KR20230156624A - Manufacturing method for hybrid type photocatalyst coating materials with enhanced antibacterial function - Google Patents

Abstract

The present invention is a hybrid photocatalyst coating with enhanced antibacterial function, which creates TiO2 photocatalyst particles with an anatase structure, surrounds the TiO2 photocatalyst particles, and deposits Ti-Cu compounds in the form of porous capsules on the surface of the particles. It relates to a photocatalytic coating agent that can achieve antibacterial and sterilizing effects while simultaneously providing chemical resistance, contamination resistance, and binder damage prevention effects.
In addition, in addition to this, a partial hydrolyzate of a Ti-Si-Zr chelate compound and a reactive silicon compound is separately prepared and a hydrothermal synthesis reaction is induced by mixing the two to provide a photocatalyst coating agent that does not exist previously.
By doubling the antibacterial/sterilizing power using the hybrid photocatalytic coating of the present invention, there is an effect of preventing the propagation of bacteria and viruses in indoor spaces, and it can be coated on organic polymer materials including plastic and painted surfaces, and the durability of the coating film is excellent. .
In addition, it has excellent fouling resistance, preventing a decrease in oxidation ability due to catalyst poison and maintaining a clean coating surface. It maintains the anatase structure, stably contains antibacterial metal components, and has an adsorption capacity without affecting the photocatalyst oxidation ability. and chemical resistance can be improved.
Additionally, since the manufacturing process is carried out at a relatively low temperature compared to the prior art, industrial productivity is excellent, and there is an advantage in that the application limit of the photocatalytic coating agent so far can be greatly expanded.

Description

{Manufacturing method for hybrid type photocatalyst coating materials with enhanced antibacterial function}

The present invention is a hybrid photocatalyst coating with enhanced antibacterial function, which manufactures a photocatalyst intermediate (hydroxide) and a binder intermediate (Ti-Si-Zr chelate compound, silane partial hydrolyzate), which are intermediate steps in the chemical process, respectively, and prepares them in a predetermined manner. By mixing in proportions, the finished product (titanium oxide, metal oxide, silicon polymer) is created through a hydrothermal synthesis process, and TiO2 photocatalyst particles with an anatase structure are created to surround the TiO2 photocatalyst particles and form a Ti-Cu compound on the surface of the particles. It relates to a photocatalyst coating that has a structure in which the is precipitated in the form of a porous capsule, and thus has the effect of enhancing antibacterial and sterilizing properties while simultaneously providing chemical resistance, contamination resistance, and binder damage prevention effects.

In addition, in addition to this, a partial hydrolyzate of a Ti-Si-Zr chelate compound and a reactive silicon compound are separately prepared and a hydrothermal synthesis reaction is induced by mixing the two to provide a photocatalyst coating agent that does not exist in the past.

Conventional photocatalytic coating agents are generally composed of three main components: photocatalyst particles, binder, and solvent.

However, the main raw materials of the photocatalysts that make up these conventional photocatalytic coatings are inorganic materials such as titanium dioxide, and due to the chemical characteristics of these inorganic materials, there is a problem of damaging the binder component or the surface of the object to be coated due to the strong oxidizing power that the inorganic materials inevitably have. Ultimately, there was a problem in which the coating could not perform its original function due to serious damage such as discoloration or rupture of the coating film itself after photocatalytic coating.

To overcome this, the binder for photocatalyst was mainly made of a mixture of inorganic materials, but in this case, there was a limitation that it was difficult to apply due to weak adhesion to plastic and painted surfaces, which are polymer materials that are coated, and existing photocatalyst coatings were made of plastic or Because it was difficult to directly coat metals, there was a limitation in that photocatalyst coating was performed after base coating, or an organic binder was mixed with the coating agent itself.

Recently, a hybrid binder that uses both organic and inorganic materials has been used, but there are limits to the application of the hybrid binder, and there is a limit to preventing problems with the durability of the coating film itself from occurring due to the oxidation power due to the chemical characteristics of the photocatalyst described above. .

Therefore, there is an urgent need to develop a hybrid photocatalyst coating technology that includes a structure that can control photocatalyst materials with strong oxidation power due to their chemical characteristics and a composition that can play the role of a stable binder with a mixture of organic/inorganic materials. am.

Republic of Korea Patent Publication No. 10-1757568

There are many technical methods to remove microorganisms such as odorous gases and bacteria in everyday living spaces. Air purification is achieved by simply coating existing facilities, decorations, and walls without applying heat or using a special reaction device. Photocatalyst coating technology, which can achieve antibacterial and anti-pollution effects, is commonly applied.

Due to the nature of the photocatalyst, it is unique in its ability to oxidize and remove trace amounts of non-decomposable organic compounds, but there is a problem that the reaction efficiency for various removal targets under various environmental conditions is quite low with simple existing photocatalyst materials. First, odorous gases can be classified into various types of substances, such as inorganic, organic, acidic, or alkaline, but generally exist as a mixture of various types of gases. There are limitations to existing neutralization or adsorption methods alone, and there are also significant limitations to using existing organic antibacterial agents or disinfectants in terms of technology for removing or preventing the development of microorganisms such as bacteria, viruses, and molds. Therefore, considering the harmfulness of the above-mentioned bacteria, viruses, and molds to the environment and the human body, an alternative method must be devised as soon as possible.

In order to solve the above-described problems, the present invention includes an aqueous dispersion of copper-containing titanium hydroxide, a Ti-Si-Zr alkoxide chelate, and a silane partial hydrolyzate, wherein the aqueous dispersion of titanium hydroxide containing copper is obtained by neutralizing titanium metal salt. It is a dispersion obtained by ultrasonic dispersion treatment by adding titanium oxide and titanium-copper complex, and the Ti-Si-Zr alkoxide chelate contains titanium alkoxide, silicon alkoxide, zirconium alkoxide, and a chelating agent, and the silane. The partially hydrolyzed product can provide a hybrid photocatalyst coating with enhanced antibacterial function, characterized by containing trialkoxysilane.

More specifically, the copper-containing titanium hydroxide aqueous dispersion contains 10 to 20% of titanium-copper complex compared to titanium oxide, and the titanium-copper complex may contain CuO in an amount of less than 20% compared to TiO2 and stirred.

In this case, the Ti-Si-Zr alkoxide chelate is a mixed Ti, Si, and Zr alkoxide containing 1 to 2 times of SiO2 as TiO2 and 0.5 to 2 times of ZrO2 as the sum of TiO2 and SiO2. It is preferably produced by adding a chelating agent to a weight ratio of 1:1 with the mixed Ti, Si, and Zr alkoxides.

In addition, the silane partial hydrolyzate is hydrolyzed at pH 2 to 5 and can be produced while maintaining a temperature of 60 degrees Celsius or less.

Additionally, the silane partially hydrolyzed product preferably has a water ratio of 0.1 mol to 0.5 mol per 1 mol of alkoxysilane. In this case, the reaction product alcohol generated during the hydrolysis process can be removed by distillation under reduced pressure. .

The hybrid photocatalytic coating further includes a solvent and a surfactant. The solvent is water or a mixture of water and an organic solvent, and the organic solvent includes an alcohol compound, a ketone compound, an ether compound, an ester compound, an aromatic compound, and an amide. It is preferable that at least one of the compounds is included, and the surfactant is a nonionic surfactant.

In addition, not only the photocatalyst coating agent itself described above but also a method for producing the photocatalyst coating agent may be provided.

Specifically, the copper-containing titanium hydroxide aqueous dispersion, Ti-Si-Zr alkoxide chelate, and silane partial hydrolyzate are mixed. Solid content of copper-containing titanium hydroxide aqueous dispersion: Solid content of Ti-Si-Zr alkoxide chelate: Silane partial hydrolyzate. A coating agent production step of mixing solids in a ratio of 1:0.5-1.0:0.2-0.5, maintaining the mixture at 120°C or higher for more than 6 hours, and then cooling to room temperature to produce a photocatalytic coating, and solvent and interface in the coating agent produced after the coating agent production step. A method for manufacturing a hybrid photocatalyst coating with enhanced antibacterial function including a mixing step of mixing activators can be provided.

In this case, the copper-containing titanium hydroxide aqueous dispersion used in the above production step is a titanium hydroxide obtaining step of neutralizing the titanium metal salt to obtain a precipitate, mixing titanium metal salt and copper metal salt and stirring to prepare a titanium-copper complex. Titanium-copper composite manufacturing step and adding the prepared titanium-copper composite to the titanium hydroxide, stirring for 2 hours, stabilizing for 24 hours, and colloidizing by ultrasonic dispersion treatment to produce an aqueous dispersion of copper-containing titanium hydroxide. It is preferable that it is produced including a step of producing a hydroxide water dispersion.

In addition, the chelated product in the production step includes an alkoxide mixing step of mixing titanium alkoxide, silicon alkoxide, and zirconium alkoxide, a mixture production step of mixing a chelating agent with the alkoxide mixed through the alkoxide mixing step, and the above. It is preferable that the mixture be produced by including a chelate production step of stirring the mixture at 70°C for 12 hours.

By doubling the antibacterial/sterilizing power using the hybrid photocatalytic coating of the present invention, there is an effect of preventing the propagation of bacteria and viruses in indoor spaces, and it can be coated on organic polymer materials including plastic and painted surfaces, and the durability of the coating film is excellent. .

In addition, it has excellent fouling resistance, preventing a decrease in oxidation ability due to catalyst poison and maintaining a clean coating surface. It maintains the anatase structure, stably contains antibacterial metal components, and has an adsorption capacity without affecting the photocatalyst oxidation ability. and chemical resistance can be improved.

Additionally, since the manufacturing process is carried out at a relatively low temperature compared to the prior art, industrial productivity is excellent, and there is an advantage in that the application limit of the photocatalytic coating agent so far can be greatly expanded.

The terms used in this application are only used to describe specific examples. Therefore, for example, a singular expression includes a plural expression, unless the context clearly requires it to be singular. In addition, terms such as “comprise” or “comprise” used in the present application are used to clearly indicate the presence of features, steps, functions, components, or combinations thereof described in the specification, and are used to clearly indicate the presence of other features. It should be noted that it is not used to preliminarily rule out the existence of any elements, steps, functions, components, or combinations thereof.

Meanwhile, unless otherwise defined, all terms used in this specification should be viewed as having the same meaning as generally understood by those skilled in the art to which the present invention pertains. Therefore, unless clearly defined in this specification, specific terms should not be interpreted in an overly idealistic or formal sense.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement it. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

The photocatalytic oxidation reaction of the present invention refers to the generation of electrons and holes when light energy greater than the band gap energy is irradiated to the photocatalyst, and the strong oxidation power of the hydroxyl radical (·OH) generated by the hole is adsorbed to the surface of the photocatalyst. It refers to a reaction in which organic matter in the gas or liquid phase is decomposed.

In other words, the photocatalyst exhibits catalytic activity by absorbing light energy, and the strong oxidizing power generated at this time oxidizes and decomposes environmental pollutants.

There are many technical methods to remove microorganisms such as odorous gases and bacteria in everyday living spaces. Air purification is achieved by simply coating existing facilities, decorations, and walls without applying heat or using a special reaction device. Photocatalyst coating technology, which can achieve antibacterial and anti-pollution effects, is commonly applied.

Due to the nature of the photocatalyst, it is unique in its ability to oxidize and remove trace amounts of non-decomposable organic compounds, but there is a problem that the reaction efficiency for various removal targets under various environmental conditions is quite low with simple existing photocatalyst materials. First, odorous gases can be classified into various types of substances, such as inorganic, organic, acidic, or alkaline, but generally exist as a mixture of various types of gases. There are limitations to existing neutralization or adsorption methods alone, and there are also significant limitations to using existing organic antibacterial agents or disinfectants in terms of technology for removing or preventing the development of microorganisms such as bacteria, viruses, and molds. Therefore, considering the harmfulness of the above-mentioned bacteria, viruses, and molds to the environment and the human body, an alternative method must be devised as soon as possible.

The present invention describes a photocatalytic coating agent that can easily remove non-decomposable harmful gases and at the same time strongly inhibit or kill harmful microorganisms and a method of manufacturing the photocatalytic coating agent.

In particular, it relates to a photocatalytic coating agent that has an enhanced sterilizing/antibacterial effect compared to the conventional Kwak Chongmae coating agent and is easily coated on polymer surfaces such as plastics and painted surfaces, enabling a strong photocatalytic oxidation reaction and excellent wear resistance, resulting in excellent durability of the coating film.

In the present invention, this photocatalytic coating agent contains a copper component and induces chemical bonding with inorganic oxide particles, resulting in higher photocatalytic activity and enhanced antibacterial properties. At the same time, it protects copper-containing anatase particles, which are photocatalyst materials, and prevents contamination by photooxidation. It is possible to manufacture a photocatalyst coating agent with excellent chemical resistance and wear resistance by combining an inorganic oxide, which facilitates the reaction and prevents the oxidation efficiency from being reduced by catalyst poisons, to the surface area.

A representative technical method that can effectively remove contaminants using photocatalysts is the applied oxidation method. In particular, the catalytic oxidation method must be able to quickly adsorb and absorb odorous gases and easily oxidize and decompose them. Since odorous gases often contain a large amount of moisture, when catalytic oxidation is induced at high temperature, the large amount of moisture causes Since the energy consumption required to heat the catalyst is large, it must be possible to effectively remove odor components at relatively low temperatures.

Types of odor components include nitrogen oxides (NOx), sulfur oxides (SOx), aldehydes such as acetaldehyde and formaldehyde, sulfides such as hydrogen sulfide, mercaptan, and methyl sulfide, and fatty acids such as acetic acid, propionic acid, and valeric acid. , amines such as dimethylamine and trimethylamine, and hydrocarbons such as aliphatics and aromatics.

The present invention produced an anatase titanium dioxide (TiO2) photocatalyst containing a copper (Cu) component and a porous inorganic oxide capsule structure on the surface through a hydrothermal crystallization technique.

Additionally, a metal oxide-siloxane compound as a binder component was prepared through a sol-gel process, mixed with the above-described capsule structure photocatalyst, and used as the main ingredient of the photocatalyst coating agent of the present invention.

More specifically, 1) copper metal salt was added to titanium hydroxide prepared by acid-alkali precipitation, treated, and mixed to form copper hydroxide. 2) After adding the Ti-Si alkoxide chelating solution to the mixture, heat and stir at about 120℃ to prepare a photocatalyst particle dispersion containing copper oxide and Ti-Si oxide on the surface of TiO2 (anatase) particles. do. Through this process, it is possible to form new photocatalyst particles with enhanced antibacterial activity by copper components, enhanced adsorption performance by Ti-Si composite oxide, and surface protection functions. This photocatalyst can demonstrate antibacterial performance even in environments where ultraviolet rays are not irradiated, and improves the surface reaction performance of the photocatalyst by increasing the adsorption capacity for odorous components or microbial particles. At the same time, it improves the surface reaction performance of the photocatalyst and the surrounding binder components that form the contact interface with the photocatalyst and the surface to be coated. Damage to the substrate can be suppressed, resulting in excellent durability of the coating film and excellent adhesion performance to polymer objects.

In addition, it can maintain the high activity of the photocatalyst semi-permanently and serves as a stabilizing photocatalyst material for the binder component.

3) Additionally, the binder component contains an inorganic metal compound that is resistant to contamination and is not damaged by photooxidation through a condensation reaction by mixing a Ti-Si-Zr ternary chelate and a partial hydrolyzate of a reactive silicon compound. A siloxane resin was prepared. Ultimately, a useful photocatalytic coating agent can be manufactured by mixing these photocatalyst materials and a binder at a certain ratio.

Hereinafter, embodiments of the present invention will be described in detail.

(Preparation of copper-containing titanium hydroxide aqueous dispersion)

Titanium dioxide can be manufactured through various processes, but representative examples include the sol-gel process, precipitation method, and evaporation method. In the case of the precipitation method during the above manufacturing process, aqueous solutions of titanium sulfate (Ti(SO4)2), titanyl sulfate (TiOSO4), and titanium chloride (TiCl4) are neutralized by adding an aqueous alkali solution such as sodium hydroxide (NaOH). This is a method of obtaining crystalline photocatalytic nanoparticles by obtaining a precipitate, drying it, and heat-treating it at high temperature.

Typically, antibacterial metal components such as Ag, Cu, and Zn are added to the photocatalyst and its coating agent made by the above-described method to increase the antibacterial effect. However, antibacterial metal components added through this method cause problems such as discoloration or lowering the activity of the photocatalyst, and have the disadvantage that the effect is difficult to maintain for a long period of time. In addition, the harmfulness caused by the leakage of antibacterial metal ions is also a problem.

Therefore, in the present invention, in order to allow the above-mentioned antibacterial metal component to exist more stably inside the coating and not affect the activity level of the photocatalyst, a compound of titanium and antibacterial metal is formed to form a porous capsule on the surface of the photocatalyst particle. By allowing it to exist, a structure is disclosed that can stably exhibit an antibacterial effect for a long period of time and at the same time block some of the oxidizing power of the photocatalyst, thereby suppressing damage to the binder material and surface to be coated.

In addition, since this capsule-type Ti-Cu compound acts as an adsorbent, it can more easily adsorb and decompose odorous components or microorganisms, contributing to improving the catalytic activity of the photocatalyst and increasing the catalytic function of the photocatalyst.

To this end, the production of photocatalyst particles containing copper components in the present invention is technically accomplished through the processes of precipitation and impregnation.

A titanium metal salt aqueous solution is neutralized and titrated with an alkaline aqueous solution to obtain a titanium hydroxide precipitate. A metal salt aqueous solution containing a predetermined mixture of titanium and copper is separately added, and through a series of processes, titanium and copper ions are deposited on the surface of the titanium hydroxide particles. It is manufactured into a fine colloidal phase within 1 nm to 50 nm. Next, an alkaline component is added to maintain pH = 9, and a composite hydroxide of titanium and copper is formed on the surface of the titanium hydroxide.

Next, a series of processes are carried out to chemically bond the amorphous titanium-copper composite oxide to the surface at the same time as crystallization of titanium dioxide by maintaining it in a water-dispersed state without a drying process and maintaining it at a high temperature and high pressure of 120°C or higher for a certain period of time. It is possible to induce Therefore, an aqueous anatase-type photocatalyst dispersion with antibacterial metal components stably attached to the surface can be used.

More specifically,

In the present invention, at least one of titanium sulfate (Ti(SO4)2), titanyl sulfate (TiOSO4), and titanium chloride (TiCl4) is selected as a titanium metal salt, and water is added to make an aqueous solution and stirred.

While stirring, an alkaline aqueous solution made by adding water to one selected from alkaline components such as ammonia water (NH4OH), soda carbonate (NaCO3), and sodium hydroxide (NaOH) is slowly added dropwise until the pH reaches 9 to produce titanium hydroxide (Ti( Precipitates of OH)2) are generated.

The titanium hydroxide obtained in the above-described process is sufficiently washed with water and then dispersed in a certain amount of distilled water to prepare an aqueous dispersion of titanium hydroxide (hereinafter referred to as titanium oxide).

Separately, at least one titanium component among titanium sulfate and titanium nitrate as the titanium component and at least one copper component among copper sulfate, copper nitrate, and copper acetate as the copper component are selected to form a mixture of the titanium component (metal salt) and the copper component (metal salt). ) are mixed in a predetermined ratio and stirred for more than 1 hour to prepare a titanium-copper composite.

In this case, the content ratio of titanium oxide and titanium-copper complex should not exceed 20% of the titanium-copper complex compared to titanium oxide. More preferably, it is 10 to 20%.

In addition, this addition ratio can be adjusted in advance in relation to the addition concentration of the titanium salt and copper salt aqueous solution in the composition of the titanium-copper complex. If the CuO content in the titanium-copper composite is more than 10% of TiO2, the yield of anatase-type TiO2 will decrease and the photocatalytic performance will be lowered, and if it is less than 5%, it may be difficult to obtain a satisfactory antibacterial and deodorizing effect. It is possible to achieve optimal effect by adjusting the composition of the titanium-copper composite and the amount of titanium oxide mixed.

The titanium-copper complex obtained by the above-described method is added to the titanium hydroxide aqueous dispersion (titanium oxide), stirred at high speed for 2 hours, and left to stand for 24 hours.

Afterwards, the aqueous dispersion of copper-containing titanium hydroxide was made into a colloid with a size of less than 1 micrometer through ultrasonic dispersion treatment. To this aqueous dispersion of copper-containing titanium hydroxide, Ti alkoxide and Si alkoxide are mixed in a predetermined ratio and added with a predetermined amount of water, and an aqueous dispersion of Ti-Cu hydroxide (copper-containing titanium hydroxide) with a solid content concentration of 20-30% is added. By adding the process of producing an aqueous dispersion, a crystallized titanium dioxide photocatalyst encapsulated in a porous mineral containing antibacterial metal components is produced.

In addition, it is possible to synthesize an antibacterial copper-containing titanium hydroxide aqueous dispersion while containing porous Ti-Si oxide on the surface through a hydrothermal synthesis reaction at 100°C-110°C.

Another method for producing an aqueous dispersion of copper-containing titanium hydroxide provided by the present invention is,

(1) Add 500 ml of distilled water or ion-exchanged water to a 1000 ml glass beaker placed on a magnetic stirrer, and while cooling and stirring to maintain the temperature below 10°C, 15 g of titanium sulfate {Ti(SO ₄ ) ₂ } was slowly added dropwise and stirred for 10 minutes. Perform continuously. While continuing to stir, 0.5 g of copper nitrate {Cu(NO ₃ ) ₂ 3H ₂ O} was slowly added, stirred for 30 minutes, and ammonia water (NH ₄ OH, 0.5 mol/l) was slowly added dropwise to reach pH 7. Perform. Through the above process, a blue-white precipitated product can be obtained. In this state, stirring is stopped and maintained for 12 hours. Next, the above precipitated product is separated and filtered, and then sufficiently washed with ion-exchanged water to obtain a titanium hydroxide gel containing Cu component (copper hydroxide). Add ion-exchanged water here to create a mixed solution with an appropriate concentration (about 10 wt% in terms of TiO ₂ ). Afterwards, ammonia water (28%) was added to the mixed solution to bring the pH to 9.5, and then dispersion was performed for 3 hours using an emulsification mixer (homo. mixer) to form a Ti-Cu mixed hydroxide colloid in the form of fine particles (1 nm to 100 nm). Let it form.

Separately, prepare a mixture of 70 ml of isopropyl alcohol and 20 ml of acetylacetone, and while stirring at room temperature, slowly add 15 g of titanium tetraisopropoxide and 10 g of tetra ethylsilicate as silicon alkoxide, then stir vigorously for 30 minutes. It is possible to prepare an aqueous dispersion of Ti-Cu hydroxide (A) by stirring to create an alkoxide mixture and gradually adding it to the Ti-Cu mixed hydroxide and stirring for 30 minutes.

(2) Alternatively, add 500 ml of distilled water or ion-exchanged water to a 1000 ml glass beaker placed on a magnetic stirrer, and slowly add 15 g of titanium sulfate {Ti(SO ₄ ) ₂ } dropwise while cooling and stirring to maintain the temperature below 10°C and stir for 10 minutes. Stirring is carried out continuously. While continuing the above stirring, 1 g of copper nitrate {Cu(NO ₃ ) ₂ 3H ₂ O} was slowly added and stirred for 30 minutes, and then ammonia water (NH ₄ OH, 0.5 mol/l) was slowly added dropwise to adjust the pH to 7. Through this process, a blue-white precipitated product can be obtained, at which point stirring is stopped and allowed to remain stagnant for 12 hours. Afterwards, the above precipitated product is separated and filtered and thoroughly washed with ion-exchanged water to obtain a titanium hydroxide gel containing Cu component (copper hydroxide). Add ion-exchanged water here to create a mixed solution with an appropriate concentration (about 10 wt% in terms of TiO ₂ ). Then, ammonia water (28%) was added to the pH to 9.5, and then dispersed for 3 hours using an emulsification mixer to form fine particles (1 nm to 100 nm) into Ti-Cu mixed hydroxide colloid. to form.

Separately, prepare a mixed solution of 70 ml of isopropyl alcohol and 20 ml of acetylacetone, and while stirring at room temperature, 15 g of titanium tetraisopropoxide and 10 g of tetra ethylsilicate as silicon alkoxide were slowly added thereto and stirred vigorously for 30 minutes. It is also possible to prepare an aqueous dispersion (B) of Ti-Cu hydroxide by stirring vigorously to create an alkoxide mixture and gradually adding it to the Ti-Cu mixed hydroxide and stirring for 30 minutes.

This type of titanium dioxide photocatalyst particle not only has enhanced antibacterial performance, but also has titanium-copper oxide (Ti-Cu oxide) attached (encapsulated) to the surface of the titanium dioxide particle in a porous form, allowing it to be used under conditions where ultraviolet rays are not irradiated. Not only does it demonstrate strong antibacterial power stably for a long period of time, but the strong oxidizing power of titanium dioxide has a blocking (insulating) effect from adjacent binders or the surface of the surface to be coated, which broadens the selection of binders and expands the range of materials applied to the surface to be coated. It will have a huge impact.

In other words, compared to simple treatments such as the addition of existing antibacterial metal salt aqueous solutions or metal ion impregnation, the durability of the stable photocatalyst oxidation ability is greatly improved, and long-term antibacterial activity is maintained while maintaining safety to the human body and the surrounding environment without prior treatment. It is an advantageous method that allows direct one-time photocatalytic coating treatment and at the same time greatly improves the durability of the coating film.

The coating agent manufactured by the above-described method has a Ti-Cu oxide particle structure rather than a TiO2 or anatase-type single particle as a photocatalyst, thereby improving antibacterial and deodorizing performance in the visible light region and additionally serving as a protective film for photocatalyst particles. Ti-Si composite oxide particles, which are a capsule component, not only improve the chemical resistance and contamination resistance of the photocatalyst coating film and do not oxidize the binder of the coating film itself, but also prevent damage to the surface of the substrate in contact with the photocatalyst coating film.

(Preparation of chelate of Ti-Si-Zr alkoxide)

The metal chelate used in the present invention is made using a chelating agent such as metal alkoxide and ketones, and can serve as a main ingredient as a photocatalyst binder of the present invention.

First, the alkoxides used in the present invention are of the following three types and are used by mixing them in an appropriate ratio.

Specifically, these metal alkoxides can be expressed by the general formula below.

Ti(OR1)n ----- (1)

Si(OR2)n ----- (2)

Zr(OR3)n----- (3)

The formula (1) above is titanium alkoxide, (2) is silicon alkoxide, and (3) is zirconium alkoxide. The present invention discloses a configuration in which these are mixed and used in a certain ratio.

Here, n is the valence of the metal, and R may be an organic group having 1 to 6 carbon atoms. The organic group in question may have a structure of any one of a methyl group, an ethyl group, and an isopropyl group.

The above three types of alkoxides are mixed in an appropriate ratio, a predetermined amount of ethanolamine, beta-diketone, and/or beta-keto ester is added as a chelating agent, and a chelation reaction is induced to finally produce a Ti-Si-Zr chelate compound. can be manufactured.

In this case, the present invention can use amines, ketones, or keto esters as chelating agents in order to adjust the progress rate of the chelated product during the hydrolysis process so that it does not overtake the condensation rate of the reactive alkoxysilane compound.

Types of metal alkoxides that can be used in the present invention include:

In the case of formula (1) above, specific examples include titanium tetraisopropoxide and titanium tetrabutoxide,

In the case of formula (2) above, tetramethoxysilane, tetraethoxysilane, etc. can be mentioned.

In the case of formula (3) above, examples include zirconium tetraethoxide, zirconium tetraisopropoxide, zirconium tetrabutoxide, and zirconium tetrabentoxide.

Additionally, as a chelating agent, at least one of monoethanolamine, diethanolamine, triethanolamine, acetylacetone, methyl acetoacetate, ethyl acetoacetate, diethyl malonate, and ethyl phenoxyacetate can be used in combination.

More specifically, Ti-Si-Zr mixed alkoxide is made by adjusting the ratio of Ti, Si, and Zr alkoxide so that TIO2/SiO2=0.5∼1 and (TiO2+SiO2)/ZrO2=0.5-2.5. It is desirable,

A chelating agent is added to the mixed Ti, Si, and Zr alkoxides in a weight ratio of 1:1, and stirred at 70°C for more than 12 hours to obtain a Ti, Si, and Zr alkoxide chelate.

Additionally, in the present invention, it is possible to provide other manufacturing examples.

(1) Add 300ml of isopropyl alcohol to a 1000ml Erlenmeyer flask equipped with a thermometer and magnetic stirrer, add 50g of titanium tetraisopropoxide as titanium alkoxide, 10g of tetra ethylsilicate as silicon alkoxide, and 20g of zirconium tetrabuthoxide as zirconium alkoxide. After sequential addition, stirring at room temperature for 5 minutes, then 100 ml of acetylacetone (Acetylacetone) was added over 10 minutes and stirred vigorously at room temperature for 20 minutes to prepare mixed chelate of Ti-Si-Zr alkoxide (A). It is possible.

(2) Alternatively, add 300 ml of isopropyl alcohol to a 1000 ml Erlenmeyer flask equipped with a thermometer and magnetic stirrer and add 50 g of Tetra ethylsilicate as silicon alkoxide, 30 g of Titanium tetraisopropoxide as titanium alkoxide, and Zirconium tetrabuthoxide as zirconium alkoxide. After adding 10 g sequentially, stirring at room temperature for 5 minutes, then 100 ml of acetylacetone was added over 10 minutes and stirred vigorously at room temperature for 20 minutes to form a mixed chelate of Ti-Si-Zr alkoxide (B). Manufacturing is also possible.

The Ti, Si, Zr alkoxide chelate maintains the photocatalytic oxidation function by creating Ti, Si, and Zr complex oxides that may exist adjacent to the photocatalyst particles, and at the same time has the effect of improving the surface fouling resistance of the coating film.

(Preparation of reactive silane partial hydrolyzate)

In general, a partially hydrolyzed product can be obtained through a predetermined process using a hydrolyzable alkoxysilane.

In the present invention, trialkoxysilane is used among organo alkoxysilanes having a reactive group, and this can be expressed by the following formula.

General formula RSi(OR4)3 ------(4)

R in the above formula is γ-chloropropyl group, vinyl group, 3,3,3-trifluoropropyl group, r-glycidoxypropyl group, r-methacryloxypropyl group, γ-mercaptopropyl group, 3 , 4-epoxycyclohexylethyl group is applicable, of which vinyl group, r-glycidoxypropyl group, and r-methacryloxypropyl group are more preferable.

In addition, R4 is an alkyl group or acyl group and includes methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, tert-butyl group, acetyl group, etc. In the present invention, the methyl group is It is more desirable.

Such alkoxysilanes can be used alone or in a mixture of two or more types, and examples of such alkoxysilanes are as follows. Examples include 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, or 2-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, which have an epoxy group.

Additionally, examples of silane compounds having a vinyl group include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl triethoxysilane, or 3-methacryloxypropyl triethoxysilane. Acryloxypropyltrimethoxysilane, etc. can be mentioned.

And N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, N-2-(aminoethyl)-3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, 3-Aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, etc. may be used. Additionally, 3-isocyanatopropyl triethoxysilane or 3-isocyanatopropyl trimethoxysilane having an isocyanate group may also be used.

Among them, 3-glycidoxypropyl trimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, 3-methacryloxypropyl trimethoxysilane, N-2-(amino Ethyl)-3-aminopropyl trimethoxysilane and the like are more preferable.

At least one of the above reactive alkoxysilanes is selected and hydrolysis is performed at a predetermined temperature and under an acid catalyst.

In the partial hydrolysis of the present invention, the pH is maintained at 2-6, more preferably at 2-5, and the reaction temperature is preferably 60°C or lower.

Additionally, the amount of water added was 0.1 to 0.5 mole of water per 1 mole of the hydrolyzable group of the hydrolyzable alkoxysilane.

Under these conditions, hydrolysis proceeds for a certain period of time, and after completion of the process, the alcohol, which is a reaction product, is removed by distillation under reduced pressure.

As a more specific example, add 200 ml of ethanol (Ethyl alcohol) to a 1000 ml Erlenmeyer flask equipped with a thermometer, magnetic stirrer, and condenser, adjust to maintain the temperature below 10°C, and add 30 g of ethyl trimethoxysilane and 30 g of ethyl trimethoxysilane while stirring on ice. Add 20 g of phenyl trimethoxysilane and 5.0 g of vinyl trimethoxysilane sequentially and mix and stir for 30 minutes to form a uniform solution. Afterwards, 20 g of 1.0% nitric acid aqueous solution was added dropwise over 1 hour while maintaining the temperature below 10°C. After the dropwise addition, the reactive silane partial hydrolyzate (A) can be produced by stirring at room temperature for 3 hours and then allowing it to sit for 48 hours.

Alternatively, add 200 ml of methanol (Methyl alcohol) to a 1000 ml Erlenmeyer flask equipped with a thermometer, magnetic stirrer, and condenser, adjust to maintain the temperature below 10°C, cool with ice, and stir while mixing 30 g of Acryl trimethoxysilane and glycythoxypropyl trime. Add 15 g of Gricythoxy propyltrimethoxysilane and 10 g of Methyl trimethoxysilane sequentially and mix and stir for 30 minutes to form a uniform solution. Afterwards, 20 g of 1.0% nitric acid aqueous solution was added dropwise over 1 hour while maintaining the temperature below 10°C. After the dropwise addition, the mixture was stirred at room temperature for 3 hours and then allowed to stand for 48 hours to prepare a reactive silane partial hydrolyzate (B).

Through the above processes, a partial hydrolyzate of silane in the form of an oligomer having a silanol group (Si-OH) is finally produced. This is later mixed with the above complexes, leading to a condensation reaction in the hydrothermal synthesis process.

(Manufacture of photocatalytic coating agent)

The above copper-containing titanium hydroxide aqueous dispersion, Ti-Si-Zr alkoxide chelate, and silane partial hydrolyzate are mixed and stirred at high speed, maintaining the temperature at 120°C or higher for more than 6 hours to generate a hydrothermal synthesis reaction, and then returning to room temperature. After cooling, solvent and other additives were mixed to complete the photocatalyst coating.

The mixing ratio is explained below.

<Mixing ratio>

Copper-containing titanium oxide solid content = 1

Solid content of Ti-Si-Zr alkoxide chelate = 0.5∼1.0

Solid content of silane partial hydrolyzate = 0.2∼0.5

In other words, a photocatalyst coating agent having a hybrid structure of photocatalyst-inorganic oxide-silicon partial hydrolyzate can be obtained.

The ratio of each solid content of the final hydrolyzed product is preferably photocatalyst solid content: solid content of Ti-Si-Zr oxide: solid content of silicon condensate = 1:0.5 to 1.0:0.2 to 0.5.

The silane compound is hydrolyzed to form a Si-OH group, which is a silanol group. In addition, the hydroxyl groups (M-OH) formed during hydrolysis of the Ti-Si-Zr alkoxide chelate become functional groups and bond to each other, and the bonding power is also strong with Ti-Cu oxide, which is the surface encapsulation of titanium dioxide photocatalyst particles. As a result, the three main components form a strong chemical bond and form a more stable compound.

Therefore, this combination can form a photocatalyst coating film with excellent adhesion performance and durability on the surface of polymer materials such as plastic while maintaining strong photooxidation power, antibacterial power, and contamination resistance, making it possible to manufacture a photocatalyst coating with new effects compared to the conventional technology. You can.

In addition, since it has a functional group that can bind to a partially hydrolyzed product, it forms an organic-inorganic hybrid structure, maintaining hydrophilicity and exhibiting a strong photooxidation ability of a photocatalyst, while also having excellent physical properties such as adsorption performance, chemical resistance, and durability. .

As described above, the Ti-Si-Zr-based amorphous oxide can form a more dense network structure by forming a siloxane bond with a reactive alkoxysilane compound, and the hardness and refractive index of the photocatalyst coating film can be adjusted depending on its added content.

The copper-containing titanium hydroxide aqueous dispersion prepared above, the Ti-Si-Zr alkoxide chelating solution, and the reactive silane compound are mixed in a certain ratio and stirred for more than 2 hours to induce hydrolysis and crystallization reactions at a temperature of 120°C or higher. Through the hydrothermal synthesis reaction process, it was possible to obtain a dispersion of Ti-Si-Zr oxide particles in a coexistence with crystalline (anatase) TiO2 particles containing Cu.

Additionally, the crystalline TiO2 of anatase structure was confirmed through the XRD analysis pattern, while the Ti-Si compound phase was confirmed to be an amorphous phase.

The composite photocatalyst dispersion obtained in this way has superior durability compared to a single or simple TiO2 monolith, and has basic characteristics that can suppress chocking of the coating film itself even when an organic binder is used.

In addition, it becomes possible to create a photocatalyst material that not only has strong antibacterial and deodorizing properties even in the visible light range, but also has excellent chemical resistance and contamination resistance of the coating film.

Through this hydrothermal reaction, the anatase photocatalyst structure was crystallized, and an amorphous inorganic oxide was coexisted to produce a photocatalyst material with enhanced antibacterial activity in a stable state.

The photocatalyst dispersion and the binder composite are measured and mixed at a certain ratio, and the following solvent and surfactant are added to produce a photocatalyst coating agent for coating plastic surfaces.

In order to confirm the mixing ratio and antibacterial activity of the above photocatalyst coating composition, it is possible to provide additional information.

(Product 1)

100 g of the aqueous dispersion of Ti-Cu hydroxide (A), 80 g of mixed chelate of Ti-Si-Zr alkoxide (A), and 50 g of reactive silane partial hydrolyzate (A) were sequentially and slowly mixed and placed in a hydrothermal synthesis reactor. Then, the photocatalyst coating agent (Product 1) is prepared by gradually heating and stirring at 120°C for 8 hours and gradually cooling to room temperature.

(Product 2)

100 g of the aqueous dispersion of Ti-Cu hydroxide (B), 80 g of mixed chelate of Ti-Si-Zr alkoxide (B), and 50 g of reactive silane partial hydrolyzate (B) were sequentially and slowly mixed and placed in a hydrothermal synthesis reactor. Then, the mixture is gradually heated and stirred at 120°C for 8 hours and slowly cooled to room temperature to prepare a photocatalyst coating agent (Product 2).

(Comparative 1)

50 g of the aqueous dispersion of Ti-Cu hydroxide (A), 100 g of mixed chelate of Ti-Si-Zr alkoxide (A), and 100 g of reactive silane partial hydrolyzate (A) were sequentially and slowly mixed and placed in a hydrothermal synthesis reactor. Then, the photocatalyst coating agent (comparative material 1) was prepared by gradually heating and stirring at 120°C for 8 hours and gradually cooling to room temperature.

(Comparative 2)

50 g of the aqueous dispersion of Ti-Cu hydroxide (B), 100 g of mixed chelate of Ti-Si-Zr alkoxide (B), and 100 g of reactive silane partial hydrolyzate (B) were sequentially and slowly mixed and placed in a hydrothermal synthesis reactor. Then, the photocatalyst coating agent (comparative material 2) was prepared by gradually heating and stirring at 120°C for 8 hours and gradually cooling to room temperature.

<Test antibacterial activity of product and comparative product>

The antibacterial activity test is performed as follows. 1.5±0.3X per strain /ml concentration of Staphylococcus aureus (ATCC 6538) and strain 2, 1.3± 0.3X Using Escherichia coli (ATCC 25922) at a concentration of /ml, 0.4 g of the above product and the comparative photocatalyst were cultured in an enrichment medium at 35°C for 18 hours, and the number of bacteria was measured.

As shown in Table 1 below, the results show that in the case of Product 1 and Product 2, the remaining strains 18 hours after strain inoculation showed residual levels that could not be visually identified and showed strong antibacterial activity, whereas Comparative Product 1 In this case, the bacterial reduction rate was relatively low. It can be seen that the cause is that the content of titanium dioxide, which contains antibacterial ingredients, is low, showing little antibacterial effect. Likewise, it can be seen that Comparative Material 2 does not exhibit antibacterial activity.

Blank Entity 1 Entity 2 strain 1 Initial strain 1.7X 1.7× 1.7× 18 hours later 5.2× <10 <10 strain 2 Initial strain 1.3× 1.3× 1.3× 18 hours later 5.9× <10 <10 Blank Comparison 1 Comparison 2 strain 1 Initial strain 1.7× 1.7× 1.7× 18 hours later 5.2× 5.7 × 7.8 × strain 2 Initial strain 1.3× 1.3× 1.3× 18 hours later 5.9× 6.4 × 7.8 ×

(menstruum)

The solvent may be a solvent having a boiling point of 200° C. or lower at normal pressure, and in particular, water or a mixture of water and an organic solvent may be used. The organic solvent may be any one or more selected from the group consisting of alcohol compounds, ketone compounds, ether compounds, ester compounds, aromatic compounds, and amide compounds.

The organic solvent acts as a medium during the polymerization reaction, helping to uniformly disperse the initial raw materials, preventing rapid temperature rise during the polymerization reaction, and providing a uniform coating to the substrate.

Examples of the alcohol compounds include methanol, ethanol, isopropyl alcohol, isobutanol, n-butanol, t-butanol, ethoxyethanol, butoxyethanol, ethylene glycol monoethyl ether, benzyl alcohol, and phene. Ethyl alcohol, 1-methoxy-2-propanol, etc. can be mentioned.

Examples of ketone compounds include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

Examples of ether compounds include dibutyl ether, propylene glycol monoethyl ether acetate, and the like.

Examples of ester compounds include ethyl acetate, butyl acetate, ethyl lactate, methyl acetoacetate, ethyl acetoacetate, and 1-methoxy-2-propanol acetate.

Examples of aromatic compounds include toluene, xylene, and the like.

Examples of amide compounds include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

(Surfactants)

A surfactant may be added to improve the adhesion and leveling properties of the coating film of the photocatalytic coating agent in the present invention.

In particular, when anionic or cationic surfactants are used, phase separation phenomena such as precipitation in the coating solution may occur, so it is preferable to use only nonionic surfactants.

In this case, the nonionic surfactants include ether-type nonionic surfactants, ether ester-type nonionic surfactants, ester-type nonionic surfactants, block polymer-type nonionic surfactants, fluorine-based nonionic surfactants, and nitrogen-containing nonionic surfactants. Surfactants, etc. can be mentioned.

Ether-type nonionic surfactants include single-chain polyoxyethylene ether-type ether-type nonionic surfactants, polyoxyethylene fatty alcohol ether, polyoxyethylene alkyl allyl ether, and polyoxyethylene alkyl such as polyoxyethylene lanoline alcohol. Alternatively, alkyl allyl ethers, ethylene oxide derivatives of alkyl phenol formalin condensate, etc. may be mentioned.

Ether ester type nonionic surfactants include polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glyceryl mono fatty acid ester, polyoxyethylene propylene glycol fatty acid ester, and polyoxyethylene sorbitol fatty acid ester.

In addition, polyether alkyl-based surfactants include polyoxyethylene alkyl ether, polyoxyethylene allyl ether, polyoxyethylene alkyl phenolethyl, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and oxyethylene. Oxypropylene block polymer, etc. are mentioned.

Claims (3)

Copper-containing titanium hydroxide aqueous dispersion, Ti-Si-Zr alkoxide chelate, and silane partial hydrolyzate,
Solid content of copper-containing titanium hydroxide aqueous dispersion: Solid content of Ti-Si-Zr alkoxide chelate: Solid content of silane partial hydrolyzate mixed in a ratio of 1:0.5~1.0:0.2~0.5 and maintained at 120℃ or higher for more than 6 hours. A coating agent production step of producing a photocatalytic coating agent after cooling to room temperature; and
A mixing step of mixing a solvent and a surfactant with the coating agent produced after the coating agent generation step;
Method for manufacturing a hybrid photocatalytic coating with enhanced antibacterial function containing
According to paragraph 2,
The copper-containing titanium hydroxide aqueous dispersion used in the production step is,
A titanium hydroxide obtaining step of neutralizing titanium metal salt to obtain a precipitate;
A titanium-copper composite manufacturing step of mixing titanium metal salt and copper metal salt and stirring to prepare a titanium-copper composite; and
Adding the prepared titanium-copper complex to the titanium hydroxide, stirring for 2 hours, stabilizing for 24 hours, and colloidizing by ultrasonic dispersion treatment to produce a copper-containing titanium hydroxide aqueous dispersion. A step of producing a copper-containing titanium hydroxide aqueous dispersion;
Method for producing a hybrid photocatalytic coating with enhanced antibacterial function, characterized in that it is produced comprising:
According to paragraph 1,
The chelate cargo in the production step is,
An alkoxide mixing step of mixing titanium alkoxide, silicon alkoxide, and zirconium alkoxide;
A mixture producing step of mixing a chelating agent with the alkoxide mixed through the alkoxide mixing step; and
A chelate production step of stirring the mixture at 70° C. for 12 hours;
Method for producing a hybrid photocatalytic coating with enhanced antibacterial function, characterized in that it is produced comprising: