KR100543602B1 - Manufacturing method of urethane-modified polyester polyol water-dispersible resin for automotive top coat and water-soluble coating composition containing same - Google Patents

Abstract

The present invention relates to a method for preparing a urethane-modified polyester polyol water-dispersible resin and a water-soluble coating composition containing the same as a resin for dispersing pigments, comprising: (1) 2 to 5% by weight of the resin in a solid content by condensation of an acid and an alcohol. Preparing a polyester polyol resin containing a hydroxyl group having a hydroxyl value of 60-120 mgKOH / g, a weight average molecular weight of 800-2500, (2) mixing a monomer sharing a hydroxyl group and a carboxyl group with the polyester polyol resin, Urethane reaction of one or two or more polyvalent isocyanates to prepare a urethane-modified polyesterpolyol prepolymer, and (3) neutralizing and dispersing the prepolymer. It shows excellent effects in all physical properties such as water resistance and chipping resistance.

Description

Method for preparing urethane-modified polyester polyol water dispersion resin for automotive top coating and water-soluble coating composition containing same

The present invention relates to a method for preparing a urethane-modified polyester polyol water-dispersion resin and a water-soluble coating composition containing the same as a resin for dispersing pigments. More specifically, the monomer containing an isocyanate group is a polyester polyol and a carboxyl group and a hydroxyl group. The present invention relates to a method for producing a urethane-modified polyester polyol water-dispersible resin produced by a monomer and a urethane reaction, and a water-soluble coating composition containing the same.

Dispersion of powders in liquids is widely used in the fields of paints, inks and pharmaceuticals.

In particular, it is known that the dispersion of pigments in paints not only affects the appearance of the coating film much, but also greatly influences the physical properties of the coating and coating films. As you know, the paint is a mixture of resins, pigments, solvents, and additives. That is, one of the most important requirements for producing such coating compounds, i.e. paints, is the dispersion of the pigment. That is, the optimum dispersion state of the pigment is applied to the intermediate product used in the manufacture of the paint or directly applied in the manufacture of the paint, so that the stability in producing the paint of the intended purpose must be ensured.

Some pigments readily disperse to form stable dispersions, while others have significant problems with dispersion. Most of these pigments do not disperse well so that agglomeration between the pigments occurs or the pigment floats on the surface, and thus a separation phenomenon between the dispersion resin and the pigment occurs in many cases. As such, maintaining the dispersion and dispersion of the pigments is ultimately very important for the storage stability and other physical property changes of the paint.

In general, it is known that the dispersion stabilization of the pigment is possible by the electrostatic repulsive force and the steric stabilization effect. Therefore, it must be designed to include both of these functions in the dispersion resin to be able to play a role as a dispersion resin less affected by pH, temperature, influx of impurities, etc. in the production of paint. Therefore, the present invention relates to the preparation of a resin in consideration of the electric repulsive force as well as the steric stabilization effect and a water-soluble coating composition containing the same.

Examples of preparing a resin for dispersing a water-soluble pigment have been known. For example, Japanese Patent Publication No. 60-212412 relates to an anionic pigment dispersion resin produced by neutralizing a maleic acid copolymer with an amine or metal, and Japanese Patent Publication No. 63-51487 relates to a pigment surface. The content regarding the resin for nonionic dispersion to which the acrylamide copolymer which has the outstanding adsorption was applied was published.

Generally, in order to impart steric stabilization effect to the resin for dispersion, it is possible to introduce a hydrophilic group in the form of a block copolymer of the polymers AB and ABA or in a grafted form. Among them, the ABA block copolymer is known to reduce the dispersion effect, most of the developed resins belong to the AB type copolymer or graft copolymer. In the case of the AB type copolymer, the pigments have excellent dispersion ability when they have polar A group and nonpolar B group. Accordingly, the present invention is to maximize the pigment dispersion stability by maximizing the pigment dispersion stability by grafting an anionic group containing a hydroxy group between the polymer formed by the urethane reaction of polyester polyol and diisocyanate to maximize the physical properties of the coating and coating film It is an object of the present invention. Moreover, if the conditions which the resin which has a steric stabilization effect should be equipped are specified, the following are mentioned. First, the barrier of the resin adsorbed on the pigment should be 100 angstrom or more to prevent attraction between the pigment particles, and the dispersion resin to be adsorbed on the pigment has a sufficient molecular weight, and the steric stabilization site is good for the intermediate medium. It must be soluble so that it can exhibit stable dispersion.

Meanwhile, a technique for preparing a latex emulsion grafted with polyethylene glycol capable of steric stabilization is disclosed in US Pat. No. 4,465,803, which is not a technique for stabilizing pigment dispersion but is applied for the purpose of improving the storage stability of latex emulsion particles. As an example, when applied to its pigment dispersion, the polyethylene glycol side chains are linked by ester bonds, which implies the possibility of hydrolysis upon dispersion.

Accordingly, in the present invention, a polyester polyol which is insoluble in water is prepared to perform urethane polymerization with one or more monomers having an isocyanate group together with a monomer which shares a carboxyl group with a hydroxy group, and the remaining carboxyl group is neutralized with an amine for water solubility in automobiles. It is an object of the present invention to provide a method for producing a resin for pigment dispersion applied to top coat and a pigment dispersion coating composition containing the resin thus prepared.

The method for producing a urethane-modified polyester polyol water-dispersion resin for automotive top coating of the present invention for achieving the above object comprises (1) a hydroxyl group of 2 to 5% by weight in the resin solids by condensation reaction of a conventional acid and alcohol, 60 -Preparing a polyester polyol resin having a hydroxyl value of 120 mgKOH / g, a weight average molecular weight of 800-2500, (2) mixing a monomer sharing a hydroxy group and a carboxyl group with the polyester polyol resin, and one or two or more polyvalent isocyanates Urethane reaction to prepare a urethane-modified polyester polyol prepolymer, and (3) neutralizing and dispersing the prepolymer.

Specific manufacturing method for explaining this in more detail is made by the following three-step reaction.

A. First Step Reaction: Polyester Polyol Synthesis step, which is generally known to synthesize polyester polyols using polyhydric alcohols and polyvalent acids.

The polyhydric alcohols commonly used in this step are mainly dihydric or trihydric alcohols. The trihydric alcohol used for maximizing dispersion is 5-10 wt% and the total alcohol content is 35-50 wt%. . The dihydric alcohols include 1,6-hexanediol, 1,4-butanediol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, ethylene glycol, diethylene glycol, cyclohexanediol, and the like. And trihydric alcohols include trimethylolpropane, trimethylol ethane, and the like. In the present invention, two or more thereof are mixed and used.

In addition, as for the polyvalent acid used at this stage, divalent and trivalent acids are mainly used, and total acid content is 50-65 weight%. The dihydric and trivalent acids include phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, maleic acid, fumaric acid, sebacic acid, cyclohexyl dicarboxylic acid, phthalic acid, and the like. .

As the catalyst in the reaction, a tin-based catalyst is used as is well known, and the catalyst applied in the present invention is dibutyltin oxide.

The reaction is carried out at 180-220 ° C. by bulk polymerization using the above raw materials, and then terminates when the acid value reaches zero. The polyester polyols prepared by this reaction generally have a hydroxyl value of 60-120 mgKOH / g and preferably have a hydroxyl value of 80-100 mgKOH / g, which is 2-5% by weight of the polyester polyol resin. It is a hydroxyl group. When the hydroxyl value is 120 mgKOH / g or more, the molecular weight of the polyester polyol cannot increase the molecular weight of the final dispersion resin, so it is difficult to cause the steric hindrance effect between pigments. When the hydroxyl value is 60 mgKOH / g or less, the molecular weight of the polyester polyol and The increase in viscosity makes it difficult to control with hydroxyl group-containing prepolymers of the desired molecular weight upon reaction with the next step, polyvalent isocyanates. In addition, the weight average molecular weight of the polyester polyol used by this invention uses 800-2500, Preferably it is 1500-1800.

B. Second Step Reaction: The step of preparing the urethane-modified polyester polyol prepolymer, which is first mixing the polyester polyol prepared in the first step reaction with an anionic group.

The anionic group is an important reaction component in ensuring the water dispersibility of the dispersion resin of the present invention. That is, the role of the anionic group in the present invention is that the aqueous carboxylic acid groups are neutralized by the amine after the solubilization-prepolymer formation of the prepolymer, so that salts are formed and solubilization is possible and enhanced, as well as stable dispersion polymer for the electrolytic material. By maintaining the, it contributes greatly to stabilization of the dispersion of the pigment due to the electrostatic repulsion effect when the pigment is dispersed, and acts as a functional group to prevent gelation of the water-dispersible resin even at low and high temperatures, and the anionic group of the present invention The amount preferably contains 1 to 15% by weight of the prepolymer solids, preferably 4 to 8% by weight, and the component containing an anion group applied in the present invention is dihydroxy alkanoic acid. As represented by α, α-dimethyrol alkanoic acid, the preferred compound is α, α-dimethyrol Lopionic acid.

[Formula 1]

Wherein R is 1-8 hydrogen or alkyl group.

The two components are homogeneously mixed at 80-120 ° C., at which time 2-15% by weight of a co-solvent, N-methyl-2-pyrrolidone, is added to maximize the effect of homogeneous mixing.

If homogeneous mixing is found, the temperature is lowered to 60 ° C. and reacted with the polyvalent isocyanate. In order to suppress the viscosity increase during the reaction with the polyisocyanate and to give a smooth synthesis process, 20-50% by weight of a solvent is added to the prepolymer solids prior to the addition of the polyisocyanate, and typical solvents include acetone and methylethyl. Ketones, dimethylformamide, hydrogenated furan and the like. After adding a solvent, polyhydric isocyanate is gradually added over 1 hour while maintaining the temperature at 60-65 ° C. Polyvalent isocyanates which react with the two components to form a prepolymer include tetramethylene diisocyanate, hexamethylene diisocyanate, dodecylmethylene diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate , Isophorone diisocyanate, 4,4-diisocyanate cyclohexylmethane, 2,4-diisocyanate toluene, 2,6-isocyanate toluene, 4,4-isocyanate naphthalene, 1,3-bis (isocyanate methyl) cyclohexane, 1,4- (isocyanate methyl) cyclohexane and the like, but in the present invention, the molecular weight is preferably from 150 to 400. In particular, since the object of the present invention is to produce a resin composition which guarantees dispersibility of the pigment, the present invention uses a polyvalent aliphatic isocyanate having structural symmetry in order to give a three-dimensional stability effect to the dispersed pigment.

In the present invention, the polyhydric isocyanate is completely added, and then maintained at 65 ° C. for at least 3 hours, and the end point is set to zero isocyanate content. The prepolymer formed in the reaction includes a carboxyl group of the α, α-dimethyrol propionic acid in the chain and a hydroxyl group of the polyester at the end of the chain at the same time. The acid value of the prepolymer has about 10-25 mgKOH / g, which is preferable. The acid value is 15-20 mgKOH / g. The prepolymer of the present invention will have a hydroxyl value of 20-80 mgKOH / g, the preferred hydroxyl value is 40-60 mgKOH / g. In the case of the acid value of the present invention, in addition to the above-mentioned characteristics, it affects the water resistance and chemical properties of the coating film, and in the case of the hydroxyl value, the surface of the pigment dispersion liquid is not easily formed by lowering the glass transition temperature of the resin. However, it should not be less than or exceeded the numerical value given above because it acts as a factor to prevent the pigment from settling easily by hydrogen bonding with water in the pigment dispersion.

C. Third Step Reaction: The final step of the urethane-modified polyester polyol water dispersion resin formation reaction is the neutralization and solubilization step.

Since the carboxylic acid remaining in the main chain of the prepolymer prepared in the above step does not participate in the reaction, a salt is formed using an appropriate neutralizing agent to increase the water dispersibility of the present pigment dispersion resin. Suitable neutralizing agents used here include amines, preferred being tertiary amines, for example diethanolamine, diethylethanolamine, dimethylethanolamine, triethylamine, tributylamine, phenyldiethanolamine, methyldi Ethanolamine, and the like, which is used alone in the present invention, preferably an amine having low volatility. The amount of neutralizing agent is used in the amount corresponding to 0.7-3.0% by weight of the present prepolymer solids, and the degree of neutralization is in the range of 70-95%.

In the reaction, 0.7-3.0% by weight of a neutralizing agent is slowly added to the prepolymer maintained at 60-65 ° C., and the reaction is terminated until the neutralizing agent is completely mixed.

The solubilization is about 40-50% by weight of the neutralized prepolymer so that distilled water is first introduced into a disperser having a dispersing speed of 500-1000 rpm to disperse the neutralized prepolymer for 30 to 60 minutes. As a result of the dispersion process, a stable water dispersion is formed. However, in the case of the present aqueous dispersion, since a certain amount of solvent is contained, the solvent is removed by depressurizing at 10-50 cmHg for 60 minutes while maintaining a stirring speed of 70 ° C. and 300 rpm. A water dispersion resin can be obtained.

The final water-dispersed urethane-modified polyester polyol water-dispersion resin prepared by the above method has a number average molecular weight of 2000-5000, a weight average molecular weight of 10000-30000, a final acid value of 1-7 mgKOH / g, 40-60 mgKOH / g of hydroxyl value, 40-50% of resin solids, pH of 6.5-8.5, particle size of 80-150 nm, and forms a water-dispersible resin having stability of 2 years or more at room temperature, and is generally used in automotive topcoats. It has a good dispersion ability for the applied oil and inorganic pigments.

In the preparation of the pigment dispersion of the present invention, in addition to the use of a small amount of dispersant such as Ser.AD FX-504, 600, Ser.AD FN-365 (trademark of Servo Delden Co., Ltd.) applied at the time of dispersing the existing pigment, Replaced with resin. In this case, the pigment dispersion is prepared by the weight ratio of the anionic pigment dispersion resin and the pigment of the present invention to a minimum of 0.5: 10, and is composed of other additives, that is, pH adjuster, antifoaming agent, co-solvent and the like. Mainly used pigments include titanium oxide, zinc oxide, metal hydroxide, metal flake, chromate, red silica, talc, china cray, organic die, red blue, iron blue, organic red, maroon, mica, carbon black, graphite , Zinc oxide, cadmium sulfide, iron oxide, zinc sulfide, phthalocyanine complex, naphthored, quinacridone or mixtures thereof, and pigment dispersions are mainly used in dispersing pigments (red devil, ball mill, bead mill, ring mill, etc.). ) To disperse.

There are various methods for determining the dispersion degree of dispersed pigments, such as softness test, microscopic examination, particle size distribution measurement, gloss measurement, transparency measurement, coloring power measurement, fluidity change during storage, and reaggregation of pigments.

Main resin, hardener, co-solvent and other additives are added to the pigment dispersion prepared by applying the dispersion resin of the present invention and mixed at low speed to prepare a water-soluble top coat for automobiles. At this time, the applied pigment dispersion is 10 to 40% by weight based on the total coating composition, 25 to 50% by weight of the main resin, 2 to 7% by weight of the curing agent, 1 to 15% by weight of the co-agent, other additives (thickeners, wetting Tinting agents, leveling agents, etc.) are used at 1-5% by weight, respectively.

The pigment dispersion used in the water-soluble top coat composition of the present invention is applied to 10 to 40% by weight relative to the total coating composition, when the pigment dispersion in the coating composition is less than 10% by weight, adhesion and abrasion resistance is reduced, If it is more than 40% by weight, it may cause a decrease in gloss, a sharp increase in viscosity during paint storage, and a settling phenomenon of the pigment.

The main resin used in the water-soluble top coat composition of the present invention can be applied alone or in combination with a water-dispersible polyurethane-urea resin or a water-dispersible acrylic resin, which is applied at 25-50% by weight of the total coating composition. Ideally, the test showed very good compatibility with the water-dispersible resin for dispersing pigments prepared according to the present invention, and the storage stability between them was quite good.

The curing agent used in the water-soluble topcoat composition of the present invention used a water-soluble amino resin in order to cause a curing reaction with the hydroxyl groups of the main resin and the resin for dispersion at a constant temperature, the present invention contains a small amount of imino groups The water-soluble modified melamine resin was applied, and it is preferable to be applied in 2-7% by weight of the total coating composition, and the applicable products include Cymel-325, 327, 370, 380, 373, 385 and the like.

In the water-soluble topcoat composition of the present invention, several additives are used in order to sufficiently exhibit the function of the water-soluble paint. In the present invention, four additives were used.

First, in the preparation of the pigment dispersion of the present invention, in order to disperse the pigment in a uniform and stable state, a dispersant is added to the milling step in addition to the resin for dispersing the pigment. In the present invention, an ionic or nonionic wet dispersant of server-delden is applied. It is preferable to apply 0.5 to 17% by weight based on the applied pigment, and the applicable products include Ser-AD FX-504, 600, Ser-AD FN-365 and the like.

Secondly, in order to suppress the generation of bubbles generated during the production of the pigment dispersion of the present invention, and to prevent the popping phenomenon caused when the coating film is formed, the antifoaming agent is added to the milling step. The antifoaming agent of was applied, and it is preferable to apply 0.5-1.5% by weight of the total pigment dispersion, and applicable products include Serdas GBR.

Third, in order to improve the wettability of the paint and smoothness of the coating film in the water-soluble coating composition of the present invention, a wetting agent is added to the finishing step. In the present invention, a wetting agent of acetylene alcohols of Air Products was applied. It is preferable to apply in 0.3-2% by weight of the total coating composition, and the applicable products include Surfynol-104BC, Surfynol-61 and the like.

Fourth, in order to smooth the precipitation of the pigment in the water-soluble coating composition of the present invention and to control the fluidity of the paint, a fluidity regulator (thickener) is introduced into the pigment dispersion production and finishing steps, respectively (particularly in the case of inorganic pigment application). In the present invention, in order to prevent the precipitation of the pigment and re-agglomeration of the pigment in the production step of the pigment dispersion, a polyurethane-type rheology modifier of Server-Delden's was added, and was applied at 1-4 wt% of the total pigment dispersion. In the finishing stage, Allied Colloid's polyacrylic fluidity regulator was added to control the fluidity of the paint, and it was applied at 1 to 3% by weight of the total paint composition, and applicable products were Ser-AD FX-1070 and Viscalex HV-30. Etc. can be mentioned.

The co-solvents used in the water-soluble top coat composition of the present invention include high-boiling co-solvents such as butyl glycol, butyl carbitol, N-methyl-2-pyrrolidone, and low-boiling co-solvents such as n-propyl alcohol and butanol. The role of the cosolvent greatly improves the smoothness of the coating film, lowers the optimum film formation temperature, facilitates the atomization of the paint during spraying, and contributes greatly to the volatilization of the main solvent, water. It also mixes very well with water and water-dispersible resins, which contributes greatly to the viscosity reduction of the paint. Therefore, it is preferable that the co-agent is applied to 1 to 15% by weight of the total coating composition.

The paint prepared in the present invention can be coated by conventional methods including brushing, dipping, flow coating, etc., but in the case of automobile coating, since automatic coating such as bell and gun coating and manual spray gun coating are applied, they are usually used. The spray technology and equipment are commercially available, and the paint prepared in the present invention may be coated on various materials such as wood, metal, glass, fiber, plastic, steel, and the like.

Hereinafter, the present invention will be described in detail with reference to Production Examples and Examples, but the present invention is not limited to the following Production Examples and Examples.

Preparation Example 1

Polyester Polyol Manufacturing

996.7 parts by weight of isophthalic acid, 289.2 parts by weight of adipic acid, 44.4 parts by weight of phthalic anhydride, 957.0 parts by weight of 1,6-hexanediol, 187.8 parts by weight of trimethylolpropane in a reactor equipped with a stirrer, a thermometer, a nitrogen injection pipe, a separator, and a cooler 2.5 parts by weight of dibutyltin oxide is used as a catalyst. The temperature is gradually raised while stirring at a rate of 200 rpm under nitrogen injection, and the temperature is raised to 200 ° C. and maintained. This reaction is condensation reaction, water is drawn out through the separator, and the reaction is controlled so that the refractive index of the dehydrated water is 1.3340 or less. When the acid value reaches 2 mgKOH / g during the reaction, the speed of the stirrer is increased to 350 rpm and the nitrogen is excessively supplied by 75 mm Hg for 10 minutes. Thereafter, the reaction is terminated when the acid value reaches 0 mgKOH / g. The polyester polyol prepared by this reaction corresponds to a hydroxyl value of 100.4 mgKOH / g, 3.04 wt%, and a molecular weight of 1680. And the content of the trihydric alcohol used at this time is 7.59% by weight.

Preparation Example 2

Manufacture of Urethane Modified Polyester Polyol Water Dispersion Resin

In the newly installed reactor, 2192.2 parts by weight of polyester polyol of Preparation Example 1, 129.82 parts by weight of α, α-dimethylolpropionic acid, 303.26 parts by weight of N-methyl-2-pyrrolidone and dibutyltin dilaurate 2.54 as a reaction catalyst The parts by weight are injected under nitrogen injection, and the temperature is raised to 100 ° C. so that the components are homogeneously mixed. When the components are completely mixed and transparent, 891.53 parts by weight of acetone is lowered to 60 ° C., and 225.77 parts by weight of hexamethylene diisocyanate is added while maintaining 60 to 65 ° C. The reaction is then continued for at least 3 hours under the same conditions. The end point of the reaction is taken when the isocyanate content reaches zero. When the reaction is completed, a prepolymer having a hydroxyl value of 40.8 mgKOH / g and an acid value of 21.3 mgKOH / g is prepared. In order to make the prepolymer into an aqueous dispersion, 73.3 parts by weight of dimethylethanolamine was slowly added to the prepolymer maintained at 65 ° C., and the reaction was continued until the neutralizing agent was completely mixed with the prepolymer. Thereafter, the neutralized prepolymer was gradually added to a container containing 3455.08 parts by weight of distilled water at a temperature of 500 to 1000 rpm, and then gradually neutralized, and then dispersed for 30 to 60 minutes to form a stable dispersion. However, since this water dispersion contains a certain amount of acetone, if the pressure is reduced over 60 minutes at 10 to 50 cmHg while maintaining a temperature of 65-75 ° C. and a stirring speed of 300 rpm, the final product has a stability of 2 years or more at room temperature. Urethane-modified polyester polyol water dispersion of is formed. The urethane-modified polyester polyol water dispersion resin of the present invention thus obtained is a stable water dispersion resin having a solid content of 42.0% by weight, a final acid value of 3.2 mgKOH / g, a hydroxyl value of 40.8 mgKOH / g, a pH of 6.5-7.5, and a particle size of 100 nanometers. .

The following is a process of preparing a pigment dispersion and a coating using the urethane-modified polyester polyol water dispersion resin prepared in the above to make a dispersion of various organic or inorganic pigments using the resin prepared in the preparation example. Next, a water-soluble paint for automobiles was prepared by adding a main resin, a curing agent, a cosolvent, and an additive.

Example 1

White Pigment Dispersion and Manufacturing Method of White Paint

1) Preparation of White Pigment Dispersion

TABLE 1

Note 1) Server-Delden Dispersant

Note 2) Server-Delden's fluidity regulator

Note 3) Server-Deldensa antifoaming agent

Note 4) Ishihara titanium dioxide

The method of preparing the copper pigment dispersion is premixed at 500 rpm for 20 minutes with a general disperser while sequentially feeding the raw materials into a predetermined container, and then the same amount of glass beads is added, using Red Devil, which is the easiest dispersing method. / 60/90/120 minutes) to prepare a pigment dispersion, and to determine the dispersion degree by measuring the particle size distribution with a hagman gauge set the time for the particle size distribution is less than 5 microns as the dispersion time, Dispersion was terminated at the same time later. The dispersion time of the white pigment dispersion of the present invention is 60 minutes.

2) Preparation of White Paint

TABLE 2

Note 1) Wetting agent of air product company

Note 2) Cytec's melamine curing agent

Note 3) Water-dispersed polyurethane-urea resin prepared in KC 0775

Note 4) Water-dispersible acrylic resin prepared in KC 0912

Note 5) Allied Colloidal Fluidity Regulator

In the method for preparing the paint, the raw materials were sequentially added to a predetermined container while being stirred and mixed at a low speed (300 to 500 rpm) with a general disperser, and then maintained at the same speed for 2 hours until the paint was stabilized. Measurement of the coating properties of the paint prepared by the present invention is spray coating the prepared paint on a metal coating coated with a medium, pre-heated in an infrared oven at 80 ℃, after coating a clear paint, 150 ℃ in a general oven, After curing for 20 minutes, the physical properties are measured.

Example 2

Process for producing black pigment dispersion and black paint

1) Preparation of Black Pigment Dispersion

TABLE 3

Note 1) Server-Delden Dispersant

Note 2) Server-Deldensa antifoaming agent

Note 3) Daegusa carbon black

The method of preparing the copper pigment dispersion is premixed at 500 rpm for 30 minutes with a general disperser while placing the raw materials in a predetermined container, and then the same amount of glass beads is added, using Red Devil, the easiest dispersing method. / 60/90/120 minutes) to prepare a pigment dispersion, and to determine the dispersion degree by measuring the particle size distribution with a hagman gauge set the time for the particle size distribution to be less than 5 microns as the dispersion time, Dispersion was terminated at the same time later. The dispersion time of the black pigment dispersion of the present invention is 90 minutes.

2) Preparation of Black Paint

TABLE 4

Note 1) Wetting agent of air product company

Note 2) Cytec's melamine curing agent

Note 3) Water-dispersed polyurethane-urea resin prepared in KC 0775

Note 4) Water-dispersible acrylic resin prepared in KC 0912

Note 5) Allied Colloidal Fluidity Regulator

In the method of preparing the paint, the raw materials were sequentially added to a predetermined container while being stirred and mixed at a low speed (300-500 rpm) with a general disperser, and then maintained at the same speed for 2 hours until the paint stabilized. Measurement of the coating properties of the paint prepared by the present invention is spray-coated the prepared paint to a metal specimen coated to halfway, preheated in an infrared oven at 80 ℃, after coating the clear paint, 150 ℃ in a general oven, After curing for 20 minutes, the physical properties are measured.

Example 3

Preparation of Micro White Pigment Dispersion and Metallic Pigment Dispersion and Method of Manufacturing Metallic Paint Containing the Same

1) Preparation of Micro White Pigment Dispersion

TABLE 5

Note 1) Chemira's micro titanium dioxide

The method of preparing the copper pigment dispersion is premixed at 500 rpm for 20 minutes with a general disperser while sequentially feeding the raw materials into a predetermined container, and then the same amount of glass beads is added, using Red Devil, which is the easiest dispersing method. / 60/90/120 minutes) to prepare a pigment dispersion, and to determine the dispersion degree by measuring the particle size distribution with a hagman gauge set the time for the particle size distribution to be less than 5 microns as the dispersion time, Dispersion was terminated at the same time later. The dispersion time of the micro white pigment dispersion of the present invention is 60 minutes.

2) Preparation of Aluminum Pigment Dispersion

TABLE 6

Note 1) Silver Line Aluminum Paste

Note 2) BASF's chrome gold paste

The method of preparing the pigment dispersion is a simple process of mixing aluminum and chromium gold paste evenly in a solvent and a dispersing resin by mixing the raw materials in a predetermined container and mixing the mixture at 200 rpm for 2 hours using a general disperser.

3) Stone Gray Metallic Paint Manufacturing

TABLE 7

Note 1) Wetting agent of air product company

Note 2) Cytec's melamine curing agent

Note 3) Water-dispersed polyurethane-urea resin prepared in KC 0775

Note 4) Allied Colloidal Fluidity Regulator

In the method of preparing the paint, the raw materials were sequentially added to a predetermined container while being stirred and mixed at a low speed (300-500 rpm) with a general disperser, and then maintained at the same speed for 2 hours until the paint stabilized. Measurement of the coating properties of the paint prepared by the present invention is spray-coated the prepared paint on a metal specimen coated to the middle, preheated in an infrared oven at 80 ° C. for 5 minutes, and then coated with a clear paint, and then 150 in a general oven. After curing for 20 minutes, the physical properties are measured.

Example 4

Preparation of Green Pigment Dispersion, Mica (Pear) Pigment Dispersion and Method of Making Mica Paint Containing the Same

1) Preparation of Green Pigment Dispersion

TABLE 8

Note 1) Server-Delden Dispersant

Note 2) Server-Deldensa antifoaming agent

Note 3) Sachtleben Chemie sieving pigment

Note 4) BASF's green pigment

The method of preparing the copper pigment dispersion is premixed at 500 rpm for 30 minutes with a general disperser while placing the raw materials in a predetermined container, and then the same amount of glass beads is added, using Red Devil, the easiest dispersing method. / 60/90/120 minutes) to prepare a pigment dispersion, and to determine the degree of dispersion by measuring the particle size distribution with Hegman gauge set the time for the particle size distribution to be 5 microns or less as the dispersion time, Dispersion was terminated at the same time later. The dispersion time of the green pigment dispersion of the present invention is 90 minutes.

2) Preparation of mica (pearl) pigment dispersion

TABLE 9

Note 1) Merck mica silver

The method for preparing the pigment dispersion is a simple process of mixing the raw materials in a predetermined container and mixing at 200 rpm for 2 hours with a general disperser to evenly disperse the mica pigment in the solvent and the dispersing resin.

3) Manufacture of emerald green mica paint

TABLE 10

Note 1) Wetting agent of air product company

Note 2) Cytec's melamine curing agent

Note 3) Water-dispersed polyurethane-urea resin prepared in KC 0775

Note 4) Allied Colloidal Fluidity Regulator

In the method of preparing the paint, the raw materials were sequentially added to a predetermined container while being stirred and mixed at a low speed (300-500 rpm) with a general disperser, and then maintained at the same speed for 2 hours until the paint stabilized. Measurement of the coating properties of the paint prepared by the present invention is spray-coated the prepared paint on a metal specimen coated to the middle, preheated in an infrared oven at 80 ° C. for 5 minutes, and then coated with a clear paint, and then 150 in a general oven. After curing for 20 minutes, the physical properties are measured.

The present invention is a pigment dispersion by adding 5 to 30% by weight of the pigment dispersion, as can be seen through Examples 1 to 4 to the urethane-modified polyester polyol water dispersion resin prepared in Preparation Examples 1, 2 To prepare a water-soluble topcoat for automobiles by adding and mixing the main resin, hardener, co-solvent and other additives to the prepared pigment dispersion. The water-soluble topcoat composition thus prepared has a pigment dispersion of 10-40 wt%, a main resin 25-50 wt%, a hardener 2-7 wt%, a coarse solvent 1-15 wt%, and other additives, respectively, based on the total coating composition. 1 to 5% by weight, according to the physical properties of the pigment dispersion obtained through the above Examples 1-4 of the present invention and a specimen to which the water-soluble topcoat was applied to the specimen to confirm the coating properties, the physical property test of Table 11 The result was obtained.

TABLE 11

# Conditions in container: No dust, no foreign matter, no hard lumps and uniformly distributed.

# Particle size: It should be less than 5u when measuring particle size with Hegman gauge

# Storage stability (storage stability): After leaving at 50 ℃ X 72 hours, the viscosity change at room temperature should be within 15%.

# Water resistance: After deposition at 40 ℃ for 240 hours, it should be free from sticking after coating for 1 hour.

# Chipping resistance: -40 ℃ X 3 hours, Laminated with Honda stone (diameter, 2.5-5 mm) at 4 bar pressure, no more than 10 peeled parts between 1 and 2 mm, 1 over 2 mm Should be less than

# Appearance: The image sharpness should be 7 or more when horizontal curing, and the image sharpness should be 6 or more when vertical curing.

# Paintability: Good spraying condition when discharging paint, good wettability

# Gloss: 60 degree gloss 90 or more.

The water-soluble topcoat composition containing the pigment dispersion prepared by the method of the present invention has excellent storage properties and a high gloss coating film is obtained when the coating film is formed, and exhibits excellent effects in terms of all properties such as water resistance and chipping resistance.

Claims (5)

(1) preparing a polyester polyol resin containing 2-5 wt% of hydroxyl groups in a resin solid content, having a hydroxyl value of 60-120 mgKOH / g, and a weight average molecular weight of 800-2500 by condensation of a conventional acid and alcohol, ( 2) mixing a monomer sharing a hydroxyl group and a carboxyl group with the polyester polyol resin, and urethane-reacting one or more polyvalent isocyanates to prepare a urethane-modified polyesterpolyol prepolymer, and (3) neutralizing and dispersing the prepolymer. Consists of the steps The acid value of the prepolymer is 10-25 mgKOH / g, the hydroxyl value is 20-80 mgKOH / g, The final water dispersion resin contains a hydroxyl value of 40-60 mgKOH / g, a weight average molecular weight of 10000-30000, particle size of 80-150 nanometers, characterized in that the polyurethane coating polyester polyol aqueous dispersion for automotive tops Method for producing a resin. The method of claim 1, wherein the monomer sharing a hydroxy group and a carboxyl group is a dihydroxy alkanoic acid, α, α- dimethyrol alkanoic acid represented by the following formula (1), characterized in that the number of polyurethane modified polyester polyol for automotive tops Method for producing a dispersion resin. [Formula 1]

Wherein R is 1 to 8 hydrogen or alkyl groups. The method of claim 2, wherein the amount of the monomer is 1 to 15% by weight of the prepolymer solids. Dispersion resin prepared by the process according to any one of claims 1 to 3 is 2-13% by weight based on the applied pigment, ionic or nonionic wet dispersant 0.5-17% by weight based on the applied pigment, pigment 25- 55% by weight and the remainder 10-40% by weight of water-soluble pigment dispersion consisting of water, 25-50% by weight of main resin, 2-7% by weight of curable resin, 1-15% by weight of solvents and 1-5% by weight of other paint additives A water-soluble top coat composition, characterized in that consisting of. The water-soluble topcoat composition according to claim 4, wherein the main resin is a water-based polyurethane-urea resin or a water-dispersible acrylic resin, alone or in combination.