniline, cyclopentanamine, cyclohexylamine, 2-aminophenol, 2-bromoaniline, ethylenediamine, hexamethyldiamine, aminoethylethanolamine, N-methylethanolamine, benzyldimethylamine, ketimine, diketamine , Diethylamine, diethylenetriamine, triethylenetetraamine, butanolamine, or a mixture thereof.

The amine compound may be included in an amount of 5 to 30 parts by weight based on 100 parts by weight of the epoxy resin, for example, it may be included in an amount of 10 to 30 parts by weight. If the content of the amine compound is less than 5 parts by weight, the internal paintability of the coating film may be poor, and if the content of the amine compound is more than 30 parts by weight, the particles become large, resulting in a storage problem, and water dispersibility is poor, resulting in a problem in the appearance of the coating film. I can.

<Other>

The electrodeposition resin composition of the present invention may further include at least one selected from an organic solvent, an epoxy neutralizing agent, and an additive.

The organic solvent can control the rise of the coating film and the internal coating property of the electrodeposition coating, for example, 5,8,11,13,16,19-hexaoxatricosein (5,8,11,13,16,19- Ether solvents such as hexaoxatricosane); Alcohol-based solvents such as 1-methoxy-2-propanol, butyl cellosolve, butyl carbitol, propylene glycol methyl ether, hexanediol, and hexyl glycol; Ketone solvents such as methyl isobutyl ketone (MIBK); Ester solvents such as dibutyltin dilaurate; Alternatively, a mixture of these and the like can be used.

The organic solvent may be included in an amount of 1 to 15 parts by weight based on 100 parts by weight of the epoxy resin.

The epoxy neutralizing agent serves to neutralize the acidity of the epoxy resin of the electrodeposition resin composition of the present invention so that the pH of the electrodeposition resin composition is in the range of 5.5 to 6.5, and the epoxy neutralizing agent is an alkyl sulfonic acid (e.g., methane Sulfonic acid), but is not limited thereto.

The epoxy neutralizing agent may be included in an amount of 1 to 15 parts by weight based on 100 parts by weight of the epoxy resin.

The additive may include an anti-cratering agent or microgel for enhancing oil resistance of the electrodeposited resin composition and controlling fluidity.

In addition, the additive may further include at least one selected from an antifoaming agent, a dispersing agent, a surface adjusting agent, an antibacterial agent, and a thickener.

The type and amount of the additional components commonly used may be appropriately selected in order to improve the flexibility and appearance of the electrodeposited coating film.

2. Pigment paste composition

The pigment paste composition used in the present invention contains a dispersion resin and a pigment.

The pigment paste composition may have a solid content of 40% to 60% by weight. When the solid content of the pigment paste composition is less than 40% by weight, the viscosity of the pigment paste is too low, and storage stability due to precipitation of relatively heavy pigments may be deteriorated, and when it is more than 60% by weight, the viscosity of the paint is too high. It may be difficult to use, and storage stability may be deteriorated due to insufficient content of the dispersion resin.

The pigment paste composition may have a pH of 5.5 to 6.5, a specific gravity of 1.35 to 1.45, an average particle diameter of 1 to 12 µm, and an Ash (ash) content of 72 to 78 in the solid content of the pigment paste composition. It may be weight percent.

<dispersion balance>

The dispersion resin contained in the pigment paste composition of the present invention functions to improve the wetting of the pigment.

The dispersion resin may be a bisphenol-type epoxy resin identical or similar to the above-described epoxy resin (base resin), but is not limited thereto.

<curing catalyst>

The pigment paste composition used in the present invention may further include a curing catalyst, and the curing catalyst may improve the curability of the pigment paste composition or the final electrodeposition coating.

The curing catalyst is not limited thereto as long as it is used in the pigment paste composition, and specifically, may be a tin-containing compound, a bismuth-containing compound, or a mixture thereof, and may be prepared and used in a liquid form or a paste form.

The tin-containing compound may be, for example, dibutyl tin oxide, dibutyl tin dilaurylate, dibutyl tin chloride, dioctyl tin chloride, dioctyl tin oxide, or a mixture thereof.

The bismuth-containing compound is, for example, Bi ₂ O ₃ or Bi(OH) _divalent , lactic acid, acetic acid, formic acid, dimethylolpropionic acid (DMPA), or It may be mixed with an acid such as methanesulfonic acid (MSA).

The curing catalyst may be included in an amount of 5 parts by weight to 450 parts by weight based on 100 parts by weight of the dispersion resin, for example, including 10 parts by weight to 300 parts by weight of the pigment paste composition or the final prepared electrodeposition coating. I can improve it.

<Pigment>

The pigment contained in the pigment paste composition used in the present invention serves to improve the appearance of the coating film.

As the pigment, a commonly used inorganic pigment may be used. The inorganic pigments are, for example, titanium oxide, zinc oxide, zinc sulfide, kaolin, clay, calcium carbonate, talc, silica, iron oxide, lead chromate, cadmium, chromium oxide, carbon black, zinc chromate, strontium chromate, It may be zinc phosphate, phosphate, silicate, barium sulfate, and the like, but is not limited thereto.

The pigment may be included in an amount of 250 parts by weight to 300 parts by weight based on 100 parts by weight of the dispersion resin, and for example, may be included in an amount of 260 parts by weight to 280 parts by weight. If the content of the pigment is less than 250 parts by weight based on 100 parts by weight of the dispersion resin, the hiding power for the body may be lowered and the covering power of the edge of the vehicle body may be poor, and if it exceeds 300 parts by weight, the appearance of the coating film This deteriorates, and workability in the electrodeposition process may be deteriorated.

<Other additives>

The pigment paste composition may further include a solvent for controlling the solid content of the pigment paste composition, controlling acidity, viscosity, and electrodeposition coating. As the solvent, a commonly known one may be used, and for example, the kind of the organic solvent described above may be applied.

In addition, the pigment paste composition may further include a commonly known antifoaming agent, a surface adjusting agent, a dispersing agent, a pH adjusting agent, and the like in order to increase the physical properties of the coating film formed by using the same. The additive may be included in an amount of 1 to 10 parts by weight based on 100 parts by weight of the dispersion resin.

3. Electrodeposition paint

In addition, the present invention provides an electrodeposition coating comprising the electrodeposition resin composition and the pigment paste composition described above.

The electrodeposition coating of the present invention is described in '1. The electrodeposition resin composition and '2. It may include the pigment paste composition described in the item'Pigment Paste Composition'.

The electrodeposition coating of the present invention introduces a urethane-based curing agent comprising an epoxy resin and an isocyanate-based compound blocked with a straight-chain alcohol containing at least three ether groups (-O-) in the molecule to the electrodeposition resin composition, and a polyol compound and By including the amine compound, there is an effect of imparting flexibility to the coating film and improving the appearance of the coating film, as well as internal coating properties and workability of the electrodeposition coating.

The electrodeposition resin composition and the pigment paste composition included in the electrodeposition coating may be mixed in a weight ratio of 4:1 to 9:1, for example, in a weight ratio of 5:1 to 8:1. When the ratio of the electrodeposition resin composition and the pigment paste composition satisfies the above range, it is useful for electrodeposition painting of automobiles, home appliances, etc., by improving the internal paintability and workability of the electrodeposition paint while having excellent rust prevention and adhesion properties of the coating film. Can be used.

Hereinafter, the present invention will be described in detail through examples. However, the following examples are merely illustrative of the present invention, and the present invention is not limited by the following examples.

<Production Example>-Preparation of urethane-based curing agent

<Production Example 1>

PAPI2940 (Dow Chemical co.), methyl isobutyl ketone, and dibutyl tin dilaurate were supplied to the reaction flask, heated to 30° C. in a nitrogen atmosphere, and maintained at 60 to 65° C., while triethylene glycol monobutyl ether was used. It was added slowly. When the addition was complete, the mixture was allowed to stand at 65° C. for 90 minutes, then trimethylolpropane was added to heat the mixture to 110° C., and then left again at this temperature for 3 hours. I did. The urethane-based curing agent A was prepared by continuously maintaining at 110° C. until no unreacted NCO remained by infrared analysis.

The content of each component is shown in Table 1 below.

ingredient Content (parts by weight) PAPI2940 346 Methyl isobutyl ketone 199.9 Dibutyltin dilaurate 0.1 Triethylene glycol monobutyl ether 430.7 Trimethylolpropane 23.3

* PAPI2940: polymethylene polyphenylisocyanate

<Production Example 2>

Each component and content are as shown in Table 2 below, and urethane-based curing agent B was prepared in the same manner as in Preparation Example 1.

ingredient Content (parts by weight) PAPI2940 301 Methyl isobutyl ketone 199.9 Dibutyltin dilaurate 0.1 Triethylene glycol monobutyl ether 545.5 Trimethylolpropane 23.3

<Production Example 3>

Each component and content are as shown in Table 3 below, and a urethane-based curing agent C was prepared in the same manner as in Preparation Example 1.

ingredient Content (parts by weight) PAPI2940 310.3 Methyl isobutyl ketone 199.9 Dibutyltin dilaurate 0.1 Tetraethylene glycol monobutyl ether 468.8 Trimethylolpropane 20.9

<Comparative Production Example 1>

Each component and content are as shown in Table 4 below, and a urethane-based curing agent D was prepared in the same manner as in Preparation Example 1.

ingredient Content (parts by weight) PAPI2940 531.6 Methyl isobutyl ketone 197.5 Dibutyltin dilaurate 0.1 Butanol 234.9 Trimethylolpropane 35.9

<Comparative Production Example 2>

Each component and content are as shown in Table 5 below, and a urethane-based curing agent E was prepared in the same manner as in Preparation Example 1.

ingredient Content (parts by weight) PAPI2940 464.3 Methyl isobutyl ketone 196.9 Dibutyltin dilaurate 0.1 2-(2-butoxyethoxy)ethanol 307.4 Trimethylolpropane 31.3

<Comparative Production Example 3>

Each component and content are as shown in Table 6 below, and a urethane-based curing agent F was prepared in the same manner as in Preparation Example 1.

ingredient Content (parts by weight) PAPI2940 390.9 Methyl isobutyl ketone 199.9 Dibutyltin dilaurate 0.1 Diethylene glycol monobutyl ether 382.7 Trimethylolpropane 26.4

<Comparative Production Example 4>

Each component and content are as shown in Table 7 below, and a urethane-based curing agent G was prepared in the same manner as in Preparation Example 1.

ingredient Content (parts by weight) PAPI2940 428.9 Methyl isobutyl ketone 199.9 Dibutyltin dilaurate 0.1 Isopropylene glycol monobutyl ether 342.2 Trimethylolpropane 28.9

<Comparative Production Example 5>

Each component and content are as shown in Table 8 below, and a urethane-based curing agent H was prepared in the same manner as in Preparation Example 1.

ingredient Content (parts by weight) PAPI2940 346 Methyl isobutyl ketone 199.9 Dibutyltin dilaurate 0.1 Isopropylene glycol monobutyl ether 430.7 Trimethylolpropane 23.3

<Example>-Preparation of electrodeposited resin composition

<Example 1-1>

EPON 828, bisphenol A-ethylene oxide adduct (1:6 molar ratio), bisphenol A and methoxypropanol were fed to a reaction vessel and heated to 140° C. under a nitrogen atmosphere. When the mixture was heated to 140° C., benzyldimethylamine was added, and the mixture was allowed to stand for 30 to 60 minutes, and the temperature was maintained at 145° C. until the epoxy equivalent reached 830 to 860 g/eq. When the epoxy equivalent was reached, the urethane-based curing agent A prepared in Preparation Example 1 was added and stirred for 30 minutes to cool the reaction mixture. When the temperature of the reaction product reached 120° C. or lower, diethanol amine and KT-22 were successively added. After the mixture was heated and reacted for 2 hours while maintaining the temperature at 120° C., vacuum was applied to the product to remove the organic solvent, and the mixture was slowly added and dispersed while sufficiently stirring to the mixture consisting of methanesulfonic acid and first deionized water being stirred. Subsequently, a second deionized water was gradually added to the dispersion and further diluted, to prepare a cationic electrodeposition resin composition A having a solid content of 36% by weight.

The content of each component is shown in Table 9 below.

ingredient Content (parts by weight) EPON 828 105 Bisphenol A-ethylene oxide adduct (1:6 molar ratio) 38 Bisphenol A 42 Methoxypropanol 11 Benzyldimethylamine 0.6 Urethane curing agent A 150 KT-22 18 Diethanolamine 12 Deionized water 300 Methanesulfonic acid 12 Deionized water (primary) 200 Deionized water (secondary) 111.4

* EPON 828: diglycidyl ether of bisphenol A (Kukdo Chemical), epoxy equivalent 188 g/eq.

* KT-22: 73% by weight methylisobutylketone solution of diketamine capped with methylisobutylketone of diethylenetriamine (Air Products)

<Example 1-2>

Except for including the urethane-based curing agent B in place of the urethane-based curing agent A in Example 1-1, a cationic electrodeposition resin composition B was prepared in the same manner as in Example 1-1.

<Example 1-3>

Except for including the urethane-based curing agent C in place of the urethane-based curing agent A in Example 1-1, a cationic electrodeposition resin composition C was prepared in the same manner as in Example 1-1.

<Comparative Example 1-1>

Except for including the urethane-based curing agent D in place of the urethane-based curing agent A in Example 1-1, a cationic electrodeposition resin composition D was prepared in the same manner as in Example 1-1.

<Comparative Example 1-2>

Except for including the urethane-based curing agent E in place of the urethane-based curing agent A in Example 1-1, a cationic electrodeposition resin composition E was prepared in the same manner as in Example 1-1.

<Comparative Example 1-3>

Except for including the urethane-based curing agent F in place of the urethane-based curing agent A in Example 1-1, a cationic electrodeposition resin composition F was prepared in the same manner as in Example 1-1.

<Comparative Example 1-4>

Except for including the urethane-based curing agent G in place of the urethane-based curing agent A in Example 1-1, a cationic electrodeposition resin composition G was prepared in the same manner as in Example 1-1.

<Comparative Example 1-5>

Except for including the urethane-based curing agent H in place of the urethane-based curing agent A in Example 1-1, a cationic electrodeposition resin composition H was prepared in the same manner as in Example 1-1.

<Example 2>-Preparation of pigment paste composition

1. An epoxy resin (CRQ00143, KCC) was added to the reaction flask and dibutyl tin oxide was added while stirring. When the viscosity increased due to the large amount of pigment, some of the deionized water was gradually added to the mixture, and the mixture was stirred well until the pigment was uniform, and finally, the remaining amount of deionized water was added and diluted. The obtained mixture was dispersed up to Hegman No. 8 with an SL-50 (BYK) disperser to prepare a dibutyl tin oxide paste.

The content of each component is shown in Table 10 below.

ingredient Content (parts by weight) Epoxy resin 909 Dibutyl tin oxide 580 Deionized water 1511

2. Epoxy resin (CRQ00143, KCC) was added to the reaction flask, and the components shown in Table 10 were sequentially added thereto while stirring. When the viscosity increased due to the increase in pigment content, SURFYNOL 104/BC (50%) was added to stir well until the pigment content became uniform, and finally, a second deionized water was added to dilute. The obtained mixture was dispersed up to Hegman No. 8 with an SL-50 disperser to prepare a pigment paste composition.

The content of each component is shown in Table 11 below.

ingredient Content (parts by weight) Epoxy resin 187.9 Dibutyl Tin Oxide Paste 360.8 Carbon black 8 Deionized water (primary) 445.8 ASP200 315.4 Titanium dioxide 473.6 SURFYNOL 104/BC (50%) 20 Deionized water (secondary) 94.3

* ASP200: Aluminum silicate (BASF)

* SURFYNOL 104/BC (50%): 50% dilution of hexanediol-based wetting agent butyl Cellosolve (Air Products)

<Experimental Example>

The pigment paste composition prepared in Example 2 while mixing and stirring 930 parts by weight of the electrodeposited resin composition prepared in Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-5 and 940 parts by weight of deionized water 130 parts by weight was gradually added to prepare a cationic electrodeposition coating having a solid content of 20% by weight. The electrodeposition paint was passed through an ultrafilter up to 20% of the initial weight, and the ultrafiltrate was changed to deionized water. Thereafter, after being left in a stirring state for one day, electrodeposition coating was performed at a temperature of 28° C. for 3 minutes with a DC voltage of 180 to 240 V.

At this time, a steel plate pretreated with zinc phosphate is used as the specimen. The coated object for 3 minutes was cured at 160° C. for 25 minutes, and the thickness and gloss, appearance (including the naked eye) and curing properties of the dried coating film are shown in Table 12 below.

1. Film thickness: Measure the film thickness using a film measuring device (MiniTest3100). It is preferable that the coating film thickness is 14 to 19 µm.

2. Illuminance: Measured with an illuminometer cut off=0.8mm and cut off=2.5mm.

(It is a value representing the height deviation within a certain distance. The smaller the value, the better the appearance)

3. Visual Appearance: When the electrodeposition-coated specimen is judged with the naked eye, it is judged whether the appearance of the coating film is rough, the appearance is poor, or the roughness is poor.

('Good' when there is no defect in appearance and the roughness of the coating film is not bad,'defective' when there is a defect in the appearance and the roughness of the coating film is poor)

4. Curability: It is judged whether or not MIBK rubbing is satisfied 50 times after curing at 160℃×15 minutes (MPT).

(After curing, rubbing 50 times in MIBK, if there is no damage to the coating film, it is'good', and if there is damage to the coating film, it is'defective')

division Coating thickness (㎛)
(28℃×220V×180sec) Appearance (Ra) Cut off 0.8mm Appearance (Ra) Cut off 2.5mm Visual appearance Curability Example 1-1 16-18 0.15~0.18 0.19~0.21 Good Good Example 1-2 18-19 0.17~0.18 0.19~0.21 Good Good Example 1-3 14~16 0.13~0.16 0.17~0.19 Good Good Comparative Example 1-1 20~22 0.21~0.23 0.25~0.28 Good Good Comparative Example 1-2 19~21 0.20~0.22 0.23~0.26 Good Good Comparative Example 1-3 16-18 0.18~0.20 0.21~0.23 Good Good Comparative Example 1-4 19~21 0.25~0.27 0.30~0.32 Good Good Comparative Example 1-5 21~23 0.26~0.28 0.32~0.34 Good Bad

In the above, the present invention has been described in detail only with respect to the described embodiments, but it is obvious to those skilled in the art that various modifications and modifications are possible within the scope of the technical idea of the present invention, and it is natural that such modifications and modifications belong to the appended claims.

Claims (6)

Including an epoxy resin, a urethane-based curing agent, a polyol compound and an amine compound,
The urethane-based curing agent includes an isocyanate-based compound blocked with a straight-chain alcohol containing at least three ether groups (-O-) in the molecule,
A straight-chain alcohol containing at least three ether groups (-O-) in the molecule is represented by the following formula (1),
The urethane-based curing agent is obtained by reacting the isocyanate-based compound and a straight-chain alcohol containing at least three ether groups (-O-) in the molecule in a weight ratio of 1:1 to 1:2, an electrodeposition resin composition:
[Formula 1]

In Formula 1,
R is a straight-chain alkyl group having 4 to 10 carbon atoms,
n is 3 to 10. delete delete The method according to claim 1.
Electrodeposition resin composition containing the epoxy resin and the urethane-based curing agent in a weight ratio of 1:1 to 1:3. The method according to claim 1,
An electrodeposition resin composition further comprising at least one selected from an organic solvent, an epoxy neutralizing agent, and an additive. An electrodeposition coating comprising the electrodeposition resin composition and the pigment paste composition according to any one of claims 1, 4, and 5.