WO1999033565A1

WO1999033565A1 - Titanium oxide-based photocatalyst, process for preparing the same, and use thereof

Info

Publication number: WO1999033565A1
Application number: PCT/JP1998/002745
Authority: WO
Inventors: Yasuhiro Masaki; Masaru Takahashi; Tadashi Yao; Kenji Ikishima; Akito Sakoda
Original assignee: Sumitomo Metal Industries, Ltd.
Priority date: 1997-12-24
Filing date: 1998-06-18
Publication date: 1999-07-08
Also published as: AU8036698A

Abstract

A titanium oxide-based photocatalyst composed mainly of a photocatalyst base material and a silicon compound, the base material comprising zirconium titanate with an atomic percentage ratio of zirconium to titanium of 0.001 to 0.5. This photocatalyst can form, on the surface of a substrate of a metallic material, an inorganic material, an organic material or the like, a photocatalyst layer having good adhesion to the substrate and good film properties, such as good processability and strength. The photocatalyst can be prepared by coating the surface of a substrate with a composition comprising a base material for a photocatalyst, a silicon compound, and a solvent and baking the coating. A material carrying the photocatalyst thereon enables a harmful material in the atmosphere or in water, or a material deposited on the material to be decomposed, rendered harmless or removed under light irradiation.

Description

Description Titanium oxide-based photocatalyst, method for producing and using the same

The present invention relates to a titanium oxide-based photocatalyst having an excellent photocatalytic action and capable of forming a photocatalyst layer having excellent properties on the surface of a substrate, and a material provided with the titanium oxide-based photocatalyst layer on the surface. And the methods of making and using them. Background art

When a semiconductor is irradiated with light having energy equal to or greater than the band gap, electrons having a strong reducing action and holes having a strong oxidizing action are generated on the irradiated surface. Substances such as organic substances in contact with the surface of the semiconductor in such a state are decomposed by the strong oxidation-reduction effect of the semiconductor.

In recent years, the photocatalytic action of such semiconductors has been used to decompose and detoxify harmful substances contained in air and water, deodorize in living spaces, antifouling (preventing contamination on solid surfaces), sterilization, and various other environmental purifications. It is being used for technology. Titanium oxide is mainly used as a semiconductor for photocatalysts. Conventionally, when a semiconductor such as titanium oxide is used as a photocatalyst, the powder has been used in a state of being suspended in a solution. However, from the viewpoint of ease of handling and wide applicability, it is more advantageous to use the photocatalyst in the state of being fixed in a thin film on the surface of a material (substrate) such as metal or ceramics. . However, when the photocatalyst is fixed to the substrate, the surface area (actual reaction area) of the photocatalyst that exerts the photocatalytic action is limited and cannot be made too large, so that sufficient photocatalytic efficiency cannot be obtained. There was a problem. In order to solve this problem, sufficient photocatalytic efficiency is required even if the surface area of the photocatalyst is small. It is necessary to improve the photocatalytic performance itself so that it can be obtained. On the other hand, when the photocatalyst is fixed to the surface of the base material in a thin film form, that is, when used as a material having a photocatalyst layer on the surface, the photocatalytic efficiency is increased because the actual reaction area of the photocatalyst is limited. In addition to the problem of not being able to do so, problems often arise that the workability, strength, and appearance of the material are not always sufficient. For example, even if the photocatalyst particles are applied to the surface of the material (substrate) as it is, the photocatalyst itself does not have a film-forming action to form a film, and the photocatalyst and the substrate are not fired after the application. The photocatalytic layer (coating) may be cracked or the coating may be separated due to the difference in the coefficient of thermal expansion of the coating. Therefore, it is not always easy to obtain a film with sufficiently satisfactory properties.

Therefore, various methods have conventionally been used to fix the photocatalyst particles to the surface of the base material.

For example, JP-A-7-171408 discloses a photocatalyst in which photocatalyst particles are adhered to a substrate via a hardly decomposable binder. The technique shown here involves applying a coating containing photocatalyst particles and a hardly decomposable binder obtained by a known method to the surface of a substrate such as various products and solidifying it. By doing so, it is said that the surface of various products can be relatively easily made into a photocatalyst.

Also, Japanese Patent Application Laid-Open No. Heisei 9-197385 discloses a method in which a support layer made of silica particles is provided on the surface of a substrate, and titania particles smaller than silica particles are provided on the surface of the support layer. Are disclosed. In this technology, the density of silica particles constituting the carrier layer is increased on the substrate side (by disposing small-diameter silica particles), the adhesion between the substrate and the carrier layer is increased, and the photocatalytic layer is formed. The silica particles on the side are coarsely dispersed (by disposing large silica particles) to adhere the titania particles firmly, and are applied to the light reflecting surface of lamps and lighting equipment. Examples have been disclosed. Further, Japanese Patent Application Laid-Open No. Hei 9-171801 discloses that a photocatalyst particle composite containing a gel of a metal oxide or metal hydroxide such as titanium oxide is provided on an adhesive layer in between to form a substrate. A fixing technique is disclosed.

However, in these technologies, as described above, in addition to the fact that the actual reaction area of the photocatalyst is small, the active point of the photocatalyst is determined by the binder and the adhesive layer added to fix the photocatalyst particles. And the photocatalytic activity is significantly reduced. Also, in the photocatalyst layer (film) fixed to the substrate, the photocatalyst particles are buried in a binder or the like or are supported with a weak bonding force, and that portion becomes a starting point and cracks in the film. And other problems. Further, as shown in the above example, the fixation of the photocatalyst to the surface of the substrate is the fixation to the surface of the molded article, and is applied after the photocatalyst layer is provided on the surface. No material for processing and a method for producing the same are disclosed. This is because, when a photocatalyst layer is provided, the workability of the substrate becomes poor and processing becomes difficult, and when severe processing is performed, the photocatalyst layer separates and the product quality deteriorates, and the photocatalytic function deteriorates. This is because there is a problem.

Therefore, for example, when a photocatalyst layer (film) is provided on the surface of a material used for building materials, home appliances, automobiles, etc., the material is formed into these product shapes and painted, and then a chemical containing the photocatalyst is sprayed. -Painting or brush painting is used. However, spray coating and brush coating methods have large paint loss, resulting in reduced yield due to inadequate surface properties of the product, etc., resulting in a significant cost increase. . Furthermore, since the object to be applied is a molded product, a large drying oven for applying and drying the chemical solution and a space therefor are required, so the photocatalyst layer (film) is used for building materials and home appliances. Only a few examples are provided on the surface of molded substrates for products and vehicles.

At present, as a material for processing building materials and home appliances, a painted metal plate (pre-coated metal plate) in which the final product color or intermediate color is painted on the surface of a metal base material using a continuous method such as π-coat Is used. Painted metal film coating The required performance (color, workability, weather resistance, corrosion resistance, concealment, lubricity, etc.) of the product is given to the product. The final product can be obtained by assembling and assembling. In this way, the processing method using a painted metal plate as a material can omit or simplify the painting step after assembling, so that the productivity is high and the economy is excellent. For this reason, painted metal sheets are becoming the mainstream of materials for building materials and home appliances, and the development of painted metal sheets provided with a photocatalytic layer on the surface that can be applied to these uses is desired.

INDUSTRIAL APPLICABILITY The present invention has an excellent photocatalytic action, and an oxidation capable of forming a photocatalytic layer (film) having excellent bondability with a base material and excellent in processability, strength and the like on the surface of a material (substrate). The purpose of the present invention is to provide a titanium-based photocatalyst, a material having a titanium oxide-based photocatalyst layer having excellent film properties on its surface, and a method for producing and using the same. is there. Disclosure of the invention

The titanium oxide photocatalyst, which combines a silicon compound with a photocatalyst consisting of a titanium oxide, has excellent photocatalytic activity and is fixed to a material (substrate) to form a photocatalyst layer (film). At this time, it has the characteristics that it has excellent bondability with the base material and has good film properties such as workability, strength, crack resistance, deterioration resistance, and appearance.

The gist of the present invention is to provide the following (1) a titanium oxide-based photocatalyst, (2) a material provided with a layer of the titanium oxide-based photocatalyst on the surface, and (3) production of the material described above. And (4) a method for producing the material using the compounding agent, and (5) a method for using the material.

(1) A silicon-based compound and a photocatalyst basic body composed of a titanium-based oxide containing zirconium titanate and having an atomic% ratio of zirconium to titanium of not less than 0.001 and not more than 0.5. Mainly titanium oxide photocatalyst. The titanium-based oxide (photocatalyst particles) in the titanium-oxide-based photocatalyst containing the silicon-based compound is particularly referred to as a “photocatalyst basic body” to be distinguished from the silicon-based compound.

This titanium oxide-based photocatalyst is composed of at least one of a silicon-based compound, silica fine particles, a polysiloxane, a silicone-based resin, and a compound in which these are partially reacted. When it is, it shows particularly excellent performance.

(2) A photocatalyst basic body and a silicon-based compound comprising a titanium-based oxide containing zirconium titanate and having an atomic percentage ratio of zirconium to titanium of not less than 0.001 and not more than 0.5. A material with a layer made of a titanium oxide-based photocatalyst whose main component is on the surface of a substrate. The “substrate” refers to a material serving as a base before forming a photocatalyst layer by fixing a powdery photocatalyst in a thin film shape. When the silicon-based compound is at least one of silica fine particles, polysiloxane, a silicone-based resin and a compound in which these are partially reacted, The titanium oxide photocatalyst formed on the surface shows particularly excellent performance.

The above-mentioned base material is a metal material or a coated metal plate having its surface coated, and a material having a barrier layer between the base material and a layer formed of a titanium oxide-based photocatalyst has an excellent photocatalytic function. It is a material having both good workability.

If the titanium oxide-based photocatalyst layer contains an organic lubricant, the moldability of the material is improved.

In addition, if the barrier layer contains rutile-type and / or Brookite-type titanium oxide particles that have been subjected to a photocatalytic inactivation treatment, the weather resistance of the titanium oxide-based photocatalyst layer is reduced. In addition to the improvement, the bending workability of the barrier layer is improved, so that the formability of the material is further improved.

(3) A photocatalyst basic body composed of a titanium-based oxide containing zirconium titanate and having an atomic% ratio of zirconium to titanium of not less than 0.001 and not more than 0.5 and a silicon-based compound as a main component Titanium oxide based photocatalyst And / or a binder containing an organic solvent.

More preferably, the aforementioned silicon-based compound is a silica fine particle, polysiloxane, a silicone-based resin, and a compounding agent in which at least one of the compounds in which these are partially reacted is present. I like it.

(4) A basic photocatalyst comprising a titanium-based oxide containing zirconium titanate and having an atomic% ratio of zirconium to titanium of not less than 0.001 and not more than 0.5. After coating the surface of the substrate with a titanium oxide-based photocatalyst mainly composed of a body and a silicon-based compound, and a binder containing water, hydrogen, or an organic solvent, the layer formed of the titanium oxide-based photocatalyst is fired. A method for producing a material provided on a substrate surface. When the silicon-based compound is a compound containing at least one of silica fine particles, poly-pi-xanine, silicone-based resin and a compound in which these are partially reacted, However, it is possible to produce a material having a titanium oxide-based photocatalyst layer having particularly excellent performance on the surface.

Using a metal material or a coated metal plate having its surface coated as a base material, the base material surface is coated with a chemical solution for forming a barrier layer, and then dried to form a barrier layer. After the surface of the barrier layer is coated with the chemical solution for forming the titanium oxide-based photocatalyst layer, and dried, the surface formed with the titanium oxide-based photocatalyst according to (1) is provided. Materials can be manufactured.

(5) A photocatalyst comprising a titanium-based oxide containing zirconium titanate and having an atomic% ratio of zirconium to titanium of not less than 0.001 and not more than 0.5. A substance consisting of a base and a layer made of a titanium oxide photocatalyst mainly composed of a silicon-based compound on the surface of a substrate, which adheres to a substance in the air or water or to the surface of the above-mentioned material. How to use a material with a titanium oxide photocatalyst layer on the surface that treats the substance under light irradiation.

When the silicon-based compound is at least one of silica fine particles, polysiloxane, silicone-based resin and a compound in which these are partially reacted, the silicon-based compound is formed on the surface of the base material. Titanium oxide based photocatalyst Show noh.

In addition, a material having a layer formed of a titanium oxide-based photocatalyst on the surface of a base material is a metal material or a coated metal plate having a surface coated thereon, and the base material and the titanium oxide-based photocatalyst are used as a base material. A material having a barrier layer between the formed layers may be used. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing preferable drying conditions after applying a chemical solution for forming a barrier layer or a chemical solution for forming a photocatalytic layer.

Fig. 2 shows the results of the weather resistance and bending workability tests performed in Example 6, showing the content of titanium oxide in the barrier layer after the photocatalytic deactivation treatment and the color difference before and after the weather resistance test. It is a figure which shows the relationship between a change and bending workability. FIG. 3 is a diagram showing an appearance of a flat panel used in an outdoor exposure test performed in Example 9. BEST MODE FOR CARRYING OUT THE INVENTION

The titanium oxide photocatalyst of the present invention (hereinafter simply referred to as “the photocatalyst of the present invention” or

The “photocatalyst”, a material having a layer formed of the photocatalyst on the surface, and methods for producing and using them are described in detail below.

(1) Titanium oxide photocatalyst

As described above, the photocatalyst of the present invention comprises a titanium-based oxide containing zirconium titanate and having an atomic percentage ratio of zirconium to titanium of 0.001 or more and 0.5 or less. It is a titanium oxide photocatalyst mainly composed of a photocatalyst basic body and a silicon compound. As described later, at least one kind of metal and / or metal compound such as V, Fe, and Zn, an aluminum compound, and an ultraviolet absorber May be included Because.

The photocatalyst of the present invention has the following structural characteristics (a) and the following operational characteristics (b). Therefore, excellent photocatalytic activity is obtained. (a) As described above, the photocatalyst of the present invention is mainly composed of a photocatalyst basic body composed of a titanium-based oxide containing zirconium titanate and a silicon-based compound. In addition, the atomic percentage ratio of Zr to Ti (∑1 ", hereinafter, the ratio of Zr and other metal elements to Ti means the atomic percentage ratio) is not less than 0.001 and 0.5. It is as follows.

The content of the silicon compound in the photocatalyst is preferably 5% by weight or more and 95% by weight or less. The titanium oxide photocatalyst also includes at least one of V, Fe, Zn, Ru, Rh, Pt, Ag, Pd, and Cu. Alternatively, a metal compound, an aluminum compound, an ultraviolet absorbent, or the like may be contained.

(b) When the photocatalyst is irradiated with light, electrons and holes are generated (charge separation). At that time, the strong electronic interaction between the two semiconductors (titanium oxide and zirconium titanate) enhances the efficiency of charge separation between electrons and holes, resulting in a photocatalyst. Exerts a high photocatalytic action.

That is, part of the zirconium titanate contained in the photocatalyst basic body is firmly bound to the titanium oxide particles via the Ti-0-Zr bond (in other words, the titanium oxide titanate). The photocatalyst particles are completely integrated with titanium oxide and some particles of zirconium titanate. I have. As a result, the electronic interaction is further strengthened through bonding, so that the efficiency of charge separation of the photocatalyst is further enhanced, and the photocatalytic performance is dramatically improved.

The photocatalyst of the present invention is composed mainly of the above-mentioned photocatalyst basic body and a silicon-based compound, and the titanium-based oxide and the silicon-based compound are in a state of being partially bonded by a reaction. . In other words, there is a strong Z r — 0— S i A bond has occurred. This is had contact to Z r S i 0 _4, known as the zircon, is easy in the same manner as Z r -〇 one S i bond is formed.

Therefore, in the titanium oxide-based photocatalyst layer (coating) formed on the surface of the substrate, the particles of the photocatalyst basic body, ie, the titanium-based oxide, are bonded to the silicon-based compound via Zr-1-1Si bonds. Thus, it has a network structure in which a film mainly composed of a silicon compound and titanium-based oxide particles are integrated. In other words, the photocatalyst basic body and the silicon-based compound are not in a state in which fine particles are simply mixed with each other, or in a state in which the photocatalyst basic body fine particles are buried in a film portion made of a silicon-based compound, but rather by a reaction. It is in the combined state. In other words, since the titanium oxide photocatalyst is bonded to the silicon compound via Zr, in this titanium oxide photocatalyst, titanium oxide, which is the main photocatalytically active site, is directly formed into a film. Less contact with parts. Furthermore, the above-mentioned electronic interaction spreads throughout the network, and the efficiency of charge separation is increased, so that the photocatalytic activity is improved. Further, when the photocatalyst of the present invention is fixed to a substrate to form a photocatalyst layer (film), the photocatalyst has excellent binding properties to the substrate, and provides an interface between the basic photocatalyst (photocatalyst particles) and the silicon-based compound. The film is hardly cracked because it is strongly bonded, and the film properties such as workability, strength, crack resistance, deterioration resistance and appearance are good.

In this photocatalyst, the silicon-based compound is at least one of silica fine particles, polysiloxane, a silicone-based resin, and a partially reacted compound thereof. Excellent in both photocatalytic activity and film properties.

As described above, a titanium-based oxide containing zirconium titanate at a predetermined ratio is used as the basic photocatalyst included in the photocatalyst of the present invention. Although performance such as photocatalytic activity is inferior to this, titanium oxide, zinc oxide, tungsten oxide, zirconium oxide, iron oxide, bismuth oxide are used instead of this titanium oxide. Or a known semiconductor photocatalyst such as They may be used in combination. Further, titanium oxide or the above-mentioned titanate oxide and at least one of these known semiconductor photocatalysts may be used in combination.

In the photocatalyst basic body mainly composed of titanium oxide and zirconium titanate, titanium oxide may be amorphous or crystalline. In the case of crystalline, it may be in the form of an anatase, a rutile, or a mixture thereof. On the other hand, zirconium titanate may be amorphous or crystalline, but crystalline is preferred because higher photocatalytic activity can be obtained.

The relationship between Ti and Zr contained in the basic photocatalyst is based on the ratio of Zr present as zirconium titanate to Ti present as titanium oxide and zirconium titanate ( When expressed as ZrZTi), the value is preferably from 0.01 to 0.5. If it is less than 0.01, the amount of zirconium titanate is small, so that the electronic interaction with titanium oxide becomes weak, and high photocatalytic activity cannot be obtained. On the other hand, if it exceeds 0.5, it becomes difficult to produce titanium oxide and zirconium titanate which are effective as a photocatalyst depending on the preparation method. A more preferable range is from 0.01 to 0.3. When Zr / Ti is within this preferred range, a zirconium titanate is contained and a photocatalytic base having high photocatalytic activity can be obtained without using a specially prepared method. .

Further, the basic photocatalyst constituting the photocatalyst of the present invention has V, Fe, Zn, Ru, Rh, Pt, Ag, Pd and the like inside and / or on the surface thereof. And at least one of Cu and Cu may be contained. The inclusion of these components further enhances the photocatalytic performance, and also imparts the functions of the components themselves to the photocatalyst, for example, antibacterial properties for Zn, Ag, and Cu. be able to. Examples of the metal compound include metal oxides, hydroxides, oxyhydroxides, nitrates, and halides. Next, the silicon-based compound constituting the photocatalyst of the present invention will be described. This silicon-based compound reacts with the basic photocatalyst, and is strongly bonded to the basic photocatalyst by a ∑1 "— 0—31 bond. As described above, particles of the titanium-based oxide are formed. When it is strongly bonded to the silicon-based compound via the Zr-0-Si bond, the charge separation efficiency of titanium oxide and zirconium titanate is higher than when it is not bonded. The formation of the Zr—0—Si bond can be confirmed by analysis methods such as IR (infrared spectroscopy) and NMR (nuclear magnetic resonance). it can.

As the silicon-based compound, a polysiloxane, a silicone resin, a silica fine particle and a partially reacted product thereof are preferable.

Polysiloxanes are tetramers represented by R ² _n Si (OR ¹ ) (where η is an integer from 0 to 3 and R ¹ and R ² are hydrocarbon groups). Reaction products obtained by hydrolysis from silicone alkoxides such as toxisilane, methyltriethoxysilane, and methyltriisopropoxysilane Things are preferred. These silicone alkoxides can be used as a raw material of a coating compounding agent as described later.

Silicone resin is derived from general-purpose resins such as acrylic resin, urethane resin, and epoxy resin by ester exchange reaction and hydrosilylation. Any resin can be used. Specifically, acrylic silicone resin, epoxy silicone resin and the like are preferable from the viewpoints of film forming properties and film strength when the photocatalyst of the present invention is fixed to a substrate. .

Examples of the silica fine particles include colloidal silica, powdered silica, and fumed silica. The particle diameter of the fine particles is preferably 30 nm or less. If the particle size exceeds 30 nm, the specific surface area becomes smaller, so that the area that reacts with the basic photocatalyst is small, the number of bonds with the basic photocatalyst is reduced, the activity is reduced, and the film is cracked. This is because film forming properties and film properties are deteriorated, such as the occurrence of cracks and a decrease in the gloss of the film itself. More preferred silica The fine particles are colloidal silica having a particle size of 2 O nm or less.

The silicon-based compound constituting the photocatalyst of the present invention may contain two or more of the above-mentioned silicon-based compounds. In that case, it is preferable from the economical viewpoint to use relatively inexpensive fine particles such as a colloidal silica force together with polysiloxane or silicone resin. In addition, the silicon-based compound is obtained by sintering silicon alkoxide, silicone resin, silica fine particles, etc. used as a raw material of a coating mixture for coating at a firing temperature during film formation. Depending on conditions such as humidity, humidity, etc., the polymer is partially hydrolyzed or has not reacted with the basic photocatalyst, or the silicone resin etc. in the titanium oxide-based photocatalyst has a photocatalytic effect. There is no problem even if it is partially oxidized.

It is desirable that the content of these silicon compounds be 5% by weight or more and 95% by weight or less based on the weight of the photocatalyst. If the amount is less than 5% by weight, the film properties such as cracking of the film and poor bonding to the base material are poor, and if it exceeds 95% by weight, the photocatalytic performance is reduced. A more preferred range is from 20% by weight to 60% by weight.

Further, the photocatalyst of the present invention may contain additives for various purposes.

For example, aluminum compounds are effective in improving photocatalytic activity, film strength, and the like. Also, by adding an inexpensive aluminum compound, the cost of the material can be suppressed. As the aluminum compound, alumina fine particles having a particle diameter of 100 nm or less, aluminum hydroxide, and the like are preferable. The content of the aluminum compound is preferably from 0.005% by weight to 20% by weight based on the weight of the photocatalyst. If the content is less than 0.05% by weight, the effect of the addition is ineffective, and if the content exceeds 20% by weight, the film is cracked and the gloss is reduced. More preferably, it is at least 2% by weight and at most 10% by weight.

Further, the material (substrate) for fixing the photocatalyst of the present invention and the photocatalyst layer (coating) When it is necessary to suppress the deterioration of the body or to suppress the activity of the photocatalyst, the photocatalyst may contain an ultraviolet absorber. Examples of the ultraviolet absorbent include organic compounds such as triazole and inorganic compounds such as titanium oxide and zinc oxide. Surface treatment of titanium oxide, zinc oxide, etc.

(Photocatalytic deactivation treatment) is preferred.

The content of these ultraviolet absorbers is not particularly limited, but is preferably 30% or less based on the weight of the photocatalyst of the present invention. This is because if it exceeds 30%, film formation is hindered.

(2) A material having a layer formed of the titanium oxide-based photocatalyst described in (1) above on the surface of a base material

This material contains zirconium titanate described in (1) above and has a ratio of zirconium to titanium (Zr / Ti) of not less than 0.001 and not more than 0.5. This material has a photocatalyst basic body composed of a tan-based oxide and a titanium oxide-based photocatalyst mainly composed of a silicon-based compound on its surface.

The photocatalyst constituting the photocatalyst layer is particularly useful when the silicon-based compound is at least one of silica fine particles, polysiloxane, silicone-based resin and a compound in which these have been partially reacted. Demonstrates excellent photocatalytic performance. Further, as described above, the photocatalyst layer (film) formed on the surface of the substrate according to the above (1) has excellent bondability with the substrate and has good film properties, so that the film is cracked. It is excellent in workability, strength and appearance.

As the base material, iron, π, nickel, zinc, manganese, aluminum, titanium, platinum, molybdenum, etc., or alloys containing these elements as main components, etc. Metal materials, inorganic materials such as ceramics, ceramics, glass, and quartz, and organic materials such as resin, wood, and activated carbon are suitable. These materials (base materials) may be used alone or in combination of two or more. The shape of the substrate is preferably determined according to the application. Plates such as thick plates and thin plates, spherical shapes such as beads, or multiple shapes such as those used as products The shape may be rough. The surface properties of the material may be porous or dense.

The material provided with a photocatalyst layer on its surface according to the present invention is the above-mentioned metal material or a coated metal plate having its surface coated (hereinafter, this metal material and a coated metal plate are collectively referred to as a substrate). A metal plate) and a barrier layer between the substrate and the layer formed by the photocatalyst, that is, a barrier on the surface (at least one side) of the substrate. It may be a material having a layer and further having the photocatalyst layer described in (1) above (hereinafter, this material is referred to as a “metal plate having a photocatalytic function”). This material has both excellent photocatalytic function and good processability.

Hereinafter, the metal plate having the photocatalytic function will be described in detail.

Metal plate:

In the metal plate having the photocatalytic function, a known coated metal plate can be used as the base material in addition to the above-described metal materials. The metal material may have various types of plating applied to its surface. In addition, the base material of the coated metal sheet is a cold-rolled steel sheet for various drawing processes, a high-tensile cold-rolled steel sheet, or Zn-plated and Zn-coated such cold-rolled steel sheets. Various types of plating such as Zn alloy plating with Al, Fe, Mn, etc., A1 plating, A1 alloy plating with A1, Mn, Zn etc. Plates are commonly used. However, the base material is not limited to the above-mentioned steel sheet or plated steel sheet, but may be any type of hot-rolled steel sheet, or a sheet subjected to the above-described various kinds of plating, or ferrite. A variety of stainless steel pots, such as stainless steel and austenitic stainless steel, or various aluminum plates may be used.

If the metal plate is a painted metal plate, the coating applied to the surface of the base metal may be acrylic, melamin, polyester, polyurethane, PVC, etc. In addition, known organic resin-based paints can be used. The thickness and color of the coating film are arbitrary, and the thickness is generally 3 to 100 m. Layer:

When the base material of a metal plate having a photocatalytic function is a coated metal plate, the coating film is damaged by the oxidizing action of holes generated by the photocatalytic reaction when the photocatalytic particles come into direct contact (hereinafter referred to as “the metal oxide”). Such damage is referred to as “choking”). Therefore, a substance capable of shielding the action of the photocatalyst is interposed between the coating of the coated metal plate and the layer of the photocatalyst of the present invention in the form of a thin film to prevent the coating from being choked by the photocatalysis.

Further, when the base material of the metal plate is a metal material having no coating film surface, for example, a stainless steel plate or the like, if the photocatalyst layer comes into direct contact with the metal material, the metal surface may be fired, Corrosion may be caused by the acid contained in the coating solution, and metal atoms or ions may diffuse from the underlying metal plate into the photocatalytic layer, resulting in a significant decrease in photocatalytic activity. Therefore, in order to suppress a decrease in photocatalytic activity, a substance for preventing metal diffusion is interposed between the metal material and the photocatalyst layer in the form of a thin film, as in the case of a coated metal plate.

Such a thin film having a function of blocking the photocatalytic action or preventing diffusion of metal from the underlayer is referred to herein as a “barrier layer”.

As the rear layer, an inorganic substance that is not decomposed even when in contact with the photocatalyst particles, or an inorganic-organic composite substance can be used. As the inorganic substance, for example, silicon oxide, aluminum oxide, zirconium oxide, or the like can be used. Among them, silicon, which has been widely used as a material to coat titanium oxide particle surfaces, in order to suppress the photocatalytic choking of titanium oxide, a common white pigment Oxides (especially SiO ₂ ) or aluminum oxides (especially A 1203) are preferred.

The above oxide particles preferably have a particle diameter of 0.01 to 1 m. The particle size can be measured by a transmission electron microscope. If the particle size exceeds 1 (jm), the adhesion of the barrier layer to the coating film or the metal surface may be impaired. The smaller the particle diameter, the better, but less than 0.0111 Those that are not are not common because they are difficult to obtain by ordinary means. These oxide particles are obtained by a known method. For example, the silicon oxide particles represented by Sio 2 can be obtained by a known sol-gel method or the like. Examples of the inorganic-organic composite material include a silicone resin, a silane coupling agent, a fluorine resin, and a titanate coupling agent.

The above-mentioned inorganic substances or inorganic-organic composite substances can be used alone or in combination. Its content (total content when used in combination) is preferably at least 20% by weight based on the weight of the barrier layer. If the content is less than 20% by weight, the adhesion to the coating film or metal surface may be insufficient. The upper limit of the content, because 1 0 0% by weight, even good force ^5, 8 0 the strength of the coating film exceeds% by weight there is and this is insufficient, rather than the preferred Ri good is 8 0 by weight%.

Furthermore, when the base material of the metal plate having a photocatalytic function is a coated metal plate, a photocatalyst inactivation treatment is applied to the rear layer to improve the weather resistance of the coating film when used outdoors. It is preferable to contain rutile-type and / or wurtzite-type titanium oxide particles which have been subjected to the treatment. The photocatalytic inactivation treatment is a treatment in which the surfaces of titanium oxide particles are coated with silica, alumina, zirconia, or the like. Since these titanium oxide particles absorb ultraviolet rays, the amount of ultraviolet rays reaching the coating film of the coated metal plate is reduced, and the deterioration of the resin is suppressed.

In addition, when the barrier layer contains an appropriate amount of titanium oxide particles that have been subjected to a photocatalytic deactivation treatment, the bendability of the NORIA layer is improved. This is presumably because, when these particles are contained in an appropriate amount, the stress generated inside the barrier layer during processing is reduced. However, in some cases, excessive content may impair the workability of the barrier layer. For this reason, it is preferable that the content of the titanium oxide particles subjected to the photocatalytic inactivation treatment be set to 80% by weight or less with respect to the weight of the phosphor layer. When the content is in the range of 20 to 65% by weight, the balance between the weather resistance and the formability is good, and it is more preferable. The layer was treated with an oxide such as silicon oxide which has a function of blocking the photocatalytic action or preventing diffusion of metal from the underlayer, and a photocatalytic inactivation treatment for improving weather resistance. In addition to titanium oxide particles, etc., contains UV absorbers such as benzotriazole type, benzopentanone type, and anilide cyanoacrylate type for the purpose of improving weather resistance May be allowed.

The thickness of the rear layer is preferably set to 0.05 to 10 wm. If the thickness is less than 0.05 μm, the effects of suppressing choking and preventing metal diffusion are insufficient. If the thickness exceeds 10 m, the effect of suppressing choking and diffusion of metal saturates, so that increasing the thickness beyond 10 m is not economical. If the thickness of the photocatalyst layer described below is appropriate, the transparency of these layers can be maintained, so even if the barrier layer and the photocatalyst layer are provided on the metal plate, the color tone, gloss, etc. of the metal plate itself There is no loss of design.

Photocatalyst layer:

Examples of the photocatalyst include a photocatalyst basic body composed of a titanium-based oxide containing zirconia titanate and a titanium oxide-based photocatalyst according to the above (1) mainly composed of a silicon-based compound. Used. This photocatalyst has excellent photocatalytic activity, and also has a film property (bonding property to the base material, when fixed on the surface of a base material (in this case, a barrier layer)) to form a photocatalyst layer (film). In terms of workability and strength).

The size of the basic photocatalyst (photocatalyst particles) is preferably in the range of 0.05 to 1 m in terms of the average particle size determined by observation with a transmission electron microscope. The smaller the photocatalyst particles are, the better the catalytic activity is, which is preferable. Particles with a particle size of less than 0.05 m are difficult to classify by ordinary means and are difficult to obtain.

The size of the crystallite constituting the basic photocatalyst is preferably from 5 to 50 nm. The crystallite size is (10%) of the anatase crystal obtained by X-ray diffraction. 1) Calculated from the diffraction peak from the plane. If the crystallite size exceeds 50 nm, the photocatalytic activity decreases, which is not preferable. Since the smaller the crystallite size, the better the photocatalytic activity, it may be as small as possible, but those smaller than 5 nm cannot be obtained by ordinary means.

The thickness of the photocatalyst layer is preferably 0.1 to 10 wm. If the thickness is less than 0.1 m, the photocatalytic effect will be insufficient. More preferably, it is at least 0.3 m. When the thickness exceeds 10 m, the photocatalytic effect is saturated, and the workability of the photocatalytic layer is deteriorated. When severe processing is performed, the thickness is more preferably 5 m or less.

The content of the basic photocatalyst is preferably in the range of 10 to 90% by weight based on the weight of the photocatalyst layer. If the content is less than 10% by weight, the photocatalytic function may be insufficient. The power at which the photocatalytic effect increases as the content of the basic photocatalyst increases is not preferred, because it exceeds 90% by weight because cracks and cracks increase on the film surface.

In addition to the titanium oxide photocatalyst described above, the photocatalyst layer may be made of a fluororesin, a colloidal alumina, a chromic acid, or a chromic acid to improve the strength and adhesion of the film. It may contain up to 90% by weight of oxalate, phosphoric acid, phosphate and the like based on the weight of the photocatalyst layer. In addition, a peptizer (anion such as ion nitrate and chloride ion) inevitably contained in a photocatalyst layer forming chemical solution described later may remain in the photocatalyst layer.

The surface of the photocatalyst layer has high wettability, a high coefficient of friction with molds and the like, and high slip resistance when pressed by a tool. For this reason, there is no problem with relatively mild bending, etc., but if severe processing such as deep drawing is performed, molding defects such as cracks, mold galling, poor dimensional shape, etc.離 Separation occurs.

In order to prevent molding defects when molding a metal plate having a photocatalytic function, the photocatalyst layer preferably contains an organic lubricant. Included in photocatalyst layer Organic lubricants used include natural waxes, polyolefin waxes, oxidized polyolefin waxes, and modified polyolefin waxes. There are waxes, crystal mouth waxes, etc., and it is better to use one or a combination of two or more of these. The above-mentioned wax particles are decomposed by photocatalysis after molding and are removed from the photocatalyst layer, so that the photocatalytic activity of the product is improved. It is not preferable to use a wax other than the above because the photocatalytic activity of the photocatalyst layer deteriorates.

The content of the organic lubricant is preferably 0.1% by weight or more based on the weight of the photocatalyst layer in order to obtain a lubricating effect at the time of molding. However, when the content of the organic lubricant exceeds 10% by weight, the efficiency of the above-described photocatalytic decomposition is significantly reduced. Therefore, the upper limit of the content of the organic lubricant is preferably set to 10% by weight based on the weight of the photocatalyst layer. The amount of the organic lubricant is suitable for each drawing process, and is preferably as small as possible. Therefore, the amount is more preferably 5% by weight or less.

The organic lubricant is preferably a granular solid lubricant. If a particulate solid lubricant is used, the surface of the photocatalyst particles is not covered with the organic lubricant, so that the photocatalytic function of the photocatalyst particles can be sufficiently exhibited. Liquid lubricants are not preferred because they cover the surface of the photocatalyst particles.

The particle size of the organic lubricant is an average particle size measured by a laser diffraction method and is preferably not less than the thickness of the photocatalytic layer. If the average particle size is smaller than the thickness of the photocatalyst layer, the lubricating effect is insufficient. If the average particle size is excessively large, the organic lubricant drops off from the photocatalyst layer and adheres to the drawn surface to deteriorate the surface properties. For this reason, the average particle size is preferably set to 5 μm or less. More preferably, the thickness is not more than the thickness of the photocatalyst layer + 3 m.

(3) A compounding agent used for manufacturing the material described in (2) above.

The titanium oxide-based photocatalyst described in (1) above is usually used in a state of being fixed as a film on the surface of a material (substrate). In this case, this photocatalyst is included Since a coating compounding agent is used, the method for producing the photocatalyst will be described in the following description of the compounding agent. This compounding agent contains a zirconium titanate photocatalyst consisting of a titanium-based oxide having a ratio of zirconium to titanium (ZrZTi) of not less than 0.001 and not more than 0.5. It is obtained by mixing and reacting a basic body, a silicon-based compound, water, and an organic solvent.

The preparation of this compounding agent may be carried out as follows.

First, titanium compounds such as titanium alkoxide and titanium oxide fine particles and zirconium compounds such as zirconium alkoxide, zirconium oxide fine particles and zirconium salt are used as raw materials. The ratio of zirconium to titanium (ZrZTi) is adjusted to be in the range of 0.01 to ◦.5 in a solvent such as alcohol or water or in air, and the reaction is carried out. Let it. The precursor of the photocatalyst basic body obtained by this operation is dried at a temperature from room temperature to about 100, except for a solvent, if necessary. Thereafter, the obtained product is calcined at an arbitrary temperature of 100 ° C. to 900 ° C. in an air atmosphere, whereby a basic photocatalyst can be produced.

In order to obtain a more active photocatalyst basic substance, the precursor obtained as described above may be added to the precursor obtained above in water or in the air, or by an acid such as nitric acid or hydrochloric acid. After a secondary reaction such as hydrolysis is caused, it is preferable to remove the solvent and the like as necessary, dry, and then calcinate at a predetermined temperature.

In addition, a titanium compound and a zirconium compound are mixed, and if necessary, a reaction such as hydrolysis is caused to the obtained precursor, and then the reaction is performed at 80 ° C to 100 ° C. A method of heating or refluxing for 2 hours or more, more preferably for 10 hours or more in a temperature range of about C, removing the solvent, etc. as necessary, drying the obtained product, and firing it. According to this, a photocatalyst basic body composed of a titanium oxide having higher activity can be obtained.

The titanium-based oxide obtained in this manner is converted into water and organic or organic solvent. By mixing with the silicon compound in the agent, a compounding agent for coating can be prepared. In addition, an S mixture can be easily prepared by the following method.

First, a titanium compound and a zirconium compound are reacted in a solution while performing a treatment such as heating, if necessary, to obtain a titanium-based oxide mainly composed of titanium oxide and zirconium titanate. Prepare a precursor. Thereafter, the silicon-based compound is introduced into the solution without isolating the reaction product, and the precursor of the titanium-based oxide is reacted with the silicon-based compound to form a Zr-0-Si bond. It is generated separately, and additives are added as needed to make a mixture.

Furthermore, a method in which a titanium compound and a zirconium compound, or each of them is reacted with a silicon compound, and then the titanium compound and the zirconium compound are mixed and reacted to form a compounding agent. Is also effective.

The compounding agent obtained as described above is applied to, for example, a material (substrate) and fired, so that the photocatalyst group body containing titanium oxide and zirconium titanate is a silicon-based compound. A material having a titanium oxide-based photocatalyst layer firmly held on the film via a Zr10-Si bond is obtained.

The basic photocatalyst includes at least one metal and / or metal compound of V, Fe, Zn, Ru, Rh, Pt, Ag, Pd, and Cu. It may be contained (supported). As the method, the photocatalyst basic body may be preliminarily supported by an impregnation method, a kneading method, or the like, or, when the carrier is a metal, the metal is added to the compounding agent after preparation. A salt may be added, and the metal may be supported on the basic photocatalyst body by reduction or the like.

As the silicon-based compound, it is preferable to use the above-mentioned polysilicon π siloxane, silicone resin, silica fine particles and the like. Silicon alkoxides may be used.

Silicon alcohol is a precursor of silicon compounds, R ² _n Si (OR

(η is an integer from 0 to 3, R ¹ and R ² mean a hydrocarbon group) It is hydrolyzed by water in the air at the time of film formation or water contained in a solvent at the time of preparation of the compounding agent, or is thermally decomposed at the time of firing to produce polysiloxane.

In the above formula representing a silicon alkoxide, the hydrocarbon group R ¹ is preferably an alkyl group having 1 to 4 carbon atoms. When the value is 5 or more, it does not easily react with the basic photocatalyst or the precursor thereof, and is hardly hydrolyzed. Moreover, it is difficult to obtain. On the other hand, the hydrocarbon group R ² is not particularly limited. Not only unsubstituted hydrocarbon groups but also substituted ones in which hydrogen is substituted with halogen or the like can be used.

A specific example of a silicon alcohol represented by R ² n S Ϊ (OR ') 4-π is a tetraalkoxysilane when η = 0. Laetoxysilane, tetramethylsilicone, etc. are used as organotrikoxysilanes when η = 1, and they are methyltrimethylsilyl. , Methyl triethoxy silane, methyl triisopropyl a phenyl silane, phenyl trimethoxy silane, phenyl triethoxy silane And the like. Examples of the diorganodialkoxysilane in the case of η = 2 include dimethyldimethoxysilane, dimethylethylethoxysilane, diphenyldimethoxysilane, and the like. When η = 3, triorganodimonoalkoxysilane is used as trimethinolemethoxysilane, trimethylethylethoxysilane, or trimethinoreisoproxysilane. And the like.

Silicon alkoxide may be used as it is as a raw material of the compounding agent, or it may be partially hydrolyzed using a pre-mixed acid or the like to form a polysiloxane, and then the raw material of the compounding agent may be used. It may be used as

As the silicone resin, the above-mentioned general-purpose resins such as the acrylic resin, the urethane resin, and the epoxy resin are subjected to an ester exchange reaction and a π-silyl conversion to form a silicone resin. Resins into which corn is introduced. At this time, the silicone content in the silicone resin is preferably set to 60% by weight or less. In particular, Acrylic silicone resins and epoxy silicone resins are preferred in terms of film strength after film formation. These resins can be used either as emulsion-type resins or those dissolved in solvents.

Further, a photo-curable silicone resin can also be used. By using a photocurable resin, a titanium oxide-based photocatalyst layer (coating) can be applied to the surface of the substrate even when heat cannot be applied during production or when the substrate itself cannot be heated due to heat. ) Can be formed.

Examples of the silica fine particles include the above-mentioned co-doped silica, powdered silica, and fumed silica. The particle size of the silica fine particles is preferably 30 nm or less for the reasons described above. A more preferred silica fine particle is a colloidal silica having a particle diameter of 20 nm or less. The colloidal silica may be either a dispersion in water or a dispersion in an organic solvent such as alcohol. These colloidal silicas may be commercially available, which can be easily prepared from silicon alkoxides using an acid.

The above-mentioned silicon-based compounds are used alone or in combination of two or more, mixed with a photocatalyst basic substance or a precursor thereof in a solvent such as water and / or an organic solvent, and reacted.

Regarding the PH of the compounding agent, the type of solvent used, and the ratio of both when using water and an organic solvent, the properties of the constituents contained in the compounding agent, such as silicone resin, It may be appropriately determined in consideration of the solubility of siloxane and the like, the hydrolysis of silicon alkoxide, the dispersibility of silica fine particles, and the like.

Examples of the organic solvent include, for example, alcohols such as methanol, ethanol, lower aliphatic alcohols such as 2-propanol and n-butanol, and alcohols. Examples include glycols such as renglycol and diethyl glycol, and carbitols such as carbitol acetate, and it is possible to use one kind or two or more kinds of these. it can. In addition, less polar Toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and the like can be used as suitable solvents.

When water is used in combination with an organic solvent as the solvent, it is preferable to use the water together with the above-mentioned hydrophilic organic solvent such as alcohol.

Further, when water is used as a solvent or a part thereof, the pH of the compounding agent is preferably 7 or less. If it exceeds 7, the dispersibility of the raw materials becomes extremely poor, and the preservability of the coating compounding agent becomes poor. More preferably, PH is 1 or more and 5 or less. When the raw materials are mixed out of the pH range during the preparation of the compounding agent, the pH can be appropriately adjusted with a basic reagent such as ammonia or an acidic reagent such as hydrochloric acid or nitric acid.

Additives can be added to the coating composition for various purposes. For example, a chelating agent is used to suppress hydrolysis of silicon alkoxide, which is rapidly hydrolyzed, or titanium alkoxide, zirconium alkoxide, etc. added as a raw material of the basic photocatalyst. It may be added.

If the material (substrate) has poor wettability and it is difficult to coat the surface of the material with a compounding agent, such as by coating, a surfactant such as an organic or silicone surfactant may be used. Leveling agents, defoamers, foam inhibitors, etc. can be added. In this case, the amount of addition depends on the type, but is preferably 0.5% by weight or less of the compounding agent. If added in excess of this, the film becomes cloudy and the photocatalytic performance decreases. A more desirable range is 0.05% by weight or less.

If the adhesion between the film and the base material after film formation is poor, use vinyl triethoxysilane, agly-doxy pro-build trimethysilane, etc. Adhesion is improved by using a silane-based or titanium-based power-splitting agent. However, if a large amount of a force-removing agent is added, the photocatalytic activity is reduced. Therefore, the amount of addition is preferably set to 10% by weight or less of the compounding agent. (4) The method for producing the material described in (2) above

The material having a surface of the titanium oxide-based photocatalyst described in the above (1) on the surface can be produced by coating the surface of the substrate with the above-described compounding agent and then firing. . Prior to firing, drying may be performed if necessary. Note that as the base material, a material of the type and shape described above may be used.

In order to coat the base material surface with the compounding agent, it is preferable to use a method such as coating or spraying. Application methods include spin coating, dip coating, spray coating, knock coating, and roll coating. There is a method such as ringing, and any method may be used. A spraying method using a spray may be used.

The temperature for firing may be set in consideration of the deterioration temperature of the base material or the thermal decomposition temperature of the film constituent material. The preferred temperature range is from 100 ° C to 300 ° C. If the firing temperature exceeds 300 ° C, the silicon-based compound having an organic moiety is decomposed, and the photocatalyst layer (coating) may turn yellow or crack.

When drying before firing, the temperature is generally in the range of room temperature to 100 ° C, and it is preferable that the lower the temperature, the longer the drying time.

The thickness of the titanium oxide photocatalyst layer formed on the surface is preferably in the range of about 0.1 m to about 20 μm. If the thickness is less than 0.1 m, sufficient photocatalytic activity may not be obtained. On the other hand, if the film thickness exceeds 20 m, the light transmittance may decrease or the photocatalytic layer (film) may crack. By setting the film thickness in the above range, a titanium oxide-based photocatalyst layer exhibiting high photocatalytic activity and having good film properties with less film cracking and separation can be obtained.

Next, a method for manufacturing the metal plate having the photocatalytic function will be described. To manufacture a metal plate having this photocatalytic function, a barrier layer is formed. After coating the surface of the base material (metal plate) with a chemical, it is dried to form a barrier layer, and then the surface of the barrier layer is coated with a chemical that forms a titanium oxide-based photocatalyst layer, and then dried. do it.

Specifically, for example, a chemical solution for forming a barrier layer is applied to at least one side of the above-mentioned known base metal plate, and dried to form a barrier layer. The titanium oxide-based photocatalyst described in (1) above or a chemical solution containing the photocatalyst and an organic lubricant is applied on the rear layer, and dried to form a photocatalyst layer.

The chemical solution that forms the barrier layer is an oxide that blocks the photocatalytic action described above or prevents the diffusion of metal from the ground, and a cross-linking agent, an antifoaming agent, and a leveling agent. And the like, and a suitable amount of these are dispersed in a solvent to obtain a coating composition.

Known silane coupling agents, melamin-isosilicate compounds, and the like can be used as the crosslinker. Anti-foaming agents such as pull-nicked surfactants and polypropylene glycol, and leveling agents such as dimethylpolysiloxane and polyacrylic acid salt In each case, known ones can be used. As the solvent, known solvents such as water, various alcohols, toluene, and xylene can be used. Furthermore, in order to improve the weather resistance, an appropriate amount of titanium oxide particles or the like and the ultraviolet absorber that have been subjected to the above-described photocatalytic inactivation treatment are contained. Furthermore, various commonly used coloring pigments, extenders, organic pigments and the like may be optionally added.

The chemical solution for forming the photocatalyst layer uses the above-mentioned titanium oxide-based photocatalyst, inorganic binder, and known coating additives such as the above-mentioned crosslinking agent, antifoaming agent, and leveling agent. Is dispersed in an appropriate amount in the above-mentioned known solvent to obtain a coating composition. When processability is required, the above-mentioned organic lubricant is further mixed to obtain a coating composition.

To apply the chemicals that form the barrier layer and photocatalyst layer to the metal plate, Known methods such as brush coating, spraying, and dipping can be applied, but the roll coating method is preferred because the coating speed is high, paint and product yield are good, and the surface properties of the product are excellent. The film thickness at the time of coating is such that the film thickness after drying is 0.05 to 10 m for the barrier layer and 0.1 to 10 m for the photocatalytic layer.

Drying after the application of the barrier layer forming chemical is basically performed at a temperature and for a time at which the metal plate itself does not soften or deform and the barrier layer sufficiently exhibits its function. You only have to make a selection.

When the base material is a coated steel plate, it is preferable that the drying temperature T, C) and the drying time t, (second) be within the ranges specified by the following formulas (1) and (2). This range corresponds to the range surrounded by the solid line in FIG.

(-0.75 t, + 145) ≤ T, ≤ (-0.75 t, + 315) '' ① (-17.75 t, + 655) ≤ T, ≤ (one 17.75 t, + 2185) When the time is lower or shorter than the range surrounded by the solid line in Fig. 1, the coating film does not dry easily, and undried solvent remains in the barrier layer. However, the adhesion of the rear layer to the substrate may not be favorable. On the other hand, if the drying temperature and the drying time are higher or longer than the range surrounded by the solid line in Fig. 1, the coating will be colored and the color tone of the substrate coated plate will change, and the coating will be applied. The design of the metal plate may cause problems, and it takes time for drying, which is not economical.

Drying after applying the photocatalytic layer forming chemical solution should be performed so that the drying temperature T ₂ (° C) and the drying time t ₂ (second) fall within the ranges defined by the following formulas (3) and ( ₂ ). . This range corresponds to the range surrounded by the broken line in FIG.

(One 0.5 t ₂ + 140) ≤ T a ≤ (—0.5 t 2 + 290)-'③ (-8 t 2 + 440) ≤ T 2 ≤ (—8 t 2 + 1040) ·' ④ Drying temperature and drying When the time is lower or shorter than the range surrounded by the broken line in FIG. 1, the same as when the barrier layer forming chemical is applied, The coating film is difficult to dry, undried solvent remains in the photocatalyst layer, and the adhesion between the photocatalyst layer and the barrier layer may not be favorable. On the other hand, when the drying temperature and the drying time are higher or longer than the range surrounded by the broken line in FIG. 1, the coating film is similarly colored and the color of the base coated plate is changed. May change, causing a problem in the design of the painted metal plate, and it takes time to dry.

On the other hand, when the base material is a metal material having no coating film such as a stainless steel plate, the drying conditions after applying the barrier layer forming chemical solution and the photocatalytic layer forming chemical solution, respectively, are as follows. This is much easier. In the case of a stainless steel sheet, the treatment may be performed in a temperature range of 100 to 500 ° C for 1 minute or more. However, if the temperature exceeds 300 ° C., the substrate may be oxidized or discolored. Therefore, the treatment time is preferably 5 minutes or less.

After drying the photocatalyst layer, it is preferable to cool at a rate of 5 to 100 ° C / sec. If the cooling rate is less than 5 ° C / sec, it takes time to cool, and if the cooling rate exceeds 100 ° C Z seconds, cracks may occur in the film (photocatalyst layer).

Processes other than those described above may be performed by a known method. A series of treatments such as application and drying of chemicals may be carried out in a notch type using a cutting plate, but using a 2-coil 2-bake continuous coil coating facility. However, it is preferable to perform treatment using a coil-shaped base metal plate because of its excellent quality and economy.

According to the manufacturing method described in (4), the material described in (2) above, which is provided with the layer formed by the photocatalyst of the present invention described in (1) above, can be easily manufactured. Can be done.

According to this method, a high photocatalytic activity is maintained even when the firing temperature range is wide from a low temperature range to a high temperature range, so that this photocatalytic layer can be formed on various substrate surfaces regardless of the material or the like. It is possible to produce a material that is not suitable.

(5) How to use

A layer formed of the titanium oxide-based photocatalyst described in (1) above is provided on the surface. In addition, the material described in (2) above exhibits a photocatalytic action by irradiating light of higher energy than the band gap of titanium oxide, and exhibits various harmful substances and adhering substances. It has an excellent effect on the treatment, ie, decomposition, removal, and detoxification. Therefore, the material provided with the layer formed of the titanium oxide-based photocatalyst on the surface allows the substance in the air or water or the substance adhering to the above-mentioned material surface under light irradiation. By performing the treatment, the photocatalytic action described above can be exerted. The term “treatment” as used herein refers to a state in which a material having the above-described photocatalyst layer on its surface is placed in the air or water, and the surface of the material is exposed to light of the above energy. It is important to keep the

Here, harmful substances are substances that are considered harmful to the human body. Specifically, N〇 x (nitrogen oxide), SO x (sulfur oxide), gases such as chlorofluorocarbon, ammonia, hydrogen sulfide, etc. contained in the atmosphere, aldehydes, amines, Organic compounds such as methanol, butanes, alcohols, BTX (benzene, toluene, xylene), phenols, etc., triphenyl methane, tricycloethyl In addition to organic halogen compounds such as ren and fin, various pesticides such as herbicides, fungicides, insecticides, various biological oxygen-requiring substances such as proteins and amino acids, and surfactants And inorganic compounds such as cyanide compounds and sulfur compounds; various heavy metal ions; microorganisms such as bacteria, actinomycetes, fungi, and algae; and the above-mentioned substances contained in water.

In addition, substances that adhere directly to the surface of a material provided with a layer formed of a photocatalyst on the surface include substances such as Escherichia coli, staphylococci, green bacterium, and power bacteria. There are oil, cigarettes, fingerprints, rain streaks, and mud.

As light having higher energy than the bandgap, light including ultraviolet rays is preferred. Specific light sources include sunlight, fluorescent lamps, black lights, mercury lamps, and xenon lamps. There are lights. In particular, light containing near-ultraviolet light having a wavelength of 300 to 400 nm is preferable. The irradiation amount and irradiation time of the light It is better to select the optimal conditions depending on the quality and quantity.

(Example 1)

A material provided with the titanium oxide photocatalyst of the present invention on the surface and a material for comparison were manufactured, and the photocatalytic performance and the properties of the photocatalytic layer (film) on the material surface were investigated.

Table 1 shows the configuration of the photocatalyst layer in the present invention example (Test No. 1-2) and Comparative Example (Test No. 1-2).

Table 1

(Note) * indicates that measurement was not possible due to poor film formation. The manufacturing method of the material (test material) used in Test No.1-1 is as follows. First, a mixed solution obtained by adding 80 g of titanium isoproboxide to 16 m1 of iso-α-knol was added dropwise to 500 g of vigorously stirred distilled water. Then, 5 g of nitric acid (60%) was added, the mixture was stirred at 80 at 24 hours, and concentrated under vacuum to obtain a translucent titanium oxide sol (solid content: 15% by weight). .

Next, 9 g of zirconium chloride and 23 ml of distilled water (concentration mol (liter)) were placed in a Teflon inner cylinder (100 ml) for 10 minutes. After stirring, the mixture was charged into an autoclave and heated at 195 ° C for 4 days under static conditions. Unreacted zirconium chloride oxychloride was removed from the obtained cloudy liquid, and then the pH was adjusted to around 5 to obtain a translucent zirconium oxide sol (solid Min 6% by weight). 30 g of this zirconium oxide sol and 65 g of the previously prepared titanium oxide sol were mixed, and the mixture was refluxed at 80 ° C for 5 hours to obtain titanium oxide and zirconia titanate. Titanium oxide mainly composed of A reaction solution containing (Zr / Ti = 0.12) was obtained.

Then, 21.3 g of this reaction solution and 5.6 g of silica sol (Nissan Chemical Co., Ltd., product name: Snowtec, solid content: 20% by weight) Add 0.48 g of toxic silane, 2.3 g of ethanol and a very small amount of silicone-based leveling agent (approximately 0.04% by weight), and add The mixture was stirred for 10 minutes using a paint shear and then used as a mixture for coating. This IB mixture was applied to a glass plate (length and width: 10 cm, thickness: lmm) using Barco Ichiyo (No. 10), and the oven was previously set to 250 ° C. For 1 minute to obtain a material provided on a glass plate with a titanium oxide-based photocatalyst containing a titanium oxide mainly composed of titanium oxide and zirconium titanate as a basic photocatalyst body.

The materials (test materials) used in Test No.1-2 contain titanium oxide and titanium-based oxides mainly composed of zirconium titanate in the same manner as in Test No.1-1. Prepare a reaction solution, use this reaction solution and a solution obtained by adding a repelling agent to ethanol as a binder, and otherwise use the same method as in Test No. 1-1. A photocatalyst film is formed on a glass plate.

Visual observation of the appearance of the film formed on the surface of the above two types of test materials showed that the material of the present invention example (test No. 1) did not show any cracks in the film, and was excellent. Appearance. On the other hand, in the materials of Test No. 1-2 (Comparative Example), the coating was cracked, and the coating was not sufficiently fixed to the base material.

Next, these two types of test materials were subjected to a decomposition test of acetate aldehyde to evaluate photocatalytic performance, and a pencil hardness test specified in 15-0-3312 and a JIS- A film bending test specified in K-5400 was performed to evaluate the film properties.

The degradation test of acetate aldehyde was performed as follows.

Each test material was cut into 50 mm squares, placed in a quartz reaction cell, and closed. It was connected to a ring line (capacity: about 1.0 liter). Next, acetaldehyde (approximately 50 ppm) diluted with air is introduced into the system, and while circulating, a UV filter (Toshiba UV-3) is used with a 250 W high-pressure mercury lamp. Light irradiation was performed through 1). At this time, the UV intensity at 365 nm of the test material surface was 0.8 mW / cm ² .

While irradiating with light, the concentration of acetoaldehyde was quantified using a gas chromatograph, and the decomposition rate constant of acetoaldehyde was determined. If the decomposition rate constant is 0.01 min- 'or more, it can be said that it has practical photocatalytic performance.

The results of the survey on photocatalytic performance and film properties are also shown in Table 1 above. As shown in the results, the material provided with the photocatalyst of the present invention on the surface (Test No. 1-1) had photocatalytic performance that could be put to practical use. Although the photocatalytic performance of this material was lower than the photocatalytic performance of the material in Test No. 1-2, which is a comparative example, this was the case when the photocatalyst contained a silicon-based compound. It is considered that this is due to the fact that the amount is small and that the silicon-based compound is contained, so that the acetyl aldehyde hardly diffuses into the film. However, in the case of Test No. 1-1, a titanium-based oxide mainly composed of titanium oxide and zirconium titanate was used as the photocatalyst basic body, and a silicon-based compound was used. Since a Si-0-Zr bond is formed between them, the efficiency of charge separation is improved within the network of the film, and the silicon compound is not directly in contact with the titanium oxide particles. As a result, the activity of the photocatalyst particles themselves is essentially enhanced. Although not shown here, the degree of reduction in photocatalytic activity was reduced compared to the case where only titanium oxide was used as the basic photocatalyst.

On the other hand, it was confirmed that the film properties in Test No. 1-1 (Example of the present invention) were superior to those in Test No. 1-2.

(Example 2) Materials (7 types) with photocatalysts with varied Zr / Ti ratios in the basic photocatalyst body were manufactured, and their photocatalytic performance was evaluated.

The manufacturing method of the material (Test No. 2-5 or 2-11) is as follows.

The titanium oxide sol and the zirconium oxide sol prepared in Test No. 1-1 of Example 1 were mixed so that the Zr / Ti ratio was from 0 to 0.30. The mixture was refluxed at 80 ° C for 5 'hours to obtain a reaction solution containing titanium oxide and a titanium-based oxide mainly composed of zirconium titanate (Test No. 2 -5 uses only titanium oxide sol). Subsequently, the reaction solution was mixed with the titanium oxide used in Example 1 and a titanium oxide mainly composed of zirconium titanate (Zr / Ti = 0.12). ), Except that methyltrimethoxysilane was not added and the sintering temperature was set to 300 ° C. By the method, a material was obtained in which a photocatalyst containing a titanium-based oxide mainly composed of titanium oxide and zirconium titanate as a basic photocatalyst was formed on a glass plate. For these test materials, a decomposition test of acetate aldehyde was performed in the same manner as in Example 1.

Table 2 shows the test results. Table 2

S-test Zr / Ti silicon-based compound acetoarte

No. Decomposition rate constant

(min— ')

2-5 0 Si0 ₂ 0.029

2-6 0.01 Si0 ₂ 0.043

2-7 0.03 SiOa 0.058

2-8 0.06 Si0 ₂ 0.077

2-9 0.12 Si0 ₂ 0.078

2-10 0.18 Si0 ₂ 0.098

2-11 0.30 Si0 ₂ 0.047 As is evident from these results, the use of titanium-based oxides mainly composed of titanium oxide and zirconium titanate as the basic photocatalyst allows the oxidation of titanium oxide. A material having a photocatalytic layer with high photocatalytic performance on the surface was obtained as compared with the case where only the photocatalyst was used (Test No. 2-5).

(Example 3)

By changing the type of the base material and the type of the additive to the basic photocatalyst, materials (six types) having the photocatalyst layer on the surface of the present invention were manufactured, and the photocatalytic performance and the appearance of the photocatalyst layer (film) and the base material A study was conducted on the adhesion to the surface.

Table 3 shows the materials with a photocatalyst layer on the surface used as test materials (Test No. 3-12 or 3-17).

Table 3

The manufacturing method of the materials used in Test No. 3-12 is as follows.

First, 27.8 g of titanium isopropoxide and 26.5 g of zirconium propoxide (a 70% content 1-pronol solution) were mixed with dehydrated ethanol (16%). g) was prepared (ZrZTi = 0.18). next. The mixture was stirred at room temperature for 30 minutes, and then dropped into 750 ml of distilled water. Further, 4.3 ml of nitric acid was added, and the mixture was stirred at about 80 ° C for 20 hours, then the solvent was removed under vacuum, and the obtained reaction product was collected at 100 ° C for 5 hours. While drying. The reaction product was calcined at 600 ° C. for 5 hours to obtain a photocatalyst base body composed of a titanium-based oxide mainly composed of titanium oxide and zirconium titanate.

20 g of the above basic photocatalyst, which was well pulverized in a mortar, and 10 g of a colloidal silica sol (Nissan Chemical Co., Ltd., product name: Snowtec OL, solid content: 20% by weight),グシシ 4 4 4 4 4 4 4 4 4 製 4 1. 4 4 製 4 製 4 製 4 4 4 信製製 1. 4 1. 1.4 g, ethanol 2.5 g and water 10 g After mixing, the pH was adjusted to 4.5 with acetic acid. In addition, the mixture was mixed well with a paint conditioner for 1 hour to obtain a binder for use in coating.

This compounding agent was applied to a white painted steel sheet (length and width: 10 cm, thickness: lmm) using a bar coater (count: 10), and the temperature was previously set to 200 ° C. The material was baked for one minute in an oven to obtain a material provided with a photocatalyst layer containing a titanium-based oxide mainly composed of titanium oxide and zirconium titanate on a coated steel sheet.

The manufacturing method of the materials used in Test No. 3-13 is as follows.

Silica fine particles dispersed in isopropanol in a reaction solution containing titanic oxide mainly composed of titanium oxide and zirconium titanate prepared in Test No. 1-1 (Solid content: 10% by weight) 10 g, methyl trimethoxysilane 3.5 g and acrylsilicon (Kanebuchi Chemical: trade name: Zemurac) 2.5 g Was added and mixed well with a paint shaker to obtain a compounding agent.

This mixture is spray-coated on stainless steel plate (400 mm x 600 mm, thickness lmm), dried at 60 ° C for 1 hour, and then dried at 180 ° C. Baking for 10 minutes, and titanic acid mainly composed of titanium oxide and zirconium titanate A material having a photocatalyst layer containing a nitride as a photocatalyst basic body on a stainless steel plate was obtained. The thickness of the photocatalyst layer (film) was about 1.8 m.

The materials used in Test No. 3-14 were manufactured by the following method.

A reaction solution (20 g) containing the basic photocatalyst prepared in Test No. 2-6 (Zr / Ti = 0.01) and silica fine particles (solids) dispersed in isopropanol were used. 10 g of 10% by weight), 4.0 g of photo-curable silicone resin (SEMICOSIL 936 UV, manufactured by Pokki Co., Ltd.) and 1.0 g of water The mixture was added to 10.0 g of Rene and mixed for 10 minutes using a paint conditioner to obtain an S mixture.

This compounding agent was applied to a quartz plate (5 cm square, lmm thick) by the dip coating method (pulling speed: 100 cm min), and then 100 ° C. After drying for 10 minutes, the resin is cured by irradiating it with ultraviolet light for 2 minutes, and a photocatalyst layer containing a titanium-based oxide mainly composed of titanium oxide and zirconium titanate as a photocatalyst basic body is formed. The material provided on the quartz plate was obtained.

The materials used in Test Nos. 3-15 and 3-16 were manufactured by the following method. Add 21.3 g of the reaction solution containing titanium oxide and titanium oxide mainly composed of zirconium titanate prepared in Test No. 1-1 to silica sol (Nissan Chemical: trade name). 5.6 g, 2.3 g ethanol, and a very small amount of silicone-based leveling agent (about 0.04% by weight) ) Is added, and then aluminum sol (Nissan Chemical: trade name: Alumina 200, solid content: 10% by weight) 2. Add lg, adjust pH, and add at room temperature. The mixture was stirred for 10 minutes using an intact solution to obtain a K mixture.

Using this compounding agent, titanium oxide and zirconium titanate were prepared in the same manner as in Example 1 except that the base material was a white painted steel plate (length: 10 cm, thickness: lmm). A material (Test No. 3-15) was obtained in which a photocatalyst layer containing a titanium-based oxide as the main photocatalyst body on a coated steel plate was obtained.

In addition, the same procedure was performed using the compounding agent prepared without adding the above-mentioned alumina. Then, a material having a photocatalyst layer on a coated steel plate (Test No. 3-16) was obtained.

On the other hand, the material used in Test No. 3-17 had a barrier layer between the base material and the photocatalyst layer. The manufacturing method is as follows.

First, a chemical solution for forming a barrier layer was prepared by diluting a commercially available silica sol (Nissan Chemical: Snowtec 0) three times with ethanol. The solution was spin-coated (300 rpm) on the stainless steel plate used in Test No. 3-13 and heat-treated for 5 minutes in an electric furnace set to 250 ° C in advance. In this way, a barrier layer (thickness: 0.07 m) was formed. Next, a photocatalytic layer was formed on the barrier layer in the same manner as in Test No. 3-13.

Visual inspection of the appearance of the film formed on the surface of the above 6 types of materials (test materials) revealed that the materials of Test Nos. 3-12 and 3-13 showed no cracks in the film. And had a good appearance. In the materials of Test Nos. 3 to 14, the film was slightly cloudy, but had no cracks and was firmly fixed to the base material.

No cracks were observed in the materials of Test Nos. 3-15 and 3-16. When the film was evaluated using a colorimeter, the L value expressed as a measure of whiteness was 0.52 in Test No. 3-15 and 1 in Test No. 3-16. It was found that the whiteness of the material was increased by the addition of aluminasol. In addition, when the pencil hardness test (JIS-G-3331) was performed, the material of Test No. 3-15 was 4H, and the material of Test No. 3-16 was 3H. It was confirmed that the film strength was increased by the addition of mina.

In addition, no cracks were observed in the material of Test No. 3-17, and the material had a good appearance.

Next, these six types of materials (test materials) were subjected to a decomposition test of acetate aldehyde to evaluate the photocatalytic performance, and were subjected to the cross-cut tape method specified in JIS_K—540. An adhesion test was performed to evaluate the film properties. The decomposition test of acetate aldehyde was performed in the same manner as in Example 1. In the adhesion test, Kata Naif was used, the stitch interval was lmm, the number of stitches was 100, and the evaluation criteria specified in JIS-K-540 were used. The adhesion of the photocatalyst layer (film) to the substrate was evaluated based on the above.

The test results are shown in Table 3 above.

As is evident from these results, acetate aldehyde was decomposed efficiently in all materials. In addition, excellent results were obtained for adhesion. In particular, the material with a barrier layer between the substrate and the photocatalyst layer (Test No. 3-17) showed improved photocatalytic performance compared to the material without a barrier layer in Test No. 3-13. Was done. This is probably because the diffusion of metal or metal ions from the underlayer was blocked by the barrier layer. After leaving the materials used in Test Nos. 3-13 and 3-17 for one month, the photocatalytic activity was measured again.The force test showed that the activity of Test No. 3-17 did not change. The activity of the material of No.3-13 decreased by about 30%.

(Example 4)

We manufactured a material with a photocatalyst on the surface using white tiles as the base material, and investigated its decomposition and removal effect on adherent substances.

Using the compounding agent prepared in Test No. 3-16 of Example 3, a commercially available white tile was applied by a dip coating method (pulling speed: 100 mmZ min.). Further, by firing at 250 ° C for 2 minutes, a photocatalyst layer including a photocatalyst basic body mainly composed of titanium oxide and zirconium titanate was provided on the tile. The material was obtained.

Using this material (test material), a decomposition test of salad oil was performed by the following method. For comparison, a similar test was performed using a white tile not coated with the binder.

A commercially available salad oil was attached to the surface of a test material (50 mm square) (adhesion amount: 0.1 mg Zcm ² ) and irradiated with light from a 350 W high-pressure mercury lamp. Trial The UV intensity on the surface of the test material was 5.0 mW / cm ² at 365 nm.

The weight of the test material was weighed at regular intervals using a precision balance, and the amount of reduction, that is, the amount of decomposition of salad oil was determined. As a result, the salad oil was completely decomposed and disappeared by irradiation for 15 hours. On the other hand, salad oil did not decrease at all under the same test conditions on the unprocessed tile used as a comparative material.

From these results, it was confirmed that the titanium oxide-based photocatalyst of the present invention had an action of decomposing and removing adhering substances.

(Example 5)

A material with a photocatalyst layer on the surface using a glass plate as a base material was manufactured, and an antibacterial activity against Escherichia coli (Escherichia coli W3110 strain) was investigated. Materials used in Test No.2-9 was sterilized with 70% ethanolate Lumpur surface of (test material), E. coli 2. 5 xl 0 ⁵ pieces Roh ml containing saline 0. 2 ml (E. coli number: the 5 x 1 0 ⁴ pieces), was dropped on the surface of the test material divided into 0. 0 2 5 ml Dzu' 8 drops. Next, light irradiation was performed for 4 hours using a white fluorescent lamp while maintaining the relative humidity at 95% (illuminance: 30000 lux).

After that, the bacterial solution on the test material was washed away with 9.8 ml of physiological saline, and the solution was diluted and spread on a standard agar medium, cultured at 35 ° C for 48 hours, and then grown. The viable cell count was determined by counting Ronnie.

As a result, surviving number of E. coli were in, 6. O xl O ³ Kodea is, the reduction rate of E. coli had reached the 8 8%.

For comparison, physiological saline containing case of the test the same number of E. coli (5 x 1 0 ⁴ pieces), was added dropwise to the front surface of the glass plate that does not quotes I bridging the ① photocatalyst 4 The number of viable bacteria was measured by the above-described method for those irradiated with light for hours, and for (2) those that were dropped on the surface of the material (test material) used in the above test and kept in a dark place for 4 hours. As a result, the number of viable bacteria that survived Is 4. 8 xl 0 ⁴ or, in the case of ② 4. 7 xl 0 in ^four, the change in the number of viable bacteria was hardly observed.

These results support that the titanium oxide-based photocatalyst of the present invention has an excellent antibacterial action.

(Example 6)

A metal plate (painted steel plate) having a photocatalytic function of the present invention was prepared, and weather resistance and bending workability were investigated (Test Nos. 6-1 to 6-7).

The method of manufacturing the coated steel sheet used in Test No. 6-1 is as follows.

16.4.4 g of tetraethoxysilane from Chisso Corporation, 35.6 g of methyltriethoxysilane, and 13% of ethanol A dispersion composed of 8 g and 130 g of ion-exchanged water was stirred at 50 ° C for 2 hours, and then an antifoaming agent and a repelling agent were added to form a paint (hereinafter referred to as “barrier layer formation”). Paint A)). On the other hand, 10 parts by weight of crystalline zirconium titanate and 90 parts by weight of titanium oxide are mixed, baked in the air at 500 ° C. for 2 hours, pulverized, and dispersed in water. A slurry having a solid content of 10% by weight was prepared. This slurry was adjusted to pH10 using sodium hydroxide and subjected to hydrothermal treatment at 150 ° C for 3 hours with an autoclave. Then, the pH was adjusted to 7 by adding nitric acid having a concentration of 60%, and the mixture was filtered to obtain titanium oxide-based photocatalyst particles containing titanium oxide and zirconium titanate. The particle size of the photocatalyst particles was 100 nm as an average particle size observed with a transmission electron microscope. 100 g of an aqueous dispersion containing 15% by weight of the photocatalyst particles based on the dry solid content was added as a silicon-based compound to Nissan Kasaku Nissan Chemical Co., Ltd. 60 g of Techex L (solid content: 20% by weight) and an antifoaming agent were added to obtain a coating composition (hereinafter referred to as “catalyst zirconium titanate”). Paint containing paint).

The above coating A for barrier layer formation was applied on one side of a polyester-coated steel sheet whose base material was a hot-dip galvanized steel sheet with a thickness of 0.5 mm to a thickness of 2 μm after drying. After roll coating, dry at 240 ° C for 60 seconds and glue. Layer was formed. Then, the above-mentioned zirconium titanate-containing coating for a catalyst is π-coated so that the film thickness after drying becomes 1.5 μm, and the furnace is continuously heated at 180 ° for 50 seconds. Then, a photocatalyst layer containing titanium oxide and zirconium titanate as photocatalyst basic bodies and colloid silica as a silicon-based compound was formed.

The method for manufacturing the coated steel sheets used in Test Nos. 6-2 to 6-7 is as follows.

100 g of the above-mentioned coating A for barrier layer formation (solids concentration: 12% by weight) was treated with a photocatalyst deactivating treatment as a rutile-type titanium oxide pigment manufactured by Ishihara Sangyo Co., Ltd. R-830 was changed in the range of 2 to 55 g, and each was shaken with a single bint sheet, and then used in the production of painted steel sheet in Test No. 6-1. It was applied to the same substrate-coated plate so that the dry film thickness became 2 m, and dried at 200 ° C for 45 seconds. On top of this, a photocatalytic layer with a dry film thickness of 1.5 m was applied using a paint containing zirconium titanate as a catalyst under the same conditions as in the method for producing the coated steel sheet in Test No.6-1 Was formed, and a coated steel sheet having a photocatalyst layer on the surface was produced.

The test No.6-1 or 6-7 coated steel sheet was subjected to a weather resistance test using Sansha Inezometer for 500 hours according to the method specified in JIS-K-172. Carried out. Thereafter, the color difference change ΔΕ before and after the execution of the weather resistance test was measured according to the method specified in JIS—Z—8719. Further, the bending workability was evaluated according to the bending test method specified in JIS-G-3312.

The results of these measurements are shown in Table 4 and FIG. Table 4

(Note) T in the column of bending interval indicates the plate thickness. As shown in Table 4 and FIG. 2, those containing titanium oxide that had been subjected to a photocatalytic deactivation treatment in the ceramic layer exhibited excellent weather resistance. In addition, even if titanium oxide subjected to photocatalyst deactivation treatment was contained in the barrier layer, the bending workability did not decrease, and the bending workability was improved when the titanium oxide was contained in an appropriate amount. (Example 7)

After applying a coating-type chromate treatment to both sides of an aluminum plate having a thickness of 0.3 mm, a white acrylic coating film was formed. On one surface, the coating A for forming a coating layer used in Example 6 was roll-coated so that the film thickness after drying became 1.5 m, and then the coating was performed at 200 ° C. Dried for seconds. Next, similarly, the paint containing zirconium titanate for a catalyst used in Example 6 was roll-coated so that the film thickness after drying was 1.5 m, and then dried under various conditions. . Cut 1 mm on the photocatalyst layer surface of each coated aluminum plate after drying at lmm intervals with a cutter knife, cut into 100 pieces, and paste adhesive tape on it Then, the photocatalyst layer (film) remaining on the substrate was counted, and the adhesion of the photocatalyst layer (film) was evaluated by counting the number of pieces. Furthermore, the surface of the coated aluminum plate having the photocatalyst layer on the surface is The color difference (ΔΕ) of the surface of the coated aluminum plate as the base material was measured according to the method specified in JIS-Z-8719.

Table 5 shows the drying conditions and the evaluation results of the photocatalyst (film) adhesion and color difference.

Table 5

Test Nos. 7-61 and 7-62 in Table 5 have too short drying time for painted aluminum plate, and test Nos. 7-63 and 7-6A have too low drying temperature. 6E is when the drying temperature is too high, and Test Nos. 7-6F and 7-6G are when the drying time is too long. The adhesion or color difference of the photocatalyst layer (coating) when these drying conditions are not in the preferable range is not as good as when the drying is performed under the preferable conditions. I got it.

(Example 8)

A 0.5 mm thick steel plate is coated on both sides with a Zn-Ni electric alloy containing 13 wt% Ni and the balance substantially consisting of Zn. After the roaming treatment, a white polyester-based coating film was formed. On one side, the coating A for forming a barrier layer used in Example 6 was roll-coated so that the film thickness after drying was 1 m, dried at 200 ° C for 40 seconds, and then dried. The catalyst-containing zirconium titanate-containing paint used in Example 6 was roll-coated so that the film thickness after drying was 1.5 m, dried under various conditions, and provided with a photocatalyst layer on the surface. A coated steel plate was obtained.

For these coated steel sheets, the adhesion of the photocatalyst layer (coating), the color difference (ΔΕ) between the surface of the coated steel sheet provided with the photocatalyst layer on the surface and the surface of the coating pan plate as the base material, and the photocatalytic activity were investigated.

The adhesion and color difference were investigated in the same manner as in Example 7. The photocatalytic activity was evaluated by performing an acetoaldehyde decomposition test and determining the time until the residual acetoaldehyde amount became 1 pPm or less. The acetate decomposition test was performed by the following method. That is, the test specimens were individually placed in a transparent glass container having a volume of 5 liters, and acetaldehyde was added to a glass container so that the concentration became 50 ppm, and the wavelength was 365 nm. The amount of acetoaldehyde in the glass container was measured by gas chromatography while irradiating a black light having a light amount of 0.3 mW / cm ² .

Table 6 shows the drying conditions, adhesion, color difference and the results of the acetate decomposition test. The mark in the column for the decomposition test of acetate aldehyde indicates that the decomposition effect was insufficient. 6 Table

In Table 6, in Test Nos. 8-71, the drying time of the coated steel sheet was too short, and in Test Nos. 8-72, 8-76 and 8-7G, the drying temperature was too low, and in Test Nos. 8-77, 8-7C and 8-7H are when the drying temperature is too high, and 8-7K when the drying time is too long. The adhesion, color difference or catalytic activity of these coated steel sheets were not as good as when they were dried under the favorable conditions described above.

(Example 9)

50 mg in terms of Cr on both sides of a hot-dip galvanized steel sheet with a thickness of 0.4 mm After facilities coating type click b menu over DOO processing / m ^2, Dainippon Lee Nki Co. PB - a primer layer having a thickness of 5 i / m provided in 1 1 P, manufactured by the same company SRF thereon A white topcoat layer with a thickness of 15 "and a thickness of 15" m was provided to produce a white painted steel plate.

The coating A for barrier layer formation used in Example 6 was applied to one side of the coated steel sheet so that the dry film thickness became 2 μm, and dried at 180 ° C for 40 seconds. The paint containing zirconium titanate for a catalyst used in Example 6 was roll-coated so that the dry film thickness became 1.5 μm, dried at 200 for 50 seconds, and then cooled. After cooling at 40 ° CZ seconds, a coated steel sheet having a photocatalyst layer on the surface was obtained (the surface having the barrier layer and the photocatalyst layer is referred to as “octahedron”). After blanking, this coated steel sheet and a white painted steel sheet with only a barrier layer formed on one side under the same conditions (the surface with only this barrier layer is referred to as “side B”) As shown in, the test surface (surface A or B) was drawn into a wall panel with a depth of 30 mm, a width of 300 mm and a length of 700 mm, with the convex surface facing the convex surface. . These panels were placed vertically with the test surface facing north and exposed outdoors for six months from July to December, after which changes in surface conditions were investigated.

When the test surface was observed six months later, it was found that the surface A had a very good white surface with no rain streaks, but the surface B had many rain streaks. Also, when the state of the 90-degree bent portion of the panel was observed, no dirt was observed on the A side, but dust and sand were deposited on the panel bent portion on the B side. It is presumed that dust and sand were deposited by linking organic substances that had accumulated on the test surface.

(Example 10)

A flat nonel having an A side and a flat nonel having a B side produced in the same manner as described in Example 9 were sealed in a draft, and the inside was sealed. After evacuating, tobacco smoke was introduced into the inside, and 1. S mg Zm ² was applied to each test surface. These flat none Are placed on the outer wall of a three-story building in such a way that the sun shines on the test surface, and are exposed for 30 days between January and February, before the tabacony is attached, and The change in color difference immediately after the application of the cocoa and after 30 days of exposure after the application of the cocoa were investigated.

Table 7 shows the results of this survey.

Table 7

As shown in Table 7, removal of tobacco was remarkable after one month of outdoor exposure on side A, which has a coating layer and a photocatalyst layer, and the good white color before the attachment of tobacco was recovered. did. On the other hand, on the B-side surface of the rear layer only, no recovery from poor color tone due to the rear cover was observed.

Also, a panel with a tapaconi attached to the test surface (Side A and Side B) prepared under the same conditions as above was used for a panel with a wavelength of 365 nm and a light amount of 0.2 mWZ cm ² . They were placed side by side in a room receiving ultraviolet light, and on day 50, the color difference between the two panels was compared. As a result, the surface A had the white color that had been recovered before it was attached; the surface B had no change in the adhesion state. Industrial applicability

INDUSTRIAL APPLICABILITY The titanium oxide photocatalyst of the present invention has an excellent photocatalytic action, has excellent bonding properties with a substrate on the surface of a material (substrate), and has good film properties such as processability, strength, and appearance. It is possible to form an excellent photocatalyst layer. Materials with a photocatalytic layer on the surface are extremely effective in decomposing and detoxifying harmful substances contained in the air and water, deodorizing in living spaces, and sterilizing (antibacterial). In particular, the layer formed with this photocatalyst is coated with a coated metal plate (pre-coated metal plate). The material provided on the surface has both excellent photocatalytic activity and good processability.

The photocatalyst and the material provided with the layer formed by the photocatalyst on the surface can be easily produced by the method of the present invention.

Claims

The scope of the claims

1. A photocatalyst basic body containing zirconium titanate and having an atomic percentage ratio of zirconium to titanium of not less than 0.001 and not more than 0.5 and a titanium oxide-based photocatalyst mainly composed of a silicon-based compound.

2. Claim 1 in which the silicon-based compound is at least one of silica fine particles, polysiloxane, silicone-based resin, and a partially reacted compound thereof. 2. The titanium oxide photocatalyst according to item 1.

3. It is formed of a photocatalyst basic body containing zirconium titanate and having an atomic percentage ratio of zirconium to titanium of not less than 0.01 and not more than 0.5 and a titanium oxide photocatalyst mainly composed of a silicon compound. Material with a layer formed on the surface of a substrate.

4. Claims in which the silicon-based compound is at least one of silica fine particles, polysiloxane, silicone-based resin, and a partially reacted compound thereof. The material according to 3.

5. The material according to claim 3, wherein the base material is a metal material or a coated metal plate, and a barrier layer is provided between the base material and the layer formed by the titanium oxide-based photocatalyst.

6. The material according to claim 4, wherein the base material is a metal material or a coated metal plate, and a barrier layer is provided between the base material and the layer formed by the titanium oxide-based photocatalyst.

7. A basic photocatalyst containing zirconium titanate and having an atomic percentage ratio of zirconium to titanium of not less than 0.001 and not more than 0.5, and a titanium oxide-based photocatalyst mainly composed of a silicon-based compound. A combination agent containing water, water and organic solvent.

8. Claims in which the silicon-based compound is at least one of silica fine particles, polysiloxane, silicone-based resin, and a partially reacted compound thereof. 7. The combination according to 7.

9. A photocatalyst basic body containing zirconium titanate and having an atomic percentage ratio of zirconium to titanium of not less than 0.01 and not more than 0.5, a titanium oxide-based photocatalyst mainly composed of a silicon-based compound, and water And / or distributions containing organic solvents A method for producing a material in which a layer formed of a titanium oxide-based photocatalyst, which is formed by coating a base material surface with a mixture and then firing, is provided on the base material surface.

10. The material according to claim 9, wherein the silicon-based compound is at least one of a silica fine particle, a polysiloxane, a silicone-based resin, and a compound in which these are partially reacted. Production method.

1 1. The surface of a metal material or a coated metal plate as a base material is coated with a chemical solution for forming a barrier layer, dried to form a barrier layer, and then the surface of the barrier layer is titrated. After coating with a photocatalyst having an atomic% ratio of zirconium to zinc of 0.001 or more and 0.5 or less and a chemical solution for forming a titanium oxide-based photocatalyst layer mainly composed of a silicon-based compound, and then drying. A method for producing a material having a layer formed of a titanium oxide-based photocatalyst on a substrate surface.

1 2. It mainly contains a photocatalyst basic body and a silicon compound containing zirconium titanate and having an atomic% ratio of zirconium to titanium of not less than 0.01 and not more than 0.5. A material having a layer formed of a titanium oxide-based photocatalyst on the surface of a substrate, which is used to treat a substance in the air or water or a substance adhering to the surface of the material under light irradiation. How to use a material with a photocatalyst layer on the surface.

13. The claim 1 wherein the silicon-based compound is at least one of silica fine particles, polysiloxane, a silicone-based resin, and a compound in which these have been partially reacted. Use of the material having a titanium oxide-based photocatalyst layer provided on the surface thereof according to 2.

1 4. A material having a layer formed of a titanium oxide-based photocatalyst on the surface of a substrate, a metal material or a painted metal plate as a base material, and a layer formed of the substrate and the titanium oxide-based photocatalyst. 13. The use of a material having a titanium oxide-based photocatalyst layer on the surface of a substrate according to claim 12, which is a material having a barrier between the two.

15 5. A material provided with a layer formed of a titanium oxide-based photocatalyst on the surface of a base material is formed of a metal material or a coated metal plate as a base material, and formed of the base material and the titanium oxide-based photocatalyst. 14. The method for using a material having a titanium oxide-based photocatalyst layer on the surface of a substrate according to claim 13, which is a material having a barrier layer between the formed layers.