Coating agent containing an amorphous type titanium oxide

multifunctional coating agent

The present invention provides a substrate having weather resistance (UV protection properties), harmful electromagnetic wave blocking properties, chemical resistance, static discharge/charge prevention properties, insect repellent properties, and other properties when the substrate surface is coated with a coating agent, and sealing properties , to a multifunctional coating agent excellent in film-forming properties and transparency.

It is known so far to improve the weather resistance of the surface of resin substrates, such as sealing materials, waterproof sheets, and various internal/external building base materials, and the resin itself has UV resistance, acid resistance and alkali resistance, and the resin surface is organic solvent or treated with one having hydrophobicity/water-repellent property, so that stain resistance is given to the resin substrate surface. Also, it is known to premix an antifungal agent to a resin substrate at a place prone to infection by bacteria or to apply an anti-fungus agent to the surface of the resin substrate so that the resin substrate becomes an antifungal agent. However, most of the conventional methods have a problem in that the weather resistance is reduced due to rainwater or the like, the lifespan or the active ingredient. In addition, the above methods cannot be applied to the already applied interior/exterior building foundation materials, etc. Thus, in some cases, it may even be necessary to reapply the entire material.

As for the materials of the building interior/exterior structural materials themselves, advances in technology for materials such as natural materials (stone, wood, sand), ceramic products (ceramics), etc. have developed materials with markedly improved weather resistance and other properties. As a result, the life and durability of the building can be extended, while the maintenance cost can be saved.

In addition, coatings having various properties used for various applications are known, but weather resistance (UV protection properties), harmful electromagnetic wave blocking properties, chemical resistance, electrostatic discharge/charge prevention properties, insect repellent properties, and substrates having other properties There are no known multifunctional coatings that provide excellent sealing properties, film forming properties and transparency.

In order to ensure the adhesive properties, water tightness, or sealing properties of components, sealing and leak-proof materials filling joints between components of building base materials and machinery/equipment are indispensable in modern building technology, e.g. For example, they play an important role in linking separate finishing materials to devices, or in absorbing thermal displacement of building base materials or building displacements caused by natural disasters during the construction process of external materials.

In addition to sealing and leak-proof materials, multifunctional materials, also called waterproof sheet materials, waterproof coating materials, cosmetic coating materials, are required to absorb displacement, expansion/contraction and deformation of the installation/application site or construction, and are capable of adapting to changes. material is needed For the application of natural mineral resin sheet material or other materials, high weather resistance and other properties are required.

Examples of multifunctional materials formed of organic polymer materials include silicone resins, modified silicone resins, polysulfides, polyurethanes, acrylic acid and other sealing materials, and in recent years, the materials have been made to have antifungal properties, fire resistance and conductivity. Examples of the basic performance required for many of the sealing materials include ensuring adhesion to parts/components, particularly durability of the resin to surfaces, and the stain resistance of the construction to contamination occurring around the sealing material.

Among the performance, the adhesive property can be obtained by selecting the material according to the arrangement and dimension of the joint and shape of the constituent member and solving the problem in application. The problem is durability and stain resistance. For durability, it is important to prevent deterioration by ultraviolet rays, ozone, moisture, bacteria, acids, alkalis, etc. that come into contact with the surface of the sealing material resin. In addition, stain resistance is one of the most important problems in terms of the appearance of the building.

A silicone resin (organopolysiloxane) sealing material, known as a sealing material, catches dust and contaminants in the air by static electricity generated when silicone resin molecules in the sealing material move to the edge, so that the surface of the sealing material is often black and dirty . Also, for oil-resistant materials, their oil content collects dust and dirt on the surface, damaging the building appearance and increasing maintenance costs. In addition, it was found that there is a problem that bacteria generated in humid places indoors/outdoors and around water stains or deteriorates the construction.

It is an object of the present invention to provide a substrate having weather resistance (UV protection properties), harmful electromagnetic wave blocking properties, chemical resistance, static discharge/charge prevention properties, insect repellent properties, and other properties, and to improve sealing properties, film forming properties and transparency. It is to provide an excellent multifunctional coating agent.

In order to improve the durability of the resin itself, in recent years, development of silicone resins or fluoroplastic materials has advanced, but satisfactory materials have not been developed in terms of constituent materials, applicability, economy, and the like. In particular, in order to protect the surface layer exposed to outside air from adverse environmental conditions such as ultraviolet rays, acid/alkali, ozone, etc., the coating agent needs to protect the surface of the sealing material, waterproofing material, sheet material or other base material. The coating layer of the formulation protects the base material from adverse environmental conditions, improves the durability of the base material, including sealing materials, and blocks or decomposes properties such as stain resistance and oil and solvent leaked from the inside of the base material In this case, the coating layer is satisfactory as a surface protective layer for basic materials such as sealing materials, waterproofing materials, sheet materials, organic polymer inner/outer materials, and the like.

The present inventors have studied in depth to achieve the above-mentioned object, and as a result, the coating containing amorphous titanium oxide has excellent weather resistance (UV protection property), harmful electromagnetic wave blocking property, chemical resistance, electrostatic discharge/charge protection property .

That is, the present invention relates to a coating agent containing an amorphous titanium oxide such as an amorphous titanium peroxide sol and a coating agent containing an amorphous titanium oxide such as an amorphous titanium peroxide sol to coat the substrate thereof with a UV blocking material or building base material, characterized in that is about

In the present invention, an example of amorphous titanium oxide is amorphous titanium peroxide TiO₃ and amorphous titanium oxide TiO₂ includes

Amorphous titanium peroxide or amorphous titanium oxide is anatase-type titanium oxide TiO₂ and rutile type titanium oxide TiO₂ Unlike , it has practically no photocatalytic action.

Amorphous titanium peroxide for use in the present invention, for example, a particularly preferred amorphous titanium peroxide sol can be prepared as follows: titanium tetrachloride TiCl with aqueous ammonia or an alkali hydroxide such as sodium hydroxide₄added to the same titanium solution. While the product is slightly bluish, non-crystalline amorphous titanium hydroxide Ti(OH)₄ Also orthotitanic acid H₄TiO₄ is called After washing and separation, the titanium hydroxide is treated with hydrogen peroxide solution to obtain a titanium peroxide solution in the amorphous state of the present invention. The amorphous titanium peroxide sol has a pH of 6.0 to 7.0 and a particle diameter of 8 to 20 nm, its appearance is a yellow transparent solution, and is stable even when stored at room temperature for a long time. Also, the concentration of the sol is usually adjusted to 1.40 to 1.60%, but the concentration can be raised as needed. When the sol is used in a low concentration, it can be diluted with distilled water or the like.

In addition, since the amorphous titanium peroxide sol is in an amorphous state at room temperature and has not yet been crystallized into anatase-type titanium oxide, it has excellent adhesion and high film-forming properties. Also, a uniform plate thin film can be formed therefrom, and its dry film is insoluble in water.

Alternatively, the amorphous titanium peroxide sol is heated to 100° C. or higher to change into an anatase-type titanium oxide sol, further coated with an amorphous titanium peroxide sol, and then dried and fixed substrate is heated to 250° C. or higher, anatase-type oxidation Titanium is obtained.

As amorphous titanium oxide for use in the present invention, a powder state or a sol state obtained by dispersing/suspending the powder in a solvent such as nitric acid is known. When amorphous titanium oxide without photocatalysis is used in a powder state, for example, a binder such as a thermosetting water-soluble resin is mixed and used.

As a substrate to which the coating material of the present invention is applied, inorganic materials such as ceramics and glass, organic polymer resins such as plastic plates and chemical fibers, organic materials such as rubber, wood, paper, and metal materials such as aluminum and iron can be used Further, the size and arrangement thereof are not limited: plate, honeycomb, fibrous, filter sheet, bead, and foam arrangement or integrated arrangement can be used.

Specific application examples of the coating agent of the present invention will be described below. As a method of coating a substrate with the coating agent of the present invention, there are a sol/gel method and a method in which a thin film is formed by sputtering, flame spraying, dipping, spin coating, spray coating or other methods. In addition, the thickness of the coating layer is measured for the purpose of blocking ultraviolet rays or other purposes or for film formation performance, but in the case of, for example, a titanium peroxide sol coating, the thickness for blocking ultraviolet rays is in the range of 0.5 µm to 1.0 µm or more am.

When an organic polymer resin plate such as a natural light acrylic plate or polycarbonate plate is coated with the coating agent of the present invention, it can completely cut (block) ultraviolet rays (400 nm or less) and provide excellent weather resistance. The coating agent of the present invention can absorb ultraviolet rays to prevent the lower layer of the organic polymer resin from being weakened by ultraviolet rays by ultraviolet rays. It can be applied to organic polymer resin boards, etc. In addition, since the coating agent of the present invention does not have a photocatalytic function, the organic polymer resin plate is not weakened by the photocatalytic action. In addition, since the coating agent of the present invention has acid resistance, it is not weakened by acid resins or the like.

When a silicone sealing material or an oil sealing material is coated with the coating of the present invention around a bathtub in a bathroom, around a window frame on an exterior wall or between tiles, the electrostatic discharge/charge prevention action of the coating agent prevents dust and contaminants from entering the surface. Prevents electrostatic adhesion, leaving the surface untarnished/stained. In addition, the oil content of the oil sealing material is prevented from leaching on the surface, so that dust or contaminants are not caught by the oil, germs are not generated, and the surface of the material is prevented from blackening or weakening. In addition, since the coating agent of the present invention has waterproof and sealing action and has excellent film-forming properties, the above-mentioned effects are not weakened even after long-term use. As mentioned hereinafter, the use of the coating agent of the present invention even having weather resistance allows the silicone resin sealing material or the modified silicone resin sealing material to be used externally.

In addition, when the TV-cathode ray tube or the display surface of a personal computer or other OA devices are coated with the coating agent of the present invention, harmful electromagnetic waves of specific wavelengths can be completely excluded (blocked). In addition, by mixing/combining the currently used electromagnetic wave shield or raw materials of fine particles of activated carbon, it is possible to block electromagnetic waves of a specific wavelength. In addition, the woven fabric, non-woven fabric, etc. applied with the coating agent of the present invention does not electrostatically charge or discharge static electricity even in winter when the air is dry. In addition, since the fabric has chemical resistance, it can be applied to plants of the same type, and the insect repellent advantageously does not need to be stored.

In addition to the amorphous titanium oxide according to the present invention, the dielectric and conductive ceramic material acts to block ultraviolet rays and prevent static electricity generation. The dielectric ceramic material is SiO₂, Ta₂O₅, TiO₂, SrTiO₃, BaTiO₃, and perovskite compounds in the Pb system. Conductive ceramic materials also include alloys composed of base metals such as copper, nickel, chromium, titanium and aluminum. The ceramic material is also used as a coating resin mixing material in the state of a UV-blocking cosmetic product or fine powder or fine powder having a diameter of about 0.001 mu m to 20 mu m. The coating agent of the present invention may contain the above ceramic material together with amorphous titanium oxide, if necessary.

Of the above ceramic materials, as a material having a photocatalytic action, an ultrafine powder of anatase-type titanium oxide having particles having a diameter of 7 nm to 20 nm or a sol having an ultrafine powder is "ST-01" (Ishihara Techno Co., Ltd.) or "SST-01" (Ishihara Techno Co., Ltd.) is commercially available. When a material having a photocatalytic action is directly coated on an organic polymer resin substrate such as a sealing material, a waterproof material, a sheet material, and the like, the material weakens the substrate. Thus, although layers are required to be formed by the intermediate layer, if the UV blocking layer is composed of a material having a photocatalytic function, such as anatase-type titanium oxide having a thickness of about 0.5 μm to 1.0 μm, the second layer is resistant to weathering and chemicals. It is effective as a protective layer with In addition, the layer acts as an antifouling layer, as floating oil particles or other contaminants may be degraded by the layer. In addition, the intermediate layer for protecting the base material from photocatalysis is, for example, a layer of a silicon compound with a thickness of about 0.5 µm to 1.0 µm, such as silicon oxide such as gelatinous silica, water-glass, or the like, amorphous titanium oxide or amorphous titanium peroxide; It may be an amorphous titanium oxide layer without the same photocatalytic action, or a layer containing both silicon oxide and amorphous titanium oxide.

In addition, a substrate coated with silicon oxide, such as gelatinous silica, mixed with amorphous titanium oxide, has hydrophilic properties on its surface in addition to UV blocking action, and provides a self-cleaning action for hydrophilic-cleaning the deposits on the surface. do. In addition, if anatase-type titanium oxide or rutile-type titanium oxide is blended/mixed, a photocatalytic action can be provided in addition to the above-mentioned action.

Next, the present invention will be described in more detail according to Examples, but the technical scope of the present invention is not limited by the Examples.

Reference Example 1 (Preparation of amorphous titanium peroxide sol)

50% titanium tetrachloride TiCl diluted 70 times with distilled water₄ solution (commercially available from SUMITOMO STTX CO.) and 25% ammonium hydroxide NH diluted 10 times with distilled water₄An OH solution (commercially available from TAKASUGI PURECHEMICAL INDUSTRY LTD.) was mixed with each other in a volume ratio of 7: 1 to carry out a neutralization reaction. After the neutralization reaction, the pH was adjusted to 6.5 to 6.8, and the mixture was left for a while to remove the supernatant. Ti(OH)₄ In order to leave the gel, distilled water was added in an amount of about 4 times the amount of the gel, and the solution was sufficiently stirred and then left to stand. When testing with silver chloride, washing with water is repeated until no chlorine ions are detected in the supernatant, and finally the supernatant is removed, leaving only the precipitate. In some cases, dehydration treatment can be performed with a centrifuge. After that, 210 ml of 35% aqueous hydrogen peroxide solution is divided into 2 parts, and every 30 minutes 3600 ml of slightly bluish white Ti(OH)₄ was added separately, and the solution was then stirred at about 5 DEG C overnight to obtain about 2500 ml of a yellow transparent amorphous titanium peroxide sol.

Since water-insoluble substances such as metatitanic acid may precipitate if heat generation is not suppressed, it is often desirable to suppress heat generation in all of the above-mentioned steps.

Example 1 (UV protection effect)

Each surface of a transparent acrylic plate having a size of 50 × 100 mm and a thickness of 2 mm was prepared according to Reference Example by dipping (1.7 wt % of TiO₃containing) was coated with an amorphous titanium peroxide sol to form a coating layer having a thickness of 1 μm to 0.5 μm. The surface of the other acrylic plate was not coated with an amorphous titanium peroxide sol to form a control substrate. In the above manner, three types of test substrates were prepared.

In addition, two black lamps each emitting a short wave of 380 nm, prepared by TOTO Corporation, a scolt tile (photocatalyst tile) having a size of 30 × 30 mm, coated with silver nitrate on its surface, as a UV-sensitive substrate. was prepared as an ultraviolet source.

The test substrate was fixed at a position of 10 mm on the silver nitrate-coated surface of the UV-sensitive substrate, and two black rays were irradiated from a position of 60 mm on the test substrate for 1 hour, so that the UV shielding effect was obtained by chemical change. It was confirmed by discoloration of the coated surface.

As a result, for the test substrate formed by coating the surface of an acrylic plate having an amorphous titanium peroxide sol having a coating thickness of 1 μm, there was no change on the surface of the ultraviolet-sensitive substrate, and it was confirmed that the ultraviolet rays were completely blocked. For the test substrate similarly coated to have a coating thickness of 0.5 mu m, its color turned light gray after 1 hour after irradiation, and it was confirmed that a small amount of ultraviolet irradiation had passed. For the test substrate (control) having an acrylic plate surface not coated with an amorphous titanium peroxide sol, it was confirmed that discoloration started 30 minutes after UV irradiation, and silver nitrate was applied 1 hour after the surface of the UV-sensitive substrate was irradiated. It turned dark gray due to the chemical change of the surface.

Example 2

Amorphous Titanium Peroxide Sol TiO₃, except that a thermosetting water-soluble resin was used as a powder binder and a coating agent composed of amorphous titanium oxide powder (manufactured by Idemitsu Kosan Co., Ltd.) instead of , and almost identical results were obtained. did.

The multifunctional coating agent of the present invention is excellent in sealing properties, film formability and transparency, and when the surface of the substrate is coated with a coating agent, weather resistance (UV protection properties), harmful electromagnetic wave blocking properties, chemical resistance, static discharge/charge prevention properties, It is possible to provide a substrate having insect repellency and other properties.