KR20040083808A - Method of producing resin for coating - Google Patents

Abstract

PURPOSE: A process for producing a resin for a coating agent is provided, which can inhibit the use of an emulsifier, prevents the lowering of properties, and polymerizes monomers easily. CONSTITUTION: The process comprises the steps of: dissolving a water-soluble resin and a polymerization initiator in water; injecting a non-ionic emulsifier, a polymerization initiator, and a monomer into the dissolved water-soluble resin. The water-soluble resin comprises at least one of a styrene/alpha-methyl styrene/acryl acid copolymer, a styrene/maleic acid copolymer, a butyl acrylate/acryl acid copolymer, and an ethylene/acryl acid copolymer. The non-ionic emulsifier contains at least one of an ethoxylate nonyl phenol and polyoxyethylene isooctylphenyl ether. The polymerization initiator contains at least one of ammonium persulfate, potassium persulfate, sodium persulfate. And the monomer comprises at least one of methylmethacrylate, 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, styrene, and vinyl acetate.

Description

Method of producing resin for coatings

The present invention relates to a method for producing a coating resin, and more particularly, to a method for producing a coating resin using a water-soluble resin.

Coatings, such as inks and paints, used to treat the surface of paper, plastics, automobiles, containers, appliances, etc. to protect the surface of the article and to enhance its appearance, are indispensable in the industry. Such a coating agent is generally used as a diluent for improving the workability of the coating process, and improve the performance of the coating film. By the way. In spite of their excellent physical properties, these organic solvents have the disadvantage of volatile organic compounds (VOC), which are the main causes of air pollution, and have a high risk of fire due to flammability.

In order to improve the above problems, there is an emulsion polymerization method using water as a dispersion medium during the polymerization reaction.

In the case of conventional emulsion polymerization, an emulsifier is used to maintain the stability of the particles of the polymer to provide and produce a polymerization site.

These emulsifiers are surfactants (Emulsifier) is applied as an indispensable element in the emulsion polymerization, it provides a place to react by forming particles swollen with micelles or monomers in the early stage of the reaction. In addition, it serves to protect the monomer droplets to stabilize the monomer source, and as the reaction proceeds gradually, the particles become larger and the size of the monomer droplets becomes smaller so that the emulsifier moves to the surface between the monomer particles, thereby maintaining the stability of the polymer particles. Do it.

By the way, the use of such an emulsifier has a disadvantage of causing physical property degradation by weakening the water resistance and adhesion of the product.

The present invention was devised to improve the above problems, and an object of the present invention is to provide a method for preparing a resin for coating, which can suppress the use of an emulsifier and prevent polymerization of monomers while preventing physical property degradation.

In order to achieve the above object, a method for preparing a coating resin according to the present invention includes the steps of dissolving a water-soluble resin in a solvent together with a polymerization initiator; It includes; a step of generating a resin by adding a nonionic emulsifier, a polymerization initiator and a monomer to the dissolved water-soluble resin.

The water-soluble resin includes at least one of a copolymer of styrene / alphamenylstyrene / acrylic acid, a copolymer of styrene / maleic acid, a copolymer of butylacrylate / acrylic acid, and a copolymer of ethylel / acrylic acid. .

The nonionic emulsifier may include any one of ethoxylate nonylphenol and polyoxyethylene isooctylphenyl ether, and the polymerization initiator may include any one of ammonium persulfate, potassium persulfate, and sodum persulfate.

Preferably the solvent is deionized water or distilled water is applied, the monomer comprises at least one of methacrylate, 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, styrene, vinyl acetate.

More preferably, the water-soluble resin is added at a weight ratio of 20 to 30% of the monomer, and the neutralizing agent is applied based on ammonia.

In addition, the content of the neutralizing agent is about 120 to 130% of the monomer is applied.

Hereinafter, a method of preparing a resin for a coating agent according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in more detail.

In the present invention, a solvent, a polymerization initiator, an auxiliary emulsifier, and a monomer are appropriately added and reacted with a water-soluble resin to produce a coating resin.

It is preferable that the water-soluble resin applied to the production of the coating resin is capable of functioning as an emulsifier in the conventional emulsion polymerization method, and has a molecular weight of about 6000 to 7500 and an acid value of about 210 to 230.

Preferably, copolymers of styrene / alphamethylstyrene / acrylic acid (SAA type), copolymers of styrene / maleic acid (SMA type), copolymers of butyl acrylate / acrylic acid (BAA type) and ethyl as water-soluble resins Copolymers of reel / acrylic acid (EAA type) and the like are applied. As the SAA type among these water-soluble resins, solury-70, which is a water-soluble resin commercially available from Hanwha Chemical, may be applied.

The water-soluble resin is preferably applied so that the weight ratio to the total monomers is about 20 to 30%.

Water-soluble resins can use water as a solvent, so there is no emission of volatile organic compounds, which is environmentally friendly, and provides excellent coating properties such as adhesiveness, transferability, and glossiness.

In addition, the volatilization content is very low, so there is little foaming provides a good workability.

In addition, there is an advantage that the change over time with respect to the viscosity of the coating agent is small, and by changing the composition and composition of the monomer, it provides an advantage that can be produced for various uses by changing the various glass transition temperature.

Looking at the reaction characteristics of the water-soluble resin in the aqueous solution phase, first, the water-soluble resin forms an aggregate structure similar to the general anionic surfactant in the aqueous solution, thereby providing an emulsion polymerization place.

Second, as the concentration of the water-soluble resin increases, the surface tension decreases and is maintained, and the formation of the association of the water-soluble resin inhibits interfacial migration to form micelles in water, thereby providing an emulsion polymerization place in micelles like a general emulsifier. do.

Third, since the water-soluble resin has hydrophilic and hydrophobic groups in its molecule, it functions as an anionic emulsifier that sufficiently forms an association in an aqueous solution.

Fourth, the water-soluble resin is capable of producing very small and stable polymer particles, unlike the general emulsion polymerization by adsorbing or crosslinking to the emulsion particles to stabilize the particles and electrostatic stabilization.

Fifth, the water-soluble resin provides a core-shell effect to complement the physical properties of the emulsion to provide an advantage of improving the water resistance and gloss.

On the other hand, as the solvent applied to dissolve the water-soluble resin and adjust the viscosity, water, preferably deionized water or distilled water is applied.

This application of water as a solvent provides the advantage of performing environmentally friendly processes as it does not emit volatile organic compounds in the manufacturing process as mentioned above.

In addition, the neutralizing agent used to help dissolve and stabilize the water-soluble resin is ammonia (NH 3), AMP (2-amino-2-methyl-1-propanol), alkylamine (Alkylamine), sodium hydroxide (NaOH), potassium hydroxide (KOH) and the like can be applied.

On the other hand, as a monomer that is applied to form a coating agent, it is preferable to apply a vinyl group (acrylate) raw material (acrylate) raw material (acrylate) raw material.

Examples of such monomers include methacrylate (MMA), 2-ethylhexyl acrylate (2-EHA), butyl acrylate (BA), ethyl acrylate (EA), styrene (SM), vinyl acetate (VAC), and the like. have.

In addition, it is preferable to apply a nonionic emulsifier to the auxiliary emulsifier used to stabilize the emulsion polymer particles and contribute to the polymerization stability.

Preferably, as the nonionic emulsifier, ethoxylated nonylphenol and polyoxyethylene isoctylphenyl ether are applied.

On the other hand, it is preferable to apply a water-soluble polymerization initiator that can control the molecular weight of the polymerization initiator to be used for generating a radical to initiate the polymerization reaction.

As the water-soluble polymerization initiator, ammonium persulfate (APS), potassium persulfate (KPS), sodum persulfate (SPS) and the like can be applied.

The following describes embodiments for producing the soft coating and hard coating by applying the above-described elements.

Example 1

First, to synthesize the soft coating agent, 466.8 g of deionized water, a water-soluble resin of Soluryl-70, a SAA type water-soluble resin manufactured by Hanwha Chemical, and 115% of a 28% solution of ammonia water (NH4OH) in a 2-liter double jacketed glass reactor were prepared. Were added together, and the water-soluble resin was dissolved while maintaining the glass reactor temperature at 70 ° C. and the pH of 8.3 to 8.7.

After dissolving the water-soluble resin, the temperature of the glass reactor was raised to 80 ° C., and then, a nonionic emulsifier liquid in which 1.95 g of Triton X-100, a polyoxyethylene isooctylphenyl ether, applied as a nonionic emulsifier was dissolved in 20 g of deionized water. After 5 minutes, 250.8 g of 2-EHA and 135 g of styrene (SM) were continuously added at 80 ° C. for 3 hours.

After completion of the monomer, the mixture was left at 80 ° C. for 1 hour, cooled to 40 ° C., and filtered to synthesize a coding agent for soft coating.

The physical properties of the soft coding agent synthesized through the above Example 1 has excellent properties of adhesiveness and water resistance as shown in Table 1 below.

division Measures How to measure Solid content (WT%) 48 ± 1 3 hours at 105 ℃ PH 8.5 ± 0.2 PH meter Viscosity (cps) 500 ± 50 #B Viscometer <RVT> Glass transition temperature (℃) -16 ℃ ± 3 DSC Minimum film forming temperature (℃) 5 or less MFFT meter Particle size (nm) 50 ± 20 Particle sizer <CHDF> Acid 50 to 55 Titration Molecular Weight 200,000 or more GPC Freeze stability 5cycle pass 8 hours at -5 ℃ and 16 hours at 20 ℃ Thermal stability pass 5 days at 50 ℃

Example 2

Meanwhile, to prepare a coating agent for hard coating, 458 g of deionized water in a 2-liter double jacketed glass reactor, 115 g of a water-soluble resin of Soluryl-70, a SAA type water-soluble resin manufactured by Hanwha Chemical, 28% of ammonia water (NH4OH) 34.8 g of the solution was added together, and the water-soluble resin was dissolved while maintaining the glass reactor temperature at 70 ° C. and the pH of 8.3 to 8.7.

After dissolving the water-soluble resin, the temperature of the glass reactor was raised to 80 ° C., and then, the resulting polymerization initiator solution in which 1.16 g of APS was dissolved in 10 g of deionized water as a nonionic emulsifier was added to the organic reactor, and 5 minutes later. A mixture of 5.9 g of Triton X-100 and 385.8 g of styrene (SM) as a monomer and a nonionic emulsifier solution in which 2.69 g of APS was dissolved in 30 g of deionized water were continuously added to a glass reactor at 80 ° C. for 3 hours.

After completion of the monomer, the mixture was left at 80 ° C. for 1 hour, cooled to 40 ° C., and filtered to synthesize a hard coating coding agent.

The physical properties of the hard coding agent synthesized through the above Example 2 have excellent properties of adhesion and water resistance as can be seen through Table 2 below.

division Measures How to measure Solid content (WT%) 48 ± 1 3 hours at 105 ℃ PH 8.5 ± 0.2 PH meter Viscosity (cps) 500 ± 50 #B Viscometer <RVT> Glass transition temperature (℃) 105 ℃ ± 3 DSC Minimum film forming temperature (℃) 80 ℃ or less MFFT meter Particle size (nm) 60 ± 20 Particle sizer <CHDF> Acid 50 to 55 Tititation Molecular Weight 200,000 or more GPC Freeze stability 5cycle pass 8 hours at -5 ℃ and 16 hours at 20 ℃ Thermal stability pass 5 days at 50 ℃

Applicant's experiment in the method of manufacturing a soft or hard coating agent using such a water-soluble resin, as the concentration of the water-soluble resin increases, the average particle diameter is reduced, the final viscosity is increased. In consideration of these properties, the mixing ratio of the preferred water-soluble resin was suitably 20 to 30% of the total monomers.

In addition, the neutralizing agent that does not affect the water resistance is preferred to use ammonia (NH 3) having room temperature dry type and high basicity, the content of the neutralizing agent to sufficiently dissolve the high acid water-soluble resin is 133% of the total Was appropriate.

APS was used as the water-soluble initiator, it was appropriate to use about 1% compared to the monomer.

In addition, a uniform particle size could be formed by applying a polymerization method in which the monomer was continuously introduced into the reactor.

As described above, according to the manufacturing method of the coating resin using the water-soluble resin according to the present invention, it is possible to provide a sufficient polymerization reaction place with only a water-soluble resin, thereby providing the advantage that no use of an anionic emulsifier, The adsorbing or crosslinking properties of the emulsion particles allow the production of stable polymer particles and provide an advantage of improving the strength of the coating film. In addition, the amount of the emulsifier can be reduced, and the low volatile content, thereby suppressing the generation of bubbles, thereby improving workability, without sacrificing the physical properties required by the coating agent, such as transferability, water resistance, adhesion, and mixing with the pigment. It is possible to provide a resin having a small particle size and providing high glossiness of solid content.

Claims (8)

In the manufacturing method of the resin for coating agents, Dissolving the water-soluble resin in water together with the polymerization initiator; And adding a nonionic emulsifier, a polymerization initiator, and a monomer to the dissolved water-soluble resin to generate a resin. The method of claim 1, wherein the water-soluble resin is a copolymer of styrene / alphamenylstyrene / acrylic acid, a copolymer of styrene / maleic acid, a copolymer of butyl acrylate / acrylic acid, and a copolymer of ethylene / acrylic acid. Method for producing a coating resin, characterized in that it comprises at least one. The method of claim 1, wherein the nonionic emulsifier comprises at least one of ethoxylate nonylphenol and polyoxyethylene isooctylphenyl ether. The method of claim 1, wherein the polymerization initiator comprises at least one of ammonium persulfate, potassium persulfate, and sodum persulfate. The method of claim 1, wherein the monomer comprises at least one of methacrylate, 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, styrene, and vinyl acetate. The method of claim 1, wherein the water-soluble resin is added in a weight ratio of 20 to 30% of the monomer. The method for producing a resin for a coating agent according to claim 1, wherein the neutralizing agent is one containing ammonia as a main component. The method of claim 7, wherein the content of the neutralizing agent is a method for producing a coating resin, characterized in that about 120 to 130% of the monomer is applied.