WO2012134211A2

WO2012134211A2 - Microgel and method for preparing same, and water-soluble paint composition

Info

Publication number: WO2012134211A2
Application number: PCT/KR2012/002358
Authority: WO
Inventors: 문태권; 이종택; 이현숙; 박종윤; 고건혁
Original assignee: 주식회사 케이씨씨
Priority date: 2011-03-31
Filing date: 2012-03-30
Publication date: 2012-10-04
Also published as: CN103562275A; KR20120111083A; KR101828605B1; WO2012134211A3; CN103562275B

Abstract

According to the present invention, a method for preparing a microgel comprises: a step of preparing a core; a step of forming a first shell on the core; and a step of forming a second shell on the first shell. The step of forming the first shell and/or the step of forming the second shell uses unsaturated monomers containing hydroxyl radicals and comprising polyalkylene glycols.

Description

Microgels and Methods for Making the Same, and Water-Soluble Coating Compositions

The present invention relates to microgels and methods for their preparation, and to water-soluble coating compositions.

Recently, regulations on volatile organic compounds for environmental protection have been strengthened, and development of water-soluble coating compositions to cope with them has been actively conducted.

Addition of an effect pigment such as aluminum or mica to the automotive coating composition can impart a so-called glamor finish to the automotive appearance. The surface coated with such an effect pigment may have a different color depending on the angle viewed by light absorption, reflection, refraction effects, and the like. This is called a metallic effect.

However, in the case of the water-soluble coating composition, unlike the solvent type coating composition, most of the volatile components are composed of water, so that drying of the volatile components may be considerably delayed compared to the solvent type. As a result, the flow of the effect pigment, staining, etc. become more severe. At this time, the drying of the volatile components may be sensitively affected by the temperature and relative humidity at the time of coating the coating composition. Therefore, in the water-soluble coating composition for automobiles, it is preferable to enlarge the temperature and humidity area | region (application window) which can be painted as much as possible.

In order to realize this, each rheology (thixotropy) at the various coating stages of the storage, transportation, painting, holding, coating composition and drying of the coating composition should be optimized. That is, when storing the paint composition, it should maintain a suitable viscosity in order to prevent the sedimentation of the pigment, and when transporting it should be easy to transport because the viscosity is moderately low, and when painting the paint should be as low as possible, so that the paint atomization well. . After arrival, the viscosity should be rapidly restored to control the flow of the coating film and the flow of the effect pigment.

The present invention is to provide a microgel and a method for preparing the same, and a water-soluble coating composition capable of maximizing the plasticity properties to maximize the temperature and humidity range.

Method for producing a microgel according to the present invention, preparing a core; Forming a first shell on the core; And forming a second shell on the first shell, and using a hydroxyl group-containing unsaturated monomer having polyalkylene glycol in at least one of forming the first shell and the second shell. .

In the forming of the second shell, an acid-containing unsaturated monomer and a hydroxyl group-containing unsaturated monomer including the polyalkylene glycol may be added and reacted to form the second shell.

The hydroxyl group-containing unsaturated monomer having the polyalkylene glycol may be represented by the following formula.

(Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ represents an alkyl group having 2 to 4 carbon atoms, n is an integer of 3 to 20)

In the preparing of the core, an acid-free or acid-containing unsaturated monomer may be added to a seed to form the core. In the forming of the first shell, the first shell may be formed by adding and reacting an acid-free or acid-containing unsaturated monomer with a hydroxyl-free or hydroxyl-containing unsaturated monomer.

In the preparing of the core, the core may be formed by injecting a hydroxyl-free or hydroxyl-containing unsaturated monomer having a polyalkylene glycol with an acid-containing unsaturated monomer. In the forming of the first shell, a neutralizing agent may be added to the core, and an acid-free or acid-containing unsaturated monomer may be added and reacted to form the first shell while inducing phase inversion.

The acid value measured after the forming of the second shell may be higher than the acid value measured after the forming of the first shell.

The acid value of the microgel may be 40 ~ 200 mgKOH / g and the hydroxyl value is 1 ~ 80 mgKOH / g.

With respect to 100 parts by weight of the total unsaturated monomer used in the preparation of the microgel, the weight of the unsaturated monomer added in the step of preparing the core is 35 ~ 60, of the unsaturated monomer added in the step of forming the first shell The weight part may be 20 to 40, and the weight part of the unsaturated monomer added in the step of forming the second shell may be 10 to 30.

The microgel according to the present invention is prepared by the method for producing a microgel described above. The water soluble coating composition according to the present invention comprises such a microgel.

Microgel according to the present invention, the core; A first shell formed on the core; And a second shell formed on the first shell and formed by reacting an acid-containing unsaturated monomer with a hydroxyl group-containing unsaturated monomer having polyalkylene glycol. The water soluble coating composition according to the present invention comprises such a microgel.

According to the present invention, it is possible to stably polymerize a relatively high acid value microgel. In addition, since the hydroxyl group-containing unsaturated monomer having polyalkylene glycol is used in the step of forming the second shell, there is an effect that can further maximize the interaction with the adjacent factors. Thereby, a viscosity and plasticity characteristic can be improved.

Accordingly, the stability of the particles can be improved during storage, the paint atomization can be well achieved during the coating film formation, and the viscosity is increased at the low shear rate after arrival to effectively control the flow of the coating film and the like. That is, the paintable temperature and humidity application window can be maximized and the rheology in the paint step can be optimized.

Hereinafter, the microgel according to the present invention, a manufacturing method thereof, and a water-soluble coating composition will be described in detail.

The method for producing a microgel according to the present invention includes preparing a core, forming a first shell on the core, and forming a second shell on the first shell. At this time, the second shell is formed by reacting an acid-containing unsaturated monomer with a hydroxyl group-containing unsaturated monomer having polyalkylene glycol.

First, a method of manufacturing a microgel according to an embodiment of the present invention will be described.

In the step of preparing the core, an acid-free or acid-containing unsaturated monomer, a polymerization initiator, an emulsifier and ionized water are added to the seed to form a core. In the step of forming the first shell, an acid-free or acid-containing unsaturated monomer, a hydroxyl-free or hydroxyl-containing unsaturated monomer, a polymerization initiator, an emulsifier and ionized water are charged to form a first shell. In the step of forming the second shell, an acid-containing unsaturated monomer, a hydroxyl group-containing unsaturated monomer, a polymerization initiator, an emulsifier and ionized water are formed by input reaction. At this time, a hydroxyl-containing unsaturated monomer having polyalkylene glycol as the hydroxyl-containing unsaturated monomer in at least one of the steps of forming the first shell and the second shell can be used. In particular, the step of forming the second shell preferably includes a hydroxyl-containing unsaturated monomer having polyalkylene glycol. Here, the above-mentioned seed may be formed by input reaction of an acid-free or acid-containing unsaturated monomer, a polymerization initiator, an emulsifier, and ionized water.

The materials of the unsaturated monomers, polymerization initiators, and emulsifiers used in each step are first discussed, and then each step is described in more detail.

As an acid-free or hydroxyl-free unsaturated monomer, the monomer used at the time of manufacture of a general microgel can be used. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl acryl Late, 2-ethylhexyl (meth) acrylate, lauryl methacrylate, phenyl acrylate, i-bonyl (meth) acrylate, cyclohexyl methacrylate, (meth) acrylamide, N-methylol (meth) Acrylic monomers, such as acrylamide, can be used. Or at least one of a polymerizable aromatic monomer such as styrene and α-methylstyrene, or a polymerizable nitrile monomer such as acrylonitrile.

The acid-containing unsaturated monomer may be at least one of two carboxylic acid groups such as single carboxylic acid group, crotonic acid, itaconic acid, maleic acid, and pmaric acid, such as acrylic acid, methacrylic acid, vinylbenzene acid, and isopentyl benzene acid. It may include one.

The hydroxyl-containing unsaturated monomer may include at least one of hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, product names PLACCEL FM1D, PLACCEL FM2D, etc. of DAICEL.

And the hydroxyl group-containing unsaturated monomer having a polyalkylene glycol may be represented by the formula (1) below.

As such, as the hydroxyl group-containing unsaturated monomer including polyalkylene glycol, polyethylene glycol acrylate, polypropylene glycol acrylate, polybutylene glycol acrylate, etc., each of which is added with ethylene oxide, propylene oxide, butylene oxide, etc., are added. Various materials can be used. In this case, a material in which ethylene oxide, propylene oxide, butylene oxide and the like are added in various amounts may be used. As an example, NOF brand name BLEMMER PE-90, BLEMMER PE-200, BLEMMER PE-350, BLEMMER PP-1000, BLEMMER PP-500, BLEMMER PP-800, BLEMMER 50PEP-300, BLEMMER 70PEP-350B, BLEMMER 55PET-800 , BLEMMER 10PPB-500B, BLEMMER AE-90, BLEMMER AE-200, BLEMMER AE-400, BLEMMER AP-150, BLEMMER AP-400, BLEMMER AP-550 and the like.

An emulsifier can be used individually or in mixture of an anionic emulsifier, a nonionic, a reactive emulsifier, etc. Anionic emulsifiers include sodium dodecyl sulfate, sodium dodecylbenzene sulfate, sodium oleic sulfate, potassium dodecyl sulfate, dioctyl sodium sulfosuccinate, sodium stearate, potassium stearate, and polyoxyethylene alkylphenyl ether ammonium sulfide Fading and so on. Nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, and polyoxyethylene polypropylene copolymers. The reactive emulsifier is an emulsifier for copolymerizing with a polymer synthesized by having an unsaturated double bond in the emulsifier component, and may have anionic or nonionic properties (for example, ADEKA brand name ADEKAREASOAP SE-1025A, DKS International company name HITENOL HS-10).

Polymerization initiators include oil-soluble initiators consisting of hydrogen peroxide, diisopropylene hydroperoxide, cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide, lauroyl peroxide, or potassium persulfate, ammonium peroxide. Any one or more of water-soluble initiators, such as sulfate and sodium persulfate, can be selected and used.

In addition, a chain transfer agent may be further used to control the molecular weight when forming the seed, the core, the first shell, and the second shell. Various materials may be used as the chain transfer agent, and for example, mercaptoethanol, α-methylstyrene dimer, methyl mercaptopropionate, and the like may be used.

In addition, the crosslinking monomer may be included in an amount of 0 to 10 parts by weight based on 100 parts by weight of the unsaturated monomer used in each of the above-described steps. When the amount of the crosslinking monomer exceeds 10 parts by weight, the interlayer adhesion may be lowered or the plasticity of the paint may be lowered. As a crosslinking monomer, the monomer which has 2 or more unsaturated bonds is used, For example, Allyl compounds, such as vinyl compounds, such as divinyl benzene, an aryl (meth) acrylate, and a di (meth) aryl (meth) acrylamide, and ethylene Alkylenediol di (meth), such as glycol di (meth) acrylate, 1, 3- butanediol di (meth) acrylate, 1, 4- butanediol (meth) acrylate, and 1, 6- hexanediol (meth) acrylate ) At least one selected from the group consisting of an acrylate compound and the like.

Each step using the above-mentioned unsaturated monomer, emulsifier, radical polymerization initiator and ionized water will be described in more detail.

First, in the step of forming the core, the core is formed on the seed after forming the seed.

The seed is formed by input reaction of an acid-free or acid-containing unsaturated monomer, a polymerization initiator, an emulsifier, and ionized water, and an acid value may be 200 mgKOH / g or less. If the acid value exceeds 200 mgKOH / g, it is because the subsequent polymerization may not be performed smoothly. The particle size of the prepared seed may be 20 ~ 200nm, which is an appropriate size to appropriately size the particle diameter of the core.

The core is formed by input reaction of an acid-free or acid-containing unsaturated monomer, a polymerization initiator, an emulsifier and ionized water, and an acid value may be 30 mgKOH / g or less. This is because if the acid value exceeds 30 mgKOH / g, the polymerization may not be performed smoothly and the core may not be smoothly formed on the seed. At this time, the acid value may be 1 ~ 30 mgKOH / g. The particle diameter of the prepared core may be 25-250 nm, which is an appropriate size to disperse the microgel in which the first shell and the second shell are formed on the core in the water-soluble coating composition to impart proper viscosity and plasticity.

In the step of forming the core, 35 to 60 parts by weight of the unsaturated monomer can be added to 100 parts by weight of the total unsaturated monomer used in the preparation of the microgel. If the unsaturated monomer is added below 35 in the step of forming the core, the size of the core may become small and may not be suitable for forming the first shell and the second shell. If more than 60 parts by weight of the unsaturated monomer is added, the core may be too large and the thickness of the first shell and the second shell may be thin, making it difficult to have adequate viscosity and plasticity.

The polymerization initiator is added by 1 to 15 parts by weight, the emulsifier is added by 1 to 25 parts by weight, and the ionized water may be added by 60 to 98 parts by weight based on 100 parts by weight of the unsaturated monomer to be added during core formation. This is only an example of a suitable range required for synthesis, the present invention is not limited thereto.

Subsequently, in the step of forming the first shell, an acid-free or acid-containing unsaturated monomer, a hydroxyl-free or hydroxyl-containing unsaturated monomer, a polymerization initiator, an emulsifier and ionized water are charged to form a first shell. The acid value measured after the forming of the first shell may be 100 mgKOH / g or less and the hydroxyl value may be 80 mgKOH / g or less. At this time, the acid value may be 1 ~ 100 mgKOH / g or less and the hydroxyl value is 0.01 ~ 80 mgKOH / g or less.

In the step of forming the first shell, 20 to 40 parts by weight of the unsaturated monomer may be added to and used with respect to 100 parts by weight of the total unsaturated monomer used in the preparation of the microgel. When the unsaturated monomer is added to less than 20 in the step of forming the first shell, the thickness of the first shell becomes thin and it is difficult to obtain the effect by forming the first shell. If more than 40 parts by weight of unsaturated monomer is added, the thickness of the first shell may be thicker than necessary, which may unnecessarily increase the cost of the material.

The polymerization initiator is added by 1 to 15 parts by weight, the emulsifier is added by 1 to 25 parts by weight, and the ionized water may be added by 60 to 98 parts by weight with respect to 100 parts by weight of the unsaturated monomer to be added at the time of forming the first shell. . This is only an example of a suitable range required for synthesis, the present invention is not limited thereto.

Subsequently, in the step of forming the second shell, an acid-containing unsaturated monomer, a hydroxyl group-containing unsaturated monomer having polyalkylene glycol, a polymerization initiator, an emulsifier, and ionized water are added and reacted to form a second shell.

In the forming of the second shell, 10 to 30 parts by weight of the unsaturated monomer may be added to and used with respect to 100 parts by weight of the total unsaturated monomer used in the preparation of the microgel. When the unsaturated monomer is added to less than 10 in the step of forming the first shell, the thickness of the first shell becomes thin and it is difficult to obtain the effect by forming the second shell. If more than 30 parts by weight of the unsaturated monomer is added, the thickness of the second shell having a high acid value becomes thicker than necessary, which may unnecessarily increase the cost of the material.

The polymerization initiator is added by 1 to 15 parts by weight, the emulsifier is added by 1 to 25 parts by weight, and the ionized water may be added by 60 to 98 parts by weight with respect to 100 parts by weight of the unsaturated monomer to be added during the formation of the second shell. . This is only an example of a suitable range required for synthesis, the present invention is not limited thereto.

The microgel thus prepared may be neutralized with a neutralizing agent consisting of a base. As such a neutralizer, inorganic bases such as ammonia, sodium hydroxide, potassium hydroxide, and inorganic bases, primary or tertiary amines such as dimethyl ethanol amine, triethyl amine, and the like can be used.

The microgel thus prepared comprises a core, a first shell formed on the core, a second shell formed on the first shell, and the second shell includes a hydroxyl group-containing unsaturated monomer having an acid-containing unsaturated monomer and a polyalkylene glycol. It is formed by reacting monomers. The acid value of the prepared microgel may be 40 ~ 200 mgKOH / g and the hydroxyl value is 1 ~ 80 mgKOH / g.

When the acid of the microgel is neutralized by the neutralizing agent, a loose network is formed by interaction with adjacent particles, which may have a high viscosity at low shear rates. At high shear rates, this structure breaks down, resulting in a lower viscosity, and at low shear rates the viscosity is again high. Accordingly, it is possible to have plasticity.

In this case, in the present invention, the acid value after the second shell is made higher than the acid value after the first shell is formed, thereby increasing the acid value step by step, thereby stably polymerizing and forming a relatively high acid value microgel. Therefore, a higher acid value can be realized than when only one layer of shell is provided, and the interaction with adjacent particles can be increased, thereby improving the plasticity characteristics. In addition, in the present invention, since the hydroxyl group-containing unsaturated monomer having polyalkylene glycol is used in forming the second shell, there is an effect of maximizing the interaction with adjacent factors.

Hereinafter, a method for preparing a microgel according to another example of the present invention will be described. Since this example is similar to the method for preparing the microgel described above, the same or extremely similar parts (particularly, usable materials, parts by weight, etc.) will not be described in detail and different parts will be described in detail.

In preparing the core, a core is formed by adding a hydroxyl-free or hydroxyl-containing unsaturated monomer, an acid-containing unsaturated monomer, a polymerization initiator, an emulsifier and ionized water with polyalkylene glycol. The core obtained by this has an acid value of 50 mgKOH / g or less, and a hydroxyl value of 50 mgKOH / g or less. In this case, the acid value may be 1-50 mgKOH / g and the hydroxyl value may be 0.01-50 mgKOH / g.

In the step of forming the first shell, a neutralizing agent is added, and an acid-free or acid-containing unsaturated monomer, a polymerization initiator, an emulsifier, and ionized water are added and reacted to form a first shell while inducing phase inversion. The acid value measured after the step of forming the first shell may be 30 mmKOH / g or less, and may be 1-30 mmKOH / g.

At this time, the neutralizing agent may be added to the amount of acid in the step of preparing the core by 0.3 to 1.5 equivalents. If the neutralizing agent is less than 0.3 equivalent, there is a problem that the degree of solubility during neutralization does not play a role of the emulsifier in the subsequent shell process. If the neutralizing agent exceeds 1.5 equivalents, it may be fully solubilized that it will not be able to act as an emulsifier in the subsequent shell process.

In the forming of the second shell, the acid-containing unsaturated monomer and the hydroxyl group-containing unsaturated monomer including polyalkylene glycol, a polymerization initiator, an emulsifier, and ionized water are formed by input reaction. The acid value of the thus prepared microgel may be 40 ~ 200 mgKOH / g and the hydroxyl value is 1 ~ 80 mgKOH / g.

Such microgels may have excellent plasticity properties. This maximizes the range of paintable temperature and humidity and optimizes rheology during the painting phase.

The water-soluble coating composition containing the microgel as mentioned above can maximize plasticity by a microgel, and can raise the density of a coating film. As a result, properties such as stain resistance, compactness, water resistance, alkali corrosion resistance, adhesion, appearance, gloss, and flip flop can be improved. This water-soluble coating composition will be described in more detail.

Water-soluble coating composition is 10-30 weight% of microgels, 5-15 weight% of auxiliary resins, 1-10 weight% of amino resins, 5-15 weight% of cosolvents, 1-20 weight% of effect pigments, 0-20 weight of colored pigments %, Thickener 0-10% by weight, antifoam 1-5% by weight and the balance of other additives.

The auxiliary resin plays a role of forming a coating film, protecting the body, improving the appearance, and the like, and various materials such as polyurethane dispersion or polyester can be used.

The amino resin serves to form a network of the coating film through a curing reaction with the main resin, and methoxy melamine, butoxy melamine, melamine containing an amino group, and the like can be used.

The co-solvent improves the smoothness of the coating film and the storage stability of the paint, lowers the minimum film forming temperature, and contributes to the volatilization of the solvent during painting. The co-solvent includes at least one of propylene glycol, N-methyl-2-pyrrolidone, n-propyl alcohol, n-butanol, propylene glycol monomethyl ether, butyl glycol, hexyl glycol, 2-ethylhexyl alcohol, butyl carbitol and the like. It may include more.

The effect pigment is for imparting a metallic effect to the coating film, and may be used alone or in combination with an aqueous flake, aluminum flake, mica pigment, and the like. At this time, the effect pigment may be included in 1 to 20% by weight, preferably 1 to 15% by weight based on the water-soluble paint composition.

Colored pigments are those which, in combination with coating-forming materials in coating compositions, impart color and concealment effects. Generally, effect pigments and transparent or translucent colored pigments are used in combination. As the coloring pigment, an azo inorganic pigment, a polycyclic organic pigment containing an vat pigment, an anthraquinone organic pigment, or the like can be widely applied. Pure metallic colors may contain no colored pigments.

Thickeners are used to prevent flowability and to contribute to paintability and coating roughness. As the thickener, an acrylic thickener, a urethane thickener, fused silica, a cellulose thickener, a benton thickener and the like can be used alone or in combination.

Antifoaming agent is used in order to suppress the generation of bubbles generated in various processes such as at the time of production of coating composition, at the time of painting work and after the arrival of the paper, or to quickly remove the bubbles generated. As the antifoaming agent, fluorine modified siloxane based, polysiloxane emulsion, organic modified siloxane based, hydrophobic silica, mineral oil and the like can be used alone or in combination.

Hereinafter, the present invention will be described in more detail by the following Preparation Examples and Comparative Examples. However, these preparation examples are only for helping understanding of the present invention, and the present invention is not limited thereto.

The monomers and use weights (g) used to form the seed, core, first step shell and second step shell in the following Preparation Examples and Comparative Examples are summarized in Table 1 below.

Table 1

Monomer type	Monomer 1	Monomer 2	Monomer 3	Monomer 3-1	Monomer 4	Monomer 5
MA	2			20	5	15
EA		50	10	50	20	20
BA	2	20	35	10
MMA	One	30		15
2-EHA			20
SM		10	30
MAA				5	25	25
2-HEMA					17	20
1,6-HDDA		5	5
BLEMMER AE-400					13

Abbreviations in Table 1 are as follows.

DIW: Deionized Water

CO-436: Sulfated ammonium salt of alkylphenoxypoly (5 moles of ethylene oxy) ethanol, manufactured by Rhodia

APS: Ammonium Persulfate

MA: methyl acrylate

EA: ethyl acrylate

BA: Butylacrylate

MMA: Methyl methacrylate

2-EHA: ethylhexyl acrylate

SM: Styrene Monomer

MAA: methacrylic acid

2-HEMA: 2-hydroxyethyl methacrylate

BLEMMER AE-400: Polyethylene glycol acrylate (10 mol addition of ethylene oxide)

1,6-HDDA: 1,6-hexanedioldiacrylate

DMEA: Dimethyl Ethanolamine

Preparation Example 1

In a 5-liter four-necked flask equipped with a thermometer, DIW 140g with ionized water, CO-436 1g with an emulsifier, and monomer 1 of Table 1 were added as monomers, and the temperature was raised to 80 ° C. Nitrogen was injected for 5 minutes while maintaining the temperature at 80 ° C. to make the reaction part nitrogen atmosphere, and then nitrogen was removed. As a polymerization initiator, 3 g of APS was dissolved in 10 g of DIW, and then charged into a reactor and aged for 30 minutes to form a seed.

A pre-emulsion prepared by mixing monomer 2 of Table 1 and 2.5 g of CO-436 in 100 g of DIW and a polymerization initiator solution in which 0.5 g of APS was dissolved in 50 g of DIW was added dropwise at the same time for 1 hour and then maintained for 1 hour to form a core.

A pre-emulsion prepared by mixing monomer 3 of Table 1 and 2.5 g of CO-436 in 100 g of DIW and an initiator solution of 0.5 g of APS dissolved in 50 g of DIW was added dropwise at the same time for 1 hour and then aged for 1 hour to form a first shell. .

Here, an acid value 81 prepared by mixing monomer 4 of Table 1 and 5 g of CO-436 in 200 g of DIW, a pre-emulsion of hydroxyl value 60, and an initiator solution having 1 g of APS dissolved in 50 g of DIW were added dropwise simultaneously for 1 hour. After aging for 1 hour, a second shell was formed.

The reactor was cooled to 40 ° C. and neutralized by dropwise adding an aqueous solution of 20 g of DMEA, neutralized in 40 g of DIW. Filtered with a 200 mesh filter to remove the aggregates and left for 1 day after packaging.

Preparation Example 2

In a 5-liter four-necked flask equipped with a thermometer, DIW 140g, CO-436 0.5g, and monomer 1 of Table 1 were added as monomers, and the temperature was raised to 80 ° C. Nitrogen was injected for 5 minutes while maintaining the temperature at 80 ° C. to make the reaction part nitrogen atmosphere, and then nitrogen was removed.

The pre-emulsion of acid value 32.6 prepared by mixing monomer 3-1 and 1.25 g of CO-436 in Table 1 to 100 g of DIW and an initiator solution of 0.5 g of APS dissolved in 50 g of DIW were added dropwise at the same time for 1 hour and then maintained for 1 hour. To form a core.

After neutralizing by dropping an aqueous solution of 20 g of DMEA dissolved in 40 g of DIW, and maintaining the mixture for 10 minutes, the monomer 2 and CO-436 2.5 g of Table 1 were mixed with 100 g of DIW, and 50 g of APS 0.5 g of DIW was added thereto. The polymerization initiator solution dissolved in was added dropwise at the same time for 1 hour and then aged for 1 hour to form a reverse phase core and a first shell.

Here, a pre-emulsion of 81 mgKOH / g, a hydroxyl value of 60 mgKOH / g, and a polymerization initiator solution in which 1 g of APS was dissolved in 50 g of DIW prepared by mixing monomer 4 and 5 g of CO-436 in 200 g of DIW for 1 hour. At the same time, after dropping, the mixture was aged for 1 hour to form a second shell.

The reactor was cooled to 40 ° C. and filtered through a 200 mesh filter to remove aggregates and left for 1 day after packing.

Comparative Example 1

Preparation Example 1, except that monomers 2 and 3 of Table 1 were used in forming the core, and monomers 4 of Table 1 were used in the formation of the first shell, and a second shell was not formed. An emulsion was prepared by the same method as described above.

Comparative Example 2

By the same method as Preparation Example 1, except that monomer 3-2 of Table 1 was used in forming the first shell and monomer 5 of Table 1 was used in forming the second shell. An emulsion was prepared.

The solids content, acid value and hydroxyl value of the final emulsions prepared in Preparation Examples 1 and 2 and Comparative Examples 1 and 2 were measured, and the pH, particle size and viscosity were measured and shown in Table 2 below. Here, particle size was measured using an Autosizer Lo-C Model laser light scattering analyzer from Malvern. Viscosity was measured in CS mode using a 600 mm cone-plate method of the Haake RS-100 model. The measurement method of particle size and viscosity was the same below.

TABLE 2

	Preparation Example 1	Preparation Example 2	Comparative Example 1	Comparative Example 2
Solid content [%]	35	35	35	35
Acid value [mgKOH / g]	42	50	42	42
Hydroxyl value [mgKOH / g]	31	31	31	31
pH	8.1	7.8	8.1	8.1
Particle Size [nm]	142	155	125	138
Viscosity [cps]	285	303	185	230

Referring to Table 2, it can be seen that the viscosity in the case according to Preparation Examples 1 and 2 is much superior to the viscosity in the case according to Comparative Examples 1 and 2. At this time, according to Preparation Example 2 it can be seen that it can have a superior viscosity than in Preparation Example 1.

Experimental Examples 1 and 2, and Comparative Experimental Examples 1 and 2

Preparation Examples 1 and 2, and microgels prepared according to Comparative Examples 1 and 2 and other components were mixed in the composition ratios of Table 3 below to prepare the water-soluble coating compositions according to Experimental Examples 1 and 2 and Comparative Experimental Examples 1 and 2 Prepared.

TABLE 3

Water Soluble Coating Composition	Weight ratio
Microgel	20
Auxiliary resin	12
Distilled water	25
Solvent	12
Amino resin	6
Additive mixture	4
Antifoam	3
corrector	3
Thickener	6
Aluminum paste	6
Coloring pigment paste	3
system	100

For Experimental Examples 1 and 2, and Comparative Experimental Examples 1 and 2 prepared above, the appearance of low temperature and high humidity coating (temperature 20 ° C., humidity 80%) was measured and shown in Table 4 below. , And the appearance of humidity 70%) is shown in Table 5 below, and the appearance of the high temperature and low humidity coating (temperature 28 ℃, humidity 60%) was measured and shown in Table 6 below. In addition, to measure the physical properties are shown in Table 7.

Table 4

		Experimental Example 1	Experimental Example 2	Comparative Experimental Example 1	Comparative Experiment 2
Paint Viscosity (Pod Cup # 4/25 ° C)		56	55	56	54
Coating thickness (μm)		10-15	10-15	10-15	10-15
Clear Coat Thickness (㎛)		35-45	35-45	35-45	35-45
Wavescan DOI	LU	52.3	50.3	47.7	48.3
	SH	62.9	61.1	60.4	60.1
	OP	71.8	69.8	64.5	64.4
	CF	65.8	63.8	60.5	60.5

Table 5

		Experimental Example 1	Experimental Example 2	Comparative Experimental Example 1	Comparative Experiment 2
Paint Viscosity (Pod Cup # 4/23 ° C)		56	55	56	54
Coating thickness (μm)		10-15	10-15	10-15	10-15
Clear coat thickness (㎛)		35-45	35-45	35-45	35-45
Wavescan DOI	LU	51.5	52.4	49.3	47.7
	SH	62.9	64.8	61.5	58.9
	OP	70.9	71.6	66.2	62.5
	CF	65.2	66.3	62.0	59.0

Table 6

		Experimental Example 1	Experimental Example 2	Comparative Experimental Example 1	Comparative Experiment 2
Paint Viscosity (Pod Cup # 4/23 ℃)		56	55	56	54
Coating thickness (μm)		10-15	10-15	10-15	10-15
Clear coat thickness (㎛)		35-45	35-45	35-45	35-45
Wavescan DOI	LU	55.3	58.4	49.0	47.9
	SH	66.5	69.3	60.8	58.8
	OP	73.6	76.2	62.9	61.4
	CF	68.4	71.1	60.1	58.5

TABLE 7

		Experimental Example 1	Experimental Example 2	Comparative Experimental Example 1	Comparative Experiment 2	Remarks
Paint storage stability		◎	○	○	○	Within 30%: Excellent (◎) Within 50%: Good (O) Within 70%: Normal (△) Above 70%: Bad (X)
Exterior	Low temperature and high humidity	◎	○	○	○	CF 65 or more: Good (◎) CF 60 to 65: Good (○) CF 55 to 60: Normal (△) CF less than 55: Bad (X)
	Medium temperature and humidity	◎	◎	○	△
	High temperature and low humidity	◎	◎	○	△
Polish	Low temperature and high humidity	○	○	△	△	LU 55 or more: Excellent (◎) LU 50 or more: Good (○) LU 45 ~ 50: Normal (△) LU 45 or less: Bad (X)
	Medium temperature and humidity	○	○	△	△
	High temperature and low humidity	◎	◎	△	△
Water resistance		○	○	△	○	δE 0.5 or less: Good (○) δE 0.5-1: Normal (△) δE 1 or more: Bad (X)
Adhesion		◎	◎	◎	◎	Attachment 100/100: Excellent (◎) Attachment 90-99: Good (○) Attachment 80-89: Normal (△) Attachment 79 or less: Bad (X)

In Tables 4 to 7, the test and evaluation methods of each property are as follows.

(1) Ford cup: The viscosity was measured using the pod cup which is a kind of viscosity cup. That is, the cylindrical composition of a fixed volume was filled with the coating composition, and the viscosity was measured according to the time taken for all the coating composition to flow out from the hole in the bottom.

(2) Paint storage stability: After putting the coating composition in a closed container, the viscosity change and the appearance change were checked after heat storage at 43 ° C for 5 days. Viscosity changes should be good within 50% with Pod Cup # 4, with no change in appearance.

(3) Coating film thickness: 10-15 micrometers was defined as the coating thickness.

(4) Clear coat: This is a paint which is subsequently coated with the coating material of the coating composition of the present invention to impart the appearance and chemical and physical durability of gloss and the like to the automotive coating film. The prescribed coating film thickness was 35-45 µm.

(5) WAVESCAN DOI: The coating quality was measured using a wave scan which is a portable device for measuring the coating quality of the finished coating film. The better the appearance quality, the higher the LU, SH, and OP values. CF is converted from each value.

(6) Gloss: Measured by LU value of WAVESCAN DOI.

(7) Water resistance: Discoloration and adhesion were evaluated after immersion in water for 240 hours.

(8) Adhesiveness: 10 * 10 cross cut was evaluated.

Referring to Tables 4 to 7, according to Experimental Examples 1 and 2, it can be seen that the paint storage stability, appearance, gloss, and water resistance at low temperature, high humidity, medium temperature, medium humidity, and high temperature and low humidity are superior to Comparative Experimental Examples 1 and 2. .

Features, structures, effects, and the like as described above are included in the present invention. Features, structures, effects, and the like illustrated in each embodiment may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

Since the microgel according to the present invention uses a hydroxyl group-containing unsaturated monomer having polyalkylene glycol in the step of forming the second shell, the interaction with adjacent factors can be further maximized, thereby improving viscosity and plasticity characteristics. In terms of the preparation method of the microgel, it is possible to stably polymerize the microgel having a relatively high acid value, and the microgel can improve the stability of the particles during storage and to make the paint atomization well during the film formation. It is very useful industrially as a composition.

Claims

Preparing a core;

Forming a first shell on the core; And

Forming a second shell on the first shell

Including,

A method for producing a microgel using a hydroxyl group-containing unsaturated monomer having a polyalkylene glycol in at least one of the step of forming the first shell and the second shell.
The method of claim 1,

In the forming of the second shell, a method of preparing a microgel in which an acid-containing unsaturated monomer and a hydroxyl group-containing unsaturated monomer including the polyalkylene glycol are added to and reacted to form the second shell.
The method of claim 1,

A hydroxyl-containing unsaturated monomer comprising the polyalkylene glycol is a method for producing a microgel represented by the following formula.

<Formula>

(Wherein R 1 represents a hydrogen atom or a methyl group, R 2 represents an alkyl group having 2 to 4 carbon atoms, n is an integer of 3 to 20)
The method of claim 1,

In the preparing of the core, an acid-free or acid-containing unsaturated monomer is added to a seed and reacted to form the core,

In the step of forming the first shell, an acid-free or acid-containing unsaturated monomer and a hydroxyl-free or hydroxyl-containing unsaturated monomer is added to the reaction method for producing a microgel.
The method of claim 1,

In the preparing of the core, the core is formed by injecting and reacting a hydroxyl-free or hydroxyl-containing unsaturated monomer having a polyalkylene glycol with an acid-containing unsaturated monomer,

In the forming of the first shell, a neutralizing agent is added to the core, and an acid-free or acid-containing unsaturated monomer is added and reacted to form the first shell while inducing phase inversion.
The method according to claim 4 or 5,

A method of making a microgel, wherein the acid value measured after the forming of the second shell is higher than the acid value measured after forming the first shell.
The method of claim 1,

The acid value of the microgel is 40 ~ 200 mgKOH / g and the hydroxyl value is 1 ~ 80 mgKOH / g method of producing a microgel.
The method according to claim 4 or 5,

Based on 100 parts by weight of the total unsaturated monomer used in the preparation of the microgel,

The weight part of the unsaturated monomer added in the step of preparing the core is 35 ~ 60,

The weight part of the unsaturated monomer added in the step of forming the first shell is 20 to 40,

Method for producing a microgel of 10 to 30 parts by weight of the unsaturated monomer added in the step of forming the second shell.
Microgel prepared by the method for producing a microgel according to claim 1.
A water-soluble coating composition comprising the microgel according to claim 9.
core;

A first shell formed on the core; And

A second shell formed on the first shell and formed by reacting an acid-containing unsaturated monomer with a hydroxyl group-containing unsaturated monomer having polyalkylene glycol;

Microgel comprising a.
A water-soluble coating composition comprising the microgel according to claim 11.