KR100875202B1 - Functional environment-friendly stone, method of manufacturing functional environment-friendly stone and apparatus for manufacturing functional environment-friendly stone - Google Patents

Abstract

A method of manufacturing functional environment-friendly stone is provided to prevent a color, a pattern and a luster of the stone from being damaged by preventing dust in atmosphere from being adhered because large amount of oily pollution materials perform a binder role. A method of manufacturing functional environment-friendly stone comprises steps of: (S120) washing the stone using water flowing by radiating an ultrasonic wave of 20 - 40 kHz or high pressure water of the 0.2~2.0 kgf/cm^2; (S130) removing foreign materials remaining on a surface of the stone by blowing and washing air of high pressure of 2.0~6.0 kgf/cm^2; (S140) activating the surface of the stone by heating it using infrared rays; (S150) coating a photocatalyst coating agent on the surface of the stone of which the surface is activated; and forming an optical catalyst coating film by hardening the photocatalyst coating agent.

Description

Functional Environment-Friendly Stone, Method of Manufacturing Functional Environment-Friendly Stone And Apparatus For Manufacturing Functional Environment-Friendly Stone}

The present invention relates to an eco-friendly functional stone, a method for manufacturing an eco-friendly functional stone and an apparatus for producing an eco-friendly functional stone, and more particularly, an eco-friendly functional stone applied with a photocatalytic coating film having a self-cleaning ability, a method for producing an eco-friendly functional stone, and eco-friendly functional materials. The present invention relates to a stone manufacturing apparatus.

Stones are made for the construction, civil engineering, and other purposes of rock, which is a solid stone or rock formed of lumps or aggregates by one or more minerals gathered by natural action. In general, the stone is used mainly as a building exterior material or flooring material because it is more durable than other materials, durable and weather resistance against acid rain, uniform pattern and color, and excellent ability to block moisture and condensation. However, since natural stone is a porous substrate, stone peeling and discoloration occur due to rain or artificial water penetration. In addition, various pollutants in the air due to the recent environmental pollution are deposited on the surface of the building exterior stone, which flows through the surface with water by the rainfall, causing staining dirt on the surface of the exterior stone after drying.

In order to prevent this problem, water-repellent paints such as polytetrafluoroethylene (PTFE) have been used for building exterior materials. However, since organic materials and organic materials, which are common sources of urban dust, act as binders and generate a lot of pollutants with dust or dirt, organic hydrophilic substances and dusts in the air during rainy weather are washed away with rain water. Paints that allow them to descend are widely used. Hydrophilic paints include acrylic resins, acrylic-silicone resins, aqueous silicones, block polymers of silicone resins and acrylic resins, acrylic-styrene resins, sorbitan fatty acid ethylene oxides, sorbitan fatty acid esters, urethane acetates, polycarbonate diols, and poly And crosslinked urethanes of isocyanates or alkyl ester polyacrylate crosslinked products. However, in the case of the coating film formed of the hydrophilic paint, the contact angle with water is several tens of degrees (°), so that a large amount of organic matter contained in urban dust cannot be effectively prevented.

Accordingly, a photocatalytic titanium dioxide coating film having a high hydrophilicity (contact angle with water of 10 ° or less) is formed on the stone surface to decompose organic compounds and to easily remove dust, such as self-cleaning. Development of environmentally friendly functional stone is required.

An object of the present invention for solving the above object is to provide an eco-friendly functional stone including a photocatalyst coating film having an excellent hydrophilic function, organic decomposition, while maintaining the texture and pattern of the stone.

In addition, another object of the present invention is to provide a method for producing an eco-friendly functional stone including a photocatalyst coating film having an excellent hydrophilic function, organic decomposition, while maintaining the texture and pattern of the stone.

In addition, another object of the present invention is to provide an apparatus for producing an eco-friendly functional stone including a photocatalyst coating film having an excellent hydrophilic function, organic decomposition, while maintaining the texture and pattern of the stone.

Eco-friendly functional stone according to an embodiment of the present invention for achieving the above object is to give a hydrophilicity, organic material resolution and antibacterial function to the stone and the stone used as a building and civil engineering materials, visible light transmittance of 90% to 98 It comprises a photocatalyst coating film which is%. Eco-friendly functional stone having such a configuration is that the contact angle with the water is less than 10 ° to easily remove dirt on the surface of the stone by rainwater during rain, as well as to have an antibacterial effect.

In addition, in order to manufacture the eco-friendly functional stone according to an embodiment of the present invention for achieving the above-mentioned other objects, first remove the foreign substances remaining on the stone surface. Subsequently, after activating the stone surface by the infrared heating method, a photocatalyst coating agent is coated on the surface of the activated stone. Thereafter, the photocatalyst coating agent is cured to form a photocatalyst coating film having a high strength of 6H or more. As a result, a contact angle with water is 10 ° or less, and an eco-friendly functional stone having organic substance resolution and antibacterial effect can be produced.

As an example, the washing removal in the production of the eco-friendly functional stone is a step of washing the stone with running water by oscillating ultrasonic wave of 20 to 40 kHz or washing with high pressure water of 0.2 to 2.0 kgf / ㎠ and 2.0 to 6.0 kgf / ㎠ And flushing with high pressure air.

The activation may be to maintain the surface temperature of the stone at 30 to 50 ℃, the coating is sprayed at a spray pressure of 0.5 to 6.0 kgf / ㎠ the photocatalyst coating agent in a coating amount of 50 to 500 mg / ㎡ It is possible to form, and the curing can be heat-treated for 3 to 10 minutes in an infrared heating furnace of 80 to 250 ℃.

In addition, in the case of manufacturing an eco-friendly functional stone according to an embodiment of the present invention for achieving the above object may include a transfer table, water washer, infrared dryer, photocatalyst coating machine and infrared heat treatment machine. The transfer table serves to transfer the stone processed as a building and civil engineering material to be processed as a functional stone. The water washer removes foreign matter remaining on the surface of the processed stone being transported. The infrared dryer dries the washed stone to activate its surface. The photocatalyst coater coats the photocatalyst coating on the surface of the activated stone. The infrared heat treatment machine cures the photocatalyst coating agent to form a photocatalyst coating film. The manufacturing apparatus of the eco-friendly functional stone having the above-described configuration maintains the excellent texture and pattern of the stone, the contact angle with the water is 10 ° or less, it can be produced at low cost eco-friendly functional stone having an organic resolution and antibacterial effect.

For example, the manufacturing apparatus may further include an air ejector provided between the water washer and the infrared dryer, and blowing air at a pressure of 2.0 to 6.0 kgf / cm 2 on the surface of the stone.

The water washer is adjustable in position, may have a configuration including washing nozzles for washing the stone in three dimensions by ejecting water at a water pressure of 0.2 to 2.0 kgf / ㎠, the coater is adjustable position, It may have a configuration including a spray gun for spraying the photocatalyst coating agent at a pressure of 0.5 to 6.0 kgf / ㎠ and three-dimensionally coating the stone.

The eco-friendly functional stone manufactured by the above-described method may have an effect of removing foreign substances on the surface of the stone easily by rain water when the contact angle with water is 10 ° or less by the formed photocatalyst coating film. In addition, by preventing a large amount of oily contaminants to act as a binder to fix the dust in the air to prevent the color, pattern and gloss of the stone is damaged. In addition, since the transmittance of visible light is 90% or more, rather than the opaque coating film, which was a problem in the application of the conventional photocatalyst coating film, it was possible to prevent the color, pattern and gloss of the stone from being damaged.

Hereinafter, with reference to the accompanying drawings, eco-friendly functional stone, a manufacturing method thereof and a manufacturing apparatus thereof according to preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and those skilled in the art may implement the present invention in various other forms without departing from the technical spirit of the present invention. In the accompanying drawings, the layers (membrane), the device, the unit or the devices are shown in larger scale than actual for clarity of the invention. In the present invention, when a layer (film), device, unit or device is referred to as being formed "on", "upper" or "lower" of each layer, device, unit or device, each A layer (membrane), device, unit or devices may be directly formed on or below the layer (membrane), device, unit or devices.

1 is a cross-sectional view showing an environmentally friendly functional stone according to an embodiment of the present invention.

Referring to Figure 1, the eco-friendly functional stone 100 of the present embodiment has a configuration including a stone 110 and a high-strength photocatalyst coating film (120).

The stone 110 is a material used as a construction and civil engineering materials, including granite, slab processed marble, boundary stone, etc., and has a state of being processed to be used as a construction and civil engineering material. The stone has fine cavities formed on the surface thereof and may be contaminated when exposed to the environment for a long time.

The photocatalyst coating film is formed on the surface of the stone to impart hydrophilicity, organic resolution and antibacterial function to the stone, and is a transparent coating film having a visible light transmittance of 90 to 98%. Here, the photocatalyst coating film has a strong hardness of 6H or more and at the same time has a contact angle with water of 10 ° or less, thereby giving an effect of easily removing dirt adsorbed on the stone surface by rain during rainfall. In addition, the coating film prevents damage to the color, pattern, and gloss of the natural stone even in the presence of the coating film due to its transparency.

The photocatalyst coating film mentioned in this embodiment is a titanium dioxide film formed by coating and drying a titanium dioxide photocatalyst sol in which 0.1 to 10% by weight of titanium dioxide particles (TiO ₂ ) having a size of about 10 to 40 nm is dispersed on a stone surface. desirable.

Manufacturing method of eco-friendly functional stone

Figure 2 is a process flow diagram showing a method for producing environmentally friendly functional stone according to an embodiment of the present invention.

Referring to Figure 2, first, to prepare a hydrophilic photocatalyst coating applied to form a photocatalyst coating film (step S110).

In detail, first, a starting material titanium hydrate (TiO (OH) ₂ ) and a solvent are mixed in a ball-mill vessel at a weight ratio of 1:50 to 200. The solvent is a mixture of water (H ₂ O) and ethylene glycol monomethyl ether (CH ₃ OCH ₂ H ₄ OH) in a weight ratio of 1: 1 to 5. As an example, 80 to 120 parts by weight of titanium hydrate and 200 to 1000 parts by weight of the mixed solution may be mixed.

Subsequently, a surfactant and a dispersant were added and mixed in the vessel. Examples of the surfactant include polyethylene glycol (H (OCH ₂ CH ₂ ) nOH), hereinafter PEG), and examples of the dispersant are tetraethyl ammonium hydroxide 20% solution; (C ₂ H ₅ ) ₄ NOH, hereinafter TEAOH). As an example, surfactants and dispersants are additives used to prevent agglomeration of particles in a ball-mill process and are not an element limiting the present invention.

Then, Mo, Bi, Co, V, Ag, Cu, Ru, Tl, Nb, Ni, Pt, Fe and the like to extend the light source used for the photocatalytic activity and photocatalytic reaction to the visible light region in addition to the ultraviolet ray to the mixture Precursor containing the transition metal is first mixed to form a primary mixture. The precursor is used in about 15 to 25% by weight of the TiO (OH) ₂ usage.

Subsequently, the primary mixture was ball-milled for 2 hours using an alumina ball, and then additionally mixed with materials such as silicon oxide, zirconium oxide, and aluminum oxide, which are binder materials for improving the bonding strength between the stone and the photocatalyst coating film. A tea mixture was prepared. Here, the binder may be used about 60 to 90% by weight of the TiO (OH) ₂ usage, preferably about 70 to 80% by weight. At this time, when the amount of the binder used is out of the range, the strength may be too low or the photocatalytic activity may not appear.

Subsequently, centrifugation removes the TiO ₂ macroparticles (50 nm or more) present in the secondary mixture, and by rotating evaporation to remove some ammonia components in the secondary mixture to proceed with the crystallization of TiO ₂ particles A preliminary photocatalyst coating is prepared. After preparing the preliminary photocatalyst coating, the concentration and the transparency may be measured, and then the concentration of the final solution may be determined by stirring by further adding a solvent.

Thereafter, the photocatalyst coating agent (sol) for dispersing 0.1 to 10% by weight of titanium dioxide particles having a size of about 10 to 40 nm suitable for spray coating may be prepared. Preferably the photocatalyst coating agent may comprise 0.1 to 5% by weight of TiO ₂ , 0 to 2% by weight of transition metal, 0.1 to 5% by weight of amorphous silica and extra solvent, and more preferably 0.1 to 3% by weight of TiO _2. , 0.1-1% by weight of transition metal, 0.5-2% by weight of amorphous silica, and excess solvent.

After the step S110 to perform a washing process to remove dirt, such as stone powder, dust remaining on the stone surface (step S120).

In general, the cleaning agent used to activate the substrate surface during photocatalyst coating is mainly a surfactant, an abrasive and a solution composed of an acid and a base. However, in the chemical cleaning method using a surfactant or an acid or basic solution as a cleaning agent, a large amount of washing water is required because no cleaning agent remains on the surface after cleaning, and equipment for purifying wastewater generated after cleaning is necessary. . In addition, the cleaning method using an abrasive such as ceria is excellent in cleaning and surface activation effect by polishing the surface by physical method using fine powder with high hardness, but the price of the abrasive is high and the application is limited according to the surface state of the base material. There is. In other words, the stone used for the production of eco-friendly functional stone has many pores and rough surface properties, making it difficult to physically clean it with abrasives.The chemical cleaning method using surfactants or acid / basic solutions uses a detergent that has been impregnated with pores. Problems that are difficult to remove and chemical reactions between the stone and the cleaning agent cause a change in the mechanical properties of the stone.

Therefore, in order to solve this problem, the present invention can remove the contaminants remaining on the surface of the stone by immersing the stone in water instead of physical polishing or chemical cleaning and oscillating ultrasonic waves of about 15 to 45 kHz for 10 minutes to wash with running water. have. The water washing using the ultrasonic wave causes a problem that the fine dust is partially present on the stone surface when the ultrasonic wave is less than about 15 kHz, and the surface of the stone is peeled off when the ultrasonic wave exceeds about 45 kHz. Accordingly, the ultrasonic water wash is performed at an ultrasound of 15 to 45 kHz and preferably at about 20 to 40 kHz.

As another example, the wash may be washed with high pressure water of about 0.2 to 2.0 kgf / cm 2 to remove contaminants remaining on the stone surface. The high pressure water washing has a problem that foreign matter such as stone powder is present on the stone surface when the washing water pressure is less than 0.2 kgf / ㎠, and expensive equipment is maintained to maintain the water pressure when the washing water pressure exceeds 2.0 kgf / ㎠. Required. Accordingly, the water washing is carried out at a water pressure of 0.2 to 2.0 kgf / cm 2 and preferably at a water pressure of about 0.5 to 1.5 kgf / cm 2.

Both the cleaning method using the above-mentioned ultrasonic oscillation and the washing method using high pressure washing water can effectively remove foreign substances on the surface of the stone, but considering the volume and weight of the stone used as building and civil engineering materials, the present invention uses high pressure washing water. It is preferable to carry out the washing process.

After the step S120 is further carried out a step of cleaning by blowing a high-pressure air for removing foreign matter and water remaining on the stone surface (step S130).

The jet cleaning of the high pressure air serves to effectively remove moisture and foreign matter remaining between the surface of the stone and the pores after the washing process using water. The air cleaning is performed by reciprocating an air-gun that ejects high pressure air in a state in proximity to the stone surface. At this time, there is a difference depending on the interval between the air-gun and the stone, but if the air pressure is less than 2.0 kgf / ㎠ in the interval of 10cm the moisture of the stone surface is not made in a quick time to dry.

After the step S130, the stone surface is infrared heated to activate the stone surface (step S140).

Activation of the stone surface using the infrared heating is a process for completely removing the water remaining in the fine cavity of the stone after the cleaning step using the air pressure and at the same time the photocatalyst coating can be applied to the optimal state on the stone surface. . In other words, by placing the stone in a dryer that generates infrared rays and heat-maintaining the surface temperature of the stone to have a temperature of 30 to 50 ° C. to completely remove the remaining moisture, when the photocatalyst coating is sprayed on the stone surface, the coating material directly It adheres to the surface and the coating is bonded to the stone in the process of spray coating repeated 3 to 4 times, and then effectively removes water and alcohol contained in the coating to control agglomeration of titanium dioxide particles during the drying of the coating film. It plays a role. At this time, if the temperature of the stone surface is 30 ℃ or less, entanglement phenomenon occurs during the spray coating of the photocatalyst coating, and when heated to 50 ℃ or more, the sprayed photocatalyst coating is rapidly dried on the stone surface and the coating on the stone is not complete.

After the step S140 to coat the photocatalyst coating on the activated stone surface (step S150).

Examples of the coating of the photocatalyst coating agent include spray coating, dip coating, electrostatic coating, electrodeposition coating, curtain flow, roller method, and the like. The stone used in the present embodiment is not a translucent base material, and since the control range of the coating layer thickness is relatively wide, it is preferable to use a spray coating excellent in mass productivity among the coating methods. In particular, in this embodiment, in order to avoid affecting the texture and pattern of the stone, it is important to form a uniform coating film as much as possible. It is desirable to coat the stone simultaneously on three sides while controlling the direction of movement and speed. More preferably, the distance between the stone surface to be coated and the spray nozzle is adjusted to about 100 to 500 mm, the air pressure is 1.0 to 5.0 kgf / cm ² , and the coating amount is performed 2 to 6 times so that the coating amount is about 50 to The photocatalyst coating agent is coated to have 500 mg / m 2. When the coating amount is 50 mg / m 2 or less during the coating process, organic matter resolution and hydrophilicity are rapidly reduced, and when the coating amount exceeds 500 mg / m 2, an opaque coating film is formed to damage the natural color and pattern of the stone. do.

After the step S150, the coated photocatalyst coating is cured to form a photocatalyst coating film (step S160).

The coating film curing process is a step for forming a photocatalyst coating film having excellent strength by curing the photocatalyst coating on the surface, heat treatment of the stone coated with the photocatalyst coating agent in an infrared heating furnace of about 80 to 250 ℃ 3 to 10 minutes By volatilizing, there is no crack and a photocatalyst coating film having a strength of 6H or more can be prepared. As the photocatalyst coating film is formed, the stone is made of environmentally friendly functional stone. It was confirmed that the photocatalyst coating film of this example had a crystal structure as shown in FIG. 3 by X-ray diffraction analysis.

Eco-friendly Functional Stone Manufacturing Equipment

Figure 4a is a conceptual diagram showing an apparatus for producing environmentally friendly functional stone according to an embodiment of the present invention, Figure 4b is a plan view showing an apparatus for producing an environmentally friendly functional stone according to an embodiment of the present invention.

Referring to Figure 4, in the case of the eco-friendly functional stone manufacturing apparatus 200 according to the present embodiment transfer table 210, water washer 220, infrared dryer 240, photocatalyst coating machine 250 and infrared heat treatment machine ( 260).

The transfer table 210 serves to transfer the stone having a size and shape that can be used as a building and civil engineering material to be processed into an eco-friendly functional stone having organic decomposition and antibacterial effect. That is, the transfer table serves to transfer the stone so that the stone can be processed by passing through the water washer 220, infrared dryer 240, photocatalyst coater 250 and infrared heat treatment machine 260, respectively. An example of the transfer table 210 may be a conveyor having a stainless steel roll.

The water washer 220 is a device provided on the transfer table 210 and removes foreign substances such as stone powder, dust and the like remaining on the surface of the stone transferred by the transfer table 210. The water washer is about 15 to 45 kHz oscillating ultrasonic water to wash the flowing water to remove contaminants remaining on the surface of the stone or water washing with a water pressure of about 0.2 to 2.0 kgf / ㎠ to remove the stone It can be divided into three-dimensional washing machine. Both the ultrasonic water washer and the high pressure wash water washer can effectively remove foreign substances on the stone surface, but considering the volume and weight of the stone used as a building and civil engineering material, the present invention performs a washing process using high pressure washing water. It is desirable to apply a water washer that can.

Specifically, the water washing machine applying the high pressure washing water is adjustable in position, and has washing nozzles for three-dimensionally washing the stone by ejecting water at a water pressure of about 0.2 to 2.0 kgf / cm 2. The washing nozzles are provided to wash the upper surface and both sides of the stone by ejecting high pressure water, and have a structure capable of reciprocating in the transport direction of the stone.

The infrared dryer 240 is provided on the transfer table 210, and completely removes the moisture remaining in the fine cavity of the stone by using the infrared rays, and then the photocatalyst coating is applied on the surface of the stone in an optimal state. It is a unit that activates the surface by maintaining a constant temperature so that it can That is, after receiving the infrared dryer 240 stone has a configuration that includes an infrared heating unit (not shown) to heat-maintain so that the surface temperature of the stone has a temperature of about 30 to 50 ℃.

As an example, the eco-friendly functional stone manufacturing apparatus of the present embodiment is provided between the water washer 220 and the infrared dryer 240, and blows air at a pressure of 2.0 to 6.0 kgf / ㎠ to the surface of the stone ( It may further include an air blower 230 for blowing. Specifically, the air blower 230 includes air guns for completely removing the high pressure air to remove moisture present on the surface of the stone and foreign matter remaining after the water washing process. The air guns are provided to clean the upper surface and both sides of the stone by ejecting high pressure air, and the reciprocating motion is possible in the transport direction of the stone.

The photocatalyst coater 250 is provided on the transfer table 210 and is a unit for coating a photocatalyst coating agent on the surface of the activated stone with a uniform thickness. The photocatalyst coater 250 is adjustable in position, and has a configuration including sprays that can spray the photocatalyst coating agent at a pressure of 0.5 to 6.0 kgf / ㎠ to three-dimensionally coating the stone. The spray guns are provided to be uniformly coated by spraying the photocatalyst coating in a state spaced apart from the upper surface and both sides of the stone, to perform a repeated coating to form a photocatalyst coating film of a predetermined thickness on the surface of the stone For this purpose, the reciprocating motion is possible in the transport direction of the stone.

The infrared heat treatment machine 260 is a unit provided on the transfer table 210 and curing the photocatalyst coating agent coated on the surface of the stone to form a photocatalyst coating film. The infrared heat treatment device may include an infrared heat treatment device for generating the heat, and may further include a warm air fan.

The manufacturing apparatus of eco-friendly functional stone having the above-described structure maintains the excellent texture and pattern of the stone, the contact angle with water is 10 ° or less, and can form a photocatalyst coating film having an organic substance resolution and antibacterial effect of 6H or more, which is eco-friendly. Functional stone can be manufactured at low cost.

Hereinafter, the present invention will be described in more detail as production examples and evaluation examples, but the scope of the present invention is not limited.

Production of Photocatalyst Coatings Dispersed Titanium Dioxide 1

In a ball-mill vessel, the surfactant Titanium hydrate TiO (OH) ₂ and a mixed solvent (water and ethylene glycol monomethyl ether were mixed in a 2: 8 ratio) in a mixed solution at a weight ratio of about 1:80 adding the TiO (OH) 10% of the _second mass, and 2%, respectively, dispersing agent and _{Ammonium metatungstate hydrate ((NH 4)} 6 H 2 W 12 O 40 · xH 2 O, less AMT) for with respect to the weight of TiO (OH) ₂ After 20% addition, the mixture was first mixed by using alumina balls for 2 hours by ball-mill, and then 80% by weight of SiO ₂ binder was added to TiO (OH) _{2 by} mass ratio. 2nd mixing. The above solution was centrifuged to remove TiO ₂ macroparticles in the initial solution, some of the ammonia contained in the solution through rotary evaporation, and TiO ₂ was crystallized to prepare an intermediate solution. Then, by performing a pressure-filtration step a final TiO ₂ particle size of 10 ~ 40nm which is 2.0% by weight of titanium dioxide particles, a transition metal (W) 0.6% by weight, the photocatalytic coating agent containing 1.5% by weight of amorphous silica, and replacement solvent (Sol) was prepared.

Titanium dioxide dispersed Photocatalyst  Coating Preparation 2

The intermediate solution prepared in Preparation Example 1 was diluted twice by administering a mixed solvent of water and ethylene glycol monomethyl ether, so that the final TiO ₂ particles had a particle size of 10 to 40 nm, 1.0 wt%, and transition metal (W). A photocatalyst coating (sol) was prepared comprising 0.4% by weight, 1.3% by weight of amorphous silica and excess solvent.

Titanium dioxide dispersed Photocatalyst  Coating Preparation 3

The intermediate solution prepared in Preparation Example 1 was diluted 20-fold by administering a mixed solvent of water and ethylene glycol monomethyl ether, and thus 0.1 wt% of titanium dioxide particles having a final TiO ₂ particle size of 10 to 40 nm and a transition metal (W). A photocatalyst coating (sol) was prepared comprising 0.15% by weight, 0.8% by weight of amorphous silica and excess solvent.

Photocatalyst Of coating film Contact angle  evaluation

Photocatalyst coating films were formed by coating / drying the photocatalyst coating agents prepared in Preparation Examples 1 to 3 on the plate stones (polishing and polishing) processed to a length of 300 mm, a width of 300 mm, and a height of 30 mm. Thereafter, water was sprayed on each photocatalyst coating film to measure the contact angle between the water droplet and the photocatalyst coating film. The results are shown in FIG. 5 below.

Referring to FIG. 5, it was confirmed that the contact of water was significantly lowered as the amount of TiO (OH) ₂ increased in the mixing ratio of TiO (OH) ₂ and the mixed solvent. Therefore, it was confirmed that the use ratio of TiO (OH) ₂ and the mixed solvent was 5:95 or less when preparing the photocatalyst coating agent.

Photocatalyst Of coating film  Transparency Assessment

Photocatalyst coating films were formed by coating / drying the photocatalyst coating agents prepared in Preparation Examples 1 to 3 on glass plates processed to a length of 300 mm, a width of 300 mm, and a height of 30 mm. Thereafter, the transparency of each photocatalyst coating film was measured. The results are shown in Figure 6 below.

Referring to FIG. 6, the transparency of the coating film was decreased as the amount of TiO (OH) ₂ increased in the mixing ratio of TiO (OH) ₂ and the mixed solvent. Therefore, it was confirmed that the use ratio of TiO (OH) ₂ and the mixed solvent in the preparation of the photocatalyst coating agent was 2: 8 or more.

Photocatalyst Of coating film  Antimicrobial Evaluation

A photocatalyst coating film coated with the photocatalyst coating agent of Preparation Example 2 was formed. E. coli was then added to evaluate the antimicrobial activity of the photocatalyst coating film. The result is shown in the photograph of FIG. Referring to the photograph of FIG. 7, it was confirmed that E. coli present in the photocatalyst coating film was completely removed after 2 hours. The photocatalyst coating film was confirmed to have excellent antimicrobial properties.

Surface condition evaluation according to stone surface treatment method

Plate stone (polishing and fine grinding), which is used for building and civil engineering materials, was processed to a size of 300 mm in length, 300 mm in width and 30 mm in height, and the surface was washed by high pressure washing. The washing gun was set to 100 mm above the surface of the stone, and then the water pressure was adjusted to (a) 0.15 kgf / cm 2 (b) 0.2 kgf / cm 2 (c) 0.5 kgf / cm 2 respectively. Washed. After washing with water, the stone was dried by air-blowing twice with reciprocating air pressure of 4 kgf / cm 2 and dried to check the state of the stone surface through a microscope. The result is shown in the photograph of FIG. 8. Referring to the photograph of FIG. 8, when the water pressure was 0.15 kgf / cm 2, it was confirmed that some stone powder exists even after washing, so that the washing should be performed at a water pressure of at least 0.2 kgf / cm 2 or more.

Photocatalyst  Coating status according to stone surface treatment method before forming coating layer

The stone washed with 0.2 kgf / ㎠ water pressure was dried in an infrared dryer at 60 ~ 80 ℃ for 5 minutes, and the surface temperature of each was (a) 25 ℃ (b) 30 ℃ (c) 50 ℃ (d) 60 ℃. After maintaining, the photocatalyst coating agent was coated under the condition of the coating amount of 500 mg / m 2, and then the uniformity of the coating was evaluated. The results are shown in Table 1 below.

TABLE 1

(■: film thickness is low, △: film is not uniform, ○: film has a uniform thickness)

Referring to Table 1, in the case of (a) stone having a surface temperature of 20 ° C., the coating was carried out twice before the coating material was dried in one coating, and the surface of the final coating film remained stained by photocatalyst sol. The (d) stone coating agent at 60 ° C. was dried before it even reached the stone, and it was confirmed that the amount of the photocatalytic coating was very low on the final stone surface.

Using spray coating Photocatalyst  How to coat the coating

A photocatalyst coating agent was coated on the stone and glass activated at 30 ° C. with a surface pressure of 0.2 kgf / cm 2 and spray coating. Specifically, the coating equipment was set so that the nozzle of the spray gun was positioned 125 mm above the stone and glass surface, and then coated by spraying the coating solution at an air pressure of 3 kgf / cm 2. 150 ° C infrared heat treatment device after coating the photocatalyst coating agent by adjusting the discharge amount of the coating agent so that the coating amount is (a) 30 mg / m 2, (b) 50 mg / m 2 (c) 500 mg / m 2 (d) 700 mg / m 2 Heat treatment was performed for 5 minutes at to form a photocatalyst coating film. Thereafter, the water contact angle and transparency of the formed coating film were evaluated, and the results are shown in Tables 2 and 3.

TABLE 2

Referring to Table 2, the contact angle of the photocatalyst coating film formed under the conditions of 50, 500, and 700 mg / m 2 showed hydrophilicity of 8 ° or less, whereas the contact angle of the photocatalyst coating film formed under the condition of 30 mg / m 2 was 13 °. It was confirmed that hydrophilicity was not expressed by showing a high value.

TABLE 3

Referring to Table 3, the photocatalyst coating film formed on the glass substrate at 30, 50, and 500 mg / m 2 conditions had a transparency of 90% or more in the visible wavelength range, and the coating amount on the glass substrate at 700 mg / m 2. In the case of the formed photocatalyst coating film, the transparency in the visible light wavelength region was about 80%, indicating that the transparency was somewhat reduced, affecting the pattern and texture of the stone.

Eco-friendly functional stone manufactured according to the present invention has an effect that the contact angle with water by the formed photocatalyst coating film is less than 10 ° can be easily removed foreign matters on the stone surface by rain water during rainfall. In addition, by preventing a large amount of oily contaminants to act as a binder to fix the dust in the air to prevent the color, pattern and gloss of the stone is damaged. In addition, since the transmittance of visible light is not less than 90%, which is not a problem in the application of the conventional photocatalyst coating film, the color, pattern, and gloss of the stone can be prevented from being damaged.

1 is a cross-sectional view showing an environmentally friendly functional stone according to an embodiment of the present invention.

Figure 2 is a process flow diagram showing a method for producing environmentally friendly functional stone according to an embodiment of the present invention.

3 is a diagram illustrating an X-ray diffraction graph of a photocatalyst coating film according to an embodiment of the present invention.

Figure 4a is a conceptual diagram showing an apparatus for producing environmentally friendly functional stone according to an embodiment of the present invention.

Figure 4b is a plan view showing an apparatus for producing environmentally friendly functional stone according to an embodiment of the present invention.

5 is a graph showing the water contact angle of the photocatalyst coating film prepared according to an embodiment of the present invention.

Figure 6 is a graph showing the light transmittance of the photocatalyst coating film prepared according to an embodiment of the present invention.

Figure 7 is a photograph showing the antimicrobial activity of the photocatalyst coating film prepared according to an embodiment of the present invention.

8 is a photograph showing the state of the stone surface according to the flush pressure of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: eco-friendly functional stone 110: stone

120: photocatalyst coating film 210: transfer table

220: water washer 230: air jet

240: infrared dryer 250: photocatalyst coating machine

260: Infrared Heat Treater

Claims (12)

stone; And It is formed on the surface of the stone to provide an eco-friendly functional stone having a configuration including a photocatalyst coating film to impart hydrophilicity, organic material decomposition and antibacterial function to the stone, The eco-functional stone is stone washing with flowing water by oscillating the ultrasonic wave of 20 to 40 kHz or washing with high pressure water of 0.2 ~ 2.0 kgf / ㎠; Removing foreign matter remaining on the stone surface by blowing with high pressure air of 2.0 to 6.0 kgf / cm 2; Infrared heating to activate the stone surface; Coating a photocatalyst coating on the surface of the activated stone; And curing the photocatalyst coating agent to form a photocatalyst coating film. The method of claim 1, wherein the photocatalyst coating film is formed by coating and drying a titanium dioxide photocatalyst sol in which 0.1 to 10% by weight of titanium dioxide particles (TiO ₂ ) having a size of 10 to 40 nm is dispersed and having a visible light transmittance of 90% to 98%. Eco-friendly functional stone, characterized in that. Washing the stone with running water by oscillating ultrasonic waves of 20 to 40 kHz or washing with high pressure water of 0.2 to 2.0 kgf / cm 2; Removing foreign matter remaining on the stone surface by blowing with high pressure air of 2.0 to 6.0 kgf / cm 2; Infrared heating to activate the stone surface; Coating a photocatalyst coating on the surface of the activated stone; And Eco-friendly functional stone manufacturing method comprising the step of curing the photocatalyst coating to form a photocatalyst coating film. delete The method of claim 3, wherein the activation is to maintain the surface temperature of the stone at 30 to 50 ℃ eco-friendly functional stone manufacturing method, characterized in that. The photocatalyst coating agent according to claim 3, wherein the photocatalyst coating agent comprises 0.1 to 3% by weight of TiO ₂ having a particle size of 10 to 40 nm, 0.1 to 1% by weight of transition metal, 0.5 to 2% by weight of amorphous silica and an extra solvent. Eco-friendly functional stone manufacturing method. The method of claim 3, wherein the coating is performed by spraying the photocatalyst coating agent at an injection pressure of 0.5 to 6.0 kgf / cm 2 and coating the coating at a coating amount of 50 to 500 mg / m 2. The method of claim 3, wherein the hardening is an environmentally friendly functional stone manufacturing method, characterized in that the heat treatment for 3 to 10 minutes in an infrared heating furnace of 80 to 250 ℃. A transfer table for transferring stone; A water washer to remove foreign substances remaining on the surface of the transferred stone; An infrared dryer for drying the washed stone to activate its surface; An air ejector provided between the water washer and the infrared dryer and blowing air at a pressure of 2.0 to 6.0 kgf / cm 2 to the surface of the stone; A photocatalyst coater for coating a photocatalyst coating on the surface of the activated stone; And Eco-friendly functional stone manufacturing apparatus comprising an infrared heat treatment machine for curing the photocatalyst coating agent. delete The eco-friendly functional stone manufacturing apparatus of claim 9, wherein the water washer is adjustable in position and includes washing nozzles for three-dimensionally washing the stone by ejecting water at a pressure of 0.2 to 2.0 kgf / cm 2. 10. The method of claim 9, wherein the coating device is position adjustable and eco-friendly functional stone manufacturing apparatus comprising a spray for three-dimensionally coating the stone by spraying a photocatalyst coating at a pressure of 0.5 to 6.0 kgf / ㎠.

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