KR20070071996A - Inverted core-shell type microgel polymer containing urethane - Google Patents

Abstract

Provided are an inverted core/shell type microgel polymer containing urethane, its preparation method, and a paint composition containing the microgel polymer which is excellent in water fastness, adhesion and pigment dispersion. The inverted core/shell type microgel polymer comprises: a core emulsion polymer which comprises 3-15 parts by weight of a carboxyl group-containing monomer, 5-20 parts by weight of a hydroxyl group-containing monomer, 35-85 parts by weight of a non-crosslinking monomer containing one olefin, 0-10 parts by weight of a crosslinking monomer containing at least two olefins, and 5-50 parts by weight of a water dispersible urethane polymer based on 100 parts by weight of a core monomer composition; and a shell emulsion polymer which comprises 70-90 parts by weight of a non-crosslinking monomer containing one olefin, 5-15 parts by weight of a monomer containing one epoxy group, and 1-15 parts by weight of a crosslinking monomer containing at least two olefins based on 100 parts by weight of a shell monomer composition, wherein the shell emulsion polymer is polymerized in the core emulsion polymer which is swollen by a neutralizer.

Description

Inverted core-shell type microgel polymer containing urethane

The present invention relates to a core emulsion polymer comprising monomers and water-dispersed urethane polymers each containing a carboxyl group, a hydroxyl group, one olefin, and optionally two or more olefins in a molecule; And a shell emulsion polymer each comprising a monomer containing one olefin, one epoxy group, and at least two olefins in a molecule, wherein the shell emulsion polymer is polymerized within the core emulsion polymer swelled by a neutralizing agent. The present invention relates to a reversed phase core / shell type microgel polymer, a method for preparing the same, and a coating composition including the same, wherein the microgel polymer according to the present invention crosslinks the inside using an olefinic crosslinking monomer and an epoxy monomer. It has a structure swelled with a neutralizing agent, so it is excellent in swelling by solvent, excellent in water resistance, adhesion and pigment dispersibility, has a plasticity viscosity behavior, and can be coated in a wide range of temperature and humidity conditions. Suitable for use in top coats.

Recently, the regulation of volatile organic compounds (VOC) to protect the global atmospheric environment is tightened, and the development of water-soluble paints to cope with this is being actively progressed.

In general, emulsion polymers are water-based and have no risk of fire, and do not emit harmful organic solvents in large quantities, making them easy to handle. However, problems such as corrosion resistance, solvent resistance, and mechanical strength remain. In addition, the emulsion resin uses an emulsifier for emulsion polymerization, in which case there is a problem that the water resistance and adhesion decreases due to the movement of the emulsifier to the surface of the coating film and the ammonium ions contained in the emulsifier. Therefore, in recent years, a tendency to apply a reactive emulsifier that can be bonded in the molecular chain to prevent the migration of the emulsifier to the surface of the coating film, but the synthetic stability due to the reduction in emulsification power due to the synthesis is also reduced.

Recently, in order to improve the disadvantage of the conventional emulsion polymer, the development of an emulsion polymer having a multi-layered particle has been made.

For example, US Pat. No. 4,539,363 describes a method for preparing a microgel emulsion polymer in which a carboxyl group of a shell composition is neutralized with an amine after forming a core / shell type polymer using a crosslinked core and a coating composition containing the same. In addition, U.S. Patent No. 4,403,003 discloses a method for synthesizing core / shell-type particles made of a shell composition containing a crosslinked core and carboxylic acid by non-water dispersion and emulsion polymerization, and using them as top coats for water-soluble automotive coatings / transparent coating systems. It is. However, when the resin described in the above patents is used, there is an advantage of showing good orientation when using metallic pigments due to excellent plasticity behavior, but sagging due to low humidity in spraying conditions due to sensitivity to temperature and humidity conditions. ) Shows a phenomenon, and in a dry condition, the coating film smoothness is inhibited due to the high viscosity, which results in a poor appearance.

In addition, British Patent No. 2,206,591 proposes a method of blending with acrylic water dispersible resin to compensate for the poor water resistance of the microgel emulsion polymer added as the main resin of automotive repair paints. However, this method has various problems such as compatibility between resins.

On the other hand, Korean Patent No. 149696 prepares a core emulsion containing a sufficient amount of carboxyl groups prepared by the emulsion polymerization method to reduce the content of the conventional core / shell type emulsifier and neutralize it with a neutralizing agent to produce a "quasi-soluble resin", Although a method for using this as a polymer dispersant stably without adding an external low molecular weight emulsion gel in the preparation of a two-stage shell emulsion has been described, the present invention reduces the emulsifier content to improve water resistance, but in addition to contamination resistance, It has a problem that the compactness, plasticity and the like are deteriorated.

The present invention has been made to solve the above problems, the present inventors emulsion polymerized the core monomer through the water-dispersed urethane polymer, and swell the prepared core with a neutralizing agent, thereby making the polymerization inside the shell monomer swelled core Including the cross-linking monomer containing two or more olefin groups and the monomer containing an epoxy group in the shell monomer, it was found through the internal cross-linking that the low molecular weight external particles exhibit plasticity when swelling the solvent, Completed.

Accordingly, an object of the present invention is to use a water-dispersed urethane as an emulsifier and to have the advantages of a coating using a conventional microgel emulsion polymer as a main resin, and at the same time, to enhance water resistance and plasticity for automobiles, buildings, automobile repairs, or plastics. It is to provide a reverse-phase core / shell microgel polymer that can be used as a paint, a method for preparing the same and a coating composition comprising the same.

The present invention in each molecule based on 100 parts by weight of the core monomer composition

3 to 15 parts by weight of a monomer containing a carboxyl group,

5-20 parts by weight of a monomer containing a hydroxy group,

35 to 85 parts by weight of the non-crosslinking monomer containing one olefin,

0-10 parts by weight of a crosslinkable monomer containing two or more olefins, and

Core emulsion polymer containing 5-50 weight part of water-dispersed urethane polymer; And

In each molecule based on 100 parts by weight of the shell monomer composition

70 to 90 parts by weight of a non-crosslinkable monomer containing one olefin,

5 to 15 parts by weight of a monomer containing one epoxy group, and

A shell emulsion polymer comprising 1 to 15 parts by weight of a crosslinkable monomer containing at least two olefins,

The shell emulsion polymer relates to a reversed phase core / shell type microgel polymer characterized in that it is polymerized inside the core emulsion polymer swollen by a neutralizing agent.

The composition used for the reversed phase core / shell type microgel polymer according to the present invention is further specified by the following.

The core emulsion polymer of the reversed phase core / shell type microgel polymer according to the present invention uses 5 to 50 parts by weight of the water-dispersed urethane polymer based on 100 parts by weight of the core monomer composition in place of a conventional reactive or non-reactive emulsifier.

A general water-dispersible polyurethane polymer is prepared by introducing an ionic group into the polymer chain, and is divided into cationic, anionic, or zwitterionic ions according to the form of the ionic group appearing on the particle surface. Thus forming positive ionomers and negative ionomers and amphoteric ionomers. The size of the anionic polyurethane dispersion is in the range of about 0.01 to 5 μm, and depends on many factors such as the content of ionic groups used in the synthesis, the type of polyol, and the content of the crosslinking agent, and the particle size of the polyurethane dispersion. It has a direct impact on stability. Dispersions with relatively large average particle size (> 1 μm) have low dispersion stability and are unstable and prone to precipitation. Dispersions with small average particle size (<0.2 μm) have good storage stability and high surface energy. As a result, the film has a strong interaction and bonding force. With anionic groups of the anionic polyurethane dispersion is COO ^- and a, COO ^{- -,} and SO ₃ shows a good moisture resistance and excellent dispersibility

The amount of the water-dispersed urethane polymer according to the present invention can be used within a range that does not affect the synthetic stability. If the amount is less than 5 parts by weight, the synthetic stability deteriorates. On the other hand, there is a problem in that the swelling effect of the solvent is lowered, the plasticity of the paint is lowered.

In addition, the water-dispersed urethane polymer is preferably obtained by neutralizing and dispersing an anionic urethane resin containing at least one vinyl monomer and having an isocyanate group with a trivalent amine and then adding a chain extender.

The core emulsion polymer of the reversed phase core / shell type microgel polymer according to the present invention contains 3 to 15 parts by weight of a monomer containing an intramolecular carboxyl group based on 100 parts by weight of the core monomer composition to provide water solubility. If the monomer is less than 3 parts by weight, the degree of water solubility during neutralization is low, so that there is a problem in that it does not act as an emulsifier in the subsequent shell emulsion process. This also causes a decrease in water resistance of the coating film.

The monomer containing a carboxyl group in the molecule may be used without limitation as long as it has at least one ethylenically unsaturated double bond in the molecule and contains at least one carboxyl group, but it is preferable to use at least one selected from the compounds of formula (1). .

[Formula 1]

In which R ⁴ represents hydrogen or a carboxyl group;

When R ⁴ is a carboxyl group, R ¹ , R ² and R ³ each independently represent hydrogen, an alkyl group, a carboxyl group, or —R ⁵ COOH, wherein R ⁵ represents alkylene;

When R ⁴ is hydrogen, R ¹ , R ² and R ³ each independently represent hydrogen, an alkyl group, or —R ⁶ COOH, wherein at least one of R ¹ , R ² and R ³ represents —R ⁶ COOH, R ⁶ represents an aromatic hydrocarbon group.

In the above, the alkyl group and the alkylene group are branched or straight-chain aliphatic or alicyclic, the carbon number is 1 to 12, preferably 1 to 8, more preferably 1 to 4, the ring member of the aromatic hydrocarbon group is 5 to 12 More preferably, benzene.

More preferred compound of formula 1 is selected from the group consisting of acrylic acid, methacrylic acid, vinylbenzene acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, monoalkylmaleate, monoalkylfumalate, and monoalkylitaconate More than one.

Since the core emulsion polymer of the reversed phase core / shell type microgel polymer according to the present invention is swollen with a neutralizing agent to form the final microgel particle, 100 wt% of the core monomer composition may react with melamine or block isocyanate for water resistance and denseness of the coating film. It contains 5-20 weight part of monomers containing an intramolecular hydroxyl group with respect to a part. If the monomer is less than 5 parts by weight, the degree of curing is low, there is a problem that the water resistance of the coating film is lowered. If the monomer exceeds 20 parts by weight, the reaction proceeds in the water phase during emulsion polymerization, causing a problem that the stability of the reaction is lowered.

The monomer containing a hydroxy group in the molecule can be used without limitation as long as it has at least one ethylenically unsaturated double bond in the molecule, and contains at least one hydroxy group, the compound of the formula (2) and the addition of the compound of the formula (2) and caprolactone It is preferably at least one selected from the group consisting of water.

[Formula 2]

In which R ⁷ represents hydrogen or an alkyl group;

R ⁸ represents —COOR ⁹ or —R ¹⁰ OH, wherein R ⁹ represents alkyl substituted by a hydroxy group and R ¹⁰ represents an alkylene group.

In the above, the alkyl group and the alkylene group are branched or linear aliphatic or alicyclic, and the carbon number thereof is 1 to 12, preferably 1 to 8, more preferably 1 to 4.

More preferred compounds of formula (2) include (meth) acrylate ethyl, (meth) hydroxypropyl (meth) acrylate, butyl (meth) acrylate, allyl alcohol, methacryl alcohol, (meth) acrylate ethyl and these and capro At least one selected from the group consisting of adducts of lactones.

The core emulsion polymer of the reversed phase core / shell type microgel polymer according to the present invention comprises 35 to 85 parts by weight of a non-crosslinkable monomer containing one olefin and 0 to 10 parts by weight of a crosslinkable monomer containing two or more olefins as an optional component. do. If the amount of the non-crosslinkable monomer containing one olefin is less than 35 parts by weight, the synthetic stability is lowered, and if it exceeds 85 parts by weight, plasticity is decreased, and the amount of the crosslinkable monomer containing two or more olefins is 10 Exceeding the weight part lowers the synthetic stability.

The monomer containing one olefin may be an alkene having 1 to 8 carbon atoms; Alkyl or cycloalkyl (meth) acrylic acid esters having 1 to 18 carbon atoms; Alkoxy alkyl (meth) acrylic acid esters having 2 to 18 carbon atoms; Vinyl aromatic compounds; Conjugated dienes having 4 to 9 carbon atoms; And (meth) acrylonitrile.

The alkenes having 1 to 8 carbon atoms include, but are not limited to, those substituted or unsubstituted with halogen or acetate, such as ethylene, propylene, vinyl acetate, vinyl chloride, or vinylidene chloride.

The alkyl or cycloalkyl (meth) acrylic acid ester having 1 to 18 carbon atoms is methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, Lauryl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, la Uryl methacrylate, and cyclohexyl methacrylate may be selected from, but is not limited thereto.

The alkoxy alkyl (meth) acrylic acid ester having 2 to 18 carbon atoms may be selected from methoxy butyl acrylate, methoxy butyl methacrylate, methoxy ethyl acrylate, and methoxy ethyl methacrylate, but is not limited thereto.

The vinyl aromatic compound is styrene, vinyltoluene, alpha-methyl styrene, ortho-methyl styrene, meta-methyl styrene, para-methyl styrene, ortho-ethyl styrene, meta-ethyl styrene, para-ethyl styrene, ortho- But may be selected from methyl-para-isopropyl styrene, para-chloro styrene, ortho, para-dichloro styrene, para-chloro styrene, ortho, para-dibromostyrene, and para-bromostyrene. Do not.

The conjugated diene of 4 to 9 carbon atoms is 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, pentadiene, 2-neopentyl-1, It may be selected from 3-butadiene, but is not limited thereto.

The monomer containing one olefin is at least one selected from the group consisting of styrene, vinyltoluene, methylstyrene, ethylene, butadiene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, alkyl acrylate and alkyl methacrylate. Most preferably used.

The crosslinking monomer containing two or more olefins is aryl acrylate, aryl methacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol Preference is given to using one or more selected from the group consisting of dimethacrylate, diarylphthalate, tripropylene glycol dimethacrylate, trimethylolpropane trimethacrylate and triarylisocyanurate. In the above, aryl is an aromatic hydrocarbon having 6 to 12 ring members.

Meanwhile, the shell emulsion polymer of the reversed phase core / shell type microgel polymer according to the present invention contains 70 to 90 parts by weight of a non-crosslinkable monomer containing one olefin as the base resin. Synthetic stability falls when the usage-amount of the said non-crosslinkable monomer containing one olefin is less than 70 weight part, and when it exceeds 90 weight part, plasticity will fall.

The non-crosslinkable monomer used in the shell emulsion polymer may be optionally selected from one or more of non-crosslinkable monomers containing one olefin used in the above-described core emulsion polymer.

The shell emulsion polymer of the reversed phase core / shell type microgel polymer according to the present invention uses a monomer containing 5 to 15 parts by weight of an epoxy group based on 100 parts by weight of the shell monomer composition for internal crosslinking reaction with the carboxyl group of the swollen core emulsion polymer. do. If the amount is less than 5 parts by weight, the adhesion or plasticity of the coating film is lowered, and if it exceeds 15 parts by weight, the synthetic stability becomes unstable.

The monomer containing one epoxy group in the molecule preferably includes a glycidyl group in the molecule, and at least one selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. More preferred.

The shell emulsion polymer of the reversed phase core / shell type microgel polymer according to the present invention uses a crosslinking monomer containing 1 to 15 parts by weight of two or more olefins based on 100 parts by weight of the shell monomer composition for internal crosslinking. If the amount of the crosslinking monomer is less than 1 part by weight, the crosslinking density of the produced particles is low, so that it is difficult to produce particles having a stable form of core / shell structure when neutralized. Securing stability and high crosslinking density of the particles produced there is a problem that does not express sufficient water swellability.

The crosslinking monomers are aryl acrylate, aryl methacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, diaryl phthalate It is preferable to use at least one selected from the group consisting of tripropylene glycol dimethacrylate, trimethylolpropane trimethacrylate and triaryl isocyanurate. In the above, aryl is an aromatic hydrocarbon having 6 to 12 ring members.

The invention also relates to 100 parts by weight of the core monomer composition, respectively,

3 to 15 parts by weight of a monomer containing a carboxyl group,

5-20 parts by weight of a monomer containing a hydroxy group,

35 to 85 parts by weight of an uncrosslinked monomer containing one olefin, and

0-10 parts by weight of a crosslinkable monomer containing two or more olefins is added and reacted,

A first step of preparing a core emulsion polymer using 5 to 50 parts by weight of a water-dispersed urethane polymer on an solid basis as an emulsifier;

A second step of swelling the inside of the core monomer by adding a neutralizing agent to the core emulsion polymer obtained in the first step; And

In each molecule based on 100 parts by weight of the shell monomer composition

70 to 90 parts by weight of a non-crosslinkable monomer containing one olefin,

5 to 15 parts by weight of a monomer containing one epoxy group, and

Reverse phase comprising a third step of preparing a shell emulsion polymer by polymerizing the shell monomer composition comprising 1 to 15 parts by weight of the crosslinkable monomer containing two or more olefins in the swollen core emulsion polymer obtained in the second step. A method for producing a core / shell type microgel polymer is disclosed.

Each step of the process for producing a reversed phase core / shell type microgel polymer according to the present invention is specified by the following.

The first step according to the present invention is to prepare a core emulsion polymer, a step of preparing a core emulsion polymer by a conventional emulsion polymerization method using a water-dispersed urethane polymer, the core emulsion polymer thus prepared is a base It is neutralized with a neutralizing agent, which serves as a polymer dispersion stabilizer in the shell emulsion preparation step.

The water-dispersed urethane polymer used as the emulsifier

Reacting a polyester polyol, a diisocyanate, or a polyol containing a carboxyl group in the molecule to prepare a polyurethane prepolymer terminated with NCO;

B) preparing an anionic polyurethane resin by reacting at least one vinylic monomer with the prepolymer obtained in step a);

Neutralizing and dispersing the anionic polyurethane resin prepared in step b) with a trivalent amine c); And

It is preferably obtained by a manufacturing process comprising the step d) of chain extension by adding a chain extender to the product of step c).

In the above, it is preferable to use triethylamine (TEA) as the trivalent amine and ethylenediamine as the chain extender.

Further, in the first step of preparing the core emulsion polymer according to the present invention, a chain transfer agent may be optionally added to control the molecular weight of the core polymer. A good chain transfer agent has a high transfer activity and should not adversely affect the rate of polymerization other than giving an adjustable molecular weight distribution. For this reason, the amount of the chain transfer agent should be determined in consideration of the type and amount of the polymerization initiator. Generally, 0 to 5 parts by weight, preferably 0.5 to 4 parts by weight, is used based on 100 parts by weight of the core monomer mixture. When the usage-amount exceeds 5 weight part, synthetic stability will fall.

As the chain transfer agent usable in the present invention, one or more selected from the group consisting of alkyl mercaptans having 2 to 15 carbon atoms, mercapto carboxylic acids having 2 to 8 carbon atoms and their esters, carbon tetrachloride and bromotrichloromethane are preferable. .

In addition, the method for preparing the reversed phase core / shell type microgel polymer according to the present invention uses a radical polymerization initiator. Radical polymerization initiators are both water-soluble and oil-soluble initiators in which radicals are formed by thermal dissociation at high temperatures, and initiators in which radicals are produced by redox reactions at low temperatures, but are water-soluble to impart polarity to the core surface. It is preferable to use a thermal dissociation radical initiator in 0.2-1.5 weight part with respect to 100 weight part of core monomer mixtures. Synthetic stability falls when the usage amount is less than 0.2 weight part, and water resistance falls when it exceeds 1.5 weight part.

The water-soluble thermal dissociation radical initiator is ammonium persulfate, potassium persulfate, sodium persulfate, cyclohexyl hydroperoxide, cumene hydroperoxide, n-octyl hydroperoxide, t-butyl hydroperoxide, sec- More preferably, it is at least one selected from the group consisting of butyl hydroperoxide, and 1-phenyl-2-methylpropyl-1-hydroperoxide.

The polymerization method of the core emulsion as described above is followed by a semi-continuous process of initial injection of water and an emulsifier into a continuous phase and injection of an initiator and a monomer, as in the conventional emulsion polymerization method, and the reaction temperature is generally 70 to 90 degrees. ℃.

The second step according to the present invention is a step of neutralizing the core emulsion containing the carboxyl group prepared in the first step with a neutralizing agent composed of a base for use as a polymer dispersant in the shell emulsion polymerization of the third step. In this case, the core emulsion polymer has a swelling and dissolution behavior competitively, and the factors influencing the competition behavior decisively include the type of neutralizing agent, the appropriate neutralization (pH value), the hydrophilicity of the core composition, and the core particle structure.

In the present invention, it is possible to obtain the following third stage shell emulsion polymerization stability without containing an external low molecular weight emulsifier and to obtain a core / shell emulsion polymer containing a minimum amount of the emulsifier, so that the neutralized core emulsion serves as a polymer dispersant. This is because the morphology of the neutralized core polymer should be controlled.

The amount of the neutralizing agent used in the second step is preferably 0.5 to 1.2 equivalents based on 1 equivalent of the carboxylic acid of the core polymer. If the neutralizing agent is less than 0.5 equivalent, the degree of solubilization at the time of neutralization has a problem that does not play a role of the emulsifier in the subsequent shell process, if the equivalent exceeds 1.2 equivalent it will not play the role of the emulsifier as in the shell process subsequent to complete solubilization there is a problem. The degree of neutralization is the most important factor in the swelling / dissolution behavior of the core emulsion polymer, and as the degree of neutralization increases, the dissolution behavior becomes stronger, so that the solubility of the core particles is promoted, but the too high degree of neutralization does not give stability to the three-stage shell emulsion polymerization. . Therefore, in order to give stability of the three-step emulsion polymerization, an appropriate degree of neutralization is required, and in the present invention, 0.5 to 1.2 equivalents are suitable for the equivalent of the carboxyl group of the core polymer, and the pH is 6.0 to 9.0.

The neutralizing agents usable in the second step include inorganic bases including ammonia, sodium hydroxide (NaOH), potassium hydroxide (KOH), and lithium hydroxide (LiOH); And

It is preferably at least one selected from the group of primary, secondary or tertiary amines comprising dimethylethanol amine, 2-amino-2-methyl-propanol 95% (from Angus), and triethyl amine.

In the third step according to the present invention, the core emulsion polymer neutralized in the second step is used as a dispersion stabilizer, so that an external low molecular weight emulsifier is not added or only a small amount of the emulsion is added as compared to a conventional core / shell emulsion polymerization method. As a step of preparing a shell emulsion for preparing the monomer, the monomer is selected according to the Tg of the core / shell polymer and the use of the end use paint.

In this case, it is preferable that the mixing ratio of the core emulsion polymer prepared in the first step and the shell emulsion polymer prepared in the second step is 1: 0.2 to 1: 2 weight ratio. If the mixing ratio of the shell emulsion polymer is less than 0.2, plasticity is lowered, and if it exceeds 1.2, the synthetic stability is lowered.

The present invention also relates to a coating composition comprising the reversed phase core / shell type microgel polymer according to the present invention at 15 to 55 parts by weight based on 100 parts by weight of the paint. If the amount is less than 15 parts by weight, the paint viscosity is lowered and the plasticity is lowered. If it is more than 55 parts by weight, the paint storage property is lowered.

The components required to prepare the water-soluble paint composition are as follows, which may be used in the same manner as to prepare a conventional water-soluble paint composition. For example, the composition is composed of 7.5 to 22.5 parts by weight of cosolvent, 1.5 to 15 parts by weight of pigment, 0.15 to 7.5 parts by weight of thickener, 0.15 to 3.0 parts by weight of antifoaming agent, and other additives.

The co-solvent is at least one selected from the group consisting of propylene glycol, N-methyl-2-pyrrolidone, n-propyl alcohol, n-butanol, butyl glycol and butyl carbitol, the role of the co-solvent affects the smoothness of the coating film It gives the storage stability of the paint and lowers the minimum film forming temperature. In order to give a metallic effect to a coating film, a pigment is used individually or in mixture of an aqueous flake aluminum flake and a mica pigment.

The thickener is used to prevent the flowability of the water-soluble coating composition, and contribute to painting workability and coating roughness, and the thickener alone or mixed with acrylic thickener, urethane thickener, fused silica, cellulose thickener, benton thickener, and the like. Used as

The antifoaming agent is used to suppress the generation of bubbles generated in various processes, such as during the production of the coating composition of the present invention, during the painting work and after the arrival of the holding, or to quickly remove the bubbles generated as an antifoaming agent as fluorine modified Siloxane type, polysiloxane emulsion, organic modified siloxane type, hydrophobic silica, mineral oil and the like are used alone or in combination.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the following examples.

Preparation Example 1 Preparation of Water Dispersible Urethane Polymer

Each thermocouple, stirrer and reflux was equipped in a four-necked 2L round flask, 20 g of FOMREZ 55-66 (polyester polyol, manufactured by WITCO, molecular weight 2,000), 12.4 g of DMPA (Dimethylolpropionic acid), NMP (N-methyl-2- 12.4 g of pyrrolidone), 28.9 g of TMXDI (manufactured by Cytec Co., Ltd.), and 0.6 g of DBTDL (Dibutryltin dilaurate) were added thereto, and the temperature was raised to 90 ° C. After 2 hours, if NCO% was measured and was within 7.3%, 30.9 g of BA (butyl acrylate) and 6.2 g of HEMA (2-hydroxy ethyl methacrylate) were added thereto, and the temperature was reduced to 70 ° C. After the reaction for 1 hour after measuring the NCO% within 4.5%, TEA (triethylamine) was added to neutralize. After about 30 minutes 238.8 g of water was added over 10 minutes. After 30 minutes, 4.3 g of ED (Ethylene diamine) was added and maintained for 1 hour, followed by packing with a 400 mesh filter. The particle size of the synthesized water-dispersed urethane composite was 211 nm and the solid content was 40 wt% when measured by LLS.

Example 1

1) Manufacture of reversed phase core / shell type microgel (1)

A thermocouple, a stirrer, and a reflux reactor were respectively mounted in a four-necked 2L round flask, and 550 g of deionized water was added thereto, and the reactor temperature was raised to 80 ° C. To a monomer mixture consisting of 132 g of ethyl acrylate, 15 g of methacrylic acid, 58 g of styrene, and 30 g of hydroxyethyl acrylate, a solution consisting of 80 g of deionized water, 1.5 g of ammonium persulfate, and 30 g of the water-dispersed urethane polymer of Preparation Example 1 was mixed. The prepared preemulsion mixture was dripped for 2 hours. After maintaining the reaction for 1 hour, a neutralizing solution consisting of 15 g of dimethylethanolamine and 35 g of deionized water was added dropwise for 10 minutes, and then maintained for 30 minutes. A monomer mixture consisting of 40 g of ethyl acrylate, 37 g of styrene, 10 g of glycidyl methacrylate, and 2.0 g of hexanediol diacrylate, and an initiator solution consisting of 35 g of deionized water and 0.5 g of ammonium persulfate were prepared at the same time for 1 hour. It dripped. The reaction was maintained for 1 hour, then cooled and packaged with filtration through a 400 mesh filter. The particle diameter of the synthesized emulsion particles was 160 nm, and the solid content was 35% by weight as measured by LLS.

2) Preparation of Paint

A water-soluble automotive topcoat was prepared by using a silver metallic paint formulation using the synthesized emulsion.

The above formulation kept the solids content of the coating material and the pigment / resin ratio constant with the solid content of the applied resin as 35% by weight. First, 72 g of the emulsion resin solution prepared above was added to a 300 ml container, and 8.0 g of an aqueous 10% dimethylethanol amine solution was slowly mixed while stirring with a high speed stirrer. 6.9 g of aluminum paste (60 wt% solids) and 7.5 g of butyl glycol of Hydrolan 2154, which are aluminum flake pigments of Eckert Berke Co., Ltd., were mixed and stirred for 10 minutes with a high speed stirrer. While continuing to stir, 1.65 g of Disinfectant Surfinol, 5.5 g of hexyl glycol, and 5.0 g of 2-ethylhexanol were added. After stirring was stopped, 4.65 g of Cymel's melamine curing agent, Cymel 325 (solid content: 80% by weight) was added, and stirring was started again. 17.5 g of deionized water was added while maintaining stirring. 13.3 g of deionized water, 1.5 g of 10% dimethylethanol amine aqueous solution, and 3.5 g of Hv-30, an alkali swellable thickener of Ciba Specialty, were added thereto, and a paint was prepared in a Pod # 40 cup for 35 seconds, in a pH range of 8.0 to 8.5. .

3) Application of paint

The prepared silver metallic paint was coated on a steel panel specimen coated with an electrodeposition and a medium coating so that the coating thickness was approximately 15 microns thick at the time of drying, and was flash-dried for 4 minutes in an 80 ° C. oven. Keshisu paint, which is a solvent-type acrylic-melamine transparent paint manufactured by Kumkang Korea Chemical Co., Ltd., was coated to have a dry coating thickness of 45 microns and cured at 150 ° C. for 30 minutes.

Table 1 shows the test results of the paint and film properties.

Example 2

1) Reversed-phase core / shell microgels (2)

Example 1 The composition of the core monomer was replaced with a monomer mixture consisting of 126 g of ethyl acrylate, 15 g of methacrylic acid, 52 g of styrene, and 30 g of hydroxyethyl acrylate, and 80 g of deionized water, 1.5 g of ammonium persulfate, and Preparation Example 1 The preemulsion mixture prepared by mixing the solution of 60 g of water-dispersed urethane polymer was added dropwise for 2 hours. The particle diameter of the synthesized emulsion particles was 135 nm, and the solid content was 34.9% as measured by LLS.

Using the synthesized emulsion to prepare a water-soluble automotive topcoat with the same silver metallic paint formulation as in Example 1 was applied to the coating as in Example 1 and the paint and coating properties test results are shown in Table 1 below.

Example 3

1) Reversed-phase core / shell microgels (3)

Example 1 The composition of the core monomer was replaced with a monomer mixture consisting of 120 g of ethyl acrylate, 15 g of methacrylic acid, 46 g of styrene, and 30 g of hydroxyethyl acrylate, and 80 g of deionized water, 1.5 g of ammonium persulfate, and Preparation Example 1 The preemulsion mixture prepared by mixing the solution of 90 g of water-dispersed urethane polymer was added dropwise for 2 hours. The particle size of the synthesized emulsion particles was 115nm, measured by LLS, the solid content was 35.0%.

Using the synthesized emulsion to prepare a water-soluble automotive topcoat with the same silver metallic paint formulation as in Example 1 was applied to the coating as in Example 1 and the paint and coating properties test results are shown in Table 1 below.

Comparative Example 1: Application of a Non-Reactive Emulsifier.

Example 1 The composition of the core monomer was replaced with a monomer mixture consisting of 138 g of ethyl acrylate, 15 g of methacrylic acid, 64 g of styrene, and 30 g of hydroxyethyl acrylate, and 80 g of deionized water, 1.5 g of ammonium persulfate, and non-reactivity of Rhodia Co., Ltd. The preemulsion mixture prepared by mixing with 10 g of a solution of CO-436, an anionic emulsifier, was added dropwise for 2 hours. The particle diameter of the synthesized emulsion particles was 110nm, as measured by LLS, the solid content was 34.9%.

Using the synthesized emulsion to prepare a water-soluble automotive topcoat with the same silver metallic paint formulation as in Example 1 was applied to the coating as in Example 1 and the paint and coating properties test results are shown in Table 1 below.

Comparative Example 2: Reactive Emulsifier Application.

Example 1 The composition of the core monomer was replaced with a monomer mixture consisting of 138 g of ethyl acrylate, 15 g of methacrylic acid, 64 g of styrene, and 30 g of hydroxyethyl acrylate, and 80 g of deionized water, 1.5 g of ammonium persulfate, and Daiichi Goyo A preemulsion mixture prepared by mixing with 10 g solution of Aquaron HS-0515 manufactured by Seiyaku Corporation was added dropwise for 2 hours. The particle diameter of the synthesized emulsion particles was 100nm, measured by LLS, the solid content was 35.0%.

Using the synthesized emulsion to prepare a water-soluble automotive topcoat with the same silver metallic paint formulation as in Example 1 was applied to the coating as in Example 1 and the paint and coating properties test results are shown in Table 1 below.

1) The water resistance was evaluated for the adhesion rate (%) by immersing the specimen in water at 40 ° C. for 10 days after discoloration, blister generation and cross cut adhesion.

2) Adhesiveness The top coat and the transparent paint were respectively applied to the coating film of the transparent paint, and the adhesion rate (%) was evaluated through the cross cut adhesiveness.

3) Rheological behavior was evaluated by observing the viscosity change in a reciprocating manner using a rheometer from 0 to 100 s ^-1 and observing low shear viscosity, high shear viscosity and viscosity recovery.

4) High Humidity Workability was evaluated by sagging resistance and popping resistance generated when coating was applied at 22 ° C and 85% relative humidity.

5) Low Humidity Workability was evaluated by sagging resistance and popping resistance generated when coating was applied at 25 ° C and 60% relative humidity.

6) Appearance (QMS) was evaluated by gross observation and the light intensity ratio measured at 25 ° and 75 ° angles measured using X-Rite MA58 photometer.

As can be seen from the examples and comparative examples, the reverse phase core / shell microgel containing the urethane prepared according to the present invention is used as a main resin for water-based paints, and it is a conventional microparticle that uses a non-reactive emulsifier or a reactive emulsifier. It has the advantages of paint using gel emulsion polymer as its main resin, and it has excellent water resistance, adhesiveness, and plasticity viscosity. It can be applied in wide temperature and humidity conditions, so it can be used as paint for building, automobile repair, and plastic. Can be.

Claims (9)

In 100 parts by weight of each of the core monomer composition 3 to 15 parts by weight of a monomer containing a carboxyl group, 5-20 parts by weight of a monomer containing a hydroxy group, 35 to 85 parts by weight of the non-crosslinking monomer containing one olefin, 0-10 parts by weight of a crosslinkable monomer containing two or more olefins, and Core emulsion polymer containing 5-50 weight part of water-dispersed urethane polymer; And In each molecule based on 100 parts by weight of the shell monomer composition 70 to 90 parts by weight of a non-crosslinkable monomer containing one olefin, 5 to 15 parts by weight of a monomer containing one epoxy group, and A shell emulsion polymer comprising 1 to 15 parts by weight of a crosslinkable monomer containing at least two olefins, And said shell emulsion polymer is polymerized inside said core emulsion polymer swollen by a neutralizing agent. The reverse-phase core according to claim 1, wherein the water-dispersed urethane polymer is obtained by neutralizing and dispersing an anionic urethane resin containing at least one vinyl monomer and having an isocyanate group with a trivalent amine and then adding a chain extender. / Shell type microgel polymer. The reverse phase core / shell type microgel polymer according to claim 1, wherein the monomer containing a carboxyl group in the molecule is at least one selected from compounds represented by the following general formula (1). [Formula 1]

In which R ⁴ represents hydrogen or a carboxyl group; R ¹ , R ² and R ³ each independently represent hydrogen, an alkyl group, a carboxyl group, or -R ⁵ COOH when R ⁴ is a carboxyl group, at least one of R ¹ , R ² and R ³ represents R ⁶ COOH R ⁵ represents alkylene; When R ⁴ is hydrogen, R ¹ , R ² and R ³ each independently represent hydrogen, an alkyl group, or —R ⁶ COOH, wherein R ⁶ represents an aromatic hydrocarbon group. The reverse phase core / shell type microgel polymer according to claim 1, wherein the monomer containing a hydroxy group in the molecule is at least one selected from the group consisting of a compound represented by the following formula (2) and an adduct of a compound represented by the following formula (2) and caprolactone: . [Formula 2]

In which R ⁷ represents hydrogen or an alkyl group; R ⁸ represents —COOR ⁹ or —R ¹⁰ OH, wherein R ⁹ represents alkyl substituted by a hydroxy group and R ¹⁰ represents an alkylene group. The method of claim 1, wherein the crosslinking monomer containing two or more olefins is aryl acrylate, aryl methacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, 1 Reverse phase core / characterized in that at least one selected from the group consisting of, 6-hexanediol dimethacrylate, diaryl phthalate, tripropylene glycol dimethacrylate, trimethylolpropane trimethacrylate and triaryl isocyanurate Shelled Microgel Polymer. The reverse-phase core / according to claim 1, wherein the monomer containing one epoxy group in the molecule is at least one selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. Shelled Microgel Polymer. In 100 parts by weight of each of the core monomer composition 3 to 15 parts by weight of a monomer containing a carboxyl group, 5-20 parts by weight of a monomer containing a hydroxy group, 35 to 85 parts by weight of an uncrosslinked monomer containing one olefin, and 0-10 parts by weight of a crosslinkable monomer containing two or more olefins is added and reacted, A first step of preparing a core emulsion polymer using 5 to 50 parts by weight of a water-dispersed urethane polymer on an solid basis as an emulsifier; A second step of swelling the inside of the core monomer by adding a neutralizing agent to the core emulsion polymer obtained in the first step; And In each molecule based on 100 parts by weight of the shell monomer composition 70 to 90 parts by weight of a non-crosslinkable monomer containing one olefin, 5 to 15 parts by weight of a monomer containing one epoxy group, and Reverse phase comprising a third step of preparing a shell emulsion polymer by polymerizing the shell monomer composition comprising 1 to 15 parts by weight of the crosslinkable monomer containing two or more olefins in the swollen core emulsion polymer obtained in the second step. Process for preparing core / shell type microgel polymer. 8. The water-dispersed urethane polymer of claim 7 used as an emulsifier Reacting a polyester polyol, a diisocyanate, or a polyol containing a carboxyl group in the molecule to prepare a polyurethane prepolymer terminated with NCO; B) preparing an anionic polyurethane resin by reacting at least one vinylic monomer with the prepolymer obtained in step a); Neutralizing and dispersing the anionic polyurethane resin prepared in step b) with a trivalent amine c); And A process for preparing a reversed phase core / shell type microgel polymer, characterized in that obtained by a manufacturing process comprising the step d) of chain extension by adding a chain extender to the product of step c). A coating composition comprising 15 to 55 parts by weight of the reversed phase core / shell type microgel polymer according to claim 1 with respect to 100 parts by weight of the paint.