KR102058879B1 - Paint composition - Google Patents

Abstract

The present invention relates to an elastic putty composition, which comprises: a photo-initiator having an aromatic ketone structure; and 30 to 60% by weight of an acrylic emulsion binder comprising an acrylic resin, wherein the glass transition temperature (Tg) of the acrylic resin is -20 to -40°C, the acrylic resin is emulsion-polymerized using a reactive emulsifier, and the acrylic monomer forming the acrylic resin comprises at least 60 wt% or more of alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms.

Description

Paint composition {PAINT COMPOSITION}

The present invention relates to a coating composition, and more particularly, to a highly elastic putty composition having improved water resistance and stain resistance and a repair method of a structure using the same.

In general, as the building continuously generates cracks due to vibration, the exterior paint surface is damaged, and the periodic cracks are required because the cracks cause damage to the exterior and the value of the building. For example, elastic putty, which is mainly used in renovation of exterior walls of apartments, is preferred because of its resistance to cracking.

The elastic modulus of the acrylic type elastic putty depends on the glass transition temperature (Tg) of the coating film. Considering the minimum temperature in winter in Korea and the surface temperature of lower surface than the air temperature, it is required to maintain the elastic modulus even at low temperature.

By the way, putty made of an acrylic binder having a low temperature Tg has a good elastic modulus itself, but the coating film at room temperature is very sticky. Therefore, when long-term exposure is made in the domestic air quality situation where there is a lot of fine dust or pollution, it may adversely affect the adhesion to the top coat due to the contamination. Therefore, although rapid follow-up painting is required, in reality, the coating site is left uncoated over the course of several months under the influence of weather (low temperature) and snow / rain, which are unsuitable for top coat, resulting in contamination and water. The swelling phenomenon etc. of the coating film by the contact of a are generate | occur | produce.

Therefore, a method of increasing Tg and supplementing Tg at low temperature by using a plasticizer has been attempted to compensate for this, but it is difficult to improve the elongation rate of the plasticizer at cryogenic temperatures such as -20 ° C.

In addition, in order to impart contamination resistance and water resistance on the surface at a level equivalent to that of the top coat, the functional groups are retained in the binder while maintaining a one-component type to introduce crosslinking by a carboxy-amine reaction or a crosslinking agent through two-component formation. Although a method of introducing the A has been attempted, in this case, the water resistance is improved due to crosslinking over the entire coating film, but there is a disadvantage in that the elongation rate is lowered.

1. Korea Patent Registration No. 10-1744500

The present invention is to solve the above problems, to provide a high-elastic putty composition having a low stickiness and excellent water resistance, stain resistance while maintaining the elongation at low temperatures.

Another object of the present invention is to provide a method for repairing a structure using the putty composition.

The elastic putty composition according to the embodiment of the present invention includes 30 to 60% by weight of an acrylic emulsion binder including an acrylic resin and a photoinitiator having an aromatic ketone structure. The glass transition temperature (Tg) of the acrylic resin is -20 ℃ to -40 ℃, the acrylic resin is emulsion polymerized using a reactive emulsifier, the acrylic monomer forming the acrylic resin is an alkyl having an alkyl group of 4 or more carbon atoms At least 60% by weight or more of (meth) acrylate.

According to one embodiment, the photoinitiator comprises at least one selected from the group consisting of benzophenone, benzyl and thioxanthone.

According to one embodiment, the content of the photoinitiator is 0.1 to 4% by weight based on the total weight of the acrylic emulsion binder.

According to one embodiment, the alkyl (meth) acrylate butyl acrylate, 2-ethylhexyl acrylate, isopropyl acrylate, normal hexyl acrylate, lauryl methacrylate and octyl decyl acryl having an alkyl group of 4 or more carbon atoms At least one selected from the group consisting of rates.

According to one embodiment, the acrylic monomer forming the acrylic resin includes at least 90% by weight of alkyl (meth) acrylate having an alkyl group of 4 or more carbon atoms.

According to one embodiment, the reactive emulsifier comprises at least one selected from the group consisting of polyoxyethylene alkyl phosphate, ammonium polyoxyethylene alkyl sulfate and reactive modified alcohol ether phosphate.

According to one embodiment, the elastic putty composition further comprises 0.1 to 2% by weight of ammonium salt-based copolymer as a wet dispersion.

According to one embodiment, the elastic putty composition, inorganic filler 30 to 60% by weight, water 1 to 20% by weight, preservative 0.01 to 1% by weight, cryostabilizer 0.1 to 2% by weight, antifoam 0.1 to 1% by weight, thickener It further comprises 0.1 to 2% by weight and 1 to 10% by weight of the pigment.

Method of repairing a structure according to an embodiment of the present invention, filling the elastic putty composition on the damaged portion of the surface of the structure to form a putty coating film; And curing the surface part by exposing the putty coating film to natural light.

According to an embodiment, the repairing method of the structure further includes forming a top coat covering the putty coating film.

According to the present invention, it is possible to form an elastic putty having excellent crack resistance even at low temperatures in winter. In addition, by crosslinking the surface of the coating film with natural light using an acrylic resin and a photoinitiator, it is possible to reduce the stickiness of the surface of the coating film and to improve the water resistance and stain resistance of the coating film. Therefore, even if the putty coating film is exposed for a long time without a phase, adhesion of contaminants can be suppressed. Therefore, it is possible to prevent the occurrence of coating defects when forming the top coat.

1 to 3 are schematic cross-sectional views showing a method for repairing a structure according to an embodiment of the present invention.

In the present application, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, parts, or combinations thereof.

High Elasticity Putty Composition

Coating composition according to an embodiment of the present invention can be used as a putty composition for forming a putty coating film. The putty composition contains an acrylic emulsion binder. The acrylic emulsion binder includes an acrylic binder. For example, the putty composition may be an aqueous composition including water.

According to one embodiment, the solid content of the acrylic emulsion binder may be 40% to 70% by weight, preferably 50% to 60% by weight.

The acrylic emulsion binder contains an acrylic resin formed by polymerization of an acrylic monomer. According to one embodiment, the glass transition temperature (Tg) of the acrylic resin may be -20 ℃ to -40 ℃. When the glass transition temperature of the acrylic resin is higher than -20 ° C, low-temperature elastic modulus is lowered, and when applied as an elastic putty for repairing cracks such as outer walls, it is difficult to prevent cracking. In addition, when the glass transition temperature of the acrylic resin is lower than -40 ℃, the stickiness (tack) of the coating film is excessively increased, contaminants are easily attached, adhesion with the top coat may be reduced, due to excessive elasticity Cracking of the top can be caused.

According to one embodiment, the acrylic monomer forming the acrylic resin may include an alkyl (meth) acrylate. Preferably, the acrylic monomer may include an alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms. In the present application, (meth) acrylate may represent acrylate or methacrylate.

The acrylic resin polymerized using the alkyl (meth) acrylate which has a C4 or more alkyl group has a C4 or more alkyl side chain. The alkyl side chain having 4 or more carbon atoms as described above can be activated by a photoinitiator having an aromatic ketone structure to form a crosslinked structure on the surface of the coating film, thereby curing the surface. Therefore, the contamination resistance, water resistance, etc. of a coating film can be improved. For example, carbon number 4 of the alkyl side chain may be activated by the photoinitiator and natural light.

For example, the acrylic monomer may include butyl acrylate, 2-ethylhexyl acrylate, isopropyl acrylate, normal hexyl acrylate, lauryl methacrylate, octyldecyl acrylate or a combination thereof.

According to an embodiment, the acrylic monomer may further include alkyl (meth) acrylate or (meth) acrylic acid having 3 or less carbon atoms for controlling the glass transition temperature. For example, the acrylic monomer may further include ethyl acrylate, acrylic acid, and the like.

According to one embodiment, with respect to the total weight of the acrylic monomer, the content of the alkyl (meth) acrylate having an alkyl group of 4 or more carbon atoms may be 60% by weight or more, preferably 80% by weight or more, more preferably 90 It may be at least weight percent. When the content of the alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms is low, the crosslinking structure is not sufficiently formed on the surface of the putty coating film, and thus the stickiness of the coating film is increased, thereby reducing the fouling resistance and water resistance of the coating film. have.

According to one embodiment, the acrylic monomer mixture is 25 to 35% by weight butyl acrylate, 5 to 10% by weight 2-ethylhexyl acrylate, 25 to 35% by weight isopropyl acrylate, 1 to 5% by weight acrylic acid, normal 20 to 30 weight percent hexyl methacrylate and 1 to 10 weight percent ethyl acrylate.

According to one embodiment, the acrylic resin is emulsion polymerized using a reactive emulsifier. According to one embodiment, the reactive emulsifier may have an alkenyl group. For example, the reactive emulsifier may include nonionic emulsifiers of ethoxylates having ionic or alkenyl groups, such as ammonium polyoxyethylene alkylphosphate, ammonium polyoxyethylene alkylsulfate, reactive modified alcohol ether phosphate. These may each be used alone or in combination.

If the reactive emulsifier is not used as described above, when the coating film is exposed outdoors, the initial contamination may occur due to the migration of the surfactant to the surface by external moisture, and the water resistance may decrease, resulting in swelling of the coating film in the rain. Can be generated.

According to one embodiment, the content of the acrylic emulsion binder, may be 30 to 60% by weight, preferably 40 to 50% by weight relative to the total weight of the putty composition. When the content of the acrylic emulsion binder is less than 30% by weight, the flexibility of the coating film may be reduced, thereby reducing the low temperature / normal temperature elongation and decreasing crack resistance. In addition, when it exceeds 60% by weight, the stickiness of the coating film increases, and cracking of the top coat may be caused due to excessive elasticity.

The putty composition according to the embodiment of the present invention further includes a photoinitiator. After the putty coating film is formed, the photoinitiator may be activated by natural light or the like to form a crosslinked structure of the acrylic resin on the surface of the putty coating film.

According to one embodiment, the photoinitiator may have an aromatic ketone structure, and may include, for example, benzophenone, benzyl, thioxanthone or a combination thereof.

According to one embodiment, the photoinitiator may be added together when preparing the acrylic emulsion binder, but the present invention is not limited thereto, and after the acrylic emulsion binder is prepared, may be added when the putty composition is blended. . According to one embodiment, the content of the photoinitiator may be 0.1 to 4% by weight based on the total weight of the solid content of the acrylic emulsion binder. When the content of the photoinitiator is less than 0.1% by weight, the crosslinked structure is not sufficiently formed on the surface of the putty coating film, thereby increasing the stickiness of the coating film, thereby reducing the fouling resistance and water resistance of the coating film. When the content of the photoinitiator exceeds 4% by weight, yellowing and decomposition of the coating may be promoted when exposed to the outdoors for a long time due to excessive activation of the photoinitiator.

Putty composition according to an embodiment of the present invention, may further comprise a wet dispersant. According to one embodiment, the wet dispersant may include an ammonium salt-based copolymer. As the wet dispersant, when sodium salt-based copolymers or nonionic copolymers are used, swelling of the putty may occur due to a decrease in the water resistance of the putty and an increase in the water absorption of the putty in rainy weather.

According to one embodiment, the content of the ammonium salt-based copolymer may be 0.1 to 2% by weight based on the total weight of the putty composition, preferably 0.5 to 1.5% by weight. When the content of the ammonium salt-based copolymer is less than 0.1% by weight, due to the characteristics of the putty having a large pigment content, the dispersion may not be made uniformly, and thus, paint may not be produced or physical properties may decrease. In addition, when the content of the ammonium salt-based copolymer is more than 2% by weight, water resistance may decrease due to the excessively added wet dispersant.

The putty composition according to an embodiment of the present invention may further include a preservative, a freeze stabilizer, an antifoam, a thickener, an inorganic filler, a pigment, water, and the like, as necessary. These may be used conventionally known for putty compositions.

The preservative prevents the composition from being corrupted and deteriorated by the microorganism under the influence of temperature and humidity. For example, the preservative, methanethiol, ethanethiol, pentanethiol, isothiazole, isothiazol, benzoisothiazolone, salicylate, cysteine, 2- Mercaptoethanol, transglutaminase, or combinations thereof.

The cryostabilizer may prevent the elongation of the elastic putty from decreasing at low temperatures. For example, the cryostabilizer may include ethylene glycol and the like.

The antifoaming agent can be used to achieve uniform and smooth surface of the coating film by removing microbubbles. For example, the antifoaming agent may include mineral oil-based, polysiloxane-based or a combination thereof.

The thickener can prevent sedimentation of the putty composition and prevent sagging during operation. For example, the thickener may include hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxymethylethyl cellulose, or a combination thereof.

The inorganic filler may be added to shorten the drying time of the putty composition and to increase the smoothness of the coating film surface. For example, the inorganic filler may include light calcium carbonate, heavy calcium carbonate, barium sulfate, bentonite, silica sand, or a combination thereof.

For example, the pigment may include titanium dioxide and the like.

For example, the putty composition may include 30 to 60% by weight of an acrylic emulsion binder including an acrylic binder and a photoinitiator, 0.1 to 2% by weight of a wet dispersant, 30 to 60% by weight of an inorganic filler, 1 to 20% by weight of water, and a preservative 0.01. To 1% by weight, cryostabilizer 0.1 to 2% by weight, antifoaming agent 0.1 to 1% by weight, thickener 0.1 to 2% by weight and pigment 1 to 10% by weight.

How to repair the structure

1 to 3 are schematic cross-sectional views showing a method for repairing a structure according to an embodiment of the present invention.

Referring to FIG. 1, a putty coating layer 20 is formed by filling a putty composition at a damaged part such as a crack generated in the structure 10.

For example, the structure 10 may be a reinforced concrete structure, and the crack may occur on the concrete surface. For example, foreign substances around the cracks may be removed before the putty composition is filled.

The putty composition may comprise an acrylic emulsion binder and a photoinitiator. The putty composition is the same as the putty composition described above, a detailed description thereof will be omitted.

Referring to FIG. 2, the photoinitiator in the putty coating film 20 is activated by natural light, and the surface portion 22 exposed to natural light is cured. Accordingly, the surface of the putty coating film is reduced in stickiness, and water resistance and stain resistance are increased. Therefore, even if the putty coating film is exposed for a long time without a phase, adhesion of contaminants can be suppressed. In addition, since hardening does not proceed in the remaining portions except the surface portion 22 of the putty coating film 20, that is, in contact with the damaged portion, the reduction in elongation of the putty coating film 20 may be prevented to maintain crack resistance. .

Referring to FIG. 3, a top coat 30 is formed to cover the putty coating film. A method of forming the top coat 30 may be a conventionally known method, for example, the top coat 30 may be formed of an aqueous paint. It can be formed by painting.

According to the present invention, it is possible to form an elastic putty having excellent crack resistance even at low temperatures in winter. In addition, by crosslinking the surface of the coating film with natural light using an acrylic resin and a photoinitiator, it is possible to reduce the stickiness of the surface of the coating film and to improve the water resistance and stain resistance of the coating film. Therefore, even if the putty coating film is exposed for a long time without a phase, adhesion of contaminants can be suppressed. Therefore, it is possible to prevent the occurrence of coating defects when forming the top coat.

Hereinafter, the effects of the present invention will be described with reference to specific examples and experimental results.

Example 1

Preparation of Emulsion Binder

With reactive modified alcohol ether phosphate emulsifier, 30% by weight butyl acrylate, 8% by weight 2-ethyl hexyl acrylate, 30% by weight isopropyl acrylate, 2% by weight acrylic acid, 25% by weight hexyl methacrylate, ethyl Emulsion binder A was synthesized by polymerizing a monomer mixture composed of 5% by weight of acrylate. The glass transition temperature of the said emulsion binder A was -29 degreeC, and solid content was 55 weight%. 0.6 wt% of benzophenone was added to the emulsion binder A.

Paint production

6.5 weight percent water, 43.6 weight percent emulsion binder A, 0.1 weight percent preservative, 0.8 weight percent cryostabilizer, 0.7 weight percent ammonium salt-based copolymer dispersion wetting agent, 0.3 weight percent antifoam, 1.5 in a paint mixing flask A putty having a solid content of 71.5 wt% was prepared by adding a wt% thickener, 45 wt% calcium carbonate, and 1.5 wt% titanium dioxide.

Example 2

<Production of Emulsion Binder>

Using ammonium polyoxyethylene alkylphosphate emulsifier, 30% by weight butyl acrylate, 8% by weight 2-ethyl hexyl acrylate, 30% by weight isopropyl acrylate, 2% by weight acrylic acid, 25% by weight hexyl methacrylate, Emulsion binder B was synthesized by polymerizing a monomer mixture composed of 5% by weight of ethyl acrylate. The glass transition temperature of the emulsion binder B was -29 ℃, solid content was 55% by weight. 0.1 wt% of benzophenone was added to the emulsion binder B.

Paint production

6.5 weight percent water, 43.6 weight percent emulsion binder B, 0.1 weight percent preservative, 0.8 weight percent cryostabilizer, 0.7 weight percent ammonium salt-based copolymer dispersion wetting agent, 0.3 weight percent antifoam, 1.5 in a paint mixing flask A putty of 71.5 wt% solids was prepared using wt% thickener, 45 wt% calcium carbonate, and 1.5 wt% titanium dioxide.

Example 3

<Production of Emulsion Binder>

Emulsion binder A was prepared in the same design as in Example 1.

Paint production

10.4 wt% water, 35 wt% emulsion binder A, 0.1 wt% preservative, 0.8 wt% freeze stabilizer, 0.7 wt% ammonium salt based copolymer dispersion wetting agent, 0.3 wt% defoaming agent, 1.5 in a paint mixing flask A putty of 71.5 wt% solids was prepared using wt% thickener, 49.7 wt% calcium carbonate, and 1.5 wt% titanium dioxide.

Example 4

<Production of Emulsion Binder>

Emulsion binder A was prepared in the same design as in Example 1.

Paint production

In a flask for mixing paints, 5.2 wt% water, 43.6 wt% emulsion binder A, 0.1 wt% preservative, 0.8 wt% freeze stabilizer, 2 wt% ammonium salt based copolymer dispersion wetting agent, 0.3 wt% defoaming agent, 1.5 A putty of 71.5 wt% solids was prepared using wt% thickener, 45 wt% calcium carbonate, and 1.5 wt% titanium dioxide.

Comparative Example 1

<Production of Emulsion Binder>

30% by weight butyl acrylate, 8% by weight 2-ethyl hexyl acrylate, 30% by weight isopropyl acrylate, 2% by weight acrylic acid, normal hexyl methacrylate using non-reactive alkyl diphenylether disulfonate emulsifier Emulsion binder C was synthesized by polymerizing a monomer mixture consisting of 25% by weight and 5% by weight of ethyl acrylate. The glass transition temperature of the emulsion binder C was -29 ℃, solid content was 55% by weight.

Paint production

6.5 weight percent water, 43.6 weight percent emulsion binder C, 0.1 weight percent preservative, 0.8 weight percent cryostabilizer, 0.7 weight percent ammonium salt-based copolymer dispersion wetting agent, 0.3 weight percent antifoam, 1.5 in a paint mixing flask A putty of 71.5 wt% solids was prepared using wt% thickener, 45 wt% calcium carbonate, and 1.5 wt% titanium dioxide.

Comparative Example 2

<Production of Emulsion Binder>

10% by weight of butyl acrylate, 2% by weight of 2-ethylhexyl acrylate, 45% by weight of isopropyl acrylate, 2% by weight of acrylic acid, 32% by weight of methyl acrylate, ethyl acrylate using a reactive modified alcohol ether phosphate emulsifier The emulsion mixture D was synthesized by polymerizing a monomer mixture composed of 9 wt% of a rate. The glass transition temperature of the said emulsion binder D was -10 degreeC, and solid content was 55 weight%. 0.6 wt% of benzophenone was added to the emulsion binder D.

Paint production

In a flask for mixing paints, 6.5 wt% water, 43.6 wt% emulsion binder D, 0.1 wt% preservative, 0.8 wt% freeze stabilizer, 0.7 wt% ammonium salt-based copolymer dispersion wetting agent, 0.3 wt% antifoaming agent, 1.5 A putty of 71.5 wt% solids was prepared using wt% thickener, 45 wt% calcium carbonate, and 1.5 wt% titanium dioxide.

Comparative Example 3

<Production of Emulsion Binder>

Using a reactive modified alcohol ether phosphate emulsifier, 28% by weight butyl acrylate, 5% by weight 2-ethyl hexyl acrylate, 35% by weight isopropyl acrylate, 2% by weight acrylic acid, 25% by weight hexyl methacrylate, Emulsion binder E was synthesized by polymerizing a monomer mixture composed of 5% by weight of ethyl acrylate. The glass transition temperature of the said emulsion binder E was -25 degreeC, and solid content was 55 weight%. 6 wt% of benzophenone was added to the emulsion binder E.

Paint production

6.5 weight percent water, 43.6 weight percent emulsion binder E, 0.1 weight percent preservative, 0.8 weight percent cryostabilizer, 0.7 weight percent ammonium salt-based copolymer dispersion wetting agent, 0.3 weight percent antifoam, 1.5 in a paint mixing flask A putty of 71.5 wt% solids was prepared using wt% thickener, 45 wt% calcium carbonate, and 1.5 wt% titanium dioxide.

Comparative Example 4

<Production of Emulsion Binder>

30% by weight butyl acrylate, 8% by weight 2-ethyl hexyl acrylate, 30% by weight isopropyl acrylate, 2% by weight acrylic acid, normal hexyl methacrylate using non-reactive alkyl diphenyl ether disulfonate emulsifier The emulsion mixture F was synthesized by polymerizing a monomer mixture composed of 25% by weight and 5% by weight of ethyl acrylate. The glass transition temperature of the emulsion binder F was -29 ℃, solid content was 55% by weight. 0.6 wt% of benzophenone was added to the emulsion binder F.

Paint production

6.2 weight% water, 43.6 weight% emulsion binder F, 0.1 weight% preservative, 0.8 weight% freeze stabilizer, 1.0 weight% sodium salt copolymer dispersing agent, 0.3 weight% antifoam, 1.5 in a paint mixing flask A putty of 71.5 wt% solids was prepared using wt% thickener, 45 wt% calcium carbonate, and 1.5 wt% titanium dioxide.

The raw materials used in this experiment were preservatives such as benzoisothiazolone, ammonium salt-based copolymer dispersion wetting agent, SN-DISPERSANT 5029 from Sanofco Corporation, sodium salt-based copolymer dispersion wetting agent, SNOVPERSANT 44S from Sanofco Co. As the glycol and the antifoaming agent, polysiloxane-based, as the thickener, hydroxyethyl cellulose, and a 10 μm size heavy calcium carbonate were used.

The following experiment was conducted using the putty made through the examples and comparative examples.

Low temperature elongation

After the specimens were prepared in accordance with the KSF-3211 acrylic coating waterproofing standard, the shape of the dumbbell type No. 3 specified in the tensile test of KS M 6518 was produced, and the elongation at -20 ° C. was measured with a tensile tester.

The elongation measurement results were classified as follows.

60% or more: ◎ Excellent

40 ~ 50%: ○ Good

Less than 40%: lack of X effect

Room temperature elongation

After the specimens were prepared in accordance with the KSF-3211 acrylic coating waterproofing standards, the shape of the dumbbell type No. 3 specified in the tensile test of KS M 6518 was produced, and the elongation at room temperature -20 ℃ was measured with a tensile tester.

The elongation measurement results were classified as follows.

300% or more: ◎ Excellent

200 ~ 300%: ○ Good

Less than 200%: X

Weathering resistance

After putty was applied to the slate substrate and dried according to the method of KS M 6010 Class 1 Class 1, a accelerated weathering test of 300 hours was performed using a xenon-arc tester.

◎ Excellent: No choking and color change is not visually confirmed

○ Good: No choking but slight color change visually confirmed

X Poor: Choking occurs or color change is visually noticeable

Pollution resistance

After plastering with a 0.5 mm thick cement board on the cement board, it was immediately installed outdoors without drying time, and after 5 months, the change in pollution level was confirmed.

◎ Excellent: Contamination is not visually confirmed

○ Good: Visually low pollution

X Poor: Severe contamination due to stickiness of coating

Water resistance

After preparing the specimens in accordance with KSF-3211's acrylic coating waterproofing standards, cut the specimens to a length of 2cm in width and 10cm in length, and then immerse them in water to 5cm height, and then visually confirm the difference between the unimmersed and immersed parts after 5 hours. It was determined whether the shape of the specimen was deformed due to moisture absorption.

◎ Excellent: No deformation of specimen or less than 1mm of deformation

○ Good: Specimen deformation is within 2mm

X bad: Specimen deformation is more than 2mm

The experimental results are summarized in Table 1 below.

Table 1

* 1) Difficult to check for other contaminants due to severe yellowing

Referring to Table 1, it can be seen that when using the putty composition of the present invention, a putty coating film excellent in low temperature elongation, room temperature elongation, accelerated weather resistance, fouling resistance and water resistance was obtained as a whole.

However, in Comparative Example 1 in which the photoinitiator was not used, the contamination resistance and water resistance of the putty coating film were greatly decreased, and when the glass transition temperature of the acrylic emulsion binder was high (-10 ° C.), the elongation rate was greatly decreased. In addition, in the case of Comparative Example 3 in which the content of benzophenone was excessively high, the accelerated weather resistance and fouling resistance decreased, and when the acrylic emulsion binder was synthesized using a non-reactive emulsifier (Comparative Example 4), the water resistance greatly decreased.

Through the above experimental results, the high-elastic putty composition of the present invention retains its elasticity even in extreme winters and retains weatherability, stain resistance, and water resistance, so there is no problem in compatibility with the top coat even if the subsequent coating work is delayed due to climate change. It can be seen.

The present invention can be used for repairing exterior walls of buildings, concrete structures, and the like.

Claims (10)

30 to 60 wt% of an acrylic emulsion binder comprising a photoinitiator having an aromatic ketone structure and an acrylic resin,
The glass transition temperature (Tg) of the acrylic resin is -20 ℃ to -40 ℃, the acrylic resin is emulsion polymerized using a reactive emulsifier, the acrylic monomer forming the acrylic resin is an alkyl having an alkyl group of 4 or more carbon atoms At least 60 wt% or more of (meth) acrylate,
Further comprising 0.1 to 2% by weight of ammonium salt-based copolymer as a wet dispersant,
The content of the photoinitiator, the elastic putty composition, characterized in that 0.1 to 4% by weight based on the total weight of the acrylic emulsion binder. The elastic putty composition of claim 1, wherein the photoinitiator comprises at least one selected from the group consisting of benzophenone, benzyl and thioxanthone. delete The alkyl (meth) acrylate butyl acrylate, 2-ethylhexyl acrylate, isopropyl acrylate, normal hexyl acrylate, lauryl methacrylate and octyl decyl acryl according to Claim 1, Elastic putty composition, characterized in that it comprises at least one selected from the group consisting of a rate. The elastic putty composition of claim 1, wherein the acrylic monomer forming the acrylic resin contains at least 90 wt% or more of an alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms. The elastic putty composition of claim 1, wherein the reactive emulsifier comprises at least one selected from the group consisting of polyoxyethylene alkyl phosphate, ammonium polyoxyethylene alkyl sulfate, and reactive modified alcohol ether phosphate. delete According to claim 1, 30 to 60% by weight of inorganic filler, 1 to 20% by weight of water, 0.01 to 1% by weight of preservative, 0.1 to 2% by weight of cryostabilizer, 0.1 to 1% by weight of antifoam, 0.1 to 2% by weight of thickener and Elastic putty composition, characterized in that it further comprises 1 to 10% by weight of the pigment. Filling the elastic putty composition of any one of claims 1, 2, 4 to 6 and 8 at the damage site of the structure surface to form a putty coating film;
Exposing the putty coating film to natural light to harden a surface portion. 10. The method of claim 9, further comprising forming a top coat covering the putty coating.

Images