KR20050069866A - Waterborne photocatalytic inorganic coating compositions comprising ticl4 of nano particle - Google Patents

Abstract

The present invention relates to an aqueous inorganic photocatalyst coating containing ultrafine titanium dioxide prepared by a gas phase oxidation reaction, and more particularly, to preparing an ultrafine titanium dioxide photocatalyst by a vapor phase oxidation reaction, n = 2 ~ 3.8 by weight molar ratio 2.9 ~ 3.6) and one-liquid crosslinkable emulsion resin as immobilized ultrafine titanium dioxide, and then mixed with pigment dispersant, coloring pigment, sieving pigment, additive, thickener, and aqueous inorganic photocatalyst. It is characterized by providing a water-based inorganic photocatalyst paint that produces paint, while maintaining the physical properties of the inorganic paint, while maximizing the decomposition characteristics of contaminants.

In the case of the conventional photocatalyst, there is a problem in that the photocatalytic activity is not exhibited to the maximum and the photocatalyst is excessively used, and the weatherability is poor and the applicable coating is limited.

Accordingly, the present invention improves the fouling resistance as a photocatalyst paint, and has a photocatalytic paint excellent in preventing adhesion of contaminants, preventing deposition of contaminants, and removal performance of attached contaminants, viscosity stability, workability, chemical resistance, Immobilization method of ultra fine titanium dioxide composition which has the performance of fouling resistance, breathability, mold resistance, heat resistance, weather resistance, antibacterial property, deodorizing property, environmental friendliness and excellent adhesion to various materials, and aqueous inorganic material containing the composition It is characterized by providing a photocatalyst paint.

Description

Waterborne photocatalytic inorganic coating compositions comprising TiCl4 of nanoparticles

The present invention relates to an aqueous inorganic photocatalyst coating containing ultrafine titanium dioxide prepared by a gas phase oxidation reaction, and more particularly, to preparing an ultrafine titanium dioxide composition by a vapor phase oxidation reaction, , n = 2 ~ 3.8 weight molar ratio 2.9 ~ 3.6) and one-component crosslinking emulsion resin as a binder to immobilize ultrafine titanium dioxide, and then mixed with a pigment dispersant, a coloring pigment, a sieving pigment, an additive, and a thickener to form an aqueous inorganic material. By preparing a photocatalyst paint, it is intended to provide an aqueous inorganic photocatalyst paint that maximizes decomposition properties of contaminants while maintaining the physical properties of the inorganic paint. In addition, ultra-fine powder titanium dioxide, which has performances such as viscosity stability, workability, chemical resistance, fouling resistance, breathability, mold resistance, heat resistance, weather resistance, antibacterial property, deodorizing property, environmental friendliness, and excellent adhesion to various materials A method of immobilizing a composition and an aqueous inorganic photocatalyst coating containing the composition are provided.

Nano-size ultra fine powder generally refers to a powder having a particle size of 50 nm or less, and is widely used as a new material due to its high specific surface area and high activity per unit weight. Nano-size titanium dioxide ultra fine powder is used as a high-quality pigment and photocatalyst, and is also used as a coating material for cosmetics, drugs, and transparent soundproof panels using the same because of its excellent UV blocking property.

Nano-size titanium dioxide (hereafter As a method for producing ultra fine powder, a physical method of producing ultra fine powder by heating and evaporating a metal and then condensing metal vapor and a chemical method of producing a metal compound by chemical reaction are used. Nano size by physical method The process of preparing ultra fine powders requires a lot of energy to evaporate the metal, so the manufacturing cost is high and the productivity is low, while it is possible to prepare powders of high purity. Low cost and high productivity have advantages. Among the chemical methods, gas phase method and liquid phase method are used.

Nanosize in relation to the vapor phase method of the chemical method of the manufacturing method Ultra-fine powder production requires a high temperature of more than 1000 ℃ and a large amount of gas. For this purpose, a technology of reacting in the gas phase while maintaining a high temperature using a flame has been commercialized. Therefore, the technology of producing the ultra fine powder has not been disclosed as an important reaction variable or know-how that controls the temperature and gas flow, the concentration of the reactants, and the additives of the primary particles.

The photocatalyst has a strong oxidizing power when irradiated with ultraviolet rays, and thus it is difficult to use the photocatalyst as a binder, which is a conventional organic resin, because it is weak to deterioration, and yellowing and choking occur in a short time. Therefore, a binder hardly decomposed by a photocatalytic reaction is used, and a binder such as polysiloxane, fluororesin, colloidal silica, silica sol, alumina sol, metal alkoxide, alkali silicate and organosilicate is generally used.

As a patent for a photocatalyst coating, U.S. Pat.No.5755867 describes a binder using a silicone resin and a titania sol as a photocatalyst, followed by coating with flexibility, hardness, shelf stability, and self-crystallization. Maintain hydrophilicity of coatings through self-cleaning, transparency, water affinity, anti-fogging, antibacterial and deordorant tests It turns out that the coating film excellent in weatherability can be formed. In addition, by using silicone resin and powdered photocatalyst (Degussa P25), it is possible to test the removal ability of VOC, surface cleanability, and UV permeability due to photooxidation power in various materials, and to form a coating film having good abrasion resistance. It is revealed.

However, in the case of the photocatalyst coating prepared by the above technique, the general coating film properties are good, but there is a problem in that excessive use of the photocatalyst due to the lack of maximum photocatalytic activity and poor weather resistance and the applicable coatings are limited.

Accordingly, in order to improve the stain resistance as a photocatalyst paint, researches on photocatalyst paints excellent in preventing adhesion of contaminants, preventing sedimentation of contaminants, and removing attached contaminants are being actively conducted.

Therefore, the present invention is an advanced step in the above technology to secure the degradability of the contaminants of the conventional photocatalyst coating as well as good weather resistance, excellent adhesion to various materials, and completed the present invention after studying a composition maximizing the photocatalytic activity It came to the following.

The present invention is to solve the above-mentioned conventional problems, it is an object of the present invention to ensure a degrading performance of the contaminants of the conventional photocatalyst paint as it is, while producing a composition with good weather resistance and maximize the photocatalytic activity.

To this end, the present invention is to prepare a super fine powder titanium dioxide composition by a gas phase oxidation reaction, and potassium carbonate ( , n = 2 ~ 3.8 weight molar ratio 2.9 ~ 3.6) and one-liquid crosslinkable emulsion resin as a binder to fix ultrafine titanium dioxide, and then mixed with pigment dispersant, coloring pigment, extender pigment, additive and thickener Photocatalyst paints have excellent physical properties such as viscosity stability, workability, chemical resistance, fouling resistance, breathability, mold resistance, heat resistance, weather resistance, antibacterial, deodorization, environmental friendliness and excellent adhesion to various materials. At the same time, there is provided a method of immobilizing ultrafine titanium dioxide which maximizes the degradability of contaminants and an aqueous inorganic photocatalyst coating using the same.

The present invention relates to an aqueous inorganic photocatalyst coating containing ultrafine titanium dioxide prepared by a gas phase oxidation reaction, and more particularly, to preparing an ultrafine titanium dioxide composition by a vapor phase oxidation reaction, n = 2 ~ 3.8 by weight molar ratio 2.9 ~ 3.6) and one-liquid crosslinkable emulsion resin as immobilized ultrafine titanium dioxide, and then mixed with pigment dispersant, coloring pigment, sieving pigment, additive, thickener, and aqueous inorganic photocatalyst. It is characterized by providing a water-based inorganic photocatalyst paint that produces paint, while maintaining the physical properties of the inorganic paint, while maximizing the decomposition characteristics of contaminants.

In the present invention, using a diffusion flame reactor consisting of a five-pipe as shown in Figure 1, Using a reaction system of argon-hydrogen-oxygen-air Nano size from A photocatalyst, which is an ultra fine powder, was prepared. The first tube was diluted with argon. The vaporized concentration of (titanium tetrachloride) is equal to, and the flow rate of the total gas is expressed as a volume fraction, which is 1 part in the first pipe, 2.5 parts in the second pipe and the third pipe, 5 parts in the fourth pipe, and Titanium dioxide photocatalyst is prepared by introducing 30 parts into five tubes.

The present invention is a nano-size produced by the gas phase oxidation reaction The present invention relates to an inorganic inorganic photocatalyst paint using the same, which synthesizes a binder for immobilizing the same in ultrafine powder.

In general, the organic binder is photodegraded by the strong oxidation action of the photocatalytic reaction of the titanium dioxide nanoparticles, so that deterioration such as yellowing and chalking occurs in a short period of time, an inorganic binder resistant to oxidation should be used for the photocatalyst paint. Inorganic binders are polymers in which the main chain is composed of elements other than carbon, and various elements or organic atomic groups are bonded to the side chain. A binder that is stable and hardly decomposed by an oxidation reaction is generally used. Therefore, as the binder used for the photocatalyst coating, it is necessary to use a binder suitable for the application such as inorganic colloidal silica, silica sol, alumina sol, water glass, metal alkoxide, silicon type, or the like.

Silicate is a composition that contains silicon, oxygen atoms and alkali metals and is almost natural. Unlike conventional glass, these silicates contain only monovalent alkali ions such as Na ⁺ or K ⁺ , so they can be easily dissolved in hot water and transformed into viscous alkali silicate solutions, making them inorganic liquid binders. It is cured through chemical bonding with inorganic materials such as stone, cement, glass, etc., and since the self-curing product forms a porous inorganic coating film, it has an advantage of excellent adhesion, coating strength and breathability. In addition, when the coating film is used, even if only a small amount of organic synthetic binder is used, the coating film can be formed without cracking and the like. In addition, since the cured coating film forms a strong inorganic bond, it has an advantage of forming a cured coating film having excellent weather resistance.

Sodium silicate containing Na ⁺ ions has the advantage of being inexpensive in terms of cost, but sodium carbonate (Na ₂ CO ₃ ) formed as a cured by-product when the cured film comes into contact with water is recrystallized from the film surface. While it has a fatal problem that white efflorescence is formed on the surface of the coating, the potassium silicate containing K ⁺ ions is potassium carbonate (K ₂ CO ₃ ). Silver has a very low recrystallization tendency due to moisture contact, so that even when the cured coating film is in contact with moisture, no milky whitening is formed on the surface of the coating film, but a small amount is easily removed by rain water.

In the present invention, as a binder, a combination of potassium silicate and a one-liquid crosslinked emulsion resin was used as a binder.

Potashium silicate The molar ratio can vary from 1.0 to about 4.0 and the silicate solution is alkaline but this alkalinity decreases with increasing molar ratio. As a result, silicate solutions with higher molar ratios are more stable to handle, which is evidenced by the following stability classification for commercial standard silicate solutions.

Molar ratio

1.0: metasilicate corrosive

2.0: Alkaline silicates highly irritant

3.3: neutral silicates not classified as unstable

Therefore, in most cases The molar ratio is at least 2.6 due to stability and is preferably 2.0 to 4.2, more preferably 2.9 to 3.6.

The curing of potassium silicate can be cured at room temperature through three main paths, and each curing mechanism is as follows.

1. Composition and Chemical Curing Reaction

: It hardens by reacting with Ca (OH) ₂ or quartz contained in coating materials such as stone and cement.

K ₂ O × nSiO ₂ + Ca (OH) ₂ → CaO × SiO ₂ + (n-1) SiO ₂ + 2KOH + CO ₂

K ₂ O × SiO ₂ + mSiO ₂ → K ₂ O × (m + n) SiO ₂

2. Curing reaction with CO _{2 in} air

K ₂ O × SiO ₂ + CO ₂ → K ₂ CO ₃ + nSiO ₂

3. Curing reaction by removing physical moisture by drying

K ₂ O × nSiO ₂ + zH ₂ O → K ₂ O → SiO ₂ + (zy) H ₂ O

It is preferable to use 30-40 weight part of 1-component bridge | crosslinking emulsion resin with respect to 100 weight part of potassium silicates.

In order to compensate for the disadvantages of poor initial water resistance of the silicate binder, the emulsion resin was used as a one-component crosslinked emulsion resin, and as mentioned above, the potashium silicate used had a molar ratio of SiO ₂ / K ₂ O of about 2.9 to 3.6. .

As shown in the compounding table of the present invention, the compounding ratio of the potassium silicate (weight molar ratio 2.9-3.6) and the emulsion resin is important. If the ratio of the potassium silicate / emulsion resin is large, cracks may occur when forming a room temperature film, and on the contrary, too small If this occurs, the emulsion resin may be degraded by the photocatalyst, resulting in poor weather resistance.

Therefore, the ratio is preferably 2/1 to 6/1, preferably 2.5 / 1 to 5/1.

A one-component crosslinked emulsion resin composition comprising a monomer mixture composed of an acrylic or methacrylic monomer having an aliphatic group and other monomers and a reaction initiator, and containing a carbonyl group in the monomer mixture, using a reaction with dihydrazide at room temperature. Through one-component crosslinking, it is possible to achieve improvement in water resistance, chemical resistance and hardness of the coating film.

In addition, the present invention is a monomer containing a carbonyl group is 3 parts by weight to 10 parts by weight based on 100 parts by weight of the total monomer mixture, dihydrazide monomers total monomer mixture 100 1.5 parts by weight to 5 parts by weight, and the reaction initiator was added dropwise for 2 to 4 hours to ion exchanged water maintained at a temperature of 80 ° C to 85 ° C for 0.5 to 1.0 parts by weight of the total monomer mixture. It provides a method for producing an acrylic emulsion resin composition, characterized in that the synthesis for a further 3 to 3 hours.

Hereinafter will be described in more detail through the emulsion resin composition and a method for producing the same according to the present invention.

The emulsion resin composition according to the present invention is prepared by radical polymerization in ion-exchanged water using a reaction initiator to various kinds of monomers having a vinyl double bond of acrylic ester or methacrylic ester, which is a commonly used method.

As the monomer having a vinyl double bond, an acrylic or methacrylic monomer having an aliphatic group and other monomers are mixed and used. At this time, in the present invention, a monomer containing a carbonyl group and a dihydrazide monomer are included in the monomer mixture.

The acrylic or methacrylic monomer having an aliphatic group in the above can be added within a conventionally used range to include 90 to 97 parts by weight of the acrylic or methacrylic monomer having an aliphatic group with respect to 100 parts by weight of the total monomer mixture. It is preferable.

The acrylic or methacrylic monomer having an aliphatic group may be ethyl acrylate, methyl acrylate, normal butyl acrylate, 2-ethylhexyl acrylate, normal butyl methacrylate, normal propyl methacrylate, methyl methacrylate or ethyl. At least one compound selected from methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, glycidyl methacrylate, lauryl methacrylate, isobornyl methacrylate, acrylic acid, methacrylic acid and the like It can be mixed and used.

As described above, the acrylic or methacrylic monomer having an aliphatic group, which is used in the emulsion resin composition, which is usually used as a binder for a photocatalyst, based on 100 parts by weight of the total monomer mixture, from 90 parts by weight to 97 parts of the acrylic or methacrylic monomer having an aliphatic group. After the addition and mixing within the range to be included by weight, the monomer containing a carbonyl group is added thereto, the addition amount is preferably added to 3 to 10 parts by weight based on 100 parts by weight of the total monomer mixture. At this time, the monomer containing the carbonyl group is added for the purpose of crosslinking reaction. When added to less than 3 parts by weight with respect to 100 parts by weight of the total monomer mixture, the crosslinking density in the final emulsion resin decreases the hardness of the coating film and the solvent resistance and weather resistance. The problem may be lowered, and when the amount exceeds 10 parts by weight, poor reactivity and a sharp increase in viscosity may occur. Therefore, the addition amount of the monomer containing a carbonyl group is suitable to add in the said range.

Acetone acetoxy ethyl methacrylate, diacetone acrylamide, etc. can be used as a monomer containing the carbonyl group.

In addition, the dihydrazide monomer is used in a 1: 1 equivalent ratio with the monomer containing a carbonyl group, and the amount used is preferably 1.5 parts by weight to 5 parts by weight based on 100 parts by weight of the total monomer mixture. As the dihydrazide monomer, sebacic acid dihydrazide, isophthalic acid dihydrazide, cumyl dihydrazide, adipic acid dihydrazide, succinic acid dihydrazide, or the like may be used. If the equivalence ratio is not 1: 1, unreacted sites remain without 100% crosslinking, resulting in a problem of deterioration of coating properties.

As described above, the reaction mixture is added dropwise to ion-exchanged water maintained at a temperature of 80 ° C. to 85 ° C. for 2 to 4 hours using a reaction initiator to a monomer mixture composed of an acrylic or methacrylic monomer having a aliphatic group and a carbonyl monomer. , The mixture is further reacted for 2 to 3 hours to polymerize.

The reaction initiator is added to the purpose of controlling the molecular weight of the acrylic emulsion resin composition with the initiation of the polymerization, the addition amount may be added within a conventional addition range in the present invention within the range of 0.5 parts by weight to 1.0 parts by weight Added. Usable reaction initiators include water-soluble peroxides such as potassium persulfate, ammonium persulfate, sodium persulfate, potassium permanganate, tertiary butyl hydroperoxide, cumene hydroperoxide, and diisopropylbenzene hydroperoxide. The same radically polymerizable initiator can be used individually or in mixture of 2 or more types, respectively.

The design of emulsion resins requires the identification and design of the required properties. The most important factors in the design of emulsion resins are glass transition temperature (Tg), water resistance and weather resistance.

Tg of emulsion resin is an important property that has a direct relationship to paint film formation and paint properties. The Tg of the emulsion resin is basically determined according to the composition of the monomer and can be controlled by combining the hard monomer and the soft monomer. Emulsion resins used for paints have a minimum film forming temperature (MFFT) that can form a continuous film, and cannot form a coating film below MFFT. Tg of the emulsion resin, which is dry at room temperature, is generally designed at 0 to + 20 ° C. If the Tg is lowered, problems such as contamination, adhesiveness, and friction resistance may occur. If the Tg is high, problems such as coating film formation and crack resistance may occur.

If water resistance is low, the elasticity of a polymer will increase the water absorption of a coating film, and water resistance will fall. In addition, the more the amount of hydrophilic polymer having moisture absorption and absorbency of the polymer itself, the lower the tensile strength and the lower the water resistance. Also, it is involved in the type and amount of the water-soluble substance contained. It becomes high and water resistance falls.

Weather resistance deteriorates gradually when the coating film is exposed to ultraviolet rays, heat, rain water, and the like. Among them, the effect of ultraviolet rays is large, and the thickness of the coating film becomes thin due to intermolecular crosslinking and cutting of the main chain, resulting in gloss deterioration, discoloration, whitening, swelling, rust, cracking, detachment, abrasion, fouling, and reduction of electrical resistance. It causes film defects. If a coating defect occurs, the thickness and weight of the coating will be reduced and the paint should be repainted or replaced. The deterioration of the coating film is determined primarily by the change in glossiness, and the discoloration of the coating film is evaluated at 20 ° mirror glossiness, and whitening at 60 ° surface gloss. That is, when the 20 ° mirror gloss value decreases by 75%, it is determined as the time of discoloration, and when the 60 ° gloss decreases by 50%, it is determined as the time of whitening. If the interatomic bond energy of the binder component is greater than the energy of light, the interatomic bond of the binder is hard to be broken and deterioration does not occur. In other words, in a small portion of the binding energy, light is dissociated or excited by light, and atoms in the portion are attacked in the presence of oxygen, and thus, automatic oxidation occurs in series, causing oxidative deterioration of the coating film. In order to prevent such a phenomenon and to minimize the deterioration phenomenon, a binder having a large bond energy between atoms is widely used, and in the paint, a deterioration phenomenon is reduced by using an ultraviolet absorber and a light stabilizer as an additive. In photocatalyst paints, since most organic compounds are decomposed by the strong oxidation of photocatalysts, the photocatalyst binder should be synthesized to have good weather resistance by using a compound having a large bond energy between atoms.

Titanium dioxide is the most widely used white pigment in paints because of its high hiding power. There are two types of anatase and rutile types depending on the difference in crystal structure. Rutile titanium dioxide is widely used as a white pigment, and the thin film coating treatment with an oxide such as alumina or silica to prevent oxidation. Anatase type titanium dioxide is used as a photocatalyst, and the photocatalytic reaction is initiated by irradiating light at about 400 nm with a transmission distance of about 4.3 times that of the rutile type. Oxidation and deterioration of the mixed resin due to the generator oxygen generated by the reaction causes whitening of the coating film.

The extender pigment has no hiding power, no coloring power, but is used to increase the salvability and mechanical properties of the coating, reduce gloss and price, and uses talc, clay, CaCO ₃ , alumium silicate, and the like. It was used together.

In addition, the most significant influence on the physical properties of the emulsion binder is an emulsifier. In general emulsion polymerization, the stability of the emulsion resin is generally imparted by using a nonionic or anionic emulsifier corresponding to 1 to 7 wt% of the total monomers. However, since such emulsifiers impair foaming, adhesion and water resistance of the coating film, a method using a soap-free emulsion and a reactive emulsifier has been widely used as a means to solve the problem. In the present invention, a reactive emulsifier having excellent water resistance is used. The reactive emulsifier is a surface-active monomer having an unsaturated bond in its molecular structure and dissolved in water, which is a continuous phase of the polymer. Possible reactive emulsifiers include those having unsaturated bonds in their molecular structure.

As a thickener for improving the storage stability of the paint, the workability of the paint, and the leveling of the final coating, it is preferable to use Natrasol 250HR, Xanthan-Gum, Metrose, CMC, Hydroxypropyl cellulose, associative thickener.

Potassium Silicate × , n = 2 ~ 3.8) has a great influence on the storage stability and flowability depending on the weight ratio, and importantly, it is important to maintain the pH at a constant level depending on the amount of pH adjuster. PH adjusting agent for stabilizing the viscosity change of the potassium silicate and the emulsion resin may be applied in various ways. For example, inorganic alkalis such as potassium hydroxide and sodium hydroxide, ammonia, monomethylamine, dimethylamine, triethylamine, monoethylamine, diethylamine, triethylamine, mono-n-propylamine, dimethyl n-propylamine , Monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-aminoethylethanolamine, N-methyldiethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, N, N-dimethylpropanol Amine, such as an amine, etc. are mentioned. These may be used alone or in combination of two or more thereof. In this invention, potassium hydroxide was chosen among these. The addition amount of the pH stabilizer should be in the range of 0.1 to 2.0% by weight so that the pH is in the range of 9 to 12. If the pH is less than 9, the viscosity is increased and hardened during storage of the prepared paint, and if the pH is higher than 12, the separation is caused by hydrolysis, so the preferred range is 0.2 to 0.4% by weight. . The pH adjuster by stabilizing the change in viscosity KOH, , TEA, NaOH are mainly used.

The pigment dispersant is added 0.3% ammonium (Quarternary ammonium) to induce a uniform pigment dispersion. As shown in the compounding table of the present invention, the pigment dispersant which induces uniform dispersion of the pigment in the binder disperses the particles in agglomerated state, and stabilizes the particles in a more approximate form to prevent the recombination of the particles from each other. Examples of the active agent include ionic, nonionic and zwitterionic compounds, but in the present invention, it is preferable to add 0.1-1.0 wt% of a cationic quaternary ammonium, and more preferably 0.2 to 0.4 wt%. If the amount of the dispersant is less than 0.1% by weight, the pigment is poorly dispersed and the viscosity of the paint is increased due to the aggregation of the pigment during storage. On the contrary, when more than 1.0 weight%, water resistance, adhesiveness, and abrasion resistance become poor.

As shown in the compounding table of the present invention, in the case of the aqueous paint, since the surface tension of the water to be used is extremely high, bubbles tend to be generated, whereas the organic solvent has a small surface tension and does not generate bubbles well. Therefore, the antifoaming agent is generally composed of the surface tension of the antifoaming agent is lower than the surface tension of the antifoaming agent and has an inherent property that is easy to transfer to the surface of the paint, and uses a surfactant, polysiloxane, glycols, fatty acid derivatives, etc. It is preferable to add 0.1-0.5 weight% of polysiloxane, and the more preferable ranges are 0.1-0.3 weight%. If the amount of the antifoaming agent is less than 0.1% by weight, no defoaming occurs, resulting in poor workability and a large amount of bubbles in the coating film. On the contrary, when it is more than 0.5% by weight, cracking occurs in the coating film, resulting in poor appearance.

Thickeners are used to increase the viscosity of the paint to prevent anti-sagging of the paint, anti-settling of the pigment during storage, and to improve the workability of the paint. Casein and starch , natural products such as natural gum, cellulose-based derivatives, alkali sweallerable thickeners and associative thickeners, etc. are widely used. In the present invention, it is preferable to add 0.1-1.0 wt% of cellulose-based. If the added amount of the thickener is less than 0.1 wt%, the thickening is insufficient, causing shedding and poor storage stability. This poor and gloss deteriorates.

Small amounts of solvent help to maintain the storage stability of the paint and to control the dryness. The solvent may be an alcohol or a petroleum solvent, but in the present invention, it is preferable to add 0.1 to 2.0% by weight of the petroleum solvent, and more preferably 0.1 to 1.0% by weight.

Here, the composition ratio of the components of the aqueous inorganic photocatalyst coating composition of the present invention is changed in accordance with the required quality, and the composition can be adjusted according to the use.

When the emulsion resin composition is prepared by the above method, it is possible to prepare an emulsion resin composition having a glass transition temperature of 0 to 30 ° C., a viscosity of 50 to 90 KU, and a nonvolatile content of 45% or more.

In addition, the present invention can be used in the production of a general coating composition emulsion resin composition having the above composition.

Hereinafter, the present invention will be described in detail with reference to the following examples and comparative examples, which are only presented to aid the understanding of the present invention, and the present invention is not limited to the following description.

<Examples 1 to 3>

As the acrylic and methacrylic monomers having aliphatic groups, normal butyl acrylate, methyl methacrylate, and methacrylic functional monomers are methacrylic acid and diacetone acrylamide monomers, which are prepared by uniformly mixing the amounts shown in Table 1 below. It was.

In a four-necked flask equipped with a stirrer, 1.5 g of reactive emulsifier (Hytenol BC-10), buffered sorbium bicarbonate 0.1, was adjusted to 63.2 to 113.8 g to make ion exchanged water 45% solids. After each g was added, the mixture was replaced with nitrogen gas, heated to 70 ° C. while stirring, and then 0.6 g of ammonium persulfate, an oxidizing agent, and 4% of the monomer mixture were added as a reaction initiator. After the start of the reaction, the remaining 96% of the monomer mixture was uniformly added dropwise for 3 hours at 80 to 85 ° C, and after aging for 2 hours, 0.05 g of tertiary butyl hydroperoxide and sodium formaldehyde sulfoxylate (2% ) 1 g of the mixed solution was added dropwise for 30 minutes, maintained for 30 minutes, adjusted to pH 7-8 with ammonia water (25%), and then maintained at 30 ° C. for 10 minutes with a 10% aqueous solution of dihydrazide monomer at 50 ° C. for a nonvolatile content of 45%. An emulsion resin as a binder for phosphorus photocatalyst was prepared.

<Examples 4 to 6>

Examples 4 to 6 were prepared in the same manner as in Examples 1 to 3, except that in Examples 1 to 3, Tg was 0 ° C., whereas Tg was + in this case. The same is true except that it is 20 ° C.

<Example 7>

The photocatalyst sol (coating solution) was prepared as follows.

10 ml of an aqueous titanium oxychloride (Millennium Performance Chemicals, TiOCl ₂ 35-36%) solution was added to 1000 ml of distilled water, and 1N-NaOH aqueous solution was added to pH 8 to precipitate titanium hydroxide. The precipitate was filtered with a suction filter, washed sufficiently with distilled water, distilled water was added, and 20 ml of 28% hydrogen peroxide solution was added to 180 ml of titanium hydroxide suspension and stirred. Peroxytitanium aqueous solution, which is a titanium dioxide precursor chelated with amorphous yellow viscous liquid by being left at 25 ° C. for 24 hours to decompose excess hydrogen peroxide solution [Ti ₂ O ₅ (OH) _x ^(2-x)- , (x> 2)] to 200 ml.

In order to show the aqueous solution and the visible light-sensitizing effect, Fe (NO ₃ ) ₃ · 9H ₂ O was added to a 0.5% hydrothermal reactor as compared to TiO ₂ and reacted at 120 ° C. for 2 hours, at which time the pressure was 5 atm.

Thus synthesized particles having a particle size of 5 ~ 20nm, specific surface area of 200 ~ 300m ² / g, and excellent storage stability of iron ions in the titanium dioxide lattice [Ti ₂ O ₅ (OH)-(Fe )-(TiO ₂ )].

The sol is a pale yellow translucent liquid that can form a film at room temperature, the coating film hardness is H ~ 2H and the pH is neutral, it can be attached to various coatings. The sol has excellent VOC and formaldehyde removal performance for indoor air quality purification.

Applying the prepared sol (coating solution) on the slide glass, and repeated four times drying to produce a film of about 1㎛ coating film thickness measured by the experimental measurement method below to obtain the following results The required purpose can be achieved. This result can be confirmed in Experiment 11 of Table 3 below.

Accelerated Pollution: -1.6

2. Accelerated weathering (choking): ○ (No abnormality in the coating)

3.MB Degradability (△ ABS): -0.1628

4. Crack Stability: △ ~ ○ (No cracks or fine cracks in the coating)

5. Storage stability: ○ (No change in viscosity within 10KU (Krebs-Unit).

<Comparative Examples 1 and 2>

Comparative Examples 1 and 2 are monomer compositions except for carbonyl monomers and dihydrazide monomers, and their preparation is as follows.

Into a four-necked flask equipped with a stirrer, 121.5 g of ion-exchanged water, 1.5 g of a reactive emulsifier (Hitenol BC-10), and 0.1 sorbium bicarbonate as a buffer, respectively, were replaced with nitrogen gas and stirred. The reaction is started by raising the temperature to 70 ° C. and then adding 0.6 g of ammonium persulfate, an oxidizing agent, and 4% of the monomer mixture as an initiator. After initiating the reaction, the remaining 96% of the monomer mixture was uniformly added dropwise for 3 hours at 80 ± 2 ° C., and aged for 2 hours to synthesize an emulsion. Immediately at the same temperature, a mixture of 0.05 g of tertiary butyl hydroperoxide and 1 g of sodium formaldehyde sulfoxylate (2%) was added dropwise for 30 minutes, held for 30 minutes, and adjusted to pH 7-8 with ammonia water (25%). An emulsion resin having 45% volatile content was prepared.

<Table 1>

<Experimental example>

Using the emulsion resins prepared in the above Examples and Comparative Examples, the formulations were evaluated as shown in Table 2 below to evaluate the low stability of the paint, and the coating was formed to evaluate the crack stability, accelerated fouling, accelerated weather resistance, and methylene blue degradability of the specimen. 3 is shown.

Ultrafine titanium dioxide photocatalyst composition prepared by gas phase oxidation reaction (average particle size: 19 nm, anatase content 77%) [3] and 3 g of a thickener in 10 g of water (ion-exchanged water) The dispersion was added to 3 to 11 g of the emulsion resin composition prepared in Examples 1 to 6 and Comparative Examples 1 to 2, followed by stirring at 500 rpm for 20 minutes, and then maintained for 10 minutes using an ultrasonic cleaner.

If the particles of the photocatalyst are 20 nm or more, the properties of the photocatalyst are significantly reduced, and if the particles are too small, the photocatalytic activity is improved as the surface area is increased, but the coagulation phenomenon occurs due to the increase of the surface area, making dispersion difficult. Therefore, the particle size is preferably 7 ~ 20 nm. In addition, when the content of the photocatalyst is 3 parts by weight or more, most organic matters are decomposed by the strong oxidizing power of the photocatalyst itself, thereby causing discoloration and choking of the coating film. On the contrary, when used at 3 parts by weight or less, the photocatalytic activity is lowered, which makes it difficult to exhibit the required photocatalytic properties.

The photocatalyst composition was added to a paste obtained by dispersing the coloring pigment (Dupont R-706) and the extender pigment with water, a pH adjuster, a solvent, a dispersant, an antifoaming agent, and a potassium silicate solution at a high speed stirrer at 2000 rpm for 20 minutes. A non-volatile matter 56 wt% of an aqueous inorganic photocatalyst white paint was prepared.

First, prepare a specimen of tin plate (KS D 3516) according to the method of manufacturing tin plate for paint test of KS M 5000-1112, until the metal gloss with 220 of KS L 6004 (waterproof finish). Evenly polished, washed with perchlorethylene containing no free chlorine or hydrochloric acid, dried with hot air, and then again returned to room temperature to sand the surface with 600 of KS L 6004 (waterproof finish) and a base coat The specimen was prepared by coating a room temperature dry type inorganic two-component binder (Technotrade Co. Heatless Glass) using a bar coater # 5 (wet film thickness = 11.43㎛) and drying the coating film for 20 hours. .

The aqueous inorganic photocatalyst coating prepared above was coated on the specimen thus prepared using Bar Coater # 14 (wet coating thickness = 32 μm), dried at room temperature for 7 days, and the physical properties of the coating were evaluated by the following method. The results are shown in Table 3.

<Table 2>

Accelerated fouling test was prepared by dispersing black carbon in mineral spirit at 20%, spraying the specimen prepared in the same way as in Experimental Example, and drying it for 80 hours at 80 ± 2 ℃, and then water It was judged by lightness index aberration before and after washing. At this time, the smaller the brightness index, the higher the pollution resistance.

Accelerated weathering test is made by QUV tester (Q-Panel Co. accelerated weathering tester) using UV-B lamp (280 ~ 315nm) according to ASTM G-53 test method of accelerated weathering test. Chalking properties were assessed after exposing one specimen for 1,000 hours.

Evaluation criteria-○: No abnormality in coating.

           (Triangle | delta): The choking phenomenon generate | occur | produced in a coating film.

-Methylene Blue Degradability-

After the specimen coated with the photocatalyst paint was immersed in a 0.001 M solution of methylene blue (MB) for 20 minutes, the specimen was dried to avoid direct sunlight, and the photocatalytic properties were measured by the degradability of MB. The photocatalytic properties were measured using a photocatalytic potentiometer (PCC-1, Sinku-Riko, Japan). After 20 minutes with a photodetector by emitting ultraviolet rays with a wavelength of 340 nm, the amount of MB degradation on the surface of the coating film was measured by ΔABS. [See Fig. 4]

In the initial light transmittance, the MB is decomposed by the irradiation of ultraviolet rays, and the light transmittance increases, and the better the photocatalyst characteristic, the greater the absolute value toward (-).

T0 = Initial transmittance

T1 = Momentary transmittance, which changes over time

In the crack stability test, the dried coating specimens were left at -16 ° C. for 8 hours and then maintained at 30 ° C. for 1 hour for 3 times with 1 CYCLE, and then the crack state of the coating was visually determined.

Evaluation criteria-○: No abnormality of crack in coating film.

           △: fine crack occurs in the coating film

           X: The crack generate | occur | produced in a coating film.

Storage stability test is to put 400g of the prepared paint in an airtight container and left for 7 days at 60 ℃ to visually determine the viscosity change and the occurrence of Lump on the glass plate.

Evaluation Criteria-○: No change in viscosity within 10KU (Krebs-Unit).

           X: Viscosity change is 10 KU or more.

<Table 3>

As shown in Table 3, in Experiment 1 in which the glass transition temperature is 0 ° C., it can be confirmed that accelerated fouling, accelerated weathering resistance, MB degradability, crack stability, and storage stability are all good.

Comparing Experiment 1 and Experiment 4, which carried out the scope of the present invention, it can be seen that the glass transition temperature of the emulsion resin should be in the range of 0 to 20 ° C. When the glass transition temperature was 20 ° C, crack stability was inferior.

Accelerated fouling was confirmed that the emulsion resin of Experiments 2 to 5 with low crosslinking degree of 1 solution and Experiments 7 to 8 using an uncrosslinked type was less contaminated.

The accelerated weathering result showed good results in all the paints, but the choking property was poor in Experiment 10, where the emulsion resin content was high.

MB degradability did not show a big difference in the whole sample, which is thought to be due to the same content of titanium dioxide.

The crack stability was affected by the glass transition temperature and the ratio of potassium silicate and emulsion resin, and the crack stability was deteriorated when the glass transition temperature was high or the potassium silicate was too large compared to the emulsion resin.

Storage stability was confirmed that the storage stability is low in the case of high crosslinking density or uncrosslinked form.

In the case of Experiment 1 in which the compounding ratio of the emulsion resin was properly adjusted while adjusting the crosslinking density of the one-component crosslinked emulsion resin within the scope of the present invention, the accelerated fouling, accelerated weather resistance, MB degradability, crack stability, and storage stability were all excellent. This can be seen in Table 3.

As described above, the present invention relates to a method for immobilizing an ultrafine titanium dioxide composition prepared by a gas phase oxidation reaction, and to an aqueous inorganic photocatalyst paint containing the composition, while maintaining the physical properties of the inorganic paint and decomposing contaminants. It is a useful invention to provide an ultrafine titanium dioxide composition and a water-based inorganic photocatalyst coating containing the composition that maximize the properties.

In particular, the aqueous inorganic photocatalyst coating composition of the present invention can be used as a transparent paint except coloring pigments and extender pigment components, and because it has excellent MB degradability like a white paint, it can produce productivity even when using a small amount of photocatalyst and The invention is useful in terms of environment friendliness.

1 is a view showing a model of the titanium dioxide ultra-fine powder production reactor by the gas phase oxidation reaction.

Figure 2 is a photograph taken by electron microscopy of the TiO2 ultrafine powder produced by the gas phase oxidation reaction.

3 is a graph showing the results of crystalline analysis of the ultrafine TiO 2 powder produced by the gas phase oxidation reaction.

4 is a view showing a model of the photocatalytic potentiometer.

Claims (8)

Ultra-fine titanium dioxide photocatalyst prepared by vapor phase oxidation reaction; × a binder of 30 to 40 parts by weight of a one-liquid crosslinked emulsion resin, based on n = 2 to 3.8, and 100 parts by weight of the potashium silicate and the potashium silicate having a weight molar ratio of 2.9-3.6; An immobilized ultrafine titanium dioxide mixture prepared by mixing the ultrafine titanium dioxide photocatalyst and a binder; An aqueous inorganic transparent photocatalyst coating, characterized in that a thickener, an antifoaming agent, and a solvent are contained in the immobilized ultrafine titanium dioxide mixture. Ultra-fine titanium dioxide photocatalyst prepared by vapor phase oxidation reaction; × a binder of 30 to 40 parts by weight of a one-liquid crosslinked emulsion resin, based on n = 2 to 3.8, and 100 parts by weight of the potashium silicate and the potashium silicate having a weight molar ratio of 2.9-3.6; An immobilized ultrafine titanium dioxide mixture prepared by mixing the ultrafine titanium dioxide photocatalyst and a binder; An aqueous inorganic colored photocatalyst paint, characterized in that the immobilized ultrafine titanium dioxide mixture contains a pigment dispersant, a coloring pigment, a sieving pigment, a thickener, an antifoaming agent and a solvent. Method for producing the one-liquid crosslinked emulsion resin composition, Mixing the acrylic or methacrylic monomer having an aliphatic group including 90 to 97 parts by weight based on 100 parts by weight of the total monomer mixture; 1.5 to 5 parts by weight of Dihi, based on 100 parts by weight of the total monomer mixture, in an equivalence ratio of 1 to 3 parts by weight of the monomer containing 3 to 10 parts by weight of the carbonyl group and 1 to 1 part of the monomer containing the carbonyl group. Adding a dragged monomer; Adding 0.5 to 1.0 parts by weight of the reaction initiator and the reaction emulsifier to the ion-exchanged water maintained at a temperature of 80 ° C to 85 ° C for 2 to 4 hours; And Method for producing a one-pack cross-linked emulsion resin composition, characterized in that it comprises a step of reacting for 2 to 3 hours to further polymerize. The method of claim 3, wherein The one-liquid crosslinkable emulsion resin composition, The acrylic or methacrylic monomer having an aliphatic group includes ethyl acrylate, methyl acrylate, normal butyl acrylate, 2-ethylhexyl acrylate, normal butyl methacrylate, normal propyl methacrylate, methyl methacrylate and ethyl methacrylate. At least one selected from the group consisting of laterate, 2-ethylhexyl methacrylate, octyl methacrylate, glycidyl methacrylate, lauryl methacrylate, isobornyl methacrylate, acrylic acid and methacrylic acid Using, The carbonyl monomer is used by mixing one or more of the compounds of acetacetoxyethyl methacrylate and diacetone acrylamide, The dihydrazide monomer is used by mixing one or more selected from compounds of sebacic acid dihydrazide, isophthalic acid dihydrazide, cumyl dihydrazide, adipic acid dihydrazide, and succinic acid dihydrazide. , The reaction initiator is a mixture of at least one selected from peroxide compounds of potassium persulfate, ammonium persulfate, sodium persulfate, potassium permanganate, tertiary butyl hydroperoxide, cumene hydroperoxide and diisopropylbenzene hydroperoxide A one-liquid crosslinked emulsion resin composition, characterized in that it is synthesized by use. The ultra fine titanium dioxide photocatalyst is Using a diffusion flame reactor consisting of five tubes; In terms of volume fraction of total gas inflow, Titanium tetrachloride is one part of gas, 2.5 parts of argon gas, 2.5 parts of hydrogen gas of 3 pipes, 5 parts of oxygen gas of 4 pipes, and 30 parts of air of 5 pipes. Inflow; In the process of preparing ultra-fine titanium dioxide photocatalyst using a reaction system of argon-hydrogen-oxygen-air; Diluted with argon To a vaporized concentration of (titanium tetrachloride); Nano size from gas A method for producing an ultrafine titanium dioxide photocatalyst, characterized by producing an ultrafine photocatalyst. The method of claim 2, The titanium dioxide photocatalyst is 3 parts by weight based on 100 parts by weight of the aqueous inorganic photocatalyst coating composition; Potassium silicate as a binder and a one-liquid crosslinkable emulsion resin include 30 parts by weight to 35 parts by weight based on 100 parts by weight of the aqueous inorganic photocatalyst coating composition; 0.1-1.0 wt% of the pigment dispersant, 0.1-0.3 wt% of the antifoaming agent; 0.1 to 1.0% by weight of thickener, 0.1 to 2.0% by weight of solvent, 15 to 20% by weight of pigmented pigment, and 20 to 25% by weight of extender pigment; An aqueous inorganic photocatalyst paint, which is prepared by mixing 25% by weight of water. The method of claim 5, The titanium dioxide photocatalyst is an aqueous inorganic photocatalyst coating composition, characterized in that the production using a powder having a particle size of 7nm to 20nm or less. The manufacturing method of the photocatalyst coating liquid is Adding 10 ml of an aqueous titanium titanium chloride (Millennium Performance Chemicals, TiOCl ₂ 35-36%) aqueous solution to 1000 ml of distilled water; Adding 1N-NaOH aqueous solution to pH 8 to precipitate titanium hydroxide; Filtering the precipitate with a suction filter and washing with distilled water sufficiently, adding distilled water and adding 20 ml of 28% hydrogen peroxide solution to 180 ml of titanium hydroxide suspension and stirring; The stirred material was allowed to stand at 25 ° C. for 24 hours to decompose excess hydrogen peroxide solution, and an aqueous solution of peroxytitanium, a precursor of titanium dioxide, chelated to an amorphous yellow viscous liquid [Ti ₂ O ₅ (OH) _x ^{(2-x) -} (x> 2)] to obtain 200 ml; Adding Fe (NO ₃ ) ₃ · 9H ₂ O to a 0.5% hydrothermal reactor as TiO ₂ in order to show the aqueous solution and the visible light sensitivity effect, and reacting at 120 ° C. for 2 hours at a pressure of 5 atm; And, Synthesized by the same method as described above, the particle size of 5 ~ 20nm, specific surface area of 200 to 300m ² / g, anatase type titanium dioxide fine particle sol [Ti ₂ O ₅ (OH )-(Fe)-(TiO ₂ )] to obtain a photocatalyst coating solution, characterized in that consisting of.