Coating Composition with Excellent Freeze Stability, Film prepared by the same and Construction Method Thereof

Abstract

The present invention relates to a paint composition having excellent freeze stability, a coating film using the same, and a method of applying the same. More specifically, the invention relates to a paint composition comprising ethylene vinyl acetate (EVA), polypropylene glycol (PPG), dioctyl sebacate (DOS), and the remainder being water; a method of applying the paint composition comprising the steps of applying the same to a substrate and drying; and a waterproof and radon-blocking coating film comprising ethylene vinyl acetate (EVA), polypropylene glycol (PPG), and dioctyl sebacate (DOS).

Description

Technology Field

[0001] The present invention relates to a paint composition having excellent freeze stability, a coating film using the same, and a method of application thereof. According to the present invention, the coating film having excellent freeze stability is not frozen at a temperature of 0°C or lower, and thus does not deteriorate in physical properties due to phase separation between water and paint components. The invention relates to a paint composition and a method of application thereof that can produce a coating film having excellent freeze stability. Background Technology

[0002] Since the exterior surfaces of typical buildings, such as rooftops, are easily exposed to rain and snow, inadequate waterproofing allows moisture to penetrate the walls and adversely affect the entire structure. In particular, the infiltrated moisture reduces the alkalinity of the concrete, which in turn accelerates the corrosion rate of the rebar.

[0003] In order to prevent such corrosion and protect construction and civil engineering structures from moisture, a waterproofing layer is generally applied. However, since water-soluble polymer emulsion paint compositions are based on water as a solvent, freezing occurs at low temperatures, for example, about 0°C, and due to this problem, there are limitations on the application of paint compositions at temperatures below 0°C.

[0004] Furthermore, even after thawing, the physical properties of the paint composition deteriorate compared to when it was frozen; once freezing occurs, the adhesion, flexibility, and durability of the paint decrease rapidly due to phase separation between the solvent (water) and other paint components even after thawing.

[0005] Therefore, as described in Patent Publication No. 10-2023-0048841, there are cases where antifreeze agents capable of lowering the freezing point are used, but these components have the problem of degrading adhesive properties or tensile properties at room temperature.

[0006] Accordingly, if a paint composition is provided that exhibits excellent freeze stability while maintaining excellent adhesive and tensile properties at room temperature, it is expected to be widely applied in related fields. The problem to be solved

[0007] One aspect of the present invention is to provide a paint composition having excellent freeze stability.

[0008] Another aspect of the present invention is to provide a coating film having water resistance and radon blocking properties.

[0009] Another aspect of the present invention is to provide a method for applying a paint composition having excellent freeze stability. means of solving the problem

[0010] According to one aspect of the present invention, a paint composition is provided comprising ethylene vinyl acetate (EVA), polypropylene glycol (PPG), dioctyl sebacate (DOS), and the remainder being water.

[0011] According to another aspect of the present invention, a waterproof and radon-blocking coating is provided, comprising ethylene vinyl acetate (EVA), polypropylene glycol (PPG), and dioctyl sebacate (DOS).

[0012] According to another aspect of the present invention, a method for applying a paint composition is provided, comprising the steps of: applying the paint composition of the present invention to a substrate; and drying. Effects of the invention

[0013] According to the present invention, an aqueous paint composition with a low freezing point is provided, and the aqueous paint composition of the present invention does not undergo freezing at 0°C; therefore, there is no deterioration in the physical properties of the paint composition due to phase separation after a change from a sub-zero temperature to a freezing temperature. Furthermore, the aqueous paint composition of the present invention exhibits excellent freeze stability with almost no change in physical properties, such as viscosity and tensile properties, before and after storage at sub-zero temperatures. Brief explanation of the drawing

[0014] Figure 1 shows a photograph of the condition of each paint composition of the example and comparative example after storing at -14°C for 24 hours. Figure 2 compares the viscosity of each paint composition of the example and comparative example after storing each paint composition at -14°C for 24 hours. Figure 3 shows the results of specifying the tensile strength of films prepared using each paint composition of the examples and comparative examples. Figure 4 shows the results of measuring the tensile strength of films prepared using the paint compositions after storing each paint composition of the examples and comparative examples at -14°C for 24 hours. Figure 5 shows the results of measuring the room temperature adhesion characteristics of films prepared using each paint composition of the examples and comparative examples. Figure 6 shows the results of measuring the adhesion characteristics of films prepared using the paint compositions after storing each paint composition of the examples and comparative examples at -14°C for 24 hours. Figure 7 schematically illustrates a radon blocking rate test apparatus using a bottle in which a paint composition is placed in a hole in the cap of a bottle containing a radon source to measure the radon blocking rate. Figure 8 shows the radon concentration in the chamber when each paint composition of the example and comparative example is used after being stored at -14°C for 24 hours. Figure 9 illustrates the process of measuring the adhesion strength of each paint composition for measuring adhesion strength. Specific details for implementing the invention

[0015] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0016] According to the present invention, a water-soluble polymer emulsion paint composition having excellent freeze stability is provided.

[0017] The paint composition of the present invention is an aqueous paint composition comprising ethylene vinyl acetate (EVA), polypropylene glycol (PPG), dioctyl sebacate (DOS), and the remainder being water.

[0018] More specifically, the paint composition comprises 10 to 50 weight% of ethylene vinyl acetate (EVA), 0.1 to 10 weight% of polypropylene glycol (PPG), 0.1 to 10 weight% of dioctyl sebacate (DOS), and the remainder being water, based on the total weight of the paint composition; preferably, it comprises 15 to 45 weight% of ethylene vinyl acetate (EVA), 1 to 7 weight% of polypropylene glycol (PPG), 1 to 7 weight% of dioctyl sebacate (DOS), and the remainder being water.

[0019] If the above ethylene vinyl acetate (EVA) is less than 10% by weight based on the total weight of the composition, there is a problem with reduced mechanical properties such as adhesion performance or tensile properties and waterproofing performance, and if it exceeds 50% by weight, there is a problem with workability due to increased viscosity. For example, the composition of the present invention contains 20 to 40% by weight of ethylene vinyl acetate (EVA) based on the total weight of the composition.

[0020] If the above polypropylene glycol (PPG) is less than 0.1% by weight based on the total weight of the composition, there is a problem with insufficient freeze-safety, and if it exceeds 10% by weight, it may be disadvantageous to mechanical properties such as adhesion performance or tensile properties of the paint. For example, the composition of the present invention contains 2 to 6% by weight of polypropylene glycol (PPG) based on the total weight of the composition.

[0021] If the above dioctyl sebacate (DOS) is less than 0.1% by weight based on the total weight of the composition, there is a problem that the physical properties of the paint composition deteriorate after storage at sub-zero temperatures, and if it exceeds 10% by weight, the tackiness of the paint increases excessively, causing the surface to become sticky and the paint film to not cure properly. For example, the composition of the present invention contains 2 to 6% by weight of dioctyl sebacate (DOS) based on the total weight of the composition.

[0022] Furthermore, the paint composition of the present invention may additionally include polyvinyl alcohol (PVA), and when polyvinyl alcohol (PVA) is additionally included, the physical properties of the paint composition may be further improved after storage at sub-zero temperatures, and the radon blocking performance may also be improved. In this case, the polyvinyl alcohol (PVA) may be included in an amount of 0.1 to 10 weight percent based on the weight of the total composition.

[0023] The paint composition of the present invention may have a viscosity of 100 cp to 500 cp at room temperature, for example, 25°C, for example, a viscosity of 150 to 400 cp.

[0024] Meanwhile, the use of the paint composition of the present invention is not particularly limited, but, for example, it can be used as a water-based paint composition for waterproofing and radon blocking.

[0025] The paint composition of the present invention described above has a simple application method and can be applied to building rooftops, building floors, building walls, roads, and various other building materials.

[0026] More specifically, the method of applying the paint composition of the present invention comprises the steps of: applying the paint composition of the present invention described above to a substrate; and drying, wherein all details regarding the paint composition described above are applied identically.

[0027] In the present invention, the application temperature of the step of applying the paint composition to a substrate may be -20°C to 50°C, for example, -15°C to 30°C. The paint composition of the present invention can be applied even at sub-zero temperatures and exhibits excellent freezing characteristics that prevent freezing, and thus is easy to store at sub-zero temperatures.

[0028] Meanwhile, the drying step may be performed by natural drying at room temperature for 6 to 24 hours, but is not limited thereto.

[0029] At this time, the substrate to which the composition of the present invention can be applied may be selected from the group consisting of cement, concrete, plastic, wood panel, sand, and gravel, but is not limited thereto, and for example, the substrate may include cases where there are cracks or gaps. That is, the application step may include a process of filling gaps present in the substrate.

[0030] As such, the paint composition of the present invention has the advantage of being easy to apply and capable of being applied even at sub-zero temperatures, making it easy to apply to buildings, building materials, etc.

[0031] According to another aspect of the present invention, a coating film produced by the paint composition of the present invention described above is provided.

[0032] More specifically, the coating film of the present invention may be a waterproof and radon-blocking coating film, and more specifically, may comprise ethylene vinyl acetate (EVA), polypropylene glycol (PPG), and dioctyl sebacate (DOS).

[0033] In the coating film of the present invention, the content of each component corresponds to the content calculated by excluding water from the content of the paint composition, but, for example, it may include 1 to 15 parts by weight of polypropylene glycol (PPG) and 1 to 15 parts by weight of dioctyl sebacate (DOS) based on 100 parts by weight of ethylene vinyl acetate (EVA), or 9 to 13 parts by weight of polypropylene glycol (PPG) and 9 to 13 parts by weight of dioctyl sebacate (DOS) based on 100 parts by weight of ethylene vinyl acetate (EVA).

[0034] As such, according to the present invention, a water-based paint composition having a low freezing point is provided, even though it is a water-soluble polymer emulsion paint using water as a solvent. The water-based paint composition of the present invention does not undergo freezing at sub-zero temperatures, and therefore, no deterioration in the physical properties of the paint due to phase separation occurs after thawing. Furthermore, the water-based paint composition of the present invention shows almost no change in physical properties, such as changes in viscosity and tensile properties, before and after freezing.

[0035] The present invention will be explained in more detail below through specific embodiments. The following embodiments are merely examples to aid in understanding the present invention and do not limit the scope of the present invention.

[0036] Examples

[0037] 1. Method for manufacturing a paint composition

[0038] After pre-stirring an equal amount of water with an ethylene vinyl acetate (EVA) emulsion (solid content 45 wt%) at a speed of 1,000 rpm for 10 minutes using a centrifugal mixer, polyvinyl alcohol (PVA), polypropylene glycol (PPG), and dioctyl sebacate (DOS) were added according to the amounts in Table 1 below, and each was stirred at a speed of 1,000 rpm for 10 minutes.

[0039] Sample name EVA (wt%) Water (wt%) PPG PVA DOS Comparative Example 1 E 50 50 - - - Comparative Example 2 EG 50 50 3 phr - - Comparative Example 3 EV 50 50 - 3 phr - Comparative Example 4 ED 50 50 - - 3 phr Comparative Example 5 EGV 50 50 3 phr 3 phr - Comparative Example 6 EVD 50 50 - 3 phr 3 phr Example 1 EGD 50 50 3 phr - 3 phr Example 2 EGVD 50 50 3 phr 3 phr 3 phr

[0040] In the table above, wt% is a weight percentage based on the total weight of EVA and water, and phr represents a weight part per 100 parts by weight of total EVA and water.

[0041] 2. Verification of freezing characteristics

[0042] The paint compositions of Comparative Examples 1 to 6 and Examples 1 and 2 prepared in 1. above were stored at -14°C for 24 hours, and the state of the emulsion was checked. For convenience, the cases before and after storing the paint composition at -14°C for 24 hours in the following examples may be mutually referred to as “before freezing” and “after freezing,” respectively.

[0043] As a result, as can be seen in Figure 1, no freezing phenomenon occurred in the samples of Comparative Example 2, Comparative Example 5, Example 1, and Example 2 even after being stored at -14℃ for 24 hours, whereas it was confirmed that the samples of Comparative Example 1, 3, 4, and 6 were completely frozen after being frozen for 24 hours.

[0044] 3. Verification of viscosity characteristics

[0045] The paint compositions that did not exhibit freezing phenomena in Section 2 above were each divided into 50g portions, and their viscosity was measured. To measure the viscosity, the experiment was conducted using a BROOKFIELD LVDV-IT+ Digital viscometer. All compositions were tested using spindle No. 7, and the viscosity was measured at 25°C while adjusting the rpm. The results are shown in Table 2 and Figure 2 below.

[0046] Sample name Before storing at -14℃ After storing at -14℃ Comparative Example 2 EG 200 200 Comparative Example 5 EGV 216 218 Example 1 EGD 214 215 Example 2 EGVD 222 223

[0047] (Unit: cp)

[0048] As a result, it was confirmed that the paint composition that did not exhibit freezing phenomena showed no significant difference in viscosity before and after storage at -14℃ for 24 hours.

[0049] 4. Verification of tensile properties

[0050] (1) Preparation of a sample film using a paint composition

[0051] 1) Experimental Example 1 - Room Temperature Storage

[0052] Using the paint compositions of Comparative Examples 1 to 6 and Examples 1 and 2 prepared in 1. above, a film shape was formed by casting using a glass frame with dimensions of 2.5 cm in width, 7.5 cm in height, and 0.1 cm in thickness, and the final film shape was prepared by drying at room temperature.

[0053] 2) Experimental Example 2 - Sub-zero storage

[0054] The paint compositions of Comparative Examples 1 to 6 and Examples 1 and 2 prepared in 1. above were stored at -14°C for 24 hours, then formed into a film shape by casting using a glass frame with dimensions of 2.5 cm in width, 7.5 cm in height, and 0.1 cm in thickness, and dried at room temperature to produce a final film shape.

[0055] (2) Tensile strength

[0056] Specimens were prepared for each composition of Experimental Example 1 and Experimental Example 2 according to ASTM D638 standards, and tensile strength was measured using a universal testing machine (UTM, Instron 5982, Norfolk, MA, USA) under conditions of a load range of 100 kN and a speed of 50 mm / min. The results of Experimental Example 1 are shown in Fig. 3, and the results of Experimental Example 2 are shown in Fig. 4.

[0057] As can be seen in Fig. 3, it was confirmed that the tensile strength of the paint compositions of Comparative Examples 3, 5, and 6 and Examples 1 and 2 was excellent.

[0058] However, as can be seen in Figure 4, the samples of Comparative Examples 1, 3, 4, and 6 were completely frozen after being stored at -14°C for 24 hours, making it impossible to measure the tensile strength, and in the case of Comparative Examples 2 and 5, the tensile strength decreased, but in the samples of Examples 1 and 2, it was confirmed that there was no change in tensile strength before and after being stored at -14°C for 24 hours.

[0059] (3) Adhesion characteristics

[0060] To measure the adhesion strength of each composition of Experimental Example 1 and Experimental Example 2, a two-component epoxy adhesive was used, and the curing temperature was 23 ± 2℃ and the humidity was 50 ± 5% for 4 days. The resin and hardener were mixed in a weight ratio of 1:1 and applied, and the adhesion strength was measured at a speed of 1 MPa / s using DeFelsko's ATM 20 instrument.

[0061] FIG. 9 illustrates the process of measuring the adhesion strength of each paint composition. First, each paint composition was applied to a base surface (1), and an adhesive was applied to the bottom surface of the dolly (2). Then, a dolly was attached to a test piece formed using each paint composition (3), and after placing equipment on each test piece, the adhesion strength was measured.

[0062] The results of Experimental Example 1 are shown in Fig. 5, and the results of Experimental Example 2 are shown in Fig. 6.

[0063] As can be seen in Figure 5, it was confirmed that the adhesion characteristics were excellent in the paint compositions excluding Comparative Examples 2 and 5.

[0064] However, as can be seen in Figure 6, the samples of Comparative Examples 1, 3, 4, and 6 were completely frozen after being stored at -14°C for 24 hours, making it impossible to measure the adhesion strength, and in the case of Comparative Examples 2 and 5, the adhesion strength decreased significantly, whereas in the samples of Examples 1 and 2, it was confirmed that there was no significant change in adhesion strength before and after being stored at -14°C for 24 hours.

[0065] (4) Radon blocking properties

[0066] 20 g of soil with a high radon emission concentration was placed in white media bottles and used as a radon source. The holes were coated on the lids of media bottles having circular holes with a diameter of 5 mm using paint compositions of Comparative Example 2 and Comparative Example 5 obtained in Experimental Example 2 and Examples 1 and 2 of the present invention as radon shielding agents to block the holes, and then air-dried for 24 hours.

[0067] After drying each bottle of media was placed in a small acrylic chamber equipped with a radon measuring device (Radon eye plus 2), the radon blocking rate was measured for 7 days by checking for gas leakage to confirm that it was completely sealed.

[0068] Figure 7 is an image schematically showing the experimental process.

[0069] A case in which a circular hole with a diameter of 5 mm in the cap of the media bottle was not coated with emulsion, causing radon from the white media bottle to be released directly and approximately 650 Bq / m³ of radon was detected over 7 days, was used as a control.

[0070] As a result, as shown in Figure 8, radon levels of 320, 290, 135, and 90 Bq / m³ were measured after 7 days for Comparative Example 2 (EG), Comparative Example 5 (EGV), Example 1 (EGD), and Example 2 (EGVD), respectively, confirming that the radon concentration in the chamber was lowest when using the paint compositions of Examples 1 and 2.

[0071] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be obvious to those skilled in the art that various modifications and variations are possible within the scope of the technical concept of the present invention as described in the claims.

Claims

Claim 1 A paint composition comprising ethylene vinyl acetate (EVA), polypropylene glycol (PPG), dioctyl sebacate (DOS), and the remainder being water. Claim 2 The paint composition according to claim 1, wherein the paint composition comprises 10 to 50 weight% of ethylene vinyl acetate (EVA), 0.1 to 10 weight% of polypropylene glycol (PPG), 0.1 to 10 weight% of dioctyl sebacate (DOS), and the remainder being water, based on the weight of the total paint composition. Claim 3 A paint composition according to claim 1, wherein the paint composition further comprises polyvinyl alcohol (PVA). Claim 4 A paint composition according to claim 3, wherein the polyvinyl alcohol (PVA) is included in an amount of 0.1 to 10 weight percent based on the weight of the total composition. Claim 5 In claim 1, the paint composition is a water-based paint composition for waterproofing and radon blocking. Claim 6 A waterproof and radon-blocking coating film comprising ethylene vinyl acetate (EVA), polypropylene glycol (PPG), and dioctyl sebacate (DOS). Claim 7 A waterproof and radon-blocking coating according to claim 6, comprising 1 to 15 parts by weight of polypropylene glycol (PPG) and 1 to 15 parts by weight of dioctyl sebacate (DOS) based on 100 parts by weight of ethylene vinyl acetate (EVA). Claim 8 A method for applying a paint composition comprising the steps of: applying a paint composition of any one of claims 1 to 5 to a substrate; and drying. Claim 9 A method for applying a paint composition according to claim 8, wherein the application temperature of the step of applying the paint composition to a substrate is -20℃ to 50℃. Claim 10 A method for applying a paint composition, wherein the drying step in claim 8 is performed by natural drying for 1 to 24 hours.

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