Electrodeposition coating composition

Abstract

The present invention provides an electrodeposition coating composition having excellent washability and bubble stability, in which the electrodeposition coating composition comprises an emulsion resin composition and a pigment dispersion, the emulsion resin composition comprising an epoxy resin, a polyurethane curing agent, and a polyether-modified organosilicon compound.

Description

Technical Field

[0001] The present invention relates to an electrodeposition coating composition having excellent water washability and bubble stability. Background Art

[0002] As a method for preventing metal materials from corroding, the surface of the metal material is usually coated, and various coating methods such as brushing, roller coating, electrodeposition coating, powder coating and spraying are applied. Among the above methods, electrodeposition coating is a widely used method because the method has excellent coating performance and less environmental pollution problems. In particular, cationic electrodeposition coating can be continuously coated, so it is advantageous in being applied to large objects to be coated.

[0003] Electrodeposition coating compositions having various compositions have been proposed in order to impart excellent processability, corrosion resistance, coating film appearance characteristics, etc. For example, Korean Patent No. 10-0211079 discloses an electrodeposition composition comprising a non-gelling cationic resin derived from polyepoxide and containing an active hydrogen group selected from aliphatic hydroxyl groups, primary amino groups, and secondary amino groups, and a cationic salt group in the resin molecule; and a fully blocked polyisocyanate curing agent substantially free of free isocyanate groups.

[0004] However, typical electrodeposition coatings have a problem of poor washability, which may result in poor stain or bubble stability. Therefore, it is desirable to develop an electrodeposition coating composition that has excellent washability and bubble stability and can provide a coating film having excellent appearance characteristics. Summary of the invention

[0005] Technical issues

[0006] The present invention provides an electrodeposition coating composition having excellent water washability and bubble stability.

[0007] Technical Solution

[0008] The present invention provides an electrodeposition coating composition, which comprises an emulsion resin composition and a pigment dispersion. The emulsion resin composition comprises an epoxy resin, a polyurethane curing agent and a polyether-modified organic silicon compound.

[0009] Beneficial Effects

[0010] The present invention provides an electrodeposition coating composition having excellent water washability and bubble stability. The electrodeposition coating composition of the present invention has excellent water washability, thereby minimizing water stains generated during the electrodeposition coating process, and has excellent bubble stability, thereby giving the coating film applied with the electrodeposition coating composition an excellent appearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The criteria for evaluating the water washability of coating films are shown. DETAILED DESCRIPTION

[0012] Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following description, and various modifications or selective mixing and use of each component may be performed if necessary. Therefore, it should be understood that all changes, equivalents and alternatives falling within the spirit and scope of the present invention are intended to be included.

[0013] The "number average molecular weight" or "weight average molecular weight" used herein is measured by a typical method known in the art, and can be measured, for example, by gel permeation chromatography (GPC). "Viscosity" is measured by a typical method known in the art, and can be measured at room temperature (25°C) using, for example, a Gardner viscometer (bubble viscometer).

[0014] The electrodeposition coating composition of the present invention comprises an emulsion resin composition and a pigment dispersion, wherein the emulsion resin composition comprises an epoxy resin, a polyurethane curing agent and a polyether-modified organosilicon compound. If necessary, the electrodeposition coating composition of the present invention may also comprise additives such as a pH regulator, a wetting agent, a catalyst, a plasticizer, and an anti-pitting agent.

[0015] <Emulsion resin composition>

[0016] Epoxy resin

[0017] The emulsion resin composition of the electrodeposition coating composition of the present invention contains epoxy resin, which is a base resin (main resin) component for curing to form a coating film and is used to impart properties such as adhesion and heat resistance to the formed coating film.

[0018] Examples of the epoxy resin may include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alkyl-phenol novelac type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, and the like, any one of which may be used alone or in combination of two or more.

[0019] The epoxy resin may have an epoxy equivalent of 150 g / eq to 250 g / eq, for example, 180 g / eq to 200 g / eq. If the epoxy equivalent of the epoxy resin is less than the above range, the curability may be reduced due to poor crosslinking with the curing agent, and if it is greater than the above range, the appearance characteristics may be reduced, such as roughening of the coating surface.

[0020] The viscosity (25° C.) of the epoxy resin may be 10000 cPs to 20000 cPs, for example 11000 cPs to 14000 cPs. If the viscosity of the epoxy resin is less than the above range, the flexibility of the coating film may be deteriorated, and if it is greater than the above range, the appearance characteristics may be reduced, such as roughening of the coating film surface.

[0021] The epoxy resin may be included in an amount of 5 to 20 parts by weight, for example, 10 to 14 parts by weight, based on 100 parts by weight of the emulsion resin composition. If the epoxy resin content is less than the above range, the bending resistance may be poor, and if it is greater than the above range, the water resistance may be poor.

[0022] Polyurethane curing agent

[0023] The emulsion resin composition includes a polyurethane curing agent. The polyurethane curing agent is a component for cross-linking the base resin to cure the base resin, and may include an isocyanate-based compound.

[0024] The isocyanate-based compound may be a monomeric isocyanate or a polymeric isocyanate. For example, the isocyanate-based compound may be a monomeric isocyanate such as methyl diphenyl diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diphenyl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, p-phenylene diisocyanate, diphenylmethane-4,4'-diisocyanate, triphenylmethane-4,4',4"-triisocyanate or a mixture thereof, or a polymeric isocyanate such as polymethylene polyphenyl isocyanate.

[0025] The polyurethane curing agent may include an isocyanate compound terminated by an end-capping agent such as an alcohol. In this case, the isocyanate group (-NCO) contained in the isocyanate compound may be prevented from reacting with active hydrogen at room temperature and from self-polymerization. For example, the polyurethane curing agent may include an isocyanate compound terminated by a linear alcohol containing three or more ether groups (-O-) in the molecule. The linear alcohol containing three or more ether groups (-O-) in the molecule may include one or more of triethylene glycol monobutyl ether and tetraethylene glycol monobutyl ether.

[0026] The NV of the polyurethane curing agent may be 75% to 85%, for example, 79% to 81%, the viscosity (25°C) may be 500cPs to 6000cPs, for example, 1000cPs to 4000cPs, and the NCO content may be 0.5% or less, for example, 0.2% or less. If the NV of the polyurethane curing agent is less than the above range, the curability may be reduced, and thus the corrosion resistance may be deteriorated. If it is greater than the above range, the resin storage performance may be reduced. If the viscosity of the polyurethane curing agent is less than the above range, the internal coating performance may be deteriorated. If it is greater than the above range, a high-build coating film may not be formed. If the NCO content of the polyurethane curing agent is greater than the above range, uncured NCO may remain, which may reduce the resin stability.

[0027] The content of the polyurethane curing agent may be 10 to 20 parts by weight, for example 13 to 18 parts by weight, based on 100 parts by weight of the emulsion resin composition. If the content of the polyurethane curing agent is less than the above range, curability may be weak, and thus corrosion resistance may become a problem, and if it is greater than the above range, an excessively deposited electrodeposition coating film may occur.

[0028] Polyether modified silicone compounds

[0029] The emulsion resin composition includes a polyether-modified organic silicon compound, which is a material having a high molecular weight and is used to increase the surface energy of the electrodeposition coating surface, thereby improving water washability and bubble stability.

[0030] The polyether-modified organic silicon compound has a polyether group as a hydrophilic group and a polydialkylsiloxane group as a hydrophobic group. Due to the above structure, the surface tension of the organic silicon is low, so that by reducing the contact angle of water on the surface of the electrodeposition coating film and increasing the surface energy, the water on the surface of the electrodeposition coating film is spread more widely, so that the fixed water can be easily gathered, thereby removing the water.

[0031] Polyether-modified organosilicon compounds are compounds in which a part of the alkyl group of polydialkylsiloxane is substituted by a group having a polyoxyalkylene group. The alkyl group contained in the polydialkylsiloxane can be an alkyl group with 1 to 6 carbon atoms, for example, can be a methyl group, an ethyl group, a propyl group, a phenyl group, etc. As polydialkylsiloxane, polydimethylsiloxane, a methylethylsiloxane-dimethylsiloxane copolymer, a methylphenylsiloxane-dimethylsiloxane copolymer, etc. can be used. Examples of polyoxyalkylene groups can include polyoxyethylene, polyoxypropylene, polyoxyethylene-polyoxypropylene, etc. Examples of substituents with polyoxyalkylene groups can include hydroxyl (polyoxyalkylene) propylene, methoxy (polyoxyalkylene) propylene, ethoxy (polyoxyalkylene) propylene, hydroxyl polyoxyalkylene, methoxy polyoxyalkylene, ethoxy polyoxyalkylene and polyoxyalkylene, etc.

[0032] The polyether-modified organosilicon compound may have a hydrophile-lipophile balance (HLB) of 9 to 14, for example 10 to 13, a number average molecular weight of 3000 to 15000 g / mol, for example 5000 to 12000 g / mol, and a propylene oxide (PO) content of 5 to 50 wt %, for example 10 to 40 wt %.

[0033] If the HLB of the polyether-modified organosilicon compound is less than the above range, the number of polydialkylsiloxane groups is large and the hydrophobicity is high, thereby possibly generating oil. If the HLB of the polyether-modified organosilicon compound is greater than the above range, the number of polyether groups is large and the hydrophobicity is high.

[0034] The hydrophilicity is high, so a large number of bubbles may be generated. If the number average molecular weight of the polyether-modified organic silicon compound is less than the above range, the surface energy may not be effectively increased, so the anti-foaming performance may be deteriorated. If it is greater than the above range, it may not be conducive to dispersion, so the appearance characteristics may be reduced or oil may be generated. If the PO content of the polyether-modified organic silicon compound is less than the above range, a large number of bubbles may be generated, so the effect of improving water washability may be insufficient. If it is greater than the above range, the effect of removing bubbles may be good, but oil may be generated.

[0035] Based on 100 parts by weight of the emulsion resin composition, the content of the polyether-modified organosilicon compound may be 0.01 to 5 parts by weight, for example 0.01 to 2 parts by weight, and for example 0.03 to 1 part by weight. If the content of the polyether-modified organosilicon compound is less than the above range, the effect of improving water washability may be insufficient, and if it is greater than the above range, the anti-foaming performance or appearance may be deteriorated.

[0036] The content of the polyether-modified organic silicon compound may be 0.01 wt % to 0.5 wt % based on the total weight of the electrodeposition coating composition. If the content of the polyether-modified organic silicon compound is less than the above range, the effect of improving water washability may be insufficient, and if it is greater than the above range, the anti-foaming performance or appearance may be deteriorated.

[0037] Polyols

[0038] The emulsion resin composition may further include a polyol, which can help extend the chain of the epoxy resin as the base resin to impart flexibility to the coating film, and is used to enhance water dispersibility, thereby improving processability and the appearance of the coating film.

[0039] As the polyol, a compound containing two or more hydroxyl groups can be used. For example, the polyol can include ethylene glycol, propylene glycol, butylene glycol, bisphenol A, ethoxylated bisphenol A (BPA), bisphenol A-ethylene oxide adduct, glycerol, trimethylolpropane, etc., and any one of these can be used alone or in combination of two or more.

[0040] The weight average molecular weight of the polyol may be 200 g / mol to 300 g / mol, such as 220 g / mol to 280 g / mol, and the epoxy equivalent is 100 g / eq to 200 g / eq, such as 130 g / eq to 170 g / eq. If the weight average molecular weight of the polyol is less than the above range, the appearance may be deteriorated, if it is greater than the above range, the internal coating performance may be reduced, if the epoxy equivalent of the polyol is less than the above range, the antirust performance may be reduced, if it is greater than the above range, the appearance may be deteriorated.

[0041] The content of the polyol may be 1 to 10 parts by weight, for example 3 to 6 parts by weight, based on 100 parts by weight of the emulsion resin composition. If the content of the polyol is less than the above range, the effect of extending the epoxy resin chain may be reduced, so that the appearance of the coating film may become rough, and if it is greater than the above range, the internal coating performance may be deteriorated.

[0042] Amine compounds

[0043] The emulsion resin composition may further include an amine compound, which is used to terminate the epoxy resin reaction and extend the chain.

[0044] The amine compound can be one commonly used in the electrodeposition resin composition. For example, the amine compound can be a primary amine, a secondary amine, a ketimine derivative obtained by reacting a primary amine with a ketone compound, or a mixture thereof. The amine compound can be a monoamine compound, a diamine compound, a triamine compound, a tetraamine compound, or a mixture thereof, and can be, for example, diethanolamine, methylethyleneamine, dimethylpropylenediamine, benzylamine, n-butylamine, aniline, cyclopentylamine, cyclohexylamine, 2-aminophenol, 2-bromoaniline, ethylenediamine, hexamethylenediamine, aminoethylethanolamine, N-methylethanolamine, benzyldimethylamine, ketimine, diketimine, diethylamine, diethylenetriamine, triethylenetetramine, butanolamine, or a mixture thereof.

[0045] The content of the amine compound may be 1 to 4 parts by weight, for example 2 to 3 parts by weight, based on 100 parts by weight of the emulsion resin composition. If the content of the amine compound is less than the above range, the internal coating properties of the coating film may be deteriorated, and if it is greater than the above range, the size of the particles may increase, thereby deteriorating the storage performance, water dispersibility, and appearance characteristics.

[0046] additive

[0047] The emulsion resin composition may further include additives such as a reaction catalyst, a plasticizer, a neutralizer, an anti-pitting agent, an edge covering additive, and the like.

[0048] The neutralizer is used to neutralize the acidity of the epoxy resin to adjust the pH value of the electrodeposition resin composition, and alkyl sulfonic acid (such as methane sulfonic acid) can be used. The anti-pitting agent and edge covering additive are used to enhance the oil resistance of the electrodeposition resin composition and adjust the fluidity, and microgel can be used. As a reaction catalyst, ethyl triphenyl potassium bromide can be used, and as a plasticizer, ethoxylated bisphenol A can be used.

[0049] The additives may be appropriately added within a content range known in the art, and for example, may be respectively included in an amount of 0.1 parts by weight to 10 parts by weight based on 100 parts by weight of the emulsion resin composition.

[0050] <Pigment dispersion>

[0051] Dispersion resin

[0052] The pigment dispersion of the electrodeposition coating composition of the present invention contains a dispersing resin. The dispersing resin is used to improve the wetting property of the pigment to disperse the pigment.

[0053] The dispersion resin may include an amine-modified epoxy resin. The NV of the amine-modified epoxy resin may be 51% to 60%, for example 53% to 55%, and the viscosity (25°C) may be 1000cPs to 8000cPs, for example 3000cPs to 6000cPs. If the NV content of the epoxy resin is less than the above range, the pigment dispersibility may be reduced, and if it is greater than the above range, the coating yield may be reduced due to high viscosity. If the viscosity of the epoxy resin (25°C) is less than the above range, the pigment dispersibility may be reduced, and if it is greater than the above range, the coating yield may be reduced due to high viscosity.

[0054] Based on 100 parts by weight of the pigment dispersion, the content of the dispersing resin may be 1 to 10 parts by weight, for example 5 to 10 parts by weight. If the content of the dispersing resin is less than the above range, the pigment dispersibility may be reduced. If it is greater than the above range, the coating yield may be reduced.

[0055] pigment

[0056] The pigment dispersion contains a pigment. As the pigment, a pigment commonly used in the art can be used. For example, inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, kaolin, clay, calcium carbonate, talc, silicon dioxide, iron oxide, lead chromate, cadmium, chromium oxide, carbon black, zinc chromate, strontium chromate, zinc phosphate, phosphate, silicate, barium sulfate, etc. can be used, any one of which can be used alone or in combination of two or more.

[0057] The content of the pigment may be 30 to 50 parts by weight, for example 35 to 45 parts by weight, based on 100 parts by weight of the pigment dispersion. If the content of the pigment is less than the above range, the opacity relative to the object to be coated may be reduced, and if it is greater than the above range, the appearance of the coating film and the workability during the electrodeposition process may be reduced.

[0058] additive

[0059] The pigment dispersion may further contain additives such as a curing catalyst, a pH adjuster, a dispersant, and the like.

[0060] The curing catalyst can improve the curability of the pigment dispersion or the electrodeposition coating containing the pigment dispersion. As the curing catalyst, a tin-containing compound, a bismuth-containing compound, a mixture thereof, etc. can be used, for example, a tin-containing compound such as dibutyltin oxide, dibutyltin dilaurate, dibutyltin chloride, dioctyltin chloride, dioctyltin oxide, etc. can be used; a bismuth-containing compound in which Bi2O3 or Bi(OH)2 is mixed with an acid such as lactic acid, acetic acid, formic acid, dimethylolpropionic acid (DMPA), methanesulfonic acid (MSA), etc.; a mixture thereof, etc.

[0061] Acids such as acetic acid may be used as pH adjusters and wetting agents may be used as dispersants.

[0062] Based on 100 parts by weight of the pigment dispersion, the content of the curing catalyst may be 10 to 50 parts by weight, for example 30 to 40 parts by weight. Additives other than the above-mentioned curing catalyst may be appropriately added within a content range known in the art, for example, based on 100 parts by weight of the pigment dispersion, each may be included in an amount of 0.1 to 10 parts by weight.

[0063] The electrodeposition coating composition of the present invention comprises the above-mentioned emulsion resin composition, a pigment dispersion and water. For example, based on 100 parts by weight of the electrodeposition coating composition, it comprises 40 to 60 parts by weight, for example 45 to 55 parts by weight of the emulsion resin composition, 2 to 8 parts by weight, for example 4 to 6 parts by weight of the pigment dispersion, and 40 to 60 parts by weight, for example 45 to 55 parts by weight of water.

[0064] If the content of the emulsion resin composition is less than the above range, the internal coating performance may be reduced. If it is greater than the above range, the curing property may be reduced, and thus the corrosion resistance may be reduced. If the content of the pigment dispersion is less than the above range, the curing property may be reduced, and thus the corrosion resistance may be reduced. If it is greater than the above range, the internal coating performance may be reduced.

[0065] Mode for Carrying Out the Invention

[0066] Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0067] [Preparation of emulsion resin pre-composition]

[0068] [Preparation Example 1]

[0069] The emulsion resin pre-composition of Preparation Example 1 was prepared according to the composition described in Table 1 below.

[0070] [Table 1]

[0071] Components (parts by weight) Preparation Example 1 Epoxy resin 130.8 Polyurethane curing agent 166.5 Bisphenol A (BPA) 55.1 Ethoxylated bisphenol A 17.6 Monoethanolamine 11.6 Diketimines 15.9 Ethyltriphenyl potassium bromide 0.13 Methanesulfonic acid (70%) 14.8 Deionized water 609 Solvent vacuum recovery -21.6

[0072] Epoxy resin: bisphenol A diglycidyl ether (epoxy equivalent 188g / eq, viscosity (25℃) 12500cPs)

[0073] Polyurethane curing agent: a polyurethane curing agent prepared from 380.4 parts by weight of polymerized methylene diphenyl diisocyanate (PAPI2940, Dow Chemical), 200 parts by weight of methyl isobutyl ketone, 400.4 parts by weight of 2-(2-butoxyethoxy)ethanol and 19.2 parts by weight of trimethylolpropane.

[0074] Diketimine: 73% diketimine in methyl isobutyl ketone, wherein diethylenetriamine is end-capped with methyl isobutyl ketone.

[0075] [Preparation of emulsion resin composition]

[0076] [Experimental Examples 1 to 13]

[0077] The emulsion resin composition of each Experimental Example was prepared according to the composition described in Table 2 and Table 3 below.

[0078] [Table 2]

[0079]

[0080] [Table 3]

[0081]

[0082] Emulsion resin pre-composition: Preparation of the emulsion resin pre-composition of Example 1

[0083] Polyether-modified organosilicon compound 1: HLB 12, number average molecular weight (Mn) 8000, propylene oxide (PO) content 30%

[0084] Polyether modified silicone compound 2: HLB 10, Mn 5000, PO content 25%

[0085] Polyether modified silicone compound 3: HLB 13, Mn 11000, PO content 35%

[0086] Polyether modified silicone compound 4: HLB 6, Mn 2800, PO content 30%

[0087] Polyether modified silicone compound 5: HLB 12, Mn 18000, PO content 35%

[0088] Polyether modified silicone compound 6: HLB 8, Mn 6000, PO content 60%

[0089] Polyether modified silicone compound 7: HLB 17, Mn 3500, PO content 30%

[0090] Organic compound: Polyacrylate copolymer (HLB 12, Mn 750, PO content 20%)

[0091] [Preparation of Pigment Dispersion]

[0092] [Preparation Example 2]

[0093] The pigment dispersion of Preparation Example 2 was prepared according to the composition described in Table 4 below.

[0094] [Table 4]

[0095] Components Content (parts by weight) Dispersion resin 77 Carbon Black 1 Titanium Dioxide 280 Curing catalyst 355 Aluminum silicate 140 Acetic acid (30% dilution) 3 Surfynol107L(EVONIK) 10 Deionized water 134

[0096] Dispersed resin: amine-modified epoxy resin (NV 54%, viscosity (25°C) 4800cPs)

[0097] Curing catalyst: dibutyltin oxide (DBTO) slurry (303 parts by weight of dispersion resin, 193 parts by weight of DBTO, 504 parts by weight of deionized water)

[0098] [Preparation of electrodeposition coating composition]

[0099] 467g of the emulsion resin of each experimental example and 480g of deionized water were mixed and stirred, and 53g of the pigment dispersion of Preparation Example 2 was gradually added thereto to prepare a cationic electrodeposition coating composition having a solid content of 20%. The cationic electrodeposition coating composition was left to stand and stirred for 24 hours, and then electroplated for 3 minutes at a temperature of 28°C and a DC voltage of 220V. As a sample, a cold-rolled steel sheet with zinc phosphate on the surface was used, and the coated object was cured in an oven at 160°C for 25 minutes. The properties of the dried coating were evaluated by the following method, and the evaluation results are shown in Table 5 below.

[0100] Illuminance value

[0101] The illuminance value is measured using an illuminance meter with Cot-off = 2.5 mm. The illuminance value is a numerical value that indicates the height deviation within a certain distance. The smaller the value, the better the appearance.

[0102] Pit Generation

[0103] Identify with the naked eye whether there is oil with inscribed shapes.

[0104] Water washability

[0105] After electrodeposition coating, the coating was immediately cured at 160°C for 25 minutes without washing to identify the residual electrodeposition solution stains on the coating. The evaluation criteria are as follows Figure 1 shown.

[0106] Bubble stability

[0107] After introducing 200 ml of the electrodeposition coating solution into a mass bottle with a volume of 500 ml, place a lid to cover the top of the cylinder and then rotate it up and down 20 times at a rate of 1 time / 1 second to determine the amount of bubbles generated immediately after rotation and the amount of bubbles remaining after 2 minutes.

[0108] [Table 5]

[0109]

[0110]

[0111] As shown in Table 5 above, the electrodeposition coating of each of Experimental Examples 1 to 7, which contains the polyether-modified organic silicon compound according to the present invention, exhibits excellent performance in the measurement items as a whole. On the other hand, the electrodeposition coating of Example 8, in which the polyether-modified organic silicon compound is not contained, exhibits poor water washability. The electrodeposition coating of each of Experimental Examples 9 to 12, in which the performance of the polyether-modified organic silicon compound is not within the range of the present invention, exhibits poor water washability. In particular, in the case of Experimental Example 9, in which the polyether-modified silicon compound has an HLB and a number average molecular weight less than the range of the present invention, a large number of pits are exhibited, in the case of Example 10, in which the polyether-modified organic silicon compound has a number average molecular weight greater than the range of the present invention, a high illumination value (poor appearance) is exhibited, in the case of Example 11, in which the polyether-modified organic silicon compound has an HLB less than the range of the present invention, pits are exhibited, and in the case of Example 12, in which the polyether-modified organic silicon compound has an HLB greater than the range of the present invention, poor bubble stability is exhibited.

[0112] Furthermore, the electrodeposition coating of Experimental Example 13, in which a polyacrylate copolymer was used instead of the polyether-modified organic silicon compound, exhibited poor bubble stability.

[0113] Industrial availability

[0114] The present invention provides an electrodeposition coating composition having excellent water washability and bubble stability. The electrodeposition coating composition of the present invention has excellent water washability, thereby minimizing water stains generated during the electrodeposition coating process, and has excellent bubble stability, thereby giving the coating film applied with the electrodeposition coating composition an excellent appearance.

Claims

1. An electrodeposition coating composition comprising: An emulsion resin composition comprising an epoxy resin, a polyurethane curing agent and a polyether-modified organosilicon compound; and Pigment dispersion, The polyether-modified organic silicon compound has a hydrophilic-lipophilic balance (HLB) of 9 to 14 and a number average molecular weight of 3000 to 15000 g / mol. 2 . The electrodeposition coating composition according to claim 1 , wherein the polyether-modified organic silicon compound has a propylene oxide (PO) content of 5 to 50% by weight. 3 . The electrodeposition coating composition according to claim 1 , wherein the content of the polyether-modified organic silicon compound is 0.01 wt % to 0.5 wt % based on the total weight of the electrodeposition coating composition.

4. The electrodeposition coating composition according to claim 1, wherein the epoxy resin has an epoxy equivalent of 150 g / eq to 250 g / eq and a viscosity (25°C) of 10000 cPs to 20000 cPs.

5. The electrodeposition coating composition according to claim 1, wherein the polyurethane curing agent has an NV of 75% to 85%, a viscosity (25°C) of 500 cPs to 6000 cPs, and an NCO content of 0.5% or less.

6. The electrodeposition coating composition according to claim 1, wherein the pigment dispersion comprises a dispersing resin and a pigment, the dispersing resin comprising an amine-modified epoxy resin having an NV of 51% to 60% and a viscosity (25°C) of 1000 to 8000 cPs.

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