Environmentally friendly polyurethane paint composition for concrete floors containing a primer composition

Abstract

The eco-friendly polyurethane-based paint composition for concrete floors according to the present invention has excellent mechanical properties such as abrasion resistance and impact resistance, excellent chemical properties such as water resistance and weather resistance, and significantly reduced moisture permeability, thereby enabling the maintenance of excellent initial performance over a long period. In addition, it reduces volatile organic compounds, resulting in excellent workability and work stability.

Description

Technology Field

[0001] The present invention relates to an eco-friendly polyurethane-based paint composition for concrete floors comprising a primer composition, and more specifically, to a paint composition comprising a primer composition for applying to a concrete floor to install a flooring material. Background Technology

[0003] In the modern construction and civil engineering industries, the role of coatings in improving the durability, wear resistance, weather resistance, and aesthetics of concrete floors is becoming increasingly important. In particular, there is a demand for technologies that extend the lifespan of concrete floors and minimize wear and chemical damage in various external environments through high-strength and high-durability coatings.

[0004] Conventional coatings for concrete floors have primarily utilized organic solvent-based agents. While these coatings offer excellent physical properties and durability, they contain large amounts of volatile organic compounds (VOCs), posing serious environmental and worker health risks. Specifically, VOCs are released into the atmosphere, causing pollution, and volatile substances within workspaces increase fire hazards and the potential for worker poisoning. Consequently, the development of eco-friendly coatings that minimize or replace organic solvents has emerged as an urgent task; however, there are significant industrial limitations, such as the degradation of mechanical and chemical properties.

[0005] Recently, research and development on water-based polyurethane paints aimed at reducing VOCs have been underway. Water-based paints can significantly reduce VOC emissions by replacing organic solvents with water, offering major advantages not only in environmental protection but also in improving working environments and regulatory compliance.

[0006] However, water-based paints have the following limitations. When water is used as a solvent, there is a possibility that physical properties such as film strength, abrasion resistance, and weather resistance may deteriorate compared to organic solvent-based paints. Additionally, paints containing water may take longer to dry, and the curing speed can be even slower in high-humidity environments, leading to reduced workability and causing difficulties in reproducing required physical properties.

[0007] Therefore, research is needed on eco-friendly polyurethane-based paint compositions for concrete floors that can effectively reduce VOCs while possessing excellent mechanical and chemical properties. Prior art literature

[0008] Korean Registered Patent Publication No. 10-1335571 (2013.11.26) The problem to be solved

[0009] The objective of the present invention is to provide an eco-friendly polyurethane-based paint composition for concrete floors that can effectively reduce volatile organic compounds while possessing excellent mechanical and chemical properties.

[0010] The specific objective of the present invention is to provide an eco-friendly polyurethane-based paint composition for concrete floors that has excellent mechanical properties, such as wear resistance and impact resistance.

[0011] Another specific objective of the present invention is to provide an eco-friendly polyurethane-based paint composition for concrete floors that has excellent chemical properties such as water resistance and weather resistance, and can maintain excellent initial performance for a long period of time by significantly reducing moisture permeability.

[0012] Another specific objective of the present invention is to provide an eco-friendly polyurethane-based paint composition for concrete floors that reduces volatile organic compounds and offers excellent workability and work stability. means of solving the problem

[0013] The polyurethane-based paint composition for concrete floors according to the present invention comprises a primer composition comprising castor oil, cement, crystalline silicon dioxide-based mineral particles, an isocyanate-based compound, an alcohol-based crosslinking agent, and water.

[0014] In one example of the present invention, the primer composition may comprise 10 to 20 weight% of the castor oil, 30 to 40 weight% of the cement, 5 to 15 weight% of the crystalline silicon dioxide-based mineral particles, 20 to 30 weight% of the isocyanate-based compound, 1 to 10 weight% of the alcohol-based crosslinking agent, and 1 to 10 weight% of water.

[0015] In one example of the present invention, the cement may contain 0.5 weight% or less of iron oxide, 5 weight% or less of magnesium oxide, and 3.5 weight% or less of sulfur oxide.

[0016] A polyurethane-based paint composition for concrete floors according to one example of the present invention may further include a lining composition, wherein the lining composition comprises castor oil, cement, crystalline silicon oxide-based mineral particles, amorphous silicon oxide-based synthetic particles, an isocyanate-based compound, and an alcohol-based crosslinking agent.

[0017] In one example of the present invention, the lining composition may comprise 15 to 25 weight% of the castor oil, 1 to 10 weight% of the cement, 5 to 15 weight% of the crystalline silicon dioxide-based mineral particles, 25 to 35 weight% of the amorphous silicon dioxide-based synthetic particles, 10 to 20 weight% of the isocyanate-based compound, and 1 to 5 weight% of the alcohol-based crosslinking agent.

[0018] In one example of the present invention, the lining composition may further include any one or more selected from zeolite-based molecular sieves and calcium carbonate particles.

[0019] In one example of the present invention, the lining composition may further include one or more selected from 1 to 10 weight% of the zeolite-based molecular sieve and 10 to 15 weight% of the calcium carbonate particles.

[0020] In one example of the present invention, the average particle size of the crystalline silicon oxide-based mineral particles, the amorphous silicon oxide-based synthetic particles, and the zeolite-based molecular sieve may be 100 to 500 μm independently of each other.

[0021] In one example of the present invention, the calcium carbonate particles may have an average particle size of 2 to 20 μm and a VO oil absorption amount of 10 to 80 ml / 100 g.

[0022] In one example of the present invention, the isocyanate compound may have an NCO content of 30 to 32% and a viscosity of 100 to 600 cps (at 25°C, 1 atm).

[0023] In one example of the present invention, the isocyanate compound may include methylene diphenyl diisocyanate.

[0024] In one example of the present invention, the alcohol-based crosslinking agent may have a molecular weight of 50 to 150 g / mol or an OH value of 300 to 500 mgKOH / g.

[0025] In one example of the present invention, the alcohol-based crosslinking agent may include a triol-based compound.

[0026] In one example of the present invention, the triol-based compound may include polypropylene triol.

[0027] In one example of the present invention, the primer composition or the lining composition may further include one or more selected from plasticizers, film-forming agents, and defoaming agents.

[0028] In one example of the present invention, the primer composition or the lining composition may further comprise one or more selected from 5 to 25 weight% of the plasticizer, 0.1 to 1 weight% of the film-forming agent, and 1 to 5 weight% of the defoaming agent.

[0029] In one example of the present invention, the lining composition may further comprise composite mineral particles, wherein the castor oil is a first castor oil, and the composite mineral particles may comprise atapulgite particles having internal pores; and a second castor oil filled into the internal pores.

[0030] In one example of the present invention, in the composite mineral particles, the second castor oil may also be applied to the surface of the composite mineral particles.

[0031] In one example of the present invention, the composite mineral particles may satisfy the following Formula 1. In Formula 1 below, V T is the total volume of the internal pores of the atapulgite particle, and V I is the total volume of the second castor oil filled into the internal pores above.

[0032] [Equation 1]

[0033] 0.2≤V I / V T ≤0.6

[0034] In one example of the present invention, the second castor oil in the composite mineral particles may be filled at a rate of 0.2 to 0.7 g per 1 g of atapulgite particles.

[0035] In one example of the present invention, the average particle size of the atapulgite particles in the composite mineral particles may be 5 to 100 μm.

[0036] In one example of the present invention, the composite mineral particles may further include a carbon coating layer formed by plasma treatment on the internal pore surface of the atapulgite particles.

[0037] In one example of the present invention, the average thickness of the carbon coating layer in the composite mineral particles may be 1 to 10 nm.

[0038] In one example of the present invention, the composite mineral particles may be manufactured by including a filling step of mixing atapulgite particles and second castor oil, and then obtaining atapulgite particles with second castor oil filled on the surface of the internal pores.

[0039] In one example of the present invention, during the filling step for manufacturing the composite mineral particles, mixing may be performed while ultrasonic waves are applied.

[0040] In one example of the present invention, during the filling step for manufacturing the composite mineral particles, mixing may be performed at a temperature of 50 to 90°C and a pressure of 2 to 10 atm.

[0041] In one example of the present invention, the composite mineral particles may be manufactured by further including a surface modification step prior to the filling step, wherein the atapulgite particles are plasma treated under a carbon gas supply to form a carbon coating layer on the internal pore surface of the atapulgite particles.

[0042] In one example of the present invention, in the surface modification step when manufacturing the composite mineral particles, the plasma output may be 30 to 300 W, the plasma treatment time may be 3 to 20 minutes, the carbon gas supply rate may be 5 to 100 sccm, and the pressure may be 0.001 to 1 mTorr.

[0043] The polyurethane-based coating film for concrete floors according to the present invention can be formed from the paint composition.

[0044] The polyurethane-based coating film for concrete floors according to the present invention comprises a primer layer formed from the primer composition of the paint composition.

[0045] A polyurethane-based coating for a concrete floor according to one example of the present invention may further include a lining layer laminated on the primer layer, and the lining layer is formed from the lining composition of the paint composition.

[0046] In one example of the present invention, the average thickness of the primer layer may be 20 to 200 μm, and the average thickness of the lining layer may be 0.5 to 8 mm. Effects of the invention

[0047] The eco-friendly polyurethane-based paint composition for concrete floors according to the present invention has the effect of excellent mechanical properties such as wear resistance and impact resistance.

[0048] In addition, the eco-friendly polyurethane-based paint composition for concrete floors according to the present invention has excellent chemical properties such as water resistance and weather resistance, and has the effect of maintaining excellent initial performance for a long period of time by significantly reducing moisture permeability.

[0049] In addition, the eco-friendly polyurethane-based paint composition for concrete floors according to the present invention has the effect of reducing volatile organic compounds, thereby providing excellent workability and work stability. Brief explanation of the drawing

[0050] Figure 1 schematically illustrates a coating film formed from a polyurethane-based paint composition for concrete floors according to the present invention. FIG. 2 is a schematic flowchart illustrating a method for manufacturing composite mineral particles, which are a component of a polyurethane-based paint composition for concrete floors according to an example of the present invention. FIG. 3 is a schematic diagram showing the internal state of a composite mineral particle, which is a component of a polyurethane-based paint composition for concrete floors according to an example of the present invention. FIGS. 4 and FIGS. 5 respectively show the measurement results for the TVOC, toluene, and formaldehyde emissions of the primer (undercoat) composition and the lining (intermediate) composition of a polyurethane-based paint composition for concrete floors according to an example of the present invention. Specific details for implementing the invention

[0051] An eco-friendly polyurethane-based paint composition for concrete floors comprising a primer composition according to the present invention will be described in detail below with reference to the attached drawings.

[0052] The drawings described in this specification are provided as examples to ensure that the concept of the present invention is sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented and may be embodied in other forms, and the drawings may be exaggerated to clarify the concept of the present invention.

[0053] Unless otherwise defined, technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art to which this invention pertains, and descriptions of known functions and configurations that could unnecessarily obscure the essence of the invention are omitted in the following description and accompanying drawings.

[0054] The background technology described in this specification is technical information that the inventor possessed or acquired during the process of deriving the present invention, and it cannot be considered as prior art disclosed to the general public prior to the filing of the present invention.

[0055] In some cases in this specification, known structures and devices may be omitted or illustrated in the form of block diagrams focusing on the core functions of each structure and device to avoid obscuring the concept of the invention.

[0056] Expressions such as "comprising," "containing," "having," and "characteristics" mentioned in this specification are open-ended descriptions having equivalent meanings and do not exclude elements, materials, or processes not additionally listed.

[0057] Unless otherwise specifically indicated, the singular form of a term used in this specification may be interpreted to include the plural form.

[0058] When a component such as a 'membrane', 'film', 'layer', or 'region' mentioned in this specification is described as being on or above another component (e.g., lamination), this includes not only cases where it is directly above in contact with the other component, but also cases where another component is interposed in between.

[0059] The term “layer” as used in this specification means that each material forms a continuum and has a dimension in which the thickness is relatively small compared to the width and length. Accordingly, the term “layer” in this specification should not be interpreted as a two-dimensional flat plane.

[0060] The term “line” as used in this specification means that each material forms a continuum and has dimensions in which the width and height are relatively small compared to the length.

[0061] The numerical ranges used in this specification include lower and upper limits and all values ​​within the range, increments logically derived from the form and width of the defined range, all of which are limited values, and all possible combinations of upper and lower limits of numerical ranges defined in different forms. Additionally, unless specifically defined in the specification of this invention, values ​​outside the numerical range that may occur due to experimental error or rounding are also included in the defined numerical ranges.

[0062] In this specification, the unit '%' used without special mention means 'weight%' unless otherwise defined.

[0064] The polyurethane-based paint composition for concrete floors according to the present invention comprises a primer composition and, preferably, may further comprise a lining composition. Furthermore, according to a preferred example, the present invention provides a coating film, i.e., a polyurethane-based coating film for concrete floors, in which a primer layer and a lining layer are laminated as shown in FIG. 1, by sequentially applying and drying the primer composition and the lining composition onto a substrate.

[0065] As such, the coating film formed by the composition according to the present invention has excellent mechanical properties such as wear resistance and impact resistance, and chemical properties such as water resistance and weather resistance, as each composition includes specific components described below, and has the effect of maintaining excellent initial performance for a long period, and has the effect of reducing volatile organic compounds, thereby providing excellent workability and work stability.

[0066] Hereinafter, a polyurethane-based paint composition for concrete floors according to the present invention is described in detail.

[0067] The polyurethane-based paint composition for concrete floors according to the present invention comprises a primer composition. The primer composition comprises castor oil, cement, crystalline silicon dioxide-based mineral particles, an isocyanate-based compound, an alcohol-based crosslinking agent, and water. Additionally, the polyurethane-based paint composition for concrete floors according to a preferred embodiment of the present invention may further comprise a lining composition. The lining composition comprises castor oil, cement, crystalline silicon dioxide-based mineral particles, amorphous silicon dioxide-based synthetic particles, an isocyanate-based compound, and an alcohol-based crosslinking agent.

[0068] The paint composition according to the present invention is a polyurethane-based paint composition, wherein during the process of applying and constructing the paint composition onto a substrate, an isocyanate-based compound and an alcohol-based crosslinking agent undergo a polymerization reaction to form urethane bonds, thereby forming a paint film.

[0069] Specifically, the isocyanate-based compound is a compound capable of forming a polyurethane and reacting with the alcohol-based crosslinking agent to generate urethane bonds. Preferably, a diisocyanate having two isocyanate groups (OCN-) or more polyisocyanates is used so that the polymer formed by polymerization can form a linear or three-dimensional network structure. Preferably, the isocyanate-based compound may be used having an NCO content of 30 to 32% and / or a viscosity of 100 to 600 cps (at 25°C, 1 atm). As a preferred example, the isocyanate-based compound may include methylene diphenyl diisocyanate.

[0070] The above alcohol-based crosslinking agent forms a polyurethane and is a compound capable of forming urethane bonds by reacting with the above isocyanate-based compound. Preferably, it is a polyhydric alcohol having two or more hydroxyl groups (OH-) so that the polymer formed by polymerization can form a linear or three-dimensional network structure. Preferably, the above alcohol-based crosslinking agent may be used having a molecular weight of 50 to 150 g / mol or an OH value of 300 to 500 mgKOH / g. As a preferred example, the above alcohol-based crosslinking agent may include a triol-based compound, and for example, the above triol-based compound may include polypropylene triol.

[0071] The above castor oil is a fatty acid compound containing multiple OH groups, and by polymerizing with an isocyanate compound to form cross-links, it can increase the elasticity of the coating film, thereby minimizing cracking and peeling and mitigating damage to the coating film caused by wear.

[0072] The above cement can be included in the composition along with other components to enhance surface hardness. As a preferred example, the cement is preferably a cement containing 0.5 weight% or less of iron oxide, 5 weight% or less of magnesium oxide, and 3.5 weight% or less of sulfur oxide. If these conditions are met, the color can be kept bright, uniform physical properties such as durability and chemical resistance can be secured, and cracks caused by expansion during construction can be prevented. Furthermore, by satisfying the cement content described below, appropriate surface strength can be achieved while simultaneously preventing the occurrence of cracks due to excessive hardness.

[0073] The above-mentioned crystalline silicon oxide-based mineral particles can improve mechanical strength, such as wear resistance and impact resistance, by being included in the composition. A specific example of the above-mentioned crystalline silicon oxide-based mineral particles may refer to quartz particles, which are a natural mineral called quartz.

[0074] The above-mentioned amorphous silicon oxide-based synthetic particles are components distinct from the above-mentioned crystalline silicon oxide-based mineral particles, such as silica fume, precipitated silica, colloidal silica, and silica gel. By using these amorphous silicon oxide-based synthetic particles together with other components, the density of the coating film can be increased, chemical resistance can be strengthened, and impact resistance can be improved.

[0075] The compositional ratio of the above composition can be appropriately controlled to a level capable of realizing the aforementioned effects, and as a preferred example, it may be as follows. As a preferred example, the primer composition may comprise 10 to 20 weight% of the castor oil, 30 to 40 weight% of the cement, 5 to 15 weight% of the crystalline silicon oxide-based mineral particles, 20 to 30 weight% of the isocyanate-based compound, 1 to 10 weight% of the alcohol-based crosslinking agent, and 1 to 10 weight% of the water. As a preferred example, the lining composition may comprise 15 to 25 weight% of the castor oil, 1 to 10 weight% of the cement, 5 to 15 weight% of the crystalline silicon oxide-based mineral particles, 25 to 35 weight% of the amorphous silicon oxide-based synthetic particles, 10 to 20 weight% of the isocyanate-based compound, and 1 to 5 weight% of the alcohol-based crosslinking agent. If these compositional ratios are satisfied, the aforementioned effects can be realized more effectively.

[0076] The above primer composition is eco-friendly as it contains water, allows for easy control of high viscosity and drying time, and offers excellent workability due to superior work safety.

[0077] The above lining composition may further include one or more selected from zeolite-based molecular sieves and calcium carbonate particles in terms of improving mechanical properties such as wear resistance and durability, and chemical properties such as weather resistance. When the zeolite-based molecular sieves or calcium carbonate particles are used, the zeolite-based molecular sieves may be included in the lining composition at 1 to 10 weight%, and the calcium carbonate particles may be included in the lining composition at 10 to 15 weight%.

[0078] When the above zeolite-based molecular sieve is included in the composition and used together with other components, it forms a uniform structure, thereby providing impact energy dispersion and chemical stability, which can mitigate local damage caused by impact.

[0079] When the calcium carbonate particles are included in the composition and used together with other components, they can support the strength and shock absorption capacity of the coating film by reinforcing the polyurethane matrix of the coating film and improving crack resistance. In a preferred example, the calcium carbonate particles may have an average particle size of 2 to 20 μm and a VO oil absorption capacity of 10 to 80 ml / 100 g.

[0080] The average particle size of the crystalline silicon oxide-based mineral particles, the amorphous silicon oxide-based synthetic particles, and the zeolite-based molecular sieve may be independently 100 to 500 μm. If this is satisfied, the aforementioned effects can be realized more effectively.

[0081] The primer composition or the lining composition may further include one or more additives selected from plasticizers, film-forming agents, and defoaming agents. When the additives are used, the primer composition or the lining composition may further include one or more selected from 5 to 25 weight% of the plasticizer, 0.1 to 1 weight% of the film-forming agent, and 1 to 5 weight% of the defoaming agent. Specific examples of the plasticizer include dioctyl terephthalate, trimethylfentanyl diisobutylate, etc., specific examples of the film-forming agent include dicarboxylic acid esters, etc., and specific examples of the defoaming agent include isoparaffins, etc.

[0082] As a preferred example, the primer composition or the lining composition may further include composite mineral particles described below. As will be further explained below, the composite mineral particles improve the wear resistance and durability of the coating surface and reduce moisture penetration, thereby improving weather resistance and the duration of initial performance.

[0083] Specifically, as illustrated in FIG. 3, the composite mineral particles may include atapulgite particles containing internal pores; and a second castor oil filled into the internal pores. Here, the castor oil filled into the internal pores of the atapulgite particles is defined as the second castor oil to distinguish it from the castor oil of the primer composition and the lining composition, and the castor oil of the primer composition and the lining composition is defined as the first castor oil.

[0084] When atapulgite particles containing a second castor oil filled in the internal pores, i.e., the composite mineral particles, are included in a composition containing an isocyanate-based compound, the isocyanate-based compound can penetrate to some extent into the internal pores of the atapulgite particles. By polymerizing with the second castor oil filled in the internal pores, the atapulgite particles, i.e., the composite mineral particles, can form a more robust bond within the polyurethane matrix. Furthermore, since the internal pores of the atapulgite particles are filled with castor oil, the elasticity increases, which can also significantly improve the impact resistance of the coating film.

[0085] Additionally, preferably, the second castor oil may also be applied to the surface of the composite mineral particles; that is, the second castor oil may also be coated on the surface of the composite mineral particles (atapulgite particles). Specifically, the preferred composite mineral particles may comprise: atapulgite particles containing internal pores; and second castor oil coated on the surface of the atapulgite particles and filled into the internal pores of the atapulgite particles. Accordingly, during the film formation process, the bonding strength may be further enhanced by the second castor oil on the particle surface polymerizing with an isocyanate-based compound. This achieves an overall enhancement of mechanical and chemical properties such as durability, weather resistance, wear resistance, and impact resistance.

[0086] The above-mentioned attapulgite particles are natural clay mineral particles, porous mineral particles composed primarily of magnesium and aluminum silicate. They possess a unique crystal structure and internal pores; in particular, by filling the internal pores, which have a high surface area, with secondary castor oil, a polymerization reaction with isocyanate-based compounds can be expected. The internal pores may include mesoporous and some microporous pores, and the surface area of ​​the internal pores is, for example, 100 to 400 m² 2 / g, specifically 150 to 300 m 2 / g. The shape of the internal pores is tubular, and the atapulgite particles may have internal pores with a tubular structure, and through these long, continuous channels, the second castor oil is filled with a wide specific surface area structure.

[0087] The average particle size of the above attapulgite particles is such that the mechanical and chemical properties of the coating film can be secured and it can be formed uniformly; for example, it may be preferable to be 5 to 100 μm. If this is satisfied, by securing an appropriate diffusion path and an appropriate internal pore surface area of ​​the second castor oil in the composite mineral particle manufacturing process described later, the filling area of ​​the second castor oil on the internal pore surface can be increased, and damage to the pore structure and decrease in physical stability due to increased service time of the coating film can be minimized.

[0088] As a preferred example, the above composite mineral particles may satisfy the following Equation 1. In the following Equation 1, V T is the total volume of the internal pores of the atapulgite particle, and V I is the total volume of the second castor oil filled into the internal pores. Here, V I / V T represents the filling rate as the total volume of the second castor oil filled relative to the total volume of the internal pores.

[0089] [Equation 1]

[0090] 0.2≤V I / V T ≤0.6

[0091] When the above composite mineral particles satisfy Equation 1, that is, the second castor oil may be filled at a volume percentage of 20 to 60 percent relative to the total volume of the internal pores of the particles. As a specific example, in the above composite mineral particles, the second castor oil may be filled at a rate of 0.2 to 0.7 g per 1 g of the atapulgite particles. In particular, when filling is performed in a high temperature and high pressure atmosphere during the filling step when manufacturing the composite mineral particles described later, the filling rate of Equation 1 may be improved.

[0092] As a more preferred example, the internal pore surface of the atapulgite particles may further include a carbon coating layer formed by plasma treatment. Specifically, the internal pore surface of the atapulgite particles is hydrophilic, which may result in weak penetration of the lipophilic second castor oil into the internal pores and weak bonding strength with the internal pore surface. Therefore, by modifying the internal pore surface of the atapulgite particles to be lipophilic, the bonding strength between the internal pore surface and the second castor oil can be significantly improved.

[0093] The average thickness of the carbon coating layer may be, for example, 1 to 10 nm. If this is satisfied, the aforementioned effect can be realized.

[0094] When the above composite mineral particles are used, the composition may contain, for example, 1 to 10 weight percent of the above composite mineral particles. If this is satisfied, excellent mechanical and chemical properties of the coating film as described above can be secured.

[0095] Below, the method for manufacturing the above-mentioned composite mineral particles is described in detail.

[0096] The above composite mineral particles can be manufactured by including a filling step of mixing atapulgite particles and second castor oil, and then obtaining atapulgite particles with second castor oil filled on the surface of the internal pores.

[0097] The filling step described above is a step of supporting the second castor oil in the internal pores of the atapulgite particles, and can be performed by mixing the atapulgite particles and the second castor oil. Here, it is preferable that the mixing be performed under conditions where ultrasound is applied. If this is satisfied, the conductive polymer solution can penetrate better into the internal pores of the particles, thereby increasing the coating area and coating rate. Additionally, it is preferable that the mixing be performed at a temperature higher than room temperature and / or a pressure higher than atmospheric pressure. If this is satisfied, the second castor oil can penetrate better into the internal pores of the particles. As a preferred example, the temperature may be 50 to 90°C, and the pressure may be 2 to 10 atm.

[0098] As described above, since the penetration level of the second castor oil can be significantly improved through surface modification via plasma treatment, the composite mineral particles may be manufactured by further including a surface modification step prior to the filling step, wherein the atapulgite particles are plasma-treated under a carbon gas supply to form a carbon coating layer on the surface of the internal pores of the atapulgite particles. The modified atapulgite particles manufactured here are used in the filling step.

[0099] Accordingly, the surface modification step is a step of modifying the surface to be lipophilic by forming a carbon coating layer on the surface of the internal pores of the atapulgite particles, and is performed by plasma treating the atapulgite particles under a carbon gas supply.

[0100] Specific conditions for the plasma treatment performed in the above surface modification step include a plasma output of 30 to 300 W, a plasma treatment time of 3 to 20 minutes, a carbon gas supply rate of 10 to 100 sccm, and a pressure of 0.001 to 1 mTorr. If these conditions are satisfied, surface damage to particles caused by excessive application of plasma, as well as side effects caused by internal pore surface damage or oxidation, can be prevented.

[0101] As described above, the polyurethane-based coating for a concrete floor according to the present invention comprises a primer layer formed by the primer composition; and may further comprise a lining layer formed by the lining composition, laminated on the upper side of the primer layer.

[0102] The average thickness of the primer layer may be 20 to 200 μm, and the average thickness of the lining layer may be 0.5 to 8 mm. If this is satisfied, the various effects described above can be maximized.

[0103] The primer composition according to the present invention forms a coating film by being applied to a concrete floor surface. Furthermore, the primer composition and the lining composition can form a coating film by being applied sequentially to a concrete floor surface. In particular, the primer composition according to the present invention can secure deep adhesion and bonding strength to a concrete floor, and preferably, excellent mechanical and chemical properties can be achieved by applying a lining composition thereon and laminating it.

[0104] The above primer composition may refer to a primer composition forming a primer layer, or in other words, an undercoat layer, and the above lining composition may refer to an intermediate composition forming a lining layer, or in other words, an intermediate layer. At this time, it goes without saying that a topcoat composition, such as paint that imparts color, may be applied over the lining layer (intermediate layer).

[0105] As for the method of forming a coating film (top layer, bottom layer), the coating film is generally formed by sequentially passing through a coating step and a drying step, and specific methods such as coating conditions and drying conditions may be referred to in various literature known in the paint field. As a specific example, the coating temperature may be 3 to 35°C, and the drying temperature and drying time may be 15 to 35°C and 3 to 48 hours, respectively. Examples of coating means include direct coating using a roller, brush, etc., and indirect coating through spraying.

[0107] The present invention will be described in detail below through examples, but these are intended to explain the invention in more detail and the scope of the present invention is not limited by the following examples.

[0109] <Primer Composition Preparation Steps>

[0110] 12 wt% castor oil (Daemyung Chemical), 35 wt% cement (KSL5204 White Portland Cement, Najin Special Cement) containing Fe2O3 0.5 wt% or less, MgO 5 wt% or less, and SO3 3.5 wt% or less, 7 wt% quartz (quartz powder, YAYANG) as crystalline silicon dioxide-based mineral particles with an average particle size of 280 μm, 25 wt% methylene diphenyl diisocyanate as an isocyanate compound, 5 wt% polypropylene triol with an OH Value of 395 mgKOH / g as an alcohol-based crosslinking agent, 7 wt% dioctyl terephthalate and 2.7 wt% trimethylfentanyl diisobutylate as plasticizers, and dicarboxylic acid ester (Loxanol) as a film-forming agent. R A primer composition of uniform properties was prepared by mixing 0.3 wt% of CA 5330 (BASF), 1 wt% of isoparaffin (Isoparaffin E, Iil Industry) as an antifoaming agent, and the remainder of water, and then stirring.

[0111] <Steps for manufacturing lining composition>

[0112] 20 wt% of castor oil (Daemyung Chemical), 5 wt% of cement (KSL5204 White Portland Cement, Najin Special Cement) containing Fe2O3 0.5 wt% or less, MgO 5 wt% or less, and SO3 3.5 wt% or less, 7 wt% of quartz (quartz powder, YAYANG) as crystalline silicon dioxide-based mineral particles with an average particle size of 280 μm, 30 wt% of silica fume particles (S5505, Sigma-Aldrich) as amorphous silicon dioxide-based synthetic particles, 5 wt% of zeolite-based molecular sieve (AS-104, ZR CATALYST), and 12 wt% of calcium carbonate particles, 18 wt% of methylene diphenyl diisocyanate as an isocyanate-based compound, and 3 wt% of polypropylene triol with an OH Value of 395 mgKOH / g as an alcohol-based crosslinking agent are mixed and subjected to stirring treatment. A lining composition of uniform properties was prepared through this process.

[0114] A lining composition was prepared in the same manner as in Example 1, except that in Example 1, the content of the zeolite-based molecular sieve was changed from 5 wt% to 3 wt%, the content of silica fume particles was changed from 30 wt% to 27 wt%, and 5 wt% of mineral particles (attapulgite particles with an average particle size of 60 μm) were further mixed.

[0116] In Example 2, a lining composition was prepared in the same manner as in Example 2, except that composite mineral particles prepared in the following step were used instead of mineral particles (atapulgite particles with an average particle size of 60 μm).

[0117] <Composite Mineral Particle Manufacturing Steps>

[0118] - Filling stage

[0119] Attapulgite particles with an average particle size of 60 μm were washed several times with distilled water to remove impurities that may be attached to the surface, and then dried sufficiently at 60°C.

[0120] The washed and dried atapulgite particles were immersed in castor oil and reacted at 25°C and 1 atm for 1.5 hours while stirring at 500 rpm with ultrasonic treatment, then removed to obtain atapulgite particles filled with castor oil in the internal pores.

[0122] A lining composition was prepared in the same manner as in Example 3, except that in the filling step of the composite mineral particle manufacturing step of Example 3, the composite mineral particles were prepared using modified atapulgite particles prepared in the following surface modification step.

[0123] - Surface modification step

[0124] Attapulgite particles with an average particle size of 60 μm were washed several times with distilled water to remove impurities that may be attached to the surface, and then dried sufficiently at 80°C.

[0125] Attapulgite particles with a carbon coating layer formed on the surface of internal pores were prepared by applying plasma while supplying gas using an RF plasma device (TruPlasma RF Air 1000, TRUMPF) to the washed and dried attapulgite particles under the processing conditions of Table 1 below. Subsequently, the attapulgite particles were washed with distilled water to remove residues, and then vacuum-dried sufficiently at 80°C to prepare modified attapulgite particles. The modified attapulgite particles prepared in this way were used in the next process, the filling step.

[0127] Output (W) 100 Pressure (mTorr) 70 Processing time (min) 20 inert gas type Argon gas Supply rate (sccm) 50 carbon gas type ethylene gas Supply rate (sccm) 20

[0129] A lining composition was prepared in the same manner as in Example 4, except that during the filling step of the composite mineral particle preparation step of Example 4, the temperature and pressure were changed from 25°C to 75°C and from 1 atm to 5 atm, respectively.

[0131] [Experimental Example 1] Impact Resistance Measurement Test of Coating

[0132] Impact resistance was measured for samples in which a coating film was formed on a substrate using the primer composition and lining composition prepared in Examples 1 to 5.

[0133] Specifically, the primer composition was applied to a glass substrate at 25°C to a thickness of 70 μm and dried for approximately 5 hours to form a primer layer. Subsequently, the lining composition was applied to the primer layer at 25°C to a thickness of 2 mm and dried sufficiently for approximately 48 hours to form a lining layer, thereby manufacturing a coating film. The impact resistance of the coating film thus manufactured was measured using the following method. After thoroughly cleaning the surface of the sample (the surface of the lining layer) with isopropanol, the cleaned sample was placed on a base at the bottom of a Gardner impact tester, and a weight was dropped so that a steel ball would impact the surface of the coating film, thereby observing the deformation and damage to the surface of the sample. Then, the presence of cracks, delamination, or deformation at the impact site of the sample was observed visually or under a microscope, and the maximum impact height at which no damage occurred was recorded. The test was conducted under the conditions shown in Table 2 below, and repeated tests were performed by increasing the impact height, with at least three tests performed at each height.

[0135] Steel ball diameter (cm) 1.5 Weight (kg) 1 Height (cm) 10~100 inert gas type Argon gas Supply rate (sccm) 50 carbon gas type ethylene gas Supply rate (sccm) 20

[0137] [Experimental Example 2] Measurement Test of Coating Resistance

[0138] Wear resistance was measured for samples prepared in the same manner as in Experimental Example 1, and the results are shown in Table 2 below.

[0139] Specifically, the surface (top layer surface) of a sample prepared in the same manner as in Experimental Example 1 was thoroughly washed with isopropanol, and then the abrasion resistance was measured using a Taber abrasion tester. Under measurement conditions, an H-18 grinding wheel was mounted, and the test was conducted for 1,000 abrasion cycles at a temperature of 25°C, 50% relative humidity, a pressurized weight of 500 g, and a rotational speed of 60 rpm, and the abrasion resistance (wear index) was measured using Equation 1 below. The results are shown in Table 3 below.

[0140] [Equation 1]

[0141] Wear Index = Wear Amount (mg) / Number of Wear (Rotations)

[0143] Examples 1 2 3 4 5 Mineral particles (untreated atapulgite particles) X O X X X Complex mineral particles Surface modification X X X O O Castor oil filling Temperature (°C) 25 25 75 Pressure (atm) 1 1 4 Impact resistance (maximum height without damage, cm) 67 69 82 85 87 Wear index (mg / 1,000 cycles) 25 21 21 20 20

[0145] [Experimental Example 3] Measurement of VOC Emission of Paint Composition

[0146] Total volatile organic compounds (TVOC), toluene, and formaldehyde emissions were measured for the primer compositions and lining compositions prepared in Examples 1 to 5.

[0147] Specifically, a test confirmation certificate regarding whether building materials emit pollutants in accordance with Article 11, Paragraph 2 of the Indoor Air Quality Management Act, Article 6, Paragraph 3 of the Enforcement Decree of the same Act, and Article 10-2, Paragraph 2 of the Enforcement Rule of the same Act was attached to FIGS. 4 and FIGS. 5 by commissioning the Korea Chemical Convergence Testing & Research Institute.

[0148] FIGS. 4 and FIGS. 5 respectively show the measurement results for the TVOC, toluene, and formaldehyde emissions of the primer composition and the lining composition of a polyurethane-based paint composition for concrete floors according to an example of the present invention. Both the primer composition and the lining composition were measured to have toluene and formaldehyde emissions below the detection limit. The TVO emission for the primer composition was 0.03 mg / m² 2It was measured as ·h, and for the lining composition, 0.15 mg / m² 2 As measured as ·h, it can be seen that the composition according to the present invention is environmentally friendly.

Claims

Claim 1 A polyurethane-based paint composition for concrete floors comprising a primer composition comprising castor oil, cement, crystalline silicon dioxide-based mineral particles, an isocyanate-based compound, an alcohol-based crosslinking agent, and water. Claim 2 A polyurethane-based paint composition for concrete floors according to claim 1, wherein the primer composition comprises 10 to 20 weight% of castor oil, 30 to 40 weight% of cement, 5 to 15 weight% of crystalline silicon dioxide-based mineral particles, 20 to 30 weight% of isocyanate-based compound, 1 to 10 weight% of alcohol-based crosslinking agent, and 1 to 10 weight% of water. Claim 3 A polyurethane-based paint composition for concrete floors according to claim 1, wherein the cement comprises 0.5 weight% or less of iron oxide, 5 weight% or less of magnesium oxide, and 3.5 weight% or less of sulfur oxide. Claim 4 A polyurethane-based paint composition for concrete floors according to claim 1, wherein the crystalline silicon dioxide-based mineral particles include quartz particles. Claim 5 A polyurethane-based paint composition for concrete floors according to claim 1, wherein the average particle size of the crystalline silicon dioxide-based mineral particles is 100 to 500 μm. Claim 6 A polyurethane-based paint composition for concrete floors according to claim 1, wherein the isocyanate-based compound has an NCO content of 30 to 32% and a viscosity of 100 to 600 cps (at 25℃, 1 atm), and the alcohol-based crosslinking agent comprises a triol-based compound. Claim 7 In claim 1, the polyurethane-based paint composition for concrete floors further comprises a lining composition, wherein the lining composition comprises castor oil, cement, crystalline silicon oxide-based mineral particles, amorphous silicon oxide-based synthetic particles, an isocyanate-based compound, and an alcohol-based crosslinking agent. Claim 8 A polyurethane-based paint composition for concrete floors according to claim 7, wherein the lining composition further comprises composite mineral particles, the castor oil is a first castor oil, and the composite mineral particles comprise atapulgite particles having internal pores; and a second castor oil filled into the internal pores. Claim 9 A polyurethane-based paint composition for concrete floors according to claim 8, wherein in the composite mineral particles, the second castor oil is also applied to the surface of the composite mineral particles. Claim 10 A polyurethane-based paint composition for concrete floors according to claim 8, wherein the composite mineral particles further comprise a carbon coating layer formed by plasma treatment on the internal pore surface of the atapulgite particles. Claim 11 A polyurethane-based coating film for concrete floors comprising a primer layer formed by a primer composition of a paint composition according to any one of claims 1 to 10.

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