KR100880461B1 - Water-soluble bake zinc-paint composition with improved corrosion resistance and a method of preparation thereof - Google Patents

Abstract

The present invention relates to a water-soluble calcined zinc coating composition excellent in corrosion resistance and a preparation method thereof, and more particularly, to a water-soluble rheology polyester resin having a number average molecular weight of 500 to 20,000; Water-soluble phosphoric acid modified epoxy ester resins having a number average molecular weight of 190 to 2500; zinc; One encapsulating agent selected from the group consisting of ammonium polyacrylate, sodium polyacrylate, sodium polyphosphate, potassium polyphosphate, acetylglycol derivative fatty acid salts, alkylphenol-ethoxylate sulforate salts and mixtures thereof; Water-soluble polymer dispersants; One pigment selected from the group consisting of soluble rust preventive pigments, low toxicity pigments, coloring and extender pigments and mixtures thereof; 1 type water-soluble melamine resin selected from the group consisting of hexamethylmethoxy melamine resin, partially alkylate melamine resin, partially metalate melamine resin, alkylate carboxylate melamine resin and mixtures thereof; Antisettling agents; Co-solvents; And it relates to a water-soluble baking zinc coating composition comprising water and a method for producing the same.

Particles of the coating composition has a structure surrounded by the encapsulating agent and the water-soluble polymer dispersant having a reactive anchoring group on the zinc surface, it is less hydrogen gas generation during storage and excellent storage stability and working stability. The coating composition is not only excellent in corrosion resistance but also has low toxicity and various mechanical and chemical properties, and thus is preferably applied to the surface of automobile parts, industrial parts, and rough products of metal materials.

Zinc, paint composition, hydrogen gas generation, storage stability

Description

WATER-SOLUBLE BAKE ZINC-PAINT COMPOSITION WITH IMPROVED CORROSION RESISTANCE AND A METHOD OF PREPARATION THEREOF}

1 is a schematic diagram showing the repulsion between the zinc particles by forming an electrical double layer between the zinc particles due to the encapsulating agent and the water-soluble polymer dispersant surrounding the surface of the zinc.

Figure 2 is a schematic diagram showing the three-dimensional stabilization of zinc surrounded by the encapsulating agent and the water-soluble polymer surrounding the surface of the zinc.

The present invention relates to a water-soluble calcined zinc coating composition having excellent corrosion resistance and a method for manufacturing the same, and more particularly, to a water-soluble calcined zinc coating composition having excellent corrosion resistance and low toxicity and having various mechanical and chemical properties. It relates to a manufacturing method.

Corrosion of steel and non-ferrous materials is very serious in the construction and industrial sectors. Due to the corrosion of steel materials, the property and industry are severely damaged every year, and are used as various anti-corrosive paints to prevent corrosion of steel and nonferrous metals. Accordingly, various types of rust-preventive paints for the material have been researched and developed according to their purpose and properties.

The corrosion of metals is due to the action of air, water, carbon dioxide and heat. Therefore, the rust preventive paint should act to prevent contact with these metal surfaces and chemically prevent rust. The rust preventive paint has a vehicle structure in which an organic part of various resins and an inorganic part of zinc (zinc) which is an rust preventive pigment are mixed.

Alkyd resin, modified alkyd resin, acrylic resin, modified acrylic resin, epoxy resin, modified epoxy resin and urethane resin are used as the resin.

Among them, the alkyd resin and the modified alkyd resin are converted to an alkali state due to zincification during storage or upon exposure to air after coating, resulting in a decrease in physical properties of the coating film itself. In addition, the ester bond in the alkyd resin not only degrades adhesion to a special metal material due to hydrolysis during the storage period, the coating film water resistance, and chemical resistance, but also seriously discolors the coating film depending on the baking temperature.

In addition, epoxy resins have high epoxy equivalents and are used as polymer type epoxy resins. Such epoxy resins have a problem in that paint pigment dispersibility is lowered due to self-aggregation.

Conventionally used paint compositions include strontium chromate pigments and lead as rust preventive pigments. These metals are classified as heavy metals and are classified as harmful substances that cause carcinogenic and reproductive toxicity to the human body when eluted. Recently, restrictions on use have been gradually strengthened for export and household goods.

In addition, the coating composition containing zinc as a rust preventive pigment expands the can containing the coating composition by hydrogen gas generation as shown in Scheme 1 below when contacted with moisture in the paint or moisture in the atmosphere during storage.

Scheme 1

Zn + 2H ₂ O ------> Zn (OH) ₂ + 2H ₂ ↑

For this reason, in the case of the coating composition containing zinc, the pressure in the can increases and explodes, resulting in explosion, such as overflowing the contents, and poor storage stability affects the painting workability.

This property is a factor of generating gas during storage due to the influence of moisture in the paint during the operation of high humidity days (relative humidity of 85% or more), careful attention, such as the introduction of an inert gas when manufacturing the coating composition. Accordingly, there are various problems such as an increase in production time and cost, and poor workability due to low storage stability.

Therefore, in addition to improving the environmental problems of the conventional coating composition, storage stability due to gas generation, coating and line workability, various steel materials and special metal materials adhesion, chemical properties and salt water resistance improvement is necessary.

In addition, the defects of hydrogen gas generated when contacting with moisture, which is a disadvantage of zinc-based pigments, are stably compatible with selected water-soluble resins while inhibiting contact between water and water of zinc pigments. A method of suppression is required.

In addition, there is a need to improve the composition and the method of manufacturing the coatings that can be applied to extend the rust resistance of automobile parts, steel, industrial parts, iron and nonferrous metals using low-toxic anti-corrosive pigments.

An object of the present invention is not only excellent in corrosion resistance, but also has low toxicity and various mechanical and chemical properties, which can be suitably applied to the surface of metal parts, automotive parts, industrial parts, steel products, and the preparation thereof. To provide a way.

The present invention to achieve the above object

Water-soluble rheopolyester resin having a number average molecular weight of 500 to 20,000;

Water-soluble phosphoric acid modified epoxy ester resins having a number average molecular weight of 190 to 2500;

zinc;

One encapsulating agent selected from the group consisting of ammonium polyacrylate, sodium polyacrylate, sodium polyphosphate, potassium polyphosphate, acetylglycol derivative fatty acid salts, alkylphenol-ethoxylate sulforate salts, and mixtures thereof;

Water-soluble polymer dispersants;

One pigment selected from the group consisting of soluble rust preventive pigments, low toxicity pigments, coloring and extender pigments and mixtures thereof;

1 type water-soluble melamine resin selected from the group consisting of hexamethylmethoxy melamine resin, partially alkylate melamine resin, partially metallate melamine resin, alkylate carboxylate melamine resin and mixtures thereof;

Antisettling agents;

One co-solvent selected from the group consisting of lower alcohols, ethers and mixtures thereof; And

It provides a water-soluble baking zinc coating composition comprising water.

Preferably, the water-soluble calcined zinc coating composition is 1 to 20% by weight of water-soluble rheopolyester resin, 5 to 30% by weight of water-soluble phosphate-modified epoxy ester resin, 30 to 60% by weight of zinc, 0 to 10% by weight of encapsulating agent, 0.05 to 10% by weight of water-soluble polymer dispersant, 5 to 40% by weight of pigment, 0.5 to 15% by weight of water-soluble melamine resin, 0.1 to 10% by weight of antisettling agent, 5 to 30% by weight of cosolvent, and balance water.

At this time, the water-soluble calcined zinc coating composition further includes one selected from the group consisting of a reaction accelerator, an antifoaming agent, a surface regulator, a surface spreading aid, an antirust and adhesion promoter, a neutralizer, a pH regulator, and a combination thereof, as necessary.

In addition, the present invention

a) adding an encapsulating agent, a water-soluble polymer dispersing agent and zinc to the reactor to uniformly mix to produce a mixture in which the zinc surface is encapsulated;

b) adding a pigment to the mixture of step a) and stirring at high speed to prepare a mixture;

c) adding a water-soluble rheopolyester resin, a water-soluble phosphate-modified epoxy ester resin, a water-soluble melamine resin, a co-solvent and water to the mixture of step b) and mixing the water uniformly. to provide.

Hereinafter, the present invention will be described in more detail.

The water-soluble baking zinc coating composition according to the present invention is surrounded by an encapsulating agent and a water-soluble polymer dispersing agent with a zinc metal surface to stericly stabilize zinc to inhibit precipitation during storage for a long time. In addition, direct contact of zinc with moisture and water is suppressed, and no hydrogen gas is generated. In addition, it is chemically stabilized, has compatibility with other resins, and is easily dispersed in water.

The water-soluble calcined zinc coating composition includes a water-soluble rheopolyester resin, a water-soluble phosphoric acid-modified epoxy ester resin, zinc, an encapsulating agent, a water-soluble polymer dispersant, a pigment, a water-soluble melamine resin, a sedimentation inhibitor, a co-solvent and water.

First, the water-soluble rheopolyester resin imparts flexibility to the water-soluble calcined zinc coating composition, and preferably uses a number average molecular weight of 500 to 20,000. If the number average molecular weight is less than the range, a brittle problem occurs, and if the number average molecular weight is exceeded, the coating film becomes stronger.

Such water soluble rheology polyester resins comprise from 1 to 20% by weight, preferably from 4 to 15% by weight of the total coating composition. If the content is less than the above range, brittleness occurs, and if it exceeds the above range, there is a problem of becoming too flexible.

The water-soluble phosphoric acid modified epoxy ester resin increases the coating film stiffness of the water-soluble baking zinc coating composition, and preferably uses a number average molecular weight of 190 to 2500. If the number average molecular weight is less than the above range, the coating film becomes brittle, and if it exceeds the above range, there arises a problem that the coating film characteristics become stronger.

The water-soluble phosphoric acid modified epoxy ester resin includes 5 to 30% by weight, preferably 10 to 20% by weight in the total coating composition. If the content is less than the range is brittle, if it exceeds the range a strong problem occurs.

Since zinc is a rust preventive pigment, it affects rust resistance, flexibility, drying rate, shelf life, and color, and therefore, it is very important to control the content in the coating composition. In the present invention, the zinc is included in the content of 30 to 60% by weight, preferably 40 to 55% by weight in the total coating composition. If the zinc content is less than the above range, sufficient antirust effect cannot be obtained, and if it exceeds the above range, the dispersion and stability of the coating composition are lowered.

In this case, zinc may be in the form of powder or flake, and when the flake pigment is used, the sedimentation and corrosion resistance of the zinc pigment may be improved and the amount of zinc powder may be reduced. The zinc has a particle diameter of 1 to 5 ㎛ used. Smaller particles of the zinc powder have the advantage of wider reaction area with the inorganic silicate solution, but zinc having a particle diameter of less than 1 μm is practically difficult to manufacture and cannot be applied. In addition, since the coating composition of the present invention forms a thin film having a thickness of at least 5 μm, when the size of the zinc particles is large, the zinc particles are exposed out of the coating layer to cause defects in the coating layer.

In particular, the water-soluble baking zinc coating composition according to the present invention includes an encapsulating agent and a water-soluble polymer dispersing agent to encapsulate the metal surface of zinc, thereby increasing compatibility with the polymer resin.

1 is a schematic diagram showing the repulsion between the zinc particles by forming an electrical double layer between the zinc particles due to the encapsulating agent and the water-soluble polymer dispersant surrounding the surface of the zinc.

Referring to FIG. 1, the encapsulated zinc particles stereochemically form a repulsion and an electric double layer to each other to form a stable dispersion state without agglomeration with each other, and have a long-term storage stability that can be represented in the dispersion theory.

Figure 2 is a schematic diagram showing the three-dimensional stabilization of zinc surrounded by the encapsulating agent and the water-soluble polymer surrounding the surface of the zinc.

Referring to FIG. 2, zinc particles have steric stability due to encapsulating agent and water-soluble polymer dispersant surrounding the zinc surface, and the water-soluble polymer not only increases compatibility with other compositions, but also makes hydrophobic contact with water in or out of the paint. (Hydrophobic) component inhibits. As a result, generation of hydrogen gas caused by conventional water contact of zinc is suppressed.

The encapsulating agent may have an amine value of 20 to 50 mgKOH / g, and an acid value of 20 to 50 mgKOH / g, preferably ammonium polyacrylate, sodium polyacrylate, sodium polyphosphate, potassium polyphosphate, acetyl glycol One kind selected from the group consisting of derivative fatty acid salts, alkylphenol-ethoxylate sulforate salts and mixtures thereof is possible.

The encapsulating agent comprises 0 to 10% by weight, preferably 0.1 to 5% by weight of the total coating composition. If the content is less than the above range, it is difficult to sufficiently obtain the above-described effects, so it is suitably used within the above range.

The water-soluble polymer dispersant may have a carboxyl group or an amine anchoring group. The water-soluble polymer dispersant may be one selected from the group consisting of alkylammonium salts of block copolymers having acidic functional groups, polymer block polymer solutions having pigment-affinity functional groups, and phosphate ester salts of polymer block copolymers having pigment-affinity functional groups. Do. Commercially available products include BYK 154 ^® , BYK 155 ^® , BYK 190 ^® , BYK 192 ^® , BYK 194 ^® , BYK 180 ^® , BYK 182 ^® , EFKA 4580 ^® , EFKA 5071 ^® , EFKA 6220 ^® , EFKA 6230 ^® , EFKA 4550 ^® , TEGO O750W ^® , tetramethyldecynediol (Air Product, trade name: sufynol 104 ^® ), or surfinol TG ^® , 2-amino-2-methyl-1-propanol, and these One selected from the group consisting of a mixture of is possible.

The water-soluble polymer dispersant is included in an amount of 0.05 to 10% by weight, preferably 0.1 to 5% by weight in the total coating composition. If the content is less than the above range, a severe gas generation problem occurs, and if the content exceeds the above range, the paint physical property lacks chemical and antirust properties.

Meanwhile, the water-soluble baking zinc coating composition of the present invention includes one pigment selected from the group consisting of soluble rust-preventive pigments, low toxicity pigments, coloring and extender pigments, and mixtures thereof.

The soluble rust preventive pigment is one selected from the group consisting of zinc chromate, zinc tetraoxyl chromate, zinc trioxyl chromate, strolium chromate and mixtures thereof, and the low toxicity pigment is zinc oxide, modified aluminum triphosphate, zinc phosphate, aluminum Modified phosphate, molybdate modified phosphate and mixtures thereof. The coloring and extender pigments are zinc oxide, titania, carbon black, barium sulfate, calcium carbonate, mica, talc and mixtures thereof. One species selected from the group consisting of is possible. Such pigments may be appropriately selected by those skilled in the art according to the intended use of the water-soluble baking zinc coating composition of the present invention.

The pigment comprises 5 to 40% by weight, preferably 7 to 30% by weight of the total coating composition. More specifically, 2 to 15% by weight of the soluble rust preventive pigment, 2 to 20% by weight of the low toxicity pigment, and 5 to 25% by weight of the coloring and sieving pigment. If the content is less than the above range, there is a problem that the rust resistance and drying is delayed, and if the content exceeds the above range, there arises a problem of lack of mechanical properties and material adhesion.

The water-soluble melamine resin is used to improve reactivity, paint chemical property adhesion, and rust resistance in the coating composition. The water-soluble melamine resin may be one selected from the group consisting of hexamethylmethoxy melamine resin, partially alkylate melamine resin, partially metalate melamine resin, alkylate carboxylate melamine resin, and mixtures thereof.

The water-soluble melamine resin is included in the content of 0.5 to 15% by weight, 1 to 10% by weight in the total coating composition. If the content is less than the above range, the gloss of the coating film does not disappear or sufficient curing reaction does not occur, so that the physical properties of the coating film are lowered. If the content exceeds the above range, the coating film is not hardened, and adhesion or cohesion is lowered. The water-soluble melamine resin is appropriately selected depending on the workability and physical properties required by the demand line, such as compatibility with the main component resin, the type of coating equipment, flexibility, coating strength, adhesion, and dryness.

In addition, the water-soluble baking zinc coating composition according to the present invention includes a sedimentation inhibitor. Since zinc or pigments as described above are heavy, the specific gravity is in the range of 2 to 7.5, the pigment precipitates during the storage of the paint, thereby deteriorating the physical properties of the coating composition or poor workability. Anti-settling agents are used to prevent the precipitation of these zinc or pigments. Representative examples include fume silica, organocrane, bentonite aerogel 300 ^® , bentonite aerogel 972 ^® , creton ^® , benton 27 ^® , benton 34 ^® and benton 38. 1, selected from the group consisting of ^® , SD-2 ^® , and mixtures thereof.

The anti-settling agent is included in an amount of 0.1 to 10% by weight, preferably 2 to 7% by weight in the total coating composition. If the content is less than the above range, the precipitation of the pigment cannot be suppressed, and if it exceeds the above range, the cost increases economically, so it is suitably used within the above range.

The co-solvent may be mixed with water, which is a solvent, and affects coating workability and paint properties such as coating appearance, foamability, paint spreadability, and dryness. The co-solvent may be one selected from the group consisting of lower alcohols, ethers and mixtures thereof having an evaporation boiling point of 100 to 300 ° C. Typically one lower alcohol selected from the group consisting of butyl alcohol, isobutyl alcohol, isopentyl alcohol, isopropyl alcohol, and combinations thereof, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl Cellosolve), ethylene glycol monoethyl ether acetel (cellosolve acetate), ethylene glycol monobutyl ether (butylcellosolve), diethylene glycol monobutyl ether, propylene glycol monomethyl ether, diacetone alcohol, diethylene glycol 1 ether selected from the group consisting of butyl ether acetate, propylene glycol methyl ether acetate, ethylene glycol butyl ether acetate, 3-methyl 3-methoxybutanol and mixtures thereof, and mixed solvents thereof One kind is possible.

The co-solvent comprises 5 to 30% by weight, preferably 10 to 20% by weight of the total coating composition. If the content is less than the above range, there is a problem of lack of bubble generation and coating film gloss, and if the content exceeds the above range, a bad smell occurs.

Water is a solvent of the composition described above, dissolves the resin in the preparation of the paint, improves the dispersion of the pigment, and imparts viscosity control, shelf life and the minimum coating film formation temperature. In addition, it creates the expected surface condition, imparts suitable properties to the painting equipment during painting, and contributes to volatilization of the solvent.

As described above, the water-soluble baking zinc coating composition according to the present invention comprises a water-soluble rheopolyester resin, a water-soluble phosphoric acid-modified epoxy ester resin, an encapsulating agent, a water-soluble polymer dispersant; Pigments, water soluble melamine resins, sedimentation inhibitors, co-solvents and water. The water-soluble calcined zinc coating composition further includes one selected from the group consisting of a reaction accelerator, a material spreading aid, an antifoaming agent, a surface adjusting agent, a surface spreading aid, a rust-preventing and adhesion promoter, a neutralizing agent, a pH adjusting agent, and a combination thereof as necessary. do.

The reaction accelerator is for increasing the curing ability of the water-soluble melamine resin, and improves workability according to the temperature of the paint reactant, and satisfies the rust resistance, chemical resistance, and drying properties required by the consumer. The reaction promoter may be one selected from the group consisting of para-toluene sulfonic acid, dinonylnaphthalene disulfonic acid, and mixtures thereof. The reaction accelerator is included in an amount of 0 to 5% by weight in the total coating composition.

The antifoaming agent prevents bubbles, controls the surface tension of the paint, and removes large and small bubbles that may occur during painting operations. If bubbles are not completely removed, the coating performance, such as durability, corrosion resistance, and water resistance, as well as damage to the appearance of the coating film is degraded, and thus has an important effect on the paint performance. The antifoaming agent may be one selected from the group consisting of a silicone antifoaming agent, a mineral oil and a polymer antifoaming agent. Typical BYK 019 ^® , BYK 020 ^® , BYK 024 ^® , EFKA 2526 ^® , EFKA 2527 ^® , EFKA 2550 ^® , TEGO-F810 ^® , TEGO-815 ^® , A-900 ^® , A-910 ^® , A-920 ^® , A-822 ^® , A-8250 ^® , DF-210 ^® , and a combination thereof. The amount of the antifoaming agent is used in the usual additive level, 0 to 5% by weight of the total coating composition.

The surface modifiers and surface spreading aids are those known in the art to prevent spreading, foaming, surface conditioning and cratering. The surface modifier may be one selected from the group consisting of reactive silicones, silicone surfactants, and polyacrylates. Typical BYK 345 ^® , BYK 347 ^® , BYK 346 ^® , BYK 340 ^® , BYK 333 ^® , TEGO wet 245 ^® , TEGO wet 265 ^® , TEGO 410 ^® , EFKA 3522 ^® , EFKA 3570 ^® , EFKA 3580 ^® , EFKA 3772 ^® , and one selected from the group consisting of a combination thereof. The content of the surface modifier and surface spreading aid is used in the usual additive level, 0 to 5% by weight of the total coating composition.

The rust preventive and adhesion enhancer improves the material adhesion ability as well as the rust preventive to strengthen the material adhesion affecting the final coating performance. The antirust and adhesion promoters are those known in the art, and typically include aqueous phenolic resins, aqueous polyester resins, titanium tetra butananolate polymers, neoalkoxy tri (dioctylpyrophosphate) titanates ( neoalkoxy tri (dioctylpyrophospate) titanate, titanium acetylacetonate, methoxy or ethoxy silane coupling aid (vinyl group, epoxy group, amino group, methacryl group, modified mercapto group) One kind is possible. The content of the rust preventive and adhesion promoter is used in the usual additive level, 0 to 5% by weight in the total coating composition.

The neutralizing agent adjusts the pH of the coating composition to 8 to 10, and may be one selected from the group consisting of dimethyl ethanol amine, triethyl amine or triethanolamine, and combinations thereof. The content of the neutralizing agent is used in the usual additive level, 0 to 5% by weight in the total coating composition.

This water-soluble baking zinc coating composition

a) adding an encapsulating agent, a water-soluble polymer dispersing agent and zinc to the reactor to uniformly mix to produce a mixture in which the zinc surface is encapsulated;

b) adding a pigment to the mixture of step a) and stirring at high speed to prepare a mixture;

c) preparing a mixture of step b) by adding a water-soluble rheopolyester resin, a water-soluble phosphoric acid-modified epoxy ester resin, a water-soluble melamine resin, a co-solvent and water and mixing them uniformly.

Specifically, in step a), an encapsulating agent, a water-soluble polymer dispersant, and zinc are added to the reactor and mixed uniformly to prepare a mixture in which the zinc surface is encapsulated.

At this time, the mixing is carried out using three cone mills, sand mills, ball mills, and is performed for 5 minutes to 1 hour at 500 to 1500 rpm, until the particles of the mixture is 10 to 20 ㎛.

Next, by adding a pigment to the mixture of step a) and stirring at high speed to prepare a mixture.

At this time, the mixing is also performed using a ball mill, and is performed at 1000 to 2500 rpm for 5 minutes to 1 hour.

Next, a water-soluble rheopolyester resin, a water-soluble phosphoric acid-modified epoxy ester resin, a water-soluble melamine resin, a co-solvent and water are added to the mixture of step b) and mixed uniformly to prepare a water-soluble calcined zinc coating composition.

At this time, if necessary, various additives such as viscosity regulators and pH regulators are added in a predetermined amount, and are performed at 800 to 1200 rpm for 10 minutes to 1 hour.

As a result, the water-soluble calcined zinc coating composition prepared above had a viscosity of 70 to 125 ku, a pH of 8 to 10, and particles of 10 to 20 μm, measured by a Crebes-stopper viscometer.

The water-soluble baking zinc coating composition prepared in this way is excellent in corrosion resistance and is preferably applied as a coating film of ferrous metals and nonferrous metals.

The coating composition is conventionally used as a coating film, and excellent initial water resistance and corrosion resistance even when coated with a thickness less than the baking paint type of the chromate and lead-based pigment type used as a reproductive toxicity and carcinogen. In particular, the composition is a low toxicity pigment and zinc phosphate-based and modified zinc phosphate-based pigments with zinc-based pigments can be introduced into the paint formulation with low toxicity is possible. In addition, the composition is excellent in dispersibility and storage stability, it is difficult to disperse pigments in the conventional water-soluble epoxy and the alkali resistance which is a drawback of the water-soluble alkyd type is characterized by improved corrosion resistance. In addition, it is excellent storage stability while maintaining the stability of baking work by introducing an adhesion promoter. In particular, water can be used as a diluent to adjust the viscosity, which can be applied to a variety of painting works.

Hereinafter, preferred embodiments of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited by the following examples.

EXAMPLE

Examples 1-2

The material spreadable additive was injected into the reactor, an encapsulating agent, a water-soluble polymer dispersant, zinc (powder and flake mixed type), an antifoaming agent, and an antisettling agent were added, followed by stirring with a ball mill at a speed of 1200 rpm for 10 minutes. Stirring was carried out until the particles of the mixture reached 20 μm, to which soluble rust preventive pigments, coloring and sieving pigments were added, followed by high speed stirring at 2000 rpm for 10 minutes.

Next, a water-soluble phosphate-modified epoxy resin, a water-soluble rheopolyester resin, a water-soluble melamine resin, a neutralizing agent, a surface regulator, a reaction promoter, and an adhesion promoter were added to the reactor and stirred at a speed of 1000 rpm for 2 hours. After stirring, distilled water was added to prepare a composition having a viscosity of 80 ku.

 At this time, the content of each composition is as shown in Table 1 below.

Composition (% by weight) Example 1 Example 2 Water-soluble rheological polyester resin ¹ 10 5 Water-soluble Phosphoric Acid Modified Epoxy Resin ² 10 15 Oil-based urethane modified epoxy resin - - Zinc ³ 40 50 Encapsulations ⁴ One 2 Water Soluble Polymer Dispersant ⁵ 0.5 0.5 Soluble Antirust Pigments ⁶ 10 5 Pigmentation and coloring pigments ⁷ 2.5 3.5 Antisettling agents ⁸ One One Water Soluble Melamine Resin ⁹ 5 5 Antifoam ¹⁰ 0.5 0.5 Neutralizer ¹¹ One One Material spreading preparation ¹² 0.5 0.5 Solvents ¹³ 12 10 Distilled water 5 0 Surface conditioners ¹⁴ 0.5 0.5 Reaction Accelerators ¹⁵ 0.5 0.5 Note) 1: water-soluble rheopolyester resin: number average molecular weight 500 to 20,000, light synthetic resin 2: water-soluble phosphoric acid modified epoxy resin: number average molecular weight 190 to 2,500, light self-synthetic resin 3: oil-based urethane-modified epoxy resin: number average molecular weight 190 To 2,500, light self-synthetic resin 4: zinc: powder and flake type, particle size 1 to 5 ㎛ 5: encapsulating agent: ammonium polyacrylate, EFKA product 6: water-soluble polymer dispersant: high molecular weight block copolymer having a pigment affinity functional group, BYK-191, BYK company 7: Soluble rust preventive pigments: strontium chromate, sambo fine chemicals 8: Coloring and sieving pigments: TiO ₂ + talc (1: 1) from Chimegi Company, from West Industry Co., Ltd. 9: Sedimentation inhibitors: Hume Silica, Degussa Product 10: Water-soluble melamine resin: Methylmethoxy modified melamine, CYMEL 303, Cytec product 11: Defoamer: Polymeric fluorine-modified defoamer, BYK product 12: Neutralizer: DMEA (dimethyl ethanol Amine), BASF product 13: Material spreading aid: polyether modified polydimethylsiloxane solution, BYK product 14: solvent: methanol 15: surface conditioner: polyether modified siloxane, BYK product 16: reaction promoter: Block Acid PTSA modified, king industry product

Experimental Example  One

In order to measure the physical properties of the coating composition prepared in Examples 1 to 2 was carried out as follows to prepare a test piece.

After cold rolled steel sheet (KS D 3512) and mechanically sanded 220 neck, air spray 40 탆 spray, dry film coating, solvent cleaning 10 ㎛ thickness carpet coating was set for 10 seconds. After that, the surface temperature of the material was adjusted to 350 ° C. in a PMT drying furnace.

A: Nonvolatile matter (%)

After the sample was taken, the initial sample weight was measured, followed by hot air drying at 105 ° C. for 3 hours, and the weight of volatile matter relative to the initial sample weight was calculated based on Equation 1 below.

[Equation 1]

Nonvolatile matter (%) = ((Initial sample weight-weight of volatile) / Initial sample weight) × 100

B: viscosity ( Ku )

It measured using the stopper viscometer at 25 degreeC.

C: particle size (µm)

It was measured with a particle size meter.

D: dry state ( MEK castle)

After the prescribed temperature of 320 ° C. × 20 seconds, the methyl ethyl ketone was buried in cotton cloth, and the dry film was rubbed with 1 kgf.

○: buried slightly after 5 times.

(Triangle | delta): It comes out after rubbing 2-4 times.

X: It buryes after rubbing once.

E: Paintability ( Dipping  And spray coating state)

The dry coating film thickness was coated with a thickness of 40 µm to obtain a smooth coating film thickness, and visually compared with each other, it was determined by dividing it into three stages of good (○), good (△), and bad (×).

F: pencil hardness Tombow )

Cut the tip of the Mitsubishi uni pencil so that the core is 4 ± 1 mm, apply the core to the grinding paper at least 400 times at right angles, polish it in a circle, and make the end smooth and sharp at an angle of 45 ° to the film surface. Five lines were drawn at least 20 cm forward with a force of about 1 kgf. At this time, the test site was erased with an eraser and then the scratches were visually observed. The hardness of the coating film was determined when there were no more than three scratches among the five lines.

G: Adhesive

According to the cross-cut test method of ASTM D 3359, the cut made to the specimen was cut with a sheath and adhered to the cellophane tape so that the scratched part was evenly attached. Subsequently, the peeling state of the coating film of the site | part where a scratch was made by peeling a cellophane tape was compared visually, and it classified and evaluated as follows.

(Circle): No peeling.

(Triangle | delta): 50% or more of coating film remainder.

X: 50% or less coating film remaining.

H: impact resistance ( Dupont 1/2 "* 500g * 30)

Dupont impact tester was used to measure the occurrence of cracks in specimens made of 1/2 ”× 500g × 30㎝, and in three stages of good (○), good (△) and bad (×) depending on the crack condition. Judgment was made separately.

I: Saline Spray

Specimens made according to ASTM B117 were made with X-shaped lines according to method 2 (scraping method) of ASTM D1654. Subsequently, according to KS D 9502, a 5 wt% NaCl aqueous solution was exposed to a salt spray machine sprayed at 35 ° C., and then exposed to a coating state by time.

(Circle): One side 1 mm or less.

(Triangle | delta): 1-2 mm.

X: 2 mm or more.

J: Topological adaptability (alkyd series, epoch clock, Urethane Paint )

After each coating composition was left for 1 day after the top coat, it was determined by dividing it into three stages of good adhesion (○), good (△), and poor (×) to alkyd, urethane, and epoxy systems.

K: flexibility (180 ° Banding )

The coating film surface of the specimen was bent inward by 180 ° and adhered with a cellophane tape to confirm whether the coating film was peeled off.

(Circle): It is not peeled at all.

(Triangle | delta): It hardly peels off.

×: Peel off.

L: hypotonic

Each paint composition was stored at 40 ° C. for 1 month, and then the precipitation state of the paint composition was checked to see if a hard precipitate occurred:

(Circle): There is no sediment at all.

△: slight precipitate.

X: generation of a large amount of precipitate.

M: Alkali resistance

According to KSM-5000-3411, the specimen was immersed in a 5 wt% NaOH aqueous solution for 72 hours in accordance with the test method for immersion resistance of the dry coating film, and then measured for bristering or 60 ° mirror gloss to obtain excellent (○) and good (△ ), And classified into three stages of defective (x).

N: Whether hydrogen gas is generated

1L of the composition was injected into a 2 L square tin tin can with a spherical inlet port of 5 cm in diameter, and the children's play balloon was completely sealed with a rubber band to prevent gas from being enclosed at the edge of the inlet port. The can was measured after 10 and 30 days of hydrogen gas generation in a thermostat at 60 ° C. The amount of hydrogen gas generation was measured by dividing according to the degree ○: no generation, △: slightly swelling, and ×: gas generation is severe, the results obtained are shown in Table 2 below.

Example 1 Example 2 Nonvolatile matter (%) 71 78 Viscosity (ku25 ℃, stopper viscometer) 75 85 Particle size (㎛) 20 20 Dry state (MEK property) ○ ○ Painting workability ○ ○ Pencil Hardness (Tombow) HB-H H-2H Adhesive ○ ○ Impact resistance (Dupont, 1/2 "* 500g * 30) ○ ○ Salt spray ○ ○ Topographic adaptability ○ ○ Flexibility (180 ° Banding) ○ ○ Storability (adjust Fc4 20-40 seconds with water) ○ ○ Alkali resistance ○ ○ Hydrogen gas generation ○ ○

Examples 3-8

To the composition of Table 3 was carried out in the same manner as in Example 1 to prepare a coating composition.

Composition (% by weight) Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Water-soluble rheological polyester resin ¹ 4 5 5 5 5 5 Water-soluble Phosphoric Acid Modified Epoxy Resin ² 15 15 10 15 10 15 Zinc ³ 50 45 40 50 50 40 Encapsulating agent ⁴ 2 One One 2 One One Water Soluble Polymer Dispersant ⁵ One One One One One One Low Toxicity Antirust Pigment ⁶ 4 5 5 4 5 5 Pigmentation and coloring pigments ⁷ 2 5 2 2 2 2 Antisettling agents ⁸ 2 2 2 2 One One Water Soluble Melamine Resin ⁹ 5 5 5 5 5 5 Antifoam ¹⁰ 0.5 0.5 0.5 0.5 0.5 0.5 Neutralizer ¹¹ 2 One One One One One Material spreading preparation ¹² 0.5 0.5 0.5 0.5 0.5 0.5 Solvents ¹³ 10 12.5 7 13 10 10 Distilled water One 0 5 0 5 5 Surface conditioners ¹⁴ 0.5 0.5 0.5 0.5 0.5 0.5 Reaction Accelerators ¹⁵ 0.5 0.5 0.5 0.5 0.5 0.5 Adhesion Promoter ¹⁶ One 0.5 0.5 0.5 0 0 DESCRIPTION OF SYMBOLS 1: Water-soluble rheopolyester resin: Number average molecular weights 500-20,000, Light paint company, 2: Water-soluble phosphoric acid modified epoxy resin: Number average molecular weight 190-2500, Light paint company 3: Zinc: Powder and flake type, Particle size 1- 5 μm 4: Encapsulating agent: sodium polyacrylate (Example 3), sodium polyphosphate (Example 4), potassium polyphosphate (Example 5), acetylglycol derivative fatty acid salts (Examples 6 and 7), alkylphenols Ethoxylate sulforate salt (Example 8), EFKA product 5: Water-soluble polymer dispersant: BYK-192 (Example 3-5, BYK product), TEGO-750W (Example 6-7, TEGO product), EFKA -6220 (Example 8, product of EFKA) (identification: the material claimed in the claims) 6: Low toxicity anti-corrosive pigment: molybdate modified phosphate, Nuobia product 7: coloring and extender pigment: TiO ₂ (Kime Article), talc (Western Products) 8: sedimentation inhibitor: fume seal Ka, Degussa Product 9: Water-soluble melamine resin: Methylmethoxy-modified melamine, Cytec product 10: Defoamer: Polymer fluorine modified and silicone defoamer BYK Product 11: Neutralizer: DMEA (dimethyl ethanolamine), BASF Product 12: Material spreadability Preparation: Polyester-modified polydimethylsiloxane, BYK product 13: Solvent: isopropyl alcohol / butyl cellosolve (1: 1, volume ratio) 14: Surface modifier: Polyether modified siloxane, BYK company 15: Reaction accelerator: Block acid PTSA modified. King Industries Product 16: Adhesion Promoter: Silan181, Dow Corning

Experimental Example  2

The physical properties of the coating compositions prepared in Examples 3 to 8 were measured as mentioned in Experimental Example 1, and the results obtained are shown in Table 4.

Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Nonvolatile matter (%) 78 73 65 71 73 67 Viscosity (Ku, Stormer Viscometer) 87 80 73 78 78 70 Particle size (㎛) 20 20 20 20 20 20 Dry state (MEK) ○ ○ ○ ○ ○ ○ Painting workability ○ ○ ○ △ △ ○ Pencil Hardness (Tombow) H H HB-H H-2H H-2H H-2H Adhesive ○ ○ ○ △ ○ ○ Impact resistance (Dupont, 1/2 "* 500g * 30) ○ ○ ○ △ ○ ○ Salt water spray resistance (120 hours rust prevention) ○ ○ ○ ○ ○ ○ Topographic adaptability ○ ○ ○ ○ ○ ○ Flexibility (after 180 ° bending) ○ ○ ○ △ ○ ○ Storability (20-40 seconds with water) ○ ○ ○ ○ ○ ○ Alkali resistance ○ ○ ○ ○ ○ ○ Hydrogen gas generation ○ ○ ○ ○ ○ ○

Referring to Table 4, the water-soluble baking zinc coating composition of the present invention can be used as a coating by diluting with 20 to 60% by weight of water than the conventional oil type. These results indicate that the use of the coating composition according to the present invention significantly reduced VOCs (Volatile Organic Compounds) compared to paints using thinners as a conventional thinner, and also significantly reduced fire stability and workplace odor. It can be improved.

In addition, it can be seen that the coating composition is excellent in workability, durability, coating hardness, mechanical properties, corrosion resistance, material adhesion and top coat adhesion. Furthermore, the generation of hydrogen gas is suppressed by the role of the encapsulating agent and the water-soluble polymer dispersant in the preparation of the paint, and the precipitation stability of the zinc powder is excellent, and there is no need to add an inert gas during the preparation of the coating composition. As a result, manufacturing processes can be simplified and production time can be reduced, which contributes to increased productivity in paint manufacturing.

The water-soluble calcined zinc coating composition according to the present invention forms mechanical coatings on surfaces of automobile parts, industrial parts, and steel (steel band) products of various metals, which require various corrosion resistances, thereby providing excellent mechanical and chemical properties including corrosion resistance. . In addition, the coating composition is manufactured in a low toxicity formulation is suitable for coating products and materials that are exported as environmentally friendly products can increase product competitiveness.

Claims (14)

Water-soluble rheopolyester resin having a number average molecular weight of 500 to 20000; Water-soluble phosphoric acid modified epoxy ester resins having a number average molecular weight of 190 to 2500; zinc; One encapsulating agent selected from the group consisting of ammonium polyacrylate, sodium polyacrylate, sodium polyphosphate, potassium polyphosphate, acetylglycol derivative fatty acid salts, alkylphenol-ethoxylate sulforate salts and mixtures thereof; Water-soluble polymer dispersants; One pigment selected from the group consisting of low toxicity pigments, coloring and extender pigments and mixtures thereof; 1 type water-soluble melamine resin selected from the group consisting of hexamethylmethoxy melamine resin, partially alkylate melamine resin, partially metalate melamine resin, alkylate carboxylate melamine resin and mixtures thereof; Antisettling agents; Co-solvents; And Including water; The encapsulating agent is a water-soluble baking zinc coating composition having an amine value of 20 to 50 mgKOH / g and an acid value of 20 to 50 mgKOH / g. The method of claim 1, The water-soluble calcined zinc coating composition is 1 to 20% by weight of water-soluble rheopolyester resin, 5 to 30% by weight of water-soluble phosphate-modified epoxy ester resin, 30 to 60% by weight of zinc, 0 to 10% by weight of encapsulating agent, water-soluble polymer dispersant 0.05 To 10% by weight, pigment 5 to 40% by weight, 0.5 to 15% by weight of the water-soluble melamine resin, 0.1 to 10% by weight of the antisettling agent, 5 to 30% by weight of the co-solvent and the balance water-soluble calcined zinc coating composition. delete delete The method of claim 1, The water-soluble polymer dispersing agent is one kind selected from the group consisting of tetramethyldecynediol, 2-amino-2-methyl-1-propanol, and mixtures thereof. The method of claim 1, The low toxicity pigment is one selected from the group consisting of zinc oxide, modified aluminum triphosphate, zinc phosphate, aluminum modified phosphate phosphate, molybdate modified phosphate, and mixtures thereof, The coloring and sieving pigment is water-soluble baking zinc coating composition is one selected from the group consisting of zinc oxide, titania, carbon black, barium sulfate, calcium carbonate, mica, talc and mixtures thereof. delete The method of claim 1, The anti-settling agent is one type selected from the group consisting of fume silica, organocray and mixtures of these water-soluble baking zinc coating composition. The method of claim 1, The co-solvents include one lower alcohol selected from the group consisting of butyl alcohol, isobutyl alcohol, isopentyl alcohol, isopropyl alcohol, and combinations thereof, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (Ethyl cellosolve), ethylene glycol monoethyl ether acetel (cellosolve acetate), ethylene glycol monobutyl ether (butylcellosolve), diethylene glycol monobutyl ether, propylene glycol monomethyl ether, diacetone alcohol, di A group consisting of one ether selected from the group consisting of ethylene glycol butylether acetate, propylene glycol methylether acetate, ethylene glycol butylether acetate, 3-methyl 3-methoxybutanol and mixtures thereof, and mixed solvents thereof It is one kind selected from water-soluble baking zinc coating composition. The method of claim 1, In addition, the water-soluble baking zinc coating composition is a water-soluble baking zinc coating comprising one or more additives selected from the group consisting of an antifoaming agent, a surface conditioner, a surface spreading aid, an antirust and adhesion promoter, a neutralizer, a pH adjuster, and a combination thereof. Composition. delete The method of claim 1, The water-soluble baking zinc coating composition is a water-soluble baking zinc coating composition having a viscosity of 75 to 125 ku, a pH of 8 to 10, and a particle size of 10 to 20 ㎛ measured by a Crebes-stopper viscometer. a) adding an encapsulating agent, a water-soluble polymer dispersing agent, zinc and an antisettling agent to the reactor and mixing it uniformly to produce a mixture in which the zinc surface is encapsulated; b) adding a pigment to the mixture of step a) and stirring at high speed to prepare a mixture; c) adding the water-soluble rheopolyester resin, the water-soluble phosphate-modified epoxy ester resin, the water-soluble melamine resin, the co-solvent and water to the mixture of step b), and mixing them uniformly. Method of Preparation of the Composition. delete

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