KR20240057540A - Aqueous binder with improved water resistance and insulation anti condensation paint using the same - Google Patents

Abstract

In this application, in order to improve the water resistance of the acrylic emulsion binder, an ester monomer with a long alkyl chain is introduced into the acrylic molecule. In addition, to increase the stability of the emulsion polymerization process of ester monomers with long alkyl chains, a method of dispersing the monomers in a surfactant in advance and adding them to the reaction is utilized.

Description

Water-based binder with improved water resistance and insulating anti-condensation paint using the same {AQUEOUS BINDER WITH IMPROVED WATER RESISTANCE AND INSULATION ANTI CONDENSATION PAINT USING THE SAME}

This application relates to a water-based binder with improved water resistance and an insulating anti-condensation paint using the same. More specifically, it relates to a paint that uses a water-based binder with improved water resistance and has excellent heat insulation and does not cause condensation. Acrylic emulsion In order to improve the water resistance of the binder, an ester monomer with a long alkyl chain is introduced into the acrylic molecule. In addition, to increase the stability of the emulsion polymerization process of ester monomers with long alkyl chains, a method of dispersing the monomers in a surfactant in advance and adding them to the reaction is utilized.

Apartments, which account for most of the housing in Korea, have verandas where washing machines and dryers are located. In general, verandas painted with water-based paints experience condensation in the winter when the temperature difference between the exterior and interior walls is large, and mold frequently occurs in the summer due to high humidity.

When condensation occurs, the water-based paint swells as it absorbs water, causing the paint to fall off the wall. If mold develops, not only does the wall become dirty, but it also has negative effects on health.

To prevent this, various methods have been used to increase the insulation of the paint to prevent the temperature of the interior wall from being too cold in winter and to add anti-fungal agents to the paint. However, since indoor paints must use water-based paints, if the inorganic pigments such as titanium dioxide contained in the paint absorb sufficient moisture, due to the nature of water-based paints with weak water resistance, they will not be able to withstand moisture and will swell on the wall, causing the coated paint to swell. Falling off occurs frequently, and in the summer, there is a problem of mold growing on the surface of paint that contains enough moisture.

Methods mainly used to improve this problem include adding ceramics with insulating properties or adding various antibacterial agents using a non-special, commercially available water-based acrylic resin (acrylic latex or emulsion).

Patent Documents 1 and 2 are characterized by increasing insulation performance by adding various porous ceramics such as glass bubbles or inorganic porous materials. Additionally, Patent Document 03 is a method of adding a material with metallic sterilizing properties to porous ceramic.

The methods described in these patents do not specifically improve the resin component, which accounts for about 50% of the composition, and cannot overcome problems that occur when the added minerals absorb moisture, causing them to fall off from the wall within a short period of time. Occurs frequently.

Republic of Korea Patent No. 10-2399896 Republic of Korea Patent No. 10-2342766 Republic of Korea Patent No. 10-2398265

According to an embodiment of the present application, in order to improve the above-mentioned problems, an acrylic emulsion binder with greatly improved water resistance was manufactured, and by using it in a paint, a paint that has excellent thermal insulation properties and can prevent condensation from occurring is provided. I want to.

One aspect of the present application relates to a method for producing an acrylic emulsion binder.

In one example, the manufacturing method includes preparing a first mixture by mixing a surfactant and a vinyl ester; Preparing a second mixture by mixing monomers and water; mixing the first mixture and the second mixture to prepare a third mixture; and mixing an initiator with the third mixture to prepare an emulsion binder.

In one example, the surfactant may be a nonionic reactive surfactant.

In one example, the vinyl ester may include a long alkyl chain.

In one example, the vinyl ester is represented by the formula:

[Chemical formula]

Here, R1 and R2 may each independently have 6 to 9 carbon atoms.

In one example, the vinyl ester may be 5 to 8 parts by weight based on 100 parts by weight of the surfactant.

In one example, the initiator may include potassium persulfate.

Another aspect of the present application relates to an acrylic emulsion binder manufactured by the acrylic emulsion binder manufacturing method described above.

Another aspect of the present application is the acrylic emulsion binder described above; and at least one additive selected from the group consisting of diatomaceous earth, silica, antifoaming agent, preservative, and dispersing agent.

According to an embodiment of the present application, an acrylic emulsion binder with improved water resistance can be provided.

According to an embodiment of the present application, an insulating paint with improved water resistance can be provided by using a binder with improved water resistance in paint mixing.

According to an embodiment of the present application, it is possible to provide a paint that can improve the phenomenon of peeling due to moisture in the paint by improving the water resistance of the paint surface painted on a wall with a lot of moisture.

Figure 1 is the chemical formula of vinyl ester.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “include” or “have” are intended to designate the presence of features, components, etc. described in the specification, but one or more other features or components, etc. may not be present or may be added. That doesn't mean there isn't one.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having meanings consistent with the meanings they have in the context of the related technology, and unless clearly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

In the verandas and laundry rooms of apartments, which occupy a large part of current residences, condensation often occurs on the walls due to the temperature difference and humidity from the outside, and mold often develops due to the moisture on the walls caused by this condensation. To prevent this, various anti-condensation paints are available.

However, since these paints are for indoor painting, they must be water-based paints that do not use solvents, so water-resistant acrylic emulsion resin must be used, and most paints are made by adding ceramic extender pigments with excellent hygroscopicity.

However, since the cause of condensation is a difference in temperature, the area where condensation mainly occurs is the area on the inner wall of the veranda that is in contact with the outer wall. In order to overcome this temperature difference, the insulating performance of the paint is also important, that is, in order to overcome this temperature difference, it is desirable to contain ingredients with excellent insulating properties.

In addition, when fine moisture on the surface is absorbed into the ceramic extender pigment, the absorbed moisture penetrates into the inside of the painted paint, causing the coated paint to swell and fall off the wall. In order to prevent this phenomenon, it is necessary to push out the moisture between the extender pigments. Minority performance is required.

In addition, acrylic emulsions used as binders for indoor paints have lower water resistance than oil-based binders and are more likely to peel off the wall when moisture penetrates into the paint. Therefore, improving the water resistance of acrylic emulsions helps maintain the durability of condensation insulating paints. plays an important role.

In order to increase the water resistance of acrylic emulsion used as a binder for indoor water-based paint, a design that increases water resistance from the emulsion polymerization stage is necessary.

In this application, in order to improve such performance, it is preferable that the monomer composition includes a composition that has high water resistance when turned into a polymer while adjusting the temperature at which the film is formed to an appropriate level of approximately -15 to 5 ° C.

Additionally, water resistance can be increased by designing the initiator to be potassium persulfate, which has slightly lower water solubility than the commonly used ammonium persulfate.

In addition, surfactants have the greatest influence on the water resistance performance of acrylic emulsion resin. Using an anionic surfactant can produce nano-sized acrylic particles that are advantageous in terms of water resistance, but the water resistance of the surfactant itself is poor, making improvement difficult, and among nonionic surfactants, reactive nonionic surfactants have excellent water resistance. It increases the water resistance of acrylic emulsion, but the size of the basic micelles is large, making it difficult to adjust the size of the final acrylic emulsion particles to nano size. A reactive surfactant with excellent water resistance is usually selected. However, due to the nature of the surfactant, water resistance is inevitably reduced, so this problem is overcome by mixing various monomers.

In other words, in order to increase the water resistance of the acrylic emulsion used as a binder to maintain the water resistance of the paint, 1) the higher the water resistance of each component in the monomer combination, the more desirable it is, and 2) the lower the water solubility of the initiator, the more advantageous. 3) It is advantageous for the size of the final acrylic particles to be small, and 4) nonionic surfactants are more advantageous than ionic surfactants, and reactive surfactants are more advantageous than nonionic surfactants.

However, there are clear limits to the water resistance of conventionally used acrylic monomers. In this application, in order to slightly increase the water resistance of the acrylic emulsion, the above-mentioned reaction mechanism and a long alkyl structure called Veova are included in the molecule to create an alkyl vinyl ester structure that has water resistance but is less compatible during emulsion reaction with acrylic monomer. We aim to improve this by using monomers.

The method for producing an acrylic emulsion binder of the present application includes preparing a first mixture by mixing a surfactant and a vinyl ester; Preparing a second mixture by mixing monomers and water; mixing the first mixture and the second mixture to prepare a third mixture; and mixing an initiator with the third mixture to prepare an emulsion binder.

In order to improve the reactivity in emulsion polymerization of vinyl esters with long alkyl chains, vinyl esters and acrylic monomers react together by using a process of mixing vinyl esters in advance with a surfactant and emulsifying them instead of mixing them in the commonly used monomer mixing tank. This can prevent the particles from growing larger. Through this process, the particle size can be controlled to 60 nm or less.

The greater the amount of vinyl ester that can be mixed in advance with the surfactant, the better. However, the reactivity of vinyl ester is significantly different from that of acrylic, so even if the content is increased, the amount that can react is not high. Approximately 5 to 8 parts by weight compared to 100 parts by weight of surfactant. It is desirable to include it as a part.

If the content of alkyl vinyl ester is less than 5 parts by weight compared to the surfactant, the water resistance performance of the final acrylic emulsion decreases. Conversely, if it exceeds 8 parts by weight, unreacted vinyl ester affects the size of the particles during reaction, resulting in large final acrylic emulsion particles. As a result, water resistance performance may deteriorate.

In general, in the case of acrylic emulsion polymerization, polymerization using vinyl ester monomer (VAc Monomer) has poor physical properties such as water resistance, but is advantageous in terms of economic efficiency, so it has been used to manufacture water-based adhesives that maintain low prices. The size of the particles after emulsion polymerization is no smaller than that of water-resistant emulsion resin, it also has a unique odor, and polyvinyl alcohol (PVA) is usually used as a dispersant, making it suitable for low-cost adhesives.

however. An ester-structured vinyl having a long alkyl chain in the molecular structure was developed to overcome the disadvantage of vinyl acetate's poor water resistance. However, during conventional emulsion polymerization, the particle size of the acrylic emulsion is 10um due to the difference in radical reactivity with the acrylic monomer. As it grew larger than this, it was difficult to use to improve water resistance, so it was rarely used. However, it has been used to slightly improve water resistance only when polymerizing polysol (emulsion made by emulsion polymerization of vinyl acetate with polyvinyl alcohol stabilizer) using vinyl acetate monomer (Vac monomer).

In the present application, in order to overcome this problem, an ester-structured vinyl monomer having a long alkyl chain in the molecular structure is dissolved in a surfactant, preferably a reactive ionic surfactant, so that a difference in reaction rate with the acrylic monomer may occur in the mechanism of acrylic emulsion polymerization. It was discovered that by reducing the area, it was possible to stably synthesize small particles, for example, an acrylic emulsion of 60 nm or less.

The mechanism of emulsion polymerization of acrylic monomer is as follows. At the beginning of the reaction, when the initiator and surfactant are dissolved in water and an acrylic monomer that does not dissolve well in water is added, a trace amount is dissolved to reach solubility phase equilibrium with water. A radical reaction occurs when a small amount of dissolved acrylic monomer encounters a radical initiator dissolved in water. In the middle stage of the reaction, as addition polymerization progresses, the molecular weight of acrylic gradually increases, becoming more hydrophobic, and settles inside spherical micelles where hydrophobicity exists. As the monomers added inside undergo a polymerization reaction, particles are created and grow larger. At this time, a copolymer is made by combining various monomers, but there are cases where the reaction does not proceed due to solubility in water and mutual reaction rates, and unreacted monomers remain. These residual monomers affect the size of the particles, and as the particles become larger, water resistance deteriorates.

Initiators may include potassium persulfate. Water resistance can be increased by designing with potassium persulfate, which has slightly lower water solubility than ammonium persulfate.

In addition, the present application provides an insulating anti-condensation paint, the paint containing the above-described acrylic emulsion binder; and at least one additive selected from the group consisting of diatomaceous earth, silica, antifoaming agents, preservatives, and dispersants.

Hereinafter, the present application will be described in more detail through experimental examples.

[Experimental Example 1]

Example 1. Vinyl alkyl ester emulsification process

In a spherical flask, add 100g of distilled water, 1000g of nonionic reactive surfactant ER10 from Adeka, 40g of itaconic acid, and 50g of sodium hydroxide, mix and stir for 30 minutes, then add 60g of Veova 10 (alkyl vinyl acetate) and stir until it appears transparent. It was stirred. Afterwards, it was stored for 24 hours.

Example 2. Emulsion polymerization process

330 parts by weight of water and 10 parts by weight of the surfactant prepared in Example 1 were dissolved in a 2 liter reaction tank and heated to 80°C. In the first dropping tank, 70 parts by weight of water, 1.5 parts by weight of lauryl sulfate, 3.0 parts by weight of the surfactant mixture prepared in Example 1, 200 parts by weight of butylacrylate monomer, and 150 parts by weight of methyl methacrylate were mixed. In another second dropping tank, 1.2 parts by weight of potassium persulfate, a radical initiator, was dissolved in 25 parts by weight of water. When the temperature of the reaction tank reached 80 degrees, the monomer mixture and the initiator solution from the two dropping tanks were added dropwise to the reaction tank over about 30 minutes. After completion of dropwise addition, the reaction was continued while maintaining the temperature at 80 degrees. After 3 hours, 0.1 part by weight of butyl hydroxide persulfate was diluted with 2 parts by weight of water and added to the reaction tank to remove the remaining unreacted monomer and complete polymerization to obtain a stable acrylic emulsion.

Comparative Example 1. Process without using vinyl ester

330 parts by weight of water and 7 parts by weight of ER10 were added to a 2 liter reaction tank and heated to 80°C. 70 parts by weight of water, 1.5 parts by weight of lauryl sulfate, 1.5 parts by weight of reactive surfactant, 200 parts by weight of butylacrylate monomer, and 150 parts by weight of methyl methacrylate were mixed in a dropping tank. In another dropping tank, 1.2 parts by weight of potassium persulfate, a radical initiator, was dissolved in 25 parts by weight of water. When the temperature of the reaction tank reached 80 degrees, the monomer mixture and the initiator solution from the two dropping tanks were added dropwise to the reaction tank over about 30 minutes. After completion of dropwise addition, the reaction was continued while maintaining the temperature at 80 degrees. After 3 hours, 0.1 parts by weight of butyl hydroxide persulfate was diluted with 2 parts by weight of water and added to the reaction tank, and the polymerization was completed by removing the remaining unreacted monomer to obtain a stable acrylic emulsion.

Comparative Example 2. When long-chain vinyl ester is used in general emulsion polymerization reaction.

330 parts by weight of water and 7 parts by weight of ER10 were added to a 2 liter reaction tank and heated to 80 degrees. 70 parts by weight of water, 1.5 parts by weight of lauryl sulfate, 1.5 parts by weight of reactive surfactant, 200 parts by weight of butylacrylate monomer, 150 parts by weight of methyl methacrylate, and 5 parts by weight of Veova 10 were mixed in a dropping tank. In another dropping tank, 1.2 parts by weight of potassium persulfate, a radical initiator, was dissolved in 25 parts by weight of water. When the temperature of the reaction tank reached 80°C, the monomer mixture and initiator solution from the two dropping tanks were added dropwise to the reaction tank over about 30 minutes. After completion of dropwise addition, the reaction was continued while maintaining the temperature at 80 degrees. After 3 hours, 0.1 parts by weight of butyl hydroxide persulfate was diluted with 2 parts by weight of water and added to the reaction tank, and the remaining unreacted reaction monomer was removed to complete the polymerization. Because the polymerization reaction was not stable, an acrylic emulsion with unstable particles larger than 10 μm was obtained.

[Experiment result]

Example 2 and Comparative Example 1 were polymerized under all conditions except that the vinyl ester to be carried out in this application was first emulsified with a surfactant. Comparative Example 2 was a process of mixing vinyl ester monomer with other monomers and dropping them into the reaction to form an acrylic emulsion, and the process conditions of Example 1 were the same as those of Example 1.

The acrylic emulsion obtained in Example 2 and Comparative Examples 1 and 2 were bar-coated on a glass film and dried for 48 hours. The dried coated surface was placed in a water tank for four and a half days, and the degree of water resistance was compared and evaluated.

It was observed that the emulsion coating film polymerized according to Comparative Example was vulnerable to moisture, causing severe white turbidity.

[Experimental Example 2]

Example 3. Preparation of elastic paint.

116 parts by weight of water, 0.3 parts by weight of butylbenzoic acid, 10.2 parts by weight of titanium dioxide, and 5.4 parts by weight of polyvinylethylene glycol were added and stirred in a 1000 rpm dissolver for about 30 minutes, then 89.6 parts by weight of the aqueous acrylic emulsion binder prepared in Example 1 and water were added. After adding 32.9 parts by weight, the mixture to which 105.4 parts by weight of diatomaceous earth was added was stirred at 500 rpm.

In order to add water-repellent and heat-insulating properties to the elastic paint, 5.0 parts by weight of hydrophobic fumed silica and 18.0 parts by weight of Sannopco sn-thickerner 622 for viscosity control were added and stirred to prepare an elastic paint.

The prepared elastic paint was applied to a thickness of approximately 1.0 millimeter on the outer surface of a copper cone-shaped container using an airless sprayer, and then dried for 48 hours. After drying, the inside of the cone was filled with ice and it was confirmed that water droplets did not form due to moisture on the outer surface for about 2 hours. Through this, it was confirmed that the coating layer using the elastic paint according to the present application maintains sufficient insulation.

Although the present application has been described above with reference to preferred embodiments, those skilled in the art may modify and change the present application in various ways without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that it is possible.

Claims (8)

Preparing a first mixture by mixing a surfactant and a vinyl ester;
Preparing a second mixture by mixing monomers and water;
mixing the first mixture and the second mixture to prepare a third mixture; and
A method of producing an acrylic emulsion binder comprising: preparing an emulsion binder by mixing an initiator with the third mixture.
According to claim 1,
Method for producing an acrylic emulsion binder where the surfactant is a non-ionic reactive surfactant.
According to claim 1,
Vinyl ester is a method of producing an acrylic emulsion binder containing a long alkyl chain.
According to claim 1,
Vinyl esters are expressed by the following chemical formula:
[Chemical formula]

Here, R1 and R2 each independently have a carbon number of 6 to 9.
According to claim 1,
A method of producing an acrylic emulsion binder in which the vinyl ester is used in an amount of 5 to 8 parts by weight based on 100 parts by weight of the surfactant.
According to claim 1,
Method for producing an acrylic emulsion binder containing potassium persulfate as an initiator.
An acrylic emulsion binder produced by the method for producing an acrylic emulsion binder according to any one of claims 1 to 6.
Acrylic emulsion binder of claim 7; and
An insulating anti-condensation paint comprising at least one additive selected from the group consisting of diatomaceous earth, silica, antifoaming agent, preservative, and dispersant.