KR102183668B1 - infrared and heat reflective water-soluble pigments composition for road comprising hydrophobic silica aerogel - Google Patents

Abstract

The present invention relates to an infrared and heat reflective water-soluble paint composition having improved heat shielding performance and water repellency, to a heat shielding paint film comprising the same, and to a heat shielding paint film construction method using the same. More specifically, the heat reflective water-soluble paint composition according to the present invention comprises: silica particles; hydrophobic silica aerogel; rutile titanium dioxide; natural silica; an aqueous emulsion resin; and a solvent.

Description

Infrared and heat reflective water-soluble pigments composition for road comprising hydrophobic silica aerogel

The present invention relates to a heat-reflecting water-soluble coating composition having remarkably improved water repellency and anti-slip function while preventing the urban heat island phenomenon.

In general, one of the biggest causes of urban heat island phenomenon is radiant heat generated from road pavements (concrete or asphalt) by solar heat, and to solve this problem, paints using a technique that reflects sunlight are in the spotlight.

However, conventional heat-reflecting paints often only reflect visible light, so if the paint is deteriorated due to contamination of the surface or environmental factors and other effects after application, the heat shielding performance is rapidly degraded. It contains problems that are difficult to maintain, such as requiring a re-application. Eventually, the performance of conventional heat reflective paints is rapidly deteriorated, and it is a reality that it appears as the biggest defect in long-term stability. Therefore, it is necessary to secure the advantages of the existing heat shielding material and at the same time maintain the heat-blocking performance even when the weather burns. There is an increasing need to find solutions that can be solved.

On the other hand, heat reflective paints used on roads including roadways, sidewalks, bicycle roads, etc. must have a certain level of anti-slip effect in wet conditions in order to prevent safety accidents.

Accordingly, research on heat reflective paints including hollow particles, etc., as in Korean Patent Registration No. 10-1946050, is being conducted. Heat-reflecting paints containing such hollow particles or the like are heat shielded by using a method in which the longitudinal particles form an air layer inside the paint to block the movement of heat. However, in order for a heat-reflecting paint including hollow particles, etc. to have a heat shielding effect, voids inside the hollow particles must be secured at a certain size or more, and accordingly, hollow particles having a large average particle diameter must be used. In the case of using hollow particles having a large average particle diameter, the coating film must be thickly applied during construction, and when the coating film is formed thick, the water repellency of the coating film is significantly lowered due to high hygroscopicity due to the characteristics of the hollow particles, thereby reducing the anti-slip effect. Furthermore, there is a problem in that the durability of the coating film is reduced due to internal heat storage by hollow particles.

Korean Patent Registration 10-1946050

The present invention provides a heat-reflecting water-soluble coating composition capable of forming a heat-shielding coating film having excellent durability and heat-shielding performance, reflecting infrared rays and having an excellent anti-slip effect in order to prevent the urban heat island phenomenon.

The heat reflection water-soluble coating composition according to the present invention comprises silica particles; Hydrophobic silica airgel; Rutile titanium dioxide; Natural silica sand; Aqueous emulsion resin; And a solvent.

In the heat reflection water-soluble coating composition according to the present invention, the silica particles may have an average particle diameter of 0.5 to 0.8 µm, a specific surface area of 5 to 9 ㎡/g, and a sphericity of 0.8 or more.

In the heat-reflective water-soluble coating composition according to the present invention, the silica particles may be dense particles having a porosity of 0.1% by volume or less.

In the heat reflecting water-soluble coating composition according to the present invention, the average particle diameter of the particles of the hydrophobic silica airgel may be 5 to 1000 μm.

In the heat reflecting water-soluble coating composition according to the present invention, the average particle diameter of the particles of rutile titanium dioxide may be 0.1 to 10 μm.

The heat reflection water-soluble coating composition according to the present invention may include 0.1 to 10% by weight of silica particles based on the total weight.

In the heat reflection water-soluble coating composition according to the present invention, the weight ratio of the silica particles and the rutile titanium dioxide may be 1: 0.1 to 25.

In the heat reflecting water-soluble coating composition according to the present invention, the weight ratio of the silica particles and the hydrophobic silica airgel may be 1:0.05 to 5.

In the heat reflective water-soluble coating composition according to the present invention, the aqueous emulsion resin may be an acrylic emulsion resin.

The heat reflection water-soluble coating composition according to the present invention may further include 1 to 10% by weight of inorganic filler and 0.1 to 3.0% by weight of polyhydric alcohol based on the total weight.

In the heat reflection water-soluble coating composition according to the present invention, the polyhydric alcohol may be one or two or more selected from the group consisting of an aliphatic dihydric alcohol, an aliphatic trihydric alcohol, an alicyclic dihydric alcohol, and an aromatic dihydric alcohol.

The present invention includes a heat-reflecting coating film formed of the above-described heat-reflecting water-soluble coating composition.

In addition, the present invention includes a method of constructing a heat reflective coating film using the above-described heat reflective water-soluble coating composition.

The method of constructing a heat-reflective coating film according to the present invention includes a coating film forming step of forming a coating film by applying the above-described heat-reflecting water-soluble coating composition to a heat shielding object; And a drying step of drying the coating film formed on the heat shielding object.

In the method of constructing a heat reflective coating film according to the present invention, a multilayer coating film may be formed by repeating the coating film forming step two or more times.

In the method of constructing a heat reflective coating film according to the present invention, the heat shielding target may be a road.

The heat-reflecting water-soluble paint composition according to the present invention reduces the surface temperature of the road by paving a heat-shielding paint with high reflectance of sunlight (heat) on a road paved with asphalt or concrete, thereby preventing urban heat islands. There is a feature that can improve the surface durability of.

Hereinafter, a heat reflective water-soluble coating composition of the present invention will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. At this time, unless there are other definitions in the technical terms and scientific terms used, they have the meanings commonly understood by those of ordinary skill in the technical field to which this invention belongs, and the gist of the present invention in the following description and accompanying drawings Description of known functions and configurations that may be unnecessarily obscure will be omitted. In addition, the singular form used in the specification and the appended claims may be intended to include the plural form unless otherwise indicated in the context. In the present specification and the appended claims, units used without special mention are based on weight, and as an example, the unit of% or ratio means weight% or weight ratio.

The present invention silica particles; Hydrophobic silica airgel; Rutile titanium dioxide; Natural silica sand; Aqueous emulsion resin; And it is to provide a heat reflection water-soluble coating composition containing a solvent.

Specifically, the heat reflection water-soluble coating composition according to the present invention comprises silica particles; Hydrophobic silica airgel; Rutile titanium dioxide; Natural silica sand; Aqueous emulsion resin; And a solvent, has a low viscosity, excellent workability, and may have improved heat shielding performance and water repellency. In addition, the coating film prepared by the heat-reflecting water-soluble coating composition according to the present invention has excellent visible and infrared reflectance, is strong against contamination, can have high durability, and has particularly excellent anti-slip effect. Accordingly, the present invention solves the problems of the conventional heat reflective paint composition including hollow particles, and at the same time provides a heat reflective paint for roads having excellent heat shielding properties.

The silica particles included in the heat reflective water-soluble coating composition according to the present invention may be dense particles having a porosity of 0.1 vol% or less, specifically, non-porous particles. When the silica particles are very dense particles, the silica particles do not absorb heat, so they may have high reflection (blocking) properties for sunlight (solar radiation heat).

The heat-reflecting water-soluble coating composition according to the present invention does not contain hollow particles by including silica particles, which are dense particles, and thus, it is possible to overcome the problems of the conventional heat reflection coating composition including hollow particles. In detail, the heat-reflecting water-soluble coating composition according to the present invention is a conventional heat shielding paint including hollow particles, etc., a thick coating film for reducing durability due to heat aging due to heat storage of the hollow particles, and having a heat shielding (heat insulation) effect It is possible to prevent the formation, destruction of the hollow structure due to volume expansion due to the solidification of moisture in the hollow particles in winter due to high water absorption and high water absorption due to the physical properties of the hollow particles.

Furthermore, since the heat-reflecting water-soluble coating composition according to the present invention includes silica particles that are dense particles rather than hollow particles, the average particle diameter of the silica particles may be 0.5 to 0.8 µm, specifically 0.55 to 0.75 µm, The specific surface area may be 5 to 9 m 2 /g, specifically 5.2 to 8 m 2 /g, and the sphericity may be 0.8 or more, specifically 0.9 or more.

Thus, the heat reflective water-soluble coating composition according to the present invention has an average particle diameter of 0.5 to 0.8 µm, specifically 0.55 to 0.75 µm, a specific surface area of 5 to 9 ㎡/g, specifically 5.2 to 8 ㎡/g, and a sphericity. By including silica particles having a value of 0.8 or more, specifically 0.9 or more, by scattering the solar radiation heat of near-infrared rays (780 to 2500 nm), which contains the largest amount of heat (thermal energy) among visible rays (380 to 780 nm) as well as infrared rays. It is possible to prevent solar radiation heat from being absorbed (converted to thermal energy) inside the heat reflective water-soluble paint composition (or a coating film formed by using the heat reflective water-soluble paint composition). In detail, the heat-reflecting water-soluble coating composition comprising silica particles satisfying the above-described physical property range reflects and scatters sunlight in a wavelength range between 380 and 1500 nm, which includes the most solar energy in the spectrum of sunlight. It can reflect more than 65%, specifically more than 75%, and more specifically more than 80% of sunlight (heat) of 0 to 4000 nm, which is the entire area, greatly affecting not only visible light but also heating of the construction surface during construction By blocking more than 65% of infrared rays, it can have high heat shielding performance.

Rutile titanium dioxide contained in the heat-reflecting water-soluble coating composition according to the present invention may have antibacterial, anti-fungal, and hardenable properties, while further having resistance to a heat source.

Accordingly, the heat-reflecting water-soluble coating composition according to the present invention may have a more improved infrared reflection effect by including silica particles and rutile titanium dioxide.

In this case, the average particle diameter of the rutile titanium dioxide may be 0.1 to 10 µm, specifically, 0.2 to 0.7 µm, and more specifically 0.2 to 0.55 µm, but is not limited thereto.

In one embodiment, the weight ratio of the silica particles and rutile titanium dioxide may be 1: 0.1 to 25, specifically 1: 1 to 15. When the weight ratio of silica particles and rutile titanium dioxide in the heat reflective water-soluble paint composition satisfies the above weight ratio range, a coating film having excellent adhesion to the substrate (heat shielding object) can be prepared, and the heat reflective water-soluble paint composition is applied during construction. It becomes easy, and when applied, a coating film having a uniform thickness can be formed.

The heat-reflecting water-soluble coating composition according to the present invention includes natural silica sand having a high surface roughness, so that unevenness can be formed on the surface of the coating film when the coating film is formed, thereby providing a coating film having an excellent coefficient of friction.

Accordingly, the heat-reflecting water-soluble coating composition according to the present invention includes silica particles, rutile titanium dioxide, and natural silica, thereby providing a coating film having an improved infrared reflection effect and an excellent coefficient of friction.

At this time, in terms of having a remarkably excellent coefficient of friction of the heat-reflecting water-soluble coating composition, the average particle diameter of the natural silica may be 300 to 2500 µm, specifically 500 to 2000 µm, and more specifically 700 to 1600 µm. Not limited. As a non-limiting example, the heat-reflecting water-soluble coating composition satisfies the range of the average particle diameter of the natural silica sand described above, and when natural silica sand having different average particle diameters are mixed and used, natural silica sand having a small average particle diameter is natural It is possible to reduce voids formed between particles in the composition while being filled between the silica sand. Accordingly, there are few voids between natural silica particles in the heat-reflecting water-soluble coating composition, so that the coating film may have an improved coefficient of friction and excellent durability (strength).

As an example, one or more natural silica sand may be selected from Pit Sand, Sea Sand, and River Sand, but is not limited thereto.

The heat-reflecting water-soluble coating composition according to the present invention includes silica particles, hydrophobic silica aerogels, rutile titanium dioxide and natural silica sand, and thus has improved heat shielding performance and excellent water repellency and anti-slip effect. Accordingly, it is possible to modify the surface of the coating film so as to prevent slipping even in wet conditions when the coating film is formed with the heat-reflecting water-soluble coating composition according to the present invention.

At this time, in terms of having high dispersibility to prevent separation of the hydrophobic silica airgel from sedimentation in the heat reflective water-soluble paint composition, the density of the hydrophobic silica airgel included in the heat reflective water-soluble paint composition according to the present invention is 0.1 to It may be 1.3 g/mL, specifically 0.5 to 1.0 g/mL, but is not limited thereto. However, when the density of the hydrophobic silica airgel is 0.1 g/mL or less, the hydrophobic silica airgel is easily blown when the composition is mixed, making it difficult to mix and disperse, and in this process, the material (hydrophobic silica airgel) may have a high loss rate. In addition, when the density of the hydrophobic silica airgel is 1.3 g/mL or more, mixing and dispersion is easy when the composition is mixed, but separation due to sedimentation may occur.

In addition, the average particle diameter of the hydrophobic silica airgel may be 5 to 1000 µm, preferably 5 to 500 µm, more preferably 10 to 100 µm. When the particle size of the hydrophobic silica airgel is 1 μm or less, it is too light to be evenly dispersed in the heat-reflecting water-soluble coating composition, and the viscosity of the composition may be too high to limit the construction method. On the contrary, if the particle size of the hydrophobic silica airgel is 2000 μm or more, the particles of the hydrophobic silica airgel are too large to be evenly dispersed, and the hydrophobic silica airgel can be easily broken, so there is a risk of deteriorating the durability of the heat reflective water-soluble coating composition itself. . Therefore, the heat-reflecting water-soluble coating composition according to the present invention including a hydrophobic silica airgel satisfying the above average particle diameter range has a low viscosity, so that the hydrophobic silica airgel is evenly dispersed in the composition, and thus can have excellent workability.

In one embodiment, the weight ratio of the silica particles and the hydrophobic silica airgel may be 1: 0.05 to 5, specifically 1: 0.08 to 3, more specifically 0.08 to 1.5. When the weight ratio of the silica particles and the hydrophobic silica airgel in the heat reflective water-soluble coating composition satisfies the above-described weight ratio range, it is possible to prevent a decrease in strength of the coating film and maintain an appropriate strength as a floor (road) paint.

Silica particles included in the heat shielding paint composition according to the present invention: natural silica sand: hydrophobic silica airgel has an average particle diameter ratio of 1: 500 to 5000: 10 to 150, specifically, 1: 1000 to 4000: 30 to 120, It is not limited thereto, and it is sufficient if the average particle diameter of natural silica is larger than the average particle diameter of silica particles or hydrophobic silica aerogels. On the other hand, the average particle diameter of rutile titanium dioxide is similar to that of the silica particles.

That is, the heat shielding coating composition according to the present invention has improved packing density as the particle size (average particle diameter) of the raw materials (silica particles, hydrophobic silica airgel, rutile titanium dioxide, natural silica sand) included in the composition varies. ). Specifically, the number of voids or air layers formed between particles in the composition as small particles (silica particles, rutile titanium dioxide, and hydrophobic silica airgel) are filled between large particles (natural silica sand) is hollow particles having a large average particle diameter. It may have a significantly smaller number of voids or air layers than conventional heat shielding paints including bays. Since these voids or air layers cause durability deterioration of the coating film when forming the coating film later, the heat shielding coating composition according to the present invention with a small number of voids or air layers can provide a coating film having improved durability when forming the coating film.

Conventional road paints have been mostly oil-based paints. In the case of such an oil-based paint, since a volatile solvent is included for drying during construction, many organic volatile components harmful to the environment are generated. On the other hand, the heat-reflecting water-soluble coating composition according to the present invention contains silica particles, hydrophobic silica aerogels, rutile titanium dioxide, natural silica sand, and aqueous emulsion resin, so that improved heat shielding performance without containing volatile organic solvents harmful to the environment And it may have water repellency properties, in addition to it may have more excellent workability.

At this time, the aqueous emulsion resin can be used without limitation, as long as it is an aqueous emulsion resin commonly used in the technical field of paints, and specifically, acrylic emulsion, acrylic silicone emulsion, urethane emulsion, fluorine emulsion, silicone inorganic resin, silica sol resin and organic It may be one or more compounds selected from inorganic hybrid resins, more specifically acrylic emulsion resins, but is not limited thereto.

In one embodiment, the heat-reflecting water-soluble coating composition according to the present invention has remarkably improved heat shielding performance, water repellency (anti-slip effect) and durability, and in order to form a coating film having uniform performance and thickness during construction, It is preferable that silica particles, hydrophobic silica airgel, rutile titanium dioxide, natural silica sand, and aqueous emulsion resin are uniformly dispersed. In this aspect, silica particles of 0.1 to 10% by weight, specifically 0.3 to 8% by weight, more specifically 0.8 to 5% by weight of the total weight of the composition; 0.1 to 5.0% by weight, specifically 0.1 to 3.0% by weight, more specifically 0.3 to 1.0% by weight of hydrophobic silica airgel; 5 to 25% by weight, specifically 5 to 20% by weight, more specifically 8 to 15% by weight of rutile titanium dioxide; 30 to 70% by weight, specifically 35 to 60% by weight, more specifically 40 to 50% by weight of natural silica sand; 10 to 30% by weight, specifically 15 to 30% by weight, more specifically 20 to 30% by weight of an aqueous 　 emulsion resin; And 5 to 15% by weight, specifically 6 to 15% by weight, more specifically 7 to 12% by weight of a solvent; may include.

In this case, the solvent is not limited in the case of a conventional solvent capable of uniformly dispersing silica particles, hydrophobic silica aerogel, rutile titanium dioxide, natural silica sand, and aqueous emulsion resin, but may preferably be an aqueous solvent. In one embodiment, the aqueous solvent may be water, but the present invention is not limited thereto.

In addition, the heat-reflecting water-soluble coating composition according to the present invention may further include 0.1 to 3.0% by weight, specifically 0.2 to 2.0% by weight, more specifically 0.3 to 1.2% by weight of polyhydric alcohol. When the heat-reflective water-soluble paint composition according to an embodiment of the present invention contains polyhydric alcohols satisfying the above-described range, the heat-reflective water-soluble paint composition has an anti-freezing effect, and it is possible to prevent degradation of physical properties such as a decrease in adhesion, and , It is possible to prevent problems such as internal cracking of the coating film due to rapid evaporation of solvent (water) in the drying step of the coating film applied to the heat shield during construction. At this time, the polyhydric alcohol is one selected from the group consisting of an aliphatic polyhydric alcohol, specifically an aliphatic dihydric alcohol, an aliphatic trihydric alcohol, an alicyclic dihydric alcohol, and an aromatic dihydric alcohol from the viewpoint of preventing the release of environmental pollutants. There can be more than one. More specifically, aliphatic dihydric alcohols include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8- Linear alcohols such as octanediol, 1,9-nonanediol, 1,10-dodecanediol, diethylene glycol, triethylene glycol, and tetraethylene glycol; 1,2-, 1,3- or 2,3-butanediol, 2-methyl-1,4-butanediol, dipropylene glycol, diethylene glycol, neopentyl glycol, 2,2-diethyl-1,3- Propanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,6-hexanediol, 3-methyl-1,6-hexanediol, 2- Methyl-1,7-heptanediol, 3-methyl-1,7-heptanediol, 4-methyl-1,7-heptanediol, 2-methyl-1,8-octanediol, 3-methyl-1,8- It may be a dihydric alcohol selected from octanediol and 4-methyloctanediol, and the like, and the aliphatic trihydric alcohol may be one or more selected from glycerin and trimethylolpropane, and the alicyclic dihydric alcohol is 1,4-cyclohexanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclopentanediol, 1,4-cycloheptanediol, 2,5-bis(hydroxymethyl)-1,4-dioxane , 2,7-norbornanediol, tetrahydrofurandimethanol, 1,4-bis(hydroxyethoxy)cyclohexane, 1,4-bis(hydroxymethyl)cyclohexane and 2,2-bis(4- It may be one or two or more selected from hydroxycyclohexyl)propane, and the aromatic dihydric alcohol is m-xylylene glycol, p-xylylene glycol, bis(hydroxyethyl)benzene and bis(hydroxyethoxy) It may be one or two or more selected from benzene, etc., but the present invention is not limited thereto.

Furthermore, the heat-reflecting water-soluble coating composition according to the present invention is 1 to 10% by weight of the total weight of the composition, specifically in order to hide the surface to be painted during construction and improve the aesthetics with a vivid color when mixed with a pigment (such as rutile titanium dioxide). It may further include 1 to 8% by weight, more specifically 1 to 5% by weight of inorganic filler.

At this time, the inorganic filler can be used without limitation, as long as a conventional inorganic filler used in the field of paint (paint). Specifically, the inorganic filler may be one or two or more selected from calcium carbonate, aluminum hydroxide, alumina, magnesium hydroxide, magnesium oxide, aluminum trioxide, aluminum nitride, silicon carbide, silicon nitride, zinc oxide, zirconium oxide, mica, talc, and kaolin. And, more specifically, it may be calcium carbonate, but the present invention is not limited thereto.

In one embodiment, the heat reflection water-soluble coating composition according to the present invention may further include an additive. In this case, the additive may be one or two or more selected from a dispersing agent, an antifoaming agent, a preservative, an anti-settling agent, an anti-freezing agent, a pH adjusting agent, and a thickening agent, but is not limited thereto. The total content of additives in the composition may be similar to the content of additives commonly included in the paint field. As a specific and non-limiting example, the heat-reflecting water-soluble coating composition according to the present invention may further include 1 to 15% by weight, specifically 3 to 10% by weight, and more specifically 3 to 8% by weight of the total weight. However, the present invention is not limited thereto.

When the heat-reflecting water-soluble coating composition according to the present invention satisfies the above-described weight range, silica particles, hydrophobic silica aerogel, rutile titanium dioxide, natural silica sand, aqueous emulsion resin, and solvent can be uniformly dispersed in the composition. May have a low viscosity. In one embodiment, the viscosity of the heat-reflective water-soluble coating composition may be 10 to 2500 cPs, specifically 500 to 2500 cPs, more specifically 1500 to 2500 cPs, based on a measurement temperature of 25° C. (±0.5° C.). Not limited.

In addition, the present invention includes a method of constructing a heat reflective coating film using the above-described heat reflective water-soluble coating composition.

In detail, the method of constructing a heat-reflective coating film according to the present invention includes a coating film forming step of forming a coating film by applying the above-described heat-reflecting water-soluble coating composition to a heat shielding object; And a drying step of drying the coating film formed on the heat shielding object. In this case, the target of the vehicle may be a road, specifically a sidewalk (india), a walking path, a driveway, a bicycle path, and the like.

In one embodiment, the method of constructing a heat reflective coating film according to the present invention may form a multilayer coating film by repeating the coating film forming step two or more times. In one embodiment, the method of constructing a heat reflective coating film according to the present invention may be repeated up to 10 times to form a multilayer coating film. In this case, the thickness of the coating film formed in the one-time coating film forming step may be 300 to 5000 µm, specifically 500 to 3000 µm, but is not limited thereto.

When a multilayer coating film satisfying the above-described range is formed, the drying time of the coating film may be 10 minutes to 180 minutes, specifically 30 minutes to 120 minutes, more specifically 40 minutes to 80 minutes, but is not limited thereto.

The method of constructing a heat reflective coating film according to the present invention may further include forming a pattern by pressing a pattern plate on the surface of the coating film before the drying step of the coating film formed by applying the heat shielding paint. This pattern formation step has the advantage that it does not require a large amount of energy, and the formed coating film can have an improved surface area and thus can have a higher infrared reflectance. At this time, the method of forming the specific pattern is described in Korean Patent No. KR 10-1970633 B1 (announcement date: 2019.04.22.), which is a prior patent of the present applicant, and briefly discussed in the present invention.

At this time, the term "before drying" in the pattern formation step means "a state in which the residual solvent is contained before the coating film is completely dried". In this case, the residual weight% of the residual solvent may be 5 to 10% by weight, specifically 5 to 8% of the total weight of the coating film. In addition, the solvent may be an aqueous solvent, specifically water, but is not limited thereto.

In one embodiment, the pattern plate may be one in which irregularities having a triangular or rectangular cross section are continuously provided. Specifically, irregularities of a right triangle having an inclination angle of 20 to 50°, specifically 25 to 45° may be formed based on the pattern to be formed. When the pattern in the shape of a right-angled triangle of the inclination angle is formed, the pattern can be pressed so that the inclination angle is formed based on the direction of sunlight when the heat reflective coating film is constructed using the pattern plate, and when the pattern is formed based on the direction of sunlight, Infrared reflectance is remarkably improved, and thus heat shielding performance can be further improved.

In one embodiment, the height of the uneven portion (pattern) formed by the pattern plate in the pattern formation step may be 0.005 to 0.1 mm, preferably 0.01 to 0.08 mm. When the height of the pattern on the heat reflective coat satisfies the above-described range, the heat reflective coat may have a large surface area. Accordingly, the heat-reflective coating film may have improved heat-shielding performance, and even if the heat-reflective coating film is formed thick, it is possible to prevent a decrease in bonding strength with the substrate (heat-shielding target), thereby having excellent durability.

As described above, in the case of a conventional heat-reflecting paint containing hollow particles, etc., construction is difficult due to high viscosity, and durability is deteriorated due to the destruction of the hollow shape due to temperature change. When the surface area is increased by forming a pattern on the coating film formed of a reflective paint, the area that absorbs heat or cold air from the outside becomes wider, and the reflective effect is insignificant, so a problem of lowering the heat shielding performance may occur. In the case of the heat-reflecting water-soluble coating composition used in the method of applying the heat-reflecting coating film according to the above, it contains silica particles, hydrophobic silica aerogels, rutile titanium dioxide, emulsion resins, and solvents, so that it has low viscosity and is convenient for construction, and the hollow particles are By not including it, it is possible to prevent destruction of the hollow particles due to temperature change, and can exhibit remarkably excellent heat shielding performance. In addition, the heat-reflecting coating film formed after construction may have excellent heat shielding performance by reflecting sunlight (heat), in particular, infrared rays. In addition, when a pattern is further formed on the surface of the heat-reflective coating film during construction, the heat-shielding performance can be further improved as the surface area of the heat-reflective coating film can be maximized.

Further, the present invention includes a heat shielding coating film formed of the above-described heat reflective water-soluble coating composition.

In detail, since the above-described heat-reflecting water-soluble coating composition has excellent water repellency, the heat-reflecting coating film formed by using it has excellent resistance to water and can prevent deterioration by water, and sunlight (heat), in particular, infrared As the blocking ability is excellent, it is possible to have remarkably improved heat shielding performance. Thus, the heat reflective coating film according to the present invention has excellent durability and may have excellent heat shielding performance.

Here, the heat reflective coating may be a multilayer coating, and the thickness of the coating may be 300 μm to 10 mm, specifically 500 μm to 5 mm, and more specifically 800 μm to 3 mm, but is not limited thereto. When the heat-reflecting coating film satisfies the above-described thickness range, the heat-reflecting coating film maximizes the heat shielding effect and prevents problems such as delay in drying due to an excessively thick layer.

In one embodiment, when the coating film according to the present invention is applied to a heat shielding object, the heat-reflective coating film may lower the surface temperature of the heat shielding object by 1 to 19°C on average, and specifically 10 to 18°C. In this case, the heat shielding target may include a road, specifically a sidewalk, a trail, a driveway, a bicycle road, and the like.

In addition, as the heat-reflective coating film according to the present invention is formed by a heat-reflecting water-soluble coating composition having excellent water repellency, the heat-reflective coating film is also excellent in water repellency and has a non-slip effect even when rain or water is accumulated, so safety accidents caused by water Can be prevented.

In addition, the heat-reflecting coating film according to the present invention has an advantage in that it has excellent wash resistance and thus high resistance to contamination.

In one embodiment, the heat reflective coating film may further include irregularities patterned on the surface. Accordingly, the heat-reflecting coating film according to the present invention further includes patterned irregularities on the surface, thereby having an improved surface area, thereby improving heat shielding performance.

At this time, the height of the patterned irregularities may be 0.005 to 0.1 mm, specifically 0.01 to 0.08 mm. When the height of the patterned irregularities satisfies the above-described range, the binding property with the substrate (heat shielding object) is high, and the surface area can be improved without significantly affecting the appearance of the heat-reflecting coating film, thereby remarkably improving the heat shielding performance. I can make it.

Further, the cross-section of the patterned irregularities may be a triangular or rectangular shape having an inclination angle of 20 to 50°, specifically 25 to 45°, and a right-angled triangle shape of 20 to 50°, specifically 25 to 45°. The coating film according to the present invention may include triangular patterned irregularities on the surface. Accordingly, the coating film according to the present invention may have a large surface area by including triangular patterned irregularities on the surface, and thus, while having high heat shielding performance, it is possible to further improve heat shielding performance by reflecting incident sunlight. have.

(Production Example 1) Preparation of silica particles

Silica powder having an average particle diameter of 4.5 μm was transferred to a carrier gas, and the silica powder was sprayed into a reactor with an initial temperature of 1460° C. in a heating furnace of 7.6 m based on the flow of the carrier gas to prepare particulate silica. The prepared silica particles had an average particle diameter of 0.65 μm, a specific surface area of 6.3 m 2 /g, and a sphericity of 0.95.

(Production Example 2) Preparation of hydrophobic silica airgel

Step 1: hydrophobic coating preparation

Add 1 to 2 drops of 35% hydrochloric acid to a mixture of unmixed methyltrimethoxysilane (MTMS) and water in a volume ratio of 1: 1, mix in a pH of 2 to 4 atmosphere, and allow to cool. A clear hydrophobic coating solution was prepared.

Step 2: hydrophobic silica airgel preparation

After uniformly mixing 5% by weight of silica sand (silica sand No. 6) and 15% by weight of the hydrophobic coating agent prepared in step 1, it was dried for 2 hours in a dryer at about 85°C. The dried silica sand was crushed and sieved to obtain a hydrophobic silica airgel. At this time, by different crushing and sieving conditions, a hydrophobic silica airgel having an average particle diameter of 100 µm and 2500 µm, respectively, was prepared.

(Examples 1 to 3)

Step 1: Heat reflection water-soluble coating composition preparation

In order to prepare a heat-reflecting water-soluble coating composition satisfying the components and contents of Table 1, the silica particles prepared in Preparation Example 1, the hydrophobic silica airgel prepared in Preparation Example 2, Sea Sand, water, a dispersant, and an antifoaming agent were used. The mixture was mixed and rotated at a speed of 700 rpm for 10 minutes to prepare a dispersion.

Rutile titanium dioxide (R-902) and calcium carbonate (SC-10000) were added to the prepared dispersion, followed by stirring at a speed of 1500 rpm for 20 minutes, followed by mixing. Thereafter, acrylic emulsion, dipropylene glycol, preservative, and thickener were added and rotated again at 1000 rpm for 30 minutes to prepare a heat reflective water-soluble coating composition.

Step 2: Preparation of patterned heat reflective coating

The heat-reflecting water-soluble coating composition prepared in step 1 was applied to a 20×20 cm specimen (steel plate, concrete, asphalt, etc.) at a thickness of 1 mm, and after 3 hours, a pattern plate having an uneven pattern having a height of 0.01 mm was applied on the coating film. A heat shielding coating film having a pattern formed thereon was prepared by pressing.

(Example 4)

Excluding only the formation of a pattern on the coating film in step 2 of Example 1, a heat reflective coating film was prepared in the same manner as in Examples 1 to 3.

(Comparative Examples 1 to 8)

Step 1: Heat reflection water-soluble coating composition preparation

Contents and specific substances in Table 1 were satisfied, and a heat reflective water-soluble coating composition was prepared using the same method as in Example 1.

Step 2: Preparation of patterned heat reflective coating

The heat-reflecting water-soluble coating composition prepared in step 1 was applied to a 20×20 cm specimen (steel plate, concrete, asphalt, etc.) at a thickness of 1 mm, and after 3 hours, a pattern plate having an uneven pattern having a height of 0.01 mm was applied on the coating film. A heat reflective coating film having a pattern formed thereon was prepared by pressing.

Airgel A: 100 μm; Airgel B: 2500 μm; TiO ₂ :r-902 (0.41 μm); Polyhydric alcohol: dipropylene glycol Classification/weight% Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Silica particles 3 One 5 3 3.5 3 3 3 5.9 3 Airgel A 0.5 0.5 0.5 0.5 3.5 0.5 0.5 0.5 Airgel B 0.5 TiO ₂ 12.7 17.2 6.2 12.7 12.7 12.7 12.7 12.7 12.7 20.6 12.7 Silica sand 43.5 41 48 43.5 47 43.5 43.5 56.2 43.5 43.5 20.6 43.5 Acrylic resin 23 23 23 23 23 23 23 23 30 32.4 23 Solvent (water) 9.8 9.8 9.8 9.8 9.8 9.8 9.8 9.8 30 18.6 9.8 PH regulator 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Dispersant 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.3 0.1 Antifoam 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.5 0.2 Antifreeze 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 Anti-settling agent 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Calcium carbonate 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 17.6 2.5 Black pigment 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Polyhydric alcohol 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 3.6 3.6 2.9 0.8 antiseptic 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.1 Thickener One Sum 100 100 100 100 100 100 100 100 100 100 100 100

(Experimental Example 1) Heat shielding performance test

After placing a 150W infrared lamp at a height of about 20 cm away from the heat reflective coating film prepared in Examples 1 to 4 and Comparative Examples 1 to 8, a temperature measuring sensor was installed in the center and inside the surface of the sample, before/after infrared irradiation. The temperature difference between the surface and the inside was measured. At this time, the average temperature at the center of the surface and inside the sample before the test was maintained at about 22.3°, and the average irradiation time was 30 minutes. The results are shown in Table 2.

(Experimental Example 2) Water contact angle test

The contact angle of each heat reflective coating film was measured using a contact angle test apparatus using distilled water for the heat reflective coating films prepared in Examples 1 to 4 and Comparative Examples 1 to 8. The results are shown in Table 2.

(Experimental Example 3) Adhesion strength test

The surface of the heat-reflective coating film prepared in Examples 1 to 4 and Comparative Examples 1 to 8 was scratched with a knife to make 25 flaws, and the top was adhered with a 3M transparent tape. It was checked whether it was separated from and, by breaking it with a hammer, it was confirmed that it peeled off together with the base material (heat shielding object: concrete and asphalt). The results are shown in Table 2.

(Experimental Example 4) Minimum coefficient of friction test

As is known, the Ministry of Land, Infrastructure and Transport, regardless of the type of resin, for the asphalt concrete pavement and the non-slip pavement material applied over the cement concrete pavement, the average condition (a section with a large straight or curved radius as a main arterial road or a dedicated automobile road; or The minimum friction coefficient is limited to 57 BPN on general roads with a traffic volume of 250 vehicles/lane/day or more (Ministry of Land, Infrastructure and Transport, Road Safety Construction (KCS 4 60 05: 2016), established on June 30, 2016) .

Accordingly, the thermally reflective coating films prepared in Examples 1 to 4 and Comparative Examples 1 to 8 were measured for sliding resistance according to ASTM E303. The results are shown in Table 2.

(Experimental Example 5) Alkali resistance test

After each of the heat reflective coatings prepared in Examples 1 to 4 and Comparative Examples 1 to 8 were prepared, each of the heat reflecting coatings was immersed in 5% sodium hydroxide aqueous solution for 168 hours, and then visually inspected for abnormalities of the coating film. I did. The results are shown in Table 2.

(Experimental Example 6) Test for harmful substances

A hazard test was performed on volatile organic compounds (VOC) using the paints of Examples 1 to 4 and Comparative Examples 1 to 8, and the results are shown in Table 2. At this time, the hazard test was performed using the test method of KS M ISO 11890-1:2017, and the detection limit (non-detection criterion) is 0.01%.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Water contact angle
(°) 97.5 97.1 97.4 97.4 20.8 20.3 97 96.5 96.1 93.4 21.5 88.2 Adhesive strength concrete Great Great Great Great Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling asphalt Great Great Great Great Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling Somewhat peeling Heat shielding performance
(℃) surface 48.5 50.5 45.8 48 61 50 55 52 48 48 48.5 51 Coefficient of friction
(BPN) Dry 71 70 69 70 57 58 72 68 68 69 55 64 Wet condition 60 59 60 59 48 47 62 58 57 59 47 55 Alkali resistance test Good Good Good Good Good Good Good Good Good Good Good Good Hazard test Not detected Not detected Not detected Not detected Not detected Not detected Not detected Not detected Not detected Not detected Not detected Not detected

As shown in Table 2, it can be seen that Examples 1 to 4 have superior water repellency (hydrophilicity), adhesive strength with a heat shielding object, heat shielding performance, and anti-slip effect to Comparative Examples 1 to 8. In particular, it can be seen that Example 4 is superior to Comparative Examples 1 to 8 even though the pattern was not formed on the coating film. In particular, looking at the examples, it can be seen that the surface temperature of Example 3 is the lowest, through which it can be seen that the higher the content of silica particles, the better the heat shielding performance. On the other hand, it was found that Comparative Example 1, in which silica particles and hydrophobic silica airgel were excluded in Example 1, had the lowest water repellency, heat shielding performance, and anti-slip effect.

As described above, the present invention has been described by the specific matters and limited embodiments and drawings, but this is provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention is Those of ordinary skill in the relevant field can make various modifications and variations from this description.

Therefore, the spirit of the present invention is limited to the described embodiments and should not be defined, and all things that are equivalent or equivalent to the claims as well as the claims to be described later fall within the scope of the spirit of the present invention. .

Claims (16)

Silica particles; Hydrophobic silica airgel; Rutile titanium dioxide; Natural silica sand; Aqueous emulsion resin; And a solvent; and
The average particle diameter of the hydrophobic silica airgel is 5 to 1000 ㎛,
The silica particles: natural silica sand: hydrophobic silica airgel has an average particle diameter ratio of 1: 500 to 5000: 10 to 150 heat reflection water-soluble coating composition. The method of claim 1,
The silica particles have an average particle diameter of 0.5 to 0.8 μm, a specific surface area of 5 to 9 m 2 /g, and a sphericity of 0.8 or more. The method of claim 2,
The silica particles are dense particles having a porosity of 0.1% by volume or less. delete The method of claim 1,
The heat reflection water-soluble coating composition of the rutile titanium dioxide has an average particle diameter of 0.1 to 10 ㎛. The method of claim 1,
A heat reflective water-soluble paint composition comprising 0.1 to 10% by weight of silica particles based on the total weight of the heat reflective water-soluble paint composition. The method of claim 1,
The weight ratio of the silica particles and rutile titanium dioxide is 1: 0.1 to 25, a heat reflective water-soluble coating composition. The method of claim 1,
The weight ratio of the silica particles and the hydrophobic silica airgel is 1: 0.05 to 5, the heat reflecting water-soluble coating composition. The method of claim 1,
The water-based emulsion resin is an acrylic emulsion resin, a heat reflective water-soluble coating composition. The method of claim 1,
The solvent is a water-based solvent, heat reflection water-soluble coating composition. The method of claim 1,
The heat reflective water-soluble paint composition further comprises 1 to 10% by weight of inorganic filler and 0.1 to 3.0% by weight of polyhydric alcohol based on the total weight. The method of claim 11,
The polyhydric alcohol is one or two or more selected from the group consisting of an aliphatic dihydric alcohol, an aliphatic trihydric alcohol, an alicyclic dihydric alcohol, and an aromatic dihydric alcohol. A heat shielding coating film formed of the heat-reflecting water-soluble coating composition according to any one of claims 1 to 3 and 5 to 12. A coating film forming step of forming a coating film by applying the heat-reflecting water-soluble coating composition of any one of claims 1 to 3 and 5 to 12 to a heat shielding object; And
A drying step of drying the coating film formed on the heat shielding object;
Heat reflection coating construction method comprising a. The method of claim 14,
A method of constructing a heat reflective coating film in which the coating film forming step is repeated two or more times to form a multilayer coating film. The method of claim 14,
The heat shielding target is a road heat reflection coating construction method.