KR100434838B1 - Water-soluble metallic paint composition containing acryl emulsion polymer having inner void - Google Patents

Abstract

PURPOSE: Provided is a water-soluble metallic paint composition which uses an acryl emulsion polymer having inner void to obtain frost effect. CONSTITUTION: The water-soluble metallic paint composition comprises 30-80 wt% of a first resin which is a polyurethane water dispersive resin; 10-60 wt% of a second resin which is a methyl or imino group-containing melamine resin; 1-20 wt% of an inner void-containing core-shell emulsion polymer which is prepared by continuous composition change addition method and is an emulsion polymer having a particle size of 0.2-0.4 micrometers and maintaining a void shape even at a temperature of 150 deg.C or more; an aluminum paste; a thickener; a dispersant; and a co-solvent. The ratio of the first resin to the second resin is 5:1 to 2:1 by weight, and the ratio of the emulsion polymer to the aluminum paste is 0.5:1 to 1:0.5 by weight.

Description

Water-soluble metallic coating composition containing an acrylic emulsion polymer having internal pores

The present invention relates to a water-soluble metallic coating composition containing an acrylic emulsified polymer having a particle diameter (150-300 nm) to enable the provision of a Frost effect to the water-soluble metallic paint and an internal pore maintaining a void form even at 150 degrees or more. will be.

Mixing light-scattering inorganic pigments or metal pigments in paints has already been developed in various directions to impart the so-called [metallic effect] of coating appearance. In particular, in the case of automotive metallic paints, the development of metallic paints of various colors applied with mica or pearl pigments, including the initial metallic paints by using aluminum flakes alone or in combination with organic pigments, has recently been a form of exotic metallic paints. Is a type of metallic paint that mixes micro TiO ₂ and aluminum metal pigments to emphasize the Frost effect through reflection of light by aluminum particles and scattering of near-ultraviolet light by micro TiO ₂ .

The core application technology of the micro TiO ₂ -containing metallic paints is the provision of frost effect through near-ultraviolet light scattering of the transparent micro TiO _{2 which} does not harm the metallic feel of the mixed metal pigment. The most important factor for this is the particle size of the applied micro TiO ₂ . . Micro TiO _{2, which} is commonly used, has a small hiding power of about 10 to 50 nanometers in particle size, thereby minimizing the reduction of metal texture of aluminum particles and reflecting / scattering light in the near ultraviolet region around aluminum particles. Different appearance characteristics in front / light source side / semi light source side.

In addition to the new effect of the appearance, this type of metallic paint has a great advantage of significantly reducing the occurrence of [motling] phenomenon, which is often caused by the deflection of reflected light due to the poor orientation of metal particles in pure metallic paint. . However, compared to ordinary TiO ₂ , the micro TiO ₂ is expensive and the productivity of the micro TiO ₂ dispersion which is not necessary in the pure metallic paint is essential.

A technique based on the light scattering principle of intrinsic particles similar to the above is an application technique of core-shell emulsion polymers having internal pores, called plastic pigments, to aqueous building paints. It aims to contribute to cost reduction and productivity improvement by applying core-shell emulsion polymer containing internal pore maximizing hiding power to water-based building paints and replacing a considerable amount of titanium dioxide without reducing inherent hiding power of coating. Its core application is also the introduction of internal pore-containing core-shell emulsion polymers with inherent hiding power by light scattering for the purpose of replacing titanium dioxide in architectural paints.

The invention price / overcome the disadvantages such as productivity, contained inside the pores for micro TiO ₂ that allows the assignment of a unique frosted effect replace the core of the metallic coating by mixing the micro-TiO ₂ Based on the above two technologies - Shell It is an object to provide a water-soluble metallic coating composition to which the emulsion polymer is applied.

An important important factor in the preparation of inter-pore-containing core-shell emulsion polymers for application to water-soluble metallic paints for the frosting effect is the control of the optimum particle diameter of the polymer.

In order to set the particle size of the internal pore-containing core-shell emulsion polymer for the purpose of imparting the frost effect of the water-soluble metallic paint, it is necessary to first look at the particle size of the existing micro-titanium.

Commercially available micro TiO ₂ single particles have a size of 10-50 nanometers, and their dispersions, which are applied to actual metallic paints, generally have particle sizes between 0.1 and 0.3 microns. This is because the micro TiO ₂ stabilizes to form 3-5 groups of particles in the dispersion process, and the dispersant and the dispersing resin are wrapped around them. In the case of cured coatings, the particle size of these micro TiO ₂ dispersions is reduced to about 0.08 -0.25 microns, which is analyzed to be due to shrinkage during curing of the outer dispersed resin powder which affected the particle size of the dispersion. For example, when commercially prepared TiO ₂ having a particle size of 0.2-0.3 micron is dispersed under a dispersant and a dispersing resin, the measured particle size of the dispersion is 0.7 micron or more. When TiO ₂ of this size is applied to a water-soluble metallic paint for the purpose of frosting effect, the inherent hiding power is significantly larger than that of micro TiO ₂ to inhibit the metallic feeling of aluminum particles, and thus the desired frosting effect cannot be obtained.

In the present invention, based on the above analysis results, it was set to 0.15-0 -.3 microns to maximize the frost effect by controlling the particle diameter of the core-shell emulsion polymer containing the internal pore for micro TiO ₂ replacement.

In addition to controlling the optimum particle size of the polymer in the preparation of core-shell emulsion polymers containing internal pores for application to water-soluble metallic paints for the frosting effect, another important factor is the design of the melting point of the polymer by the shell forming monomer design. .

The premise of the melting point design of the emulsion polymer is the application baking temperature of the water-soluble metallic paint containing it. In the case of normal new metallic paints on a metallic base coating -On- The paint method coats 140-150 degree curable clear coats in which case the applied internal pore-containing acrylic emulsion polymers must maintain the inherent concealed form of the polymer at temperatures above 150. Of course, the application to the dry small-type water-soluble metallic refinish paint of 60 degrees or less can be applied only by controlling the particle size for the frost effect.

Recently, many kinds of internal pore-containing acrylic emulsion polymers are manufactured / sold. However, in most cases, it is aimed at application at room temperature dry building paints, and it has a particle size of 350-450 nanometers that maximizes the visual concealment rate. The decay of a pore causes the binder to lose its hiding power due to its inherent particle diameter. Therefore, the direct application of these conventional commercialized internal pore-containing emulsion polymers to water-soluble metallic paints is an impossible reality due to the above mentioned particle size and melting point problems. Polymer particles with low-cost internal pores used to replace expensive TiO ₂ used for concealment in aqueous building materials are typically controlled to 400-500 nanometers and are thick shells to prevent internal pores from drying out. Since it is contained, it is impossible to reduce it to nanometer by the conventional manufacturing method, and it is insufficient to show a frost effect in metallic coating. In addition, since the metallic paint is cured at a baking temperature of 100-150 ° C., the conventional polymer pigments lose pores due to melting, and thus the particle-specific hiding power is lost.

As a result, acrylic emulsion polymers containing internal pores that can be used for application to water-soluble metallic paints for frosting effect must first contain pore inside and have a final particle size of 250-350 nanometers. Internal pores should not be depressed at the baking temperature of the paint.

Therefore, in the present invention, first, a process of preparing an internal pore-containing core-shell emulsion polymer that maintains a void form even at a particle diameter (150-300 nm) and 150 ° C. or higher to enable the frosting effect on a water-soluble metallic paint will be described.

Korean Patent No. 79058 discloses a concealment force over conventional polymer particles and improves the hiding power even if the shell contains a thin shell by using a continuous composition change method to improve the conventional method using a thick shell to protect internal pores during drying. It mentions the manufacturing technology of polymer pigments that contributed to the reduction.

The present invention is a water-soluble metallic coating composition composed of a first resin, a second resin, an internal pore-containing core-shell emulsion polymer, an aluminum paste, a thickener, a dispersant, and a co-solvent, wherein the first resin is used as a polyurethane water dispersion resin. Is 30 to 80% by weight of the coating composition solids, the second resin is a melamine resin containing methyl or imino groups, the amount of which is 10 to 60% by weight of the coating composition solids, the first resin and the second The solid content weight ratio of the resin is 5: 1 to 2: 1, and the internal pore-containing core-shell emulsion polymer is prepared by the continuous composition change addition method, and has a particle size of 0.2 to 0.4 microns and maintains the shape of pores even at a temperature higher than 150 ° C. The amount of the emulsified polymer to be used is 0.5: 1 to 1: 0.5 weight ratio and 1 to 20% by weight of the coating composition in the aluminum paste and solid content. .

In preparing a core-shell emulsion polymer containing pores therein, a process for preparing a core polymer from an acid monomer having a carboxyl group and a common monomer, and continuously forming an envelope-forming monomer mixture in the presence of the prepared core particles. It is composed of a process of encapsulating by emulsion polymerization by the composition change addition method, and neutralizing and swelling the generated core-shell particles with a base to form internal pores upon drying. The skin forming step is composed of a plurality of steps and a metallic paint The shell is crosslinked with a crosslinking agent so that the internal pores are not depressed at the baking temperature of and the core-shell emulsion polymer having a final particle size of 250-350 nanometers is included to maximize the frosting effect.

Hereinafter, a method of preparing a core-shell emulsion polymer having internal pores and having a final particle size of 250-350 nanometers and not internally depressing even at a temperature of 140-150 ° C. will be described in detail.

Core-shell emulsion polymer containing the internal pores used in the present invention is prepared by the manufacturing method of Korean Patent No. 79058. The first step is to prepare a core emulsified polymer containing an acid monomer having a carboxyl group necessary to contain internal pores after drying. The core particles may be prepared in a single step in the overall process, but preferably, the core particles may be prepared in a plurality of steps including a step of preparing a seed polymer to prepare particle diameters and particle diameter distributions, pore sizes and distributions of the final particles. Easy to adjust The seed polymer uses a conventional emulsion polymerization technique, and it is not necessary to include a small amount or acid monomer since the purpose is to provide nuclear particles in which the acid monomer mixture is polymerized and grown thereon. The acid monomer used may be selected from one or more of acrylic acid, methacrylic acid, itaconic acid, crotonic acid, fumaric acid, aconic acid, maleic acid or anhydrides thereof, mono methyl maleate, monomethyl fumarate and monomethylitaconate. It is preferable to use 0-10% by weight, preferably 0-5% by weight, based on the monomer mixture, and the copolymer is ethylenically unsaturated monomers such as styrene, vinyltoluene, ethylene, butadiene, vinylacetate, vinylchloride, vinylidene chloride, At least one of acrylonitrile, alkyl acrylates and alkyl methacrylates is selected.

Emulsifiers are used alone or in combination with nonionic or anionic emulsifiers, 0.1-2.0% by weight relative to the monomer weight. Representative nonionic emulsifiers are octyl phenoxy ethyl polyethoxy ethanol and nonylphenoxyethyl polyethoxy ethanol. Representative anionic emulsifiers include sodium lauryl sulfate, sodium dodecyl benzene sulfonate, sodium octyl phenoxy ethyl polyethoxy ethyl sulfate, and sodium salts of sulfosuccinate derivatives.

The water-soluble radical initiator to be added to the reaction mixture is a thermal decomposition initiator such as alkali metal persulfate, ammonium persulfate, hydrogen peroxide, tertiary butyl hydroperoxide, or the like, or an alkali metal sulfide, hyposulfite and sodium. Redox initiators in the form of a mixture with a reducing agent such as formaldehyde sulfoxylate may be used, the amount of which is used in the range of 0.1-2% by weight based on the monomers, and the reaction temperature is 30-300 minutes for the decomposition half life of the polymerization initiator. Set to fall within the range of.

When the seed is formed through the seed forming step, a core synthesis step using a hydrophilic monomer is performed. In the core synthesis step, it contains 15 to 60% by weight of acid monomer, 39 to 85% by weight of general ethylenically unsaturated monomer, and 0 to 2% by weight of crosslinkable monomer. The amount of this monomer mixture should be in the range of 2-30% by weight of the monomer mixture used in the whole process, with or without the presence of the seed stage, and 4-10 times that of the seed forming monomer in the presence of the seed stage. Use it to a degree. When such a monomer mixture is added to the reaction system, it should be maintained within a selected speed range in consideration of the stability of synthesis, control of exotherm, and particle growth behavior, but usually in the range of 30 minutes to 3 hours. The choice of emulsifier, initiator and reaction temperature in the core formation stage is the same as in the seed formation step.

Core-shell emulsifier containing internal pore used in the present invention The average particle diameter of coalescing is about 0.25-0.35 microns and it provides the concealment rate by using aluminum plate pigments to give a metallic feel to automotive topcoats. It is not necessary to favor the inherent concealment rate of ordinary polymer pigments. Just control the decay of the contribution. Therefore, it is desirable to control the core emulsion particle size small for easy control of the subsequent shell manufacturing process, regardless of the presence or absence of the seed step, 0.05-0.2 micron in the non-swelling state of the particle size of the synthetic polymer below pH5, Preferably 0.06-0.15 microns are suitable.

The monomer mixture used in the shelling step preferably contains at least one of the aforementioned general ethylenically unsaturated monomers and contains 0-5% by weight of monomers, as described in Korean Patent No. 79058. Glass transition temperature and toughness index should be considered. The emulsifier and polymerization initiator used in the shell forming step are selected from those generally used in the emulsion polymerization. Examples of the emulsifying agent are used to explain the core manufacturing step, and the amount of the emulsifier used is in a concentration range that can satisfy the synthetic stability and particle growth behavior at the same time. It is usually maintained at 0.01 to 2.0% by weight of monomer.

The shell forming step may consist of a single step or a plurality of steps. Preferably, the shell forming step includes a first step of forming a shell and a second step of forming a monomer composition in a conventional emulsion polymerization method. It is good. In this case, the neutralization process, which is an essential step in preparing the hollow particles, may be composed of a primary shell forming step. In this case, it is preferable to proceed with the neutralization process, which is an essential step in preparing the hollow particles, after forming the primary shell.

Thus, the primary role of the primary shell polymer in the multi-stage emulsion polymer composed of core-neutral shell-neutralized-secondary shell is to control the sharp focus due to the neutralization of core particles and to maximize the hydrophilicity due to ionization of the particle surface layer. It is preferable to use an acryl-based monomer mixture in forming the outer grains for buffering the encapsulation efficiency of the shell, and the weight ratio thereof is in the range of 1: 1 to 1:10, more preferably 1: 1 to 1 for core particles. A range of 1: 5 is suitable.

On the other hand, the main role of the secondary shell polymer is to prevent particles from drying during the drying process, and it is preferable to add a monomer mixture having an appropriate toughness index by adding a continuous change of monomer composition to perform emulsion polymerization. Suitable ranges of from 1: 1 to 1:30, more preferably from 1: 1 to 1:20, for the particles up to. In addition, it is a feature of the present invention to introduce crosslinking monomers into the primary and secondary shell manufacturing processes in order to suppress swelling of the core and shell polymers involved in neutralization and to prevent internal pores from swelling. Examples of the crosslinking monomer used include acrylic methacrylate dimethacrylate, such as ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexane Diol dimethacrylate, and the like, and diacrylates include 1,4-butanediol, diacrylate, 1,6-hexanedioldiacrylate, and the like. The amount is preferably 0.01 to 5% by weight of the shell polymer. Suitably 0.05 to 2% by weight.

On the other hand, the base used in the neutralization process is selected from volatile bases of ammonia and tertiary amine, but is selected from fixed bases of alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and the amount of the base used is pH 7 of the emulsion dispersion after neutralization. It is recommended to be within the range of -12, but organic solvents may be used during or before neutralization to help the base particles penetrate into the particles.

The particle size of the final emulsion polymer prepared according to the present invention is suitable for 0.2 to 0.4 microns, preferably 0.025-0.35 microns, the inner pore diameter of 0.01-0.2 microns, preferably 0.03-0.15 microns.

A method for producing a core-shell emulsion polymer having an inner pore size of 0.25-0.35 microns and having no internal pores at a temperature of 140-150 ° C. is described in Preparation Examples 1) and 2). The preparation of the core-shell emulsion polymer applied to is described in Preparation Example 3).

Preparation Example 1

Into a 2 L four-necked flask equipped with a thermometer, a nitrogen inlet tube, a dropping tank, a stirrer, and a reflux condenser, 991 g of ion-exchanged water and 0.5 g of sodium dodecyl benzene sulfonate were added, and heated to 80 ° C. while blowing nitrogen. An aqueous solution of 0.48 g of sodium persulfate dissolved in 20 g of ion-exchanged water is added. While maintaining the reaction temperature at 80 ° C, an emulsified mixture consisting of 76 g of ion-exchanged water, 0.4 g of sodium dodecyl benzene sulfonate, 52 g of butyl acrylate, 66 g of methyl methacrylate, and 1.4 g of methacrylic acid was slowly added dropwise over 1 hour. Then, aged for 1 hour, and then cooled to prepare a seed polymer. An aqueous solution of 1.4 g of sodium persulfate dissolved in 50 g of ion-exchanged water was added. While maintaining the reaction temperature at 80 ° C., an emulsified mixture consisting of 120 g of ion-exchanged water and 1.75 g of sodium dodecyl benzene sulfonate was slowly added dropwise over 2 hours, then aged for 1 hour, and cooled to prepare a core polymer. The average particle diameter measured by the light scattering measuring apparatus was 140 nm, and solid content was 29.7%.

In a 2 L four-necked flask, 797 g of ion-exchanged water and 140 g of core polymer were added, heated to 80 ° C., and an aqueous solution of 0.5 g of sodium persulfate dissolved in 30 g of ion-exchanged water was added.

200 g of ion-exchanged water, 1.5 g of methyl methacrylate, 83 g of methyl methacrylate, 42 g of butyl acrylate, 0.63 g of ethylene glycol dimethacrylate (EGDMA), sodium dodecyl An emulsified mixture of 3.5 g of benzene sulfonate was slowly added dropwise over 2 hours, then aged for 1 hour, and then maintained at 80 ° C. for 1 hour with pH adjusted to near 11.0 by addition of ammonia water. The average particle diameter before neutralization was 0.21 micron, and the particle diameter after neutralization was 0.222 micron. While maintaining the same temperature continuously, an aqueous solution of 1.74 g of sodium persulfate was added to 50 g of ion-exchanged water.

45 g of butyl acrylate, 32 g of methyl methacrylate, 68 g of styrene, 0.76 g of ethylene glycol dimethacrylate were added to the first supply tank, and 10 g of methyl methacrylate, 22 g of butyl acrylate and 113 g of styrene, and EGDMA 1.48 were added to the second supply tank. After the g was added, the monomer mixture was fed at a rate of 1.1 cc / min. over 1.5 hours from the second feed tank to the first feed tank equipped with the stirring device and from the third feed tank to the reaction flask for 1.5 hours. The polymerization proceeds while feeding at a rate of 2.2 cc / min. After the feeding of the monomer mixture is completed, the mixture is aged for 1 hour and then cooled.

The average particle diameter of the final emulsion was 0.22 microns, the average diameter of the pores was 0.1 micron, the solid content was 29.8%, and the viscosity was 190 center poise.

Preparation Example 2

After proceeding to the neutralization step by the same production method as in Preparation Example 1, the weight ratio and the composition of the first feed monomer composition and the second feed monomer composition are differently emulsion-polymerized in the second shell forming step. 23 g of butyl acrylate, 16 g of methyl methacrylate, 34 g of styrene, and 0.6 g of diaryl methacrylate were placed in the first feed tank, and 21.3 g of butyl acrylate, 10.7 g of methyl methacrylate, 113 g of styrene, and dia 1.2 g of ryl methacrylate was added, and then the monomer mixture was fed from the second feed tank to the first feed tank at a rate of 0.73 cc / min. And at the same time from the first feed tank to the reactor at a rate of 2.2 cc / min. Proceeding the emulsion polymerization. Subsequent progress was the same as in Example 1 except that the final emulsion polymer had an average particle diameter of 0.456 microns, a pore diameter of 0.345 microns, a solid content of 24.9%, and a viscosity of 230 centipoise.

Preparation Example 3

The emulsion polymerization is carried out for the purpose of comparison with Preparation Example 1. The difference from Preparation Example 1 is that in the second shell forming step, the monomer mixture is put in a single feed tank without using two feed tanks, and the same addition rate is 2.2 cc / min. It was polymerized while feeding to the reactor. Therefore, the mixture of 67 g of butyl acrylate, 42 g of methyl methacrylate, and 181 g of styrene is slowly added dropwise over 1.5 hours. The average particle size of the final emulsion was 0.49 microns, mostly observed in a recessed form with a solids content of 29.6% and a viscosity of 445 centipoise.

Hereinafter, water-soluble metallic coatings prepared by applying the inner-pore-containing core-shell emulsion polymers prepared in Preparation Examples 1) and 2) 3) will be described. Examples 1) and 2) and Comparative Examples 1) and 2, respectively. The application of the experiments in accordance with the change of composition in the water-soluble metallic paint is described by dividing into 3), 3) and 4).

In applying the internal-pore-containing core-shell emulsion polymer prepared above, the most important matter is the solid content ratio of the aluminum paste and the core-cell emulsion polymer applied to the water-soluble metal paint.

The solid content ratio of the aluminum paste and the core-cell emulsion polymer that enables the frosting effect of the metal coating targeted in the present invention is 0.5: 1 to 1: 0.5, and 1 to 20% of the total coating composition is used. The amount of solids of the aluminum paste applied determines the amount of core-cell emulsion polymer used for the frosting effect. The aluminum paste used in the water-soluble paint of the present invention has been introduced into a variety of products by various inhibitory treatment for application to the particle size or water-soluble paint, but in the present invention, the organic inhibitor of the particle size of about 20 microns Type Silver Paste's Aqua Paste 5245 AR (metallic pigment: flake-type aluminum powder) was used in an amount of 2-5% by weight of the total paint. If the weight of the aluminum paste used is less than 2, the hiding power of the entire coating is drastically reduced and it is difficult to obtain a normal coating, and when applied over 5%, the mechanical properties are lowered and the price is not raised, and the frosting effect is difficult to expect. In addition, the main resin KUD-224 used in Examples and Comparative Examples of the present invention is an UD (Urethane Dispersion) binder of KCC (Kumgang Goryeo Chemical Co., Ltd.), has an acid value of 10 to 500 mgKOH / g and a weight average molecular weight of 10,000 to 100,000. It is a urethane water dispersion resin with 40 to 45% of solid content. The usage-amount is 20 to 60 weight% in weight part of normal metallic paint.

On the other hand, the main resin and the amino resin, which is a curing agent used in the above-mentioned ratio, used a methyl group or an amino group-containing melamine, which is used in a solid ratio of the main resin to 5: 1 to 2: 1 to supplement mechanical properties of the coating film. to be. As the curing agent amino resin used in Examples and Comparative Examples of the present invention, Cymel 325 manufactured by Cyanamide Co., Ltd. (solid content 60%) was used. In addition, in the present invention, unlike the micro-titanium-containing metallic paint does not require a separate dispersion process, but the additive is used in order to fully exhibit the function of the water-soluble paint, the present invention uses the following two additives have.

First, in the paint composition of the present invention, in order to prevent the sedimentation phenomenon during the storage of the paint, 1-5% of the polyacrylate-based thickener is used as the total weight of the paint. This is to prevent various problems that may occur in the characteristics. In Examples and Comparative Examples of the present invention was used as a thickener and rheology control agent was used Biscallex HV30 (Viscalex HV30: 30% solids) of Melide Kloid.

Particular attention should be paid to the application of this solution to a sufficient neutralization stage prior to injection. If it is added without sufficient neutralization by amine, gel particles may be formed by rapid pH change in paint.

Secondly, in the coating composition of the present invention, an acrylate-based dispersant was used to prevent dispersing effect and re-agglomeration when the aluminum paste was dispersed together with the initial solvent content under a low shear rate. This prevents the inhibited aluminum paste from reaggregating and oxidizing in the entire paint system containing solvent and water. It is 0.005 to 1 weight% with respect to all the water-soluble coating compositions. Beyond the usage range, it can cause severe cratering.

In addition, in the water-soluble coating composition of the present invention, glycols, carbitols and alcohols are added as cosolvents, and the role of the cosolvents greatly improves the smoothness of the coating film, lowers the minimum film formation temperature, and makes the coating atomization during painting work. Not only is it smooth, it also contributes greatly to the improvement of workability. The amount of the co-solvent used in the present invention is 2 to 20% by weight based on the total water-soluble paint composition.

The following examples and comparative examples more specifically describe the manufacturing process, components, efficacy and effects of the coating to which the inner-pore-containing core-shell emulsion polymer of the present invention is applied, but are not intended to limit the scope of the present invention. .

Examples 1) to 2) relate to a water-soluble metallic coating application test to which the core-shell emulsion polymers prepared according to Preparation Examples 1) and 2) are applied. Comparative Examples 1) and 2) refer to core-shell polymers and aluminum pastes. Solid content ratio of more than or less than 1: 0.5 to 0.5: 1 ratio, and Comparative Example 3) relates to the coating application of the core-shell emulsion polymer applied to the existing building paint prepared by Preparation Example 3) . In addition, Comparative Example 2) described the preparation of the micro titanium dispersion and its application to a water-soluble metallic paint.

Forming a coating film and evaluating various conditions to obtain the results as shown in [Table 1], in particular, the present invention prepared in Examples 1), 2) is applied to the dispersion of the conventional micro titanium dispersion water-soluble metallic coating of Comparative Example 2) Equivalent results were obtained in terms of and all evaluation items.

Example 1

1) Metallic pigments: flake aluminum powder from Silverline

2) Dispersant: Water-soluble acrylic copolymer ammonium salt of Ciba Specialty Co., Ltd.

3) Main resin (first resin): KCC's UD (Urethane Dispersion) binder

4) Cured Resin (Second Resin): Amino Resin of Cyanamide

5) Fluidity regulator: Acrylic copolymer emulsion of Melidecloid

6) N, N-dimethylethanolamine (DMEA: N, N-Dimethyl Ethanol Amine)

The compositions of 1 to 13 are sequentially added in AlpM 500-700 in the order described in Example 1 and adjusted with an aqueous amine solution so that the pH of the entire coating composition is 8-9. In the case of applying the water-soluble coating composition prepared in this way, spray or bell paint the water-soluble coating composition on a primer-coated coating to 15 to 20 microns with a dry coating film and 5 minutes at 80 ° C. using an IR oven at room temperature for 5 minutes. The flash-off was applied, the solvent-type clear paint was applied, and the method of heat-hardening for 20 to 30 minutes was carried out at 130-150, and comprehensive physical properties and an external appearance were checked.

Comparative Example 1

Note) *: Solid content 0.2, **: Solid content: 1.0

A water-soluble coating composition was prepared in the same manner as in Example 1), except that 1 part by weight of Comparative Example 1) was adjusted, and physical properties and appearance were examined.

Example 2

Note) *: Solids 3.0, **: Solids: 1.5

In the order described in Example 2, the compositions of 1 to 13 are sequentially added in AlpM 500-700 and adjusted with an aqueous amine solution so that the pH of the entire coating composition is 8-9. When applying the water-soluble coating composition prepared in this way, spray or bell-coated the water-soluble coating composition to 15 to 20 microns with a dry coating film on the primer-coated coating, and 5 minutes at 80 ℃ using an oven oven for 5 minutes at room temperature The flash-off was given, the solvent-type clear coating material was applied, and it heat-hardened to 130-150 for 20 to 30 minutes, and comprehensive physical property and an external appearance were checked.

Comparative Example 2

Note) *: Solids 4.5, **: Solids: 1.5

A water-soluble coating composition was prepared in the same manner as in Example 2) except that the weight part of 1 described in Comparative Example 2 was adjusted, and physical properties and appearance were examined.

Comparative Example 3

The compositions of 1 to 13 are sequentially added in AlpM 500-700 in the order described above and adjusted with an aqueous amine solution so that the pH of the entire coating composition is 8-9. In the case of applying the water-soluble coating composition prepared in this way, spray or bell paint the water-soluble coating composition on a primer-coated coating to 15 to 20 microns with a dry coating film and 5 minutes at 80 ° C. using an IR oven at room temperature for 5 minutes. The flash-off was given, the solvent-type clear coating material was applied, and it heat-hardened to 130-150 for 20 to 30 minutes, and comprehensive physical property and an external appearance were checked.

Comparative Example 4

1) Dispersion Resin: Avecia

2) Dispersion Resin: KCC's water-soluble alkyd resin

3) Inorganic Pigments: Micro TiO ₂ from tayca

The mixture was added sequentially at 1 to 8 at AlpM 600, and after 30 minutes of preliminary stirring, it was dispersed with a bead mill for 1 hour. The dispersion was added sequentially from 9 to 19 with stirring at AlpM 500 and terminated after 20 minutes of maintenance. The prepared paints were checked for physical properties and appearance after coating in the same manner as in Example 1).

[Table 1]: Paint and Coating Properties

* IV / SV / FF: Metal orientation, brightness, scattering measurement

(Device name Al-Cope)

* Mottling / Frost Effect: Observe the appearance of coating

* Water resistance and post-water attachment: Adhesiveness by E and gross cut after 40 C x 10 days

* Cold Chip Review:-40C x 4 hours after chipping

* Paint storage: Store at room temperature-25 C

Heat storage-50 C x 3 days

Claims (6)

A water-soluble metallic coating composition composed of a first resin, a second resin, an internal pore-containing core-shell emulsion polymer, an aluminum paste, a thickener, a dispersant, and a co-solvent, wherein the first resin is a polyurethane water-dispersible resin, and the amount thereof is 30 to 80% by weight of the solids of the composition, the second resin is a melamine resin containing methyl or imino groups, the amount of which is 10 to 60% by weight of the solids of the coating composition, the solids of the first and second resins The weight ratio is 5: 1 to 2: 1, and the internal pore-containing core-shell emulsion polymer is prepared by a continuous composition change addition method and has a particle diameter of 0.2 to 0.4 microns and maintains the shape of pores even at a temperature of 150 ° C. or higher. The amount of water-soluble water is 0.5: 1 to 1: 0.5 by weight and 1 to 20% by weight of the coating composition in the solid content of the aluminum paste. Metallic paint composition. The water-soluble metallic coating according to claim 1, wherein the polyurethane water dispersion resin has an acid value of 10 to 50 mg KOH / g, a weight average molecular weight of 10000 to 100000, and the amount of the aqueous dispersion is 40 to 45% by weight of the solid content of the coating composition. Composition. The water-soluble metallic coating composition according to claim 1, wherein the aluminum paste mixed with the core-shell emulsion polymer is organic or inorganic inhibited for application to a water-soluble paint. According to claim 1, wherein the thickener is applied alkali swellable acrylate-based polymer which is neutralized by amines to impart the central effect and the flow characteristics during painting work by the self phase expansion, the amount of use is 0.005 ~ of the solid composition of the coating composition A water-soluble metallic coating composition, characterized in that 0.1% by weight. The water-soluble metallic coating composition according to claim 1, wherein the dispersant is used in an amount of 0.001 to 0.1% by weight of the coating composition solids to prevent re-agglomeration of the aluminum paste. The water-soluble metallic coating composition according to claim 1, wherein the co-solvent is used in combination of butyl glycol, butyl carbitol and propanol, and is added in an amount of 2 to 20 wt% based on the coating composition.